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<strong>Wednesday</strong>, 8:00am - 9:30am<br />
■ WA01<br />
C - Ballroom D1, Level 4<br />
Multi-stage Stochastic Optimization Applied to<br />
Energy Planning<br />
Sponsor: Energy, Natural Resources and the Environment/ Energy<br />
Sponsored Session<br />
Chair: Steffen Rebennack, Assistant Professor, Colorado School of Mines,<br />
Division of Economics & Business, Boulder, CO, United States of America,<br />
steffen@ufl.edu<br />
1 - Quasi-Monte Carlo Methods for Hydroelectric Energy Planning<br />
Tito Homem-de-Mello, University of Illinois at Chicago, Chicago, IL,<br />
United States of America, thmello@uic.edu, Erlon Finardi,<br />
Vitor de Matos<br />
We study a multi-stage stochastic programming model for hydroelectric energy<br />
planning in Brazil. Sampling techniques are used to generate scenario trees from the<br />
stochastic process defining the water inflows, and also to select scenarios within that<br />
tree. We analyze the use of Quasi-Monte Carlo methods for the problem. We also<br />
discuss statistical performance measures that allow us to compare methods, and<br />
present numerical results to evaluate the effectiveness of the proposed approach.<br />
2 - Reservoir Hydropower Operations: Valuing Flexibility<br />
Stein-Erik Fleten, Professor, NTNU Norway, Department of Industrial<br />
Economics and Technology Management, Trondheim, Norway,<br />
Stein-Erik.Fleten@iot.ntnu.no, Martin Prokosh, Camilla Kolsrud<br />
In this talk we provide insights into how storage flexibility impacts the expected<br />
revenue of hydropower plants. Using daily data going back ten years from 14<br />
different hydropower plants with significant seasonal reservoir capacity, and who<br />
operate in a well-functioning market, we conduct an empirical analysis of the<br />
different factors affect the ability of hydropower producers to exploit high prices.<br />
Storage flexibility on average accounts for 22% of actual revenues, ranging from 0<br />
to 40%.<br />
3 - Optimal Control of Energy Storage using the Knowledge Gradient<br />
with Nonparametric Beliefs<br />
Warren Powell, Professor, Princeton University, Sherrerd Hall,<br />
Princeton, NJ, 08544, United States of America,<br />
powell@princeton.edu, Emre Barut<br />
We consider different natural gas and pumped hydro storage problems as stochastic<br />
control problems which can be solved using tunable policies governed by tunable<br />
parameters. We present a novel stochastic search algorithm using the knowledge<br />
gradient adapted to nonparametric beliefs, which produces policies that are easy to<br />
implement. We demonstrate that the logic produces policies that slightly outperform<br />
actual performance.<br />
4 - Decomposition Approach for G-T Expansion Planning with Implicit<br />
Multipliers Evaluation<br />
Fernanda Thome, PSR, Rio de Janeiro, Brazil, fernanda@psr-inc.com,<br />
Marcia H.C. Fampa, Luiz Carlos da Costa Jr., Silvio Binato<br />
Algorithms solving stochastic hydrothermal operation problems usually take<br />
computational advantages in the elimination of constraints whose explicit<br />
representation does not affect the problem’s optimal solution. This work presents a<br />
new methodology for solving generation-transmission expansion planning problems<br />
based on Benders decomposition technique and the evaluation of the Lagrange<br />
multipliers associated to those non-explicit constraints and required in the<br />
construction of the Benders cuts.<br />
■ WA02<br />
C - Ballroom D2, Level 4<br />
Refinery Operations with Spot and Forward Markets<br />
Cluster: Energy: Modeling the Interface Between Markets and<br />
Operations<br />
Invited Session<br />
Chair: Simin Huang, Tsinghua University, Department of Industrial<br />
Engineering, Beijing, China, huangsimin@mail.tsinghua.edu.cn<br />
1 - Considering the Effect of Outside Options in the Capacity Planning<br />
for Hydrogen Fueling Station<br />
Ruwen Qin, Assistant Professor, Missouri University of Science and<br />
Technology, Department of Engineering Management, Rolla, United<br />
States of America, qinr@mst.edu, Scott Grasman, Kevin Martin<br />
We model and analyze the effect of an outside option in determining the optimal<br />
capacity for hydrogen fueling stations. Through assessing the economic consequence<br />
of the decision, this study suggests opportunities for gaining additional profits.<br />
INFORMS Austin – 2010 WA03<br />
361<br />
2 - Financial Engineering for Refinery Operations: Challenges<br />
and Opportunities<br />
Li Zheng, Professor, Tsinghua University, Department of Industrial<br />
Engineering, Beijing, 100084, China, lzheng@tsinghua.edu.cn<br />
Over the past decade, the world has witnessed the extreme price volatility from<br />
both crude supply and final product market. Financial engineering tools have been<br />
used to hedge the financial risk in refinery operations recently. In this talk, we<br />
present the challenges of the problem and provide some potential ideas for future<br />
research.<br />
3 - Integrated Financial and Operational Model for Crude Oil<br />
Procurement in Refineries<br />
Zhen Liu, Assistant Professor, Missouri University of Science &<br />
Technology, United States of America, zliu@mst.edu, Simin Huang<br />
The world seems to have entered into an era of higher crude oil price volatility. As<br />
the crude oil cost is about 90% of the refinery input cost, there has been significant<br />
volatility in the margins and profitability of any petroleum refinery. An integrated<br />
financial and operational model is developed to hedging the financial risk.<br />
4 - Financial Engineering Model for Crude Transportation in Refineries<br />
Zhihai Zhang, Associate Professor, Tsinghua University, Department<br />
of Industrial Engineering, Beijing, 100084, China,<br />
zhzhang@tsinghua.edu.cn<br />
The crude transportation cost in refineries could be up to several billion dollars and<br />
the volatility of freight rates can be substantial. A decision-making model for<br />
optimal oil tanker selection procedure is developed to help refining companies<br />
manage the freight market risk.<br />
■ WA03<br />
C - Ballroom D3, Level 4<br />
Challenges for the US Biofuels Industry: Economic and<br />
Technological Uncertainties<br />
Sponsor: Energy, Natural Resources and the Environment//Forestry<br />
Sponsored Session<br />
Chair: Hayri Onal, University of Illinois at Urbana-Champaign, Dept<br />
Agricultural and Consumer Economics, Urbana, IL, 61801, United States<br />
of America, h-onal@illinois.edu<br />
1 - Modeling Uncertainty in Biomass Greenhouse Gas Emissions with<br />
the Calculating Uncertainty in Biomass<br />
Aimee Curtright, Physical Scientist, RAND Corporation, Pittsburgh,<br />
PA, 15213, acurtrig@rand.org, Henry Willis, David Johnson,<br />
Costa Samaras<br />
The greenhouse gas (GHG) intensity of biofuels depends on how feedstocks are<br />
produced, transported, and processed. This paper will describe the Calculating<br />
Uncertainty in Biomass Emissions (CUBE) model, a tool developed for the National<br />
Energy Technology Laboratory to examine uncertainties in bio-feedstock GHG<br />
estimates. The limits on the precision of results, the value of additional emissions<br />
information, and the sources and magnitude of uncertainty will be discussed.<br />
2 - Ecosystem Costs in a Logistical Model of Cellulosic<br />
Ethanol Production<br />
David Lambert, Professor and Head, Department of Agricultural<br />
Economics, Kansas State University, lambertd@k-state.edu,<br />
Jason Bergtold, Elizabeth Canales<br />
Network models of biomass use for cellulosic ethanol production often ignore<br />
ecosystem opportunity costs. Building upon an existing MIP model, we incorporate<br />
ecosystem opportunity costs arising from soil erosion, loss of organic and inorganic<br />
matter, and carbon sequestration values associated with crop residue and energy<br />
crop harvest for ethanol production.<br />
3 - Strategic Biofuel Supply Chain Planning Under Supply, Demand,<br />
and Technology Uncertainties<br />
Yueyue Fan, University of California-Davis, Davis, CA, 95616, United<br />
States of America, yyfan@ucdavis.edu<br />
This talk focuses on modeling and computational challenges in strategic biofuel<br />
supply chain planning under supply, demand, and technology uncertainties. Using a<br />
case study based on California settings, the economic feasibility, infrastructure<br />
requirements, and the environmental impact of converting biowastes to fuel are<br />
analyzed.
WA04<br />
4 - Projections for US Flex-fuel Vehicle Structure and Renewable<br />
Fuel Standards<br />
Xirong Jiang, Senior consulting decision analyst, Lumina Decision<br />
Systems, Inc, 26010 Highland Way, Los Gatos, CA, 95033, United<br />
States of America, xirong@lumina.com, Surya Swamy, Max Henrion,<br />
Costa Samaras<br />
We use ATEAM (Analytica Transportation Energy Assessment Model) to explore a<br />
variety of scenarios to see how rapidly the US needs to adopt flex-fuel vehicles to<br />
consume the volume of biofuels productions set by the 2010 revision of the<br />
Renewable Fuel Standard, including high-blend E15 or E20 options.<br />
■ WA04<br />
C - Ballroom D4, Level 4<br />
Decision Analysis II<br />
Contributed Session<br />
Chair: John Mamer, UCLA Anderson Grad. School of Mgmt.,<br />
110 Westwood Plaza, D518, Los Angeles, CA, 90095-1481,<br />
United States of America, jmamer@anderson.ucla.edu<br />
1 - Value of Information in Spreadsheet Monte Carlo Simulation Models<br />
Mike Middleton, Decision Toolworks, 2105 Buchanan St, San<br />
Francisco, United States of America, Mike@DecisionToolworks.com<br />
For a spreadsheet planning model with uncertain inputs, value of information about<br />
each input is useful for evaluating information-gathering efforts and for comparing<br />
their importance. This paper describes non-macro computation methods for<br />
spreadsheet Monte Carlo simulation, calculation of value of information for each<br />
uncertain input, charts for presenting the results, and insights to be gained.<br />
2 - The Role of Supply Chain Structure in the Food vs. Biofuel Tradeoff<br />
Adaora Okwo, Georgia Institute of Technology, 765 Ferst Dr.,<br />
Atlanta, United States of America, aokwo@gatech.edu<br />
We present a micro model of the food vs biofuel tradeoff. Most macro models<br />
informing the policy discussion fail to incorporate contracting and downstream<br />
market power in the agricultural supply chain; both of which can significantly<br />
influence a farmer’s decisions on which crops to supply and in which quantities. We<br />
present a two-echelon decentralized supply chain model to illustrate the impact of<br />
contract parameters and market power on the equilibrium supply response for food<br />
and energy crops.<br />
3 - Corn Ethanol Plant Investment using Real Options Analysis<br />
Dexin Luo, Geogia Institute of Technology, 765 Ferst Drive, Atlanta,<br />
GA, United States of America, dexin.luo@gatech.edu, Valerie Thomas<br />
We apply real options analysis of entry-exit decision to corn ethanol plants with two<br />
different processes: dry-milling and wet-milling. We incorporate uncertainties<br />
regarding ethanol and corn prices and technical change. The study shows the<br />
influence of technical change on the investment decision of individual firms with<br />
comparison to the increase of dry-milling plants in the U.S.<br />
4 - Dealing with the Growth of Knowledge<br />
Norimasa Kobayashi, Assistant Professor, Tokyo Institute of<br />
Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8552, Japan,<br />
nkoba@valdes.titech.ac.jp<br />
Binmore (2009) criticizes that our real decision environments are so essentially<br />
“large” that the complete state space assumption of Bayesianism does not hold. I<br />
model the growth of knowledge formalizing Popper (1935), and discuss how well<br />
the decision on incomplete decision analytic models perform in different<br />
circumstances. Particularly, I discuss that in non-cooperative games, incomplete<br />
mental models may result both in inefficiency and efficiency.<br />
5 - Fire Sales and Search<br />
John Mamer, UCLA Anderson Grad. School of Mgmt., 110<br />
Westwood Plaza, D518, Los Angeles, CA, 90095-1481, United States<br />
of America, jmamer@anderson.ucla.edu, Steven Lippman<br />
We study a model of asset sales via search with semi-rational buyers. A seller has a<br />
finite (or infinite) number of items to sell, independent buyers arrive according to a<br />
Poisson process. Each potential buyer knows the price of the last sale, and offers the<br />
minimum of his reservation value and the price of the last sale. As a result, the<br />
seller faces a falling offer distribution, each sales price setting the maximum offer for<br />
subsequent sales.<br />
INFORMS Austin – 2010<br />
362<br />
■ WA05<br />
C - Ballroom D5, Level 4<br />
Multicriteria Decision Making<br />
Contributed Session<br />
Chair: Judit Lienert, Dr., Eawag: Swiss Federal Institute of Aquatic<br />
Science and Technology, Ueberlandstrasse 133, P.O. Box 611,<br />
Duebendorf, CH-8600, Switzerland, judit.lienert@eawag.ch<br />
1 - A Method for Multiobjective Optimization using Trust<br />
Region Method<br />
Jong-hyun Ryu, Purdue University, 315 N. Grant Street, West<br />
Lafayette, IN, 47907, United States of America, ryuj@purdue.edu,<br />
Sujin Kim<br />
We propose a method for approximating the Pareto front in a blackbox<br />
multiobjective problem. At each iteration, each objective function on a certain<br />
region (trust region) is approximated by a quadratic function, and a scalarization<br />
method is applied to collect points to approximate the Pareto front. The region is<br />
iteratively updated so as to maintain the spread of solutions. Numerical results are<br />
presented to demonstrate the effectiveness of the proposed algorithm.<br />
2 - Evolutionary Computation-based Multi-objective Approach to<br />
Rehabilitate Interconnected Infrastructure<br />
Avery White, Student, Texas A&M University, 3136 TAMU, College<br />
Station, TX, United States of America, sacredfaith@tamu.edu,<br />
Emily Zechman, Lufthansa Kanta, Alex Sprintson<br />
In the event of urban fires, cascading failures between water and electrical<br />
distribution infrastructure systems may exacerbate municipal losses. Under-designed<br />
water distribution systems may be further disabled through power loss. This<br />
research takes an evolutionary computation-based approach to identify pipe<br />
replacement strategies for urban fire scenarios to provide fire flows, maintain water<br />
quality for normal operating conditions, and minimize pipe replacement costs.<br />
3 - Application of Dynamic Multiobjective Programming to Supply<br />
Chain of Crude Oil<br />
Moses Olusola Okesola, Student, University of South Africa,<br />
9,Solomon Okonkwo Street, Unity Estate, Egbeda, Lagos, 234,<br />
Nigeria, okesolaj@yahoo.com<br />
The Dynamic Multiobjective Programming (DMP) has been largely deficient in<br />
decision problems related to integrated supply chain of crude oil in literature.We<br />
tend to review developed methods for solving MOPP using DP technique and<br />
identify their deficiencies.The research will focus on upstream supply chain of crude<br />
oil in Nigeria by treating each activity along the supply chain separately with the<br />
grand objective to optimize return function from one stage to another.<br />
4 - Reducing Pharmaceuticals in Hospital Wastewater - MCDA Multistakeholder<br />
Elicitation Challenges<br />
Judit Lienert, Dr., Eawag: Swiss Federal Institute of Aquatic Science<br />
and Technology, Ueberlandstrasse 133, P.O. Box 611, Duebendorf,<br />
CH-8600, Switzerland, judit.lienert@eawag.ch, Peter Reichert,<br />
Nele Schuwirth<br />
Pharmaceuticals in water bodies are of concern; they can be reduced by point<br />
source measures. In a project with engineers, natural, and social scientists, we<br />
studied two exemplary hospitals. We used MCDA to support the decision between<br />
68 technological and organizational alternatives to reduce medicals. We elicited<br />
preferences from 26 stakeholders. Our elicitation procedure reduces the time<br />
demand, but remains methodologically satisfactory. We present elicitation challenges<br />
and main results.
■ WA06<br />
C - Ballroom E, Level 4<br />
Tutorial: New Developments for Solving Real World<br />
Optimization Problems by Marrying Simulation<br />
and Optimization<br />
Cluster: Tutorials<br />
Invited Session<br />
Chair: Fred Glover, CTO, OpTek Systems, Inc., 1919 Seventh Street,<br />
Boulder, CO, 80302, United States of America, glover@opttek.com<br />
1 - New Developments for Solving Real World Optimization Problems<br />
by Marrying Simulation and Optimization<br />
Manuel Laguna, Professor, University of Colorado at Boulder,<br />
419 UCB, Boulder, CO, 80309, United States of America,<br />
laguna@colorado.edu, Jay April, Marco Better<br />
Companies invest billions of dollars each year in applications that can be handled by<br />
combining simulation and optimization. These notably include problems that<br />
involve uncertainty and complex nonlinearities, as in the areas of capital<br />
investment, workforce composition and management, energy resource and<br />
transmission planning, health care systems, financial portfolio optimization,<br />
production and inventory systems, security and emergency response planning. We<br />
identify latest advances and applications in these areas from combining simulation<br />
and optimization, together with opportunities for future applications.<br />
■ WA07<br />
C - Ballroom F & G, Level 4<br />
Supply Chain Optimization I<br />
Contributed Session<br />
Chair: Shuang Chen, PhD Candidate, University of Florida, 285 Corry<br />
Village Apt 13, Gainesville, United States of America, scljj@ufl.edu<br />
1 - A News-Vendor Model With External Fund Availability<br />
Benjamin Melamed, Professor, Rutgers Business School - Newark<br />
and New Brunswick, 94 Rockafeller Rd., Piscataway, 08554,<br />
United States of America, melamed@rbs.rutgers.edu, Junmin Shi,<br />
Michael N. Katehakis, Ben Sopranzetti<br />
The classical news-vendor (NV) problem is to find the optimal order quantity which<br />
maximizes the expected profit in a probabilistic demand framework. In this talk we<br />
present studies when there is external funding available. We treat the corresponding<br />
optimization problem as a capital-asset portfolio problem, and obtain the optimal<br />
ordering strategy. In addition, some risk issues, such as bankruptcy risk, have are<br />
discussed.<br />
2 - A Model for Planning and Operating the Norwegian Seafood<br />
Value Chain<br />
Peter Schütz, SINTEF Applied Economics, S.P. Andersens vei 5,<br />
Trondheim, Norway, peter.schutz@sintef.no, Kristin Uggen,<br />
Kjetil Midthun<br />
We discuss a model for planning the slaughtering and processing of farmed salmon.<br />
The model also includes the operations of the well boats, such as loading conditions<br />
at the cages and cleaning before assigning them to new regions. The problem is<br />
subject to uncertainty, as the number of fish in a cage, their weight and size can<br />
only be estimated, but is unknown until the fish is slaughtered.<br />
3 - The Optimum Base-Stock Levels in a Two-Echelon Supply Chain<br />
with Service Level Constraints<br />
Yat-wah Wan, National Dong Hwa University, Institute of Logistics<br />
Management, Shou-Feng, Hualien, 974, Taiwan - ROC,<br />
ywan@mail.ndhu.edu.tw, Tsung-Shung Chang<br />
In a two-echelon supply chain of non-zero replenishment lead times, retailers adopt<br />
base-stock policies and set minimum service levels. The objective is to find globally<br />
optimal base-stock inventory levels of the whole chain. Such levels are found from<br />
(i) the sample-path monotone properties of ordered quantities and of inventories on<br />
hand with respective to base-stock levels, and (ii) in some cases, the local optima of<br />
the objective function are decreasing with respect to base-stock levels.<br />
4 - Optimizing the Kenya Coffee Supply Chain<br />
Rose Karimi, Rutgers University, 1 Washington Park, Newark, NJ,<br />
07102, United States of America, kiwanuka@pegasus.rutgers.edu,<br />
Yao Zhao<br />
We compare the profitability of two models: the inventory control model and the<br />
selling-through model.In the first model based on current price information, a<br />
decision is made to either sell all or a portion of the coffee, or to hold the coffee in<br />
expectation of a more favorable price in the future while in the second model all<br />
coffee is sold.<br />
INFORMS Austin – 2010 WA08<br />
363<br />
5 - Case Pack Configuration and Procurement Planning<br />
Shuang Chen, PhD candidate, University of Florida, 285 Corry<br />
Village Apt 13, Gainesville, United States of America, scljj@ufl.edu,<br />
Joseph Geunes<br />
We consider a retail planning problem where retailers must order in case packs<br />
containing multiple individual products. We simultaneously consider case pack<br />
configuration and procurement decisions. We first solve this quadratically<br />
constrained quadratic program with integer variables using an exact linear method.<br />
Then we propose an integrated approach combining module design and lot sizing<br />
decisions, as well as an iterative heuristic. Our approaches perform very well<br />
compared to solver Baron.<br />
■ WA08<br />
C - Room 11A, Level 4<br />
Joint Session Location Analysis/ MIF: Public-Sector<br />
Facility Location<br />
Sponsor: Location Analysis/ Minority Issues<br />
Sponsored Session<br />
Chair: Michael Johnson, Associate Professor, University of Massachusetts<br />
Boston, Department of Public Policy/Public Affairs, 100 Morrissey Blvd.,<br />
Boston, MA, 02125-3393, United States of America,<br />
michael.johnson@umb.edu<br />
1 - A Multi Objective Available Coverage Model<br />
Hari Rajagopalan, Assistant Professor, Francis Marion University,<br />
School of Business, P.O. Box 100547, Florence, SC, 29501,<br />
United States of America, hrajagopalan@fmarion.edu, Cem Saydam,<br />
Elizabeth Sharer, Kay Lawrimore<br />
Demand for ambulances fluctuates spatially and temporally. Recent advances in<br />
computing and spatial data have enabled EMS managers to practice dynamic<br />
redeployment plans. In this paper we address the issue of redeployment by explicitly<br />
considering the number of redeployment trips to be made while meeting the<br />
coverage requirements with nearly minimal fleet size and develop fast heuristics.<br />
We present computational statistics using real data from Charlotte, NC.<br />
2 - Equity Across Groups in Facility Location<br />
Tammy Drezner, Professor, California State University, Fullerton, 800<br />
State College Blvd., Fullerton, CA, 92834, United States of America,<br />
tdrezner@Exchange.fullerton.edu, Zvi Drezner<br />
An equity model between groups of demand points is proposed. The set of demand<br />
points is divided into two or more groups. For example, rich neighborhoods and<br />
poor neighborhoods, urban and rural neighborhoods. We wish to provide equal<br />
service to the different groups by minimizing the deviation from equality among<br />
groups. The objective function, to be minimized, is the sum of squares of differences<br />
between all pairs of service distances between demand points in different groups.<br />
3 - Solving a Multi-Period School Location Problem with Capacity<br />
Constrains using Tabu Search<br />
Eric Delmelle, Assistant Professor, University of North Carolina at<br />
Charlotte, Department of Geography and Earth Scienc, Charlotte,<br />
NC, 28223, United States of America, Eric.Delmelle@uncc.edu,<br />
Jean-Claude Thill<br />
In rapidly expanding areas, it may be necessary to build additional schools to meet<br />
anticipated demand. A tabu search algorithm is used to solve a multi-period<br />
capacitated p-median model, applied to a a school network location problem. The<br />
model is flexible as it allows facility closure.<br />
4 - Foreclosed Housing Selection using Multi-Criteria Decision Models<br />
Michael Johnson, Associate Professor, University of Massachusetts<br />
Boston, Department of Public Policy/Public Affairs, 100 Morrissey<br />
Blvd., Boston, MA, 02125-3393, United States of America,<br />
michael.johnson@umb.edu, David Turcotte, Rachel Drew<br />
Acquisition of foreclosed housing for redevelopment is a key element of U.S.<br />
housing policy. This task requires balancing multiple criteria and assessing decisionmaker<br />
preferences, which can be difficult to quantify. We describe a multi-criteria<br />
decision model for acquisition of real-estate-owned foreclosed housing in which we<br />
adapt methods from stochastic processes, urban economics and facility location to<br />
rank candidates for acquisition by a community-based organization.
WA09<br />
■ WA09<br />
C - Room 11B, Level 4<br />
Empirical Studies in Operations Management<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Serguei Netessine, Professor, INSEAD, Boulevard de Constance,<br />
Fontainebleau, 77305, France, serguei.netessine@insead.edu<br />
1 - Global Sourcing and Operational Performance<br />
Karan Girotra, INSEAD, Boulevard De Constance, Fontainebleau,<br />
France, Karan.GIROTRA@insead.edu, Marcelo Olivares<br />
This study aims to provide the first large-scale empirical estimates on the<br />
consequences of global sourcing on firm-level inventory performance. We compile a<br />
novel data-set by merging data from US customs manifests and public data on firmlevel<br />
inventory performance. We estimate the impact of imports on inventory<br />
performance and the benefit of oft prescribed operational strategies: importing<br />
intermediate products (postponement) and importing low variability products.<br />
2 - The Inventory Billboard Effect<br />
Gerard Cachon, The Wharton School, 3730 Walnut St., JMHH Suite<br />
500, Philadelphia, PA, 19104, United States of America,<br />
cachon@wharton.upenn.edu, Santiago Gallino, Marcelo Olivares<br />
The challenges associated with identifying an inventory billboard effect are<br />
discussed. Then, using detailed data from car dealerships, we measure the extent<br />
that inventory drives sales.<br />
3 - Organizational Structure, Trust and Sourcing<br />
Anupam Agrawal, University of Illinois at Urbana-Champaign,<br />
Wohlers Hall, Champaign, IL, 61820, United States of America,<br />
anupam@illinois.edu<br />
This paper focuses on the linkages between the organizational structure of a buying<br />
firm, its relationships with its suppliers, and the resultant incoming quality of<br />
components - how do these change dynamically? The research is based on ongoing<br />
practices at a leading automobile manufacturer. The sourcing related organizational<br />
arrangements are different in the car and truck making units of this firm, and lead<br />
to different results on the above two dimensions (quality and relationships).<br />
4 - An Empirical Analysis of Service-based Strategies in the Automotive<br />
Industry: The Role of Warranties<br />
Serguei Netessine, Professor, INSEAD, Boulevard de Constance,<br />
Fontainebleau, 77305, France, serguei.netessine@insead.edu,<br />
Morris Cohen, Jose Guajardo<br />
We empirically analyze the role of warranties as part of the competitive strategy of<br />
car manufacturers, using data from the US automotive industry. Challenges in<br />
estimation, as well as implications for firms and consumers are discussed.<br />
■ WA10<br />
C - Room 12A, Level 4<br />
Operations Economics<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Fuqiang Zhang, Washington State University in St. Louis, One<br />
Brookings Drive, St. Louis, MO, 63130, United States of America,<br />
fzhang22@wustl.edu<br />
1 - Competition and the Value of Additional Replenishment Opportunity<br />
Yen-Ting Lin, University of North Carolina, Kenan-Flagler Business<br />
School, Chapel Hill, NC, United States of America,<br />
Yen-Ting_Lin@unc.edu, Ali Parlakturk<br />
We consider a manufacturer serving two competing retailers who sell their products<br />
during a selling season. The retailers place a regular order before the selling season<br />
begins. In addition, quick response allows a retailer to place a second order after<br />
better demand is obtained. We examine the value of this additional ordering<br />
opportunity for the retailers, manufacturer as well as the whole supply chain.<br />
2 - Dynamic Price and Lead Time Quotation for MTO Systems with<br />
Contract Customers and Spot Purchasers<br />
Baykal Hafizoglu, Arizona State University, Industrial Engineering,<br />
SCIDSE, 699 S. Mill Ave., #501, Tempe, AZ, 85281, United States of<br />
America, baykal@asu.edu, Esma Gel, Pinar Keskinocak<br />
We consider dynamic price and lead time quotation for a MTO company with<br />
demand from contract customers and spot purchasers. Contract customers are<br />
offered a uniform price and lead time, and prioritized service. Spot purchasers are<br />
subject to dynamically quoted price and lead times, which they accept or reject with<br />
known probability. We discuss the potential of dynamic quotation, various<br />
properties of optimal control policies and the optimal mix of contract customers and<br />
spot purchasers.<br />
INFORMS Austin – 2010<br />
364<br />
3 - Horizontal Alliances and Mergers in Multitier Supply Chains<br />
Soo-Haeng Cho, Assistant Professor, Tepper School of Business,<br />
Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15215,<br />
United States of America, soohaeng@andrew.cmu.edu<br />
Supply chains often consist of multiple tiers in each of which one or more firms<br />
compete. Firms that belong to the same tier often form alliances or merge together.<br />
The primary objective of such alliances or mergers is to reduce marginal costs<br />
through economies of scale in R&D and production. In this paper, we examine the<br />
effect of the cost-reducing alliances and mergers in one tier on non-participating<br />
firms in the same tier and on firms in the upstream or downstream tiers.<br />
4 - Coordinating Capacity Investments in Joint Ventures<br />
Philippe Chevalier, Professor, CORE, Université catholique de<br />
Louvain, Voie du Roman Pays 34, Louvain-la-Neuve, 1348, Belgium,<br />
Philippe.Chevalier@uclouvain.be, Guillaume Roels, Ying Wei<br />
We model a strategic alliance between several manufacturing firms that decide to<br />
pool their resources so as to hedge their profits against demand variability. We<br />
propose a type of contract that coordinates capacity investments and compare this<br />
contract with several other contracts proposed in the literature.<br />
■ WA11<br />
C - Room 12B, Level 4<br />
Finance/Operations Link: Flow Models<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Nico Vandaele, Professor, Katholieke Universiteiet Leuven,<br />
Naamsestraat 69, Leuven, Belgium, Nico.Vandaele@econ.kuleuven.be<br />
1 - A Newsvendor Perspective on Value-based Performance and<br />
Risk Management<br />
Gerd Hahn, Catholic University of Eichstaett-Ingolstadt, Auf der<br />
Schanz 49, Ingolstadt, 85049, Germany, gerd.hahn@kuei.de,<br />
Heinrich Kuhn<br />
Economic Value Added (EVA) as a prevalent indicator of shareholder value creation<br />
is applied to the well-known newsvendor or cost-volume-profit model. An<br />
integrated approach to performance and risk management is developed exploiting<br />
properties of the EVA concept. We provide a managerial framework for decisionmaking<br />
considering the risk preference of the newsvendor. A numerical example is<br />
utilized to highlight implications of the presented approach.<br />
2 - Working Capital Decisions in Supply Chains Under Consideration of<br />
Cost of Capital Rates<br />
Erik Hofmann, Senior Lecturer, University of St. Gallen,<br />
Dufourstrasse 40a, LOG-HSG, St. Gallen, 9000, Switzerland,<br />
erik.hofmann@unisg.ch<br />
In this paper, working capital decisions are extended to supply chains, due to the<br />
deficiencies resulting from a single-company perspective. The weighted cash<br />
conversion cycle (WCCC) is combined with the weighted average cost of capital<br />
(WACC) model. The amount of funds in an inter-organizational setting is<br />
considered, transforming the WACC from an exogenous into an endogenous<br />
decision figure. A numerical study illustrates several performance impacts on supply<br />
chain companies.<br />
3 - Linking Operations and Finances: The Stochastic Lot<br />
Sizing Problem<br />
Lien Perdu, Katholieke Universiteit Leuven, Naamsestraat 69,<br />
Leuven, 3000, Belgium, lien.perdu@kuleuven-kortrijk.be,<br />
Nico Vandaele<br />
In contrast with a traditional cost model, we integrate a financial flow dimension in<br />
the stochastic lot sizing problem. The original model was built to optimize lead times<br />
and whereas the new objective function is based on the Economic Value Added<br />
concept, which allows a broader applicability.<br />
4 - Analysis of Card Based Flow Control in a Make-to-Order<br />
Production Shop<br />
Steven Harrod, Assistant Professor, University of Dayton, 1143<br />
Ashburton Dr, Dayton, OH, 45459, United States of America,<br />
steven.harrod@udayton.edu, John Kanet<br />
We examine the performance of a make-to-order production shop when a “pull”<br />
regimen (Kanban, Conwip, or POLCA) is enforced. After simulating random job<br />
routings, we conclude that flow control approaches do in fact reduce the number of<br />
jobs in process but total system inventory (including ready jobs) increases. Further<br />
we find that selection of priority rule has a greater influence on shop WIP than<br />
selection of a particular card based flow control system.
■ WA12<br />
C - Room 13A, Level 4<br />
Tactical and Operational Issues in Supply<br />
Chain Management<br />
Sponsor: Manufacturing and Service Operations Management/<br />
Supply Chain<br />
Sponsored Session<br />
Chair: Sila Cetinkaya, Professor, Texas A&M University, Industrial and<br />
Systems Engineering, College Station, TX, United States of America,<br />
sila@tamu.edu<br />
Co-Chair: James Lavin, NC State University, 1321 Crab Orchard Dr #002,<br />
Raleigh, 27606, United States of America, jalavin@ncsu.edu<br />
1 - Uniform vs Retailer-Specific Pricing in a Supply Chain<br />
Asoo Vakharia, Professor, University of Florida, Department of ISOM,<br />
Gainesville, FL, 32611-7169, United States of America,<br />
asoo.vakharia@warrington.ufl.edu, Lan Wang<br />
Should a supplier adopt a uniform or a retailer-specific price when selling a product<br />
to retailers with differing capabilities? Would the choice between these pricing<br />
strategies be moderated by the competitive market structure? Insights into this<br />
problem are provided for the cases of deterministic and stochastic end-product<br />
demand.<br />
2 - An Order-up-to-level (OUL) Inventory Model with Stochastic<br />
Demand and Lead Times<br />
Daniel Silva, OR Sr. Analyst, Kimberly Clark, Latin American<br />
Operations, KR 11A no 94 - 45, Piso 5, Bogota, Colombia,<br />
daniel.f.silvaizquierdo@kcc.com, Germàn Riaño<br />
We extend a periodic review, stochastic demand model to include stochastic lead<br />
times. We assume Normally distributed lead-time demand and solve for expected<br />
fill-rate, we achieve a better approximation than traditional methods. There is no<br />
closed form solution for the optimal OUL, but the fill rate function is convex and we<br />
use iterative methods to solve. Simulation results confirm fill rate goals are met by<br />
our model, while traditional models over-shoot. Real data results will be presented.<br />
3 - Stochastic Perturbed Demand Inventory Model<br />
James Lavin, NC State University, 1321 Crab Orchard Dr #002,<br />
Raleigh, 27606, United States of America, jalavin@ncsu.edu,<br />
Anita Vila-Parrish, Russell King<br />
Stockouts cause customers to lose faith in a retailer and potentially turn elsewhere<br />
to meet their future demands. Most inventory models use a penalty cost when a<br />
stockout occurs. An alternative first proposed by Schwartz (1966) instead discounts<br />
expected demand when stockouts occur through use of a “disappointment factor.”<br />
We extend Schwartz’s model for the case with stochastic demand.<br />
4 - A Supply-side Rationale for a Firm to Bundle<br />
Qingning Cao, PhD Candidate, University of Texas at Dallas, 800<br />
West Campbell Road, Richardson, TX, 75080-3021, United States of<br />
America, qxc071000@utdallas.edu, Jun Hang, Kathryn Stecke<br />
This paper examines a retailer’s two-product bundling decision when the supply of<br />
one product is limited. This paper derives the retailer’s optimal prices, stocking<br />
levels, and profits under unbundling and bundling. Demonstrating that limited<br />
supply can induce the retailer to bundle, this paper highlights a new supply-side<br />
rationale for bundling.<br />
■ WA13<br />
C - Room 13B, Level 4<br />
Incentives in Service Operations<br />
Sponsor: Manufacturing and Service Operations Management/<br />
Service Management Special Interest Group<br />
Sponsored Session<br />
Chair: Nitin Bakshi, Assistant Professor, London Business School, Sussex<br />
Place, London, NW1 4SA, United Kingdom, nbakshi@london.edu<br />
Co-Chair: Sang-Hyun Kim, Assistant Professor, Yale University, 135<br />
Prospect Street, New Haven, CT, 06520-8200, United States of America,<br />
sang.kim@yale.edu<br />
1 - Optimal Preventive Maintenance Under Contracting<br />
Sang-Hyun Kim, Assistant Professor, Yale University, 135 Prospect<br />
Street, New Haven, CT, 06520-8200, United States of America,<br />
sang.kim@yale.edu<br />
We investigate how various maintenance service contracts impact the optimal<br />
structure and performance of well-known preventive maintenance policies, such as<br />
age replacement and block replacement policies. We focus on comparing the results<br />
with those found in the classical reliability theory literature.<br />
INFORMS Austin – 2010 WA14<br />
365<br />
2 - Delaying the Delay Announcements<br />
Achal Bassamboo, Northwestern University,<br />
2001 Sheridan Road, Evanston, IL, United States of America,<br />
a-bassamboo@kellogg.northwestern.edu, Gad Allon<br />
This paper studies the impact of postponement of delay announcement on the<br />
ability of the firm to communicate non-verifiable congestion information to its<br />
customers as well as on the profits and utilities for the firm and the customers<br />
respectively. We show that this postponement can help the firm create credibility<br />
and augment the equilibrium language. However, in other settings this delay can<br />
also detract the equilibrium language.<br />
3 - An Auction Mechanism for Optimal Procurement From Multiple<br />
Suppliers with Asymmetric Information<br />
Yimin Yu, Assistant Professor, City University of Hong Kong, Hong<br />
Kong, yiminyu@cityu.edu.hk, Saif Benjaafar<br />
We study a retailer offering a procurement contract through a sealed auction to<br />
multiple suppliers. The production cost and the capacity of each supplier are private<br />
information. We design a modified VCG type auction to achieve the first best such<br />
that it is a dominant strategy for each supplier to reveal its true information.<br />
Furthermore, this auction has the following appealing properties: (1)Individual<br />
rational; (2)No free riding; (3)Budget balanced; (4)Coalition proof for the retailer.<br />
4 - Strategic Diagnosis and Pricing in Expert Services<br />
Mehmet Fazil Pac, PhD Candidate, Wharton School of Business,<br />
University of Pennsylvania, 3730 Walnut Street, Jon M. Huntsman<br />
Hall, Office 527.6, Philadelphia, PA, 19104, United States of America,<br />
mpac@wharton.upenn.edu, Senthil Veeraraghavan<br />
Customers often cannot identify the type of service they need, therefore they rely<br />
on experts, who also sell the service, for the diagnosis of their problem. The<br />
information asymmetry arising upon diagnosis leads to inefficiencies in the<br />
provision of the service. The expert has an incentive to over-provide or to ration<br />
services, based on the demand, capacity and the waiting cost. We investigate<br />
diagnosis, pricing and queue joining decisions in expert service markets using a<br />
queuing framework.<br />
■ WA14<br />
C - Room 14, Level 4<br />
Supply Chain Management VIII<br />
Contributed Session<br />
Chair: Wanxi Li, University of Wisconsin Milwaukee, 3202 N. Maryland<br />
Ave., Milwaukee, WI, 53201, United States of America,<br />
wanxili@uwm.edu<br />
1 - The Influence of Psychological Contract Violation on Supply Chain<br />
Decision-Making Behaviors<br />
Stephanie Eckerd, Ohio State University, 4943 Common Market<br />
Place, Dublin, United States of America, eckerd.2@osu.edu<br />
Conflict is an inevitable phenomenon in buyer-supplier relationships. In the face of<br />
varying types of conflict, individuals may respond differently depending on the level<br />
of psychological contract violation experienced. We report the results of a behavioral<br />
experiment that determines how those in boundary-spanning roles respond to<br />
conflict in the supply chain, specifically evaluating their economic decisions before<br />
and after an occurrence of conflict.<br />
2 - Procurement and Pricing in a Decentralized Multi-tier<br />
Assembly System<br />
Wanxi Li, University of Wisconsin Milwaukee, 3202 N. Maryland<br />
Ave., Milwaukee, WI, 53201, United States of America,<br />
wanxili@uwm.edu, Xiang Fang<br />
In a decentralized multi-tier assembly system, an assembler needs sets of modules<br />
produced by different module sub-assemblers, and each module needs multiple<br />
components purchased from different suppliers. The assembler faces stochastic<br />
demand. We characterize the equilibrium order quantity and pricing decisions,<br />
based on which we provide insights on the design of such multi-tier assembly<br />
systems.
WA15<br />
■ WA15<br />
C - Room 15, Level 4<br />
Continuous Optimization<br />
Contributed Session<br />
Chair: John Carlsson, Assistant Professor, University of Minnesota, 111<br />
Church St SE, 130C, Minneapolis, MN, 55455, United States of America,<br />
jgc@me.umn.edu<br />
1 - The Scalar Equivalence of Optimization Criteria<br />
Surachai Charoensri, University of Texas at Arlington, Arlington, TX,<br />
76019, United States of America, surachai.charoensri@mavs.uta.edu,<br />
H. W. Corley<br />
We show that existing optimization criteria are equivalent to the maximization of a<br />
real-valued function in a one-dimensional Euclidean space. All and only solutions to<br />
an optimization problem in the original criterion can be obtained by scalarization<br />
without the typical convexity/concavity assumptions on the original objective<br />
functions. Examples include minimax, Pareto, and set-valued optimization, as well<br />
as cone-ordered optimization in abstract spaces.<br />
2 - Computational Studies of Randomized Multidimensional<br />
Assignment Problems<br />
Mohammad Mirghorbani, The University of Iowa, 208 Engineering<br />
Research Facility, 330 S. Madison Street, Iowa City, IA, 52240,<br />
United States of America, smirghor@engineering.uiowa.edu,<br />
Paul Krokhmal<br />
We propose a new heuristic approach for solving randomized multidimensional<br />
assignment problems (MAPs) with linear sum or bottleneck objectives that is based<br />
on recently obtained asymptotical properties of optimal value of random MAPs. The<br />
approach allows for drastic reduction of search space while guaranteeing high<br />
quality of the solution, and transforms the original problem into a maximum clique<br />
problem in multipartite graphs.<br />
3 - Convex Relaxations for Cubic Polynomial Problems<br />
Helder Inacio, Student, Georgia Institute of Technology, Georgia<br />
Institute of Technology, Atlanta, GA, 30332, United States of<br />
America, hinacio@isye.gatech.edu, Shabbir Ahmed, Matthew Realff<br />
We study convex relaxations for problems with polynomial constraints with degree<br />
less than or equal to 3. Specifically for terms of the form x^2 y we derive convex<br />
nonlinear underestimators in a similar fashion to McCormick underestimators for<br />
bilinear terms. We compare these estimators with other convex underestimators.<br />
4 - A Non-convex Geometric Partitioning Algorithm for<br />
Multi-vehicle Routing<br />
John Carlsson, Assistant Professor, University of Minnesota,<br />
111 Church St SE, 130C, Minneapolis, MN, 55455,<br />
United States of America, jgc@me.umn.edu<br />
We consider a stochastic vehicle routing problem in which vehicle depot locations<br />
are fixed and client locations in a service region are unknown, but are assumed to<br />
be i.i.d. samples from a given probability density function. We present an algorithm<br />
for partitioning the service region into sub-regions so as to minimize the maximum<br />
workload of any vehicle when the service region is simply connected and point-topoint<br />
distances follow some “natural” metric, such as any L^{p} norm.<br />
■ WA16<br />
C - Room 16A, Level 4<br />
Manufacturing II<br />
Contributed Session<br />
Chair: Paul E “Gene” Coffman, Jr, Technical Leader, Ford Motor<br />
Company, 6100 Mercury Drive, Dearborn, MI, 48126-2746,<br />
United States of America, gcoffman@ford.com<br />
1 - Optimization of Stochastic Flow Lines using Exact Linear<br />
Programming Formulations<br />
Raik Stolletz, Associate Professor, Technical University of Denmark,<br />
Department of Management Engineering, Lyngby, Denmark,<br />
raist@man.dtu.dk<br />
Several sampling approaches have been proposed to analyze stochastic flow lines<br />
with finite buffer capacities. If the number of buffers is given, the performance can<br />
be evaluated via a Linear Programming formulation. This presentation shows<br />
linearization approaches if the number of buffers is a decision variable. We develop<br />
a two-step optimization approach, where a discrete time approximation is used to<br />
get a first solution to speed up the solution of the exact linearization.<br />
INFORMS Austin – 2010<br />
366<br />
2 - Forecasting Stochastic Lead Times<br />
Jack Hayya, Professor Emeritus, Penn State University, School of<br />
Business, University Park, 16802, United States of America,<br />
jch@psu.edu, Uttarayan Bagchi<br />
Consider the case of iid lead times, which theoretically cannot be predicted.<br />
However, these lead times are subject to order crossover which transforms the iid<br />
lead times to an AR(1) process. But this AR(1) process contains outliers which make<br />
the residuals nonnormal. So we fit an ARCH(1) model with t-residuals.<br />
3 - Virtual Manufacturing at Ford Motor Company<br />
Paul E “Gene” Coffman, Jr, Technical Leader, Ford Motor Company,<br />
6100 Mercury Drive, Dearborn, MI, 48126-2746, United States of<br />
America, gcoffman@ford.com<br />
Eight years ago, Ford launched a Virtual Manufacturing Center and initiated a<br />
strategy to significantly reduce launch concerns by verifying new vehicles virtually<br />
before physical prototypes are built and by simulating manufacturing operations<br />
early in a new vehicle program. Ford’s recent success in customer satisfaction<br />
surveys is due in part to the 80% reduction in launch concerns achieved to date.<br />
We will describe the key elements of the strategy and the tools used to achieve<br />
these results.<br />
■ WA17<br />
C - Room 16B, Level 4<br />
OR For Infrastructure Development in India<br />
Cluster: OR/MS in India<br />
Invited Session<br />
Chair: Ashok Mittal, Professor, IIT Kanpur, IME Dept., IIT Kanpur,<br />
Kanpur, UP, 208016, India, mittal@iitk.ac.in<br />
1 - Modeling Complex Aerospace Supply Chain With Delivery<br />
Guarantees<br />
Dinesh Kumar, Professor, Indian Institute of Management Bangalore,<br />
Bannerghatta Road, Bangalore, Ka, 560076, India,<br />
dineshk@iimb.ernet.in<br />
Aerospace has one of the complex supply chains that deals with assembly of<br />
millions of parts sourced from multiple vendors across the globe. Aircraft<br />
manufacturers expect their suppliers to deliver the parts just in time at their<br />
manufacturing facilities. In this paper we have used queueing models to analyse an<br />
assembly type manufacturing system with an objective to maximize the probability<br />
of on-time delivery of the parts.<br />
2 - Optimal Route Selection in a Computer Integrated Raw Material<br />
Handling Complex of an Integrated Steel Plant<br />
Salil K Dutta, SAIL- Durgapur Steel Plant India, TQM Deptt,<br />
Durgapur, 713203, India, salil_kumar_dutta@yahoo.co.in<br />
For efficient operation of Raw Materials Handling Complex of an Integrated Steel<br />
Plant, a PC based System is conceptualized. Two interactive modules: i) Optimal<br />
Blend-mix Module based on a mathematical programming model ii) Route Selection<br />
and Prioritization Module based on a integer programming model in conjunction<br />
with a Heuristic, has been proposed.<br />
3 - Understanding Passanger Switching Behavior and Yield<br />
Management for Indian Railways<br />
Ashok Mittal, Professor, IIT Kanpur, IME Deptt, IIT Kanpur, Kanpur,<br />
UP, 208016, India, mittal@iitk.ac.in, Rahul Sharma<br />
Indian rail provides different type of accomodation to rail passangers. For most of<br />
the trains seats in the choice class are not available until booked well in advance.<br />
We model the switching behavior of the passanges classified in different need<br />
categories. We use this behaviour to model yield management for Indian railways.
■ WA18<br />
C - Room 17A, Level 4<br />
OR in Practice I<br />
Sponsor: CPMS, The Practice Section<br />
Sponsored Session<br />
Chair: Laura Galli, DEIS University of Bologna, Viale Risorgimento, 2,<br />
Bologna, 40136, Italy, l.galli@unibo.it<br />
Co-Chair: Bjarni Kristjansson, President, Maximal Software, Inc., 933 N.<br />
Kenmore St., Suite 218, Arlington, VA, 22201, United States of America,<br />
bjarni@maximalsoftware.com<br />
1 - OR at Ford<br />
Erica Klampfl, Technical Leader, Ford Research & Advanced<br />
Engineering, RIC Building, MD 2122, 2101 Village Rd, Dearborn, MI,<br />
48124, United States of America, eklampfl@ford.com<br />
I will provide a sampling of OR problems in areas such as Sustainability,<br />
Manufacturing, Purchasing, Product Development, Marketing, and Finance. We<br />
apply an analytical approach to understand the environmental implications of our<br />
products, enhance the sustainability of our business, and provide sound scientific<br />
input for corporate strategy and regulatory interactions.<br />
2 - Robust Planning and Online Re-scheduling for the Train<br />
Routing Problem<br />
Laura Galli, DEIS University of Bologna, Viale Risorgimento, 2,<br />
Bologna, 40136, Italy, l.galli@unibo.it, Alberto Caprara, Leo Kroon,<br />
Gabor Maroti, Paolo Toth<br />
Train Routing is a problem that arises in the early phase of the passenger railway<br />
planning process. However, train delays often disrupt the routing schedules thus<br />
railway nodes are responsible for a large part of the delay propagation. In this paper,<br />
we propose robust models and re-scheduling algorithms for train routing, and<br />
design a simulation framework to evaluate and compare their effectiveness. We<br />
present computational results based on real-world data from the Italian railways.<br />
3 - Combinatorial Model for Crew Scheduling in Train Transportation<br />
Hector Ramirez Cabrera, CMM, Universidad de Chile, Avda. Blanco<br />
Encalada 2120, Santiago, Chile, hramirez@dim.uchile.cl, Jorge<br />
Amaya, Paula Uribe<br />
This crew scheduling problem can be expressed as follows: given a set of crew teams<br />
(a pair composed by a driver and an assistant) and a set of trips (travel from one<br />
station to another one), the aim is to find an optimal allocation of these crews to<br />
the given trips satisfying operational constraints, such as labor laws, specific contract<br />
conditions, among others. The objective of our problem is to equilibrate the number<br />
of working hours realized by each crew in a given period of time.<br />
■ WA19<br />
C - Room 17B, Level 4<br />
Computational and Robust Approaches to Inventory<br />
and Revenue Management<br />
Sponsor: Revenue Management and Pricing Section<br />
Sponsored Session<br />
Chair: Dan Iancu, IBM T.J. Watson Research Center, P.O. Box 218,<br />
Yorktown Heights, NY, 10598, United States of America,<br />
dan.iancu@us.ibm.com<br />
1 - A Dynamic Near-optimal Algorithm for Online Linear Program with<br />
Application to Revenue Management<br />
Zizhuo Wang, Stanford University, 14 Comstock Cir, Apt 106,<br />
Stanford, United States of America, zzwang@stanford.edu, Yinyu Ye,<br />
Shipra Agrawal<br />
We study a network revenue management problem where the customers come<br />
sequentially and decisions are made online. Our approach is distribution-free. We<br />
only assume that the customers come in a random order. By using a dynamic<br />
pricing algorithm where the prices come from the solution of a series of linear<br />
program, our algorithm is near-optimal given the initial inventory is large enough.<br />
This algorithm can be applied to a wide range of revenue management and resource<br />
allocation problems.<br />
2 - A Geometric Characterization of the Power of Finite Adaptability in<br />
Multi-stage Stochastic Optimization<br />
Andy Sun, Massachusetts Instititute of Technology, Operations<br />
Research Center, 50 Memorial Drive, Cambridge, MA, United States<br />
of America, sunx@mit.edu, Vineet Goyal, Dimitris Bertsimas<br />
We show a significant role that geometric properties of the uncertainty sets, such as<br />
symmetry, play in determining the power of robust and finitely adaptable solutions<br />
in multi-stage stochastic and adaptive optimization problems. We propose good<br />
approximation solution policies with performance guarantees that depend on the<br />
geometric properties of the uncertainty sets. To the best of our knowledge, these are<br />
the first approximation results for the multi-stage problems in such generality.<br />
INFORMS Austin – 2010 WA21<br />
367<br />
3 - Distributionally Robust Pricing and Replenishment Decisions for<br />
Multiple Products<br />
Dan Iancu, IBM T.J. Watson Research Center, P.O. Box 218,<br />
Yorktown Heights, NY, 10598, United States of America,<br />
dan.iancu@us.ibm.com<br />
In the current presentation, we discuss formulations and computational aspects<br />
related to determining pricing and replenishment policies for multiple products<br />
under uncertain customer demand. In particular, we look for policies directly<br />
parameterized in the model disturbances. Preliminary computational results, based<br />
on both synthetic, as well as real data from a large US retailer, are very promising,<br />
with adjustable policies considerably improving over open-loop decisions.<br />
■ WA20<br />
C - Room 18A, Level 4<br />
Challenges and Perspectives in Price<br />
Demand Relationship<br />
Sponsor: Revenue Management and Pricing Section<br />
Sponsored Session<br />
Chair: Aihong Wen, PROS Holdings, Inc., 3100 Main St Suite 900,<br />
Houston, TX, 77002, United States of America, awen@prospricing.com<br />
1 - Using Forecasts of Competitor Prices to Increase Sales<br />
Evan Brott, Scientist, PROS, 3100 Main Street #900, Houston, TX,<br />
77025, United States of America, EBROTT@prosrm.com<br />
Accurate predictions of competitor prices are invaluable for developing pricing<br />
strategies. By analyzing market conditions and recent pricing actions, we show a<br />
method of calculating an array of expected future competitor prices. Businesses may<br />
utilize this array to position themselves at a preferred position relative to a major<br />
competitor. Additionally, we show how the array can be used as input into rankbased<br />
optimization, to maximize margins subject to the expected competitive<br />
landscape.<br />
2 - A General Framework for using Customer Sensitivity to Execute<br />
Pricing Strategies<br />
Ed Gonzalez, Associate Scientist, PROS, 3100 Main St, Suite 900,<br />
Houston, TX, 77002, United States of America,<br />
EGonzalez@prosrm.com<br />
In this presentation, we demonstrate a general framework which allows for the<br />
automation of pricing strategies based on both business rules and fiscal goals. The<br />
main components of this framework are (1) developing price sensitivity (2)<br />
optimizing over given constraints and (3) measuring the effects of a pricing strategy<br />
at both the macro and micro level.<br />
3 - Data Mining Techniques in Modeling Price Elasticity<br />
Aihong Wen, PROS Holdings, Inc., 3100 Main St Suite 900, Houston,<br />
TX, 77002, United States of America, awen@prospricing.com<br />
Modeling price elasticity has always been a key step in pricing optimization. This<br />
presentation discusses the motivation behind seeking data mining tools for this<br />
challenging task, as well as our proposals and case study.<br />
■ WA21<br />
C - Room 18B, Level 4<br />
Carbon Reduction Policy Analysis<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Brian Jacobs, Assistant Professor, Michigan State University,<br />
Supply Chain Mgt Dept, N349 North Business Complex, East Lansing,<br />
MI, 48824-1122, United States of America, jacobsb@bus.msu.edu<br />
1 - Investment Planning for Electricity Generation Expansion Under<br />
CO2 Emission Reduction Policies<br />
Dong Gu Choi, Georgia Institute of Technology, 765 Ferst Drive, NW,<br />
Atlanta, GA, 30332, United States of America,<br />
doonggus@gatech.edu, Valerie Thomas<br />
As electricity demand increases and existing power plants age, electricity generators<br />
decide on supply technologies for new investment. This talk addresses the effects of<br />
CO2 emission reduction policies on the investment decision of an electricity<br />
generating firm. A dynamic programming model,incorporating policy uncertainty, is<br />
developed for technology investment choice.
WA23<br />
2 - China’s Regional CO2 Emissions: Characteristics and Emission<br />
Reduction Policies<br />
Lei Meng, Xi’an Jiaotong University, Box 1875, No.28 Xianning West<br />
Road, Xi’an, 710049, China, mleenig@gmail.com, Yong Xue,<br />
Ju’e Guo<br />
This paper analyzes the characteristics of regional CO2 emissions in China, using<br />
province level panel data from 1997 to 2007. The results show that there’re<br />
remarkable regional disparities among eastern coastal, midland and western areas.<br />
In view of uneven regional development and reverse distribution of energy<br />
resources and consumption, the CO2 emission reduction policies need customized<br />
combination of tax, price, investment and transfer payment to meet the actual<br />
situation in various areas.<br />
3 - Shareholder Value Effects of Voluntary Emissions Reductions<br />
Brian Jacobs, Assistant Professor, Michigan State University, Supply<br />
Chain Mgt Dept, N349 North Business Complex, East Lansing, MI,<br />
48824-1122, United States of America, jacobsb@bus.msu.edu<br />
Recent empirical evidence has demonstrated that the stock market reacts negatively<br />
to firm announcements of voluntary emissions reductions. In this work, we study<br />
how certain contextual factors influence the market reaction. Factors include the<br />
type of emission (regulated or unregulated), firm and industry characteristics,<br />
energy prices, and whether the firm’s announcement was standalone or part of a<br />
government or NGO initiative.<br />
4 - Optimal Fuel Conversion Strategy of Power Plant Under Different<br />
Carbon Policies<br />
Xiaohua Wu, Rensselaer Polytechnic Institute, 903 Peoples Ave<br />
Apt 3, Troy, NY, 12180, United States of America, wux4@rpi.edu,<br />
Aparna Gupta<br />
The carbon policy will accelerate the fuel type conversion process. In this paper, a<br />
general model of optimizing the long term fuel conversion strategy of a generator<br />
under different carbon policies is built and analyzed. The stochastic price evolutions<br />
of fuels, electricity and carbon emission are modeled to identify the impact of<br />
market fluctuations. Key decision factors are optimized to achieve the generator’s<br />
best economic performance and create a framework to assess policy impact.<br />
■ WA23<br />
C - Room 18D, Level 4<br />
Optimization in the Service Sector<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Ada Barlatt, Assistant Professor, University of Waterloo,<br />
Department of Management Sciences, 200 University Avenue West,<br />
Waterloo, ON, N2L3G1, Canada, abarlatt@uwaterloo.ca<br />
1 - Public School’s Meal Program: Finding the Best<br />
Cost-effective Menu<br />
Betzabe Rodriguez, Assistant Professor, University of Puerto Rico at<br />
Mayaguez, Call Box 9000, Mayaguez, PR, 00681, Puerto Rico,<br />
betzabe.rodriguez@upr.edu, Magaly Gonzalez<br />
Meal’s assortment highly affects the operational costs in the supply chain for the<br />
Puerto Rico School’s Meal Program (PRSMP). The government must comply with<br />
nutritional and service requirements while balancing delivery frequencies and<br />
transportation costs. We have developed a mathematical formulation for the<br />
operational costs of the food supply chain, with the objective to find a low cost<br />
meal’s assortment for the PRSMP.<br />
2 - Applying Value-at-Risk and Conditional Value-at-Risk to the<br />
Selective Newsvendor<br />
Arleigh Waring, University of Michigan, 1205 Beal Ave, Ann Arbor,<br />
MI, 48109, United States of America, awaring@umich.edu<br />
The selective newsvendor considers a single product firm that sells to several<br />
different markets in a single selling season. The firm decides which markets to serve<br />
and the total inventory to procure a priori. We evaluate the selective newsvendor<br />
using two common risk measures: Value-at-Risk and Conditional Value-at-Risk. We<br />
show the optimal order quantity and describe a selection criterion for the markets to<br />
serve and then compare the inherent tradeoffs between the two methods.<br />
3 - Evaluating Tradeoffs in Implementing Alternative<br />
Workweek Schedules<br />
Ada Barlatt, Assistant Professor, University of Waterloo, Department<br />
of Management Sciences, 200 University Avenue West, Waterloo,<br />
ON, N2L3G1, Canada, abarlatt@uwaterloo.ca, Juan Vera<br />
Climate change, 24/7 retail outlets, and technological advances have led to changes<br />
in the way people work. Around the globe, employees are switching to from the<br />
traditional 9AM to 5PM schedule to alternative workweek (AWW) schedules. In this<br />
presentation we will discuss the models developed to evaluate the tradeoffs between<br />
the benefits (e.g., increased operating hours) and the concerns (e.g., facilitating<br />
employee communication) in implementing AWW schedules.<br />
INFORMS Austin – 2010<br />
368<br />
■ WA24<br />
C - Room 19A, Level 4<br />
Network Models for Counterterrorism<br />
Sponsor: Public Programs, Service and Needs<br />
Sponsored Session<br />
Chair: Susan Martonosi, Assistant Professor, Harvey Mudd College,<br />
Department of Mathematics, 301 Platt Boulevard, Claremont, CA, 91711,<br />
United States of America, martonosi@math.hmc.edu<br />
1 - A Network Flow Approach to Terrorist Network Disruption<br />
Susan Martonosi, Assistant Professor, Harvey Mudd College,<br />
Department of Mathematics, 301 Platt Boulevard, Claremont, CA,<br />
91711, United States of America, martonosi@math.hmc.edu,<br />
Doug Altner<br />
We present a new network disruption technique that tries to make otherwise<br />
secretive members of a terrorist group more visible. Through vertex deletion, this<br />
technique forces the secretive members to increase their participation in network<br />
communication. This talk will illustrate our disruption metric based on network<br />
flows, address graph-theoretic characteristics of promising vertices to target and<br />
discuss some computational challenges.<br />
2 - Diverting Communication Through a Clandestine Leader in a<br />
Social Network<br />
Doug Altner, Assistant Professor, United States Naval Academy,<br />
United States of America, altner@usna.edu, Susan Martonosi<br />
This talk investigates the following optimization problem: given a social network<br />
with a key vertex and a finite budget for deleting vertices, which vertices should be<br />
deleted to maximize the amount of communication that must be sent through the<br />
key vertex if the amount of communication between each pair of vertices equals the<br />
maximum flow between them? We present a meta-heuristic approach to this<br />
problem as well as computational results.<br />
3 - Tradeoffs in the Structure of Terrorist Networks<br />
Alexander Gutfraind, Postdoctoral Fellow, Los Alamos National<br />
Laboratory, Theoretical Division, Mail Stop B284, Los Alamos, NM,<br />
87545, United States of America, gfriend@lanl.gov<br />
Terrorist groups and other secret societies have a network structure reflecting their<br />
objectives of survival and attack. This talk will introduce a model that quantifies<br />
those using discrete optimization. Solving the model shows that the optimal<br />
structure of such networks is based on cells. Open non-violent activism pays under<br />
just two conditions: extreme tolerance and extreme repression. The model can also<br />
be used to design vital infrastructure networks.<br />
4 - Counter-Radicalization Influence Campaigns and Social Networks:<br />
What Does the Data Say?<br />
Richard Colbaugh, Sandia National Laboratories/New Mexico Tech,<br />
22 Camino Don Carlos South, Santa Fe, NM, 87506,<br />
United States of America, rcolbau@sandia.gov, Kristin Glass<br />
This talk presents results of a model-based, empirically-grounded study of social<br />
networks and influence campaigns and summarizes the practical implications of<br />
these findings. Interestingly our investigation reveals that some conventional<br />
wisdom regarding social networks and influence is either incomplete or incorrect.<br />
We consider two main topics: 1.) understanding influence generation/propagation/ -<br />
measurement as network dynamics phenomena, and 2.) roles for social media in<br />
influence campaigns.<br />
■ WA25<br />
C - Room 19B, Level 4<br />
Transportation, Intelligent Systems II<br />
Contributed Session<br />
Chair: Ali Guner, Research Assisstant, Wayne State University,<br />
4815 Fourth St., Detroit, MI, 48202, United States of America,<br />
arguner@wayne.edu<br />
1 - A Real Time Dynamic Rideshare System<br />
Ali Haghani, Professor, University of Maryland, College Park, 1173<br />
Glenn L. Martin Hall, College Park, MD, 20742, United States of<br />
America, haghani@umd.edu, Keivan Ghoseiri, Hadi Sadrsadat,<br />
Masoud Hamedi<br />
This paper presents an optimization model for a real-time dynamic rideshare system.<br />
The model maximizes the overall system performance in real time subject to ride<br />
availability, capacity, and passenger and driver time window constraints while<br />
considering users’ preferences. Model formulation and results are presented.
2 - Robust Multiple Priority Traffic Signal Control with Vehicle-to-<br />
Infrastructure Communication Systems<br />
Qing He, University of Arizona, 1127 E James E. Rogers Way,<br />
Tucson, AZ, 85721, United States of America,<br />
heqing@email.arizona.edu, Larry Head, Jun Ding<br />
This paper examines the multiple priority problems in traffic signal control under<br />
the condition that vehicle-to-infrastructure communication is available. Given the<br />
current multiple priority request information from on-board equipment (OBE), a<br />
robust MILP is developed with actuated control integrated to mitigate the delay for<br />
both vehicles with priority and passenger cars. A numerical experiment with<br />
VISSIM and GAMS shows the effectiveness of proposed approach.<br />
3 - Relationship of Pretrip Traveler Information System to<br />
Non-motorized and Public Traffic in China<br />
Yi Zhang, School of Transportation Engineering, Tongji University,<br />
No.4800 Cao’an Road, Shanghai, China, Shanghai, China,<br />
darrenzhy@gmail.com, Meiping Yun, Xiaoguang Yang<br />
Traveler information system is able to change travelers’ travel behavior and alleviate<br />
congestion. Based on a Travel Desire Survey in Zhongshan City, China, the<br />
relationship of pretrip traveler information system to non-motorized and public<br />
traffic was examined. The commuters’ propensity to change travel mode from<br />
private car to non-motorized and public traffic was obtained. It is also showed that<br />
the propensity would vary in the context of different trip distance and travelers’<br />
characteristics.<br />
4 - Dynamic Routing in Stochastic Time-Dependent Networks for<br />
Milk-Run Tours with Time Windows<br />
Ali Guner, Research Assisstant, Wayne State University,<br />
4815 Fourth St., Detroit, MI, 48202, United States of America,<br />
arguner@wayne.edu, Ratna Babu Chinnam, Alper Murat<br />
JIT requires frequent and reliable pick-ups and deliveries within specified time<br />
windows. However, growing congestion on road networks is increasing variability in<br />
travel times, making it difficult to achieve efficient and reliable deliveries. We<br />
investigate the impact of utilizing real-time ITS information to route the vehicle.<br />
Our dynamic routing algorithm handles milk-run tours under a TSP framework,<br />
while modeling congestion on arcs as stochastic and time-dependent congestion<br />
states.<br />
■ WA26<br />
C - Room 4A, Level 3<br />
Data Mining and Knowledge Discovery in Health Care<br />
Sponsor: Data Mining<br />
Sponsored Session<br />
Chair: Durai Sundaramoorthi, Assistant Professor, Missouri Western State<br />
University, 4525 Downs Drive, Saint Joseph, MO, 64507, United States of<br />
America, dsundaramoorthi@missouriwestern.edu<br />
1 - An Adaptive Pain Management Framework<br />
Ching-Feng Lin, Student, UTA, 212 S Cooper St. #220, Arlington,<br />
TX, 76013, United States of America, ching-feng.lin@mavs.uta.edu,<br />
Victoria Chen, Robert Gatchel<br />
The Eugene McDermott Center for Pain Management at the University of Texas<br />
Southwestern Medical Center at Dallas conducts a two-stage interdisciplinary pain<br />
management program that considers a wide variety of treatments. We structure this<br />
decision-making process using dynamic programming to generate adaptive<br />
treatment strategies for this two-stage program. State transition models were<br />
derived using data from the two-stage pain management program.<br />
2 - The Role of Insurance Claims Databases in Healthcare Research<br />
Yihan Guan, PhD Candidate, Stanford University, Huang Engineering<br />
Center 212F, Stanford, CA, 94305, United States of America,<br />
yihan@stanford.edu, Margret Bjarnadottir<br />
Health insurance claims data have been used in a wide spectrum of health care<br />
research during the past two decades, including studying drug therapy outcomes,<br />
assessing quality of care, estimating population disease burden, predicting health<br />
care cost, and detecting adverse drug effects. This talk discusses the evolution of<br />
applications of claims data, the current research frontier associated with claims data,<br />
and some future opportunities.<br />
3 - Analyzing Patient Discharge Data From an Urban Hospital using<br />
Data Mining Techniques<br />
Xiuli (Shelly) Qu, Assistant Professor, North Carolina A&T State<br />
University, 1601 E. Market Street, 424 McNair Hall, Greensboro, NC,<br />
27411, United States of America, xqu@ncat.edu, Xiaochun Jiang,<br />
Lauren Davis<br />
As aging is beginning to impact the baby boom generation, they begin to experience<br />
more chronic diseases and need more inpatient care. To deal with this trend,<br />
hospitals need to reduce the average length of stay (ALOS). In this study, data<br />
INFORMS Austin – 2010 WA27<br />
369<br />
mining techniques were used to analyze the inpatient discharge data from an urban<br />
hospital. Four models were built to predict ALOS. Our results indicated that the<br />
Ensemble model was the best fit and age and chronic disease were the important<br />
predictors.<br />
4 - Examining Relationships Between Medical Home and<br />
Patient Experience<br />
Sharon Johnson, Associate Professor, Worcester Polytechnic<br />
Institute, Department of Management, 100 Institute Road,<br />
Worcester, MA, 01566, United States of America, sharon@wpi.edu,<br />
Edward Westrick, Lori Pelletier<br />
The Patient-Centered Medical Home (PCMH) is a new model for comprehensive<br />
primary care that seeks to strengthen the physician-patient relationship. This<br />
exploratory study utilizes Pearson correlation coefficients to examine relationships<br />
between PPC-PCMH Survey results, which measure adoption of PCMH structures,<br />
and patient experience data. The results show an unexpected negative correlation<br />
between the PPC-PCMH structures of access and communication and the related<br />
patient experience measure.<br />
■ WA27<br />
C - Room 4B, Level 3<br />
Linear Programming<br />
Contributed Session<br />
Chair: Holly Floyd, Texas State University-San Marcos, 250 S. Stagecoach<br />
Trl. #136, San Marcos, United States of America, hf1046@txstate.edu<br />
1 - Explore the Higher-Order Rescaling Perceptron Algorithm<br />
Dan Li, Department of Industrial and Systems Engineering,<br />
Lehigh University, 200 West Packer Ave, Bethlehem, PA, 18015,<br />
United States of America, dal207@lehigh.edu, Tamàs Terlaky<br />
The rescaling perceptron algorithm solves LO problems with high probability in<br />
O(nln(1/r)) iterations, where r is the radius of the largest inscribed ball. It uses one<br />
vector to rescale the system at each iteration. We realize rescaling by using parallel<br />
processors and several vectors in one higher-order step. We explore how the<br />
number and quality of vectors affect the rescaling rate. With properly chosen<br />
vectors, we get better rescaling rates and improve the complexity.<br />
2 - A New Method to Solve Linear Programming Problems<br />
Oscar Buitrago, Professor, Universidad Libre de Colombia,<br />
oscary.buitragos@unilibrebog.edu.co, osyesu@gmail.com, Bogotà<br />
D.C, Colombia, oscary.buitragos@unilibrebog.edu.co, Andres Ramirez<br />
Many methods have been developed for solving LP problems, including the famous<br />
Simplex and interior point algorithms. In this study a new procedure for solving LP<br />
problems is described, based on orthogonal projections that move through the<br />
polyhedron frontier which defines the feasible region until it reaches the optimal<br />
point.<br />
3 - Optimal Deployment Plan of Emission Reduction Technologies<br />
Muhammad Bari, Student, Texas A&M University, University Dr.,<br />
College Station, TX, 77843, United States of America,<br />
ehsanulbarihome@yahoo.com, Josias Zietsman, Luca Quadrifoglio,<br />
Mohamadreza Farzaneh<br />
The objective of this research was to develop methodologies for optimal deployment<br />
of emission reduction technologies for non-road equipment in a cost effective and<br />
optimal manner. The multi-objective problem consists of two weighted objectives,<br />
(i) maximizing NOx reduction and (ii) maximizing fuel savings. The models<br />
developed in this study serves as a tool to assist the decision makers to decide about<br />
the deployment preference of technologies.<br />
4 - A Multi-Period Energy and CO2 Emission Optimization Toward<br />
Sustainable Automotive Manufacturing<br />
Seog-Chan Oh, Senior Researcher, General Motors R&D, 30500<br />
Mound Road, Warren, MI, 48090, United States of America,<br />
seog-chan.oh@gm.com, Stephan Biller<br />
Fluctuating energy prices and enactment of climate change legislations add<br />
increasing uncertainty in costs associated with energy and CO2 emission for<br />
automotive companies. To combat the challenges, we propose a mixed-integer<br />
optimization model to maximize the reduction of energy and CO2 emission costs for<br />
the automotive manufacturing process. Given a multi-year budget, we analyze<br />
different scenarios, assuming different impacts of energy prices and environmental<br />
regulations.
WA28<br />
■ WA28<br />
C - Room 4C, Level 3<br />
Health Management of Complex Systems<br />
Sponsor: Quality, Statistics and Reliability<br />
Sponsored Session<br />
Chair: Qingyu Yang, Assistant Professor, Wayne Sate University,<br />
4815 Fourth Street, Detroit, MI, 48202, United States of America,<br />
qyang@wayne.edu<br />
Co-Chair: Jian Liu, Assistant Professor, University of Arizona,<br />
Rm 268, 1127 E. James E. Rogers Way, Tucson, AZ, 85741,<br />
United States of America, jianliu@email.arizona.edu<br />
1 - Multi-level Multi-State Information Integration for System<br />
Performance Prediction<br />
Jian Liu, Assistant Professor, University of Arizona, Rm 268, 1127 E.<br />
James E. Rogers Way, Tucson, AZ, 85741, United States of America,<br />
jianliu@email.arizona.edu<br />
Heterogeneous data available at different levels of a complex system create great<br />
opportunity to more accurately predict the system level performance. This research<br />
provides a Bayesian approach that simultaneously combines multi-state event data<br />
of interdependent components and subsystems. A simulation example demonstrates<br />
the capability of the approach.<br />
2 - Sensor Recovery in Multivariate Condition Monitoring Systems<br />
Haitao Liao, Assistant Professor, The University of Tennessee, 211<br />
Pasqua Building, Knoxville, TN, 37996, United States of America,<br />
hliao4@utk.edu, Jian Sun<br />
Loss of sensor readings due to malfunction of connectors and/or sensors is crucial to<br />
fault diagnosis and prognosis in a multichannel condition monitoring system. To<br />
improve the operational reliability of the overall system, effective sensor recovery<br />
becomes an important, value added technique. This work addresses a statistical<br />
sensor recovery methodology to enhance multichannel condition monitoring.<br />
3 - Power Reliability Management in Smart Grids via Virtual<br />
Energy Provisioning<br />
Tongdan Jin, Texas State University, 601 University Drive, San<br />
Marcos, TX, 78666, United States of America, tj17@txstate.edu,<br />
Ying Yu, Mahmoud Mechehoul<br />
We propose a novel demand side management concept called Online Purchase<br />
Electricity Now (OPEN) to minimize load variations and generation uncertainties<br />
caused by renewable energies. The OPEN system allows customers to order and<br />
request advanced electricity via the Internet as if performing online purchasing. It<br />
aims for customers to achieve “order exactly what they need, and consume exactly<br />
what they ordered”. The new concept has great potentials and promises for smart<br />
grid technologies.<br />
4 - Failure Profile Analysis of Repairable Systems<br />
Qingyu Yang, Assistant Professor, Wayne Sate University, 4815<br />
Fourth Street, Detroit, MI, 48202, United States of America,<br />
qyang@wayne.edu, Yong Chen, Yili Hong, Jianjun Shi<br />
The relative failure frequency among major failure modes of a repairable system is<br />
referred to as failure profile. Identification of failure profile can provide valuable<br />
information for system design and maintenance management. In this research, a<br />
statistical model and two testing procedures are developed to study the statistical<br />
properties of the failure profile. The efficiency of the developed methods is verified<br />
by a case study of a high throughput screening (HTS) process.<br />
■ WA29<br />
C - Room 5A, Level 3<br />
Renewable Energy Integration Into Power Systems for<br />
Smart Operations<br />
Sponsor: Quality, Statistics and Reliability<br />
Sponsored Session<br />
Chair: Eunshin Byon, PhD, Postdoctoral Research Associate, Texas A&M<br />
University, 241 Zachry, 3131 TAMU, College Station, TX, 77840,<br />
United States of America, esbyun@neo.tamu.edu<br />
1 - Impact of Environmental Factors to the Degradation of Solar<br />
Photovoltaic Module<br />
Rong Pan, Assistant Professor, Arizona State University, Sch Compt<br />
Infor & Dec Sys Engr, Tempe, AZ, 85287, United States of America,<br />
Rong.Pan@asu.edu<br />
To make the solar energy economically competitive, PV manufacturers typically<br />
provide 20-30 year warranties to their customers. In this talk, we present a practical<br />
approach to weather modeling and its usage in PV module degradation analysis. We<br />
have analyzed the performance data of several PV modules collected over a long<br />
time of period (approximately 15 years). These data will be used to demonstrate the<br />
methodology to be developed in this study.<br />
INFORMS Austin – 2010<br />
370<br />
2 - Hierarchical Simulation Modeling Framework for Electrical Power<br />
Quality and Capacity<br />
Esfandyar Mazhari, University of Arizona, 1127 East James E. Rogers<br />
Way, Tucson, AZ, 85721-0020, United States of America,<br />
emazhari@email.arizona.edu, Young-Jun Son<br />
A two level hierarchical simulation modeling framework is proposed for an electric<br />
power network involving PV-based solar generators, various storage units, and grid,<br />
where the lower level model concerns power quality and the higher level model<br />
concerns capacity. The higher level is based on agent-based modeling while the<br />
lower level is based on circuit-level, continuous time modeling. An integration and<br />
coordination framework is developed, and it is demonstrated with a utility level<br />
scenario.<br />
3 - Reliability Issues in Power System Planning and Operation with<br />
Renewable Energy Sources<br />
Chanan Singh, Regents Professor, Texas A&M University,<br />
Department of Electrical & Computer Engi, College Station, TX,<br />
77843, United States of America, singh@ece.tamu.edu<br />
Renewable energy sources are fast penetrating the power grid. It is estimated that<br />
wind power alone may be close to 20 percent of the power scenario in America and<br />
many European nations have similar targets.Such significant penetrations of<br />
renewable energy pose considerable challenges for power system reliability in<br />
planning and operation. This presentation will review this problem and share some<br />
results to model and analyze the impact of their integration on reliability of the<br />
power grid.<br />
4 - Virtual Models of Wind Turbines<br />
Andrew Kusiak, Professor, The University of Iowa, Mechanical and<br />
Industrial Engineering, Iowa City, IA, 52242, United States of<br />
America, andrew-kusiak@uiowa.edu<br />
Complex nature of the wind, makes modeling wind turbines is a major challenge.<br />
Data mining offers algorithms for modeling wind turbines. A methodology for the<br />
development of virtual models of wind turbines is presented. The virtual models are<br />
developed and tested with data collected at a wind farm. Several data-mining<br />
algorithms for parameter selection and model extraction are analyzed. The research<br />
results are illustrated with industrial case studies.<br />
■ WA30<br />
C - Room 5B, Level 3<br />
Reliability III<br />
Contributed Session<br />
Chair: Elias Keedy, PhD Student, University of Houston, S350<br />
Engineering Bldg 1, Houston, TX, 77204, United States of America,<br />
eliekeedy@yahoo.com<br />
1 - Reliability Modeling in the Design of a New Energy Concept<br />
Sarah Riddell Powers, Lawrence Livermore Natl Lab, 7000 East<br />
Avenue, L-153, Livermore, CA, United States of America,<br />
powers22@llnl.gov<br />
Laser Inertial Fusion Energy (LIFE) is an advanced energy technology under<br />
development at LLNL. Achieving high system availability is a key project goal for<br />
the economic competitiveness of LIFE. A model is developed to simulate and study<br />
the reliability of various system designs, maintenance strategies and optimal spare<br />
component levels. Results show the advantage of design modularity in achieving<br />
high system availability without needing high component reliability thus expediting<br />
time to market.<br />
2 - Optimal Maintenance for Linear Consecutively Connected Systems<br />
Rui Peng, Department of Industrial and Systems Engineering,<br />
National University of Singapore, Singapore, ISE Department, BLK<br />
E1A, NUS, Singapore, Singapore, Singapore, g0700981@nus.edu.sg,<br />
Gregory Levitin, Szu Hui Ng, Min Xie<br />
This paper considers a linear multi-state consecutively connected system (LMCCS)<br />
consisting of N+1 linear ordered elements. Each element can provide a connection<br />
between the position in which it is allocated and the next few positions. The system<br />
fails if the first element is not connected with the (N+1)th element. A framework is<br />
proposed to solve the cost optimal maintenance strategy of the system subject to<br />
reliability requirement.<br />
3 - Comparative Study of Stochastic Models to Estimate Reliability of<br />
Infrastructure Systems<br />
Raha Akhavan-Tabatabaei, Assistant Professor, Universidad de los<br />
Andes, Cra 1 Este # 19A-40, Bogotà, Colombia,<br />
r.akhavan@uniandes.edu.co, Edgar Mauricio Sànchez Silva,<br />
Juan Sebastian Borrero<br />
We consider the problem of infrastructure reliability subject to progressive<br />
deterioration and shocks. We consider the deterioration mechanisms and compare<br />
the performance of various stochastic models in describing the remaining life of a<br />
component. Some conclusions are shown and stochastic models are classified<br />
according to their efficiency.
4 - Reliability and Maintenance of Stents Based on Probabilistic<br />
Analysis of Multiple Failure Processes<br />
Elias Keedy, PhD Student, University of Houston, S350 Engineering<br />
Bldg 1, Houston, TX, 77204, United States of America,<br />
eliekeedy@yahoo.com, Qianmei Feng<br />
The high demand in counteracting the effects of atherosclerosis and the ignorance of<br />
the probabilistic aspects in existing studies make the investigation of stents reliability<br />
a competitive concern. Based on fracture mechanisms, we analyze two processes:<br />
delayed and instantaneous failures. General reliability and maintenance models are<br />
developed to acquire an optimal replacement policy of stents. Our work provides<br />
new perspectives on approaching reliability concepts in medical devices evolution.<br />
■ WA31<br />
C - Room 5C, Level 3<br />
Forecasting I<br />
Contributed Session<br />
Chair: Ozden Gur Ali, Koc University, Sariyer, Istanbul, Turkey,<br />
oali@ku.edu.tr<br />
1 - Social Media Aided Event Forecasting<br />
Mohammad Ali Abbasi, PhD Student, Arizona State University, 699<br />
S. Mill Ave. #553, Attn: Mohammad Ali Abbasi, Tempe, AZ, 85281,<br />
United States of America, ali.abasi@asu.edu<br />
We introduce a novel method to forecast social events and behaviors of<br />
communities in the society. We’ve crawled tweets and blog posts of specific groups<br />
for a period of 5 months and classify them using opinion mining methods to extract<br />
members’ intention for specific events. Simultaneously we track the communities’<br />
real (on the ground) activities. Experiments showed that with enough number of<br />
online activities we can forecast the events related to the communities with high<br />
confidence.<br />
2 - Time Series Forecasting in Oracle Crystal Ball<br />
Samik Raychaudhuri, Oracle Americas Inc., 2033 N Fork Dr,<br />
Lafayette, CO, 80026, United States of America, samikr@gmail.com,<br />
Eric Wainwright<br />
In this presentation we will have an overview of the functionality provided by<br />
Oracle Crystal Ball’s (CB) Predictor engine. CB Predictor has an intuitive interface<br />
for selecting, managing and cleaning data, outlier detection and filling in missing<br />
values, running multiple seasonal and nonseasonal forecasting algorithms and<br />
regression on large datasets, and a coherent way of presenting and extracting results<br />
or generating reports. We will also have a sneak preview of forthcoming features.<br />
3 - Using Conditional Kernel Density Estimation for Wind Power<br />
Density Forecasting<br />
Jooyoung Jeon, University of Oxford, 2 Alan Bullock Close,<br />
St Clements, Oxford, United Kingdom,<br />
joo.jeon@smithschool.ox.ac.uk, James Taylor<br />
Wind power is recognized as one of the most promising renewable energy resources.<br />
Despite great benefits from wind power density forecasting, most research has<br />
focused on point forecasting. We develop a novel approach to producing wind<br />
power density forecasts. The inherent uncertainty in wind speed and direction and<br />
the stochastic relationship of wind power to wind speed and direction are addressed<br />
using Monte Carlo simulation of a VARMA-GARCH model and conditional kernel<br />
density estimation.<br />
4 - Driver Moderator Model - Mining with Domain Knowledge<br />
Ozden Gur Ali, Koc University, Sariyer, Istanbul, Turkey,<br />
oali@ku.edu.tr<br />
We devise an interpretable method that predicts SKU sales as a function of the<br />
pricing, promotion and product availability decisions by the retailers consistently<br />
across similar situations. The method results in interpretable models, leverages<br />
domain knowledge, does concurrent model estimation and feature selection and<br />
relies on data pooling for generalization capability. We evaluate our method with<br />
two multi-store large scale grocery databases from Turkey and the USA.<br />
INFORMS Austin – 2010 WA33<br />
371<br />
■ WA32<br />
C - Room 6A, Level 3<br />
Applications and Heuristics Methods in<br />
Integer Programming<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: Haibo Wang, Assistant Professor, Texas A&M International<br />
University, 5201 University Blvd, Laredo, TX, 78041, United States of<br />
America, hwang@tamiu.edu<br />
1 - An Approach for Parallel Machine Job Scheduling Problem with<br />
Interrelated Processing Times<br />
Bahram Alidaee, The University of Mississippi, School of Business,<br />
University, United States of America, balidaee@bus.olemiss.edu,<br />
Haibo Wang<br />
This paper addresses the parallel machine job scheduling problem with interrelated<br />
processing times, which has applications in many areas such as storage allocation in<br />
computer design, organization restructuring, continuous project scheduling, and<br />
scheduling in political campaigns. we present a quadratic unconstrained binary<br />
optimization(QUBO) model and solve it with a neighborhood search heuristic. The<br />
computational time and the optimization gap reduction are reported.<br />
2 - Solving Large Max Cut Problems using Tabu Search<br />
Gary Kochenberger, Professor, University of Colorado at Denver,<br />
1250 14th Street, Denver, 80217, United States of America,<br />
Gary.Kochenberger@ucdenver.edu, Haibo Wang, Fred Glover,<br />
Zhipeng Lu, Jin-Kao Hao<br />
Large Max Cut Problems continue to pose a challenge for most approaches<br />
presented in the literature. In this paper we report our experience with a new Tabu<br />
Search approach for the general unconstrained binary quadratic program as it is<br />
applied to max cut test problems. Best known results on many instances with up to<br />
10,000 vertices are reported.<br />
3 - Warehouse Management - Cross Docking<br />
Jun Huang, Texas A&M International University, United States of<br />
America, huangjundragon@sina.com, Haibo Wang<br />
Warehouse management is a critical topic in logistic research field. The warehouse is<br />
divided into several functional areas such as reserve storage area, order picking area<br />
and cross docking. This study will combine the cross docking problem with storage<br />
area layout design and products allocation by using the graph partition method as<br />
finding a partition of the vertices of a given graph into subsets satisfying certain<br />
properties. Thus, the aforementioned problem can be solved more properly.<br />
■ WA33<br />
C - Room 6B, Level 3<br />
Integrating Constraint Programming and OR<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: Tallys Yunes, Department of Management Science, University of<br />
Miami, Coral Gables, FL, 33124-8237, United States of America,<br />
tallys@miami.edu<br />
1 - Relaxation Based on Multivalued Decision Diagrams<br />
John Hooker, Carnegie Mellon University, Tepper School of Business,<br />
Pittsburgh, PA, United States of America,<br />
john@hooker.tepper.cmu.edu, Sam Hoda, Willem-Jan van Hoeve<br />
We solve scheduling problems with a branching method in which a multivalued<br />
decision diagram (MDD) plays the role of both the linear relaxation in mixed<br />
integer programming and the constraint store in constraint programming. We obtain<br />
order-of-magnitude speedups on problems with multiple “among” constraints,<br />
which are used in employee scheduling, assembly line sequencing, etc.<br />
2 - A Logic-Based Benders’ Decomposition Approach for Solving an<br />
Aircraft Maintenance Scheduling Problem<br />
J. Christopher Beck, University of Toronto, 5 King’s College Rd,<br />
Toronto, ON, M5S 3G8, Canada, jcb@mie.utoronto.ca,<br />
Maliheh Aramon Bajestani<br />
We address a flight maintenance problem where the goal is to schedule<br />
maintenance jobs to maximize the expectation that an existing flying program will<br />
have a full complement of aircraft. The schedule must consider the aircraft failure<br />
probabilities and maintenance capacities. We present a logic-based Benders’<br />
decomposition that exhibits multiple orders-of-magnitude improvement over an<br />
existing mixed-integer programming model.
WA34<br />
3 - Improving the Held and Karp Approach with<br />
Constraint Programming<br />
Willem-Jan van Hoeve, Carnegie Mellon University, 5000 Forbes<br />
Avenue, Pittsburgh, PA, 15213, United States of America,<br />
vanhoeve@andrew.cmu.edu, Michel Rueher, Jean-Charles Régin,<br />
Louis-Martin Rousseau<br />
We show that domain filtering algorithms developed for the weighted spanning tree<br />
constraint can be adapted to the Held and Karp procedure to solve the TSP. In<br />
addition, we introduce a special-purpose filtering rule based on the underlying<br />
mechanisms used in Prim’s algorithm. Finally, we explore two different branching<br />
schemes to close the integrality gap.<br />
■ WA34<br />
C - Room 7, Level 3<br />
Joint Session ICS/ Complex/ QSR: Sensing, Prediction<br />
and Prognostics in Complex Systems<br />
Sponsor: Computing Society/ Complex Systems/ Quality,<br />
Statistics and Reliability<br />
Sponsored Session<br />
Chair: Satish Bukkapatnam, Professor, Oklahoma State University, 318,<br />
Enginnering North, School of Industrial Engineering, Stillwater, OK,<br />
74075, United States of America, satish.t.bukkapatnam@okstate.edu<br />
1 - Willingness-to-Pay Prediction using Empirical Mode Decomposition<br />
and Local Gaussian Process<br />
Satish Bukkapatnam, Professor, Oklahoma State University, 318,<br />
Enginnering North, School of Industrial Engineering, Stillwater, OK,<br />
74075, United States of America, satish.t.bukkapatnam@okstate.edu,<br />
Changqing Cheng, Akkarapol Sa-ngasoongsong<br />
Prediction of customer preferences over time is important for effective design of a<br />
product portfolio. However, the preferences evolution follows a nonlinear and<br />
nonstationary dynamics. We present two new approaches, based a local gaussian<br />
process (LGP) and empirical mode decomposition (EMD) for accurate prediciton of<br />
customer willingness-to-pay (WTP).<br />
2 - Identification of a Mixture of Hidden Markov Models using<br />
Metaheuristic Search<br />
Dragan Djurdjanovic, Assistant Professor, The University of Texas at<br />
Austin, 1 University Station, C2200, ETC 5.122, Austin, TX, 78712,<br />
United States of America, dragand@me.utexas.edu, Michael Cholette<br />
Mixture of Hidden Markov Models (HMMs) was recently proposed for modeling of<br />
degradation of systems working under variable operating conditions. We present a<br />
method for identification of a mixture of HMMs from a sequence of observations<br />
corresponding to a known sequence of operating conditions. The method utilizes a<br />
metaheuristic search to initialize the Baum-Welch algorithm and maximize the<br />
likelihood of observations.<br />
3 - Weather Forecasts and Power Grid Operations<br />
Victor Zavala, Argonne National Laboratory, Math and Comp.<br />
Science Div., Bdg 240, 9700 S Cass Ave, Argonne, IL, 60439,<br />
United States of America, vzavala@mcs.anl.gov, Mihai Anitescu,<br />
Emil Constantinescu<br />
We review motivations and challenges arising in the implementation of advanced<br />
numerical weather prediction models in power grid operations. In particular, we<br />
analyze trade-offs between computational bottlenecks, resolution, accuracy, and<br />
economic performance of power systems.<br />
4 - Binary Code Provenance and Heredity Detection Modeling<br />
and Error Analysis<br />
LiYing Cui, Reserach Assistant, Penn State University, 310 Leonhard<br />
Building, University Park, PA, 16802, United States of America,<br />
luc5@psu.edu, Soundar Kumara<br />
Information in this digital era exists as binary code. Due to the information<br />
explosion in recent years there is a need to detect the lineage among information.<br />
In the cases of malware, it will be necessary identify the variants and to predict the<br />
functionality of future viruses. In this work, we propose a binary code provenance<br />
and heredity detection and prediction method based on CyGene (Gene equivalent<br />
in Cyber engineering) detection. The error analysis of this method is studied<br />
thoroughly based on the ideas of false positives and false negatives.<br />
INFORMS Austin – 2010<br />
372<br />
5 - On the Optimal Control of Large Scale Systems with<br />
Stochastic Interactions<br />
Eugene Perevalov, Lehigh University, Department of Industrial &<br />
Systems Engineerin, Bethlehem, PA, 18017, eup2@lehigh.edu<br />
We study the problem of efficient control of large-scale systems that can be modeled<br />
by a collection of homogeneous elements with stochastic interactions. For the<br />
general case, we formulate the efficient control problem as an inverse inference<br />
problem in Bayesian networks. For the case of systems with a high degree of<br />
uniformity in the element interactions, we propose to use the renormalization<br />
group (RG) approach for the purpose of characterizing the phase structure of the<br />
system and feasibility of efficient control. We give several examples and perform<br />
numerical experiments to check the validity of the proposed approach.<br />
■ WA35<br />
C - Room 8A, Level 3<br />
Advances in Anomalous Diffusion I<br />
Sponsor: Applied Probability<br />
Sponsored Session<br />
Chair: Iddo Eliazar, Professor, Holon Institute of Technology,<br />
P.O. Box 305, Holon, 58102, Israel, eliazar@post.tau.ac.il<br />
1 - Universal Generation of Fractal Statistics<br />
Iddo Eliazar, Professor, Holon Institute of Technology, P.O. Box 305,<br />
Holon, 58102, Israel, eliazar@post.tau.ac.il, Joseph Klafter<br />
We present a stochastic superposition model which is capable of generating - in a<br />
universal fashion - various “fractal statistics”. The stochastic superposition model is<br />
general and robust, and arises naturally in diverse fields of science and engineering.<br />
Universally-generated “fractal statistics” include: anomalous diffusion - power-law<br />
growth of temporal dispersion; Lévy flights - power-law amplitudinal fluctuations;<br />
1/f noises - power-law temporal correlations.<br />
2 - Detecting the Origins of Anomalous Siffusion: P-variation Test and<br />
its Applications<br />
Marcin Magdziarz, Dr, Wroclaw University of Technology,<br />
Wyspianskiego 27, Wroclaw, 50-370, Poland,<br />
marcin.magdziarz@pwr.wroc.pl<br />
Motivated by growing interest in single molecule spectroscopy, we propose a<br />
method to detect mechanisms leading to subdiffusion. We introduce the so-called pvariation<br />
test, which allows distinguishing between two models of subdiffusion on<br />
the basis of one realization of the unknown process. We apply our approach to<br />
experimental data (random motion of an individual molecule inside the E. coli cell).<br />
3 - Aging, Ergodcity Breaking and Universal Fluctuations in Continuous<br />
Time Random Walks<br />
Igor Sokolov, Prof., Humboldt University Berlin, Newtonstr. 15,<br />
Berlin, D-12489, Germany, igor.sokolov@physik.hu-berlin.de<br />
We consider subdiffusive transport within the continuous time random walk<br />
(CTRW) model. The anomalous diffusion under CTRW is a process with nonstationary<br />
increments and shows explicit dependence of observables on the time<br />
elapsed from preparing the system in its present state. This corresponds to aging of<br />
the process, leading to death of linear response to an external stimulus and intrinsic<br />
ergodicity breaking. Different manifestations of these properties will be discussed.<br />
■ WA36<br />
C - Room 8B, Level 3<br />
Panel Discussion: Research in Teaching Schools<br />
Sponsor: INFORM-ED<br />
Sponsored Session<br />
Moderator: John Kros, Associate Professor of Marketing and Supply<br />
Chain Management, East Carolina University, 3121 Bate Building,<br />
Greenville, NC, 27858, United States of America, krosj@ecu.edu<br />
1 - Panel Discussion: Doing Research at Balanced Model Schools<br />
Panelists:John Kros, Associate Professor of Marketing and Supply<br />
Chain Management, East Carolina University, 3121 Bate Building,<br />
Greenville, NC, 27858, United States of America, krosj@ecu.edu,<br />
Marvin Brown,Assistant Professor of CIS, Grambling University,<br />
403 Main Street, Grambling LA 71245, United States of America,<br />
brownm@gram.edu, Christopher Keller,Assistant Professor of<br />
Marketing and Supply Chain Management, East Carolina University,<br />
3136 Bate Building, School of Business, Greenville NC 27858, United<br />
States of America, kellerc@ecu.edu, Scott Nadler, Assistant Professor,<br />
University of Central Arkansas, COB 312, Conway AR 72035,<br />
United States of America, SNadler@uca.edu<br />
This is a session set up by the INFORM-ED forum it is a panel on the topic of<br />
“Doing Research at Balanced Model Schools.”
■ WA37<br />
C - Room 8C, Level 3<br />
Stochastic Control, Dynamic Games and Their<br />
Applications<br />
Sponsor: Applied Probability<br />
Sponsored Session<br />
Chair: Hector Jasso-Fuentes, Mathematics Department, CINVESTAV-IPN,<br />
Apartado Postal 14-740, 07000, Mexico DF, Mexico, Mexico,<br />
hjasso@math.cinvestav.mx<br />
1 - Some New Results in Controlled Switching Diffusions<br />
Ari Arapostathis, Professor, University of Texas at Austin,<br />
1 University Station (C0803), Department Electrical and Computer<br />
Eng., Austin, TX, 78712, United States of America,<br />
ari@mail.utexas.edu<br />
We study the stability and ergodic control problems of controlled switching<br />
diffusions, modeled by a coupled system of Ito stochastic differential equations,<br />
under no assumption of irreducibility. Stability is defined as positive recurrence<br />
relative to an open ball in the space of the continuous component. We show among<br />
others that if the model is stable, then the upper envelope of the class of invariant<br />
probability measures is a finite measure, and we study the implications of this<br />
property.<br />
2 - Control of Inventories with Markov Demand<br />
Alain Bensoussan, Research Professor, University of Texas at Dallas,<br />
School of Management, Office 3.211, Dallas, 830688,<br />
United States of America, axb046100@utdallas.edu<br />
We consider inventory control problems in discrete time. The horizon is infinite, and<br />
we consider discounted payoffs as well non-discounted payoffs (ergodic control). We<br />
may have backlog or not. We may have set up costs or not. We show how the base<br />
stock policy and the s,S policy can be extended.<br />
3 - Overtaking Equilibria for Zero-sum Markov Games<br />
Onesimo Hernandez-Lerma, Prof., CINVESTAV-IPN, Math.<br />
Department, A.Postal 14-740, Mexico D.F. 07000, Mexico,<br />
ohernand@math.cinvestav.mx<br />
We study overtaking (a.k.a. catching-up) optimality for a class of zero-sum Markov<br />
games that includes stochastic differential games, and games with a countable state<br />
space.<br />
4 - Joint Optimization of Pricing Strategies and Inventory Control with<br />
Continuous Stochastic Demand<br />
Yongqiang Wang, University of Maryland, College Park, 3182 AVW,<br />
College Park, MD, United States of America, yqwang@umd.edu,<br />
Michael Fu, Steven Marcus<br />
We analyze the dynamic pricing problem for inventory systems with price-sensitive<br />
continuous stochastic demands. An analytical solution for a special demand is<br />
provided. For more general demand models, we propose a simulation-based method<br />
for solving the dynamic pricing problem, assuming a finite number of price changes<br />
over the time horizon of interest. In the framework of our simulation-based<br />
algorithm, we can also jointly optimize the price and the initial inventory level.<br />
■ WA38<br />
C - Room 9A, Level 3<br />
Complementarity Problems<br />
Sponsor: Optimization/Linear Programming and Complementarity<br />
(Joint Cluster ICS)<br />
Sponsored Session<br />
Chair: Hande Benson, Associate Professor, Drexel University, Department<br />
of Decision Sciences, LeBow College of Business, Philadelphia, PA, 19104,<br />
United States of America, hvb22@drexel.edu<br />
1 - Single Timescale Regularization Schemes for Monotone<br />
Nash Games<br />
Uday Shanbhag, Asst. Professor, University of Illinois at Urbana<br />
Champaign, Urbana, Il, United States of America,<br />
udaybag@illinois.edu, Aswin Kannan<br />
We consider single-timescale schemes for the distributed computation of equilibria<br />
arising from montone Nash games, Specifically, we propose iterative regularization<br />
counterparts of Tikhonov and proximal-point schemes where<br />
regularization/centering parameters are updated after every projection step, rather<br />
than when an approximate solution of the regularized problem is available.<br />
Convergence theory, particularly in limited coordination settings, is presented along<br />
with numerical results.<br />
INFORMS Austin – 2010 WA39<br />
373<br />
2 - Controlling PHEV Recharging Through Effective Electricity<br />
Price Signals<br />
Lizhi Wang, Iowa State University, 3016 Black Engineering, Ames,<br />
IA, 50014, United States of America, lzwang@iastate.edu, Pan Xu<br />
We use a bilevel optimization model to design effective electricity price signals to<br />
control PHEV recharging profile. Various studies have shown that uncontrolled<br />
PHEV recharging could have a significant impact on the capacity adequacy, cost<br />
efficiency, and reliability of power systems. Price signals could serve as a demand<br />
management tool to control the recharging activities. Our models will be able to<br />
compare the effectiveness of different price signals.<br />
3 - A Branch-and-bound Algorithm for the Bilevel Mixed Integer Linear<br />
Programming Problem<br />
Pan Xu, Iowa State University, 3038 Black Engineering, Ames,<br />
United States of America, panxu@iastate.edu, Lizhi Wang, Shan Jin,<br />
Sarah Ryan<br />
We present a new algorithm for the bilevel mixed integer linear programming<br />
problem. This algorithm consists of two levels of branch-and-bound. At the upper<br />
level, we break the non-convex feasibility region into convex pieces. At the lower<br />
level, we solve a linear program with complementarity constraints, which is a<br />
simple case of mathematical program with equilibrium constraints.<br />
4 - Lateral Transhipment with Customer Switching<br />
Wenjing Shen, Drexel University, 101 N. 33rd Street, Philadelphia,<br />
United States of America, ws84@drexel.edu, Xinxin Hu, Yi Liao<br />
We consider a lateral transshipment problem between two retailers where an<br />
uncertain fraction of the unfulfilled demand may switch to another retailer with<br />
inventory. We show that the firm with surplus inventory may not transship all<br />
request inventory and identify conditions when full, partial or no transshipment<br />
takes place. We provide sufficient conditions for a unique Nash equilibrium and<br />
evaluate the impact of customer switching behavior on inventory decisions and<br />
equilibrium profits.<br />
■ WA39<br />
C - Room 9B, Level 3<br />
Joint Session OPTIM/ ICS:<br />
Sponsor: Optimization/ Computing Society<br />
Sponsored Session<br />
Chair: Jeff Linderoth, University of Wisconsin-Madison, 1513 University<br />
Av., Madison, WI, United States of America, linderoth@wisc.edu<br />
1 - Disjunctive Cuts for Convex Mixed Integer Nonlinear<br />
Program (MINLP)<br />
Mustafa Kilinc, Graduate Student, University of Wisconsin-Madison,<br />
3226 Mechanical Engineering Building, 1513 University Avenue,<br />
Madison, WI, 53706, United States of America, kilinc@wisc.edu,<br />
Jeff Linderoth, James Luedtke<br />
Stubbs and Mehrotra [1999] generalized the disjunctive cutting plane method of<br />
Balas et al. into a branch-and-cut method for convex MINLPs which generates cuts<br />
by solving a convex projection problem in a higher dimensional space. Thus, it is<br />
computationally expensive to be included in a MINLP solver in practice. Our new<br />
method achieves this by solving a cut generating linear program iteratively.<br />
Computational results shows significant improvements in root node gap closure and<br />
solution times.<br />
2 - New Linear Relaxations for Quadratically Constrained Quadratic<br />
Programming Problems<br />
Mahdi Namazifar, University of Wisconsin-Madison, 1513 University<br />
Ave, Madison, WI, United States of America, namazifar@wisc.edu,<br />
Jeff Linderoth, James Luedtke<br />
We study a novel approach to build polyhedral relaxations for nonconvex<br />
quadratically constrained quadratic programming (QCQP) problems. This approach<br />
considers all of the constraints of the problem at once and tries to find tight<br />
relaxations for the problem which are reasonable in size. We present numerical<br />
comparisons in terms of lower bounds and relaxation size.<br />
3 - Inequalities for a Nonseparable Quadratic Set<br />
Hyemin Jeon, University of Wisconsin-Madison, Room 3227,<br />
Mechanical Engineering Bldg., 1513 University Avenue, Madison,<br />
United States of America, jeon5@wisc.edu, Jeff Linderoth<br />
We consider a nonseparable quadratic set which appears in applications such as<br />
portfolio optimization, and investigate ways to obtain a good approximation of its<br />
convex hull. Our work starts from transforming the set using Cholesky factorization,<br />
and studying its linear outerapproximation to obtain strong valid inequalities. Lifting<br />
plays a vital role in generating these inequalities.
WA40<br />
4 - Pooling Problems with Binary Variables<br />
Jeff Linderoth, University of Wisconsin-Madison, 1513 University<br />
Av., Madison, WI, United States of America, linderoth@wisc.edu,<br />
James Luedtke, Claudia D’Ambrosio, Andrea Lodi, Andrew Miller<br />
The pooling problem is a bilinear program that models linear blending in a network.<br />
Often, pooling problems contain binary variables that model network design issues.<br />
We study how to tighten relaxations of pooling problems with binary variables by<br />
studying the convex hull of simple sets associated with these problems.<br />
■ WA40<br />
C - Room 9C, Level 3<br />
Solver APIs II<br />
Cluster: John Forrest-fest | COIN-OR 10th (Joint Cluster Computing)<br />
Invited Session<br />
Chair: Matthew Saltzman, Clemson University, Department of<br />
Mathematical Sciences, Martin Hall, Box 340975, Clemson, SC, 29631,<br />
United States of America, mjs@clemson.edu<br />
1 - The COIN-OR Open Solver Interface: A Status Report<br />
Matthew Saltzman, Clemson University, Department of<br />
Mathematical Sciences, Martin Hall, Box 340975, Clemson, SC,<br />
29631, United States of America, mjs@clemson.edu<br />
The Open Solver Interface (OSI) is the oldest multi-solver API in COIN-OR. We<br />
discuss its current status and plans for the future.<br />
2 - A COIN OSI Solver Plugin for Microsoft Solver Foundation<br />
Lou Hafer, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada,<br />
lou@cs.sfu.ca<br />
MsfOsi implements a solver plugin that allows Microsoft Solver Foundation to use<br />
COIN solvers through the OSI API. There are interesting differences in design<br />
philosophy. This talk will examine what it takes to bridge the gap.<br />
3 - The Optimization Services Solver Interface<br />
Kipp Martin, University of Chicago, 5807 South Woodlawn, Chicago,<br />
IL, 60637, United States of America, kmartin@chicagobooth.edu<br />
In this talk we describe how to use the Optimization Services (OS) project to<br />
interface with COIN-OR solvers. The OS interface is quite flexible and allows the<br />
user to generate linear and nonlinear instances for solvers. In addition, there is an<br />
interface for solver options and solver results.<br />
■ WA41<br />
C - Room 10A, Level 3<br />
Vehicle Routing I<br />
Contributed Session<br />
Chair: Ahmed El-Nashar, Doctoral Student, University of Central Florida,<br />
4000 Central Florida Blvd, Orlando, FL, 32816, United States of America,<br />
aelnasha@mail.ucf.edu<br />
1 - Efficient School Bus Routing for Special Needs Students<br />
Behrooz Kamali, University of Arkansas, 4207 Bell Engineering<br />
Center, Fayetteville, AR, 72701, United States of America,<br />
bkamali@uark.edu, Ed Pohl, Scott J. Mason<br />
Special needs and medically fragile students ride specialized buses to and from<br />
school daily. Unfortunately, special needs service-to-school assignments are often<br />
made without any consideration of a student’s geographical location. We present<br />
optimization models that seek to improve administration-based performance metrics<br />
via smarter network assignments and effective bus routing decisions.<br />
2 - A New Capacitated Path Covering Problem<br />
Macarena Donoso, PhD Student, Diego Portales University, Ejercito<br />
441, Santiago, Chile, macarena.donosop@gmail.com, Ignacio Basulto<br />
We formulated and solve a particular capacitated vehicle routing problem. A path is<br />
built between two points of the network, for every vehicle of the fleet. Every route<br />
exceeds neither the vehicle capacity nor the maximum time of the trip. The<br />
objective is minimize the travelling cost. The nodes that to be not covered, must be<br />
inside a distance coverage to the the network. We propose an integer programming<br />
formulation and, an heuristic algorithm of resolution based on ants colonies was<br />
developed.<br />
INFORMS Austin – 2010<br />
374<br />
3 - A Near Optimal Algorithm for Multivehicle Dispatching and Routing<br />
with Time Windows<br />
Ahmed El-Nashar, Doctoral Student, University of Central Florida,<br />
4000 Central Florida Blvd, Orlando, FL, 32816, United States of<br />
America, aelnasha@mail.ucf.edu, Dima Nazzal<br />
We propose a metaheuristic for solving the VRPTW for a depot with limited number<br />
of docks. The metaheuristics clusters customers into groups based on their proximity<br />
to one another. A modified local improvement algorithm is applied to each cluster<br />
to find the best sequence for visiting customers with different dispatching times.<br />
Finally, an assignment problem formulation is used to determine the dispatching<br />
time and the visiting sequence for each vehicle to minimize the total traveled<br />
distance.<br />
■ WA42<br />
C - Room 10B, Level 3<br />
Computational Optimization and Applications I<br />
Sponsor: Optimization/Computational Optimization and Software<br />
(Joint Cluster ICS)<br />
Sponsored Session<br />
Chair: Michele Samorani, PhD Candidate, Leeds School of Business,<br />
University of Colorado at Boulder, UCB 419, Boulder, CO, 80309-0419,<br />
United States of America, Michael.Samorani@Colorado.EDU<br />
1 - Solving Hard Combinatorial Optimization Problems as Implicit<br />
Hitting Set Problems<br />
Erick Moreno-Centeno, Assistant Professor, Texas A&M University,<br />
Industrial and Systems Engineering, College Station,<br />
United States of America, e.moreno@tamu.edu, Richard Karp<br />
The hitting set (HS) problem is: given a set U and a family S of subsets of U, find a<br />
minimum-cardinality set that intersects each set in S. In the implicit HS problem<br />
(IHS), S is given via an oracle which verifies that a given set is a HS or returns a<br />
not-intersected set from S. Many NP-hard problems can be solved as IHS. We solve<br />
IHS by combining efficient heuristics and exact methods. We present computational<br />
results for the minimum-feedback-vertex-set and the maximum-weight-trace<br />
problems.<br />
2 - Envy Quotes and the Iterated Core-Selecting Combinatorial Auction<br />
Abraham Othman, Graduate Student, Computer Science<br />
Department, Carnegie Mellon University, 5000 Forbes Ave,<br />
Pittsburgh, PA, 15213, United States of America,<br />
aothman@cs.cmu.edu, Tuomas Sandholm<br />
We describe an iterated combinatorial auction in which the allocation and prices<br />
converge to a solution in the core of the agents’ true valuations. In each round of<br />
the iterative mechanism, agents act on hints that suggest the prices of the bundles<br />
they are interested in. Prior work has required agents to have perfect information<br />
about every agent’s valuations to achieve a solution in the core. Here a core solution<br />
is reached even in the private value setting.<br />
3 - Data Mining Driven Neighborhood Search<br />
Michele Samorani, PhD Candidate, Leeds School of Business,<br />
University of Colorado at Boulder, UCB 419, Boulder, CO, 80309-<br />
0419, United States of America, Michael.Samorani@Colorado.edu,<br />
Manuel Laguna<br />
Metaheuristic approaches based on neighborhood search escape local optimality by<br />
applying predefined rules and constraints. Our general approach learns (offline) the<br />
guiding constraints that, when applied online, will result in effective escape<br />
directions from local optima. The user must define the neighborhood and provide<br />
an attribute representation of a solution and of a pair of solutions. We show our<br />
results on a set of task allocation and matrix bandwidth minimization problems.
■ WA44<br />
C - Room 2, Level 2- Mezzanine<br />
Resource Allocation in Healthcare<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: David Hutton, Stanford University, Palo Alto, CA,<br />
United States of America, billdave@stanford.edu<br />
1 - Cost-Effectiveness of Screening and Treating Acute HIV Infection in<br />
Men Who Have Sex with Men<br />
Jessie Juusola, PhD Candidate, Stanford University, Dept of<br />
Management Science & Engineering, 499 Terman Engineering<br />
Center, Stanford, CA, 94305, United States of America,<br />
jjuusola@stanford.edu, Eran Bendavid, Doug Owens, Margaret<br />
Brandeau, Elisa Long<br />
Given the highly infectious nature of acute HIV infection, identifying and treating<br />
acutely infected individuals could play a significant role in reducing HIV<br />
transmission. We develop a dynamic compartmental model of the HIV epidemic in<br />
the US to estimate the costs and health benefits of screening for acute infection and<br />
treating acutely infected men who have sex with men. We find such programs likely<br />
to be a cost-effectiveness method of reducing the burden of HIV in this high-risk<br />
group.<br />
2 - Initiatives Management in Public Healthcare Administration<br />
Zehra Bilginturk Yalcin, University of Texas, Austin, Operations<br />
Research and Industrial Eng, Graduate Program, Austin, TX, 78712,<br />
United States of America, zehra.yalcin@gravitant.com, Ilyas M. Iyoob<br />
A Public Healthcare Administration agency in a large state in the US is constantly<br />
running multiple initiatives within the organization. The agency faces the issue of<br />
selecting, prioritizing and scheduling initiatives based on the objectives of interest at<br />
the time, while maintaining dependencies between initiatives as well as limited<br />
resources and Federal budget constraints. The problem is modeled as an MIP and<br />
serves as a useful decision support tool in Public Healthcare Administration.<br />
3 - Modeling Cost-Effectiveness Data for Medical Decision Making:<br />
A Statistical Framework<br />
Megan DeFauw, University of Michigan, mcdefauw@umich.edu,<br />
Vijayan Nair, Joseph Norman, Allison Rosen<br />
The effect of treatment on cost and QALYs in CEA is determined through simulation<br />
or a clinical study. In either case, the mean cost-effectiveness ratio is a poor<br />
characterization of treatment effect. We develop a statistical framework exploiting<br />
the stochastic evolution of disease processes over time to characterize the effect of<br />
treatment and also exploit the concept of stochastic dominance to aid in decisionmaking<br />
when the utility function is unknown. Finally, we illustrate with an<br />
example.<br />
■ WA45<br />
C - Room 6, Level 2- Mezzanine<br />
Pierskalla Finalists V<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: Mariel Lavieri, Assistant Professor, University of Michigan, 1205<br />
Beal Avenue, Ann Arbor, MI, 48109-2117, United States of America,<br />
lavieri@umich.edu<br />
1 - Real-time Differentiation of Nonconvulsive Status Epilepticus From<br />
Other Encephalopathies using Quantitative EEG Analysis:<br />
A Pilot Study<br />
Jicong Zhang, PhD Candidate, University of Florida, 303 Weil Hall,<br />
ISE Department, Gainesville, FL, 32611, United States of America,<br />
jicong@ufl.edu, Panos Pardalos, Chang-Chia Liu, Petros<br />
Xanthopoulos, Scott Bearden, Basim M. Uthman<br />
Generalized NonConvulsive Status Epilepticus (NCSE) and some non-epileptic<br />
encephalopathies have similar clinical symptoms and exhibit similar EEG<br />
waveforms. To distinguish NCSE from some non-epileptic encephalopathies is<br />
difficult and significant clinically. Nonlinear dynamics are extracted from EEG and<br />
classifiers are designed to differentiate NCSE and toxic/metabolic encephalopathy.<br />
The results showed strong evidence that nonlinear dynamic measures can be useful<br />
in clinical diagnosis of NCSE.<br />
INFORMS Austin – 2010 WA47<br />
375<br />
2 - A Bilevel Model for Designing Preventive Healthcare<br />
Facility Networks<br />
Yue Zhang, Assistant Professor, The University of Toledo, 2801 West<br />
Bancroft Street, Toledo, OH, 43606, United States of America,<br />
Yue.Zhang@sauder.ubc.ca, Oded Berman, Vedat Verter,<br />
Patrice Marcotte<br />
This paper presents a methodology for designing a network of preventive healthcare<br />
facilities to improve its accessibility to potential clients, so as to maximize<br />
participation to preventive healthcare programs. We formulate the problem as a<br />
mathematical program with equilibrium constraints. We use the model to analyze<br />
an illustrative case, the network of mammography centers in Montreal. A number<br />
of interesting results and managerial insights are discussed.<br />
3 - Inferring Model Parameters in Network-based Disease Simulation<br />
Eva Enns, Stanford University, 117 Encina Commons, Stanford, CA,<br />
94035, United States of America, evaenns@stanford.edu,<br />
Margaret Brandeau<br />
Many models of infectious disease ignore the underlying contact structure through<br />
which the disease spreads. However, in order to evaluate the efficacy of certain<br />
disease control interventions, it may be important to include this network structure.<br />
We present a network modeling framework of the spread of disease and a<br />
methodology for inferring important model parameters, such as those governing<br />
network structure and network dynamics, from readily available data sources.<br />
4 - The Mayo Clinic Optimizes Patient Transport Staffing<br />
Dustin Kuchera, MS, Business Analyst, Mayo Clinic, 626 8th St SW,<br />
Rochester, MN, 55902, United States of America,<br />
kuchera.dustin@mayo.edu, Thomas R. Rohleder, PhD<br />
In this paper, we report on the implementation of simple integrated queuing and<br />
mathematical programming methods to optimize staffing for patient transport at the<br />
Mayo Clinic. A tool was developed and implemented in Microsoft Excel and Visual<br />
Basic for Applications and includes an easy-to-use interface. Results of the<br />
implementation include significant staff savings via more efficient scheduling.<br />
5 - Prioritization of Medical Equipment for Maintenance Decisions<br />
Sharareh Taghipour, PhD Candidate, University of Toronto,<br />
5 King’s College Road, Toronto, ON, M5S 3G8, Canada,<br />
sharareh@mie.utoronto.ca, Dragan Banjevic, Andrew K.S. Jardine<br />
Clinical engineering departments in hospitals are responsible for establishing and<br />
regulating a Medical Equipment Management Program to ensure that medical<br />
devices are safe and reliable. To mitigate functional failures, significant and critical<br />
devices should be identified and prioritized. We present a multi-criteria decisionmaking<br />
model to prioritize medical devices according to their criticality.<br />
■ WA47<br />
C - Room 8, Level 2- Mezzanine<br />
New Directions in Project Management<br />
Cluster: Topics in Project Management<br />
Invited Session<br />
Chair: Willy Herroelen, Emeritus Professor, K.U.Leuven, Research Center<br />
for Operations Management, Department of Decision Sciences &<br />
Information Management, Naamsestraat 69, Leuven, B-3000, Belgium,<br />
willy.herroelen@econ.kuleuven.be<br />
1 - A New Approach for Project Risk Analysis<br />
Stefan Creemers, K.U.Leuven, Research Center for Operations<br />
Management, Department of Decision Sciences & Information<br />
Management, Naamsestraat 69, Leuven, B-3000, Belgium,<br />
stefan.creemers@econ.kuleuven.be, Erik Demeulemeester,<br />
Stijn Van de Vonder<br />
Most quantitative project risk analysis techniques provide insight in the risk profile<br />
of the project and in the feasibility of certain project completion dates. Far fewer<br />
efforts exist that aim at identifying the underlying risk factors that cause the project<br />
schedule to slip. We introduce an approach to calculate the impact that each risk<br />
has on the project completion date. Such an approach allows to focus mitigation<br />
efforts on those risks whose mitigation would be most effective.<br />
2 - On the Interaction Between Railway Scheduling and Resource<br />
Flow Networks<br />
Erik Demeulemeester, Professor, KU Leuven, Naamsestraat 69,<br />
Leuven, B-3000, Belgium, erik.demeulemeester@econ.kuleuven.be,<br />
Wendi Tian<br />
In previous research, we have shown that in realistic situations railway scheduling<br />
improves both the stability and the expected project length over roadrunner<br />
scheduling. In this research, we introduce the concept of resource flow networks<br />
and analyze what the impact is of the resulting combinations on average project<br />
length, its standard deviation, the timely project completion probability and the<br />
stability cost. Extensive computational results will be presented on small and larger<br />
projects.
WA48<br />
3 - Proactive Execution Policies for the Stochastic RCPSP<br />
Filip Deblaere, KU Leuven, Naamsestraat 69, Leuven, B-3000,<br />
Belgium, filip.deblaere@econ.kuleuven.be, Erik Demeulemeester,<br />
Willy Herroelen<br />
We propose a methodology for the determination of a project execution policy for<br />
the stochastic RCPSP that attempts to minimize the project execution costs, defined<br />
as the sum of the expected costs due to activity starting time deviations and the<br />
expected penalties or bonuses associated with late or early project completion. We<br />
show that our approach significantly outperforms existing proactive scheduling<br />
procedures for resource-constrained projects with uncertain activity durations.<br />
■ WA48<br />
C - Room 9, Level 2- Mezzanine<br />
Software Demonstrations<br />
Cluster: Software Demonstrations<br />
Invited Session<br />
1 - FICO - Building Optimization Applications in Xpress<br />
Oliver Bastert, Product Management, FICO, 901 Marquette Avenue,<br />
Suite 3200, Minneapolis, MN, 55402, United States of America<br />
This tutorial will focus on developing and deploying complete optimization<br />
applications using FICO’s array of mathematical modeling and optimization tools.<br />
These tools can be used for modeling, solving, analyzing and visualizing<br />
optimization problems, and integrating them seamlessly in business applications.<br />
During this tutorial, Bastert will explain how Xpress-Mosel, Xpress-IVE and Xpress-<br />
Application Developer can decrease development time for new optimization<br />
applications and enable you and your customers to make smarter decisions. The<br />
proven technologies offered by FICO can be used in range of applications such as<br />
supply chain management, transportation, finance, energy, manufacturing, retail,<br />
insurance and manufacturing industries, to name a few.<br />
2 - Palisade Corporation - DecisionTools Suite Software Introduction<br />
Thompson Terry, Senior Risk Analyst, Trainer, Consultant, Palisade<br />
Corporation, 798 Cascadilla Street, Ithaca, NY, 14850, United States<br />
of America, tterry@palisade.com<br />
Palisade’s DecisionTools Suite includes 7 software packages that can be used by a<br />
wide variety of departments and individuals within any organization to better assess<br />
risk and make well-informed decisions. This comprehensive example demonstrates<br />
how all the components of the Suite can be used together to assess the likelihood of<br />
success of a new product launch, determine critical variables to limit risk exposure,<br />
optimize the inclusion of the new product into existing manufacturing facilities, and<br />
plan for the expansion of both production and distribution networks.<br />
■ WA49<br />
C -Room 10, Level 2- Mezzanine<br />
Machine Learning and Business Intelligence<br />
Sponsor: Information Systems<br />
Sponsored Session<br />
Chair: Maytal Saar-Tsechansky, Assistant Professor, University of Texas at<br />
Austin, 1 University Station, Austin, 78712, United States of America<br />
1 - Active Inference and Active Learning for Data Streams<br />
Foster Provost, Professor, New York University, 44 West 4th Street<br />
#8-86, New York, NY, 10012, United States of America,<br />
fprovost@stern.nyu.edu, Josh Attenberg<br />
We consider applications where predictive models are applied to a stream of<br />
instances that can repeat, such as web pages for ad impressions, and where there is<br />
a budget for applying human resources to acquire ground truth labels for carefully<br />
chosen instances—both for learning and for direct inference (in lieu of using the<br />
predictive model). We introduce strategies for allocating human resources, which<br />
consider: p(x), which may be highly skewed; error cost; and the value for (active)<br />
learning.<br />
2 - Bias in Cross Validation<br />
Claudia Perlich, Chief Scientist, Media 6 Degrees, 16 Oakrdige Rd,<br />
Mt Kisco, United States of America, claudia@media6degrees.com,<br />
Grzegorz Swirszcz<br />
Evaluation of model performance has a long tradition in statistics and machine<br />
learning. Non-parametric estimations of model performance include bootstrapping,<br />
jackknife, random sub-sampling and cross-validation. We show that cross-validation<br />
to data with low signal can lead to `holdout’ predictions with perfectly opposite<br />
ranking. While such a `model’ would raise suspicion, great harm can be done if it is<br />
integrated in an automated process that includes stacking or ensemble selection<br />
methods.<br />
INFORMS Austin – 2010<br />
376<br />
3 - Collaborative Information Acquisition (Talk)<br />
Danxia Kong, The University of Texas at Austin,<br />
1 University Station, Austin, TX, 78712, United States of America,<br />
Danxia.Kong@PhD.mccombs.utexas.edu, Maytal Saar-Tsechansky<br />
Most information acquisition policies aim to improve the predictive accuracy of a<br />
model. However, in practice, a predictive model is used with other models to inform<br />
arbitrarily complex decisions. This paper discusses a new kind of collaborative<br />
information acquisition (CIA) policies, where multiple predictive models<br />
collaboratively prioritize information acquisitions to promote the decisions they<br />
inform. We present a framework and a specific CIA policy that yields superior<br />
decision performance.<br />
■ WA50<br />
C -Room 11, Level 2- Mezzanine<br />
Managing Workload Dependencies in the Cloud<br />
Cluster: Cloud Computing<br />
Invited Session<br />
Chair: Hani Jamjoom, IBM Research, 19 Skyline Dr., Hawthorne,<br />
United States of America, jamjoom@us.ibm.com<br />
1 - Uncovering Causal Factors in HPC Workloads<br />
Anshul Sheopuri, Research Staff Member, IBM TJ Watson Research<br />
Center, 19 Skyline Drive, Hawthorne, United States of America,<br />
sheopuri@us.ibm.com, Zon-yin Shae, Eric Shiu, Hani Jamjoom<br />
Scheduling and Pricing engines are critical components of a High Performance<br />
Computing (HPC) system. To deploy these engines in a HPC system, it is important<br />
to understand the causal factors of demand fluctuations - number of users, time of<br />
day, time of month, etc. The objective of our work is to bring scheduling and pricing<br />
models in HPC to market by validating or invalidating the assumptions used for<br />
developing these models by uncovering the causal factors of demand fluctuations.<br />
2 - Using Application Dependencies for Workload Migration Decisions<br />
in Cloud Datacenter Environments<br />
Petros Zerfos, Research Staff Member, IBM T.J. Watson Research<br />
Center, 19 Skyline Drive, Hawthorne, NY, 10532, United States of<br />
America, pzerfos@us.ibm.com, Hani Jamjoom, Yew Huey Liu,<br />
Kang-Won Lee, Vivek Shrivastava<br />
Virtual machine (VM) migration can optimize the use of physical servers in cloud<br />
datacenters. Enterprise applications consist of multiple interdependent VMs. Current<br />
research optimizes for intra-server constraints (e.g., CPU); it ignores inter-server<br />
dependencies (e.g., network communication). Our work formulates the VM<br />
migration problem to also account for inter-VM dependencies, and proposes an<br />
online approximation. Using workloads from a datacenter, we explore the efficacy<br />
of our solution.<br />
3 - Overdriver: Enabling High Data Center Utilization Through<br />
Aggressive Memory Oversubscription<br />
Dan Williams, Cornell University, 4104 Upson Hall, Ithaca, NY,<br />
14853, United States of America, djwill@cs.cornell.edu,<br />
Hani Jamjoom, Yew Huey Liu, Hakim Weatherspoon<br />
With the intense competition between cloud providers, resource oversubscription is<br />
essential for achieving higher utilization and profits from the underlying<br />
infrastructure. Resource oversubscription, however, comes at a price: it increases the<br />
likelihood of overload due to insufficient physical resources. We present Overdriver,<br />
a system that aggressively oversubscribes memory and immediately reacts to<br />
mitigate the effects of all types of overload, including transient overload.
■ WA51<br />
C -Room 12, Level 2- Mezzanine<br />
Optimal Routing Through Military Networks<br />
Sponsor: Military Applications<br />
Sponsored Session<br />
Chair: Chris Odom, ENS, US Navy, Colorado School of Mines,<br />
Engineering Hall 816 15th Street, Golden, CO, 80401, United States of<br />
America, codom@mines.edu<br />
1 - Routing and Scheduling Supply Ships for the Combat<br />
Logistics Force<br />
Gerald Brown, Operations Research Department, Naval Postgraduate<br />
School, Monterey, CA, 93943, United States of America,<br />
ggbrown@nps.navy.mil, Matthew Carlyle, Patrick Burson, Jeff Kline,<br />
Anton Rowe<br />
We synchronously route a fleet of supply ships between ports and combatant<br />
customer ships throughout an area of operations, or worldwide. Key concerns<br />
include keeping combatant inventories above required operational safety stock<br />
levels, minimizing port visit and other supply ship costs, sourcing costs, and the cost<br />
of fuel consumed. We show how the system works and what we have learned in<br />
practice along with our Military Sealift Command sponsor.<br />
2 - Interdicting Networks to Competitively Minimize Evasion with<br />
Synergy Between Applied Resources<br />
Brian Lunday, Assistant Professor, Department of Mathematical<br />
Sciences, U.S. Military Academy, Department of Math. Sci.<br />
(Building 601), United States Military Academy, West Point, NY,<br />
10996, United States of America, lunday@vt.edu, Hanif Sherali<br />
We examine the problem of minimizing the maximum probability of evasion by an<br />
entity traversing a network from a given source-and-terminus, incorporating novel<br />
forms of superadditive synergy between resources applied to arcs in the network.<br />
We propose an alternative model for sequential overt and covert deployment of<br />
subsets of interdiction resources, and conduct comparative analyses between models<br />
for purely overt (with or without synergy) and composite overt-covert strategies.<br />
3 - New Results on the Network Diversion Problem<br />
Christopher Cullenbine, PhD Candidate, Colorado School of Mines,<br />
1500 Illinois Street, Golden, CO, 80401, United States of America,<br />
ccullenb@mines.edu, Kevin Wood, Alexandra Newman<br />
The network-diversion problem seeks a minimum-weight, minimal s-t cut in a<br />
graph that contains a pre-specified edge. The problem arises in intelligencegathering<br />
and war-fighting scenarios. We use Lagrangian relaxation with a stronger<br />
integer linear-programming formulation to modify edge weights for near-minimumweight<br />
cut enumeration. We also describe new NP-completeness results,<br />
polynomially solvable special cases, and provide computational results that show<br />
improvements over the original.<br />
4 - Routing Military Vehicles in a Threat Environment Accounting for<br />
Arc-Dependent Risk Costs<br />
Chris Odom, ENS, US Navy, Colorado School of Mines, Engineering<br />
Hall 816 15th Street, Golden, CO, 80401, United States of America,<br />
codom@mines.edu, Alexandra Newman, Kevin Wood<br />
A directed graph with nodes representing waypoints and sets of arcs denoting paths<br />
for vehicle transit models the area of operations. We develop an integer program<br />
and modify an enumeration algorithm to determine a path that maximizes the<br />
probability of mission success subject to flow balance and side constraints. We<br />
account for arc-dependent risk costs for the case in which a threat contributes risk<br />
to two or more arcs, and we provide preliminary numerical results.<br />
■ WA52<br />
C -Room 13, Level 2- Mezzanine<br />
Decision Support for Military Operations<br />
Cluster: Homeland Security and Defense<br />
Invited Session<br />
Chair: Janet Spoonamore, Army Research Office, P.O. Box 1221,<br />
Research Triangle Park, NC, 27709, United States of America,<br />
janet.spoonamore@us.army.mil<br />
1 - Solution Method for Large Scale Chance-constrained Problems -<br />
Application Potential to Defense and Homeland Security Problems<br />
Miguel Lejeune, George Washington University, 2201 G Street, NW<br />
Funger 415, Washington, DC, 20052, United States of America,<br />
mlejeune@gwu.edu<br />
We introduce a new method for the solution of chance-constrained problems. It is<br />
based on the extraction of patterns which define sufficient/minimal conditions for<br />
the chance constraint to hold and allows the exact reformulation of the stochastic<br />
problem as a linear problem. The method is computationally very efficient and<br />
INFORMS Austin – 2010 WA53<br />
377<br />
allows the very fast solution of problems in which up to 50000 scenarios are used to<br />
characterize uncertainty. Applications to defense and homeland security problems<br />
will be discussed.<br />
2 - Army Research Office Program - Decision and Neural Sciences<br />
Janet Spoonamore, Army Research Office, P.O. Box 1221,<br />
Research Triangle Park, NC, 27709, United States of America,<br />
janet.spoonamore@us.army.mil<br />
The Decision and Neuro Sciences program addresses development of new advanced<br />
modeling, simulation, optimization and other analysis methodologies to support<br />
command-level decision-making at the operational level. The program includes two<br />
thrusts - one addressing advanced numerical methods - especially addressing<br />
stochastic behaviors and second addressing modeling of cognitive and neural<br />
phenomenology of decision making.<br />
3 - Tactical Behavior Composition<br />
Evan Clark, Intelligent Automation, Inc., 15400 Calhoun Drive,<br />
Suite 400, Rockville, MD, 20855, United States of America,<br />
eclark@i-a-i.com, Jeffrey Smith<br />
Behavior composition for computer generated forces is a technique that facilitates<br />
the creation and validation of agent behavior. It refers to the practice of creating<br />
reusable primitives that can be combined to construct new complex agent<br />
behaviors. Research in behavior composition has often focused on the use of<br />
procedural primitives. This paper discusses a framework for commander agent<br />
behavior composition that includes not only procedural primitives, but also those<br />
representing tactical concepts such as spatial relationships, subordinate coordination,<br />
terrain analysis, firepower and mobility. These primitives give the domain expert the<br />
ability to influence the manner in which tactical decisions are made. These<br />
primitives are elements of a tactics description language called Tesla Using the Tesla<br />
language, a tactical behavior expert composes tactic templates which can later be<br />
used by commander agents in course of action development and to solve tactical<br />
problems.<br />
4 - Resource-constrained Project Scheduling Under Uncertainty:<br />
Models, Algorithms and Applications<br />
Haitao Li, University of Missouri - St. Louis, 229 CCB, One<br />
University Blvd, St. Louis, MO, 63121, United States of America,<br />
lihait@umsl.edu<br />
This research studies the stochastic resource-constrained project scheduling problem<br />
(SRCPSP), which has a wide range of applications in machine scheduling, supply<br />
chain design, project portfolio optimization and personnel/manpower optimization.<br />
The SRCPSP is modeled as a Markov decision process (MDP) to cope with both<br />
structural and non-structural randomness. Techniques from optimization, artificial<br />
intelligence, simulation and statistics are built into an approximate dynamic<br />
programming (ADP) framework to tackle the “curses of dimensionality”.<br />
Preliminary computational results on the deterministic RCPSP are promising.<br />
■ WA53<br />
C -Room 14, Level 2- Mezzanine<br />
Marketing<br />
Contributed Session<br />
Chair: Nancy Ryan, Associate Professor of Marketing, St. Edward’s<br />
University, 3001 South Congress Avenue, Austin, TX, 78701,<br />
United States of America, nancym@stedwards.edu<br />
1 - Differences Between Imagers and Verbalizers in Users’<br />
Preference-making<br />
Sangwon Lee, The Pennsylvania State University, 343 Leonhard<br />
Building, University Park, PA, 16802, United States of America,<br />
sangwon.advance@gmail.com, Richard Koubek<br />
Understanding target users is a crucial issue in establishing design and marketing<br />
strategies for computer-based applications. To contribute to the comprehension of<br />
target users, this study examines the effects of cognitive style (imagers vs.<br />
verbalizers) on user preference based on usability and aesthetics through an<br />
experiment using four simulated systems with different levels of usability and<br />
aesthetics.<br />
2 - The Market Entry Decision Based on Time-series Country Efficiency<br />
Gary Chao, Kutztown University, P.O. Box 730, Kutztown, PA,<br />
19530, United States of America, chao@kutztown.edu, Maxwell Hsu<br />
Companies may examine country ranking reports before they expand business<br />
operations abroad. Most reports focus on some socio-economic variables and<br />
compute the country ranking results using a weighted averaging method. This<br />
research picks up an attractive foreign market by taking advantage of the data<br />
envelopment window analysis (DEWA) in finding a relatively more efficient<br />
marketplace to invest. We apply to evaluate the efficiency of 22 countries based on<br />
the globalEDGE data from 2002 to 2008.
WA54<br />
3 - Let Me Stack Them Up: An Analysis of Internet Marketing<br />
Service Contract<br />
Ryan Choi, PhD Student, University of California, Irvine, 6454<br />
Adobe Circle, Irvine, CA, United States of America, jihungc@uci.edu<br />
We examine two service contracts which Amazon.com offers to its competing<br />
sellers; i.e., Selling on Amazon (SOA) and Fulfillment by Amazon (FBA). We<br />
analyze how Amazon is incentivized to offer one or both of these contracts.<br />
Compared to pure competition, either contract is more likely offered when<br />
consumers’ valuation gap gets small. Assuming that this valuation gap disappears<br />
once a contract is signed up, Amazon’s contracting decision varies depending on<br />
which seller has a cost advantage.<br />
4 - Attracting Customers with Attractive Signage and Architecture<br />
Nancy Ryan, Associate Professor of Marketing, St. Edward’s<br />
University, 3001 South Congress Avenue, Austin, TX, 78701,<br />
United States of America, nancym@stedwards.edu, Helene Caudill<br />
Retail establishments should not overlook the importance of signage and<br />
architecture. We conducted a laboratory study using over 125 students who<br />
reviewed the exterior signs and architecture of five different restaurants. Results<br />
reveal how important these two features are in terms of customers’ intentions to eat<br />
there.<br />
■ WA54<br />
C -Room 15, Level 2- Mezzanine<br />
Technology Assessment and Forecasting II<br />
Sponsor: Technology Management/New Product Development<br />
Sponsored Session<br />
Chair: Fred Phillips, Professor, Alliant International University, Avenue of<br />
Nations, San Diego, CA, 92131, United States of America,<br />
fphillips@alliant.edu<br />
1 - How do Small Biotechnology Firms Innovate? The Cases<br />
From Taiwan<br />
Yu-Shan Su, Associate Professor, National Taiwan Normal University,<br />
162, HePing East Road, Section 1, Taipei, 106, Taiwan - ROC,<br />
bellesu222@yahoo.com.tw<br />
How do small firms innovate? How do a small firm’s internal capabilities and<br />
external alliances contribute to its innovativeness? The main purpose of this study is<br />
to adopt theoretical angle of open innovation to discuss small biotechnology firms in<br />
Taiwan. This study offers an integrated perspective of open innovation in the<br />
literature.<br />
2 - Forecasting Timely Revolutions in Organizational Performance<br />
Charles Weber, Associate Professor, Portland State University, P.O.<br />
Box 751, Engineering and Technology Management, Portland, OR,<br />
97207, United States of America, charles.weber@etm.pdx.edu,<br />
Nitin Mayande<br />
It has been shown that subsystem-level learning activities and firm-exogenous<br />
learning activities can induce delayed, timely revolutions in organizational<br />
performance. This paper develops a method for forecasting revolutions in<br />
organizational performance in an open innovation system. Firm-internal and firmexternal<br />
factors are taken into consideration.<br />
3 - Forecasting the Development of Clean Coal and Natural<br />
Gas Technologies<br />
Christopher Ordowich, SRI International, 1100 Wilson Blvd,<br />
Arlington, VA, United States of America,<br />
christopher.ordowich@sri.com, John Chase<br />
This study estimates the costs and efficiencies of several types of coal and natural gas<br />
power plants with and without carbon capture technologies through 2050.<br />
Improvements in plant efficiency and reductions in capital and O&M costs are<br />
modeled using technology learning curves established by a detailed analysis of<br />
historic performance data. Combined with demand and input cost forecasts, the<br />
learning curves were used to project the cost and adoption of each plant type over<br />
time.<br />
4 - Exploring the Societal Dimensions of IT: A Look at the Future of<br />
Sustainable IT Services<br />
Robert Harmon, Professor of Marketing & Technology Management,<br />
Portland State University, P.O. Box 751, Portland, OR, 97207,<br />
United States of America, harmonr@pdx.edu, Haluk Demirkan<br />
Green IT, the first wave of sustainable IT, developed strategies for reducing energy<br />
costs and carbon footprints, primarily in data centers. Green IT has been productoriented<br />
and internally focused within the IT function. The second wave of<br />
sustainable IT will be service-oriented and focused beyond the IT function to serve<br />
the organization’s business ecosystem and society at large. This work explores the<br />
key dimensions driving the development and applications of sustainable IT services.<br />
INFORMS Austin – 2010<br />
378<br />
5 - Inter-institutional Relationships and Emergency Management<br />
Fred Phillips, Professor, Alliant International University, and General<br />
Informatics LLC, 10622 Sunset Ridge Drive, San Diego, CA, 92131,<br />
United States of America, fp@generalinformatics.com<br />
Public disasters from the Exxon Valdez spill to the US mortgage meltdown involve<br />
many agencies. In improved networks of institutions, the fox will not guard the<br />
henhouse, accountability is enhanced rather than clouded, and remediation is<br />
quick, with blame assigned later. This paper advocates a new field of High-<br />
Performance Inter-Organizational Interaction (HPII). It maps dimensions of HPII<br />
against an extended Multiple Perspectives schema. Recent disasters and research<br />
directions are discussed.<br />
■ WA55<br />
C -Room 16, Level 2- Mezzanine<br />
New Product Innovation Strategy<br />
Sponsor: Technology Management/New Product Development<br />
Sponsored Session<br />
Chair: Sreekumar Bhaskaran, Assistant Professor,<br />
Southern Methodist University, 6212 Bishop Blvd, Dallas, TX, 75205,<br />
United States of America, sbhaskar@mail.cox.smu.edu<br />
1 - Managing Delegated Search Over Design Spaces<br />
Sanjiv Erat, University of California San Diego, San Diego, CA,<br />
United States of America, serat@ucsd.edu, Vish Krishnan<br />
Organizations increasingly seek solutions to open-ended design problems by<br />
employing an approach where the search over a solution space is delegated to<br />
outside agents. We study this new class of problems, and through an analytical<br />
model, we examine the relationship between problem specification, award<br />
structure, and breadth of solution space searched by outside agents towards<br />
characterizing how a firm should effectively manage such open-ended design<br />
contests.<br />
2 - Drivers of Value and Growth: An Examination of Innovation in the<br />
Solar Energy Supply Chain<br />
Jane Davies, University of Cambridge, Judge Business School,<br />
Trumpington Street, Cambridge, CB2 1AG, United Kingdom,<br />
j.davies@jbs.cam.ac.uk, David Kirkwood<br />
The introduction of government incentives has seen a plethora of firms enter the<br />
solar sector. These include both start-ups and firms diversifying from other<br />
industries. Along with incumbents, these firms face the dual pressures of reducing<br />
production costs while increasing the technology efficiency of solar power. We<br />
combine secondary data and case study analysis of 70 solar firms to show that<br />
process and technological innovation have differential effects on revenue growth<br />
and market value.<br />
3 - Design and Introduction of Conspicuous Durable Products<br />
Vishal Agrawal, Georgia Institute of Technology, 800 W Peachtree St<br />
NW, Atlanta, GA, United States of America,<br />
Vishal.Agrawal@mgt.gatech.edu, Stylianos Kavadias, Beril Toktay<br />
We study the implications of exclusivity-seeking consumer behavior on the design<br />
and introduction decisions for a durable product, namely the durability and pricing<br />
choices of the firm. We draw upon the traditional market models of vertically<br />
differentiated durable products to incorporate exclusivity-seeking behavior, and<br />
show that firms should instead consider designing products that undergo slow value<br />
erosion in conjunction with a high-price, low-volume product introduction strategy.<br />
4 - Product Introduction Timing for Start-ups<br />
Sinan Erzurumlu, Assistant Professor, Babson College, Tomasso 123,<br />
Babson Park, MA, 02457, United States of America,<br />
serzurumlu@babson.edu, Sreekumar Bhaskaran, Karthik<br />
Ramachandran<br />
We study how a start-up organization should structure its development process.<br />
While cash constraints pressure the firm to launch a product as soon as possible (to<br />
avoid or delay bankruptcy), it could affect the future products. We develop optimal<br />
policies for the start-up firm to determine whether and when to launch an existing<br />
product under technological uncertainty about future development of products.
■ WA56<br />
C - Room 1, Level 1<br />
Simulation Optimization and Global Optimization of<br />
Expensive Functions<br />
Sponsor: Simulation Society<br />
Sponsored Session<br />
Chair: Peter Frazier, Assistant Professor, Cornell University, 232 Rhodes<br />
Hall, Ithaca, NY, 14853, United States of America, pf98@cornell.edu<br />
1 - Simulation-Optimization Methods for Resource Allocation to<br />
Achieve Equity<br />
Muer Yang, University of Cincinnati, Dept of QAOM, College of<br />
Business, Cincinnati, OH, 45221, United States of America,<br />
yangmr@mail.uc.edu, Theodore Allen, Michael Fry, David Kelton<br />
This paper uses simulation-optimization models to allocate limited resources under<br />
uncertainty to achieve equity. By equity, we mean that all jobs, customers, etc.<br />
should have approximately equivalent performance measures (e.g., time in queue).<br />
We can provide probabilistic guarantees of global optimality for these allocations.<br />
We present one possible application of this work in allocating voting machines to<br />
precincts for local and national elections.<br />
2 - Global Optimization with Reponse Surfaces for Expensive<br />
Simulation Models<br />
Christine Shoemaker, Professor, Cornell University, 210 Hollister<br />
Hall, Cornell University, Ithaca, NY, 14853, United States of America,<br />
cas12@cornell.edu<br />
We will describe an effective algorithm for global optimization of simulation models<br />
that are computationally expensive and apply it to several problems, including an<br />
environmental simulation model involving systems of nonlinear partial differential<br />
equations. We will demonstrate applications of up to 30 decision variables.<br />
3 - Noise-Tolerant Bayesian Bisection<br />
Peter Frazier, Assistant Professor, Cornell University, 232 Rhodes<br />
Hall, Ithaca, NY, 14853, United States of America, pf98@cornell.edu,<br />
German Gutierrez, Shane Henderson<br />
We consider the stochastic optimization problem where we observe noisy<br />
derivatives of the objective function. These derivatives observations are expensive to<br />
obtain, and so our goal is to optimize the function as accurately as possible with a<br />
bounded number of observations. We derive the optimal sequential sampling policy<br />
using dynamic programming for a simplified version of this problem, and then<br />
discuss the use of this policy in the original problem.<br />
■ WA57<br />
C - Room 2, Level 1<br />
Recent Advances in Portfolio Optimization<br />
Sponsor: Financial Services Section<br />
Sponsored Session<br />
Chair: Chaithanya Bandi, Massachusetts Institute of Technology, 77 Mass<br />
Ave, Cambridge, MA, 02139, United States of America, cbandi@mit.edu<br />
1 - Fairness in Multi-account Optimization with Transaction Costs<br />
Dan Iancu, Stanford University, Stanford GSB, Stanford, CA, United<br />
States of America, Iancu_dan@gsb.stanford.edu, Dimitris Bertsimas,<br />
Nikolaos Trichakis<br />
In this work, we focus on the problem faced by fund managers when executing<br />
rebalancing trades for multiple accounts simultaneously. We formulate a model that<br />
addresses two key issues, namely how to split the trading costs across the accounts,<br />
and how to incorporate all the information in a scheme for rebalancing the accounts<br />
in a fair way.<br />
2 - Estimating the NIH Efficient Frontier<br />
Dimitrios Bisias, PhD Student, MIT, 70 Pacific Street Apt.327,<br />
Cambridge, MA, 02139, United States of America, dbisias@mit.edu,<br />
Andrew Lo, James Watkins<br />
The National Institutes of Health (NIH) is the preeminent source of funding for<br />
biomedical research, hence its funding allocation decisions have enormous impact<br />
on public health and social welfare. Modern financial portfolio theory is used to<br />
estimate the risk/reward trade-offs of NIH allocation decisions by treating<br />
appropriation as an investment and the decrease in years of life lost as the<br />
investment return.<br />
INFORMS Austin – 2010 WA58<br />
379<br />
3 - Optimal Portfolio Strategy with Liquidity Capacity<br />
Wei Chen, Analytical Solutions Manager, SAS Institute Inc., SAS<br />
Campus Dr., Cary, NC, 27513, United States of America,<br />
Wei.Chen@sas.com<br />
Liquidity is essential for banks to maintain long-term viability. An optimal portfolio<br />
strategy should not only manage the cash flow gaps but also provide adequate low<br />
cost contingent funding sources in distressed events. This paper proposes a model of<br />
finding minimal cost portfolio with a chance constrained level of positive excess<br />
cash flow and self-sustaining liquidity capacity. The model results in a tractable<br />
linear programming problem using the scenario based approach.<br />
■ WA58<br />
C - Room 3, Level 1<br />
Finance-Risk Management<br />
Contributed Session<br />
Chair: D.J. Alexander-Houle, Adjunct; Program Manager, University of<br />
Phoenix, HP, 14207 Torrey Vista Dr, Houston, TX, 77014, United States of<br />
America, dahoule@sbcglobal.net<br />
1 - A Coherent Valuation Approach for Valuing Risky Projects<br />
S. Reza Seyedshohadaie, Texas A&M University, 3131 TAMU,<br />
College Station, United States of America, sreza@tamu.edu,<br />
Sergiy Butenko, Ivan Damnjanovic<br />
We present a coherent valuation approch for valuing risky projects in partially<br />
complete markets. The model is based on the exposure to risk and the trade-off<br />
between risk and reward. We demonstrate the application of the model on a largscale<br />
engineering project.<br />
2 - Estimation Error Reduction in Portfolio Optimization with<br />
Conditional Value-at-Risk<br />
Gah-Yi Vahn, PhD Student, UC Berkeley, 4141 Etcheverry Hall,<br />
Mail Code 1777, Berkeley, CA, 94704, United States of America,<br />
gyvahn@berkeley.edu, Andrew Lim<br />
We introduce a novel method of obtaining robust solutions to data-driven portfolio<br />
optimization with Conditional Value-at-Risk (Expected Shortfall). This method can<br />
be interpreted as penalizing model uncertainty in the optimization problem. We<br />
present some analysis of the method and empirical results that show the superior<br />
performance of this method when the underlying log-return data is both wellbehaved<br />
(multivariate Gaussian) and heavy-tailed (multivariate t).<br />
3 - Dynamic Models for Consumer Default Risk<br />
Jonathan Crook, Professor, University of Edinburgh, Credit Research<br />
Centre, Business School, 50 George Square, Edinburgh, EH10 4SW,<br />
United Kingdom, j.crook@ed.ac.uk, Tony Bellotti<br />
This talk explains the use of survival analysis for the prediction of default for<br />
consumer loans. The talk will explain how macroeconomic variables can be<br />
incorporated into the model and show results from the parameterisation of such a<br />
model and the predictive performance of it using a data set relating to credit cards.<br />
The model is used to stress test the portfolio of loans using Monte Carlo simulation<br />
to estimate the Value at Risk and Expected Shortfall of the portfolio.<br />
4 - Risk Tolerance Tempered with Optimal Time Increments<br />
D.J. Alexander-Houle, Adjunct; Program Manager, University of<br />
Phoenix, HP, 14207 Torrey Vista Dr, Houston, TX, 77014,<br />
United States of America, dahoule@sbcglobal.net, G. R. Houle<br />
How people reason about economic choices is risk tolerance.Of social concern is the<br />
risk shift from pooled to personal responsibility. Using the fractal nature of people<br />
creates the framework for risk complexities Grable indicates as, “underlying factor<br />
within Ö decision frameworks” and the aggressiveness of decisions will reflect risk<br />
tolerance levels (2008, p. 4). Research results identifying worst case performance<br />
illustrates a foundation for creating systemic risk tolerance.
WA61<br />
■ WA61<br />
H - Room 400, 4th Floor<br />
Operations Management V<br />
Contributed Session<br />
Chair: Heping Liu, North Dakota State University, Department of<br />
Industrial & Manufacturing, Fargo, ND, 58108, United States of America,<br />
hepingliu@yahoo.com<br />
1 - Constraint and Flight Rule Management for Space<br />
Mission Operations<br />
John Chachere, Senior Computer Scientist, Stinger Ghaffarian<br />
Technologies, 1060 Arbor Road, Menlo Park, CA, 94025, United<br />
States of America, john.m.chachere@nasa.gov, Jeremy Frank,<br />
Javier Barreiro<br />
NASA’s Mission Operations Directorate (MOD) has formalized thousands of<br />
operational constraints to help govern human spaceflight missions. MOD collects,<br />
develops, documents and applies these constraints to ensure the safety of the crew,<br />
as well as proper operation of the spacecraft systems and payloads. These constraints<br />
are stored in human-readable documents and also used to configure tools used by<br />
the flight controllers who plan and fly missions. We have begun developing a novel<br />
capability for authoring and maintaining such constraints called the Constraint and<br />
Flight Rule Management system (ConFRM). ConFRM provides history tracking and<br />
commenting features that allow authors to trace the history of constraints<br />
throughout their lifecycle. ConFRM maintains links between related constraints,<br />
and between constraints and source information used to create the constraints.<br />
ConFRM uses these links to ensure consistency between constraints throughout<br />
their lifecycle, and provides authors and reviewers the ability to navigate between<br />
constraints and related data. Finally, ConFRM enables export of constraints into<br />
many different forms, including human readable documents and tool<br />
configurations, thereby eliminating manual labor and reducing transcription errors.<br />
2 - Reverse Ranking and Overshooting in Supply Chains with Private<br />
Inventory Information<br />
Alexandre Belloni, Assistant Professor, Duke University,<br />
1 Towerview Drive, Durham, NC, 27708, United States of America,<br />
abn5@duke.edu, Giuseppe Lopomo, Shouqiang Wang<br />
We study contracts for a single supplier with fixed capacity selling to multiple<br />
retailers who are privately informed on their inventory levels. In symmetric<br />
environments, instead of a balancing policy, it is optimal for the supplier to make<br />
retailers with lower initial inventory levels end up with a larger final positions<br />
(reverse ranking). We characterize when it is optimal to ``overshoot” to provide a<br />
larger quantity to a retailer than it would get in the corresponding centralized<br />
system.<br />
3 - Backup Agreements in Multiple Component Procurements with<br />
Demand Updates<br />
Mingchang Wu, PhD Student, University of Connecticut, 2100<br />
Hillside Road, Storrs Mansfield, Storrs Mansfield, CT, 06269, United<br />
States of America, mingchang.wu@business.uconn.edu, Suresh Nair,<br />
Lakshman Thakur<br />
We study a supply chain where a manufacturer buys two different components<br />
from two suppliers to produce one product for the selling season.This is an<br />
extension of Eppen and Iyer’s work,where we now look at components rather than<br />
end product.With each supplier,the manufacturer has a particular backup<br />
agreement.Our objective is to derive an optimal purchase policy which describes the<br />
optimal commitments to each supplier and a reaction plan to the demand updates at<br />
the later stage.<br />
4 - The Optimum Policies to the Distribution/Inventory System Problem<br />
in the Medical Center<br />
Jimmy Alexander Carvajal Beltran, Student, Universidad de los<br />
Andes, Carrera 1 N° 18A - 12, Bogotà, Colombia,<br />
ja.carvajal911@uniandes.edu.co, Ciro Alberto Amaya Guio,<br />
Fabiàn Andrés Castaño Giraldo, Nubia Milena Velasco Rodriguez<br />
This paper describes a new approach for solving the budget constrained distribution<br />
and inventory problem for one warehouse and n retailers. This is a typical situation<br />
in medical supply networks where a single warehouse supplies a set of pharmacies<br />
with the main objective of minimizing total costs. To solve the problem, we propose<br />
an iterative algorithm which uses mathematical programming methods. We present<br />
the principal ideas of this approach and results using random instances.<br />
5 - Simulation Modeling for Clinic Telephone Systems<br />
Heping Liu, North Dakota State University, Department of Industrial<br />
& Manufacturing, Fargo, ND, 58108, United States of America,<br />
hepingliu@yahoo.com, Jing Shi<br />
Clinic telephone systems can guide patients to obtain optimal healthcare delivery<br />
services. In our research, simulation modeling is used to optimize clinic telephone<br />
systems with the functions of leaving messages and call-back services. Centralization<br />
and decentralization are two considered telephone system frames. According to<br />
operator utilization and patient satisfaction level, various scenarios are designed and<br />
simulated. The obtained results can benefit the telephone system configuration.<br />
INFORMS Austin – 2010<br />
380<br />
■ WA62<br />
H - Room 402, 4th Floor<br />
Aviation Applications III<br />
Contributed Session<br />
Chair: Akira Kondo, Federal Aviation Administration, 800 Independence<br />
Ave., SW, Washington, DC, 20591, United States of America,<br />
akira.kondo@faa.gov<br />
1 - Customer Profitability Analysis for Marketing Initiatives in a<br />
Fractional Airline<br />
Jintao Ouyang, CitationAir, 5 American Lane, Greenwich, CT,<br />
06831, United States of America, jouyang@citationair.com,<br />
Aang Daniel, Roger Zhan, Haiyuan Wang<br />
Due to the operation nature of fractional airlines, operation costs such as charter<br />
premium and position do not directly link to specific customers. A regression based<br />
statistical method is presented to associate these costs to each customer. We also<br />
identify the factors that affect the profitability of customers. These factors can be<br />
used for marketing initiatives such as contract renewal, customer retention, and<br />
devising new pricing schemes.<br />
2 - Optimized Airport Security Study<br />
Shannon Harris, Technomics, Inc, 201 12th Street South, Suite 612,<br />
Arlington, VA, 22202, United States of America,<br />
sharris@technomics.net, Joon Kim, Jaime Gonzalez,<br />
Elizabeth Wilson<br />
The current security measures implemented at airports produce “soft targets” in the<br />
form of lengthy queues that heighten the risk of a terrorist attack. This study<br />
examines Washington Dulles and designs a model to improve the allocation and<br />
usage of security resources. Two alternative designs make use of layered, defense-indepth<br />
security measures and the concept of unpredictability. The best alternative is<br />
selected by analyzing simulation outputs based on a value function.<br />
3 - A Value-based Time-Phased Bayesian Network (VTBN) for<br />
Augmented Safety Risk Assessment<br />
James Luxhoj, Professor, Rutgers University, 96 Frelinghuysen Road,<br />
Dept. of ISE, Piscataway NJ 08854, United States of America, jluxhoj@rci.rutgers.edu,<br />
Michael Morton<br />
The use of Unmanned Aircraft Systems (UAS) for civil applications is increasing in<br />
the United States. There is a need to develop advanced risk models that capture the<br />
complexities of integrating aviation regulations, functions, hazards and causal factors<br />
into a probabilistic model for augmented safety assurance. This presentation<br />
introduces a Bayesian Network that integrates the use of value functions and time<br />
phasing for modeling safety risk analysis of small UAS applications.<br />
4 - Departure Demand, Efficiency, Taxi-out Delay, and Unimpeded<br />
Taxi-out Time<br />
Akira Kondo, Federal Aviation Administration, 800 Independence<br />
Ave., SW, Washington, DC, 20591, United States of America,<br />
akira.kondo@faa.gov<br />
Taxi-out delays play an important role in the computation of key airport<br />
performance metrics. In this system, departure demand and resulting airport<br />
departure efficiency significantly impact crucial parts in System Airport Efficiency<br />
Rate (SAER). This study provides a new definition of taxi-out times and how<br />
estimation of unimpeded taxi-out time affects computation of taxi-out delays.<br />
■ WA63<br />
H - Room 404, 4th Floor<br />
Decision Analysis For Public Health<br />
Sponsor: Decision Analysis<br />
Sponsored Session<br />
Chair: Ozgur Araz, Postdoctoral Fellow, University of Texas at Austin,<br />
Patterson Lab 628, Austin, TX, 78712, United States of America,<br />
oaraz@mail.utexas.edu<br />
1 - Comparing Cost-effectiveness of Physical Activity Interventions<br />
Shinyi Wu, Assistant Professor, University of Southern California,<br />
3715 McClintock Ave., GER 240C, Los Angeles, CA, 90089,<br />
United States of America, shinyiwu@usc.edu<br />
We conducted a systematic review and developed a method to compare costeffectiveness<br />
(CE) across a wide variety of physical activity (PA) intervention<br />
strategies. Study quality was variable. Decision prompts were most cost-effective but<br />
had tiny effects. School-based and other wide-reach interventions ranked well. High<br />
intensity programs were least cost-effective but had the largest effect sizes. The CE,<br />
effect size, and study quality should all be considered when choosing PA<br />
interventions.
2 - A Decision Analytic Approach for Modeling School Closures During<br />
an Influenza Pandemic<br />
Ozgur Araz, Postdoctoral Fellow, University of Texas at Austin,<br />
Patterson Lab 628, Austin, TX, 78712, United States of America,<br />
oaraz@mail.utexas.edu, Sean Burke, Paul Damien, Lauren Meyers,<br />
Bryce van de Geijn, Alison Galvani<br />
In this presentation, we present a decision analytic approach for making school<br />
closure decisions during an influenza pandemic. We build a mass action model and<br />
assume the severity of the disease is uncertain for the decision makers. A decision<br />
tree is used to evaluate several closure and reopening decisions simultaneously<br />
based on their cost effectiveness. Lastly, we perform several sensitivity analyses on<br />
decision making parameters and present our results.<br />
3 - Dynamics of a Pharmaceutical Risk Sharing Agreement<br />
Reza Mahjoub, PhD Student, Ivey Business School, 1151 Richmond<br />
St., London, ON, Canada, rmahjoub@ivey.uwo.ca, Fredrik Odegaard,<br />
Greg Zaric<br />
Some new drugs such as cancer drugs could be very costly to develop and<br />
manufacture while their effectiveness and efficiency in real life may be unproven. A<br />
risk sharing agreement is a contract between the drug manufacturer and a<br />
healthcare payer to manage uncertainties regarding the cost and effectiveness of<br />
those drugs. We develop a model to examine the dynamics of a risk sharing contract<br />
for a drug manufacturer.<br />
■ WA64<br />
H - Room 406, 4th Floor<br />
Health Care, Modeling and Optimization V<br />
Contributed Session<br />
Chair: Ilgin Acar, Anadolu University, Department Of Industrial<br />
Engineering, Iki Eylul Campus, Eskisehir, 26555, Turkey,<br />
ipoyraz@anadolu.edu.tr<br />
1 - Consensus by Averaging Phylogenetic Trees<br />
Scott Provan, University North Carolina, Department Statistics and<br />
Operations Research, Chapel Hill, NC, 27599, United States of<br />
America, Scott_Provan@UNC.edu, Ezra Miller, Megan Owen<br />
We introduce a new notion of the consensus tree for a set of phylogenetic trees, by<br />
representing them as points in the phylogenetic tree space of Billera, Holmes, and<br />
Vogtmann. The property of non-positive curvature of this space ensures that the<br />
consensus tree captures the correct notion of an “average” tree, and that there is an<br />
algorithm for computing this tree. We give as applications reconstructing species<br />
trees from gene trees and comparing the structure of blood vessels in the brain.<br />
2 - A Probabilistic Optimization Approach to Analyze Large Scale<br />
Emergency Medical System on Highways<br />
Ana Iannoni, Ecole Centrale Paris - Laboratoire Genie Industriel,<br />
Grande Voie des Vignes, Chatenay Malabry, 92295, France,<br />
iannoni93@hotmail.com, Reinaldo Morabito, Cem Saydam<br />
In this study we present optimization methods based on greedy heuristics<br />
embedding an approximate hypercube queuing model. The proposed approach can<br />
support two decisions in the operation of emergency systems on highways: the<br />
location and districting of the ambulances. We applied these methods to a case study<br />
and to instances of up to 100 ambulances. The present approach is an alternative for<br />
the analysis of large scale systems, which provides reasonable accuracy and<br />
affordable running times.<br />
3 - A Multi-class Open Queuing Network with Priority Discipline<br />
Applied to the Emergency Department<br />
Sumi Kim, Yonsei University, Shinchon-dong, Seodaemun-gu, Seoul,<br />
Korea, Republic of, sumi_kim@yonsei.ac.kr, Seongmoon Kim<br />
We formulate the patient flows in the emergency department using a multi-class<br />
open queueing network. The unique aspect of this paper is that it incorporates the<br />
priority discipline with the queueing network, in order to control the waiting time<br />
of more urgent patients. A case study based on actual data from an emergency<br />
department demonstrates how effective the introduced model and the policy with<br />
the priority discipline are in controlling the waiting time and improving the quality<br />
of service.<br />
4 - Optimal Clinical Scheduling with No-shows<br />
Ji Lin, PhD Candidate, Purdue University, Weldon School of<br />
Biomedical Engineering, 206 S. Martin Jischke Drive, West Lafayette,<br />
IN, 47907, United States of America, lin35@purdue.edu,<br />
Mark Lawley, Kumar Muthuraman<br />
The accessibility and efficiency of outpatient care are largely affected by the<br />
appointment schedules. Patient no-show causes waste of physician time and<br />
revenue loss. Random booking results in long waiting time and overtime. Patients<br />
usually have different no-show rates. Thus, we propose MDP model and optimal<br />
scheduling policies for heterogeneous no-show patients. Approximate Dynamic<br />
Programming methods are developed to solve the curse of dimensionality.<br />
INFORMS Austin – 2010 WA65<br />
381<br />
5 - Workload Scoring of Nurse to Patient Assignments<br />
Ilgin Acar, Anadolu University, Department Of Industrial<br />
Engineering, Iki Eylul Campus, Eskisehir, 26555, Turkey,<br />
ipoyraz@anadolu.edu.tr, Steven Butt<br />
This work is the first to explicitly consider incorporating travel distances into the<br />
construction of a nurse’s patient assignments through the construction of a<br />
workload score based on nurse travel distances and patient acuity measures. The<br />
workload scores were developed through consultation with charge nurses using<br />
AHP. The resulting tool displays a nurse’s assigned rooms and associated workload<br />
score in an accessible spreadsheet format.<br />
■ WA65<br />
H - Room 408, 4th Floor<br />
Inventory Management V<br />
Contributed Session<br />
Chair: Ayse Gönül Karaarslan, PhD Candidate, Eindhoven University of<br />
Technology, P.O. Box 513, Eindhoven, 5600 MB, Netherlands,<br />
a.g.karaarslan@tue.nl<br />
1 - A Simulation-optimization Approach to the Inventory Mangement of<br />
Perishable and Substitutable Items<br />
Bret Myers, Villanova University, 442 Hartford Square, West Chester,<br />
PA, 19380, United States of America, bret.myers@villanova.edu<br />
A simulation-optimization approach is used to analyze inventory policy for two<br />
perishable and substitutable items. A set of perishable items is considered under a<br />
periodic system of inventory control where demand for a preferred item can be<br />
satisfied by a substitute item with in the event of a stockout of the preferred item.<br />
The retailer is faced with the decision of determining the order-up-to levels which<br />
maximize expected total profit.<br />
2 - Policy Parameter Adjustments to Meet Desired Service Level<br />
Requirements for (r, NQ) Inventory Models<br />
Yasin Unlu, University of Arkansas, 4207 Bell Engineering Center,<br />
Fayetteville, AR, 72701, United States of America, yunlu@uark.edu,<br />
Manuel D Rossetti<br />
This study introduces a simulation optimization based procedure for setting policy<br />
parameters of continuous review (r, NQ) inventory models in the face of complex<br />
demand cases. The experiments done with various demand scenarios show that the<br />
procedure yields promising results in terms of attaining specified target service<br />
levels.<br />
3 - A Multiple-level Supply Chain Coordination Model by (Q, r) Policies<br />
in a Fuzzy Environment<br />
Xinmin Wu, OR Specialist, SAS, Sas Campus Drive, Cary, 27513,<br />
United States of America, xinmin.wu@sas.com, Don Warsing<br />
we present a serial multiple-level supply chain coordination model by (Q,r) policies<br />
in a fuzzy risk environment. Sources of risk and uncertainty in our model include<br />
demand, lead time, supplier yield, which are modeled by fuzzy sets. Heuristics are<br />
presented to determine local optimal policies on the basis of techniques identified in<br />
the literature on fuzzy sets. A coordination process with an external coordinator is<br />
implemented to improve supply chain performance based on global view.<br />
4 - A Modified Base Stock Policy for an Assemble to Order System<br />
with Different Review Periods<br />
Ayse Gönül Karaarslan, PhD Candidate, Eindhoven University of<br />
Technology, P.O. Box 513, Eindhoven, 5600 MB, Netherlands,<br />
a.g.karaarslan@tue.nl, Ton de Kok, Gudrun P. Kiesmüller<br />
We have a single item assembled from two components. The inventory levels are<br />
reviewed periodically and customer demand is stochastic. One of the components<br />
has a longer lead time, higher holding cost and shorter review period compared to<br />
the other one. We analyze a modified base stock policy such that one stockpoint is<br />
controlled by an order-up to policy. The orders for the other stockpoint are<br />
synchronized depending on its order-up-to level and the inventory level of the<br />
other component.
WA66<br />
■ WA66<br />
H - Room 410, 4th Floor<br />
Transportation, Other<br />
Contributed Session<br />
Chair: Gokhan Memisoglu, PhD Student, Texas A&M University,<br />
Department of Industrial and Systems Eng, Texas A&M University,<br />
College Station, TX, 77843-3131, United States of America,<br />
gmemis@tamu.edu<br />
1 - A Net Present Value Model for Investment in Airport Assets<br />
Alexandre de Carvalho, Instituto de Pesquisa EconÙmica Aplicada -<br />
IPEA, Diretoria de Estudos Regionais e Urbanos, SBS Quadra 1,<br />
Edificio BNDES, sala 718, Brasilia, DF, 70076-900, Brazil,<br />
alexandre.ywata@ipea.gov.br, Alessandro VM de Oliveira,<br />
Reinaldo C. Garcia<br />
Improvement and expansion in infrastructure transport assets are among the main<br />
concerns facing the transport specialists due to the high investments involved. The<br />
timing and the combination of new transport investments is key to analyze their<br />
long-term effects. This paper proposes an investment model based on Net Present<br />
Value (NPV) analysis. In particular, the model is applied to: (i) the building of a new<br />
airport; and (ii) the expansion of already existing “major” and “minor” airports.<br />
2 - Network Connectivity Analysis for Port Competitiveness Study<br />
Ek Peng Chew, Associate Professor, National University of Singapore,<br />
10 Kent Ridge Crescent, Singapore, 669606, Singapore,<br />
isecep@nus.edu.sg, Loo Hay Lee, Jianlin Jiang, Chee Chun Gan<br />
Port connectivity is an important factor that deserves much attention in the study of<br />
port competitiveness. Determining how well one port connects to others is hardly<br />
easy, as it being an abstract concept might bring about different interpretations and<br />
definitions in different cases. In this paper, we will propose a measure using<br />
network anaylsis to measure port connectivity.<br />
3 - Student Assignment Models for a School System<br />
Trivikram Rao, PhD Student, University of Louisville, Department of<br />
Industrial Engineering, JB Speed School of Engineering, Louisville,<br />
KY, 40292, United States of America, trivikram.rao@louisville.edu,<br />
Arsalan Paleshi, Bulent Erenay<br />
This research proposes a mathematical programming approach for student<br />
assignment to schools while incorporating quantitative, qualitative constraints such<br />
as travel cost, parental preferences, and socio-economic constraints. The model’s<br />
sensitivity in cost, parental satisfaction terms to certain constraints is tested. Also,<br />
extension of this approach to other assignment problems is discussed.<br />
4 - Optimal Deployment of Emissions Reduction Technologies for<br />
Large Fleets<br />
Gokhan Memisoglu, PhD Student, Texas A&M University,<br />
Department of Industrial and Systems Eng, Texas A&M University,<br />
College Station, TX, 77843-3131, United States of America,<br />
gmemis@tamu.edu, Mohamadreza Farzaneh, Kiavash Kianfar<br />
In states that have serious air quality problems, such as Texas and California, public<br />
fleet managers are under pressure to reduce emissions from their fleet. In order to<br />
help them with this problem, this research study will create an optimization model<br />
capable of determining the most efficient assignment of emission reduction<br />
strategies among vehicles and equipment in a large fleet. To achieve the goal, this<br />
study will focus on Texas Department of Transportation’s (TxDOT’s) fleet.<br />
■ WA67<br />
H - Room 412, 4th Floor<br />
Simulation I<br />
Contributed Session<br />
Chair: Ahmet Ozkul, Assistant Professor of Management, University of<br />
New Haven, 300 Boston Post Rd., Maxcy Hall, West Haven, CT, 06516,<br />
United States of America, aozkul@newhaven.edu<br />
1 - Incorporating Analytic Hierarchy Process with Simulation to Assess<br />
Health Service Quality<br />
Yan Li, The University of Texas-Pan American, 508 E Redbud Ave,<br />
Mcallen, TX, 78504, United States of America,<br />
tongjijacky@hotmail.com, Jianzhi Li<br />
While improving quality in health care is currently at the forefront of professional,<br />
political, and managerial attention, it has yet to fully understand the key dimensions<br />
constituting health-care quality and develop valid approaches to their measurement.<br />
The methodology proposed in this paper, AHP based simulation, will provide great<br />
insights in tackling this problem and open up a world of possibilities for future<br />
research.<br />
INFORMS Austin – 2010<br />
382<br />
2 - Modeling Parameter Uncertainty in Stochastic Simulations<br />
Canan Gunes, PhD Student, Carnegie Mellon University, 5000<br />
Forbes Avenue, Pittsburgh, PA, 15213, United States of America,<br />
cgunes@andrew.cmu.edu, Bahar Biller<br />
We consider a stochastic simulation and demonstrate how to account for stochastic<br />
uncertainty and parameter uncertainty in the output analysis. We further<br />
decompose the variance of the output data into terms associated with each type of<br />
uncertainty and use this decomposition to develop a data-collection schema for<br />
reducing parameter uncertainty. We illustrate our approach with inventory system<br />
simulations.<br />
3 - A Discrete Simulation Approach to the Design of a Warehouse for<br />
Air Cargo Operations<br />
Carlos Osorio, Politecnico Grancolombiano, Calle 57 3-00 Este Fac<br />
Ingenieria, Bogota, Colombia, caosorio@poli.edu.co,<br />
Oscar Javier Parra Ortega<br />
This paper shows the application of discrete simulation for designing the main air<br />
cargo warehouse of one of the biggest airlines in Colombia and South America. The<br />
research begins with the evaluation of the operations carried out in the warehouse;<br />
the current performance is analyzed using key logistics indicators, and prospective<br />
scenarios are then generated and evaluated. Preeliminary results are also reported.<br />
4 - Simulation to Identify Errors in Generalized Tournaments<br />
Christopher Keller, Assistant Professor of Marketing and Supply<br />
Chain Management, East Carolina University, 3136 Bate Building,<br />
School of Business, Greenville, NC, 27858, United States of America,<br />
kellerc@ecu.edu<br />
This paper presents a Monte Carlo simulation of ranking participants in a<br />
generalized tournament, including variations in: number of participants;<br />
completeness of the tournament; and paired comparison errors. Some paired<br />
comparison errors are not reliably identifiable and a complete and accurate ordering<br />
of participants is unlikely. Using a partial ordering topological rank, jackknife<br />
estimates of the average rank do admit the identification of some of the paired<br />
comparison errors.<br />
5 - Simulating Social Networks in Understanding Dynamics of<br />
Customer Purchase Behavior: Case of Cult Brands<br />
Ahmet Ozkul, Assistant Professor of Management, University of New<br />
Haven, 300 Boston Post Rd., Maxcy Hall, West Haven, CT, 06516,<br />
United States of America, aozkul@newhaven.edu, Aqin Hu<br />
When we consider customers as actors in a purchasing relationship of products,<br />
Social Network Analysis may be used to reveal unknown patterns and explain<br />
customer behavior. Using a simulation analysis, we create a market of M customers<br />
and N products. Customers create a relationship when they buy a given product.<br />
The number of links and frequency of the purchase determine the nature of the<br />
relationship. We calculate social network measures in each cycle to observe the<br />
dynamics.<br />
■ WA68<br />
H - Room 415, 4th Floor<br />
Innovation/Entrepreneurship I<br />
Contributed Session<br />
Chair: Arash Dadvand, CGN and Associates, 415 SW Washington St,<br />
Peoria, IL, 61602, United States of America, adadvand@cgn.net<br />
1 - Diffusion of Innovation Products: Network Effects and<br />
Bandwagon Effects<br />
Shuzhen Sun, School of Industrial Engineering & Management,<br />
Oklahoma State University, School of Industrial Engineering & Mgt.,<br />
Oklahoma State University, Stillwater, Ok, 74078,<br />
United States of America, zhener18@gmail.com, Di Xu<br />
Bandwagon effects and network effects play important roles in consumers’ purchase<br />
decisions. This paper uses the small-world network model to study the two effects<br />
on the diffusion of innovation products. Simulations are conducted to examine the<br />
diffusion process and adoption rate under different levels of bandwagon pressures,<br />
different strength of network effects,and different network configurations, on the<br />
assumption that bandwagon effects exist in all conditions.<br />
2 - A System Dynamics Model to Understand Innovation in the<br />
Design Process<br />
Nur Ozge Ozaltin, University of Pittsburgh, 1048 Benedum Hall,<br />
Pittsburgh, PA, 15261, United States of America, noo7@pitt.edu,<br />
Mary Besterfield-Sacre, Larry Shuman<br />
To improve innovation, it should be better understood how the teams navigate the<br />
design process from initial conception to prototype. We examine the bioengineering<br />
design process to investigate associations between design patterns and the quality of<br />
the resulting artifact. We identify the critical patterns and factors that lead to<br />
innovation.
3 - Entrepreneurship and Community Development: A Fallacy From<br />
Central Mexico<br />
Eliseo Vilalta-Perdomo, Head Dept Industrial and Systems<br />
Engineering, Tecnológico de Monterrey, Av Gral Ramón Corona<br />
2514, Col. Nuevo México, Zapopan, 45201, Mexico,<br />
eliseo.vilalta@itesm.mx, Cynthia Montaudon-Tomas<br />
To consider entrepreneurship as a dynamo for economic development is challenged<br />
throughout this work done in central Mexico. Two programs from different rural<br />
communities in Guanajuato are studied. Probably the most promising finding is to<br />
recognize that individual economic development and community social<br />
development are not linked. A proposal to increase quality of life in rural<br />
communities is presented. It is centered on creating and maintaining self-organized<br />
web-based networks.<br />
4 - Efficient Targeted Concept Development Method<br />
Arash Dadvand, CGN and Associates, 415 SW Washington St, Peoria,<br />
IL, 61602, United States of America, adadvand@cgn.net<br />
Breakthrough competitive advantage are accomplished by competitive concepts.<br />
Concept development is costly, hard to manage and may not result in a viable<br />
solution. This is a method to formulate a problem, effectively and efficiently create<br />
concepts based on generic cross-industry patented solutions, and prioritize concepts<br />
to meet predefined goals. Final set of concepts could be optimized and improved.<br />
■ WA69<br />
H - Salon F, 6th Floor<br />
Transportation, Rail<br />
Contributed Session<br />
Chair: Katharina Beygang, University of Kaiserslautern, Department of<br />
Mathematics, OR Group, Postfach 3049, Kaiserslautern, 67653, Germany,<br />
beygang@mathematik.uni-kl.de<br />
1 - Extensions to the Online Delay Management Problem on a<br />
Single Train Line<br />
Christiane Zeck, University of Kaiserslautern, Department of<br />
Mathematics, OR Group, Postfach 3049, Kaiserslautern, 67653,<br />
Germany, zeck@mathematik.uni-kl.de, Sven O. Krumke,<br />
Clemens Thielen<br />
The online delay management problem consists in deciding when to wait for<br />
delayed passengers in order to minimize the total passenger delay. Viewing this<br />
problem in the context of game theory, we determine an optimal online strategy.<br />
We also introduce a new objective function modeling a refund system for delayed<br />
passengers with the aim of maximizing the profit. For this problem, there cannot be<br />
a competitive deterministic online algorithm, but we present a 2-competitive<br />
randomized algorithm.<br />
2 - Railway Routing Algorithms for Hazardous Materials<br />
Marc Meketon, Oliver Wyman, 212 Carnegie Center, Princeton, NJ,<br />
08540, United States of America, Marc.Meketon@oliverwyman.com,<br />
Paul Stephens<br />
New Federal Railroad Administration guidelines require examining various<br />
hazardous material routing alternatives. The shortest path may traverse large<br />
population centers or other non-desirable areas. Finding a set of acceptable paths is<br />
challenging for large railroads where the “K-shortest” paths differ insignificantly.<br />
This research discusses solutions to the important, but difficult, task of identifying<br />
different paths with acceptable distance and cost that also represent real<br />
alternatives.<br />
3 - Efficient Usage of Railway Infrastructure Through<br />
Pricing Mechanisms<br />
Arnt-Gunnar Lium, Research Scientist, SINTEF Technology and<br />
Society, P.O. Box 4760 Sluppen, Trondheim, N 7465, Norway,<br />
arnt-gunnar.lium@sintef.no, Adrian Werner<br />
Railroad infrastructure is very costly to develop; hence, increased utilization will<br />
have a significant positive impact on society. One way of increasing utilization over<br />
the day is to implement tariffs such that railroad operators adapt their schedules in a<br />
socio-economical optimal way. We look into how bi-level programming can be<br />
combined with stochastic service network design to determine socio-economical<br />
optimal tariffs.<br />
4 - Extensions to the Train Marshalling Problem<br />
Katharina Beygang, University of Kaiserslautern, Department of<br />
Mathematics, OR Group, Postfach 3049, Kaiserslautern, 67653,<br />
Germany, beygang@mathematik.uni-kl.de, Sven O. Krumke<br />
Shunting yards, consisting of a hump and a set of parallel classification tracks, play<br />
an important role in railroad life. They are used for the rearrangement of cars<br />
according to their destinations. The Train Marshalling Problem consists of<br />
minimizing the number of classification tracks needed for the rearrangement of a<br />
given car sequence. It is well known to be NP-complete. We give competitive<br />
polynomial time algorithms for the online variant as well as lower bounds on the<br />
competitiveness.<br />
INFORMS Austin – 2010 WA71<br />
383<br />
■ WA70<br />
H - Salon G, 6th Floor<br />
Planning and Strategies for Airline Operations<br />
Sponsor: Aviation Applications<br />
Sponsored Session<br />
Chair: Sergey Shebalov, Principal Research Analyst, Sabre Holdings,<br />
Dallas/Fort Worth, TX, United States of America,<br />
Sergey.Shebalov@sabre-holdings.com<br />
1 - Baggage Capacity and Demand Management Becomes Even<br />
More Sophisticated<br />
Desmond Di Wang, Northwestern University, 2145 Sheridan Road,<br />
Evanston, IL, 60208, United States of America,<br />
diwang2007@u.northwestern.edu, Diego Klabjan<br />
While sophisticated forecasting management systems exist for the passengers and<br />
cargo load of an aircraft, this is not the case for baggage despite significant costs<br />
associate with baggage mishandling. It is thus desirable to detect excessive baggage<br />
load early during the booking process to avoid dire consequences for both<br />
passengers and the airline. We present methodologies behind a system for baggage<br />
load forecasting any number of days before the day of operations.<br />
2 - Short-term Maintenance Allocation<br />
Sergey Shebalov, Principal Research Analyst, Sabre Holdings,<br />
Dallas/Fort Worth, TX, United States of America,<br />
Sergey.Shebalov@sabre-holdings.com<br />
Short-term maintenance allocation involves building and supporting maintenance<br />
schedule for each tail to ensure its operationability. We present a model that creates<br />
an optimal set of maintenance blocks for a given tail assignment and allocates<br />
maintenance events to them. We optimize aircraft utilization and maintenance cost<br />
while maintenance capacity is constrained. We extend our formulation to allow<br />
overnight aircraft swaps and thus integrate maintenance allocation and tail<br />
assignment.<br />
3 - Planeside Manpower Planning at United Airlines<br />
Feryal Kuran, United Airlines, 1200 E. Algonquin Rd., Elk Grove<br />
Village, IL, United States of America, Feryal.Kuran@united.com,<br />
Kumar Satyam<br />
Planeside Tool is a major component of the Ramp Operations automation strategy at<br />
United Airlines. Initial phase enables manual assignment of resources to cover<br />
arrival and departure packages. Model, developed by Enterprise Optimization,<br />
suggests best assignment of resources to packages and lunches over multiple hours<br />
considering various factors. Weighting of factors can be adjusted depending on<br />
needs of operations. Model enables improved coverage of flights and better<br />
utilization of resources.<br />
4 - Structured Deplaning: A Simulation and Optimization of<br />
Implementable Strategies<br />
Andrew Wald, Northwestern University, 2145 Sheridan Road,<br />
Evanston, IL, 60208, United States of America,<br />
andrewwald@gmx.com, Diego Klabjan<br />
Deplaning naturally occurs row by row down the length of an aircraft. Using<br />
simulation and optimization, we design deplaning strategies (e.g., deplane by group)<br />
that significantly reduce the overall deplaning time. These evaluations are<br />
established through field observations and simulation, and have been tested across<br />
several equipment types.<br />
■ WA71<br />
H - Salon H, 6th Floor<br />
Resource Efficiency and Distribution Models in DEA<br />
Cluster: In Honor of Bill Cooper<br />
Invited Session<br />
Chair: Subhash Ray, University of Connecticut, CT, United States of<br />
America, subhash.ray@uconn.edu<br />
1 - Using DEA to Help the Regulator Set Promulgated Insurance Rates<br />
Patrick Brockett, University of Texas, TX, United States of America,<br />
brockett@mail.utexas.edu, William Cooper, Jing Ai, Charles Yang,<br />
Linda Golden, Utai Pitaktong<br />
We offer a methodology for setting efficient promulgated insurance rates illustrated<br />
through an application to title insurance rate setting. In title insurance, losses<br />
constitute a tiny percentage of the premium, and expenses dominate the rates.<br />
Rates are set (in Texas) by the regulator relying upon average expenses and loss<br />
ratios. This inflates rates and rewards inefficiency, since inefficient agents with<br />
higher expenses drive up the average expense resulting in higher promulgated rates.<br />
We use DEA to: identify those title agents that efficiently utilize their resources to<br />
produce policies, and show how rates can be promulgated based upon the expenses<br />
of only these efficient agents, thus encouraging efficient management and<br />
reasonable rates.
WA72<br />
2 - A DEA Approach to Simulation Output Analysis of an Agent-based<br />
Model of a Distribution Network<br />
William Sawaya, Assistant Professor, Texas A&M University, Eng.<br />
Tech. and Industrial Distribution, College Station, TX, 77845,<br />
United States of America, sawaya@tamu.edu, Andrew Johnson, Sri<br />
Nagendra Jayanty<br />
Simulation output analysis for comparing different systems configurations can be<br />
complicated by the fact that there are often multiple performance variables of<br />
interest. This complexity can be further compounded in agent-based system because<br />
it is conceivable that there are multiple agents that each have their own<br />
performance information. This research presents a DEA approach analyzing<br />
simulation output of different system configurations for multiple organizations in a<br />
distribution network.<br />
3 - Cost Efficiency in a Model of Production and Distribution<br />
Subhash Ray, University of Connecticut, CT, United States of<br />
America, subhash.ray@uconn.edu<br />
This paper develops a measure of overall cost efficiency in an integrated model of<br />
production and distribution. The DEA model introduced by Ray et al (2008) for<br />
multi-location cost minimization in the presence of input price variation across<br />
locations is combined with the standard transportation model. The principal<br />
innovation is that optimal quantities produced at different locations and the<br />
quantities shipped to different destinations are determined simultaneously in a<br />
unified DEA model that minimizes total production and distribution cost.<br />
■ WA72<br />
H - Salon J, 6th Floor<br />
Joint Session TSL/ SPPSN: Aiding Disaster Relief<br />
Through Optimization<br />
Sponsor: Transportation Science and Logistics Society/ Public<br />
Programs, Service and Needs<br />
Sponsored Session<br />
Chair: Irina Dolinskaya, Assistant Professor, Northwestern University,<br />
2145 Sheridan Road, M235, Evanston, IL, 60208, United States of<br />
America, dolira@northwestern.edu<br />
1 - Continuous Approximations for Relief Routing<br />
Michael Huang, Northwestern University, 2145 Sheridan Rd,<br />
Evanston, IL, 60208, United States of America, Michael-<br />
Huang@u.northwestern.edu, Karen Smilowitz<br />
In relief routing, solutions must be found quickly and should be easy to implement.<br />
We describe a simple policy and develop analytic approximations to measure its<br />
effectiveness. We demonstrate the accuracy of the approximations’ by comparing<br />
the predicted values against simulations of the policy. Finally, we test the solutions<br />
from the policy against more sophisticated polices generated with a Tabu search.<br />
2 - A Review on Recent OR Research in Disaster<br />
Operations Management<br />
Rajan Batta, Professor and Associate Dean, University at Buffalo<br />
(SUNY), Department of Industrial & Systems Engg, 438 Bell Hall,<br />
Buffalo, NY, 14260, United States of America, batta@buffalo.edu,<br />
Gina Galindo<br />
Disasters have attracted the attention of OR researches who are interested on<br />
applying scientific techniques to improve DOM effectiveness, and reduce the<br />
consequences of disasters on the economy and human lives. In this talk a review on<br />
recent OR research in DOM is offered and some future research directions are<br />
proposed.<br />
3 - Modeling Disaster Relief Networks<br />
Luis de la Torre, PhD Candidate, Northwestern University, 2145<br />
Sheridan Road, IEMS, Tech C210, Evanston, IL, 60201, United States<br />
of America, ledelatorre@u.northwestern.edu, Irina Dolinskaya,<br />
Karen Smilowitz<br />
This talk presents our research in last mile operations of disaster relief distribution.<br />
In particular, we focus on how distribution problems are represented in operations<br />
research models and characteristics of distribution in practice. We discuss<br />
implications of problem assumptions in both modeling and implementation.<br />
INFORMS Austin – 2010<br />
384<br />
■ WA73<br />
H - Salon K, 6th Floor<br />
Supply Chain: Reverse Logistics, Cost of Quality<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Theresa Barker, PhD, University of Washington, Box 352650,<br />
Seattle, WA, 98115, United States of America,<br />
barkertj@u.washington.edu<br />
1 - Cost Sharing for Economic Lot-Sizing Problems with<br />
Remanufacturing Options<br />
Mohan Gopaladesikan, School of Industrial Engineering, Purdue<br />
University, 315 N. Grant Street, Grissom Hall 308, West Lafayette,<br />
IN, 47907, United States of America, mohang@purdue.edu,<br />
Nelson Uhan<br />
We consider a class of cooperative games that model the cost sharing issues that<br />
arise from the economic lot-sizing problem with remanufacturing options. By<br />
investigating the properties of various mathematical programming formulations and<br />
relaxations for the underlying lot-sizing problem, we obtain some insights into the<br />
existence of cost allocations in the core and the approximate core of these games, as<br />
well as the algorithmic aspects of computing such cost allocations.<br />
2 - Robust Design of Computer Remanufacturing and<br />
Recycling Facilities<br />
Suzanne Marcotte, Professor, Universite du Quebec a Montreal,<br />
315 rue Ste-Catherine Est, Montreal, QC, H2X 3X2, Canada,<br />
Suzanne.Marcotte@cirrelt.ca, Benoit Montreuil<br />
This presentation will describe the capacity planning of resources required in a<br />
computer remanufacturing and recycling facility. It will describe the generic process<br />
and the operations and decisions to be taken. Each operation of this process is<br />
characterized by sources of uncertainty and variability. It will then present results<br />
on the capacity required given various level of uncertainty.<br />
3 - Integrating Cost of Quality in Supply Chain Modeling:<br />
A Preliminary Study<br />
Krystel K. Castillo-Villar, Texas Tech University-Tecnologico de<br />
Monterrey, Box 43061, Lubbock, TX, 79409-3061,<br />
United States of America, krystel.castillo@ttu.edu, Neale R. Smith,<br />
James L. Simonton<br />
This work presents a preliminary methodology to compute the cost incurred by<br />
various actors within the supply chain due to the cost of poor quality or cost of<br />
quality (CoQ). We consider a generic consumer goods supply chain, consisting of<br />
three tiers, namely suppliers, manufacturers, and retailers. The purpose of this work<br />
is to provide a guide to translate defect rates at supplier, manufacturing plant, and<br />
retailer to quality costs. The study recommends ways quality engineers can use the<br />
methodology to make decisions regarding investment in prevention activities,<br />
rework process, inspection, among others. The practical implications of this research<br />
are a better selection of suppliers and manufacturing plants based on quality and<br />
cost considerations and a better understanding of CoQ not just as an internal, but<br />
also as an external performance measure. The study offers insights based on the<br />
findings and provides guidelines for future research.<br />
■ WA74<br />
H - Room 602, 6th Floor<br />
Optimal Sensor Location and Deployment<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Yi-Chang Chiu, University of Arizona, Tucson, AZ,<br />
United States of America, chiu@email.arizona.edu<br />
1 - Permanent Traffic Counter Location Problem on<br />
Transportation Network<br />
Fatemeh Sayyady, Research Assistant, North Carolina State<br />
University, 2501 Stinson Drive, 208 Mann Hall, Raleigh, NC, 27695,<br />
United States of America, fsayyad@ncsu.edu, George List,<br />
Yahya Fathi, John Stone<br />
We consider the problem of determining an optimal placement for the traffic<br />
counters on a large-scale highway network, subject to a budget constraint. We<br />
formulate the problem as a mixed integer linear programming problem, and show<br />
that it has structural similarities with the p-median problem as well as the knapsack<br />
problem. A reasonably fast Lagrangian-heuristic approach is presented to solve large<br />
size instances of the problem where CPLEX fails to report optimal values.
2 - Traffic Sensor Deployment Under Probabilistic Disruptions and<br />
Generalized Surveillance Effectiveness Measures<br />
Xiaopeng Li, University of Illinois at Urbana-Champaign, B156<br />
Newmark Civil Engineering Laborator, 205 N. Mathews Ave,<br />
Urbana, IL, 61821, United States of America, li28@illinois.edu,<br />
Yanfeng Ouyang<br />
We propose a reliable sensor location model to optimize surveillance effectiveness<br />
when sensors are subject to site-dependent probabilistic failures, and a general<br />
effectiveness measure is proposed to encompass most existing measures needed for<br />
engineering practice. We formulate a compact mixed-integer program and develop a<br />
variety of solution algorithms. We also propose alternative formulations in the form<br />
of reliable fixed-charge sensor location models.<br />
3 - A Continuum Approximation Approach to Reliable Traffic Sensor<br />
Deployment on Highway Corridors<br />
Xiaopeng Li, University of Illinois at Urbana-Champaign, B156<br />
Newmark Civil Engineering Laborator, 205 N. Mathews Ave,<br />
Urbana, IL, 61821, United States of America, li28@illinois.edu,<br />
Yanfeng Ouyang<br />
We propose a continuum approximation framework for the reliable deployment of<br />
traffic sensors to optimize surveillance effectiveness when sensors are subject to sitedependent<br />
probabilistic failures.<br />
4 - Optimal Advance Detector Location for Green Termination Systems<br />
on High Speed Isolated Intersections<br />
Lili Du, NEXTRANS Center, Purdue University, 2700 Kent Avenue,<br />
West Lafayette, IN, 47906, United States of America,<br />
ldu@purdue.edu, Anuj Sharma, Srinivas Peeta<br />
This model finds near-optimum solutions very efficiently, and results from the<br />
approximation method are shown to be very close to those from the discrete<br />
methods.<br />
<strong>Wednesday</strong>, 11:00am - 12:30pm<br />
■ WB01<br />
C - Ballroom D1, Level 4<br />
Planning for Uncertainty in Energy Systems<br />
Sponsor: Energy, Natural Resources and the Environment/ Energy<br />
Sponsored Session<br />
Chair: Sarah Ryan, Professor, Iowa State University, 3004 Black<br />
Engineering Bldg., Ames, IA, 50011-2164, United States of America,<br />
smryan@iastate.edu<br />
1 - Electric Power System Generation Expansion Planning Problems<br />
Considering Risk<br />
David Coit, Associate Professor, Rutgers University, Industrial &<br />
Systems Engineering, 96 Frelinghuysen Rd., Piscataway, NJ, 08854,<br />
United States of America, coit@rutgers.edu, Hatice Tekiner,<br />
Frank Felder<br />
GEP problems are solved to determine generation options to add and where/when<br />
to be constructed considering risk. In studies, decision makers are risk neutral; but<br />
often they are risk averse. We solve a multiobjective optimization problem to<br />
minimize cost and risk. We define a subset of scenarios to represent the stochastic<br />
nature. Multiobjective optimization problem is solved to find a Pareto Front.<br />
2 - Generation Expansion Portfolio Optimization with Stochastic<br />
Production Tax Credit for Wind Power<br />
Jo Min, Iowa State University, IMSE Department, 3004 Black,<br />
Ames, IA, 50011, United States of America, jomin@iastate.edu,<br />
Jin Lee, Chenlu Lou, Chung-Hsiao Wang<br />
We construct and analyze a generation expansion portfolio model consisting of<br />
conventional power plants and windmills. Specifically, a mean - variance utility<br />
function is optimized under the assumption that the fuel price, electricity price, and<br />
production tax credit for wind power are random variables. Via parametric quadratic<br />
programming, we analytically derive various managerial insights with respect to the<br />
degrees of risk aversion, renewable portfolio standards, and production capacities.<br />
3 - Computational Issues in Solving Large-Scale Stochastic Grid<br />
Expansion Problems<br />
Jean-Paul Watson, Sandia National Laboratories,<br />
jwatson@sandia.gov, David Woodruff<br />
Grid generation and transmission expansion problems are frequently expressed as<br />
stochastic mixed-integer programs, commonly multi-stage due to long-term<br />
planning horizons. However, these models are very difficult to solve, due to multiple<br />
exogenous uncertainty sources and scenario tree depth. We investigate the issue of<br />
decomposition solver performance on such problems, focusing on Progressive<br />
Hedging. Computational results and solution strategies are reported for several test<br />
problems.<br />
INFORMS Austin – 2010 WB02<br />
385<br />
4 - Scenario Reduction Methods for Rolling Stochastic Energy<br />
Planning Programs<br />
Yan Wang, PhD Student, Iowa State University, 3004 Black<br />
Engineering, Ames, IA, 50010, United States of America,<br />
yanwang@iastate.edu, Sarah Ryan<br />
A medium-term fuel procurement and electricity generation planning problem is<br />
naturally solved as a rolling horizon series of stochastic programs with evolving fuel<br />
price forecasts. We examine the accuracy and computational efficiency of a scenario<br />
reduction heuristic that emphasizes the initial decision rather than the distribution<br />
of scenarios.<br />
■ WB02<br />
C - Ballroom D2, Level 4<br />
Risk Management & Stochastic Programming in<br />
Gas and Power Systems<br />
Cluster: Energy: Modeling the Interface Between Markets<br />
and Operations<br />
Invited Session<br />
Chair: Qipeng Phil Zheng, Assistant Professor, West Virginia University,<br />
Industrial & Management Systems Eng, P.O. Box 6070, Morgantown, WV,<br />
26505, United States of America, Qipeng.Zheng@mail.wvu.edu<br />
1 - Forecasting PHEV Sales and Recharging Activities<br />
Lizhi Wang, Iowa State University, 3016 Black Engineering, Ames,<br />
IA, 50014, United States of America, lzwang@iastate.edu,<br />
Zhaoyang Duan, Brittni Gutierr<br />
Sales of plug-in hybrid electric vehicles (PHEVs) and PHEV users recharging<br />
behavior are two critical factors for studying the potential impact of PHEVs on<br />
electric power systems. We present novel approaches to making more accurate and<br />
revealing forecasts of these factors. We will forecast the sales of PHEVs as a function<br />
of several interacting sub-factors, and forecast PHEV users’ recharging behavior as a<br />
function of available recharging infrastructures.<br />
2 - Identification and Prevention for Blackout on Large-scale<br />
Power Grid<br />
Hongsheng Xu, University of Florida, 303 Weil Hall, P.O. Box<br />
116595, Gainesville, FL, 32611, United States of America,<br />
xuhongsh@ufl.edu<br />
A blackout is the situation where there is a total loss of power to a relatively wide<br />
area, and how to quickly identify it in the power grid is key to preventing it from<br />
cascading. In this paper, we are focusing on detecting the possible blackout using<br />
our proposed evaluation criteria and algorithms. The results above could lead to<br />
some strategy guidance for designing and operation power grid. A computational<br />
study is presented in which we apply our model to the simulated data sets.<br />
3 - Midterm Coordination of Natural Gas Storage and<br />
Power Generation<br />
Cong Liu, Postdoctor, Argonne national Laboratory, 9700 S. Cass<br />
Ave., Bldg 221, Argonne, IL, 60439, United States of America,<br />
liuc@anl.gov, Jianhui Wang, Mohammad Shahidehpour, Zuyi Li<br />
In this talk, we will investigate the midterm coordination of natural gas resources<br />
and power generation. The objective is to minimize the integrated social cost<br />
including cost of power and natural gas systems while satisfying their complex<br />
coupled network constraints. The original problem will be decomposed into subproblems<br />
for each week. Lagrangian relaxation will be used to relax weekly<br />
coupling constrains of gas storage reservoirs.<br />
4 - Expansion Planning Models for Combined Electricity and<br />
Natural Gas Systems<br />
Alexey Sorokin, University of Florida, 303 Weil Hall, P.O. Box<br />
116595, Gainesville, FL, United States of America, sorokin@ufl.edu,<br />
Vladimir Boginski, Qipeng Phil Zheng<br />
Natural gas is playing an increasingly important role in global energy market<br />
because of its environment friendly properties, especially for electricity generation.<br />
We consider transmission expansion problem for gas and electricity networks, as<br />
well as for LNG terminal location planning. The multiple stage expansion model is<br />
proposed.
WB03<br />
■ WB03<br />
C - Ballroom D3, Level 4<br />
Environmental Legislation, Carbon Trading and Supply<br />
Chain Management<br />
Sponsor: Energy, Natural Resources and the Environment//Forestry<br />
Sponsored Session<br />
Chair: Eda Kemahlioglu-Ziya, University of North Carolina-Chapel Hill,<br />
CB#3490, Chapel Hill, NC, United States of America,<br />
Eda_KemahliogluZiya@unc.edu<br />
1 - Strategic Carbon Footprint Labeling in a Supply Chain<br />
Rob Zuidwijk, Rotterdam School of Management, P.O. Box 1738,<br />
Rotterdam, Netherlands, RZuidwijk@rsm.nl, Charles Corbett,<br />
Chien-Ming Chen<br />
When firms plan to put carbon footprint labels on their products, it is often not<br />
unambiguous how those carbon footprints should be determined. Current standards<br />
for carbon footprint reporting also leave room for ambiguity. This gives firms some<br />
flexibility in how to allocate carbon emissions to different products. In this paper,<br />
we examine conditions under which that flexibility in fact helps to reduce the firm’s<br />
total carbon footprint without compromising profits.<br />
2 - How Does Product Recovery Affect Quality Choice?<br />
Gilvan Souza, Associate Professor, Indiana University, Kelley School<br />
of Business, 1309 E 10th St, Bloomington, IN, 47401,<br />
United States of America, gsouza@indiana.edu, Atalay Atasu<br />
We study the impact of product recovery (remanufacturing or recycling) on product<br />
quality, where quality increases market valuation for the product. We find that the<br />
recovery cost structure and the presence of take-back legislation significantly impact<br />
quality. Product recovery can be welfare improving, underscoring benefits of<br />
environmental legislation.<br />
3 - The Effect of Remanufacturing on New Products<br />
Vishal Agrawal, Georgia Institute of Technology, 800 W Peachtree St<br />
NW, Atlanta, GA, United States of America,<br />
Vishal.Agrawal@mgt.gatech.edu, Atalay Atasu, Koert Van Ittersum<br />
In this paper, we experimentally investigate the effect of remanufactured products<br />
on the perceived value of new products. We incorporate this effect to analytically<br />
investigate an OEM’s strategy in the presence of competition from third-party<br />
remanufacturers. Our research shows that an OEM may not always benefit from<br />
preempting third-party remanufacturers. Instead, an OEM may find it more<br />
profitable to allow third-party competitors to remanufacture its products.<br />
4 - Complying with Take-Back Legislation: A Cost Comparison and<br />
Benefit Analysis of Compliance Schemes<br />
Gokce Esenduran, The Ohio State University, 2100 Neil Avenue,<br />
Columbus, OH, United States of America,<br />
esenduran_1@fisher.osu.edu, Eda Kemahlioglu-Ziya<br />
We compare three compliance schemes (i.e. individual, collective and collective with<br />
individual financial responsibility) that firms follow to comply with take-back<br />
legislations. We model each scheme as a two-stage Nash game and find the key<br />
market/operating conditions that make one preferable to the others. As the most<br />
cost effective scheme may fall short on environmental benefits, i.e. collection<br />
rate\treatability level, we identify how environmental benefits compare between the<br />
three schemes.<br />
■ WB04<br />
C - Ballroom D4, Level 4<br />
Decision Analysis III<br />
Contributed Session<br />
Chair: Rebeca Díaz, Full Time Teacher, Technological Institute of Superior<br />
Studies of Coacalco, Av. 16 de septiempre No. 54, Cabecera, Municipal,<br />
Coacalco, Edo, de México, México D.F., 55700, Mexico,<br />
rbkdiazt@hotmail.com<br />
1 - Integrated Multi-Time-Scale and Multi-Organizational-Scale<br />
Decision Making Model<br />
Christian Wernz, Assistant Professor, Virginia Tech, Industrial and<br />
Systems Engineering, 250 Durham Hall (0118), Blacksburg, VA,<br />
24061, United States of America, cwernz@vt.edu, Abhijit Deshmukh<br />
In organizations, hierarchically interacting agents make decisions at different time<br />
scales. Typically, higher level agents make decisions about strategic variables with<br />
lower frequency compared to lower level agents, which make decisions about<br />
operational variables more often. We develop a multiscale decision model for<br />
hierarchical agents, and present an analysis of three-level agent interactions.<br />
INFORMS Austin – 2010<br />
386<br />
2 - Selection of Talents Based on Decision Making Theory<br />
Shaikh Akhlaque-E-Rasul, Concordia University, 1515 St. Catherine<br />
West, Montreal, Canada, akhlaque1045@hotmail.com,<br />
Sudhir P. Mudur<br />
It is always a difficult task to select the best candidate from many. Sometimes,<br />
biased opinions may skew the selection process. To overcome any bias and to rank<br />
the candidates, we show how decision makers can apply the decision-making<br />
theory of material science, which was developed by D. H. Jee. In the present work,<br />
several case studies from our daily life that benefit from the use of this theory are<br />
presented.<br />
3 - Inclusion of Preference-Dependence in Multi-attribute<br />
Utility Theory (MAUT)<br />
Johannes Siebert, Akademischer Rat, University of Bayreuth,<br />
Lehrstuhl Prof. Schluechtermann, Universitaetsstr. 30, Bayreuth,<br />
95440, Germany, Johannes.Siebert@uni-bayreuth.de<br />
Decision makers express preferences -here considered as factors- as ratios to<br />
averages of the alternative. A Taylor expansion of the product of these factors yields<br />
first and higher order terms. The former depend on each one preference only<br />
whereas the later depend on two or more preferences and are used to model<br />
dependencies. The new model is termed aggregate utility factor model (AUFM). In a<br />
computer-based experiment practicability and consistence in decision making are<br />
confirmed.<br />
4 - CUT: A New Multi-criteria Approach for Non-additive<br />
Concavifiable Preferences<br />
Nikolaos Argyris, London School of Economics and Political Science,<br />
Houghton Street, London, N1 0HP, United Kingdom,<br />
n.argyris@lse.ac.uk, Jose Figueira, Alec Morton<br />
We propose a new multi-criteria approach for concavifiable preferences: Concave<br />
UTility (CUT). CUT defines a space of value functions consistent with a DM’s<br />
expressed preferences. CUT has analogies with existing aggregation-dissagregation<br />
approaches, e.g. the UTA procedure, however CUT is more general as it does not<br />
require that preferences are additive. We describe how CUT can be used in an<br />
interactive setting: pre-ordering a finite set of discrete alternatives and multi-criteria<br />
optimization.<br />
5 - Studying the Effect of Improved Individual Skills in Negotiation and<br />
Collective Decision Making<br />
Rebeca Díaz, Full Time Teacher, Technological Institute of Superior<br />
Studies of Coacalco, Av. 16 de septiempre No. 54, Cabecera,<br />
Municipal, Coacalco, Edo, de México, México D.F., 55700, Mexico,<br />
rbkdiazt@hotmail.com, Leopoldo Viveros, Mario Chew<br />
Some questions about group decision making relate to the skills of the members, for<br />
instance: Does the group make better decisions than those of its most skilled<br />
member? If the members do not share objectives, how the skills at decision making<br />
and negotiation influence the decision? To study these issues we developed an<br />
environment in which the skills of each member can be controlled, using a<br />
simulated job-sequencing problem as a benchmark and final year engineering<br />
students as subjects.<br />
■ WB05<br />
C - Ballroom D5, Level 4<br />
Stochastic Optimization<br />
Contributed Session<br />
Chair: Asad Ata, Southern Methodist University, P.O. Box: 750123,<br />
Dallas, TX, 75275-0122, United States of America, ata.asad@gmail.com<br />
1 - Equity Valuation and Debt Selection via Stochastic Programming<br />
Davi Valladao, PhD Student, Pontifical Catholic University of Rio de<br />
Janeiro, Rua Marqu’s de São Vicente, 225, Rio de Janeiro, RJ,<br />
22451-041, Brazil, davimichel@gmail.com, Geraldo Veiga,<br />
Alvaro Veiga<br />
We develop a multistage stochastic programming model for equity valuation and<br />
debt selection for a firm with a predetermined project portfolio. We consider fixed<br />
and floating interest rate debt with different maturities. Moreover, the price of each<br />
corporate bond is given by a risk free valuation multiplied by a discount factor. We<br />
assume this factor to be a concave piecewise linear function of the new debt issued,<br />
with each segment based on different leverage rate levels.<br />
2 - On a Class of Stochastic Programs with Endogenous Uncertainty:<br />
Algorithm and Applications<br />
Bruno Flach, PSR, Praia de Botafogo 228/1701, Rio de Janeiro,<br />
22260020, Brazil, bruno@psr-inc.com<br />
We study a class of stochastic programming problems in which the probability<br />
distribution of the random parameters is decision-dependent. We propose a<br />
convexification technique coupled with a cut-generation algorithm for the MINLP<br />
formulation and the incorporation of importance sampling concepts into the<br />
stochastic programming framework so as to allow the solution of large instances.<br />
The applicability of our methodology is illustrated by an example in the area of<br />
power systems’ reliability.
3 - A Stochastic Programming Model for Seasonal View Selection<br />
Problem in Database Management Systems<br />
Rong Huang, Research Assistant, North Carolina State University,<br />
484 Daniels Hall, Campus Box 7913, Raleigh, NC, 27695-7913,<br />
United States of America, rhuang@ncsu.edu, Rada Chirkova,<br />
Yahya Fathi<br />
We introduce the stochastic seasonal view selection problem with random query<br />
sets, and model it as a two-stage stochastic integer programming problem. We<br />
propose exact and inexact methods for solving the problem and present the results<br />
of a computational experiment.<br />
4 - A New Hybrid Method for Solving Multistage Stochastic<br />
Programming Problems<br />
Nezir Aydin, Research Assistant, Wayne State University, 4815<br />
Fourth Street, Room: 1067, Detroit, MI, 48202, United States of<br />
America, aydin@wayne.edu, Alper Murat, Leslie Monplaisir<br />
In this study, we propose a creative way of combining the Progressive Hedging<br />
Algorithm (PHA) and Sampling Average Approximation (SAA) methods for solving<br />
multi-stage Stochastic Programming (SP) problems such that the exactness and<br />
speed of attaining a solution can be traded-off. Through extensive experimental<br />
results, we demonstrate the effectiveness of this hybrid approach over the pure<br />
strategies (SAA or PHA only) under specific circumstances using multi-product lotsizing<br />
problem.<br />
5 - An LP Based State Space Approach to Stochastic Dynamic<br />
Programming Problem<br />
Asad Ata, Southern Methodist University, P.O. Box: 750123, Dallas,<br />
TX, 75275-0122, United States of America, ata.asad@gmail.com,<br />
Eli Olinick, Chester Chambers, Eli Snir<br />
A linear programming (LP) approach is discussed to solve a stochastic dynamic<br />
programming (SDP) problem. An attempt is made to alleviate the curse of<br />
dimensionality by formulating the problem as a discrete time, infinite horizon,<br />
stochastic dynamic programming model with a finite state space. The model results<br />
as an instance of Unichain Markov Decision Process. The LP produces a profit<br />
maximizing policy and states the likelihood the resulting markov system is in any<br />
particular state.<br />
■ WB06<br />
C - Ballroom E, Level 4<br />
Tutorial: Robust Vehicle Routing<br />
Cluster: Tutorials<br />
Invited Session<br />
Chair: Fernando Ordonez, Associate Professor, University of Southern<br />
California, Department of Industrial and Systems Eng, 3715 McClintock<br />
Ave, Los Angeles, CA, 90007, United States of America, fordon@usc.edu<br />
1 - Robust Vehicle Routing<br />
Fernando Ordonez, Associate Professor, University of Southern<br />
California, Department of Industrial and Systems Eng, 3715<br />
McClintock Ave, Los Angeles, CA, 90007, United States of America,<br />
fordon@usc.edu<br />
Vehicle routing problems in many industrial applications must take into account<br />
uncertain demand, traffic conditions and/or service times. In this tutorial we present<br />
recent work on the use of robust optimization for vehicle routing problems (VRP)<br />
under uncertainty. We outline different robust VRP models, depending on the<br />
formulation, source of the uncertainty, and correlation in the uncertainty.<br />
Furthermore, we discuss previous computational results that illustrate when such a<br />
robust model is convenient and when it is not. We show with results in two<br />
different applications that robust optimization is useful to find a routing plan when<br />
routes will be adapted to the outcome of the uncertainty.<br />
■ WB07<br />
C - Ballroom F & G, Level 4<br />
Supply Chain, Closed-loop I<br />
Contributed Session<br />
Chair: Sameer Kumar, Professor of Operations and Supply Chain<br />
Management, Opus College of Business, University of St. Thomas,<br />
Mail # TMH 343, 1000 LaSalle Avenue, Minneapolis, MN, 55403-2005,<br />
United States of America, skumar@stthomas.edu<br />
1 - Analysis of Bullwhip Effect Under Retailer and Customer<br />
Forecasting with Price-sensitive Demand Function<br />
Yungao Ma, School of Management, Xi’an Jiaotong University,<br />
Shaanxi, China, 710049, Xi’an, 710049, China,<br />
ma.gao@stu.xjtu.edu.cn, Zhiping Yuan, Yufei Huang<br />
In a single two-stage supply chain with one supplier and one retailer, we analyze<br />
the impact of demand forecast by retailer and price forecast by customers on<br />
INFORMS Austin – 2010 WB08<br />
387<br />
Bullwhip Effect (BWE) under moving average (MA) and exponential smoothing<br />
(ES) forecasting methods. Results show that: first, demand forecast can reduce BWE<br />
under price-sensitive demand function; second, price forecast can reduce BWE<br />
under certain conditions when customers consider price fluctuation; besides, BWE<br />
under ES is not always significant compared to that under MA.<br />
2 - Product Recoveries in China: Remanufacturing vs. Refurbishing<br />
Yao Chen, Shanghai Jiaotong University, No.535 Fahua Road,<br />
Shanghai, Shanghai, China, yaochen514@msn.com, Fangruo Chen<br />
The markets for recovered products in China consist of both remanufactured and<br />
refurbished products, where the former must match the quality limit. Relative to<br />
new products, the two type of recovered products enjoy a cost advantage, but suffer<br />
from a lower willingness-to-pay by the consumers. We characterize the equilibrium<br />
market structure when all the three products compete with each other with a<br />
emphasis on the conditions under which the remanufacturing products can survive<br />
the competition.<br />
3 - Variable-level Disassembly Planning for Facilitating<br />
Remanufacturing Between Different Products<br />
Yoo S. Hong, Associate Professor, Seoul National University, 599<br />
Kwanakro, Kwanakgu, Seoul, Korea, Republic of, yhong@snu.ac.kr,<br />
Changmuk Kang<br />
In order to resolve the mismatch between return supply of end-of-life (EOL)<br />
products and demand of a new product, an EOL product has to be disassembled and<br />
remanufactured at a part level, and used for producing a different product. This<br />
study solves a problem of planning disassembly of different kinds of products of<br />
which return and demand change over time. Each product is disassembled into<br />
variable levels according to its return and demand of serviceable parts.<br />
4 - Closed Loop Supply Chains for U.S., Japan and EU Auto Industries<br />
- A System Dynamics Study<br />
Sameer Kumar, Professor of Operations and Supply Chain<br />
Management, Opus College of Business, University of St. Thomas,<br />
Mail # TMH 343, 1000 LaSalle Avenue, Minneapolis, MN, 55403-<br />
2005, United States of America, skumar@stthomas.edu<br />
System Dynamics analysis of the U.S., Japan and EU auto industries’ reverse value<br />
chains was conducted to explore the impact of government regulations, financial<br />
incentives and market pricing for remanufactured and recycle materials on cash<br />
flows and use of such raw materials for car manufacturers in these three market<br />
segments.<br />
■ WB08<br />
C - Room 11A, Level 4<br />
Location Modeling Applications<br />
Sponsor: Location Analysis<br />
Sponsored Session<br />
Chair: Rajan Batta, Professor and Associate Dean, University at Buffalo<br />
(SUNY), Department of Industrial & Systems Engg, 438 Bell Hall, Buffalo,<br />
NY, 14260, United States of America, batta@buffalo.edu<br />
1 - Ambulance Location, Relocation and Relocation with<br />
Uncertainty Models<br />
Bo Zeng, Assistant Professor, University of South Florida,<br />
Department of IMSE, Tampa, FL, 33620, United States of America,<br />
bzeng@usf.edu, Shengyong Wang<br />
Various location models for ambulances have been extensively studied. In this talk,<br />
we first present a dynamic relocation model that could be combined with any<br />
existing location models. Then, a stochastic relocation model that includes request<br />
uncertainties will be presented. Finally, numerical study will be given to show the<br />
effectiveness of those models on response times in difference situations.<br />
2 - Centralized Dispatch Approximation for the Transshipment Problem<br />
Dmitry Krass, Professor, University of Toronto, Rotman School of<br />
Management, 105 St. George Street, Toronto, ON, M5S 3E6, Canada,<br />
Krass@Rotman.Utoronto.Ca, Alex Shlakhter<br />
In the transshipment problem a number of retailers facing stochastic demand must<br />
place orders before the demand is known, but can transship inventory once the<br />
demand is realized. We show that by assuming a central depot through which all<br />
transshipments must flow, the computations of the (approximately) optimal<br />
ordering policy are greatly simplified. Moreover, the performance of the<br />
approximate policy is excellent. We also analyze and obtain analytical results for the<br />
monotone policy case.
WB09<br />
3 - Facility Location Problem with Network Oligopoly<br />
Paul Berglund, University at Buffalo, 786 West Ferry Street, Buffalo,<br />
NY, 14222, United States of America, berglund@buffalo.edu,<br />
Changhyun Kwon<br />
We formulate an equilibrium facility location problem on a discrete network, where<br />
the locating firm acts as the leader in a Stackelberg-Nash-Cournot competitive<br />
equilibrium problem. To maximize expected profits the locating firm must solve a<br />
problem with equilibrium constraints. Finding an optimal solution is hard for large<br />
problems. Therefore a heuristic solution procedure based on simulated annealing is<br />
presented.<br />
4 - Locating Temporary Depots to Facilitate a Post-Disaster Relief<br />
Operation: A Case Study<br />
Yen-Hung Lin, PhD Candidate, University at Buffalo (SUNY), 438<br />
Bell Hall, Buffalo, NY, 14260, United States of America,<br />
yl48@buffalo.edu, Peter Rogerson, Alan Blatt, Marie Flanigan, Rajan<br />
Batta<br />
A case study through HAZUS simulation software of a historical earthquake scenario<br />
is used to evaluate the performance of a disaster relief operation with a distributed<br />
supply strategy. The distributed supply strategy locates several temporary depots in<br />
the area impacted by a recent earthquake event so that demand can be fulfilled by<br />
either temporary depots or the central depot. The items being supplied are of three<br />
categories (water, food and medicine) and have different priorities.<br />
■ WB09<br />
C - Room 11B, Level 4<br />
Behavioral Issues<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Mirko Kremer, Pennsylvania State University, 460 Business<br />
Building, State College, PA, 16802, United States of America,<br />
Mirko.Kremer@psu.edu<br />
1 - Explanations of Newsvendor Biases Do Not Square<br />
Neil Bearden, Assistant Professor, INSEAD, 1 Ayer Rajah Ave,<br />
Singapore, 138636, Singapore, Neil.BEARDEN@insead.edu,<br />
Sameer Hasija<br />
We show that now-conventional explanations of biases in newsvendor experiments<br />
do not hold up to close scrutiny. The accounts implicitly assume that decision<br />
behaviour is invariant with respect to problem framing, but we show that order<br />
quantities are strongly contingent on the way the problem is presented. Finally, we<br />
argue for an eliminitavist stance on explanation in behavioural operations: the<br />
attempt to give simple accounts of decision behaviour in complex problems should<br />
be abandoned.<br />
2 - On the Ability to Identify Pareto-improving Supply Contracts<br />
Mirko Kremer, Pennsylvania State University, 460 Business Building,<br />
State College, PA, 16802, United States of America,<br />
Mirko.Kremer@psu.edu, Tony Haitao Cui<br />
Formal analyses of risk-sharing supply contracts typically focus on identifying<br />
contracts that induce maximal channel efficiency, while allowing for a flexible<br />
allocation of channel profits. As a first step toward a better understanding of the<br />
bargaining process toward such Pareto contracts, we investigate empirically how<br />
sellers and buyers choose from sets of contracts. We further explore how the ability<br />
to identify Pareto-improvements is sensitive to the framing of the contract.<br />
3 - Revenue Sharing versus Buyback Contracts: Influence of<br />
Supplier Preferences<br />
Karen Donohue, Associate Professor, University of Minnesota,<br />
Carlson School of Management, Minneapolis, MN, United States of<br />
America, donoh008@umn.edu, Yinghao Zhang, Tony Haitao Cui<br />
Prior analytical research shows that buyback and revenue sharing contracts achieve<br />
equivalent channel-coordinating solutions when applied in a single supplier-buyer<br />
setting. More recently, behavioral research suggests that the two contracts do not<br />
always perform equivalently. We examine how supplier preferences, such as loss<br />
aversion and time discounting, can lead suppliers to prefer one contract type over<br />
the other depending on the ratio of overage and underage costs.<br />
4 - Product Quality Choice and Inventory Risk Under Strategic<br />
Consumer Behavior<br />
Robert Swinney, Assistant Professor, Stanford University, 518<br />
Memorial Way, Stanford, CA, 94305-5015, United States of America,<br />
Swinney_Robert@GSB.Stanford.Edu, Sang-Hyun Kim<br />
We analyze a model in which a firm selling a single, seasonal product sets both<br />
product quality and quantity before selling to a population of forward-looking<br />
customers. The size of the market is uncertain to the firm, and customers anticipate<br />
the price path of the product and may strategically delay a purchase to pay a lower<br />
price. We consider the impact of both demand uncertainty and customer behavior<br />
on the optimal quality and quantity of the product.<br />
INFORMS Austin – 2010<br />
388<br />
■ WB10<br />
C - Room 12A, Level 4<br />
Managing the Distribution Channel with Competing<br />
Products and Supply Risk<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Yunzeng Wang, University of California-Riverside, A. Gary<br />
Anderson Graduate School of Mgmt, Riverside, United States of America<br />
1 - Split Award Auctions for Supplier Retention<br />
Aadhaar Chaturvedi, IESE Business School, Av. Pearson 21,<br />
Barcelona, Spain, achaturvedi@iese.edu, Damian Beil,<br />
Victor Martinez de Albeniz<br />
Traditionally, buyers use auctions select the lowest-cost supplier. By doing so, they<br />
might alienate the losing suppliers. This involves a future cost of supplier<br />
qualification if they defect from the supply base. This paper considers the trade-off<br />
between the purchasing cost and the qualifying cost paid to maintain the supply<br />
base. We find the optimal split award that minimizes long-run costs and the optimal<br />
supply base size that the buyer should maintain.<br />
2 - Nature of Coordination Contracts for Supply Chain Management:<br />
Classifications and Structural Results<br />
Meng Lu, The Chinese University of HK, Shatin, N.T., Hong Kong,<br />
China, mlu@se.cuhk.edu.hk, Houmin Yan, Suresh Sethi<br />
In this paper, based on the group decision-making and game theory, we define a<br />
framework for supply chain contracts and classify into groups. With precise<br />
mathematical definitions, and subsequently developed structural properties and<br />
sufficient conditions, we are not only able to measure the goodness of supply<br />
contracts but also to reveal the nature of the supply coordination. We develop<br />
indexes to measure coordination contracts in terms of coordination strength and<br />
decision sequence dependency.<br />
3 - Heterogeneous and Nonlinear Frontier Analysis: Supply-Chain<br />
Transaction Cost Perspective<br />
John Liu, Chair Professor, Hong Kong PolyU, CD 401b, Kowloon,<br />
Hong Kong - PRC, lgtjliu@polyu.edu.hk, Jason Jianfeng Mao<br />
Inspired by the works of Williamson (2008), transaction cost economics of supply<br />
chain management is emerging as a challenging research area, due to heterogeneity<br />
and non-linearity of transaction costs as incurred in outsourcing operations of SCM.<br />
We herein develop a degenerative frontier model which incorporates both<br />
heterogeneity and nonlinearity. We obtain convexity properties, and develop a<br />
solution method which converts a DF problem into a sequence of convex problems.<br />
■ WB11<br />
C - Room 12B, Level 4<br />
Empirical Research in Operations Management<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Vishal Gaur, Associate Professor, Johnson School, Cornell<br />
University, 321 Sage Hall, Ithaca, NY, 14850, United States of America,<br />
vg77@cornell.edu<br />
1 - The impact of New Product Introduction on Plant Productivity in the<br />
NA Automotive Industry<br />
Serguei Netessine, Professor, INSEAD, Boulevard de Constance,<br />
Fontainebleau, 77305, France, serguei.netessine@insead.edu, Manu<br />
Goyal, Anand Gopal, Matthew Reindorp<br />
We empirically estimate productivity losses during new product introductions in the<br />
automotive industry. We show that productivity losses can be mitigated through<br />
manufacturing flexibility and different forms of organizational learning.<br />
2 - An Empirical Study of Pricing in the U.S. Automobile Industry<br />
Antonio Moreno, The Wharton School, 3730 Walnut St,<br />
Philadelphia, United States of America, amore@wharton.upenn.edu,<br />
Gerard Cachon, Christian Terwiesch<br />
Despite the abundant theoretical literature on dynamic pricing, price postponement<br />
and operational flexibility, there is limited empirical evidence on how firms actually<br />
adjust their prices, and how operational practices play a role in their pricing<br />
decisions. Using a detailed transactional dataset of the US auto industry, we study<br />
the impact of operational strategic decisions on pricing.
3 - Improving Retail Store Performance by Incorporating Traffic<br />
Characteristics in Labor Planning<br />
Vidya Mani, The University of North Carolina at Chapel Hill,<br />
The Kenan-Flagler Business School, Chapel Hill, NC, 27599,<br />
United States of America, vidya_mani@unc.edu, Saravanan Kesavan,<br />
Jayashankar Swaminathan<br />
Managing store labor is critical to improving customer service as well as controlling<br />
costs for retailers. Using data from a large retailer, we show how labor planning can<br />
be improved by incorporating store traffic characteristics in managerial staffing<br />
decisions.<br />
4 - An Empirical Estimation of the Impact of Airline Flight Schedules on<br />
Flight Delays<br />
Vinayak Deshpande, Purdue University, 100 S. Grant St,<br />
West Lafayette, IN, 47907, United States of America,<br />
vinayak@purdue.edu, Mazhar Arikan<br />
Airline flight delays have come under increased scrutiny lately, with FAA data<br />
revealing that airline on-time performance was at its worst level in 13 years in<br />
2007. Our goal is to examine the impact of the scheduled time block allocated for a<br />
flight on on-time arrival performance. We combine empirical flight data published<br />
by BTS, with the Newsvendor framework from the Operations literature to conduct<br />
this analysis. Our results show that airlines systematically under-schedule flights.<br />
■ WB12<br />
C - Room 13A, Level 4<br />
Emerging Topics in Supply Chain Management<br />
Sponsor: Manufacturing and Service Operations Management/<br />
Supply Chain<br />
Sponsored Session<br />
Chair: Tingting Cui, University of California-Berkeley, Berkeley, CA,<br />
United States of America, tingting@ieor.berkeley.edu<br />
1 - Modeling and Mitigating the Effects of Supply Chain Disruption<br />
on Wargames<br />
Shilan Jin, SUNY at Buffalo, 435 Bell, SUNY at Buffalo,<br />
North Campus, Amherst, NY, 14260, United States of America,<br />
sjin6@buffalo.edu, Zigeng Liu, Jun Zhuang<br />
We integrate supply chain risk management with a government-terrorist game in<br />
war zones. The equilibrium outcomes of wargames depend on the government’s<br />
resources delivered through military supply chains, which are subject to disruptions.<br />
We study the government’s optimal pre-disruption strategies, including inventory<br />
protection, capacity backup protection and the combination.<br />
2 - Asymmetries of the Pull-to-Center Effect in the<br />
Newsvendor Experiments<br />
Tianhu Deng, PH. D student, UC, Berkeley, IEOR Department, 4141<br />
Etcheverry Hall, Mail Code 1777, Berkeley, United States of America,<br />
tianhu_deng@berkeley.edu<br />
It has been frequently observed in newsvendor games, the subjects’ average order<br />
quantity lies in between the optimal order quantity and the mid-point of the<br />
demand, in both high profit and low profit settings. This phenomenon is called pullto-center<br />
effect. Some researchers found that the pull-to-center effect is stronger in<br />
the high-profit setting than the low profit setting while others found the opposite<br />
result. We present explanations for this discrepancy.<br />
3 - Impact of Social Contagion in Make-to-Stock and Make-to-Order<br />
Supply Chains<br />
Shan Li, Operations Research Scientist, Amazon.com, 605 5th<br />
Avenue South, Seattle, WA, 98104, United States of America,<br />
lisapine@berkeley.edu, Teck Ho, Z. Max Shen<br />
We first analyze the impact of social contagion in a make-to-stock supply chain. We<br />
show that an out-of-stock phenomenon that occurs earlier in a product’s life cycle<br />
always leads to a greater loss in a firm’s customer assets. We then analyze the<br />
impact of social contagion in a make-to-order spply chain. We demonstrate that a<br />
lengthy lead time can slow down social contagion, decelerate customer purchases,<br />
and thus significantly decrease a firm’s total customer assets.<br />
4 - Flexible Nonhomogeneous Supply Chain Design Under Supply<br />
Chain Disruptions<br />
Ye Xu, University of California-Berkeley, Berkeley, CA,<br />
United States of America, yex207@berkeley.edu, Z. Max Shen<br />
We look at the flexibility design problem of a general supply chain with unbalanced<br />
structure, and nonhomogeneous demands and suppliers. Besides demand<br />
uncertainty, supply disruption is also considered in our model. We discuss solution<br />
algorithms for a series of models, and show that the marginal value of flexibility<br />
does not diminish as capacity increases. Rather, more flexibility is encouraged when<br />
more capacity is available.<br />
INFORMS Austin – 2010 WB14<br />
389<br />
■ WB13<br />
C - Room 13B, Level 4<br />
Dynamically Managing Customer Loyalty and Learning<br />
Sponsor: Manufacturing and Service Operations Management/<br />
Service Management Special Interest Group<br />
Sponsored Session<br />
Chair: Dan Adelman, Professor, University of Chicago, 5807 South<br />
Woodlawn Ave., Chicago, IL, 60637, United States of America,<br />
dan.adelman@chicagobooth.edu<br />
1 - Dynamic Capacity Allocation to Customers Who Remember<br />
Past Service<br />
Adam Mersereau, University of North Carolina, Kenan-Flagler<br />
Business School, Chapel Hill, NC, United States of America,<br />
ajm@unc.edu, Dan Adelman<br />
We study the problem of a supplier dynamically allocating limited capacity among a<br />
portfolio of customers, where each customer’s orders depend positively on the fill<br />
rates provided to her in the past. Customers differ from one another in their<br />
contribution margins, their demand volatilities, and the length of their memories.<br />
We develop an approximate dynamic programming algorithm that rationalizes the<br />
fill rates the supplier should target for each customer.<br />
2 - Optimal Hiring and Retention Policies for Heterogeneous Workers<br />
with Learning<br />
Alessandro Arlotto, University of Pennsylvania, 3730 Walnut Street,<br />
500 Jon M. Hunstman Hall, Philadelphia, PA, 19104, United States<br />
of America, alear@wharton.upenn.edu, Stephen E. Chick,<br />
Noah Gans<br />
We study the hiring and retention of heterogeneous workers that learn over time.<br />
We formulate the problem as an infinite-armed bandit and characterize the optimal<br />
hiring and retention policy in detail. We develop approximations that allow the<br />
efficient implementation of the optimal policy and the evaluation of its<br />
performance. We present numerical examples that show, among other things, that<br />
the active screening and monitoring of employees leads to substantial gains.<br />
3 - Signaling Service Quality in Queues<br />
Senthil Veeraraghavan, Assistant Professor, Wharton School of<br />
Business, University of Pennsylvania, 3730 Walnut Street, Jon M.<br />
Huntsman Hall, Suite 500, Philadelphia, PA, 19104,<br />
United States of America, Senthilv@wharton.upenn.edu<br />
We study how a high quality service firm signals quality to differentiate from a low<br />
quality firm through expensive signaling efforts. Rational consumers try to learn<br />
quality through these imperfectly advertised signals. Their decisions are based on<br />
signaling efforts of the firms, congestion in the market, and the service value. We<br />
show that it is likely that a high quality firms may incur lower revenues due to<br />
signaling efforts.<br />
■ WB14<br />
C - Room 14, Level 4<br />
Supply Chain Management IX<br />
Contributed Session<br />
Chair: Nomesh Bolia, Dr, IIT Delhi, #276 Block III, IIT Delhi, New Delhi,<br />
DL, 110016, India, nomesh@mech.iitd.ac.in<br />
1 - Measurement and Optimization of Supply Chain Responsiveness<br />
Sin-Hoon Hum, National University of Singapore, NUS Business<br />
School, 15 Kent Ridge Drive, Singapore, 119245, Singapore,<br />
bizhumsh@nus.edu.sg, Mahmut Parlar<br />
We consider make-to-order supply chains with multiple stages where each stage is<br />
completed in a random length of time. We define the responsiveness of such a<br />
supply chain as the probability that an order placed now will be fulfilled within t<br />
time units. We optimize the responsiveness of the supply chain by maximizing the<br />
probability that the order will be fulfilled within some promised time interval<br />
subject to a budget constraint.<br />
2 - Behavior of a Remanufacturing System in Presence of Varying<br />
Suppliers Reliability for New Product<br />
Suman Niranjan, Assistant Professor, Savannah State University,<br />
College of Business Administration, 3219 College Street, Savannah,<br />
GA, 31404, United States of America, suman1130@gmail.com<br />
In this paper we study a two-echelon remanufacturing system, which focuses on<br />
what should be the right mix of new and remanufactured components used in the<br />
manufacturing of a new product, and why should we care about the mix?.<br />
Moreover we study this problem in the presence of unreliable suppliers for new<br />
component. We analyze the performance of the system initially by developing a set<br />
of dynamic equations used in simulation based optimization framework.
WB15<br />
3 - The Analysis of Performance in One Single and Dual Channels<br />
Zhaoqiong Qin, Associate Professor, North Carolina A&T State<br />
University, 1601 E. Market Street, Greensboro, NC, 27411,<br />
United States of America, zqin@ncat.edu<br />
Suppliers routinely decide whether to distribute their products through one single<br />
channel or dual channels. Conventional wisdom says that dual distribution channels<br />
outperform one single channel based on the whole supply chain’s performance in<br />
the capacity and the supplier’s profit. However, this paper finds that the channel<br />
structure including centralized and/or decentralized in the distribution plays an<br />
important role in these performances.<br />
4 - Fuzzy Logic Based Methods to Quantify Supply Chain Performance<br />
Nomesh Bolia, Dr, IIT Delhi, #276 Block III, IIT Delhi, New Delhi,<br />
DL, 110016, India, nomesh@mech.iitd.ac.in, Pranav Saxena,<br />
Jalaj Bhandari<br />
Globalization and dynamic market conditions have forced companies to focus on<br />
methods to evaluate the performance of their supply chains and improvise where<br />
needed. Hence there is an increasing interest in quantifying performance. However<br />
there are a lot of uncertainties in supply chain parameters (hence performance<br />
measures), and relative importance of these performance measures. We apply fuzzy<br />
logic to address these issues and develop an appropriate performance index for<br />
supply chains.<br />
■ WB15<br />
C - Room 15, Level 4<br />
Convex Optimization<br />
Contributed Session<br />
Chair: David Papp, Rutgers Center for Operations Research, 640<br />
Bartholomew Rd, Piscataway, NJ, 08854, United States of America,<br />
dpapp@rutcor.rutgers.edu<br />
1 - Convex Relaxation for the Planted k-disjoint-clique Problem<br />
Brendan Ames, PhD Candidate, University of Waterloo, 200<br />
University Avenue West, Waterloo, ON, N2L3G1, Canada,<br />
bpames@math.uwaterloo.ca, Stephen Vavasis<br />
We consider the k-disjoint-clique problem. For a given graph G, the problem is to<br />
find within the graph k disjoint cliques that cover the maximum number of nodes<br />
of G. The k-disjoint-clique problem is NP-hard, but we show that a convex<br />
relaxation can solve it in polynomial time for certain input instances. The input<br />
instances for which our algorithm finds the optimal solution consist of k disjoint<br />
large cliques that are then obscured by noise edges and noise nodes.<br />
2 - A Convexity Result for an (S-1,S) Inventory Model Under<br />
Time Limits on Backorders<br />
Emre Tokgoz, Emre.Tokgoz-1@ou.edu, Hillel Kumin<br />
The (S-1,S) inventory model with time limits on backorders has previously been<br />
solved by minimizing a function of two variables, one of which is integer. We<br />
investigate the convexity of the objective function and develop new convexity<br />
results for functions with m integer and n continuous variables.<br />
3 - A Holloway-Inspired Enhancement for the Frank-Wolfe Approach to<br />
the Convex Hull Problem<br />
Xinyu Wang, PhD Student, Southern Methodist University,<br />
P.O. Box 750123, Dallas, TX, 75275-0122, United States of America,<br />
xwang@smu.edu, Richard Helgason<br />
The extreme points of a convex hull can be found by using the Frank-Wolfe<br />
quadratic programming method. We investigate a novel Holloway-Inspired<br />
enhancement to the Frank-Wolfe method. The enhancement tries to avoid zigzag in<br />
the later stage of the projection point computation and gives us faster convergence.<br />
Experimental results indicate the enhancement leads to a significant speedup.<br />
4 - A Polyhedral Projection Method for Solving Variational Inequalities<br />
Sudhanshu Singh, PhD Student, UNC Chapel hill, UNC Department<br />
of STOR, B 44, hanes hall, CB# 3260, UNC Chapel Hill, Chapel hill,<br />
NC, 27599-3260, United States of America, sssingh@email.unc.edu,<br />
Shu Lu<br />
Most projection based methods for solving variational inequalities suffer from the<br />
drawback that the projection on a general convex set is not easy to find. This talk<br />
presents a projection method which replaces the feasible set by a polyhedral convex<br />
set in each iteration. The proposed algorithm uses (sub)gradient information to<br />
generate the polyhedron. It is easy to implement and its convergence is analyzed<br />
under some mild assumptions.<br />
INFORMS Austin – 2010<br />
390<br />
5 - Generalized Sum-of-squares Cones and Their Applications<br />
David Papp, Rutgers Center for Operations Research, 640<br />
Bartholomew Rd, Piscataway, NJ, 08854, United States of America,<br />
dpapp@rutcor.rutgers.edu, Farid Alizadeh, Ricardo Collado<br />
We consider the cone of sum-of-squares vectors with respect to an arbitrary bilinear<br />
multiplication in a finite dimensional space. We show that these cones are feasible<br />
sets of semidefinite optimization problems, extending Nesterov’s results on real<br />
valued sum-of-squares functions. Different choices of spaces and multiplications<br />
give rise to a diverse set of applications; we show a few in combinatorial<br />
optimization, geometric optimization, and shape-constrained statistical estimation.<br />
■ WB16<br />
C - Room 16A, Level 4<br />
Remanufacturing<br />
Contributed Session<br />
Chair: Pei-Fang Tsai, Assistant Professor, National Taipei University of<br />
Technology, 1, Sec. 3, Chung-hsiao E. Rd., Taipei, 10608, Taiwan - ROC,<br />
ptsai@ntut.edu.tw<br />
1 - Inventory Management in Closed-loop Supply Chains Under<br />
Non-stationary Demand<br />
Ibrahim Dogan, Wayne State University, Industrial & Manufacturing<br />
Engineering, 4815 Third Street, Detroit, MI, 48202, United States of<br />
America, aq9742@wayne.edu, Ratna Babu Chinnam<br />
This study aims to analyze remanufacturer’s inventory control policy under nonstationary<br />
demand. The objective is to decide on virgin product replenishment<br />
quantities under used product returns. The exact solution to this inventory control<br />
problem in our setting is complex and time demanding. We offer and analyze a<br />
number of different sub-optimal policies.<br />
2 - Used Product Returns Policy Under Demand and<br />
Return Uncertainty<br />
Samar Mukhopadhyay, Professor, SungKyunKwan University-GSB,<br />
53 Myungryun dong 3-ga, Jongno gu, Seoul, 110745, Korea,<br />
Republic of, samar@skku.edu, Robert Setaputra<br />
Reusing still usable components from a used up product makes sound<br />
environmental and economic sense. Uncertainty in the quantity of returns and<br />
demand complicates the operation. Our decision variable is the return policy,<br />
characterized by the amount refunded to the consumer. The trade-off is between<br />
increased revenue due to reduced input cost and increased cost due to higher return<br />
amount. Optimal return policy and managerial insights on sensitivity analyses will<br />
be presented.<br />
3 - Remanufacturing Planning with Variable Quality Returns<br />
Xiaoning Jin, PhD Student, University of Michigan, 2300 Hayward<br />
Street, Ann Arbor, MI, 48109, United States of America,<br />
xnjin@umich.edu, S. Jack Hu, Jun Ni<br />
There is a need for remanufacturers to grade quality of the returns prior to recovery<br />
processes because of the quality uncertainty of returns.Since some returns require<br />
more capacity and cost to bring the unit up to a required quality standard than<br />
others,quality variability information will have great impacts on remanufacturing<br />
decisions.We’ll develop a quality-dependent remanufacturing model to obtain the<br />
optimal control of the remanufacturing quantity that minimize the expected total<br />
cost.<br />
4 - Best Partial Disassembly Strategy for Retrievable<br />
End-of-Life Products<br />
Pei-Fang Tsai, Assistant Professor, National Taipei University of<br />
Technology, 1, Sec. 3, Chung-hsiao E. Rd., Taipei, 10608, Taiwan -<br />
ROC, ptsai@ntut.edu.tw<br />
A product reaches its end of life when it is malfunctioned or undesirable to the<br />
users. This research focuses on returned products in two categories: those are<br />
qualified to be repaired or remanufactured, and those can be retrieved for useable<br />
parts. The best partial disassembly strategy is proposed and formulated as a<br />
multicommodity flow problem with applicability established. The objective is to<br />
obtain maximum potential benefits inherent in the end-of-life production planning.
■ WB17<br />
C - Room 16B, Level 4<br />
Decision Making in Interdependent Systems<br />
Contributed Session<br />
Chair: Kash Barker, Lecturer, University of Oklahoma, 202 W. Boyd,<br />
Room 124, Norman, OK, 73019, United States of America,<br />
kashbarker@ou.edu<br />
1 - Decision Analysis Tool for Assessing Hurricane Impact on Regional<br />
Workforce Productivity<br />
Joost Santos, Assistant Professor, Engineering Management and<br />
Systems Engineering, The George Washington University,<br />
1776 G Street NW, Rm 164, Washington, DC, 20052,<br />
United States of America, joost@gwu.edu<br />
This research develops a workforce recovery model based on input-output analysis<br />
to estimate sector inoperability and economic losses. Based on our simulated<br />
hurricane scenarios, service sectors in Virginia suffer the largest workforce<br />
productivity impact-accounting for nearly 40% of the total economic losses.<br />
Sensitivity analysis of inoperability and loss reduction objectives can provide insights<br />
on identification and prioritization of critical workforce sectors to expedite disaster<br />
recovery.<br />
2 - Resilience Assessment and Improvement of Urban<br />
Infrastructure Systems<br />
Leonardo Dueñas-Osorio, Assistant Professor, Rice University, 6100<br />
Main Street, MS-318, Houston, TX, 77005, United States of America,<br />
leonardo.duenas-osorio@rice.edu, Min Ouyang<br />
This paper proposes an annual resilience metric, which reflects the capacity of<br />
infrastructure systems to resist, absorb and recover from all possible disruptive<br />
events. Taking the transmission power grid and gas transmission system of in Harris<br />
County, Texas, as an example, the effectiveness of different resilience improvement<br />
measures are analyzed and discussed. This study can provide insight and direction to<br />
design and retrofit resilient interdependent infrastructure systems.<br />
3 - Interdependency Models to Compare Industry Preparedness and<br />
Reactive Strategies to Disruptive Events<br />
Cameron MacKenzie, Graduate Student, Industrial Engineering,<br />
University of Oklahoma, 202 W. Boyd, Room 124, Norman, OK,<br />
73019, United States of America, cmackenzie@ou.edu, Kash Barker<br />
We use a risk-based interdependency model to quantify the effect of preparedness<br />
strategies such as maintaining inventory and the effect of reactive strategies such as<br />
choosing alternate transportation routes or different suppliers if a disruptive event<br />
occurs. We examine the conditions that incentivize industries to prepare for a<br />
disruptive event and how those decisions impact their reactions to a supply chain<br />
disruption. We deploy the model with a case study using actual commodity data.<br />
4 - Dynamic Analysis of Interdependent Inoperability in Multi-modal<br />
Transportation Networks<br />
Raghav Pant, Graduate Student, Industrial Engineering,<br />
University of Oklahoma, 202 W. Boyd, Room 124, Norman, OK,<br />
73019, United States of America, Raghav.Pant-1@ou.edu,<br />
Kash Barker<br />
We study time-dependent production losses to regions due to disruptions in<br />
important transportation facilities (e.g., ports), by integrating the Dynamic<br />
Inoperability Input-Output Model (DIIM) with a network queuing model. Network<br />
model-driven initial inoperability and recovery time estimates strengthen our ability<br />
to evaluate supply chain risk management options and enhance risk management<br />
decisionmaking. Examples using commodity flow data for inland port disruptions<br />
are illustrated.<br />
5 - Impact of Disasters on National Freight Flows<br />
Saniye Gizem Aydin, Graduate Student, Industrial Engineering,<br />
University of Oklahoma, 202 W. Boyd, Room 124, Norman, OK,<br />
73019, United States of America, gizemaydin@ou.edu,<br />
P. Simin Pulat, Guoqiang Shen, Manjunath Kamath, Ricki Ingalls<br />
Transportation systems are vulnerable to disasters and absolutely vital for the<br />
economy. There are relatively few studies concerning the regional freight flow<br />
impact of the disaster, even fewer on national impact. Northridge Earthquake,<br />
Hurricane Katrina and I-40 Bridge collapse cases are studied. A spatial input-output<br />
model, distance and traffic volume based changes are used for measuring the<br />
importance, and the influence on decision making within the interdependent freight<br />
flow environment.<br />
INFORMS Austin – 2010 WB19<br />
391<br />
■ WB18<br />
C - Room 17A, Level 4<br />
OR in Practice II<br />
Sponsor: CPMS, The Practice Section<br />
Sponsored Session<br />
Chair: Brian Lewis, Vice President, Professional Services, Vanguard<br />
Software, 1100 Crescent Green, Cary, NC, 27518, United States of<br />
America, brian.lewis@vanguardsw.com<br />
Co-Chair: Bjarni Kristjansson, President, Maximal Software, Inc., 933 N.<br />
Kenmore St., Suite 218, Arlington, VA, 22201, United States of America,<br />
bjarni@maximalsoftware.com<br />
1 - An Integrated Framework of Service Quality for Global Delivery of<br />
Contact Center Services<br />
Nanda Kambhatla, Senior Manager, Human Language Technologies,<br />
IBM India - Research, ‘D’ Block, Embassy Golf Links, Koramangala<br />
Inner Ring Road, Bangalore, 560071, India, kambhatla@in.ibm.com,<br />
Mayuri Duggirala, Ramana Polavarupu, Dinesh Garg<br />
We present a framework of provider-perceived service quality for contact center<br />
services, incorporating key dimensions of service quality based on interviews with<br />
service providers in contact center services. Our findings indicate that benchmarking<br />
and error management are significant provider-perceived dimensions of service<br />
quality in contact center services which predict business performance outcomes.<br />
Avenues for further research, as well as insights for research and practice are<br />
suggested.<br />
2 - Decision Support System for Continuous Production<br />
Krystsina Bakhrankova, Researcher, Institute of Technology and<br />
Society - Applied Economics, S. P. Andersens Veg 5, Box 4760<br />
Sluppen, Trondheim, 7465, Norway,<br />
Krystsina.Bakhrankova@sintef.no<br />
The paper develops a model-based decision support system (DSS) for a European<br />
chemical plant with a multi-stage continuous production process. The system<br />
comprises two modules - energy cost minimization and output maximization, where<br />
a gist of the two underlying formulations is presented. The planning tool is tested on<br />
real data instances - it reflects the essence of the researched production process,<br />
provides substantial energy cost savings and improved production capacity<br />
utilization.<br />
3 - Optimizing Long-range Plans at Novartis<br />
Brian Lewis, Vice President, Professional Services,<br />
Vanguard Software, 1100 Crescent Green, Cary, NC, 27518,<br />
United States of America, brian.lewis@vanguardsw.com<br />
Long-range strategic planning decisions are not easily modeled with classic<br />
optimization techniques. Using Monte Carlo simulation-based forecasting,<br />
simulation optimization, and grid computing, Vanguard Software built a drug<br />
development pipeline model for Novartis which forecasts long-range R&D<br />
performance and optimizes strategic decisions such as investments in new drugs. In<br />
our presentation, we discuss the underlying model, lessons learned, and other<br />
practical issues.<br />
■ WB19<br />
C - Room 17B, Level 4<br />
Revenue Management of Opaque and<br />
Non-traditional Channels<br />
Sponsor: Revenue Management and Pricing Section<br />
Sponsored Session<br />
Chair: Benjamin Marcus, Suffolk University, 8 Ashburton Place, Boston,<br />
MA, United States of America, bmarcus@suffolk.edu<br />
1 - Valuation of Opaque Products<br />
Leo MacDonald, Assistant Professor, Coles College of Business, KSU,<br />
Kennesaw, GA, United States of America, lmacdon4@kennesaw.edu,<br />
Benjamin Marcus<br />
Service providers (airlines, hotels, etc) often use opaque sales channels (Hotwire,<br />
Priceline) to increase revenues. A fundamental challenge for these providers is<br />
setting appropriate rates. Set rates too high and no purchase occurs; set rates too<br />
low and forgo the additional revenue. The focus of this research is to determine<br />
customer valuation of opaque versus non-opaque services through a choice<br />
experiment and develop a discrete-choice model to support the decision making<br />
process.
WB20<br />
2 - Pricing Opaque and Traditional Channels Jointly<br />
Benjamin Marcus, Suffolk University, 8 Ashburton Place, Boston,<br />
MA, United States of America, bmarcus@suffolk.edu<br />
Despite the benefits to both firms and consumers, there are distinct challenges to<br />
selling products through opaque channels. We develop a model of a service provider<br />
selling inventory across a traditional channel and an opaque channel in order to<br />
identify optimal pricing policies in this setting. In addition, we use this model to<br />
explore the effects that different characterizations of customer behavior and product<br />
commoditization on the opaque channel can have on these policies.<br />
■ WB20<br />
C - Room 18A, Level 4<br />
Pricing and Revenue Management I<br />
Contributed Session<br />
Chair: Craig Sorochuk, Assistant Professor of Decision Science, University<br />
of Wyoming, 1000. East University Avenue, Department of MGMT and<br />
MKT (#3275), Laramie, WY, 82071, United States of America,<br />
csorochu@uwyo.edu<br />
1 - HOT Lane Pricing for Revenue Generation and Congestion<br />
Management: An Analysis of Demand Responses<br />
Lin Qiu, Wilbur Smith Associates, 317 Center St. N, Vienna, 22180,<br />
United States of America, lin.w.qiu@gmail.com, Lei Zhang<br />
High Occupancy Toll Lane has attracted significant interests as a means for<br />
congestion management and revenue generation. Using combined stated-preference<br />
and revealed-preference data for the I-394 corridor, this study develops models to<br />
capture the inter-relationships between pricing schemes, travelers’ mode choices<br />
and dynamic attitudes towards HOT lanes. The estimated attitude and behavior<br />
changes form a reliable basis for projecting revenues and assessing congestion<br />
mitigation effects.<br />
2 - Market Share Characterization Through Scenario Analysis<br />
Amit Shinde, Research Associate, Arizona State University,<br />
699 S. Mill Avenue, Tempe, AZ, 85281, United States of America,<br />
amit.shinde@asu.edu, Mani Janakiram, George Runger<br />
The supply chain interactions within the high-technology industry are very<br />
complex. Multiple products with moderate differences in performance and price<br />
compete within the same market segment. We present data mining models for<br />
characterizing elements of such supply chains. These models are capable of<br />
assimilating knowledge from a variety of business scenarios, expert judgment and<br />
historical trends.<br />
3 - Designing Public Storage Warehouses with Customer Choice<br />
Yeming Gong, EM Lyon Business School, 23 Avenue Guy de<br />
Collongue, Ecully, France, gong@em-lyon.com<br />
Public storage is a booming industry. A major question is how to design public<br />
storage facilities to fit market segments to maximize revenue. This paper propose a<br />
method to design public storage warehouses with considering the choice behavior of<br />
customers. We solve the problem by column generation.<br />
4 - Computing Regulated Bertrand-Nash Equilibrium Prices Under<br />
Mixed Logit Demand<br />
William Morrow, Assistant Professor, Iowa State University, 2014<br />
Black Engineering Building, Ames, 50011, United States of America,<br />
wrmorrow@iastate.edu<br />
Bertrand-Nash equilibrium prices have been used to analyze mergers, new product<br />
introductions, and regulatory policy in large differentiated product markets. We<br />
present a framework with regulatory costs that may not be differentiable, as with<br />
the Corporate Average Fuel Economy Standards. Two nonsmooth fixed-point<br />
formulations of the first-order conditions are shown to provide reliable and efficient<br />
methods for computing equilibrium prices in a large-scale example from the<br />
automotive industry.<br />
5 - The Newsvendor Problem with Pricing and Secondary Revenues<br />
Craig Sorochuk, Assistant Professor of Decision Science, University of<br />
Wyoming, 1000. East University Avenue, Department of MGMT and<br />
MKT (#3275), Laramie, WY, 82071, United States of America,<br />
csorochu@uwyo.edu, John Wilson<br />
We present an expected profit model for a newsvendor who receives revenues from<br />
selling primary items as well as from selling secondary items that are only available<br />
if a primary item has already been purchased. Numerical examples are provided for<br />
a newsvendor whose primary items for sale are tickets to a performance event and<br />
whose secondary items for sale are concessions items, parking, etc.<br />
INFORMS Austin – 2010<br />
392<br />
■ WB21<br />
C - Room 18B, Level 4<br />
Green Supply Chain Management<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Vipul Jain, Assistant Professor, Indian Institute of Technology<br />
Delhi, Department of Mechanical Engineering, Indian Institute of<br />
Technology Delhi, New Delhi, 110016, India, vjain@mech.iitd.ac.in<br />
1 - A Green Approach to Supplier Selection<br />
Amit Kumar, Research Scholar, Indian Institute of Technology,<br />
Department of Mechanical Engineering, Delhi, New Delhi, India,<br />
akumar@icfi.com, Vipul Jain<br />
As the climate change movement gathers momentum, there’s a pressing need to<br />
assess suppliers based on their environmental performance along with other criteria.<br />
This paper proposes a comprehensive approach based on Data Envelopment<br />
Analysis with Carbon Footprint monitoring. The approach applies to heterogeneous<br />
suppliers and incorporates region specific emission compliance standards as well.<br />
Overall, it encourages suppliers to go green and cut down their emissions to survive<br />
the competition.<br />
2 - Carbon Footprint, Information Disclosure, and Shareholder Pressure<br />
Chien-Ming Chen, UCLA Institute of the Environment, La Kretz<br />
Hall, Suite 300, Box 951496, Los Angeles, CA, 90095, United States<br />
of America, cmchen@ioe.ucla.edu, Charles Corbett, Magali Delmas<br />
This study examines the causal relationship between corporate carbon efficiency,<br />
voluntary information disclosure, and shareholder’s pressure for greener business<br />
practices. Our analysis draws on the newly compiled direct and supply chain<br />
emission inventories of over 1000 public companies in North America. In the<br />
presentation we will present our preliminary findings.<br />
3 - Evaluation and Management on Logistics Carbon Emission<br />
Xiao Qing Wang, IBM Research, Building 19 Zhongguancun<br />
Software Park, Beijing, China, xqwangxq@cn.ibm.com, Jin Dong,<br />
Hongwei Ding, Minmin Qiu, Wei Wang<br />
Logistics carbon emission management is addressed and carbon emissions from<br />
several key operational stages in logistics industry are studied and evaluated. A<br />
general logistics carbon emission evaluation framework considering different<br />
transportation modes, different warehouses and different carry modes is proposed.<br />
Carbon emission evaluation methods on transportation, storage and carry<br />
operational stages are presented.<br />
4 - Measuring Carbon Emissions From Intermodal Freight Operations<br />
Anthony Craig, PhD Candidate, MIT, 77 Massachusetts Ave,<br />
E40-222, Cambridge, MA, 02139, United States of America,<br />
tcraig@mit.edu, Edgar Blanco, Yossi Sheffi<br />
Estimating the carbon emissions from intermodal shipments is difficult for shippers<br />
due to limited information and the complexity of intermodal operations. The<br />
structure of the rail network, terminal locations, and relative efficiency of rail and<br />
drayage operations all impact the actual emissions. Using data from an intermodal<br />
freight operator we compare the calculated carbon emissions for a set of shipments<br />
with the results obtained from popular carbon estimation methods.<br />
■ WB22<br />
C - Room 18C, Level 4<br />
Workforce Management<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Foaad Iravani, University of California-Los Angeles, Anderson<br />
School of Management, 110 Westwood Plaza, Los Angeles, CA, 90095,<br />
United States of America, firavani@anderson.ucla.edu<br />
1 - Skill Mix and Cross-Training in Professional Service Firms<br />
Vincent Hargaden, PhD Student, Rensselaer Polytechnic Institute,<br />
Industrial & Systems Engineering Dept, 110 8th Street, Troy, NY,<br />
12180, United States of America, hargav@rpi.edu, Jennifer Ryan<br />
A comprehensive mixed integer programming model has been developed for the<br />
workforce planning process in professional service firms. We will present results<br />
from the model which show the impact of skill mix, skill capability levels and crosstraining<br />
on key performance metrics such as project completion rates, staff<br />
utilization and profit.
2 - A Hiring Plan Model for Call Center Management<br />
Tao Huang, Progressive Insurance, 6300 Wilson Mills Rd,<br />
Mayfield Village, OH, 44143, United States of America,<br />
Tao_Huang@progressive.com, Janet Dolohanty, Steve Callitsis<br />
We have developed a hiring plan model for call center management. The model<br />
identifies locations and schedules for the hiring need defined by the capacity<br />
planning and staff-on-hand while taking into account site specific monetary<br />
variables and nonmonetary constraints. The model outputs the optimal combination<br />
of schedules that minimizes hiring cost and specifies the agents required to improve<br />
the peak-hour service level performance.<br />
3 - The Soft Resource Allocation Problem<br />
Foaad Iravani, University of California-Los Angeles, Anderson School<br />
of Management, 110 Westwood Plaza, Los Angeles, CA, 90095,<br />
United States of America, firavani@anderson.ucla.edu, Sriram Dasu,<br />
Reza Ahmadi<br />
We propose optimization models for workforce allocation in a leading software<br />
company that produces tax software. Every year, the firm struggles with a high<br />
workload imposed by changes in tax forms announced by the IRS. In this<br />
competitive market, any delay in the release of the product leads to significant<br />
losses. We develop models for organizing and staffing the development activities to<br />
meet the deadline at the lowest cost.<br />
■ WB23<br />
C - Room 18D, Level 4<br />
Municipal Waste Management, Analytics and<br />
Optimization<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Heng Cao, CTO for Business Analytics & Optimization, IBM China<br />
Research Center, A2/F, Diamond, Zhong Guang Cun Software,<br />
Haidian District, Beijing, 100193, China, hengcao@us.ibm.com<br />
1 - Decision Support System for Municipal Solid Waste Collection<br />
using Forecasting and Optimization<br />
Tianzhi Zhao, IBM Research - China, Diamond Building A, ZGC<br />
Software Park, 8 Dongbeiwang West Road, Beijing, 100193, China,<br />
zhaotzhi@cn.ibm.com, Jun Zhang, Jin Dong, Heng Cao, Wenjun Yin<br />
Municipal solid waste management (MSWM) is becoming a major issue facing cities<br />
around the world due to rapid urbanization and growth of population. In this paper,<br />
an analytics based decision support system is proposed for MSWM. The system<br />
model is composed of two components, one for waste generation prediction,<br />
another one for collection vehicle routing optimization. A GIS application is<br />
integrated into the system to provide route information to as well as map out the<br />
outputs from the model.<br />
2 - Disturbance Analysis Model for the Maintenance Plan of Power Grid<br />
Feng Jin, Dr., IBM Reaserch - China, Bulding 10, 399 Keyuan Road,<br />
Pudong, Shanghai, 201203, China, jinfsh@cn.ibm.com, Hairong Lv,<br />
Jun Luo, Wenjun Yin, Jin Dong, Qiming Tian<br />
To keep the maintenance plan of power gird stable, especially to avoid chainreaction,<br />
a probability model is proposed to analyze the effected plans once a plan is<br />
disturbed by various factors. In this model, we consider not only the traditional<br />
variation of start time, but also the variation of process time and workload under<br />
the complex grid topology. A case in a typical Chinese power company is studied to<br />
validate the model. The result shows the plan change rate is greatly reduced.<br />
3 - An Effort Estimation Model in Project Delivery using Hidden<br />
Setup Cost<br />
Saeed Bagheri, IBM T J Watson Research Center, 1101 Kitchawan<br />
Road, Yorktown Heights, NY, 10598, United States of America,<br />
sbagher@us.ibm.com, Nianjun Zhou, Krishna Ratakonda<br />
We discuss the relationship between delivered projects and required effort. In<br />
particular, we analyze the logarithmic model and its shortcomings in required effort<br />
estimation for large projects. We introduce the hidden setup cost and its related<br />
linear model and explain how its existent leads to the above behavior in logarithmic<br />
models. Our proposed model facilitates effort estimation for project delivery in<br />
services and manufacturing. We illustrate this, using projects in software<br />
development.<br />
INFORMS Austin – 2010 WB25<br />
393<br />
■ WB24<br />
C - Room 19A, Level 4<br />
Joint Session SPPSN/ HAS: Emergency Medical<br />
Services: New Directions<br />
Sponsor: Public Programs, Service and Needs/ Health Applications<br />
Sponsored Session<br />
Chair: Laura McLay, Assistant Professor, Virginia Commonwealth<br />
University, 1015 Floyd Ave, Box 843083, Richmond, VA, 23284,<br />
United States of America, lamclay@vcu.edu<br />
1 - A Markov Chain Model for an EMS System with Repositioning<br />
Armann Ingolfsson, University of Alberta, Edmonton, AB, Canada,<br />
armann.ingolfsson@ualberta.ca, Ramon Alanis, Bora Kolfal<br />
We propose and analyze a Markov chain model of an Emergency Medical Services<br />
system that repositions ambulances using a compliance table policy, which is<br />
commonly used in practice. We validate the model against a detailed simulation<br />
model. We demonstrate that the model provides accurate approximations to such<br />
performance measures as the response time distribution and the distribution of the<br />
number of busy ambulances, and that it can be used to identify near-optimal<br />
compliance tables.<br />
2 - An Equitable EMS Location Model: Minimizing Envy Toward<br />
Neighbors’ Chance of Access to Service<br />
Sunarin Chanta, PhD Student, Clemson University, 203 Freeman<br />
Hall, Department of Industrial Engineering, Clemson, SC, 29634,<br />
United States of America, schanta@clemson.edu, Maria Mayorga,<br />
Laura McLay<br />
The model is developed for finding optimal locations in order to balance disparity in<br />
service between zones. The objective is to minimize the sum of “envy” among all<br />
zones with respect to an ordered set of p operating EMS stations weighted by the<br />
proportion of demand in each zone. Tabu search is provided to solve the problem.<br />
The performance of the proposed model is tested and compared to other location<br />
models such as the p-center and maximal-covering-location (MCLP) problems.<br />
3 - Estimating Travel Speeds in Road Networks From GPS Data<br />
Shane Henderson, Professor, Cornell University, School of ORIE,<br />
Rhodes Hall, Cornell University, Ithaca, NY, 14853, United States of<br />
America, sgh9@cornell.edu, Dawn Woodard, Brad Westgate,<br />
David Matteson<br />
We estimate the speeds vehicles travel on road networks from widely spaced GPS<br />
readings as recorded by ambulances. We use a Bayesian formulation and estimate<br />
the posterior distribution of road travel speeds and other quantities using Markov<br />
chain Monte Carlo (MCMC). In this talk I will sketch the problem and data,<br />
describe the MCMC algorithm, and present some sample results.<br />
4 - Fire Department and Other Emergency Medical Service<br />
John Hall, National Fire Protection Association, Norwood, MA,<br />
United States of America, jhall@NFPA.org<br />
People with emergency medical conditions may call an ambulance, possibly fire<br />
department based, and may seek medical assistance at any of several locations. This<br />
paper will discuss concepts and data sources and uses for a comprehensive system to<br />
track the flow of people in and out of emergency medical service.<br />
■ WB25<br />
C - Room 19B, Level 4<br />
Transportation, Planning I<br />
Contributed Session<br />
Chair: David Novak, Assistant Professor, University of Vermont,<br />
55 Colchester Ave., Kalkin 310, Burlington, VT, 05405-0157,<br />
United States of America, dnovak@bsad.uvm.edu<br />
1 - Exploring Theoretical Properties of Bounded Rational User<br />
Equilibrium Flow Distributions<br />
Yingyan Lou, Assistant Professor, The University of Alabama, A127K<br />
Bevill Building, Box 870205, Tuscaloosa, AL, 35405,<br />
United States of America, ylou@eng.ua.edu<br />
This paper investigates theoretical properties of the boundedly rational user<br />
equilibrium (BRUE) flow set for transportation networks. Probabilistic methods are<br />
explored to address the uncertainty in link flows characterized by the non-convex<br />
BRUE flow set. Entropy maximization is used to identify the most likely link flow<br />
pattern. Finite sampling approaches are also investigated to derive various measures<br />
from assumptions on the continuous link flow probability space over the BRUE flow<br />
set.
WB26<br />
2 - Toolkit for Anticipating and Evaluating Roadway Expansion and<br />
Tolling Impacts<br />
Daniel Fagnant, Graduate Research Assistant, The University of<br />
Texas at Austin, ECJ Suite 6.9, MailCode C1761, Austin, TX, 78712,<br />
United States of America, annette.perrone@engr.utexas.edu,<br />
Kara Kockelman, Chi Xie<br />
We present a new toolkit for forecasting the traffic volumes, travel times, network<br />
reliability, emissions, and safety impacts of roadway expansion and tolling projects.<br />
Trip tables are estimated using constrained maximum entropy methods, based on<br />
link-level traffic counts. Incremental logit models anticipate mode and time of day<br />
splits. All impacts are monetized and compared over project lifetimes, to generate<br />
benefit-cost ratios and other success indicators for Austin case studies.<br />
3 - Simulation of Vessel Traffic and Dredging Impact Analysis in<br />
Delaware River<br />
Ozhan Alper Almaz, PhD Student, Rutgers University, Industrial &<br />
Systems Engineering Departm, 100 Brett Road, Piscataway, NJ,<br />
08854, United States of America, alperalmaz@gmail.com,<br />
Tayfur Altiok<br />
We considered modeling of vessel traffic in the Delaware River Main Channel. A<br />
high fidelity simulation model was developed to investigate effects of deepening and<br />
dredging in the River on the navigational efficiency based on several assumptions.<br />
In this regard, vessel calls to terminals, lightering and barge operations, tidal and<br />
navigational rules in the River, terminal and anchorage properties and vessel<br />
profiles were considered.<br />
4 - Evaluating the Effects of Trip Importance on System-Wide<br />
Performance in Transportation Networks<br />
David Novak, Assistant Professor, University of Vermont,<br />
55 Colchester Ave., Kalkin 310, Burlington, VT, 05405-0157,<br />
United States of America, dnovak@bsad.uvm.edu<br />
We introduce measures for evaluating network robustness and identifying and<br />
ranking the most critical or important links in a transportation network called the<br />
Network Robustness Index, and comparing disparate networks using a scalable,<br />
system-wide performance over all links in the network called the Network Trip<br />
Robustness. We show that the relationships between network robustness, the<br />
capacity-disruption level, and network connectivity are non-linear and are not<br />
necessarily intuitive.<br />
■ WB26<br />
C - Room 4A, Level 3<br />
Joint Session DM/ ICS: Bayesian Computational Issues<br />
in Data Mining<br />
Sponsor: Data Mining/ Computing Society<br />
Sponsored Session<br />
Chair: Tevfik Aktekin, Assistant Professor of Decision Sciences, University<br />
Of New Hampshire, 15 Academic Way, Department of Decision Sciences,<br />
Durham, NH, 03824, United States of America, tevfik.aktekin@unh.edu<br />
1 - Modeling Brazilian Swap Curve in a Hidden Markov Framework with<br />
Macroeconomic Variables<br />
Richard Munclinger, Economist, IMF, 1301 20th Street, NW, Apt.<br />
107, Washignton, DC, 20036, United States of America,<br />
richardmunch@gmail.com<br />
We apply a hidden Markov model of the term structure to modeling Brazilian swap<br />
rates. We find that multiple regimes are identified in the data and that<br />
macroeconomic variables improve time series fit without destroying regime<br />
dependency. This work has two main contributions. Firstly, we include<br />
macroeconomic variables in conjunction with a hidden Markov framework.<br />
Secondly, we propose and apply a Bayesian MCMC algorithm to estimate hidden<br />
Markov models of the term structure.<br />
2 - Explaining HIV Mortality, Bayesian Spatial Models Applied with<br />
MCMC Methods<br />
Rasim Muzaffer Musal, Assistant Professor, Texas State University,<br />
404 Rio Grande apt 209, Austin, TX, 78701, United States of<br />
America, rm84@txstate.edu, Tevfik Aktekin<br />
We propose Bayesian Zero Inflated Poisson models to investigate the effects of<br />
poverty and inequality on the number of HIV related deaths in NY counties. In<br />
doing so, we quantify inequality via the Theil Index and Poverty via the ratios of<br />
the two Census 2000 variables. MCMC methods are utilized in eliciting posteriors.<br />
We present the computational complexities that are present in these methods and<br />
emphasize the methods for spatial effects.<br />
INFORMS Austin – 2010<br />
394<br />
3 - Bayesian Analysis of Discrete Time Queueing Networks with a<br />
Gridlock Prediction Application<br />
Toros Caglar, George Washington University, 2201 G St., NW, Funger<br />
Hall, Suite 415, Washington, DC, 20052, United States of America,<br />
toros@gwu.edu, Refik Soyer<br />
Analysis of discrete time queues and their networks have been mostly prevalent in<br />
the context of computer and communication systems. In this study, we aim to<br />
utilize a Bayesian approach for the analysis of these queues with an application in<br />
emergency room (ER) gridlock prediction, which requires transient analysis. We will<br />
also address the challenges presented by the large state space formed by the ERhospital<br />
network and the MCMC simulation necessitated by the Bayesian analysis.<br />
4 - Bayesian State Space Modeling of Mortgage Default Risk<br />
Tevfik Aktekin, Assistant Professor of Decision Sciences, University of<br />
New Hampshire, 15 Academic Way, Department of Decision<br />
Sciences, Durham, NH, 03824, United States of America,<br />
tevfik.aktekin@unh.edu, Refik Soyer, Feng Xu<br />
We consider discrete time Bayesian state space models with Poisson measurements<br />
to model the mortgage default risk at the aggregate level with a stochastic default<br />
rate and macroeconomic covariates. We discuss parameter updating and estimation<br />
using Markov chain Monte Carlo methods where the use of the efficient forward<br />
filtering backward sampling algorithm within a Gibbs sampler is developed. We use<br />
actual U.S. residential mortgage data and discuss insights gained from Bayesian<br />
analysis.<br />
■ WB27<br />
C - Room 4B, Level 3<br />
Network Optimization I<br />
Contributed Session<br />
Chair: Chase Rainwater, University of Arkansas, INEG Department,<br />
Fayetteville, AR, 72701, United States of America, cer@uark.edu<br />
1 - Integrated Dynamic Single Facility Location and Inventory<br />
Planning Problems<br />
Jiaming Qiu, Student, Rensselaer Polytechnic Institute,<br />
110 8th St., Troy, NY, 12180, United States of America, qiuj@rpi.edu,<br />
Thomas Sharkey<br />
We analyze a class of problems which determines the relocation and inventory plan<br />
of a single facility over a finite horizon in order to meet dynamic customer<br />
demands. Dynamic programming algorithms are presented to solve the problem<br />
under different objective functions and construct the efficient frontier for biobjective<br />
problems, most of which run in polynomial time.<br />
2 - Hybrid Wired-cum-wireless Sensor Network Location-allocation<br />
Problem in Industrial Environment<br />
Sima Maleki, Graduate Research Assistant, University of<br />
Tennessee/Industrial and Information Engineering Department,<br />
Knoxville, Knoxville, TN, 37996, United States of America,<br />
smaleki@utk.edu, Mohammad Mehdi Sepehri, Hamid Farvaresh,<br />
Rapinder Sawhney<br />
A hybrid wired-cum-wireless sensor network consists of a wireless network and a<br />
wired backbone. The proposed designs consider limitations of wireless<br />
communication and constraints in industrial applications to minimize the network<br />
cost over a life of a network. The joint problem of configuring the hybrid network,<br />
locating the nodes and sensor clustering is formulated as a Mixed Integer Nonlinear<br />
Programming model. Results illustrate the cost effectiveness and longevity of hybrid<br />
configuration.<br />
3 - Social Optimality and Pricing in Shared Computing Centers<br />
Ishai Menache, postdoc, MIT, 77 Massachusetts avenue, 32-D632,<br />
Cambridge, MA, 02139, United States of America, ishai@mit.edu,<br />
Nahum Shimkin, Asuman Ozdaglar<br />
Motivated by the recent advent of cloud computing facilities that offer online<br />
computing power on demand, we consider a large service facility that offers<br />
simultaneous service to a large number of heterogeneous users. Our main concern<br />
here is in maximizing the social utility, which comprises of the users’ service utility<br />
minus their delay cost. We show that the social optimum may be achieved by<br />
simple per-unit pricing, which charges a fixed amount per unit time and resource<br />
from all users.<br />
4 - Methodologies for Solving Dynamic Fortification Problems<br />
Chase Rainwater, University of Arkansas, INEG Department,<br />
Fayetteville, AR, 72701, United States of America, cer@uark.edu,<br />
Huy-Nhiem Nguyen, Ed Pohl, Scott J. Mason<br />
The fortification of critical infrastructure elements is an issue of notable importance.<br />
However, research in this area has studied the problem of fortification from purely a<br />
static perspective. This work presents a dynamic model that considers the temporal<br />
impacts of resource allocation decisions in a potentially changing infrastructure.<br />
Specifically, we propose decomposition-based solution approaches to solve this<br />
general class of problems.
■ WB28<br />
C - Room 4C, Level 3<br />
Prognostics and Health Management<br />
(PHM / Sensors / RFID)<br />
Sponsor: Quality, Statistics and Reliability<br />
Sponsored Session<br />
Chair: Sagar Kamarthi, Associate Professor, Northeastern University,<br />
360 Huntington Ave, Boston, MA, 02115, United States of America,<br />
sagar@coe.neu.edu<br />
Co-Chair: Abe Zeid, Northeastern University, 360 Huntington Ave,<br />
Boston, 02115, United States of America, zeid@coe.neu.edu<br />
1 - A Bayesian Inventory Model using Real-time Condition<br />
Monitoring Information<br />
Jennifer Ryan, Associate Professor, RPI, Industrial and Systems<br />
Engineering, 110 8th Street, Troy, NY, 12180,<br />
United States of America, ryanj6@rpi.edu, Rong Li, Zhi Zeng<br />
We consider a manufacturer who periodically replenishes inventory for a machine<br />
part which is used simultaneously on a large set of geographically dispersed<br />
machines. This part is subject to deterioration, which can be captured by condition<br />
monitoring. We model the associated degradation signal using a Wiener process. In<br />
such a setting, we show how real-time sensor data can be used to improve the<br />
inventory management of spare parts.<br />
2 - Application of Fuzzy Graph on Sensor Deployment Strategy for<br />
Fault Diagnosis<br />
Zhenhua Wu, Research Assistant, TAMU, 3902 College Main Street,<br />
Apt.806, Bryan, TX, 77801, United States of America,<br />
wuzhenhua34@tamu.edu, Sheng-jen Hsieh, Jianzhi Li<br />
I am sorry It only allows 500 characters, I can not submit my abstract. Is there any<br />
way we can solve it? My email is: wuzhenhua34@tamu.edu Thank you!<br />
3 - Short Term Performance of Condition Monitored Degrading<br />
Manufacturing Systems<br />
Saumil Ambani, University of Michigan, 1210 HH Dow, Ann Arbor,<br />
MI, 48105, United States of America, sambani@umich.edu, Lin Li,<br />
Jun Ni<br />
Steady state performance of manufacturing systems has been studied for over 50<br />
years, but its short term behavior remains relatively unexplored. In this<br />
presentation, we focus on the development of an analytical model for predicting the<br />
short term performance of a condition monitored degrading system. This approach<br />
allows us to incorporate real time information from the plant floor, such as buffer<br />
contents and condition of the machines, to make effective short term decisions.<br />
■ WB29<br />
C - Room 5A, Level 3<br />
Joint Session QSR/ DM: Data Mining for<br />
Process Monitoring<br />
Sponsor: Quality, Statistics and Reliability/ Data Mining<br />
Sponsored Session<br />
Chair: Myong Jeong, Rutgers University, 640 Bartholomew Road,<br />
Piscataway, NJ, United States of America, mjeong@rci.rutgers.edu<br />
1 - Hybrid Novelty Score-Based Control Charts for Multivariate<br />
Process Monitoring<br />
Gulanbaier Tuerhong, Korea University, Anam-dong, Seongbuk-gu,<br />
Seoul, Korea, Republic of, gulambar@korea.ac.kr, Seoung Bum Kim<br />
We propose a new nonparametric multivariate control chart that can effectively<br />
handle large amounts of complex data through integration of one of the one-class<br />
classification algorithm with control chart techniques. Control limits of the proposed<br />
chart are established based on a bootstrap method. Experimental results with<br />
simulated data showed that the proposed control chart outperformed Hotelling’s T2<br />
control charts.<br />
2 - An Economic Design of the Integrated Process Control<br />
Minjae Park, Rutgers University, 126 Montgomery St. Apt 2F,<br />
Highland Park, NJ 08904, United States of America,<br />
pminj88@gmail.com<br />
The economic cost model is developed for the integration of statistical process<br />
control (SPC) and automatic process control (APC). SPC is used to detect special<br />
causes by monitoring process performance. On the other hand, APC is used to<br />
improve the process by an adjustment controller. Both are needed to effectively<br />
keep processes close to target. The long run expected cost is also suggested as the<br />
criteria to evaluate the performance of economic cost model.<br />
INFORMS Austin – 2010 WB30<br />
395<br />
3 - Detection of Potential Failure Wafers Based on Fail Bit Counts Data<br />
Seung Hoon Tong, Principal Engineer, Samsung Electronics Co., Ltd.,<br />
San#16 Banwol-Dong, Gyeonggi-Do, Hwasung-City, 445-701, Korea,<br />
Republic of, shtong@samsung.com, In Kap Chang, Jeong Hee<br />
Hwang, Kun Han Kim, Seung Sik Jung<br />
We present a method for detection of potential failure wafers based on fail bit<br />
counts data from wafer electrical test stage in semiconductor manufacturing. The<br />
number of fail bit each wafer has superior capability for classifying potential failure<br />
wafers than wafer yield itself. We developed two quality measures considering the<br />
magnitude and clustering level of fail bit patterns and showed real applied<br />
examples.<br />
4 - Logistic Regression-Based Control Charts for Fault Identification<br />
Jihoon Kang, Korea University, Anam-dong, Seongbuk-gu, Seoul,<br />
Korea, Republic of, joker404@hanmail.net, Seoung Bum Kim<br />
Identification of process variables that contribute to out-of-control signal has been<br />
one of important problems in statistical process control. In the present study we<br />
integrated a logistic regression algorithm with control chart techniques for fault<br />
identification in multivariate process control. Simulation studies demonstrated the<br />
accuracy and efficiency of the proposed fault identification method.<br />
■ WB30<br />
C - Room 5B, Level 3<br />
Statistics/Quality Control I<br />
Contributed Session<br />
Chair: Michael Wood, Principal Lecturer, University of Portsmouth,<br />
Strategy and Business Systems, Richmond Building, Portland St,<br />
Portsmouth, PO1 3DE, United Kingdom, michael.wood@port.ac.uk<br />
1 - A New Monitoring Scheme for Various Types of Mean Shifts<br />
Chang-Ho Chin, Assistant Professor, Kyung Hee University,<br />
1 Seocheon-dong, Yongin-si, 446-701, Korea, Republic of,<br />
chin@khu.ac.kr, Taek-Jin Jeong<br />
The EWMA control chart is more sensitive to small mean shifts than to large ones as<br />
opposed to the Shewhart control chart. The right selection of control charts to the<br />
underlying process is directly linked with the timely detection of mean shifts. For<br />
processes possibly with various types of mean shifts, we propose a control charting<br />
scheme of selecting and applying a right control chart to the process. Simulation<br />
results show the proposed scheme outperforms conventional ones.<br />
2 - An Adaptive Sequential Methodology for n-Dimensional Quadratic<br />
Response Surface Optimization<br />
Adel Alaeddini, Wayne State University, Department of Industrial<br />
Engineering, Detroit, MI, 48202, United States of America,<br />
dz3027@wayne.edu, Kai Yang, Alper Murat<br />
Despite their ability in modeling a wide range of process and product design, RSM<br />
techniques are not the most effective methodologies for applications with limited<br />
resources. In this paper, we develop an adaptive methodology for response surface<br />
optimization (ASRSM) for expensive experiments with noisy data requiring high<br />
design performance. We also show that in terms of both design optimality and<br />
experimentation efficiency it compares favorably with optimal designs.<br />
3 - Modeling Data using Kalman Filtering: A Proposal for SPC<br />
Andre Korzenowski, Prof. Ms., PPGEP/UFRGS, Av. Osvaldo Aranha,<br />
99 - 5° andar, Porto Alegre, RS, 90.035-190, Brazil,<br />
andre@korzenowski.com, Marcelo Portugal, Carla ten Caten<br />
The aim of this paper is to compare forecasting in univariate time series models<br />
applied in Statistical Process Control (SPC). A structural model in state space via<br />
Kalman’s filtering and an ARIMA model with exogenous variables were fitted. The<br />
modeling was applied in real data series of five different products in a plastic<br />
production. The results obtained indicate that structural model had better<br />
performance than ARIMA model when compared by RMSE.<br />
4 - Problems with Statistical Methods in Management Research - and a<br />
Few Solutions<br />
Michael Wood, Principal Lecturer, University of Portsmouth, Strategy<br />
and Business Systems, Richmond Building, Portland St, Portsmouth,<br />
PO1 3DE, United Kingdom, michael.wood@port.ac.uk<br />
A case study of a typical journal paper leads to three conclusions. (1) The value of a<br />
statistical approach is seriously limited by various factors: e.g. difficulties of<br />
generalizing to contexts other than the sample studied. (2) The conventional<br />
hypothesis testing format makes results almost meaningless: instead, I suggest using<br />
confidence levels for hypotheses - and suggest two ways of doing this (one a<br />
bootstrap method on a spreadsheet). (3) The analysis should be far more userfriendly.
WB31<br />
■ WB31<br />
C - Room 5C, Level 3<br />
Forecasting II<br />
Contributed Session<br />
Chair: Nitin Shenoy, Teaching Assistant, Texas Tech University, Texas Tech<br />
Industrial Engineering Department, Lubbock, Tx, 79409-3061, United<br />
States of America, nitin.shenoy@ttu.edu<br />
1 - Wrong Response Functions: Their Detection and Implications<br />
Steven Shugan, Professor, University of Florida, 2030 NW 24th<br />
Avenue, Gainesville, FL, 32605, United States of America,<br />
sms@ufl.edu<br />
This paper first explains why simple tests are unable to detect wrong response<br />
functions. Next, the paper shows that wrong response functions use dampening and<br />
inflated parameters to filter error variance to obtain better predictions. This<br />
dampening is problematic when decisions require the correct response. Fortunately,<br />
it is possible to detect dampening with specific tests for dampening. This paper<br />
shows how to do that and demonstrates the effectives of those tests.<br />
2 - Role of Forecast Effort on Supply Chain Profitability Under Various<br />
Information Sharing Scenarios<br />
Linda (Xiaowei) Zhu, West Chester University of PA, 312A<br />
Anderson, West Chester, United States of America,<br />
xzhu@wcupa.edu, Xuemei Su, Samar Mukhopadhyay, Xiaohang Yue<br />
We analyze several forecast systems and their impact on forecast accuracy, forecast<br />
costs and profit. Specifically, we consider a supplier who sells a product to a buyer<br />
in a single selling season. Three different forecast systems, namely, Non-Information<br />
Sharing, Information Sharing, and Supplier Forecasting were studied. We derive<br />
optimal price and forecast accuracy level and discuss forecast variance and the<br />
related forecast costs.<br />
3 - Unpacking the Future: A Nudge Towards Wider Interval Forecasts<br />
Kriti Jain, Doctoral Student, INSEAD, 1, Ayer Rajah Avenue,<br />
Singapore, Singapore, kriti.jain@insead.edu, Kanchan Mukherjee,<br />
Neil Bearden, Anil Gaba<br />
With few exceptions, forecasters tend to underestimate uncertainty, for example, a<br />
typical analyst’s 90% confidence intervals for future quantities will likely capture<br />
only 50-60% of the actual realizations. Using a series of lab and field experiments,<br />
we show that unpacking the distal future into intermediate more proximal futures<br />
has a substantial effect on subjective forecasts. We refer to this phenomenon as the<br />
time unpacking effect and show that it persists with expert judgments as well.<br />
4 - The Welfare Implications of Carbon Taxes and Carbon Caps: A<br />
Look at U.S. Households<br />
Kara Kockelman, The University of Texas in Austin, ECJ Suite 6.9,<br />
Austin, TX, United States of America, kkockelm@mail.utexas.edu,<br />
Binny Paul, Sumala Tirumalachetty<br />
Household expenditure and vehicle choice data are used here to anticipate the<br />
economic impacts of energy taxes versus household-level carbon-emissions caps<br />
(with trading) across different income classes. Translog utility models were<br />
estimated and then maximized subject to money and carbon budget constraints.<br />
U.S. trade accounts were used to infer the carbon footprints of 9 goods’ sectors, with<br />
vehicle choice and fuel economy modeled in detail. Cap and trade was found less<br />
regressive.<br />
5 - Propane Demand Modeling for Residential Sectors -<br />
A Regression Analysis<br />
Nitin Shenoy, Teaching Assistant, Texas Tech University, Texas Tech<br />
Industrial Engineering Department, Lubbock, Tx, 79409-3061,<br />
United States of America, nitin.shenoy@ttu.edu, Milton Smith<br />
When winter space heating contributes significantly to the propane demand system;<br />
it is useful, for forecasting purposes, to separate total demand system in to two<br />
components: Large houses and Small houses. Examination of historical data<br />
indicates that the propane demand depends largely on weather conditions.<br />
Regression analysis techniques were used to show the combined effect of these<br />
weather conditions on propane demand.<br />
INFORMS Austin – 2010<br />
396<br />
■ WB32<br />
C - Room 6A, Level 3<br />
Computing Economic Equilibria<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: James Orlin, Professor, Massachusetts Institute of Technology, E53-<br />
363, Cambridge, MA, 02139, United States of America, jorlin@mit.edu<br />
1 - A New Convex Program for Fisher Markets and Convergence of<br />
Proportional Response Dynamics<br />
Nikhil Devanur, Microsoft Research, 1 Microsoft Way, Redmond,<br />
WA, United States of America, nikdev@microsoft.com<br />
We give a new convex program that captures the equilibrium of spending constraint<br />
utilities, thus resolving an open problem. The new program also demystifies the<br />
convergence properties of “proportional response” dynamics: a simple, distributed<br />
way to converge to market equilibria. We show that the proportional response<br />
dynamics is equivalent to gradient descent on the new convex program, with KLdivergence<br />
instead of Euclidean distance.<br />
2 - Equilibrium Computation for Low Dimensional Markets<br />
Amin Saberi, Stanford University, Terman Engineering Building,<br />
Room 317, Stanford, CA, 94305, United States of America,<br />
saberi@stanford.edu<br />
I will describe a model of markets in which every good has a value or desirability in<br />
each of the k dimensions. The utility of every agent in a bundle is a function of the<br />
values of the goods in that bundle in each dimension. In this model, I will present<br />
polynomial-time approximation schemes for computing the equilibria when k is<br />
bounded. Joint work with Costis Daskalakis<br />
3 - Improved Algorithms for Computing Fisher’s Market Prices<br />
James Orlin, Professor, Massachusetts Institute of Technology,<br />
E53-363, Cambridge, MA, 02139, United States of America,<br />
jorlin@mit.edu<br />
Irving Fisher developed a simple model of a market economy. Nevertheless, it is still<br />
non-trivial to develop efficient algorithms for determining the market clearing<br />
prices. We develop a combinatorial algorithm for computing the market equilibrium<br />
that runs in O(n^4 log n) time, improving the previous best bound of O(n^8 log U).<br />
■ WB33<br />
C - Room 6B, Level 3<br />
Business Analytics and Optimization Practices<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: Jin Dong, IBM Research - China, Building 19 ZGC Software Park,<br />
8 Dongbeiwang West Road, Beijing, 100193, China, dongjin@cn.ibm.com<br />
1 - Supply Risk Management using Approximate<br />
Dynamic Programming<br />
Lei Zhao, Tsinghua University, Department of Industrial Engineering,<br />
Tsinghua University, Beijing, 100084, China, lzhao@tsinghua.edu.cn,<br />
Xiaobo Zhao, Weijun Ding, Jiarui Fang, Jan Fransoo<br />
We consider a production system that is subject to failures at part suppliers.<br />
Mitigation planning and emergent capacity can be used to hedge against the risk at<br />
a higher cost. We model and solve the problem using finite-horizon approximate<br />
dynamic programming.<br />
2 - Mail Performance Measurement Study Process Improvements via<br />
Business Analytics & Optimization at IBM<br />
Hua Ni, IBM, 8000 Grainger Ct, Springfield, VA, 22153, United<br />
States of America, huani@us.ibm.com, Christine Friesz<br />
IBM conducts an ongoing measurement study of single-piece First-Class Mail service<br />
performance for the United States Postal Service. In this talk, we will present recent<br />
process improvement initiatives designed to strengthen the quality and operational<br />
efficiency of the measurement study, which leveraged Business Analytics and<br />
Optimization (BAO) methodologies such as optimization, simulation, and<br />
predicative analytics. We will also share the challenges and lessons learned from<br />
these efforts.<br />
3 - Using Simulation in Global Supply Network Rationalization<br />
Changrui Ren, IBM, Building 19 ZGC Software Park, 8 Dongbeiwang<br />
WestRoad, Haidian District, Beijing, China, rencr@cn.ibm.com,<br />
Xu Yang, Jin Dong, Qinhua Wang, Bing Shao, Miao He<br />
This presentation will introduce a real case showing how simulation could be the<br />
key enablement for a supply chain network rationalization project in the<br />
pharmaceutical industry. An IBM tool - Supply Chain Process Modeler (SCPM) has<br />
been applied in this project. Five major simulation scenarios are designed based on<br />
the pain points the client has, and numerical results show that simulation has<br />
addressed the key issues and provided the client accountable evaluation results for<br />
decision-making.
4 - WISE-BPM: Accelerating Blueprint for Rollout Project in SAP<br />
System Implementation<br />
Qinhua Wang, IBM Research - China, Building19, Zhongguancun<br />
Software Park, Beijing, 100193, China, wangqinh@cn.ibm.com,<br />
Bing Shao, Miao He, Changrui Ren, Jin Dong<br />
In SAP system implementation, business process model of a rollout project should<br />
be conducted through localizing the global template. Simultaneously, global<br />
template changes should be synchronized to all rollout projects, which causes<br />
conflicts, information loss and duplication easily. WISE-BPM addresses this problem<br />
through an additional version control system to rollout global template changes, a<br />
localization flag and a mapping system to avoid information duplication and loss<br />
respectively.<br />
■ WB34<br />
C - Room 7, Level 3<br />
Stochastic Optimization and Equilibrium Problems:<br />
Analysis and Stochastic Approximation Algorithms<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: Uday Shanbhag, Asst. Professor, University of Illinois at Urbana<br />
Champaign, Urbana, Il, United States of America, udaybag@illinois.edu<br />
1 - Simulation-based Optimization in the Presence of Convexity<br />
Eunji Lim, Assistant Professor, University of Miami, University of<br />
Miami, Coral Gables, United States of America, lim@miami.edu<br />
We consider the problem of computing a response surface when the underlying<br />
function is known to be convex. We introduce a methodology that incorporates the<br />
convexity into the function estimator. The proposed response surface estimator is<br />
formulated as a quadratic program and exhibits convergence properties as a global<br />
approximation to the true function. Numerical results will illustrate the convergence<br />
behavior of the proposed estimator and its potential application to simulation<br />
optimization.<br />
2 - Single Timescale Regularized Stochastic Approximation Schemes<br />
for Monotone Stochastic Nash Games<br />
Jayash Koshal, Department of Industrial & Enterprise Systems<br />
Engineering, UIUC, 117 Transportation Building, 104 S. Mathews,<br />
Urbana, 61801, United States of America, koshal1@illinois.edu,<br />
Angelia Nedich, Uday Shanbhag<br />
We consider the distributed computation of equilibria arising in monotone stochastic<br />
Nash games over continuous strategy sets. We develop single timescale projectionbased<br />
stochastic approximation schemes for computing equilibria when the<br />
associated gradient map is merely monotone and establish its global convergence. In<br />
an extension where players choose their steplengths independently we claim the<br />
convergence of the scheme if the deviation across their choices is suitably<br />
constrained.<br />
3 - On the Characterization of Solution Sets of Smooth and Nonsmooth<br />
Stochastic Nash Games<br />
Uma Ravat, Graduate Student, University Of Illinois, Urbana, IL,<br />
61801, United States of America, ravat1@illinois.edu,<br />
Uday Shanbhag<br />
Solution sets of deterministic Nash games over continuous strategy sets can be<br />
characterized using variational analysis. A direct application of such results to<br />
stochastic regimes is challenging as the expectation yields a far less tractable<br />
nonlinear function. We develop an analytical framework to examine existence of<br />
stochastic Nash equilibrium under general probability measures in possibly<br />
nonsmooth regimes. We apply it to classes of Nash-Cournot games with risk and<br />
stochastic constraints.<br />
4 - Optimal Coverage of Rectangular Request Areas using Multiple<br />
Rectangular Targets<br />
Manish Bansal, PhD Student, Texas A&M University, 3131 TAMU,<br />
College Station, TX, 77843, United States of America,<br />
bans1571@neo.tamu.edu, Kiavash Kianfar<br />
We consider positioning k target rectangles on 2-dimensional plane to partially<br />
cover a set of existing rectangular areas (requests) to maximize total coverage<br />
reward. Applications include camera surveillance and imaging. We show this<br />
problem is NP-hard and present a novel branch-and-bound algorithm over a<br />
reduced solution space to solve the problem exactly. To our knowledge no<br />
algorithm has been proposed before for this problem and our algorithm is memory<br />
and performance efficient.<br />
INFORMS Austin – 2010 WB36<br />
397<br />
■ WB35<br />
C - Room 8A, Level 3<br />
Advances in Anomalous Diffusion II<br />
Sponsor: Applied Probability<br />
Sponsored Session<br />
Chair: Iddo Eliazar, Professor, Holon Institute of Technology, P.O. Box<br />
305, Holon, 58102, Israel, eliazar@post.tau.ac.il<br />
1 - Anomalous Mixing and Reaction Induced by Spatially<br />
Fractional Dispersion<br />
David Benson, Colorado School of Mines, 1500 Illinois St., Golden,<br />
CO, 80401, United States of America, dbenson@mines.edu,<br />
Diogo Bolster, Tanguy Le Borgne, Marco Dentz<br />
Long-range mass transfer changes the character of mixing of two fluids of different<br />
chemical composition and the consequent chemical reaction. For mixing-limited<br />
equilibrium reactions following the space-fractional Advection-Dispersion equation<br />
(fADE), the scalar dissipation and global reaction rates decay as power-laws in time.<br />
As opposed to the Fickian (local) transport model, local reaction rates are not zero<br />
where the concentration has zero gradient.<br />
2 - Diffusive Processes Run with Non-linear Clocks: Complexity,<br />
Ergodicity and Fractional F-P Equations<br />
John Cushman, Professor, Purdue University, 550 Stadium Mall<br />
Drive, West Lafayette, IN, 47906, United States of America,<br />
75674.1670@compuserve.com<br />
We study stochastic processes run with deterministic, but non-linear clocks. The<br />
clock is used to stretch or compress the process. The clock does not change the<br />
fractal dimension or complexity of the process. Ergodicity is analyzed for several<br />
processes and compared to their classical analogs. Fokker-Planck equations for<br />
several of the processes are derived and in some cases shown to possess fractional<br />
derivatives. A number of misconceptions concerning power-law second moments<br />
are discussed.<br />
3 - Influence of Anomalous Diffusion on the Robustness and Time<br />
Evolution of Morphogen Gradients<br />
Katja Lindenberg, Distinguished Professor, University of California,<br />
San Diego, Department of Chemistry & Biochemistry, 9500 Gilman<br />
Drive MC 0340, La Jolla, CA, 92093-0340, United States of America,<br />
klindenberg@ucsd.edu, Santos B. Yuste, Enrique Abad<br />
Crowded cellular environments are subdiffusive. The usual picture of morphogen<br />
gradients evolving as a result of a source of normal diffusive particles (morphogens)<br />
coupled to a degradation mechanism that removes them from the system must be<br />
modified. We aim to investigate how subdiffusive motion of the morphogens affects<br />
the evolution and robustness of the concentration profile against changes in the<br />
degradation rate. We find interesting fluctuation buffering effects caused by<br />
subdiffusion.<br />
■ WB36<br />
C - Room 8B, Level 3<br />
Education I<br />
Contributed Session<br />
Chair: Thomas Groleau, Associate Professor of Business Administration,<br />
Carthage College, 2001 Alford Park Drive, Kenosha, WI, 53140,<br />
United States of America, tgroleau@carthage.edu<br />
1 - Vertical Integration: Results From a Cross-Course<br />
Student Collaboration<br />
David Lewis, University of Massachusetts Lowell, 1 University<br />
Avenue, College of Management, Lowell, MA, 01854,<br />
United States of America, David_Lewis@uml.edu, Thomas Sloan<br />
We report the results of a cross-class project involving Sophomore-level students in<br />
a Management Science (MS) class with Junior-level students in an Operations<br />
Management (OM) class. The students formed virtual teams and developed a<br />
simulation model of a call center. Results were strongly linked with the presence or<br />
absence of a team champion.<br />
2 - Approach to Improve the Expense Efficiency of Research Capacity<br />
of Universities<br />
Jongwoun Youn, PhD Candidate, KUBS(Korea University Business<br />
School), Anam-Dong, Seongbuk-Gu, Seoul, Korea, Seoul, Kr, 136-<br />
701, Korea, Republic of, yjw333@korea.ac.kr, Kwang-Tae Park<br />
Competitiveness of university can be expressed by education and research capacity.<br />
Research capacity is an essential indicator for estimating the development of<br />
university as well as that of our society. Thus, we want to propose the approach to<br />
improve the expense efficiency of research capacity.
WB37<br />
3 - Teaching Decision Tree Classification using Microsoft Excel<br />
Thaddeus Sim, Assistant Professor of Business Administration,<br />
Le Moyne College, 1419 Salt Springs Road, Syracuse, NY, 13214,<br />
United States of America, simtk@lemoyne.edu, George Kulick,<br />
Kaan Ataman<br />
Data mining is the extraction of useful patterns from data to aid with decision<br />
making, and decision makers are increasingly viewing data mining as an essential<br />
analytical tool. Unfortunately, data mining does not get as much attention in the<br />
traditional OR/MS classroom as other more popular areas. We discuss our<br />
experiences in teaching a popular data mining method in an undergraduate OR/MS<br />
elective course, and outline a procedure to implement the decision tree algorithm in<br />
Microsoft Excel.<br />
4 - A Different IE Teaching Experience: Active Learning<br />
Ali Kefeli, PhD Candidate, North Carolina State University,<br />
2717 Brigadoon Dr., Apt 24, Raleigh, NC, 27606,<br />
United States of America, akefeli@ncsu.edu, Michael G. Kay<br />
In this work, we take findings of a Felder and Brent (2008) and provide a critical<br />
analysis of a senior level industrial engineering class at North Carolina State<br />
University. We investigate each mistake laid out by Felder and Brent and argue how<br />
avoiding them resulted in a better educational outcome. We provide sample<br />
assessment tools such as class assignments and midterm questions, as well as active<br />
learning exercises, technological tools and student evaluations.<br />
5 - Pre-Analytics with Cash for Clunkers<br />
Thomas Groleau, Associate Professor of Business Administration,<br />
Carthage College, 2001 Alford Park Drive, Kenosha, WI, 53140,<br />
United States of America, tgroleau@carthage.edu<br />
In summer 2009 nearly 700,000 new vehicles were purchased through the U.S.<br />
government Cash Allowance Rebate System (CARS). The resulting dataset provides<br />
a freely available pre-analytics training ground for a variety of classes. Using basic<br />
desktop productivity software, students can practice data cleansing, data organizing,<br />
and basic statistics on a very large dataset. Student can also prepare the data for<br />
more detailed analysis with specialized geospatial or statistical software.<br />
■ WB37<br />
C - Room 8C, Level 3<br />
Queueing Models of Call Centers<br />
Sponsor: Applied Probability<br />
Sponsored Session<br />
Chair: Itai Gurvich, Assistant Professor, Kellogg School of Management,<br />
Northwestern University, 2001 Sheridan Rd., Evanston, IL, 60208,<br />
United States of America, i-gurvich@kellogg.northwestern.edu<br />
1 - Approximate Dynamic Programming Techniques for Skill-based<br />
Routing in Call Centers<br />
Sandjai Bhulai, VU University Amsterdam, Department of<br />
Mathematics, Faculty of Sciences, Amsterdam, 1081 HV,<br />
Netherlands, sbhulai@few.vu.nl, Dennis Roubos<br />
We consider the problem of dynamic multi-skill routing in call centers. We obtain<br />
near optimal dynamic routing policies that are scalable with the size of the problem<br />
instance and can be computed online. The algorithm is based on approximate<br />
dynamic programming techniques. We compare the performance with<br />
decomposition techniques. Numerical experiments demonstrate that our method<br />
outperforms leading routing policies and has close to optimal performance.<br />
2 - Comparing Erlang C and A for Modeling Real Call Centers<br />
Tom Robbins, Assistant Professor, East Carolina University, 1006<br />
Gemstone Circle, Winterville, 28590, United States of America,<br />
Robbinst@ecu.edu, DJ Medeiros, Terry Harrison<br />
Erlang C is a widely used model for call centers. Erlang C makes many assumptions<br />
with one of the most problematic being no abandonment. Many authors have<br />
recently advocated the use of the more complicated Erlang A model. We present the<br />
results of a simulation study that compares the performance of these models over a<br />
range of realistic call center conditions. We find that while the Erlang A model is<br />
often more accurate, it is not always so. We also find the models have different<br />
biases.<br />
3 - Routing to Manage Resolution and Waiting Time in Call Centers<br />
with Heterogeneous Servers<br />
Yong-Pin Zhou, Michael G. Foster School of Business, Box 353200,<br />
University of Washington, Seattle, WA, 98195-3200, United States of<br />
America, yongpin@uw.edu, Kevin Ross, Geoff Ryder, Vijay Mehrotra<br />
In many call centers, agents exhibit very different performance for the same call<br />
type, where performance is defined by the average call handling time and the call<br />
resolution probability. We explore strategies for determining call routing policies,<br />
where call assignments are dynamically determined based on the specific attributes<br />
of the agents and/or the current state of the system. We test several strategies using<br />
data obtained from a financial service firm and present empirical results.<br />
INFORMS Austin – 2010<br />
398<br />
4 - Call Centers with Hyperexponential Patience<br />
Alex Roubos, VU University Amsterdam, Department of<br />
Mathematics, De Boelelaan 1081A, Amsterdam, 1081 HV,<br />
Netherlands, aroubos@few.vu.nl<br />
We show that customers’ patience can be modeled by the hyperexponential<br />
distribution; which allows an exact analysis. A framework is developed in order to<br />
compute all kinds of practical service levels. This framework utilizes the recursive<br />
relation between the queue lengths at successive service completion epochs. Our<br />
approach shows overall better performance compared to current algorithms.<br />
Moreover, the computation times are short and our approach can therefore readily<br />
be applied in practice.<br />
■ WB38<br />
C - Room 9A, Level 3<br />
First-order Optimization Methods and<br />
Their Applications<br />
Sponsor: Optimization/Linear Programming and Complementarity<br />
(Joint Cluster ICS)<br />
Sponsored Session<br />
Chair: Zaiwen Wen, NSF Math Institutes’ postdoc, United States of<br />
America, zw2109@columbia.edu<br />
1 - Bundle-type Methods Uniformly Optimal for Smooth and<br />
Non-smooth Convex Optimization<br />
Guanghui Lan, Assistant Professor, University of Florida,<br />
Department of Industrial and Systems Engineering, Gainesville, FL,<br />
United States of America, glan@ise.ufl.edu<br />
The study of Bundle or level-type methods has been focused on non-smooth convex<br />
programming (CP) problems. In this talk we present new bundle-type methods<br />
which are optimal, not only for non-smooth, but also for smooth convex<br />
programming problems. Surprisingly, the optimal rates of convergence are obtained<br />
without even requiring any smoothness information. We also demonstrate the<br />
superior practical performance of these methods over existing optimal methods for<br />
convex programming.<br />
2 - Fast Splitting and Alternating Linearization Methods for<br />
Convex Optimization<br />
Shiqian Ma, Columbia University, 500 W. 120th Street, Mudd Blvd,<br />
Room 313, New York, NY, 10027, United States of America,<br />
sm2756@columbia.edu, Donald Goldfarb<br />
In this talk, we present two classes of splitting and alternating direction methods for<br />
which we can obtain iteration complexity bounds. The basic and accelerated<br />
versions of these methods require 1/e and 1/e^(1/2) iterations to obtain an eoptimal<br />
solution, respectively. These complexity results are the first ones that have<br />
been given for splitting and alternating direction type methods.<br />
3 - A Unified Approach for Minimizing Composite Norms<br />
Necdet Aybat, Columbia University, IEOR Department,<br />
Columbia University, New York, NY, United States of America,<br />
nsa2106@columbia.edu, Garud Iyengar<br />
FALC is a first-order augmented Lagrangian algorithm to solve<br />
min{mu1|X|_*+mu2|C(X)-d|_1:A(X)=b},where X in R^{m*n},by inexactly solving a<br />
sequence of problems.FALC converges to the optimal X_* if it is unique. For all e>0,<br />
iterates are e-feasible, e-optimal in O(1/e) iterations.FALC can also solve:<br />
min{mu1|X|_p+mu2|C(X)-d|_q+:A(X)=b, F(X)-G is psd, |H(X)-h|_r
2 - A Probabilistic Comparison Between Split Cuts and Type 1<br />
Triangle Cuts<br />
Qie He, School of Industrial & Systems Engineering, Georgia<br />
Institute of Technology, 765 Ferst Drive NW, Atlanta, GA, 30332,<br />
United States of America, qie.he@gatech.edu, George L. Nemhauser,<br />
Shabbir Ahmed<br />
The nontrivial facets for mixed-integer programs (MIP) with two rows and two<br />
integer variables are split (or Gomory) cuts, three types of triangle cuts, and<br />
quadrilateral cuts. This talk presents a probabilistic comparison of split and type 1<br />
triangle cuts. Under a reasonable distribution of the problem parameters of the MIP,<br />
we show that the average performance of a single split cut is better than a single<br />
type 1 triangle cut in terms of dominance and volume cut off from the linear<br />
relaxation.<br />
3 - A Polyhedral Study of the Triplet Fromulation for Single Row Facility<br />
Layout Problem<br />
Sujeevraja Sanjeevi, PhD Student, Texas A&M University, TAMU<br />
3131, College Station, TX, 77843-3131, United States of America,<br />
sujeevraja@tamu.edu, Kiavash Kianfar<br />
We present a polyhedral study of the triplet formulation for the Single Row Facility<br />
Layout Problem, introduced by Amaral (Dis. App. Math., 2009). We show that this<br />
polytope is of dimension n(n-1)(n-2)/3, where n is the number of facilities. We then<br />
prove that several valid inequalities (VIs) proposed by Amaral are facet-defining.<br />
This provides a theoretical support for the strength of the LP lower bounds obtained<br />
by Amaral. We also present a generalized class of VIs that encompass Amaral’s VIs.<br />
4 - Finding Good MIP Solutions by Restricted Tree Search<br />
Menal Guzelsoy, Georgia Institute of Technology,<br />
mguzelsoy@gatech.edu, George L. Nemhauser, Martin Savelsbergh<br />
Starting with the branch-and-bound tree associated with the solution of a restricted<br />
mixed integer program (MIP), i.e., a MIP in which some variables are fixed, we<br />
expand certain nodes of the search tree by using dual information to selectively free<br />
previously fixed variables in the hope of quickly finding improved solutions.<br />
■ WB40<br />
C - Room 9C, Level 3<br />
Panel Discussion: COIN-OR Technology Forum<br />
Cluster: John Forrest-fest | COIN-OR 10th (Joint Cluster Computing)<br />
Invited Session<br />
Moderator: Ted Ralphs, Associate Professor, Lehigh University, 200 West<br />
Packer Avenue, Bethlehem, PA, 18015, United States of America,<br />
ted@lehigh.edu<br />
1 - Panel Discussion: COIN-OR Technology Forum<br />
Panelists: Ted Ralphs, Associate Professor, Lehigh University, 200<br />
West Packer Avenue, Bethlehem, PA, 18015, United States of<br />
America, ted@lehigh.edu, Lou Hafer, Simon Fraser University,<br />
Burnaby BC V5A 1S6, Canada, lou@cs.sfu.ca, William Hart, Sandia<br />
National Laboratories, PO Box 5800, Albuquerque NM, United States<br />
of America, wehart@sandia.gov, Kipp Martin, University of Chicago,<br />
5807 South Woodlawn, Chicago IL 60637, United States of America,<br />
kmartin@chicagobooth.edu<br />
Following up on last year’s successful forum, this panel discussion will be an<br />
opportunity for users and developers of COIN-OR software to discuss recent and<br />
future developments within COIN-OR. If you want to get involved, provide<br />
feedback, or just learn about COIN-OR, please join us!<br />
■ WB41<br />
C - Room 10A, Level 3<br />
Vehicle Routing II<br />
Contributed Session<br />
Chair: Sam Thangiah, Professor, Slippery Rock University, 250 ATS,<br />
Computer Science Department, Slippery Rock, PA, 16057,<br />
United States of America, sam.thangiah@sru.edu<br />
1 - Backhaul Vehicle Routing Problem with Time Constraint<br />
Yuanyuan Dong, Southern Methodist University, P.O. Box 750123,<br />
Dallas, TX, 75275-0123, United States of America,<br />
njdyy03@gmail.com, Junfang Yu<br />
A backhaul vehicle routing problem has been studied in which maximum profit is<br />
desired during backhaul trip but travel time is constrained. A heuristic algorithm,<br />
adapted from genetic algorithm, has been developed and implemented for the<br />
problem. Empirical study has been performed to show the efficiency and<br />
effectiveness of the algorithm.<br />
INFORMS Austin – 2010 WB42<br />
399<br />
2 - Hybrid Genetic Algorithm for the Split Delivery Vehicle<br />
Routing Problem<br />
Joe Wilck, The University of Tennessee - Knoxville, 411 East<br />
Stadium, Knoxville, TN, United States of America, jwilck@utk.edu,<br />
Gautham Rajappa, Michael Vanderlan<br />
The SDVRP allows customers to be assigned to multiple routes. A genetic algorithm<br />
is presented where results from a construction heuristic are used to rank the<br />
importance of certain node relationships. If nodes 2 and 9 appear on the same route<br />
in many solutions, and those solutions have significantly lower distances when<br />
compared to solutions where nodes 2 and 9 are not on the same route, then the<br />
nodes 2 and 9 have a higher probability of being placed on the same route in future<br />
generations.<br />
3 - Solving Large Scale Dial-A-Ride Problem using a Two-Stage<br />
Heuristic Based on Clustering-Routing<br />
Taehyeong Kim, University of Maryland, Dept of Civil &<br />
Environmental Eng, 1173 Glenn L. Martin Hall, College Park, MD,<br />
20742, United States of America, tommykim@umd.edu, Ali Haghani<br />
In this paper, a static DARP model with time varying travel times and multiple<br />
depots is formulated. Also, a heuristic methodology using two-stage is proposed to<br />
solve this problem. At first stage, initial solution is constructed using clusteringrouting<br />
algorithm. And then, it is improved at next stage. The model is used to solve<br />
a real world problem that is provided by the MTA in Baltimore, MD and the results<br />
of implementing the model are compared with those of current system operations.<br />
4 - Multi-depot, Multi-Destination, Mix-Fleet Vehicle Routing Problem<br />
with Real-Life Constraints<br />
Sam Thangiah, Professor, Slippery Rock University, 250 ATS,<br />
Computer Science Department, Slippery Rock, PA, 16057,<br />
United States of America, sam.thangiah@sru.edu, Joseph Forsythe<br />
This paper presents a real-life multi depot, multi-destination, mix-fleet vehicle<br />
routing problem with 1200 pickup locations, 2000 customers and 60 vehicles. The<br />
precise distances between pickup locations are obtained using digitized road maps<br />
instead of Euclidean distance. Heuristics for solving the problem and results for the<br />
real-life data set are reported.<br />
■<br />
WB42<br />
C - Room 10B, Level 3<br />
Computational Optimization and Applications II<br />
Sponsor: Optimization/Computational Optimization and Software<br />
(Joint Cluster ICS)<br />
Sponsored Session<br />
Chair: Ali Ekici, Assistant Professor, University of Houston, Department of<br />
Industrial Engineering, E221A Engineering Building 2, Houston, TX,<br />
77204, United States of America, aekici@Central.UH.EDU<br />
1 - On the Parallel Computation of Individual Penalties in<br />
Scheduling Jobs<br />
Irinel Dragan, Professor Emeritus of Mathematics, University of<br />
Texas at Arlington, U.T.Arlington, Mathematics, Arlington, TX,<br />
76019-0408, United States of America, dragan@uta.edu<br />
For scheduling n jobs on a single machine, with a common due date. and given<br />
weights, we want to find a schedule which minimizes the total penalty. We build a<br />
scheduling game and we propose to compute in parallel the individual penalties as<br />
the Shapley Value expressed by means of the Average per capita formula<br />
(Dragan,1992).<br />
2 - Experience in Developing Heuristic Algorithms to Solve Large-scale<br />
Non-convex NLP Problem<br />
Vladimir Krichtal, Senior Development Engineer, Transpower NZ, 96<br />
The Terrace, P.O. Box 1021, Wellington, New Zealand,<br />
Vladimir.Krichtal@transpower.co.nz, Conrad Edwards<br />
Transpower, as the New Zealand power system operator, uses an LP dispatch and<br />
pricing model. The model is derived from a non-convex NLP one, with quadratic<br />
circuit losses approximated by piece-wise linear functions. Sometimes the solver<br />
does not solve the resulting LP model correctly. The types of incorrect solutions are<br />
identified. Some of these incorrect solutions are prevented via market rule changes.<br />
Other can be fixed using heuristic iterative MIP algorithms.<br />
3 - Cutting Stock Problem with Setup Costs<br />
Ali Ekici, Assistant Professor, University of Houston, Department of<br />
Industrial Engineering, E221A Engineering Building 2, Houston, TX,<br />
77204, United States of America, aekici@Central.UH.EDU,<br />
Azadeh Mobasher<br />
We study the weighted cutting stock problem which is a more general version of the<br />
well-known cutting stock problem. The objective in weighted cutting stock problem<br />
is to minimize total production cost including both waste and setup costs. Since the<br />
problem is NP-hard, we develop heuristic algorithms to find good solutions and test<br />
their effectiveness on randomly generated instances.
WB44<br />
■ WB44<br />
C - Room 2, Level 2- Mezzanine<br />
Appointment Scheduling in Healthcare<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: Serhan Ziya, University of North Carolina, 356 Hanes Hall<br />
CB# 3260, Chapel Hill, NC, 27599, United States of America,<br />
ziya@email.unc.edu<br />
Co-Chair: Nan Liu, Mailman School of Public Health, Columbia<br />
University, 600 W 168th ST, 6th Floor, New York, NY, 10032, United<br />
States of America, nl2320@columbia.edu<br />
1 - A Comparison of Traditional and Open-access Appointmentscheduling<br />
Policies<br />
Rachel Chen, University of California at Davis, Graduate School of<br />
Management, Davis, CA, 95616, United States of America,<br />
rachen@ucdavis.edu, Lawrence Robinson<br />
Under traditional scheduling, patients are booked in advance, but may not show up.<br />
Under open-access scheduling, a random number of patients call in the morning to<br />
make an appointment for that same day. Thus under either policy the number of<br />
patient arrivals will be random, for different reasons. We find that the open-access<br />
schedule in general outperforms the traditional schedule, except when patient<br />
waiting time is held in little regard or when no-show probability is small.<br />
2 - Adaptive Appointment Systems with Patient Preferences<br />
Wen-Ya Wang, University of Minnesota, 111 Church St SE,<br />
Minneapolis, MN, 55455, United States of America,<br />
wenya@ie.umn.edu, Diwakar Gupta<br />
We propose a framework for the design of the next generation of appointment<br />
systems that dynamically learn and update patients’ preferences, and use this<br />
information to improve booking decisions. Analytical results leading to a partial<br />
characterization of an optimal booking policy are presented. Examples show that<br />
heuristic decision rules, based on this characterization, perform well and reveal<br />
insights about tradeoffs among a variety of performance metrics important to clinic<br />
managers.<br />
3 - Controlling Demand for Appointment-based Services in the<br />
Presence of No-show Customers<br />
Nan Liu, Mailman School of Public Health, Columbia University,<br />
600 W 168th ST, 6th Floor, New York, NY, 10032,<br />
United States of America, nl2320@columbia.edu, Serhan Ziya<br />
Customer no-shows is a major problem for many service systems that work with<br />
appointments. In this talk, we model the scheduled appointments as a single-server<br />
queue and investigate how to maximize system throughput taking into account<br />
waiting time dependent no-shows. We also study how to adjust the system design<br />
in response to changes in customer no-show behavior. Both analytical and<br />
numerical results will be presented.<br />
■ WB45<br />
C - Room 6, Level 2- Mezzanine<br />
Modeling and Optimizing Quality of Care and Efficiency<br />
of Delivery<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: Eva Lee, Professor & Director, Georgia Institute of Technology,<br />
Center for Operations Research in Medici, Industrial & Systems<br />
Engineeriing, Altanta, GA, 30332-0205, United States of America,<br />
eva.lee@gatech.edu<br />
1 - Quantifying Reductions in Variability of Intraoperative Time From<br />
Meta-analysis of Trial Results<br />
Franklin Dexter, Professor, University of Iowa, Department of<br />
Anesthesia, 6JCP, Iowa City, IA, 52242, United States of America,<br />
franklin-dexter@uiowa.edu<br />
Electronic medical record data were used to facilitate meta-analysis of randomized<br />
clinical trials. For interventions affecting anesthetic durations, usually there are<br />
many (> 20) clinical trials each with small N (
4 - Influenza Vaccine Supply Chain: Role of Consumption Externality<br />
and Yield Uncertainty<br />
Kenan Arifoglu, PhD Student, Northwestern University, 2145<br />
Sheridan Road, Room C 210, Evanston, IL, 60208, United States of<br />
America, kenanarifoglu2011@u.northwestern.edu, Sarang Deo,<br />
Seyed Iravani<br />
We consider the inefficiency in flu vaccine supply chain and study the impact of two<br />
critical factors: yield uncertainty (supply side) and self-interested consumers<br />
(demand side). Contrary to previous economic models, we find that consumers may<br />
demand more vaccinations than is socially optimal when they jointly consider the<br />
availability and infection externalities. We study two partially-centralized supply<br />
chains to investigate the benefits of government interventions on demand and<br />
supply side.<br />
■ WB47<br />
C - Room 8, Level 2- Mezzanine<br />
Project Scheduling and Risk Management<br />
Cluster: Topics in Project Management<br />
Invited Session<br />
Chair: Richard Wendell, Professor, Katz Graduate School of Business,<br />
University of Pittsburgh, Pittsburgh, PA, 15260, United States of America,<br />
wendell@katz.pitt.edu<br />
Co-Chair: Timothy Lowe, Professor, Tippie College of Business,<br />
University of Iowa, Iowa City, IA, United States of America,<br />
timothy-lowe@uiowa.edu<br />
1 - New Product Design and Pricing in a Duopoly Market with<br />
Forward-looking Consumers<br />
Ted Klastorin, Burlington Northern/Burlington Resources Professor,<br />
Department of Information Systems & Operations Mgt, Michael G<br />
Foster School of Business, University of Washington, Seattle, WA,<br />
98195-3200, United States of America, tedk@u.washington.edu,<br />
Aysun Ozler, Yong-Pin Zhou<br />
We study the introduction of a new product into a durable goods duopoly market.<br />
In our model, an innovator firm begins to develop a product; after a random time<br />
period, information about this product leaks and an imitator firm begins to develop<br />
a competing product. Consumers are forward looking and make purchases based on<br />
the available product and their expectations on future products. We derive<br />
implications for both profit-maximizing firms with respect to the design and pricing<br />
of the products.<br />
2 - Planning Stochastic Projects Under the Threat of a Disruptive Event<br />
Gary Mitchell, Assistant Professor, Pamplin School of Business<br />
Administration, University of Portland, 5000 N. Willamette Blvd,<br />
Portland, OR, 97035, United States of America, mitchelg@up.edu,<br />
Ted Klastorin, Issariya Sirichakwal<br />
We consider the issue of planning a stochastic project when there is a threat of an<br />
exogenous disruptive event that may stop work on one or more tasks (possibly the<br />
entire project). Our goal is to minimize expected total project costs, including<br />
resource costs, overhead/indirect costs, and penalty costs. We analyze a model to<br />
determine when the project manager should take proactive steps during the<br />
planning phase or wait and take contingent actions after a disruption occurs.<br />
3 - Agility in Projects - Theoretical and Computational Results<br />
Karolina Glowacka, Assistant Professor, Stevens Institute of<br />
Technology, Howe School of Technology Management, Hoboken, NJ,<br />
07030, United States of America, kglowack@stevens.edu, Richard<br />
Wendell, Timothy Lowe<br />
In this research we show that a lack of agility can be a significant factor in project<br />
delays. We characterize the concept of agility in projects, show how agility can have<br />
a significant impact on the likelihood of achieving a target-time for a project, and<br />
give some general properties on agility with respect to a project’s structure. We also<br />
discuss how and where to build agility into key project activities.<br />
4 - Integration of Project Management and Software Development<br />
Processes in a Complex Project<br />
Laura Anderson, Manager, Advanced Estimating & Infrastructure<br />
Solutions, IBM Research - Almaden, 650 Harry Road, San Jose, CA,<br />
95120, United States of America, laurac@almaden.ibm.com,<br />
Ruoyi Zhou<br />
Project management continues to increase in complexity, with special challenges<br />
due to agile methodologies and geographically dispersed teams. We describe our<br />
experience in software project management for a medium sized research and<br />
development project using IBM’s Rational Jazz. We discuss the observed<br />
advantages of Jazz in systematizing the overall process, with narrative observations,<br />
quantitative measurements, and objective measures of the value of such a project<br />
management system.<br />
INFORMS Austin – 2010 WB50<br />
401<br />
■ WB49<br />
C -Room 10, Level 2- Mezzanine<br />
Systems Analysis and Design<br />
Sponsor: Information Systems<br />
Sponsored Session<br />
Chair: Vijay Khatri, Indiana University, 1309 E. 10th Street, BU 560F,<br />
Bloomington, IN, 47405, United States of America, vkhatri@indiana.edu<br />
Co-Chair: Jeffrey Parsons, jeffreyp@mun.ca<br />
1 - A Cognitive Perspective on Developing and Interpreting<br />
Conceptual Models<br />
Palash Bera, Assistant Professor, Texas A&M InternationalUniversity,<br />
5201, University Blvd., Laredo, TX, 78041, United States of America,<br />
palash.bera@tamiu.edu<br />
Conceptual models are often used to document features of the domain to be<br />
reflected in the Information Systems. Developing and interpreting conceptual<br />
models can be considered as cognitive tasks performed by modelers. In a laboratory<br />
setting, this study contrasts the cognitive difficulties faced by two groups of<br />
modelers- one who develops the models and the other who interprets the same<br />
models. The results indicate that the cognitive difficulties faced by the groups are of<br />
different nature.<br />
2 - Business Informational Sabotage: An Exploration into Incidence<br />
Rates and Causes<br />
John Erickson, University of Nebraska at Omaha, College of<br />
Business, 6001 Dodge Street, Omaha, NE, 68182, United States of<br />
America, johnerickson@mail.unomaha.edu, George Gresham,<br />
John Hafer<br />
This study represents an exploratory effort into the occurrence rates of nineteen<br />
types of organizational information sabotage, moral attitudes towards the acts and<br />
the saboteurs. Roughly 40% of the respondents indicated awareness of sabotage and<br />
up to 31% admitted committing one/some acts of sabotage. Demographic variables<br />
were tested for significance.<br />
3 - Experiments in Paired Software Development<br />
Radha Mahapatra, Associate Professor, University of Texas at<br />
Arlington, 701 S. West St., Arlington, TX, 76019-0437,<br />
United States of America, mahapatra@uta.edu, Sridhar Nerur,<br />
VenuGopal Balijepally, George Mangalaraj<br />
A core practice in recently popularized agile software development methods is<br />
paired development, where two developers work together to jointly design and<br />
develop application systems. We have conducted a series of experiments to<br />
understand the efficacy of paired development vis-á-vis the traditional practice of<br />
software development by developers working individually. Findings from these<br />
experiments will be presented.<br />
■ WB50<br />
C -Room 11, Level 2- Mezzanine<br />
Information Systems I<br />
Contributed Session<br />
Chair: Zsolt Ugray, Associate Professor, USU, 3515 Old Main Hill, Logan,<br />
United States of America, Zsolt.Ugray@usu.edu<br />
1 - Bundling of Information Sources using the Value of Information<br />
Pantea Alirezazadeh, PhD Student, University of Connecticut, 2100<br />
Hillside rd, Unit 1041, Storrs, CT, 06269, United States of America,<br />
pantea.alirezazadeh@business.uconn.edu, Fidan Boylu, Ram Gopal<br />
We present a method for acquiring information from multiple information sources<br />
with different reliabilities based on the incremental value of information. We<br />
evaluate the value of information that can be provided by third-party data providers<br />
and measure the value of different combinations of information sources based on<br />
their contribution to expected utility and provide heuristic solutions to select an<br />
optimal combination of these information sources.<br />
2 - Understanding Time Inconsistent Preferences in Real Options<br />
Based it Investment Justification<br />
Ram Kumar, UNC- Charlotte, 9201 University City Blvd, Charlotte,<br />
NC, United States of America, rlkumar@uncc.edu,<br />
Sarah Khan<br />
The literature on the use of Real Options in IT (and other) investment justification<br />
assumes that decison makers will be able to exercise options optimallly. However, in<br />
practice, decision makers can have time inconsistent preferences. The effects of<br />
these preferences on the use of Real Options Analysis is analyzed. This analysis has<br />
important implications for decison makers.
WB51<br />
3 - Multicriteria Model for Selecting Information Systems Based on the<br />
PROMETHEE Method<br />
Jônatas Almeida, Federal University of Pernambuco, Recife-PE,<br />
Brazil, jonatasaa@yahoo.com.br, Ana Paula Costa, Adiel Almeida<br />
This paper discusses the importance of the process of selecting Information Systems<br />
(ISs) integrated with an IS planning methodology. A model which integrates an<br />
adapted version of an IS planning methodology called Business System Planning<br />
(BSP) and the multicriteria method PROMETHEE II is presented. As a contribution,<br />
this paper identifies the need for ISs to start from the company’s strategic vision,<br />
including how value is to be added to the business, considering aspects for the<br />
organization.<br />
4 - Franchisee Attitudes Toward the Adoption of Advanced Internet<br />
Technologies and Innovations<br />
Zsolt Ugray, Associate Professor, USU, 3515 Old Main Hill, Logan,<br />
United States of America, Zsolt.Ugray@usu.edu, Kelley O’Reilly<br />
We present findings from a case study exploring franchisees’ attitudes and<br />
perceptions of using advanced Internet technologies and innovations. We illustrate<br />
that the dual role of owner-operators, in which they are both decision makers and<br />
users of technologies, provides a dichotomy of perspectives that yield insights into<br />
aspects of business leadership, customer service, and operational proficiency.<br />
■ WB51<br />
C -Room 12, Level 2- Mezzanine<br />
Analyses for Rotary Wing Aircraft<br />
Sponsor: Military Applications<br />
Sponsored Session<br />
Chair: Caolionn O’Connell, Institute for Defense Analyses, 4850 Mark<br />
Center Drive, Alexandria, VA, 22311, United States of America,<br />
coconnel@ida.org<br />
1 - Rotary Wing Aircraft Capacity for Operations in Afghanistan<br />
Matthew Grund, Research Analyst, CNA, 4825 Mark Center Drive,<br />
Alexandria, VA, 22311, United States of America, grundm@cna.org,<br />
Greg Cox<br />
Senior leaders in the Department of Defense have expressed concern that there is<br />
insufficient rotary wing capacity in Afghanistan to effectively carry out the required<br />
missions. Our work broadly explores three ways of increasing rotary wing capacity<br />
in Afghanistan: increasing the number of aircraft in theater, increasing the hours<br />
flown by aircraft already in theater, and increasing the efficiency of flight hours<br />
already being flown by aircraft in Afghanistan.<br />
2 - Utility Assessment of Rotary Wing Aircraft<br />
Dana Paterson, Senior Analyst, Naval Air Systems Command,<br />
Bldg 2109, Room S211, Patuxent River, MD, 20670,<br />
United States of America, dana.paterson@navy.mil<br />
Decision makers faced with making a choice among a finite set of rotary-wing<br />
aircraft, aircraft designs or aircraft concepts must have information products<br />
describing the utility of each member of the set. This briefing is a description of a<br />
senior analyst’s method beginning with identification of the decision to be made and<br />
ending with an exposition of his preferred method for describing the decision space<br />
for the decision maker.<br />
3 - A Forensic Analysis of Cost Growth in Rotary Wing Programs<br />
Caolionn O’Connell, Institute for Defense Analyses, 4850 Mark<br />
Center Drive, Alexandria, VA, 22311, United States of America,<br />
coconnel@ida.org<br />
An analysis of cost growth in rotary wing (RW) programs and how it compares to<br />
other major defense acquisition programs (MDAPs). The brief will also include a<br />
discussion of possible root causes for RW cost growth and a suggested cost<br />
estimating methodology for future programs.<br />
4 - Army Aviation Force Structure<br />
Steven Stoddard, US Army, Burke, VA, United States of America,<br />
steven.stoddard@us.army.mil<br />
The Army has the responsibility to provide manned, trained, and equipped units to<br />
support operations. We explain how the Army manages the supply of helicopter<br />
units to meet as much demand as possible. We answer three questions: 1.<br />
What happens if the Army adds more helicopters? 2. What happens if the Army<br />
uses its helicopter units more often? 3. What happens if the Army alters its active -<br />
reserve mix?<br />
INFORMS Austin – 2010<br />
402<br />
■ WB52<br />
C -Room 13, Level 2- Mezzanine<br />
Assessing Terrorism Probabilities and All-Hazards Risk<br />
in the U.S. Department of Homeland Security<br />
Cluster: Homeland Security and Defense<br />
Invited Session<br />
Chair: Steve Bennett, Asst. Director, Risk Analytics Division, Office of<br />
Risk Management and Analysis, U.S. Department of Homeland Security,<br />
Washington, DC, 20528, United States of America, steve.bennett@dhs.gov<br />
1 - Relative Probabilities of Terrorist Attacks: Rational Adversaries with<br />
Uncertain Value Tradeoffs<br />
Evan Levine, DHS Office of Risk Management and Analysis,<br />
2929 Connecticut Ave NW, Apt 709, Washington, DC, 20008,<br />
United States of America, evan.levine@dhs.gov<br />
Many analyses conducted to inform counterterrorism decisions depend on estimates<br />
of the relative probabilities of different attack types. We describe a method of using<br />
uncertainty in utility function value tradeoffs to model the adversary’s decision<br />
process and solve for the relative probabilities of attacks in closed form. The process<br />
we describe is an extension of value-focused thinking, and is suitable for application<br />
outside of counterterrorism, including general business decision-making.<br />
2 - Informing All-hazards Decision-making at the U.S. DHS:<br />
Constructing an Appropriate Scenario Set<br />
Julie Waters, Risk Analyst, Office of Risk Management and Analysis,<br />
U.S. Department of Homeland Security, Washington, DC, 20528,<br />
United States of America, julie.waters@dhs.gov, Evan Levine,<br />
Steve Bennett<br />
The Homeland Security National Risk Assessment (HSNRA) methodology, developed<br />
by DHS, uses an order-of-magnitude estimation technique to quantify the dominant<br />
risks across the disparate hazards confronted by the Nation. In this presentation, we<br />
discuss how the space of possible events relevant to homeland security is discretized<br />
into scenarios that form the units of analysis for frequency and consequence<br />
elicitation and the process by which dominant scenarios are identified.<br />
3 - Eliciting Probabilities From the Intel Community to Support<br />
Terrorism Risk Assessments at U.S. DHS<br />
Natasha Hawkins, Risk Analyst, U.S. Department of Homeland<br />
Security, Washington, DC, 20528, United States of America,<br />
natasha.hawkins@dhs.gov, Tony Cheesebrough, Steve Bennett<br />
Probability elicitations for terrorism involve engaging intelligence community<br />
experts who generally communicate threat judgments in qualitative terms. This<br />
presentation will discuss challenges and opportunities in applying expert elicitation<br />
methods to the elicitation of intelligence information in DHS and provide an<br />
opportunity for the OR/MS community to provide input and suggestions for<br />
improvement and enhancement.<br />
4 - RAPID: Supporting Risk-informed Strategic Policy and Resource<br />
Allocation Decisions at the U.S. DHS<br />
Debra Elkins, Section Chief, Risk Assessments and Analysis, U.S.<br />
Department of Homeland Security, U.S. Department of Homeland<br />
Security, Washington, DC, 20528, United States of America,<br />
debra.elkins@dhs.gov, Steve Bennett, Tony Cheesebrough,<br />
Natasha Hawkins<br />
The Risk Assessment Process for Informed Decision-making (RAPID) is a risk<br />
assessment conducted within the DHS Office of Risk Management and Analysis that<br />
supports strategic policy and budgetary decision-making across the U.S. Department<br />
of Homeland Security. This presentation will describe the technical risk analysis<br />
methodologies used in RAPID and provide an opportunity for the OR/MS<br />
community to provide input and suggestions for improvement and enhancement.
■ WB53<br />
C -Room 14, Level 2- Mezzanine<br />
Operations/Marketing Interface I<br />
Contributed Session<br />
Chair: Baokun Li, Dr., Southwestern University of Finance and<br />
Economics, 555 Liutai Ave, Wenjiang District, Chengdu, 611130, China,<br />
flyinghorse1967@yahoo.com<br />
1 - Market-based Joint Decisions on Price, Delivery Time, Service<br />
Level, and Supplier Selection<br />
Li Qian, South Dakota State University, Solberg Hall 115B,<br />
Brookings, 57006, United States of America, li.qian@sdstate.edu<br />
This paper models the demand as a linear or log-linear function of attributes<br />
including price, guaranteed delivery time, and service level. With stochastic delivery<br />
time, the service level is not always binding at the minimal value reserved by the<br />
manager or the market, as assumed in most literature. A market-oriented approach<br />
for supplier selection or investment is proposed in consideration of operation<br />
performances in cost, delivery time, service level, and/or quality in an integrated<br />
manner.<br />
2 - Cooperative Advertising in a Dynamic Durable Goods Supply Chain<br />
Anshuman Chutani, UT Dallas, School of Management, SM 30,<br />
Richardson, TX, 75080, United States of America,<br />
anshuman.chutani@student.utdallas.edu, Suresh Sethi<br />
We analyze dynamic advertising and pricing policies in a durable goods supply chain<br />
with co-operative advertising. We consider a stackelberg game where manufacturer<br />
announces the wholesale price and its share in the retailer’s advertising<br />
expenditure. The retailer responds with its optimal advertising and pricing policies.<br />
The sales dynamics follows the model suggested by Sethi, Prasad and He (2008). We<br />
analyze two different demand specifications, linear and iso-elastic.<br />
3 - Can We All Get Along? Incentive Contracts to Bridge the Marketing<br />
and Operations Divide<br />
Kinshuk Jerath, Assistant Professor, Carnegie Mellon University,<br />
5000 Forbes Ave, Pittsburgh, PA, 15213, United States of America,<br />
kinshuk@cmu.edu<br />
The marketing and operations management arms in a firm must work in<br />
coordination. However, a major source of conflict is that marketing compensation is<br />
usually heavily weighted towards sales whereas operations compensation is usually<br />
heavily weighted towards expense reduction. In this paper, we invoke agency<br />
theory to determine compensation plans for sales and operations managers to<br />
coordinate their activities in the best interests of the firm.<br />
4 - Computing Reasonable Allocations in Coalition Games<br />
Baokun Li, Dr., Southwestern University of Finance and Economics,<br />
555 Liutai Ave, Wenjiang District, Chengdu, 611130, China,<br />
flyinghorse1967@yahoo.com<br />
We introduce a new kind of coalition gain allocation, Proportion Allocation, which<br />
is inspired from the Coarsening at Random mechanism in statistics. Based on the<br />
Proportion Allocation and traditional Shapley value, a reasonable class of allocations<br />
is dened and related algorithm is given for calculating them. Besides, a simulated<br />
annealing method is constructed to solve for the stable allocation, nucleolus, for<br />
coalition games.<br />
■ WB54<br />
C -Room 15, Level 2- Mezzanine<br />
Characterizing Uncertainty and Learning for<br />
Technology Choice Decisions<br />
Sponsor: Technology Management/New Product Development<br />
Sponsored Session<br />
Chair: Thomas Rand-Nash, Doctoral Candidate, Massachusetts Institute of<br />
Technology Materials Systems Laboratory, 77 Massachusetts Avenue,<br />
Cambridge, MA, 02139, United States of America, trand@mit.edu<br />
1 - Learning-Derived Cost Evolution in Materials Selection<br />
Trisha Montalbo, MIT, 77 Massachusetts Ave, E38-420, Cambridge,<br />
United States of America, trisha@mit.edu, Richard Roth<br />
We investigate the impact of considering cost evolution due to learning by doing in<br />
the selection of materials for a manufacturing firm. A multi-product, multi-period<br />
selection framework is developed to analyze the problem because single-product<br />
selection methods are unable account for benefits realized through shared learning<br />
among products. The use of test beds as a strategy for introducing new materials to<br />
a firm is also evaluated.<br />
INFORMS Austin – 2010 WB55<br />
403<br />
2 - Cost-Optimal Reinspection Plans<br />
Hadi Zaklouta, Graduate Student Researcher, MIT Materials Systems<br />
Laboratory, 292 Main Street, E38-435, Cambridge, MA, 02139,<br />
United States of America, zaklouta@mit.edu, Randolph Kirchain,<br />
Richard Roth<br />
This paper compares single and double inspection plans effect on cost and quality. A<br />
cost model is proposed that accounts for appraisal and internal/external failure<br />
costs. All units are tested with one or two tests. In plan RR, rejects are retested and<br />
replaced after rejection. In plan AR, accepts are retested and rejects replaced. Nonconformance<br />
rate and test error rates are known. The AR plan is best for high<br />
warranty/scrap cost ratio; the RR plan for low; a single test plan otherwise.<br />
3 - Learning as a Driver Technology Choice Decisions in Manufacturing<br />
Thomas Rand-Nash, Doctoral Candidate, Massachusetts Institute of<br />
Technology Materials Systems Laboratory, 77 Massachusetts Avenue,<br />
Cambridge, MA, 02139, United States of America, trand@mit.edu<br />
This work explores process technology decision making in the presence of learning<br />
effects in manufacturing, and hopes to characterize the conditions under which<br />
learning-related production cost effects impact technology choice decision making.<br />
Relevant factors considered include learning rates, production volume as a function<br />
of demand, market structure, and budget constraints.<br />
4 - Shifting Grounds: How Industry Emergence Changes the<br />
Effectiveness of Knowledge Creation Strategies<br />
Sebastian Fixson, Babson College, Babson Park, MA,<br />
United States of America, sfixson@babson.edu, Won Hee Lee<br />
The knowledge management literature has identified various aspects, advantageous<br />
and disadvantageous, of both inward-looking and outward-looking knowledge<br />
creation strategies. With a longitudinal empirical study we explore the dynamics of<br />
firms’ knowledge creation strategies during the period of industry emergence. We<br />
find that the emergence of an industry changes the effectiveness of the different<br />
knowledge creation strategies.<br />
■ WB55<br />
C -Room 16, Level 2- Mezzanine<br />
Sustainability and NPD<br />
Sponsor: Technology Management/New Product Development<br />
Sponsored Session<br />
Chair: Cheryl Druehl, Assistant Professor, George Mason University,<br />
4400 University Dr, MS 5F4, Fairfax, VA, 22030, United States of<br />
America, cdruehl@gmu.edu<br />
1 - New Business Models to Enable Clean and Renewable Generation<br />
in the Electric Power Industry<br />
Edward Anderson, Associate Professor, University of Texas,<br />
1 University Station B6500, Austin, TX, 78733, United States of<br />
America, Edward.Anderson@mccombs.utexas.edu, Geoffrey Parker<br />
Over the coming decades, electric power companies must transform their business<br />
models to accommodate the smart grid and growing demand for clean renewable<br />
energy. Many researchers are examining aspects of this problem, such as power<br />
companies’ infrastructure portfolios, consumer behavior, pricing structures, etc. To<br />
complement this analysis, we build and analyze a top-down systems model of a<br />
typical power company and its market “ecosystem” using the system dynamics<br />
methodology.<br />
2 - Does “To Go Green” Translate into Profitability?<br />
Asoo Vakharia, Professor, University of Florida, Department of ISOM,<br />
Gainesville, FL, 32611-7169, United States of America,<br />
asoo.vakharia@warrington.ufl.edu, Arda Yenipazarli<br />
Consumers are frequently integrating “green” product attributes when making<br />
purchasing decisions. We propose a firm level analytical model to enable decisions<br />
on whether to upgrade the “green” content of an existing product, replace the<br />
existing product with a “green” product, or provide a portfolio of an existing and<br />
“green” product.<br />
3 - Reviving the Electric Car Movement: Developing Green<br />
Infrastructure for Sustainable Transportation<br />
Cheryl Druehl, Assistant Professor, George Mason University, 4400<br />
University Dr, MS 5F4, Fairfax, VA, 22030, United States of America,<br />
cdruehl@gmu.edu, Michael Naor<br />
An innovative new business model for sustainable transportation is described. A<br />
case study approach is used to study the unique product and service development<br />
process required to electrify the automobile industry, focusing on a clean tech<br />
company building innovative green infrastructure for sustainable transportation in<br />
Israel.
WB56<br />
■ WB56<br />
C - Room 1, Level 1<br />
Human Decision-Making and Social<br />
Network Simulation<br />
Sponsor: Simulation Society<br />
Sponsored Session<br />
Chair: Young-Jun Son, Professor, The University of Arizona, Systems and<br />
Industrial Engineering, Tucson, AZ, 85721, United States of America,<br />
son@sie.arizona.edu<br />
1 - Hyper-Networks and Their Properties<br />
W. K. Victor Chan, Assistant Professor, Rensselaer Polytechnic<br />
Institute, ISE Dept, CII 5015, 110 8th Street, Troy, NY, 12180-3590,<br />
United States of America, chanw@rpi.edu, Cheng Hsu<br />
A hyper-network is an integration of multi-layered (role-based) connections of<br />
members in a community, such as the Internet and an ecosystem. In this talk, we<br />
formally define hyper-networks and present their analytical properties. We show<br />
that hyper-networks can reveal otherwise hidden social structures and provide<br />
estimation formulae for determining average vertex-vertex distances and average<br />
vertex degrees.<br />
2 - Simulation-based Workforce Assignment Considering Position in a<br />
Social Network<br />
Nurcin Celik, PhD, The University of Arizona, 1127 E James E.<br />
Rogers Way, Tucson, AZ, 85721-0020, United States of America,<br />
nurcinkoyuncu@gmail.com, Dong Xu, Hui Xi, Young-Jun Son,<br />
Robin Lemaire, Keith Provan<br />
A novel modeling framework is proposed to help managers devise optimal<br />
workforce assignments that consider both short and long-term aspects of the<br />
organizational social network. The framework involves the evaluation module (via<br />
agent-based simulation) to calculate the position and equivalence values between<br />
each pair of workforce members and the assignment module (via multi-objective<br />
optimization) to select an optimal workforce mix. The framework is illustrated with<br />
the Kuali organization.<br />
3 - Dynamic Control and Simulation of Manufacturing Process with<br />
Different Forms of Uncertainties<br />
Hyunsoo Lee, Texas A&M University, 3131 TAMUS, College Station,<br />
TX, 77843, United States of America, hsl@neo.tamu.edu,<br />
Amarnath Banerjee<br />
We show a method for capturing and dynamically controlling uncertainties under<br />
changes in manufacturing condition. Ambiguity and variance type uncertainties are<br />
incorporated into a Fuzzy colored Petri Net with stochastic time delay model and it<br />
is controlled using a new and effective learning method for simulation-based<br />
optimization. A semiconductor process with serial and batch machines is controlled<br />
and a given objective is achieved using the suggested simulation based optimization<br />
method.<br />
■ WB57<br />
C - Room 2, Level 1<br />
Financial Optimization in Energy and<br />
Communication Systems<br />
Sponsor: Financial Services Section<br />
Sponsored Session<br />
Chair: Jim Bander, Credit Risk Optimization Manager,<br />
Toyota Financial Services, 3200 W Ray Road, Chandler, AZ, 85226,<br />
United States of America, jim.bander@gmail.com<br />
1 - Energy Portfolio Investment with Entry Decisions<br />
Zhen Liu, Assistant Professor, Missouri University of Science &<br />
Technology, United States of America, zliu@mst.edu, Scott Grasman,<br />
Jianjun Deng<br />
We formulate energy portfolio problems as an optimization problem to maximize<br />
long-term profit through stochastic control and numerical analysis methods, and<br />
solve the following problems: (1) the optimal time to build a new alternative green<br />
energy power generating plant, and (2) the optimal dispatch from the existing coal<br />
plant and the new plant.<br />
2 - Reducing Price Volatility of Electricity Consumption for a Firm’s<br />
Energy Risk Management<br />
Xiaohua Wu, Rensselaer Polytechnic Institute, 903 Peoples Ave<br />
Apt 3, Troy, NY, 12180, United States of America, wux4@rpi.edu,<br />
Aparna Gupta<br />
Smart Grid technologies allow firms to manage electricity price volatility and<br />
fluctuations. We develop a framework to assess strategies for optimally shifting peak<br />
load consumption using distributed storage systems of Smart Grids. Risk<br />
management is achieved by optimal investment in storage systems and peak load<br />
shifting under stochastic electricity prices.<br />
INFORMS Austin – 2010<br />
404<br />
3 - A Regime-switching Approach to the Valuation of Weather Options<br />
M.I.M Wahab, Ryerson University, Toronto, ON, M5B 2K3, Canada,<br />
wahab@ryerson.ca, R. S. Elias, L. Fang<br />
Regime-switching processes are used to model the stochastic behavior of<br />
temperature with aim of valuation of temperature-based weather options. Three<br />
different models are used to predict the expected heating degree days (HDD) and<br />
cooling degree days (CDD) that play a crucial role in valuation of weather options.<br />
Temperature dataset from Toronto, Canada, is used for the analysis. Results<br />
demonstrate that one of the models captures temperature dynamics more accurately<br />
than the other two models.<br />
4 - Path-Vector Contracting: Profit Maximization and Risk Management<br />
Praveen Kumar, Rensselaer Polytechnic Inst, 110 8th Street,<br />
Troy, NY, United States of America, muthup@rpi.edu<br />
We consider an Internet Service Provider’s problem of providing end-to-end (e2e)<br />
services with bandwidth guarantees, using a path-vector based approach. The spotpricing<br />
framework for e2e bandwidth guaranteed services utilizes a path contracting<br />
strategy by formulating it as a stochastic optimization problem with the objective of<br />
maximizing expected profit subject to risk constraints.<br />
5 - Flash Crashes - Volatility, Smart Order Routing, and<br />
Market Fragmentation<br />
Bruce Weber, London Business School, Regent’s Park, London,<br />
NW14SA, United Kingdom, bweber@london.edu<br />
Advances in IT have lowered costs but also fostered trading practices that may<br />
negatively impact the entire market. A national market system for securities with<br />
multiple fragmented liquidity pools is simulated. We analyze how trading rules at<br />
different exchanges and software for smart order routing can lead to illiquidity and<br />
“flash crashes.” Under certain conditions, high frequency trading can lead to<br />
securities market aberrations, and curbs on computer-driven trading may be<br />
warranted.<br />
■ WB58<br />
C - Room 3, Level 1<br />
Finance-Theory and Empirics<br />
Contributed Session<br />
Chair: Vinod Cheriyan, Georgia Institute of Technology, Industrial and<br />
Sytems Engineering, 765 Ferst Drive NW, Atlanta, Georgia,<br />
vinod.cheriyan@gatech.edu<br />
1 - The Empirical Research of Media Effect in China Stock Market<br />
Yahui Zhang, The School of Management, Xi’an Jiaotong University,<br />
#28 Xianning West Road, Mailbox 1875, Xi’an, China,<br />
kailey@stu.xjtu.edu.cn, Leiming Fu, Difang Wan<br />
This research explores the existence of media effect in China stock market through<br />
event research and analyses the affecting factors. Results show that media effect is<br />
significant and presented as negative cumulative abnormal return within the event<br />
window, which can be mitigated by better corporate governance. CAR is positively<br />
correlated with the B/M ratio of equity, financial leverage, ROA and position<br />
accumulation significantly, the affect of firm size and news type are not significant.<br />
2 - MIDAS Instruments for Multiple Parameters<br />
Stephen Goldberger, PhD candidate, UNC, University of North<br />
Carolina, Chapel Hill, NC, 27514, United States of America,<br />
sgoldber@email.unc.edu<br />
Many Time Series models in Econometrics are dependent on the condition that an<br />
error term is expected to be zero given all information available at the beginning of<br />
time t. I extend the MIDAS (Mixed Data Sampling) Instruments framework<br />
developed by Eric Ghysels and Johnathan Wright to create a GMM estimator for a<br />
vector of parameters dependent on this moment condition.<br />
3 - Can Oil Prices Help Estimate Commodity Futures Prices? The<br />
Cases of Copper and Silver<br />
Gonzalo Cortazar, P. Universidad Catolica de Chile, Vicuna<br />
Mackenna 4860, Santiago, Chile, gcortaza@ing.puc.cl,<br />
Francisco Eterovic<br />
We use prices of long term oil futures contracts to estimate copper and silver prices.<br />
We show that the Cortazar et al (2008) multi-commodity model applied to oilcopper<br />
and oil-silver which have low correlation seems not to be effective. We then<br />
propose a modified multi-commodity model that uses the non-stationary long term<br />
process of oil to help estimate long term copper and silver futures prices, achieving a<br />
much better fit than using available individual or multi-commodity models.
4 - A Bounded-rational Model of Price Bubbles and Business Cycles<br />
Vinod Cheriyan, Georgia Institute of Technology, Industrial and<br />
Sytems Engineering, 765 Ferst Drive NW, Atlanta, GA,<br />
vinod.cheriyan@gatech.edu, Anton Kleywegt<br />
Various markets exhibit growth and collapse in prices that are sometimes called<br />
bubbles. Related to that is the notion of business cycles. We consider a model in<br />
which investors behave reasonably, although with imperfect expectations, that<br />
attempt to provide insight into the formation of bubbles and business cycles. We<br />
also present results on the convergence of the process to an attractor that describes<br />
a business cycle, and consider where in the cycle most time is spent.<br />
■ WB61<br />
H - Room 400, 4th Floor<br />
Operations Management VI<br />
Contributed Session<br />
Chair: Andrew Kach, Doctoral Student, New Mexico State University,<br />
Department of Management, P.O. Box 3001, Las Cruces, NM, 88003,<br />
United States of America, akach@nmsu.edu<br />
1 - Advance Demand Information, Capacity Restrictions and<br />
Customer Prioritization<br />
Bisheng Du, PhD Student, Aarhus University, Fuglesangs Alle 4,<br />
Department of Business Studies, Aarhus, 8210, Denmark,<br />
bisd@asb.dk, Christian Larsen, Alan Scheller-Wolf<br />
We study a single supplier with fixed capacity selling products to buyers having<br />
different priorities. The buyers can place pre-orders before their demand is observed,<br />
and can also issue additional orders upon observing updating demand information.<br />
Since the supplier guarantees delivery of pre-ordered goods (these are not<br />
constrained by her capacity) buyers with lower priorities may consider pre-ordering<br />
in order to secure inventory. We find optimal policies for the supplier and buyers.<br />
2 - Centrality and Heterogeneity During the Evolution of<br />
Inter-organisational Networks<br />
Nuno Oliveira, PhD Student, LSE, Houghton Street, London,<br />
United Kingdom, n.r.oliveira@lse.ac.uk<br />
Although extant research has reported a linkage between network centrality and<br />
heterogeneity, the understanding on the co-evolution of both variables is little. For a<br />
inter-organisatitional network of a 48 million British pounds building project, we<br />
show that network heterogeneity decreases whilst network centrality has a U-shape<br />
throughout a 3-year period. Implications for researchers and practitioners are also<br />
presented.<br />
3 - Security as a Moderator of Stress on Airline Performance<br />
Andrew Kach, Doctoral Student, New Mexico State University,<br />
Department of Management, P.O. Box 3001, Las Cruces, NM, 88003,<br />
United States of America, akach@nmsu.edu, Jeffrey Teich<br />
Heightened security in airports is used as a preventative action to reduce passenger<br />
engagement in terrorist acts or disruptive behavior; however, high safety measures<br />
may have an adverse impact on airline performance. More specifically: How does<br />
increasing levels of security impact the relationship between passenger stress levels<br />
on airline performance?<br />
■ WB62<br />
H - Room 402, 4th Floor<br />
Aviation Applications IV<br />
Contributed Session<br />
Chair: Ioannis Simaiakis, PhD Candidate, Massachusetts Institute of<br />
Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, United<br />
States of America, ioa_sim@mit.edu<br />
1 - Future Aircraft Network and Schedules<br />
Yan Shu, Graduate Student, Georgia Institute of Technology, 686<br />
Cherry Street, Atlanta, 30332, United States of America,<br />
yshu@gatech.edu, Ellis Johnson, Barry Smith, John-Paul Clarke<br />
We propose a three-step approach to build flight schedule from scratch. We<br />
implement our algorithms into solutions.<br />
2 - Optimizing Staffing Plans at Airports<br />
Prem Kumar Viswanathan, Scientist, Transport and Mobility<br />
Laboratory, Ecole Polytechnique Federale de Lausanne, GC B3 435,<br />
EPFL, Ecublens, VD, 1015, Switzerland, prem.viswanathan@epfl.ch,<br />
Michel Bierlaire<br />
Minimizing operating costs for maintaining ground personnel at airports is a<br />
complex problem due to uneven flight activities, passenger service expectations and<br />
staffing inflexibilities due to shift durations. In this work, we develop a method to<br />
find optimal shift timings that considers non-productive time due to activity<br />
changeovers, the mix of full-time and part-time workers and passenger waiting time<br />
criteria.<br />
INFORMS Austin – 2010 WB63<br />
405<br />
3 - A Colored Stochastic Petri Net Based Approach to Performance<br />
Analysis of JFK International Airport<br />
Poornima Balakrishna, Sensis Corporation, 11111 Sunset Hills Rd,<br />
Suite 130, Reston, VA, 20190, United States of America,<br />
pbalakri@sensis.com<br />
We model the airport departure process using colored stochastic Petri nets and<br />
airport surveillance data. This formal specification of the probabilistic airport system<br />
is then analyzed through simulation. The use of surveillance data in the model<br />
enables identification of bottlenecks on the airport surface including gate area and<br />
taxiway intersections. We measure congestion through analysis of queue lengths,<br />
delays and resource utilization and report on both airline and airport performance.<br />
4 - Estimation of Airport Performance Metrics<br />
Ioannis Simaiakis, PhD Candidate, Massachusetts Institute of<br />
Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139,<br />
United States of America, ioa_sim@mit.edu, Hamsa Balakrishnan<br />
Operational throughput and taxi times are two key metrics of airport performance.<br />
In this work, we show how the maximum throughput capacity of an airport can be<br />
represented as a function of arrival and departure demand. We also illustrate how<br />
unimpeded taxi times may be estimated by representing taxi time as a function of<br />
takeoff and the queues. We use convex-optimization to estimate these metrics<br />
without assuming the form of the solutions, and by only imposing operational<br />
constraints.<br />
■ WB63<br />
H - Room 404, 4th Floor<br />
Game Theory and Homeland Security<br />
Sponsor: Decision Analysis<br />
Sponsored Session<br />
Chair: Jun Zhuang, Assistant Professor, University at Buffalo, SUNY, 403<br />
Bell Hall, Buffalo, NY, 14260, United States of America,<br />
jzhuang@buffalo.edu<br />
1 - Mixed Strategy Nash Equilibria in Symmetric Signaling Games<br />
Barry Cobb, Virginia Military Institute, 335 Scott Shipp Hall,<br />
Lexington, United States of America, cobbbr@vmi.edu, Atin<br />
Basuchoudhary, Gregory Hartman<br />
Signaling games are characterized by asymmetric information where the more<br />
informed player has a choice about what information to provide to its opponent.<br />
Decision trees are used to derive the Nash equilibrium strategies for signaling games<br />
where the more informed player has an arbitrary number of possible types. The<br />
technique is demonstrated by analyzing an interactive game between a terrorist and<br />
a governmental agency.<br />
2 - Solving Massive Scale Security Games with Arbitrary Schedules:<br />
A Branch and Price Approach<br />
Milind Tambe, University of Southern California, 3737 Watt Way,<br />
PHE 410, Los Angeles, CA, 90089, United States of America,<br />
tambe@usc.edu, Manish Jain, Fernando Ordonez, Chris Kiekintveld,<br />
Erim Kardes<br />
Security games are used in deployed decision-support tools in use by LAX police<br />
and the Federal Air Marshals Service. The algorithms used to solve these games find<br />
optimal randomized schedules to allocate security resources for infrastructure<br />
protection. Unfortunately, the state of the art algorithms fail to scale to large<br />
problems with arbitrary scheduling constraints. We introduce ASPEN, a branch-andprice<br />
approach that overcomes this limitation.<br />
3 - Quantifying Unobserved Attributes in Expert Elicitation of<br />
Terrorist Preferences<br />
Chen Wang, University of Wisconsin-Madison, 3237 Mechanical<br />
Engineering, 1513 University Avenue, Madison, WI, 53706,<br />
United States of America, cwang37@wisc.edu, Vicki Bier<br />
A terrorist values targets according to a multi-attribute utility function in which<br />
some attributes are unknown to the defender. A group of experts ranks potential<br />
targets by their attractiveness to the terrorist. The defender infers the weights of the<br />
known attributes, and the importance of the unobserved attributes, using either<br />
probabilistic inversion or Bayesian density estimation.<br />
4 - Modeling Arbitrary Layers of Continuous Level Defenses in Facing<br />
with A Strategic Attacker<br />
Jun Zhuang, Assistant Professor, University at Buffalo, SUNY, 403<br />
Bell Hall, Buffalo, NY, 14260, United States of America,<br />
jzhuang@buffalo.edu, Mohsen Golalikhani<br />
We propose a class of models for the optimal assignment of defensive resources in a<br />
game between a defender and an attacker. The novelty of our model is that we<br />
allow the defender to assign her continuous-level defensive resources to any subset<br />
(or arbitrary layers) of targets due to functional similarity or geographical proximity.<br />
The results show that our model could significantly increase the defender’s payoff,<br />
especially when the cost of defense is high, or the attack cost is intermediate.
WB64<br />
■ WB64<br />
H - Room 406, 4th Floor<br />
Health Care, Modeling and Optimization VI<br />
Contributed Session<br />
Chair: Song Chew, Assistant Professor, Southern Illinois University<br />
Edwardsville, Edwardsville, Edwardsville, IL, 62026, United States of<br />
America, schew@siue.edu<br />
1 - Simulating Clinics: The Challenge of Data Collection and Analysis<br />
Helida Dodd, President, Dodd Consulting Group, 10223 SW 89 St,<br />
Miami, FL, 33176, United States of America, helida@doddcg.com,<br />
Martha Centeno<br />
We discuss a simulation study of an Endoscopy center, challenges, and lessons<br />
learned. The goal of the project was to find ways to increase throughput to 80<br />
patients/day. It was quickly apparent that the stumbling block would be the lack of<br />
data available. Some data is collected via the information system, but there is no<br />
reporting application to measure performance. Data is also collected manually<br />
sporadically in different areas, but it is not readily analyzed because of the lack of<br />
manpower.<br />
2 - Simulation-based Optimal Staffing Policies Under Cyclic Demand<br />
Mina Loghavi, University of Tennessee, 331 SMC, 916 Volunteer<br />
Blvd., Knoxville, TN, 37996, United States of America,<br />
mloghavi@utk.edu, Robin Clark, Charles Noon, Bogdan Bichescu<br />
We consider the objectives of minimizing staffing cost and maintaining acceptable<br />
patient waiting times in an emergency department (ED). We employ simulation and<br />
optimization to explore the best policies for ED staffing over repeating cycles of<br />
stochastic demand. In contrast to SIPP-based methods, this approach is feasible in<br />
periods when demand temporarily exceeds capacity and when additional constraints<br />
are present. We present insights from computational analysis on real-world datasets.<br />
3 - Setting Staffing Levels Under Time-varying Demand in the Context<br />
of an Emergency Department<br />
Mieke Defraeye, PhD Student, K.U.Leuven, Naamsestraat 69,<br />
Leuven, Belgium, mieke.defraeye@econ.kuleuven.be,<br />
Inneke Van Nieuwenhuyse<br />
When determining capacity levels in a healthcare system (such as an emergency<br />
department), a key feature that has to be taken into account is the time-varying<br />
demand for service. Due to these fluctuations in demand, determining capacity<br />
levels to achieve a certain service level is often complicated. In this presentation, an<br />
approach to determine staffing levels that results sufficiently small waiting times,<br />
will be presented.<br />
4 - Applying Inventory Control Practices Within the Sisters of Mercy<br />
Health Care Supply Chain<br />
Server Apras, University of Arkansas, 1343,N.Leverett,15,<br />
Fayetteville, AR, 72703, United States of America, sapras@uark.edu<br />
The goal of this research is to lay a foundation for the application and acceptance of<br />
more advanced inventory control practices within the healthcare supply chain.The<br />
project examines the demand characteristics and optimal control policies for bulk<br />
pharmaceuticals within the Sisters of Mercy’s network to compare to the current<br />
ordering and inventory control strategies to document potential cost savings.Also,a<br />
multiechelon inventory analysis examines the benefits of centralized inventory<br />
control<br />
5 - Outpatient Appointment Scheduling using Genetic Algorithms<br />
Song Chew, Assistant Professor, Southern Illinois University<br />
Edwardsville, Edwardsville, Edwardsville, IL, 62026,<br />
United States of America, schew@siue.edu<br />
Outpatient appointment scheduling has been an active area of research. The goal of<br />
the research is to strike a balance between patient waiting time, and doctor idle time<br />
and overtime. The objective of our work is to determine the optimal total number of<br />
patients for a clinical session, and the optimal number of patients assigned to each<br />
time slot in the session so as to minimize the total cost using genetic algorithms.<br />
INFORMS Austin – 2010<br />
406<br />
■ WB65<br />
H - Room 408, 4th Floor<br />
Inventory Management VII<br />
Contributed Session<br />
Chair: Haitao Li, University of Missouri - St. Louis, 229 CCB, One<br />
University Blvd, St. Louis, MO, 63121, United States of America,<br />
lihait@umsl.edu<br />
1 - Making Better Fulfillment Allocation Decisions on the Fly<br />
Jason Acimovic, Massachusetts Institute of Technology,<br />
77 Massachusetts Ave, E62-459, Cambridge, MA, 02139,<br />
United States of America, acimovic@mit.edu, Stephen Graves<br />
E tailers manage complicated distribution networks, serving customers with<br />
heterogeneous service time requirements. What is the best way to fulfill each of<br />
these customers’ orders for items with low inventory levels? We partner with an etailer<br />
to examine this question. We find the value of the improvement gap by<br />
comparing a greedy strategy with an ex post facto optimization. We then develop an<br />
approximate dynamic programming heuristic and evaluate its performance on toy<br />
and actual examples.<br />
2 - Two-stage, Two-product, Capacitated Supplier Problem with<br />
Uncertain Demand<br />
Ramesh Bollapragada, Associate Professor, College of Business, San<br />
Francisco State University, 1600 Holloway Avenue, San Francisco,<br />
CA, 94132, United States of America, rameshb@sfsu.edu, Laoucine<br />
Kerbache, Kai Luo<br />
We investigate a finite-horizon two-product (expensive and cheaper product from<br />
capacitated local and far-away suppliers, respectively), one retailer problem with<br />
two-stages, and uncertain demand. In the first stage, we determine the order<br />
quantity vector to place with suppliers, and in the second stage we determine the<br />
allocation of inventory to the two products given limited shelf-space. Optimal and<br />
heuristic solutions are discussed.<br />
3 - Optimal Control of a Manufacturing/Remanuacturing Systems with<br />
Quality Grade Differentiation<br />
Morteza Pourakbar, Erasmus University Rotterdam, BurgOudlaan 50,<br />
Rotterdam, Netherlands, pourakbar@few.eur.nl, Mohsen Elhafsi,<br />
Saif Benjaafar<br />
We consider a manufacturing/remanufacturing system where each demand is<br />
coupled with the return of an item that may be remanufacturable. Returned items<br />
differ in their quality grades with grades affecting remanufacturing cost and time.<br />
Decisions must be made regarding whether or not to accept a returned item and<br />
whether to produce a new item or remanufacture a returned one and if so from<br />
which grade.<br />
4 - New Model and Heuristics for Safety Stock Placement in General<br />
Acyclic Supply Chain Networks<br />
Haitao Li, University of Missouri - St. Louis, 229 CCB,<br />
One University Blvd, St. Louis, MO, 63121,<br />
United States of America, lihait@umsl.edu, Dali Jiang<br />
We model the safety stock placement problem in general acyclic supply chain<br />
networks as a project scheduling problem, for which the constraint programming<br />
(CP) techniques are both effective and efficient in finding high quality solutions. We<br />
further integrate CP with a genetic algorithm (GA), which improves the CP solution<br />
quality significantly. The performance of our hybrid CP-GA algorithm is evaluated<br />
on randomly generated test instances. CP-GA is able to find optimal solutions to<br />
small problems in fractions of a second, and near optimal solutions of about 5%<br />
optimality gap to medium size problems in less than two minutes on average.<br />
■ WB66<br />
H - Room 410, 4th Floor<br />
Facilities Planning and Design<br />
Contributed Session<br />
Chair: Li Zhang, Royal Bank of Scotland, 399 Main Ave., Apt 614,<br />
Norwalk, CT, 06851, United States of America, lieezhang@gmail.com<br />
1 - Framework for Measuring Rationale Clarity of Collaborative<br />
Design Decisions<br />
John Chachere, Senior Computer Scientist, Stinger Ghaffarian<br />
Technologies, 1060 Arbor Road, Menlo Park, CA, 94025, United<br />
States of America, john.m.chachere@nasa.gov, John Haymaker<br />
Designers often must convey clear rationale supporting design decisions. We define<br />
rationale as a set of assertions about components (managers, stakeholders,<br />
designers, gatekeepers, goals, constraints, alternatives, and analysis) with variable<br />
clarity (coherent, concrete, connected, consistent, credible, certain, and correct). We<br />
relate these definitions in the Rationale Clarity Framework to enhance objectivity in<br />
evaluating tools and processes for design decision making.
2 - Order and Inventory Management System for a Food Bank<br />
Arsalan Paleshi, PhD Student, University of Louisville, Department<br />
of Industrial Engineering, JB Speed School of Engineering,<br />
Louisville, KY, 40292, United States of America,<br />
a0pale01@louisville.edu, Bulent Erenay, Trivikram Rao<br />
This project creates an Excel tool to support a food bank’s need for a less labor<br />
intensive, inexpensive ordering and inventory management system. Additionally<br />
application of lean principles like KANBAN, ANDON and visual management to<br />
control inventory are suggested. The extension of similar methods for other cases is<br />
also discussed.<br />
3 - A Study of Spine Layout for Semiconductor Manufacturing Plant<br />
Under the Multi-Floor Environment<br />
Chikong Huang, Professor, National Yunlin University of Science &<br />
Technology, 123 University Rd., Sec. 3, Department of Industrial<br />
Management, Touliu, Yunlin, 640, Taiwan - ROC,<br />
huangck@yuntech.edu.tw, Ming-Ru Tsai<br />
This study focuses on the spine layout in multiple floors by arranging workstations<br />
along several closed-loop moving tracks. The objective is to minimize the horizontal<br />
and vertical handling costs. The model and solution algorithm using Tabu search are<br />
developed and they are also verified by a numerical example.<br />
4 - Layout Analysis and Lead-time Calculations with PEM Forklifts<br />
Abhijit Gosavi, Missouri University of Science and Technology, 219<br />
Engineering Management, Rolla, MO, 65409, United States of<br />
America, gosavia@mst.edu, Suzanna Long, Scott Grasman<br />
PEM forklifts utilize hydrogen-based fuels and have been shown, in certain<br />
conditions, to be more economical than traditional battery-powered forklifts. We<br />
analyze the impact of using PEM forklifts on manufacturing layout and the lead<br />
time, including material-handling time, calculations. We use simulation to compare<br />
layouts that use PEM forklifts and battery-powered forklifts on the basis of the lead<br />
time and the empty travel time.<br />
5 - Kernel Method of Performance Estimation in Autonomous Vehicle<br />
Storage and Retrieval Systems<br />
Li Zhang, Royal Bank of Scotland, 399 Main Ave., Apt 614, Norwalk,<br />
CT, 06851, United States of America, lieezhang@gmail.com,<br />
Changjian Huang<br />
In this study, a systematic simulation combined with kernel learning method is<br />
proposed for use in Autonomous Vehicle Storage and Retrieval Systems (AVS/RSs).<br />
The proposed method reflects the nonlinear relationship between system<br />
performance and factors and provides universal usage in performance estimation for<br />
various system designs. Simulation results indicate that the developed models<br />
provide accurate and computational efficient estimations.<br />
■ WB67<br />
H - Room 412, 4th Floor<br />
Simulation II<br />
Contributed Session<br />
Chair: Byung-In Kim, Associate Professor, Pohang University of Science<br />
and Technology, Nam-Gu, Hyoja-Dong, POSTECH, Pohang, Korea,<br />
Republic of, bkim@postech.ac.kr<br />
1 - Revenue Management Under Customer Choice Behavior<br />
Marco Bijvank, University of Montreal, CP 6128 Succ Centre-Ville,<br />
Pavillon André-Aisenstadt, Montreal, QC, H3C 3J7, Canada,<br />
bijvankm@iro.umontreal.ca, Pierre L’Ecuyer<br />
Observations from practice and recent research suggest a shift to customer oriented<br />
revenue management. During this presentation we discuss how to design a<br />
simulation tool to incorporate very general demand processes and different discrete<br />
choice models. We also show how this tool can be applied in practice to understand<br />
the customer choice decision making.<br />
2 - Formation Control Strategies for Groups of Mobile<br />
Autonomous Agents<br />
Wei Zhao, IBM Research - China, Diamond Building,ZGC Software<br />
Park, Beijing, China, wzhaow@cn.ibm.com, Wenjun Yin, Jin Dong,<br />
Bin Zhang, Ming Xie, Long Wang<br />
This paper presents the control strategies for multiple mobile autonomous agents to<br />
achieve leader-following formations. Each follower agent establishes a Bezier<br />
trajectory between its current position and that of its leader agent. Considering the<br />
nonholonomic properties of the agent, the optimization of Bezier curve’s curvature<br />
to choose appropriate scale factor is conducted by penalty function method.<br />
Simulations and experimental results show the effectiveness of our control<br />
strategies.<br />
3 - Demonstrating Simulations of Inventory and Production<br />
Management using VBA in Microsoft Excel<br />
Amanda Baty, Texas Tech University, 3424 Frankford Ave<br />
Apt 8B, Lubbock, TX, 79407, United States of America,<br />
amanda.baty@ttu.edu, Dr. Rafael Moras<br />
INFORMS Austin – 2010 WB69<br />
407<br />
Based on simulations by Dr. Paul Jensen and W.G. Lesso, “Advanced PNG Game” is<br />
a single product simulation using spreadsheets. The standard deviation of demand,<br />
lead time, and production level can be adjusted, for a cost, in each of the 52<br />
simulated weeks. The objective is to minimize total cost.<br />
4 - Agent-based Simulation for Emergency Evacuation of<br />
Heterogeneous Populations in a High-rise Building<br />
Jeongin Koo, PhD Student, POSTECH, San31, Hyoja-Dong, Namgu,<br />
Pohang, Korea, Republic of, xession@postech.ac.kr, Yong Seog Kim,<br />
Byung-In Kim<br />
An efficient evacuation plan is critical for the safety of residents in high-rise<br />
buildings during catastrophic events. Although there are some research works on<br />
building evacuation using simulation, most of them do not consider the<br />
handicapped people. This research presents an agent-based simulation of<br />
heterogeneous populations including various types of people with disabilities for a<br />
24-story real world building evacuation. Using the model, several evacuation plans<br />
are tested and evaluated.<br />
■ WB68<br />
H - Room 415, 4th Floor<br />
Innovation/Entrepreneurship II<br />
Contributed Session<br />
Chair: David Gomulya, Foster Business School, University of Washington,<br />
MacKenzie 355, Box 353200, Seattle, WA, 98195,<br />
United States of America, dgomulya@u.washington.edu<br />
1 - Institutional Conditions and Venture Capital Investment in<br />
Developing Countries<br />
Theodore Khoury, Oregon State University, Bexell 422B, Corvallis,<br />
OR, 97331, United States of America,<br />
ted.khoury@bus.oregonstate.edu, Marc Junkunc, Santiago Mingo<br />
Focusing on entrepreneurial ventures in developing countries, we explore how<br />
venture capital (VC) investments are shaped by firms’ stage of development and<br />
host country institutional conditions. Using a panel of 443 VC investments occurring<br />
in Latin America over 12 years, we find that larger investments are affiliated with<br />
later stage firms, higher transaction costs and lower political hazard risk. Also,<br />
political hazards moderate the relationship between development stage and<br />
investment size.<br />
2 - New Ventures and Timing of Alliance Formation: The Dynamics of<br />
Temporal Congruence and Contingency<br />
David Gomulya, Foster Business School, University of Washington,<br />
MacKenzie 355, Box 353200, Seattle, WA, 98195, United States of<br />
America, dgomulya@u.washington.edu<br />
While alliances have been shown to increase new-venture survival, the literature<br />
remains silent regarding the effect of timing of alliance formations. Related<br />
literatures regarding timing have also been unable to explain their conflicting<br />
findings, which show the effect of timing can range from positive to negative. To fill<br />
gaps, I develop a novel model based on temporal changes during pre- and postformation<br />
phases of an alliance. I show the effect can indeed range from positive to<br />
negative.<br />
■ WB69<br />
H - Salon F, 6th Floor<br />
Joint Session TSL/ SPPSN: Risk and Recovery of<br />
Transportation Networks to Disaster<br />
Sponsor: Transportation Science and Logistics Society/ Public<br />
Programs, Service and Needs<br />
Sponsored Session<br />
Chair: Nicholas Lownes, Assistant Professor, University of Connecticut,<br />
261 Glenbrook Rd., U-2037, Storrs, CT, 06269, United States of America,<br />
nlownes@engr.uconn.edu<br />
1 - Resilience of Fright Transportation Networks<br />
Xiaodong Zhang, University of Maryland, College Park, MD, 20742,<br />
United States of America, xzhang@umd.edu, Elise Miller-Hooks,<br />
Reza Faturechi<br />
The problem of measuring network resilience in transportation networks and<br />
determining optimal pre-event remedial actions is formulated as a two-stage<br />
stochastic program. The formulation explicitly recognizes that post-disaster<br />
performance depends not only on the inherent capability of the system to absorb<br />
externally induced changes, but also on the actions that can be taken in the<br />
immediate aftermath of the disaster to restore system performance. An L-shaped<br />
method is proposed for its solution.
WB70<br />
2 - Debris Operations<br />
Kael Stilp, Georgia Institute of Technology, 765 Ferst Drive, NW,<br />
Atlanta, GA, United States of America, mstilp3@isye.gatech.edu,<br />
Monica Villarreal, Antonio Carbajal, Ozlem Ergun, Pinar Keskinocak<br />
Debris operations following a disaster is a lengthy and costly process, involving<br />
multiple interrelated stages. Each stage contains a unique set of social fairness<br />
concerns with which need to be considered as well the computationally difficult<br />
objectives of efficiency. We present an encompassing set of models with<br />
computational analysis of each stage and discuss their interrelated nature.<br />
3 - Many-to-many Transportation Network Risk Assessment<br />
Qixing Wang, University of Connecticut, 261 Glenbrook Road, Unit<br />
2037, Storrs, CT, 06269, United States of America,<br />
qiw09005@engr.uconn.edu, Nicholas Lownes<br />
This work presents an extension to game-theoretic network risk models through the<br />
many-to-many application. A model that can be applied to large-scale networks is<br />
presented along with application results. Results provide a measure of link risk and<br />
can be used as decision support for sensor placement strategies.<br />
■ WB70<br />
H - Salon G, 6th Floor<br />
Emerging Applications in Aviation<br />
Sponsor: Aviation Applications<br />
Sponsored Session<br />
Chair: Wenwei Cao, Doctoral Student, Georgia Institute of Technology,<br />
765 Ferst Dr NW, GA-Tech ISyE, Atlanta, GA, 30332-0205, United States<br />
of America, cww@gatech.edu<br />
1 - The Role of Air Travel in the Worldwide Spread of Vector<br />
Borne Diseases<br />
Lauren Gardner, Graduate Research Assistant, University of Texas at<br />
Austin, Earnest Cockrell Jr. Hall, 6.204, Austin, TX, 78712, United<br />
States of America, lmgardner@mail.utexas.edu, David Fajardo,<br />
Travis Waller<br />
Increased passenger air traffic has lead to an increased risk of importation and<br />
establishment of vector-borne diseases. As such, it is critical to be able to identify the<br />
risk associated with air travel routes between vector-compatible environments. This<br />
problem requires modeling the interaction between three overlapping networks: a<br />
vector survivability network, a social network and an airport network. We study the<br />
the role of the airport network in connecting the vector-survivability network.<br />
2 - Crew Rostering in Fractional Airlines<br />
Wenwei Cao, Doctoral Student, Georgia Institute of Technology, 765<br />
Ferst Dr NW, GA-Tech ISyE, Atlanta, GA, 30332-0205, United States<br />
of America, cww@gatech.edu, Ellis Johnson, Ozlem Ergun<br />
We consider a crew rostering problem in fractional airlines where rosters are<br />
generated through a bidding process. Instead of creating bid-lines beforehand, the<br />
management can only control the capacities on schedule lines and vacation periods.<br />
We propose an optimization based framework for capacity decision-making. Within<br />
the framework, a model incorporating training considerations is solved via column<br />
generation.<br />
3 - Transforming US Army Supply Chains: An Analytical Architecture for<br />
Enterprise Management<br />
Greg Parlier, Institute for Defense Analyses, Madison, AL,<br />
United States of America, gparlier@ida.org<br />
A comprehensive analytical architecture to enable US Army Logistics<br />
Transformation is presented, incorporating an “engine for innovation” to accelerate<br />
and sustain continual improvement. Strategic management challenges are<br />
addressed, including decision support systems, human capital investment needs,<br />
organizational design and strategic alignment for a learning organization.<br />
■ WB71<br />
H - Salon H, 6th Floor<br />
Health and Education Applications of DEA<br />
Cluster: In Honor of Bill Cooper<br />
Invited Session<br />
Chair: Emmanuel Thanassoulis, Aston University, Operations &<br />
Information Management Group, Birmingham, AL,<br />
United States of America, e.thanassoulis@btinternet.com<br />
1 - Analysis by DEA of Health Referral Costs in England<br />
Emmanuel Thanassoulis, Aston University, Operations & Information<br />
Management Group, Birmingham, AL, United States of America,<br />
e.thanassoulis@btinternet.com, Maria C. Portela, Mike Graveney<br />
INFORMS Austin – 2010<br />
408<br />
The paper is drawn from an analysis by DEA of patient referral costs on behalf of a<br />
Primary Care Trust (PCT) in England. The paper focuses on General Practitioners<br />
(GPs) contracted to the PCT. GPs are the gateway to health services in England.<br />
Clinical decisions by GPs heavily influence referral costs incurred by the PCT. The<br />
paper formulates models to determine the scope for savings in referrals costs and<br />
decomposes them into those attributable to mix of in and out patient referrals and<br />
those attributable to price differentials between in and out patient cases.<br />
2 - A Decade of Clinical Productivity Change and the Determinants of<br />
Relative Clinical Efficiency in Pennsylvania Coronary Artery Bypass<br />
Graft Programs<br />
Jon Chilingerian, Brandeis University, The Heller School for Social<br />
Policy and Management, South Street, Waltham, MA, 02454-9110,<br />
United States of America, chilinge@brandeis.edu<br />
We present evidence on the growth of clinical productivity change in hospitals<br />
performing coronary artery bypass grafts (CABGs) over a decade. Analyzing<br />
outcome and severity-adjusted hospital clinical in Pennsylvania between 1994-2004,<br />
frontier methodology was used to measure and evaluate clinical productivity<br />
change, medical progress (i.e., shifts in the clinical frontiers), and relative clinical<br />
efficiency over time. In Pennsylvania, the average hospital’s clinical productivity for<br />
CABG surgeries grew by more than 30%. We found strong support, however, that<br />
medical-technical progress, rather than improvement in clinical efficiency, was the<br />
underlying reason for the growth. Factors associated with clinical efficiency<br />
included: employing hospitalists; having a higher percent of salaried physicians in<br />
relation to FTEs on salary; and strategic choices that focused on open heart<br />
cardiovascular surgeries. All of these factors are associated with performance and<br />
are under a clinical department’s control.<br />
3 - DEA in the 100 Largest U.S. Public School Districts<br />
N.K. Kwak, Saint Louis University, Department of Decision Sciences<br />
and MIS, St. Louis, MI, United States of America, kwakn@slu.edu,<br />
Walter Garrett<br />
This paper reports on a study of the 100 largest U.S. public school districts, which<br />
are together responsible for educating 22 percent of all public school students. Using<br />
data from the U.S. Department of Education, we use DEA to assess the efficiencies<br />
of those districts and to identify common characteristics of efficient districts. The<br />
results may be useful for benchmarking inefficient districts to improve their<br />
performance.<br />
■ WB72<br />
H - Salon J, 6th Floor<br />
Facility Logistics III<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Ananth Krishnamurthy, University of Wisconsin, 1513 University<br />
Ave, Madison, United States of America, ananth@engr.wisc.edu<br />
1 - Modeling Inventory Visibility in Supply Chain Networks<br />
Sandeep Srivathsan, Research Associate, Oklahoma State University,<br />
School of IE&M, 322 EN, Stillwater, OK, 74078, United States of<br />
America, sandeep.srivathsan@okstate.edu, Manjunath Kamath<br />
We develop stochastic models of two-echelon supply chains where a retailer has<br />
visibility of production facilities’ net inventory levels and vice versa. Order<br />
placement and fulfillment policies depend on the net inventory levels and the<br />
models developed can be used to obtain insights into the benefits of inventory<br />
visibility on overall supply chain performance. We present models developed under<br />
Markovian assumptions and then discuss strategies to develop models for more<br />
general settings.<br />
2 - Evaluation of Decision Criteria to Select Efficient Order<br />
Picking Systems<br />
Detlef Spee, Detlef.Spee@iml.fraunhofer.de, Tim Geissen,<br />
Michael ten Hompel<br />
Order picking systems contribute to the competitive capability of companies.<br />
Increased requirements regarding performance and quality aspects necessitate<br />
flexible systems that meet present and future demands. The paper focuses on the<br />
decisions which are made during the planning process to select a proper order<br />
picking method. Therefore, relevant order picking methods are systematized and<br />
selection criteria are evaluated by the use of a market study amongst suppliers of<br />
order picking systems.<br />
3 - Estimating the WIP on a Conveyor Based Material Handling System<br />
with Multiple Stations<br />
Dima Nazzal, Assistant Professor, University of Central Florida, 4000<br />
Central Florida Blvd., Orlando, FL, 32816, United States of America,<br />
dnazzal@mail.ucf.edu, Vernet Lasrado<br />
We present a method to improve the estimates of the work in process (WIP) on a<br />
closed loop conveyor. We estimate the total traveling WIP and the WIP waiting to<br />
be loaded on the conveyor. A probabilistic distribution has been derived for the<br />
loading process and we test this model with a detailed simulation of a<br />
semiconductor manufacturing facility.
■ WB73<br />
H - Salon K, 6th Floor<br />
Reducing Transportation Emissions and GHG<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Hakob Avetisyan, PhD Student, University of Maryland, College<br />
Park, MD, United States of America, havetisy@umd.edu<br />
1 - Freeway Congestion Mitigation and the Emissions<br />
Minimization Problem<br />
Alex Bigazzi, Portland State University, Portland, OR,<br />
United States of America, bigazzi@pdx.edu, Miguel Figliozzi<br />
We present a freeway control problem that not only minimizes delays but also takes<br />
emissions into account. We formulate several variants of a freeway traffic control<br />
problem. Utilizing real-world sensor data from Portland Oregon and calibrated<br />
emissions models we present and analyze solution results under different traffic<br />
conditions and levels of elasticity.<br />
2 - Modeling a Novel Method for Reducing Transportation Greenhouse<br />
Gas Emissions<br />
Erica Wygonik, University of Washington, Seattle, WA,<br />
United States of America, ewygonik@uw.edu, Anne Goodchild<br />
A model is developed to evaluate parameters effecting emissions to consider the<br />
environmental impacts of aggregating personal travel into shared-use services. This<br />
model indicates whether shared-use vehicles show significant benefit to the<br />
environment over personal vehicles, and under what conditions those emissions<br />
savings would be realized, using grocery store shopping in Seattle, Washington as<br />
the first case study to quantify and compare the total environmental impacts.<br />
3 - Greener Construction of Transportation Construction Projects<br />
Through Optimization<br />
Hakob Avetisyan, PhD Student, University of Maryland, College<br />
Park, MD, United States of America, havetisy@umd.edu,<br />
Elise Miller-Hooks, Suvish Melanta<br />
Optimization-based techniques are presented that permit a contractor to develop an<br />
equipment-usage plan that adheres to current environmental standards and<br />
anticipated new regulations, accounting for recent laws that might affect<br />
construction, and possible future carbon tax or cap and trade programs. These<br />
techniques aid contractors in trading off project cost, duration and resulting GHG<br />
emissions in bid development and aid contractors in making green construction<br />
decisions.<br />
■ WB74<br />
H - Room 602, 6th Floor<br />
Public Transit IV<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Luca Quadrifoglio, Assistant Professor, Texas A&M Univeristy,<br />
CE/TTI bldg - Room 301I, 405 Spence St., College Station, TX, 77843,<br />
United States of America, lquadrifoglio@civil.tamu.edu<br />
1 - A Logit-based Assignment on a Transit Schedule Hypergraph<br />
Mark Hickman, Associate Professor, University of Arizona, Civil<br />
Engineering, 1209 E. Second St., Bldg 72, Tucson, AZ, 85721-0072,<br />
United States of America, mhickman@email.arizona.edu,<br />
Hyunsoo Noh<br />
A hyperpath has been a common network structure in transit assignment. Using the<br />
hyperpath, we propose a logit-based transit assignment on a transit scheduled<br />
network. We introduce a link-based and time-expanded network and two<br />
hyperpath algorithms, and we investigate the stochastic user equilibrium situation<br />
under hard capacity constraints.<br />
2 - Evaluating the Use of “Transfers” for Improving Zoning<br />
Paratransit Systems<br />
Chung-Wei Shen, Texas A&M University, CE/TTI Building, Room<br />
309C, 3136 TAMU, College Station, TX, 77840, United States of<br />
America, tzungwei0610@yahoo.com.tw, Luca Quadrifoglio<br />
For paratransit agencies, the zoning strategy divides their service area into smaller<br />
zones to different provider to simplify the management. After dropping customers<br />
off for cross zone trips, the vehicles will return without passengers on-board<br />
resulting in deadheading miles. Using transfers on boundaries is a promising method<br />
to decrease deadheading miles while applying zoning strategies. This study evaluates<br />
the performance of transfers on zoning paratransit systems through simulation<br />
method.<br />
INFORMS Austin – 2010 WC01<br />
409<br />
3 - The Design of Single-Line Demand Adaptive Systems:<br />
An Evaluative Framework<br />
Fausto Errico, CIRRELT, 2920, Chemin de la tour, Montreal, QC, H3T<br />
1J4, Canada, Fausto.Errico@cirrelt.ca, Teodor Gabriel Crainic,<br />
Federico Malucelli, Maddalena Nonato<br />
Demand-Adaptive Systems (DASs) display features of both traditional fixed-line bus<br />
services and purely on-demand systems such as dial-a-ride. A DAS bus line serves a<br />
given set of compulsory stops according to a predefined schedule. On the other<br />
hand, passengers may issue requests for transportation between two optional stops,<br />
inducing detours in the vehicle routes. The design of a DAS line is a complex<br />
planning process. We propose, evaluate and compare several possible design<br />
strategies.<br />
<strong>Wednesday</strong>, 1:30pm - 3:00pm<br />
■ WC01<br />
C - Ballroom D1, Level 4<br />
Technology Policy and Energy Markets<br />
Sponsor: Energy, Natural Resources and the Environment/ Energy<br />
Sponsored Session<br />
Chair: Ekundayo Shittu, Assistant Professor, Tulane University, 7<br />
McAlister Dr., New Orleans, LA, 70118, United States of America,<br />
eshittu@tulane.edu<br />
1 - Volatility Pricing for Renewable Energy Sources<br />
Xiaoyue Jiang, Assistant Professor, Tulane University,<br />
7 McAlister Dr, New Orleans, LA, 70118, United States of America,<br />
xjiang@tulane.edu, Geoffrey Parker, Ekundayo Shittu, Anjali<br />
Sheffrin<br />
In recognizing the negative effects of volatility to reliability of the power grid, we<br />
have proposed an analytical framework that models capacity volatility by<br />
capacity@risk and prices volatility through a QoS-centric capacity market<br />
mechanism. In this work, we will apply this framework to renewable sources<br />
including solar and wind. We will price each type of sources based on their volatility<br />
characteristics. Real data from one of the ISOs in the US will be used to gain<br />
practical insights.<br />
2 - Flexible the Better? On the Design of RPS in Presence of Green<br />
Consumers and Emissions Trading<br />
Yihsu Chen, Assistant Professor, University of California Merced,<br />
Merced, CA, 95343, United States of America,<br />
yihsu.chen@ucmerced.edu, Lizhi Wang<br />
Emissions trading, green pricing programs and renewable portfolio standard (RPS)<br />
are three concurrent policies implemented in US to reduce reliance on fossil fuel<br />
and GHG emissions. Despite their differences in policy targets, they are closely<br />
related and integrated with competitive electric markets. We examines market<br />
outcomes of two aspects of RPS design in this talk: bundling and double counting.<br />
3 - The Influence of Market Structure and Policy on Technology<br />
Portfolio Investments<br />
Ekundayo Shittu, Assistant Professor, Tulane University,<br />
7 McAlister Dr., New Orleans, LA, 70118, United States of America,<br />
eshittu@tulane.edu, Geoffrey Parker, Xiaoyue Jiang<br />
We study firms’ incentives to invest in a portfolio of technologies under different<br />
markets and environmental policies. The impacts of policies are critical to<br />
understanding how competition and energy production mix. We pay attention to<br />
the representation of the technologies in the portfolio because of implications on<br />
cost. We demonstrate intriguing results that describe how investments and adoption<br />
incentives are shaped by strategic interactions between market structure and<br />
regulatory policy.
WC02<br />
■ WC02<br />
C - Ballroom D2, Level 4<br />
Energy I<br />
Contributed Session<br />
Chair: Le Xie, Assistant Professor, Texas A&M University, 3128 TAMU,<br />
216M Zachry Bldg, College Station, TX, 77843, United States of America,<br />
lxie@mail.ece.tamu.edu<br />
1 - Why Your Plug-in Vehicle with a 40-mile Battery Pack May<br />
Only Go 25<br />
Orkun Karabasoglu, PhD Candidate, Carnegie Mellon University,<br />
5000 forbes ave. 402 Scaife hall, Pittsburgh, PA, 15213,<br />
United States of America, karabasoglu@cmu.edu, Jeremy Michalek<br />
We investigate the effects of driving patterns on the range, gasoline consumption,<br />
greenhouse gas emissions, and lifecycle costs of conventional, hybrid, and plug-in<br />
hybrid vehicles. We find that drive cycle (style) can have a greater effect on<br />
consumption, cost and emissions than vehicle design or charging frequency. Plug-in<br />
vehicle range drops 35% under aggressive, rather than standard cycles, and drive<br />
cycle can affect which vehicles are optimal.<br />
2 - Stochastic Control for Smart Grid Users with Flexible Demand<br />
Yong Liang, PhD Student, University of California-Berkeley, 1117<br />
Etcheverry Hall, Berkeley, CA, 94720, United States of America,<br />
yongliang@berkeley.edu, Z. Max Shen, Alan Sanstad<br />
We propose a stochastic optimal control model for smart grid users to make the<br />
optimal energy usage decisions incorporating energy consumption and generation.<br />
The main feature of this model is its ability to dynamically adjust consumptions by<br />
responding to the pricing signals from the electricity grid, deal with stochastic new<br />
job arrivals as well as scheduling the jobs based on their own deadlines. The model<br />
leads to a dynamic programming problem, which is solved using ADP techniques.<br />
3 - Quantifying the Economic Impact of Variable Energy Forecast on<br />
Power System Scheduling<br />
Le Xie, Assistant Professor, Texas A&M University, 3128 TAMU,<br />
216M Zachry Bldg, College Station, TX, 77843, United States of<br />
America, lxie@mail.ece.tamu.edu, Haifeng Wang, Jin Dong,<br />
Wenjun Yin<br />
The integration of variable resources such as wind and photovoltaic has posed<br />
fundamental challenges to the operation of electric energy systems. We attempt to<br />
quantify the value of variable energy forecast in improving the efficiency of power<br />
system scheduling. We demonstrate in a realistic system that only by explicitly<br />
valuing near-term prediction and inter-temporal variations in the system scheduling<br />
model could the economic potential of these variable resources be fully utilized.<br />
■ WC03<br />
C - Ballroom D3, Level 4<br />
Environmental Operations<br />
Contributed Session<br />
Chair: Bin Dai, HKUST, A601, HKUST, Kowloon, Hong Kong - PRC,<br />
dbbudstar@gmail.com<br />
1 - Stochastic Cost Estimation Approach for Full-Scale Reverse<br />
Osmosis Desalination Plants<br />
Seong-Hee Kim, Associate Professor, Georgia Institute of Technology,<br />
765 Ferst Dr, Atlanta, GA, 30332, United States of America,<br />
skim@isye.gatech.edu, Pyung-Kyu Park, Jae-Hong Kim,<br />
Varun Gandhi, Pranay Mane, Hoon Hyung, Chuljin Park<br />
A stochastic approach was developed to estimate the construction and operation<br />
cost of a seawater reverse osmosis (SWRO) desalination plant. The stochastic cost<br />
model was further coupled with a process simulation model that predicts<br />
performance measures such as water production rate and produced water quality.<br />
The case study demonstrates the effectiveness of the coupled model in ranking and<br />
comparing a large number of design and operating conditions for the full-scale<br />
SWRO plant.<br />
2 - Self-Insurance: The Case of the Canadian Oil Sands<br />
Kalinga Jagoda, Assistant Professor, Mount Royal University,<br />
4825 Mount Royal Gate SW, Calgary, AB, T3E7N9, Canada,<br />
kjagoda@mtroyal.ca, Pamini Thangarajah<br />
In Canadian oil sands much of the negative publicity is around land pollution and<br />
there are calls for establishment of disaster relief program to manage hazardous<br />
events. Using the theory of public goods, we analyze the self insurance aspects of<br />
such program and the efficient provision levels.<br />
INFORMS Austin – 2010<br />
410<br />
3 - A Study on Setting Recycling Subsidy for Waste PCs in Taiwan<br />
Through Bi-level Nonlinear Programming<br />
Hsu-Shih Shih, Professor, Tamkang University, Taiwan, ROC,<br />
151 Ying-Chuan Rd., Tamsui, Taipei, 25137, Taiwan - ROC,<br />
hshih@mail.tku.edu.tw, Chia-Wei Hsu, Bo-Han Huang<br />
The study investigates a recycling subsidy decision for waste PCs in Taiwan through<br />
bi-level nonlinear programming (BLNP) for environmental protection. The upperlevel<br />
unit is RFMB (Recycling Fund Management Board) which hopes to balance<br />
the recycling fund and others by controlling the subsidy et al.; the lower-level’s is<br />
the recycling industry which likes to get maximum profits by controlling the<br />
recycling rate. The BLNP model can help obtain an optimal solution for the<br />
recycling system.<br />
4 - Design of Solar Radiation Management by Projecting Man-made<br />
Particles to Counter Global Warming<br />
Ka Shek Lee, Associate Professor, Department of Industrial<br />
Engineering and Logistics Managemen, The Hong Kong University of<br />
Science and Technology, IELM, HKUST, Kowloon, Hong Kong - PRC,<br />
nlee@ust.hk, Bin Dai<br />
Currently, mitigation efforts to counter global warming such as carbon emission<br />
reduction are proving time inefficient, therefore it desires for an alternative to cool<br />
the earth on an emergency basis. In this study, we proposed to project atmospheric<br />
man-made particles to manage the solar radiation. Fluid dynamics and scattering<br />
theory are employed to model particles’ life time and radiation forcing to determine<br />
particles’ size, projection height and amount required for selecting materials.<br />
5 - Performance Analysis on Introducing Intercity High-speed<br />
Railway System<br />
Bin Dai, HKUST, A601, HKUST, Kowloon, Hong Kong - PRC,<br />
dbbudstar@gmail.com, Ka Shek Lee<br />
Carbon emission reduction contributes to mitigate global warming. Transportation<br />
accounts for 20% global carbon emission and electricity-powered railway system is<br />
carbon efficient. In this study, discrete choice model is employed to capture the<br />
travel demand shift by introducing high-speed railway system. Performance analysis<br />
is conducted to evaluate the carbon emission reduction, energy and time saving<br />
conditioning on intercity distance and city size. Results show its attractiveness.<br />
■ WC04<br />
C - Ballroom D4, Level 4<br />
Sustainability I<br />
Contributed Session<br />
Chair: Thomas Sloan, University of Massachusetts Lowell,<br />
1 University Avenue, College of Management, Lowell, MA, 01854,<br />
United States of America, Thomas_Sloan@uml.edu<br />
1 - Managing Pollution in Oligopolistic Markets with<br />
Sustainability Constraints<br />
Sung Hoon Chung, The Pennsylvania State University, 244 Leonhard<br />
Bldg., University Park, United States of America, sxc447@psu.edu,<br />
Robert Weaver<br />
We present a differential variational inequality framework to consider the<br />
equilibrium patterns of oligopolistic markets through pollution taxes and quotas for<br />
sustainability. An algorithm is proposed to compute the oligopolistic firms’<br />
equilibrium output rate, shipping pattern, and pollution flow with or without the<br />
central authority. A numerical example is also presented to illustrate the use of our<br />
theory.<br />
2 - Technology Base Second Tier Distribuitors Sustainability in Mexico<br />
Guillermo Torres, PhD in Administration, Tecnologico De Estudios<br />
Superiores De Coacalco, Av. 16 de Septiembre # 54, Coacalco de<br />
Berriozàbal, 55700, Mexico, chapultepec19@hotmail.com,<br />
Eduardo G. Hernandez-Martinez<br />
At present, it has become increasingly hard for businesses to survive in a globalized<br />
market, when traditional differentiators must adjust to new circumstances since<br />
they are less efficient as opposed to new scenes. This study is focused on identifying<br />
competitiveness of small business in Mexico, who are specialized in trading and/or<br />
distributing computer equipment, that increasingly find it more difficult to compete<br />
against the large chains.<br />
3 - A Stochastic Linear Programming Model for the Management of<br />
Emission Rights<br />
Justyna Dyduch, Cracow University of Economics, Department of<br />
Industrial and Ecological, ul. Rakowicka 27, 31-510 Kraków, Cracow,<br />
Poland, dyduchj@uek.krakow.pl<br />
The management of emission rights means using them to cover enterprise’s<br />
emissions, selling or buying them on the market, banking and borrowing them. We<br />
describe a multi-stage recourse model that optimizes the production, the use and<br />
acquisition of emission rights. The model is established to maximize enterprise’s<br />
total profit.
4 - Sustainable and Maintainable: An Equipment Maintenance Model<br />
with Environmental and Economic Inputs<br />
Thomas Sloan, University of Massachusetts Lowell, 1 University<br />
Avenue, College of Management, Lowell, MA, 01854, United States<br />
of America, Thomas_Sloan@uml.edu, Joseph Sarkis<br />
An MDP model using traditional economic measures and environmental measures is<br />
used to optimize equipment maintenance decisions. Increased deterioration leads to<br />
more energy usage, more scrap, and greater environmental burdens. Maintenance<br />
reduces these burdens but has environmental and economic impacts. The impacts of<br />
using different cleaning solvents to perform maintenance are estimated using data<br />
from the Toxic Use Reduction Institute (TURI).<br />
■ WC05<br />
C - Ballroom D5, Level 4<br />
Dynamic Programming/Control I<br />
Contributed Session<br />
Chair: Srinivasa Puranam, Rutgers University, 1 Washington Park,<br />
Newark, NJ, 07102, United States of America, karti@pegasus.rutgers.edu<br />
1 - Further Insight on Optimizing Taboo Criteria in Markov<br />
Decision Processes<br />
Michael N. Katehakis, Professor, Rutgers Business School,<br />
1 Washington Park, Newark, United States of America,<br />
mnk@andromeda.rutgers.edu, Srinivasa Puranam<br />
Optimization of systems is often based on costs associated with the states of the<br />
system. However, in many applications it is difficult to determine costs for all states.<br />
In such situations, one could consider maximizing taboo criteria such as the taboo<br />
mean return times for a propitiously defined set of taboo states. This is a hard<br />
problem and well-known methods can not be applied. However, we can provide<br />
further insight and heuristics for this problem.<br />
2 - Risk-Averse Control Problem for Undiscounted Infinite Horizon<br />
Markov Decision Models<br />
Ozlem Cavus, Rutgers Center for Operations Research, 640<br />
Bartholomew Road, Piscataway, NJ, 08854, United States of<br />
America, ozlem_cavus@yahoo.com, Andrzej Ruszczynski<br />
The Markov risk measure is introduced and used to formulate risk-averse control<br />
problems for finite and infinite horizon models by Ruszczynski. In this study, this<br />
new concept is used to formulate and solve an infinite horizon insurance problem<br />
where one of the control decisions is to purchase insurance. Furthermore, riskaversion<br />
is introduced for undiscounted infinite horizon Markov control models<br />
with absorption.<br />
3 - Managing Data Quality Risk in Accounting Information Systems<br />
Manuel Nunez, Associate Professor, School of Business, UConn,<br />
2100 Hillside Road Unit 1041, Storrs, CT, 06269, United States of<br />
America, mnunez@business.uconn.edu, Xue Bai, Jayant Kalagnanam<br />
The quality of data contained in accounting information systems has a significant<br />
impact on internal business decision-making and external regulatory compliance.<br />
We present a methodology for managing the risks associated with the quality of<br />
transactional data in accounting information systems. This methodology models the<br />
error introduction and propagation process in transactional data flow, and finds<br />
optimal control policies to mitigate data quality risks using a Markov decision<br />
process.<br />
4 - Vehicle Routing with Traffic Congestion and Drivers’ Driving and<br />
Working Rules<br />
Marco Schutten, University of Twente, Fac. Management and<br />
Governance, P.O. Box 217, Enschede, 7500 AE, Netherlands,<br />
m.schutten@utwente.nl, Leendert Kok, Erwin Hans, Henk Zijm<br />
We develop a solution method for the VRPTW, time-dependent travel times, and<br />
driving hours regulations. The major difficulty of this VRPTW extension is to<br />
optimize each vehicle’s departure times to minimize the duty time of each driver.<br />
We propose a restricted dynamic programming heuristic for constructing the vehicle<br />
routes, and an efficient heuristic for optimizing the vehicle’s departure times for<br />
each (partial) vehicle route, such that the complete algorithm runs in polynomial<br />
time.<br />
5 - Optimal Bidding in Sequential Auctions with Random<br />
External Demand<br />
Srinivasa Puranam, Rutgers University, 1 Washington Park, Newark,<br />
NJ, 07102, United States of America, karti@pegasus.rutgers.edu,<br />
Michael N. Katehakis<br />
We consider the problem of sequentially bidding in N auctions of identical items<br />
when items acquired are sold in a secondary market. The demand size and the sales<br />
price are random variables with known distributions. The objective is to acquire<br />
items through a sequence of auctions and sell them in the secondary market at<br />
maximum expected profit. We present a Markov decision processes model for this<br />
problem and study monotonicity properties of the optimal bids, for several cases of<br />
interest.<br />
INFORMS Austin – 2010 WC07<br />
411<br />
■ WC06<br />
C - Ballroom E, Level 4<br />
Tutorial: Searching and Hiding on Networks<br />
Cluster: Tutorials<br />
Invited Session<br />
Chair: J. Cole Smith, Professor, University of Florida, Industrial and<br />
Systems Engineering, 303 Weil Hall, P.O. Box 116595, Gainesville, FL,<br />
United States of America, cole@ise.ufl.edu<br />
1 - Searching and Hiding on Networks<br />
J. Cole Smith, Professor, University of Florida, Industrial and Systems<br />
Engineering, 303 Weil Hall, P.O. Box 116595, Gainesville, FL,<br />
United States of America, cole@ise.ufl.edu<br />
The problem of deploying and controlling a set of searchers on a network to locate a<br />
hidden target is referred to as a search game. There are countless variations of this<br />
game, depending on, e.g., whether or not the target is mobile, and the searchers’<br />
communication and control capabilities. This tutorial will examine classical results in<br />
this field, discuss contemporary search literature, and explore research directions in<br />
this field as driven by future security challenges.<br />
■ WC07<br />
C - Ballroom F & G, Level 4<br />
Supply Chain Optimization II<br />
Contributed Session<br />
Chair: Haitao Li, University of Missouri - St. Louis, 229 CCB, One<br />
University Blvd, St. Louis, MO, 63121, United States of America,<br />
lihait@umsl.edu<br />
1 - Game Theoretic Analysis of Supply Chain<br />
Satish Tyagi, Wayne State University, Department of Industrial,<br />
Manufacturing Engineering, Detroit, MI, 48202,<br />
United States of America, styagi.nifft@gmail.com, Kai Yang<br />
The aim of this paper is to exploit the salient features of Game Theory in modeling<br />
and to investigate SC functioning under various alliances. In order to give a realistic<br />
view to model, a comprehensive objective function has been formulated by<br />
combining different objectives. This paper introduces a novel approach Gaussian<br />
Particle Swarm Optimization which is embedded with beneficial attributes viz. (1)<br />
Gaussian probability distribution, and (2) Time Varying Acceleration Coefficients.<br />
2 - Measuring the Bullwhip Effect in the Supply Chain Based on the<br />
Demand Forecasting Coordination Level<br />
Seong-Hyun Nam, Associate Professor, University of North Dakota,<br />
Management Department, Grand Forks, ND, 58202-8377,<br />
United States of America, snam@business.und.edu<br />
This paper studies the role of coordination in relation of the bullwhip effect. It seeks<br />
to derive a bullwhip effect measure using a stochastic optimal control theory. In<br />
particular, we measure how much the supply chain bullwhip effect mitigation<br />
depends on the level of supply chain coordination of demand forecast and develop<br />
the strategic coordination policy.<br />
3 - Heuristic Procedures for Biomass-to-Biorefinery Supply Chains<br />
Ambarish Acharya, PhD Candidate, Mississippi State University, Dept<br />
of Industrial & Systems Engineering, Mississippi State, MS, 39762,<br />
United States of America, ama206@msstate.edu, Daniela Gonzales,<br />
Sandra Eksioglu<br />
The objective of this research is modeling and solving coordinated biomass-tobiorefinery<br />
supply chain design and management problem. We discuss a number of<br />
special cases of this problem where the location, capacity and number of facilities is<br />
known. We propose solution procedures to solve the general problem and its special<br />
cases.<br />
4 - Optimizing the Supply Chain Configuration for<br />
Make-to-Order Manufacturing<br />
Haitao Li, University of Missouri - St. Louis, 229 CCB,<br />
One University Blvd, St. Louis, MO, 63121,<br />
United States of America, lihait@umsl.edu, Keith Womer<br />
Configuring an MTO supply involves determining both sourcing and scheduling<br />
supply chain activities to meet customer’s demand in a cost effective and time<br />
efficient way. We develop an optimization model and algorithm for optimally<br />
configuring MTO supply chains. Managerial insights are derived and discussed.
WC08<br />
■ WC08<br />
C - Room 11A, Level 4<br />
Facility Location I<br />
Contributed Session<br />
Chair: Priyanka Verma, Indian Institute of Technology Kanpur, IME<br />
Department, Kanpur, 208016, India, priyankav08@gmail.com<br />
1 - A Location-allocation-local Search Procedure for Territory Design<br />
with Multiple Balance Constraints<br />
Roger Z. Ríos-Mercado, Universidad Autónoma de Nuevo León,<br />
CIDET-FIME, AP 111 - F, Cd. Universitari, San Nicolàs de los Garza,<br />
66450, Mexico, roger@yalma.fime.uanl.mx<br />
In this talk, a commercial territory design problem motivated by a real-world<br />
application in the bottled beverage distribution industry is addressed. A novel<br />
location-allocation-local search algorithm is presented and fully evaluated over a<br />
wide range of instances. The results indicate the excellent performance of some of<br />
the procedure components. It also shown how the algorithm finds design plans of<br />
significantly better quality than those currently handled by the company.<br />
2 - Hospital Location Planning in Singapore<br />
Kok-Choon Tan, Assoc Prof, National University of Singapore, NUS<br />
Bisiness School, 15 Kent Ridge Drive, Singapore, 119245, Singapore,<br />
kokchoon@nus.edu.sg, Joe SIM<br />
Singapore is currently served by 6 public hospitals which provide affordable and<br />
good quality healthcare. This research aims to enhance the health ministry’s<br />
capabilities in planning new acute and community hospitals, which are costly<br />
investments. We will describe the use of Urban OR techniques to develop a decision<br />
support system that allows policy makers to compare the impact among different<br />
choices of new hospital locations with the corresponding sizes and capabilities.<br />
3 - Enabling Easy Consumer Access to Services and Products<br />
Baris Hasdemir, UMASS, Isenberg School of Management,<br />
Finance and Operations Management, Amherst, 01003,<br />
United States of America, hasdemir@som.umass.edu, Agha Ali<br />
Enabling better access to services for spatially dispersed populations is pertinent in<br />
today’s fiscally constrained socio-political landscape. A network of centers provides<br />
better access if the centers are located so as to serve maximal populations within<br />
each of multiple threshold distances. Computational studies using a model with<br />
distance differentiation of the population involving 1,829 model instances reveal<br />
insights about possible access for the 224M people living in 23K places in the US.<br />
4 - Facility Location and Relocation Problem (FLRP-U)<br />
Under Uncertainty<br />
Ayse Durukan Sonmez, PhD Candidate, University of Houston,<br />
Department of Industrial Engineering, Engr. Bldg 2, Houston, TX,<br />
77204, United States of America, adurukan@uh.edu, Gino Lim<br />
FLRP-U is a facility location and relocation problem that considers future demand<br />
changes as well as uncertainties in number of future facilities. The objective is to<br />
minimize the sum of the initial weighted distance and the expected future distance,<br />
within a given budget for opening and closing of facilities. We propose a<br />
decomposition algorithm that can produce near optimal solutions for FLRP-U. Our<br />
numerical results compare the performance of our algorithm with exact solution<br />
techniques.<br />
5 - Single/two Stage Warehouse Location Problem: Solution Technique<br />
and Strong, Weak, Hybrid Formulations<br />
Priyanka Verma, Indian Institute of Technology Kanpur, IME<br />
Department, Kanpur, 208016, India, priyankav08@gmail.com,<br />
RRK Sharma<br />
For the single stage uncapacitated warehouse location problems, hybrid<br />
formulations are shown to be the best performer against weak and strong<br />
formulations for large sized problems. Vertical decomposition approach is presented<br />
for the single and two stage capacitated warehouse location problem. Large sized<br />
complex warehouse location problem is decomposed into the smaller and relatively<br />
simpler versions of the capacitated plant location problems by the use of vertical<br />
decomposition approach.<br />
INFORMS Austin – 2010<br />
412<br />
■ WC09<br />
C - Room 11B, Level 4<br />
Retail Operations and Assortment Planning<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Felipe Caro, UCLA Anderson School of Management,<br />
110 Westwood Plaza, Suite B-420, Los Angeles, CA, 90095,<br />
United States of America, fcaro@anderson.ucla.edu<br />
1 - Dynamic Assortment Strategies for Variety-Seeking Consumers<br />
Dorothee Honhon, University of Texas at Austin, IROM, B6500,<br />
Austin, TX, United States of America,<br />
Dorothee.Honhon@mccombs.utexas.edu, Gurhan Kok<br />
In this project, we first characterize the static optimal assortment for a retailer with<br />
variety-seeking consumers. We then characterize the optimal assortment sets in the<br />
dynamic strategy that offers possibly different assortments each period. We show<br />
that it is possible to generate a high level of satisfaction at the customer level by<br />
having a mixed assortment strategy.<br />
2 - Dynamic Assortment Customization with Limited Inventories<br />
Fernando Bernstein, Duke University, 1 Towerview Dr., Durham,<br />
NC, 27708, United States of America, fernando@duke.edu,<br />
Gurhan Kok, Lei Xie<br />
We consider a retailer with limited inventories of a category of substitutable<br />
products and heterogeneous customer preferences. Customers arrive sequentially<br />
and the firm decides which subset of the products to offer to a customer depending<br />
on the customer type, the inventory levels and the time-to-go in the season. We<br />
show that limiting the choice set of some customers can significantly increase<br />
profitability.<br />
3 - Dynamic Assortment Models: A Portfolio Approach<br />
Felipe Caro, UCLA Anderson School of Management,<br />
110 Westwood Plaza, Suite B-420, Los Angeles, CA, 90095,<br />
United States of America, fcaro@anderson.ucla.edu, Rene Caldentey<br />
We investigate optimal dynamic assortment planning strategies for a retailer with<br />
limited shelf space. The retailer can choose among basic and fashion items with low<br />
and high risk (and return) respectively. We present two models within this setting.<br />
One is theoretical where we explicitly model the vogue trend as a stochastic process<br />
that the retailer tries to follow. The second model has a similar objective but a much<br />
simpler formulation intended for easy implementation in practice.<br />
■ WC10<br />
C - Room 12A, Level 4<br />
Track and Trace Technologies in Supply Chains<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Gary Gaukler, Texas A&M University, TAMU-3131, College Station,<br />
United States of America, gaukler@tamu.edu<br />
1 - Item-level RFID Tagging and Inventory Record Accuracy<br />
John Aloysius, University of Arkansas, WCOB 226 University of<br />
Arkansas, Fayetteville, United States of America,<br />
JAloysius@walton.uark.edu, Bill Hardgrave, Sandeep Goyal<br />
Previous research has demonstrated that case-level RFID tagging can improve<br />
inventory record accuracy for consumer packaged goods. The increased visibility<br />
provided by item-level tagging however enables tracking items in-store right up to<br />
the point-of-sale. We report the results of experiments in the field that investigate<br />
the potential of item level tagging in the retail store.<br />
2 - The Impact of Supply Network and Product Characteristics on<br />
Tracking Technology Assimilation<br />
Rahul Basole, Tennenbaum Institute, Georgia Tech, 760 Spring Street<br />
NW, Atlanta, GA, 30332, United States of America,<br />
rahul.basole@ti.gatech.edu, Maciek Nowak<br />
This research examines the influence of supply network and product characteristics<br />
on the extent of tracking technology (TT) adoption and use. We develop and test a<br />
theoretical model through a global survey of supply chain executives. Our results<br />
provide insights into how factors such as product value, handling risk, and supply<br />
network complexity impact the level of TT assimilation. This study yields important<br />
implications for the management of emerging IT in a supply chain operations<br />
context.
3 - The Impact of Product Contamination in the Food Supply Chain<br />
Vijaya Chebolu-Subramanian, Texas A&M University, 3131 TAMU,<br />
College Station, TX, 77483, United States of America,<br />
cheb12@neo.tamu.edu, Gary Gaukler<br />
In this talk we discuss the impact of product contamination in a food supply chain<br />
(e.g., e. coli contamination of spinach). We consider a real world situation in which<br />
a contaminated food product has entered a supply chain and is being sold at the<br />
retailer. We develop a quantitative model to quantify the overall cost of the<br />
contamination event and evaluate the effect of the product and supply chain<br />
attributes on the performance metrics of the model.<br />
■ WC11<br />
C - Room 12B, Level 4<br />
Supply Chain Issues & Sustainability<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Chelliah Sriskandarajah, The University of Texas at Dallas, 800<br />
West Campbell Road, SM30, School of Management, Richardson, TX,<br />
75080, United States of America, chelliah@utdallas.edu<br />
1 - Optimal Life Cycle Inventory Management<br />
Burcu Keskin, Assistant Professor, University of Alabama, Alston<br />
Hall, Tuscaloosa, AL, United States of America, bkeskin@cba.ua.edu,<br />
Charles Schmidt<br />
We consider inventory replenishment of a product with nonstationary, stochastic<br />
demand that moves probabilistically from one stage of the life cycle to the next,<br />
each with its own demand and cost information, until the end-of-life. The planning<br />
horizon is neither infinite nor of a known finite length. Via analytical analysis, we<br />
show that stage-dependent base stock policy is optimal. Via numerical analysis, we<br />
show the impact of not modeling the random product life on cost and inventory<br />
levels.<br />
2 - On the Tradeoff Between Remanufacturing and Recycling<br />
Tharanga Rajapakshe, University of Texas at Dallas, 800 West<br />
Campbell Road, SM30, School of Management, Richardson, TX,<br />
75080, United States of America, tharanga@utdallas.edu,<br />
Srinagesh Gavirneni, Milind Dawande, Chelliah Sriskandarajah<br />
Motivated by our interactions with two Dallas-based reverse-logistics firms, we<br />
analyze the tradeoff between two well-known product-recovery approaches:<br />
recycling and remanufacturing. Our analysis exploits the supply- and demand-side<br />
implications as well as product design characteristics of these approaches. We<br />
provide a complete theoretical characterization of the tradeoff and develop rich<br />
insights on the influence of ability of sustainability and disposal costs.<br />
3 - Inventory Models for Medium-size Depository Institutions Under the<br />
New Federal Reserve Policy<br />
Yunxia Zhu, The University of Texas at Dallas, 800 West Campbell<br />
Road, SM30, School of Management, Richardson, TX, 75080,<br />
United States of America, yunxia.zhu@student.utdallas.edu, Milind<br />
Dawande, Chelliah Sriskandarajah<br />
We study two new multi-period models — designed specifically to capture the<br />
operations of a medium-size Depository Institution — that emerge from its objective<br />
to minimize the total cost incurred in managing the inventory of cash over a finite<br />
planning horizon under the new Federal Reserve policy. We develop several<br />
managerial insights from a comprehensive test bed and demonstrate a procedure to<br />
easily adapt the optimal solutions based on projected data to near-optimal real-time<br />
solutions.<br />
4 - Scheduling Robotic Cells Served by a Dual-Arm Robot<br />
Manoj Vanajakumari, Texas A&M University, College Station, TX,<br />
United States of America, manoj@entc.tamu.edu, Avanti Sethi,<br />
Chelliah Sriskandarajah, Neil Geismar<br />
We assess the benefits of implementing a dual-arm robot in a flow shop<br />
manufacturing cell. The robot has the ability to tend two adjacent machines<br />
simultaneously. We identify optimal sequences for two and three machine cells and<br />
also derive structural results for cells with an arbitrary number of machines. For<br />
cells processing different part-types, we completely analyze two-machine cells. For<br />
each case we compare the productivity of single-arm and dual-arm robotic cells.<br />
INFORMS Austin – 2010 WC13<br />
413<br />
■ WC12<br />
C - Room 13A, Level 4<br />
Retail Supply Chain Management<br />
Sponsor: Manufacturing and Service Operations Management/<br />
Supply Chain<br />
Sponsored Session<br />
Chair: Sandra Transchel, The Penn State University, University Park, State<br />
College, PA, United States of America, sxt37@psu.edu<br />
1 - Multi-echelon Inventory System for E-Retailer Fulfillment Centers<br />
Juan Li, Cornell University, Ithaca, NY, 14853, jl879@cornell.edu,<br />
John Muckstadt<br />
The customers of e-retailers have different timeliness requirements on order<br />
delivery. The demand process has significant impact on designing the fulfillment<br />
centers. In this paper, a multi-echelon system is designed for this type of system. We<br />
describe an algorithm to compute the optimal order-up-to level for this system.<br />
2 - Joint Inventory Pricing and Assortment Decisions for<br />
Vertically Differentiated<br />
Mrinmay Deb, Student, Penn State University, 462A Business<br />
Building, University Park, State College, PA, 16802,<br />
United States of America, mud166@psu.edu, Susan Xu<br />
We determine the joint pricing, inventory, and assortment decisions of a retailer<br />
stocking quality differentiated products. Consumers choose their first choice based<br />
on the vertical choice model. We consider two cases: inventory is abundant (riskless<br />
case) and inventory is finite (risky case) and find the optimal prices and optimal<br />
assortments in each case.<br />
3 - Joint Pricing and Inventory Decisions Under<br />
Stockout-Based Substitution<br />
Sandra Transchel, The Penn State University, University Park,<br />
State College, PA, United States of America, sxt37@psu.edu,<br />
Anna-Lena Beutel, Stefan Minner<br />
We consider a joint inventory and pricing problem for partially substitutable<br />
products in a given assortment. Both price and inventory decisions have to be made<br />
under demand uncertainty. Additionally, the retailer has to take into account that<br />
customers are willing to substitute their first choice product if this is not available.<br />
We present structural properties of the proposed model and provide managerial<br />
insights into the interaction of pricing, stocking decision, and product<br />
cannibalization.<br />
■ WC13<br />
C - Room 13B, Level 4<br />
Managing Service Systems with Self-interested Actors<br />
Sponsor: Manufacturing and Service Operations Management/<br />
Service Management Special Interest Group<br />
Sponsored Session<br />
Chair: Eren Cil, University of Oregon, 1208 University of Oregon,<br />
Lindquist College of Business, Eugene, OR, 97403-1208,<br />
United States of America, erencil@uoregon.edu<br />
1 - A Service Marketplace with Multiple Classes and Multiple<br />
Skilled Agents<br />
Eren Cil, University of Oregon, 1208 University of Oregon, Lindquist<br />
College of Business, Eugene, OR, 97403-1208, United States of<br />
America, erencil@uoregon.edu, Gad Allon, Achal Bassamboo<br />
We consider a service marketplace in which customers have different service needs.<br />
Each customer can be served by either a group of agents specialized to cater<br />
particular needs of that customer or a general pool of agents who can handle any<br />
requests but not as competently as the specialized agents. We analyze how the selfinterested<br />
customers choose between the dedicated and the general service, and<br />
characterize the response of the agents in the general pool to the customers’<br />
choices.<br />
2 - Price Competition Under Multinomial Logit Demand Funcations with<br />
Random Coefficients<br />
Margaret Pierson, Harvard Business School, Morgan Hall, Boston,<br />
MA, United States of America, mpp2002@columbia.edu,<br />
Awi Federgruen, Gad Allon<br />
We postulate a general class of price competition models with Mixed MNL demand<br />
functions under affine cost. By imposing a natural upper bound for the price levels<br />
of each firm, we characterize the equilibrium behavior of these models in the case<br />
of single-product firms and then generalize the results to the multi-product case.<br />
This work provides a justification for the many structural estimation methods which<br />
require that equilibria correspond with the solutions to this system of FOC<br />
equations.
WC14<br />
3 - Coordinating Diagnosis and Service in a Service Supply Chain<br />
Mehmet Fazil Pac, PhD Candidate, Wharton School of Business,<br />
University of Pennsylvania, 3730 Walnut Street, Jon M. Huntsman<br />
Hall, Office 527.6, Philadelphia, PA, 19104, United States of America,<br />
mpac@wharton.upenn.edu<br />
We consider a service consisting of two phases; diagnosis and service. Each phase is<br />
provided by a self-interested agent. Diagnostic accuracy depends on the effort<br />
exerted by the diagnosis agent. Investing more time in diagnosis leads to higher<br />
valuation of the actual service by customers, however it also leads to lower<br />
throughput and more congestion for the system. Using a queuing framework, we<br />
analyze the agents’ diagnosis and pricing decisions under the presence of strategic<br />
customers.<br />
4 - Service Control of a Queue Under Different Delay<br />
Information Structures<br />
Brent Dooley, Wharton School, 3730 Walnut St., 500 Jon M.<br />
Huntsman Hall, Philadelphia, PA, 19104, United States of America,<br />
dooleyb@wharton.upenn.edu, Noah Gans, Omar Besbes<br />
We analyze the problem of profit-maximization for an M/M/1 queue with dynamic<br />
service rate control when customers have access to varying degrees of state/policy<br />
information. In particular, we examine customer equilibrium behavior and its<br />
implications on optimal service rate policies.<br />
■ WC14<br />
C - Room 14, Level 4<br />
Supply Chain Management X<br />
Contributed Session<br />
Chair: Jie Yang, Associate Professor, University of Houston-Victoria,<br />
14000 University Blvd, Sugar Land, TX, 77479, United States of America,<br />
jieuhv@gmail.com<br />
1 - Mid-term Planning Coordination Between Maker and Retailer by<br />
Capacity Reservation<br />
Seung-Jin Ryu, Research Associate, Waseda University, 51-14-07, 3-<br />
4-1 Okubo, Shinjuku, Tokyo, 1698555, Japan, sjryu@aoni.waseda.jp,<br />
Hisashi Onari<br />
Collaborative SCM is the collaborated initiatives among SC members to deal with<br />
various problems over SC. It is the challenging issue, in high-tech industry,<br />
especially experiencing severe market demand change, keeping the stable and<br />
profitable operation level. We propose the mid-term planning coordination method<br />
between maker and retailer by capacity reservation. Also, we verify strengths and<br />
weaknesses of the proposed method by dynamic simulation with various business<br />
environments.<br />
2 - Transportation Pricing of a Truckload Carrier<br />
Aysegul Toptal, Assistant Professor, Bilkent University, Department of<br />
Industrial Engineering, Ankara, Turkey, toptal@bilkent.edu.tr,<br />
Safa Bingol<br />
In this study, we investigate the transportation pricing problem of a truckload<br />
carrier in a setting that consists of a retailer, a truckload carrier and a less than<br />
truckload carrier. Numerical evidence shows that the truckload carrier may increase<br />
his/her gainings significantly through better pricing and there is further opportunity<br />
of savings if the truckload carrier and the retailer coordinate their decisions.<br />
3 - Does Agility Matter in Improving Supply Chain Performance?<br />
Evidence From a Transition Economy<br />
Jie Yang, Associate Professor, University of Houston-Victoria, 14000<br />
University Blvd, Sugar Land, TX, 77479, United States of America,<br />
jieuhv@gmail.com<br />
This study develops and empirically tests a conceptual framework to investigate the<br />
antecedents of manufacturers’ supply chain agility and the connection of their<br />
agility with performance in an emerging economy. Drawing upon the information<br />
theory, this study argues that technical (IT capability) and relational factors<br />
(information sharing and trust, and operational collaboration) are the antecedents<br />
of a manufacturer’s supply chain agility.<br />
INFORMS Austin – 2010<br />
414<br />
■ WC15<br />
C - Room 15, Level 4<br />
Organization Theory I<br />
Contributed Session<br />
Chair: Theresa Edgington, Baylor University, One Bear Place, #98005,<br />
Waco, 76798, United States of America, theresa_edgington@baylor.edu<br />
1 - A Clustering Approach For Multi-Facility Location Problem<br />
Cem Iyigun, Department of Industrial Engineering, Middle East<br />
Technical University, Ankara, Turkey, iyigun@ie.metu.edu.tr,<br />
Adi Ben-Isreal<br />
A new clustering approach is proposed. The method is a generalization of Weiszfeld<br />
method and applied for solving K facilities location problem. The problem is relaxed<br />
using probabilistic assignments, and is decomposed into K single facility location<br />
problems, that are coupled by the probabilities, and can be solved in parallel.<br />
2 - Considering the Relationship Between Empowerment and<br />
Resistance to Change<br />
Nathan Culmer, The University of Iowa, 2800 UCC, Iowa City, IA,<br />
52242, United States of America, nathan-culmer@uiowa.edu<br />
Both psychological and team level empowerment have been shown to have<br />
desirable effects in organizations while employee resistance to change can have<br />
undesirable effects on organizational or work group progress. Interestingly, these<br />
characteristics share some common theoretical elements. This paper considers<br />
possible theoretical relationships between empowerment as a motivational construct<br />
and the influence that empowerment can exert on employee resistance to change.<br />
3 - Institutional Barriers to Application of Continuous Improvement<br />
Processes From Safety to Energy Efficiency<br />
Rodney Lacey, Lecturer, Univ of California Davis, Graduate School of<br />
Management, One Shields Avenue, Davis, CA, 95616,<br />
United States of America, rolacey@ucdavis.edu<br />
Historic institutional differences between the fields of safety and energy efficiency<br />
could limit transfers of continuous improvement programs. Three differences of<br />
commensuration (Espeland and Stevens, 1998) between lives and units of energy<br />
are potential barriers: being efficient is commendable, rather than inefficiency<br />
deplorable; moral value of efficiency gains varies across industries; and there are no<br />
moral objections to making tradeoffs between efficiency and other goals.<br />
4 - To Build or Break Away? Exploring the Antecedents of Category<br />
Spanning Nanotechnology Innovation<br />
Tyler Wry, U of Alberta, 3-23 Business Building, Edmonton, AB, T6G<br />
2R6, Canada, twry@ualberta.ca<br />
Category spanning has implications for innovation and institutional change. Still,<br />
studies have focused primarily on its detrimental effects, eliding consideration of<br />
causal antecedents. Examining the nanotube technology field, I argue that patterns<br />
of linkage amongst categories enable spanning. Competing hazard rate models are<br />
supportive. Further, I find these linkages are shaped endogenously by prominent<br />
actors and condition the effects category richness, social networks, and social<br />
influence.<br />
5 - Evidentiary Analysis of Organizational Coordination and Questions<br />
of Group Fragmentation<br />
Theresa Edgington, Baylor University, One Bear Place, #98005,<br />
Waco, TX 76798, United States of America,<br />
theresa_edgington@baylor.edu<br />
Analysis processes contribute to organizations by increasing their knowledge, which<br />
is necessary to maximize decision-making and resolution outcomes. We investigate<br />
whether a core group provides exemplary coordination by investigating its database.<br />
Utilizing quantitative analysis, the evidence refutes this claim, contributing to the<br />
literature by identifying eleven coordination process indicators.<br />
■ WC16<br />
C - Room 16A, Level 4<br />
Flexible Manufacturing Systems<br />
Contributed Session<br />
Chair: Mabel Chou, Associate Professor, National University of Singapore,<br />
BIZ 1 Mochtar Riady Building, #8-66, 15 Kent Ridge Drive, Singapore,<br />
119245, Singapore, mabelchou@nus.edu.sg<br />
1 - Value of Flexibility<br />
Sanjeev Bordoloi, Associate Professor, University of St Thomas, 1000<br />
LaSalle Ave, TMH 434, Opus College of Business, Minneapolis, MN,<br />
55403, United States of America, sbordoloi@stthomas.edu<br />
Economic justification of investments in flexibility has become increasingly<br />
important. This paper tries to provide possible measures for flexibility so that<br />
managerial decision making for flexibility can be validated. We offer a model that<br />
minimized production planning costs and then use some of its characteristics for<br />
flexibility measurements.
2 - Joint Maintenance and Operations Decision Making in Flexible<br />
Manufacturing Systems<br />
Merve Celen, University of Texas at Austin, 1 University Station<br />
C2200, Austin, TX, 78712-0292, United States of America,<br />
merve@mail.utexas.edu, Dragan Djurdjanovic<br />
In semiconductor manufacturing, the dynamic interactions among operation types,<br />
chamber degradations and wafer yields necessitate a joint decision making of<br />
maintenance scheduling and product dispatching. To address this problem, we<br />
devise an integrated decision making policy with the objective of maximizing an<br />
adaptive profit function with respect to operation-dependent degradation models<br />
and production target by using a metaheuristic method based on the results of<br />
discrete-event simulations.<br />
3 - Dynamic Control of Closed Flexible Queueing Network with<br />
Application to Shipbuilding<br />
Fang Dong, Ph.D Candidate, University of Michigan, Industrial &<br />
Operations Engineering, 1205 Beal Ave., Ann Arbor, MI, 48109-<br />
2117, United States of America, ppfang@umich.edu,<br />
Mark Van Oyen, David Singer<br />
The U.S. Shipbuilding Industry is facing the challenge of building ships on-time and<br />
at budgeted cost. We introduce operational flexibility to ship production to mitigate<br />
the issues like high variability in production workload and low facility utilization.<br />
We formulate this problem as a flexible, controlled closed queueing network with<br />
CONWIP release policy. Under an effective control policy, the flexible system can<br />
significantly reduce ship completion time, and improve workshop utilization.<br />
4 - A Graph-theoretic Methodology for Deadlock Resolution in<br />
Automated Manufacturing Cells<br />
Venkatesh Angirasa, Research Scientist & Manager, Group for<br />
Decision Technology Solutions, SETLabs, Infosys Technologies,<br />
Electronics City, Hosur Road, Bangalore, 560100, India,<br />
venkatesh_angirasa@infosys.com<br />
We present a deadlock detection and resolution strategy for manufacturing cells<br />
with alternate part routing. We distinguish between cells with centralized buffers<br />
and those with dedicated I/O buffers for individual machines. A unified bipartite<br />
graph of the part-machine relationship enables the detection and resolution scheme<br />
in both cases. Resolution policies are developed to accommodate varying<br />
manufacturing systems requirements. An efficient algorithm is proposed to manage<br />
deadlocks.<br />
5 - Value of the Third Chain: Effect of Partial Production Postponement<br />
on Process Flexibility<br />
Mabel Chou, Associate Professor, National University of Singapore,<br />
BIZ 1 Mochtar Riady Building, #8-66, 15 Kent Ridge Drive,<br />
Singapore, 119245, Singapore, mabelchou@nus.edu.sg,<br />
Geoffrey A. Chua, Chung Piaw Teo<br />
Using a multi-item newsvendor model with second-stage supply and partial capacity<br />
sharing, we discover that the flexibility loss of the 2-chain is no longer negligible<br />
under partial postponement. For small systems, this loss can be as high as 20% to<br />
30%. However, we find that by adding another layer of flexibility, a third chain, the<br />
flexibility loss can be restored to the same level as 2-chain with full postponement.<br />
We show that the value of the third chain extends even to very large systems.<br />
■ WC17<br />
C - Room 16B, Level 4<br />
Supply Chain, Practice and Empirics<br />
Contributed Session<br />
Chair: Orrin Cooper, University of Pittburgh, 233 Mervis Hall, Pittsburgh,<br />
PA, 15260, United States of America, orc1@pitt.edu<br />
1 - Key Metrics and Current Industry Practices in Supply<br />
Chain Measurement<br />
Ramesh Bollapragada, Associate Professor, College of Business, San<br />
Francisco State University, 1600 Holloway Avenue, San Francisco,<br />
CA, 94132, United States of America, rameshb@sfsu.edu, Calvin Lee,<br />
Tuna Cencki<br />
The paper identifies current business practices and key measurements in supply<br />
chain performance management. Our survey based research indicates that supply<br />
chain professionals give high importance to quality and reliability factors, increasing<br />
company’s competitiveness, and not just to cost factors, while creating effective<br />
supply chains. The research underlines that more steps need to be taken to connect<br />
supply chain partners, and create models for the quantification of intangible metrics.<br />
INFORMS Austin – 2010 WC18<br />
415<br />
2 - Information Transmission and the Bullwhip Effect<br />
Robert Bray, PhD Student, Graduate School of Business, Stanford<br />
University, 311 Sheridan Ave, Palo Alto, CA, 94305,<br />
United States of America, rlbray@stanford.edu, Haim Mendelson<br />
We study the bullwhip effect in a sample of 4,689 public U.S. companies over 1974-<br />
2008. The traditional bullwhip is negative, but the “demand-uncertainty” bullwhip<br />
is positive. We decompose the total bullwhip into deterministic and stochastic<br />
components, and further decompose the latter by information transmission lead<br />
times. Bullwhips come in several flavors—-firms can anticipate much, but not all, of<br />
the bullwhip.<br />
3 - Business Relationship Functions and Supply Chain Relationship<br />
Quality: Evidence From China<br />
Yongtao Song, School of Management, PO Box 2341, Xi’an Jiaotong<br />
University, Xi’an, 710049, China, xjtusyt@gmail.com, Qin Su<br />
This paper adopts a functional view to analyze the value that buyers attain from<br />
buyer-seller relationships and investigates the links between business relationship<br />
functions (BRF), supply chain relationship quality (SCRQ) and buyer’s performance.<br />
The results indicate that BRF have a direct and an indirect effect on buyer’s<br />
performance through the mediating effect of SCRQ. Moreover, the availability of<br />
alternative suppliers has a moderating influence on the relationship between BRF<br />
and SCRQ.<br />
4 - 3rd Party Logistics Provider Selection with Performance<br />
Metrics and ANP<br />
Orrin Cooper, University of Pittburgh, 233 Mervis Hall, Pittsburgh,<br />
PA, 15260, United States of America, orc1@pitt.edu, Jennifer Shang,<br />
Pandu Tadikamalla<br />
Selecting a third party logistics provider with the Analytical Network Process (ANP)<br />
allows one to measure the interrelated influences of performance metrics in the<br />
supply chain. The criteria in the decision matrix are organized according to the<br />
temporal stages or flow of a product through the supply chain. A general model is<br />
presented and applied to case data and tested for robustness with detailed sensitivity<br />
analysis.<br />
■ WC18<br />
C - Room 17A, Level 4<br />
Industry Applications<br />
Contributed Session<br />
Chair: Fubin Qian, PhD Candidate, Molde University College,<br />
Britvegen 2, N-6411, Fannestrandveien 76, 6416, Molde, Norway,<br />
fubin.qian@himolde.no<br />
1 - Dynamic Capacity Planning for Short Life Cycle Products<br />
Saman Alaniazar, PhD Candidate, Wayne State University, 4815<br />
Fourth St., Detroit, MI, 48202, United States of America,<br />
saman.alaniazar@wayne.edu, Alper Murat, Ratna Babu Chinnam<br />
We study capacity planning for short life cycle products. Given the non-stationary<br />
and region-based nature of the demand in this type of products, our model employs<br />
a hybrid-strategy of short-term demand forecasting and long-term demand<br />
modeling to monitor amount and time of expansions. Moreover, we consider and<br />
apply a risk model in the process of capacity planning. We report experimental<br />
results based on an implementation of the model in an agent based system for<br />
Tamagotchi Case.<br />
2 - Optimizing Credit Lines<br />
Lisa Kart, Director, Analytics, FICO, Austin, TX, 78704,<br />
United States of America, lisakart@fico.com<br />
Over the past several years, FICO has helped banks optimize credit line decisions<br />
using predictive and decision modeling in a framework of constrained optimization.<br />
Hear about the approach, how the analytics were implemented, and the results<br />
achieved for banks across the globe.<br />
3 - The Industry Emergence Funnel: Towards a Conceptual Framework<br />
for Public Sector Coordination, Investment Prioritization and<br />
Strategy Development<br />
Eoin O’Sullivan, University of Cambridge, Cambridge,<br />
United Kingdom,eo252@cam.ac.uk<br />
This paper introduces a conceptual framework for analyzing the emergence of novel<br />
technology-based industries. We make the case for an industry-level analogue of<br />
established, firm-level “funnel” models of innovation. The features of the proposed<br />
framework are based on observed patterns of historical emergence of technologybased<br />
industries analyzed using roadmapping techniques.
WC19<br />
4 - A Tabu Search Heuristic for Offshore Helicopter Routing Problem<br />
with Focus on Passenger Safety<br />
Fubin Qian, PhD candidate, Molde University College, Britvegen 2,<br />
N-6411, Fannestrandveien 76, 6416, Molde, Norway,<br />
fubin.qian@himolde.no, Irina Gribkovskaia, Gilbert Laporte, ÿyvind<br />
Halskau<br />
A mathematical model is proposed to improve passenger transportation safety by<br />
minimizing the expected number of fatalities in offshore helicopter transportation.<br />
Tabu search heuristics are developed. Both the mathematical model and heuristics<br />
are capable of producing general solutions, namely solutions allowing a second visit<br />
to installations. Computational results show that safety performance can be<br />
significantly improved by introducing general solution strategy to helicopter routing<br />
problem.<br />
■ WC19<br />
C - Room 17B, Level 4<br />
Dynamic Optimization in Energy Pricing<br />
Sponsor: Revenue Management and Pricing Section<br />
Sponsored Session<br />
Chair: Canan Uckun, University of Chicago, 5807 South Woodlawn<br />
Avenue, Chicago, IL, 60637, United States of America,<br />
cuckun@chicagobooth.edu<br />
1 - Market Power Analysis in Electricity Markets with<br />
Time-of-use Pricing<br />
Emre Celebi, University of Waterloo, Department of Management<br />
Sciences, 200 University Ave. West, Waterloo, ON, N2L 3G1, Canada,<br />
ecelebi@engmail.uwaterloo.ca, David Fuller<br />
We propose variational inequality models for electricity markets with time-of-use<br />
(TOU) pricing. The demand response is dynamic in the model through a<br />
dependence on the lagged demand. Different market structures are examined<br />
within this context. With an illustrative example, the welfare gains/losses are<br />
analyzed after an implementation of TOU pricing scheme over the single pricing<br />
scheme. Also, break-up of a large supplier into smaller parts is investigated.<br />
2 - Enabling Price-Responsive Demand Management in<br />
Electricity Markets<br />
Hung-po Chao, ISO New England, hchao@iso-ne.com<br />
The traditional approach to demand response suffers from the missing property right<br />
problem that could undermine electricity market efficiency. A multi-settlement<br />
retail tariff solves the problem by allowing each customer to establish a contractbased<br />
baseline through demand subscription before joining a demand response<br />
program. A two-settlement system with demand subscription and dynamic default<br />
rate facilitates price-responsive demand for general consumer benefits.<br />
3 - An ADP Approach to Decomposing Smart Grid Pricing Problems<br />
Canan Uckun, University of Chicago, 5807 South Woodlawn<br />
Avenue, Chicago, IL, 60637, United States of America,<br />
cuckun@chicagobooth.edu, Dan Adelman<br />
In the electricity smart grid, millions of homes will receive price signals<br />
simultaneously. We can formulate the problem of optimizing prices through time as<br />
a dynamic programming problem, containing state information for each home.<br />
However, the problem has such large scale that it is intractable using standard<br />
solution methods. We propose a new decomposition approach to solving this<br />
dynamic program approximately.<br />
■ WC20<br />
C - Room 18A, Level 4<br />
Pricing and Revenue Management II<br />
Contributed Session<br />
Chair: Oben Ceryan, Ross School of Business, University of Michigan,<br />
701 Tappan St, Ann Arbor, MI, 48109, United States of America,<br />
oceryan@umich.edu<br />
1 - Dynamic Revenue Management with Nonlinear Pricing<br />
Wei Wei, Case Western Reserve University, Dept of Operations,<br />
Weatherhead School, 10900 Euclid Ave, Cleveland, OH, 44106-7235,<br />
United States of America, wei.wei@case.edu, Matthew J. Sobel<br />
We compare linear pricing with multi-part tariffs in a class of dynamic revenue<br />
management models with stochastic iso-elastic demand. Each period a firm sets<br />
multiple prices corresponding to a multi-part tariff and decides how much inventory<br />
to hold back for sale later. There is a nearly explicit myopic optimum that can be<br />
computed easily. The results exploit the homogeneity of an associated Markov<br />
decision process. We illustrate the results with a numerical example.<br />
INFORMS Austin – 2010<br />
416<br />
2 - Pricing and Timing of New Version Releases in the Presence of<br />
Strategic Consumers<br />
Shubin Xu, Lundquist College of Business, University of Oregon,<br />
Eugene, OR, 97403, United States of America, sxu@uoregon.edu,<br />
Michael Pangburn<br />
We study a firm offering successive product versions. Due to ongoing R&D or<br />
improving technology, each new version implies an opportunity cost associated with<br />
continued use of the prior product. The firm decides the time between successive<br />
introductions, and price. In turn, consumers strategically choose whether to<br />
purchase or wait for a later version. We consider the firm’s profit maximizing policy<br />
assuming a homogeneous market and then extend the analysis to address consumer<br />
heterogeneity.<br />
3 - Integrating Capacity Control Concepts into the Locate-to-Order-<br />
Systems of Automotive Manufacturers<br />
Thomas Volling, Technische Universität Braunschweig, Institute of<br />
Automotive Management and Industrial Production,<br />
Katharinenstrasse 3, Braunschweig, 38106, Germany,<br />
t.volling@tu-bs.de, Thomas S. Spengler<br />
Lead times in the automotive industry exceed customers’ expectations for the<br />
delivery of new cars. As a consequence, most manufacturers have established hybrid<br />
order fulfillment strategies combining elements from build-to-order and build-tostock<br />
(BTS) production. The focus of the contribution is on the BTS share of<br />
vehicles. A capacity control is developed to support the allocation of preconfigured<br />
cars to customer requests. Assignments are evaluated based on product specific<br />
opportunity costs.<br />
4 - Dynamic Optimal Design for Sequential Online Auctions<br />
Xi Chen, University of Washington, Box 352650, Industrial<br />
Engineering, Seattle, 98195, United States of America,<br />
chenxi07@uw.edu, Archis Ghate, Arvind Tripathi<br />
Retailers often conduct a sequence of online auctions to sell identical items as a<br />
revenue generation and inventory management tool. We show that under a second<br />
order condition on the single- auction expected revenue function, a threshold policy<br />
is optimal for inventory scrapping and a monotone staircase with unit jump policy is<br />
optimal for lot sizing. This condition is met in all common auction mechanisms. We<br />
investigate an extension where the minimum bid is also optimized.<br />
5 - Product Upgrades and Pricing with Strategic Consumers<br />
Oben Ceryan, Ross School of Business, University of Michigan,<br />
701 Tappan St, Ann Arbor, MI, 48109, United States of America,<br />
oceryan@umich.edu, Ozge Sahin, Izak Duenyas<br />
We consider a firm that allows upgrading of customers purchasing a lower quality<br />
product to a higher quality product if there is excess demand for the former and<br />
excess capacity for the latter. We investigate the optimal pricing and capacity<br />
decisions in the presence of strategic consumers that consider product prices as well<br />
as upgrade possibilities when choosing which product to purchase.<br />
■ WC21<br />
C - Room 18B, Level 4<br />
Service Contract and Incentive Design<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Hermann Jahnke, Professor, Bielefeld University,<br />
Universitaetsstrasse 25, Bielefeld, 33615, Germany, hjahnke@wiwi.unibielefeld.de<br />
1 - After-sales Contract Analysis for Service Supply Chains<br />
Dong Li, Rotterdam School of Management, Erasmus University, P.O.<br />
Box 1738, Rotterdam, Netherlands, dli@rsm.nl, Yugang Yu, Nishant<br />
Mishra, Xinguo Ming<br />
The multiple types of contract of the service supply chain may cause conflicting<br />
incentives. We use a game-theoretic frame to model the behavior of a service supply<br />
chain, and compare the different type of contracts and show that how the<br />
parameters affect the optimal solutions. We also find out that the inefficiency can be<br />
coordinated with a revenue-sharing performance based contract.<br />
2 - Incentive Design in Industrial Product Service Systems:<br />
A Simulation Study<br />
Partha Datta, Assistant Professor, IIM Calcutta, Diamond Harbour<br />
Road, Joka, Calcutta, 700104, India, parthapriya.datta@gmail.com<br />
Powerful incentives and risks are normally used in industrial service contracts to<br />
transfer risks to measure compliance with performance measures. This paper studies<br />
the uncertainty in service delivery driven by the agreed contract type and incentive<br />
mechanism using agent based discrete event simulation model under multiple<br />
scenarios.
3 - Lower Price Limits for Flat-fee Service Contracts Under Risk<br />
Hermann Jahnke, Professor, Bielefeld University, Universitaetsstrasse<br />
25, Bielefeld, 33615, Germany, hjahnke@wiwi.uni-bielefeld.de,<br />
Jan Thomas Martini<br />
Many manufacturers of capital equipment offer services under flat-fee service<br />
contracts. We address the determination of lower price limits for such contracts.<br />
Under these contracts, the service providers assume part of the customer’s risk. We<br />
focus on the impact this risk has on price limits. Our modeling tool, almost<br />
stochastic dominance, allows us to examine decision making under risk without<br />
precisely knowing the decision makers’ risk preferences as well as a multi-person<br />
decision context.<br />
4 - Towards a Theory of Service Improvisation<br />
Enrico Secchi, Clemson University, 128 Cochran Rd. Apt. 1,<br />
Clemson, SC, 29631, United States of America,<br />
esecchi@clemson.edu, Aleda Roth<br />
This paper examines the role of improvisation in the context of service delivery<br />
systems. Drawing from organizational improvisation literature and service<br />
operations and marketing, we develop antecedents and consequences of service<br />
improvisation. First, we define the concept of service improvisation. Second, we<br />
highlight the importance of the interplay between planning and execution. Finally,<br />
we develop a theoretical link between service delivery and the emergence of service<br />
innovations.<br />
■ WC22<br />
C - Room 18C, Level 4<br />
Service System Design and Effectiveness<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Adelina Gnanlet, Assistant Professor, California State University,<br />
Fullerton, 800 N. State College Blvd, Dept of Mgmt, Fullerton, CA,<br />
92832, United States of America, agnanlet@fullerton.edu<br />
1 - Impact of Labor and Capacity Flexibilities on Quality and a<br />
Financial Performance of Hospitals<br />
Adelina Gnanlet, Assistant Professor, California State University,<br />
Fullerton, 800 N. State College Blvd, Dept of Mgmt, Fullerton, CA,<br />
92832, United States of America, agnanlet@fullerton.edu,<br />
Muge Yayla-Kullu, Chris McDermott<br />
To reduce costs and meet variable demand, service firms frequently cross-train<br />
employees and use flexible capacity in capital intensive service firms. Higher crosstraining<br />
is cost-effective but may not provide adequate quality of service due to<br />
learning effects. Flexible capacity may not be conducive to provide highest level of<br />
quality for certain demand segments. We determine the effects of cross-training and<br />
flexible capacity on quality and financial performance of hospitals.<br />
2 - Impact of Task Complexity on Productivity in Professional Services<br />
Anil Akpinar, IE Business School, C/ Maria de Molina 12, Madrid,<br />
28006, Spain, aakpinar.PhD2010@alumno.ie.edu, Fabrizio Salvador<br />
In this paper we explore the effect of task complexity on the flexibility efficiency<br />
trade-off in knowledge worker productivity. Using a longitudinal data from one of<br />
the largest multinational technology and consulting firm, we provide empirical<br />
evidence that while specialization and variety jointly drives productivity, their<br />
effects are quite distinct for varying levels of task complexity.<br />
3 - More with Less - Service Resource Scheduling by Time<br />
Capacitated Splits<br />
Pasi Porkka, Assistant Professor, Aalto University School of<br />
Economics, P.O. Box 21220, Helsinki, Fin-00076, Finland,<br />
porkka@hse.fi<br />
The balancing of resource time used for production or services and for capacity<br />
consuming set-ups is critical for the realistic planning of high capacity utilization.<br />
We combine the allocation of shared resources, the time-based splitting of tasks and<br />
variable set-ups in mobile service operations. The potential for substantial capacity<br />
time savings is demonstrated. Extensions and solution approaches for realistic<br />
applications are discussed.<br />
4 - The Impact of Service Quality Variation on Service Quality,<br />
Operational Efficiency, and Performances<br />
Hong-il Kim, PhD Candidate, Korea University Business School,<br />
Anam-dong, Seongbuk-gu, Seoul, 136-701, Korea, Republic of,<br />
itlime@korea.ac.kr, Hosun Rhim, Shijin Yoo, Daeki Kim<br />
We investigate how service quality variation affects service quality, operational<br />
efficiency, and business performances. Data of branch operation in a retail bank is<br />
collected. Perceived service quality of customers is surveyed with SERVERPF<br />
questionnaire. HLM (Hierarchical Linear Modeling) and DEA (Data Envelopment<br />
Analysis) are used.<br />
INFORMS Austin – 2010 WC24<br />
417<br />
■ WC23<br />
C - Room 18D, Level 4<br />
Service Management and Virtual Enterprise<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Munish Goyal, Research Staff Member, IBM Research, AC2 L1,<br />
ISB, GACHIBOWLI, Hyderabad, AP, 500032, India,<br />
mungoyal@in.ibm.com<br />
1 - Value Based Dynamic Resource Allocation in a Service Cloud<br />
Munish Goyal, Research Staff Member, IBM Research, AC2 L1, ISB,<br />
GACHIBOWLI, Hyderabad, AP, 500032, India,<br />
mungoyal@in.ibm.com, M Rammohan Rao<br />
Cloud computing is a pool of virtualized computer resources which can be<br />
dynamically added or removed in response to changing business demands while<br />
meeting service level agreements at the minimal energy or operational cost. In this<br />
work, we develop relative value based dynamic resources allocation strategies where<br />
a unit of resource is allocated to a customer request with the highest value above<br />
the energy value threshold at any time. Algorithm is supported with numerical<br />
results.<br />
2 - Negotiation Based Completion Risk Management for<br />
Virtual Enterprise<br />
Min Huang, Professor, Northeastern University, Box 135#,<br />
Northeastern University, Shenyang, 110004, China,<br />
mhuang@mail.neu.edu.cn, Hongyu Jiang, W.H. Ip, Qing Wang,<br />
Xingwei Wang<br />
In the view of the distribution feature of decision-making in a virtual enterprise, a<br />
novel decision-making framework based-on negotiation is proposed for the<br />
completion risk management of VE. Under this framework, according to the<br />
characteristics of the problem, the evaluation mechanism of the owner is designed<br />
based on PERT, and then the concession tactic is proposed. The example analysis<br />
shows that this framework can achieve effective risk management.<br />
3 - Service Parts Inventory Control Under Obsolescence<br />
Cerag Pince, PhD Candidate, Erasmus University, Burg. Oudlaan 50,<br />
Rotterdam, 3000 DR, Netherlands, pince@few.eur.nl,<br />
Rommert Dekker, Hans Frenk<br />
We consider a single location inventory system of a slow moving item where<br />
Poisson demand rate drops to a lower level at a known future time. Under the<br />
assumptions of full backordering and fixed lead time, we incorporate obsolescence<br />
into a one-for-one policy with the option to reduce the base stock level in advance.<br />
We show that when obsolescence can be foreseen, early adaptation of base stock<br />
levels leads to important savings.<br />
■ WC24<br />
C - Room 19A, Level 4<br />
Decision Making for Wildfire Response and Evacuation<br />
Sponsor: Public Programs, Service and Needs<br />
Sponsored Session<br />
Chair: Nada Petrovic, Graduate Student, Physics Department,<br />
Broida Hall, UC Santa Barbara, Santa Barbara, CA, 93106-9530,<br />
United States of America, petrovic@physics.ucsb.edu<br />
1 - Dynamic Resource Allocation in Wildfire Suppression<br />
Nada Petrovic, Graduate Student, Physics Department, Broida Hall,<br />
UC Santa Barbara, Santa Barbara, CA, 93106-9530, United States of<br />
America, petrovic@physics.ucsb.edu, David Alderson, Jean Carlson<br />
Wildfire response demands dynamic decision tools because fires and suppression<br />
evolve simultaneously. Time delays can lead to larger fires and thus greater demand<br />
for resources. We capture this tension using a queuing model that treats fire<br />
progression as a birth and death process, with rates that incorporate intrinsic fire<br />
dynamics and suppression. Using this framework we explore trade-offs in<br />
effectiveness and time delay of response.<br />
2 - A Space-Time Flow Optimization Model for<br />
Neighborhood Evacuation<br />
David Alderson, Assistant Professor, Naval Postgraduate School,<br />
Naval Postgraduate School, 1411 Cunningham Road, Monterey, CA,<br />
93943, United States of America, dlalders@nps.edu,<br />
William Langford<br />
We model the evacuation of vehicles in a residential neighborhood using a spacetime<br />
network flow representation. Our model solves for “best case” evacuation<br />
routes and clearing times, as could be identified and implemented by a central<br />
authority. Our models are large but can be solved efficiently and quickly. We apply<br />
this model to the Mission Canyon neighborhood near Santa Barbara, California, and<br />
contrast our results to a previous simulation-based study.
WC25<br />
3 - Influence of Information Networks on Collective<br />
Evacuation Dynamics<br />
Danielle Bassett, Postdoctoral Research Associate, University of<br />
California Santa Barbara, 6213 Broida Hall, Santa Barbara, CA,<br />
93106, United States of America, dbassett@physics.ucsb.edu, Jean<br />
Carlson, David Alderson<br />
The collective behavior of humans during an evacuation is a poorly understood,<br />
complex phenomenon which we model as a combined centralized-decentralized<br />
consensus problem, influenced by information flow over layers of technological,<br />
social, and geographic networks. An individual’s belief regarding disaster severity is<br />
constantly updated until reaching a decision threshold. We describe differential<br />
dynamics over these layers, indicating sensitivity of human decision-making to<br />
information origin.<br />
4 - Making Emergency Evacuation Decisions with<br />
Uncertain Information<br />
Emily Craparo, Naval Postgraduate School, Glasgow Hall Room 226,<br />
Monterey, CA, United States of America, emcrapar@nps.edu,<br />
David Alderson, Jean Carlson<br />
In emergency situations, time-critical decisions must be made based on uncertain<br />
information. Situational awareness is improved through additional observation of<br />
the threat; however, observation delays action. We consider an individual decisionmaker<br />
who faces an uncertain threat and who must decide when (and whether) to<br />
perform a costly evacuation. We model this evacuation decision problem using<br />
dynamic programming and establish optimal evacuation policies under a variety of<br />
cost models.<br />
■ WC25<br />
C - Room 19B, Level 4<br />
Transportation, Planning II<br />
Contributed Session<br />
Chair: Chi Xie, Research Fellow, The University of Texas at Austin,<br />
1 University Station, Austin, TX, 78712, United States of America,<br />
chi.xie@mail.utexas.edu<br />
1 - Composite Variable Formulation for Truckload Relay<br />
Network Design<br />
Hector Vergara, Graduate Research Assistant, University of Arkansas,<br />
4207 Bell Engineering Center, Fayetteville, AR, 72701,<br />
United States of America, hvergara@uark.edu, Sarah Root<br />
Full truckload (TL) trucking usually considers a Point-to-Point dispatching method.<br />
Alternatively, multi-zone dispatching under a network configuration of relay points<br />
can be used to improve driver retention. We propose a new mathematical<br />
formulation for strategic relay network design that places relay points and<br />
determines driver routes. Our model minimizes total costs while considering<br />
operational constraints such as driver tour length and load circuity within the<br />
variable definition.<br />
2 - An Optimal Cycle Length Model for Feeder Transit Services<br />
Shailesh Chandra, Student, Department of Civil Engineering, Texas<br />
A&M University, 3136 TAMU, College Station, 77843-3136, United<br />
States of America, chandrashailesh@gmail.com, Chung-Wei Shen,<br />
Luca Quadrifoglio<br />
A simulation based generic model has been derived for estimating optimal cycle<br />
lengths of a demand responsive transit “feeder” services. For input parameters such<br />
as the shape size and daily demand density of an area, the success of this model has<br />
been validated by a case study.<br />
3 - Transportation Planning for Squatter Developments<br />
Hani Al-Naghi, PhD Candidate, American University of Beirut,<br />
P.O.Box 11-0236, Riad El Solh, Beirut 11, Beirut, Lebanon,<br />
haa31@aub.edu.lb, Nabil Nehme<br />
This paper addresses urban transportation planning issues related to squatter<br />
developments and their integration with the surrounding areas. A general<br />
framework encompassing all criteria related to social, economics, land use and<br />
political aspects, is formulated and applied to selected case studies in Lebanon.<br />
4 - A Primal-dual Mathematical Programming Framework for Traffic<br />
Assignment Problems<br />
Chi Xie, Research Fellow, The University of Texas at Austin,<br />
1 University Station, Austin, TX, 78712, United States of America,<br />
chi.xie@mail.utexas.edu, Travis Waller<br />
Traffic assignment problems have been formulated as mathematical programs,<br />
variational inequalities, complementarity systems, and fixed-point models. It is well<br />
known that the last three modeling techniques all provide a common functional<br />
form for modeling different traffic assignment problems. This talk presents a<br />
uniform primal-dual mathematical programming framework, which can be used to<br />
accommodate a variety of traffic assignment problems.<br />
INFORMS Austin – 2010<br />
418<br />
■ WC26<br />
C - Room 4A, Level 3<br />
Interface Between Efficient Data Collection and<br />
Flexible Data Modeling<br />
Sponsor: Data Mining<br />
Sponsored Session<br />
Chair: Peter Qian, University of Wisconsin-Madison, 1300 University Ave,<br />
Madison, WI, 53706, United States of America, peterq@stat.wisc.edu<br />
1 - Improvement on Cross-Validation via Sliced Statistical Design<br />
Xinwei Deng, Visiting Assistant Professor, University of Wisconsin-<br />
Madison, Department of Statistics, 1300 University Ave., Madison,<br />
WI, 53706, United States of America, xdeng@cs.wisc.edu, Peter Qian<br />
A training data is often used to construct models to predict the future response. The<br />
cross-validation is a traditional method to compare different models and assess their<br />
prediction performance. It can provide a nearly unbiased estimate of prediction<br />
error, but can be with high variability. In this work, we proposed a novel sliced<br />
statistical design strategy to improve the performance of cross-validation,<br />
substantially outperforms the usual method in various classification problems.<br />
2 - Regularized REML for Estimation and Selection of Fixed and<br />
Random Effects in Linear Mixed-Effects Mo<br />
Sijian Wang, Assistant Professor, University of Wisconsin, Madison,<br />
1300 University Ave., Madison, WI, 53706, United States of America,<br />
wangs@stat.wisc.edu<br />
In the practice of LMM, inference on the structure of random effects component is<br />
of great importance not only to yield proper interpretation of subject specific effects<br />
but also to draw valid statistical conclusions. In this paper, we propose a novel<br />
method of regularized restricted maximum likelihood to select fixed and random<br />
effects simultaneously in the LMM. We also investigate large sample properties for<br />
the proposed estimation, including the oracle property.<br />
3 - Consistent Selection of the Number of Clusters via<br />
Clustering Stability<br />
Junhui Wang, University of Illinois at Chicago, 851 S Morgan St,<br />
Chicago, IL, 60607, United States of America, jwang@math.uic.edu<br />
In cluster analysis, one major challenge is to estimate the number of clusters. In this<br />
talk, I will present a novel selection criterion that is applicable to all kinds of<br />
clustering algorithms. The key idea is to select the number of clusters such that the<br />
resulting clustering algorithm has the smallest instability, which measures its<br />
robustness against the sampling randomness. Numerical examples and asymptotic<br />
selection consistency will be discussed.<br />
4 - Optimal Supersaturated Design for Variable Selection via Lasso<br />
Dadi Xing, PhD Student, Purdue University, 224-7 Arnold Drive,<br />
West Lafayette, IN, 47906, United States of America,<br />
hwan@purdue.edu, Hong Wan, Yu Zhu<br />
In the supersaturated design(SSD) study, most existing criteria for constructing<br />
optimal SSD are motivated and further justified from the estimation perspective. We<br />
will propose a number of optimality criteria for the construction of SSD from the<br />
perspective of variable selection with Lasso. The properties of these criteria will be<br />
discussed. A computing algorithm will be used to construct such optimal SSD, and<br />
examples of simulation and real applications will also be presented.<br />
■ WC27<br />
C - Room 4B, Level 3<br />
Network Optimization II<br />
Contributed Session<br />
Chair: Nan Jiang, Student, University of Texas, Austin, 1 University<br />
Station C1761, ECJ 6.2, Austin, TX, 78712, United States of America,<br />
njiang@mail.utexas.edu<br />
1 - A Reformulation-Linearization Technique for the Two-level Facility<br />
Location Problem<br />
Youngho Lee, Korea University, Sungbuk Ku Anam Dong 5-1, Seoul,<br />
Korea, Seoul, Korea, Republic of, shadowpp@korea.ac.kr,<br />
Gigyoung Park<br />
In this paper, we deal with an two-level facility location problem based on the tree<br />
topology. In particular, we develop a model for this problem and apply the<br />
reformulation-linearization technique (RLT) to construct various enhanced<br />
tightened versions of the proposed model. And we derive necessary and sufficient<br />
conditions for a family of some inequalities to be facet-defining.
2 - Continous Network Design Problem with Emission Constraint<br />
Nan Jiang, Student, University of Texas, Austin, 1 University Station<br />
C1761, ECJ 6.2, Austin, TX, 78712, United States of America,<br />
njiang@mail.utexas.edu, ManWo Ng, Travis Waller<br />
In this paper, a traffic network design model with emission constraint and its<br />
solution method are presented. The resulting solutions are a set of capacity<br />
improvements to a given network, for a given demand, subject to user-specified<br />
budget constraints and emission constraint and resulting in minimal system total<br />
cost. Application results prove this model decreases system emission and provide<br />
information useful for planning road network improvements under air quality<br />
constraints.<br />
■ WC28<br />
C - Room 4C, Level 3<br />
Manufacturing Process Optimization<br />
Sponsor: Quality, Statistics and Reliability<br />
Sponsored Session<br />
Chair: Roshan Vengazhiyil, Coca-Cola Associate Professor, Georgia<br />
Institute of Technology, Industrial and Systems Engineering, Atlanta, GA,<br />
30332, United States of America, roshan@isye.gatech.edu<br />
1 - An Interactive Method to Multiresponse Surface Optimization Based<br />
on Pairwise Comparisons<br />
Dong-Hee Lee, Pohang University of Science and Technology,<br />
Department of Industrial and Management, Pohang, Korea, Republic<br />
of, princeps@postech.ac.kr, Kwang-Jae Kim, Murat Köksalan<br />
In multiresponse surface optimization, responses are often in conflict. To obtain a<br />
satisfactory compromise, the preference information of a decision maker (DM) on<br />
the tradeoffs among the responses should be incorporated into the problem. We<br />
propose an interactive method where the DM provides preference information in<br />
the form of pairwise comparisons. The results of pairwise comparisons are used to<br />
estimate the preference parameter values in an interactive manner. The method is<br />
effective in that a highly satisfactory solution can be obtained.<br />
2 - Analysis of Computer Experiments with Functional Response<br />
Ying Hung, Rutgers, Camden, NJ, United States of America,<br />
yhung@stat.rutgers.edu, Roshan Vengazhiyil, Shreyes Melkote<br />
We develop an efficient implementation of kriging for analyzing functional<br />
responses. The main contribution of this paper is to develop a two-stage model<br />
building procedure and a general framework which can be used irrespective of the<br />
data structure. The methodology is illustrated using a computer experiment<br />
conducted for optimizing residual stresses in machined parts.<br />
3 - New Variable Selection Methods Under Engineering<br />
Inequality Constraints<br />
Hin Kyeol Woo, Georgia Institute of Technology, 765 Ferst Drive,<br />
Atlanta, GA, 30329, United States of America, hinkyeol@gatech.edu,<br />
Andres Hernandez, Jye Chyi Lu, Martha Grover<br />
This presentation discusses new variable selection methods under engineering<br />
inequality constraints. A case study of nanoparticle synthesis with a solubility<br />
constraint motivates and illustrates the research. Simulation experiments explore<br />
properties of the proposed method.<br />
■ WC29<br />
C - Room 5A, Level 3<br />
Maintenance Management and Service Logistics<br />
Sponsor: Quality, Statistics and Reliability<br />
Sponsored Session<br />
Chair: Alaa Elwany, Assistant Professor, Eindhoven Unviersity of<br />
Technology, Eindhoven, Netherlands, elwany@tue.nl<br />
Co-Chair: Nagi Gebraeel, Associate Professor, Georgia Tech, 765 Ferst Dr.,<br />
Atlanta, United States of America, nagi.gebraeel@isye.gatech.edu<br />
1 - Modified Block Replacement Can Outperform Age Replacement in<br />
Terms of Spare Parts Ordering<br />
Rommert Dekker, Erasmus University Rotterdam, Burg Oudlaan 50,<br />
Rotterdam, 3062 PA, Netherlands, rdekker@ese.eur.nl<br />
It is well known that age replacement outperforms block replacement as better<br />
information on the likelihood of failures is used. Yet block replacement allows a<br />
more appropriate ordering of spare parts as replacements can be planned in time. In<br />
this presentation we present a study which shows that the better spare parts<br />
planning can offset the advantages of age replacment. The study also reveals what<br />
kind of inventory policies are useful in this respect.<br />
INFORMS Austin – 2010 WC30<br />
419<br />
2 - Upgrading Policy After Redesign of a Component for<br />
Reliability Improvement<br />
Kurtulus Oner, Assistant Professor, Eindhoven University of<br />
Technology, P.O. Box 513, Eindhoven, 5600 MB, Netherlands,<br />
k.b.oner@tue.nl, Geert-Jan Van Houtum, Gudrun P. Kiesmüller<br />
We introduce a model for studying the following two upgrading policies that an<br />
OEM may implement after the redesign of a component: (i) Upgrade all<br />
preventively at time 0, (ii) Upgrade one-by-one correctively. We develop a problem<br />
formulation for the comparison of the two policies and perform exact analysis. We<br />
conduct a numerical study and derive insights on the optimality of the policies.<br />
3 - Component Reliability Criticality or Importance Metrics for Systems<br />
with Degrading Components<br />
David Coit, Associate Professor, Rutgers University, Industrial &<br />
Systems Engineering, 96 Frelinghuysen Rd., Piscataway, NJ, 08854,<br />
United States of America, coit@rutgers.edu, Hao Peng, Qianmei Feng<br />
This paper proposes new importance measures (IMs) for systems with either<br />
independent or dependent degrading components. As functions of time, the<br />
proposed IMs can provide timely feedback on the critical components based on the<br />
observed degradation. The correlation between components and the dependency of<br />
failure thresholds are considered through multivariate distributions. Numerical<br />
examples show that the proposed IMs are effective in assessing criticality of<br />
degrading components.<br />
4 - Maintenance Policy Based on MultiCriteria Decision Aiding<br />
Cristiano Cavalcante, Federal University of Pernambuco, Caixa<br />
Postal, 5125, Cep 52070960, Recife, PE, 52070960, Brazil,<br />
cristianogesm@gmail.com, Adiel Almeida<br />
Maintenance planning is very sensitive to characteristics of the system, the context<br />
and the objectives of the decision maker. Regarding this problem, the most common<br />
analyses consist of evaluating the cost rate function. But, in some specific contexts<br />
the consequence of failures has distinct dimensions, which are difficult to represent<br />
by only one criterion (monetization). Thus, we discuss models based on MCDA<br />
(MultiCriteria Decision Aiding) approach, in order to support maintenance<br />
planning.<br />
■ WC30<br />
C - Room 5B, Level 3<br />
Statistics/Quality Control II<br />
Contributed Session<br />
Chair: Xuan Huang, Assistant Professor, University of Alabama at<br />
Birmingham, 345 Lincoln Ave., Apt 115, Amherst, MA, 01002, United<br />
States of America, xuan@som.umass.edu<br />
1 - Comparison of Ozone Levels Among Five Cities using<br />
Control Charts<br />
Gautam Eapi, PhD Student, University of Texas at Arlington, Civil<br />
Engineering, Box 19308, Arlington, TX, 76019, United States of<br />
America, gautam.raghavendra@gmail.com, Melanie Sattler,<br />
Mostafa Ghandehari<br />
Ozone is one of the six criteria pollutants, as specified by the USEPA. Statistical<br />
quality control can be helpful in improving quality. In this paper, data for ozone<br />
levels of five different cities across the U.S. is analyzed by using control<br />
charts.Control charts are used to compare the cities. In addition, out of control data<br />
points are discussed.<br />
2 - A Bayesian Approach to Estimating Market Implied Risk<br />
Neutral Densities<br />
James Delaney, Assistant Professor, Temple University, Department<br />
of Statistics (006-12), 1810 N 13th Street, Philadelphia, PA, 19122-<br />
6012, United States of America, james.delaney@gatech.edu,<br />
Marc Sobel<br />
Contemporaneous prices of financial derivatives provide much information about<br />
the so-called “market implied risk neutral distribution” (MIRND) of the security that<br />
underlies those derivatives. Here we propose a Bayesian model to provide the<br />
regularity necessary for estimating a MIRND that corresponds to a set of options’<br />
prices. We provide details on a much more generally useful technique for simulating<br />
from the very complex posterior distribution of this model’s parameters.<br />
3 - Orthogonal Polynomial and Saddle Point Approximations for Sums<br />
of Non-identical Binomial Random Variables<br />
Aysun Taseli, Research Assistant, Northeastern University,<br />
360 Huntington Avenue, 334 Snell Engineering, Boston, 02115,<br />
United States of America, aysunt_qpl@yahoo.com, James Benneyan<br />
We compare performance and discuss relative advantages of saddle point<br />
approximations (SPA) and cumulant based orthogonal polynomial expansions for<br />
estimating the convolution of non-identical binomial distributions. Some important<br />
healthcare and service applications of this distribution involve methods that require<br />
repetitive computation of probabilities. Both SPA and a normalized Gram-Charlier<br />
expansion are shown to be accurate and fast compared to the exact PDF and Monte<br />
Carlo estimation.
WC31<br />
4 - Beta Model-based Control Chart for Fraction Monitoring with<br />
Correlated Process Variables<br />
Michel Anzanello, Professor, Federal University of Rio Grande do<br />
Sul, Av. Osvaldo Aranha, 99, Porto Alegre, 90.035-190, Brazil,<br />
michel.anzanello@gmail.com, Angelo Sant’Anna, Carla ten Caten<br />
Although widely used to monitor processes where quality characteristics vary with<br />
adjustments in control variables, model-based control charts’ efficiency is<br />
jeopardized by high correlated control variables. Our method integrates Principal<br />
Components Analysis to Beta model-based control charts to overcome such<br />
limitation. Sensitivity Analysis using Monte Carlo simulation validates the method.<br />
5 - Dimension Reduction of Multivariate Autocorrelated Processes<br />
Xuan Huang, Assistant Professor, University of Alabama at<br />
Birmingham, 345 Lincoln Ave., Apt 115, Amherst, MA, 01002,<br />
United States of America, xuan@som.umass.edu<br />
In traditional multivariate literature, Principal Components Analysis (PCA) is the<br />
standard tool for dimension reduction. For autocorrelated processes, however, PCA<br />
fails to take into account the time structure information. It is arguable that PCA is<br />
still the best choice. In this presentation I propose an enhanced dimension reduction<br />
method which by design takes into account both cross-correlation and<br />
autocorrelation information. I demonstrate it through case studies and simulations.<br />
■ WC31<br />
C - Room 5C, Level 3<br />
Health Care, Therapy and Treatment<br />
Contributed Session<br />
Chair: Chunhua Men, University of California, San Diego, 3855 Health<br />
Sciences Dr. #0843, La Jolla, CA, 92093, United States of America,<br />
cmen@ucsd.edu<br />
1 - Identifying and Quantifying Protein Values for Obtaining<br />
Cancer Biomarkers<br />
Chaitra Gopalappa, PhD Student, University of South Florida, 4202 E<br />
Fowler Ave, Tampa, United States of America, chaitrag@gmail.com<br />
Identifying proteins that are only produced in the cancerous state of cells (cancer<br />
biomarkers) can lead to its use as a diagnostic tool for early detection of cancer. The<br />
task prior to detecting biomarkers (proteins that distinguish cases from controls),<br />
i.e., identifying and quantifying the amount of all proteins, is an analytically<br />
challenging task that requires mathematical models. We present the analytical<br />
challenges and the mathematical models.<br />
2 - Retrofitting Tissue and Cell Banking: Best Practices and Emerging<br />
Business Models<br />
Katrina Nordstrom, Professor, Aalto University School of Science and<br />
Technology, Department Biotechnology and Chemical technol,<br />
Kemistintie 1A 16100 Aalto, Espoo, Finland,<br />
katrina.nordstrom@tkk.fi, Marko Narhi, Petri Lehenkari,<br />
Ari P.J. Vepsalainen, Olli Natri, Mika Pietila<br />
The study explores “retrofitting” of blood banking by development of business<br />
models based on best practices for collection, processing, storage and delivery of<br />
cells and tissues. Plausible business models examine production of bone marrow,<br />
umbilical cord blood stem cells and hematopoietic stem cells. A framework is also<br />
specified for classifying and evaluating the capabilities and hurdles of supply chains<br />
for living products for safe and traceable future products and therapies.<br />
3 - Turkey Disposal and Recycling Network Design Model for<br />
Drug Industry<br />
Ayse Gunes, Assistant Specialist, Industrial Engineer, Scientific and<br />
Technical Research Council of Turkey (TUBITAK), 06100<br />
Kavaklidere, Ankara, Turkey, ayse.gunes@tubitak.gov.tr,<br />
Bahar Ozyoruk<br />
In Turkey, to determine the tendency of people, we first have made a survey related<br />
to drug use, recycling, etc. with military personnel. We have developed a model that<br />
provides waste disposal and recycling of paper in the minimum cost. In the<br />
developed model, human and environmental health, hazardous waste disposal and<br />
recycling for reuse are discussed and the model are solved with GAMS program.<br />
This study includes case study, it is important for healthcare logistics and global<br />
health topics.<br />
4 - Linearity Effects in Brachytherapy Treatment Planning<br />
Asa Holm, PhD Student, Linköpings Universitet, Matematiska<br />
institutionen, Linköpings universitet, Linköping, 58183, Sweden,<br />
asa.holm@liu.se, Torbjörn Larsson, Asa Carlsson Tedgren<br />
Modern optimization techniques for inverse planning of HDR brachytherapy makes<br />
it possible to efficiently calculate dose plans. On of the tenets of such techniques is<br />
the use of linear penalty functions. Plans generated with these techniques tend to<br />
have a few dwell positions that dominate the solution, however physicians prefer<br />
homogeneous plans. In this talk we show that one reason for the long dwell times is<br />
the linear penalties and introduce a solution that reduces the effects of linearity.<br />
INFORMS Austin – 2010<br />
420<br />
5 - Optimization Models for Online Adaptive Radiotherapy<br />
Chunhua Men, University of California, San Diego, 3855 Health<br />
Sciences Dr. #0843, La Jolla, CA, 92093, United States of America,<br />
cmen@ucsd.edu, Steve Jiang<br />
Traditional treatment plan optimization models based on a snapshot of the patient’s<br />
anatomy prior to treatment are not suitable for online adaptive radiotherapy (ART)<br />
which allows real-time treatment adaptations based on the current patient anatomy.<br />
In this work, we develop and evaluate various optimization models for online ART.<br />
To obtain real-time treatment plans, we implement the algorithms on GPU. Tests on<br />
clinical cancer cases showed the effectiveness and the efficiency of these models.<br />
■ WC32<br />
C - Room 6A, Level 3<br />
Computational Stochastic Programming<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: Shabbir Ahmed, Associate Professor, Georgia Institute of Tech,<br />
765 Ferst Drive NW, Atlanta, GA, United States of America,<br />
sahmed@isye.gatech.edu<br />
1 - A Preconditioning Technique for Schur Complement Systems<br />
Arising in Stochastic Optimization<br />
Mihai Anitescu, Computational Mathematician, Argonne National<br />
Laboratory, Math and Computer Science Division, 9700 S Cass Ave,<br />
Argonne, IL, 60439, United States of America, anitescu@mcs.anl.gov,<br />
Cosmin Petra<br />
We discuss a parallel interior-point method for stochastic programming that uses a<br />
Schur complement mechanism. We propose a stochastic preconditioner to improve<br />
scalability. The spectral analysis of the preconditioned matrix indicates an<br />
exponential clustering of the eigenvalues around 1. The numerical experiments<br />
performed on the relaxation of a unit commitment problem show good<br />
performance, in terms of both the accuracy of the solution and the execution time.<br />
2 - Models and Formulations for Optimization with Multivariate<br />
Stochastic Dominance Constraints<br />
James Luedtke, University of Wisconsin-Madison, 1513 University<br />
Av., Madison, WI, United States of America, jrluedt1@wisc.edu,<br />
Benjamin Armbruster<br />
Multivariate stochastic dominance constraints provide an interesting modeling tool<br />
for problems having multiple stochastic objectives. Recently proposed models use<br />
extensions of the notion of positive linear stochastic dominance, but appear<br />
computationally challenging to use. We propose to use a different notion of<br />
dominance, based on expected utility theory, and present linear and integer<br />
programming formulations for the corresponding problem.<br />
3 - Learning Price Functions in Cournot Games<br />
Uday Shanbhag, Asst. Professor, University of Illinois at Urbana<br />
Champaign, Urbana, Il, United States of America,<br />
udaybag@illinois.edu, Sean Meyn, Hao Jiang<br />
We consider a regime where firms compete in a Nash-Cournot game without the<br />
knowledge of the precise parameters of the price functions. We show that the<br />
resulting trajectory can be characterized. Convergence of the learning update<br />
scheme is examined in deterministic and stochastic regimes.<br />
■ WC33<br />
C - Room 6B, Level 3<br />
Optimization Strategies for Real-World Applications<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: Eva Lee, Professor & Director, Georgia Institute of Technology,<br />
Center for Operations Research in Medici, Industrial & Systems<br />
Engineeriing, Altanta, GA, 30332-0205, United States of America,<br />
eva.lee@gatech.edu<br />
1 - On the Simultaneity of Row and Column Generation<br />
Jon Petersen, PhD Student, Georgia Institute of Technology,<br />
765 Ferst Drive NW, Atlanta, GA, 30309, United States of America,<br />
Petersen@gatech.edu, Ellis Johnson<br />
While both constraint generation and column generation have been successfully<br />
employed in solving practical real-world problems, they are often thought of as<br />
being mutually exclusive. The efficacy of solving large-scale models can be improved<br />
by using these two principles concurrently. We propose a new method for doing so,<br />
and present computational results to validate our approach.
2 - Audience Space Aggregation for Ad Planning<br />
John Turner, University of California - Irvine, The Paul Merage<br />
School of Business, Irvine, CA, 92697, United States of America,<br />
john.turner@uci.edu<br />
Whether serving ads on web pages or in newer media such as video games,<br />
targeting constraints lead to a combinatorial explosion in the number of audience<br />
segments. Using an aggregation heuristic for large transportation problems, we<br />
allocate impressions to ad campaigns at an appropriate granularity. Computational<br />
results show that a little bit of disaggregation goes a long way: Near-optimal<br />
solutions are achieved despite a high degree of aggregation.<br />
3 - Constraint Optimal Selection Techniques (COSTs) for<br />
Linear Programming<br />
H. W. Corley, IMSE Department, The University of Texas at<br />
Arlington, Arlington, TX, 76019, United States of America,<br />
corley@uta.edu, Jay Rosenberger, Goh Saito<br />
We present a Constraint Optimal Selection Technique (COST) for efficiently solving<br />
large-scale nonnegative linear programming problems. We provide a geometric<br />
interpretation of the COST and computational comparisons with the CPLEX primal<br />
simplex, dual simplex, and barrier algorithms.<br />
■ WC34<br />
C - Room 7, Level 3<br />
Optimization on Graphs<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: Doug Altner, Assistant Professor, United States Naval Academy,<br />
United States of America, altner@usna.edu<br />
1 - Integer Programming Techniques for Matroid Circuit Problems<br />
John Arellano, PhD Student, Rice University, 6100 Main St. MS 134,<br />
Houston, TX, 77030, United States of America, jda2@rice.edu,<br />
Illya Hicks<br />
Although some combinatorial optimization problems associated with matroids can<br />
be solved in polynomial time, finding particular circuits in matroids is an NP-hard<br />
problem. It is related to compressive sensing and finding the degree of redundancy<br />
of sensor networks. In this talk, we attempt to solve these types of problems to<br />
optimality using integer programming techniques and present computational results.<br />
2 - Over Restriction of Network Expansion Big M Constraints<br />
Kael Stilp, Georgia Institute of Technology, 765 Ferst Drive, NW,<br />
Atlanta, GA, United States of America, mstilp3@isye.gatech.edu,<br />
Ozlem Ergun, Pinar Keskinocak<br />
We discuss a multi period network expansion model where flow capacities are big-<br />
M constrained and nodes have supply and demand of commodities. The objective is<br />
to minimize unsatisfied demand over all of the periods. We show computational<br />
results behind restricting the M value to infeasible values as a means of speeding up<br />
computation and achieving better solutions. To further understand the results we<br />
discuss theoretical reasonings for the occurrence.<br />
3 - Coverings and Matchings in r-Partite Hypergraphs<br />
Doug Altner, Assistant Professor, United States Naval Academy,<br />
United States of America, altner@usna.edu, Paul Brooks<br />
We present a few results regarding matchings and coverings in r-partite<br />
hypergraphs. First, we present an alternate proof showing the integrality gap of the<br />
standard BILP for r-dimensional matching is at least r-k where k is the smallest<br />
positive integer such that r-k is a prime power. Second, we prove r-dimensional<br />
covering is NP-hard for intersecting hypergraphs. Third, we prove a few upper<br />
bounds on the covering number of a special class of intersecting hypergraphs that<br />
are not balanced.<br />
INFORMS Austin – 2010 WC36<br />
421<br />
■ WC35<br />
C - Room 8A, Level 3<br />
Advances in Anomalous Diffusion III<br />
Sponsor: Applied Probability<br />
Sponsored Session<br />
Chair: Mark Meerschaert, Michigan State University, Department of<br />
Statistics and Probability, East Lansing, MI, United States of America,<br />
mcubed@stt.msu.edu<br />
1 - Approximation of Tempered Operator Stable Processes<br />
Boris Baeumer, University of Otago, Department of Mathematics and<br />
Statistics, Dunedin, New Zealand, bbaeumer@maths.otago.ac.nz,<br />
Mihaly Kovacs<br />
Operator stable processes are characterised by the scaling matrix H and mixing<br />
measure M. By randomly choosing a direction and then generating a onedimensional<br />
jump distance, the resulting process lies in the domain of attraction of<br />
the operator stable process. All tempered processes lie in the domain of attraction of<br />
a Gaussian. We show that for some tempered op-stable processes the speed of<br />
convergence of the approximant to the tempered process is faster than the<br />
convergence to the Gaussian.<br />
2 - Cauchy Problems Solved by Running Subordinate Processes<br />
Erkan Nane, Assitant Professor, Auburn University, 221 Parker Hall,<br />
Auburn, AL, 36849, United States of America, ezn0001@auburn.edu<br />
Subordinated Markov processes will be studied. These are obtained by taking<br />
Markov processes and replacing the time parameter with other processes such as<br />
Brownian motion, symmetric stable process, an inverse of a stable subordinator, or<br />
local time of an stable process of index between 1 and 2. We obtain frational<br />
Cauchy problems or Cauchy problems involving the powers of the generator of the<br />
Markov Process by running these subordinated Markov processes.<br />
3 - Space-time Duality for Fractional Diffusion<br />
Mark Meerschaert, Michigan State University, Department of<br />
Statistics and Probability, East Lansing, MI, United States of America,<br />
mcubed@stt.msu.edu, Boris Baeumer, Erkan Nane<br />
Fractional diffusion equations govern scaling limits of random walk models. The<br />
limit process is a stable Levy motion that models the jumps, subordinated to an<br />
inverse stable process that models the waiting times. Using Zolotarev duality, we<br />
relate the density of a spectrally negative stable process with index $1
WC37<br />
2 - A Simple Management Tool to Increase High School Track<br />
Team Participation<br />
Sambhavi Lakshminarayanan, Assistant Professor, Medgar Evers<br />
College - CUNY, S-Building, Department of Business Admin, 1637<br />
Bedford Avenue, Brooklyn, NY, 11225, United States of America,<br />
sLakshminarayanan@mec.cuny.edu, Ashwin Acharya<br />
Convincing busy high school students to make a significant time commitment to<br />
participate in athletics is a challenge. However, schools and athletic coaches consider<br />
it highly desirable, if not necessary, for students to participate in athletic activities.<br />
This paper discusses an approach developed by the senior members of the track<br />
team at an academically focused high school to increase team numbers and<br />
retention.<br />
3 - Teaching Business Statistics using Participatory Learning Methods<br />
in a Multicultural Setting<br />
Mark Ferris, Saint Louis University, 3674 Lindell Blvd, Room 457,<br />
Saint Louis, MO, 63104, United States of America, ferrisme@slu.edu,<br />
Reuven Levary<br />
Teaching pedagogy in business schools emphasize participatory learning methods<br />
such as class discussion, group problem solving and case studies. The predominant<br />
teaching methods for international students may not include a participatory<br />
component, rather it is a system that emphasizes the teacher as the prime source of<br />
knowledge. A strategy for ensuring the contribution of international students in a<br />
participatory learning environment for statistics was developed, implemented and<br />
evaluated.<br />
4 - Undergraduate and Graduate Students’ Perception about<br />
Web-Enhanced and Online Courses<br />
Hiral Shah, Assistant Professor, St Cloud State University, 720 Fourth<br />
Ave S - ECC 101, St Cloud, MN, 56301, United States of America,<br />
hashah@stcloudstate.edu, Devang Mehta<br />
The purpose of this study was to compare the perceptions of students about<br />
completely online courses against web-enhanced courses. Data were collected from<br />
both graduate and undergraduate students enrolled at two different higher<br />
education institutions. The results of this study will enable instructors to modify<br />
their teaching styles using either of these methods of teaching.<br />
5 - What is Academic Quality? A Comparison of Traditional and Adult<br />
Students’ Perceptions<br />
Helene Caudill, Associate Professor of Management, St. Edward’s<br />
University, 3001 South Congress Avenue, Austin, TX, 78704,<br />
United States of America, helenec@stedwards.edu<br />
There are numerous definitions of academic quality, but the one that I believe<br />
affects student satisfaction and faculty reputations most often is the perception of<br />
what students believe to be “quality in the classroom.” With responses from over<br />
250 students, the results indicate that students focus on three main areas: the<br />
credentials of the faculty member, the usefulness of the materials and assignments,<br />
and the communication skills of the faculty member.<br />
■ WC37<br />
C - Room 8C, Level 3<br />
Applied Probability<br />
Contributed Session<br />
Chair: Raja Jayaraman, Postdoctoral Research Fellow, University of<br />
Arkansas, Industrial Engineering, Bell 4207, Fayetteville, AR, 72701,<br />
United States of America, rjayaram@uark.edu<br />
1 - The Action Gambler and Equal-sized Wagering<br />
David Hartvigsen, Professor, University of Notre Dame, 354 Mendoza<br />
College of Business, Notre Dame, IN, 46556-5646, United States of<br />
America, Hartvigsen.1@nd.edu<br />
A gambler, with a bankroll B, faces a sequence of n identical, independent, win-lose<br />
bets. When the total amount wagered (the total action) must be at least B, we show<br />
that wagering B/n on each bet maximizes the expected utility of the final bankroll<br />
iff the probability of winning a single bet is at most some p* (which is an explicit<br />
function of B, n, and the utility function).<br />
2 - Optimal Sequential Selection of a Unimodal Subsequence From a<br />
Random Sample<br />
Alessandro Arlotto, University of Pennsylvania, 3730 Walnut Street,<br />
500 Jon M. Hunstman Hall, Philadelphia, PA, 19104, United States<br />
of America, alear@wharton.upenn.edu, J. Michael Steele<br />
The length of the longest unimodal subsequence in a random sample of size $n$ is<br />
known to be asymptotic to $2\sqrt{2n}$. We study the sequential version of the<br />
same problem in which, at every decision time $k\in\{1,...,n\}$, a decision-maker<br />
has to select or reject the current observation in order to form a unimodal<br />
subsequence of maximal expected length. We show that this expected length is<br />
asymptotic to $2\sqrt{n}$.<br />
INFORMS Austin – 2010<br />
422<br />
3 - On Pro-rata Pricing Strategy for Extended Product Warranties<br />
Raja Jayaraman, Postdoctoral Research Fellow, University of<br />
Arkansas, Industrial Engineering, Bell 4207, Fayetteville, AR, 72701,<br />
United States of America, rjayaram@uark.edu, Timothy Matis<br />
Product warranties play a challenging and decisive role in today’s dynamic business<br />
environment. Several strategies and models have been proposed assuming fixed cost<br />
associated with various repair actions available to the manufacturer towards<br />
rectifying product failures. In this presentation we shall address pro-rata pricing and<br />
its overall effect towards minimizing expected cost for products carrying extended<br />
warranties.<br />
■ WC38<br />
C - Room 9A, Level 3<br />
Theory and Applications in Copositive Programming<br />
Sponsor: Optimization/Linear Programming and Complementarity<br />
(Joint Cluster ICS)<br />
Sponsored Session<br />
Chair: Samuel Burer, Associate Professor, University of Iowa, S346<br />
Pappajohn Business Building, Iowa City, IA, 52242-1994,<br />
United States of America, samuel-burer@uiowa.edu<br />
1 - New Approximations for Copositive Matrices<br />
Samuel Burer, Associate Professor, University of Iowa, S346<br />
Pappajohn Business Building, Iowa City, IA, 52242-1994,<br />
United States of America, samuel-burer@uiowa.edu, Hongbo Dong<br />
We introduce a new hierarchy of inner approximations of the copositive matrices.<br />
The distinguishing feature of the hierarchy is its recursive nature, which deals with<br />
smaller (but more) matrices as the recursive depth increases. For fixed depth, the<br />
resulting inner approximation is a polynomially sized linear-semidefinite program.<br />
2 - Mixed Zero-One Linear Programs Under Objective Uncertainty:<br />
A Completely Positive Representation<br />
Chung Piaw Teo, Professor, National University of Singapore, NUS<br />
Business School, BIZ1 8-72, NUS, 15 Kent Ridge Drive, Singapore,<br />
119245, Singapore, bizteocp@nus.edu.sg, Zhichao Zheng,<br />
Karthik Natarajan<br />
We analyze mixed 0-1 linear programs under objective uncertainty using a moment<br />
based approach, assuming descriptive statistics of the objective coefficients are<br />
known, but not the exact form of the distribution. Our main result shows that<br />
computing the supremum of the expected optimal objective value of such problem<br />
is a completely positive program. The result is extended to objective coefficients over<br />
Euclidean space, uncertain moments and more complicated objective functions.<br />
3 - Separating Doubly Nonnegative and Completely Positive Matrices<br />
Kurt Anstreicher, Professor, University of Iowa, Department of<br />
Management Sciences, Iowa City, IA, 52242, United States of<br />
America, kurt-anstreicher@uiowa.edu, Hongbo Dong<br />
Completely Positive (CP) matrices can be used to formulate a variety of NP-Hard<br />
problems. A natural issue in the optimization setting is to separate a given Doubly<br />
Nonnegative (DNN) but non-CP matrix from the CP cone. We describe<br />
constructions for such a separation that apply to 5x5 DNN but non-CP matrices, as<br />
well as to larger matrices with block structure. Computational results illustrate the<br />
ability of these procedures to generate improved bounds on difficult problems.<br />
■ WC39<br />
C - Room 9B, Level 3<br />
Column Generation in Integer Programming<br />
Sponsor: Optimization/Integer Programming<br />
Sponsored Session<br />
Chair: Wilbert Wilhelm, Professor, Texas A&M University, Department of<br />
Industrial and Systems Eng, TAMUS 3131, College Station, 77843-3131,<br />
United States of America, wilhelm@tamu.edu<br />
1 - A Stabilized Dynamic Constraint Aggregation/Column Generation<br />
Method for the MDVSP<br />
Guy Desaulniers, Ecole Polytechnique de Montréal and GERAD, CP.<br />
6079, Succ. Centre-ville, Montréal, Canada,<br />
Guy.Desaulniers@polymtl.ca, Pascal Benchimol, Jacques Desrosiers<br />
In a column generation context, dynamic constraint aggregation that reduces the<br />
number of constraints in the master problem was recently introduced to reduce<br />
degeneracy. Dual variable stabilization is also effective at reducing the number of<br />
column generation iterations. In this talk, we present a method that combines both<br />
techniques and we report computational results for the multi-depot vehicle<br />
scheduling problem.
2 - Partial Path Column Generation for the Vehicle Routing Problem<br />
Mads Jepsen, PhD., Technical University of Denmark,<br />
Produktionstorvetbygn. 424, Kgs. Lyngby, 2800, Denmark,<br />
makj@man.dtu.dk, David Pisinger, Björn Petersen<br />
This paper presents a column generation algorithm for the Capacitated Vehicle<br />
Routing Problem (CVRP). The Set Partitioning model with elementary routes, have<br />
shown superior results. However, algorithms for solving the pricing problems do not<br />
scale well. We suggest to relax the constraint that ‘each column is a route’ into<br />
‘each column is a part of the giant tour’. This way, the length of the partial path can<br />
be bounded and a better control of the size of the solution space is obtained.<br />
3 - Unified Branch-Cut-and-Price for Routing and Scheduling<br />
Marcus Poggi de Aragao, PUC-Rio, R. M. S. Vicente 225, Rio de<br />
Janeiro, Brazil, poggi@inf.puc-rio.br, Eduardo Uchoa, Artur Pessoa<br />
We extend the 1978 Picard-Queyranne approach to routing and sheduling<br />
problems. The resulting Branch-Cut-and-Price adds a number of families of valid<br />
inequalities described on variables from the original as well as on the ones from<br />
extended formulations. Several variants of these problems are tackled with minor<br />
adaptations. We address stabilization and performance issues. A wide range of<br />
experimental results are presented. Finally, the generality and the evolution of the<br />
approach is discussed.<br />
4 - A Branch-and-cut Equivalent to Branch and Price<br />
Wilbert Wilhelm, Professor, Texas A&M University, Department of<br />
Industrial and Systems Eng, TAMUS 3131, College Station, 77843-<br />
3131, United States of America, wilhelm@tamu.edu, Deepak Warrier<br />
Branch and price is a leading approach to solve integer programs but suffers from<br />
serious shortcomings, including converging slowly, failing to indicate it if prescribes<br />
tighter bounds than the linear relaxation of the original problem, and failing to<br />
readily incorporate cutting planes to tighten bounds. This paper describes a branchand-cut<br />
equivalent that prescribes the same bounds but overcomes these<br />
shortcomings. Computational tests compare the effectiveness of the two approaches.<br />
■ WC40<br />
C - Room 9C, Level 3<br />
Decision Analysis IV<br />
Contributed Session<br />
Chair: Kash Barker, Lecturer, University of Oklahoma, 202 W. Boyd,<br />
Room 124, Norman, OK, 73019, United States of America,<br />
kashbarker@ou.edu<br />
1 - Optimal Pricing, Modularity Level and Consumer Return for MC<br />
Products using Uncertainty<br />
Na Liu, The Institute of Textiles and Clothing, The Hong Kong<br />
Polytechnic University, Hunghom, Kowloon, Hong Kong, Hong<br />
Kong, Hong Kong - PRC, 08900900r@polyu.edu.hk, Jason Choi<br />
Mass customization (MC) is a pertinent industrial practice. MC retailers can gain<br />
substantial advantages if return is considered. We study the optimal decisions under<br />
a mean-variance analytical formulation. Structural properties are revealed and the<br />
closed-form optimal solutions are derived. Sensitivity analysis is subsequently<br />
conducted to explore how the risk sensitivity and other parameters affect the<br />
optimal decisions. Counter-intuitive findings are obtained and insights are<br />
generated.<br />
2 - Determining the Objective-based Feasibility of Installing a Sewage<br />
Treatment Plant at a University<br />
Mario Chew, Full Time Teacher, Technological Institute of Superior<br />
Studies of Coacalco, Av. 16 de septiembre No. 54, Cabecera,<br />
Municipal, Coacalco, Edo. de Mexico, México D.F., 55700, Mexico,<br />
mchew@tesco.edu.mx, Verónica Velàzquez<br />
A typical feasibility analysis of a Waste Water Treatment Plant (WWTP) calculates<br />
economical or technical metrics, which are used to decide if the WWTP is to be<br />
installed. If the fundamental objectives of the decision maker aren’t technical or<br />
economical, such an analysis is not satisfactory; this is the case when a University<br />
contemplates acquiring a WWTP. Here, we use Keeney’s Value-Focused Thinking to<br />
incorporate the fundamental objectives of a University to the feasibility analysis of a<br />
WWTP.<br />
3 - Using Decision Analysis to Model the Triune Relationship of Supply,<br />
Demand, and Price<br />
Jeff Stonebraker, Assistant Professor, North Carolina State University,<br />
College of Management, Raleigh, United States of America,<br />
jeff_stonebraker@ncsu.edu<br />
Bayer was deciding whether to develop the third generation product used in the<br />
treatment of hemophilia A. Bayer also wanted to right size its production capacity to<br />
meet the demand while maximizing profitability. We use decision analysis to model<br />
Bayer’s supply-demand-price conundrum.<br />
INFORMS Austin – 2010 WC41<br />
423<br />
4 - Telling Value Stories with Value Diagrams<br />
Somik Raha, Student, Stanford University, 1329 Park Drive #12,<br />
Mountain View, CA, 94040, United States of America,<br />
somik.raha@gmail.com<br />
We will examine how decision diagrams currently tell value stories, and propose<br />
“Value Diagrams” to tell richer value stories that help clarify the value frame, create<br />
mutual understanding on value and inform our value thinking in decision diagrams.<br />
We will show through case studies how this can help us make decisions that are<br />
aligned with our values.<br />
5 - A Simple Interval-Valued Decision Tree<br />
Kash Barker, Lecturer, University of Oklahoma, 202 W. Boyd,<br />
Room 124, Norman, OK, 73019, United States of America,<br />
kashbarker@ou.edu<br />
Important to decision making is recognition of what today’s decisions have on<br />
future options. An oft-used tool to aid in this problem is the decision tree. To<br />
address situations when uncertainty arises in the metrics associated with different<br />
decision paths, a simple decision tree is developed for uncertain parameters where<br />
only bounds, not distributions, are known. Single- and multiobjective trees are<br />
discussed.<br />
■ WC41<br />
C - Room 10A, Level 3<br />
Metaheuristics I<br />
Contributed Session<br />
Chair: Heidi Taboada, Assistant Professor in Industrial, Manufacturing and<br />
Systems Engineering, Univeristy of Texas at El Paso, 500 W. University<br />
Ave., El Paso, TX, United States of America, hataboada@utep.edu<br />
1 - A New Evolutionary Algorithm Based on Adaptive Echolocation<br />
Heidi Taboada, Assistant Professor in Industrial, Manufacturing and<br />
Systems Engineering, Univeristy of Texas at El Paso, 500 W.<br />
University Ave., El Paso, TX, United States of America,<br />
hataboada@utep.edu, Karla Gutierrez<br />
A new evolutionary algorithm that is based on the principle of echolocation, also<br />
called biosonar is presented. This principle is active in numerous animals such as<br />
bats. These animals use it as radar in order to find food, obstacles or locate objects.<br />
The algorithm developed uses the radar method in order to explore the search space<br />
to obtain optimal solutions. The new method is tested on the well-known single<br />
objective redundancy allocation problem.<br />
2 - A Solution Method for the Constrained Level of Repair<br />
Analysis Problem<br />
Jose Espiritu, Assistant Professor in Industrial Engineering,<br />
Univeristy of Texas at El Paso, 500 West University Avenue, El Paso,<br />
TX, 79902, United States of America, jfespiritu@utep.edu,<br />
Carlos Ituarte-Villareal<br />
A Level of Repair Analysis model, determines the most cost-effective<br />
maintenance/replacement policy for each component within a system. In the<br />
present research we develop a heuristic approach to solve the Level of Repair<br />
Analysis considering budget constraints to indicate the optimal maintenance levels<br />
at which items will be removed, repaired and replaced to meet operational<br />
standards in a least optimal cost.<br />
3 - Tabu Search with Strategic Oscillation for a Maximum Dispersion<br />
Territory Design Problem<br />
Jabneel R. Maldonado-Flores, Universidad Autonoma de Nuevo<br />
Leon, CIDET-FIME, AP111-F, Cd. Universitaria, San Nicolàs de los<br />
Garza, NL, 66450, Mexico, jabneelmf@gmail.com,<br />
Roger Z. Rìos-Mercado, José Luis Gonzàlez Velarde<br />
We address a districting problem motivated by the application of the WEEE<br />
recycling directive in the European Union. In contrast to classical territory design,<br />
maximum territory dispersion is sought for avoiding the creation of monopolies<br />
forbidden by law in some countries. A tabu search with strategic oscillation is<br />
proposed and evaluated over a wide range of instances with very promising<br />
empirical results.<br />
4 - Bicriteria Optimization of Energy Efficient Placement and Routing in<br />
Heterogenous Sensor Networks<br />
Mustafa Baydogan, Research Assistant, Arizona State University,<br />
1802 E Randall Dr. Apt 3, Tempe, AZ, 85281, United States of<br />
America, mbaydoga@asu.edu, Nur Evin Ozdemirel<br />
We locate different type of sensors and route data generated to a base station under<br />
two conflicting objectives: minimization of network cost and maximization of<br />
network lifetime by satisfying connectivity and coverage requirements as well as<br />
sensor node and link capacity constraints. We propose formulations and use an<br />
exact solution approach to find Pareto solutions and develop a multiobjective GA to<br />
approximate the efficient frontier, as the exact solution requires long computation<br />
times.
WC42<br />
5 - An Evolutionary Approach Based on Viral Replication for Solving<br />
Combinatorial Optimization Problems<br />
Claudia Valles, MS student, The University of Texas at El Paso, 500<br />
W. University Av., El Paso, TX, United States of America,<br />
cevalles@miners.utep.edu, Heidi Taboada<br />
A new algorithm that mimics the performance of viruses is presented. The<br />
replication mechanism as well as the hosts’ infection processes are used to develop<br />
this new metaheuristic.The problem presented to show the performance of the<br />
proposed algorithm is the multiple objective redundancy allocation problem. The<br />
solution to this multiobjective problem is a set of Pareto-optimal solutions.<br />
■ WC42<br />
C - Room 10B, Level 3<br />
Optimization and Scheduling for Supercomputers<br />
Sponsor: Optimization/Computational Optimization and Software (Joint<br />
Cluster ICS)<br />
Sponsored Session<br />
Chair: Xueping Li, Assistant Professor, University of Tennessee, 408 East<br />
Stadium Hall, Knoxville, TN, 37996, United States of America,<br />
Xueping.Li@utk.edu<br />
1 - Making Software Maintenance More Efficient on Kraken, the 1st<br />
Academic Petaflop Computer<br />
Mark Fahey, Scientific Computing Group Leader, National Institute<br />
for Computational Sciences, 1 Bethel Valley Road, P.O. Box 2008 MS<br />
6173, Oak Ridge, TN, 37831, United States of America,<br />
mfahey@utk.edu<br />
The National Institute for Computational Sciences is the newest NSF High<br />
Performance Computer center delivering 600 millions compute hours yearly to the<br />
TeraGrid and is the 3rd fastest machine on the Top500. I will describe Kraken’s<br />
capabilities and then talk about some infrastructure to (1) improve software<br />
installation and maintenance and (2) track library usage by all the users; both with<br />
the ultimate goal of improving the user experience while simultaneously make<br />
NICS more efficient.<br />
2 - Maintenance and Spare Part Inventory Control of Supercomputers<br />
Xiaoyan Zhu, Assistant Professor, University of Tennessee, 408 East<br />
Stadium Hall, Knoxville, TN, 37996, United States of America,<br />
xzhu5@utk.edu, Haitao Liao<br />
To ensure the normal operation of a supercomputer, maintenance must be<br />
performed effectively with the availability of spare parts to replace degraded or<br />
failed units. This work provides a preliminary model that simultaneously<br />
manipulates maintenance schedules and the number of spare parts to be held in<br />
inventory to minimize the overall operating cost (downtime cost, and procurement<br />
and holding costs for spare parts) while ensuring a high fill rate of spare parts.<br />
3 - User Strategies for Super Computer Scheduling<br />
Joe Wilck, The University of Tennessee - Knoxville, 411 East<br />
Stadium, Knoxville, TN, United States of America, jwilck@utk.edu,<br />
Jonathan Celso, Xueping Li, Mark Fahey<br />
We present strategies exhibited by users when using a super computer that has<br />
priority scheduling. The schedule is prioritized to run jobs that utilize the most<br />
nodes for the longest amount of time, and then backfills smaller jobs for the<br />
remaining capacity. Due to maintenance schedules, the users know that the queue<br />
must be cleared weekly.<br />
4 - Supply Chain Management Models and Heuristics for Data<br />
Cache Management<br />
Zhe Zhang, Research Staff Member, Oak Ridge National Laboratory,<br />
ORNL, 1 Bethel Valley Road, P.O. Box 2008 MS6008, Oak Ridge, TN,<br />
37831-6008, United States of America, zhezhang@ornl.gov,<br />
Xiaoyan Zhu, Rui Xu, Galen Shipman, Xiaosong Ma, Xueping Li<br />
For better application I/O performance, modern operating systems place certain data<br />
blocks in faster storage devices based on future access predictions. In Computer<br />
Science this method is named caching. While enhancing the system costeffectiveness,<br />
caching also creates challenges in data management, including data<br />
placement and transfer. In this work we exploit the similarities between the caching<br />
and supply chain management problems and apply SCM models and heuristics in<br />
data cache management.<br />
INFORMS Austin – 2010<br />
424<br />
■ WC44<br />
C - Room 2, Level 2- Mezzanine<br />
Cost Effectiveness Models in Health Care<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: Greg Zaric, Associate Professor, Ivey Business School,<br />
1151 Richmond St., London, Canada, gzaric@ivey.uwo.ca<br />
Co-Chair: David Hutton, Stanford University, Palo Alto, CA, United States<br />
of America, billdave@stanford.edu<br />
1 - Cost Effectiveness of a Safe Consumption Site in Toronto, Canada<br />
Eva Enns, Stanford University, 117 Encina Commons, Stanford, CA,<br />
94035, United States of America, evaenns@stanford.edu, Greg Zaric,<br />
Jennifer Jairam, Ahmed Bayoumi<br />
The establishment of a safe consumption site (SCS) in Toronto, Canada has been<br />
proposed to reduce the spread of disease through the sharing of drug use<br />
equipment. We developed a compartmental model of the spread of HIV and<br />
hepatitis C through populations of drug users and non-drug users matching those of<br />
the Toronto area. We account for geographically disparate drug user groups and<br />
mixing patterns between them, as well the influence of a centralized SCS on drug<br />
user mixing behavior.<br />
2 - Cost-Effectiveness of Stockpiling Masks and Respirators for the<br />
Next Influenza Pandemic<br />
David Hutton, Stanford University, Palo Alto, CA,<br />
United States of America, billdave@stanford.edu, Nayer Khazeni<br />
Surgical masks were used Mexico during the initial outbreak of the 2009 pandemic<br />
influenza (H1N1). Several countries are stockpiling masks to use in future<br />
pandemics. We use mathematical models of influenza disease spread to determine<br />
the minimal necessary effectiveness and compliance to make stockpiling of masks<br />
effective and cost-effective in an influenza pandemic. We compare these results with<br />
other mitigation strategies involving pharmaceuticals.<br />
3 - Cost-Effectiveness of a 21-gene Recurrence Score Assay in<br />
Patients with Early Stage Breast Cancer<br />
Malek Hannouf, University of Western Ontario,<br />
University of Western Ontario, London, ON, Canada,<br />
Malek.Bassam@schulich.uwo.ca, Bin Xie, Muriel Brackstone,<br />
Greg Zaric<br />
We developed a Markov model to evaluate the cost effectiveness of a 21-gene<br />
recurrence score assay versus current Canadian clinical guidelines in women with<br />
early stage breast cancer. The model was parameterized using 5 and 10 year follow<br />
up data from the Manitoba Cancer Registry and cost data from Manitoba Health.<br />
■ WC45<br />
C - Room 6, Level 2- Mezzanine<br />
Radiation Therapy Optimization<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: Timothy Chan, Assistant Professor, University of Toronto, 5 King’s<br />
College Road, Toronto, ON, M5S 3G8, Canada, tcychan@mie.utoronto.ca<br />
1 - Quantifying the Trade-off Between Beam-on-time and Treatment<br />
Plan Quality<br />
Ehsan Salari, PhD Student, University of Florida, ISE Department,<br />
P.O. Box 116595, Gainesville, FL, 32611-659, United States of<br />
America, esalari@ufl.edu, Edwin Romeijn<br />
Beam-on-time is an important aspect of IMRT treatment efficiency, but its<br />
optimization is traditionally postponed until the leaf sequencing phase of treatment<br />
planning. However, there is a trade-off between treatment plan quality and beamon-time.<br />
The aim of this study is to incorporate the beam-on-time into a direct<br />
aperture optimization model. We formulate a bi-criteria optimization model and<br />
develop a solution method that efficiently obtains the entire set of Pareto-optimal<br />
treatment plans.<br />
2 - A Beam Angle Optimization Approach for Intensity Modulated<br />
Proton Therapy Treatment Planning<br />
Gino Lim, Associate Professor PhD, University of Houston, E211,<br />
Engineering Building 2, Houston, TX, 77204, United States of<br />
America, ginolim@uh.edu, Wenhua Cao<br />
We present an LP based local neighborhood search algorithm for solving the BAO<br />
problem in IMPT treatment planning. Three prostate cancer cases at M. D. Anderson<br />
were tested. Optimized angle sets demonstrated evident advantages comparing with<br />
the lateral opposed angles currently used at M. D. Anderson. Furthermore, we<br />
applied a worst case robust analysis that accounts for range uncertainties and setup<br />
errors on the optimized angles in order to validate the robustness of plan quality.
3 - An Inverse Optimization Approach to Determine Objective Function<br />
Weights in Radiation Therapy<br />
Taewoo Lee, PhD student, University of Toronto, 5 King’s College<br />
Road, Toronto, ON, M5S 3G8, Canada, taewoo.lee@utoronto.ca,<br />
Timothy Chan, Michael Sharpe, Tim Craig<br />
In a multi-objective optimization model for radiation therapy treatment planning,<br />
the determination of weights for different organ-specific objective functions is based<br />
on subjective beliefs and manual iterative loops. We present a linear inverse<br />
optimization model that objectively and efficiently determines the weights using<br />
historical treatment data from prostate cancer patients.<br />
4 - Dynamic Robust IMRT Optimization<br />
Timothy Chan, Assistant Professor, University of Toronto,<br />
5 King’s College Road, Toronto, ON, M5S 3G8, Canada,<br />
tcychan@mie.utoronto.ca, Velibor Misic<br />
Previous robust IMRT optimization studies used an uncertainty set to model data<br />
uncertainty, solved a single treatment planning problem and delivered the solution<br />
in all fractions. In this talk, we present a dynamic robust optimization methodology<br />
where prior data observations are used to update the uncertainty set and guide<br />
treatment re-optimization. We present results for a lung case demonstrating<br />
simultaneous improvement in tumor coverage and lung sparing over non-dynamic<br />
robust treatments.<br />
■ WC46<br />
C - Room 7, Level 2- Mezzanine<br />
Game-Theoretic Applications in Healthcare II<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: Murat Kurt, PhD Student, University of Pittsburgh, Department of<br />
Industrial Engineering, 3700 O’Hara Street, 1048 Benedum Hall,<br />
Pittsburgh, PA, 15217, United States of America, muk7@pitt.edu<br />
Co-Chair: Reza Yaesoubi, Post-Doctoral Research Fellow, Harvard Medical<br />
School, 641 Huntingtone Ave., Boston, MA, 02115, United States of<br />
America, reza.yaesoubi@gmail.com<br />
1 - Influenza Vaccine Supply Chain Coordination with Certain Delivery<br />
and Asymmetric Information<br />
Javad Nasiry, HKUST, Clear Water Bay, Kowloon, Hong Kong - PRC,<br />
Javad.NASIRY@insead.edu, Stephen E. Chick, Sameer Hasija<br />
We develop a model to investigate the effects of information asymmetry between a<br />
manufacturer and a single buyer on flu vaccine supply chain coordination. We<br />
design an optimal menu of output-based screening contracts and develop a simple<br />
alternative menu that can achieve screening with no loss of efficiency under some<br />
conditions. The policy implications of the model are further discussed.<br />
2 - Imaging Room and Beyond: The Underlying Economics Behind<br />
Physicians’ Test-Ordering Behavior<br />
Tinglong Dai, PhD Student, Carnegie Mellon University, Tepper<br />
School of Business, Pittsburgh, PA, 15213, United States of America,<br />
dai@cmu.edu, Sridhar Tayur, Mustafa Akan<br />
Excessive diagnostic tests have long been viewed as one major aspect of health care<br />
inefficiency and are often attributed to the fee-for-service payment model. In this<br />
study we investigate the underlying operational and economic drives behind<br />
physicians’ test-prescribing behavior in the outpatient setting, motivated by a<br />
collaborative study with a major outpatient clinic. Our work also provides insights<br />
into the effects of the increasingly popular “comparison shopping” of health<br />
services.<br />
3 - Stochastic Dynamic Allocation of Deceased-donor Kidneys<br />
M Gisela Bardossy, University of Maryland, R.H.Smith School of<br />
Business, and Institute for Systems Research, College Park, MD,<br />
United States of America, bardossy@umd.edu, Inbal Yahav<br />
Deceased-donor kidneys are currently allocated to candidates through a priority<br />
point system that combines waiting times and human tissue matches. In this paper<br />
we evaluate a stochastic dynamic programming approach in search of rules of<br />
allocation that maximize a multicriteria objective to balance efficiency with equity.<br />
We test our approach on the current candidates’ kidney waiting list and find<br />
promising results.<br />
INFORMS Austin – 2010 WC47<br />
425<br />
■ WC47<br />
C - Room 8, Level 2- Mezzanine<br />
Diversification in Projects<br />
Cluster: Topics in Project Management<br />
Invited Session<br />
Chair: Karolina Glowacka, Assistant Professor, Stevens Institute of<br />
Technology, Howe School of Technology Management, Hoboken, NJ,<br />
07030, United States of America, kglowack@stevens.edu<br />
1 - Impacts of Change Orders on Project Performance<br />
Young Hoon Kwak, Associate Professor, The George Washington<br />
University, Department of Decision Sciences, 2201 G Street, NW,<br />
Suite 415, Washington, DC, 20052, United States of America,<br />
kwak@gwu.edu, Kunhee Choi, Jane Park<br />
Change orders are inevitable in infrastructure projects that often result in project<br />
disruptions, disputes, and delays. We attempt to quantify the impacts of change<br />
orders on project performance. Two different benchmarks, the original threshold<br />
versus the amended threshold, of project cost, schedule, and other variables are<br />
analyzed to measure the effect of change orders using 1372 infrastructure projects.<br />
We also apply project portfolio analysis to determine the key effects on change<br />
order.<br />
2 - Analytic Contingency Setting: An Algorithm for<br />
Estimating Contingencies<br />
Homayoun Khamooshi, Assistant Professor, The George Washington<br />
University, Decision Sciences,Funger Hall Room 408, 2115 G Street,<br />
NW, Washington, DC, 20052, United States of America,<br />
hkh@gwu.edu, Denis Cioffi<br />
To cover contingencies, usually a fixed percentage of a project budget is set aside.<br />
Our model uses the binomial probability distribution to estimate the potential<br />
number of risk realizations at a given confidence level, and ranked risk impacts are<br />
added over this number of risks, yielding the required contingency funds to provide<br />
coverage of the accepted risks. The budget found with this method compares<br />
extremely well with one ascertained from a numerical simulation of the risk<br />
occurrences.<br />
3 - Integrating Innovation Projects and Lean Six Sigma Projects in the<br />
Organizational Portfolio<br />
Frank T. Anbari, Clinical Professor, Drexel University, Goodwin<br />
College of Professional Studies, 3001 Market St., Suite 100,<br />
Philadelphia, PA, 19104, United States of America,<br />
anbari@drexel.edu<br />
There are two concurrent, major waves affecting management thinking currently:<br />
project management/ innovation and Lean Six Sigma/ process improvement.<br />
Management researchers in each of these two important areas are seldom aware of<br />
the progress achieved in the other area. We aim to provide a clear vision of the<br />
integration of the project management office (PMO)/ innovation and Lean Six<br />
Sigma operations to enhance the organization’s performance through continual<br />
improvement of its total system.<br />
4 - OptForceTM: A New Approach to Strategic Workforce Planning<br />
Jay April, OptTek Systems, Inc., 2241 17th Street, Boulder, CO,<br />
80302, april@opttek.com<br />
Companies annually invest billions of dollars in programs to pursue objectives such<br />
as improving workforce productivity, customer satisfaction, customer contracting<br />
requirements and legal settlements. OptForceTM provides significant benefits in<br />
these settings, by evaluating and selecting portfolios of proposed investments in<br />
programs to generate new decision alternatives that offer improved returns.
WC48<br />
■ WC48<br />
C - Room 9, Level 2- Mezzanine<br />
Tutorial: The Role and Challenges for Optimization in<br />
Competitive Electricity Markets<br />
Cluster: Tutorials<br />
Invited Session<br />
Chair: Shmuel Oren, Professor, University of California-Berkeley, IEOR<br />
Department, 4135 Etcheverry Hall, Berkeley, CA, 94720,<br />
United States of America, oren@ieor.berkeley.edu<br />
1 - The Role and Challenges for Optimization in Competitive<br />
Electricity Markets<br />
Shmuel Oren, Professor, University of California-Berkeley, IEOR<br />
Department, 4135 Etcheverry Hall, Berkeley, CA, 94720,<br />
United States of America, oren@ieor.berkeley.edu<br />
This tutorial will describe key challenges in designing and operating competitive<br />
electricity markets. It will review the basic components of electricity markets and<br />
alternative structural approaches adopted in different systems. We will discuss the<br />
underlying optimization problems being solved in scheduling, operating and<br />
simulating electricity markets. New computational challenges and research activities<br />
in this area will also be reviewed.<br />
■ WC49<br />
C -Room 10, Level 2- Mezzanine<br />
Intellectual Property Issues in Technology<br />
Sponsor: Information Systems<br />
Sponsored Session<br />
Chair: Eric Walden, Wetherbe Professor of ISQS, Rawls College of<br />
Business, Box 42101, Lubbock, TX, 79409, United States of America,<br />
eric.walden@ttu.edu<br />
1 - On the Downloading vs. Uploading of Unauthorized Copies of<br />
Intellectual Property<br />
Jared Hansen, Assistant Professor, University of North Carolina at<br />
Charlotte, 9201 University City Boulevard, Charlotte, NC, 28223,<br />
United States of America, Jared.Hansen@uncc.edu, Eric Walden<br />
This research examines differences in ethical and legal perceptions regarding the<br />
downloading versus uploading of music files through unauthorized file sharing. Two<br />
explanations are tested (to explain willingness to participate): (1) restrictedness of<br />
use, (2) word of mouth (WOM). Survey results indicate different effects for<br />
uploading and downloading behavior. In short, consumers use different heuristics in<br />
deciding whether to participate in downloading versus uploading.<br />
2 - Digital Piracy: Trends in the Perception of Consequences<br />
Abbe Forman, Assistant Professor Teaching/Instruction, Temple<br />
University, 435 Alter Hall, 1805 N. Broad St, Philadelphia, PA,<br />
19122, United States of America, abbe.forman@temple.edu<br />
Digital piracy continues to be an alarming problem. Attempts to slow or stop the<br />
theft of intellectual property have been nearly futile. Many people do not believe<br />
that digital piracy is a crime or that they will “get caught”. This study represents an<br />
analysis of the literature regarding perceived consequences of digital piracy between<br />
2001 and 2009. Additionally, the results of an open ended questionnaire asking<br />
specifically about perceived consequences will be presented.<br />
3 - Designing Content Licensing Arrangements for Boundary<br />
Management in Hybrid Business Models<br />
Karl Lang, Professor of Information Systems, Baruch College,<br />
Zicklin School of Business, City University of New York,<br />
Karl.Lang@baruch.cuny.edu, Sirkka Jarvenpaa<br />
Using data from economic experiments and case studies from the music industry we<br />
find that boundary management, i.e. managing the organizational tension that the<br />
overlapping of commercial and sharing economies create, is a key success/failure<br />
factor for hybrid business models that combine elements of the private investment<br />
and collective action models. We argue that licensing design specifying the content<br />
access and reuse rights for consumers is a critical for effective boundary<br />
management.<br />
4 - Running in the Pack vs. Running Alone: When Does It Make Sense<br />
to Jointly Develop a Technology?<br />
Nitin Aggarwal, Assistant Professor, San Jose State University,<br />
1 Washington Square, San Jose, CA, 95192-0244,<br />
United States of America, aggarwal_n@cob.sjsu.edu<br />
We collect data from 436 experts involved in technology development to confirm<br />
that technology is made up of bundles of intellectual property, mostly owned by<br />
different entities. The data shows that there are significant transaction costs - search,<br />
coordination, and opportunism - involved in assembling the bundle. Initially, these<br />
costs are lower for hierarchies, but they gradually increase with complexity, nonsubstitutability,<br />
and IP distribution patterns, thereby making networks economical.<br />
INFORMS Austin – 2010<br />
426<br />
■ WC50<br />
C -Room 11, Level 2- Mezzanine<br />
Information Systems II<br />
Contributed Session<br />
Chair: Narges Kasiri, Assistant Professor, SUNY Oneonta, 2004 E<br />
Matthews, stillwater, OK, 74075, United States of America,<br />
kasiri@okstate.edu<br />
1 - Differential Privacy in the Context of Masking Numerical Data<br />
Krish Muralidhar, Professor, University of Kentucky, School of<br />
Management, Lexington, KY, 40506-0034, United States of America,<br />
krishm@uky.edu, Rathin Sarathy<br />
Recently, researchers at Microsoft have proposed a new privacy standard called<br />
Differential Privacy. In this study, we evaluate the efficacy of using differential<br />
privacy when numerical confidential data is masked.<br />
2 - Analysis of Spamming Behavior at Different Aggregation Levels and<br />
Implications for IT Security<br />
Serpil Sayin, Dr., Koç University, Rumeli Feneri Yolu, Sariyer,<br />
Istanbul, 34450, Turkey, ssayin@ku.edu.tr, John Quarterman,<br />
Manoj Parameswaran, Andrew Whinston<br />
Using e-mail spam data from different blocklist sources, we analyze the observed<br />
spamming behavior at the single IP and Autonomous System (AS) levels. Our single<br />
IP level study reveals the variability in the spamming tactics employed by different<br />
botnets. Our AS level analysis indicates that the distribution of spam contribution is<br />
highly skewed across organizations. We discuss the role of a reputation system in<br />
alternative incentive mechanisms to address IT security concerns.<br />
3 - When Should Software Firms Commercialize New Products via<br />
Freemium Business Models<br />
Marius Florin Niculescu, George Institute of Technology, College of<br />
Management, 800 West Peachtree Street NW, Atlanta, GA, 30308,<br />
United States of America, marius.niculescu@mgt.gatech.edu,<br />
D. J. Wu<br />
Freemium approach, whereby a firm gives away for free a certain level or type of<br />
consumption while making money on premium consumption, is spreading fast in<br />
the software industry. We advance a multiperiod framework with network<br />
externalities in order to describe several freemium business models. We solve firm’s<br />
optimal pricing strategy under each model, derive conditions when freemium<br />
models are superior to conventional for-fee and seeding models, and discuss<br />
managerial and policy implications.<br />
4 - Valuing RFID Investment in the Retail Sector: A Real Options Model<br />
Narges Kasiri, Assistant professor, SUNY Oneonta, 2004 E Matthews,<br />
stillwater, OK, 74075, United States of America, kasiri@okstate.edu,<br />
Ramesh Sharda<br />
The investment in Item-level RFID in the retail sector similar to any other IT<br />
investments is associated with high uncertainties in its potential benefits and costs.<br />
A real options approach is appropriate to analyze the cost and benefits of the<br />
investment problem. We apply a system dynamics simulation technique to generate<br />
the parameters of the real options model and discuss various options and scenarios<br />
retailers have in implementing item-level RFID in retail operations management.<br />
■ WC51<br />
C -Room 12, Level 2- Mezzanine<br />
Analysis at US Army Aviation and Missile<br />
Command (AMCOM)<br />
Sponsor: Military Applications<br />
Sponsored Session<br />
Chair: Wayne Bruno, Director, Command Analysis, U.S. Army Aviation &<br />
Missile Command, BLDG 5308, Restone Arsenal, Al, 35898,<br />
United States of America, wayne.bruno@us.army.mil<br />
1 - A Method for Determining the Mismatch Between Supply and<br />
Demand in the Army Supply Chain<br />
David Berkowitz, Professor of Marketing, University of Alabama -<br />
Huntsville, 301 Sparkman Drive, College of Business Administration,<br />
Huntsville, AL, 35899, United States of America, berkowd@uah.edu,<br />
Lucas Neidert, Al Wilhite, Fan Tseng<br />
Our paper develops a method for determining the mismatch between inventory<br />
control point supply and the field level demand for a Class IX item. We identify the<br />
characteristics of items that are likely to be in short supply. We determine the<br />
probability structure for supply. Then we run a regression based model to help<br />
predict demand. Finally we match the results to project a supply on hand at the end<br />
of a period.
2 - Demonstrating the Business Case for Condition-Based<br />
Maintenance (CBM) in Army Aviation<br />
Josh Kennedy, Chief, Ops Analysis Branch, Command Analysis<br />
Directorate, US Army Aviation & Missile Command, Bldg 5308,<br />
Redstone Arsenal, AL, 35898, United States of America,<br />
josh-kennedy@us.army.mil<br />
The Army’s Aviation & Missile Command is pursuing a large-scale CBM program for<br />
its helicopter fleet. DoD has directed CBM as a reliability and sustainability driver in<br />
life cycle systems management. The objectives for AMCOM’s CBM program are:<br />
decrease Soldier maintenance burden, increase availability, enhance safety, and<br />
reduce costs. However, the investment required for a CBM program is substantial.<br />
This presentation outlines how AMCOM made a clear business case for this<br />
investment.<br />
3 - Application of Cost-Benefit Analysis (CBA) to Respond to Army<br />
Aviation Maintenance Issues<br />
Tina Theiss, Operations Research Analyst, Command Analysis<br />
Directorate, US Army Aviation & Missile Command, Bldg 5308,<br />
Redstone Arsenal, AL, 35898, United States of America,<br />
tina.theiss@us.army.mil<br />
Currently, there is no cyclic Army Aviation sustainment program to mitigate risk<br />
associated with the long term effects of airframe aging and use. At the same time,<br />
the Army has initiated a thorough CBA process to accompany unfunded<br />
requirements, the net result of which should be a strong value proposition stating<br />
that the benefits of a new requirement more than justify the costs. This presentation<br />
discusses how we applied the CBA process to respond to shortfalls with helicopter<br />
maintenance.<br />
■ WC52<br />
C -Room 13, Level 2- Mezzanine<br />
Homeland Security<br />
Contributed Session<br />
Chair: Hiram Moya, PhD Candidate, Texas A&M University,<br />
2807 Henry Ct., College Station, TX, 77845, United States of America,<br />
Hiram@tamu.edu<br />
1 - Infrastructure Security via Game Theory<br />
Zhe Duan, Rutgers University, 900 Davidson Road, Apt. 94,<br />
Piscataway, NJ, 08854, United States of America,<br />
duanzhe@gmail.com, Melike Baykal-Gursoy<br />
Recent attacks in Mumbai, Russia, and the attempted attack in New York city have<br />
forced governments to devote significant time and resources to secure<br />
infrastructures. In this paper, we study how to secure infrastructures via game<br />
theory. The uncertainty of the timing and the location of an attack is alleviated by<br />
considering the occupancy level of each location. Zero-sum and non-zero sum<br />
games are solved and equilibrium policies are obtained.<br />
2 - Protecting Electric Power Systems From Terrorist Attacks<br />
Vanlapha Santithammarak, PhD Student, Texas Tech University,<br />
2619 19th St. Apt 10, Lubbock, 79410, United States of America,<br />
vanlapha.santithammarak@ttu.edu, Milton Smith<br />
Terrorist attacks designed to weaken the economy are increasing concern after 9/11.<br />
Electrical power systems should be regarded as likely targets of terrorists due to the<br />
most effects of economic activities. The objective of this study is to investigate the<br />
methods for protecting from physical attacks and reducing vulnerability in power<br />
system networks.<br />
3 - Safe Path Optimization with Local Protection Required<br />
Ruben Dario Yie Pinedo, University at Buffalo (SUNY), Department<br />
of Industrial & Systems Engg, 308 Bell Hall, Buffalo, NY, 14260,<br />
United States of America, rubenyie@buffalo.edu, Rajan Batta,<br />
Moises Sudit<br />
The edges in a network can be exposed to certain events that compromise the safety<br />
of the vehicle. To reduce the likelihood of an event protection could be used. This<br />
talk will discuss the problem of routing several vehicles from multiple origins to<br />
multiple destinations. The network contains zones in which local protection is<br />
required. Local escorts are not allowed to leave their jurisdiction zones. The main<br />
objective is to minimize the total treat level to which the vehicles are exposed.<br />
4 - A Risk Based Sensor Allocation Problem<br />
Amir Ghafoori, PhD Student, Rutgers University, Department of<br />
Industrial and Systems Eng, 96 Frelinghuysen Road, Piscataway, NJ,<br />
08854, United States of America, ghafoori@eden.rutgers.edu<br />
We develop a risk based model for underwater sensor allocation to detect divers.<br />
The model investigates various aspects of sensor placement problems for underwater<br />
application and attempts to put sensors in the set of candidate grid points. Each<br />
sensor type brings its specifications to the model and poses a level of complexity.<br />
Finally an optimal scheme of sensor positioning is proposed in order to minimize<br />
the average total risk in the field.<br />
INFORMS Austin – 2010 WC53<br />
427<br />
5 - Transient Analysis of the Border Crossing Process using Congestion<br />
Based Policies<br />
Hiram Moya, PhD Candidate, Texas A&M University,<br />
2807 Henry Ct., College Station, TX, 77845,<br />
United States of America, Hiram@tamu.edu<br />
Trade is the U.S. depends on an efficient flow of inspected containers in and out of<br />
the border ports of entry (POE), while focusing on security, and being cost effective.<br />
This research focuses on all commercial traffic at a southern border POE, where<br />
there is a non-steady state, terminating system. Using transient analysis, we present<br />
analytical and experimental results of congestion based policies with a fixed number<br />
of servers, by implementing a primary inspection station service switch.<br />
■ WC53<br />
C -Room 14, Level 2- Mezzanine<br />
Operations/Marketing Interface II<br />
Contributed Session<br />
Chair: Kunpeng Li, Sam Houston State University, Avenue I, Huntsville,<br />
TX, United States of America, kli@shsu.edu<br />
1 - The Effect of Traffic on Retail Store Conversion Rate and Sales<br />
Olga Perdikaki, Assistant Professor, Texas A&M, Mays Business<br />
School, College Station, 77843-4217, United States of America,<br />
operdikaki@tamu.edu, Jayashankar Swaminathan,<br />
Saravanan Kesavan<br />
In this paper, we use proprietary data pertaining to a retailer to study the<br />
relationship between traffic and store sales performance, measured as the number of<br />
transactions and sales volume. We find that store sales performance exhibits<br />
diminishing returns to scale with respect to store traffic and increases in traffic<br />
variabilities are associated with declines in store sales performance. Finally, we find<br />
that store labor moderates the impact of traffic on store sales performance.<br />
2 - Product Line Decision with Incomplete Information<br />
Michael Lim, Asst Professor, University of Illinois, 350 Wohlers Hall,<br />
1206 S. 6th Street, Champaign, 61820, United States of America,<br />
mlim@illinois.edu<br />
We study manufacturer’s product line length decision under information asymmetry<br />
where retailer has a private information regarding local consumers’ preference. We<br />
use mechanism design to construct a contract that elicits retailer’s information rent.<br />
Our analysis identifies the condition in which the manufacturer have more (or less)<br />
incentive to extend the product line compared to full information case. We will also<br />
discuss some insights and policy implications from the model.<br />
3 - Return Policies and Informational Tools in Experience<br />
Goods Markets<br />
Eylem Koca, University of Maryland, College Park, Smith School of<br />
Business, VMH 3330, College Park, MD, 20740,<br />
United States of America, ekoca@umd.edu, Gilvan Souza<br />
We investigate the role of return policies and informational tools provided by the<br />
seller in consumer purchasing behavior and on the overall market outcome. We<br />
build a model of consumer learning and analyze a seller’s decision process in a twoperiod<br />
setting. We attain significant analytical findings with no distributional<br />
assumptions, and fully study the joint optimization problem under uniform<br />
valuations. Finally, we study competition in a duopoly setting, and look at some<br />
extensions.<br />
4 - Shelf Space Competition Between Store and National Brands<br />
Shu-Jung Sunny Yang, Lecturer in Management, The University of<br />
Melbourne, Level 10, 198 Berkeley Street, Melbourne, 3010,<br />
Australia, sunnyy@unimelb.edu.au, Chia-wei Kuo, Pei-Ju Lu<br />
Shelf space allocation is one of the retailer’s most challenging operational decisions.<br />
We propose a game-theoretic model in which one retailer, acting as a leader by<br />
deciding the total shelf space available and selling both national and store brands,<br />
maximizes her category profit, and one national-brand manufacturer, acting as a<br />
follower, maximizes his own profit. Our analysis suggests that the allocation of the<br />
shelf space depends on two thresholds of total shelf space for both brands.<br />
5 - Optimal Price Reduction Strategy in Product Sales<br />
Kunpeng Li, Sam Houston State University, Avenue I, Huntsville, TX,<br />
United States of America, kli@shsu.edu, Chongqi Wu<br />
Consumers with high valuation are willing to pay a higher price than those with<br />
low valuation. Therefore, firms should make sure that consumers with high<br />
valuation buy first. Later on, firms reduce the product price and sell to consumers<br />
with low valuation. Under such a setting, our paper investigates many important<br />
questions in the decisions of product design and introduction.
WC54<br />
■ WC54<br />
C -Room 15, Level 2- Mezzanine<br />
Innovation Management for Sustainability<br />
Sponsor: Technology Management/New Product Development<br />
Sponsored Session<br />
Chair: Hsueh-Ming Wang, Associate Professor, University of Alaska<br />
Anchorage, ESM Department 3211 Providence Dr., Anchorage, AK,<br />
99508, United States of America, afhsw1@uaa.alaska.edu<br />
1 - Curriculum Development for the Innovation Management Program<br />
for Sustainability<br />
Seong Dae Kim, Assistant Professor, University of Alaska Anchorage,<br />
PM Department at University Center, Room 155, 3901 Old Seward<br />
Highway, Anchorage, AK, 99503, United States of America,<br />
afsdk1@uaa.alaska.edu, Hsueh-Ming Wang<br />
The curriculum is focusing on the sustainability through the innovation of quality of<br />
life. This program will help students for building industry careers as system<br />
designers, architects, project managers, developers, and entrepreneurs and providing<br />
students with broad understanding of green engineering, energy saving lighting, and<br />
innovation of quality of life as well as to stimulating the development and<br />
application of energy efficient lighting, green technologies with quality innovation.<br />
2 - The Critical Factors for Decision-making of the Technology<br />
Policies of the Industrialized Countries for Municipal Solid<br />
Waste Management<br />
Leslie Simmons, PhD Student, University of Alaska, 3211 Providence<br />
Dr, Anchorage, AK, 99508, United States of America,<br />
aflfs@uaa.alaska.edu, Hsueh-Ming Wang<br />
In the United States of America, landfill disposal is a major method to handle<br />
municipal solid waste. It may generate pollutants and carbon emissions in the<br />
environment. Some industrialized countries, such as Germany, Denmark, and<br />
Japan, are using technologies to reduce, reuse, recycle, or combust to limit amounts<br />
of land disposed municipal solid waste. Technology policies from governments<br />
generate different outcomes of solid waste management. Many factors may affect<br />
policy-making process. This research evaluates critical factors that impact technology<br />
policies by surveying and comparing results in industrialized countries. Critical<br />
impact factors for decision-making priorities differ between the USA and other<br />
industrialized countries. These different technology policies may affect<br />
environmental protection and carbon emissions in the future.<br />
3 - Cognitive Oriented Integration for Innovation Management<br />
Hsueh-Ming Wang, Associate Professor, University of Alaska<br />
Anchorage, ESM Department 3211 Providence Dr., Anchorage, AK,<br />
99508, United States of America, afhsw1@uaa.alaska.edu,<br />
Muchiu Chang<br />
The acceptance of a new product depends on the market needs of the innovation<br />
and service compliance through the product life. We develop an innovation<br />
management process by cognitive based consumer behaviors integration. It includes:<br />
new ideas to lead the customer needs, adopting new technology in design, patent<br />
mapping market anaylsis, and life cycle management. Modeling simulation is a<br />
robust solution to virtually validate and verify the life cycle behaviors of various<br />
design concepts.<br />
4 - Agility Management for the Project Sustainability<br />
Peter Lang, Graduate Student, University of Alaska Anchorage, ESM<br />
Department, 3211 Providence Dr., Anchorage, AK, 99508, United<br />
States of America, peter@alaskadatatech.com, Hsueh-Ming Wang<br />
The projectized organization surrounding culturalvalues addresses concerns of<br />
balancing versus optimizing various value propositioning factors. Information<br />
Technology for project portfolios selection processes may profit by looking across a<br />
variety of fields ranging from project management to the cognitive sciences to<br />
increase project agility. The solutions may obtain by meta-modeling balancing,<br />
aligning, and integrating a proposed adaptive risk management approach.<br />
INFORMS Austin – 2010<br />
428<br />
■ WC55<br />
C -Room 16, Level 2- Mezzanine<br />
Innovation and the Economy<br />
Sponsor: Technology Management/New Product Development<br />
Sponsored Session<br />
Chair: Erica Fuchs, PhD, Carnegie Mellon University, 5000 Forbes<br />
Avenue, Baker Hall 129, Pittsburgh, PA, 15217, United States of America,<br />
erhf@andrew.cmu.edu<br />
1 - Patents, Materials Transfer Agreements (MTAs), and the Flow of<br />
Scientific Knowledge<br />
David Mowery, Professor, University of California Berkeley, HAAS,<br />
mowery@haas.berkeley.edu, Neil Thompson, Arvids Ziedonis<br />
How does university involvement in academic patenting affect academic science?<br />
This paper extends the work of Murray and Stern (2007) to cover a broader sample<br />
of published scientific papers in the biomedical and other disciplines, and examines<br />
the effects of both patenting and material transfer agreements (MTAs) on citations<br />
to scientific papers.<br />
2 - Economic Downturns, Inventor Careers, and Technology<br />
Trajectories in the U.S<br />
Wunmi Akinsanmi, PhD Student, Carnegie Mellon University,<br />
5000 Forbes Avenue, Baker Hall 129, Pittsburgh, PA, 15217,<br />
United States of America, eyidearie@gmail.com, Erica Fuchs<br />
This research explores the relationship between the telecommunications bubble<br />
burst and the quantity, direction and locus of U.S. innovation. We focus on<br />
optoelectronics, a general purpose technology with applications in energy,<br />
biomedical, telecommunications, computing and military. Leveraging USPTO patents<br />
and inventor CVs, we analyze how inventors’ pre-bubble productivity, mobility,<br />
social capital and degree of specialization influence these same post-bubble and<br />
thereby the national trend.<br />
3 - Intellectual Property, Prior Knowledge & New Firm Survival<br />
Sonali Shah, Buerk Fellow and Assistant Professor, University of<br />
Washington, Box 353200, Seattle, WA, 98195, United States of<br />
America, skshah@u.washington.edu, Sheryl Winston Smith<br />
We examine the joint effects of founders’ prior knowledge and intellectual property<br />
protection on the survival of young firms. We examine three different sources of a<br />
founder’s prior knowledge: prior industry experience, prior entrepreneurial<br />
experience, and prior entrepreneurial experience in the same industry. Taken<br />
together, our findings show the importance of patents as strategic, as well as<br />
appropriability, tools and are in-line with evolutionary economic theory.<br />
■ WC56<br />
C - Room 1, Level 1<br />
Simulation and Optimization I<br />
Contributed Session<br />
Chair: Honggang Wang, Stanford University, Department of Energy<br />
Resources Engi, Stanford, CA, 94305, United States of America,<br />
honggang@stanford.edu<br />
1 - Stochastic Dominance Based Ranking and Selection in Simulation<br />
Demet Batur, University of Nebraska- Lincoln, 175 Nebraska Hall,<br />
Lincoln, NE, United States of America, dbatur2@unl.edu,<br />
Fred Choobineh<br />
We present a ranking and selection procedure where simulated systems are<br />
compared based on the stochastic dominance relationship of a performance metric<br />
of interest. The system which stochastically dominates all other systems is deemed<br />
as the best system. If there is not a unique best system, but a number of systems<br />
with crossing distribution functions, then the proposed procedure selects a set of<br />
nondominated systems with a probability of correct selection guarantee.<br />
2 - Modeling the Relative Efficiency of Job Assignment in Differing<br />
Social Structures<br />
Paul Kerl, Georgia Institute of Technology, 765 Ferst Drive, NW,<br />
Atlanta, GA, 30332, United States of America, paul.kerl@gatech.edu,<br />
Joel Sokol<br />
In the recent and distant past, people have found their job in many different ways,<br />
from inherited positions to national testing and matching. We use stylized<br />
assignment models to examine several social structures and measure the relative<br />
benefit of structural characteristics. These characteristics include job inheritance,<br />
split social structures, heuristic selection versus optimal selection of jobs, job<br />
mobility, and the marginal value of information about person-job matching.
3 - Use of Retrospective Optimization for Placement of Oil Wells<br />
Under Uncertainty<br />
Honggang Wang, Stanford University, Department of Energy<br />
Resources Engi, Stanford, CA, 94305, United States of America,<br />
honggang@stanford.edu, David Echeverri Ciaurri, Louis Durlofsky<br />
Determining well locations in oil reservoirs under geological uncertainty remains a<br />
challenging problem in field development. We simulate (with a reservoir simulator)<br />
multiple model realizations to estimate the expected field performance for a certain<br />
well placement. The presented RO framework generates a sequence of sample-path<br />
problems with increasing sample sizes. The numerical results show that the RO<br />
algorithm finds a solution yielding a 70% increase in the NPV for the problem<br />
considered.<br />
4 - Water Quality Monitoring Network Design using Optimization<br />
via Simulation<br />
Chuljin Park, PhDStudent, Georgia Technology of Institute, 765 Ferst<br />
Dr NE, Main Building #124, Atlanta, GA, 30332, United States of<br />
America, cpark41@mail.gatech.edu, Seong-Hee Kim, Ilker Telci,<br />
Mustafa Aral<br />
The problem of designing a water quality monitoring network for river systems is to<br />
find the optimal location of a finite number of monitoring devices that minimizes<br />
the expected detection time of a contaminant spill event with good detection<br />
reliability. We set a stochastic constraint on detection reliability and solve the<br />
monitoring design problem using optimization via simulation.<br />
■ WC57<br />
C - Room 2, Level 1<br />
Risk Analysis<br />
Contributed Session<br />
Chair: John Chachere, Senior Computer Scientist, Stinger Ghaffarian<br />
Technologies, 1060 Arbor Road, Menlo Park, CA, 94025,<br />
United States of America, john.m.chachere@nasa.gov<br />
1 - Why Do Groups Cooperate More Than Individuals to Reduce Risks?<br />
Min Gong, Columbia University, 1190 Amsterdam Ave,<br />
406 Schermerhorn Hall - MC 5501, New York, NY, 10027,<br />
United States of America, mingong@gmail.com, Jonathan Baron,<br />
Howard Kunreuther<br />
We find that groups are less cooperative than individuals in a prisoner’s dilemma,<br />
but are more cooperative than individuals in a stochastic version of the game.Three<br />
processes are tested: risk concern, cooperation expectation, and social pressure. Data<br />
shows that guilt aversion and blame avoidance cause groups to be more risk<br />
concerned than individuals, which drives groups to cooperate to reduce risks.<br />
Groups also have higher cooperation expectations for their counterpart than<br />
individuals have.<br />
2 - Decision Support for Inland Waterways Emergency Response<br />
Leily Farrokhvar, University of Arkansas, 4207 Bell Engineering, W<br />
Dickson Street, Fayetteville, AR, 72701, United States of America,<br />
lfarrokh@uark.edu, Heather Nachtmann, Ed Pohl<br />
Emergency planning involving transportation resources requires thorough<br />
contingency planning in case of route destruction due to natural or man-made<br />
events. Inland waterways can provide emergency transportation to a large area of<br />
the United States. We explore the potential for communities to benefit from inland<br />
waterway emergency response through the development of a decision support<br />
framework to support an inland waterway-based emergency response system.<br />
3 - Quantitative Method for Analyzing Engineering Defect<br />
Risks in Projects<br />
John Chachere, Senior Computer Scientist, Stinger Ghaffarian<br />
Technologies, 1060 Arbor Road, Menlo Park, CA, 94025,<br />
United States of America, john.m.chachere@nasa.gov<br />
Engineering defects often cause complex systems to fail. I provide a quantitative<br />
model of defects linking causes in an upstream development project to effects on<br />
downstream operations failure risks. The Model integrates: a simulation of the<br />
development project, a probabilistic analysis of operations failure risks, and a<br />
rational model of project decisions (e.g., organizational structure) and product<br />
decisions (e.g., subsystem redundancies). I evaluate an example project.<br />
INFORMS Austin – 2010 WC61<br />
429<br />
■ WC58<br />
C - Room 3, Level 1<br />
Financial Engineering I<br />
Contributed Session<br />
Chair: Arun Chockalingam, Visiting Assistant Professor, Purdue<br />
University, 315 N. Grant Street, West Lafayette, IN, 47907,<br />
United States of America, achockal@purdue.edu<br />
1 - Margining Option Portfolios by Offsets with Two, Three and<br />
Four Legs<br />
Dmytro Matsypura, Dr, The University of Sydney,<br />
Merewether Building H04, Sydney, 2006, Australia,<br />
dmytro.matsypura@sydney.edu.au, Vadim Timkovsky<br />
As shown in [Rudd and Schroeder, 1982], the problem of margining option portfolios<br />
where option spreads with two legs are used for offsetting can be solved in<br />
polynomial time by network flow algorithms. In this paper we extend this result to<br />
the case where option spreads with three and four legs can also be used for<br />
offsetting and propose a general method of margining option portfolios.<br />
2 - Cross Validation and Various Techniques in Utilizing Financial Time<br />
Series Data for Model Validation<br />
Wing-Ho Choi, Gradient Analytics, 14614 North Kierland Boulevard,<br />
Scottsdale, AZ, 85254, United States of America, wc447@cornell.edu,<br />
Derek Koh<br />
When modeling financial data using insamples and outsamples, one has to account<br />
for the information overlap of return information which can create an optimistic<br />
bias on results. This is typically done by imposing a blackout period between in and<br />
out samples. The period is dependant on the return horizon where a long horizon<br />
results in a larger blackout period. This paper modifies the cross-validation<br />
technique and explores methods that optimizes the use of data available for<br />
financial modeling.<br />
3 - New Estimation Techniques for Fractional Brownian Motion with<br />
Applications to Finance<br />
Daniel Scansaroli, PhD Candidate, Lehigh University, 200 West<br />
Packer Ave., Industrial Engineering Department, Bethlehem, PA,<br />
18015, United States of America, djse@lehigh.edu, Robert H. Storer,<br />
Vladimir Dobric<br />
We explore financial applications of fractional Brownian motion and present two<br />
new methods of estimating the parameters of this process based on ergodic theory.<br />
We evince that in a fractional Brownian market, the typical assumption of<br />
independent increments results in an underestimation of market risk and a term<br />
structure of volatility. We conclude by applying our new technique to the equity<br />
market to show the behavior of the Hurst index that over the last 35 years.<br />
4 - Moving-boundary Approaches for American Security Valuation<br />
Arun Chockalingam, Visiting Assistant Professor, Purdue University,<br />
315 N. Grant Street, West Lafayette, IN, 47907, United States of<br />
America, achockal@purdue.edu, Kumar Muthuraman<br />
Pricing American options gives rise to a free-boundary problem in PDEs (PIDEs if<br />
the asset price process is discontinuous). We present a computational scheme that<br />
solves for the option price and optimal-exercise policy by converting the freeboundary<br />
problem into a sequence of fixed-boundary problems. This scheme is<br />
general enough to handle a variety of market models. We also discuss error bounds<br />
for options priced with sub-optimal exercise policies and the implications of these<br />
bounds.<br />
■ WC61<br />
H - Room 400, 4th Floor<br />
Operations Management VII<br />
Contributed Session<br />
Chair: Jieling Han, PhD Student, Department of ISOM / University of<br />
Washington, Department of ISOM, Box 353200, University of<br />
Washington, Seattle, WA, 98115, United States of America, hanjl@uw.edu<br />
1 - Optimal Pallet Loading Problem with Complex Stacking Constraints<br />
Amit Garg, Senior Logistics Engineer, Penske Logistics,<br />
amit.garg@penske.com, Vishwa Ram, Prasad Natarajan,<br />
Kevin Troyer, Mitch Plesha<br />
Optimal Pallet Loading Problem is an important problem in the logistics industry.<br />
We investigate a particular problem for a food manufacturer where several<br />
categories of items need to be placed on the least number of pallets. Each item<br />
category primarily differs with other categories in the stacking constraints and<br />
product charactrestics. There are also specific business rules that dicatate how any<br />
two or more item categories can be placed on the same pallet. Current solution<br />
techniques and available commerical software solutions are unable to solve this<br />
problem because of the pecularities of the business rules and packing preferences in<br />
near real time for several thousand orders every day. Therefore, we implement a<br />
heuristc solution that takes various stacking rules and packing preferences and<br />
minimizes the number of pallets required for each order.
WC62<br />
2 - Profit- vs. Cost-orientation in the Newsvendor Problem: Insights<br />
From a Behavioral Study<br />
Sebastian Schiffels, Technische Universitaet Muenchen,<br />
TUM School of Management, Muenchen, 80333, Germany,<br />
sebastian.schiffels@wi.tum.de, Jens Brunner, Rainer Kolisch,<br />
Andreas Fuegener<br />
Our research investigates differences in the behavior of individuals in a profit- vs. a<br />
cost- orientated newsvendor problem. Our hypothesis is that individuals order more<br />
in the cost orientated than in the profit orientated newsvendor setting. Previous<br />
studies (e.g. Schweitzer and Cachon 2000) show that individuals deviate from the<br />
expected optimal decision in the newsvendor game. In fact, they tend to order less<br />
(more) than the expected profit maximizing order quantity if per unit profit margin<br />
is high (low). To test our hypothesis we set up a laboratory study which takes into<br />
account the profit or the cost perspective and three critical ratios. Our results<br />
confirm our hypothesis as well as the findings of previous studies. In each of the<br />
defined critical ratios the average order quantity in the cost orientated newsvendor<br />
game is significantly higher than in the profit orientated problem. The results imply<br />
that people underlie systematical different biases when facing profit and cost<br />
orientated situations.<br />
3 - Dynamic Scheduling Policy in a Make-to-stock System with Two<br />
Demand Classes of Different Variability<br />
Jieling Han, PhD Student, Department of ISOM / University of<br />
Washington, Department of ISOM, Box 353200, University of<br />
Washington, Seattle, WA, 98115, United States of America,<br />
hanjl@uw.edu, Apurva Jain<br />
We consider the dynamic scheduling policy in a make-to-stock queue with a single<br />
server, exponential processing times, standard holding and backorder cost rates, and<br />
two demand classes that differ in their variability. We partially characterize the<br />
optimal scheduling policy and propose heuristics. We then analyze the case where<br />
the centralized server has information about the arrival process of the more variable<br />
demand class and show the value of this information.<br />
■ WC62<br />
H - Room 402, 4th Floor<br />
Transportation, Operations<br />
Contributed Session<br />
Chair: Rodrigo Britto, University of Maryland, 3909 Stoconga Drive,<br />
Betlsville MD 20705, United States of America, rbritto@rhsmith.umd.edu<br />
1 - Mapping Transportation Waste<br />
Bernardo Villarreal, Professor, Universidad de Monterrey, I. Morones<br />
Prieto 4500 Pte, San Pedro Garza Garcia, NL, 62638, Mexico,<br />
bvillarreal@udem.edu.mx<br />
Value stream mapping was developed originally to identify and eliminate waste in<br />
the manufacturing area. This is extended to design improvement programs oriented<br />
to eliminate waste for transport operations. The definition of several types of waste<br />
specific to transportation with the goal of improving efficiency as the relevant<br />
performance measure is suggested. Application to real examples is provided.<br />
2 - An Integrated Model for Resource Allocation and Scheduling in a<br />
Transshipment Container Terminal<br />
Nabil Nehme, PhD Candidate, American University of Beirut, P.O.<br />
Box 11-0236, Riad El Solh, Beirut 11, Beirut, Lebanon,<br />
nhn02@aub.edu.lb, Isam Kaysi, Farah Mneimneh, Bacel Maddah<br />
This paper considers the coordination between quay and yard sides in a<br />
transshipment process at a container terminal. A model is developed to minimize<br />
the number of cranes used and to determine the optimal schedule for unloading<br />
containers for a vessel. Several insights are drawn illustrating the importance of<br />
coordination.<br />
3 - A New Packing Heuristic Based Approach for the VRP with Threedimensional<br />
Loading Constraints<br />
Yi Tao, PhD Candidate, Sun Yat-sen Business School, Sun Yat-sen<br />
University, No.135 West Xinggang Road, Guangzhou, 510275, China,<br />
kenjimore@gmail.com, Fan Wang<br />
We consider the Three-Dimensional Loading Capacitated Vehicle Routing Problem<br />
which combines the routing of vehicles and the loading of three dimensional shaped<br />
goods into the vehicles while minimizing the total cost. We propose a least waste<br />
packing heuristic based approach for solving the loading subproblem, which is<br />
iteratively invoked by a simple tabu search algorithm for the routing. Numerical<br />
experiments on test instances have shown our method outperforms existing ones.<br />
INFORMS Austin – 2010<br />
430<br />
4 - Comparing Organizational Forms in the Trucking Industry<br />
Johan Lundin, PhD Student, Lund University, Box 118, Lund,<br />
22100, Sweden, johan.lundin@tlog.lth.se, Fredrik Eng Larsson<br />
Studies on organizational forms pertaining to efficiency show that pricing and<br />
deciding upon the right level of output can vary between forms (Porter and Scully,<br />
1987). Never before has the trucking been studied from this perspective, which is<br />
why we focus on exploring the truck investment decision based on economic<br />
efficiency. The methodology draw on industrial organization and game theory using<br />
a two-stage supply chain model under deterministic demand expressed as a Cournot<br />
competition model.<br />
5 - Assessment of the Impact of Undesirable Outputs on the<br />
Productivity of US Motor Carriers<br />
Rodrigo Britto, University of Maryland, 3909 Stoconga Drive,<br />
Betlsville, MD, 20705, United States of America,<br />
rbritto@rhsmith.umd.edu, Thomas Corsi<br />
This research evaluates the impact of undesirable outputs (i.e; crashes and fatalities)<br />
on the productivity of motor carriers during the years 1999-2003. The nonparametric<br />
direction output distance function and an additive DEA model are used<br />
to model both desirable and undesirable outputs. Tobit regression is applied in a<br />
second stage to analyze the drivers of efficiency.<br />
■ WC63<br />
H - Room 404, 4th Floor<br />
Decision Analysis V<br />
Contributed Session<br />
Chair: Onur Bakir, Visiting Assistant Professor, Bilkent University, Bilkent<br />
Universitesi, Endüstri Mühendisligi Bˆlümü, Ankara, 06800, Turkey,<br />
nonur@bilkent.edu.tr<br />
1 - Deciding on the Decision Frame (The Most Important Decision of<br />
the Analysis)<br />
Roberto Ley-Borras, Director, Consultoria en Decisiones, Oriente 13<br />
A No. 1122, Orizaba, Ver., Mexico, rley@decidir.org<br />
Identifying the right decision frame is generally regarded as a critical part of a<br />
decision analysis, but there are few guidelines on how to achieve that. This talk<br />
presents a simple algorithm and some advice on generating decision frames and<br />
selecting the one that is best for the decision-maker’s current priorities and<br />
circumstances. Our proposed approach is considering the selection of the decision<br />
frame a decision situation by itself and using DA tools to gain clarity on the best<br />
frame.<br />
2 - Modified Repertory Grid Approach to Developing Criteria for MCDM<br />
Eric Johnson, Decision Strategies, Inc., 10260 Westheimer Road,<br />
Suite 250, Houston, TX, 77079, United States of America,<br />
ERJohnson@DecisionStrategies.com<br />
Multi-criterion decision making has been widely used for decisions where<br />
stakeholders do not agree on a single overriding objective. Assessment of criterion<br />
weights and scores is well understood. But all too often the criteria are too vague to<br />
be properly judged, or are understood differently by different judges, leading to<br />
results that aren’t compelling or don’t even make sense. This talk describes a novel<br />
protocol for eliciting objectives, and illustrates its benefit in a disguised case.<br />
3 - A Multiple Criteria Sorting Method Based on Support<br />
Vector Machines<br />
Esra Karasakal, Industrial Engineering Department, Middle East<br />
Technical University, Ankara, 06530, Turkey, esra@ie.metu.edu.tr,<br />
Asli Duman<br />
In this study we develop a method based on Support Vector Machines (SVM) for<br />
multiple criteria sorting problems. We modify SVM models to handle preference<br />
ordering of classes. We compare the proposed method with SVM models on several<br />
example problems.<br />
4 - Risk Aversion and Value of Information Under Various Approaches<br />
Onur Bakir, Visiting Assistant Professor, Bilkent University, Bilkent<br />
Universitesi, Endüstri Mühendisligi Bölümü, Ankara, 06800, Turkey,<br />
nonur@bilkent.edu.tr<br />
A previous study explored the relationship between the value of information and<br />
risk aversion using the buying price approach. In this presentation, we discuss<br />
whether similar conclusions hold for other approaches to evaluate information. The<br />
information acquisition problem is analyzed in a two-action lottery setting. We<br />
derive conditions under which there exists a monotonic relationship between the<br />
decision maker’s risk tolerance and the value of information.
■ WC64<br />
H - Room 406, 4th Floor<br />
Health Care, Processes<br />
Contributed Session<br />
Chair: Imran Hasan, Purdue University, 315 N Grant St., West Lafayette,<br />
United States of America, ihasan@purdue.edu<br />
1 - Estimation of Service Value Function<br />
Geun Wan Park, PhD Candidate, Korea University Businsess School,<br />
Korea Universtiry, Anam-dong, Seongbuk-gu, Seoul, 136-701,<br />
Korea, Republic of, gw_park@hotmail.com, Kwang-Tae Park<br />
We consider a dental clinic service as the series of service stages. We want to<br />
estimate service value function of each service stage. The function is usually linear<br />
function according to preexisting literatures. However, we think the function can be<br />
different based on different service stage (for example, quadratic function or cubic<br />
function, etc.) These functions to be estimated will be useful to determine the<br />
service value of the dental clinic service appropriately.<br />
2 - A Survey of the Unintended Consequences of Implementing Health<br />
Information Technology<br />
Shinyi Wu, Assistant Professor, University of Southern California,<br />
3715 McClintock Ave., GER 240C, Los Angeles, CA, 90089,<br />
United States of America, shinyiwu@usc.edu, Caitlin Hawkins<br />
Health information technology (HIT) has demonstrated many benefits but<br />
unintended consequences (UCs) of its implementation cause barriers to realization.<br />
We analyzed 215 responses to an online survey to discover the types and causes of<br />
UCs experienced by various settings of healthcare organizations and how they coped<br />
with them. The results showed that UCs persist over years and the most frequent<br />
UCs are workflow problems caused by workarounds, software design, and lack of<br />
stakeholder engagement.<br />
3 - Utility of Patient Length of Stay Information<br />
Imran Hasan, Purdue University, 315 N Grant St., West Lafayette,<br />
United States of America, ihasan@purdue.edu, Yuehwern Yih<br />
Emergency Department Crowding has become a major problem in ED in the<br />
US.One of the reasons cited for this problem is the unavailability of beds in the<br />
intensive care unit.A large number of models for the prediction of length of stay<br />
have been developed, but there has been no research pertaining to the advantages<br />
of such predictive models.Our goal is to evaluate the impact of knowing the LOS in<br />
advance, and how it can help in the planning of admissions and capacity decisions<br />
in the ICU.<br />
■ WC65<br />
H - Room 408, 4th Floor<br />
Inventory Management VI<br />
Contributed Session<br />
Chair: Ozden Cakici, PhD Student, University of Rochester, Carol G<br />
Simon Hall 4th Floor, Rochester, NY, 14627, United States of America,<br />
engin.cakici@simon.rochester.edu<br />
1 - Managerial Application of Reducing Lead Times on Safety Stock<br />
Zhi Tao, PhD Student, Kent State University, Dep. of M&IS, Kent,<br />
44242, United States of America, ztao@kent.edu<br />
In this paper, I extend Ever’s paper (1999) by applying it to normal distribution of<br />
lead time and demand and making interactive graphs to show the decision rule of<br />
reducing safety stock based on the coefficient of variation of demand. Implication of<br />
the findings on vendor managed inventory is further explored.<br />
2 - Comparison of Continuous and Periodic Review Inventory Policies<br />
with Continuous Time Costing<br />
Ozden Cakici, PhD Student, University of Rochester, Carol G Simon<br />
Hall 4th Floor, Rochester, NY, 14627, United States of America,<br />
engin.cakici@simon.rochester.edu, Harry Groenevelt,<br />
Abraham Seidmann<br />
We develop a unified analysis characterizing both periodic and continuous<br />
inventory review policies assuming a general convex inventory related cost function<br />
and stationary demand with independent increments. The use of continuous costing<br />
allows us to correctly compare the economic performance of a variety of periodic<br />
and continuous review policies, while also providing the ability to assess the impact<br />
of tactical measures like lead time reduction and review policy changes.<br />
INFORMS Austin – 2010 WC67<br />
431<br />
■ WC66<br />
H - Room 410, 4th Floor<br />
Miscellaneous Applications of Operations Research<br />
Contributed Session<br />
Chair: Scott Parr, Researcher, Florida Atlantic University, 777 Glades rd.,<br />
Boca Raton, FL, 33431, United States of America, sparr1@fau.edu<br />
1 - Sequential Testing of K-out-of-n Systems Under<br />
Precedence Constraints<br />
Tonguç Unlüyurt, Sabanci University, Tuzla, Istanbul, Turkey,<br />
tonguc@sabanciUniversityedu, Elif Ozdemir<br />
We consider the minimum expected cost sequential testing problem for k-out-of-n<br />
systems under precedence constraints. Mainly the problem is to find a feasible<br />
strategy that produces the minimum cost binary decision tree that evaluates the kout-of-n<br />
function at hand when it is costly to learn the values of individual<br />
variables. We summarize the results from the literature and report our initial results<br />
of the heuristic algorithms that we develop.<br />
2 - Transit Signal Priority for Emergency Evacuation<br />
Scott Parr, Researcher, Florida Atlantic University, 777 Glades rd.,<br />
Boca Raton, FL, 33431, United States of America, sparr1@fau.edu,<br />
Evangelos Kaisar<br />
This research answers the question, during an urban evacuation should regional<br />
planners allow transit units signal priority when police assisted traffic controls are<br />
not an option. A case study of Washington D.C. shows allowing transit signal<br />
priority (TSP) during an urban evacuation has little to no effect on evacuation<br />
clearance time or evacuee travel time. Furthermore, four non-prioritized units are<br />
required to accomplish the task of three prioritized vehicles.<br />
3 - An Integration of Genetic Algorithm and GIS For<br />
Sensor Optimization<br />
Berna Dengiz, Professor, Baskent University, Baglica Kampusu<br />
Eskisehir Road 20.km, Etimesgut, Ankara, 06530, Turkey,<br />
bdengiz@baskent.edu.tr, Derya Oktay, Orhan Dengiz<br />
This study presents a geographical information system (GIS) based procedure for the<br />
optimization of sensor locations and sensor location parameters using genetic<br />
algorithms (GAs). The considered problem which is a special case of the well-known<br />
setcovering problem is NP-complete. A sensor siting optimization is an integrated<br />
system that consists of objects used in numerous subjects which can be called as<br />
sensor, like bare eye, camera, radar, radio, base station terminal and sensor coverage<br />
area can be defined as viewshed (the total visibility of visible points). The sensor<br />
operating parameters are as follows: location, height , range, azimuth, vertical<br />
viewing angles, tilt and pitch values. Each different configuration of these<br />
parameters results in different coverage area for a sensor. In this work, the<br />
optimization of sensor siting mainly focus on finding out sensor sites and sensor<br />
running parameters on terrain at the area of interest which provides maximum<br />
coverage.<br />
■ WC67<br />
H - Room 412, 4th Floor<br />
Simulation III<br />
Contributed Session<br />
Chair: Javier Faulin Fajardo, Professor, Public University of Navarre,<br />
Campus Arrosadia, Pamplona, 31006, Spain, javier.faulin@unavarra.es<br />
1 - Simulation of Contribution Rates to Fund Potential U.S. State and<br />
Federal Parental Leave Policies<br />
Beth Neary, PhD Student, Indiana University, 1315 E. 10th St. -<br />
Room 341, Bloomington, IN, 47405, United States of America,<br />
bneary@indiana.edu<br />
The United States is the only developed nation that lacks a national paid parental<br />
leave program. Several U.S. states, including California, New Jersey, and soon<br />
Washington, have instituted their own benefit programs. This project seeks to<br />
inform state and federal policy development by simulating the costs of potential paid<br />
leave provisions. Specifically, Monte Carlo simulation estimates payroll tax<br />
contribution rates for varying benefit period lengths, subsidy levels, and weekly<br />
caps.<br />
2 - Simulating Team Selection Strategies for Youth Sports Programs<br />
Stephanie Marhefka, Undergraduate Researcher, University of<br />
Arkanas, Department of Industrial Engineering, Fayetteville, AR,<br />
72701, United States of America, smarhefk@uark.edu,<br />
Scott J. Mason, Ed Pohl<br />
In this presentation we discuss several strategies for forming youth sports teams.<br />
The goal is to find a strategy that yeilds a balnced set of teams and accounts for<br />
pairing of coaches with children as well as skill levels of children. An Excel-Based<br />
VBA model is used to compare three player allocation heuritic models. Once teams<br />
are selected a season is simulated and the records of the teams are analyzed for<br />
balance. One strategy is shown to be superior.
WC68<br />
3 - Calibration of Computer Models using Stochastic Approximation<br />
Szu Hui Ng, Department of Industrial and Systems Engineering<br />
National University of Singapore, ISE Department, NUS, Singapore,<br />
isensh@nus.edu.sg<br />
Computer models are widely used to simulate real processes. However, there always<br />
exist some parameters which are unobservable in the real process but need to be<br />
specified in the model. The procedure to adjust these unknown parameters to fit the<br />
model to observed data is known as calibration. Here, we propose an effective and<br />
efficient algorithm based on the stochastic approximation approach for calibration.<br />
We demonstrate its feasibility and apply it to a disease microsimulation model.<br />
4 - Simulation of Multimodal Transport of Goods Between the Regions<br />
Atlantic and Mediterranean in Spain<br />
Alejandro Garcia del Valle, Professor, University La Coruna,<br />
Mendizabal s/n, Ferrol, 15403, Spain, agvalle@udc.es, Diego Crespo<br />
Pereira, Rosa Rios Prado, David del Rio Vilas, Javier Faulin Fajardo<br />
The roads congestion and environmental impacts they generate are a significant<br />
problem in developed countries. Spain has road, rail and sea: it is therefore crucial<br />
to study the multimodal transport. The sea-road inter-modality presents an<br />
interesting case of freight transport simulation. We will study how the goods could<br />
be distributed among the existing infrastructure. The proposed simulation model<br />
will address the transportation costs and the mechanisms of choice for users.<br />
■ WC68<br />
H - Room 415, 4th Floor<br />
Strategy/Strategic Planning I<br />
Contributed Session<br />
Chair: Dale Amburgey, Director of Enrollment Analysis, Saint Joseph’s<br />
University, 5600 City Avenue, Philadelphia, PA, 191931, United States of<br />
America, dale.amburgey@sju.edu<br />
1 - Temporal Fit, Misfit, and Performance: Testing Pace Entrainment in<br />
the Movie Production Industry<br />
Miles Zachary, Texas Tech University, RCOBA Box 42101,<br />
Lubbock, TX, 79409, United States of America,<br />
miles.zachary@ttu.edu, Jeremy Short, Tyge Payne<br />
Entrainment theory is concerned with the effects of pace and/or phase<br />
synchronizations of two or more activities within a system. This paper utilizes<br />
entrainment theory to develop hypotheses and longitudinally test a model of<br />
temporal fit, misfit, and performance in the movie industry in order to examine the<br />
understudied and elusive role of time and timing’s relationship to organizational<br />
performance.<br />
2 - Competitive Dynamics in Buyer-supplier Relationships<br />
Yan Emma Liu, The University of Melbourne, Level 10, 198 Berkeley<br />
Street, Parkville, Melbourne, Australia, yanliu@unimelb.edu.au,<br />
Shu-Jung Sunny Yang<br />
This paper studies the impact of co-optitive awareness on buyer-supplier<br />
relationships. We develop a behavioral game-theoretic model, based on prospect<br />
theory, to investigate the motivation of vertical (dis)integration. Our analysis shows<br />
that value creation is directly proportional to downstream organization redundancy<br />
and value appropriation is influenced by upstream organization redundancy. Our<br />
research highlights the risk of ignoring behavioral drivers in decision making.<br />
3 - The Stakeholders’ Involvement in the Strategic Planning Process<br />
Baris Carikci, TUBITAK, Kocaeli, Kocaeli, Turkey,<br />
bcarikci@yahoo.com<br />
The tendency of Turkish public organization in favor of strategic management has<br />
become a apparent fact in Turkey. The aim of the paper is to explain the tools to<br />
uncover the relation between a successful strategic management process and<br />
stakeholders’ involvement in the examples of distinguished Turkish public<br />
institutions. With these basic tools, public sector can improve the tools they use to<br />
initiate their stratagic management programs.<br />
4 - Using Business Intelligence in College Admissions:<br />
A Strategic Approach<br />
Dale Amburgey, Director of Enrollment Analysis, Saint Joseph’s<br />
University, 5600 City Avenue, Philadelphia, PA, 191931,<br />
United States of America, dale.amburgey@sju.edu, John Yi<br />
Data from first-year enrolling students were analyzed to develop predictive models.<br />
A decision tree analysis, a neural network analysis, and a multiple regression<br />
analysis were conducted to predict each student’s GPA at the end of the first year of<br />
academic study. Overall model performance was evaluated by using the average<br />
square error. Suggestions for future analysis include expansion of the study to<br />
include more student-centric variables and to evaluate GPA at other student levels.<br />
INFORMS Austin – 2010<br />
432<br />
■ WC69<br />
H - Salon F, 6th Floor<br />
Reverse Logistics I<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Theresa Barker, PhD, University of Washington, Box 352650,<br />
Seattle, WA, 98115, United States of America,<br />
barkertj@u.washington.edu<br />
1 - Coordination in Reverse Supply Chains: A System<br />
Dynamics Approach<br />
Fereshteh Mafakheri, PhD Candidate, HEC Montreal, Montreal, QC,<br />
Canada, fereshteh.mafakheri@hec.ca, Fuzhan Nasiri<br />
A reverse supply chain is dealing with recovering a maximum value from products<br />
at the end of their life cycle by promoting recycling, re-manufacturing, refurbishing,<br />
and reusing activities. The objective is to protect the environment while creating<br />
profit through material or energy recovery. In this paper, we explore a System<br />
Dynamics approach to investigate the benefits of coordination between various<br />
parties involved in a reverse supply chain for used printer cartridges.<br />
2 - Incentives and Reverse Logistics Channels with Remanufacturing<br />
Chester Xiang, Assistant Professor, Clarkson University,<br />
8 Clarkson Ave, Potsdam, NY, 13699, United States of America,<br />
cxiang@clarkson.edu, Dennis Yu<br />
We study a closed-loop supply chain with remanufacturing. The customer demand<br />
is divided into two segments, i.e., business and individual customers, which show<br />
different responses to incentives of returning used products. The reverse logistics<br />
channels exhibit economies of scale. A third party can be used as a used-product<br />
collecting agent. We investigate the manufacture’s incentive schemes, reverse<br />
logistics channel strategies, and resulting financial and social impacts.<br />
3 - Part Recovery Under Quality and Demand Uncertainty with<br />
Environmental Costs<br />
Gonca Yildirim, University of Florida, University of Florida,<br />
Gainesville, FL, 32611, United States of America, gonca@ufl.edu,<br />
Elif Akcali, Pelin Bayindir<br />
We consider acquisition and stocking decisions, motivated by the operations of a<br />
salvaging facility that collects a particular end-of-life product, performs a series of<br />
disassembly and recovery operations to reclaim a reusable part and sells the<br />
recovered part in the used parts market. We model uncertainties in demand and<br />
quality classification of the parts and include environmental fees that create a nonnegligible<br />
tradeoff against the operational costs in acquisition and stocking decisions.<br />
4 - The Impact of Legislation on Product Recovery: Reuse or Recycle?<br />
Ibrahim Karakayali, Post-doctoral Research Fellow, McGill<br />
University, Desautels Faculty of Management, 1001 Sherbrooke St.<br />
West, Montreal, QC, H3A1G5, Canada,<br />
ibrahim.karakayali@mcgill.ca, Luk Van Wassenhove, Tamer Boyaci,<br />
Vedat Verter<br />
In this study, we develop stylized models to assess the effects of material recovery<br />
targets (induced by legislation such as WEEE) on industry decisions pertaining to<br />
product reusability and recycling. We conduct a comparative analysis of centralized<br />
setting where there is cannibalization among the new and the remanufactured<br />
products. Our analytical framework also incorporates multiple stakeholders<br />
including the OEM, consumers, regulator, and environmentally conscious groups.<br />
■ WC70<br />
H - Salon G, 6th Floor<br />
Fleet-Level Environmental Evaluation of New Aircraft<br />
and Technologies<br />
Sponsor: Aviation Applications<br />
Sponsored Session<br />
Chair: William Crossley, Professor, Purdue University, School of<br />
Aeronautics and Astronautics, 701 W. Stadium Ave, West Lafayette, IN,<br />
47907-2045, United States of America, crossley@purdue.edu<br />
1 - Evaluating Future Environmental Impact of US Aviation via System<br />
Dynamics and Resource Allocation<br />
William Crossley, Professor, Purdue University, School of Aeronautics<br />
and Astronautics, 701 W. Stadium Ave, West Lafayette, IN, 47907-<br />
2045, United States of America, crossley@purdue.edu<br />
This study integrates system dynamics (SD) and resource allocation (RA) to evaluate<br />
environmental impact of new aircraft and technologies. SD models observed<br />
aviation trends and behaviors like order-delivery, price-demand elasticity, and<br />
environmental policy dynamics. RA determines the fleet mix to maximize airline<br />
profits subject to constraints. Results illustrate the impact of demand, policies, and<br />
new aircraft technologies on emissions and noise over the 2005-2040 period.
2 - Revenue-based Allocation Model for Fleet-level Environmental<br />
Impacts of Airline Operations<br />
Muharrem Mane, Post-doctoral Researcher, Purdue University,<br />
School of Aeronautics and Astronautics, 701 W. Stadium Ave,<br />
West Lafayette, IN, 47907-2045, United States of America,<br />
mane@purdue.edu, Dan DeLaurentis, William Crossley<br />
This work uses a resource allocation model of airline operations to estimate the<br />
impact that new technology and new aircraft have on fleet-level CO2 and NOx<br />
emissions and airport noise. To approximate airline decision-making, we created a<br />
simplified revenue model based on flight frequency and trip length. Using this in the<br />
resource allocation objective function, we can approximate airline operations and<br />
study the impact of aircraft-specific improvements on fleet-level environmental<br />
metrics.<br />
3 - Decomposition Approach for Aircraft Allocation Under<br />
Environmental Considerations<br />
Isaac Tetzloff, Graduate Student, Purdue University, School of<br />
Aeronautics and Astronautics, 701 W. Stadium Ave, West Lafayette,<br />
IN, 47907-2045, United States of America, isaact@purdue.edu,<br />
William Crossley<br />
Previous work to allocate aircraft amongst 257 domestic and international airports<br />
used one large integer programming problem. Assumptions and abstractions<br />
simplified the problem to represent a majority of commercial airline operations with<br />
at least the arrival or destination airport in the US. Decomposing the problem into<br />
smaller allocation problems maintains runtimes similar to the previous model, and<br />
now includes multiple airlines, more aircraft models, and ‘one-way’ routes.<br />
4 - Examining the Potential Environmental Impact of Legacy and<br />
Budget Carrier Competitive Balance<br />
Datu Agusdinata, Post-doctoral Researcher, Purdue University,<br />
School of Aeronautics and Astronautics, 701 W. Stadium Ave,<br />
West Lafayette, IN, 47907-2045, United States of America,<br />
bagusdin@purdue.edu<br />
Legacy and budget carriers in the US operate and compete using different business<br />
(e.g. cost & fare structure) and operations (e.g. fleet composition, network structure,<br />
and level of service) models. Based on a logit model to ascertain the market share of<br />
each carrier, this study investigates how the competition may evolve over time and<br />
assesses the resulting emissions and noise impact under multiple scenarios of<br />
technology improvement rate, demand growth, and relative cost advantage.<br />
■ WC71<br />
H - Salon H, 6th Floor<br />
Decision Support Models in DEA<br />
Cluster: In Honor of Bill Cooper<br />
Invited Session<br />
Chair: Vladimir Krivonozhko, Institute for Systems Analysis,<br />
KrivonozhkoVE@mail.ru<br />
1 - DEA Models for Decision Making Support in Negotiation Process<br />
Vladimir Krivonozhko, Institute for Systems Analysis,<br />
KrivonozhkoVE@mail.ru, Alexander Piskunov, Andrey Lychev,<br />
Maria Piskunova<br />
In this paper, an approach is proposed on evaluation of agreements on transnational<br />
projects during the negotiation process. One can show that the negotiation process<br />
can be represented as the behaviour of decision making units (countries) in the<br />
multidimensional space of economic indicators using DEA models. In this case, the<br />
goals that can be reached by units as a result of accomplishment of joint project can<br />
be determined as points in the multidimensional space. Optimal directions toward<br />
these goals and cones of possible directions can be found with the help of Analytic<br />
Hierarchy Process (AHP). Our approach is illustrated on the real-life data taken from<br />
open international sources.<br />
2 - The Winner is Kobe: Site Selection for the Next-generation<br />
Supercomputing Center in Japan<br />
Kaoru Tone, National Graduate Institute for Policy Studies, Japan,<br />
tone@grips.ac.jp<br />
The Next Generation Supercomputer R&D Project is an endeavor to create a 10<br />
Pflop/s system by 2012. It will be considered to be one of the “Key Technologies of<br />
National Importance of Japan.” Its goals are: (1). Development and installation of<br />
the most advanced high performance supercomputer system; (2). Development and<br />
wide use of application software to utilize the supercomputer to the maximum<br />
extent; (3) Provision of a flexible computing environment by sharing the next<br />
generation supercomputer through connection with other supercomputers ; (4)<br />
Establishment of an “Advanced Computational Science and Technology Center.” In<br />
this talk, I will report how the site selection was decided using AHP and DEA.<br />
INFORMS Austin – 2010 WC72<br />
433<br />
3 - A Cost-constrained Measure of Energy Efficiency<br />
Kankana Mukherjee, Babson College, kmukherjee@babson.edu,<br />
Subhash Ray, Lei Chen<br />
We provide a measure of energy-use efficiency for a firm with cost constraints.<br />
Using DEA, we investigate the energy efficiency of the US manufacturing sector<br />
across states. Our results indicate that in many states the actual energy use by the<br />
typical firm exceeds the optimal use without any increase in cost. We also find that<br />
an effective tax on energy use in manufacturing would reduce the aggregate energy<br />
usage while at the same time increasing the aggregate labor employment in this<br />
sector.<br />
4 - Eco-efficiency Within Selected US Industries using Data<br />
Envelopment Analysis<br />
Paul Rouse, University of Auckland, p.rouse@auckland.ac.nz<br />
We set out to provide further empirical evidence on the relationship between firm<br />
environmental performance and economic performance. In contrast to other studies<br />
which have used either partial productivity measures or purely accounting ratios,<br />
we use a frontier production model, data envelopment analysis (DEA), using<br />
multiple inputs and multiple outputs to estimate economic performance. Using data<br />
from four U.S. industries that are typically viewed as ‘highly environmentally<br />
sensitive’ for a three year (2006 to 2008) period, we find some evidence that higher<br />
levels of environmental performance are significantly associated with higher levels<br />
of economic efficiency. Our empirical evidence is therefore broadly consistent with<br />
the ‘Porter’ hypothesis; that is greater firm environmental performance is associated<br />
with higher levels of economic performance. Results, however, are mixed with<br />
positive and statistically significant coefficients on both environmental strengths and<br />
weaknesses. We then use the Fare and Grosskopf ‘weak disposability’ framework to<br />
explain the conflicting results in the regression analyses using the KLD strengths<br />
and weaknesses.<br />
■ WC72<br />
H - Salon J, 6th Floor<br />
Facility Logistics Interactive Session: Distribution<br />
Center Operations<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Russell Meller, Hefley Professor of Logistics and Entrepreneurship,<br />
University of Arkansas, 4207 Bell Engineering, Fayetteville, AR, 72701,<br />
United States of America, rmeller@uark.edu<br />
1 - Decentralized Control of High Density Storage Systems<br />
Kevin Gue, Associate Professor, Auburn University, Department of<br />
Industrial & Systems Engin, Auburn, AL, United States of America,<br />
kevin.gue@auburn.edu, Kai Furmans<br />
We describe a decentralized control algorithm for a grid-based, high density storage<br />
system based on the “slide puzzle architecture.” When executed with constant<br />
work-in-process, the system provides very high throughput, and yet it consumes<br />
less space than a typical automated storage and retrieval system.<br />
2 - The Fishbone Triangle Design for Dual-Command Cycles in a<br />
Unit-Load Warehouse<br />
Russell Meller, Hefley Professor of Logistics and Entrepreneurship,<br />
University of Arkansas, 4207 Bell Engineering, Fayetteville, AR,<br />
72701, United States of America, rmeller@uark.edu, Letitia Pohl,<br />
Kevin Gue<br />
The fishbone warehouse design improves upon traditional warehouse designs for<br />
single-command cycles, but is not as efficient for the travel-between leg of a dualcommand<br />
cycle. The fishbone triangle design was developed to address this issue.<br />
We have developed a set of analytical expressions for travel-between in the fishbone<br />
triangle warehouse, which allows us to optimize this non-traditional warehouse<br />
design. We will present results on its performance.<br />
3 - Determining the Optimal Aisle-width for a Semi-automated Picking<br />
System in a Distribution Center<br />
Pratik Parikh, Assistant Professor, Wright State University,<br />
3640 Col Glenn Hwy, 207 Russ Eng Center, Dayton, OH, 45435,<br />
United States of America, pratik.parikh@wright.edu, Sheena Finney<br />
We consider the aisle-design problem for a semi-automated picking system that uses<br />
a person-on-board material handling equipment, such as an order picker truck.<br />
Using a previously developed model to determine the optimal storage level for such<br />
a system, we conduct a simulation study to determine the aisle-width (narrow or<br />
wide) that minimizes total system cost. We also compare our results with those<br />
obtained for a manual system to generate managerial insights when designing such<br />
systems.
WC73<br />
4 - A Network Model for Warehouses with Non-Traditional Aisles<br />
Omer Ozturkoglu, Auburn University, Department of<br />
Industrial&Systems Engineering, Auburn, AL, 36849, United States<br />
of America, ozturom@auburn.edu, Kevin Gue, Russell Meller<br />
We show how to construct non-traditional aisle designs for unit-load warehouses<br />
with multiple pickup and deposit (P&D) points, using a network model to represent<br />
storage locations and P&D points. The model uses a meta-heuristic to search for<br />
optimal angles of cross aisles and picking aisles.<br />
■ WC73<br />
H - Salon K, 6th Floor<br />
Joint Session TSL/ SPPSN: Methods to Support<br />
Regional Evacuation<br />
Sponsor: Transportation Science and Logistics Society/ Public<br />
Programs, Service and Needs<br />
Sponsored Session<br />
Chair: Irina Dolinskaya, Assistant Professor, Northwestern University,<br />
2145 Sheridan Road, M235, Evanston, IL, 60208, United States of<br />
America, dolira@northwestern.edu<br />
1 - Design of an Evacuation Network for Hurricane Evacuation<br />
Xinghua Wang, Texas A&M University, 303K Zachry, TAMU,<br />
College Station, United States of America, wxh55@tamu.edu,<br />
Justin Yates, Halit Uster<br />
We consider large scale evacuations in expected extreme event situations such as<br />
hurricanes. We present a mixed integer model to minimize total costs under time<br />
constraints while determining associated facility locations and traffic flows to<br />
construct evacuation routes. We develop a Benders decomposition based solution<br />
approach and report numerical results using Texas-based real data facilitated by GIS.<br />
2 - An Integrated Demand-Supply Framework for<br />
Evacuation Operations<br />
Yu Ting Hsu, Purdue University, West Lafayette, IN,<br />
United States of America, yhsu@purdue.edu, Srinivas Peeta<br />
Evacuation operations involve perspectives from both the demand and supply sides.<br />
This study proposes an integrated operational framework to address the interactions<br />
between evacuation flow management and individual behavior, by using robust<br />
evacuation behavior models that consider the various factors that influence<br />
evacuation-related decision-making.<br />
3 - Large-Scale Evacuations with Arc Routing<br />
Mark Hickman, Associate Professor, University of Arizona, Civil<br />
Engineering, 1209 E. Second St., Bldg 72, Tucson, AZ, 85721-0072,<br />
United States of America, mhickman@email.arizona.edu,<br />
Moshe Dror<br />
We consider a routing of public vehicles to evacuate persons during a large-scale<br />
emergency. To facilitate the evacuation, we consider a routing of vehicles along<br />
roadways to pick up people at their residences or other locations. We present an arc<br />
routing model for this case and illustrate the model on a large-scale case study.<br />
■ WC74<br />
H - Room 602, 6th Floor<br />
Hazardous Material Transportation<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Changhyun Kwon, Assistant Professor, University at Buffalo,<br />
400 Bell Hall, Buffalo, NY, 14260, United States of America,<br />
chkwon@buffalo.edu<br />
1 - Value-at-Risk Model for Hazmat Transport<br />
Yingying Kang, PhD Candidate, University at Buffalo - SUNY,<br />
Department of Industrial Engineering, 438 Bell Hall, Buffalo, NY,<br />
14260, United States of America, ykang4@buffalo.edu, Rajan Batta,<br />
Changhyun Kwon<br />
We propose a new measurement of risk in hazmat transportation, namely Value-at-<br />
Risk (VaR). The VaR measurement aims to gauge the cutoff risks within a certain<br />
confidence level, instead of minimizing the expected risk or maximal risk of a<br />
hazmat path directly. This allows the choice of a hazmat route according to decision<br />
makers’ risk preferences. Furthermore, we display that the route choice with the<br />
VaR model depends on the level of risk tolerance.<br />
INFORMS Austin – 2010<br />
434<br />
2 - Environmental Risk Analysis of Railroad Transportation of<br />
Hazardous Materials<br />
Rapik Saat, Postdoctoral Research Associate, University of Illinois at<br />
Urbana-Champaign, 205 N Mathews RM3214, Urbana, IL, 61801,<br />
United States of America, mohdsaat@illinois.edu, Chris Barkan<br />
This presentation will describe a quantitative risk analysis of rail transportation of<br />
hazardous materials using an environmental consequence model in conjunction<br />
with a geographic information system (GIS) exposure analysis along the U.S. rail<br />
network. The annual risk estimate incorporates the estimated remediation cost,<br />
route-specific probability distributions of soil type and depth to groundwater, annual<br />
traffic volume, railcar accident rate, and tank car safety features.<br />
3 - Dual Toll Pricing for Hazardous Material Transport with Linear Delay<br />
Jiashan Wang, University at Buffalo- SUNY, Department of Industrial<br />
Engineering, Buffalo, NY, United States of America,<br />
jw282@buffalo.edu, Yingying Kang, Rajan Batta, Changhyun Kwon<br />
We propose a dual toll pricing method to mitigate risk of hazmat transportation. We<br />
aim to control both regular and hazmat vehicles to reduce the risk. We incorporate<br />
a new risk measure to consider duration-population-frequency of hazmat exposure.<br />
We formulate the model as an MPEC problem and then decompose the formulation<br />
into first-stage and second-stage problems. For each stage problem, we present<br />
methods to solve them separately. A numerical example is provided.<br />
<strong>Wednesday</strong>, 3:30pm - 5:00pm<br />
■ WD01<br />
C - Ballroom D1, Level 4<br />
Joint Session ENRE/ QSR: Renewable Energy<br />
Integration into Power Systems for Smart Operations<br />
Sponsor: Energy, Natural Resources and the Environment/ Quality,<br />
Statistics and Reliability<br />
Sponsored Session<br />
Chair: Eunshin Byon, PhD, Postdoctoral Research Associate, Texas A&M<br />
University, 241 Zachry, 3131 TAMU, College Station, TX, 77840,<br />
United States of America, esbyun@neo.tamu.edu<br />
1 - Optimizing the Acquisition and Operation of On-site<br />
Electricity Generation<br />
Kris Pruitt, kpruitt@mymail.mines.edu, Rob Braun,<br />
Alexandra Newman<br />
We present a mixed-integer, nonlinear program for designing and operating an onsite<br />
generation system to supply electricity to a large, commercial building. The<br />
system design includes renewable and non-renewable generation, net-metering to<br />
the grid, and on-site storage. The model determines the optimal mix of generators<br />
and storage units to acquire, along with their operating levels over time, to<br />
minimize total cost subject to system performance characteristics and the building’s<br />
demand.<br />
2 - Simulation and Optimization of Wind Farm Operations Under<br />
Stochastic Conditions<br />
Eunshin Byon, PhD, Postdoctoral Research Associate, Texas A&M<br />
University, 241 Zachry, 3131 TAMU, College Station, TX, 77840,<br />
United States of America, esbyun@neo.tamu.edu<br />
This research aims at developing models and associated solution tools to devise<br />
optimal maintenance strategies for wind turbines, helping reduce the operation<br />
costs and enhancing the marketability of wind power. We provide an integrated<br />
framework including optimization models, and a discrete event-based simulation<br />
model characterizing the dynamic operations of wind power systems. We highlight<br />
the benefits of the resulting strategies through a case study.<br />
3 - Reliability Evaluation of Wind Turbine via Computer Simulation and<br />
Laboratory Experiments<br />
Haitao Liao, Assistant Professor, The University of Tennessee, 211<br />
Pasqua Building, Knoxville, TN, 37996, United States of America,<br />
hliao4@utk.edu, Seyed Ahmad Niknam, Janet Twomey<br />
It is important to ensure the long-term reliability of wind generators for secured,<br />
uninterrupted power extraction from the wind. This research aims at evaluating the<br />
reliability of wind generators in time-varying environments via computer simulation<br />
and laboratory experiments.
■ WD02<br />
C - Ballroom D2, Level 4<br />
Energy II<br />
Contributed Session<br />
Chair: Nicolas Lopez, Research Assistant, The University of Texas at<br />
El Paso, 500 West University Avenue, El Paso, TX, 79902,<br />
United States of America, nlopez3@miners.utep.edu<br />
1 - Incorporating Gas Pricing Into Oil & Gas Asset Development<br />
Planning - An Example<br />
Chaiyaporn Wiboonkij-Arphakul, Decision Analyst, Chevron, Tower<br />
III, SCB Park Plaza, 19 Ratchadapisek Rd, Chatuchak, Bangkok,<br />
10900, Thailand, cwiboonkij@gmail.com, Ing Jye Tsai<br />
As gas is sold in the $ per BTU, there is a clear incentive for one to maximize profits<br />
by accelerating the development of high-BTU wells. However, doing so in some<br />
environment (e.g., under Gas Sales Agreement) may lead to the loss of low-BTU gas<br />
reserves and the delivery shortfall penalty. For Chevron Thailand, profit is<br />
maximized through the ranking of drilling projects’ profitability index while BTU<br />
forecast is only used to ensure that future production meets contractual<br />
specifications.<br />
2 - A Framework to Integrate Renewable Energy to Improve the Energy<br />
Efficiency: An OR Application<br />
Haifeng Wang, IBM Research - China, Building19, Zhongguancun<br />
Software Park, 8 Dongbeiwang West Rd, Haidian District, Beijing,<br />
China, whf@cn.ibm.com, Wenjun Yin, Jin Dong, Feng Gao<br />
This paper focuses on developing a framework for smart grid to utilize weather and<br />
renewable energy production forecasting to help integrate distributed renewable<br />
energy and energy storage into the electric distribution and transmission system. A<br />
demand-supply matching model is developed, in which power demand is modeled a<br />
given stochastic process, and the optimal unit planning policy is researched.<br />
Moreover, the renewable energy efficiency is evaluated for different feasible policies.<br />
3 - A Greedy Approach to Scheduling Outage Tasks for Distribution<br />
Power Network<br />
Ming Zhao, IBM Research - China, Diamond building, ZGC Software<br />
Park, Haidian District, Beijing, 100193, China,<br />
papayazm@gmail.com, Feng Jin, Hairong Lv, Qiming Tian, Jin Dong,<br />
Wenjun Yin<br />
Because of the complexity of distribution power network, outage task scheduling<br />
problem is usually large-scale, which results in unpractical long running time for<br />
many traditional methods. In this paper, combination weight between different<br />
tasks was defined. Then, a weight-based greedy algorithm was proposed to facilitate<br />
the procedure. In this way, computational complexity was reduced from O(t^n) to<br />
O(tn). Test results on a real distribution system show the efficiency of the approach.<br />
4 - Hybrid Power Systems Optimization Considering Different<br />
Renewable Energy Technologies<br />
Nicolas Lopez, Research Assistant, The University of Texas at El Paso,<br />
500 West University Avenue, El Paso, TX, 79902, United States of<br />
America, nlopez3@miners.utep.edu, Jose Espiritu<br />
Hybrid power systems need to be evaluated based on the requirements of high<br />
penetration renewable energy technology applications. Additionally, modeling and<br />
analysis storage systems integration are also necessary to increase the effectiveness<br />
of hybrid power configurations. In the present talk, a software based simulation to<br />
understand the Hybrid power systems response considering various renewable<br />
energy technologies and energy storage options is presented.<br />
■ WD03<br />
C - Ballroom D3, Level 4<br />
Interactive Multiple Criteria Decision Making<br />
Sponsor: INFORMS Section on Multiple Criteria Decision Making<br />
Sponsored Session<br />
Chair: Murat Köksalan, Middle East Technical University, ODTU 06531,<br />
Ankara, Turkey, koksalan@ie.metu.edu.tr<br />
1 - An Interactive Approach for MCDM using a Hybrid<br />
Tchebycheff/Linear Utility Function<br />
Ozgen Ozbey, SUNY Buffalo, 308A Bell Hall, Department of<br />
Industrial and Systems Eng, Buffalo, 14260-1900, United States of<br />
America, oozbey2@buffalo.edu, Mark H. Karwan<br />
We improve our previously developed MILP formulation to estimate a Decision<br />
Maker’s (DM) utility function used during an interactive method employing<br />
pairwise comparisons. The utility function is approximated by a Tchebycheff or<br />
hybrid function with Tchebycheff and linear components. We consider a DM’s<br />
precision and “strength of preferences” to obtain a most preferred solution among<br />
implicit alternatives in an effective manner. We present computational results and<br />
comparisons with other methods.<br />
INFORMS Austin – 2010 WD04<br />
435<br />
2 - Interactive Evolutionary Multi-Criteria Scheduling<br />
Jon Marquis, Senior Systems Engineer, Raytheon, 1151 East<br />
Hermans Road, Tucson, AZ, 85756, United States of America,<br />
jonemailbox1@gmail.com, John Fowler, Esma Gel, Pekka Korhonen,<br />
Jyrki Wallenius, Murat Köksalan<br />
We present a new approach to multi-criteria scheduling using an interactive<br />
evolutionary algorithm with a scheduling heuristic to develop solutions. The<br />
algorithm sends a subset of the solutions to the decision maker (DM) for evaluation<br />
and uses the resulting preference information to evaluate new solutions and guide<br />
the algorithm. We apply the algorithm to the weighted completion time, total<br />
tardiness, and maximum lateness criteria.<br />
3 - Solving Multiobjective Mixed Integer Programs using Convex Cones<br />
Murat Köksalan, Middle East Technical University, ODTU 06531,<br />
Ankara, Turkey, koksalan@ie.metu.edu.tr, Jyrki Wallenius,<br />
Banu Lokman, Pekka Korhonen<br />
We assume that the decision maker’s preferences are consistent with a quasiconcave<br />
utility function. Based on the convex cones derived from past preferences, we create<br />
constraints to prevent solutions in the implied inferior regions. We guarantee<br />
finding the most preferred solution and our computational results show that a<br />
reasonable number of pairwise comparisons are required.<br />
■ WD04<br />
C - Ballroom D4, Level 4<br />
Sustainability II<br />
Contributed Session<br />
Chair: Amrou Awaysheh, Assistant Professor of Operations Management,<br />
IE Business School, Maria de Molina, 12 - 5 planta, Madrid, 28006,<br />
Spain, amrou.awaysheh@ie.edu<br />
1 - The Impact of Green Vehicles on the Market Value of Automakers<br />
Qindong Liu, University of Connecticut School of Business,<br />
2100 Hillside Road, Storrs, CT 06269, United States of America,<br />
qindong.liu@business.uconn.edu, Jan Stallaert<br />
We conduct an event study to explore how stock markets react to automakers’ fuelefficient<br />
product strategies. We find automakers’ green technology and product<br />
innovations have a positive impact on their market valuation, although the<br />
technology and market segment choices have different implications. The abnormal<br />
returns could be explained by both internal and external factors. More interesting,<br />
our analysis indicates that product design variables moderate those relationships.<br />
2 - A LCA Method Considering Multi-Scenario and System Uncertianty<br />
Jianzhi Li, Assistant Professor, The University of Texas - Pan<br />
American, 1201 W University Dr., Edinburg, TX, 78539,<br />
United States of America, jianzhi.li06@gmail.com, Xiaowei Wang<br />
Current LCA approaches failed to consider spatial and temporal system uncertainty<br />
in its calculation. A new LCA method is proposed which considers uncertain future<br />
multi-scenario. The LCI data are collected as per scenario including pollution<br />
emissions and character information that are used to generate personal, spatial and<br />
temporal factors, which reflect the diversity of environment. The impacts is obtained<br />
by summing up the results of each scenario wighted by the scenario probabilities.<br />
3 - The Impact of Social Issues Management on Firm Performance -<br />
An Event Study<br />
Amrou Awaysheh, Assistant Professor of Operations Management, IE<br />
Business School, Maria de Molina, 12 - 5 planta, Madrid, 28006,<br />
Spain, amrou.awaysheh@ie.edu, Robert D. Klassen<br />
The management of social issues can have a substantial impact on a firm’s financial<br />
performance. Social issues are complex, and managing them requires a range of<br />
practices. Examples include establishing workforce policies for safe work practices or<br />
diversity; however, a firm may also be involved in negative practices, such as the<br />
use of illegal labor practices. This paper will present the results from an ongoing<br />
event study that examines the impact of social issues management on a firm’s value.
WD05<br />
■ WD05<br />
C - Ballroom D5, Level 4<br />
Dynamic Programming/Control II<br />
Contributed Session<br />
Chair: Suleyman Demirel, PhD Candidate, Ross School of Business,<br />
University of Michigan, 701 Tappan Ave, Ann Arbor, MI, 48104,<br />
United States of America, sdemirel@umich.edu<br />
1 - Ad Valorem Tax and the Cumulated Output of<br />
Exhaustible Resources<br />
Runfang Xu, PhD Candidate, Xi’an Jiaotong University, No.28,<br />
Xianning West Road, Xi’an, 710049, China, runfangxu@yahoo.com,<br />
Xinmei Liu<br />
This paper, after modifying the Hotelling model and using the dynamic control<br />
method, researches the relation between ad valorem tax and cumulated output of<br />
exhaustible resources under monopoly. It is shown that the cumulated output is<br />
lower than perfect competition when the ad valorem tax rate equals to zero. And<br />
the cumulated output is decreased more when the ad valorem tax rate more than<br />
zero. However, the cumulated output is increased when the ad valorem tax rate less<br />
than zero.<br />
2 - Sensitivity-Based Nested Partitions for Solving Markov<br />
Decision Processes<br />
Weiwei Chen, University of WIsconsin-Madison, 1513 University<br />
Avenue, Madison, WI, 53706, United States of America,<br />
wchen26@wisc.edu, Leyuan Shi, Yanjia Zhao, Xiaohong Guan<br />
This paper introduces an algorithm to solve finite-horizon total-cost Markov<br />
decision processes with non-stationary policies. It is based on Nested Partitions (NP)<br />
global optimization framework, and combines the search power of a local optimizer<br />
using sensitivity-based analysis. An intelligent partitioning approach is developed to<br />
determine the new partitions adaptively based on the information from previous<br />
iterations. The numerical example shows the effectiveness of the proposed<br />
algorithm.<br />
3 - Dynamic Airline Asset Allocation Incorporating Econometric<br />
Demand Models<br />
Navindran Davendralingam, Purdue University, School of<br />
Aeronautics and Astronautics, 701 West Stadium Avenue, West<br />
Lafayette, 47906, United States of America, davendra@purdue.edu,<br />
William Crossley<br />
Operational adjustments by airlines translate to latent passenger observations who<br />
dictate future demand trends based on cost feasibility and ancillary benefits offered<br />
by various ticket itineraries being published. The current proposed research develops<br />
a conceptual dynamic framework that builds upon previous paradigms in dynamic<br />
programming, econometrics and system engineering to maximize revenue for a<br />
given airline using tactical asset allocation subject to reflexive demand feedback.<br />
4 - Resource Taxation and the Cumulated Output of Exhaustible<br />
Resource Under the Externality<br />
Runfang Xu, PhD candidate, Xi’an Jiaotong University, No.28,<br />
Xianning West Road, Xi’an, 710049, China, runfangxu@yahoo.com,<br />
Xinmei Liu<br />
How to enhance cumulated output and how to lengthen the total lifetime of<br />
exhaustible resources is a very popular topic. Firstly, this paper constructs a dynamic<br />
optimal control model under the condition of externality. Secondly, this paper,<br />
applying simulation, analyses the relationship between resource taxation and<br />
cumulated output and total lifetime. Finally, the results are confirmed by data from<br />
China.<br />
5 - Production and Inventory Control for a Two-Stage Assemble-to-<br />
Order System with Uncertain Capacities<br />
Suleyman Demirel, PhD Candidate, Ross School of Business,<br />
University of Michigan, 701 Tappan Ave, Ann Arbor, MI, 48104,<br />
United States of America, sdemirel@umich.edu, Roman Kapuscinski,<br />
Izak Duenyas<br />
Consider a firm assembling product from subcomponents, where both assembly<br />
capacity and subassembly capacities are uncertain. The assembly capacity is<br />
common, while each component has dedicated subassembly resources. The firm<br />
may hold inventory of subassemblies. We analyze a multi-period inventory model<br />
for two products, and derive the optimal replenishment policy of the subassemblies<br />
as well as the optimal priority scheduling of the assembly resource.<br />
INFORMS Austin – 2010<br />
436<br />
■ WD07<br />
C - Ballroom F & G, Level 4<br />
Supply Chain, Closed-loop II<br />
Contributed Session<br />
Chair: Jo Min, Iowa State University, IMSE Department, 3004 Black,<br />
Ames, IA, 50011, United States of America, jomin@iastate.edu<br />
1 - Hybrid Manufacturing/Remanufacturing System in Cascade Reuse<br />
Yasutaka Kainuma, Tokyo Metropolitan University, 6-6, Asahigaoka,<br />
Hino, Tokyo, 191-0065, Japan, kainuma@sd.tmu.ac.jp<br />
In this research, we constructed a cascade reuse hybrid<br />
manufacturing/remanufacturing model. We proposed the optimal ordering policy<br />
minimizing manufacturer’s total costs when manufacturing two grades of products.<br />
In the data examples, comparing the proposal policy with the policy of the actual<br />
operations of company-A, we could confirm the optimality of the proposal policy.<br />
2 - Joint Inventory-promotion Decision in Closed-loop Hybrid<br />
Manufacturing System<br />
S. Phil Kim, PhD Candidate, Purdue University, 315 N. Grant Street,<br />
West Lafayette, IN, 47907, United States of America,<br />
ksphil@purdue.edu, Seokcheon Lee, J. George Shanthikumar<br />
In this paper, Markov decision process is used for the joint inventory-promotion<br />
decision problem in a closed-loop hybrid system. The stochastic returns are<br />
correlated with the volume of circulation. The demands are also stochastic and<br />
influenced by the promotion decision. The state space can be divided into<br />
promotion-desired and promotion-not-desired spaces. For a given decision on the<br />
promotion, we show that the optimal solution structure is completely defined by<br />
two points in the state space.<br />
3 - ANP Methodology and Reverse Supply Chain<br />
Sharon Ordoobadi, University of Massachusetts, 285 Old westport<br />
Road, Dartmouth, United States of America, sordoobadi@umassd.edu<br />
The objective is development of a decision tool to help with selection of the third<br />
party reverse logistics provider. The criteria to be considered in the evaluation<br />
process are identifgied. The ANP methodology is applied to rank the potential<br />
providers. The provider with the highest ranking is chosen to perform the reverse<br />
logistic function.<br />
4 - Closed-loop Supply Chain with Dynamic Returns and Incentives<br />
Pietro De Giovanni, NOVA School of Business and Economics,<br />
Campus Campolide, 1099, Lisbon, Portugal,<br />
pietro.degiovanni@fe.unl.pt<br />
In a closed-loop supply chain (CLSC), a single manufacturer and a single retailer<br />
invest in green activities to enhance the product return. Coordination is evaluated<br />
by means of a pay-back contract while the return policy is managed in an active<br />
manner. The return rate is thus modeled as a dynamic equation that evolves over<br />
time according to the green activities. We investigate the conditions under which<br />
coordination is Pareto-improving.<br />
5 - Product Weight Reduction Investment and Collection Rate in a<br />
Closed Loop Supply Chain<br />
Jo Min, Iowa State University, IMSE Department, 3004 Black, Ames,<br />
IA, 50011, United States of America, jomin@iastate.edu, Wenbo Shi,<br />
Karla Valenzuela<br />
We investigate a Stackelberg game consisting of a manufacturer/remanufacturer<br />
who directly sells to customers and a collector of the used products. The collector is<br />
the follower who determines the collection rate and the manufacturer is the leader<br />
who determines the price and the product weight reduction investment. As the cost<br />
saving of remanufacturing increases, the product weight and collection rate both<br />
increase. i.e., the environmental policies of reduce and reuse may be selfcontradictory.
■ WD08<br />
C - Room 11A, Level 4<br />
Facility Location II<br />
Contributed Session<br />
Chair: Jiamin Wang, Associate Professor, Long Island University, Roth<br />
Hall 202, Long Island University, 720 Northern Blvd, Brookville, 11548,<br />
United States of America, jiamin.wang@liu.edu<br />
1 - A Heuristic Procedure for the Integrated Facility Layout Design and<br />
Flow Assignment Problem<br />
Seyed Ali Taghavi, Wayne State University, 4815 Fourth Street,<br />
detroit, MI, 48202, United States of America, dz3738@wayne.edu,<br />
Alper Murat<br />
We study integrated lay-out design problem and product flow assignment problem.<br />
The lay-out design decisions involve planar location of unequal-area machines with<br />
duplicates. The product flows are assigned to machines according to the product<br />
processing routes. We propose a heuristic procedure based on the alternating<br />
location-assignment heuristic. Then, we apply a perturbation algorithm to escape<br />
local optima. A sequential location heuristic is also used to speed up the location<br />
problem.<br />
2 - Application of Hybrid Analysis of a Discrete Space Location in a<br />
School Location Problem<br />
Farshad Majzoubi, PhD Student, University of Louisville, Department<br />
of Industrial Engineering, JB Speed School of Engineering,<br />
Louisville, KY, 40292, United States of America,<br />
f0majz01@louisville.edu, Bulent Erenay, Trivikram Rao<br />
This research develops a generic Excel model using the Hybrid Analysis method for<br />
discrete space location problems, and combines it with an Analytical Hierarchy<br />
Process approach to act as a decision support tool to select the optimal location to<br />
open a school when both quantitative and qualitative factors are involved.<br />
Keywords: Location allocation, Hybrid analysis, Analytical Hierarchy Process<br />
3 - A Minimax Approach to EMS-Helicopter Station and Heliport<br />
Location Problems<br />
Takehiro Furuta, Dr., Assistant Professor, Tokyo University of<br />
Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan,<br />
takef@fw.ipsj.or.jp, Ken-ichi Tanaka<br />
We propose location models for EMS-helicopter systems. The helicopters require<br />
their stations and heliports to pick up patients. We formulate the model as an<br />
integer programming problem which seeks to find locations of both stations and<br />
heliports to minimize the maximum transportation time. Our model is applied to<br />
analyzing optimal locations using an idealized city model under various<br />
assumptions.<br />
4 - A Median Problem on a Network with Random Travel Speeds and a<br />
Desirable Travel Time Level<br />
Jiamin Wang, Associate Professor, Long Island University, Roth Hall<br />
202, Long Island University, 720 Northern Blvd, Brookville, 11548,<br />
United States of America, jiamin.wang@liu.edu<br />
We consider a facility location problem on a network when the travel speeds along<br />
links are discrete random variables. For each customer, a utility “loss” incurs if<br />
travel time to reach a facility is beyond a desirable level. The objective is to locate<br />
facilities so as to maximize the expected total customer utility. A dominant point set<br />
is identified and solution methods are developed. It is also shown that some classic<br />
deterministic models are special cases of the problem under study.<br />
■ WD09<br />
C - Room 11B, Level 4<br />
Service Operations<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Gad Allon, Northwestern University, 2001 Sheridan Road,<br />
Evanston, IL, United States of America, gallon@kellogg.northwestern.edu<br />
1 - The Concert Queuing Arrivals Game: Finite Customer Analysis<br />
Sandeep Juneja, Associate Professor, Tata Institute, HB Road, Colaba,<br />
Mumbai, 400005, India, juneja@tifr.res.in, Nahum Shimkin<br />
We consider a queuing system where a finite number of customers arrive. Each<br />
customer is free to choose her arrival time (before or after the opening time) and is<br />
interested in early service completion with minimal wait. We analyze the<br />
equilibrium behavior of this system and study its convergence to the associated fluid<br />
limit as the number of customers increases to infinity.<br />
INFORMS Austin – 2010 WD10<br />
437<br />
2 - Bounded Rationality in Service Systems<br />
Tingliang Huang, Kellogg School of Management, Northwestern<br />
University, Leverone 529, Jacobs Center, 2001 Sheridan Road,<br />
Evanston, IL, 60208, United States of America, tinglianghuang@kellogg.northwestern.edu,<br />
Achal Bassamboo, Gad Allon<br />
The traditional economics and queueing literature typically assume that customers<br />
are fully rational. In contrast, in this paper, we study canonical service models with<br />
boundedly rational customers. We capture bounded rationality using a framework<br />
in which better decisions are made more often, while the best decision needs not<br />
always be made.<br />
3 - Hyperbolic Discounting in a Service System: Implications for Pricing<br />
& Information Provision<br />
Erica Plambeck, Professor, Stanford Graduate School of Business, 518<br />
Memorial Way, Stanford, CA, 94305, United States of America,<br />
plambeck_erica@GSB.Stanford.Edu, Qiong Wang<br />
People often lack the self control to undergo an unpleasant service that would be in<br />
their long-run self interest. This “hyperbolic discounting” has implications for<br />
optimal pricing, scheduling and whether or not to give a customer real-time<br />
information about how long he must wait to complete service.<br />
4 - Advance Selling When Consumers Regret<br />
Javad Nasiry, HKUST, Clear Water Bay, Kowloon, Hong Kong, Hong<br />
Kong, Hong Kong - PRC, Javad.NASIRY@insead.edu, Ioana Popescu<br />
We develop a model to capture the emotional consequences of decision making<br />
under uncertainty. Negative outcomes trigger regret as consumers reflect ex-post<br />
what would have been had they decided alternatively. We investigate how regret<br />
affects consumers’ behavior and how firms can account for consumer regret in<br />
designing their pricing policies.<br />
■ WD10<br />
C - Room 12A, Level 4<br />
Pricing Issues in Supply Chain Management<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Srinagesh Gavirneni, Cornell University, 325 Sage Hall, Ithaca, NY,<br />
14853, United States of America, nagesh@cornell.edu<br />
1 - Pricing and Logistics Decisions for a Private-Sector Provider in the<br />
Cash Supply Chain<br />
Mili Mehrotra, Assistant Professor, University of Minnesota, 321<br />
19th Ave. S, Carlson School of Management, Minneapolis, MN,<br />
United States of America, milim@umn.edu, Vijay Mookerjee,<br />
Chelliah Sriskandarajah, Milind Dawande<br />
For secure-logistics providers, the Fed’s cash recirculation policy presents an<br />
opportunity to offer fit-sorting services to Depository Institutions. We address the<br />
logistics and joint pricing of the new fit-sorting and the traditional transportation<br />
services. We characterize the behavior of the optimal prices and quantify the impact<br />
of the logistics network.<br />
2 - The Multi-Product Newsvendor Problem with<br />
Customer-Driven Substitution<br />
Joonkyum Lee, Cornell University, 301A Sage Hall, Cornell<br />
University, Ithaca, NY, 14853, United States of America,<br />
jl883@cornell.edu, Amr Farahat<br />
We study the stocking problem faced by a newsvendor offering multiple<br />
substitutable products where a customer’s probability of choosing any given product<br />
depends on the set of available products at the time of purchase. We present a<br />
tractable method that is guaranteed to yield an upper bound on the optimal<br />
expected profit. Numerical tests show that the true expected profits of the solutions<br />
obtained typically lie within a few percentage points of the upper bound and often<br />
outperform benchmarks.<br />
3 - Robust Pricing with Two Substitutable Products<br />
Zhi-Long Chen, Professor, University of Maryland,<br />
Robert H. Smith School of Business, College Park, MD, 20742,<br />
United States of America, ZChen@rhsmith.umd.edu, Ming Chen<br />
We study a dynamic pricing problem involving two substitutable products. Given<br />
limited demand information, we use three types of bounds to model demand<br />
uncertainty. We propose a robust optimization approach for the problem and<br />
develop a fully-polynomial time approximation scheme based on a DP formulation.<br />
We report computational results and related managerial insights on how the optimal<br />
prices change with model parameters.
WD11<br />
4 - Quality, Inspection, and Pricing Policies in Supply Chains<br />
Murat Erkoc, Assistant Professor, University of Miami, Miami, FL,<br />
United States of America, merkoc@miami.edu, Haresh Gurnani<br />
We consider a decentralized supply chain where market demand depends on the<br />
supplier’s quality investment and the buyer’s inspection policies. The supplier<br />
chooses the quality level and the wholesale price, whereas the buyer sets the<br />
inspection policy and the resale price. Building quality raises costs for the supplier<br />
and inspection is costly for the buyer. However, they reduce external and internal<br />
failure costs. We investigate equilibrium quality investment, inspection, and pricing<br />
policies.<br />
■ WD11<br />
C - Room 12B, Level 4<br />
Green Supply Chains<br />
Sponsor: Manufacturing and Service Operations Management<br />
Sponsored Session<br />
Chair: Feryal Erhun, Stanford University, 380 Panama St, Stanford, CA,<br />
94305, United States of America, ferhun@stanford.edu<br />
Co-Chair: Tim Kraft, Stanford University, 920 South California Avenue,<br />
Palo Alto, CA, 94306, United States of America, tkraft@stanford.edu<br />
1 - Effect of Carbon Emission Regulations on Transport Mode Selection<br />
in Supply Chains<br />
Tarkan Tan, T.Tan@tue.nl, Kristel Hoen, Jan Fransoo,<br />
Geert-Jan Van Houtum<br />
We investigate the effect of two regulation mechanisms to drive down carbon<br />
emissions on the transport mode selection decision: an emission cost and an<br />
emission constraint. We use an accurate calculation method to determine the<br />
carbon emissions and incorporate them explicitly in our model. Our results show<br />
that introducing an emission cost for freight transport, e.g. via a market mechanism<br />
such as cap-and-trade, will not result in large emission reductions.<br />
2 - The Carbon-Constrained EOQ<br />
Saif Benjaafar, Professor, University of Minnesota, 111 Church Street<br />
SE, Minneapolis, United States of America, saif@umn.edu, Xi Chen<br />
We examine the impact of carbon emission consideration on the management of<br />
inventory systems. We do so in the context of the classic economic order quantity<br />
model (EOQ). We incorporate carbon emission considerations by accounting for<br />
emissions associated with ordering, purchasing, inventory holding, and sales. We<br />
examine how different emission control policies (such as strict caps, carbon taxes,<br />
and carbon trading) affect ordering decisions and the corresponding costs and<br />
emission levels.<br />
3 - Replacement Decisions for Potentially Hazardous Substances<br />
Tim Kraft, Stanford University, 920 South California Avenue, Palo<br />
Alto, CA, 94306, United States of America, tkraft@stanford.edu,<br />
Dariush Rafinejad, Feryal Erhun, Robert Carlson<br />
As public awareness of environmental hazards increases, a growing concern for<br />
firms is the negative environmental impact of their products. We study the decisions<br />
of firms and stakeholders when a substance within a product is considered<br />
potentially hazardous. We find large firms should plan their replacement decisions<br />
to avoid costs, while small firms should invest to establish niche market positions. In<br />
addition, NGOs and regulatory bodies should take a pragmatic approach when<br />
pressuring firms.<br />
■ WD12<br />
C - Room 13A, Level 4<br />
Different Approaches to Demand Management in Retail<br />
Sponsor: Manufacturing and Service Operations Management/<br />
Supply Chain<br />
Sponsored Session<br />
Chair: Gilvan Souza, Associate Professor, Indiana University, Kelley<br />
School of Business, 1309 E 10th St, Bloomington, IN, 47401, United<br />
States of America, gsouza@indiana.edu<br />
1 - Shelf Loathing: Cross Docking at an Online Retailer<br />
Kyle Cattani, Associate Professor, Indiana University, Kelley School<br />
of Business, 1309 E 10th St, Bloomington, IN, 47405, United States<br />
of America, kcattani@indiana.edu, Gilvan Souza, Shengqi Ye<br />
We analyze basic trade-offs inherent in cross-docking transactions at an online<br />
retailer. Rather than picking the item from inventory on the warehouse shelves, in<br />
a cross-docking transaction the item moves directly from the receiving dock to the<br />
shipping dock. While the cross-docking transaction reduces the shelving and picking<br />
costs, it potentially increases holding costs and risks changing the customer’s<br />
expectations for how soon a product will be delivered.<br />
INFORMS Austin – 2010<br />
438<br />
2 - The Impact of Category Captainship on Retail Assortment<br />
and Consumers<br />
Mumin Kurtulus, Assistant Professor, Vanderbilt University,<br />
Owen Graduate School of Management, 401 21st Avenue South,<br />
Nashville, TN, 37203, United States of America,<br />
mumin.kurtulus@owen.vanderbilt.edu, Alper Nakkas<br />
Category captainship is a practice where a retailer relies on one of the leading<br />
manufacturers in the category for recommendations on retail assortment. In this<br />
paper, we investigate the impact of category captainship on the assortment offered<br />
at the retailer and its impact on the consumers. We identify the conditions under<br />
which category captainship practices can hurt the consumers.<br />
3 - Pricing Policy in a Supply Chain: Negotiation or Posted Pricing?<br />
Goker Aydin, Associate Professor, Indiana University, Kelley School<br />
of Business, Bloomington, IN, 47405, United States of America,<br />
ayding@indiana.edu, Hyun-Soo Ahn, Chia-wei Kuo<br />
This paper examines the choice between posted pricing and negotiation when<br />
selling to the end customers. We find that the retailer and the manufacturer<br />
disagree only when the retailer prefers posted pricing, but the manufacturer wishes<br />
the retailer to use negotiation. Such friction arises when the capacity or the cost of<br />
negotiation is moderate. Surprisingly, in this region of friction, a decrease in capacity<br />
or an increase in negotiation costs translates into higher profit for the retailer.<br />
4 - Motivating Marketing Effort Under Price Delegation: Optimal Retail<br />
Contract Design<br />
Shanshan Hu, Asst Professor, Indiana University, Kelley School of<br />
Business, 1309 E 10th St, Bloomington, IN, 47405, United States of<br />
America, hush@indiana.edu, Wenbin Wang, Xinxin Hu,<br />
Robert Jacobs<br />
Motivated by the interaction between an appliance manufacturer and its regional<br />
retailers, this paper investigates the contract design problem for the manufacturer.<br />
We provide answers to three related questions: (a) how to elicit actual demand<br />
information from the retailer, (b) how to motivate retailer to promote sales, and (c)<br />
how to construct the contract through relatively simple terms used in practice.<br />
■ WD15<br />
C - Room 15, Level 4<br />
Organization Theory II<br />
Contributed Session<br />
Chair: Christopher Rump, Associate Professor, Bowling Green State<br />
University, Applied Statistics & Operations Research, Bowling Green, OH,<br />
43403, United States of America, cmrump@bgsu.edu<br />
1 - Assembly of Successful Teams: Insights From the<br />
Study of MMORPGs<br />
Mengxiao Zhu, Northwestern University, 2145 Sheridan Rd, C210,<br />
Evanston, IL, 60208, United States of America,<br />
mzhu@northwestern.edu, Noshir Contractor, Seyed Iravani<br />
Teamwork is crucial to accomplish difficult tasks successfully and efficiently. This<br />
paper investigated the influence of compositional and structural factors on team<br />
performance. Compositional factors are related to the attributes of team members,<br />
such as expertise diversity and demographic homophily. Structural factors measure<br />
the intra/inter team social structures of formal and informal relations. An analysis of<br />
MMORPG combat teams identifies the impact of these factors on team performance.<br />
2 - Developing Innovative Capabilities in Biotechnology Firms:<br />
Internal Building and External Leveraging<br />
Yuanyuan Wu, Doctoral Student, McGill University, Desautels<br />
Faculty of Management, 1001 Sherbrooke Street W., Montreal, QC,<br />
H3A1G5, Canada, yuanyuan.wu@mail.mcgill.ca, Paola Perez-Aleman<br />
This paper explores the initiation and development of innovative capabilities in<br />
Montreal-based biotech firms through a multiple-case study design. The existing<br />
literature separately focuses on internal resources or network leveraging. By<br />
contrast, this study combines these two aspects, and uncovers different implications<br />
of the combination on the path and pace of capability development. The results<br />
extend the role of collaboration in firms with different nature and timing patterns.<br />
3 - The Evolution of Product Categories: How ‘Spaghetti’ Western<br />
Impacted American Western Movies<br />
Moritz Fliescher, PhD Candidate, New York University, Leonard N.<br />
Stern School of Business, 44 West 4th Street, Room 7-157,<br />
New York, NY, 10012, United States of America,<br />
moritz.fliescher@stern.nyu.edu, Gino Cattani<br />
We add to the category dynamics literature by arguing that established categories<br />
can evolve. We argue that categories that have an overlapping schema for their<br />
respective labels have the potential to influence each other. We propose that<br />
innovations of one category can drive the evolution of another category through<br />
audience legitimization. We highlight one empirical instance of this by looking at<br />
the influence of western movies produced in Europe on the meaning of the Western<br />
genre in the US.
4 - Towards a Systematic Understanding of How Interest-affiliated<br />
Actors Impact Technology Trajectories<br />
Theodore Khoury, Oregon State University, Bexell 422B, Corvallis,<br />
OR, 97331, United States of America,<br />
ted.khoury@bus.oregonstate.edu, Desiree F. Pacheco<br />
How do specific actors change technology trajectories? Focusing on actors with<br />
specific interest-affiliations that are impactful to innovation paths, we propose how<br />
the strategic actions available to a specific actor’s position can alter the diffusion of<br />
technological innovations over time. We reinforce our proposed theory with clean<br />
energy technology illustrations, and consider various influential actor positions in<br />
both market and non-market roles.<br />
5 - Constrained Clustering for Departmental Reorganization<br />
Christopher Rump, Associate Professor, Bowling Green State<br />
University, Applied Statistics & Operations Research, Bowling Green,<br />
OH, 43403, United States of America, cmrump@bgsu.edu<br />
Using data collected from a questionnaire asking how faculty viewed their<br />
connection to other disciplines in the College of Business, we employed an<br />
optimization model to reorganize into fewer departmental clusters in order to rectify<br />
large disparities that have developed over time between departmental faculty sizes.<br />
We compare these results to those found via traditional hierarchical clustering<br />
models as well as ad-hoc groupings proposed by members of the college Faculty<br />
Council.<br />
■ WD16<br />
C - Room 16A, Level 4<br />
Managing Product Variety<br />
Contributed Session<br />
Chair: Muge Yayla-Kullu, Asst. Prof., RPI, Lally School of Mgmt., 110 8th<br />
St., Troy, NY, 12180, United States of America, YAYLAH@rpi.edu<br />
1 - Allocating Capacity Among Quality Differentiated Products:<br />
Evidence From Airline Industry<br />
Praowpan Tansitpong, RPI, 110 8th St, Troy,<br />
United States of America, tansip@rpi.edu, Muge Yayla-Kullu<br />
This paper explores how the customer perceived quality and the resource<br />
consumption differences of the products may impact the product line and capacity<br />
allocation decisions of the firms. We empirically investigate the airline industry in<br />
three regions of the world; Asia Pacific, EMEA and North America. We find that<br />
both attributes have a significant impact in all the regions.<br />
2 - A Unified Framework for Planning a Platform Achieving Both<br />
Strategic and Operational Benefits<br />
Changmuk Kang, Ph.D Student, Seoul National University, 599<br />
Kwanakro, Kwanakgu, Seoul, Korea, Republic of, muk83@snu.ac.kr,<br />
Yoo S. Hong<br />
Whereas operational benefit of platform sharing, which is reducing differentiation<br />
cost, has been well known, its strategic role of establishing commonly preferred<br />
identity has less been noticed in literature. This study presents a unified framework<br />
for planning a product platform meeting a firm’s strategic goals of both identity<br />
establishment and efficient variety offering. A quality function deployment and<br />
versatility index based approach is applied to identify appropriate platform<br />
components.<br />
3 - Assortment Planning with Multiple Quality Levels: A Dynamic<br />
Programming Approach<br />
Mark McElreath, Clemson University, 150 Freeman Hall, Clemson,<br />
SC, 29634, United States of America, mmcelre@clemson.edu,<br />
Maria Mayorga<br />
The optimal solution to the assortment planning problem with vertical and<br />
horizontal differentiation in which consumer preference is described by a locational<br />
choice model is unknown. We propose a two part solution: a dynamic program to<br />
find the optimal vertical attributes embedded into a line search to find the optimal<br />
horizontal attributes. We compare our approach to metaheuristics, explore the<br />
optimal solution space, and provide insight into the properties of an optimal<br />
assortment.<br />
4 - Product Variety, Out-Of-Stock, and Sales<br />
Xiang Wan, University of Maryland, Van Munching Hall 3354,<br />
College Park, MD, 20742, United States of America,<br />
xwan@rhsmith.umd.edu, Martin Dresner, Philip Evers<br />
Product variety has been analyzed by an extensive body of literature. High product<br />
variety stimulates sales, while it raises the difficulty of logistics management and<br />
reduces sales. This paper proposes a framework to investigate the direct and indirect<br />
(through logistics performance) impacts on sales. The results indicate that the<br />
influence of product variety on sales depends on variety in both the degree and<br />
dimensions.<br />
INFORMS Austin – 2010 WD18<br />
439<br />
■ WD17<br />
C - Room 16B, Level 4<br />
Manufacturing III<br />
Contributed Session<br />
Chair: Zulal Gungor, Prof., Gazi University, Maltepe, Ankara, Turkey,<br />
zulalg@gazi.edu.tr<br />
1 - Total Productive Maintenance Policy Framework and<br />
Implementation of 5s Rules<br />
Bahar Ozyoruk, Assistant Prof.Dr., Gazi University, Faculty of<br />
Egineering, Department of Industrial Engineering Maltepe, Ankara,<br />
06570, Turkey, bahar@gazi.edu.tr<br />
Total Productive Maintenance (TPM) has attracted the attention of industries all<br />
over the world. Many companies benefit from this policy by increasing the overall<br />
efficiency of machine is trying to use existing capacity more efficiently. In this study,<br />
a firm which produces foam in the process of transition to implement TPM and 5S<br />
implementation of the rules are discussed. The results obtained were presented as<br />
comparatively.<br />
2 - Multi-objective Decision Making (MODM) Approach in Optimizing<br />
Product Design by the Help of House of Quality: A Case Study<br />
Zulal Gungor, Prof., Gazi University, Maltepe, Ankara, Turkey,<br />
zulalg@gazi.edu.tr, Elif Kilic<br />
In practice, the values of design requirements (DRs) having only a few alternatives<br />
can be discrete in the Quality Function Deployment. We propose a Mixed Integer<br />
Goal Programming (MIGP) formulation to get the optimum solution from a limited<br />
number of DRs alternatives. The solution of MIGP model provides decision makers<br />
with different alternative results by the usage of the lexicographic goal<br />
programming (LGP) approach. The applicability of the proposed models is<br />
demonstrated with a problem.<br />
■ WD18<br />
C - Room 17A, Level 4<br />
Business Applications<br />
Contributed Session<br />
Chair: Alba Bonko, President, Biz Intelligence Solutions, LLC, 9737 NW<br />
41st Street, Miami, FL, 33178, United States of America,<br />
alba_n_nunez@hotmail.com<br />
1 - Work as a Love Object. A New Framework for Analyzing the<br />
Work-self Relation<br />
Brad Almond, Assistant Professor of Management, Texas A&M<br />
University, Division of Business, 1901 S. Clear Creek Rd., Killeen,<br />
TX, 76549, United States of America, brad.almond@ct.tamus.edu<br />
Building on popular fascination with the idea of “loving what you do,” this paper<br />
explores how work functions as a love object by developing a multi-dimensional<br />
model and testing its structure and relation to key work outcomes using factor<br />
analysis and structural equation modeling. Explores implications for management<br />
and organizations.<br />
2 - Allocation of Bulk Tanks to Customer Sites<br />
Tejinder Pal Singh, Sr. Research Associate, American Air Liquide,<br />
12800 W. Little York Rd, Houston, TX, 770941, United States of<br />
America, tejinder.singh@airliquide.com, Kimberly Ellis<br />
Bulk tank allocation (BTA) problem consists of allocation of tanks to customer sites<br />
for distribution of gases. Distribution is based mainly on Vendor Managed Inventory<br />
(VMI) model. In BTA problem, the goal is to minimize the distribution costs by<br />
having right tank sizes at customer sites. A right tank size at a customer will ensure<br />
that the customer doesn’t run out of the product often and at the same time doesn’t<br />
need deliveries frequently.<br />
3 - Optimal Contract Problems in Online Advertising with<br />
Risk Considerations<br />
Md. Tanveer Ahmed, University at Buffalo, SUNY, 333 Bell Hall,<br />
Buffalo, NY, 14260, United States of America,<br />
mtahmed@buffalo.edu, Changhyun Kwon<br />
In this paper, we study the optimal contract problem for online display<br />
advertisements with pay-per-view pricing scheme. We first provide and analyze a<br />
single contract model, which is shown to be equivalent to the newsvendor problem.<br />
We then consider a stochastic optimization problem with two different contracts and<br />
show that no mixed contract is optimal. However, we show that a mixed strategy<br />
may be optimal when we consider the risk attitude of the publisher.
WD19<br />
4 - Development of a Global Part Sourcing Optimization Model with<br />
Currency Risk Analysis<br />
Don Zhang, Cost Optimization Analyst, Ford Motor Company, 2101<br />
Village Rd., Dearborn, MI, 48121, United States of America,<br />
xzhang35@ford.com, Mark Everson, Leonardo Vaquero,<br />
Dawn Gontko, David Shepps<br />
Ford Motor Company operates globally across six continents. Under the “One Ford”<br />
initiative, Ford has been leveraging increased economies of scale. One of these<br />
efforts is to source globally the common parts shared by many vehicle programs. We<br />
have developed a mixed integer programming optimization model and exchange<br />
rate risk assessment methodology to optimize sourcing decisions. We will discuss<br />
our approach for deciding the optimal sourcing decisions and risk assessment for<br />
various scenarios.<br />
5 - Continuous Improvement and Efficiency Training:<br />
Challenges and Opportunities<br />
Alba Bonko, President, Biz Intelligence Solutions, LLC, 9737 NW<br />
41st Street, Miami, FL, 33178, United States of America,<br />
alba_n_nunez@hotmail.com, Rebeca Lergier, Martha Centeno<br />
We discuss paradigms used in training courses, and highlight some of their strengths<br />
and weakness. Training courses paradigms range from the “recipe” to the<br />
“academic”. The former disregards foundations of the methods, whereas the latter<br />
fails to show practical applications. We propose a scheme that is enterprise-centered,<br />
so that practicing professionals can effectively use quantitative methods, and with<br />
management policies, as part of the continuous improvement cycle of the<br />
enterprise.<br />
■ WD19<br />
C - Room 17B, Level 4<br />
Practical Applications of Pricing and RM Theory<br />
Sponsor: Revenue Management and Pricing Section<br />
Sponsored Session<br />
Chair: Scot Hornick, Partner, Oliver Wyman, 155 N. Wacker Drive,<br />
16th Floor, Chicago, IL, 60606, United States of America,<br />
Scot.Hornick@oliverwyman.com<br />
1 - Market-Response-Based Inventory Management for Airlines<br />
and Hotels<br />
James Rider, Associate Partner, Oliver Wyman, 55 Baker Street,<br />
London, W1U 8EW, United Kingdom,<br />
James.Rider@OliverWyman.com, Jessica McLaughlin, Bejugum Rao,<br />
Daniel Sack<br />
Most of the prevalent seat and room inventory management methods are no longer<br />
adequate to serve the needs of today’s dynamic marketplace. In our novel Market<br />
Response-Based Inventory Management (MRBIM) approach, we generate<br />
recommendations for pricing and availability decisions by taking into account<br />
dynamic marketplace data. Demand is managed more effectively by understanding<br />
customer’s willingness to pay and knowing prevailing competitor prices and<br />
availability. Revenue is maximized by adjusting own fares/rates and availability,<br />
possibly multiple times a day. To facilitate MRBIM implementation, we developed<br />
statistical methods to estimate demand parameters with data that is likely to be<br />
readily available at a typical airline or hotel company. We developed approaches to<br />
interface with current inventory allocation models. Piloting of MRBIM approach at<br />
multiple airlines has revealed consistent revenue benefits.<br />
2 - Dynamic Pricing for Aftermarket Auto Parts<br />
Bruce Spear, Associate Partner, Oliver Wyman, 1166 Avenue of the<br />
Americas, New York, NY, 10036, United States of America,<br />
Bruce.Spear@OliverWyman.com, Todd Ebe, Bejugum Rao<br />
We present an application of dynamic pricing at an auto-glass wholesaler. We<br />
estimate customer’s sensitivity to the wholesaler’s price by customer type, part type<br />
and geography. We determine optimal prices that maximize the wholesaler’s<br />
contribution, i.e. revenue minus cost of goods sold, knowing competitors’ prices. We<br />
show the revenue benefits (>4%) due to optimal prices evaluated in a test-control<br />
setting. We discuss data and measurement challenges. Our future efforts will include<br />
extending the approach to retail auto-glass business as well as optimizing part prices<br />
by considering own and competitor inventory levels.<br />
3 - Revenue Management Concepts for Freight Railways Practicing<br />
Dynamic Routing<br />
Marc Meketon, Oliver Wyman, 212 Carnegie Center, Princeton, NJ,<br />
08540, United States of America, Marc.Meketon@oliverwyman.com,<br />
David Lehlbach<br />
Most railways world-wide operate on a fixed scheduling plan that allows only one<br />
route per railcar. However, as railways begin to plan their next generation of carscheduling<br />
systems, they should consider the possibility of dynamic train scheduling<br />
that changes the operating plan and the rules for routing cars dynamically. As a<br />
simple example, when faced with capacity limitations in a certain corridor, it may<br />
make sense to divert some cars to an alternate route. While dynamic planning could<br />
increase efficiencies, it could also change customer service. Some customers could<br />
INFORMS Austin – 2010<br />
440<br />
get shorter transit times, others longer. Since service levels change, any move<br />
towards dynamic planning should involve pricing and revenue management<br />
considerations. This talk discusses a number of these considerations and gives<br />
guidance to railways looking to make the jump to the next level of planning.<br />
■ WD20<br />
C - Room 18A, Level 4<br />
Pricing and Revenue Management III<br />
Contributed Session<br />
Chair: Dincer Konur, PhD Candidate, University of Florida,<br />
Industrial and Systems Engineering Department, Gainesville, FL, 32611,<br />
United States of America, dincer@ufl.edu<br />
1 - A Segmentation Study in Applying Revenue Management to the<br />
Hospitality Industry<br />
Murtaza Das, The Rainmaker Group, 5755 North Point Parkway,<br />
Alpharetta, GA, 30022, United States of America,<br />
murtazadas@gmail.com, Renaud Menard<br />
Segmentation is a fundamental step in applying revenue management and pricing<br />
which directly impacts forecasting accuracy, and thus revenue optimization. While<br />
forecast accuracy and revenue optimization are paramount to a sound revenue<br />
management strategy, operational limitations should also be considered in the<br />
segmentation analysis. We review the current approaches of segmentation in the<br />
hospitality RM industry, present simulation results, and point out challenges.<br />
2 - A Statistical Methodology to Find Segment Level Parameters using<br />
Aggregate Level Data<br />
Hamed Hasheminia, Sauder School of Business-UBC,<br />
2053 Main Mall, Vancouver, BC, V6Z2T9, Canada,<br />
hamed.hasheminia@sauder.ubc.ca, David Gillen<br />
We develop a novel statistical procedure to estimate segmental demand functions<br />
from aggregate level data. To achieve our result we combine the invaluable<br />
information hidden in integer numbers, characteristics of integer numbers, and use<br />
MLE to estimate parameters at the segment level. The method is applied to estimate<br />
how demands for different segments of passengers (i.e. single passengers, couples,<br />
and so forth) are affected by price, time to the flight, etc.<br />
3 - Modeling Supplier Wholesale Pricing Decisions with Competitive<br />
Buyers Under Cournot Competition<br />
Dincer Konur, PhD Candidate, University of Florida, Industrial and<br />
Systems Engineering Department, Gainesville, FL, 32611,<br />
United States of America, dincer@ufl.edu, Joseph Geunes<br />
We model a supplier’s wholesale pricing decision for competitive non-identical<br />
buyers as a Stackelberg game. To determine a Stackelberg equilibrium, we first solve<br />
the buyers’ game and analyze the buyers’ quantity decisions under two different<br />
cooperation levels. We then determine the supplier’s optimal wholesale price, and<br />
conduct numerical studies to characterize the value of the information to the<br />
supplier, as well as the effects of buyer and market heterogeneity.<br />
■ WD22<br />
C - Room 18C, Level 4<br />
Service System Development<br />
Sponsor: Service Science<br />
Sponsored Session<br />
Chair: Ari P.J. Vepsalainen, Professor, Aalto University School of<br />
Economics, Department of Business Technology, P.O. Box 21220,<br />
Helsinki, 00076, Finland, ari.vepsalainen@hse.fi<br />
1 - Functional Selection of Business Processes - Who Works<br />
for the Market?<br />
Ari P.J. Vepsalainen, Professor, Aalto University School of Economics,<br />
Department of Business Technology, P.O. Box 21220, Helsinki,<br />
00076, Finland, ari.vepsalainen@hse.fi, Mika Raulas,<br />
Markku Tinnilä, Jukka Kallio<br />
The analysis of the functional needs of different communities and market processes<br />
highlights the full market potential of service development. With extreme functional<br />
specialization, companies and workers will be providing narrower service to<br />
increasing number and variety of market activities and communities. Our case<br />
studies illustrate the working conditions of functional selection and the potential coevolution<br />
of private, public and commercial institutions.
2 - Dynamic Policies in Knowledge-Based Service System with<br />
Feedback Information<br />
Qifeng Shao, Northwestern University, 2145 Sheridan RD, IEMS<br />
C210, Evanston, IL, 60208, United States of America,<br />
qshao@northwestern.edu, Seyed Iravani<br />
We propose a modeling framework of a knowledge based service system with an<br />
information feedback mechanism. The feedback system provides information<br />
regards correctness of the agent’s decisions. With help from the feedback system, the<br />
agent adjusts processing strategies to deal with information crises that can change<br />
the state of arrival customers. Besides the optimal strategy, we examined several<br />
heuristics and found one effective policy with a simple threshold design.<br />
3 - A Simulation Based Framework for Service Facility Internal<br />
Layout Design<br />
Ming Xie, IBM Research - China, Diamond Building, ZGC Software<br />
Park, Beijing, China, xieming@cn.ibm.com, Jinyan Shao, Bin Zhang,<br />
Wenjun Yin, Jin Dong<br />
Service facilities, including bank branches, supermarkets, etc. are closely related to<br />
our lives. Whereas, it is a difficult task to make decisions on how to design internal<br />
layout and configuration for them. In this paper, we propose a service facility<br />
internal layout optimization framework as well as how to model the system into a<br />
multi-agent system. Then, a bank branch scenario from real world is adopted to<br />
demonstrate the methodology and implementation.<br />
■ WD23<br />
C - Room 18D, Level 4<br />
Retail Managment<br />
Contributed Session<br />
Chair: Mahesh Kumar, Assistant Professor, R.H. Smith School of Business,<br />
University of Maryland, 4321 Van Munching Hall, College Park, MD,<br />
20742, United States of America, kumarmahesh@gmail.com<br />
1 - Assortment Planning of Configurable Products<br />
Edward Umpfenbach, PhD Student, Wayne State University,<br />
20011 12 Mile, Roseville, MI, 48066, United States of America,<br />
as6964@wayne.edu, Alper Murat, Ratna Babu Chinnam<br />
Considerable work has been done to optimize the assortments of high sales density<br />
products. We introduce a method to estimate demand and substitution parameters<br />
of a configurable product given sales data, then solve a joint supply chain planning<br />
and assortment planning problem.<br />
2 - The Impact of Execution Errors on Inventory Record Inaccuracy and<br />
Retail Out-Of-Stock<br />
Howard Hao-Chun Chuang, Doctoral Student, Mays Business<br />
School, Texas A&M University, Wehner 301C - TAMU 4217,<br />
College Station, TX, 77840, United States of America,<br />
hchuang@mays.tamu.edu, Rogelio Oliva<br />
We model a continuous (Q,R) inventory system and analyze the impact of<br />
execution errors on inventory record inaccuracy and retail out of stock. The<br />
existence of multiple errors could disrupt ordering decisions and reduce on-shelf<br />
availability. We formalize the argument analytically and develop a system dynamics<br />
model. We perform Monte-Carlo sensitivity simulation to identify the most costly<br />
execution errors. Then we provide suggestions to improve operational accuracy<br />
within a retail store.<br />
3 - A Pooling Procedure to Improve Sales Forecasts for Retail Fashion<br />
Goods with Limited Past Sales Data<br />
Mahesh Kumar, Assistant Professor, R.H. Smith School of Business,<br />
University of Maryland, 4321 Van Munching Hall, College Park, MD,<br />
20742, United States of America, kumarmahesh@gmail.com<br />
Most sales forecasting methods are likely to perform poorly if only a small amount<br />
of past sales data is available for analysis. The situation is common for new fashion<br />
items in a store, especially during the early weeks of a selling season. We overcome<br />
this limitation of a forecasting method by pooling data from groups of similar items<br />
using a two-step clustering procedure. The new procedure is flexible to use and is<br />
computationally fast. Its effectiveness is demonstrated on a real-world data.<br />
INFORMS Austin – 2010 WD24<br />
441<br />
■ WD24<br />
C - Room 19A, Level 4<br />
Joint Session SPPSN/ TSL: Decision Support for<br />
Emergency Response and Public Safety<br />
Sponsor: Public Programs, Service and Needs/ Transportation<br />
Science and Logistics Society<br />
Sponsored Session<br />
Chair: Alex Savachkin, Assistant Professor, University of South Florida,<br />
4202 E. Fowler Avenue ENB 118, Tampa, FL, 33620, United States of<br />
America, alexs@usf.edu<br />
1 - Non-Pharmaceutical Interventions (NPI) for the Mitigation of<br />
Pandemic Influenza<br />
Dayna Martinez, Doctoral student, University of South Florida,<br />
Tampa, FL, 33620, United States of America, dlmartin@mail.usf.edu,<br />
Tapas K. Das, Alex Savachkin<br />
In the event of an influenza pandemic, non-pharmaceutical interventions (NPI),<br />
such as social distancing, will likely be the only effective containment measure<br />
available in the early phase of the pandemic. In this research, we examine various<br />
NPI strategies, such as quarantine of isolated cases, household quarantine, school<br />
and workplace closures, and study their effect on the infection attack rate and the<br />
societal and economic cost of the pandemic.<br />
2 - Developing an Agent-based Model for Poliovirus Transmissions for<br />
Post-eradication Outbreak Response<br />
Hazhir Rahmandad, Assistant Professor, Virginia Tech, 7054 Haycock<br />
Rd., room 430, falls church, va, 22043, United States of America,<br />
hazhir@vt.edu, Kimberly Thompson, Radboud Duintjer-Tebbens,<br />
Kun Hu<br />
Given the possibility of reintroductions of live polioviruses into communities after<br />
eradication, designing effective and efficient responses to potential outbreaks is<br />
necessary. In this study we develop an individual-based simulation model of<br />
poliovirus transmission dynamics in a population and use this model the explore<br />
alternative response strategies. We also explore the importance of different<br />
assumptions with regard to human contact network and transmission mechanisms.<br />
3 - Agent-based Simulation of Mass Egress From Large Public Events:<br />
Current State and Next Steps<br />
Douglas A. Samuelson, President and Chief Scientist, InfoLogix, Inc.,<br />
Annandale, VA, United States of America,<br />
samuelsondoug@yahoo.com<br />
We review a variety of recent work on agent-based simulation of mass egress,<br />
especially from sports arenas, noting the capabilities, limitations and design<br />
compromises in some of the most interesting models. We then discuss next steps,<br />
including modeling group movement, movement by emergency responders,<br />
placement of treatment centers, effects of toxic air- and water-borne plumes, and<br />
integration of planning and training models with real-time crisis management<br />
information systems.<br />
4 - Decision Support Systems for Pandemic Influenza (PI) Surveillance<br />
Alfredo Santana-Reynoso, PhD Candidate, University of South<br />
Florida, 4202 E. Fowler Avenue ENB118, Tampa, FL, 33620,<br />
United States of America, asantan2@mail.usf.edu, Diana Prieto,<br />
Alex Savachkin, Sharad Malavade<br />
PI contingency plans have concentrated their efforts into a new virus strain of low<br />
transmissibility and high severity originated in SE Asia. The H1N1 2009 outbreak<br />
featured higher transmissibility and lower severity than expected, and was<br />
originated in North America. This presentation analyzes how these scenarios have<br />
been managed by the current PI surveillance systems. Robust multi-epoch decision<br />
support systems for PI surveillance adaptable to a more diverse range of situations<br />
are presented.
WD25<br />
■ WD25<br />
C - Room 19B, Level 4<br />
Transportation, Planning III<br />
Contributed Session<br />
Chair: Wei Fan, Assistant Professor, The University of Texas at Tyler,<br />
Department of Civil Engineering, 3900 University Blvd., Tyler, TX, 75799,<br />
United States of America, wfan@uttyler.edu<br />
1 - Expansion Planning of Road Networks via<br />
Agent-Based Optimization<br />
Alireza Kabirian, University of Alaska - Anchorage, Rasmuson Hall,<br />
Suite 318D, 3211 Providence Dr, Anchorage, AK, 99508,<br />
United States of America, a_kabirian@yahoo.com<br />
We develop optimization models and methodologies for expansion planning of an<br />
existing network of roads over a long-run horizon. Specifically, we aim at<br />
determining where and when new roads should be constructed and which and<br />
when old roads should be reconstructed to minimize public construction costs as<br />
well as travelers’ expenses. This decision support model helps transportation<br />
managers in public sector make comprehensive and data-driven decisions about<br />
expansion of road infrastructures.<br />
2 - The Changes in Users’ Perceptions on Transportation Problems in<br />
the Last 10 Years<br />
Xiaoyu Zhu, PhD Candidate, University of Florida, 365 Weil Hall,<br />
P.O. Box 116580, Gainesville, FL, 32611, United States of America,<br />
shuxy03@ufl.edu<br />
To improve the transportation system, it is important to understand the travelers’<br />
perceptions about transportation issues to assess user acceptance of the policies.<br />
With developments in transportation, the perceptions might change greatly in the<br />
last decade. To understand the people’s perceptions about the most important<br />
transportation issue will provide more information for value the project efficiency<br />
and public acceptance.<br />
3 - A Sensor-based Vehicle Routing Problem Algorithm<br />
Chrysafis Vogiatzis, University of Florida, Weil 303, Gainesville, FL,<br />
32611, United States of America, chvogiat@ufl.edu, Panos Pardalos<br />
Vehicle routing has always been a vital problem for transportation and traffic<br />
congestion. Throughout the years, solutions have been proposed but are usually<br />
hard to implement because of the continuous time nature of the problem, which<br />
cause alterations in conditions and constraints. We propose an online algorithm<br />
which searches for an optimal solution based on the input provided by vehicle to<br />
vehicle sensor communication using augmented lagrange relaxation.<br />
4 - Optimal Toll Design with Uncertain Demand<br />
Wei Fan, Assistant Professor, The University of Texas at Tyler,<br />
Department of Civil Engineering, 3900 University Blvd., Tyler, TX,<br />
75799, United States of America, wfan@uttyler.edu<br />
An optimal toll design problem (OTDP) under a second-best link based congestion<br />
pricing scheme is discussed in this presentation, in which the selection of both toll<br />
locations and toll levels needs to be optimally determined with uncertain demand. A<br />
bi-level optimization model is formulated and a simulation-based genetic algorithm<br />
procedure is proposed to solving the OTDP. Numerical results are presented and<br />
future research directions are also given.<br />
■ WD27<br />
C - Room 4B, Level 3<br />
Networks and Graphs<br />
Contributed Session<br />
Chair: Alex Sprintson, Assistant Professor, Texas A&M University, TAMU<br />
3128, College Station, 77843, United States of America, spalex@tamu.edu<br />
1 - Screen Sizes of Paths<br />
Anthony Harrison, Texas State University, 601 University Drive,<br />
San Marcos, United States of America, ah1411@txstate.edu,<br />
Nathaniel Dean<br />
Sphere of infuence graphs (SIGs) are a representation of spatial relationships<br />
between points. They can be useful in areas related to pattern matching. We<br />
consider a graph invariant for SIGS called the screen size. This is the smallest integer<br />
k such that a given SIG can be realized on a k by k grid. We find the screen size for<br />
paths and then explore integer programming formulations for the problem and<br />
explain some of the difficulties encountered with this approach.<br />
INFORMS Austin – 2010<br />
442<br />
2 - Reliable Networks That Can be Modeled by Graphs with Edge<br />
Connectivity Equal to Two<br />
Leandro Teixeira, Centro de Anàlises de Sistemas Navais, Praça Barao<br />
de Ladàrio, AMRJ , Centro, rio de janeiro, RJ, 20091-000, Brazil,<br />
leandrodteixeira@yahoo.com.br, Nair Abreu, Leonardo Lima<br />
Deterministic and probabilistic parameters can be used to measure the reliability of a<br />
graph that models a network. Consider that each node of the network is reliable<br />
and its failure is related to the probabilities of the edge failures of the graph when<br />
these probabilities occur randomly and independently. In this work, a class of graphs<br />
with maximum reliability among all graphs with edge connectivity equal to two is<br />
presented.<br />
3 - An Efficient Algorithm for the Distributed Data Retrieval Problem<br />
Alex Sprintson, Assistant Professor, Texas A&M University, TAMU<br />
3128, College Station, 77843, United States of America,<br />
spalex@tamu.edu, Zakia Asad, Mohammad Asad R Chaudhry<br />
We consider the problem of accessing large volumes of data stored on multiple<br />
locations across a storage network. We assume that data is stored in either original<br />
or encoded form on multiple servers across the network. Our goal is to find a set of<br />
disjoint paths of minimum total cost that connect the client with some of the servers<br />
across the network such that client is able to retrieve the required data. We present<br />
an efficient polynomial-time algorithm for this problem.<br />
4 - An Efficient Heuristic Algorithm for Minimum Labeling Spanning<br />
Tree Problem<br />
Kaveh Farokhi Sadabadi, Faculty Research Assistant, University of<br />
Maryland, ENCE Department, 1173 Glenn L. Martin Hall, College<br />
Park, MD, 20742, United States of America, kfarokhi@umd.edu,<br />
Ali Haghani<br />
We propose a heuristic algorithm to solve Generalized Minimum Labeling Spanning<br />
Tree problem. This is an NP hard problem with applications in telecommunications<br />
and network design. Many algorithms are proposed to solve GMLST. Maximum<br />
Vertex Covering (MVCA) and Genetic Algorithm (GA) are well-known. Global<br />
optimality of these methods is not guaranteed, nor are they efficient to deal with<br />
large problems. Reported examples show the efficiency and quality of the proposed<br />
method compared to others.<br />
■ WD28<br />
C - Room 4C, Level 3<br />
Computer Models: Prediction and Calibration<br />
Sponsor: Quality, Statistics and Reliability<br />
Sponsored Session<br />
Chair: Lulu Kang, Assistant Professor, Illinois Institute of Technology,<br />
Engineering 1 Building, Applied Math, 10 West 32nd Street, Chicago, IL,<br />
60616, United States of America<br />
1 - Model Calibration with Minimal Adjustments<br />
Chia-Jung Chang, PhD Student, Georgia Institute of Technology,<br />
755 Ferst Drive, Atlanta, GA, United States of America,<br />
cchang43@gatech.edu, Roshan Vengazhiyil<br />
Model calibration refers to estimating unknown parameters in a physics-based<br />
model from real data. When model assumption is violated, the estimates become<br />
inaccurate leading to poor model prediction. Besides, all works ignore the<br />
potentially important bias that can occur in the observations. In this work, we<br />
develop a methodology for calibrating the physical model in the presence of both<br />
model and experimental biases. Two real case studies are presented to demonstrate<br />
the prediction ability.<br />
2 - Improving Prediction by Integrating Analytical Models with Finite<br />
Element Models<br />
Shan Ba, Georgia Institue of Technology, 765 Ferst Drive, NW,<br />
Atlanta, GA, 30332, United States of America, shan.ba@gatech.edu,<br />
Roshan Vengazhiyil, Ramesh Singh<br />
For the micro grooving process, we develop an innovative two-step design of<br />
experiments approach to efficiently extract information from both the simple<br />
analytical force model and the complex finite element model. The simple but less<br />
accurate analytical model can be adjusted by data from the time-consuming finite<br />
element simulations, and finally forms an effective surrogate micromachining<br />
cutting model which is fast, accurate and economically viable to use.<br />
3 - Kernel Sum Regression and Interpolation<br />
Lulu Kang, Georgia Institute of Technology, Atlanta, GA, 30332,<br />
United States of America, lkang@isye.gatech.edu,<br />
Roshan Vengazhiyil<br />
In this paper, we propose a new nonparametric regression method, called kernel<br />
sum regression method. It utilizes iterative kernel regression to achieve better<br />
prediction accuracy. Meanwhile, if the the number of kernel regression goes to<br />
infinity, the kernel sum regression becomes an interpolation method. We also<br />
investigated some properties of the kernel sum regression and interpolation<br />
methods, and provide algorithm to estimate the bandwidth parameters.
■ WD29<br />
C - Room 5A, Level 3<br />
Quality Improvement in Complex Systems<br />
Sponsor: Quality, Statistics and Reliability<br />
Sponsored Session<br />
Chair: Ran Jin, Georgia Institute of Technology, 755 Ferst Dr. NW,<br />
Atlanta, United States of America, jinr@gatech.edu<br />
1 - Challenges of using Feature Selection Methods for<br />
Waveform Signals<br />
Nasim Arbabzadeh, Rutgers University, 23667 BPO WAY, Piscataway,<br />
NJ, 08854, United States of America, nasim@eden.rutgers.edu,<br />
Susan Albin<br />
Recent technological advances in data capture and processing result in highdimensional<br />
waveform signals, making the analysis difficult for the process<br />
engineers. Feature selection methods can be used to reduce the features to a<br />
manageable number. In this paper, different feature selection methods have been<br />
compared on several real datasets, including NIR spectra and vertical depth profile,<br />
and the impact of different sampling frequencies on their performances has been<br />
investigated.<br />
2 - Generalized Selective Assembly<br />
Matthias H Tan, Student, Jeff Wu/ Department of Industrial &<br />
Systems Engineering, Georgia Institute of Technology, 301 10th<br />
Street NW, Apt 208A, Atlanta, GA, 30318, United States of America,<br />
mtan6@gatech.edu, Jeff Wu<br />
This paper develops a generalized version of selective assembly, called GSA, for<br />
improving the quality of assemblies of single units of different component types.<br />
Two variants are considered: direct selective assembly, which uses measurements on<br />
component characteristics, and fixed bin selective assembly, which only requires<br />
sorting components into bins. We formulate the problem of matching N components<br />
of each type to give N assemblies that minimize quality cost as linear integer<br />
programs.<br />
3 - Relationship Between Seamless Tube Quality and Piercing<br />
Vibration Data<br />
Weidong Zhang, Vice Director and Associate Professor, National<br />
Cecter for Materials Service Safety,University of Science and<br />
Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing,<br />
100083, China, zwd@ustb.edu.cn, Ran Jin, Jianjun Shi<br />
We can get vibration data of seamless tube piercing by two cameras. There may be<br />
some relationship between quality of seamless tube and vibration data. We can find<br />
the relationship by system informatics method.<br />
■ WD30<br />
C - Room 5B, Level 3<br />
Statistics/Quality Control III<br />
Contributed Session<br />
Chair: David Han, Assistant Professor, University of Texas at San Antonio,<br />
One UTSA Circle, San Antonio, TX, 78249, United States of America,<br />
david.han@utsa.edu<br />
1 - A Variable Sampling Hotelling T2 Chart for Monitoring Simple Linear<br />
Quality Profiles<br />
Galal Abdella, PhD Student, Wayne State University, 4815 4th Street,<br />
Detroit, MI, 48202, United States of America, bb2941@wayne.edu,<br />
Kai Yang, Adel Alaeddini<br />
We design a variable sampling T2 scheme to enhance the detecting speed of offtarget<br />
conditions while keeping the total number of samples low. We constructed an<br />
optimization model solved by using the genetic algorithm. The performance of the<br />
proposed scheme is compared with its fixed sampling counterparts under different<br />
conditions.<br />
2 - Beta Model-based Control Chart for Fraction Monitoring<br />
Carla ten Caten, Profa. PhD., PPGEP/UFRGS, Av. Osvaldo Aranha,<br />
99 - 5° andar, Porto Alegre, RS, 90.035-190, Brazil,<br />
tencaten@producao.ufrgs.br, Angelo Sant’Anna, Michel Anzanello<br />
Modelo-based control charts often use multiple regression models. We propose a<br />
Beta model-based control chart (BMCC) for monitoring fraction that varies with the<br />
adjustment of control variables. The BMCC monitors deviances on Beta model’s<br />
residuals. We use sensitivity analysis to compared BMCC with Hawkins (1991) and<br />
Haworth’s(1996) methods.<br />
INFORMS Austin – 2010 WD31<br />
443<br />
3 - Analysis Methods for Non-regular Fractional Factorial Designs<br />
Shilpa Shinde, Arizona State University, 1249 E Spence Avenue<br />
Apt#343, tempe, AZ, 85281, United States of America,<br />
scvmadha@asu.edu, Douglas Montgomery<br />
Non-regular designs are very effective alternatives to regular fractional factorials.<br />
Their use is restricted due to the lack of robust analysis techniques. We present a<br />
new analysis and variable selection technique which will help identify significant<br />
effects in a non-regular design.<br />
4 - Exact Inference for Progressively Type-I Censored Exponential<br />
Failure Data<br />
David Han, Assistant Professor, University of Texas at San Antonio,<br />
One UTSA Circle, San Antonio, TX, 78249, United States of America,<br />
david.han@utsa.edu, N. Balakrishnan, G. Iliopoulos<br />
Progressively Type-I censored life-test is discussed under the assumption of<br />
exponential distribution. For small sample sizes, a practical modification is proposed<br />
to guarantee a feasible test under this scheme. We then obtain the exact sampling<br />
distribution of the MLE of the mean parameter under the condition ensuring its<br />
existence. Using the exact method as well as the asymptotic and bootstrap methods,<br />
we then discuss construction of confidence intervals and their performance via<br />
simulations.<br />
■ WD31<br />
C - Room 5C, Level 3<br />
Quality Management I<br />
Contributed Session<br />
Chair: Karl Majeske, Associate Professor of Quantitative Methods<br />
Management, Oakland University, School of Business Administration,<br />
Rochester, MI, 48309, United States of America, majeske2@oakland.edu<br />
1 - CUSUM Control Charts for Respiratory Syndromic Surveillance<br />
Huifen Chen, Professor, Chung-Yuan University, Department of<br />
Industrial and Systems Eng., Chung-Yuan University, Chungli, 320,<br />
Taiwan - ROC, huifen@cycu.edu.tw, Chaosian Huang<br />
This work applies CUSUM charts for detecting outbreaks of the respiratory<br />
syndrome. The data, daily ambulatory-care visits based on population of size 160<br />
thousand, are from Taiwan National Health Insurance Research Database. We<br />
construct a standardized CUSUM chart based on residuals of a fitted regression<br />
model with an ARMA error term using the 2005 and 2006 data. The CUSUM chart<br />
seems to be able to detect aberrations of respiratory syndrome when used to<br />
monitor the 2007 and 2008 data.<br />
2 - An Integrated Approach for Multivariate Process Control in<br />
Automobile Manufacturing<br />
Xiaoyu Ma, PhD Student, Industrial&manufacturing engineering<br />
department, wayne state university, 4815 4th Street, detroit, MI,<br />
48202, United States of America, eb1946@wayne.edu, Alper Murat,<br />
Kai Yang, Adel Alaeddini<br />
Increasing availability of multivariate process data demands us to develop effective<br />
analysis techniques. We developed a comprehensive approach that uses statistical<br />
and optimization techniques. It performs abnormal signal detection, influential<br />
features selection in optimized fashion during multivariate statistical control<br />
practice. This approach can help root cause analysis in automobile manufacturing<br />
process and examples with real data are presented.<br />
3 - Sustaining Quality Performance Through Collective Mindfulness<br />
Hung-Chung Su, Student, University of Minnesota, 3-150 321-19th<br />
Avenue South, Minneapolis, MN, 55455, United States of America,<br />
suxxx051@umn.edu, Kevin Linderman<br />
Organizational mindfulness is an emerging construct that has not receive enough<br />
attention in the quality management. We provide evidence of the five dimensions of<br />
organizational mindfulness and examine its impact on innovation, improvement<br />
and the reliability of quality performance. We discuss the implications for sustaining<br />
quality performance and possible contributions to the organizational learning and<br />
dynamic capability literature.<br />
4 - Dynamic Part Fitting to Improve Automotive Body Quality<br />
Karl Majeske, Associate Professor of Quantitative Methods<br />
Management, Oakland University, School of Business<br />
Administration, Rochester, MI, 48309, United States of America,<br />
majeske2@oakland.edu<br />
The gaps and flushness between assemblies, such as door-to-fender, represent a<br />
highly visible automotive body quality characteristic. Traditional design and<br />
assembly methods attach a door to the body by bolting hinges into established<br />
mounts. This technique uses vision system data to orient parts during final assembly<br />
to optimize quality.
WD33<br />
■ WD33<br />
C - Room 6B, Level 3<br />
Optimization Models in Data Mining with Applications<br />
in Biomedicine<br />
Sponsor: Computing Society<br />
Sponsored Session<br />
Chair: Petros Xanthopoulos, University of Florida, 303 Weil Hall,<br />
P.O. Box 116595, Gainesville, FL, 32611, United States of America,<br />
petros.xanthopoulos@gmail.com<br />
1 - Early Detection of Cardiovascular Disease<br />
Tsung-Lin Wu, tlwu@isye.gatech.edu, Eva Lee<br />
Cardiovascular diseases are the No 1 cause of death in US. Coronary heart disease is<br />
caused by atherosclerosis, the narrowing of the coronary arteries due to fatty build<br />
ups of plaque, producing angina pectoris, heart attack or both. We present novel<br />
early detection based on classification of traditional risk factors and novel<br />
biomarkers. The results can detect risk conditions of arteries and allow clinicians to<br />
perform early intervention. This work is joint with cardiologists at Emory U.<br />
2 - Robust Data Mining with Application in Biomedicine<br />
and Engineering<br />
Petros Xanthopoulos, University of Florida, 303 Weil Hall, P.O. Box<br />
116595, Gainesville, FL, 32611, United States of America,<br />
petros.xanthopoulos@gmail.com, Panos Pardalos, Mario Guarracino<br />
Supervised and unsupervised learning under uncertainty has become a very<br />
important problem in data analysis. In this talk we present some algorithms based<br />
on robust optimization for addressing data uncertainty issues.<br />
3 - Rule Extraction From Support Vector Machines and Applications to<br />
Medical Diagnosis<br />
Sara Nourazari, University of Oklahoma, 100 East Boyd, SEC T 301,<br />
Norman, OK, 73019, United States of America, sara.n@ou.edu,<br />
Theodore Trafalis<br />
Among the classification methods, the propositional if-then rules are very popular<br />
providing a transparent classification decision. In the case of high-dimensional data,<br />
SVMs often perform significantly better but suffer from incomprehensibility. In this<br />
work we evaluate different techniques to extract expressive rules from SVMs and<br />
apply those in real life cases such as medical diagnosis.<br />
4 - Network Based Models for Analysis of SNPs<br />
Zeynep Ertem, Texas A&M University, 1313 Zachry, College Station,<br />
TX, 77840, United States of America, zeynepsertem@gmail.com,<br />
Sergiy Butenko<br />
Constructing associated graph-theoretic models becomes more important as<br />
communicating vast amount of information accumulated in the laboratories each<br />
day is getting harder. Single Nucleotide Polymorphisms (SNPs) are of paramount<br />
importance in DNA related studies due to their role in variation of species. In this<br />
talk, we first survey metwork based models arising in computational biology and<br />
then concentrate on applications of cluster-detection algorithms to analyze SNP<br />
data.<br />
5 - Parametric Support Vector Machines<br />
Altannar Chinchuluun, Dr, Centre for Process Systems Engineering,<br />
Imperial College London, London, United Kingdom,<br />
a.chinchuluun@imperial.ac.uk, Ashwin Arulselvan,<br />
Stratos Pistikopoulos<br />
Support vector machines have been extensively studied and used in practice as a<br />
data mining tool especially in the field of biomedicine. We study the parametric<br />
support vector machine, where in we introduce the degree of misclassication as the<br />
parameter. Multiparametric prorgamming techniques are used for the resulting<br />
multiparametric mixed integer programs.<br />
INFORMS Austin – 2010<br />
444<br />
■ WD35<br />
C - Room 8A, Level 3<br />
Ranking and Internet Applications<br />
Sponsor: Applied Probability<br />
Sponsored Session<br />
Chair: Mariana Olvera, Columbia University, 500 W. 120th Street,<br />
Mudd Building, Room 306, New York, NY, 10027,<br />
United States of America, molvera@ieor.columbia.edu<br />
1 - User Selection Process for More Profitable Display Advertising<br />
Ana Radovanovic, Research Scientist, Google Research,<br />
76 Ninth Ave., New York, NY, 10011, United States of America,<br />
anaradovanovic@google.com<br />
One of the key performance objectives in display advertising business is maximizing<br />
the proportion of user clicks out of all of the shown ads by a given advertiser.<br />
However, the click probability significantly depends on users we are showing a<br />
certain ad to. We introduce a self-organizing online policy for updating user<br />
members’ lists and show that this policy allows us to achieve nearly optimal longterm<br />
proportion of clicks out of all online inventory that is handled by a publisher.<br />
2 - Implicit Renewal Theory for Ranking Algorithms<br />
Mariana Olvera, Columbia University, 500 W. 120th Street,<br />
Mudd Building, Room 306, New York, NY, 10027,<br />
United States of America, molvera@ieor.columbia.edu,<br />
Predrag Jelenkovic<br />
We present a stochastic framework to analyze the qualitative large scale behavior of<br />
a family of ranking algorithms, in the same spirit of Google’s PageRank algorithm,<br />
via implicit renewal theory. Our analysis is based on a stochastic recursion<br />
constructed on a tree, and the techniques we develop can be applied to both linear<br />
and non-linear recursions. We extend prior work to allow a general correlation<br />
structure among the different inputs of the algorithm.<br />
■ WD36<br />
C - Room 8B, Level 3<br />
Quality Management II<br />
Contributed Session<br />
Chair: Scott Dellana, Associate Professor, East Carolina University, Bate<br />
3102, Dept of Marketing & Supply Chain Mgmt, Greenville, NC, 27858,<br />
United States of America, dellanas@ecu.edu<br />
1 - A Robust Technique to Process Qualitative Customer Data and<br />
Build Satisfaction Models<br />
Jose Luis Ribeiro, Dr., UFRGS, Av. Osvaldo Aranha 99,<br />
Porto Alegre, RS, 90035-190, Brazil, ribeiro@producao.ufrgs.br,<br />
Maria Auxiliado Tinoco<br />
Customer survey may be used to collect qualitative data and build satisfaction<br />
models. However, due to respondents’ lack of engagement, customer survey is<br />
usually contaminated with noise. Following robust regression principles, we<br />
developed a technique to process qualitative data according to its consistence,<br />
supporting the construction of robust satisfaction models.<br />
2 - Supply Chain Quality Management Practices and Perceptions:<br />
A Preliminary Empirical Study<br />
Scott Dellana, Associate Professor, East Carolina University, Bate<br />
3102, Dept of Marketing & Supply Chain Mgmt, Greenville, NC,<br />
27858, United States of America, dellanas@ecu.edu, John Kros<br />
Recent global supply quality problems have underscored the need for a better<br />
understanding of quality across the supply chain. Studies in supply chain quality are<br />
few, limited, and with mixed results warranting more extensive study. We examine<br />
quality management practice by industry class and supply chain organizational<br />
position and compare agreement between perceived supplier quality management<br />
practices reported by customers and quality practices reported by their supplier<br />
groups.
■ WD37<br />
C - Room 8C, Level 3<br />
Stochastic Processes<br />
Contributed Session<br />
Chair: Tianke Feng, Industrial and Systems Engineering, University of<br />
Florida, 303 Weil Hall, P.O. Box 116595, University of Florida,<br />
Gainesville, FL, 32611, United States of America, fengtk@ufl.edu<br />
1 - Sharp Bounds for the Distribution of Critical-path Length<br />
Munevver Mine Subasi, Assistant Professor, Florida Institute of<br />
Technology, 150 W. University Blvd, Melbourne, FL, 32901, United<br />
States of America, msubasi@fit.edu, Ersoy Subasi, Andras Prekopa<br />
In PERT we are frequently concerned with the problem to estimate the values of the<br />
probability distribution or expectation of the critical-path length. We develop a<br />
bounding technique to obtain sharp bounds for the values of the distribution of the<br />
critical-path length under moment information and the assumption that the random<br />
length of each arc follows a beta distribution.<br />
2 - Evolutionary Computation-based Statistical Estimation Models for<br />
Complex System Analysis Based on Count Data<br />
Emily Zechman, Assistant Professor, Texas A&M University, 3136<br />
TAMU, College Station, TX, 77843, United States of America,<br />
ezechman@tamu.edu, Seth Guikema, Royce Francis<br />
Count data is ubiquitous in engineering practice, and forecasting future counts of<br />
events based on past data is a critical problem. Examples include forecasting power<br />
outages and estimating the risk of traffic accidents. This research will explore<br />
flexible, data-adaptive regression models for count data that preserve insights into<br />
system behavior while allowing exploration of new combinations of model<br />
structures. A new evolutionary computation-based method will be developed and<br />
demonstrated.<br />
3 - The Replacement Problem in Manufacturing Stochastic Systems<br />
Eva Selene Hernàndez Gress, PhD, Universidad Autónoma del<br />
Estado de Hidalgo, Abasolo 600 Col. Centro, Pachuca, 42000,<br />
Mexico, evah@uaeh.edu.mx<br />
The Replacement Problem is modeled with Linear and Dynamic Programming. This<br />
problem can be modeled also as a finite, irreducible, homogeneous Markov Chain.<br />
The transition probabilities matrix and the optimal basis associated to the Linear<br />
Programming model are perturbed to find regions of feasibility and optimality. Some<br />
perturbations bounds of the transition probabilities are explored and a perturbation<br />
bound for the optimal basis is also proposed.<br />
4 - Markov Decision Processes with Uncertain Rewards<br />
Chin Hon Tan, PhD Student, Department of ISE, University of<br />
Florida, 303 Weil, University of Florida, Gainesville, FL, 32611,<br />
United States of America, chinhon@ufl.edu, Joseph Hartman<br />
Sequential decision problems can often be modeled as Markov decision processes.<br />
Classical solution approaches assume that the parameters of the model are known.<br />
However, the rewards are often estimated and uncertain in practice. In this paper,<br />
we look at the marginal change in the value function as a result of the error in the<br />
reward estimate and identify the region in which a policy remains optimal. We<br />
illustrate this work with a stochastic lot-sizing problem.<br />
5 - Sequential Stochastic Assignment Problem with<br />
Postponing Decisions<br />
Tianke Feng, Industrial and Systems Engineering, University of<br />
Florida, 303 Weil Hall, P.O. Box 116595, University of Florida,<br />
Gainesville, FL, 32611, United States of America, fengtk@ufl.edu,<br />
Joseph Hartman<br />
The sequential stochastic assignment problem has wide applications in<br />
abandonment problems and health care management, and has been well studied. It<br />
assumes that jobs arrive randomly with random values. Upon arrival, a job’s value is<br />
known and the decision maker immediately decides whether to accept or reject it.<br />
In this research, we study the value of postponing decisions by allowing a decision<br />
maker to hold jobs. We analyze the optimal threshold policies for this version of the<br />
problem.<br />
INFORMS Austin – 2010 WD39<br />
445<br />
■ WD38<br />
C - Room 9A, Level 3<br />
Algorithms for Real-Time Equilibrium and<br />
Relocation Problems<br />
Sponsor: Optimization/Linear Programming and Complementarity<br />
(Joint Cluster ICS)<br />
Sponsored Session<br />
Chair: Miguel F. Anjos, University of Waterloo, 200 University Avenue<br />
West, Waterloo, ON, Canada, anjos@stanfordalumni.org<br />
1 - Parametric Complementarity Problems for Online Optimal Control<br />
Mihai Anitescu, Computational Mathematician, Argonne National<br />
Laboratory, Math and Computer Science Division, 9700 S Cass Ave,<br />
Argonne, IL, 60439, United States of America, anitescu@mcs.anl.gov,<br />
Victor Zavala<br />
We demonstrate that if points along the solution manifold of a nonlinear model<br />
predictive control problem are consistently strongly regular, it is possible to track the<br />
manifold approximately by solving a single linear complementarity problem (LCP)<br />
at each control step. We derive a fast, augmented Lagrangean tracking algorithm<br />
and demonstrate the developments through a numerical case study.<br />
2 - Real-time Optimization and Differential Variational Inequalities<br />
Victor Zavala, Argonne National Laboratory, Math and Comp.<br />
Science Div., Bdg 240, 9700 S Cass Ave, Argonne, IL, 60439,<br />
United States of America, vzavala@mcs.anl.gov, Mihai Anitescu<br />
We present new insights into how to achieve higher frequencies in real-time<br />
optimization. The basic idea is that, instead of solving a full NLP problem at each<br />
sampling time, we solve a single, truncated QP problem. We prove that this<br />
corresponds to a time-stepping scheme applied to a differential variational<br />
inequality. We propose a fast and stable scheme using augmented Lagrangian<br />
regularization and projected Gauss-Seidel to track the solution manifold.<br />
3 - A Stochastic Optimization Model for Ambulance Relocation<br />
Joe Naoum-Sawaya, University of Waterloo, 200 University Av W,<br />
Waterloo, Canada, jnaoumsa@engmail.uwaterloo.ca, Samir Elhedhli<br />
In this talk, we present our recent work on implementing a real time ambulance<br />
relocation system for the Region of Waterloo Emergency Medical Services. We<br />
formulate a stochastic optimization model and devise a heuristic that finds good<br />
solutions quickly. Results using the Region of Waterloo EMS data are presented.<br />
■ WD39<br />
C - Room 9B, Level 3<br />
Algorithms and Applications for Integer Programming<br />
Sponsor: Optimization/Integer Programming<br />
Sponsored Session<br />
Chair: Yongpei Guan, University of Florida, 303 Weil Hall, Gainesville, FL<br />
United States of America, guan@ise.ufl.edu<br />
1 - Fast Algorithms for Special Cases of the Minimum Cost<br />
Flow Problem<br />
Bala Vaidyanathan, Operations Research Advisor, FedEx Express,<br />
3680 Hacks Cross Road, Memphis, TN, 38125, United States of<br />
America, bala.vaidyanathan@gmail.com<br />
We consider special cases of the minimum cost flow problem when the nodes lie on<br />
a line, a circle, or a tree. We show that the properties of these problems can be<br />
exploited to develop specialized algorithms that run significantly faster than<br />
minimum cost flow algorithms for general networks. These problems find<br />
applications in areas such as transportation, electric power transmission, production<br />
planning, telecommunications, computational biology, and computational music.<br />
2 - Polyhedral Results for MIPs with Cardinality Constraints<br />
Ilksen Icyuz, University of Florida, 303 Weil Hall, Gainesville, 32611,<br />
United States of America, eceicyuz@ufl.edu, Jean-Philippe Richard<br />
We consider several mixed integer programs arising from applications that contain<br />
various forms of cardinality constraints. For these models, we review existing<br />
polyhedral results and obtain new strong valid inequalities based on disjunctive and<br />
lifting techniques. We also characterize situations in which these inequalities are<br />
sufficient to completely define the associated convex hulls. Finally, we present the<br />
results of a computational study aimed at testing the strength of these new cuts.
WD40<br />
3 - Strong Formulations for Lot-Sizing Problems with Disruptions<br />
Zhili Zhou, University of Florida, 303 Weil Hall, Gainesville, FL,<br />
32611, United States of America, zlzhou@ufl.edu, Yongpei Guan<br />
Most previous research on lot-sizing problems assumed no disruptions. However,<br />
disruptions occur in practice, which lead to extra outsourcing or production costs, as<br />
compared to the normally scheduled case. We formulate this problem as a robust<br />
integer program, and derive facet-defining inequalities for the problem. Final<br />
computational experiments show the effectiveness of our proposed approach.<br />
4 - New Cutting Planes for Cardinality Optimization<br />
Ismael De Farias, Texas Tech University, Lubbock, TX, United States<br />
of America, ismael.de-farias@ttu.edu, Ming Zhao, Rajat Gupta,<br />
Ernee Kozyreff<br />
We study the cardinality optimization polytope and extensions, particularly the set<br />
of the minimum 0-norm optimization problem. We present new cutting planes for<br />
them and computational results on their use in branch-and-cut.<br />
■ WD40<br />
C - Room 9C, Level 3<br />
Robust Optimization<br />
Contributed Session<br />
Chair: Bacel Maddah, Assistant Professor, American University of Beirut,<br />
P.O. Box 11-0236 Riad El Solh, Beirut, 1107-2020, Lebanon,<br />
bm05@aub.edu.lb<br />
1 - Handling Uncertainty in Supplier Selection using<br />
Robust Optimization<br />
Sheela Siddappa, Technical Architect, Infosys Technologies Limited,<br />
Electronic City, Bangalore, India, sheela_siddappa@infosys.com,<br />
Paresh Kumar Marwaha<br />
Selecting the right set of suppliers to procure items can help reduce company’s<br />
expense and improve customer satisfaction. This research tries to account for<br />
uncertainty in supplier’s performance, capacity, and cost while selecting the<br />
suppliers. We develop a two step process 1) select suppliers based on the uncertainty<br />
in their performance 2) estimate procurement quantity from each supplier based on<br />
the uncertainty in supplier’s capacity, cost, etc. A Robust Optimization methodology<br />
is adopted.<br />
2 - The Relational Algebra of Constraint Sets in Robust Optimization<br />
G. N. Srinivasa Prasanna, International Institute of Information<br />
Technology - Bangalore, 26/C Electronics City, Bangalore, India,<br />
gnsprasanna@iiitb.ac.in<br />
A relational-algebra for identifying, classifying, & visualizing relationships among<br />
different constraint sets (input assumptions) in a robust optimization (RO)<br />
framework is presented. Set-theoretic relations between alternative constraint sets<br />
are specified in an expression-based query language (composed of set-disjointness,<br />
union, intersection, etc.) We can compare, visualize & analyze different sets of<br />
assumptions, facilitating decision-support in general, & RO in particular.<br />
3 - Loading of Ships at Refineries when Arrival Times are Uncertain -<br />
A Robust Optimization Approach<br />
Jens Bengtsson, Norwegian School of Economics and Business<br />
Administration, Helleveien 30, Bergen, Norway,<br />
jens.bengtsson@nhh.no, Patrik Flisberg, Mikael Rönnqvist<br />
Ships that arrive to refinery ports are either served from product or component<br />
tanks. Arrival times of ships are uncertain and as such the inventory levels in the<br />
tanks will be uncertain and can in extreme cases be full or empty. Both these<br />
outcomes may be costly to the refiner. In this paper we take the arrival time<br />
uncertainty into account and analyze the production planning and loading problem<br />
by using robust optimization.<br />
4 - The Newsvendor Problem with Ambiguous Demand Distribution<br />
Bacel Maddah, Assistant Professor, American University of Beirut,<br />
P.O. Box 11-0236 Riad El Solh, Beirut, 1107-2020, Lebanon,<br />
bm05@aub.edu.lb, Ebru Bish, F. Jordan Srour, Kyle Lin<br />
We study the newsvendor problem when the demand distribution is “ambiguous” in<br />
terms of being within a given Kullback-Leibler distance from a nominal distribution.<br />
Our approach is novel as no precise estimate of demand parameters (e.g., moments,<br />
percentiles, and range) is required. We derive the optimal newsvendor ordering<br />
policy in this setting.<br />
INFORMS Austin – 2010<br />
446<br />
■ WD41<br />
C - Room 10A, Level 3<br />
Metaheuristics II<br />
Contributed Session<br />
Chair: Fan Wang, Prof., Sun Yat-sen Business School, Sun Yat-sen<br />
University, No.135 West Xinggang Road, Guangzhou, 510275, China,<br />
fanwang@gmail.com<br />
1 - A Modified Particle Swarm Optimization Algorithm<br />
Junhyuk Park, Pohang University of Science and Technology,<br />
Nam-Gu, Hyoja-Dong, POSTECH Eng 4-207, Pohang, Korea,<br />
Republic of, sacarlee@postech.ac.kr, Byung-In Kim, Jongsung Lee<br />
In classical PSO algorithms, the global best solution has a strong influence on the<br />
entire population. As a result, particles may rapidly converge to a premature global<br />
best solution without exploring enough search space. In this presentation, we<br />
extend the searching capability of particles by limiting the influence of global best<br />
solution. We compare the performance of the algorithm with several existing<br />
algorithms.<br />
2 - A Genetic Algorithm for the Team Formation Problem<br />
Paul Rubin, Michigan State University, The Eli Broad Graduate<br />
School of Managem, Michigan State University, East Lansing, MI,<br />
48824, United States of America, rubin@msu.edu, Lihui Bai<br />
We consider the team formation problem that assigns individuals with various<br />
values of attributes to teams so that the differences across teams with respect to<br />
each attribute are minimal. The problem is formulated as a mixed integer linear<br />
program and solved by a genetic algorithm with a constraint programming solver.<br />
Numerical results on randomly generated as well as real problems are reported.<br />
3 - Exploration of a Functional Programming Approach for<br />
Developing a Metaheuristic<br />
Dennis Drinka, Exploration of a Functional Programming Approach<br />
for Developing a Metaheuristic, University of Alaska Anchorage,<br />
3211 Providence Drive, Anchorage, AK, 99508,<br />
United States of America, afded@uaa.alaska.edu<br />
This presentation explores the use of a functional programming approach to drive a<br />
metaheuristic for solving a combinatorial optimization problem. In particular, it<br />
explores the use of LINQ to Objects to implement a tabu search procedure. It will<br />
demonstrate the use of this approach on the All Units Quantity Discount problem<br />
and describe how functional programs can easily be embedded within existing<br />
imperative programming solution approaches.<br />
4 - Self Adaptation GA Applied to Routing Problems<br />
Jaime Mora Vargas, Tecnológico de Monterrey, Research and<br />
Graduate Division, Campus Estado de México, Mexico,<br />
jmora@itesm.mx], Nestor Velasco-Bermeo, Miguel Gonzàlez-<br />
Mendoza<br />
Mathematical Programming (MP) has proven to be an effective strategy to tackle<br />
down optimization problems. Traditional methods fail to solve such problems due to<br />
the “combinatory explosion”, an exponential increase of the solution space<br />
theorically identified as “NP-Hard” problems, based on such tendency new strategies<br />
have been proposed; the combination of mathematical programming and hybrid<br />
metaheuristics, the later having as main characteristic the adaptation ability to the<br />
environment’s changes without the need to fine tune the parameters or re-run the<br />
method. GA’s have proven to be one of the most successful methods to solve most<br />
of the classic optimization problems. Though the benefits of such algorithms<br />
disappear when situation analyzed changes. Based on such inconvenient a new<br />
approach is proposed. A hybrid GA with MP and the incorporation of “autoadaptation”<br />
lets the algorithm not just to evolve solution candidates but its own<br />
parameters based on the current state (individual’s aptitude according to each<br />
generation). The problems solved are ; Vehicle Routing Problem With Time Window<br />
(VRPTW) and Multi-depot Vehicle Routing Problem With Time Window<br />
(MDVRPTW).<br />
5 - A Compromised Large-scale Neighborhood Search Heuristic for<br />
Heterogeneous VRP<br />
Fan Wang, Prof., Sun Yat-sen Business School, Sun Yat-sen<br />
University, No.135 West Xinggang Road, Guangzhou, 510275, China,<br />
fanwang@gmail.com, Yi Tao<br />
We addressed the Heterogeneous VRP with fixed costs and routing costs in which a<br />
limited fleet of different vehicles is available for sending goods to customers with<br />
known demand along the network with the objective of minimizing the total cost.<br />
We propose a compromised large-scale neighborhood search heuristic where the<br />
neighborhood aims to relax the subset-disjoint restriction during the process of<br />
multi-exchange neighborhood search.
■ WD42<br />
C - Room 10B, Level 3<br />
Optimization Algorithms<br />
Sponsor: Optimization/Computational Optimization and Software<br />
(Joint Cluster ICS)<br />
Sponsored Session<br />
Chair: Ilya Safro, Argonne National Laboratory, 9700 S. Cass Avenue,<br />
Argonne, IL, 60439, United States of America, safro@mcs.anl.gov<br />
1 - Beyond Fisher’s Linear Dicriminant Function<br />
Shuichi Shinmura, Professor, Seikei University, 3-3-1 Kichijoujikitamachi,<br />
Musashino, 180-8633, Japan, shinmura@econ.seikei.ac.jp<br />
Fisher founded linear discriminant function (LDF). LDF assume two groups are the<br />
same normal distribution, nevertheless few data satisfy this assumption. If data<br />
satisfy this, error rate equals to the minimum error rate (MNM). Therefore, LDF<br />
should be defined by MNM criterion. Revised IPLP-OLDF looks for the estimate of<br />
MNM using mixture of LP and IP. Evaluation of 13,500 models shows the mean of<br />
error rates of Revised IPLP-OLDF using LINGO are less than those of LDF & logistic<br />
regression.<br />
2 - A Separation Heuristic for Gap Inequalities<br />
Konstantinos Kaparis, Dr., University of Southampton,<br />
Southampton, SO17 1BJ, United Kingdom, K.Kaparis@soton.ac.uk,<br />
Laura Galli, Adam Letchford<br />
Laurent and Poljak introduced a class of valid inequalities for the max-cut problem,<br />
called gap inequalities, which include many other known inequalities as special<br />
cases. Even though they have received limited attention they can make very good<br />
cutting planes for the Max-Cut problem. We describe a separation heuristic for these<br />
and we present computational results which illustrate the potentials of the proposed<br />
scheme.<br />
3 - Polynomial Complexity Algorithm for Integer<br />
Transportation Problem<br />
Vladimir Tsurkov, Prof., Computing Center of Russian Academy of<br />
Sciences, Vavilov Str., 40, Moscow, 119333, Russia, tsur@ccas.ru,<br />
Alexander Tizik<br />
A net optimization large scale problem from telecommunication area is solved by<br />
means of the known method of column generation. The intermediate problem has<br />
transportation kind of restrictions. Algorithm of polynomial complexity is proposed.<br />
Method is based on iterative solutions of two-dimensional knapsack problems.<br />
4 - Multiscale Approach for the Network Compression-friendly Ordering<br />
Ilya Safro, Argonne National Laboratory, 9700 S. Cass Avenue,<br />
Argonne, IL, 60439, United States of America, safro@mcs.anl.gov<br />
We present a fast multiscale approach for the network minimum logarithmic<br />
arrangement problem. This type of arrangement plays an important role in a<br />
network compression. The algorithm is of linear complexity and exhibits good<br />
scalability which makes it practical and attractive for using on large-scale instances.<br />
Its effectiveness is demonstrated on a large set of real-life networks.<br />
■ WD44<br />
C - Room 2, Level 2- Mezzanine<br />
Network Modeling in Healthcare<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: Eva Enns, Stanford University, 117 Encina Commons, Stanford,<br />
CA, 94035, United States of America, evaenns@stanford.edu<br />
1 - Modeling HIV Spread in Africa using Sexual Contact Network Data<br />
Benjamin Armbruster, Northwestern University, 2145 Sheridan Road<br />
(Tech Bldg), Evanston, IL, 60208-3119, United States of America,<br />
armbruster@northwestern.edu, Stephane Helleringer<br />
Using a unique data set from the Likoma Network Study, we examine the structure<br />
of the sexual contact network, how it changes over time, and how this affects<br />
models of disease spread.<br />
2 - The Impact of the Health Delivery Supply Chain on Adherence to<br />
HIV Treatment<br />
Jessica McCoy, Stanford University, Stanford, California 94305,<br />
United States of America,jhmccoy@stanford.edu, Eric Johnson<br />
Adherence to HIV treatment is a predictor of viral suppression, and transmission<br />
rates are much lower in adherent populations. The health delivery supply chain in a<br />
resource-limited region potentially creates or removes barriers for patients seeking<br />
regular treatment. We develop a model to gain insights about the impact that the<br />
supply chain has on patients’ ability to be adherent (and hence on HIV prevalence)<br />
in a community.<br />
INFORMS Austin – 2010 WD45<br />
447<br />
3 - Controlling Epidemics over Multi-level Co-evolving Networks<br />
Achla Marathe, Asociate Professor, Virginia Tech, CRC XV VBI,<br />
Blacksburg, 24061, United States of America, amarathe@vbi.vt.edu,<br />
Stephen Eubank, Bryan Lewis, Jiangzhou Chen, Madhav Marathe<br />
Human behavior, epidemics and social contact networks are closely intertwined and<br />
co-evolve. Effective planning and response strategies must take these complicated<br />
interactions into account. We will describe an interactionist approach for studying<br />
these co-evolving social systems with the goal of supporting public health<br />
epidemiology. Individual and collective behavioral adaptation is critical in these<br />
systems and will be highlighted via illustrative case studies.<br />
4 - Optimal Link Removal for Epidemic Control Over Networks<br />
Eva Enns, Stanford University, 117 Encina Commons, Stanford, CA,<br />
94035, United States of America, evaenns@stanford.edu, Jeff<br />
Mounzer, Margaret Brandeau<br />
Control of infectious diseases which spread through close contact often focuses on<br />
interrupting the network of contacts. We examine the problem of determining<br />
which links should be removed from a contact network to maximize infections<br />
averted, given a constraint on the maximum number of links that can be removed.<br />
We formulate the problem as a non-convex quadratically constrained quadratic<br />
program. We evaluate the performance of approximate and heuristic solutions.<br />
■ WD45<br />
C - Room 6, Level 2- Mezzanine<br />
Health Care, Other<br />
Contributed Session<br />
Chair: S.Reza Sajjadi, Post- Doctoral Research Fellow, North Dakota State<br />
University, NDSU Department2485, 120A CIE, P.O.Box 6050, Fargo, ND,<br />
58108-6050, United States of America, reza.sajjadi@ndsu.edu<br />
1 - Feature Level Selection in Disease Clusters<br />
Saylisse Davila, Arizona State University, 151 E Broadway Rd #210,<br />
Tempe, AZ, United States of America, saylisse@asu.edu,<br />
George Runger, Eugene Tuv<br />
Most public health surveillance methods focus on detecting the presence of disease<br />
clusters. However, identifying the specific location of disease clusters can be equally<br />
important. Nowadays, health data is often recorded in large databases. Finding the<br />
specific location of these disease clusters among a large number of records and<br />
variables can be an intricate task. We will present a methodology that can be used<br />
to identify the ranges and/or levels of variables that define the clusters.<br />
2 - Impact of Medicare Part D on Generic Drug Utilization in Long Term<br />
Care Facilities<br />
Changmi Jung, Carnegie Mellon University, 4800 Forbes Ave.,<br />
Rm 242, Pittsburgh, PA, 15213, United States of America,<br />
changmi@andrew.cmu.edu, Rema Padman, Shamena Anwar<br />
This study examines the impact of Medicare Part D program on generic drug<br />
prescription rates in Long Term Care Facilities. We analyze prescription orders from<br />
a regional online pharmacy to induce a general pattern using the Difference in<br />
Difference method on four different therapeutic drug classes.<br />
3 - A Comparison of Drug Price Increases in the<br />
Pharmaceutical Industry<br />
Kathleen Martino, Rutgers University, 1 Washington Park, Newark,<br />
NJ, 07102, United States of America, martinok2@gmail.com,<br />
Yao Zhao<br />
Motivated by the current events regarding prescription drug prices, this empirical<br />
study examines if factors such as therapeutic class, manufacturer, and active<br />
ingredient levels play a role in the established price of prescription drugs. We<br />
examine both the wholesale price set by manufacturers and the markup set by<br />
distributors for both brand and generic drugs. We also quantify the difference<br />
between brand and generic drug prices as a drug moves downstream from<br />
manufacturers to pharmacies.<br />
4 - Optimization of the Dynamic Operational Decisions for Ambulance<br />
Dispatch: A Reallocation Model<br />
Sandra Milena Santa, Universidad de los Andes, Carrera 1 N° 18A -<br />
12, Bogotà, CU, Colombia, sm.santa30@uniandes.edu.co, Andres<br />
Correa, Ciro Alberto Amaya Guio, Nubia Milena Velasco Rodriguez<br />
Ambulance dispatch as a response to some emergency medical services (EMS) needs<br />
to be executed effectively meeting time response and coverage demand<br />
requirements. Reallocation of ambulances gives the possibility of meeting and<br />
improving these standards response, but it is important to have in mind that these<br />
decisions carry transport costs and consume time. Therefore, we present a dynamic<br />
model as a decision support tool that allows evaluating the necessity to update<br />
location of ambulances.
WD46<br />
5 - Patient Flow in a Multiple-Route High-Variability Primary Care Clinic<br />
S.Reza Sajjadi, Post- Doctoral Research Fellow, North Dakota State<br />
University, NDSU Department2485, 120A CIE, P.O.Box 6050, Fargo,<br />
ND, 58108-6050, United States of America, reza.sajjadi@ndsu.edu,<br />
Jing Shi, Kambiz Farahmand<br />
Simulation modeling of patient flow in an outpatient primary care clinic is<br />
considered in this study. In schedule-based clinics where patient arrivals follow the<br />
schedule given to the patients, inefficient layout and communication system as well<br />
as variability increase the waiting time of the patients in the clinics and thus result<br />
in patient dissatisfaction. Considering waiting time and distance traveled, the<br />
simulation model investigates a number of scenarios to improve the current<br />
situation.<br />
■ WD46<br />
C - Room 7, Level 2- Mezzanine<br />
Statistical Modeling and Analysis in Healthcare<br />
Applications<br />
Sponsor: Health Applications<br />
Sponsored Session<br />
Chair: Li Zeng, Assistant Professor, University of Texas at Arlington,<br />
Industrial & Manuf. Sys. Engr. Department, Arlington, Tx, 76019-0017,<br />
United States of America, lzeng@uta.edu<br />
1 - Minimizing Rehospitalization Costs Through Machine Learning<br />
Mohsen Bayati, Stanford University, 350 Serra Mall, Packard<br />
Building, room 278, Stanford, CA, 94305, United States of America,<br />
bayati@stanford.edu, Mark Braverman, Eric Horvitz<br />
Nearly one in every five patients is rehospitalized within 30 days of their discharge.<br />
In 2004 the estimated cost of unplanned readmissions to Medicare was $17.4<br />
billion. In this talk, I will demonstrate how online machine learning and<br />
optimization tools can be applied to electronic health records to identify patients<br />
with the highest risk of rehospitalization. We validated these predictions on a major<br />
hospital’s database and obtained cost-effective policies for minimizing<br />
rehospitalizations.<br />
2 - In-N-Out: An Energy Balance Model of Obesity<br />
Joanna Lankester, PhD candidate, Stanford University, 300 Pasteur<br />
Lane, Grant S131, Stanford, CA, 94305, United States of America,<br />
jl3@stanford.edu, Margaret Brandeau, Julie Parsonnet<br />
Obesity, which is associated with heart disease, diabetes, and other common and<br />
sometimes life-threatening conditions, has increased in prevalence dramatically over<br />
the last 50 years. To understand the rise in obesity, we are developing a model of<br />
body weight in the U.S. population from a perspective of energy balance. The model<br />
quantifies the changes over time in factors that influence body weight so that we<br />
can explore variability in obesity between individuals with similar energy intake.<br />
3 - Reducing Medication Errors in Pediatrics<br />
Michelle McGaha, PhD Graduate Student, Texas A&M University,<br />
3131 TAMU, College Station, TX, 77843, United States of America,<br />
michelle.mcgaha@neo.tamu.edu, Kiavash Kianfar, Lewis Ntaimo,<br />
Amarnath Banerjee<br />
Medication errors are common in the complex setting of pediatric medicine. We<br />
discuss the obstacles in determining the prevalence of pediatric medication errors<br />
and present a taxonomy chart of the most common pediatric medication errors, as<br />
well as defining characteristics for each error type. We discuss the challenges and<br />
highlight prevention strategies and meaningful use of health IT in reducing<br />
medication errors in the future.<br />
INFORMS Austin – 2010<br />
448<br />
■ WD47<br />
C - Room 8, Level 2- Mezzanine<br />
Project Management<br />
Contributed Session<br />
Chair: Eduardo G. Hernandez-Martinez, PhD, Tecnologico de Estudios<br />
Superiores de Coacalco, 16 de Septiembre 54, Coacalco, 55700, Mexico,<br />
eghm2@yahoo.com.mx<br />
1 - Analyzing Robustness of Team Communication-performance<br />
Relationships<br />
Deanna Kennedy, Assistant Professor, University of Washington,<br />
Bothell, 1501 Copperfield Pkwy #412, College Station, TX, 77845,<br />
United States of America, kennedy.deanna@gmail.com,<br />
Rebecca Perryman, Sara McComb<br />
Patterns in team communication relate to time and cost performance. We examine<br />
optimality when tradeoffs are made between the two performance outcomes.<br />
Further, we analyze the robustness of communication patterns by estimating the<br />
performance of sampled data from hyperspheres centered at optimal points.<br />
Implications are discussed.<br />
2 - Ensuring OR/MS Project Success: A Change<br />
Management Perspective<br />
Robert Levasseur, Professor of Management, Walden University,<br />
2614 Vista Cove Road, St. Augustine, FL, 32084-3069,<br />
United States of America, robert.levasseur@waldenu.edu<br />
Research into the reasons for project failure suggests that a high percentage of those<br />
failures are the result of non-technical problems, such as poor communication and<br />
resistance to change. The purpose of this presentation is to explore ways in which<br />
OR/MS project leaders can increase the odds of project success by applying basic<br />
principles and practices of change management.<br />
3 - Theory of Latency in integrated Concurrent Engineering<br />
John Chachere, Senior Computer Scientist, Stinger Ghaffarian<br />
Technologies, 1060 Arbor Road, Menlo Park, CA, 94025, United<br />
States of America, john.m.chachere@nasa.gov, John Kunz,<br />
Ray Levitt<br />
We observed Stanford and NASA teams using Integrated Concurrent Engineering<br />
(ICE) to accelerate conceptual design by a factor of ten. We assert that ICE teams<br />
manage ten enabling factors that decimate information response latency, and thus<br />
project duration. Latency is a unifying principle and a practical metric that can<br />
describe, evaluate and manage engineering design collaboration. ICE is the “Just in<br />
Time” of knowledge work; ICE flows information with minute latency and high<br />
reliability.<br />
4 - New Method for Project Crashing using Excel Solver<br />
Pamela Zelbst, Sam Houston State University, 1256 Avenue I,<br />
Huntsville, TX, 77341, United States of America, mgt_pjz@shsu.edu,<br />
Kunpeng Li, Bin Shao<br />
We developed a new method for project crashing using Excel Solver. The method<br />
uses AON network. The Excel formulation is much simpler and straightforward<br />
than the traditional method using AOA network.<br />
5 - A Discrete-event Approach for the Task Planning of<br />
PMBOK-based Projects<br />
Eduardo G. Hernandez-Martinez, PhD, Tecnologico de Estudios<br />
Superiores de Coacalco, 16 de Septiembre 54, Coacalco, 55700,<br />
Mexico, eghm2@yahoo.com.mx, Guillermo Torres<br />
This work presents an approach based on Supervisory Control Theory for the task<br />
planning of projects based on the PMBOK. The goal is a formal strategy to obtain<br />
automatically a gant chart considering all possible tasks concurrences according to<br />
times, resources availability and resources sharing. Unlike the graph methods<br />
reported on the PMBOK based on the user experience, the approach permits the<br />
time optimization establishing only the resources list and the restrictions of the tasks<br />
execution.
■ WD50<br />
C -Room 11, Level 2- Mezzanine<br />
Information Systems III<br />
Contributed Session<br />
Chair: Yun Huang, Northwestern University, 4146 Oakton st #2, Skokie,<br />
IL, 60076, United States of America, yun@northwestern.edu<br />
1 - The Value of Information: Evidence of Decreasing Price Dispersion<br />
in India’s Crop Market<br />
Chris Parker, PhD Candidate, London Business School,<br />
Regent’s Park, London, NW14SA, United Kingdom,<br />
cparker.PhD2007@london.edu, Nicos Savva, Kamalini Ramdas<br />
This paper aims to measure the effect of a new text message based information<br />
service on price dispersion empirically. Our dataset contains information about<br />
several crops, with diverse supply chain characteristics, and information about the<br />
adoption level of the technology. Having information about multiple crops allows us<br />
to identify factors impacting different types of crops. Results show that adoption<br />
levels are associated with lower price dispersion between markets.<br />
2 - Value From New Electronic Markets: A Diffusion Analysis of Two<br />
Equity Options Exchanges<br />
Chris Parker, PhD Candidate, London Business School,<br />
Regent’s Park, London, NW14SA, United Kingdom,<br />
cparker.PhD2007@london.edu, Bruce Weber<br />
Two all-electronic options exchanges opened for trading in 2000 and 2004. The<br />
exchanges gained trading volumes in competition with four incumbent markets. To<br />
explain the markets’ diffusion patterns, we model broker order routing decisions.<br />
The model generates hypotheses, which we test using a panel of quarterly<br />
disclosures from major brokerage firms. We conclude that firm heterogeneity is<br />
more influential than network effects in explaining the diffusions of the new<br />
markets at the broker level.<br />
3 - An Online Retailer’s Incentive to Become an Online Marketplace<br />
Kihoon Kim, Assistant Professor, Korea University Business School,<br />
Anam-Dong, Seongbuk-Gu, Seoul, 136701, Korea, Republic of,<br />
kihoonk@gmail.com<br />
When an online retailer develops into an online marketplace, the online retailer can<br />
invite other online retailers to sell the same product it deals with in the online<br />
marketplace. This paper investigates under what conditions the online retailer is<br />
advised to transform itself to the online marketplace, considering the online<br />
retailer’s trade-off of its referral revenue against the loss of some of its loyal<br />
customers. We also characterize optimal pricing structures of the online<br />
marketplace.<br />
4 - IOS Appropriation and Net Enablement<br />
Mei Cao, University of Wisconsin-Superior, Department of Business<br />
and Economics, Superior, United States of America,<br />
mcao1@uwsuper.edu, Qingyu Zhang<br />
The objective of the study is to uncover the nature of IOS appropriation and net<br />
enablement as an antecedent of supply chain collaboration. Reliable and valid<br />
instruments were developed through rigorous empirical analysis including<br />
structured interviews, Q-sort, and a large-scale study. Data were collected through a<br />
Web survey of U.S. manufacturing firms in various industries. Predictive validity is<br />
evaluated by demonstrating its strong relationship with supply chain collaboration.<br />
5 - Encounter in Virtual Space<br />
Yun Huang, Northwestern University, 4146 Oakton st #2, Skokie, IL,<br />
60076, United States of America, yun@northwestern.edu,<br />
Roger Chen, Noshir Contractor, Hani Mahmass<br />
Many virtual worlds such as massively multiplayer online role-playing games<br />
(MMORPGs) are often designed to mimic the real world along several dimensions,<br />
including the spatial requirements for engaging in activities. This paper examines<br />
the impact of virtual “geographical distance” between players in EverQuest II on the<br />
process of relation building in game. The results show that players are more likely to<br />
meet and interact with each other if they have more overlapping activity spaces.<br />
INFORMS Austin – 2010 WD54<br />
449<br />
■ WD53<br />
C -Room 14, Level 2- Mezzanine<br />
Operations/Finance Interface<br />
Contributed Session<br />
Chair: Amit Mitra, Auburn University, College of Business, Office of the<br />
Dean & Department of Manag, Auburn, AL, 36849-5240,<br />
United States of America, mitraam@auburn.edu<br />
1 - Vicarious Learning From Operational Failures<br />
Manpreet Hora, Georgia Institute of Technology, 800 W Peachtree St.<br />
NW, Atlanta, GA, 30308, United States of America,<br />
manpreet.hora@mgt.gatech.edu, Robert D. Klassen<br />
The occurrence of a rare operational failure in a firm (incident firm) provides an<br />
opportunity for vicarious learning for other firms (knowledge-seekers). Employing a<br />
field experiment, we examine the firm-level characteristics that enable vicarious<br />
learning. Results suggest that saliency of the incident firm and complementarities<br />
between the incident firm and the knowledge-seekers have a positive association<br />
with vicarious learning.<br />
2 - Investigating the Impact of Operational Variables on Manufacturing<br />
Cost by Simulation Optimization<br />
Wen-Chyuan Chiang, Prof., Collins College of Business, The<br />
University of Tulsa, The University of Tulsa, Tulsa, OK 74104, Tulsa,<br />
United States of America, wen-chyuan-chiang@utulsa.edu,<br />
Rui Zhang<br />
We focus on the relationship between operational variables (setup time, scrap rate,<br />
downtime rate) and the manufacturing cost. Keeping such parameters low is<br />
beneficial for reducing the average variable cost, but the required maintenance will<br />
incur an additional fixed cost. Therefore, a simulation based optimization approach<br />
is applied to determine the optimal level of the operational variables for minimizing<br />
the average cost. Sensitivity analysis and explanations are also provided.<br />
3 - Managing Operations Risks: An Options Perspective<br />
Wei Chen, Katz Graduate School of Business, University of<br />
Pittsburgh, 233 Mervis Hall, Pittsburgh, PA, 15260,<br />
United States of America, wchen@katz.pitt.edu, Jennifer Shang<br />
When dealing with demand and supply uncertainties, operations managers must<br />
also consider risks such as exchange rate variation, distribution cost surge, and<br />
political upheaval. These uncertainties can significantly influence a firm’s<br />
profitability. We address these risks from the perspectives of financial markets,<br />
operations control, and stochastic programming, and show that real options is a<br />
useful framework for understanding risk hedging in operations.<br />
4 - An Integrated Model Utilizing R&D Costs for Two-dimensional<br />
Warranty Policies<br />
Jay Patankar, Professor, The University of Akron, Department of<br />
Management, College of Bus. Administration, Akron, OH, 44325-<br />
4801, United States of America, jgp@uakron.edu, Amit Mitra<br />
Some consumer durables, such as automobiles, involve warranties involving two<br />
attributes. These are time elapsed since sale of the product and usage of the product<br />
at a given point in time. An avenue to impact warrant costs is through research on<br />
product development. The objective then becomes to determine warranty<br />
parameters, while constraining the sum of the expected unit warranty costs and<br />
research and development costs per unit sales, under a limited research and<br />
development budget.<br />
■ WD54<br />
C -Room 15, Level 2- Mezzanine<br />
Technology Management<br />
Sponsor: Technology Management/New Product Development<br />
Sponsored Session<br />
Chair: Gulru Ozkan, Assistant Professor, Clemson University, Department<br />
of Management, 101 Sirrine Hall, Clemson, SC, 29634, United States of<br />
America, gulruo@clemson.edu<br />
1 - Better Selection or Efficient Contracting?: A Model of Knowledge<br />
Vendor Selection and Contracting<br />
Zhijian Cui, PhD Candidate, INSEAD, Constance de Blvd,<br />
Fontainebleau, France, Zhijian.CUI@insead.edu, Sameer Hasija<br />
We are studying the vendor selection and contracting issue for knowledge driven<br />
processes. In particular, we study three vendor selection process: (1)Selection is<br />
based on initial talks with the vendor and subsequently the contract is negotiated<br />
with the selected vendor. (2)The vendors are informed about the SLA and asked to<br />
bid for the contract. (3) The vendors are asked to propose a contract to the client.
WD55<br />
2 - Innovation in Top-Down and Bottom-Up Strategy Processes<br />
Fabian Sting, INSEAD, Boulevard de Constance, Fontainebleau,<br />
France, fabian.sting@insead.edu, Christoph Loch<br />
We study strategy processes at six German manufacturing organizations using an<br />
organizational search perspective. While the final decision on strategic initiatives<br />
remains at the top, strategic initiatives are distributed across hierarchical levels,<br />
depending on where expertise is concentrated. The organizations also use multiple<br />
mechanisms to coordinate decentralized actors. Coordination and top-down decision<br />
making is weighed against the creativity that stems from delegated search.<br />
3 - Managing New Product Development Knowledge for Competing<br />
Firms: Case of Joint Development<br />
Gulru Ozkan, Assistant Professor, Clemson University,<br />
Department of Management, 101 Sirrine Hall, Clemson, SC, 29634,<br />
United States of America, gulruo@clemson.edu, Cheryl Gaimon<br />
We introduce a stochastic game on knowledge sharing (KS) and knowledge<br />
development (KD) strategies for two NPD firms. First, leader sets allocations of<br />
profit, then firms decide on KS for joint development of a new product. Next, firms<br />
jointly pursue KD and launch the product. Insights include impact of uncertainty.<br />
4 - A Decision Model to Manage Network Security Technologies for<br />
Information Assurance<br />
Soumyo Moitra, Senior Member of Technical Staff, Software<br />
Engineering Institute, Carnegie Mellon University,<br />
4500 Forbes Ave, Pittsburgh, PA, 15213, United States of America,<br />
smoitra@sei.cmu.edu<br />
This paper describes a model to manage technologies to protect informational assets.<br />
The focus is on the valuation of information and a methodology to arrive at the<br />
value at risk is presented. This assessment is used by the model to evaluate the<br />
benefits of different levels of security technologies. Sensitivity analysis with respect<br />
to the value of information is presented.<br />
■ WD55<br />
C -Room 16, Level 2- Mezzanine<br />
Inventions, Innovation and Technology Management<br />
Sponsor: Technology Management/New Product Development<br />
Sponsored Session<br />
Chair: Kun Liu, Assistant Professor, Wayne State University,<br />
5201 Cass Ave, Detroit, United States of America, ek9525@wayne.edu<br />
1 - Abandonment of Patented Inventions in<br />
Innovation-Intensive Industries<br />
Kun Liu, Assistant Professor, Wayne State University, 5201 Cass Ave,<br />
Detroit, United States of America, ek9525@wayne.edu<br />
Little research has examined how firms abandoned some inventions in innovationintensive<br />
industries. Distant innovation search is associated with a greater<br />
technological distance between newly acquired inventions and abandoned<br />
inventions, as well as a younger average age of abandoned inventions. Abandoning<br />
younger inventions and more focused abandonment of inventions are associated<br />
with greater market value as measured by Tobin’s Q.<br />
2 - Continuous Quality/Time/Cost Tradeoffs<br />
Bruce Pollack-Johnson, Associate Professor of Mathematical<br />
Sciences, Villanova University, 800 Lancaster Avenue, Villanova, PA,<br />
19085, United States of America, bruce.pollackjohnson@villanova.edu,<br />
Matthew Liberatore<br />
We use an example of a translation project to illustrate how quality can be modeled<br />
as a continuous function of time and cost. Given a project deadline and budget,<br />
overall quality can then be maximized using a nonlinear programming model.<br />
Alternatively, iso-quality curves can be drawn, to visualize the continuous tradeoffs<br />
between time, cost, and quality, and then used to pick a combination that seems<br />
best for a particular situation.<br />
3 - Launching Technologically Advanced Products in<br />
Segmented Markets<br />
John N Angelis, Rochester Institute of Technology,<br />
105 Lomb Memorial Drive, Rochester, United States of America,<br />
jangelis@saunders.rit.edu<br />
We focus on how competing profit-maximizing firms should set price and quality<br />
for a new technologically-advanced product sold to a segmented market. We<br />
analyze a closed-loop Stackelberg game with perfect information. If the late entrant<br />
possesses a large enough cost disadvantage, it should only target the least innovative<br />
segment. We also find that a firm with a large cost advantage may not necessarily<br />
earn higher profits by being the first mover.<br />
INFORMS Austin – 2010<br />
450<br />
4 - Realizing the Value of RFID in a Global Enterprise<br />
Ann Marucheck, Professor, Kenan-Flagler Business School, McColl<br />
Bldg CB 3490, UNC-Chapel Hill, Chapel Hill, NC, 27599, United<br />
States of America, ann_marucheck@unc.edu, Noel Greis,<br />
Monica Nogueira, Anders Duus, Hong Tham Nguyen<br />
For many organizations, understanding the potential benefits of RFID and justifying<br />
its investment continue to be challenges. In this research, we comprehensively<br />
study over 4000 cases of RFID projects as reported in the IDTechEX database.<br />
Specifically, we contrast the benefits realized by early adopters of RFID with more<br />
recent adopters. We further suggest measures that can determine how RFID<br />
provides economic value to an enterprise and identify the drivers of determining<br />
that value.<br />
■ WD56<br />
C - Room 1, Level 1<br />
Simulation and Optimization II<br />
Contributed Session<br />
Chair: Xueping Li, Assistant Professor, University of Tennessee,<br />
408 East Stadium Hall, Knoxville, TN, 37996, United States of America,<br />
Xueping.Li@utk.edu<br />
1 - Allocating Manpower to Minimize Lmax in a Job Shop<br />
Benjamin Lobo, North Carolina State University, 400 Daniels Hall,<br />
College of Engineering, Raleigh, NC, 27695, United States of<br />
America, bjlobo@gmail.com, James Wilson, Thom Hodgson,<br />
Russell King, Kristin Thoney<br />
Most job shops are constrained not only by machines, but also by the number of<br />
workers available to operate these machines. Different worker allocations to<br />
machine groups can impact the Lmax value of a schedule. Using a relaxation of the<br />
problem to generate a lower bound on Lmax, we develop a procedure to allocate<br />
workers to machines that minimizes this lower bound. Computational experience is<br />
presented.<br />
2 - Improved Fully Sequential Procedure with Mean and<br />
Variance Update<br />
Huizhu Wang, Georgia Institute of Technology, 765 Ferst Dr, Atlanta,<br />
GA, 30332-0205, United States of America, huizhuwang@gmail.com,<br />
Seong-Hee Kim<br />
Ranking and selection (R&S) procedures compare a number of simulated systems<br />
and try to find a system with the best performance measure. Fully-sequential R&S<br />
procedures are shown to be efficient but its probability of correct selection tends to<br />
be higher than the nominal level especially for a large number of systems. We study<br />
sources for conservativeness and present a procedure with improved efficiency.<br />
3 - Simulation-based Optimization and Stochastic Programming<br />
Tahir Ekin, PhD Candidate, George Washington University,<br />
2201 G Street, NW Funger 415, Washington, DC, 20052, United<br />
States of America, ekin@gwu.edu, Refik Soyer, Nicholas Polson<br />
We provide a simulation-based approach to optimization and stochastic<br />
programming. First, we consider a Monte Carlo solution to linear programming and<br />
then show that it naturally extends to two-stage stochastic programming with<br />
uncertainty. One advantage of our approach is that it is straightforward to add<br />
parameter uncertainty and does not need derivative information.<br />
4 - Parametric Moment Closure of Non-linear State Dependent<br />
Stochastic Systems<br />
Ritesh Arora, Graduate Research Assistant, Missouri University of<br />
Science and Technology, Dpt. of Engg. Management & Systems<br />
Engg., Rolla, MO, 65409, United States of America,<br />
ra95d@mail.mst.edu, Ivan Guardiola<br />
This research highlights the use of parametric moment closure approximations for<br />
non-linear stochastic systems. A general birth-and-death non-linear stochastic<br />
process will be analyzed and closed under various underlying parametric<br />
distribution assumptions. It results that closure under neglect is considerably less<br />
robust than parametric closure. We highlight this theoretical endeavor through an<br />
analysis of aphid population stochastic model.<br />
5 - Simulation and Optimization of Supply Chain Models<br />
for Supercomputing<br />
Xueping Li, Assistant Professor, University of Tennessee, 408 East<br />
Stadium Hall, Knoxville, TN, 37996, United States of America,<br />
Xueping.Li@utk.edu, Zhe Zhang<br />
Cache design is a great challenge in data management in supercomputing and a key<br />
component to improve the performance by storing data for future access. It is in the<br />
similitude of behaviors of a supply chain in which suppliers attempt to meet the<br />
demands from customers. We develop, simulate and optimize supply chain models<br />
for the cache design of supercomputers and evaluate the performances.
■ WD57<br />
C - Room 2, Level 1<br />
Portfolio Analysis<br />
Contributed Session<br />
Chair: Mark Zschocke, University of Waterloo, 200 University Avenue<br />
West, Waterloo, ON, N2L3G1, Canada, mszschoc@uwaterloo.ca<br />
1 - The Efficient Frontier for Weakly Correlated Assets<br />
Xili Zhang, Research Associate, School of Business<br />
Administration,South China University of Technology,<br />
381 Wushan Road, TianHe District, Guangzhou, 510641, China,<br />
zhangxili831@gmail.com, Michael J. Best<br />
Best and Hlouskava have shown that for a Markowitz portfolio selection problem<br />
having a diagonal covariance matrix and no short sales constraints, the efficient<br />
frontier is traced out in a monotonic fashion whereby assets are reduced to zero and<br />
subsequently remain at zero in order of their expected returns. We show that if the<br />
correlation matrix of the assets is “nearly” diagonal (in a sense to be made precise)<br />
then the efficient frontier will be traced out in a similar way.<br />
2 - Sharpe Ratios and Implied Risk Free Rates<br />
Michael J. Best, Professor, University of Waterloo,<br />
200 University Avenue West, Waterloo, ON, N2L 3G1, Canada,<br />
mjbest@uwaterloo.ca<br />
For the usual mean-variance Markowitz portfolio optimization model having just a<br />
budget constraint, the choice of a market portfolio implies a unique risk free rate.<br />
However, practical portfolio optimization problems have many inequality<br />
constraints. These constraints may cause kinks or points of non-differentiability on<br />
the resulting efficient frontier. We show that choosing a kink point as a market<br />
portfolio results in a continuum of implied risk free rates and give a formula for<br />
them.<br />
3 - Goal Programming Models for Mutual Funds Portfolio Selection<br />
From Global Markets<br />
Mehrdad Tamiz, Professor, Kuwait University, College of Business<br />
Administration, Kuwait City, Kuwait, mtamiz@yahoo.co.uk<br />
A vast number of criteria can be taken into consideration in portfolio selection other<br />
than expected return and variance of return. This talk examines several factors<br />
representing criteria in a Goal Programming setting for Portfolio Selection of mutual<br />
funds. The selection is from 20 mutual funds from 10 countries representing 7<br />
regions, with 7 factors that belong to mutual funds attributes, macroeconomics and<br />
regional preferences.<br />
4 - Servitization, Alliance, and Firm Value<br />
Yeonsung Yoo, Korea University Business School, Anam-dong,<br />
Seongbuk-Gu, Seoul, 136-701, Korea, Republic of,<br />
yooys@korea.ac.kr, Hosun Rhim<br />
We examine impacts of strategic alliance to the shareholder value by measuring the<br />
stock market reaction associated with companies’ alliance announcements. Firms<br />
are categorized to understand the impacts of servitization and productization.<br />
Sample includes Fortune 500 companies.<br />
5 - Competitive Project Portfolio Management<br />
Mark Zschocke, University of Waterloo, 200 University Avenue<br />
West, Waterloo, ON, N2L3G1, Canada, mszschoc@uwaterloo.ca,<br />
Benny Mantin, Beth Jewkes<br />
We develop a Competitive Project Portfolio Management (CPPM) model wherein<br />
two competing firms consider investing into two projects targeting, separately, a<br />
mature and an emerging market. The returns firms obtain from investments into<br />
these markets follow an s-shaped curve and depend on both firms’ actions. We find<br />
that different forms of interactions may arise and outline optimal CPPM strategies.<br />
We also discuss the market conditions that can lead to these outcomes.<br />
INFORMS Austin – 2010 WD61<br />
451<br />
■ WD58<br />
C - Room 3, Level 1<br />
Financial Engineering II<br />
Contributed Session<br />
Chair: Stephen Stoyan, University of Southern California, 3715<br />
McClintock Avenue, GER 240, Los Angeles, CA, 90089, United States of<br />
America, stoyan@usc.edu<br />
1 - Corporate Cash Holding, Production and Investments Applied to<br />
the Agribusiness Sector<br />
Astrid Prajogo, Princeton University, ORFE Deparment,<br />
Sherrerd Hall, Princeton, NJ, 08544, United States of America,<br />
aprajogo@princeton.edu, John Mulvey, Davi Valladao<br />
We propose a multistage stochastic program of a firm facing uncertain investment<br />
opportunities and a convex cost of external financing. The model endogenously<br />
determines the best production, investment, financing and cash holding policies<br />
over the planning horizon. The implications of corporate cash holdings are<br />
illustrated for the agricultural sector.<br />
2 - Efficient Monte Carlo Barrier Option Pricing Under a<br />
Jump-Diffusion Process<br />
Samim Ghamami, University of Southern California,<br />
University Park Campus, Los Angeles, CA, United States of America,<br />
ghamami@usc.edu, Sheldon Ross<br />
We present efficient simulation procedures for pricing barrier options when the<br />
underlying security price follows a geometric Brownian motion with jumps.<br />
Metwally and Atiya [2002] developed a simulation approach in the same setting for<br />
pricing knock-out options, but no variance reduction was introduced. We improve<br />
upon M&A’s approach by innovative applications of well-known variance reduction<br />
techniques. We also show how to use simulation to price knock-in options.<br />
3 - Optimal Execution Strategy in the Presence of Price Impact<br />
Mauricio Junca, University of California, 4141 Etcheverry Hall,<br />
Berkeley, CA, United States of America, mjunca@berkeley.edu<br />
An investor needs to execute a long position in the asset by selling at discrete points<br />
in time, affecting the price of the asset and possibly incurring in a fixed transaction<br />
cost. The objective is to maximize the discounted revenue. This problem is<br />
formulated as an impulse control problem and we characterize the value function<br />
using the viscosity solutions framework. We also analyze the case where there is no<br />
transaction cost and how this formulation relates with a singular control problems.<br />
4 - An Algorithm for Portfolio Problems with Discrete<br />
Choice Constraints<br />
Stephen Stoyan, University of Southern California,<br />
3715 McClintock Avenue, GER 240, Los Angeles, CA, 90089,<br />
United States of America, stoyan@usc.edu<br />
We consider portfolio models that incorporate a comprehensive set of realistic<br />
financial constraints, one of which includes the number of securities to hold.<br />
Uncertainty is considered in the design through the use of stochastic programming.<br />
The resulting large-scale problem forms a mixed-integer program, where we present<br />
a model specific decomposition algorithm that generates solutions in reasonable<br />
time. Computational limitations involved with the approach will also be discussed.<br />
■ WD61<br />
H - Room 400, 4th Floor<br />
Supply Chain, Risk Management<br />
Contributed Session<br />
Chair: Cigdem Gurgur, Professor, Purdue University, Doermer School of<br />
Business, 2101 East Coliseum Blvd., Fort Wayne, IN, 46805,<br />
United States of America, gurgurc@ipfw.edu<br />
1 - Incentives to Invest in Multi-layer IT security Defense in<br />
Supply Chain Firms<br />
Tridib Bandyopadhyay, Assistant professor, Kennesaw State<br />
University, 1000 Chastain Road, Kennesaw, GA, 30144,<br />
United States of America, tbandyop@kennesaw.edu, Dengpan Liu,<br />
Srinivasan Raghunathan<br />
Supply chain firms have integrated business processes. This makes their IT risk<br />
interdependent. Multilayer IT security defense works like stage-gates, bringing<br />
interdependency between the efficacies of the successive layers. Thus SC firms face a<br />
complex inter-firm, inter-layer IT security investment decision scenario. We provide<br />
a game theoretic model that captures above multi-faceted interdependencies of IT<br />
security risk in SC firms, and analyze their incentives to invest in IT security.
WD63<br />
2 - Supplier Selection in Make-to-order Environment with Risks<br />
Tadeusz Sawik, Professor, AGH University of Science & Technology,<br />
Department of OR & IT, Krakow, 30059, Poland,<br />
ghsawik@cyf-kr.edu.pl<br />
A mixed integer programming approach that uses conditional value-at-risk via<br />
scenario analysis is proposed for supplier selection and order allocation in supply<br />
chains with risks. Given a set of customer orders for products, the decision maker<br />
needs to decide from which supplier and when to purchase parts required for each<br />
order to meet its due date and to mitigate the impact of low probability supply<br />
disruptions and high probability supply delays.<br />
3 - A Multi-Product Risk-Averse Newsvendor with Exponential<br />
Utility Function<br />
Sungyong Choi, Rutgers University, 1 Washington Street,<br />
Room #1072, Newark, NJ, 07102, United States of America,<br />
sungyongchoi@gmail.com, Andrzej Ruszczynski<br />
We consider a risk-averse multi-product newsvendor using an exponential utility<br />
function. We study the asymptotic behavior of the solution with respect to the<br />
number of products and degree of risk aversion. Then, under reasonable conditions,<br />
we obtain closed-form approximation which are easy to compute and much more<br />
accurate than the risk-neutral solution. Then we obtain the analytical and<br />
numerical insights for the interplay between risk aversion and demand dependence<br />
structure.<br />
4 - Flexible Supply Contract Design using Options in Apparel<br />
Supply Chain<br />
Bong-Sung Chu, Keio University, 3-14-1, Hiyoshi, Kohokuku,<br />
Yokohama, Japan, superkensin@yahoo.co.jp, De-Bi Cao<br />
The major risks in a supply chain mostly come from mismatch of supply and<br />
demand with the dynamic demand changes. To avoid the risks, nowadays, flexible<br />
supply contract models using options are attracting significant attention. This paper<br />
addresses the flexible supply contract design with various types of financial options<br />
which give holders the right and opportunity to be guaranteed a certain trading<br />
quantity without stock out or opportunity loss in a single-period two-stage supply<br />
chain.<br />
5 - Competition, Diversification and Supplier Selection Under<br />
Supply Disruptions<br />
Cigdem Gurgur, Professor, Purdue University, Doermer School of<br />
Business, 2101 East Coliseum Blvd., Fort Wayne, IN, 46805,<br />
United States of America, gurgurc@ipfw.edu<br />
In this study we consider supplier selection and quantity allocation decisions for a<br />
single firm facing supply unreliability and demand uncertainty. We use a traditional<br />
newsvendor framework to determine the optimal number of suppliers to place an<br />
order with and the corresponding quantities of those orders. We explicitly address<br />
the strategic behavior of suppliers in pricing decisions and we show how the pricing<br />
decisions of the suppliers change in response to procurement decisions.<br />
■ WD63<br />
H - Room 404, 4th Floor<br />
Decision Analysis VI<br />
Contributed Session<br />
Chair: Jing Ai, A Decision Analysis Approach to Enterprise Risk<br />
Management, The University of Hawaii at Manoa, Shidler College of<br />
Business, 2404 Maile Way C305, Honolulu, HI, 96822,<br />
United States of America, jing.ai@hawaii.edu<br />
1 - Novel Methods to Support Decision Making and Communicating<br />
about Risks in Distributed Environments<br />
Bonnie Ray, Manager, Risk Analytics, IBM T. J. Watson Research<br />
Center, P.O. Box 218, Yorktown Heights, NY, 10598, United States of<br />
America, bonnier@us.ibm.com, Lea Deleris<br />
I provide an overview of a current joint research initiative between IBM Research,<br />
IBM Dublin, and University College Cork, partially funded by IDA Ireland. The<br />
research focuses on development of new methods to 1)extract risk information from<br />
text to form probabilistic graphical models using NLP techniques, 2)reason about<br />
risk when probabilistic information is imprecise, 3)plan for risk in complex<br />
environments using stochastic CP techniques and 4)communicate about risks in<br />
distributed settings.<br />
2 - A Comparison of Simultaneous Kelly Betting Strategies<br />
Andrew Grant, University of Sydney, H69 Economics and Business<br />
Bldg, Cnr Codrington and Rose Sts, Darlington, NS, 2008, Australia,<br />
andrew.grant@sydney.edu.au, Peter Buchen<br />
We consider the problem of Kelly betting on simultaneous games, and the relative<br />
performance of betting strategies that use multi-bets compared to those that do not.<br />
We develop a simulation model to test the performance of three Kelly betting<br />
strategies using the empirical odds distribution from the 2007-08 English Premier<br />
League Season. The results suggest that using multi-bets of all levels outperforms<br />
the portfolio optimization approach of betting on single game outcomes only.<br />
INFORMS Austin – 2010<br />
452<br />
3 - Census Uncertainty and Congressional Reapportionment<br />
Dennis Leber, National Institute of Standards and Technology,<br />
100 Bureau Dr, Gaithersburg, MD, 20899-8980, United States of<br />
America, dennis.leber@nist.gov, Jeffrey Herrmann<br />
The U.S. Constitution requires a decennial census, the results of which are used for<br />
the reapportionment of congressional representatives. The census results are only<br />
estimates and contain uncertainty. The Census Bureau can quantify this uncertainty<br />
through statistical sampling, but this uncertainty is ignored during reapportionment.<br />
This talk will present decision methods that consider attribute value uncertainty and<br />
apply these methods to the problem of reapportioning congressional seats.<br />
4 - A Decision Analysis Approach to Enterprise Risk Management<br />
Jing Ai, A Decision Analysis Approach to Enterprise Risk<br />
Management, The University of Hawaii at Manoa, Shidler College of<br />
Business, 2404 Maile Way C305, Honolulu, HI, 96822,<br />
United States of America, jing.ai@hawaii.edu, Tianyang Wang<br />
Enterprise Risk Management (ERM) is an emerging corporate risk management<br />
concept that proposes to manage risks in an integrated strategic system. One of the<br />
most important challenges in ERM is the modeling of corporate decision making<br />
process in light of dependent risks associated with fragmented business activities.<br />
This paper presents a decision analysis approach to accomplish this task. It serves as<br />
a practical guideline for managers to optimally allocate resources given risk<br />
considerations.<br />
■ WD64<br />
H - Room 406, 4th Floor<br />
Health Care, Strategy and Policy<br />
Contributed Session<br />
Chair: Vikram Tiwari, Assistant Professor, University of Houston,<br />
2200 Business Center Dr, Apt 5104, Pearland, TX, 77584,<br />
United States of America, vtiwari@Central.UH.EDU<br />
1 - Clostridium Difficile: System Dynamics Modelling of Hospital<br />
Infection Outbreaks<br />
David Lane, Reader in Management Science, London School of<br />
Economics, Houghton St., London, WC2A 2AE, United Kingdom,<br />
d.c.lane@lse.ac.uk, Diogo Quintas, Alec Morton<br />
LSE and UK National Audit Office staff constructed a simulation model to<br />
understand and control Clostridium difficile outbreaks. Different contamination<br />
stages, various transmission mechanisms and bed, toilet and staff hand cleaning<br />
were represented. The model synthesised information from a range of sources. It<br />
also allowed users to explore and understand the complex consequences of the<br />
interaction of a number of transmission vectors and policy interventions aimed at<br />
combating outbreaks.<br />
2 - Outcome Quality and Efficiency - A Healthcare Perspective<br />
Scott Lindsey, University of Utah, Operations and Information<br />
Systems, Salt Lake City, UT, United States of America,<br />
scott.lindsey@business.utah.edu, Sriram Thirumalai<br />
This study explores relationships between and operational drivers of outcome<br />
quality and efficiency within healthcare operations. In the hospital setting, these<br />
drivers include process standardization, operational focus, and operational<br />
effectiveness. The study involves the use of stochastic frontier analysis based on data<br />
from the U.S. Department of Health and Human Services and State of California.<br />
Study findings, limitations and directions for future research are identified.<br />
3 - Comparison of Markov and Discrete Event Simulation Models for<br />
Advanced Prostate Cancer<br />
Lanting Lu, Associate Research Fellow, Peninsula College of<br />
Medicine & Dentistry, Veysey Building, Salmon Pool Lane, Exeter,<br />
EX2 4SG, United Kingdom, lanting.lu@pms.ac.uk<br />
This work compares discrete event simulation (DES) cost-utility model and Markov<br />
cost-utility model built for an economic evaluation of a health technology degarelix,<br />
for advanced prostate cancer, and highlights the differences in the assumptions, the<br />
input data requirements and outcome estimations. The DES model gives more<br />
accurate and detailed outputs and conducting a probabilistic sensitivity analysis<br />
using the simulation model is found to be more straightforward than using the<br />
Markov model.
4 - Operating Room Utilization Study<br />
Jihan Wang, Ph.D Student, Wayne State University, 4815 4th Street,<br />
Rm. 2033, Detroit, MI, United States of America,<br />
aw0984@wayne.edu, Kai Yang, Susan Yu<br />
The successful management of operating rooms (OR) is very important<br />
measurement to any hospital. The OR utilization is a well-acknowledged metric to<br />
evaluate the performance of the facility. This research investigated 11 factors that<br />
people think will impact the utilization, such as first case delays and case<br />
cancellations. We determined the most important factors affecting utilization<br />
through statistical analysis of the data from Detroit VA medical center.<br />
5 - Incentive Games in Healthcare Delivery: Pay-for-Performance in<br />
Primary Care<br />
Vikram Tiwari, Assistant Professor, University of Houston,<br />
2200 Business Center Dr, Apt 5104, Pearland, TX, 77584,<br />
United States of America, vtiwari@Central.UH.EDU, Ana Groznik<br />
In existing compensation system, primary care physicians’ reimbursement from<br />
health insurance companies is not tied to patients’ long-term health outcome. Using<br />
stylized two-stage game theoretical models we compare some structural options of<br />
payments for physicians in the pay-for-performance market. We identify the<br />
tradeoffs faced by physicians and insurance companies and derive necessary<br />
conditions for different reimbursement structures to be optimal (tied to different<br />
patient characteristics).<br />
■ WD65<br />
H - Room 408, 4th Floor<br />
Supply Chain, Shipping and Transportation<br />
Contributed Session<br />
Chair: Fatih Mutlu, Assistant Professor, Qatar University, Industrial<br />
Engineering Department, Doha, 2713, Qatar, fatihmutlu@qu.edu.qa<br />
1 - Cost Benefit Analysis of the Cargo Screening Processes using<br />
Alternative Evaluation Methods<br />
David Menachof, Peter Thompson Chair in Port Logistics, University<br />
of Hull Logistics Institute, Cottingham Road, Hull, HU6 7RX, United<br />
Kingdom, D.Menachof@hull.ac.uk, Uwe Aickelin, Galina Sherman,<br />
Peer-Olaf Siebers<br />
Cost benefit analysis using three different methods, scenario analysis, decision trees<br />
and simulation, are conducted. These methods are examined in a real world<br />
situation and compared to actual data using different probabilistic methods of<br />
estimating costs for port security risk assessment studies. Results show that in simple<br />
situations, all methods can be equally used. As complexity increases, we show how<br />
these tools can be used and focus on the limitations of each method.<br />
2 - Distributor’s Integrated Inventory and Shipment Decisions<br />
Sudarsan Rangan, Texas A & M University, 4217 TAMU, College<br />
Station, TX, United States of America, srangan@mays.tamu,edu,<br />
Ismail Capar, Malini Natarajarathinam<br />
This analysis is based on a problem faced by a spare parts distributor that supplies n<br />
retailers. The distributor has to decide on his inventory system and replenish retailer<br />
inventories using a VMI policy. We analyze this problem to provide optimal<br />
inventory acquisition and shipment decisions to minimize the overall cost at the<br />
distributor.<br />
3 - The Impact of Ship Unloading Time Variability on Port Selection<br />
Cesar Meneses, Research Assistant, Arizona State University,<br />
University Drive and Mill Avenue, Tempe, AZ, 85287, United States<br />
of America, cesar.meneses@asu.edu, Rene Villalobos<br />
We develop a port selection model based on additional inventory costs caused by<br />
the variability of service times observed between the arrival of a ship to a port and<br />
the time a container is released from the port. In particular, we seek to minimize<br />
total landed costs by selecting the proper port.<br />
4 - Contract Problems Between a Retailer and a For-Hire Carrier<br />
Fatih Mutlu, Assistant Professor, Qatar University, Industrial<br />
Engineering Department, Doha, 2713, Qatar, fatihmutlu@qu.edu.qa<br />
We study transportation contract problems between a retailer and a for-hire carrier<br />
delivering retailer’s replenishments. We model a decentralized carrier-retailer<br />
channel and design frameworks to set contract terms according to individual<br />
incentives. The terms are i) freight rate, which is based on a two-part tariff<br />
structure, and ii) shipment size. We also analyze the centralized channel to<br />
benchmark the channel profits. We propose modifications on the initial contracts to<br />
assure coordination.<br />
INFORMS Austin – 2010 WD68<br />
453<br />
■ WD67<br />
H - Room 412, 4th Floor<br />
Transportation, Freight II<br />
Contributed Session<br />
Chair: Dung-Ying Lin, Assistant Professor, National Cheng Kung<br />
University, No. 1 University Road, Department of Transportation and<br />
Commun., Tainan City, Taiwan - ROC, dylin@mail.ncku.edu.tw<br />
1 - An Integrated Analysis on Global-US Freight Network<br />
Jiahui (Carol) Wang, Research Assistant, University of Oklahoma,<br />
202 W. Boyd St., Room 124, Norman, OK, 73019, United States of<br />
America, jiahuiwang@ou.edu, Guoqiang Shen, P. Simin Pulat<br />
This research studies on US international freight transportation by an integrated<br />
view on global freight network and domestic freight network, in which, the<br />
international freight flows are extended between US ports to final<br />
destinations/origins (state, census tract, traffic analysis zone…, and the final census<br />
block level). This research also provides insights into the impact of international<br />
freight flows on domestic freight flows starting from each port.<br />
2 - Discrete Time Formulation for the Assignment Problem Applied in<br />
Cross Docking Facilities<br />
Georgios Saharidis, Professor, University of Thessaly and Kathikas<br />
Institute of Research and Technology, Pedion Areos, Volos, 38334,<br />
Greece, saharidis@gmail.com, Mihalis Golias<br />
A cross-docking facility is a freight distribution facility representing a critical point in<br />
a supply chain. The scheduling of the inbound trucks at a cross docking facility is a<br />
classical assignment problem. In this paper two mathematical formulations are<br />
presented to schedule inbound trucks to doors at a cross-docking facility, and<br />
compared to the classical machine scheduling formulation.<br />
3 - Scheduling Commercial Vehicle Queues at a Canada-US<br />
Border Crossing<br />
Michael Haughton, School of Business & Economics, Wilfrid Laurier<br />
University, Waterloo, ON, Canada, mhaughton@wlu.ca,<br />
K.P. Sapna Isotupa<br />
Using the context of queue operations at a major Canada-U.S. commercial border<br />
crossing for truck-borne trade flows, we report on a computer simulation study to<br />
predict the likely impacts of smoothing those flows. We quantify the operational<br />
and resource efficiencies of flow smoothing, not only for trans-border trucking<br />
companies and other commercial organizations involved in trans-border supply<br />
chains but also for government authorities with regulatory jurisdiction at border<br />
crossings. Our study achieves two major goals. First, it extends the queueing<br />
literature’s range of settings in which queue management systems based on flow<br />
smoothing are studied. Second, it adds quantitative precision to the post-9/11<br />
discourse on reducing impediments to the performance of commercial trucking<br />
operations that support trans-border supply chains.<br />
4 - Quantifying the Value of Information Sharing in Supply Chain<br />
Inventory Management<br />
Dung-Ying Lin, Assistant Professor, National Cheng Kung University,<br />
No. 1 University Road, Department of Transportation and Commun.,<br />
Tainan City, Taiwan - ROC, dylin@mail.ncku.edu.tw, Nai-Wen Hsu<br />
We first develop a model in which each stakeholder in the supply chain<br />
independently chooses the optimal inventory policy that has the lowest total<br />
expected cost (TEC) with stochastic demand. Then a model recognizing the<br />
inventory coordination is developed to estimate the total expected cost of the<br />
coordinated supply chain. The value of information sharing in supply chain<br />
inventory management is quantified by the difference of TECs between these two<br />
models.<br />
■ WD68<br />
H - Room 415, 4th Floor<br />
Strategy/Strategic Planning II<br />
Contributed Session<br />
Chair: Michael Bean, Forio Business Simulations, 333 Bryant Street,<br />
San Francisco, CA, 94133, United States of America, mbean@forio.com<br />
1 - A Representation Model and Innovation Heuristics for Business<br />
Ecosystems of Product-Service Systems<br />
Minjeong Baek, Master Student, Seoul National University, 599<br />
Kwanakro, Kwanakgu, Seoul, Korea, Republic of,<br />
kelly706@snu.ac.kr, Changmuk Kang, Yoo S. Hong<br />
A business ecosystem is growing more complex in recent days, as more products<br />
and services are integrated as a product-service system, and more stakeholders are<br />
involved. This study presents a rigorous model for representing and analyzing a<br />
business ecosystem consisting of various stakeholders that interact with products<br />
and services. Based on this model, six heuristic rules for innovating an ecosystem<br />
and industry cases have been proposed.
WD69<br />
2 - The Demand-side Dynamics of Firms’ Intra-industry Exit in a<br />
Geographically Fragmented Industry<br />
Lalit Manral, Assistant Professor, University of Central Oklahoma,<br />
100 N Universtiy Drive, Edmond, OK, 73034, United States of<br />
America, lmanral@uco.edu, Kathryn Harrigan<br />
This paper explores the demand-side dynamics of firms’ selective exit from<br />
geographic sub-markets in a geographically fragmented industry. It provides<br />
theoretical arguments and empirical evidence to explain how the demand-side<br />
structural conditions differentially influence firms’ choice to manage their<br />
geographic scope over time. A unique panel dataset drawn from a natural<br />
experiment in the US long-distance telecommunications services industry during<br />
1984-1996 is used to test the hypotheses.<br />
3 - Strategic Capacity Investment and Pricing Decisions for<br />
Substitutable Products with Partial Flexibility<br />
Sharethram Hariharan, Graduate Research Associate, Oklahoma<br />
State University, 322 Engineering North, OSU Stillwater, Stillwater,<br />
ok, 74078, United States of America, sharethramh@gmail.com,<br />
Tieming Liu, Ho-Yin Mak, Z. Max Shen<br />
We study the capacity investment and responsive pricing decisions for a firm facing<br />
random demands for two substitutable products. Resources are partially flexible. A<br />
resource can be used to produce the other type of product, but with some efficiency<br />
loss. We evaluate the impacts of demand variability, correlation and risk-aversion on<br />
these decisions.<br />
4 - Creating Web-based Simulations and Interactive Data Visualizations<br />
Michael Bean, Forio Business Simulations, 333 Bryant Street, San<br />
Francisco, CA, 94133, United States of America, mbean@forio.com<br />
Simulations and interactive data visualizations that run in browsers have the<br />
advantages of global accessibility, simple distribution, and the ability to monitor and<br />
collect data on usage. However, simulations need to be modified in order to<br />
effectively use the online medium. Usability design is critical to create simulations<br />
that will be used by a diverse, global audience with limited knowledge of<br />
simulation, short attention spans, and unarticulated use objectives.<br />
■ WD69<br />
H - Salon F, 6th Floor<br />
Reverse Logistics II<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Theresa Barker, PhD, University of Washington, Box 352650,<br />
Seattle, WA, 98115, United States of America,<br />
barkertj@u.washington.edu<br />
1 - An Optimization Model to Determine Product Servicing Policies in<br />
Green Supply Chains<br />
Ruth Gledhill-Holmes, PhD Student, University of Central Florida,<br />
4000 Central Florida Blvd, Orlando, FL, 32816, United States of<br />
America, ruth_gledhill_holmes@yahoo.com, Ola Batarseh,<br />
Dima Nazzal<br />
This research considers the possible service policy options necessary to extend and<br />
maximize a product’s usable life (hence resulting in reduced production rates and<br />
the associated environmental benefits of this) in conjunction with the possible<br />
recovery options for maximizing the re-capture of end-of-use products (hence<br />
resulting in reduced waste, reduced need for first-use materials, and recovery of<br />
value for the manufacturer).<br />
2 - Integrating Environmental Considerations into Pricing and<br />
Production Planning Models<br />
Dima Nazzal, Assistant Professor, University of Central Florida, 4000<br />
Central Florida Blvd., Orlando, FL, 32816, United States of America,<br />
dnazzal@mail.ucf.edu, Ali Bozorgi<br />
We propose and test a multi period optimization model that integrates the<br />
environmental impact of a product into the production and pricing decisions. The<br />
model considers the trade-off between economic and environmental objectives.<br />
3 - A Model for Reverse Logistics Under Uncertainty<br />
Theresa Barker, PhD, University of Washington, Box 352650, Seattle,<br />
WA, 98115, United States of America, barkertj@u.washington.edu,<br />
Zelda Zabinsky<br />
Many mixed-integer linear programming models have been developed for reverse<br />
logistics. These models typically require producers to make certain network design<br />
decisions in advance, such as how to collect the return product and where to<br />
perform testing. We present an integrated MILP model that combines high-level and<br />
detailed network design decisions, along with chance-constrained programming to<br />
analyze the tradeoffs between various network configurations.<br />
INFORMS Austin – 2010<br />
454<br />
4 - Creating Value Through Product Stewardship and Take-Back<br />
Ronald Lembke, Associate Professor, Supply Chain, University of<br />
Nevada, MGRS /0028, Reno, NV, 89557, United States of America,<br />
rtl@unr.edu, Zac Rogers, Dale Rogers<br />
Secondary markets provide a place for unwanted items to be bought and sold,<br />
which diverts them from landfills, reducing the products’ ecological impact and<br />
creating economic value. Secondary markets divert a large number of products from<br />
landfills and create jobs, resulting in substantial economic value in the process.<br />
Although not reflected in current government metrics, a conservative estimate is<br />
that the secondary market represents 2.28 percent of the 2008 U.S. GDP.<br />
■ WD70<br />
H - Salon G, 6th Floor<br />
Optimization Models in Air Traffic Management<br />
Sponsor: Aviation Applications<br />
Sponsored Session<br />
Chair: Andrew Churchill, Graduate Research Assistant,<br />
University of Maryland, 1173 Martin Hall, College Park, MD, 20742,<br />
United States of America, churchil@umd.edu<br />
1 - The Impact of Induced Technological Change on Air Traffic<br />
Management<br />
Megan Ryerson, Institute of Transportation Studies, 109 McLaughlin<br />
Hall, UC Berkeley, Berkeley, CA, 94720, United States of America,<br />
msmirti@berkeley.edu<br />
Short-haul aviation is a focus of transportation policy today due to growing aircraft<br />
diversity and uncertainty surrounding carbon emissions policies. We develop an<br />
analytic total logistics cost model of short-haul corridor serving multiple passenger<br />
groups and find that turboprops, alone and in a fleet mix with jets, minimize cost<br />
for levels of policy seen today. This aircraft mix in response to a carbon emissions<br />
policy has implications for air traffic management.<br />
2 - Converging Upon Basic Feasible Solutions Through<br />
Dantzig-Wolfe Decomposition<br />
Joseph Rios, NASA, Mail Stop 210-15, Moffet Field, CA, 94035,<br />
United States of America, Joseph.L.Rios@nasa.gov, Kevin Ross<br />
We derive an important property for solving integer programs by examining the<br />
master problem in Dantzig-Wolfe Decomposition. Namely, if a linear program can be<br />
decomposed appropriately, a mapping exists between basic feasible solutions in the<br />
master and original problems. This has implications for integer programs where the<br />
convex hull has mostly integer corner points. We highlight the significance through<br />
experiments on a large-scale traffic flow model for the National Airspace System.<br />
3 - Collaborative Strategies for Traffic Management in the Airspace<br />
Flow Program<br />
Amy Kim, amykim0603@gmail.com, Mark Hansen<br />
We investigate methods that aim to minimize the user-cost impact of a future AFP<br />
that employs rerouting and ground delay. Methods are assessed using a simple flight<br />
cost specification; the deterministic part represents flight costs known to the FAA,<br />
while the stochastic part represents costs known only to the airline. Models<br />
featuring different allocation schemes, user inputs, and timing of information gather<br />
are compared. We explore tradeoffs between information quality and timeliness.<br />
4 - Assessing the Impact of Stochastic Capacity Variation on<br />
Coordinated Air Traffic Flow Management<br />
Andrew Churchill, Graduate Research Assistant, University of<br />
Maryland, 1173 Martin Hall, College Park, MD, 20742, United States<br />
of America, churchil@umd.edu, David Lovell, Michael Ball<br />
In this research, an integer optimization model for coordination between air traffic<br />
flow management initiatives and a three parameter characterization of resource<br />
capacity are used to understand the effects of random capacity variations.<br />
Employing the optimization model within a Monte Carlo simulation, the results<br />
suggest that each of the three parameters characterizing capacity have marginally<br />
increasing impacts over a wide range of conditions.
■ WD72<br />
H - Salon J, 6th Floor<br />
Facility Logistics Session: Warehouse Order Picking<br />
Sponsor: Transportation Science and Logistics Society<br />
Sponsored Session<br />
Chair: Russell Meller, Hefley Professor of Logistics and Entrepreneurship,<br />
University of Arkansas, 4207 Bell Engineering, Fayetteville, AR, 72701,<br />
United States of America, rmeller@uark.edu<br />
1 - Boosting Productivity in Multiple-Aisle Order-Picking by Cellular<br />
Bucket Brigades<br />
Yun Fong Lim, Assistant Professor, Singapore Management<br />
University, 50 Stamford Road #04-01, Singapore, Singapore,<br />
yflim@smu.edu.sg<br />
We introduce a new design of bucket brigades for order-picking in multiple, parallel<br />
aisles. Workers pick products from one side of an aisle when they proceed in one<br />
direction and they pick from the other side of the aisle, possibly for other customer<br />
orders, when they proceed in the reverse direction. We assume hand-off times are<br />
significant and propose simple rules for workers to share work. The new design can<br />
be substantially more productive than traditional bucket brigades.<br />
2 - Using Storage Profiles with Bucket Brigade Order Picking to<br />
Improve Productivity<br />
Don Eisenstein, Professor of Operations Management, University of<br />
Chicago, Booth School of Business, 5807 South Woodlawn Avenue,<br />
Chicago, IL, 60637, United States of America,<br />
Don.Eisenstein@chicagobooth.edu, Yeming Gong<br />
We compare bucket brigade and zone order picking protocols using various storage<br />
profiles. We find that the flexibility of a bucket brigade protocol can lead to some<br />
considerable advantages in productivity.<br />
3 - Modeling the Throughput Performance of a Picking Machine Order-<br />
Fulfillment Technology<br />
Jennifer Pazour, PhD Candidate, University of Arkansas,<br />
4207 Bell Engineering Center, Fayetteville, AR, 72701,<br />
United States of America, jpazour@uark.edu, Russell Meller<br />
Picking machines are an example of a stock-to-picker piece-level fulfillment<br />
technology that consists of two or more pick stations, a common storage system,<br />
and an integrated conveyor system. We develop a stability function model based on<br />
queuing theory that is capable of determining if a picking machine will be able to<br />
meet a throughput requirement. We then illustrate how a manager could use our<br />
analytical model to answer picking machine design questions.<br />
■ WD73<br />
H - Salon K, 6th Floor<br />
Joint Session TSL/ SPPSN: Mitigating Disaster Impact<br />
Through Planning for Emergency Response<br />
Sponsor: Transportation Science and Logistics Society/ Public<br />
Programs, Service and Needs<br />
Sponsored Session<br />
Chair: Elise Miller-Hooks, University of Maryland, 1173 Glenn Martin<br />
Hall, College Park, MD, 20742, United States of America,<br />
elisemh@umd.edu<br />
1 - A Robust P-center Model for Emergency Facility Location Planning<br />
Chung-Cheng Lu, Assistant Professor, National Taipei University of<br />
Technology, 1 Section 3, Chung-Hsiao E. Road, Information and<br />
Logistics Management, Taipei, 106, Taiwan - ROC,<br />
jasoncclu@gmail.com<br />
This study deals with the p-center problem with uncertain travel times between<br />
emergency facilities and affected areas which may arise in large-scale disasters. The<br />
uncertain travel times are represented by intervals and a robust optimization<br />
approach that minimizes the worst-case deviation from optimal solutions was<br />
developed. Numerical experiments were conducted to demonstrate the effectiveness<br />
of the approach and to examine the tradeoff between robustness and optimality.<br />
2 - Locating Support Facilities for Large Scale Emergencies<br />
Anurag Verma, Graduate Student, Texas A&M University, Industrial<br />
and Systems Engineering, College Station, TX, 77843-3131,<br />
United States of America, anuragverma@tamu.edu, Gary Gaukler<br />
We provide large scale emergency facility location models that account for the<br />
unavailability of a disaster response facility depending on its location and the<br />
position of the disaster. We find that the locations suggested by the models in this<br />
paper significantly reduce the expected cost of transportation of supplies when we<br />
consider the damage a disaster causes to the support facilities and areas near it.<br />
INFORMS Austin – 2010 WD74<br />
455<br />
3 - Decision Support for Urban Search and Rescue<br />
Lisa (Lichun) Chen, lcchen@umd.edu, Elise Miller-Hooks<br />
The urban search and rescue (USAR) team deployment problem seeks an optimal<br />
deployment of USAR teams to disaster sites so as to maximize the expected number<br />
of saved lives over the search and rescue period. A multistage stochastic program<br />
that captures problem uncertainty and dynamics is presented. A column generationbased<br />
technique is proposed for its solution. The techniques is illustrated on a case<br />
study involving the 2010 Haiti earthquake.<br />
4 - Using TRANSIMS for On-line Transportation System Management<br />
During Emergencies<br />
Adel Sadek, Associate Professor, University at Buffalo, the State<br />
University of New York, 233 Ketter Hall, Buffalo, NY, 14260,<br />
United States of America, asadek@buffalo.edu, Daniel Fuglewicz,<br />
Alan Blatt, Yunjie Zhao<br />
The topic of transportation systems management during emergencies has recently<br />
received national attention. This study has two primary objectives: (1) to assess the<br />
level to which the TRANSIMS model can be used for the online management of<br />
transportation systems during emergencies; and (2) to develop any additional<br />
functionality needed for that. As a case study, the research uses the Buffalo-Niagara<br />
area known for its winter weather and numerous snow storms.<br />
■ WD74<br />
H - Room 602, 6th Floor<br />
Joint Session TSL/ Service Science: Emergency<br />
Transportation, Logistics, and Evacuation Service<br />
Sponsor: Transportation Science and Logistics Society/<br />
Service Science<br />
Sponsored Session<br />
Chair: Tao Yao, Assistant Professor, Pennsylvania State University, 349<br />
Leonhard Building, University Park, PA, 16802, United States of America,<br />
tyy1@engr.psu.edu<br />
1 - Distributing Supplies in a Multi-city Infectious Disease Outbreak<br />
Fernando Ordonez, Associate Professor, University of Southern<br />
California, Department of Industrial and Systems Eng, 3715<br />
McClintock Ave, Los Angeles, CA, 90007, United States of America,<br />
fordon@usc.edu, Yingtao Ren<br />
We consider the distribution of medicine to mitigate a multi-city infectious disease<br />
outbreak under parameter uncertainty. We build a two-stage stochastic<br />
programming model which has integer variables in both stages. This problem is<br />
solved with a modified Bender’s method to recover dual information from the<br />
second stage MIP and to speed up convergence. We illustrate the use of the model<br />
and the algorithm in planning an emergency response to a hypothetical national<br />
smallpox outbreak.<br />
2 - Evacuation Planning Under Uncertainty: A Distributional Robust<br />
Chance-Constrained Approach<br />
Tao Yao, Assistant Professor, Pennsylvania State University, 349<br />
Leonhard Building, University Park, PA, 16802, United States of<br />
America, tyy1@engr.psu.edu, Byung Do Chung, Bo Zhang<br />
This talk provides a Chance-constrained Programming approach for evacuation<br />
transportation planning which are robust to uncertainty. We focus on demand<br />
uncertainty with partial distributional information and develop an approximation<br />
scheme to reformulate the problem as a deterministic convex program which is then<br />
proved to be safe and computationally tractable. Numerical experiments are<br />
provided to illustrate the performance of the proposed approach.<br />
3 - Demand Management for Evacuation Planning<br />
Douglas Bish, Assistant Professor, Grado Department of Industrial<br />
and Systems Engineering, Virginia Tech, Blacksburg, VA, 24061,<br />
United States of America, drb1@vt.edu<br />
In hurricane evacuations traffic often overwhelms the infrastructure, causing<br />
congestion that can increase the risk to the population. Supply management<br />
strategies are used in evacuation planning, but they are often insufficient. We study<br />
the use of demand management strategies that attempt to structure the evacuation<br />
demand in order to minimize congestion. Specifically, we study network flow<br />
problems that incorporate important aspects of evacuee behavior and evacuation<br />
management issues.<br />
4 - Optimal Evacuation Routing Under Dynamic Stochastic Risks<br />
Chi Xie, Research Fellow, The University of Texas at Austin, 1<br />
University Station, Austin, TX, 78712, United States of America,<br />
chi.xie@mail.utexas.edu, Tao Yao, Travis Waller<br />
We propose a risk-based modeling framework and solution procedure for dynamic<br />
evacuation planning under hazardous material releases, which integrates the latest<br />
atmospheric dispersion modeling and network flow modeling techniques. A robust<br />
dynamic evacuation routing model is presented for devising evacuation plans that<br />
minimize the most risky exposure to the evacuating population under timedependent,<br />
uncertain hazardous effluents.