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Technical Sessions – Monday July 11

Technical Sessions – Monday July 11

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FB-21 IFORS 20<strong>11</strong> - Melbourne<br />

2 - Integration of Multi-criteria Decision Analysis and Lifecycle<br />

Assessment to Measure Environmental Impacts<br />

of Biomass Production<br />

Tanja Myllyviita, Finnish environment institute, P.O.Box <strong>11</strong>1,<br />

FI-80101, Joensuu, Finland, tanja.myllyviita@joensuu.fi, Anne<br />

Holma, Riina Antikainen, Katja Lähtinen, Pekka Leskinen<br />

Life-cycle assessment (LCA) evaluates environmental impacts of a product<br />

from processing of raw-material to disposal with environmental impact categories.<br />

MCDA was applied to assess the importance of different LCA impact<br />

categories in biomass production. Experts valuated impact categories with a<br />

MCDA-application. The most important impact categories were natural landuse<br />

and climate change. Also biodiversity was considered important. The results<br />

indicate that MCDA can provide suitable tools for the weighting phase in<br />

LCA, which enables transforming the environmental impacts into one number.<br />

3 - On Elicitation Techniques of Near-consistent Pairwise<br />

Comparison Matrices<br />

Jozsef Temesi, Operations Research and Actuarial Studies,<br />

Corvinus University of Budapest, Fovam ter 8, 1093, Budapest,<br />

Hungary, jozsef.temesi@uni-corvinus.hu<br />

Pairwise comparison matrices (PCMs) are frequently used in various multicriteria<br />

decision-making methods. One of the most important properties of a<br />

PCM is consistency. My presentation will define the near-consistency of the<br />

PCM, and the error-free property of the decision-maker. Based on these definitions<br />

several methods can be generated to obtain the elements of a pairwise<br />

comparison matrix. Different elicitation techniques will be introduced, and —<br />

in case of non-consistent matrices — adjustment methods will be analyzed for<br />

both informed and uninformed decision-makers.<br />

4 - An Analysis of the Major Drivers of Stock Market Prices-<br />

Case Study for the Zimbabwe Stock Exchange (2007-<br />

2008)<br />

Kelvin T Chirenje, Applied Maths, National University of<br />

Science and Technology, 10 Rukumbati Rd, Zengeza 3, +263,<br />

Chitungwiza, Harare, Zimbabwe, kchirenje@gmail.com<br />

This research is aimed at assessing the main factors that influenced the stock<br />

prices on the Zimbabwe Stock Exchange (ZSE) to be continuously bullish from<br />

2007-2008, despite harsh economic conditions which prevailed in the country<br />

and explore the applicability of traditional theorist to the ZSE. Furthermore, the<br />

research will outline why the stock market was performing extraordinarily well<br />

in an economy down the drain with many corporations reporting subnormal<br />

profits and some shutting down<br />

� FB-21<br />

Friday, 13:15-14:45<br />

Meeting Room 218<br />

Stochastic Open Pit Mine Planning and<br />

Supply Chains<br />

Stream: Mining Applications<br />

Invited session<br />

Chair: Gary Froyland, School of Mathematics and Statistics,<br />

University of New South Wales, 2052, Sydney, NSW, Australia,<br />

g.froyland@unsw.edu.au<br />

1 - Open Pit Mine Planning with Uncertain Geology via<br />

Multi-stage Integer Stochastic Programming with Endogenous<br />

Uncertainty<br />

Gary Froyland, School of Mathematics and Statistics, University<br />

of New South Wales, 2052, Sydney, NSW, Australia,<br />

g.froyland@unsw.edu.au, Natashia Boland, Irina Dumitrescu<br />

Geological uncertainty is a major source of financial risk for mining projects.<br />

It is particularly difficult to handle as the timing of the resolution of the uncertainty<br />

is dependent upon earlier decisions made. We model the problem of NPV<br />

optimisation under geological uncertainty as a multi-stage integer stochastic<br />

programming under endogenous uncertainty. Our model allows mining and<br />

processing decisions to flexibly adapt over time, in response to observation of<br />

the geology of the material mined. We also discuss a number of model reductions<br />

to decrease computational effort.<br />

124<br />

2 - Dealing with Price Uncertainty in Mine Planning<br />

Andrés Weintraub, University of Chile, Santiago, Chile,<br />

aweintra@dii.uchile.cl, Roger Wets, David Woodruff, Jean-Paul<br />

Watson, Rafael Epstein, Jaime Gacitua<br />

We consider the problem of uncertainty in future copper prices, reflected<br />

through scenarios with probabilites. Non-anticipativity constraints are imposed<br />

on the basic problem constraints. For larger problems solving the problem with<br />

the non-anticipativity constraints is very difficult computationally. We develop<br />

an approach for this problem based on Progressive Hedging, where the problem<br />

is decomposed by scenarios, and convergence to a feasible solution is attained<br />

through penalizing deviations from non-anticipativity. Positive results were<br />

obtained for an open pit mine problem.<br />

3 - Effective Computational Models For Oil Refinery Operations<br />

Juan Kuther, Maths and Stats, Curtin University, GPO BOX<br />

U1987, 6845, Perth, WA, Australia,<br />

juan.kok@postgrad.curtin.edu.au, Louis Caccetta<br />

Petroleum refineries are very complex systems, giving rise to computationally<br />

difficult optimization models. Resolution of these problems is crucial for production<br />

planning and in particular in the evaluation and selection of crudes,<br />

feedstocks, products and processing options. These large-scale production<br />

planning models, which can are formulated as non-convex Mixed Integer Nonlinear<br />

Programming (MINLP) models, are very difficult to solve. Currently<br />

available tools are deficient and usually give rise to inconsistent predictions of<br />

refinery productivity and operation. Recent advances in a number of disciplines<br />

including computer science, mathematical programming, heuristics and complimentary<br />

disciplines like constraint programming and artificial intelligence<br />

motivate this research. These recent advances in technology will be utilised to<br />

formulate effective oil refinery production planning models.<br />

4 - Collaborative Resource Constrained Scheduling : A<br />

Coal Industry Example<br />

Anu Thomas, Industrial Engineering and Operations Research,<br />

IITB Monash Research Academy, IIT Bombay, Powai, 400076,<br />

Mumbai, MH, India, anuthomas@iitb.ac.in, Gaurav Singh,<br />

Mohan Krishnamoorthy, Jayendran Venkateswaran<br />

We present a collaborative resource constrained scheduling problem motivated<br />

by the mining industry. In this model, there are several independent mines<br />

which have delivery jobs to be completed by certain due dates (ship arrival<br />

times). These jobs also require trains (of certain sizes) that are independently<br />

provided by a rail operator having a finite number of trains. We present MIP<br />

formulations, heuristic algorithms and computational results to compare centralised<br />

and decentralised decision making for minimising total weighted tardiness<br />

of all the jobs while maximising train utilisation.

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