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Editor in Chief<br />

Carl K. Chang<br />

Iowa State University<br />

____________<br />

chang@cs.iastate.edu<br />

Associate Editor<br />

in Chief<br />

Sumi Helal<br />

University of Florida<br />

__________<br />

helal@cise.ufl.edu<br />

Area Editors<br />

Computer Architectures<br />

Steven K. Reinhardt<br />

AMD<br />

Databases and Information<br />

Retrieval<br />

Erich Neuhold<br />

University of Vienna<br />

Distributed Systems<br />

Jean Bacon<br />

University of Cambridge<br />

Graphics and Multimedia<br />

Oliver Bimber<br />

Johannes Kepler University Linz<br />

High-Performance Computing<br />

Vladimir Getov<br />

University of Westminster<br />

Information and<br />

Data Management<br />

Naren Ramakrishnan<br />

Virginia Tech<br />

Multimedia<br />

Savitha Srinivasan<br />

IBM Almaden Research Center<br />

Networking<br />

Ahmed Helmy<br />

University of Florida<br />

Software<br />

Robert B. France<br />

Colorado State University<br />

David M. Weiss<br />

Iowa State University<br />

Editorial Staff<br />

Scott Hamilton<br />

Senior Acquisitions Editor<br />

_____________<br />

shamilton@computer.org<br />

Judith Prow<br />

Managing Editor<br />

___________<br />

jprow@computer.org<br />

Chris Nelson<br />

Senior Editor<br />

James Sanders<br />

Senior Editor<br />

COMPUTER<br />

Associate Editor in Chief,<br />

Research Features<br />

Kathleen Swigger<br />

University of North Texas<br />

__________<br />

kathy@cs.unt.edu<br />

Associate Editor in Chief,<br />

Special Issues<br />

Bill N. Schilit<br />

Google<br />

schilit@computer.org<br />

____________<br />

Column Editors<br />

AI Redux<br />

Naren Ramakrishnan<br />

Virginia Tech<br />

Education<br />

Ann E.K. Sobel<br />

Miami University<br />

Embedded Computing<br />

Tom Conte<br />

Georgia Tech<br />

Green IT<br />

Kirk W. Cameron<br />

Virginia Tech<br />

Industry Perspective<br />

Sumi Helal<br />

University of Florida<br />

IT Systems Perspectives<br />

Richard G. Mathieu<br />

James Madison University<br />

Invisible Computing<br />

Albrecht Schmidt<br />

University of Duisburg-Essen<br />

The Known World<br />

David A. Grier<br />

George Washington University<br />

The Profession<br />

Neville Holmes<br />

University of Tasmania<br />

Security<br />

Jeffrey M. Voas<br />

NIST<br />

Contributing Editors<br />

Lee Garber<br />

Bob Ward<br />

Design and Production<br />

Larry Bauer<br />

Design<br />

Olga D’Astoli<br />

Cover Design<br />

Kate Wojogbe<br />

Computing Practices<br />

Rohit Kapur<br />

rohit.kapur@synopsys.com<br />

________________<br />

Perspectives<br />

Bob Colwell<br />

bob.colwell@comcast.net<br />

_____________<br />

Web Editor<br />

Ron Vetter<br />

vetterr@uncw.edu<br />

___________<br />

Software Technologies<br />

Mike Hinchey<br />

Lero—the Irish Software<br />

Engineering Research Centre<br />

Web Technologies<br />

Simon S.Y. Shim<br />

San Jose State University<br />

Advisory Panel<br />

Thomas Cain<br />

University of Pittsburgh<br />

Doris L. Carver<br />

Louisiana State University<br />

Ralph Cavin<br />

Semiconductor Research Corp.<br />

Dan Cooke<br />

Texas Tech University<br />

Ron Hoelzeman<br />

University of Pittsburgh<br />

Naren Ramakrishnan<br />

Virginia Tech<br />

Ron Vetter<br />

University of North Carolina,<br />

Wilmington<br />

Alf Weaver<br />

University of Virginia<br />

Administrative<br />

Staff<br />

Products and<br />

Services Director<br />

Evan Butterfield<br />

Manager,<br />

Editorial Services<br />

Jennifer Stout<br />

2010 IEEE Computer<br />

Society President<br />

James D. Isaak<br />

cspresident2010@jimisaak.com<br />

__________________<br />

CS Publications Board<br />

David A. Grier (chair), David<br />

Bader, Angela R. Burgess, Jean-<br />

Luc Gaudiot, Phillip Laplante,<br />

Dejan Milojičić, Linda I. Shafer,<br />

Dorée Duncan Seligmann, Don<br />

Shafer, Steve Tanimoto, and<br />

Roy Want<br />

CS Magazine<br />

Operations Committee<br />

Dorée Duncan Seligmann<br />

(chair), David Albonesi, Isabel<br />

Beichl, Carl Chang, Krish<br />

Chakrabarty, Nigel Davies, Fred<br />

Douglis, Hakan Erdogmus, Carl<br />

E. Landwehr, Simon Liu, Dejan<br />

Milojičić, John Smith, Gabriel<br />

Taubin, Fei-Yue Wang, and<br />

Jeffrey R. Yost<br />

Senior Business<br />

Development Manager<br />

Sandy Brown<br />

Senior Advertising<br />

Coordinator<br />

Marian Anderson<br />

Circulation: Computer (ISSN 0018-9162) is published monthly by the IEEE Computer Society. IEEE Headquarters, Three Park Avenue, 17th Floor, New York, NY<br />

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Editorial: Unless otherwise stated, bylined articles, as well as product and service descriptions, reflect the author’s or firm’s opinion. Inclusion in Computer<br />

does not necessarily constitute endorsement by the IEEE or the Computer Society. All submissions are subject to editing for style, clarity, and space.<br />

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CONTENTS<br />

ABOUT THIS ISSUE<br />

Growing interest in cloud <strong>computing</strong> also raises the<br />

question of cost/benefit. In this issue, we feature an<br />

article describing a federated, open-source cloud platform<br />

that lowers the entry barriers to systems and<br />

applications research communities, an economic model<br />

for determining whether to lease or buy storage, and an<br />

analysis of energy consumption and battery life in<br />

mobile devices offloading computation to the cloud. We<br />

also look at puzzle-based learning, ethical codes of conduct<br />

in the legal realm, and the linkage of software<br />

development and business strategy.<br />

COMPUTING PRACTICES<br />

20 Puzzle-Based Learning for<br />

Engineering and Computer<br />

Science<br />

Nickolas Falkner, Raja Sooriamurthi,<br />

and Zbigniew Michalewicz<br />

To attract, motivate, and retain students and<br />

increase their mathematical awareness and<br />

problem-solving skills, universities are<br />

introducing courses or seminars that explore<br />

puzzle-based learning. The authors introduce<br />

and define this learning approach, describe<br />

course variations, and highlight early student<br />

feedback.<br />

PERSPECTIVES<br />

29 Using Codes of Conduct<br />

to Resolve Legal Disputes<br />

Peter Aiken, Robert M. Stanley, Juanita<br />

Billings, and Luke Anderson<br />

In the absence of other published standards of<br />

care, it is reasonable for contractual parties to<br />

rely on an applicable, widely available code of<br />

conduct to guide expectations.<br />

COVER FEATURES<br />

35 Open Cirrus: A Global<br />

Cloud Computing Testbed<br />

Arutyun I. Avetisyan, Roy Campbell, Indranil<br />

Gupta, Michael T. Heath, Steven Y. Ko,<br />

Gregory R. Ganger, Michael A. Kozuch,<br />

David O’Hallaron, Marcel Kunze, Thomas T.<br />

Kwan, Kevin Lai, Martha Lyons, Dejan S.<br />

Milojicic, Hing Yan Lee, Yeng Chai Soh,<br />

http://computer.org/computer<br />

For more information on <strong>computing</strong> topics, visit the Computer Society Digital Library at www.computer.org/csdl.<br />

Ng Kwang Ming, Jing-Yuan Luke,<br />

and Han Namgoong<br />

Open Cirrus is a cloud <strong>computing</strong> testbed<br />

that, unlike existing alternatives, federates<br />

distributed data centers. It aims to spur<br />

innovation in systems and applications<br />

research and catalyze development of an<br />

open source service stack for the cloud.<br />

44 To Lease or Not to Lease<br />

from Storage Clouds<br />

Edward Walker, Walter Brisken,<br />

and Jonathan Romney<br />

Storage clouds are online services for leasing<br />

disk storage. A new modeling tool,<br />

formulated from empirical data spanning<br />

many years, lets organizations rationally<br />

evaluate the benefit of using storage clouds<br />

versus purchasing hard disk drives.<br />

51 Cloud Computing for Mobile<br />

Users: Can Offloading<br />

Computation Save Energy?<br />

Karthik Kumar and Yung-Hsiang Lu<br />

The cloud heralds a new era of <strong>computing</strong><br />

where application services are provided<br />

through the Internet. Cloud <strong>computing</strong> can<br />

enhance the <strong>computing</strong> capability of mobile<br />

systems, but is it the ultimate solution for<br />

extending such systems’ battery lifetimes?<br />

RESEARCH FEATURE<br />

57 Linking Software<br />

Development and<br />

Business Strategy<br />

through Measurement<br />

Victor R. Basili, Mikael Lindvall, Myrna<br />

Regardie, Carolyn Seaman, Jens Heidrich,<br />

Jürgen Münch, Dieter Rombach,<br />

and Adam Trendowicz<br />

The GQM + Strategies approach extends the<br />

goal/question/metric paradigm for<br />

measuring the success or failure of goals and<br />

strategies, adding enterprise-wide support<br />

for determining action on the basis of<br />

measurement results. An organization can<br />

thus integrate its measurement program<br />

across all levels.<br />

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IEEE Computer Society: http://computer.org<br />

Computer: http://computer.org/computer<br />

computer@computer.org<br />

___________<br />

IEEE Computer Society Publications Office: +1 714 821 8380<br />

Cover image © Lolaferari Dreamstime.com<br />

6 The Known World<br />

Utter Chaos<br />

David Alan Grier<br />

10 32 & 16 Years Ago<br />

Computer, April 1978 and 1994<br />

Neville Holmes<br />

NEWS<br />

13 Technology News<br />

Will HTML 5 Restandardize the Web?<br />

Steven J. Vaughan-Nichols<br />

16 News Briefs<br />

Linda Dailey Paulson<br />

MEMBERSHIP NEWS<br />

66 IEEE Computer Society<br />

Connection<br />

69 Call and Calendar<br />

COLUMNS<br />

76 AI Redux<br />

Probabilistic Analysis of an Ancient<br />

Undeciphered Script<br />

Rajesh P.N. Rao<br />

81 Software Technologies<br />

When TV Dies, Will It Go to the Cloud?<br />

Karin Breitman, Markus Endler, Rafael<br />

Pereira, and Marcello Azambuja<br />

Flagship Publication of the IEEE<br />

Computer Society<br />

April 2010, Volume 43, Number 4<br />

84 Invisible Computing<br />

Questioning Invisibility<br />

Leah Buechley<br />

87 Education<br />

Cutting Across the Disciplines<br />

Jim Vallino<br />

90 Security<br />

Integrating Legal and Policy Factors in<br />

Cyberpreparedness<br />

James Bret Michael, John F. Sarkesain,<br />

Thomas C. Wingfield, Georgios Dementis,<br />

and Gonçalo Nuno Baptista de Sousa<br />

96 The Profession<br />

Computing a Better World<br />

Kai A. Olsen<br />

DEPARTMENTS<br />

4 Elsewhere in the CS<br />

71 Computer Society Information<br />

72 Career Opportunities<br />

74 Advertiser/Product Index<br />

93 Bookshelf<br />

Reuse Rights and Reprint Permissions: Educational or personal use of this<br />

material is permitted without fee, provided such use: 1) is not made for profit;<br />

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the copy; and 3) does not imply IEEE endorsement of any third-party products<br />

or services. Authors and their companies are permitted to post their IEEE-copyrighted material on<br />

their own Web servers without permission, provided that the IEEE copyright notice and a full citation<br />

to the original work appear on the first screen of the posted copy.<br />

Permission to reprint/republish this material for commercial, advertising, or promotional purposes<br />

or for creating new collective works for resale or redistribution must be obtained from the IEEE by<br />

writing to the IEEE Intellectual Property Rights Office, 445 Hoes Lane, Piscataway, NJ 08854-4141<br />

or pubs-permissions@ieee.org. _______________ Copyright © 2010 IEEE. All rights reserved.<br />

Abstracting and Library Use: Abstracting is permitted with credit to the source. Libraries are permitted<br />

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IEEE prohibits discrimination, harassment, and bullying. For more information, visit www.ieee.org/<br />

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ELSEWHERE IN THE CS<br />

Computer Highlights Society Magazines<br />

The IEEE Computer Society offers a lineup<br />

of 13 peer-reviewed technical magazines<br />

that cover cutting-edge topics in <strong>computing</strong><br />

including scientific applications, design and<br />

test, security, Internet <strong>computing</strong>, machine intelligence,<br />

digital graphics, and computer history. Select articles from<br />

recent issues of Computer Society magazines are highlighted<br />

below.<br />

The March/April issue of Software features an overview<br />

of tools and technologies for improved collaboration titled<br />

“Collaboration Tools for Global Software Engineering,” by<br />

Filippo Lanubile, Christof Ebert, Rafael Prikladnicki, and<br />

Aurora Vizcaíno. Effective tool support for collaboration<br />

is a strategic initiative for any company with distributed<br />

resources, no matter whether the strategy involves offshore<br />

development, outsourcing, or supplier networks. Software<br />

needs to be shared, and appropriate tool support is the only<br />

way to do this efficiently, consistently, and securely.<br />

No single solution has yet emerged to unify communications<br />

among the various and proliferating messaging<br />

systems available today. In “Understanding Unified Messaging,”<br />

in the January/February issue of IT Pro, Clinton M.<br />

Banner of Alcatel-Lucent surveys the issues and solutions—<br />

both proprietary and open—that are in development.<br />

“Integrating Visualization and Interaction Research to<br />

Improve Scientific Workflows,” by the University of Minnesota’s<br />

Daniel F. Keefe, identifies three goals—improving<br />

accuracy, linking multiple visualization strategies, and<br />

making data analysis more fluid—that serve as a guide<br />

for future interactive-visualization research targeted<br />

COMPUTER<br />

at improving visualization tools’ impact on scientific<br />

workflows.<br />

The article, which appears in the March/April issue of<br />

CG&A, also offers four examples that illustrate the potential<br />

and challenges of integrating visualization research and<br />

interaction research: 3D selection techniques in brain visualizations,<br />

interactive multiview scientific visualizations,<br />

fluid pen- and touch-based interfaces for visualization, and<br />

modeling human performance in interactive visualizationrelated<br />

tasks.<br />

The Cell Broadband Engine is a heterogeneous chip<br />

multiprocessor that combines a PowerPC processor core<br />

with eight single-instruction, multiple-data accelerator<br />

cores and delivers high performance on many computationally<br />

intensive codes. “Application Acceleration with the<br />

Cell Broadband Engine” by Guochun Shi, Volodymyr Kindratenko,<br />

Frederico Pratas, Pedro Trancoso, and Michael<br />

Gschwind appears in the January/February issue of CiSE.<br />

Demand-response systems provide detailed powerconsumption<br />

data to utilities and those angling to assist<br />

consumers in understanding and managing energy use.<br />

Such data reveals information about in-home activities that<br />

can be mined and combined with other readily available<br />

information to discover more about occupants’ activities.<br />

“Inferring Personal Information from Demand-Response<br />

Systems” by Mikhail Lisovich, Deirdre Mulligan, and Stephen<br />

Wicker appears in the January/February issue of S&P.<br />

The March/April issue of Intelligent Systems focuses<br />

on new paradigms in business and market intelligence.<br />

The emergence of user-generated Web 2.0 content offers<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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opportunities to listen to the voice of the market as articulated<br />

by a vast number of business constituents. An<br />

overview in this issue of IS includes five short articles by<br />

distinguished experts on today’s trends in business and<br />

market intelligence. Each article presents a unique, innovative<br />

research framework, computational methods, and<br />

selected results and examples.<br />

In the world of Web 2.0, Internet 2, and open systems,<br />

most learning is still done in traditional classrooms. As<br />

education costs continue to far outpace inflation, what is<br />

e-learning’s role? In the March/April issue of Internet Computing,<br />

Stephen Ruth of George Mason University addresses<br />

these questions in “Is E-Learning Really Working? The<br />

Trillion Dollar Question.”<br />

Spectacles is a hardware/software platform developed<br />

from off-the-shelf components and ready for market. It<br />

includes local computation and communication facilities,<br />

an integrated power supply, and modular system building<br />

blocks such as sensors, voice-to-text and text-to-speech<br />

components, localization and positioning units, and microdisplay<br />

units. Its see-through display components are<br />

integrated into eyeglass frames. “Wearable Displays—for<br />

Everyone!” by Alois Ferscha and Simon Vogl appears in the<br />

January-March issue of PvC.<br />

The January/February issue of Micro continues a<br />

seven-year tradition of featuring top picks from computer<br />

architecture conferences. Guest editor Trevor Mudge of<br />

the University of Michigan participated in a program committee<br />

of 31 computer architects from both industry and<br />

academia. The committee reviewed 91 submissions, selecting<br />

13 papers for abridgment in the magazine. Topics range<br />

from practical prefetching to application-domain-specific<br />

<strong>computing</strong> and nonvolatile memory.<br />

Current media-synchronization techniques range from<br />

the very theoretical to the very practical. In “Modeling<br />

Media Synchronization with Semiotic Agents,” researchers<br />

from the City University of Hong Kong and the University of<br />

Reading describe a modeling technique for mapping theoretical<br />

models to system implementations. The technique<br />

combines agent technology with semiotics to offer a sound<br />

theoretical framework for expressing and manipulating<br />

media-synchronization attributes in real-world applications.<br />

Read more in the January-March issue of Multimedia.<br />

reduced 70%<br />

reduced 70%<br />

As CMOS technology scales down to the nanometer<br />

range, variation control in semiconductor manufacturing<br />

becomes ever more challenging. Introducing D&T’s March/<br />

April special issue in “Compact Variability Modeling in<br />

Scaled CMOS Design,” guest editors Yu Cao of Arizona State<br />

University and Frank Liu of IBM Austin Research Laboratory<br />

preview five articles that address these challenges.<br />

An article by Fred Brooks, renowned computer scientist<br />

and author of The Mythical Man-Month, opens the first issue<br />

of Annals in 2010. In “Stretch-ing Is Great Exercise—It Gets<br />

You in Shape to Win,” Brooks recounts the history of the<br />

IBM Stretch Project (1955-1961). Although the company lost<br />

$35 million on the project in 1960, Brooks describes how<br />

Stretch drove technologies that enabled the rapid development<br />

of IBM’s successful 7000-series computers and the<br />

architectural innovations of its System/360 product family.<br />

Editor: Bob Ward, Computer; bnward@computer.org<br />

____________<br />

http://computer.org/cn/ELSEWHERE<br />

April Theme:<br />

AGILITY AND<br />

ARCHITECTURE<br />

APRIL 2010<br />

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THE KNOWN WORLD<br />

Utter Chaos<br />

As far as I can tell, they live<br />

<strong>lives</strong> of utter chaos. The<br />

three of them, all young<br />

physicians who seem<br />

no older than 16, seize<br />

control of the locker room every<br />

morning. They apparently finish a<br />

rather raucous game just as I arrive<br />

to begin my swim.<br />

They typically appear with an<br />

explosion of noise, a clash of locker<br />

doors, and a litter of sweaty athletic<br />

clothes that bear the seals of expensive<br />

and exclusive institutions of<br />

higher education. They talk as if no<br />

one else is listening, as if they were<br />

standing in the most private seminar<br />

room of the local hospital, albeit<br />

standing buck naked, dripping wet,<br />

and yelling for no good reason.<br />

Surprisingly, they talk not of<br />

women or sports or one of the few<br />

topics of male discourse but of medicine.<br />

They pay inordinate attention<br />

to every corner and fold of their<br />

own bodies and speculate on what<br />

signs of good or ill they find. If you<br />

believe their words, these young doctors<br />

are the most medicated human<br />

beings on the planet. They spend an<br />

unusual amount of time talking about<br />

the medicines that they prescribe<br />

for themselves in much the same<br />

way that a small child will discuss<br />

the color of a recently encountered<br />

COMPUTER<br />

David Alan Grier, George Washington University<br />

No matter what we may believe, scientific practice often begins with<br />

a season when we don’t know what we know.<br />

puppy. One can be grateful that these<br />

physicians know the effects of their<br />

own medicine but simultaneously<br />

worried that these pharmaceuticals<br />

will impair their judgment when they<br />

recommend some treatment.<br />

For the most part, these young<br />

men talk about their cases and the<br />

treatments that they recommend.<br />

Although most of the medical terms<br />

are a complete mystery to the rest of<br />

us, we can all tell that these are young<br />

doctors who don’t know yet how to<br />

be professional physicians. They’re<br />

a little too offended when someone<br />

questions their judgment. They give<br />

far too many details about their<br />

patients and make it far too easy for<br />

the rest of us to identify, or at least<br />

imagine, the individual in question.<br />

These young physicians, in spite<br />

of their enthusiasm, their elite educations,<br />

and their practical experience<br />

with drugs, are still learning how to<br />

organize and discipline their practice.<br />

They’re living a medicine of<br />

utter chaos. Their conversation cycles<br />

around the various bodily systems,<br />

maps every symptom to every possible<br />

cause imaginable, and identifies<br />

extraordinary lists of information that<br />

they would like to extract from their<br />

patients.<br />

Even with this chaos, they’re still<br />

in love with their profession and still<br />

excited to encounter new problems.<br />

Yet they don’t realize that they’re<br />

only now learning to discipline their<br />

professional activity, to build a framework<br />

that will guide their work. Well<br />

before they reach the age of 30, they<br />

will learn to organize their professional<br />

knowledge into a structure that<br />

will guide the rest of their <strong>lives</strong>.<br />

UNINHIBITED SPECULATION<br />

We usually live so completely<br />

within our professional knowledge<br />

that we remember the effort required<br />

to discipline our thoughts only when<br />

we approach a topic that is new to us.<br />

New ideas can dislocate that mental<br />

structure, that vague semantic network,<br />

which gives us a foundation in<br />

the field.<br />

Over the past three months, I have<br />

had many opportunities to demonstrate<br />

that a career in computer<br />

science can still leave you grossly<br />

ignorant of many subjects and completely<br />

disoriented as you try to learn<br />

the basics of a new topic. The search<br />

tools of modern digital libraries give<br />

you little guidance in this work. You<br />

can retrieve hundreds of articles that<br />

seem relevant, spend hours reading<br />

material about some peripheral bit<br />

of research, and never find that key<br />

document describing the basic concepts<br />

of the field.<br />

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After years of doing this kind of<br />

research, I’ve learned that all new<br />

fields of scientific endeavor will go<br />

through periods of utter chaos before<br />

they settle into a regular discipline<br />

with well-defined terms, stable categories,<br />

and general methods. The task<br />

of any researcher is to work through<br />

the early literature and find that key<br />

moment when ideas begin to solidify.<br />

THE CHAOS OF<br />

RÖNTGEN’S XfiRAYS<br />

The early days of physics produced<br />

many fields that began in chaos and<br />

moved quickly into order. Few present<br />

a more dramatic story than the discovery<br />

of X-rays by Wilhelm Röntgen<br />

in late 1895. To both scientists and the<br />

public, X-rays seemed to be an entirely<br />

new phenomenon that didn’t exactly<br />

fit into the theories of electricity and<br />

magnetism that had been maturing<br />

over the prior 50 years.<br />

Röntgen discovered X-rays in<br />

early November and was mystified<br />

by them. Being a careful scientist, he<br />

attempted to identify the basic nature<br />

of this radiation. He assembled his<br />

notes from this work into an article<br />

that is little more than a list of observations.<br />

“A Discharge from a large<br />

induction coil is passed through a<br />

Hittorf’s vacuum tube,” he begins.<br />

This apparatus will cause a piece of<br />

paper covered with barium platinocyanide<br />

to glow. “The fluorescence is<br />

still visible at two meters distance,”<br />

he wrote. “It is easy to show that the<br />

origin of the fluorescence lies within<br />

the vacuum tube.”<br />

In the last paragraphs of the article,<br />

Röntgen admitted that he didn’t have<br />

a theory that explained the properties<br />

of X-rays. He rejected as “unlikely” the<br />

idea that they were a form of electromagnetic<br />

radiation and hence related<br />

to visible light. Instead, he speculated<br />

that his discovery was an entirely new<br />

form of energy. “Should not the new<br />

rays,” he asked, “be ascribed to longitudinal<br />

waves in the ether?”<br />

Had X-rays been less novel, had<br />

they not been able to a pass through<br />

soft human tissue and reveal the<br />

hidden bones, then Röntgen’s speculations<br />

about the luminiferous ether<br />

and longitudinal waves would have<br />

percolated through the community<br />

of physicists and would have been<br />

tested in a relatively systematic way.<br />

However, X-rays were indeed novel,<br />

and they could reveal the inner parts<br />

of the human body, so Röntgen’s<br />

ideas quickly moved into the laboratory<br />

and living room.<br />

All new fields of<br />

scientific endeavor<br />

will go through<br />

periods of utter<br />

chaos before they<br />

settle into a regular<br />

discipline with welldefined<br />

terms, stable<br />

categories, and<br />

general methods.<br />

THE EXCITEMENT<br />

OF THE POPULAR PRESS<br />

Barely four weeks after the original<br />

article appeared, news of this<br />

strange new ray reached all the<br />

capitals of Europe. “The invention of<br />

neither the telephone nor the phonograph<br />

has stirred up such scientific<br />

excitement as this Röntgen discovery<br />

in photography,” reported the London<br />

correspondent for The New York<br />

Times. “The papers everywhere are<br />

full of reports of experiments, and of<br />

reproductions of more or less ghastly<br />

anatomical pictures.”<br />

In general, the Times and other<br />

newspapers offered accurate descriptions<br />

of the experiments and the<br />

phenomena that had been observed.<br />

Yet, the papers weren’t scholarly<br />

journals and couldn’t distinguish<br />

well-conceived theory from rampant<br />

assumption. They speculated about<br />

what Röntgen meant when he mentioned<br />

“longitudinal waves in the<br />

ether” and listened to everyone who<br />

claimed credit for the discovery. “A<br />

French savant is said to have been<br />

securing similar results for several<br />

years by the use of an ordinary kerosene<br />

lamp,” offered the Times, which<br />

also claimed that it had found “that<br />

this discovery was not only made by<br />

a Prague professor in 1885” and that<br />

“a full report of the achievement was<br />

made to the Austrian Academy of Sciences<br />

in 1885.”<br />

ORGANIZING IGNORANCE<br />

Surprisingly, the popular press<br />

wasn’t alone in publishing speculation.<br />

The discovery of X-rays<br />

created a massive wave of papers<br />

that crashed on the scholarly community<br />

that winter. More than 125<br />

appeared before the first anniversary<br />

of the discovery. Some were good.<br />

Some were poorly conceived and ill<br />

written. Some identified the major<br />

applications for the waves. Some<br />

wandered into strange and unsupported<br />

speculations.<br />

The articles appeared so quickly<br />

that few could have been reviewed<br />

only by an editor and not an outside<br />

referee. Researchers would read a<br />

description of X-rays in a newspaper,<br />

conduct an experiment, and see their<br />

results published in fewer than six<br />

weeks. Many of these articles were<br />

part of a growing chain of work, in<br />

which one article spawns new experiments,<br />

which in turn spawn new<br />

work. Unfortunately, most of these<br />

researchers were engaged in speculation<br />

that was no better informed<br />

than the newspapers. On 14 February<br />

1896, Columbia physicist Michael<br />

Pupin published a simple framework<br />

for studying these waves, but his<br />

ideas had limited influence in those<br />

first months.<br />

Less than two weeks after Pupin’s<br />

paper appeared, a pair of researchers<br />

built a simple X-ray apparatus and<br />

started applying it to everything that<br />

they could find. A colleague asked<br />

them to “undertake the location of a<br />

bullet in the head of a child that had<br />

been accidentally shot.” They agreed<br />

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THE KNOWN WORLD<br />

to do it but had enough doubts about<br />

the process to test the safety of their<br />

machine. “Accordingly, Dr. Dudley,<br />

with his characteristic devotion to<br />

the cause of science,” explained the<br />

report, “lent himself to the experiment.”<br />

They taped a coin to one side<br />

of his head, placed a photographic<br />

plate on the other, and exposed him<br />

to the X-ray machine for an hour.<br />

The experiment produced no<br />

useful outcome, but it may have<br />

spared the child. “The plate developed<br />

nothing,” they reported. But<br />

three weeks after the experiment,<br />

Dudley lost all of his hair in the area<br />

where the X-rays had been directed.<br />

“The spot is perfectly bald, being two<br />

inches in diameter,” they noted. “We,<br />

and especially Dr. Dudley, shall watch<br />

with interest the ultimate effect.”<br />

THE ELECTRICAL ENGINEERS<br />

START ORGANIZING<br />

Twelve full months passed before<br />

the scientific community began to<br />

develop a coherent approach to the<br />

study of X-rays. The key article is a<br />

report from the American Institute<br />

of Electrical Engineers (AIEE) that<br />

appeared in December 1896. “We<br />

were very much surprised, something<br />

like a year ago, by this very great discovery,”<br />

the report begins, “but we<br />

cannot say that we know very much<br />

more about it now than we did then.<br />

The whole world seems to have been<br />

working on it for all this time without<br />

having discovered a great deal with<br />

respect to it.”<br />

This report also reveals much<br />

about the nature of scientific practice<br />

at the time. It was a record of a discussion<br />

among a half-dozen senior<br />

scientists, all of whom lived within<br />

easy travel distance to New York and<br />

could easily congregate there for a<br />

meeting. Most important, they represented<br />

most of the major research<br />

universities and, among them, knew<br />

most of the scientists who could<br />

contribute to the field. When they discussed<br />

and debated ideas, they were<br />

speaking for an entire community.<br />

COMPUTER<br />

The report is strong and detailed<br />

but a little cautious as none of the participants<br />

wished to offend the others<br />

or give a conclusion that might be<br />

disproved later. The majority of the<br />

group concluded that X-rays were a<br />

form of electro-magnetic radiation<br />

and that they “most likely consist of<br />

vibrations of such small wavelengths<br />

as to be comparable with the distances<br />

between molecules of the most<br />

dense substances.” That hypothesis<br />

would be the basis for the serious<br />

study of X-rays.<br />

The flood of papers<br />

has continued to rise,<br />

as scientists from<br />

laboratories near and<br />

far try to make a name<br />

for themselves.<br />

THE POWER OF PUBLICATION<br />

Scientific periodicals have always<br />

had a central role in the process that<br />

turns chaos into order, although that<br />

role has often changed. At the time<br />

of Röntgen’s discovery, the editors<br />

of the oldest and most prestigious<br />

scientific journal in the English language,<br />

the Philosophical Transactions,<br />

stated that they selected articles for<br />

publication because of “the importance<br />

and singularity of the subjects,<br />

or the advantageous manner of<br />

treating them.” At the same time,<br />

they rejected the idea that they<br />

were validating or proving the science<br />

of any article that appeared in<br />

the Transactions. They didn’t pretend<br />

“to answer for the certainty of the<br />

facts, or propriety of the reasonings<br />

contained in the several papers so<br />

published,” they explained, “which<br />

must still rest on the credit or judgment<br />

of their respective authors.”<br />

The editors could take such a stand<br />

because the scientific community<br />

was still relatively small. Readers had<br />

other information to help them assess<br />

the articles. Moreover, they actually<br />

knew most of the people and laboratories<br />

engaged in active research and<br />

contributing to the field.<br />

The role of periodicals changed<br />

substantially over the next 50 years.<br />

By the middle of the 20th century,<br />

scientific periodicals were acting as<br />

validators—institutions that verified<br />

scientific research. “Science is<br />

moving rapidly,” noted the editor of<br />

the journal Science. He argued that scientific<br />

periodicals “in every discipline<br />

should take their responsibilities with<br />

respect to critical reviews” of every<br />

paper submitted to them. As an editor<br />

of a leading journal, he felt that Science<br />

needed to set the standard for<br />

scientific publication and regularly<br />

published articles that described<br />

the process of peer review, the rules<br />

that should guide reviewers, and the<br />

kinds of judgments that editors should<br />

make.<br />

At the same time it was promoting<br />

peer review, Science’s editor acknowledged<br />

that the expansion of scientific<br />

research was making it difficult for<br />

editors to validate every article that<br />

reached their desks. “With the great<br />

flood of manuscripts that today’s<br />

editors receive, in every scientific<br />

discipline, it is not possible to spend<br />

so much time and effort debating<br />

details,” he wrote. And as the century<br />

progressed, the flood of manuscripts<br />

only increased.<br />

THE ORIGINAL COLD FUSION<br />

As the waters rose, so rose the calls<br />

for scientific periodicals to test and<br />

validate the papers that they published.<br />

These calls reached a high<br />

point in 1989, when a pair of researchers<br />

announced to the public that they<br />

had made a discovery every bit as dramatic<br />

as the story of X-rays a century<br />

before. Two chemists “started a scientific<br />

uproar last month by asserting<br />

that they had achieved nuclear fusion<br />

at room temperature,” reported The<br />

New York Times. The writer added,<br />

“Many scientists remain skeptical.”<br />

The story of cold fusion lived<br />

for two years as laboratories<br />

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tried to make sense of the report. As the<br />

narrative unfolded, it quickly turned into a<br />

debate over the process of validating scientific<br />

ideas. Many claimed that the scientists who had<br />

performed the original experiments had taken<br />

their ideas too quickly to the public press. Their<br />

supporters argued that traditional laboratories<br />

were too skeptical of new ideas and that the<br />

scientific journals wouldn’t protect the patent<br />

rights of the discoverers. As the excitement of<br />

the moment faded and the realities of the story<br />

became clear, most commentators concluded<br />

that the public had not been well served. “Some<br />

scholars lunge too hastily for glory,” editorialized<br />

Times science writer Nicholas Wade. He<br />

told scientists to never announce their claims<br />

“until your manuscript has at least been<br />

accepted for publication in a reputable journal.”<br />

Nothing has become easier since the<br />

cold fusion controversy or those<br />

first exciting days of X-rays. Science<br />

has expanded. The number of<br />

subdisciplines has increased. The<br />

flood of papers has continued to rise, as scientists<br />

from laboratories near and far try to<br />

make a name for themselves. In that flood are<br />

ideas good and bad, breathtakingly original<br />

and utterly derivative. They’re the gift of painstaking<br />

research, the theft by 15 minutes of edits<br />

with a word processor, an instantaneous forgery<br />

by a clever bit of code that mocks the way<br />

that scientists write.<br />

By themselves, scientific journals aren’t the<br />

only institutions that attempt to organize the<br />

utter chaos of scientific research. They’re part<br />

of an infrastructure that includes laboratories,<br />

funding agencies, professional societies, review<br />

boards, and other institutions. These organizations<br />

will have to continue to grow and evolve as<br />

editors and publishers grapple with the forces<br />

acting on the scientific community, just as my<br />

young physician friends will have to mature<br />

into wise doctors who know how to draw disciplined<br />

judgment from the anarchy of energetic<br />

speculation.<br />

David Alan Grier is an associate professor of<br />

international science and technology policy at<br />

George Washington University and is the author<br />

of When Computers Were Human (Princeton,<br />

2005) and Too Soon to Tell (Wiley, 2009). Contact<br />

him at grier@computer.org.<br />

_____________<br />

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32 & 16 YEARS AGO<br />

APRIL 1978<br />

INTERNATIONAL DATA (p. 6) “AFIPS has named a panel<br />

of US experts to study foreign countries’ activities which<br />

restrict the international exchange of information. The<br />

panel is also expected to respond to the State Department’s<br />

position paper, Protecting Privacy in International<br />

Data Processing.”<br />

SOFTWARE QUALITY (p. 10) “For computer software<br />

systems, quality appears to be a characteristic that can<br />

be neither built in with assurance at system creation<br />

time nor retrofitted with certainty after a product is<br />

in use. Apart from the issues of logistics (copying and<br />

distributing software) there appears to be a continuing<br />

need to demonstrate some minimum level of quality in<br />

typical wide-use software systems. At the same time<br />

this appears to be impossible to accomplish: the best<br />

designed systems have had errors revealed many years<br />

after introduction, and several programs that had been<br />

publicly ‘proved correct’ contained outright mistakes!”<br />

SOFTWARE REVALIDATION (p. 14) “The problems of revalidating<br />

software following maintenance have received<br />

little attention, yet typically 70 percent of the effort<br />

expended on software occurs as program maintenance.<br />

There are two reasons to perform maintenance on a<br />

software system: to correct a problem or to modify the<br />

capabilities of the system. Revalidation must verify the<br />

corrected or new capability, and also verify that no other<br />

capability of the system has been adversely affected<br />

by the modification. Revalidation is facilitated by good<br />

documentation and a system structure in which functions<br />

are localized to well-defined modules.”<br />

ERROR DETECTION (p. 25) “It is well known that one<br />

cannot find all the errors in a program simply by testing<br />

it for a set of input data. Nevertheless, program testing is<br />

the most commonly used technique for error detection<br />

in today’s software industry. Consequently, the problem<br />

of finding a program test method with increased errordetection<br />

capability has received considerable attention<br />

in the field of software research.<br />

“There appear to be two major approaches to this problem.<br />

One is to find better criteria for test-case selection. The<br />

other is to find a way to obtain additional information (i.e.,<br />

information other than that provided by the output of the<br />

program) that can be used to detect errors.”<br />

PROGRAM TESTING (p. 41) “So, there is certainly no need<br />

to apologize for applying ad hoc strategies in program<br />

testing. A programmer who considers his problems well<br />

and skillfully applies appropriate techniques—regardless<br />

of where the techniques arise—will succeed.”<br />

SYMBOLIC<br />

PROGRAM<br />

EXECUTION<br />

(p. 51) “The<br />

notion of<br />

symbolically<br />

executing a program<br />

follows quite<br />

naturally from normal<br />

program execution. First assume<br />

that there is a given programming language (say, Algol-<br />

60) and the normal definition of program execution for<br />

that language. One can extend that definition to provide<br />

a symbolic execution in the same manner as one extends<br />

arithmetic over numbers to symbolic algebraic operations<br />

over symbols and numbers. The definition of the symbolic<br />

execution is such that trivial cases involving no symbols<br />

are equivalent to normal executions, and any information<br />

learned in a symbolic execution applies to the corresponding<br />

normal executions as well.”<br />

COMPONENT PROGRESS (p. 64) “It is clear, looking back,<br />

that progress in component performance, size, cost, and<br />

reliability has been reflected in corresponding improvements<br />

in systems. Looking forward then, an analysis of<br />

coming developments in logic and memory components<br />

appears to be one approach to forecasting future system<br />

characteristics. Prediction at the system level, however,<br />

is complicated by various options in machine organization,<br />

such as parallel processing and pipelining, which<br />

interact with component features to establish the performance<br />

limits of the system.”<br />

HEMISPHERICAL KEYBOARD (p. 99) “A new hemisphericalshaped<br />

typing keyboard, called the Writehander, permits<br />

typing all 128 characters of the ASCII code with<br />

one hand.<br />

“To use the keyboard, the typist places his four fingers<br />

on four press-switches and his thumb on one of eight<br />

press-switches. The four finger-switches operate as the<br />

lower four bits of the 7-bit ASCII code, selecting one of<br />

16 character groups which contain the desired character.<br />

Each group contains eight letters, numerals, or symbols.<br />

The thumb then presses one switch to select the desired<br />

character from the group of eight. The shape and switch<br />

locations have been designed so that the fingers naturally<br />

locate themselves on the switches, according to the<br />

designer, Sid Owen.”<br />

PDFs of the articles and departments of the April issues of<br />

Computer for 1978 and 1994 are available through the IEEE<br />

Computer Society’s website: www.computer.org/computer.<br />

10 COMPUTER<br />

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APRIL 1994<br />

ATM (p. 8) “This year is an important one for asynchronous<br />

transfer mode. The technology now has the backing<br />

of vendors.<br />

“Membership of the ATM Forum, a consortium formed<br />

in October 1991 to accelerate the development and implementation<br />

of ATM products and services, has risen to 465<br />

with new faces from the likes of Microsoft and Novell.<br />

According to Fred Sammartino, forum president, 1994<br />

will be the year many companies set up serious trial<br />

implementations with intent to later incorporate the<br />

technology.”<br />

MBONE (p. 30) “Short for Multicast Backbone, MBone is<br />

a virtual network that has been in existence since early<br />

1992. It was named by Steve Casner of the University of<br />

Southern California Information Sciences Institute and<br />

originated from an effort to multicast audio and video<br />

from meetings of the Internet Engineering Task Force.<br />

Today, hundreds of researchers use MBone to develop<br />

protocols and applications for group communication.<br />

Multicast provides one-to-many and many-to-many<br />

network delivery services for applications such as<br />

videoconferencing and audio where several hosts need<br />

to communicate simultaneously.”<br />

MOBILE COMPUTING (p. 38) “Recent advances in technology<br />

have provided portable computers with wireless<br />

interfaces that allow networked communication even<br />

while a user is mobile. Whereas today’s first-generation<br />

notebook computers and personal digital assistants<br />

(PDAs) are self-contained, networked mobile computers<br />

are part of a greater <strong>computing</strong> infrastructure. Mobile<br />

<strong>computing</strong>—the use of a portable computer capable of<br />

wireless networking—will very likely revolutionize the<br />

way we use computers.”<br />

TELEROBOTICS (p. 49) “The significant communication<br />

latency between an earth-based local site and an<br />

on-orbit remote site drove much of the Steler [Supervisory<br />

Telerobotics Laboratory (at the Jet Propulsion<br />

Laboratory)] design. Such a large latency precludes<br />

direct real-time control of the robot in what nonetheless<br />

remains a real-time operation. To meet these<br />

real-time control requirements, our group devised<br />

a control scheme similar to the one used to control<br />

spacecraft.… Instead of transmitting programs to the<br />

remote site, we transmit command blocks (a set of data<br />

parameters) that control the execution of the remote<br />

site software that provides task-level control. This<br />

allows the remote site to handle a variety of control<br />

modes without requiring changes in the remote site<br />

software.”<br />

DIGITAL SOUPS (p. 65) “Last August, Apple Computer<br />

released a much-talked-about new computer called the<br />

Newton MessagePad. It’s the first platform in a series of<br />

Newton products that fall under the term personal digital<br />

assistant (Sharp’s ExpertPad is another). Although Apple<br />

doesn’t describe ‘the Newton’ as a computer, it’s actually<br />

an advanced system that includes handwriting recognition,<br />

full memory management and protection, and<br />

preemptive multitasking. But one feature that the MessagePad<br />

doesn’t have is files. The Newton stores similar<br />

data objects in formats called ‘soups.’ These soups are<br />

available to all applications.”<br />

SOFTWARE STANDARDS (p. 68) “The International<br />

Organization for Standardization is developing a suite<br />

of standards on software process under the rubric of<br />

Spice, an abbreviation for Software Process Improvement<br />

and Capability Determination. Spice was inspired<br />

by numerous efforts on software process around the<br />

world, including the Software Engineering Institute’s<br />

work with the Capability Maturity Model (CMM), Bell<br />

Canada’s Trillium, and ESPRIT’s Bootstrap.”<br />

VIDEOCONFERENCING (p. 96) “For the past two years,<br />

United Technologies Corp. (UTC) has been experimenting<br />

with desktop video communications in its Topdesc (Total<br />

Personal Desktop Communications) program, which has<br />

the goals of completeness and convenience: allowing<br />

separated personnel to communicate as completely and<br />

easily as if they were at the same location, and doing<br />

so whenever and from wherever it is convenient. This<br />

means that parties should be able to see objects and<br />

documents and collaborate easily using computer data.<br />

In addition, the communications unit must be sized and<br />

priced to fit into an office or lab.”<br />

THE SOFTWARE CRISIS (p. 104) “There’s been so much<br />

talk about a ‘software crisis’ over the past decade or two<br />

that you’d think software practitioners were the original<br />

Mr. Bumble, barely able to program their way out of a<br />

simple application problem. But when I look around, I see<br />

a world in which computers and the software that drives<br />

them are dependable and indispensable. They make my<br />

plane reservations, control my banking transactions, and<br />

send people into space. They even wage war—in entirely<br />

new and apparently successful ways.”<br />

Editor: Neville Holmes; neville.holmes@utas.edu.au<br />

_________________<br />

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TECHNOLOGY NEWS<br />

Will HTML 5<br />

Restandardize<br />

the Web?<br />

Steven J. Vaughan-Nichols<br />

The World Wide Web Consortium is developing HTML 5 as a standard<br />

that provides Web users and developers with enhanced functionality<br />

without using the proprietary technologies that have<br />

become popular in recent years.<br />

In theory, the Web is a resource<br />

that is widely and uniformly<br />

usable across platforms. As<br />

such, many of the Web’s<br />

key technologies and architectural<br />

elements are open and<br />

platform-independent.<br />

However, some vendors have<br />

developed their own technologies<br />

that provide more functionality than<br />

Web standards—such as the ability to<br />

build rich Internet applications.<br />

Adobe System’s Flash, Apple’s<br />

QuickTime, and Microsoft’s Silverlight<br />

are examples of such proprietary<br />

formats.<br />

In addition, Google’s Gears and<br />

Oracle’s JavaFX—which the company<br />

acquired along with Sun Microsystems—have<br />

technologies that enable<br />

creation of offline and client-side Web<br />

applications.<br />

Although these approaches provide<br />

additional capabilities, they have<br />

also reduced the Web’s openness and<br />

platform independence, and tend to<br />

lock in users to specific technologies<br />

and vendors.<br />

In response, the World Wide Web<br />

Consortium (W3C) is developing<br />

HTML 5 as a single standard that provides<br />

Web users and developers with<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

enhanced functionality without using<br />

proprietary technologies.<br />

Indeed, pointed out Google<br />

researcher Ian Hickson, one of the<br />

W3C’s HTML 5 editors, “One of our<br />

goals is to move the Web away from<br />

proprietary technologies.”<br />

The as-yet-unapproved standard<br />

takes HTML from simply describing<br />

the basics of a text-based Web to creating<br />

and presenting animations, audio,<br />

mathematical equations, typefaces,<br />

and video, as well as providing offline<br />

functionality. It also enables geolocation,<br />

a rich text-editing model, and<br />

local storage in client-side databases.<br />

The Web isn’t just about reading<br />

the text on the page and clicking<br />

on the links anymore, noted Bruce<br />

Lawson, standards evangelist at<br />

browser developer Opera Software.<br />

Added W3C director Tim Berners-<br />

Lee, “HTML 5 is still a markup language<br />

for webpages, but the really big<br />

shift that’s happening here—and, you<br />

could argue, what’s actually driving<br />

the fancy features—is the shift to the<br />

Web [supporting applications].”<br />

“HTML 5 tries to bring HTML into<br />

the world of application development,”<br />

explained Microsoft senior<br />

principal architect Vlad Vinogradsky.<br />

Published by the IEEE Computer Society<br />

“Microsoft is investing heavily in<br />

the W3C HTML 5 effort, working with<br />

our competitors and the Web community<br />

at large. We want to implement<br />

ratified, thoroughly tested, and stable<br />

standards that can help Web interoperability,”<br />

said Paul Cotton, cochair of<br />

the W3C HTML Working Group and<br />

Microsoft’s group manager for Web<br />

services standards and partners in<br />

the company’s Interoperability Strategy<br />

Team.<br />

At the same time though, Web<br />

companies say their proprietary technologies<br />

are already up and running,<br />

unlike HTML 5.<br />

Adobe vice president of developer<br />

tools Dave Story said, “The HTML 5<br />

timeline states that it will be at least a<br />

decade before the evolving efforts are<br />

finalized, and it remains to be seen<br />

what parts will be implemented consistently<br />

across all browsers.”<br />

In fact, while HTML 5 recently<br />

became a working draft, it’s not<br />

expected to become even a W3C candidate<br />

recommendation until 2012 or<br />

a final W3C standard until 2022.<br />

Nonetheless, some browser<br />

designers, Web authors, and websites—<br />

such as YouTube—are already adopting<br />

HTML 5 elements. For more<br />

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TECHNOLOGY NEWS<br />

PLAYING WITH HTML 5<br />

Several websites očer a taste of what HTML 5 will bring. Some of the applications work<br />

with only certain browsers.<br />

YouTube’s beta HTML 5 video project (www.youtube.com/html5) works with the standard’s<br />

video tag. Browsers must support the video tag and have a player that uses the<br />

H.264 codec. Otherwise, YouTube will use Flash to play video.<br />

Mozilla Labs’ BeSpin (https://bespin.mozillalabs.com) is an experimental programmer’s<br />

editor that uses a variety of HTML 5 elements.<br />

FreeCiv.net (www.freeciv.net) is an online game by the FreeCiv.net open source project<br />

that supports HTML 5’s Canvas element. HTML 5-compatible browsers display map<br />

changes faster than those that aren’t compatible.<br />

Google Wave (https://wave.google.com/wave), a cross between social networking<br />

and groupware, uses several HTML 5 elements.<br />

Merge Web Design’s HTML 5 Geolocation (http://merged.ca/iphone/html5geolocation)<br />

is, as the name indicates, a demo of HTML 5-based geolocation.<br />

Sticky Notes (http://webkit.org/demos/sticky-notes/index.html) is the WebKit Open<br />

Source Project’s demo of HTML 5’s client-side database storage API. WebKit is an open<br />

source Web browser engine now used by, for example, Apple’s Safari browser.<br />

information, see the “Playing with<br />

HTML 5” sidebar.<br />

BACKGROUNDER<br />

HTML is the predominant markup<br />

language for webpages. It uses tags<br />

to create structured documents via<br />

semantics for text—such as headings,<br />

paragraphs, and lists—as well<br />

as for links and other elements. HTML<br />

also lets authors embed images and<br />

objects in pages and can create interactive<br />

forms.<br />

HTML, which stemmed from the<br />

mid-1980s Standardized General<br />

Markup Language, first appeared as<br />

about a dozen tags in 1991.<br />

The Internet Engineering Task<br />

Force began the first organized effort<br />

to standardize HTML in 1995 with<br />

HTML 2.0.<br />

The IETF’s efforts to maintain<br />

HTML stalled, so the W3C took over<br />

standardization.<br />

In 1996, the W3C released HTML<br />

3.2, which removed the various proprietary<br />

elements introduced over<br />

time by Microsoft and Netscape.<br />

HTML 4.0, still not a final standard,<br />

followed in 1998. The approach<br />

provides mechanisms for style<br />

sheets, scripting, embedded objects,<br />

richer tables, enhanced forms, and<br />

improved accessibility for people<br />

with disabilities.<br />

COMPUTER<br />

However, HTML was still primarily<br />

focused on delivering text, not multimedia<br />

or client-based applications.<br />

Because of this, proprietary technologies<br />

such as Apple’s QuickTime<br />

and Microsoft’s multimedia players,<br />

both first released in 1991; and Adobe<br />

Flash, which debuted in 1996, have<br />

been used for video.<br />

Technologies such as Google<br />

Gears and Oracle’s JavaFX, both<br />

first released in 2007, make creating<br />

Web-based desktop-style applications<br />

easier for developers.<br />

HTML 5<br />

W3C is designing HTML 5 to create<br />

a standard with a feature set that<br />

handles all the jobs that the proprietary<br />

technologies currently perform,<br />

said specification editor Michael<br />

Smith, the consortium’s special-missions-subsection<br />

junior interim floor<br />

manager.<br />

In addition, HTML 5 will support<br />

newer mobile technologies such as<br />

geolocation and location-based services<br />

(LBS), as well as newer open<br />

formats such as scalable vector<br />

graphics. SVG, an open XML-based<br />

file format, produces compact and<br />

high-quality graphics.<br />

Developers would thus be able<br />

to develop rich webpages and Webbased<br />

applications without needing to<br />

master or license multiple proprietary<br />

technologies.<br />

And browsers would be able to do<br />

more without plug-ins.<br />

Canvas. One of HTML 5’s key<br />

new features is Canvas, which lets<br />

developers create and incorporate<br />

graphics, video, and animations, usually<br />

via JavaScript, on webpages.<br />

HTML Canvas 2D Context is an<br />

Apple-originated technology for rendering<br />

2D graphics and animations on<br />

the client rather than on Web servers.<br />

By rendering graphics locally, the<br />

bottlenecks of server and bandwidth<br />

restrictions are avoided. This makes<br />

graphics-heavy pages render faster.<br />

Video tags. HTML 5’s codecneutral<br />

video tags provide a way to<br />

include nonproprietary video formats,<br />

such as Ogg Theora and H.264,<br />

in a page.<br />

The tag and underlying code<br />

tell the browser that the associated<br />

information is to be handled as an<br />

HTML 5-compatible video stream.<br />

They would also let users view<br />

video embedded on a webpage without<br />

a specific video player.<br />

Location-based services. A location<br />

API offers support for mobile<br />

browsers and LBS applications by<br />

enabling interaction with, for example,<br />

GPS technology and data.<br />

Working offline. AppCache lets<br />

online applications store data and<br />

programming code locally so that<br />

Web-based programs can work as<br />

desktop applications, even without<br />

an Internet connection.<br />

HTML 5 has several other features<br />

that address building Web applications<br />

that work offline. These include<br />

support for a client-side SQL database<br />

and for offline application and data<br />

caching.<br />

Web applications thus can have<br />

their code, graphics, and data stored<br />

locally.<br />

Web Workers. The Web Workers<br />

element runs scripts in the background<br />

that can’t be interrupted by<br />

other scripts or user interactions.<br />

This speeds up background tasks.<br />

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Syntax and semantics. HTML 5<br />

makes some changes to the syntax<br />

and the semantics of the language’s<br />

elements and attributes.<br />

For example, as Figure 1 shows,<br />

HTML can be written in two syntaxes:<br />

HTML and XML.<br />

Using XML will enable more complex<br />

webpages that will run faster on<br />

Web browsers.<br />

XML requires a stricter, more accurate<br />

grammar than HTML and thus<br />

necessitates less work by the local<br />

computer to run quickly and correctly.<br />

However, XML pages require more<br />

work by the developer to achieve the<br />

higher accuracy level.<br />

HTML+RDFa. The W3C recently<br />

began dividing HTML 5 into subsections<br />

for easier development.<br />

For example, HTML+RDFa<br />

(Resource Description Framework in<br />

attributes) provides a way to embed<br />

resource description frames in<br />

webpages.<br />

RDF is a method for conceptually<br />

describing or modeling information<br />

implemented in Web resources.<br />

This would let developers incorporate<br />

machine-readable data into<br />

webpages, which would enable faster<br />

page rendering.<br />

TRIALS AND TRIBULATIONS<br />

Both nailing down details and the<br />

standardization process itself have<br />

been problematic for HTML 5.<br />

For example, the open source<br />

community supports making the<br />

open Ogg Theora format the default<br />

video codec for HTML 5’s video tag.<br />

Adobe, Google, and Microsoft<br />

opposed this, expressing videoquality,<br />

patent-related, and other<br />

concerns.<br />

According to Google’s Hickson,<br />

“There is no suitable codec that all<br />

vendors are willing to implement<br />

and ship.”<br />

The W3C thus decided not to select<br />

one as a default.<br />

What’s really slowing HTML 5<br />

is that the standardization effort<br />

“combines the worst elements of the<br />

Figure 1. HTML 5 lets HTML be written in two syntaxes: HTML and XML. XML’s stricter,<br />

more accurate grammar requires more work by the developer but less work by the<br />

local computer to run quickly and correctly. The browser ćrst parses out the various<br />

terms in HTML and XML and then sends them serially in an e cient and logical manner<br />

for rendering.<br />

IETF process and the W3C process,”<br />

said Adobe principal scientist Larry<br />

Masinter, a member of the W3C’s<br />

HTML Working Group.<br />

“[As is the case with] the IETF [process],<br />

there is the chaos of an open<br />

mailing list, wide-ranging comments,<br />

and free participation but without<br />

the ‘adult supervision’ that the IETF<br />

supplies in the form of the Internet<br />

Engineering Steering Group and area<br />

directors,” he explained.<br />

From the W3C, he added, there’s<br />

too much bureaucracy and the voting<br />

members don’t have enough responsibility<br />

and accountability for the<br />

final results.<br />

Another potential implementation<br />

concern is that some companies are<br />

already extending HTML 5 in ways<br />

that the final standard is unlikely to<br />

support.<br />

HTML 5 will blur the line between<br />

desktop and online applications and<br />

thus create an opportunity for malware<br />

writers, according to Dmitri<br />

Alperovitch, vice president of threat<br />

research with security vendor McAfee.<br />

By letting Web applications run on<br />

local systems, HTML 5 would allow<br />

Web-based malware to do the same.<br />

Timely user acceptance may<br />

be an issue for HTML 5.<br />

Trevor Lohrbeer, CEO<br />

of Lab Escape, a data-visualization-tool<br />

vendor, said<br />

sweeping Internet technologies must<br />

be supported by at least 80 percent<br />

of browsers before being considered<br />

reliable enough for deployment.<br />

He estimated HTML 5 won’t<br />

achieve this level of support until<br />

2013 at the earliest.<br />

However, Jay Baker, director of<br />

architecture at Viewlocity, a supplychain-management<br />

software vendor,<br />

said his company plans to adopt<br />

HTML 5 fairly aggressively.<br />

“Although there is a learning<br />

curve associated with HTML 5,” he<br />

explained, “many of the new features<br />

make today’s common hacks and<br />

workarounds obsolete.”fi<br />

Steven J. Vaughan-Nichols is a freelance<br />

technology writer based in Mills<br />

River, North Carolina. Contact him at<br />

sjvn@vna1.com.<br />

__________<br />

Editor: Lee Garber, Computer;<br />

l.garber@computer.org<br />

_____________<br />

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NEWS BRIEFS<br />

New Technique Provides<br />

Energy Wirelessly<br />

Amethod for transferring<br />

energy wirelessly promises<br />

to streamline the<br />

device-charging process<br />

as well as provide power<br />

to an array of electronic devices such<br />

as cellular phones and MP3 players.<br />

WiTricity Corp.’s wireless energy<br />

system comes as a flat pad on which<br />

devices sit or as a domed pod that<br />

powers or charges devices placed<br />

nearby. Manufacturers could also<br />

place the WiTricity components into<br />

a computer or other electronic device<br />

that requires charging.<br />

The charging system is powered<br />

via an electrical outlet or battery,<br />

WiTricity Corp.’s energy system can provide power to or charge nearby devices<br />

wirelessly. The charging system turns incoming electric current into a magnetic field,<br />

which then induces current in and a magnetic field around a resonating coil. This<br />

induces a magnetic field in a coil in a nearby device, thereby transferring energy.<br />

Source: WiTricity Corp.<br />

COMPUTER<br />

noted David Schatz, the company’s<br />

director of business development and<br />

marketing.<br />

First, the charger converts incoming<br />

AC power to DC, then the radio<br />

amplifier creates and amplifies<br />

high-frequency signals, said Schatz.<br />

The high-frequency current flowing<br />

through the charger’s power source<br />

excites a tuned resonator coil that<br />

starts oscillating, which creates an<br />

oscillating magnetic field.<br />

The device being powered has a<br />

coil tuned to the same frequency as<br />

the charger. This induces the magnetic<br />

field to flow from the charger<br />

to the other device, thereby trans-<br />

ferring energy.<br />

So far, Schatz noted, the researchers<br />

have transferred electricity<br />

wirelessly over a distance of two<br />

meters. However, he said, the larger<br />

the resonator, the stronger the magnetic<br />

field and the farther the system<br />

could transfer power to devices.<br />

Because WiTricity’s system requires<br />

access to an energy source, it will not<br />

be a go-anywhere technology, Schatz<br />

noted. However, he added, it eventually<br />

may be able to work at outdoor<br />

locations with their own power<br />

sources, such as perhaps bus stops.<br />

Menno Treffers, chair of the<br />

Wireless Power Consortium and<br />

Philips Electronics’ senior director<br />

of standardization, said WiTricity’s<br />

approach appears to have the same<br />

limited-transmission-range issues<br />

as the technology developed by the<br />

consortium, to which WiTricity does<br />

not belong.<br />

When WiTricity demonstrated its<br />

product at January’s Computer Electronics<br />

Show, it powered a 32-inch<br />

TV from about half a meter away.<br />

WiTricity is also working on some<br />

specialized, classified military systems,<br />

according to Schatz.<br />

The company is already selling<br />

its components and systems<br />

directly to vendors and also plans to<br />

license the intellectual property to<br />

manufacturers.<br />

Now, Schatz said, research must<br />

look into how to integrate the technology<br />

within electronics devices.<br />

He predicted computer electronics<br />

companies will soon start working<br />

on incorporating WiTricity technology<br />

into products that will ship in<br />

2011.<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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Researchers Pioneer Innovative<br />

Antiphishing Approach<br />

Researchers have developed<br />

an innovative approach<br />

to identifying webpages<br />

that phishers use to trick<br />

victims into entering confidential<br />

information such as user<br />

names, passwords, and bank-account<br />

and credit-card numbers.<br />

Scientists at Taiwan’s Academia<br />

Sinica focused their efforts on<br />

recognizing the pages based on<br />

their appearance rather than their<br />

content, as current antiphishing<br />

approaches do.<br />

Phishers typically create webpages<br />

that look like those belonging<br />

to banks, e-commerce operations,<br />

or other businesses on which users<br />

might enter financial or accountaccess<br />

information. When a user<br />

enters such data on a fake page, the<br />

phisher captures the information and<br />

utilizes it to defraud the victim.<br />

Surveys by Gartner Inc., a market<br />

research firm, found that due to<br />

phishing attacks in the US alone, 3.6<br />

million people lost about $3.2 billion<br />

in 2007 and 5 million lost about $1.8<br />

billion in 2008.<br />

Traditional antiphishing approaches<br />

focus on user complaints and content<br />

analysis, explained Dave Cowings,<br />

Symantec Security Response’s senior<br />

manager for operations.<br />

Verified user complaints will<br />

put phishers’ pages on blacklists of<br />

websites.<br />

Some traditional approaches<br />

analyze the content of websites that<br />

appear similar to well-known sites. If<br />

the content on a suspect page is the<br />

same as on a genuine site but the URLs<br />

are different, the software assumes the<br />

suspect page originated with phishers.<br />

However, this approach can miss<br />

small differences between pages and<br />

thereby yield false positive findings.<br />

Also, said Academica Sinica<br />

researcher Kuan-Ta Chen, phishers<br />

commonly attempt to circumvent<br />

traditional approaches by designing<br />

webpages without actual text—such<br />

as by using images of text instead—<br />

thereby making content analysis<br />

useless.<br />

The Academia Sinica system analyzes<br />

the appearance of genuine and<br />

phishers’ versions of pages and looks<br />

for subtle differences.<br />

The system examines the appearance<br />

of websites that are common<br />

phishing targets, focusing on keypoints.<br />

According to Chen, keypoints<br />

are small, easily identifiable parts<br />

of a page, such as edges, corners, or<br />

areas with large color or contrast differences.<br />

Analyzing keypoints can<br />

identify tiny differences and also<br />

eliminates the need to examine entire<br />

pages, saving both time and computational<br />

overhead.<br />

In addition to copying pages<br />

imprecisely, Chen explained, “phishers<br />

[sometimes] add messages to their<br />

pages designed to convince victims<br />

that they must enter private information<br />

immediately and also include<br />

advertisements that, when clicked on,<br />

direct users to yet another malicious<br />

website.”<br />

The Academia Sinica system looks<br />

for such differences.<br />

The researchers have already<br />

examined 2,058 pages on 74 websites<br />

that phishers commonly replicate,<br />

including the top five targets: eBay,<br />

PayPal, Marshall & Ilsley Bank, Charter<br />

One Bank, and Bank of America.<br />

In tests, Chen said, his system has<br />

accurately recognized phishing sites<br />

between 95 and 98 percent of the<br />

time.<br />

The scientists have implemented<br />

their technology in their Phishgig<br />

website (http://mmnet.iis.sinica.edu.<br />

___________<br />

tw/proj/phishgig), from which users<br />

can download a Firefox browser<br />

plugin capable of detecting phishing<br />

pages. Once Phishgig detects a fraudulent<br />

page, it displays a warning that<br />

users can heed or ignore.<br />

The team is developing plugins for<br />

other browsers, including Internet<br />

Explorer and Google Chrome.<br />

Marty Lindner—principal engineer<br />

at CERT, a security research center<br />

at Carnegie Mellon University’s Software<br />

Engineering Institute—said the<br />

approach will probably be effective<br />

only long enough for phishers to<br />

figure out how to circumvent it.<br />

The most important aspect of<br />

phishing security is careful behavior<br />

by potential victims, he explained,<br />

and many users are insufficiently<br />

cautious.<br />

Chen said he realizes that phishers<br />

commonly change their methods,<br />

so his team is monitoring activity<br />

to see if and how they alter their<br />

approaches in response to the new<br />

technique.<br />

Meanwhile, he noted, the technology<br />

works only with copies of<br />

the pages the system has already<br />

examined.<br />

Chen said the researchers are<br />

open to commercialization opportunities.<br />

News Briefs written by Linda Dailey<br />

Paulson, a freelance technology<br />

writer based in Portland, Oregon.<br />

Contact her at ldpaulson@yahoo.com.<br />

Editor: Lee Garber, Computer;<br />

l.garber@computer.org<br />

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NEWS BRIEFS<br />

MIT Media Lab researchers have built an<br />

interface project called the Living<br />

Wall. The project would let users touch the<br />

wall to activate lamps, music systems, and<br />

other items in a room.<br />

The Living Wall uses electronically<br />

enabled wallpaper covered with electronically<br />

conductive paints that create not only<br />

decorative patterns but also circuitry that<br />

helps enable device control.<br />

Earlier wall-based interfaces required<br />

energy-hungry projectors to throw images<br />

on the walls for decoration.<br />

The Living Wall project, led by MIT assistant<br />

professor Leah Buechley, takes a<br />

dičerent, inexpensive, and energy-ećcient<br />

approach.<br />

The researchers used a copper-based<br />

conductive paint to draw lines that function<br />

as circuits. This, in essence, applies a large,<br />

exible printed circuit board to a wall.<br />

They then magnetically attached electronic<br />

components—such as accelerometers,<br />

light sensors, touch sensors, temperature<br />

sensors, and Bluetooth wireless-communications<br />

modules for controlling smaller devices<br />

such as computers and cellular phones—to<br />

the wall’s circuit board.<br />

The wireless modules could be used to<br />

control larger appliances in the future,<br />

according to Buechley.<br />

Users press the touch sensors to control<br />

devices. The other sensors monitor envi-<br />

Anew technology promises<br />

to enable fast, wireless<br />

personal-area networks<br />

that could let users download<br />

videos to and access<br />

the Internet via mobile devices at<br />

high speeds.<br />

IEEE has approved standard<br />

802.15.3c-2009, which defines how<br />

to design interoperable WPAN radio<br />

equipment capable of providing ad<br />

hoc connectivity, quality of service,<br />

and reliability.<br />

The technology would offer theo-<br />

COMPUTER<br />

RESEARCHERS BUILD A WALL THAT ACTS LIKE A REMOTE CONTROL<br />

ronmental variables near the wall to make<br />

lighting, temperature, and other adjustments<br />

as necessary.<br />

The system runs at about 20 volts, she<br />

noted, and draws about 2 amps and 40<br />

watts when fully loaded with devices to<br />

retical maximum data rates of 5.8<br />

gigabits per second at distances<br />

up to 10 meters under ideal conditions,<br />

4 to 5 Gbps under typical<br />

conditions, and 1 to 2 Gbps under<br />

conditions degraded by, for example,<br />

obstacles in transmission paths<br />

or interference from other signals,<br />

noted Bob Heile, chair and CEO of<br />

the ZigBee Alliance and also chair<br />

of the IEEE’s 802.15 WPAN Working<br />

Group.<br />

Today’s fastest wireless systems<br />

are generally much slower, he said.<br />

control. By comparison, a laptop consumes<br />

about 50 watts and a microwave, about<br />

1,000 watts.<br />

Buechley said her team is discussing<br />

commercializing the technology with several<br />

companies, which she declined to name.<br />

MIT’s Living Wall project uses wallpaper and paint, both electronically enabled,<br />

that create not only decorative patterns but also electronic circuitry. This lets users<br />

touch the wall and control electronic items in the same room.<br />

Wireless Technology Promises<br />

Ultrafast Personal Area Networks<br />

For example, IEEE 802.11n, Wi-Fi’s<br />

speediest version, offers up to 600<br />

Mbps.<br />

IEEE 802.15.3c-2009 is fast largely<br />

because it works in the unlicensed<br />

57-to-64-GHz frequency range, which<br />

offers large amounts of available<br />

bandwidth.<br />

The standard’s completion is a<br />

key data-communications milestone<br />

because it is the first IEEE 802 series<br />

wireless standard to specify operation<br />

in the 60-GHz spectrum and<br />

offer data rates of at least 1 Gbps,<br />

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explained Paul Nikolich, IEEE 802<br />

LAN/MAN standards committee<br />

chair and chief strategy officer at YAS<br />

Broadband Ventures.<br />

This technology is fast enough to<br />

provide the consumer-electronics<br />

market with effective options for wirelessly<br />

connecting high-performance<br />

elements of home-entertainment<br />

systems, such as a high-definition TV<br />

and a set-top box, Heile noted.<br />

He said IEEE 802.15.3c-2009 could<br />

also provide connections in other set-<br />

tings, such as body-area networks for<br />

medical applications.<br />

In addition, the standard’s high<br />

data rates and ability to provide<br />

guaranteed time slots for designated<br />

transmissions support applications,<br />

such as high-end video, that require<br />

quality of service.<br />

Like other radio-based technologies,<br />

IEEE 802.15.3c-2009 is<br />

implemented via a chip that includes<br />

a transmitter, receiver, and antenna.<br />

Heile said the system can identify<br />

lost packets and get replacements to<br />

the destination fast enough to preserve<br />

packet order with minimal<br />

delay. Thus, he noted, it can coexist<br />

with interference from other technologies<br />

operating in the 60-GHz band.<br />

If successful, the new technology<br />

could provide an improved way to<br />

play video and other types of multimedia<br />

via wireless technologies,<br />

said Filomena Berardi, Connectivity<br />

Group research analyst with IMS<br />

Research.<br />

IEEE SOFTWARE<br />

offers pioneering ideas,<br />

expert analyses, and<br />

thoughtful insights for<br />

software professionals<br />

who need to keep up<br />

with rapid technology<br />

change. It’s the authority<br />

on translating software<br />

theory into practice.<br />

www.computer.org/<br />

software/SUBSCRIBE<br />

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COMPUTING PRACTICES<br />

Puzzle-Based Learning<br />

for Engineering and<br />

Computer Science<br />

Nickolas Falkner, University of Adelaide<br />

Raja Sooriamurthi, Carnegie Mellon University<br />

Zbigniew Michalewicz, University of Adelaide<br />

To attract, motivate, and retain students and increase their<br />

mathematical awareness and problem-solving skills, universities are<br />

introducing courses or seminars that explore puzzle-based learning.<br />

We introduce and define this learning approach with a sample syllabus<br />

and course material, describe course variations, and highlight early<br />

student feedback.<br />

Arecent article describes a puzzle-based freshman<br />

seminar introduced at the University of<br />

California, Santa Barbara, to motivate and<br />

retain computer engineering students. 1 The<br />

author argues that attracting students to computer<br />

science and engineering programs represents only<br />

one aspect of a broader problem, the shortage of a skilled<br />

information technology workforce, and that recruitment<br />

efforts must be augmented with additional strategies for<br />

retaining and motivating students—strategies that are<br />

missing in curricula recommendations of the IEEE Computer<br />

Society and the ACM.<br />

The problem may be even broader. Today’s marketplace<br />

needs more skilled graduates capable of solving real<br />

problems of innovation in a changing environment. Missing<br />

in the majority of engineering and computer science<br />

curricula is a focus on developing problem-solving skills.<br />

Further, many courses that introduce elements of problemsolving<br />

skills do so at the programs’ third or fourth level,<br />

after students have already faced the majority of their inacademy<br />

intellectual challenges.<br />

While some courses with a design content emphasis<br />

might meet this requirement, most engineering students<br />

never learn how to think about solving problems in general.<br />

Throughout their education, they are constrained<br />

to concentrate on textbook questions at the end of each<br />

COMPUTER<br />

chapter, solved using material discussed in the chapter.<br />

This constrained form of “problem solving” is not sufficient<br />

preparation for addressing real-world problems. On<br />

entering the real world, students find that problems do not<br />

come with instructions or a guidebook. One of our favorite<br />

examples for illustrating this point is a puzzle on breaking<br />

a chocolate bar:<br />

A rectangular chocolate bar consists of m × n small rectangles,<br />

and you wish to break it into its constituent parts. At<br />

each step, you can only pick up one piece and break it along<br />

any of its vertical or horizontal lines. How should you break<br />

the chocolate bar using the minimum number of steps?<br />

If you do not know the answer, which textbook would<br />

you search to discover the solution? The same applies to<br />

solving many real-world problems: Which textbook should<br />

you search to find a solution, if that is the solution strategy<br />

you’ve learned?<br />

Students often have difficulty applying independent<br />

thinking or problem-solving skills regardless of the nature<br />

of a problem. At the same time, educators are interested<br />

in teaching “thinking skills” rather than “teaching information<br />

and content.” The latter approach has dominated<br />

in the past. As Alex Fisher 2 wrote “though many teachers<br />

would claim to teach their students ‘how to think’, most<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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would say that they do this indirectly or implicitly in the<br />

course of teaching the content which belongs to their special<br />

subject. Increasingly, educators have come to doubt<br />

the effectiveness of teaching ‘thinking skills’ in this way,<br />

because most students simply do not pick up the thinking<br />

skills in question.”<br />

Further, many analysts lament students’ decreasing<br />

mathematical skills. A recent Mathematics Working<br />

Party Final Report, issued by the University of Adelaide, 3<br />

includes statements such as, “There is an urgent need to<br />

raise the profile and importance of mathematics among<br />

young people” and “The declining participation in mathematics<br />

and related subjects is not limited to Australia.”<br />

Our universities, the University of Adelaide and Carnegie<br />

Mellon University, have introduced a new puzzle-based<br />

learning course to address all the issues raised here.<br />

PUZZLEfiBASED LEARNING APPROACH<br />

The puzzle-based learning approach aims to encourage<br />

engineering and computer science students to think about<br />

how they frame and solve problems not encountered at<br />

the end of some textbook chapter. Our goal is to motivate<br />

students while increasing their mathematical awareness<br />

and problem-solving skills by discussing a variety of puzzles<br />

and their solution strategies. The course is based on<br />

the best traditions introduced by Gyorgy Polya and Martin<br />

Gardner over the past 60 years. 4,5<br />

Many teachers have used puzzles for teaching purposes,<br />

and the puzzle-based learning approach has a tradition that<br />

exceeds 60 years. 6 Historians found the first mathematical<br />

puzzles in Sumerian texts from circa 2500 BC. However,<br />

some of the best evidence for the puzzle-based learning<br />

approach can be found in the works of Alcuin, an English<br />

scholar born around 732 AD, whose main work, Problems<br />

to Sharpen the Young, included more than 50 puzzles.<br />

Some 1,200 years later, one of Alcuin’s puzzles—the “river<br />

crossing problem”—is still used in artificial intelligence<br />

textbooks to educate computer science students.<br />

In our course, we concentrate on educational puzzles<br />

that support problem-solving skills and creative thinking.<br />

These educational puzzles satisfy most of the following<br />

criteria.<br />

Independence<br />

The puzzles are not specifically tied to a single problem-solving<br />

domain.<br />

Generality<br />

Educational puzzles should explain some universal mathematical<br />

problem-solving principles. This is key. Most people<br />

agree that problem solving can only be learned by actually<br />

solving problems. This activity, however, must be supported<br />

by instructor-provided strategies. These general strategies<br />

allow for solving yet unknown problems in the future.<br />

Simplicity<br />

Educational puzzles should be easy to state and remember.<br />

This is important because easy-to-remember puzzles<br />

increase the chance students will remember the solution<br />

method, including the universal mathematical problemsolving<br />

principles.<br />

Eureka factor<br />

Educational puzzles should initially frustrate the problem<br />

solver, but hold out the promise of resolution. A puzzle<br />

should be interesting because its result is not immediately<br />

intuitive. Problem solvers often use intuition to start their<br />

quest for the solution, and this approach can lead them<br />

astray. Eventually they reach a “Eureka moment”—Martin<br />

Gardner’s Aha!—when students recognize the correct path<br />

to solving the puzzle. A sense of relief accompanies this<br />

moment, and the frustration felt during the process dissipates,<br />

giving the problem solvers a sense of reward at their<br />

cleverness for solving the puzzle. The Eureka factor also<br />

implies that educational puzzles should have elementary<br />

solutions that are not obvious.<br />

There is a strong connection<br />

between the ability to solve puzzles<br />

and the ability to solve industry and<br />

business problems.<br />

Entertainment factor<br />

Educational puzzles should be entertaining and engaging.<br />

Entertainment is often a side effect of simplicity,<br />

frustration, the Eureka factor, and an interesting setting<br />

such as playing in a casino environment, fighting against<br />

dragons, or dropping eggs from a tower.<br />

THE LURE OF EDUCATION<br />

Educational puzzles can play a major role in attracting<br />

students to computer science and engineering programs,<br />

and can be used in talks to high school students and<br />

during open-day events. Puzzles can also be a factor that<br />

helps retain and motivate students. Above all, they are<br />

responsible for developing critical thinking and problemsolving<br />

skills as well as raising the profile and importance<br />

of mathematics. Further, there is a strong connection<br />

between the ability to solve puzzles and the ability to<br />

solve industry and business problems. Many real-world<br />

problems can be perceived as large-scale puzzles. William<br />

Poundstone, when investigating the purpose of famous<br />

Microsoft/Silicon Valley interview puzzles, 7 wrote,<br />

“At Microsoft, and now at many other companies, it is believed<br />

that there are parallels between the reasoning used to solve<br />

puzzles and the thought processes involved in solving the real<br />

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COMPUTING PRACTICES<br />

Real world<br />

Abstract/model<br />

world<br />

problems of innovation and a changing marketplace. […] When<br />

technology is changing beneath your feet daily, there is not much<br />

point in hiring for a specific, soon-to-be-obsolete set of skills. You<br />

have to try to hire for general problem-solving capacity, however<br />

difficult that may be. […] Both the solver of a puzzle and a<br />

technical innovator must be able to identify essential elements<br />

in a situation that is initially ill-defined. It is rarely clear what<br />

type of reasoning is required or what the precise limits of the<br />

problem are.”<br />

Puzzle-based versus problem-based versus<br />

project-based learning<br />

The ultimate goal of puzzle-based learning is to lay a<br />

foundation for students to be effective problem solvers in<br />

the real world. At the highest level, problem solving in the<br />

real world calls into play three categories of skills: dealing<br />

with the vagaries of uncertain and changing conditions;<br />

harnessing domain-specific knowledge and methods; and<br />

critical thinking and applying general problem-solving<br />

strategies.<br />

These three skill categories are captured in the three<br />

forms of learning Figure 1 depicts. In this continuum, each<br />

layer of skills builds upon the layers below it. Puzzle-based<br />

learning focuses on domain-independent, transferable<br />

skills. In addition, we aim to foster introspection and<br />

reflection on the personal problem-solving process: What<br />

was I thinking? What is the solution? Why did I not see it?<br />

Both problem-based and project-based learning are well<br />

established methodologies. 8,9 By our description, problembased<br />

learning requires significant domain knowledge.<br />

This is the form of learning typically emphasized in a<br />

domain-specific undergraduate course such as electromagnetism,<br />

data structures, or circuit theory. Project-based<br />

learning, on the other hand, deals with complex situations<br />

in which usually no clearly unique or correct way<br />

of proceeding exists. For example, “How can we increase<br />

the adherence of cystic fibrosis patients to following their<br />

treatment protocol?” Determining the best solution in such<br />

a situation can be difficult.<br />

The pedagogical objectives of project-based learning<br />

include dealing with ambiguity and complexity, integrating<br />

COMPUTER<br />

Working in teams<br />

identifying the question<br />

Acquisition of<br />

domain knowledge<br />

Critical thinking<br />

logical reasoning<br />

Dealing with uncertainty<br />

and changing conditions<br />

Reasoning with<br />

domain-specific methods<br />

Abstract reasoning<br />

domain independent<br />

Figure 1. Problem solving in the real world requires a continuum of<br />

learning and skills in which each layer of skills builds upon the layers<br />

below it.<br />

a variety of approaches, user testing of the proposed<br />

solutions’ value, and working with a team<br />

composed of diverse backgrounds and skills. In<br />

both problem-based and project-based learning,<br />

the problem drives the learning: Students must<br />

assess what they already know, the knowledge<br />

they need to address the problem, and how to<br />

bridge the knowledge and skill gap.<br />

Puzzle-based learning focuses on domainindependent<br />

critical thinking and abstract<br />

reasoning. This leads us to ask, “What is the difference<br />

between a puzzle and a problem?” One<br />

way to characterize the difference measures the<br />

extent to which domain-specific knowledge is needed to<br />

solve it. The general flavor of puzzles asserts that their<br />

solution should require only domain-neutral general reasoning<br />

skills—biologists, musicians, and artists should all<br />

be able to solve the same puzzle. The different styles of<br />

reasoning required for problem-based and puzzle-based<br />

learning could be compared to the difference between a<br />

field investigator and an armchair detective: one emphasizes<br />

pure reasoning more.<br />

Dropping eggs<br />

The well-known egg-drop experiment provides an<br />

example that compares and contrasts problem-based and<br />

puzzle-based learning. The traditional problem-based<br />

learning version of this experiment involves finding a way<br />

to drop an egg from a maximal height without breaking<br />

it. A puzzle-based learning version of this experiment also<br />

involves dropping an egg from a building, but the question<br />

under investigation, although related, is quite different.<br />

In the problem-based learning approach, students conduct<br />

a series of physical experiments to determine how to<br />

maximize the height from which an egg can be dropped<br />

without breaking. There are two broad approaches:<br />

Dampen the impact’s effect (leading to padding-based<br />

solutions) or lessening the impact (leading to delivery<br />

mechanisms such as a parachute). The team-based learning<br />

outcomes of such an experiment determine different<br />

ways to dampen or lessen an impact.<br />

A puzzle-based learning approach to a similar problem<br />

does not involve a physical experiment, but rather<br />

a thought experiment. One approach would be to ask a<br />

question along the lines of the following: Using multiple<br />

eggs, what would be an effective strategy for determining<br />

the highest floor from which I could drop an egg without<br />

breaking it? This question has interesting variations. This<br />

thought experiment has three entities: the number of eggs,<br />

number of drops, and number of floors.<br />

One puzzle-based learning question could be, “Given a<br />

fixed number of eggs and a number of allowed drops, what<br />

is the maximum height of a building whose breaking floor<br />

we can determine? This could be denoted as F e,d .<br />

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An alternate question could be, “Given a fixed number of<br />

floors—say, 100—and a number of eggs—say, three—what<br />

is the maximum number of drops needed to determine<br />

the breaking floor (D e,f )?” Yet another version might be to<br />

ask how many eggs would be needed to determine the<br />

breaking floor given a fixed number of floors and allowed<br />

number of drops (E f,d ).<br />

Note that all three puzzle-based learning versions of<br />

the problem require only basic math skills and analytical<br />

reasoning. One goal of puzzle-based learning is to foster<br />

the skill of analyzing and understanding problems clearly.<br />

Part of this requires the clarification of any assumptions<br />

needed to solve the problem. For example, for the egg-drop<br />

thought experiment, some reasonable assumptions include<br />

“all eggs behave the same way” and “an egg that survives<br />

a drop is not damaged and may be dropped again.” To<br />

constrain the problem, we would consider assumptions<br />

such as “an egg surviving a drop from floor x would have<br />

survived a drop from any floor less than x.”<br />

Suppose, given a fixed number of eggs, e, and a specified<br />

number of drops, d, we want to determine the maximal<br />

height of a building whose breaking floor we can determine<br />

(F e,d ). Applying the heuristic of “try to solve a similar<br />

but simpler problem,” let us consider the situation where<br />

we have only one egg (e = 1). In this case, we are required<br />

to search sequentially.<br />

If we are allowed 10 drops (d = 10), then we can determine<br />

the breaking floor of a ten-floor building by starting<br />

at floor one and working our way up. Now suppose we had<br />

two eggs (e = 2). What strategy could we follow? Students<br />

who have had some prior programming experience often<br />

give binary search as a possible strategy, although this is<br />

not the best solution.<br />

Students are led through the reasoning process in a<br />

lecture environment and encouraged to contribute and<br />

refine their suggestions, with controlled prompting. By<br />

considering examples and reasoning about what happens<br />

if the first egg does or doesn’t break, students are guided<br />

through the general version of this puzzle, culminating in<br />

the derivation of the general solution.<br />

Puzzle-based learning shares many pedagogical goals<br />

with the emerging paradigm of computational thinking. 10<br />

Puzzle-based learning resonates with the computational<br />

thinking emphasis on abstraction and analytical thinking.<br />

With reference to Figure 1, computational thinking straddles<br />

the problem skill spectrum but places more emphasis<br />

on problem-based and project-based learning. With its<br />

emphasis on domain-independent, rigorous, and transferable<br />

reasoning, we believe that puzzle-based learning<br />

lays a basis for computational thinking in the curriculum.<br />

PUZZLEfiBASED LEARNING COURSES<br />

A few different versions of the puzzle-based learning<br />

course are currently being taught. The course can be<br />

offered as a three-unit full semester elective course, typically<br />

of three contact hours per week, split into lectures<br />

and tutorials; a three-unit full-semester freshman seminar<br />

of three contact hours per week; or a one-unit freshman<br />

seminar and a one-unit core module as part of some other<br />

course.<br />

One important point about puzzle-based learning<br />

courses is that they are not about presenting and discussing<br />

a variety of puzzles, but rather about presenting,<br />

discussing, and understanding problem-solving principles<br />

and some mathematical principles in the context<br />

of puzzles that serve as entertaining illustrations of the<br />

concepts presented. Also, the process of understanding<br />

problem-solving principles leads students through a variety<br />

of topics, exposing them to many important concepts<br />

at early stages of their college education.<br />

The process of understanding<br />

problem-solving principles leads<br />

students through a variety of topics,<br />

exposing them to many important<br />

concepts.<br />

Despite a variety of possible puzzle-based learning<br />

offerings, the course’s structure is very much the same.<br />

The topics listed below correspond to a 12-week semester<br />

regardless of whether each topic is allocated one hour<br />

or three. Although the topics have some dependency, as<br />

we build and develop our model for problem solving, the<br />

later topics’ order can be rearranged. The topic structure<br />

also supports a high-level first pass and a secondary,<br />

detailed pass model for younger students or for development<br />

over a multiyear curriculum. Similar topic structures<br />

are employed across both secondary and tertiary student<br />

environments, as well as our presentations of puzzle-based<br />

learning concepts to industry, as the following list shows:<br />

1. Introduction. What it is it all about?<br />

2. The problem. Rule #1: Understand the problem.<br />

3. Intuition. Rule #2: Be cautious of your intuitions—<br />

guess, but verify.<br />

4. Modeling. Rule #3: Reason, model, calculate.<br />

5. Some mathematical principles. Do you know how much<br />

you already know?<br />

6. Constraints. Am I aware of all of the constraints?<br />

7. Optimization. What is the best arrangement, and is it<br />

one that I can actually use?<br />

8. Probability. Counting skills and counterintuitive<br />

results.<br />

9. Statistically speaking. What does an apparently convincing<br />

statement actually mean?<br />

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10. Let’s simulate. Can we generate the answer?<br />

11. Pattern recognition. What is next?<br />

12. Strategy. Shall we play?<br />

We illustrate each topic with a variety of puzzles presented<br />

interactively. The course introduces a few simple<br />

problem-solving rules that we refer to in every class.<br />

Each week, students receive homework assignments<br />

that cover one or more puzzles addressed in class. The<br />

following week, at the beginning of class, the instructor<br />

presents and discusses solutions. In one instance of the<br />

course, homework contributes 30 percent toward the<br />

final grade, and the final exam contributes the remaining<br />

70 percent. Students can access all lecture slides, audio<br />

Without understanding the problem,<br />

all efforts to find a solution usually<br />

simply waste time: the dictum of<br />

solve the right problem and solve the<br />

problem right.<br />

lecture recordings, and additional material, including<br />

course software. Sample course work might include a<br />

sample lecture that poses the following question: “The<br />

problem: What are you after?” The lecture introduces the<br />

most important problem-solving rule.<br />

First rule of problem solving<br />

Be sure you understand the problem and all the basic<br />

terms and expressions used to define it.<br />

Indeed, without understanding the problem, all<br />

efforts to find a solution usually simply waste time: the<br />

dictum of solve the right problem and solve the problem<br />

right. Underspecificationfican be used as a tool that<br />

encourages students to determine what they know,<br />

what they don’t know and must find out, and what they<br />

cannot find out.<br />

The approach places the emphasis for knowledge discovery<br />

on the students and forces them to accept that,<br />

on occasion, they must provide their best guess. The first<br />

puzzle we use to illustrate this simple observation is one<br />

of Martin Gardner’s favorites.<br />

Puzzle 1<br />

A farmer has the following: 20 pigs, 40 cows, and 60<br />

horses. How many horses does he have, if he calls the<br />

cows horses?<br />

It takes students a short time to understand the problem,<br />

“calling,” which has little to do with “having.” The<br />

farmer still has 60 horses.<br />

This example can be followed by another classic.<br />

COMPUTER<br />

Puzzle 2<br />

You drive a car at a constant speed of 40 kph from A to<br />

B, and on arrival at B, you return immediately to A but at<br />

a higher speed of 60 kph. What was your average speed<br />

for the whole trip?<br />

Again, many students would jump immediately into<br />

the obvious answer of 50 kph without much understanding<br />

of what the average speed is—or rather, how<br />

average speed is defined. Most students are surprised to<br />

discover the correct answer of 48 kph. The next time, in<br />

any course they take in their programs, they will think<br />

twice before they answer a question on some average.<br />

We seek to foster this clear and thoughtful analysis to<br />

hone and guide intuition.<br />

Homework<br />

Clearly, there are strong connections between the process<br />

of understanding the problem and critical thinking. A lecture<br />

might include a slide with a statement containing loose terminology,<br />

strawman arguments, and logical fallacies, and<br />

students are asked to discuss it. We seek to encourage a focus<br />

on critical thinking toward finding a solution.<br />

One weekly assignment given to the students at the end<br />

of this lecture proceeded as follows.<br />

With a 7-minute hourglass and an 11-minute hourglass,<br />

find the simplest way to time the boiling of an egg for 15<br />

minutes.<br />

Note that we are not after any solution, but the simplest<br />

solution. One week later, after all homework has been<br />

handed in, the lecturer has interesting material for discussion,<br />

as some students found the solution A:<br />

Start with the 7- and 11-minute hourglasses, when the<br />

egg is dropped into the boiling water.<br />

After 7 minutes, invert the 7-minute hourglass.<br />

After 4 additional minutes (when sand in the<br />

11-minute hourglass stops), invert the 7-minute hourglass<br />

again.<br />

When the sand stops in the 7-minute hourglass, 15<br />

minutes will have elapsed.<br />

Whereas other students found solution B:<br />

Start the 7- and 11-minute hourglasses.<br />

After 7 minutes, drop the egg into the boiling water.<br />

After 4 additional minutes (when the sand in an<br />

11-minute hourglass stops), invert the 11-minute<br />

hourglass.<br />

When the sand stops in the 11-minute hourglass<br />

again, 15 minutes will have elapsed from the time<br />

the egg dropped into the water.<br />

Which of these solutions is simpler? Solution A takes<br />

15 minutes to complete and requires two inversions.<br />

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Solution B requires 22 minutes, but only one inversion.<br />

Most students believed that solution A was simpler, as<br />

it required less time. They were, however, less certain<br />

about that when they were told that the hourglasses<br />

involved were quite heavy, weighing 100 kg each. Such<br />

a puzzle provides excellent material not only for a discussion<br />

on understanding the problem, but also on what<br />

the simplest solution means. This also introduces the<br />

concept of multiobjective optimization, a concept students<br />

are usually exposed to during their third year of<br />

studies.<br />

OTHER EXAMPLES<br />

We can use many different puzzles to illustrate fundamental<br />

concepts of probability, statistics, pattern<br />

recognition, games, constraint processing, and optimization.<br />

Here we present a few examples.<br />

Puzzle 3<br />

A farmer sells 100 kg of mushrooms for $1 per kg. The<br />

mushrooms contain 99 percent moisture. A buyer makes<br />

an offer for these mushrooms at the same price a week<br />

later. However, another week later the mushrooms would<br />

have lost 98 percent of their moisture content. How much<br />

will the farmer lose if he accepts the offer?<br />

This is a good example for resisting immediately intuitive<br />

answers—it might not be obvious that the farmer will<br />

lose $50.<br />

Puzzle 4<br />

A bag contains a single ball, which is known to be either<br />

white or black, with equal probability. A white ball is put in,<br />

the bag shaken, and a ball is then randomly removed. This<br />

ball happens to be white. What is the probability now that<br />

the bag currently contains the white ball? Puzzle 4 thus<br />

introduces basic concepts in probability.<br />

Puzzle 5<br />

There are n dots on the flat surface of a plane. Two<br />

players, A and B, move alternatively, with A moving first.<br />

The game’s rules are the same for both players: At each<br />

move, they can connect two points, but they cannot<br />

connect points that were already directly connected to<br />

each other or connect a point with itself. They build a<br />

graph with predefined n vertices by connecting some of<br />

the dots.<br />

The winner is the one who connects the graph (a graph<br />

is connected if there is a path between any two nodes of<br />

the graph; however, not every two nodes must be connected<br />

directly). Which player, A or B, has a winning<br />

strategy?<br />

This puzzle introduces graphs and investigating the<br />

concept of strategies—discovering the winning strategies<br />

of the first or second player is not trivial.<br />

More puzzles<br />

We collected and organized a few hundred educational<br />

puzzles into meaningful subsets. All teaching materials<br />

and the new textbook (Puzzle-Based Learning: Introduction<br />

to Critical Thinking, Mathematics, and Problem Solving) are<br />

now in active use—the text follows the structure of the<br />

course given earlier. Chapter 13 of the text includes a collection<br />

of problems without a solution. These can be used<br />

for homework, assignments, and exams.<br />

There are many ways to evaluate students’ progress in<br />

the puzzle-based learning course. These vary from evaluations<br />

based on participation through evaluations based<br />

From this point, students could still<br />

discuss different interpretations of<br />

the result, encouraging thought.<br />

on homework to final exams. Many students might be<br />

a bit nervous on encountering a final exam loaded with<br />

puzzles. However, the exam can be organized in many<br />

ways that will make it meaningful. For example, last<br />

semester the final exam questions included the following<br />

two examples.<br />

Question 1<br />

Five minutes after midnight of April 13th, 2004, a heavy<br />

rain fell in Melbourne. What is the probability that, 72 hours<br />

later, it would be sunny there? Justify your answer.<br />

This question checked students’ skills for understanding<br />

the problem before providing an answer. (For the curious,<br />

the probability is zero percent.)<br />

Question 2<br />

The hour and minute indicators of my watch cover each<br />

other every 65 minutes. Is my watch running too quickly or<br />

too slowly? Justify your answer.<br />

This question tested students’ modeling skills and<br />

rewarded them for identifying the implicit question “When<br />

should the hands of a watch cover each other,” and for<br />

modeling the problem, even if they reached an incorrect<br />

conclusion.<br />

Wide range<br />

As a glimpse into the range of approaches to a<br />

problem consider the following: In class we examined<br />

different reasoning styles—quantitative versus qualitative<br />

versus intuitive versus wild guess. Both quantitative<br />

and qualitative methods are rigorous, using numbers<br />

and algebra while the other uses language and logic.<br />

One student group went through the precise calculations<br />

to determine when an overlap should occur on<br />

a correct watch, while another group qualitatively<br />

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reasoned that if a clock were correctly running, then at<br />

60 minutes past noon, the minute hand would be over<br />

the 12 and the hour hand over the 1. Five minutes later,<br />

the minute hand would be over the 1 and the hour hand<br />

would have moved a little forward. From this point,<br />

students could still discuss different interpretations of<br />

the result, encouraging thought.<br />

For more information on the nature of puzzles and<br />

the approaches used in puzzle-based learning, we direct<br />

readers to the website associated with the text, ____<br />

www.<br />

PuzzleBasedLearning.edu.au.<br />

___________________<br />

UNIVERSITY OF ADELAIDE<br />

We now explore two of this course’s implementations:<br />

the primary development site at the University of Adelaide<br />

and another at Carnegie Mellon University, Pittsburgh. The<br />

initial implementation of puzzle-based learning offered<br />

Students are interested in the<br />

material, but their interest can<br />

easily be capped when they feel<br />

constrained by the assessment<br />

mechanisms.<br />

a one-unit course set as a component of a thee-unit firstyear<br />

course, Introduction to Electronic Engineering. After<br />

gaining support from the Dean of the Faculty of Engineering,<br />

Computer and Mathematical Sciences, from 2009, the<br />

university placed this one-unit offering into introductory<br />

courses across the engineering programs available within<br />

the university.<br />

A three-unit, first-year course for students planning<br />

to major in computer science launched simultaneously<br />

in 2009, and was made available to all nonengineering<br />

students at the university. We refer to the one-unit offering<br />

as PBL-E (PBL for Engineers), and the three-unit offering<br />

as PBL Main. The courses cover the same material, but at<br />

different levels of depth.<br />

The intake for the two courses is quite different, as<br />

PBL-E students have a higher Tertiary Entrance Rank on<br />

average and have also taken two mathematics courses<br />

from secondary school. The students in PBL Main might<br />

have a single course of mathematics if enrolled in the<br />

Bachelor of Computer Science program, or might have no<br />

mathematics beyond the middle of Secondary School, if<br />

from other programs.<br />

In 2008, 325 students undertook the first offering<br />

of one-unit PBL, with a weekly one-hour lecture,<br />

supported with online forums and assessed through<br />

weekly assignments and a final, hour-long examination.<br />

In 2009, 428 students undertook the one-unit PBL<br />

COMPUTER<br />

course, with another 102 students undertaking the<br />

three-unit PBL Main course. The PBL-E course remained<br />

essentially the same in structure, but the three-unit<br />

course added an additional lecture per week, along<br />

with weekly tutorials. This let instructors explore the<br />

material’s development in further depth. The majority<br />

of PBL Main homework consisted of two questions to<br />

be completed during the week, rather than the single<br />

question posed by PBL-E.<br />

Patterns of learning<br />

Lectures in PBL follow a set pattern. Each week, the<br />

first lecture presents the solution to the previous homework,<br />

identifies key points for that week’s lectures, then<br />

builds on the topic area. The lecture concludes with the<br />

next assignment. Lectures are recorded and the lecture<br />

slides, recordings, and all assignment work made available<br />

on the course’s electronic forum. These forums also<br />

provide message boards for student interaction.<br />

PBL Main has a second lecture that develops the<br />

themes of the week’s topic. Lecture materials are developed<br />

in parallel, with the single PBL-E lecture derived<br />

from a revision and abridgement of the two PBL Main<br />

lectures for that topic to maintain currency between<br />

the two courses.<br />

The university offers tutorials for PBL Main that let students<br />

take part in collaborative problem-solving exercises,<br />

while a tutor provides assistance and guidance. Tutorial<br />

groups can hold up to 25 students, divided into subgroups<br />

of five to eight for problem solving. During these sessions,<br />

we introduce fundamental mathematical concepts useful<br />

in the later course, including counting and the bases of<br />

probability, such as factorials, combinations, and permutations.<br />

This addresses the differences in mathematical<br />

preparation identified in the intake.<br />

While a good grasp of mathematics can be useful for<br />

PBL, it is not essential. Problem specification has been<br />

a key concern, as the larger classes contain students<br />

accustomed to a completely specified problem, and thus<br />

feel uncomfortable when confronted with problems not<br />

completely specified or, in the student’s opinion, not sufficiently<br />

and exactly specified. While some students regard<br />

this as a challenge, and also as an intellectual freedom,<br />

others have found it to be a stumbling block.<br />

Assessment of the course has proven to be one of the<br />

largest implementation issues. Students are interested in<br />

the material, but their interest can easily be capped when<br />

they feel constrained by the assessment mechanisms, or<br />

feel they haven’t received sufficient, personalized feedback.<br />

Early assessment for PBL-E revolved around a mark<br />

for each assignment out of five, followed by feedback to<br />

the group that demonstrated the marking scheme and<br />

solution. Instructors also presented the previous lesson’s<br />

solution at the lecture’s start, which corresponded with the<br />

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hand-in time, to let students immediately gain feedback on<br />

the quality of their solution.<br />

PBL-E’s student numbers posed a significant resource<br />

issue: Without detailed feedback, it takes approximately<br />

two to three minutes to mark each assignment. Thus, the<br />

marking load starts at approximately eight hours for each<br />

assignment, with a team of markers employed and trained<br />

to provide consistency of response.<br />

PBL Main has a much smaller enrollment but employs<br />

detailed, personalized feedback that also takes approximately<br />

eight hours to complete a week’s assignments. The<br />

requirement for a consistent and reproducible marking<br />

scheme that can be assigned to multiple markers constrains<br />

the range of problems that can be offered. Problems<br />

with too many possible solutions become effectively<br />

impossible to mark across 450 students.<br />

In response to this, we have considered many alternatives<br />

and are currently developing problems that might<br />

have multiple possible solutions, all of which may appear<br />

to be correct when, in fact, only one is. Again, this is an<br />

issue of problem and solution specification. Controlled use<br />

of multiple-choice questions, with between eight and ten<br />

options, lets markers quickly identify the flaw in reasoning<br />

and correctly mark the student’s work. We also investigate<br />

the possibility of reducing the dependency on a markbased<br />

assessment for this course.<br />

Early student response shows that they enjoy the course<br />

material and it does develop their thinking skills. However,<br />

several students, especially in PBL-E, encounter issues<br />

with the assessment model and its perceived lack of feedback.<br />

Others worry that the assessment mechanism can<br />

develop a negative and unproductive approach to the<br />

course. We are actively seeking to address these concerns<br />

by allocating more resources to marking and feedback,<br />

and through the use of automated marking mechanisms<br />

that allow more rapid response. Future implementations<br />

of PBL-E may include tutorials or alternative assessment<br />

mechanisms.<br />

CARNEGIE MELLON UNIVERSITY<br />

Carnegie Mellon University offered puzzle-based learning<br />

as a nine-unit, three-credit freshman seminar in spring<br />

2009. Given the spring course’s seminar nature, instructors<br />

capped enrollment at 15, but we found it encouraging to<br />

see that the wait list exceeded the class’s enrollment.fiThe<br />

class had an interdisciplinary mix of students majoring<br />

in Information Systems, Computer Science, Psychology,<br />

Statistics, Cognitive Science, Economics, and Physics. The<br />

class met twice a week for 80 minutes.<br />

In addition to the knowledge gained from the Adelaide<br />

experience, the smaller size of this class let us experiment<br />

with several alternative themes. For example, after the<br />

introductory classes, each session started with a puzzle<br />

of the day.<br />

First, a student would present a puzzle of his or her<br />

choice. The class as a whole tried to solve this puzzle,<br />

with hints and guidance provided by the puzzle poser.<br />

Puzzles chosen by the students ranged the gamut from<br />

logic puzzles to diagrammatic reasoning to physical-puzzle<br />

tangrams. Students submitted a one-page write-up of their<br />

puzzle, solution, and—most importantly—their reflection<br />

on the puzzle: What captured their interest in the puzzle<br />

and its variations, and how did the solution tie in with the<br />

overall course’s instruction?<br />

In addition to the daily puzzle, we also conducted a<br />

puzzlethon that again presented a puzzle of the students’<br />

choice. But this time the class voted on the best puzzle (a<br />

combination of presentation and the puzzle’s nature) and<br />

instructors distributed prizes to the winners.<br />

During our discussion of scientific and mathematical<br />

induction, given the smaller size of the class, we played<br />

Robert Abbott’s inductive game Eleusis, 11 which models the<br />

To emphasize the link between<br />

the thought processes involved in<br />

solving puzzles and addressing open<br />

real-world problems, we examined a<br />

few case studies.<br />

scientific method. To introduce students to some problemsolving<br />

thoughts of leaders in the field, we watched a few<br />

videos. These included Polya’s “Let us teach guessing” in<br />

which he beautifully illustrates several problem-solving<br />

heuristics embraced by puzzle-based learning in the process<br />

of deriving a solution to the five-plane problem; an<br />

interview with Herb Simon on being a researcher with<br />

advice to undergraduates; Richard Feynman’s discussion<br />

of problem solving and induction; and Will Shortz’s documentary<br />

Wordplay on crossword puzzles, their creators,<br />

and solvers.<br />

We also visited the Pittsburgh Super<strong>computing</strong> Center<br />

open house to glimpse problem solving in the real world.<br />

To emphasize the link between the thought processes<br />

involved in solving puzzles and addressing open real-world<br />

problems, we examined a few case studies, including the<br />

recently cracked Netflix Prize (www.netflixprize.com) and<br />

the classic work of Mosteller 12 in resolving the authorship<br />

of some of the disputed Federalist papers.<br />

Student evaluation was done with components for class<br />

participation, puzzle presentations, homework assignments,<br />

three exams, and a few in-class quizzes. It has<br />

been gratifying to see that the response to the class has<br />

been favorable, with some students commenting it was<br />

the best class they had that semester. Some have also commented<br />

on the revisiting of PBL themes in their subsequent<br />

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discipline-specific courses. Carnegie Mellon University’s<br />

Doha, Qatar, campus hosted a summer 2009 version of this<br />

course, while the freshman seminar is slated to be offered<br />

in Pittsburgh during spring 2010.<br />

Puzzle-based learning is an in-progress experiment<br />

that seeks to foster general domain-independent<br />

reasoning and critical thinking skills that can lay<br />

a foundation for problem-solving in future course<br />

work. As fun as puzzles inherently are, they provide<br />

only a means to this pedagogical end. Our preliminary<br />

experience in different instantiations of the course and<br />

educational contexts has been encouraging and well<br />

received as we explore this approach. We continue collecting<br />

relevant data to demonstrate the benefit of our<br />

approach. Early results 13 indicate that students who enroll<br />

in our course perceive an improvement in their thinking<br />

and general problem-solving skills.<br />

References<br />

1. B. Parhami, Puzzling Problems in Computer Engineering,<br />

Computer, Mar. 2009, pp. 26-29.<br />

2. A. Fisher, Critical Thinking: An Introduction, Cambridge<br />

University Press, 2001.<br />

3. University of Adelaide, Mathematics Working Party<br />

Final Report, internal document, June 2008.<br />

4. G. Polya, How to Solve It: A New Aspect of Mathematical<br />

Method, Princeton Univ. Press, 1945.<br />

5. M. Gardner, Entertaining Mathematical Puzzles, Dover<br />

Publications, 1961.<br />

6. M. Danesi, The Puzzle Instinct: The Meaning of Puzzles<br />

in Human Life, Indiana Univ. Press, 2002.<br />

7. W. Poundstone, “How Would You Move Mount Fuji?”<br />

Microsoft’s Cult of the Puzzle—How the World’s<br />

Smartest Companies Select the Most Creative Thinkers,<br />

Little Brown and Company, 2000.<br />

8. P.C. Blumenfeld et al., “Motivating Project-Based<br />

Learning: Sustaining the Doing, Supporting the<br />

Learning,” Educational Psychologist, vol. 26, nos. 3<br />

and 4, 1991, pp. 369-398.<br />

9. J.D. Bransford et al., “Teaching Thinking and Problem<br />

Solving: Research Foundations,” Am. Psychologist,<br />

vol. 41, 1986, pp. 1078-1089.<br />

10. J.M. Wing, “Computational Thinking,” Comm. ACM,<br />

Mar. 2006, pp. 33-35.<br />

11. M. Gardner, Penrose Tiles to Trapdoor Ciphers, Mathematical<br />

Assoc. of America, 1997.<br />

12. F. Mosteller and D. Wallace, “Deciding Authorship,”<br />

Mathematics: People, Problems, Results, D.M. Campbell<br />

and J.C. Higgins, eds., Wadsworth Publishing,<br />

1984.<br />

COMPUTER<br />

13. N.J.G. Falkner, R. Sooriamurthi, and Z. Michalewicz,<br />

“Puzzle-Based Learning: The First Experiences,”<br />

Proc. 20th Ann. Conf. Australasian Assoc. for Eng.<br />

Education (AaeE 09), 2009.<br />

Nickolas Falkner is a lecturer in the School of Computer<br />

Science at the University of Adelaide. He received a PhD in<br />

discovery and classification of information in large systems<br />

from the University of Adelaide. His research interests<br />

include wireless sensor networks, automated network configuration,<br />

data fusion, and data stream management.<br />

He is also active in educational research, with a focus on<br />

increasing student participation, retention, and enthusiasm.<br />

Contact him at jnick@cs.adelaide.edu.au.<br />

_________________<br />

Raja Sooriamurthi is an associate teaching professor<br />

with Carnegie Mellon's Information Systems Program and<br />

also has a faculty appointment at Carnegie Mellon's Heinz<br />

College. He received his PhD in computer science from Indiana<br />

University, Bloomington. His research interests are in<br />

artificial intelligence, case-based reasoning, and CS/IS pedagogy.<br />

His pedagogical efforts have been recognized with<br />

several awards for distinguished teaching. Sooriamurthi<br />

is a member of the IEEE Computer Society, the ACM, and<br />

Decision Sciences Institute. Contact him at raja@cmu.edu.<br />

__________<br />

Zbigniew Michalewicz is a professor in the School of<br />

Computer Science, University of Adelaide. He is also at<br />

the Institute of Computer Science, Polish Academy of Sciences<br />

and at the Polish-Japanese Institute of Information<br />

Technology, Poland. He received a PhD in computer science<br />

from the Polish Academy of Science. His research interests<br />

include problem-solving methodologies, evolutionary computation,<br />

modern heuristic methods, and adaptive business<br />

intelligence. Michalewicz is a Fellow of the Australian Computer<br />

Society. Contact him at zbyszek@cs.adelaide.edu.au.<br />

___________________<br />

Selected CS articles and columns are available for free<br />

at http://ComputingNow.computer.org.<br />

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PERSPECTIVES<br />

Using Codes of Conduct<br />

to Resolve Legal Disputes<br />

Peter Aiken, Virginia Commonwealth University<br />

Robert M. Stanley and Juanita Billings, Data Blueprint<br />

Luke Anderson, Duane Morris LLC<br />

In the absence of other published standards of care, it is reasonable<br />

for contractual parties to rely on an applicable, widely available code<br />

of conduct to guide expectations.<br />

When legal disputes arise, the primary<br />

focus of judges, juries, and arbitration<br />

panels is on interpreting facts. In<br />

cases of alleged underperformance,<br />

they must evaluate facts against contract<br />

language, which typically states that services will<br />

be provided in accordance with industry standards. Legal<br />

arbiters seek well-articulated “standards of care” against<br />

which to evaluate the behavior of contractual parties and,<br />

in the absence of other published standards, increasingly<br />

rely on codes of conduct (CoCs) to establish an objective<br />

context. In fact, they have successfully applied CoCs—<br />

including the ACM/IEEE-CS CoC—in instances where the<br />

parties were not even affiliated with the CoC-sponsoring<br />

organization.<br />

We illustrate the current application of CoCs with a<br />

fictional enterprise resource planning (ERP) system implementation<br />

failure that is a compilation of real-life cases.<br />

Subject to binding panel arbitration, the plaintiff and defendant<br />

in the case presented conflicting interpretations of the<br />

same facts: From the plaintiff’s perspective, the defendant<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

Published by the IEEE Computer Society<br />

failed to migrate the ERP system as promised; the defendant<br />

countered that defective and poor-quality data delayed<br />

the migration. Using the ACM/IEEE-CS CoC as a reference,<br />

expert testimony convinced the arbitration panel that the<br />

defendant’s position was untenable, and the panel accordingly<br />

awarded the plaintiff a multimillion-dollar judgment.<br />

CASE STUDY<br />

Acme Co. received a directive from its parent corporation<br />

mandating replacement of its legacy pay and<br />

personnel systems with a specific ERP software package<br />

designed to standardize payroll and personnel processing<br />

enterprise-wide. Upon the vendor’s “referred specialist”<br />

recommendation, Acme Co. contracted with ERP Systems<br />

Integrators to implement the new system and convert its<br />

legacy data for $1 million.<br />

The contracted timeline was six months, beginning in<br />

July and wrapping up with a “big bang” conversion at the<br />

end of December. The year-end conversion failed, allegedly<br />

due to ERP Systems Integrators’ poor data migration<br />

practices, and Acme Co. had to run the old and new sys-<br />

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PERSPECTIVES<br />

ARBITRATION VERSUS CIVIL SUITS<br />

In contrast to civil suits tried in a court of law, arbitration vests the<br />

functions of judge and jury in a panel of arbitrators, typically<br />

lawyers or industry professionals, whose time is paid for by the<br />

involved parties. Arbitration is private and frequently subject to<br />

cončdentiality and nondisclosure agreements—because only the<br />

participants know the details, arbitration inćuences future litigation<br />

at a slower rate than do public court proceedings.<br />

An arbitration panel does not issue an opinion; instead, it hands<br />

down a one-page decision to award damages (or not)—typically<br />

monetary—to one party or the other. The reasoning supporting<br />

any judgment thus must be inferred from the parties’ arguments.<br />

Arbitration decisions are čnal and generally cannot be appealed.<br />

Remaining rules of court are much like those in a trial. A preliminary<br />

phase is dedicated to evidence gathering, motion exchanges,<br />

depositions, and other discovery forms. Lawyers for each party try<br />

to convince the panel of the validity of their client’s position.<br />

tems in parallel—a complex and expensive situation that<br />

it had carefully planned to avoid and that ERP Systems<br />

Integrators had assured them would not occur. When the<br />

conversion was pushed into April of the following year,<br />

Acme Co. slowed and then ceased paying ERP Systems<br />

Integrators’ invoices. In July, ERP Systems Integrators<br />

pulled its implementation team and Acme Co. initiated<br />

arbitration.<br />

Most IT projects are governed by contracts that assign<br />

responsibilities to each party and provide specific remedies<br />

for delayed implementation or project failure. Such<br />

contracts require the parties to submit to private, binding<br />

arbitration to resolve disputes. As the “Arbitration versus<br />

Civil Suits” sidebar indicates, this process slightly differs<br />

from civil litigation in a court of law. However, the use of<br />

CoCs applies equally to both settings.<br />

Almost a year passed before the arbitration hearing.<br />

Meanwhile, Acme Co. and ERP Systems Integrators<br />

deposed witnesses, and experts scrutinized sales materials,<br />

project artifacts (e-mails, status reports, project plans,<br />

and so on), contract documents, application software,<br />

migration tools, and contents of the shared-drive implementation<br />

environment.<br />

THE “STANDARD OF CARE” DILEMMA<br />

The arbitration panel had to resolve three key issues:<br />

Who was responsible for project management? Acme<br />

Co. produced paperwork indicating that responsibility<br />

rested with ERP Systems Integrators. The plaintiff<br />

claimed that it had no idea how to implement such a<br />

system and had hired the defendant to provide such<br />

expertise—including project management.<br />

What standards applied to the programming used for<br />

data conversion? Acme Co. attacked specific conversion<br />

software changes as harmful in that they<br />

COMPUTER<br />

increased the amount of incorrect data within the<br />

converted database by an unnecessarily complicated<br />

order of magnitude. ERP Systems Integrators<br />

responded that the referenced software changes did<br />

not constitute “software engineering” and thus were<br />

not subject to CoC guidance.<br />

How significant were project communication failures?<br />

During discovery, numerous intracompany e-mails<br />

from ERP Systems Integrators described the project<br />

in a markedly more pessimistic tone than the communications<br />

delivered to Acme Co. in compliance with<br />

contract provisions.<br />

These issues collectively fell under the “standard of<br />

care” portion of the contract. The dilemma Acme Co.<br />

faced—one common to companies in the same position—was<br />

detailing the standard of care it expected from<br />

ERP Systems Integrators. The contract language specified<br />

that ERP Systems Integrators “warrants that the services<br />

it provides hereunder will be performed in a professional<br />

and workmanlike manner in accordance with industry<br />

standards.”<br />

As the following exchange shows, ERP Systems Integrators<br />

could not provide more detail regarding the warranty<br />

statement:<br />

Question: What are the industry standards that you are<br />

referring to?<br />

Defense: There is nothing written or codified, but they<br />

are the standards recognized by the consulting firms<br />

in our industry.<br />

Question: I understand that the industry standards that<br />

you are referring to here are not written down anywhere;<br />

is that correct?<br />

Defense: That is my understanding.<br />

Question: Have you made an effort to locate these<br />

industry standards and have simply not been able to<br />

do so?<br />

Defense: I would not know where to begin to look.<br />

For its part, Acme Co. argued that suitable Internetbased<br />

CoCs were available to guide various behaviors.<br />

The “Online Codes of Conduct” sidebar describes one<br />

useful resource, the Online Ethics Center, that aggregates<br />

numerous CoCs. In particular, the plaintiff referenced the<br />

ACM/IEEE-CS Software Engineering Code of Ethics and<br />

Professional Practice. The “SECEPP” sidebar provides a<br />

brief history of this CoC.<br />

Acme Co. successfully argued to the arbitration panel<br />

that, when faced with obscure or publicly available standards,<br />

contracting parties should expect the accessible<br />

standards to apply. The plaintiff then cited objective,<br />

concrete portions of SECEPP that directly supported its<br />

positions on the three disputed issues.<br />

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PROJECT<br />

MANAGEMENT<br />

RESPONSIBILITY<br />

In pre-arbitration depositions,<br />

ERP Systems Integrators<br />

asserted that it was not the<br />

project manager and that the<br />

contract specified its performance<br />

solely at the direction<br />

of Acme Co. The plaintiff contended<br />

that, while contract<br />

language did exist, overall<br />

project management lay<br />

with the defendant because<br />

it assumed that role in spite<br />

of its denials. In its defense,<br />

Acme Co. cited Section 2.7<br />

of SECEPP, which states that<br />

“<strong>computing</strong> professionals<br />

have a responsibility to share<br />

technical knowledge with<br />

the public by encouraging<br />

understanding of <strong>computing</strong>,<br />

including the impacts of<br />

computer systems and their<br />

limitations.”<br />

The panel members<br />

understood SECEPP to be<br />

analogous to a building<br />

code and that, because of its<br />

broad wording, applied to the<br />

project in general and not<br />

specifically to its software<br />

engineering aspects.<br />

Expert testimony supported<br />

Acme Co.’s claims.<br />

Referencing widely published<br />

and accepted principles 1 that<br />

supplemented SECEPP, the<br />

plaintiff prepared a framework of project management<br />

behaviors as shown in Table 1. Specific evidence included<br />

a timesheet signed weekly by ERP Systems Integrators<br />

charging approximately 2,000 hours against the<br />

job category “Project Manager” and the task “Project<br />

Management.”<br />

It was obvious from the evidence that ERP Systems Integrators<br />

was hired in a specialist capacity and that Acme Co.<br />

had no ability to provide oversight. The arbitration panel<br />

determined that the defendant acted as, and clearly was,<br />

the project manager.<br />

RELEVANT PROGRAMMING STANDARDS<br />

ERP Systems Integrators blamed the conversion failure<br />

on “bad data.” However, Acme Co. provided evidence of<br />

ONLINE CODES OF CONDUCT<br />

The Online Ethics Center for Engineering and Research (http://onlineethics.org) is a joint project of<br />

the Center for Ethics, Engineering, and Society at the National Academy of Engineering and the<br />

Ethics Education Library at the Center for the Study of Ethics in the Professions at the Illinois Institute<br />

of Technology. Funded by a grant from the National Science Foundation, the website brings together<br />

more than 50 CoCs from organizations including:<br />

Institute of Electrical<br />

and Electronics Engineers<br />

(IEEE)<br />

<br />

-<br />

<br />

<br />

<br />

<br />

<br />

-<br />

<br />

<br />

<br />

<br />

Association for<br />

Computing Machinery<br />

(ACM)<br />

<br />

<br />

<br />

<br />

<br />

Institute for Certification<br />

of Computing<br />

Professionals (ICCP)<br />

<br />

<br />

<br />

<br />

While not uničed, the collection exhibits a striking cohesiveness.<br />

SECEPP<br />

Data Management<br />

Association (DAMA)<br />

<br />

-<br />

<br />

<br />

Originally adopted in 1972 by the ACM and the IEEE Computer Society, the Software Engineering<br />

Code of Ethics and Professional Practice principally served as a method of “self-regulation,”<br />

listing violations and accompanying sanctions. In 1993, SECEPP was revised to “clarify and formally<br />

state” the consensus of professional ethical requirements for which “the profession (is) accountable<br />

to the public.” The more comprehensive code was also designed to serve “as an aid to individual<br />

decision making.” 1 In the years since adoption, SECEPP (www.computer.org/computer/code-ofethics.pdf)<br />

has provided the foundation for numerous subsequent guidelines. Knowledgeable<br />

persons are aware of the code’s positive impact on professionalism within the IT industry. 2<br />

______________________<br />

______<br />

References<br />

1. R.E. Anderson et al., “Using the New ACM Code of Ethics in Decision Making,” Comm. ACM, Feb.<br />

1993, pp. 98-107.<br />

2. S. Rogerson, “An Ethical Review of Information Systems Development and the SSADM<br />

Approach,” Centre for Computing and Social Responsibility, De Montfort Univ., UK, 2 Jan.<br />

2008; www.ccsr.cse.dmu.ac.uk/staff/Srog/teaching/ssadm.htm.<br />

flawed programming practices, missing analysis data, and<br />

measurably lower-quality converted data.<br />

Failure to test for other values<br />

The plaintiff alleged that the defendant failed to follow<br />

generally accepted testing standards. Evidence consisted<br />

of instances involving poorly implemented conversion<br />

software.<br />

For example, the conversion software was supposed to<br />

check a specific field value for one of two possible values—<br />

say, “1” and “2” corresponding to the values “male” and<br />

“female,” respectively. The software executed by ERP Systems<br />

Integrators checked to see if the source field value<br />

was “1” and, if so, assigned the value “male” to the converted<br />

field; if the source field value was not “1,” it assigned<br />

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PERSPECTIVES<br />

Table 1. Summary evidence of project management behaviors.<br />

Process area<br />

the value “female” to the converted field without determining<br />

and reporting possible nonconforming values.<br />

Section 1.2 of SECEPP states that “to minimize the<br />

possibility of indirectly harming others, <strong>computing</strong><br />

professionals must minimize malfunctions by following<br />

generally accepted standards for system design and<br />

testing.” Accepted software engineering programming<br />

standards would call for testing for positive confirmation<br />

of “2” before setting the converted value to “female” and<br />

for reporting incoming values and numbers of values not<br />

“1” or “2.” The defendant’s failure to follow these standards<br />

permits “3” in the source data to be assigned the value<br />

“female” after conversion, resulting in demonstrably lowerquality<br />

converted data.<br />

Failure to prevent duplicate record insertion<br />

Acme Co. demonstrated that ERP Systems Integrators’<br />

software produced other structure-related conversion<br />

errors. 1 The defendant’s e-mail traffic revealed an urgent<br />

need to get records in the system “even if they weren’t<br />

the correct ones.” Instead of attempting to determine<br />

why the conversion programs would not successfully<br />

complete, ERP Systems Integrators identified the lines of<br />

code prohibiting the insertion of duplicate records and<br />

“commented them out,” thereby inactivating the software<br />

functionality.<br />

Consequently, there were 63,131 customers instead<br />

of approximately 6,000 and 100,236 employee records<br />

instead of approximately 10,000 in the system after con-<br />

COMPUTER<br />

Defendant lead<br />

Methodology Demonstrated<br />

Plainti<br />

lead<br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

?<br />

<br />

<br />

<br />

?<br />

<br />

<br />

version. This in turn increased the data clean-up<br />

cost. Due to the inherent complexities of working<br />

in a multiflawed environment, 2 the cost to clean<br />

up 10 times more data is often much greater than<br />

10 times the cost of cleaning up the original data.<br />

Section 6.08 of SECEPP states that software<br />

engineers should “take responsibility for detecting,<br />

correcting and reporting errors in software<br />

and associated documents.” The arbitration panel<br />

agreed with the plaintiff that the code provided<br />

an objective measure to assess responsibility for<br />

minimizing software malfunctions and correcting<br />

errors, and as such could reasonably guide Acme<br />

Co.’s expectations.<br />

COMMUNICATION FAILURE<br />

RESPONSIBILITY<br />

Acme Co. alleged that ERP Systems Integrators<br />

withheld important information from the on-site<br />

consulting team. The plaintiff presented e-mails of<br />

defendant personnel exchanging dire predictions<br />

about the project’s fate. One message warned it<br />

could become “our biggest mess!” These starkly<br />

contrasted with the rosy reports presented by ERP<br />

Systems Integrators during status meetings.<br />

On the subject of a client’s obligation to communicate<br />

project failure indicators, SECEPP is unambiguous: According<br />

to Section 2.06, “any signs of danger from systems<br />

must be reported to those who have opportunity and/<br />

or responsibility to resolve them.” The evidence clearly<br />

showed a pattern by the defendant of communicating one<br />

message internally (project failure) and a second message<br />

to plaintiff (everything okay).<br />

A second communication failure occurred at a more<br />

systematically significant level. All project management<br />

guidelines stress the importance of treating project<br />

planning diagrams as living documents, and most are<br />

managed via specialized software that permits determination<br />

of planned versus actual. Drawing on the Project<br />

Management Body of Knowledge (PMBOK), Acme Co. demonstrated<br />

that by never updating the project plan shown in<br />

Figure 1, developed using a simple spreadsheet, ERP Systems<br />

Integrators was unable to report fact-based measures<br />

of progress and thus failed to meet expected standards.<br />

Project statistic metadata lets stakeholders and implementers<br />

respond to challenges with all parties speaking<br />

the same vocabulary. Static project plans are out of date<br />

as soon as any task deviates from the plan and, as a result,<br />

management cannot determine the status of and impact<br />

on subsequent tasks.<br />

Additional evidence indicating a vastly overbooked<br />

resource pointed to a project that was out of control. Figure<br />

2 indicates a “plan” for one individual to accomplish the<br />

work of 18 others. This kind of error occurs in projects<br />

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Figure 1.<br />

where the existing environment has not<br />

been understood well enough to properly<br />

plan.<br />

Acme Co. proved that ERP Systems<br />

Integrators had not performed legacy<br />

system analysis 3 and that it failed to<br />

adequately manage project risk. These<br />

activities are subsumed under Section<br />

2.5 of SECEPP: “Give comprehensive<br />

and thorough evaluations of computer<br />

systems and their impacts, including<br />

analysis of possible risks.”<br />

The arbitration panel concluded<br />

that ERP Systems Integrators’ failure<br />

to update project plans, communicate<br />

responsibly, and manage risk appropriately<br />

constituted an inadequate<br />

standard of care. The defendant had<br />

obviously foreseen failure and hid<br />

from the plaintiff information indicating<br />

that the project had no possibility<br />

of succeeding.<br />

RESOLUTION AND DISCUSSION<br />

Days after the arbitration hearing concluded, the panel<br />

issued a one-page decision awarding $5 million to Acme<br />

Co.: five times the project’s worth. The decision was particularly<br />

hard-hitting because ERP Systems Integrators’<br />

insurance carrier denied coverage for the incident based<br />

on the evidence of its “failure to perform in a workmanlike<br />

manner.”<br />

The ruling favorable to the plaintiff indicated overwhelming<br />

support for its CoC-based case. The arguments<br />

Acme Co. presented are deciding factors in a growing<br />

number of real-life judicial disputes. In technology<br />

contexts where key issues revolve around competing<br />

Figure 2.<br />

<br />

interpretations of behaviors, CoCs are influencing various<br />

contracting parties as well as the IT, business, and consulting<br />

communities.<br />

Because arbitration results are private, word-of-mouth<br />

has been the chief means of propagating the success of<br />

comparing litigant behavior against CoCs. Moving from<br />

arbitration into case law, CoCs will be increasingly applied.<br />

In spite of limited current awareness, SECEPP is well on its<br />

way to becoming a de facto standard as it enjoys growing<br />

awareness throughout the legal community and increasing<br />

compliance in the IT profession. 4<br />

More extensive application of publicly available standards—and<br />

growing awareness of them—will positively<br />

impact the IT industry. Five initial benefits accrue to organizations<br />

capitalizing on CoC knowledge:<br />

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PERSPECTIVES<br />

Increasing use and broader applicability. As awareness<br />

of CoCs grows, so also will their popularity. Moreover,<br />

as the legal community becomes more familiar<br />

with CoC-based arguments, they will be applied<br />

more broadly. CoC expertise could become ubiquitous<br />

and perhaps as branded as the PMP designation<br />

from the Program Management Institute (www.pmi.<br />

org/CareerDevelopment/Pages/Obtaining-Credential.<br />

___ aspx). CoCs are not only easy to use, they are unambiguous<br />

about specific, holistic IT professional<br />

responsibilities—to the project, stakeholders, our<br />

profession, and society.<br />

Public codification of conduct standards by IT professionals.<br />

Evidence is mounting that public CoCs<br />

serve as standards for evaluating the performance<br />

and determining the responsibilities not only of IEEE<br />

members, but IT professionals in general. Organizations<br />

and professionals are using CoCs to determine<br />

specific attributes of compliance and noncompliance.<br />

Preventing and resolving disputes. Guidance to first<br />

prevent and subsequently settle disputes is generally<br />

welcome. CoCs provide objective particulars that litigants<br />

can use in a proactive manner. Following a CoC<br />

is one way to promote a successful project environment<br />

and insulate contracting parties from potential<br />

legal liability. In doing so, it is possible to identify critical<br />

prelitigation and other decision points that allow<br />

parties to better deal with or entirely avoid disputes.<br />

Better understanding of IT project implementation. The<br />

current dispute resolution process favors contractors.<br />

Understanding CoC utility enables organizations to<br />

rethink their relationships with clients. This could<br />

impact how organizations evaluate, select, and interact<br />

with IT professionals.<br />

Organization-wide CoC applicability. SECEPP is guided<br />

by the philosophy that CoCs generally apply to organizations—including<br />

those that do not have members<br />

belonging to the ACM or IEEE Computer Society—as<br />

well as to their leaders. The potential implications for<br />

organizations and leadership are staggering.<br />

Seeking a legal resolution to a dispute over contracted<br />

IT services is a growing trend. This is not surprising given<br />

the alarming statistic that up to 70 percent of IT projects<br />

fail (www.it-cortex.com/stat_failure_rate.htm). Litigation<br />

of software-intensive endeavors has been called a “major<br />

growth industry,” with forecasted legal costs rising “faster<br />

than any other aspect of software development.” 5<br />

As companies increasingly rely on IT systems to drive<br />

their business, failures and delayed implementations can<br />

cause costly ripples throughout their organization. Many<br />

are unwilling to absorb these costs and, consequently,<br />

expect IT professionals and especially their vendor partners<br />

to share responsibility.<br />

COMPUTER<br />

The evidence speaks for itself. Courts, juries,<br />

and arbitration panels are finding that failure<br />

to follow generally accepted public<br />

standards for design and testing of software<br />

are grounds for seeking damages. A<br />

wider understanding of the existence and usefulness of<br />

existing ethical and professional standards will represent<br />

added value to in-house IT managers and enhance the<br />

stature of IT professionals. An organization’s ability to<br />

evaluate conduct and, when appropriate, consider potential<br />

legal matters more knowledgeably is paramount to<br />

imposing accountability on all participants.<br />

Acknowledgments<br />

The authors express gratitude to the anonymous reviewers<br />

for their comments. They also thank the hundreds of<br />

unnamed data management and legal professionals with<br />

whom they have worked and who have contributed to a better<br />

understanding of this field as it is practiced and as it should<br />

be practiced.<br />

References<br />

1. V.Y. Yoon, P. Aiken, and T. Guimaraes, “Managing Organizational<br />

Data Resources: Quality Dimensions,” Information<br />

Resources Management J., July-Sept. 2000, pp. 5-13.<br />

2. P. Aiken and P. Piper, “Estimating Data Reverse Engineering<br />

Projects,” Proc. 5th Ann. Systems Reengineering Workshop,<br />

Naval Surface Warfare Center, 1995, pp. 133-145.<br />

3. P. H. Aiken, “Reverse Engineering of Data,” IBM Systems J.,<br />

Apr. 1998, pp. 246-269.<br />

4. D. Gotterbarn, “How the New Software Engineering Code<br />

of Ethics Affects You,” IEEE Software, Nov./Dec. 1999, pp.<br />

58-64.<br />

5. T. DeMarco and T. Lister, “Both Sides Always Lose: Litigation<br />

of Software-Intensive Contracts,” CrossTalk, Feb. 2000;<br />

www.stsc.hill.af.mil/crossTalk/2000/02/demarco.html.<br />

Peter Aiken is an associate professor of information systems<br />

at Virginia Commonwealth University and founding<br />

director of Data Blueprint, a data management consulting<br />

firm based in Richmond, Virginia. Contact him at _____<br />

peter@<br />

datablueprint.com.<br />

Robert M. Stanley is a senior member of the technical<br />

staff and a project lead specializing in project and quality<br />

management for Data Blueprint. Contact him at _______ bstanley@<br />

datablueprint.com.<br />

Juanita Billings is a senior member of the technical staff<br />

and a project lead specializing in legal support, systems<br />

analysis, and project management for Data Blueprint. Contact<br />

her at jbillings@datablueprint.com.<br />

___________________<br />

Luke Anderson is a law partner specializing in technology<br />

and intellectual property matters with Duane Morris<br />

LLC in Atlanta, Georgia. Contact him at ________<br />

landerson@<br />

duanemorris.com.<br />

Selected CS articles and columns are available for free at<br />

http://ComputingNow.computer.org.<br />

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COVER FEATURE<br />

Arutyun I. Avetisyan, Institute for System Programming of the Russian Academy of Sciences<br />

Roy Campbell, Indranil Gupta, Michael T. Heath, and Steven Y. Ko, University of Illinois at<br />

Urbana-Champaign<br />

Gregory R. Ganger, Carnegie Mellon University<br />

Michael A. Kozuch and David O’Hallaron, Intel Labs<br />

Marcel Kunze, Karlsruhe Institute of Technology, Germany<br />

Thomas T. Kwan, Yahoo! Labs<br />

Kevin Lai, Martha Lyons, and Dejan S. Milojicic, HP Labs<br />

Hing Yan Lee and Yeng Chai Soh, Infocomm Development Authority of Singapore<br />

Ng Kwang Ming and Jing-Yuan Luke, Malaysian Institute of Microelectronic Systems<br />

Han Namgoong, Electronics and Telecommunications Research Institute, South Korea<br />

Open Cirrus is a cloud <strong>computing</strong> testbed<br />

that, unlike existing alternatives, federates<br />

distributed data centers. It aims to spur<br />

innovation in systems and applications<br />

research and catalyze development of an<br />

open source service stack for the cloud.<br />

There is growing interest in cloud <strong>computing</strong><br />

within the systems and applications research<br />

communities. However, systems researchers<br />

often find it difficult to do credible work<br />

without access to large-scale distributed data<br />

centers. Application researchers could also benefit from<br />

being able to control the deployment and consumption<br />

of hosted services across a distributed cloud <strong>computing</strong><br />

testbed.<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

OPEN CIRRUS:<br />

A GLOBAL CLOUD<br />

COMPUTING<br />

TESTBED<br />

Published by the IEEE Computer Society<br />

Pay-as-you-go utility <strong>computing</strong> services by companies<br />

such as Amazon and new initiatives by Google, IBM,<br />

Microsoft, and the National Science Foundation (NSF)<br />

have begun to provide applications researchers in areas<br />

such as machine learning and scientific <strong>computing</strong> with<br />

access to large-scale cluster resources. However, system<br />

researchers, who are developing the techniques and software<br />

infrastructure to support cloud <strong>computing</strong>, still have<br />

trouble obtaining low-level access to such resources.<br />

Open Cirrus (http://opencirrus.org) aims to address this<br />

problem by providing a single testbed of heterogeneous<br />

distributed data centers for systems, applications, services,<br />

and open source development research. The project is a<br />

joint initiative sponsored by Hewlett-Packard (HP), Intel,<br />

and Yahoo! in collaboration with the NSF, the University<br />

of Illinois at Urbana-Champaign (UIUC), the Karlsruhe Institute<br />

of Technology (KIT), the Infocomm Development<br />

Authority (IDA) of Singapore, the Russian Academy of<br />

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COVER FEATURE<br />

Open source cloud stack (Zoni, Hadoop, Tashi)<br />

Shared infrastructure (>10*1,000 cores)<br />

Global services (sign-on, monitoring, store, sustainability dashboard, and so on)<br />

COMPUTER<br />

HP<br />

UIUC Intel<br />

CMU<br />

Yahoo!<br />

KIT<br />

RAS<br />

MIMOS<br />

Figure 1. Open Cirrus testbed. Each of the 10 current sites<br />

consists of a cluster with at least 1,000 cores and associated<br />

storage. The testbed očers a cloud stack consisting of<br />

physical and virtual machines and global services such as<br />

sign-on, monitoring, storage, and job submission.<br />

Sciences (RAS), the Electronics and Telecommunications<br />

Research Institute (ETRI) of South Korea, the Malaysian Institute<br />

of Microelectronic Systems (MIMOS), and Carnegie<br />

Mellon University (CMU). Additional members are expected<br />

to join Open Cirrus later this year.<br />

As Figure 1 shows, the current testbed is composed of 10<br />

sites in North America, Europe, and Asia. Each site consists<br />

of a cluster with at least 1,000 cores and associated storage.<br />

Authorized users can access any Open Cirrus site using the<br />

same login credential.<br />

MOTIVATION AND CONTEXT<br />

Open Cirrus has four main goals.<br />

First, the project aims to foster systems-level research<br />

in cloud <strong>computing</strong>. In the current environment, only big<br />

service providers such as Yahoo!, Google, Amazon, and Microsoft<br />

have access to large-scale distributed data centers<br />

to develop and test new systems and services. Most cloud<br />

<strong>computing</strong> researchers must typically rely on simulations<br />

or small clusters. Open Cirrus aims to help democratize<br />

innovation in this area by providing two unique features<br />

essential to systems-level research:<br />

Open Cirrus sites allow access to low-level hardware<br />

and software resources—for example, install OS,<br />

access hardware features, and run daemons.<br />

The testbed comprises heterogeneous sites in different<br />

administrative domains around the world,<br />

enabling researchers to leverage multiple data centers.<br />

Second, Open Cirrus seeks to encourage new cloud<br />

<strong>computing</strong> applications and applications-level research.<br />

Providing a platform for real-world applications and services<br />

is an important part of Open Cirrus. Particularly<br />

exciting are<br />

IDA<br />

ETRI<br />

the potential for developing new application models<br />

and using them to understand the necessary systemslevel<br />

support, and<br />

using the federated nature of Open Cirrus to provide<br />

a platform for new kinds of federated applications<br />

and services that run across multiple data centers.<br />

Third, Open Cirrus offers a collection of experimental<br />

data. Cloud <strong>computing</strong> researchers often lack data<br />

sets with which to conduct high-quality experimental<br />

evaluations. Open Cirrus sites will let researchers<br />

import, store, and share large-scale data sets such as<br />

Web crawls and data-center workload traces. With<br />

such facilities, Open Cirrus could become a “watering<br />

hole” where researchers with similar interests can exchange<br />

data sets and develop standard cloud <strong>computing</strong><br />

benchmarks.<br />

Fourth, Open Cirrus aims to develop open source<br />

stacks and APIs for the cloud. To become widespread,<br />

cloud <strong>computing</strong> requires a nonproprietary and vendor-neutral<br />

software stack. Open Cirrus will serve as<br />

a platform that the open source community can use to<br />

design, implement, and evaluate such codes and interfaces<br />

for all cloud stack levels. Open source is as much<br />

about community as it is about software, and Open<br />

Cirrus seeks to become the foundation offia largerfiopen<br />

cloud community.<br />

The Open Cirrus sites are working together to provide<br />

a single federated testbed, as opposed to each site<br />

building and operating a separate cluster, for three<br />

reasons:<br />

collaborating on a single, larger effort will achieve<br />

greater impact than participants could individually;<br />

testing in the different site environments will improve<br />

the quality of software and services; and<br />

pooling resources will improve efficiency because the<br />

sites will be sharing innovations.<br />

One measure of efficiency is management cost. Figure 2<br />

shows ballpark cost figures gleaned from the current Open<br />

Cirrus sites. While the costs of running a cloud infrastructure<br />

increase with the number of sites, the savings from<br />

sharing software development and operational methods<br />

reduces overall costs. For example, several participating<br />

organizations are prominent developers of the software<br />

components in the Open Cirrus service architecture. By<br />

sharing these new systems and the lessons learned in deploying<br />

them, all of the sites benefit.<br />

ARCHITECTURE, DESIGN,<br />

AND IMPLEMENTATION<br />

Several high-level architectural choices drove the Open<br />

Cirrus design:<br />

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Systems versus application-only research. In contrast<br />

to clusters such as Google/IBM, Microsoft Windows<br />

Azure, and Amazon EC2/S3, Open Cirrus enables<br />

research using physical machines in addition to virtualized<br />

machines. This requires provisioning of the bare<br />

metal, enabling root access to provisioned servers,<br />

providing isolation at the network level, and reclaiming<br />

access in case of fraudulent or erroneous behavior.<br />

Federated versus unified sites. In contrast to a unified<br />

architecture such as PlanetLab, Open Cirrus federates<br />

numerous sites with various hardware, services, and<br />

tools. The sites exist on different continents, under<br />

different regulations and subject to different privacy<br />

concerns. Commonality is enabled by Open Cirrus<br />

global services under development, such as global<br />

sign-on and monitoring. Some local services may<br />

vary across sites, but common practices and regulations<br />

will promote consistent administration and<br />

oversight.<br />

Data-center focus versus centralized homogeneous<br />

infrastructure. Compared to a centralized approach<br />

such as Emulab, Open Cirrus revolves around multiple<br />

data centers. This data-center focus enables<br />

independent research while sharing resources. It has<br />

implications for security, enforcing authorizations<br />

between users and individual sites, and integration<br />

with existing organizational regulations.<br />

Service architecture design<br />

Design of the Open Cirrus service architecture is guided<br />

by a desire to create a unified and coherent resource,<br />

rather than several completely disjoint clusters.<br />

Direct access to physical resources. Systems research is<br />

supported by allowing direct access to physical resources<br />

on the machine. For example, researchers can have root<br />

passwords, install kernel images, and access processors,<br />

chipsets, and storage. However, some resources, particularly<br />

network resources needed for proper isolation such<br />

as virtual local area network (VLAN) switch configurations,<br />

may be virtualized or unavailable.<br />

Similar operating environments. Given that multiple<br />

organizations with different practices manage the Open<br />

Cirrus sites, it’s infeasible for these sites to have identical<br />

operating environments. However, it’s possible to create<br />

similar operating environments by defining a minimum<br />

set of services that every site must offer.<br />

Support for near-production use. While supporting<br />

cloud <strong>computing</strong> system software research is Open Cirrus’<br />

central mission, robust research often requires access to<br />

real-world use cases. Therefore, Open Cirrus sites strive<br />

to offer high-quality services to researchers who aren’t<br />

necessarily conducting research at the systems level. This<br />

use provides the workloads, traces, and testing needed for<br />

insights into real-world use.<br />

Annual cost per site in $K<br />

$1,800<br />

$1,600<br />

$1,400<br />

$1,200<br />

$1,000<br />

$800<br />

$600<br />

$400<br />

$200<br />

$0<br />

1 5 10 20 50<br />

Number of sites<br />

Global services available from any site. A small set<br />

of global services is available from any Open Cirrus site.<br />

Examples include the global sign-on authentication service,<br />

global monitoring, and a moderate-scale storage service for<br />

configuration files, intermediate results, or binaries.<br />

Service stack architecture<br />

A typical Open Cirrus site consists of foundation, utility,<br />

and primary domain services, as Figure 3 shows.<br />

Zoni. The foundation service for the software architecture<br />

is Zoni. Fundamentally, Zoni is the software<br />

component responsible for managing physical resources<br />

in the cluster and is crucial to providing users with baremetal<br />

server access to conduct software system research.<br />

This component provides five key functions:<br />

allocation of server nodes;<br />

isolation of node groups, called domains;<br />

provisioning of key software in a domain;<br />

out-of-band server management; and<br />

debugging of allocated nodes.<br />

(Shared) Innovation on OC<br />

OC development<br />

Running/managing OC<br />

System administration<br />

Invest./maint. for 1K cores<br />

Figure 2. Open Cirrus management costs: annual cost per<br />

site for dičerent numbers of sites. While the costs of running<br />

a cloud infrastructure increase with the number of sites, the<br />

savings from sharing software development and operational<br />

methods reduces overall costs.<br />

Zoni maintains a database of all available cluster resources.<br />

User requests, which are primarily for some<br />

number of nodes, are satisfied by allocating resources<br />

from that inventory. Users request allocations of physical<br />

nodes for various reasons. One common reason is to conduct<br />

controlled performance measurements; another is<br />

for experimentation with system software that involves<br />

aspects of networking—for example, developing a new<br />

cluster management system may require controlling a<br />

Dynamic Host Configuration Protocol (DHCP) server.<br />

Experiments that belong to this latter group must be iso-<br />

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COVER FEATURE<br />

lated from other activities in the cluster to maintain both<br />

experimental integrity and cluster stability. Node allocations<br />

isolated from the rest of the cluster in this way are<br />

domains. The current implementation creates domains<br />

by programming the cluster switches to create VLANs.<br />

To bootstrap a domain for remote users, Zoni must<br />

also provide a mechanism for provisioning software onto<br />

at least one of the allocated nodes. This feature is currently<br />

implemented through a process based on Preboot<br />

Execution Environment (PXE) booting. However, even<br />

though the software may be provisioned properly, there<br />

is no guarantee that it will behave as intended or boot at<br />

all. Consequently, Zoni also provides users with out-ofband<br />

debugging and management facilities. Currently, the<br />

key debugging facility is remote console access, and the<br />

management facility consists primarily of remote power<br />

control. Both are provided through the Intelligent Platform<br />

Management Interface (IPMI).<br />

Primary domain services. Naturally, not all cluster<br />

users are interested in managing a Zoni domain; some are<br />

interested in developing higher-level services, and some<br />

are interested in simply using the services offered. To<br />

serve these last two user groups, one domain in each site<br />

is designated the primary domain and provides a stable<br />

set of services for production use.<br />

To support users working with very large data sets, a<br />

cluster storage system, in particular the Hadoop distributed<br />

file system (HDFS), is used to aggregate the storage<br />

of all the nodes in the domain. A key property of HDFS is<br />

that it supports location-aware <strong>computing</strong>—that is, the file<br />

system exports the location of data blocks in such a way<br />

that runtime services can schedule a <strong>computing</strong> task that<br />

processes a block on the node that contains that block.<br />

This capability reduces pressure on the cluster network.<br />

To support a diverse set of user needs, the recommended<br />

primary domain services include a virtual<br />

machine management (VMM) layer, which provides a convenient<br />

mechanism for allocating resources to various<br />

users and services. Hadoop, for example, implements a<br />

map/reduce programming paradigm and offers a popular<br />

runtime system for building cloud services. The Maui<br />

Cluster Scheduler combined with the Torque resource<br />

manager is another popular runtime system that provides<br />

COMPUTER<br />

Foundation services (Zoni) Site utility services Primary domain services<br />

Domain<br />

isolation<br />

(VLAN)<br />

Physical<br />

machine<br />

control<br />

(IPMI)<br />

Networking<br />

(DNS,<br />

DHCP)<br />

Provisioning<br />

(PXE)<br />

Monitoring<br />

(Ganglia)<br />

Power<br />

management<br />

Accounting<br />

and<br />

billing<br />

Attached<br />

storage<br />

(NFS)<br />

Domain<br />

isolation<br />

(DLS)<br />

Resource<br />

telemetry<br />

(RTS)<br />

Application frameworks<br />

(Hadoop, MPI, Maui/Torque)<br />

Virtual machine management<br />

(AWS-compatible systems<br />

such as Tashi and Eucalyptus)<br />

Cluster storage<br />

(HDFS)<br />

Figure 3. Open Cirrus site services. A typical site consists of foundation, utility, and primary domain services.<br />

a job submission service. By providing the two services<br />

through a disjoint set of virtual machines, the primary<br />

domain’s administrator can dynamically adjust the pool<br />

of resources available to each service according to need<br />

simply by adding or removing VMs. Of course, users<br />

whose jobs aren’t accommodated by one of the existing<br />

application framework services may request a private<br />

pool of VMs.<br />

Different sites may select any VMM service as long as<br />

it supports the EC2 interface from Amazon Web Services<br />

(AWS). Good candidates include Tashi and Eucalyptus.<br />

Tashi is an open source cluster management system for<br />

cloud <strong>computing</strong> on massive Internet-scale data sets being<br />

developed as an Apache Incubator project; it is designed<br />

specifically to complement Open Cirrus. While Tashi is<br />

similar to other systems that manage logical clusters of<br />

VMs, it was developed to support research in coscheduling<br />

computation, storage, and power.<br />

Coscheduling of computation and storage using the<br />

location information provided by storage systems such as<br />

Hadoop must overcome additional challenges in a virtualized<br />

environment. In particular, instances of the Hadoop<br />

runtime executing within VMs may be unable to correctly<br />

assess the relative distances to data blocks whose locations<br />

HDFS described with nonvirtualized location information.<br />

Two additional services may overcome this problem: The<br />

Data Location Service (DLS) is a clearinghouse for data<br />

location information independent of a storage mechanism,<br />

and the Resource Telemetry Service (RTS) provides<br />

a means to obtain an abstract distance measure between<br />

two location identifiers. 1<br />

Example. Figure 4 illustrates how Open Cirrus services<br />

fit together. In this example, the cluster is partitioned<br />

into four domains. From left to right, the first domain is<br />

used for low-level systems research, where researchers<br />

install their own OS kernels and run their own experimental<br />

codes and services. The second domain runs<br />

a VMM system that provides users with virtual clusters<br />

of VMs that share physical nodes and storage in<br />

the Zoni domain. Users build their own services and<br />

applications on top of these virtual clusters. The third<br />

domain provides a dedicated storage service that applications<br />

running on the second partition use. The fourth<br />

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domain offers a sandbox for developing the<br />

next version of the Tashi cluster management<br />

component.<br />

Site utility services. To manage an Open<br />

Cirrus site easily, many additional, less critical<br />

services are required. For example, a monitoring<br />

service such as Ganglia not only enables the site<br />

administrator to monitor the cluster’s health, it<br />

also facilitates collection of cluster operational<br />

data that may inform future research projects.<br />

Some conventional network file system storage<br />

is convenient for storing user scripts, small<br />

data sets, and small output files. Site utilities<br />

also include facilities for tracking resources<br />

consumed by users and managing the cluster’s<br />

power consumption.<br />

Open Cirrus federation<br />

The Open Cirrus testbed provides a unique opportunity<br />

for experimenting with issues involving federation in<br />

cloud <strong>computing</strong>. To support these experiments, developers<br />

are adding a small set of “global” services—common<br />

services that run at participating sites to provide a common<br />

infrastructure.<br />

Global sign-on. While users are granted access to each<br />

site separately, this authentication clearinghouse service<br />

enables users to access all granting sites with the same<br />

credentials.<br />

Global monitoring. By collecting the monitoring output<br />

from each site into a central location, administrators can<br />

quickly assess the health of the entire testbed, users can<br />

determine which sites are busy, and cross-site statistics<br />

can be archived for future research.<br />

User directories. Mounting a user directory in a<br />

common location at each site facilitates the distribution<br />

of small files, such as execution scripts and configuration<br />

files, for conducting experiments.<br />

Global storage. Similarly, some data sets may be made<br />

available across all sites, either through replication or<br />

some other distribution technology, as appropriate.<br />

Scheduling. Ultimately, users may find it convenient to<br />

submit a job without having to specify where the job must<br />

run. A global scheduling component could automatically<br />

dispatch jobs to the optimal cluster according to some<br />

criteria: load balancing, minimizing data movement, minimizing<br />

energy consumption, and so on.<br />

Resource tracking. As jobs are scheduled across multiple<br />

sites, the resources that users consume may need to<br />

be tracked and credits exchanged between sites based on<br />

resource consumption.<br />

RESEARCH USING OPEN CIRRUS<br />

Table 1 summarizes basic characteristics of the current<br />

Open Cirrus sites. More important than physical charac-<br />

Services<br />

Virtual cluster<br />

Systems research Tashi<br />

Zoni service<br />

Applications<br />

Virtual cluster<br />

Storage service Tashi development<br />

Network-isolated<br />

Zoni domains<br />

Physical cluster<br />

Figure 4. Example service hierarchy possible in Open Cirrus, with the<br />

cluster partitioned into four domains.<br />

teristics are the types of collaboration that Open Cirrus<br />

enables.<br />

Approximately 100 research projects at 10 sites use<br />

Open Cirrus at the systems and applications levels.<br />

Systems-level projects include robust adaptive routing<br />

over redundant layer-2 networks, data computation<br />

overlay for aggregation and analyses, and Open Cirrus<br />

and PlanetLab federation (at HP); use of optical switches<br />

to break data-center networking bottlenecks, power-aware<br />

workload scheduling, and optimizing service energy-delay<br />

product (at Intel); and applying RAID techniques to HDFS,<br />

pipelining data between map and reduce stages of Hadoop<br />

jobs to improve user interaction, and deploying log-analysis<br />

techniques to improve performance of Hadoop clusters<br />

(at Yahoo!).<br />

Applications-level projects include computerized<br />

language translation, astrophysics, graph data mining,<br />

and computer design simulation (at CMU); real-time<br />

streaming applications such as gesture recognition<br />

from video and simulation of material that changes its<br />

shape under software control (at Intel); DNA sequencing,<br />

search, and annotation (at ETRI); and continuously<br />

extracting knowledge from webpages, natural-language<br />

processing, large-scale graph algorithms, analysis<br />

of Wikipedia group dynamics, statistical machine<br />

translation, large-scale document analysis, statistical<br />

machine-learning algorithms, and computational sustainability<br />

(at Yahoo!).<br />

In most of these research projects, Open Cirrus offers<br />

the benefits of running experiments at scale; leveraging<br />

commonly shared stack, services, and best practices;<br />

and creating synergies across the layers. Systems-level<br />

research—for example, networking, power, and cooling—leverages<br />

applications to better understand the<br />

cloud load, while applications improve in performance<br />

and scalability using results from the underlying systems<br />

research.<br />

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COVER FEATURE<br />

Site Cores Servers<br />

OPEN CIRRUS ECONOMIC MODEL<br />

The emergence of each individual site in Open Cirrus<br />

and the expected growth of the federation are driven by<br />

the economy in today’s cloud <strong>computing</strong> environment.<br />

Explicit break-even points for the choice between renting<br />

versus owning a cloud infrastructure implicitly justify<br />

Open Cirrus’ economic rationale.<br />

Single site<br />

Consider a medium-sized organization—for example, a<br />

start-up or a university department—seeking to provide a<br />

Web service to a client population. The service will run in<br />

a cloud, accessing stored data and consuming CPU cycles.<br />

Suppose this service is identical to the UIUC Open Cirrus<br />

site: 128 servers (1,024 cores) and 524 Tbytes. Should the<br />

organization rent the infrastructure from a cloud provider,<br />

such as EC2 (Elastic Compute Cloud) and S3 (Simple Storage<br />

Service) from Amazon Web Services, or should it buy<br />

and maintain a cloud?<br />

At average AWS rates of US$0.12 per Gbyte/month<br />

and $0.10 per CPU-hour, renting the cloud infrastructure<br />

would incur a monthly storage cost of 524 × 1,000<br />

× $0.12, or $62,880; the total monthly cost would be<br />

$62,880 + 1,024 × 24 × 30 × $0.10 = $136,608. In the<br />

case of owning a cloud, amortized monthly costs would<br />

be split among the hardware, power, and network 45<br />

percent, 40 percent, and 15 percent, respectively. 2-4 If the<br />

service lifetime is M months, it would incur a monthly<br />

storage cost, assuming $300 1-Tbyte disks and scaling<br />

for power and networking, of 524 × $300/0.45/M, or<br />

$349,333/M; the total monthly cost, based on actual systems<br />

cost and the salary of one system administrator for<br />

about 100 servers, 3,4 would be $700,000/0.45/M + $7,500,<br />

or $1,555,555/M + $7,500.<br />

COMPUTER<br />

Public<br />

partition<br />

(servers)<br />

Table 1. Characteristics of current Open Cirrus sites.<br />

Memory<br />

size<br />

(Tbytes)<br />

Storage<br />

size<br />

(Tbytes) Spindles<br />

Network data<br />

rate Focus<br />

CMU 1,165 159 50 2.40 892 784 1 Gbps Tashi, distributed file systems,<br />

applications/data sets<br />

ETRI 1,024 256 200 0.50 128 256 1 Gbps Large data sets, cloud infrastructure<br />

HP 1,024 256 178 3.30 632 1,152 10 Gbps internal;<br />

1 Gbps x-rack<br />

Networking, federation<br />

IDA 2,400 300 100 4.80 59+ 600 1 Gbps Applications based on Hadoop, Pig<br />

Intel 1,364 198 198 1.77 610 746 1 Gbps Tashi, Zoni, MPI, Hadoop<br />

KIT 2,656 232 128 10.00 280 192 40 Gbps Applications with high throughput<br />

MIMOS 1,024 167 16 0.50 36 258 1 Gbps Platform, tools, testing, security<br />

UIUC 1,024 128 64 2.00 524 258 1 Gbps Data sets, cloud infrastructure<br />

RAS 1,136 142 600 9.10 36 142 1 Gbps Hadoop, Tashi, Zoni, Pig, MPI<br />

Yahoo! 3,200 480 400 2.40 1,200 1,600 1 Gbps Hadoop, Pig<br />

The break-even point for storage would be $349,000/M<br />

< $62,880, or M > 5.55 months; the overall break-even<br />

point would be $1,555,555/M + $7,500 < $136,608, or<br />

M > 12 months. Thus, if the service runs for more than 12<br />

months, owning the cloud infrastructure is preferable to<br />

renting it. Similarly, it’s better to own storage if you use it<br />

for more than six months.<br />

Clouds are typically underutilized. 2 With X percent<br />

resource utilization, the break-even time becomes<br />

12 × 100/X months. Given the typical hardware lifetime<br />

of 36 months, the break-even resource utilization is<br />

12 × 100/X < 36, or X > 33.3 percent. Even at the<br />

current 20 percent CPU utilization rates observed in industry,<br />

storage utilization greater than 47 percent would<br />

make ownership preferable, as storage and CPU account<br />

evenly for costs.<br />

Federated sites<br />

Federation can help absorb overloads due to spikes—for<br />

example, at conference deadlines—or underprovisioning. 2,4<br />

Figure 5 plots the costs incurred by a single underprovisioned<br />

cloud for three options: offloading only to AWS,<br />

offloading to five federated clouds and AWS, and offloading<br />

to 49 federated clouds and AWS.<br />

A federation of six sites can defer costs up to 250 percent<br />

overload, while with 50 sites the break-even point is roughly<br />

2,500 percent. (This assumes that other sites are utilized<br />

50 percent and not idle; otherwise, the break-even point<br />

would be 500 percent and 5,000 percent, respectively.) The<br />

detailed data and spreadsheet for this calculation are available<br />

at http://opencirrus.org. Note that this is only a starting<br />

step—the calculation can be expanded by accounting for<br />

the economic costs of disasters, such as massive failure,<br />

project cancellation, and start-up time.<br />

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RELATED WORK<br />

We can broadly divide existing cloud <strong>computing</strong> testbeds<br />

into those that mainly support applications research<br />

and those that can support systems research. Table 2 compares<br />

the most prominent testbeds.<br />

The Google/IBM cluster (www.google.com/intl/en/<br />

press/pressrel/20071008_ibm_univ.html), TeraGrid, 5 and<br />

Microsoft Windows Azure platform (www.microsoft.<br />

com/windowsazure) all focus on supporting <strong>computing</strong><br />

applications research. Thus, these testbeds don’t enable<br />

access to bare-metal hardware or root access to the OS;<br />

instead, services such as MPI and Hadoop are installed<br />

to ease access to the resources. For example, the Google/<br />

IBM cluster is configured with the Hadoop service and<br />

targets data-intensive applications research such as largescale<br />

data analytics. TeraGrid is a multisite infrastructure<br />

mainly used for scientific research, and Microsoft provides<br />

a Windows Azure interface but no access to systems-level<br />

data.<br />

The Open Cloud Testbed (www.opencloudconsortium.<br />

org) focuses on cloud <strong>computing</strong> middleware research and<br />

is currently configured as a smaller-scale testbed with four<br />

32-node sites.<br />

Testbeds such as PlanetLab, 6 Emulab, 7 DETER (cyber-<br />

DEfense Technology Experimental Research), 8 ___________________________<br />

___<br />

and<br />

Amazon EC2 (http://aws.amazon.com) are designed to support<br />

systems research but with diverse goals.<br />

PlanetLab consists of a few hundred machines spread<br />

around the world and is mainly designed to support<br />

Characteristics Open Cirrus<br />

Type of<br />

research<br />

Systems and<br />

services<br />

Approach Federation of<br />

heterogeneous<br />

data centers<br />

Participants CMU, ETRI, HP,<br />

Intel, IDA, KIT,<br />

MIMOS, RAS,<br />

UIUC, Yahoo!<br />

Monthly cost in $K<br />

100,000<br />

10,000<br />

1,000<br />

100<br />

Table 2. Comparison of cloud <strong>computing</strong> testbeds.<br />

Google/<br />

IBM cluster TeraGrid PlanetLab Emulab<br />

Dataintensive<br />

applications<br />

Cluster<br />

supported<br />

by Google<br />

and IBM<br />

Google,<br />

IBM, MIT,<br />

Stanford<br />

Univ.,<br />

Univ. of<br />

Washington<br />

Distribution 10 sites Centralized—one<br />

data center<br />

in Atlanta<br />

Scientific<br />

applications<br />

Multisite<br />

heterogeneous<br />

clusters for<br />

super<strong>computing</strong><br />

Many<br />

universities<br />

and<br />

organizations<br />

11 partners<br />

in US<br />

Existing data center<br />

Open Cirrus 6<br />

Open Cirrus 50<br />

10<br />

100 200 300 400 500 600 700 800 900 1,000<br />

Utilization (percent)<br />

Figure 5. Costs incurred by a single underprovisioned cloud<br />

for three options: oćoading only to Amazon Web Services<br />

(existing data center), oćoading to ve federated clouds<br />

(Open Cirrus 6) and AWS, and oćoading to 49 federated<br />

clouds (Open Cirrus 50) and AWS.<br />

wide-area networking and distributed systems research.<br />

Although it doesn’t provide access to bare-metal hardware,<br />

it does provide root access to the OS through a lightweight<br />

virtualization similar to FreeBSD jails.<br />

Emulab, the original Zoni service, is a single-site testbed<br />

where each user can reserve a certain number of machines<br />

(typically a few tens) and get exclusive access to bare-metal<br />

hardware. Emulab also provides mechanisms to emulate<br />

different network characteristics. Open Cirrus provides<br />

Emulab-like flexibility for systems research with federation<br />

and heterogeneity, which are crucial for cloud <strong>computing</strong>.<br />

Systems and<br />

services<br />

Nodes<br />

hosted by<br />

research<br />

institution<br />

Many<br />

universities<br />

and<br />

organizations<br />

More than<br />

700 nodes<br />

worldwide<br />

Open Cloud<br />

Testbed<br />

Systems Interoperability<br />

across<br />

clouds using<br />

open APIs<br />

Singlesite<br />

cluster<br />

with<br />

exible<br />

control<br />

Univ. of<br />

Utah<br />

More<br />

than 300<br />

machines<br />

Multisite heterogeneous<br />

clusters<br />

Amazon<br />

EC2<br />

Commercial<br />

use<br />

Raw access<br />

to virtual<br />

machines<br />

APRIL 2010<br />

LANL<br />

cluster<br />

Systems<br />

Reuse of<br />

LANL’s<br />

retiring<br />

clusters<br />

Four centers Amazon CMU,<br />

LANL, NSF<br />

480 cores distributed<br />

in<br />

four locations<br />

Several<br />

unified<br />

data<br />

centers<br />

Thousands<br />

of<br />

older but<br />

still useful<br />

nodes at<br />

one site<br />

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COVER FEATURE<br />

The DETER testbed is an installation of the Emulab<br />

software and is mainly used for security research—for<br />

example, collecting a large-scale worm trace. Consisting<br />

of two heterogeneous sites, DETER may be viewed as a<br />

federated Emulab installation. However, the two sites are<br />

tightly coupled: The controller resides in one site and controls<br />

physical resources in both sites. In Open Cirrus, all<br />

sites are loosely coupled.<br />

Amazon EC2 provides VMs on a pay-as-you-go basis.<br />

Although it allows complete control over the VMs, users<br />

can’t control network resources, reducing its flexibility as<br />

a systems research testbed.<br />

Finally, CMU’s Garth Gibson is leading an effort to recycle<br />

Los Alamos National Laboratory’s retiring clusters<br />

(typically with a few thousand machines) by making them<br />

available for systems research.<br />

Other related cloud <strong>computing</strong> efforts such as Reservoir<br />

(http://sysrun.haifa.il.ibm.com/hrl/reservoir) and<br />

RightScale (www.rightscale.com) aren’t testbeds per se.<br />

Reservoir (Resources and Servers Visualization without<br />

Barriers) is an EU-funded grid <strong>computing</strong> project that enables<br />

massive-scale deployment and management of IT<br />

services across administrative domains. RightScale is a<br />

cloud services management platform.<br />

Open Cirrus offers unique opportunities for<br />

cloud <strong>computing</strong> research that no existing<br />

alternatives offer. It federates heterogeneous<br />

sites, systems and applications research, and<br />

data sets. In addition, it provides an open<br />

source service stack with nonproprietary APIs for cloud<br />

<strong>computing</strong>. And through shared innovation, Open Cirrus<br />

will have a greater impact on research communities<br />

around the globe.<br />

While working on Open Cirrus during the past year,<br />

we realized the value of common stacks and services,<br />

but even more, we came to appreciate the benefits of a<br />

research community working together toward the same<br />

goals. Heterogeneity of the individual sites has contributed<br />

to the diversity of solutions and has strengthened our approaches,<br />

even though it does make global services more<br />

complex to develop, deploy, and maintain.<br />

Future work on Open Cirrus will revolve around<br />

increased use across the sites. In particular, we’re exploring<br />

applications that can be used on multiple sites<br />

to increase their performance, scale, and reliability. Another<br />

area of interest is standards, but we need more<br />

experience in using stacks and services before exploring<br />

standardization.<br />

Acknowledgments<br />

Partial funding for the Open Cirrus UIUC site was provided by<br />

NSF. Funding for the Open Cirrus CMU/PDL site was provided<br />

by Intel, NSF, ARO, and the PDL Consortium. Open Cirrus is<br />

COMPUTER<br />

a trademark of Yahoo! Inc. Several people made significant<br />

contributions to Open Cirrus, including A. Chien, R. Gass,<br />

K. Goswami, C. Hsiung, J. Kistler, M. Ryan, C. Whitney, and<br />

especially J. Wilkes, who was instrumental in formulating<br />

the original Open Cirrus vision as well as the concept of a<br />

management layer like Zoni.<br />

References<br />

1. M.A. Kozuch et al., “Tashi: Location-Aware Cluster Management,”<br />

Proc. 1st Workshop Automated Control for<br />

Datacenters and Clouds (ACDC 09), ACM Press, 2009, pp.<br />

43-48.<br />

2. M. Armbrust et al., “Above the Clouds: A Berkeley View<br />

of Cloud Computing,” tech. report UCB/EECS-2009-28,<br />

EECS Dept., Univ. of California, Berkeley, 2009; www.eecs.<br />

________________________________<br />

berkeley.edu/Pubs/TechRpts/2009/EECS-2009-28.pdf.<br />

3. J. Hamilton, “Internet-Scale Service Efficiency,” keynote<br />

at 2nd Large-Scale Distributed Systems and Middleware<br />

Workshop (LADIS 08), 2008; http://mvdirona.com/jrh/<br />

TalksAndPapers/JamesRH_Ladis2008.pdf.<br />

_________________________<br />

4. A. Greenberg et al., “The Cost of a Cloud: Research Problems<br />

in Data Center Networks,” ACM SIGCOMM Computer<br />

Communication Rev., Jan. 2009, pp. 68-73.<br />

5. C. Catlett et al., “TeraGrid: Analysis of Organization,<br />

System Architecture, and Middleware Enabling New Types<br />

of Applications,” High Performance Computing and Grids in<br />

Action, L. Grandinetti, ed., IOS Press, 2007, pp. 225-249.<br />

6. L. Peterson et al., “A Blueprint for Introducing Disruptive<br />

Technology into the Internet,” ACM SIGCOMM Computer<br />

Communication Rev., Jan. 2003, pp. 59-64.<br />

7. B. White et al., “An Integrated Experimental Environment<br />

for Distributed Systems and Networks,” ACM SIGOPS Operating<br />

Systems Rev., winter 2002, pp. 255-270.<br />

8. T. Benzel et al., “Design, Deployment, and Use of the<br />

DETER Testbed,” Proc. DETER Community Workshop Cyber<br />

Security Experimentation and Test, Usenix Assoc., 2007;<br />

__________________________________<br />

www.isi.edu/deter/docs/200708-usecdw-deter-design-<br />

_______ deploy.pdf.<br />

Arutyun I. Avetisyan is deputy director of the Institute for<br />

System Programming of the Russian Academy of Sciences<br />

(ISP RAS), RAS’s representative in Open Cirrus. Contact<br />

him at __________<br />

arut@ispras.ru.<br />

Roy Campbell is Sohaib and Sara Abbasi Professor in the<br />

Department of Computer Science at the University of Illinois<br />

at Urbana-Champaign (UIUC). Contact him at rhc@<br />

________ illinois.edu.<br />

Indranil Gupta is an associate professor in the Department<br />

of Computer Science at UIUC, where he also heads<br />

the Distributed Protocols Research Group. Contact him at<br />

____________<br />

indy@illinois.edu.<br />

Michael T. Heath is a professor and Fulton Watson Copp<br />

Chair in the Department of Computer Science at UIUC,<br />

where he’s also director of the Computational Science and<br />

Engineering Program. Contact him at ____________<br />

heath@illinois.edu.<br />

Steven Y. Ko is a postdoctoral research associate in the Department<br />

of Computer Science at Princeton University who<br />

worked on Open Cirrus as a PhD student at UIUC. Contact<br />

him at steveko@cs.princeton.edu.<br />

_________________<br />

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Gregory R. Ganger is a professor in the Department of<br />

Electrical and Computer Engineering at Carnegie Mellon<br />

University (CMU), where he’s also director of the Parallel<br />

Data Lab. Contact him at ______________<br />

ganger@ece.cmu.edu.<br />

Michael A. Kozuch is a principal researcher for Intel Labs<br />

Pittsburgh working in the area of computer architecture<br />

and system software. Contact him at _____________<br />

michael.a.kozuch@<br />

intel.com.<br />

David O’Hallaron is the director of Intel Labs Pittsburgh<br />

and an associate professor in the Department of Computer<br />

Science and the Department of Electrical and Computer<br />

Engineering at CMU. Contact him at ______________<br />

david.ohallaron@intel.<br />

___ com.<br />

Marcel Kunze heads the Cloud Computing research group<br />

at the Steinbuch Centre for Computing, Karlsruhe Institute<br />

of Technology, Germany, and is a technical lead in Open<br />

Cirrus. Contact him at _______________<br />

marcel.kunze@kit.edu.<br />

Thomas T. Kwan is director of research operations at<br />

Yahoo! Labs, where he manages multiple cloud <strong>computing</strong><br />

research partnerships for Yahoo!. Contact him at ______ tkwan@<br />

yahoo-inc.com.<br />

Kevin Lai is a research scientist in the Social Computing<br />

Lab at HP Labs and has worked on various projects at the<br />

intersection of operating systems and incentive engineering.<br />

Contact him at klai@hp.com.<br />

________<br />

Martha Lyons is a Distinguished Technologist at HP Labs<br />

focused on incubating and delivering innovative capabilities<br />

to HP’s customers. Contact her at _______________<br />

martha.lyons@hp.com.<br />

Dejan S. Milojicic is a scientist and senior researcher manager<br />

in the Strategy and Innovation Office at HP Labs and director of<br />

Open Cirrus. Contact him at _______________<br />

dejan.milojicic@hp.com.<br />

Hing Yan Lee is program director of the National Grid<br />

Office at the Infocomm Development Authority (IDA) of<br />

Singapore. Contact him at _________________<br />

lee_hing_yan@ida.gov.sg.<br />

Yeng Chai Soh is a professor in the School of Electrical and<br />

Electronic Engineering at Nanyang Technological University,<br />

Singapore, and is also affiliated with IDA. Contact him<br />

at _____________<br />

eycsoh@ntu.edu.sg.<br />

Ng Kwang Ming is director of the Grid Computing Lab at the<br />

Malaysian Institute of Microelectronic Systems (MIMOS).<br />

Contact him at ________________<br />

kwang.ming@mimos.my.<br />

Jing-Yuan Luke is a staff engineer in the Grid Computing<br />

Lab at MIMOS. Contact him at _____________<br />

jyluke@mimos.my.<br />

Han Namgoong is a director in the Cloud Computing Research<br />

Department of the Software Research Laboratory at<br />

the Electronics and Telecommunications Research Institute<br />

(ETRI), South Korea. Contact him at nghan@etri.re.kr.<br />

Selected CS articles and columns are available for free at<br />

http://ComputingNow.computer.org.<br />

COMPUTING LIVES<br />

www.computer.org/annals/<strong>computing</strong>-<strong>lives</strong><br />

___________________________________________________<br />

___________<br />

The “Computing Lives” podcast series of selected articles from the IEEE Annals of the History<br />

of Computing cover the breadth of computer history. This series features scholarly accounts<br />

by leading computer scientists and historians, as well as fi rsthand stories by computer pioneers.<br />

APRIL 2010<br />

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COVER FEATURE<br />

Edward Walker, University of Texas at Austin<br />

Storage clouds are online services for<br />

leasing disk storage. A new modeling<br />

tool, formulated from empirical data<br />

spanning many years, lets organizations<br />

rationally evaluate the benefit of using<br />

storage clouds versus purchasing hard<br />

disk drives.<br />

Hard disk drives provide storage for a broad range<br />

of devices, from mobile phones to large IT<br />

server farms. In 2008, approximately 590 million<br />

hard disk drives were shipped worldwide, 1<br />

largely driven by the vast amount of information<br />

our digital society is generating. For example, a report<br />

from researchers at the University of California, Berkeley,<br />

estimates that 92 percent of the five exabytes (10 18 ) of<br />

new information created in 2002 was stored on magnetic<br />

media, primarily hard disk drives. 2<br />

At the same time, the business of selling infrastructure<br />

as a service through the Internet is growing. This technology<br />

trend, also known as cloud <strong>computing</strong>, lets individuals<br />

and organizations outsource their IT requirements to<br />

remote data centers, paying for only what they use. The<br />

cloud <strong>computing</strong> industry’s worth was estimated at more<br />

than $16 billion in 2008, and it’s expected to grow to $42<br />

billion by 2012. 3<br />

Several online services currently lease storage infrastructure.<br />

These storage clouds let anyone with a credit<br />

card purchase storage capacity online, paying a monthly<br />

fee for the storage they use. __________<br />

Amazon.com’s S3 service<br />

(http://aws.amazon.com/s3), for example, lets users store<br />

COMPUTER<br />

TO LEASE OR NOT<br />

TO LEASE FROM<br />

STORAGE CLOUDS<br />

Walter Brisken and Jonathan Romney, National Radio Astronomy Observatory<br />

arbitrary objects of up to 5 Gbytes each in their online<br />

storage repositories. The S3 service uses a tiered pricing<br />

structure, with storage getting cheaper as more is used. As<br />

of late 2008, Amazon.com reported that users stored more<br />

than 40 billion objects in the S3 service. 4<br />

With the significant growth of society’s storage requirements,<br />

and the availability of pay-per-use online storage<br />

services, when should a consumer consider using storage<br />

clouds? We focus on the problem of resolving this buy-orlease<br />

storage decision.<br />

BUY OR LEASE<br />

An organization’s decision to buy or lease long-term<br />

assets is often a critical dilemma. The literature describes<br />

numerous models to assist firms in resolving this acquisition<br />

decision. 5-7 However, there is a significant lack of work<br />

in applying these models to compare the cost of purchasing<br />

versus leasing storage from cloud services. Important<br />

studies have examined the cost of performing scientific<br />

experiments using the Amazon.com cloud services, 8,9 but<br />

these prior works are difficult to generalize outside the<br />

scope of the applications used in the studies.<br />

We believe our proposed model for evaluating the benefits<br />

of purchasing versus leasing storage from a cloud<br />

service is the first reported in the literature, offering a<br />

method for deriving a reasonable estimate of the best possible<br />

outcomes from the alternative investment choices.<br />

Furthermore, our model, which we formulated using<br />

empirical disk price data we’ve been collecting weekly<br />

from Pricewatch.com over many years, is agnostic to the<br />

application using the storage cloud. Our empirical data<br />

tracks the lowest prices for serial advanced technology<br />

attachment (SATA) disk drives for sale online since the<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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technology’s introduction in 2003. This data is significant<br />

because SATA is the predominant drive technology used<br />

in desktop and nearline systems.<br />

Most organizations use financial models as only one data<br />

point in deciding whether to buy or lease an asset. Other<br />

factors also influence their decision. 7 However, our proposed<br />

model bridges a critical gap in the literature and, more<br />

importantly, the market. Our model helps users understand<br />

the premium they’re paying for what seems to be an arbitrarily<br />

priced online storage market. Our research agenda<br />

aims to provide a quantitative framework for rationally reasoning<br />

about the cost of leasing infrastructure from cloud<br />

services, and extends our prior work on leasing from compute<br />

clouds. 10 Importantly, the systematic understanding of<br />

the real cost of leasing assets from cloud services lets users<br />

make rational decisions with innovative pricing structures.<br />

This promotes market transparency and ultimately supports<br />

a competitive product market.<br />

PRELIMINARIES<br />

A key principle in economic finance is the time value<br />

of money. Basically, this principle states that an investor<br />

always prefers to receive some fixed amount of money<br />

today rather than in the future. Hence, when making<br />

buy-or-lease decisions, investors often compare future<br />

cash flows in an investment over time, discounted to their<br />

present value by some interest rate. 5-7 The discounting<br />

interest rate used reflects the risk involved in raising the<br />

capital needed to invest.<br />

In equation form, the simplified standard capitalbudgeting<br />

format for calculating a purchased asset’s net<br />

present value (NPV) is as follows:<br />

NPV P =<br />

N<br />

<br />

T = 0<br />

P P C T T<br />

(1+ I ) K T<br />

S<br />

+ E , N (1+ I ) K<br />

where P is the annual profit resulting from the purchased<br />

T<br />

P asset in year T; C is the asset’s expected annual operat-<br />

T<br />

ing cost at year T; I is the firm’s cost of capital, defined<br />

K<br />

as the interest rate of its outstanding debt used to finance<br />

the purchase; 11 N is the asset’s productive life in years; S is<br />

the asset’s salvage value after N years; and E is the asset’s<br />

purchase (capital) cost.<br />

Similarly, the equation for calculating a leased asset’s<br />

NPV is as follows:<br />

NPV L =<br />

L P C T T<br />

( ) T<br />

N<br />

<br />

T = 0<br />

1+ I K<br />

<br />

LT ( ) T<br />

N<br />

<br />

T = 0<br />

1+ I R<br />

L where C is the leased asset’s expected annual operat-<br />

T<br />

ing cost at year T; L is the lease payment at year T; and<br />

T<br />

I is the interest rate for financing the lease payments. In<br />

R<br />

this formulation, the lease’s financing rate is generally<br />

regarded as smaller than the cost of capital, I , because of<br />

K<br />

,<br />

Table 1. Parameter terms in the buy-or-lease decision model.<br />

Term Description<br />

Cost of electric utility ($/kilowatt hour)<br />

Size of purchased disk drives (Gbytes)<br />

Proportional difierence between human efiort in main -<br />

taining a purchased versus a leased storage infrastructure<br />

ϒ Used disk depreciation factor on salvage ([0.0, 1.0])<br />

C Disk controller unit cost ($)<br />

H Annual human operator salary ($)<br />

T<br />

I Risk-free interest rate (percent)<br />

F<br />

Κ Current per-Gbyte storage price ($/Gbyte)<br />

LT Pc PD VT Expected annual per-Gbyte lease payment ($/Gbyte/year)<br />

Disk controller power consumption (kW)<br />

Disk drive power consumption (kW)<br />

Expected storage requirement in year T (Gbytes)<br />

the involved payment structure’s predictability. 5<br />

With this NPV formulation for asset purchase and lease,<br />

investors can make the buy-or-lease decision using the<br />

following criteria: If the incremental NPV (NPV) 0 <br />

buy; if NPV < 0 lease, where NPV = NPV P – NPV L .<br />

DECISION MODEL<br />

We derive a buy-or-lease decision model that calculates<br />

the comparative NPVs from storage purchase versus<br />

lease. Our model accounts for the expected capital expenditure<br />

from SATA hard disk drive purchase, replacement,<br />

and end-of-use salvage. It also accounts for the expected<br />

operational expenditure for utility consumption and<br />

human operator cost. The “Derivation of the Decision<br />

Model” sidebar describes how we derived our decision<br />

model. We summarize it as follows: If NPV 0 buy; if<br />

NPV < 0 lease, where<br />

C − E + L T T T<br />

ΔNPV =<br />

( 1+ I F ) T<br />

N<br />

S<br />

∑<br />

+ − C<br />

N<br />

T = 0<br />

( 1+ I F )<br />

S =γ ∗ Ω∗⎡⎢ V ⎤ ∗ K ∗e T ⎥Ω −0.438T<br />

C =−ρ∗H − 365 ∗24<br />

T T ( ⎡⎢ ⎤⎥Ω )<br />

( )∗δ ∗ P + P ∗ V C D T<br />

( ⎡⎢ ⎤ − ⎡⎢ V ⎤ ⎥Ω T −1 ⎥Ω )∗Ω∗K ∗e −0.438T<br />

E T = 1.03∗ V T<br />

Table 1 lists the model parameters. We assume ⎡V⎤ fl is<br />

an operator returning the minimum number of fl-sized<br />

disk drives needed to store V Gbytes of data. The derived<br />

terms S, C T , and E T represent the expected end-of-life disk<br />

salvage value, the operating cost in year T, and the capital<br />

cost in year T, respectively.<br />

EXAMPLE APPLICATION<br />

We used our decision model to evaluate the advantages<br />

of purchasing versus leasing storage from a hypothetical<br />

storage cloud vendor.<br />

.<br />

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COVER FEATURE<br />

We calculate the incremental net present value (ΔNPV) as<br />

follows:<br />

ΔNPV = NPV − NPV P L<br />

⇒<br />

PT − C P<br />

T<br />

( 1+ IK ) T<br />

N<br />

L<br />

S<br />

P − C L T T<br />

T<br />

∑ + − E − +<br />

T T<br />

T =0 ( 1+ IK ) ( 1+ IK ) ( 1+ IR ) T<br />

N<br />

N<br />

∑ ∑<br />

T =0<br />

T =0<br />

⇒<br />

C L P − CT<br />

T<br />

( 1+ IK ) T<br />

N<br />

S<br />

L T<br />

∑ + +<br />

N<br />

T =0 ( 1+ IK ) ( 1+ IR ) T<br />

N<br />

∑ − E.<br />

T =0<br />

Assuming that profit from storage is equal in both the buy and<br />

lease cases—that is, using 1 Tbyte of storage from a purchased<br />

disk or from a storage cloud results in the same level of<br />

productivity—the above simplification results in the removal of<br />

the profit term P T .<br />

Capital cost<br />

Three components make up the cost of purchasing storage E:<br />

The consumer needs a disk controller to house the purchased<br />

disks.<br />

The consumer purchases disk drives in blocks based on<br />

increasing storage needs.<br />

The consumer must periodically replace disks due to<br />

failure.<br />

These components contribute to the future cash flow E as<br />

follows:<br />

E =<br />

COMPUTER<br />

DERIVATION OF THE DECISION MODEL<br />

( ( ⎡⎢ V ⎤ − ⎡⎢ V ⎤ T ⎥Ω T −1⎥Ω<br />

)∗Ω+R T )∗G T<br />

( ) T<br />

E T<br />

1+ I K<br />

⇒ E = + C<br />

T<br />

( 1+ IK )<br />

E = V T ( ( ⎡⎢ ⎤ − ⎡⎢ V ⎤ T ⎥Ω T −1⎥Ω<br />

)∗Ω+R T )∗G , T<br />

where Ω represents the hard disk drive size in Gbytes; V T is the<br />

storage requirement in Gbytes at year T; ⎡V T ⎤ Ω is an operator that<br />

returns the minimum number of Ω-sized disk drives needed to<br />

store V T ; G T is the predicted cost per Gbyte of disk storage at year<br />

T; R T is the disk replacement in Gbytes at year T; and C is the disk<br />

controller cost.<br />

The important insight in this formulation is that the capital<br />

cost isn’t all incurred at the start of the project, unlike in traditional<br />

NPV models. Rather, it’s a time-varying formula in which<br />

users can grow their storage systems as their requirements<br />

evolve. We modify ΔNPV to reflect this growth in capital cost:<br />

ΔNPV =<br />

N<br />

∑<br />

T =0<br />

S<br />

+<br />

1+ IK L P C − CT − ET<br />

T<br />

( )<br />

( ) T<br />

1+ I K<br />

Operating cost<br />

− C<br />

LT +<br />

N<br />

( ) T<br />

N<br />

∑<br />

T =0<br />

1+ I R<br />

P We estimate the operating cost of purchased storage, C , by T<br />

calculating the electric utility cost associated with running the<br />

+ C<br />

disk controller and the disk units, plus the cost of a human<br />

operator to manage the system/data. These cost components<br />

P contribute to C as follows:<br />

T<br />

P C = (365⋅24)∗δ ∗ PC + P T<br />

( ∗⎡⎢ V ⎤ D T ⎥Ω )+α∗H , T<br />

where δ is the utility cost ($/kilowatt per hour); P is the control-<br />

C<br />

ler’s power requirement in kWs; P is the power requirement in<br />

D<br />

kWs per disk drive; and α is the proportion of the human operator<br />

cost, H , required to maintain the system/data at year T.<br />

T<br />

L The operating cost for leased storage, C , only includes the<br />

T<br />

cost of a human operator to manage the data. Thus, we calculate<br />

L L<br />

C as CT = β∗HT , where β is the proportion of the human opera-<br />

T<br />

tor cost required to maintain the data on the leased storage at<br />

year T. Substituting ρ for (α – β), we can modify ΔNPV to reflect the<br />

operating costs as follows:<br />

ΔNPV =<br />

N<br />

∑<br />

T =0<br />

−ρ∗H T − 365⋅24<br />

( )∗δ ∗( P + P ∗⎡⎢ V ⎤ C D T ⎥Ω )− ET ( ) T<br />

L T<br />

1+ I K<br />

S<br />

− C + +<br />

.<br />

N<br />

( 1+ IK ) ( 1+ IR ) T ∑<br />

T =0<br />

Approximating the best outcomes<br />

N<br />

Consumers often find it difficult to estimate their capital cost<br />

and the lease financing rates available to them. We therefore suggest<br />

an approximate method of evaluating the buy-or-lease<br />

decision by deriving the best possible outcome in both the purchase<br />

and lease cases.<br />

From the well-known economic Law of One Price, 1 we can<br />

derive the upper bounds for NPV P and NPV L by substituting I K and<br />

I R with the risk-free interest rate I F . The “Corollary for Estimating<br />

the Upper-bound Present Value” sidebar explains this in more<br />

detail. In turn, we can estimate the risk-free interest rate, I F , from<br />

the published return on an instrument such as government treasury<br />

bills. We can therefore derive an approximation of the<br />

decision criteria using these best NPVs, letting us further simplify<br />

the currently derived version of ΔNPV to:<br />

ΔNPV =<br />

N<br />

∑<br />

T =0<br />

( )∗δ ∗( P + P ∗⎡⎢ V ⎤ C D T ⎥Ω )− E + L T T<br />

( ) T<br />

−ρ∗H T − 365∗24<br />

S<br />

− C +<br />

.<br />

( 1+ IF ) N<br />

Disk price trends<br />

1+ I F<br />

We haven’t yet provided a function for the term G , which we need<br />

T<br />

to calculate E and to estimate the cost of disk storage at year T.<br />

T<br />

Since April 2003, we’ve been collecting SATA disk price data<br />

from Pricewatch.com on a weekly basis. We collected price data<br />

for all available disk drive sizes each week—250 Gbytes, 500<br />

Gbytes, and so on—regardless of manufacturer or model. Figure<br />

A plots the 10 lowest prices each week for SATA disk drives across<br />

all the available drive sizes. Approximating the observed exponential<br />

trend line using regression analysis, we obtain the formula<br />

′ − 0.0012 X G = 1.2984e .<br />

X<br />

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′ The function G predicts the cost per Gbyte<br />

X<br />

of SATA disk storage X days from 20 April 2003,<br />

′ with G = 1.2984 when X = 0. We can therefore<br />

X<br />

approximate the function G by assuming that<br />

T<br />

the future disk price trend conforms to the<br />

equation K ∗ eC ∗ T , where K represents the lowest<br />

storage price per Gbyte available to the consumer<br />

at T = 0; and T represents the number of<br />

years in the future. We therefore derive G as G T T<br />

= K ∗ e –0.0012∗ 365 ∗ T⇒ G = K ∗ e T –0.438∗ T .<br />

Disk replacement rates<br />

Any realistic cost model for disk storage ownership<br />

must estimate the disk replacement cost.<br />

A recent large-scale study of disk failures measured<br />

the annualized replacement rate (ARR) of<br />

disk drives in real data centers. 2 The study<br />

observed ARRs in the range of 0.5 to 13.5 percent,<br />

with the most commonly observed ARRs in<br />

the 3 percent range.<br />

In our model, we approximate R T with this<br />

empirical approximation of the disk replacement<br />

rate by using the formula R T = 0.03 * Ω *<br />

⎡V T ⎤ Ω . In this formula, the constant 0.03 represents the observed<br />

3 percent disk replacement rate. 2 Thus, we can simplify E T to:<br />

–0.438∗ T<br />

E = (( ⎡V ⎤ – ⎡V ⎤ ) ∗ Ω + 0.03 ∗ Ω ∗⎡V⎤ ) ∗ K ∗ e T T Ω T – 1 Ω T Ω<br />

⇒ E = (1.03 ∗⎡V⎤ – ⎡V ⎤ ) ∗ Ω ∗ K · e T T Ω T – 1 Ω –0.438∗ T .<br />

Disk salvage value<br />

$/GByte<br />

We assume a hard disk drive can be sold in the used market for<br />

some salvage value at the end of its life. To predict this salvage<br />

value, we leverage the future disk price prediction formula, discounting<br />

the predicted price by some depreciation factor, γ, in the<br />

We assume this vendor lets users purchase raw disk<br />

storage over the Internet. We’re only interested in the storage<br />

cloud’s pricing structure for the end user, and we don’t<br />

assume any particular service access technology. Table 2<br />

shows the assumed tiered monthly pricing structure. For<br />

illustrative purposes, we don’t consider data uploading or<br />

downloading costs.<br />

Single-user computers<br />

Single-user computers make up the vast majority of all<br />

shipped disk storage capacity. 2 For our study, we assume<br />

the same user owns and operates the single-user computer.<br />

This user’s storage requirement grows at a moderate rate<br />

of 100 Gbytes per year. Therefore, regardless of where<br />

data is stored, we assume the level of effort in managing<br />

the system/data is approximately equal in both cases<br />

because of the low storage volume involved—that is,<br />

= 0. We assume the user must purchase a new disk<br />

controller (C = $1,000), specified to consume 0.5 kW of<br />

power. Also, as storage is required, the user will purchase<br />

2.5<br />

2.0<br />

1.5<br />

1.0<br />

0.5<br />

y = 1.2984e – 0.0012 X<br />

Disk price<br />

Exponential (disk price)<br />

0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000<br />

Start date: 20 April 2003<br />

Days<br />

Figure A. Weekly SATA disk price data collected from Pricewatch.com from<br />

20 April 2003 to 19 August 2008.<br />

range [0, 1]. In equation form, this gives us the salvage value S = γ<br />

* Ω * ⎡V T ⎤ Ω ∗ K ∗ e –0.438 ∗ T , simplifying into ΔNPV as shown by<br />

Equation 1 in the main text.<br />

References<br />

1. O.A. Lamont and R.H. Thaler, “Anomalies: The Law of One<br />

Price in Financial Markets,” J. Economic Perspective, vol. 17, no.<br />

4, 2003, pp. 191-202.<br />

2. B. Schroeder and G. Gibson, “Disk Failures in the Real World:<br />

What Does an MTTF of 1,000,000 Hours Mean to You?” Proc.<br />

5th Usenix Conf. File and Storage Technologies (FAST 07),<br />

Usenix Assoc., 2007, pp. 1-16.<br />

COROLLARY FOR ESTIMATING THE<br />

UPPER-BOUND PRESENT VALUE<br />

We derive the following corollary from the economic Law of<br />

One Price, which states, “In an efficient market, identical<br />

goods will have only one price.”<br />

Corollary 1. The upper bound of the present values for the purchase<br />

and lease price equilibrium in an efficient market is derived<br />

from the risk-free interest rate, I . F<br />

Informal proof: In an efficient market, an arbitrager has no<br />

opportunity to make a risk-free profit. Assuming an efficient market<br />

in which financing at the risk-free rate is possible for a subset of<br />

agents, the proof is by contradiction. Thus, if the present value of<br />

the lease price is higher than that derived from the risk-free rate, I , F<br />

an arbitrager can purchase disks from monies borrowed at the riskfree<br />

rate, lease at this higher price, and pocket the risk-free profit.<br />

Also, if the present value of the purchase price is higher than that<br />

derived from the risk-free rate, I , an arbitrager can purchase a disk<br />

F<br />

from monies borrowed at the risk-free rate, sell the disk at some<br />

future instance at this higher price, and pocket the risk-free profit.<br />

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Year<br />

(T)<br />

ΔNPV (thousands of dollars)<br />

–50<br />

COVER FEATURE<br />

0<br />

–100<br />

–150<br />

–200<br />

–250<br />

–300<br />

0 2 4 6<br />

Operational years<br />

8 10 12<br />

Figure 1. The calculated NPV values for a medium-size enterprise deciding<br />

whether to buy or lease storage with life expectancy from 0 to 10 years.<br />

ΔNPV (thousands of dollars)<br />

150<br />

100<br />

50<br />

0<br />

–50<br />

–100<br />

–150<br />

–200<br />

0 2 4 6 8 10 12<br />

Operational years<br />

Figure 2. The calculated NPVs for a large-size enterprise deciding whether to<br />

buy or lease storage with life expectancy from 0 to 10 years.<br />

500-Gbyte disk drives ( = 500), with a present cost of<br />

$150 per drive (K = $0.30), each specified to consume 0.01<br />

kW of power. Finally, we assume the electric utility cost<br />

is $0.04 per kilowatt hour (kWh), and the end-of-life disk<br />

salvage depreciation factor is 0.1.<br />

Table 3 shows the worksheet for the buy-or-lease deci-<br />

COMPUTER<br />

Table 2. Hypothetical storage cloud pricing structure.<br />

Default Storage > 50 Tbytes Storage > 100 Tbytes Storage > 500 Tbytes<br />

$0.15/Gbyte/month $0.14/Gbyte/month $0.13/Gbyte/month $0.12/Gbyte/month<br />

Storage<br />

requirement<br />

in Gbytes (V T )<br />

Purchased<br />

drives<br />

Table 3. Buy-or-lease decision model worksheet for a single-user computer.<br />

Operating<br />

cost (C T )<br />

Capital<br />

cost<br />

(E T )<br />

Lease<br />

payment<br />

(L T ) Recurring cost (CPV T )<br />

sion model for an expected storage life<br />

expectancy of 0 to 6 years. We compute the<br />

values for the “purchased drive” column<br />

using V T 500 – V T–1 500 , and the NPVs using<br />

Equation 1. In addition, we calculate the<br />

recurring costs (CPV T ) and salvage values<br />

(SPV T ) representing terms in the formula:<br />

ΔNPV = CPV + SPV – C<br />

T T<br />

C – E + I T T T<br />

CPV = T<br />

( 1 + I K ) T<br />

T<br />

∑<br />

T – 0<br />

SPV .<br />

T =<br />

S<br />

( 1 + I K ) T<br />

Salvage value<br />

(SPV T )<br />

Incremental<br />

net present<br />

value (NPV)<br />

0 100 1 ($178.70) $154.50 $98 ($236) $15.00 ($1,221)<br />

1 200 0 ($178.70) $2.90 $278 ($141) $9.58 ($1,131)<br />

2 300 0 ($178.70) $1.87 $458 $131 $6.12 ($863)<br />

3 400 0 ($178.70) $1.21 $638 $575 $3.91 ($421)<br />

4 500 0 ($178.70) $0.78 $818 $1,188 $2.50 $190<br />

5 600 1 ($182.21) $17.79 $998 $1,947 $3.19 $950<br />

6 700 0 ($182.21) $0.65 $1,178 $2,884 $2.04 $1,886<br />

Notes: C = $1,000, = 500 Gbytes, Κ = $0.30 ($150 per 500 Gbytes), = 0, = 0.1, = $0.04, P = 0.5 kW, P = 0.01 kW, and I = 1 percent.<br />

C D K<br />

The worksheet shows that for an<br />

expected storage life expectancy of less<br />

than four years, leasing is always the preferred<br />

option. This is because of the high<br />

cost of the disk controller the user purchases<br />

at the outset. If the storage system<br />

will likely exist for more than four years,<br />

however, purchasing storage is the superior<br />

choice.<br />

Medium-size enterprises<br />

Medium-size enterprises—those with<br />

clusters of tens to hundreds of servers—<br />

made up approximately 50 percent of all<br />

data centers installed in the US from 2000 to 2007. 12 We<br />

assume our medium-size enterprise has a storage requirement<br />

that grows at 1 Tbyte a year to serve a moderate-size<br />

data center of tens or low hundreds of servers.<br />

For such an enterprise, the human operator burden<br />

in owning and operating a storage cluster will be larger<br />

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than that of leasing from the storage cloud vendor. We<br />

therefore assume the proportional difference in the operator’s<br />

level of effort required to manage the system/data<br />

(H T = $70,000 per year) is = 0.5. We assume that<br />

the firm must purchase an enterprise-class RAID disk<br />

controller (C = $2,000), specified to consume 0.7 kW<br />

of power. Also, as storage is needed, the enterprise will<br />

purchase 1-Tbyte disk drives ( = 1,000), with a present<br />

cost of $300 per drive (K = $0.30), each specified<br />

to consume 0.01 kW of power. Finally, we assume the<br />

electric utility cost is $0.04 per kWh, and the end-of-life<br />

disk salvage depreciation factor is 0.1.<br />

Figure 1 shows the calculated NPV values for a storage<br />

life expectancy of 0 to 10 years. In all the operational lifetimes<br />

examined, the model shows that leasing is always<br />

preferable to purchasing storage. In this case, the clear<br />

recommendation to the medium-size enterprise is to lease<br />

storage from the storage cloud vendor.<br />

Large-size enterprises<br />

Next, we look at the benefits of purchasing versus leasing<br />

storage for a large-size enterprise—for example, a<br />

data center with thousands of servers. In this scenario, we<br />

assume the large enterprise’s storage requirement grows<br />

at 10 Tbytes per year.<br />

In this case, the human operator burden in owning and<br />

operating a storage cluster is even larger than that of leasing<br />

from the storage cloud vendor. We therefore assume<br />

the proportional difference in the operator’s level of effort<br />

required to manage the system/data (H T = $70,000/year)<br />

is = 1.0. We also assume that the firm must purchase an<br />

enterprise-class RAID disk controller (C = $2,000), specified<br />

to consume 0.7 kW of power. Furthermore, we assume<br />

the controller has a peak capacity of 100 Tbytes, and the<br />

firm will purchase additional controllers as the storage<br />

need arises.<br />

For the actual storage, the enterprise will purchase<br />

1-Tbyte disk drives ( = 1,000), with a present cost of<br />

$300 per drive (K = $0.30), each specified to consume 0.01<br />

kW of power. Finally, as before, we assume the electric utility<br />

cost is $0.04 per kWh, and the end-of-life disk salvage<br />

depreciation factor is 0.1.<br />

Figure 2 shows the calculatedNPVs for a storage life<br />

expectancy of 0 to 10 years. As the graph shows, leasing<br />

storage is advantageous up to a nine-year storage life<br />

expectancy. After that, it becomes more advantageous for<br />

the enterprise to purchase and maintain a storage cluster.<br />

Thus, the final decision to buy or lease storage will depend<br />

on the expected use of the storage and data. For example,<br />

if the storage is destined for use by a server cluster with<br />

a five-year life expectancy, the enterprise should lease<br />

storage. However, if the storage is destined for a long-term<br />

archival system with an indefinite life expectancy, the<br />

enterprise should purchase storage instead.<br />

LATENCY IS NOT ZERO<br />

A common flawed assumption in designing distributed<br />

systems is the notion that latency is zero. In fact, latency isn’t<br />

zero for cloud services. Accessing storage from across the<br />

commodity Internet can incur a substantial cost in terms<br />

of I/O latency. Our model doesn’t account for this latency.<br />

However, future extensions can incorporate this factor by<br />

estimating the profit parameter, P T , which we assumed to<br />

be equal when deriving our current model. We can use this<br />

profit parameter to reward services with faster response<br />

times. For example, an enterprise might naïvely consider a<br />

service that’s two times faster to be more productive, and<br />

hence two times more profitable. For the moment, we leave<br />

this substantive extension to a future time.<br />

Our primary purpose in this article is to stimulate<br />

discussion, debate, and future work in the quantitative<br />

modeling of the cloud <strong>computing</strong> industry.<br />

To this end, we propose a model to assist consumers,<br />

researchers, and policy makers in estimating the<br />

benefit of leasing from storage clouds.<br />

Ultimately, an organization’s buy-or-lease decision will<br />

depend on their anticipated parameters in the analysis.<br />

Our model simply provides a first stepping-stone for rational<br />

decision making to prevail in the cloud <strong>computing</strong><br />

market.<br />

Acknowledgments<br />

This article is based on work supported in part by US National<br />

Science Foundation grant 0721931.<br />

References<br />

1. K. Chandar, “SSD & HDD Market Tracker,” iSuppli<br />

research report, 2009; www.isuppli.com/Abstract/<br />

________________________________<br />

ABSTRACT - SSD_HDD Market Tracker 2009.pdf.<br />

2. P. Lyman and H.R. Varian, “How Much Information?”<br />

Oct. 2003, School of Information Management and Systems,<br />

Univ. of Calif., Berkeley; ______________<br />

www2.sims.berkeley.<br />

_____________________________<br />

edu/research/projects/how-much-info-2003.<br />

3. N. Leavitt, “Is Cloud Computing Really Ready for<br />

Prime Time?” Computer, Jan. 2009, pp. 15-20.<br />

4. A. Henry, “Keynote Address: Cloud Storage FUD<br />

(Failure, Uncertainty, and Durability),” presented at<br />

the 7th Usenix Conf. File and Storage Technologies,<br />

2009; www.usenix.org/media/events/fast09/tech/<br />

____________<br />

videos/henry.mov.<br />

5. R.W. Johnson and W.G. Lewellen, “Analysis of Leaseor-Buy<br />

Decision,” J. Finance, vol. 27, no. 4, 1972, pp.<br />

815-823.<br />

6. G.B. Harwood and R.H. Hermanson, “Lease-or-Buy<br />

Decisions,” J. Accountancy, vol. 142, no. 3, 1976, pp.<br />

83-87.<br />

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COVER FEATURE<br />

7. P.F. Anderson and J.D. Martin, “Lease vs. Purchase<br />

Decisions: A Survey of Current Practice,” Financial<br />

Management, vol. 6, no. 1, 1977, pp. 41-47.<br />

8. M. Palankar et al., “Amazon S3 for Science Grids: A<br />

Viable Solution?” Proc. Int’l Workshop Data-Aware<br />

Distributed Computing, ACM Press, 2008, pp. 55-64.<br />

9. E. Deelman et al., “The Cost of Doing Science on the<br />

Cloud: The Montage Example,” Proc. ACM/IEEE Conf.<br />

Super<strong>computing</strong>, IEEE Press, pp. 1-16.<br />

10. E. Walker, “The Real Cost of a CPU Hour,” Computer,<br />

Apr. 2009, pp. 35-41.<br />

11. W.G. Lewellen, The Cost of Capital, Wadsworth Publishing,<br />

1970.<br />

12. US Environmental Protection Agency, Energy<br />

Star Program, Report to Congress on Server and<br />

Data Center Energy Efficiency, Public Law 109-<br />

431, Aug. 2007; www.energystar.gov/ia/partners/<br />

___________________________________<br />

prod_development/downloads/EPA_Datacenter_<br />

Report_Congress_Final1.pdf.<br />

___________________<br />

Edward Walker is a researcher with the Texas Advanced<br />

Computing Center at the University of Texas at Austin.<br />

His research interests include distributed systems, storage<br />

systems, and operating systems. Walker received a PhD in<br />

Welcomes Your Contribution<br />

COMPUTER<br />

Computer<br />

magazine<br />

looks ahead<br />

to future<br />

technologies<br />

computer science from the University of York, UK. He is a<br />

member of IEEE and the ACM. Contact him at ewalker@ ______<br />

computer.org.<br />

Walter Brisken is a scientist at the National Radio Astronomy<br />

Observatory. His research interests include pulsars,<br />

the ionized interstellar medium, and very long baseline<br />

interferometry. Brisken received a PhD in physics from<br />

Princeton University. He is a member of the American<br />

Astronomical Society. Contact him at _____________<br />

wbrisken@nrao.edu.<br />

Jonathan Romney is a scientist at the National Radio<br />

Astronomy Observatory. His research interests include<br />

active galactic nuclei and astronomical instrumentation.<br />

Romney received a PhD in astronomy from the California<br />

Institute of Technology. He is a member of the American<br />

Astronomical Society, the International Astronomical<br />

Union, and the International Union of Radio Science (URSI).<br />

Contact him at jromney@aoc.nrao.edu.<br />

________________<br />

Selected CS articles and columns are available for free<br />

at http://ComputingNow.computer.org.<br />

Computer, the flagship publication of the IEEE<br />

Computer Society, publishes peer-reviewed<br />

technical content that covers all aspects of<br />

computer science, computer engineering,<br />

technology, and applications.<br />

Articles selected for publication in Computer<br />

are edited to enhance readability for the nearly<br />

100,000 <strong>computing</strong> professionals who receive<br />

this monthly magazine.<br />

Readers depend on Computer to provide current,<br />

unbiased, thoroughly researched information on<br />

the newest directions in <strong>computing</strong> technology.<br />

To submit a manuscript for peer review,<br />

see Computer’s author guidelines:<br />

www.computer.org/computer/author.htm<br />

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COVER FEATURE<br />

Karthik Kumar and Yung-Hsiang Lu, Purdue University<br />

The cloud heralds a new era of <strong>computing</strong><br />

where application services are provided<br />

through the Internet. Cloud <strong>computing</strong><br />

can enhance the <strong>computing</strong> capability of<br />

mobile systems, but is it the ultimate solution<br />

for extending such systems’ battery<br />

lifetimes?<br />

Cloud <strong>computing</strong> 1 is a new paradigm in which<br />

<strong>computing</strong> resources such as processing,<br />

memory, and storage are not physically present<br />

at the user’s location. Instead, a service<br />

provider owns and manages these resources,<br />

and users access them via the Internet. For example,<br />

Amazon Web Services lets users store personal data via<br />

its Simple Storage Service (S3) and perform computations<br />

on stored data using the Elastic Compute Cloud (EC2).<br />

This type of <strong>computing</strong> provides many advantages<br />

for businesses—including low initial capital investment,<br />

shorter start-up time for new services, lower maintenance<br />

and operation costs, higher utilization through virtualization,<br />

and easier disaster recovery—that make cloud<br />

<strong>computing</strong> an attractive option. Reports suggest that there<br />

are several benefits in shifting <strong>computing</strong> from the desktop<br />

to the cloud. 1,2 What about cloud <strong>computing</strong> for mobile<br />

users? The primary constraints for mobile <strong>computing</strong> are<br />

limited energy and wireless bandwidth. Cloud <strong>computing</strong><br />

can provide energy savings as a service to mobile users,<br />

though it also poses some unique challenges.<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

CLOUD COMPUTING<br />

FOR MOBILE USERS:<br />

CAN OFFLOADING<br />

COMPUTATION<br />

SAVE ENERGY?<br />

Published by the IEEE Computer Society<br />

SAVING ENERGY FOR MOBILE SYSTEMS<br />

Mobile systems, such as smart phones, have become<br />

the primary <strong>computing</strong> platform for many users. Various<br />

studies have identified longer battery lifetime as the most<br />

desired feature of such systems. A 2005 study of users in<br />

15 countries 3 found longer battery life to be more important<br />

than all other features, including cameras or storage. A<br />

survey last year by ChangeWave Research 4 revealed short<br />

battery life to be the most disliked characteristic of Apple’s<br />

iPhone 3GS, while a 2009 Nokia poll showed that battery<br />

life was the top concern of music phone users.<br />

Many applications are too computation intensive to<br />

perform on a mobile system. If a mobile user wants to use<br />

such applications, the computation must be performed in<br />

the cloud. Other applications such as image retrieval, voice<br />

recognition, gaming, and navigation can run on a mobile<br />

system. However, they consume significant amounts of<br />

energy. Can offloading these applications to the cloud save<br />

energy and extend battery lifetimes for mobile users?<br />

Low-power design has been an active research topic for<br />

many years. In IEEE Xplore, searching “low” and “power”<br />

in the document title produces more than 5,000 results.<br />

There are four basic approaches to saving energy and extending<br />

battery lifetime in mobile devices:<br />

Adopt a new generation of semiconductor technology.<br />

As transistors become smaller, each transistor<br />

consumes less power. Unfortunately, as transistors<br />

become smaller, more transistors are needed to provide<br />

more functionalities and better performance; as<br />

a result, power consumption actually increases.<br />

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COVER FEATURE<br />

Communication D<br />

COMPUTER<br />

Never<br />

offioad<br />

Computation C<br />

Depends<br />

on<br />

bandwidth<br />

B<br />

Always<br />

offioad<br />

Figure 1. Očoading is benećcial when large amounts of<br />

computation C are needed with relatively small amounts of<br />

communication D.<br />

Avoid wasting energy. Whole systems or individual<br />

components may enter standby or sleep modes to<br />

save power.<br />

Execute programs slowly. When a processor’s clock<br />

speed doubles, the power consumption nearly octuples.<br />

If the clock speed is reduced by half, the<br />

execution time doubles, but only one quarter of the<br />

energy is consumed.<br />

Eliminate computation all together. The mobile system<br />

does not perform the computation; instead, computation<br />

is performed somewhere else, thereby extending<br />

the mobile system’s battery lifetime.<br />

We focus on the last approach for energy conservation.<br />

Ofioading computation to save energy<br />

Sending computation to another machine is not a new<br />

idea. The currently popular client-server <strong>computing</strong> model<br />

enables mobile users to launch Web browsers, search<br />

the Internet, and shop online. What distinguishes cloud<br />

<strong>computing</strong> from the existing model is the adoption of virtualization.<br />

Instead of service providers managing programs<br />

running on servers, virtualization allows cloud vendors<br />

to run arbitrary applications from different customers on<br />

virtual machines.<br />

Cloud vendors thus provide <strong>computing</strong> cycles, and users<br />

can use these cycles to reduce the amounts of computation<br />

on mobile systems and save energy. Thus, cloud <strong>computing</strong><br />

can save energy for mobile users through computation<br />

offloading. 5 Virtualization, a fundamental feature in cloud<br />

<strong>computing</strong>, lets applications from different customers run<br />

on different virtual machines, thereby providing separation<br />

and protection.<br />

Energy analysis for computation ofioading<br />

Various cost/benefit studies focus on whether to offload<br />

computation to a server. 6,7 The following example provides<br />

a simple analysis for this decision.<br />

Suppose the computation requires C instructions. Let<br />

S and M be the speeds, in instructions per second, of the<br />

cloud server and the mobile system, respectively. The same<br />

task thus takes C/S seconds on the server and C/M seconds<br />

on the mobile system. If the server and mobile system exchange<br />

D bytes of data and B is the network bandwidth, it<br />

takes D/B seconds to transmit and receive data. The mobile<br />

system consumes, in watts, P c for <strong>computing</strong>, P i while<br />

being idle, and P tr for sending and receiving data. (Transmission<br />

power is generally higher than reception power,<br />

but for the purpose of this analysis, they are identical.)<br />

If the mobile system performs the computation, the<br />

energy consumption is P c × (C/M). If the server performs<br />

the computation, the energy consumption is [P i × (C/S)] +<br />

[P tr × (D/B)]. The amount of energy saved is<br />

P c × C<br />

M − P i<br />

× C<br />

S − P tr<br />

D<br />

× . (1)<br />

B<br />

Suppose the server is F times faster—that is, S = F × M.<br />

We can rewrite the formula as<br />

C<br />

M × Pc − P ⎛ ⎞ i<br />

⎝<br />

⎜ F ⎠<br />

⎟ − P D<br />

× . (2)<br />

tr B<br />

Energy is saved when this formula produces a positive<br />

number. The formula is positive if D/B is sufficiently small<br />

compared with C/M and F is sufficiently large. The values<br />

of M, P , P , and P are parameters specific to the mobile<br />

i c th<br />

system. For example, an HP iPAQ PDA with a 400-MHz<br />

(M = 400) Intel XScale processor has the following values:<br />

P fi 0.9 W, P fi 0.3 W, and P fi 1.3 W.<br />

c i tr<br />

If we use a four-core server, with a clock speed of 3.2<br />

GHz, the server speedup F may be given by (S/M) fi [(3.2<br />

× 1,024 × 4 × X)/400], where X is the speedup due to<br />

additional memory, more aggressive pipelining, and so<br />

forth. If we assume X = 5, we obtain the value of F fi 160.<br />

The value of F can increase even more with cloud <strong>computing</strong><br />

if the application is parallelizable, since we can<br />

offload computation to multiple servers. If we assume that<br />

F = 160, Equation 2 becomes<br />

C<br />

400<br />

⎛ 0.3 ⎞<br />

× 0.9 −<br />

⎝<br />

⎜<br />

160⎠<br />

⎟ − 1.3 × D<br />

B<br />

D<br />

≈ 0.00225 × C − 1.3 × . (3)<br />

B<br />

For offloading to break even, we equate Equation 3 to<br />

zero and obtain<br />

B ≈ 577.77 × o D<br />

, (4)<br />

C<br />

where B o is the minimum bandwidth required for offloading<br />

to save energy, determined by the ratio of (D/C). If (D/C)<br />

is low, then offloading can save energy. Thus, as Figure<br />

1 shows, offloading is beneficial when large amounts of<br />

computation C are needed with relatively small amounts<br />

of communication D.<br />

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Sample applications bene ting from ofioading<br />

Two sample applications illustrate the benefits of<br />

offloading: a chess game and image retrieval.<br />

Chess is one of the world’s most popular games. A<br />

chessboard has 8 × 8 = 64 positions. Each player controls<br />

16 pieces at the beginning of the game. Chess is<br />

Markovian, meaning that the game is fully expressed by<br />

the current state. Each piece may be in one of the 64 possible<br />

locations and needs 6 bits to represent the location.<br />

(This is an overestimate: Some pieces have restrictions—<br />

for example, a bishop can move to only half of the board,<br />

that is, 32 possible locations). To represent a chess game’s<br />

current state, it is sufficient to state that 6 bits × 32 pieces<br />

= 192 bits = 24 bytes; this is smaller than the size of a<br />

typical wireless packet.<br />

The amount of computation for chess is very large; Claude<br />

Shannon and Victor Allis estimated the complexity of chess<br />

to exceed the number of atoms in the universe. Chess can be<br />

parallelized, 8 making the value of F in Equation 2 very large.<br />

Since the amount of computation C is extremely large, and D<br />

is very small, chess provides an example where offloading is<br />

beneficial for most wireless networks.<br />

An image retrieval application retrieves images similar<br />

in content to a query from an image collection. The<br />

program accomplishes this by comparing numerical representations<br />

of the images, called features. The features<br />

for the image collection can be computed in advance;<br />

for a query, the program computes its features during<br />

retrieval and compares these with the image collection.<br />

Since most of the computation is done in advance, less<br />

computation is performed online, and the value of C is<br />

small. D is large since considerable data must be sent. As<br />

a result, even if the values of F become fl, D/B might still<br />

be too large when compared to C/M in Equation 2. Thus,<br />

offloading saves energy only if B is very large—that is,<br />

at high bandwidths.<br />

The “Mobile Image Processing” sidebar has more detail<br />

on the advantages of mobile devices offloading image retrieval<br />

to the cloud.<br />

Making computation ofioading more attractive<br />

Analysis indicates that the energy saved by computation<br />

offloading depends on the wireless bandwidth B, the<br />

amount of computation to be performed C, and the amount<br />

of data to be transmitted D. Existing studies thus focus on<br />

determining whether to offload computation by predicting<br />

the relationships among these three factors.<br />

However, there is a fundamental assumption underlying<br />

this analysis with the client-server model: Because the<br />

server does not already contain the data, all the data must<br />

be sent to the service provider. The client must offload the<br />

program and data to the server. For example, typically a<br />

newly discovered server for computation offloading does<br />

not already contain a mobile user’s personal image collec-<br />

MOBILE IMAGE PROCESSING<br />

Mobile devices such as cell phones and PDAs are becoming<br />

increasingly popular. Most of these devices are equipped<br />

with cameras and have several gigabytes of ash storage<br />

capable of storing thousands of images. With such large image<br />

collections, two functionalities become important: accessing<br />

specićc sets of images from the collection, and transmitting the<br />

images over a wireless network to other devices and servers for<br />

storage.<br />

For accessing a specićc set of images, content-based image<br />

retrieval (CBIR) can be a better alternative than manually browsing<br />

through all of them. For example, a user might want to view<br />

all images containing a specićc person or captured at a specićc<br />

location. Mobile image retrieval allows the user to obtain the<br />

relevant pictures by comparing images and eliminating the<br />

irrelevant matches on the mobile system.<br />

Several studies propose performing CBIR on mobile<br />

devices. 1-4 Because these mobile devices are battery powered,<br />

energy conservation is important. 2-4 It is energy e cient to par -<br />

tition CBIR between the mobile device and server depending on<br />

the wireless bandwidth. 3 As the bandwidth increases, očoad -<br />

ing image retrieval saves more energy.<br />

Most of the energy consumption for očoaded applications<br />

is due to transmission. For image retrieval, transmitting the<br />

images over a wireless network consumes signićcant amounts<br />

of energy. The images may be preprocessed on the mobile<br />

device before transmission5 to reduce the transmission energy.<br />

This reduction in transmission energy is achieved by reducing<br />

the ćle sizes. However, the amount of energy saved depends on<br />

the wireless bandwidth and the image contents.<br />

Preprocessing the images saves energy if the reduction in<br />

transmission energy compensates for the energy spent due to<br />

preprocessing. If the wireless bandwidth is high, the value of the<br />

former reduces. Moreover, di erent images may have di erent<br />

values of the latter based on their contents. Hence preprocessing<br />

must be adaptive based on the wireless bandwidth and the<br />

image contents. Wireless transmission energy is the most signić -<br />

cant bottleneck to energy savings in mobile cloud <strong>computing</strong>,<br />

and such techniques will become increasingly signićcant as it<br />

becomes more popular.<br />

References<br />

1. J. Yang et al., “A Fast Image Retrieval System Using Index<br />

Lookup Table on Mobile Device,” Proc. 19th Int’l Conf. Pattern<br />

Recognition (ICPR 08), IEEE Press, 2008, pp. 265-271.<br />

2. C. Zhu et al., “iScope: Personalized Multimodality Image<br />

Search for Mobile Devices,” Proc. 7th Int’l Conf. Mobile Systems,<br />

Applications, and Services (Mobisys 09), ACM Press,<br />

2009, pp. 277-290.<br />

3. Y-J. Hong, K. Kumar, and Y-H. Lu, “Energy-Efficient Content-<br />

Based Image Retrieval for Mobile Systems,” Proc. IEEE Int’l<br />

Symp. Circuits and Systems (ISCAS 09), IEEE Press, 2009, pp.<br />

1673-1676.<br />

4. D. Chen et al., “Tree Histogram Coding for Mobile Image<br />

Matching,” Proc. 2009 Data Compression Conf., IEEE CS Press,<br />

2009, pp. 143-152.<br />

5. Y. Nimmagadda, K. Kumar, and Y-H. Lu, “Energy-Efficient<br />

Image Compression in Mobile Devices for Wireless Transmission,”<br />

Proc. IEEE Int’l Conf. Multimedia and Expo (ICME 09), IEEE<br />

Press, 2009, pp. 1278-1281.<br />

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COVER FEATURE<br />

(a)<br />

(b)<br />

User<br />

User<br />

tion. However, cloud <strong>computing</strong> changes that assumption:<br />

The cloud stores data and performs computation on it. For<br />

example, services like Google’s Picasa and Amazon S3<br />

can store data, and Amazon EC2 can be used to perform<br />

computation on the data stored using S3.<br />

This results in a significant change in the value of D for<br />

most applications. There is no longer a need to send the<br />

data over the wireless network; it suffices to send a pointer<br />

to the data. Also, the value of F is elastic: Large numbers of<br />

processors can be obtained on the cloud. This increases<br />

the energy savings in Equation 2: A very small D and very<br />

large F imply that energy can always be saved.<br />

CHALLENGES AND POSSIBLE SOLUTIONS<br />

Does this make cloud <strong>computing</strong> the “ultimate” solution<br />

to the energy problem for mobile devices? Not<br />

quite. While cloud <strong>computing</strong> has tremendous potential<br />

to save energy, designers must consider several issues<br />

including privacy and security, reliability, and handling<br />

real-time data.<br />

Privacy and security<br />

In cloud <strong>computing</strong>, Web applications and data replace<br />

traditional stand-alone programs, which are no longer<br />

stored in users’ computers. Shifting all data and <strong>computing</strong><br />

resources to the cloud can have implications for privacy<br />

and security. Because the data is stored and managed in<br />

the cloud, security and privacy settings depend on the IT<br />

management the cloud provides.<br />

A bug or security loophole in the cloud might result in<br />

a breach of privacy. For example, in March 2009, a bug<br />

in Google caused documents to be shared without the<br />

owners’ knowledge, 9 while a July 2009 breach in Twitter<br />

allowed a hacker to obtain confidential documents. 10<br />

Cloud service providers typically work with many thirdparty<br />

vendors, and there is no guarantee as to how these<br />

vendors safeguard data. For example, a phishing attack in<br />

2007 duped a staff member for salesforce.com into reveal-<br />

COMPUTER<br />

Data<br />

Data<br />

E (data) E (data)<br />

Encrypt Internet<br />

E(data)<br />

Encrypt<br />

E (data) E (data)<br />

Internet<br />

Cloud<br />

storage<br />

Data<br />

Decrypt Data<br />

Cloud<br />

storage<br />

Figure 2. Two encryption scenarios for cloud <strong>computing</strong>. (a) Data remain decrypted at the cloud storage site, preventing<br />

unauthorized access through the Internet; the cloud vendor cannot access the data either. (b) Data are decrypted by the cloud<br />

vendor to enable necessary operations on the data.<br />

ing a password; 13 the attacker then used the password to<br />

access confidential data.<br />

Another potential privacy violation is the “tracking”<br />

of individuals through location-based navigation data<br />

offloaded to the cloud. Moreover, data stored at one location<br />

may not be secure at another due to different access<br />

rules. For example, the EU has stricter privacy protection<br />

than the US, where laws such as the Patriot Act give government<br />

agencies and other entities more power to access<br />

personal information. Since the storage locations are typically<br />

unknown to the user, determining what laws apply to<br />

safeguarding data can be difficult. This may raise serious<br />

security concerns for a company that stores its trade secrets<br />

in the cloud, or a user who uploads a patentable idea<br />

from a mobile system to the cloud.<br />

Clearly, some types of data cannot be stored in the<br />

cloud without considering these privacy and security implications.<br />

One possible solution is to encrypt data before<br />

storage. However, encryption alone will not solve the problem.<br />

Figure 2 shows two encryption scenarios. In Figure 2a,<br />

the data remain encrypted at the cloud storage site. This<br />

can prevent unauthorized access even when the storage is<br />

breached in the cloud; the cloud vendor cannot access the<br />

data either. In Figure 2b, the cloud vendor decrypts data to<br />

perform operations on that data. For example, in the case<br />

of a document, the cloud vendor must know which words<br />

are used to check spelling; for a spreadsheet, the cloud<br />

application must know the numbers for calculation. This<br />

is the general case for cloud services.<br />

Another possible privacy and security solution is to<br />

use a technique called steganography, as described in the<br />

“Data Outsourcing and Privacy” sidebar. Steganographic<br />

techniques can be used to transform the data so that operations<br />

can be performed without exposing them.<br />

Performing encryption or steganographic techniques<br />

before sending data to the cloud requires some additional<br />

processing C p on the mobile system and consumes additional<br />

energy. Equation 2 thus can be rewritten as<br />

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DATA OUTSOURCING AND PRIVACY<br />

Data outsourcing refers to sending data outside users’ immediate <strong>computing</strong><br />

environment. This is an increasingly important concern for cloud <strong>computing</strong>. As<br />

government agencies shift to the cloud (for example, www.apps.gov and www.data.<br />

gov), information like healthcare, criminal, and tax records move to the cloud. This<br />

makes security and privacy a critical concern.<br />

Multimedia content like images and videos have signićcant redundancy. This<br />

makes it possible to hide data in multimedia using steganography. 1 Figure A shows<br />

an example of steganography: images (a) and (c) look identical, but image (c) contains<br />

image (b) hidden in it. Applying appropriate transformations to image (c) can<br />

obtain image (b). Steganographic techniques can be used to transform the data<br />

before storage so that operations can still be performed on the data.<br />

(a) (b) (c)<br />

Figure A. An example of steganography: images (a) and (c) look identical,<br />

but image (c) contains image (b) hidden in it. Applying appropriate<br />

transformations to image (c) can obtain image (b).<br />

For text documents and spreadsheets, however, there is little redundancy. This<br />

makes it di cult to transform the data and still perform operations. For example,<br />

it is hard to spell check a text document that has alphabets mapped onto symbols.<br />

If the mapping is one-to-one and onward, alphabet frequency can be easily used<br />

to determine the words. Similarly, if the elements in a spreadsheet are transformed,<br />

performing meaningful mathematical operations on them is di cult.<br />

Performing computation on encrypted or steganographic data still remains an<br />

open research problem.<br />

Developing a hybrid cloud is an interim solution to the data outsourcing problem.<br />

A hybrid cloud is “a cloud <strong>computing</strong> environment in which an organization<br />

provides and manages some resources in-house and has others provided externally”<br />

(searchcloud<strong>computing</strong>.com). _________________<br />

The claim is that this is more feasible<br />

currently because large enterprises already have the substantial investments in<br />

their infrastructure required to provide resources in-house. In addition, many<br />

organizations would prefer to keep sensitive data under their own control to<br />

ensure privacy and security.<br />

Reference<br />

1. F.A.P. Petitcolas, R.J. Anderson, and M.G. Kuhn, “Information Hiding—A Survey,”<br />

Proc. IEEE, Special Issue on Protection of Multimedia Content, vol. 87, no. 7, 1999,<br />

pp. 1062-1078.<br />

C<br />

M × Pc − P ⎛ ⎞ i<br />

⎝<br />

⎜ F ⎠<br />

⎟ − Ptr D<br />

×<br />

B − Pc × C p<br />

, (5)<br />

M<br />

where P c × (C p /M) is the additional energy required to protect privacy and<br />

security. If this value is significant, cloud <strong>computing</strong> might not save energy<br />

for the mobile user. Instead, it may be more energy efficient to perform<br />

operations on the mobile system, since C p = 0 when the device performs<br />

the computation.<br />

Reliability<br />

Another potential concern with mobile<br />

cloud <strong>computing</strong> is reliability. 11 A mobile<br />

user performing computation in the cloud<br />

depends on the wireless network and<br />

cloud service. Dependence on the wireless<br />

network implies that cloud <strong>computing</strong><br />

may not even be possible, let alone energy<br />

efficient, when connectivity is limited.<br />

This is typical in regions like national<br />

parks; a user may thus not be able to organize,<br />

retrieve, or identify any images<br />

captured in the park. Mobile cloud <strong>computing</strong><br />

is also difficult in locations such<br />

as the basement of a building, interior of<br />

a tunnel, or subway. In these cases, where<br />

the value of B in Equation 2 can become<br />

very small or even zero, cloud <strong>computing</strong><br />

does not save energy.<br />

Dependence on the cloud for important<br />

computations could lead to problems<br />

during service outages. Several service<br />

providers such as Google, Amazon, and<br />

T-Mobile have experienced such outages,<br />

as Table 1 shows. These can significantly<br />

reduce the value of F in Equation 2.<br />

Data storage presents another reliability<br />

problem. In October 2009, both<br />

T-Mobile’s and Microsoft’s mobile Sidekick<br />

service crashed, and all customers<br />

lost their data and contacts. One option<br />

in such scenarios involves an independent<br />

backup of data with an alternate service<br />

provider, which might increase the value<br />

of D in Equation 2.<br />

Real-time data<br />

Some applications—including chess,<br />

searching newly captured images for<br />

content-based image retrieval, mobile surveillance,<br />

and context-aware navigation<br />

—have real-time data. In such scenarios,<br />

D in Equation 2 is no longer a pointer to<br />

the data; it refers to the actual data. For<br />

applications like chess, the value of D is<br />

small and hence offloading can still save<br />

energy. When the value of D is large,<br />

offloading may not save energy. In such<br />

cases, performing the computation on the<br />

mobile system may be more energy efficient.<br />

A possible solution is partitioning<br />

computation between the mobile system<br />

and the cloud to reduce energy consumption.<br />

Such a solution may include partially<br />

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COVER FEATURE<br />

processing the real-time data on the mobile system. If the<br />

processed data are smaller in size, sending the processed<br />

data to the server reduces the wireless transmission energy.<br />

Our analysis suggests that cloud <strong>computing</strong> can<br />

potentially save energy for mobile users. However,<br />

not all applications are energy efficient<br />

when migrated to the cloud. Mobile cloud<br />

<strong>computing</strong> services would be significantly<br />

different from cloud services for desktops because they<br />

must offer energy savings. The services should consider<br />

the energy overhead for privacy, security, reliability, and<br />

data communication before offloading.<br />

Acknowledgments<br />

We thank Jibang Liu for the steganography images used in<br />

this article.<br />

References<br />

1. M. Creeger, “CTO Roundtable: Cloud Computing,” ACM<br />

Queue, June 2009, pp. 1-2.<br />

2. Google Tech Talk, “Away with Applications: The Death<br />

of the Desktop,” 4 May 2007; http://video.google.com/<br />

__________________________<br />

videoplay?docid=-6856727143023456694.<br />

3. CNN.com, “Battery Life Concerns Mobile Users,” 23 Sept.<br />

2005; www.cnn.com/2005/TECH/ptech/09/22/phone.<br />

____ study.<br />

4. J. Paczkowski, “Iphone Owners Would Like to Replace<br />

Battery,” All Things Digital, 21 Aug. 2009; http://<br />

digitaldaily.allthingsd.com/20090821/iphone-ownerswould-like-to-replace-battery-att.<br />

COMPUTER<br />

Table 1. Service provider outages. 11,12<br />

Outage date Vendor Service<br />

July 2008 Amazon S3 outage<br />

Feb 2008 Amazon S3 outage<br />

August 2008 Google Gmail service outage<br />

October 2009 T-Mobile/Microsoft Sidekick loses users’ data<br />

build your career<br />

IN COMPUTING<br />

5. K. Yang, S. Ou, and H.H. Chen, “On Effective Offloading<br />

Services for Resource-Constrained Mobile Devices Running<br />

Heavier Mobile Internet Applications,” IEEE Comm.<br />

Magazine, vol. 46, no. 1, 2008, pp. 56-63.<br />

6. C. Wang and Z. Li, “Parametric Analysis for Adaptive Computation<br />

Offloading,” ACM SIGPLAN Notices, vol. 39, no. 6,<br />

2004, pp. 119-130.<br />

7. R. Wolski et al., “Using Bandwidth Data to Make Computation<br />

Offloading Decisions,” Proc. IEEE Int’l Symp. Parallel<br />

and Distributed Processing (IPDPS 08), 2008, pp. 1-8.<br />

8. M. Newborn, “A Parallel Search Chess Program,” Proc. ACM<br />

Ann. Conf. Range of Computing: Mid-80’s Perspective, ACM<br />

Press, 1985, pp. 272-277.<br />

9. J. Kincaid, “Google Privacy Blunder Shares Your Docs<br />

without Permission,” TechCrunch, 7 Mar. 2009; ____ http://<br />

___________________________________<br />

techcrunch.com/2009/03/07/huge-google-privacy-blunder-<br />

_______________________<br />

shares-your-docs-without-permission.<br />

10. R. McMillan, “Hacker: I Broke into Twitter,” PCWorld.<br />

com, 1 May 2009; www.pcworld.com/businesscenter/<br />

______________________________<br />

article/164182/hacker_i_broke_into_twitter.html.<br />

11. M. Armbrust et al., “Above the Clouds: A Berkeley View of<br />

Cloud Computing,” tech. report UCB/EECS-2009-28, EECS<br />

Dept., Univ. of California, Berkeley, 2009.<br />

12. T-Mobile Forums, “A Message from Our Chief Operations<br />

Officer, Jim Alling,” 6 Oct. 2009; http://forums.t-mobile.<br />

com/t5/Previous-Sidekick-Models/A-Message-From-Our-<br />

_____________________________<br />

Chief-Operations-Officer-Jim-Alling/m-p/200661.<br />

13. R. McMillan, “Salesforce.com Warns Customers of Phishing<br />

Scam,” PCWorld, 6 Nov. 2007; http://www.pcworld.<br />

___________________________________<br />

com/businesscenter/article/139353/salesforcecom_warns_<br />

customers_of_phishing_scam.html.<br />

______________________<br />

Karthik Kumar is a PhD candidate in the School of Electrical<br />

and Computer Engineering at Purdue University.<br />

His research interests include energy conservation for<br />

mobile systems and resource allocation for scalable <strong>computing</strong>.<br />

Kumar is a student member of IEEE. Contact him<br />

at kumar25@purdue.edu.<br />

_______________<br />

Yung-Hsiang Lu is an associate professor in the School of<br />

Electrical and Computer Engineering at Purdue University.<br />

His research focuses on energy efficiency of <strong>computing</strong><br />

systems. Lu received a PhD in electrical engineering from<br />

Stanford University. He is a senior member of IEEE. Contact<br />

him at yunglu@purdue.edu.<br />

_____________<br />

www.computer.org/buildyourcareer<br />

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RESEARCH FEATURE<br />

Linking Software<br />

Development<br />

and Business<br />

Strategy through<br />

Measurement<br />

Victor R. Basili, Mikael Lindvall, Myrna Regardie, and Carolyn Seaman,<br />

Fraunhofer Center for Experimental Software Engineering<br />

Jens Heidrich, Jürgen Münch, Dieter Rombach, and Adam Trendowicz,<br />

Fraunhofer Institute for Experimental Software Engineering<br />

The GQM + Strategies approach extends the goal/question/metric<br />

paradigm for measuring the success or failure of goals and strategies,<br />

adding enterprise-wide support for determining action on the basis<br />

of measurement results. An organization can thus integrate its<br />

measurement program across all levels.<br />

Most organizations that develop software try<br />

to retain their competitive edge by reducing<br />

software-related risks. Effective risk management<br />

requires aligning business goals<br />

with development strategies and translating<br />

the results into a quantitative project management<br />

plan. In addition, organizations must also justify cost and<br />

resources for software and system development and other<br />

IT services. Often, such justification demands a concrete<br />

demonstration of how such development will contribute<br />

to the organization’s overall business goals—the top-level<br />

goals the organization desires to accomplish.<br />

Working against both alignment and justification is the<br />

lack of methods for linking business goals and softwarerelated<br />

efforts. Without a deep understanding of how software<br />

development fits into their organization’s business<br />

objectives, decision makers can neither plan development<br />

nor evaluate the organization-wide success of development<br />

strategies.<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

Published by the IEEE Computer Society<br />

To address this need, we have developed GQM + Strategies,<br />

which uses measurement to link goals and strategies on all<br />

organizational levels. The approach is based on rationales for<br />

deciding when and how to transform goals into operations<br />

and how to evaluate the success of strategies with respect<br />

to those goals. The “Why Business Alignment?” sidebar describes<br />

our motivation for developing this approach.<br />

As the name implies, GQM + Strategies is based on the<br />

goal/question/metric (GQM) paradigm 1 but adds the ability<br />

to create measurement programs that ensure alignment<br />

between goals and strategies from the highest strategic<br />

business levels to individual development projects and vice<br />

versa. 2 Although we derived the approach from software<br />

development experiences, it is not necessarily applicable<br />

solely to this domain.<br />

GOAL-ORIENTED APPROACHES<br />

Software development organizations often encounter<br />

problems when instituting measurement programs, such<br />

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RESEARCH FEATURE<br />

as collecting too much data, failing to gather useful or correct<br />

data, and not having a mechanism for analyzing the<br />

data in a way that contributes to sound strategic decisions.<br />

This leads to numerous problems, including decreased<br />

cost-effectiveness of the measurement program and disillusionment<br />

about metrics on the part of developers and<br />

managers. The end result is often the eventual failure of<br />

the measurement program as a whole.<br />

COMPUTER<br />

WHY BUSINESS ALIGNMENT?<br />

With the increasing dependence on software and other<br />

information technology (IT) has come a commensurate<br />

growth in software system size and complexity. This growth in<br />

turn has magnified the cost, schedule, and quality concerns<br />

that have always plagued software development. For decades,<br />

software engineering researchers and practitioners<br />

have attempted to reduce development cost, shorten development<br />

time, and increase quality. Although great strides<br />

have been made in all three areas, software growth along all<br />

dimensions (size, complexity, pervasiveness, criticality, and so<br />

on) has outpaced the ability to control all the developmentrelated<br />

factors.<br />

Ečorts to dećne and understand these relationships have made<br />

one notion crystal clear: Issues related to software cost, schedule,<br />

and quality are inextricably linked with the larger issues that face<br />

the businesses developing the software—regardless of the specićc<br />

business objectives. Some businesses sell what they develop,<br />

either as contracted custom software or as commercial shrinkwrapped<br />

applications. Others sell a product or service, of which<br />

software is a signićcant component. Still others might develop<br />

software only to support their organizational IT infrastructure so<br />

that they can develop and market products more ečectively.<br />

Finally, some have no commercial interest at all, such as nonproćt<br />

organizations, government entities, or educational institutions.<br />

Although all these organizational conćgurations challenge their<br />

development projects in dičerent ways, the point is that all have a<br />

larger business context, which encompasses larger business goals,<br />

strategies, and success measures. All software development<br />

projects must consider context factors—the variables that represent<br />

the organizational environment and ačect the kind of models<br />

and data the project can use.<br />

The problem is not that businesses fail to achieve their objectives,<br />

but rather that they do not always state these objectives<br />

explicitly or clearly enough to verify that they have indeed achieved<br />

those objectives. It is even less clear how a business translates its<br />

objectives into its lower organizational levels and into individual<br />

projects. At present, no methodology bridges the gap between<br />

business strategies and their project-level implementation.<br />

Quantitative data is a prerequisite to understanding the relationships<br />

between the business and project-level goals and<br />

verifying the achievement of objectives—one reason that software<br />

development maturity requires the use of quantitative measures.<br />

However, popular software improvement strategies, such as Capability<br />

Maturity Model Integration and the IT Infrastructure Library,<br />

are not directly and explicitly linked to business value. Consequently,<br />

the investment in collecting data does not result in the<br />

expected benećts, and the contribution of project performance to<br />

the achievement of strategic goals remains unclear.<br />

To address these problems, researchers have developed<br />

goal-oriented approaches—so called because they<br />

use goals, objectives, strategies, or other mechanisms to<br />

guide the choice of data to be collected and systematically<br />

analyzed. The GQM approach, for example, provides a<br />

method for an organization or a project to define goals,<br />

refine those goals into specifications of the data to be collected,<br />

and then analyze and interpret the resulting data in<br />

light of the original goals. Implicit in the GQM approach is<br />

the use of interpretation models, which help practitioners<br />

interpret the resulting data in a specific context. The GQM<br />

approach has served the software industry for several decades<br />

in defining measurement programs, but it does not<br />

explicitly provide support for motivating and integrating<br />

the measurement of goals at various organizational levels,<br />

such as project goals, business objectives, and corporate<br />

strategies. It also does not encourage users to explicitly<br />

document assumptions, estimated unknowns that can<br />

affect data interpretation.<br />

Another goal-oriented approach, Balanced Scorecard<br />

(BSC), 3 links strategic objectives and measures through a<br />

scorecard, which consists of four perspectives: financial,<br />

customer, internal business processes, and learning and<br />

growth. BSC does not dictate a static set of measures, but<br />

rather serves as a framework for strategic measurement<br />

and management. As such, it is a tool for defining strategic<br />

goals from multiple perspectives beyond a purely financial<br />

focus, but it does not address lower-level goal setting.<br />

Practical Software Measurement (PSM) 4 offers detailed<br />

guidance on software measurement, including providing<br />

a catalog of specific measures and information on how an<br />

organization can apply those measures in projects. PSM<br />

also includes a process for choosing measures according<br />

to the issues and objectives relevant to a software development<br />

project. For the most part, however, approaches such<br />

as BSC and PSM do not support the alignment of objectives<br />

at different organizational levels, or this is simply not the<br />

focus of these approaches.<br />

Researchers have also proposed various combinations<br />

of GQM, BSC, and PSM 5-8 that recognize the need to link<br />

higher- and lower-level goals. However, because these<br />

approaches do not support different goals at explicitly<br />

linked organizational levels, it is difficult to feed analytical<br />

results and interpretations back up the chain. In<br />

contrast, GQM + Strategies creates mappings between the<br />

data related to goals at different levels so that insights<br />

gained relative to one goal at one level—whether project<br />

or departmental, or a business objective—can support and<br />

contribute to satisfying goals at other organizational levels<br />

without requiring that each level share the same goals.<br />

Some application domains have specific requirements<br />

that emphasize the need to link business goals to lowerlevel<br />

properties. Organizations are becoming increasingly<br />

aware, for example, that the IT infrastructure itself im-<br />

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Goal + Strategies element GQM graph<br />

inffiuences<br />

Context/<br />

assumption<br />

inffiuences<br />

Figure 1. GQM + Strategies components. The primary components are the Goal + Strategies element and the GQM graph. The<br />

Goal + Strategies element includes a single goal and derived strategies, as well as all context information and assumptions that<br />

explain how goals and strategies link. The GQM graph refiects a single GQM goal, the corresponding questions and metrics, and an<br />

interpretation model.<br />

poses significant risks, which has led to several regulatory<br />

constraints in both the IT governance and IT service domains,<br />

such as the Sarbanes-Oxley Act in the US. 9<br />

The solutions proposed by models in these domains<br />

offer connections between predefined sets of goals and attributes<br />

of the IT infrastructure. They are sharply focused<br />

on a particular domain, such as IT governance, and define<br />

a very detailed model that fits that domain quite well. To<br />

apply such an approach, however, the organization must<br />

strictly follow the prescribed model. Release 4 of the Control<br />

Objectives for Information and Related Technology<br />

(CoBIT) standard (www.isaca.org), for example, is based<br />

on a process model that subdivides IT into four domains<br />

and 34 processes.<br />

Approaches such as CoBIT and the IT Infrastructure<br />

Library (ITIL) provide no mechanism for adapting and tailoring<br />

the solution, nor do they support addressing the<br />

specific context or documenting inherent assumptions.<br />

No clearly defined interpretation model indicates if an<br />

overall strategy is working or has to be changed to avoid<br />

business failure.<br />

COMPONENTS OF AN<br />

INTEGRATED APPROACH<br />

Goal<br />

Strategy<br />

realized<br />

by a<br />

set of<br />

leads to<br />

a set of<br />

> made<br />

measurable<br />

through<br />

< measures<br />

achievement<br />

of<br />

GQM + Strategies aims to address the weaknesses of existing<br />

goal-oriented approaches by providing both explicit<br />

links among organizational levels and the flexibility to<br />

tailor the approach to the organization’s specific needs and<br />

objectives. Eight conceptual components form the basis for<br />

constructing a consistent model. Figure 1 illustrates how<br />

these components interrelate.<br />

GQM goal<br />

Goal + Strategies element GQM graph<br />

made measurable through<br />

Question<br />

Question<br />

Interpretation model<br />

is part of<br />

Metric<br />

Metric<br />

Metric<br />

Business goals: goals the organization wishes to accomplish<br />

in general to achieve its strategic objectives.<br />

Context factors: environmental variables that represent<br />

the organizational environment and affect the<br />

kind of models and data that can be used.<br />

Assumptions: estimated unknowns that can affect the<br />

interpretation of the data.<br />

Strategies: a set of possible approaches for achieving a<br />

goal that may be refined by a set of concrete activities.<br />

Level i goals: a set of lower-level goals inherited from<br />

the previous level’s (i 1) goals as part of the previous<br />

level’s goal strategy—an example is a goal related to<br />

a project that is part of a selected software strategy.<br />

Interpretation models: models that help interpret<br />

data to determine if the goals at all levels have been<br />

achieved.<br />

Goal + Strategies element: a single goal and derived<br />

strategies (including a set of concrete activities), as<br />

well as all context information and assumptions that<br />

explain how the goal and corresponding strategies<br />

are linked.<br />

GQM graph: a single GQM goal that measures a<br />

Goal + Strategies element and its corresponding questions,<br />

metrics, and interpretation models.<br />

All organizations have business goals, such as improving<br />

customer satisfaction, garnering market share, and<br />

reducing production costs, and they devise strategies<br />

to deal with them, taking into account the context and<br />

making explicit any assumptions. Strategies specify how<br />

to achieve the goal and should, in turn, define lower-level<br />

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RESEARCH FEATURE<br />

Figure 2. A GQM + Strategies model for ABC, a company that provides its customers with information services through the Web.<br />

GQM + Strategies enforces the explicit documentation of the relevant context factors and assumptions that are necessary for<br />

understanding and evaluating each goal. A Goal + Strategies element consists of a goal and an associated strategy (bottom of each<br />

goal box). Each element, in turn, is associated with a GQM graph (green rectangle to the right of the goal) representing questions and<br />

metrics as well as an interpretation model that evaluates if the goal was achieved.<br />

goals for various parts of the organization, such as software,<br />

hardware, and marketing. An organization might<br />

devise a separate set of strategies to deal with these lowerlevel<br />

goals. The number of goal and strategy levels depends<br />

on the organization’s internal structure.<br />

Assumptions and context information about the organization<br />

strongly influence the definition of goals and<br />

strategies. Measuring the effectiveness and the accomplishment<br />

of goals and the effectiveness of strategies at<br />

all levels is critical for business success. And making goals<br />

connected and transparent at all levels helps in communicating<br />

and achieving them. What most organizations need<br />

is support for these concepts.<br />

The components in Figure 1 provide this support by allowing<br />

multiple goal levels and multiple strategies for each<br />

goal (a GQM + Strategies element), as well as a measurement<br />

plan (GQM graph). The GQM + Strategies element provides<br />

the basic components for deriving the goals and strategies<br />

as influenced by the context; the basic known facts about<br />

the market, the organization, the product, and so on; and<br />

the assumptions—factors that are assumed or guessed<br />

but not known for sure. A key element is making the context<br />

and assumptions explicit so that they can be verified.<br />

The relevant context and assumptions aid in defining the<br />

rationale for choosing specific goals and strategies. A set<br />

COMPUTER<br />

Business level<br />

Software level<br />

Project level<br />

GQM + Strategies elements<br />

Goal 1: Increase profit<br />

from software service usage<br />

Strategy 1: Deliver<br />

added functionality<br />

Goal 2: Deliver 5% new<br />

functionality every 6 months<br />

within 10% of budget<br />

Strategy 2: Use MoSCoW<br />

and Cocomo<br />

Goal 3: Apply MoSCoW<br />

and Cocomo effectively<br />

Strategy 3: Conduct<br />

training, determine tools,<br />

perform pilot study<br />

GQM goals<br />

G1: Evaluate<br />

trend in profit<br />

G2: Evaluate<br />

functional<br />

growth of each<br />

release<br />

G3: Evaluate<br />

effectiveness<br />

of MoSCow<br />

and Cocomo<br />

Questions Metrics Interpretation model<br />

Q1: What is<br />

the current<br />

profit?<br />

Q2: What is<br />

the profit for<br />

year 2 and<br />

year 3?<br />

Q3: How<br />

many M<br />

requirements<br />

in each release?<br />

Q4: How<br />

long between<br />

releases?<br />

Q5: Cost<br />

estimation<br />

accuracy? BV: budget<br />

variance<br />

Q6: How<br />

extensive<br />

was the<br />

training?<br />

Q7: What is<br />

cost of<br />

training?<br />

P0: current<br />

annual<br />

profit<br />

PX: annual<br />

profit for<br />

year x<br />

MR: number<br />

of customerrequested<br />

requirements<br />

(M)<br />

implemented<br />

RD: release<br />

duration<br />

NT: number<br />

of trainees<br />

TC: hours<br />

spent in<br />

training<br />

If P2 0<br />

and<br />

P3 2<br />

and …<br />

then goal is<br />

satisfied<br />

of predefined goals and strategies can become part of an<br />

organization-specific experience base and allow different<br />

parts of the organization to select and adapt predefined<br />

goals and strategies.<br />

Associated with each GQM + Strategies element is a<br />

measurement plan that uses the GQM approach measurement<br />

and evaluation framework to specify how to<br />

evaluate the goal, what data to collect, and how to interpret<br />

that data. The nodes of each GQM graph consist of<br />

a measurement goal, which describes what knowledge<br />

needs to be gained from the measurement activity; a set<br />

of questions to be answered; the metrics and data items<br />

required to answer the questions; and an interpretation<br />

model that specifies how the data items are to be<br />

combined and what the criteria are for determining the<br />

goal’s success.<br />

The nodes are related semihierarchically. A goal can<br />

have several associated measurement goals, each of<br />

which is the basis for an entire GQM graph. However, different<br />

GQM structures are likely to use some of the same<br />

questions and metrics, and interpretation models might<br />

combine data from different GQM structures, thus optimizing<br />

metrics collection. The results of the lower-level<br />

interpretation models feed into the higher-level ones to<br />

provide feedback on lower-level goal achievement.<br />

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With the complete model, an organization can<br />

not only define measurement consistent with<br />

larger, upper-level organizational concerns, but<br />

also interpret and roll up the resulting measurement<br />

data at each level.<br />

AN APPLICATION<br />

To illustrate the features of our approach, we<br />

consider a fictitious but representative type of<br />

organization, ABC, which provides information<br />

services to its customers through the Web. Customers<br />

do not buy the software, but rather pay a<br />

service fee for access to information and to software<br />

that searches, analyzes, and presents that<br />

information. Thus, the business model implies that<br />

the number of customer accesses to ABC’s system<br />

determines the company’s revenue. Figure 2 represents<br />

a model of this application.<br />

Business goals<br />

Although the approach is flexible enough to accommodate<br />

several different entry points, the starting point of the<br />

GQM + Strategies process in this example is a business goal.<br />

As Goal 1 shows, one of ABC’s business goals is to increase<br />

profit from software service use. The GQM + Strategies approach<br />

enforces the explicit documentation of the relevant<br />

context factors and assumptions necessary for understanding<br />

and evaluating each goal. For Goal 1, one such<br />

context factor is that how often customers access ABC<br />

software products determines the amount of revenue generated<br />

at ABC.<br />

The GQM + Strategies goal template documents other<br />

details. Each template includes the desired magnitude of<br />

improvement, the time frame for achieving the goal, the<br />

scope of responsibility for achieving the goal, and any<br />

constraints or conflicting goals as well as relationships to<br />

other goals. Figure 3 shows a partial template for Goal 1.<br />

The GQM graph in Figure 2 is based on the measurement<br />

goal, G1. In full GQM notation, G1 is<br />

Analyze the trend in profit for the purpose of evaluation<br />

with respect to a 10 percent increase in annual income per<br />

year from the point of view of ABC’s management in the<br />

context of the ABC organization.<br />

This goal leads to questions Q1 and Q2: What is the current<br />

profit (measured by P 0 ), and what is the profit for each<br />

succeeding year (as measured by P x )? The decision maker<br />

analyzes the results using the criteria incorporated in the<br />

interpretation model (far right), which says that<br />

Starting in year 2, if the profit for the current year (P ) is 2<br />

at least 10 percent (1.1 times) higher than the profit for the<br />

initial preceding year (P ), then the goal has been satisfied.<br />

1<br />

Activity: Increase<br />

Focus: Net income<br />

Object: ABC Web services<br />

Magnitude: 10% per year<br />

Time frame: Annually, beginning in 2 years<br />

Scope: Development groups assessed at CMMI level 2 or higher<br />

Constraints: Available resources, ability to sustain CMMI levels<br />

Relations: CMMI-related goals<br />

Figure 3. Business goal “Increase pro t from software service usage”<br />

expressed in the GQM + Strategies goal template. Business goals are at the<br />

top level of the GQM + Strategies model. They become measurable through<br />

the derivation of one or more GQM graphs, which are then associated<br />

with other GQM graphs at other organizational levels.<br />

The full interpretation model, not shown for simplicity,<br />

includes an “else” part related to the effectiveness of the<br />

chosen strategies.<br />

The strategies associated with each goal come from a<br />

list of potential strategies that the GQM + Strategies user<br />

has enumerated, taking into account influencing context<br />

factors. Possible strategies for meeting Goal 1 are to deliver<br />

added capabilities to encourage heavier system use,<br />

increase rates charged to customers, or reduce development<br />

costs. The user opted for the strategy of delivering<br />

added functionality in the product releases at regular and<br />

frequent intervals. At this point, the user must also make<br />

explicit the assumption that this added functionality will<br />

lead to increased customer satisfaction, which will in turn<br />

lead to heavier use.<br />

The assumption is that ABC has enough projects with<br />

a Capability Maturity Model Integration maturity level<br />

greater than 1 that, if just those projects provide a 15 percent<br />

improvement, ABC will see a 10 percent improvement<br />

overall. In general, all context information and assumptions<br />

are attached to goals, strategies, and their relations<br />

(as Figure 1 shows) and are documented in a corresponding<br />

graph (not shown).<br />

Software-development goals<br />

At the next level down in the model is a goal derived<br />

from the strategy (or strategies) chosen at the top level.<br />

Goal 2 is to deliver a new release of the software every six<br />

months that incorporates at least 5 percent more functionality<br />

than the previous release and to keep the cost<br />

of this increased functionality to within 10 percent of the<br />

current budget.<br />

These are really two interrelated but separate software<br />

goals, so the user defines them in separate GQM + Strategies<br />

goal templates. Figure 4 elaborates the first of these goals<br />

(increasing functionality by 5 percent). At this level, the<br />

goal is specific to software development, so it is treated as<br />

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RESEARCH FEATURE<br />

Activity: Deliver<br />

Focus: More usable functionality, for example, M (must) type requirements<br />

from the backlog of customer-requested requirements<br />

Object: Each release of ABC Web services software<br />

Magnitude: 5% more functionality than the prior release<br />

Time frame: Every 6 months, beginning in 2 years<br />

Scope: Web services development projects with CMMI level 2 or higher<br />

Constraints: Available resources, ability to sustain CMMI levels, ability to estimate<br />

cost, and schedule for a release<br />

Relations: Achievement of cost and schedule estimate accuracy, ability to improve<br />

CMMI levels of development groups<br />

Figure 4. Software goal template for the goal “Deliver 5 percent new<br />

functionality every six months.” A separate but related software goal,<br />

which would have its own template, would address the 10 percent cost<br />

variance. Both these goals are derived from a higher-level strategy that<br />

addresses the business goal of increasing revenue from increased use of<br />

ABC’s software products.<br />

for x = 2, 3, …<br />

if Px ≥ 1.1 * Px–1 then<br />

the goal has been satisfied,<br />

else if functionality was increased appropriately, then<br />

either some assumption is incorrect or we have chosen the wrong level of strategy.<br />

Figure 5. Re ning the interpretation model from Figure 2 by adding<br />

an “else” part. Full interpretation—the exact reason that a particular<br />

goal was not satis ed—depends on goals at lower levels. This iterative<br />

re nement ensures that goals at all levels are linked and makes goal<br />

interrelationships explicit.<br />

a goal at the software level, as opposed to one at the business<br />

level. In general, the name accorded the lower levels<br />

depends on the organization applying GQM + Strategies and<br />

the number of levels to be modeled.<br />

The software goal template asks for the same categories<br />

of information as the business goal template in Figure<br />

3. The user defines the measurement and interpretation<br />

model for this goal and refines the interpretation model<br />

for the business goal. As Figure 5 shows, the refinement of<br />

Figure 2’s interpretation model involves adding an “else”<br />

part that recognizes that full interpretation depends on the<br />

lower-level goals. For example, if the functionality was not<br />

increased by 5 percent, perhaps the strategy associated<br />

with Goal 2 was not effective. The interpretation model becomes<br />

increasingly detailed, with more conditional logic,<br />

at each lower level in the overall GQM + Strategies model.<br />

The organization must decide to develop and carry out a<br />

strategy for accomplishing a software goal. The strategy for<br />

Goal 2 in Figure 2 is to adopt an approach such as rating the<br />

importance of different requirements, as in the MoSCoW<br />

prioritization approach 10 for requirements and release planning,<br />

and to adopt the Constructive Cost Model (Cocomo) 11<br />

for cost estimation. The user must explicitly document an<br />

COMPUTER<br />

important context factor relevant to this strategy:<br />

Someone with expertise in the MoSCoW approach<br />

(a consultant who recommends it) is available, but<br />

ABC has no staff with such experience.<br />

Three assumptions relevant to this strategy,<br />

which the user must also document, follow:<br />

The organization can estimate the percentage<br />

of functionality delivered, for example, by<br />

using a proxy such as additional lines of code<br />

delivered, number of function points delivered,<br />

or a formula based on an actual requirements<br />

count.<br />

The difficulty and importance of requirements<br />

are weighted in some way (hard, medium,<br />

easy) to provide input to the cost model.<br />

The backlog of customer-requested requirements<br />

continues to grow.<br />

As with the business goal, the software goal<br />

has an associated set of GQM structures that<br />

define how to evaluate the goal (G2 in Figure 2).<br />

In full GQM notation, G2 is<br />

Analyze each six-month release for the purpose<br />

of evaluation with respect to incorporation<br />

of 5 percent new functionality as compared to the<br />

previous release from the point of view of the Web<br />

services project manager in the context of the ABC<br />

organization.<br />

This goal leads to questions Q3 and Q4: How many new<br />

requirements of must (M) importance were included in<br />

each release? How much time elapsed between releases?<br />

The interpretation of this software goal’s achievement is<br />

If, at each six-month milestone, the growth in functionality<br />

of a release is 5 percent, then the level 2 goal is<br />

satisfied for this release; else, assumptions about MoSCoW<br />

are incorrect or we have not chosen the correct strategy.<br />

At this point, the user can also further refine the business<br />

goal’s interpretation. If the business goal is satisfied<br />

(ABC’s profit increased by 10 percent), but Goal 2 is not,<br />

then the assumptions are wrong. The delivery of a particular<br />

requirement alone might have caused the gain, for<br />

example.<br />

Project-specific goals<br />

The last goal level in Figure 2 consists of goals derived<br />

from the previous level’s strategy that apply to a particular<br />

software development group or project. In the sample<br />

application, Goal 3 is to apply the MoSCoW and Cocomo<br />

approaches effectively. The relevant development group<br />

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has developed a strategy for this goal that involves training<br />

personnel, acquiring tools that will assist in applying these<br />

methods, and piloting these methods on a single project. A<br />

relevant assumption is that training for these approaches<br />

can be targeted to a few specific individuals, so the impact<br />

of the training on cost and schedule is reasonable.<br />

The GQM graph at this level, only part of which is shown<br />

in Figure 2, involves evaluating the effectiveness of using<br />

MoSCoW and Cocomo and of the training and other tools.<br />

The GQM + Strategies user then uses these results to revisit<br />

the interpretation of higher-level goals. Some of the questions<br />

and metrics defined at the second level are reusable<br />

at subsequent levels—a benefit of basing GQM + Strategies<br />

on the GQM approach.<br />

SUPPORTING STRATEGIC MEASUREMENT<br />

In all cases, specifying a strategy for goal achievement<br />

creates explicit links among goals at the various levels, from<br />

business objectives to project operations, which is critical<br />

to strategic measurement. In the example, the highest-level<br />

goal was to increase profit, the next-level goal was to provide<br />

new functionality in short releases, and the lowest-level<br />

goal was to use specific application methods to achieve the<br />

previous level goals. The linking strategy specified that ABC<br />

will achieve its increased profit goal by providing customers<br />

with more functionality. Often such links are implicit, but<br />

making them explicit has many benefits.<br />

Templates<br />

Templates also support strategic measurement by guiding<br />

users in defining all goal types at the necessary detail<br />

level. In the example, the full template for the business<br />

goal partially described in Figure 3 includes more extensive<br />

information about the target increase in income,<br />

the time frame, and any constraints or conflicting goals.<br />

GQM + Strategies includes templates for all goal types in the<br />

measurement model.<br />

Tracking assumptions<br />

Although the ABC example did not show it, our approach<br />

also builds in the ability to track context factors<br />

and assumptions at each level (through the requirement<br />

to document them along with all strategy documentation)<br />

so that users can more easily assess the effects of<br />

changes in either context or assumptions. In the example,<br />

the approach required that users document the assumption<br />

about the training required for MoSCoW and Cocomo<br />

so that, if the assumption turns out to be false, the model<br />

will indicate what elements the assumption affects and,<br />

consequently, what requires reevaluating.<br />

Interpretation models<br />

Interpretation models tie together measurement goals,<br />

context factors, assumptions, and data, thus making it<br />

easier to correctly and usefully interpret measurement<br />

results. This idea stems from the original GQM approach,<br />

but we have broadened it to allow interpretation models<br />

at each level to inform not only that level, but also higher<br />

levels as the data is aggregated and rolled up. In the ABC<br />

example, the results of applying the interpretation model<br />

at the lowest level will yield information about how the<br />

piloting of MoSCoW and Cocomo went, as well as information<br />

about the training and tools. The information from the<br />

lower level can help diagnose any problems encountered at<br />

the next level up. Further, the results of the interpretation<br />

at the second level can inform the analysis at the top level.<br />

At the top level, if profit does not increase as expected, the<br />

analytical results from the second level will help determine<br />

if the problem is due to higher costs, inadequate functionality<br />

delivered, late releases, or some other cause.<br />

Our approach explicitly links goals<br />

at different levels, from business<br />

objectives to project operations,<br />

which is critical to strategic<br />

measurement.<br />

Flexibility<br />

Our approach is flexible enough to accommodate other<br />

software measurement approaches and business strategy<br />

approaches. ABC might have used BSC to define its business<br />

goals and strategies and then used that description as<br />

a starting point for applying GQM + Strategies. PSM might<br />

have been useful later in applying our approach, when ABC<br />

needed to define the metrics.<br />

Shared measurement planning and experience<br />

Because all goal levels are linked, measurement planning<br />

and results are organization-wide rather than limited<br />

to a single project or department. Often the results are<br />

lower costs and better return on the investment in a measurement<br />

program, greater likelihood that the program<br />

will succeed, more effective risk identification and management,<br />

and greater compliance with software process<br />

improvement models such as CMMI.<br />

A substantial benefit is that sharing makes it more<br />

feasible to build a measurement experience base that<br />

can become a valuable corporate asset. Such a base can<br />

make project measurement and planning easier over time<br />

and consequently decrease project costs. It might begin<br />

with the set of generic experiences already available in<br />

GQM + Strategies and add value as the organization populates<br />

it with organization-specific models.<br />

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RESEARCH FEATURE<br />

Any part of the ABC model in Figure 2 is reusable. The<br />

assumptions and context factors are particularly important<br />

because they capture the properties that might not<br />

hold when the organization reuses the model for a different<br />

situation. However, because the model requires the explicit<br />

capture of assumptions and context factors and links these<br />

to particular goals and strategies, the organization can<br />

clearly see which parts of the model need to be reevaluated<br />

when an assumption or context factor changes. The<br />

result is the flexibility to adapt goals and strategies to particular<br />

market needs and to analyze the consequences to<br />

the organization.<br />

APPLICATION SCENARIOS<br />

We have already taken steps to apply the GQM + Strategies<br />

approach in various industrial settings. Although our approach<br />

focuses on software development, it is finding<br />

equal utility in broader contexts, as the applications in<br />

Table 1 illustrate.<br />

A few studies are ongoing to get more insights into<br />

the deployment of GQM + Strategies. So far, most of the<br />

studies have reached the phase of initially setting up a<br />

GQM + Strategies grid, but they have not yet progressed to<br />

the point of using and maintaining it.<br />

The GQM + Strategies approach provides many<br />

features for organizations that want to create a<br />

software measurement program that is consistent<br />

with and contributes to the achievement of<br />

goals at all organizational levels. Our sample<br />

application illustrates the use of GQM + Strategies in a<br />

single context with three goal levels. Other situations<br />

might call for additional levels, but generally the process<br />

of capturing multilevel goals includes a business goal<br />

level, a set of lower-level goals, and a project-specific goal<br />

level. Each of these levels, in turn, can have multiple peer<br />

goals. Regardless of how many levels the organization<br />

COMPUTER<br />

Table 1. Ongoing applications of the GQM + Strategies approach.<br />

Business Domain Application<br />

European telecommunications<br />

company<br />

Telecommunications Drive strategic improvement programs, support paradigm<br />

shift toward purpose-driven metrics<br />

European automotive supplier Automotive Support CMMI’s Measurement and Analysis process area<br />

European network testing<br />

company<br />

International software<br />

company<br />

Telecommunications Evaluate cost, benefit, and schedule for modernizing<br />

existing product suite<br />

Embedded systems used in<br />

telecommunications<br />

Increase the visibility at all organizational levels of how<br />

strategic decisions impact operations<br />

Asian insurance company Information systems Align strategies and goals for new business domain<br />

Asian systems engineering<br />

organization<br />

Joint research project to<br />

develop a common software<br />

platform<br />

Safety-critical software for aerospace<br />

application<br />

Support of complex, dynamic business processes<br />

in a variety of domains, including logistics,<br />

retail, and customized industrial facilities<br />

Increase visibility of goals and strategies and derived<br />

measurement goals to enhance supplier collaboration<br />

Align project objectives and business objectives of involved<br />

research and industry partners<br />

requires, all levels must be based on well-defined goals,<br />

each with an associated strategy, documented context<br />

factors and assumptions, and a measurement and evaluation<br />

framework.<br />

The most important benefit of applying GQM + Strategies<br />

is the resulting transparency of measurement motivations<br />

and goals at different organizational levels, which makes<br />

it easier to identify goal relationships and conflicts and<br />

facilitates communication for organizational segments,<br />

such as marketing and software development. In the ABC<br />

example, without the GQM + Strategies model, project personnel<br />

might have misdirected their training efforts or<br />

chosen the wrong tools. The model helped project personnel<br />

understand why they were being asked to implement<br />

MoSCoW and Cocomo, which was likely to produce more<br />

focused training or tailoring. This is one of the many benefits<br />

of using our approach in a short development cycle.<br />

Acknowledgments<br />

GQM + Strategies is registered trademark No.<br />

302008021763 at the German Patent and Trade Mark<br />

Office; international registration number IR992843.<br />

References<br />

1. V. Basili, G. Caldiera, and D. Rombach, “Goal, Question,<br />

Metric Paradigm,” Encyclopedia of Software Engineering,<br />

vol. 1, J.J. Marciniak, ed., John Wiley & Sons, 1994, pp.<br />

528-532.<br />

2. V. Basili et al., “Bridging the Gap between Business Strategy<br />

and Software Development,” Proc. Int’l Conf. Information<br />

Systems, Association for Information Systems Electronic<br />

Library; http://aisel.aisnet.org/icis2007/25.<br />

3. R. Kaplan and D. Norton, “The Balanced Scorecard—Measures<br />

That Drive Performance,” Harvard Business Rev.,<br />

Jan.-Feb. 1992, p. 71.<br />

4. US Dept. of Defense and US Army, Practical Software and<br />

Systems Measurement: A Foundation for Objective Project<br />

Management, v. 4.0c, Mar. 2003; www.psmsc.com.<br />

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5. S.A. Becker and M.L. Bostelman, “Aligning Strategic and<br />

Project Measurement Systems,” IEEE Software, May/June<br />

1999, pp. 46-51.<br />

6. L. Buglione and A. Abran, “Balanced Scorecards and GQM:<br />

What Are the Differences?” Proc. 3rd European Software<br />

Measurement Conf., Federation of European Software Measurement<br />

Assoc., 2000, pp. 18-20.<br />

7. A.J. Bianchi, “Management Indicators Model to Evaluate<br />

Performance of IT Organizations,” Proc. Int’l Conf. Management<br />

of Engineering and Technology, vol. 2, IEEE Press,<br />

2001, pp. 217-229.<br />

8. D. Card, “Integrating Practical Software Measurement and<br />

the Balanced Scorecard,” Proc. 27th Ann. Int’l Computer<br />

Software and Applications Conf., IEEE CS Press, 2003, p.<br />

362.<br />

9. Sarbanes-Oxley Act of 2002, Public Law No. 107-204, 116<br />

Stat. 745, codified in sections of 11, 15, 18, 28, and 29 in<br />

US Code, 30 July 2002.<br />

10. D. Clegg and R. Barker, Case Method Fast-Track: A RAD<br />

Approach, Addison-Wesley Professional, 1994.<br />

11. B.W. Boehm et al., Software Cost Estimation with COCOMO<br />

II, Prentice Hall, 2000.<br />

Victor R. Basili is a professor in the Department of Computer<br />

Science at the University of Maryland and chief<br />

scientist of the Fraunhofer Center for Experimental<br />

Software Engineering. His research interests include measuring,<br />

evaluating, and improving the software process<br />

and product via empirical studies. Basili received a PhD in<br />

computer science from the University of Texas. Contact him<br />

at basili@fc-md.umd.edu.<br />

_______________<br />

Mikael Lindvall is a senior scientist and division director<br />

at the Fraunhofer Center for Experimental Software<br />

Engineering. His research interests include agile methods,<br />

software process improvement, software architectures, and<br />

experience and knowledge management. Lindvall received<br />

a PhD in computer science from Linköping University,<br />

Sweden. Contact him at mikli@fc-md.umd.edu.<br />

Myrna Regardie is a senior engineer at the Fraunhofer<br />

Center for Experimental Software Engineering. Her research<br />

interests include software process improvement,<br />

measurement, and project and knowledge management.<br />

Regardie received a BS in mathematics from Juniata College,<br />

Huntingdon, Pennsylvania. Contact her at ________<br />

mregardie@<br />

fc-md.umd.edu.<br />

___________<br />

Carolyn Seaman is an associate professor of information<br />

systems at the University of Maryland, Baltimore County,<br />

and a scientist at the Fraunhofer Center for Experimental<br />

Software Engineering. Her research interests include<br />

software evolution, management of software projects,<br />

and qualitative research methods in software engineering.<br />

Seaman received a PhD in computer science from the<br />

University of Maryland. Contact her at ___________<br />

cseaman@fc-md.<br />

umd.edu.<br />

______<br />

_______________<br />

Jens Heidrich is a department head at the Fraunhofer Institute<br />

for Experimental Software Engineering. His research<br />

interests include project management, quality assurance,<br />

and measurement. Heidrich received a PhD in computer<br />

science from the University of Kaiserslautern, Germany.<br />

Contact him at jens.heidrich@iese.fraunhofer.de.<br />

______________________<br />

Jürgen Münch is division manager for quality management<br />

at the Fraunhofer Institute for Experimental Software Engineering.<br />

His research interests include quality assurance,<br />

process management, and measurement. Münch received<br />

a PhD in computer science from the University of Kaiserslautern.<br />

Contact him at ______________________<br />

juergen.muench@iese.fraunhofer.<br />

__ de.<br />

Dieter Rombach is a professor and chair of the Software<br />

Engineering Department at the University of Kaiserslautern<br />

and executive director of the Fraunhofer Institute<br />

for Experimental Software Engineering. His research<br />

interests include software methodologies, modeling and<br />

measurement of the software process and resulting products,<br />

software reuse, and distributed systems. Rombach<br />

received a PhD in computer science from the University<br />

of Kaiserslautern. Contact him at _______________<br />

dieter.rombach@iese.<br />

fraunhofer.de.<br />

_________<br />

Adam Trendowicz is a researcher at the Fraunhofer Institute<br />

for Experimental Software Engineering. His research<br />

interests include software cost modeling, measurement,<br />

and process improvement. Trendowicz received a PhD in<br />

computer science from the University of Kaiserslautern.<br />

Contact him at adam.trendowicz@iese.fraunhofer.de.<br />

________________________<br />

Selected CS articles and columns are available for free at<br />

http://ComputingNow.computer.org.<br />

Join the<br />

IEEE<br />

Computer Society<br />

www.computer.org<br />

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COMPUTER SOCIETY CONNECTION<br />

Ken Birman Wins<br />

Kanai Award<br />

Ken Birman<br />

is a founding<br />

member of<br />

TRUST, a<br />

consortium<br />

that explores<br />

challenges in trustworthy <strong>computing</strong>.<br />

Kenneth P. Birman, N.<br />

Rama Rao Professor<br />

at Cornell University,<br />

recently received the<br />

IEEE Computer Society’s 2009<br />

Tsutomu Kanai Award. The award<br />

recognizes major contributions to<br />

state-of-the art distributed <strong>computing</strong><br />

systems and their applications.<br />

Birman was recognized “for funda-<br />

COMPUTER<br />

mental and practical contributions<br />

to distributed <strong>computing</strong>, fault tolerance,<br />

reliability and distributed<br />

systems management.”<br />

Birman’s work has focused on the<br />

development of trustworthy distributed<br />

<strong>computing</strong> systems. Early in his<br />

career, he developed the Isis Toolkit, a<br />

reliable group communication system<br />

that introduced the virtual synchrony<br />

model for fault tolerance. The widely<br />

adopted Isis was at the core of such<br />

mission-critical systems as the<br />

French air traffic control system, the<br />

New York Stock Exchange, and the US<br />

Navy’s Aegis-class warships.<br />

Birman’s group subsequently<br />

developed a series of systems that<br />

explored challenges of extreme<br />

COMPUTING<br />

THEN<br />

Learn about <strong>computing</strong> history<br />

and the people who shaped it.<br />

http://<strong>computing</strong>now.<br />

computer.org/ct<br />

scale using gossip and peer-topeer<br />

protocols. These included<br />

Horus, Ensemble, Bimodal Multicast,<br />

the Astrolabe platform, and<br />

the Gossip Objects platform. Ideas<br />

and technology from these efforts<br />

have helped shape modern cloud<br />

<strong>computing</strong> systems, including<br />

the communication layer of IBM’s<br />

flagship WebSphere product, Microsoft’s<br />

cluster management platform,<br />

and Amazon’s data-center management<br />

systems.<br />

Birman became a Fellow of the<br />

ACM in 1998 and won the 2009<br />

IEEE Transactions on Parallel and<br />

Distributed Systems Outstanding<br />

Achievement Award.<br />

Tsutomu Kanai Award<br />

The Tsutomu Kanai Award was<br />

established in 1997 by an endowment<br />

from Hitachi in honor of its<br />

president. The award consists of<br />

a crystal model, certificate, and<br />

$10,000 honorarium. The IEEE<br />

Computer Society Awards Committee<br />

considers the seminal nature<br />

of the achievements, their practical<br />

impact, breadth, and depth, as<br />

well as the quality of the nomination.<br />

The awards honor technical<br />

achievements as well as service<br />

to the computer profession and to<br />

the Society. Birman will accept his<br />

award at the Computer Society’s<br />

2010 awards ceremony in Denver.<br />

The deadline to make a nomination<br />

for the 2010 Tsutomu Kanai<br />

Award is 15 October. For more information,<br />

visit www.computer.org/<br />

portal/web/awards/kanai.<br />

________________<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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Francine Berman Wins Kennedy Award<br />

Francine Berman<br />

was one of<br />

two founding<br />

principal<br />

investigators<br />

on the National<br />

Science<br />

Foundation’s TeraGrid Project.<br />

rancine Berman, vice<br />

president for research at<br />

Rensselaer Polytechnic<br />

Institute, recently received<br />

the IEEE Computer Society’s Ken<br />

Kennedy Award for outstanding<br />

contributions to programmability<br />

or productivity in high-performance<br />

<strong>computing</strong>. She is a pioneer in grid<br />

<strong>computing</strong> and a leading advocate<br />

for the development of a national<br />

cyberinfrastructure for the access,<br />

use, stewardship, and preservation<br />

of digital data. Berman’s work has<br />

had a major impact on the direction<br />

of computational science and<br />

the cyberinfrastructure. Her citation<br />

reads “For her influential leadership<br />

in the design, development and<br />

deployment of national-scale cyber<br />

infrastructure, her inspiring work<br />

as a teacher and mentor, and her<br />

exemplary service to the high-<br />

performance community.”<br />

Berman is co-chair of the Blue<br />

Ribbon Task Force on Sustainable<br />

Digital Preservation and Access,<br />

an international group focusing<br />

on the economic sustainability of<br />

digital information that must be<br />

accessed and preserved for many<br />

decades.<br />

In 2001, Berman became director<br />

of both the San Diego Supercomputer<br />

Center and the National Partnership<br />

for Advanced Computational Infrastructure,<br />

a consortium of more than<br />

40 national and international partners<br />

who worked together to create a<br />

comprehensive national <strong>computing</strong><br />

infrastructure.<br />

Berman is a founding member and<br />

co-chair of the Computing Research<br />

Association’s Committee on the Status<br />

of Women in Computing Research<br />

and currently serves on the Anita<br />

Borg Institute for Women and Technology<br />

Board of Trustees.<br />

Before moving to RPI, Berman<br />

held the High Performance Computing<br />

Endowed Chair in the<br />

Jacobs School of Engineering at<br />

the University of California, San<br />

Diego. In 2000, she was named an<br />

ACM Fellow for pioneering work in<br />

application scheduling for parallel<br />

distributed <strong>computing</strong>. Berman<br />

received a BA in mathematics from<br />

the University of California, Los<br />

Angeles, and an MA and PhD in<br />

Top Educators Honored<br />

he IEEE Computer Society<br />

sponsors an active<br />

and prestigious awards<br />

program as part of its<br />

mission to promote the free exchange<br />

of ideas among computer professionals<br />

around the world and to recognize<br />

its members for their outstanding<br />

accomplishments. Several noted<br />

educators recently received two<br />

Computer Society awards that honor<br />

achievement in education.<br />

COMPUTER SCIENCE<br />

& ENGINEERING<br />

UNDERGRADUATE<br />

TEACHING AWARD<br />

The IEEE Computer Society<br />

Computer Science & Engineering<br />

Undergraduate Teaching Award is<br />

presented each year for outstanding<br />

contributions to undergraduate education<br />

through teaching and service,<br />

for helping to maintain interest in<br />

the field, and for making a statement<br />

mathematics from the University<br />

of Washington.<br />

Ken Kennedy Award<br />

The IEEE Computer Society Ken<br />

Kennedy Award was established<br />

in memory of the founder of Rice<br />

University’s nationally ranked computer<br />

science program and one of<br />

the world’s foremost experts on<br />

high-performance <strong>computing</strong>. A certificate<br />

and $5,000 honorarium are<br />

awarded jointly by the ACM and the<br />

Computer Society for outstanding<br />

contributions to programmability<br />

or productivity in high-performance<br />

<strong>computing</strong> together with significant<br />

community service or mentoring<br />

contributions.<br />

about the importance with which<br />

the Society views undergraduate<br />

education.<br />

Judy Robertson<br />

Judy Robertson of Heriot-Watt University,<br />

the 2009 award winner, was<br />

honored “for outstanding contributions<br />

to the undergraduate education<br />

through teaching and the innovative<br />

use of pioneering technologies in<br />

teaching.” Robertson is the principal<br />

investigator of a grant funded by the<br />

UK’s Engineering and Physical Sciences<br />

Research Council that supports<br />

high school teachers who use gamemaking<br />

projects with their students.<br />

She received a BS and PhD in computer<br />

science and artificial intelligence<br />

from the University of Edinburgh.<br />

Elizabeth Burd<br />

Elizabeth Burd of Durham University,<br />

the 2008 winner, was recognized<br />

“for outstanding contributions to<br />

APRIL 2010<br />

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COMPUTER SOCIETY CONNECTION<br />

Microsoft and IEEE have announced<br />

a collaboration that aims to<br />

increase the number of students<br />

engaged in technical pursuits. The IEEE<br />

Computer Society, which has long<br />

očered its student members access to<br />

free Microsoft software, is participating<br />

in the collaboration.<br />

“As an information provider to technical<br />

professionals, this collaboration<br />

with Microsoft will give us an expanded<br />

ability to introduce students to more<br />

internships, scholarships, and contests,”<br />

said Violet Doan, the Computer Society’s<br />

membership director.<br />

“Engineers make tremendous contributions<br />

to society by creating technologies<br />

that drive global economic<br />

growth,” said Walid Abu-Hadba, vice<br />

president of developer and platform<br />

evangelism at Microsoft. “The Microsoft-IEEE<br />

collaboration will provide<br />

aspiring engineers around the world<br />

undergraduate education through<br />

teaching and the organization of<br />

programs to promote excellence in<br />

undergraduate teaching.” Burd is<br />

the leader of Durham’s Technology<br />

Enhanced Learning Research Group.<br />

Her most recent grant, supported by<br />

the Teaching and Learning Research<br />

Program, focuses on investigating<br />

the use of multitouch software in<br />

classrooms.<br />

Call for Papers | General Interest<br />

I<br />

EEE Micro seeks general-interest submissions<br />

for publication in upcoming issues. These<br />

works should discuss the design, performance,<br />

or application of microcomputer and microprocessor<br />

systems. Of special interest are articles on<br />

performance evaluation ion and<br />

workload character-<br />

COMPUTER<br />

MICROSOFT AND IEEE COOPERATE<br />

TO SUPPORT STUDENTS<br />

with tools and resources to convert their<br />

innovative thinking into marketplace<br />

innovation by equipping today’s technical<br />

students for tomorrow’s jobs.”<br />

Microsoft and IEEE will work together<br />

to provide IEEE student members<br />

with access to Microsoft servers,<br />

development tools, and eLearning,<br />

including privileged access to more<br />

than 300 software titles as part of the<br />

MSDN Academic Alliance, a subscription<br />

service traditionally available only<br />

through educational institutions. An<br />

added benećt is the opportunity for<br />

science, technology, engineering, and<br />

math students to explore job opportunities<br />

with Microsoft partners and<br />

customers through the Microsoft Students<br />

to Business program.<br />

Learn more about IEEE Computer Society<br />

student activities at www.computer.<br />

org/portal/web/studentactivities/<br />

____ home.<br />

TAYLOR L. BOOTH<br />

AWARD<br />

Recipients of the Taylor L. Booth<br />

Award are presented with a bronze<br />

medal and $5,000 honorarium in<br />

recognition of an outstanding record<br />

in computer science and engineering<br />

education. A successful candidate<br />

must meet at least two of the following<br />

criteria in the computer science<br />

and engineering field:<br />

ization. Summaries of work in progress and descriptions<br />

of recently completed works are most<br />

welcome, as are tutorials. Micro does not accept<br />

previously published material.<br />

Check our author center (www.computer.org/mc/<br />

_________<br />

mi cro/author.htm) for word, fi gure, and reference<br />

limits. All submissions pass through peer review<br />

co consistent istent with<br />

other professional-level technical<br />

pu publications, ublications, and eediting<br />

for clarity, readability, and<br />

co conciseness. Contac Contact IEEE Micro at _____ micro-ma@<br />

computer.org with aany<br />

questions.<br />

Achieving recognition as a<br />

teacher of renown.<br />

Writing an influential text.<br />

Leading, inspiring, or providing<br />

significant education content<br />

during the creation of a curriculum<br />

in the field.<br />

Inspiring others to a career in<br />

computer science and engineering<br />

education.<br />

Michael Heath<br />

Michael Heath, chair of computer<br />

science at the University of Illinois<br />

at Urbana-Champaign, was selected<br />

in 2009 “for contributions to computational<br />

science and engineering<br />

education, curriculum and scholarship.”<br />

Heath is director of both the<br />

computational science and engineering<br />

program and the Center for<br />

Simulation of Advanced Rockets at<br />

UIUC. He was named an ACM Fellow<br />

in 2000.<br />

James P. Cohoon<br />

and Jack W. Davidson<br />

James P. Cohoon and Jack W.<br />

Davidson of the University of<br />

Virginia were recognized as winners<br />

in 2008 “for sustained effort<br />

to transform introductory computer<br />

science education through<br />

lab-based multimedia pedagogy<br />

coupled with examples that attract<br />

a diverse student body.” Cohoon’s<br />

research involves algorithms, probabilistic<br />

search, genetic algorithms,<br />

simulated annealing, and diversity<br />

in computer science education.<br />

Davidson performs research in<br />

programming languages, computer<br />

security, embedded systems, and<br />

computer architecture.<br />

Taylor L. Booth founded the<br />

University of Connecticut’s<br />

Booth Engineering Center<br />

for Advanced Technology and was a<br />

candidate for IEEE Computer Society<br />

president at the time of his death in<br />

1986. For more information on Computer<br />

Society awards, visit ____<br />

www.<br />

computer.org/portal/web/awards.<br />

______________________<br />

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CALL AND CALENDAR<br />

CALLS FOR ARTICLES FOR<br />

IEEE CS PUBLICATIONS<br />

IEEE Micro seeks contributions<br />

on a wide range of topics related to<br />

multicore processing for a September/<br />

October 2010 special issue on European<br />

multicore processing projects.<br />

Suitable topics include advancements<br />

in multicore architecture, interconnection<br />

networks, and design-space<br />

exploration.<br />

Articles are due by 19 April.<br />

Visit www.computer.org/portal/web/<br />

________________<br />

<strong>computing</strong>now/micfp5 to view the<br />

complete call for papers.<br />

IT Professional seeks papers for a<br />

January/February 2011 issue focusing<br />

on green IT.<br />

Green IT is, and will continue to<br />

be, a hot topic due to increasing<br />

awareness of the harmful effects of<br />

green gas emissions, new stringent<br />

environmental legislation, rising concern<br />

about electronic waste disposal<br />

practices that damage the environment,<br />

and corporate-image concerns<br />

that are pushing businesses and individuals<br />

to adopt green practices.<br />

Articles are due by 1 July. Visit<br />

www.computer.org/portal/web/<br />

_______________<br />

<strong>computing</strong>now/itcfp1 to view the<br />

complete call for papers.<br />

CALLS FOR PAPERS<br />

ICEBE 2010, IEEE Int’l Conf. on<br />

e-Business Eng., 20-22 October,<br />

Shanghai; papers due 20 April; ____<br />

http://<br />

conferences.computer.org/icebe/2010/<br />

cfp.htm<br />

____<br />

CW 2010, Int’l Conf. on Cyberworlds,<br />

20-22 October, Singapore; papers due<br />

30 April; ________________<br />

www3.ntu.edu.sg/SCE/<br />

cw2010/cfp.htm<br />

___________<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

CALENDAR<br />

MAY<br />

2-3 May: VG 2010, IEEE/EG Int’l<br />

Symp. on Volume Graphics, Norrkoping,<br />

Sweden; www.eurographics2010.<br />

se/vg2010<br />

_______<br />

3-6 May: ASYNC 2010, IEEE Int’l<br />

Symp. on Asynchronous Circuits<br />

and Systems, Grenoble, France; ____ http://<br />

asyncsymposium.org/async2010<br />

17-20 May: CCGrid 2010, IEEE Int’l<br />

Symp. on Cluster Computing and<br />

the Grid, Southbank, Australia; ____ www.<br />

manjrasoft.com/ccgrid2010<br />

28-31 May: CSO 2010, 3rd Int’l Joint<br />

Conf. on Computational Sciences<br />

and Optimization, Huangshan Mountain,<br />

China; www.gip.hk/cso2010<br />

JUNE<br />

9-11 Jun: EuroVis 2010, IEEE Eurographics<br />

Symp. on Visualization,<br />

Talence, France; www.eurovis.org<br />

9-12 Jun: CCC 2010, IEEE Int’l Conf.<br />

on Computational Complexity, Cambridge,<br />

Massachusetts; http://facweb.<br />

cs.depaul.edu/jrogers/complexity<br />

______________________<br />

SUBMISSION INSTRUCTIONS<br />

The Call and Calendar section lists conferences, symposia, and workshops that the IEEE<br />

Computer Society sponsors or cooperates in presenting.<br />

Visit www.computer.org/conferences for instructions on how to submit conference<br />

or call listings as well as a more complete listing of upcoming computer-related<br />

conferences.<br />

Published by the IEEE Computer Society<br />

28-30 Jun: WET ICE 2010, IEEE<br />

Int’l Workshops on Enabling<br />

Technologies: Infrastructures for<br />

Collaborative Enterprises, Larissa,<br />

Greece; http://wetice.org<br />

AUGUST<br />

17-19 Aug: MASCOTS 2010, Int’l<br />

Symp. on Modeling, Analysis and<br />

Simulation of Computer and Telecommunications<br />

Systems, Miami;<br />

http://mascots2010.cis.fiu.edu<br />

20-22 Aug: SocialCom 2010, IEEE Int’l<br />

Conf. on Social Computing, Bloomington,<br />

Minnesota; www.iisocialcom.<br />

org/conference/socialcom2010<br />

23-26 Aug: ICPR 2010, 20th Int’l<br />

Conf. on Pattern Recognition, Istanbul;<br />

www.icpr2010.org<br />

24-26 Aug: EMS 2010, Int’l Conf. on<br />

Eng. Management and Service Sciences,<br />

Wuhan, China; www.scirp.org/<br />

_________<br />

conf/ems2010<br />

SEPTEMBER<br />

12-18 Sep: ICSM 2010, Int’l Conf. on<br />

Software Maintenance, Timisoara,<br />

Romania; http://icsm2010.upt.ro<br />

20-24 Sep: Cluster 2010, IEEE Int’l<br />

Conf. on Cluster Computing, Heraklion,<br />

Crete; www.cluster2010.org<br />

OCTOBER<br />

3-8 Oct: MODELS 2010, IEEE Model-<br />

Driven Eng. Languages and Systems,<br />

Oslo, Norway; http://models2010.ifi.<br />

uio.no<br />

APRIL 2010<br />

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COMPUTER<br />

CALL AND CALENDAR<br />

EVENTS IN 2010<br />

May<br />

2-3 ..........................VG 2010<br />

3-6 ......................ASYNC 2010<br />

17-20 ....................CCGrid 2010<br />

28-31 .......................CSO 2010<br />

June<br />

9-11 .................... EuroVis 2010<br />

9-12 ........................CCC 2010<br />

28-30 ..................WET ICE 2010<br />

August<br />

17-19 .................MASCOTS 2010<br />

20-22 . . . . . . . . . . . . . . . . SocialCom 2010<br />

23-26 ...................... ICPR 2010<br />

24-26 .......................EMS 2010<br />

20-22 Oct: CW 2010, Int’l Conf. on<br />

Cyberworlds, Singapore; _______<br />

www3.ntu.<br />

____________<br />

edu.sg/sce/cw2010<br />

20-22 Oct: ICEBE 2010, IEEE Int’l<br />

Conf. on e-Business Eng., Shanghai;<br />

http://conferences.computer.<br />

org/icebe<br />

2 Free Sample Issues!<br />

A $26 value<br />

The magazine of computational tools<br />

and methods for 21st century science.<br />

Cloud Computing<br />

Computational Astrophysics<br />

Computational Nanoscience<br />

Computational Engineering<br />

Geographical Information<br />

Systems<br />

http://cise.aip.org | www.computer.org/cise<br />

Send an e-mail to jbebee@aip.org to receive the two<br />

most recent issues of CiSE. (Please include your mailing address.)<br />

Recent Peer-Reviewed Topics:<br />

SC 2010<br />

stablished 21 years ago, the SC conference has built a community of participants<br />

E that includes researchers, scientists, <strong>computing</strong> center stač members, IT and data<br />

center managers, application developers, computer builders, program managers,<br />

journalists, and congressional stačers.<br />

The technical program addresses virtually every area of scientific and engineering<br />

research as well as technological development, innovation, and education. Its presentations,<br />

tutorials, panels, and discussion forums have contributed to breakthroughs in<br />

many new and innovative areas of <strong>computing</strong>.<br />

SC 2010 is sponsored by the IEEE Computer Society Technical Committee on Scalable<br />

Computing in cooperation with ACM SIGARCH. The conference takes place 13-19 November<br />

in New Orleans. Visit www.sc-conference.org for complete conference details.<br />

23-26 Oct: FOCS 2010, Symp. on<br />

Foundations of Computer Science,<br />

Las Vegas; http://theory.stanford.<br />

_________<br />

edu/focs2010/<br />

NOVEMBER<br />

1-3 Nov: SRDS 2010, IEEE Int’l Symp.<br />

on Reliable Distributed Systems,<br />

New Directions<br />

Petascale Computing<br />

Reproducible Research<br />

Software Engineering<br />

New Delhi, India; www.scs.ryerson.<br />

________________<br />

ca/iwoungan/SRDS2010<br />

13-19 Nov: SC 2010, Int’l Conf. for<br />

High-Performance Computing, Networking,<br />

Storage, and Analysis,<br />

New Orleans; www.sc-conference.<br />

org<br />

______________<br />

MEMBERS<br />

$47/year<br />

for print & online<br />

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PURPOSE: The IEEE Computer Society is the world’s largest<br />

association of <strong>computing</strong> professionals and is the leading<br />

provider of technical information in the field.<br />

MEMBERSHIP: Members receive the monthly magazine<br />

Computer, discounts, and opportunities to serve (all activities<br />

are led by volunteer members). Membership is open to all IEEE<br />

members, affiliate society members, and others interested in the<br />

computer field.<br />

COMPUTER SOCIETY WEB SITE: www.computer.org<br />

OMBUDSMAN: To check membership status or report a change<br />

of address, call the IEEE Member Services toll-free number,<br />

+1 800 678 4333 (US) or +1 732 981 0060 (international). Direct<br />

all other Computer Society-related questions—magazine delivery<br />

or unresolved complaints—to ____________<br />

help@computer.org.<br />

CHAPTERS: Regular and student chapters worldwide provide the<br />

opportunity to interact with colleagues, hear technical experts,<br />

and serve the local professional community.<br />

AVAILABLE INFORMATION: To obtain more information on any<br />

of the following, contact Customer Service at +1 714 821 8380 or<br />

+1 800 272 6657:<br />

Membership applications<br />

Publications catalog<br />

Draft standards and order forms<br />

Technical committee list<br />

Technical committee application<br />

Chapter start-up procedures<br />

Student scholarship information<br />

Volunteer leaders/staff directory<br />

IEEE senior member grade application (requires 10 years<br />

practice and significant performance in five of those 10)<br />

PUBLICATIONS AND ACTIVITIES<br />

Computer: The flagship publication of the IEEE Computer Society,<br />

Computer, publishes peer-reviewed technical content that<br />

covers all aspects of computer science, computer engineering,<br />

technology, and applications.<br />

Periodicals: The society publishes 13 magazines, 18 transactions,<br />

and one letters. Refer to membership application or request<br />

information as noted above.<br />

Conference Proceedings & Books: Conference Publishing<br />

Services publishes more than 175 titles every year. CS Press<br />

publishes books in partnership with John Wiley & Sons.<br />

Standards Working Groups: More than 150 groups produce<br />

IEEE standards used throughout the world.<br />

Technical Committees: TCs provide professional interaction in<br />

more than 45 technical areas and directly influence computer<br />

engineering conferences and publications.<br />

Conferences/Education: The society holds about 200<br />

conferences each year and sponsors many educational activities,<br />

including <strong>computing</strong> science accreditation.<br />

Certifications: The society offers two software developer<br />

credentials.<br />

For more information, visit www.computer.org/certification.<br />

revised 20 Jan. 2010<br />

EXECUTIVE COMMITTEE<br />

President: James D. Isaak*<br />

President-Elect: Sorel Reisman*<br />

Past President: Susan K. (Kathy) Land, CSDP*<br />

VP, Standards Activities: Roger U. Fujii (1st VP)*<br />

Secretary: Jeffrey M. Voas (2nd VP)*<br />

VP, Educational Activities: Elizabeth L. Burd*<br />

VP, Member & Geographic Activities: Sattupathu V. Sankaran†<br />

VP, Publications: David Alan Grier*<br />

VP, Professional Activities: James W. Moore*<br />

VP, Technical & Conference Activities: John W. Walz*<br />

Treasurer: Frank E. Ferrante*<br />

2010–2011 IEEE Division V Director: Michael R. Williams†<br />

2009–2010 IEEE Division VIII Director: Stephen L. Diamond†<br />

2010 IEEE Division VIII Director-Elect: Susan K. (Kathy) Land, CSDP*<br />

Computer Editor in Chief: Carl K. Chang†<br />

* voting member of the Board of Governors † nonvoting member of the Board of Governors<br />

BOARD OF GOVERNORS<br />

Term Expiring 2010: Piere Bourque; André Ivanov; Phillip A. Laplante;<br />

Itaru Mimura; Jon G. Rokne; Christina M. Schober; Ann E.K. Sobel<br />

Term Expiring 2011: Elisa Bertino, George V. Cybenko, Ann DeMarle,<br />

David S. Ebert, David A. Grier, Hironori Kasahara, Steven L. Tanimoto<br />

Term Expiring 2012: Elizabeth L. Burd, Thomas M. Conte, Frank E.<br />

Ferrante, Jean-Luc Gaudiot, Luis Kun, James W. Moore, John W. Walz<br />

EXECUTIVE STAFF<br />

Executive Director: Angela R. Burgess<br />

Associate Executive Director; Director, Governance: Anne Marie Kelly<br />

Director, Finance & Accounting: John Miller<br />

Director, Information Technology & Services: Carl Scott<br />

Director, Membership Development: Violet S. Doan<br />

Director, Products & Services: Evan Butterfield<br />

Director, Sales & Marketing: Dick Price<br />

COMPUTER SOCIETY OFFICES<br />

Washington, D.C.: 2001 L St., Ste. 700, Washington, D.C. 20036<br />

Phone:<br />

Email: ____________<br />

hq.ofc@computer.org<br />

Los Alamitos: 10662 Los Vaqueros Circle, Los Alamitos, CA 90720-1314<br />

Phone: +1 714 821 8380<br />

Email: ___________<br />

help@computer.org<br />

Membership & Publication Orders:<br />

Phone:<br />

Email: ___________<br />

help@computer.org<br />

Asia/Pacific: Watanabe Building, 1-4-2 Minami-Aoyama,<br />

Minato-ku, Tokyo 107-0062, Japan<br />

Phone:<br />

Email: _____________<br />

tokyo.ofc@computer.org<br />

IEEE OFFICERS<br />

President: Pedro A. Ray<br />

President-Elect: Moshe Kam<br />

Past President: John R. Vig<br />

Secretary: David G. Green<br />

Treasurer: Peter W. Staecker<br />

President, Standards Association Board of Governors:<br />

W. Charlston Adams<br />

VP, Educational Activities: Tariq S. Durrani<br />

VP, Membership & Geographic Activities: Barry L. Shoop<br />

VP, Publication Services & Products: Jon G. Rokne<br />

VP, Technical Activities: Roger D. Pollard<br />

IEEE Division V Director: Michael R. Williams<br />

IEEE Division VIII Director: Stephen L. Diamond<br />

President, IEEE-USA: Evelyn H. Hirt<br />

Next Board Meeting:<br />

11 June 2010, Denver, CO, USA<br />

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72<br />

CAREER OPPORTUNITIES<br />

SOFTWARE ENGINEER: High Performance<br />

Computing, Maxeler Technologies.<br />

Maxeler Technologies provides<br />

software and hardware systems which<br />

accelerate high performance scientific<br />

<strong>computing</strong> applications by an order of<br />

magnitude. Tier 1 companies currently<br />

use Maxeler consulting and hardware<br />

solutions to gain a competitive advantage.<br />

We’re currently seeking software<br />

engineers with experience of high performance<br />

software development (C/<br />

C++/Java/FORTRAN) for positions based<br />

in London. See http://www.maxeler.<br />

com/careers/ for more information or to<br />

apply.<br />

HEWLETT-PACKARD COMPANY has an<br />

opportunity for the following position in<br />

Cupertino, CA. PPM Developer: Reqs exp<br />

with: HP Project & Portfolio Mgmt s/w<br />

with the following modules: Demand<br />

Mgmt, Project Mgmt, Program Mgmt,<br />

Resources Mgmt, Finance Mgmt, Change<br />

Mgmt;Oracle PL/SQL; Shell Scripting;<br />

Process design; Organization change<br />

mgmt. Also requires Bachelors degree in<br />

CS, CE or rel field of study and 4 yrs. exp<br />

in job offered or rel. Send resume & refer<br />

to Job#CUPAHO2.: Please send resumes<br />

COMPUTER<br />

with job number to Hewlett-Packard<br />

Company, 19483 Pruneridge Ave., MS<br />

4206, Cupertino, CA 95014. No phone<br />

calls please. Must be legally authorized<br />

to work in the U.S. without sponsorship.<br />

EOE.<br />

PROJECT MANAGER, Senior Solutions<br />

Architect New York, NY. Utilize knowl. of<br />

complete SDLC & OO, JSF & Struts. Concepts<br />

to lead & participate in the design,<br />

development & maint. of complex software<br />

systems. Design & develop Java/<br />

J2EE/SOA applicatns using RSA, WID &<br />

WPS, BPEL, BPM, Webservices, SOAP/<br />

JMS. Familiar w/Datapower SOA Appliance.<br />

BS/MS-Engineering or foreign<br />

equivalent + related exp. Resumes: UTC<br />

Associates, Inc., 80 Wall St, Suite 1118,<br />

NY, NY 10005.<br />

HP ENTERPRISE SERVICES, LLC is accepting<br />

resumes for the following position<br />

in Oklahoma City, OK: Services<br />

Information Developer (Ref. #HPESOCF-<br />

WA1). SW design, develop, implementation,<br />

consulting & testing. Project requirement<br />

analysis. Requires Master’s<br />

or foreign degree equivalent in Comp<br />

NEW TENURE TRACK FACULTY POSITION<br />

IN THE SCHOOL OF SYSTEMS AND ENTERPRISES<br />

AT STEVENS INSTITUTE OF TECHNOLOGY<br />

Faculty Position in Software Engineering<br />

The School of Systems and Enterprises at Stevens Institute of Technology invites applications<br />

for a full-time, tenure-track faculty position in Software Engineering. We are especially interested<br />

in candidates with research interests in modeling, simulation and visualization of complex<br />

systems; and synergies with systems engineering and security systems engineering. The<br />

successful candidate will have the ability to develop an innovative and impactful research<br />

program in this area. Furthermore, an enthusiasm for teaching and conducting collaborative<br />

research is essential.<br />

An application, formatted as a single .pdf file, should include the candidate’s curriculum<br />

vitae, a statement of research interest, a statement of teaching interest, three scientific manuscripts,<br />

and up to 5 references.<br />

This appointment will be at the Associate or Assistant Professor Rank, dependent on scholarly<br />

achievement and accomplishments. Applications should be submitted to:<br />

Jon Wade, Ph.D., Professor and Associate Dean of Research<br />

School of Systems and Enterprises, Stevens Institute of Technology<br />

1 Castle Point on Hudson, Hoboken, NJ 07030<br />

Email: jon.wade@stevens.edu Tel: 775.636.5811<br />

_____________<br />

This position will remain open until filled. Screening of candidates will start in<br />

April 2010. Stevens Institute of Technology is an equal opportunity/affirmative<br />

action employer and is dedicated to recruiting a diverse faculty community.<br />

We welcome all qualified applicants to apply, including women, minorities,<br />

veterans, and individuals with disabilities.<br />

www.stevens.edu/sse<br />

Cisco Systems, Inc. is accepting resumes for<br />

the following position:<br />

Richfield, OH<br />

Software Engineer<br />

(Ref#: RICH1)<br />

Responsible for the definition, design, development,<br />

test, debugging, release, enhancement<br />

and maintenance of networking software.<br />

Please mail resumes with reference number to<br />

Cisco Systems, Inc., Attn: J51W, 170 W. Tasman<br />

Drive, Mail Stop: SJC 5/1/4, San Jose, CA 95134.<br />

No phone calls please. Must be legally<br />

authorized to work in the U.S. without sponsorship.<br />

EOE.<br />

www.cisco.com<br />

Cisco Systems, Inc. is accepting resumes for<br />

the following position:<br />

Malvern, PA<br />

Solution Consultant<br />

(Ref#: MAL1)<br />

Provide specific solution, technology, and<br />

product consulting for software product.<br />

Please mail resumes with reference number<br />

to Cisco Systems, Inc., Attn: J51W, 170 W.<br />

Tasman Drive, Mail Stop: SJC 5/1/4, San Jose,<br />

CA 95134. No phone calls please. Must be<br />

legally authorized to work in the U.S. without<br />

sponsorship. EOE.<br />

www.cisco.com<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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Sci, Comp Eng, Electrical Eng, or related<br />

field + 4 yrs of exp in job offered, or as<br />

a programmer analyst, engineer, developer,<br />

or related occupation. Oracle SQL;<br />

Javascript; SOAP/Web Services; XML;<br />

AJAX; ASP.NET; C#. Please mail resumes<br />

with reference # to: Ref. # HPESOCF-<br />

WA1, Hewlett-Packard Company; 19483<br />

Pruneridge Avenue, MS 4206, Cupertino,<br />

CA 95014. No phone calls. Must be legally<br />

authorized to work in the U.S. without<br />

sponsorship. EOE.<br />

TECHNICAL CONSULTANT (Milpitas,<br />

CA) Provide prof’l computer consulting<br />

svcs in form of systems analysis, dsgn &<br />

dvlpmt, systems integration &/or testing<br />

consulting. Min req MS in Comp Sci.<br />

Resume: HR, GSPANN Technologies, Inc,<br />

362 Fairview Way, Milpitas, CA 95035.<br />

HEWLETT-PACKARD COMPANY is accepting<br />

resumes for a Software Designer<br />

in Vancouver, WA. (Ref. #VANSWD11).<br />

Design, develop, maintain, test, and provide<br />

quality/performance assurance of<br />

embedded software for enterprise class<br />

print and finishing devices. Mail resumes<br />

with reference # to: Ref. #VANSWD11,<br />

Hewlett-Packard Company, 19483<br />

Pruneridge Avenue, MS 4206, Cupertino,<br />

CA 95014. No phone calls please. Must<br />

be legally authorized to work in the U.S.<br />

without sponsorship. EOE.<br />

ADJILITY CONSULTING in Short Hills,<br />

NJ seeks Documentum Systems Engineer<br />

for Documentum imaging systems<br />

including configuration & issue troubleshooting<br />

& configuring application for<br />

system optimizations. Req Bachelor’s &<br />

5 yrs exp with EMC Documentum Content<br />

Server, EMC Documentum Captiva,<br />

EMC Documentum .Net & Java development,<br />

2 yrs exp with Windows platforms<br />

& Unix platforms, working knowledge of<br />

infrastructure topics and EMC Documentum<br />

System Administrator certification.<br />

Requires up to 100% travel to client locations<br />

w/in U.S. Email resume to _____<br />

38.adjil-<br />

___________<br />

ity@hiredesk.com.<br />

.NET DEVELOPER - Dsgn, dvlp, test<br />

& implmt applic s/w utilizing knowl of<br />

& exp w/ .NET 2.0/3.0/3.5, C#, VB.NET,<br />

AJAX, Classic ASP, VB 6, C++, IIS, Oracle<br />

8i/9i, SQL Server 2000/2005/2008,<br />

Java, Tomcat, JavaScript, Web Services,<br />

Cisco Systems, Inc. is accepting resumes for the following<br />

positions in San Jose/Milpitas/Santa Clara, CA<br />

IT Analyst (Ref#: SJ6)<br />

Responsible for evaluating and documenting business needs, recommending<br />

business process and Information Technology solution alternatives and<br />

coordinating delivery of technical solutions to clients.<br />

Network Consulting Engineer (Ref#: SJ9)<br />

Responsible for the support and delivery of Advanced Services to company’s<br />

major accounts.<br />

Manager, Advanced Services (Ref#: SJ52)<br />

Supervise the activities of a technical team with responsibility for results in<br />

terms of customer satisfaction and delivery assurance.<br />

Please mail resumes with reference number to Cisco Systems, Inc., Attn: J51W, 170<br />

W. Tasman Drive, Mail Stop: SJC 5/1/4, San Jose, CA 95134. No phone calls please.<br />

Must be legally authorized to work in the U.S. without sponsorship. EOE.<br />

www.cisco.com<br />

Georgia State University<br />

Department of Computer Science<br />

The Department of Computer Science of Georgia<br />

State University invites applications for an anticipated<br />

tenure-track position for Assistant or Associate<br />

Professor beginning the Fall semester, 2010,<br />

pending budgetary approval. Earned Ph.D. in Computer<br />

Science, or a closely related discipline, and<br />

excellent records of publications and funding are<br />

required. Preference is for individual with specialty<br />

in distributed systems and networking. An offer<br />

of employment will be conditional on background<br />

verification.<br />

Applicants should send: letter of interest, C.V. without<br />

birth date, but with citizenship status, and three<br />

letters of recommendation and transcripts of all<br />

graduate work to:<br />

Dr. Yi Pan, Chair<br />

Department of Computer Science<br />

Georgia State University<br />

34 Peachtree Street, Suite 1450<br />

Atlanta, Georgia, 30303<br />

Applications can also be sent via email to ___ pan@<br />

______ cs.gsu.edu and will be accepted until position is<br />

filled.<br />

Georgia State University, a Research University of<br />

the University System of Georgia, is an AA/EEO<br />

employer.<br />

Assistant Professor –<br />

Computer Engineering<br />

University of Pittsburgh<br />

The Department of Electrical and Computer Engineering<br />

(ECE) at the University of Pittsburgh<br />

(http://www.engr.pitt.edu/electrical/about/jobs.<br />

___ html) is searching for a tenure stream assistant<br />

professor in the area of Computer Engineering.<br />

The start date for this position is approximately<br />

Sept. 1, 2010. The preferred candidate will fill a<br />

core need in the area of “Computer Engineering,”<br />

with a demonstrated research focus is on one of the<br />

following Swanson School of Engineering Focus<br />

Areas: “Energy,” “Bioengineering,” “Manufacturing”<br />

(including RFID), “Sustainability,” or “Nanoscience<br />

and Engineering.” ECE partners with the<br />

Department of Computer Science to offer BS, MS<br />

and PhD degrees in Computer Engineering.<br />

To ensure full consideration, applications must be<br />

received by April 15, 2010, although later applications<br />

may be considered if time allows. Please<br />

send a resume (or CV), contact information for at<br />

least four references, plus a letter summarizing your<br />

teaching and research interests to:<br />

Chair, ECE Search Committee<br />

348 Benedum Engineering Hall,<br />

University of Pittsburgh<br />

Pittsburgh, PA 15261<br />

or alternatively to: __________<br />

eesearch@pitt.edu<br />

The University of Pittsburgh is an affirmative action,<br />

equal opportunity employer.<br />

APRIL 2010 73<br />

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74<br />

CAREER OPPORTUNITIES<br />

Cisco Systems, Inc. is accepting resumes for<br />

the following position:<br />

San Bruno/San Francisco, CA<br />

Quality Assurance<br />

Engineer<br />

(Ref#: SBR4)<br />

Responsible for all aspects of Quality Assurance<br />

and testing for multiple projects.<br />

Please mail resumes with reference number to<br />

Cisco Systems, Inc., Attn: J51W, 170 W. Tasman<br />

Drive, Mail Stop: SJC 5/1/4, San Jose, CA 95134.<br />

No phone calls please. Must be legally<br />

authorized to work in the U.S. without sponsorship.<br />

EOE.<br />

www.cisco.com<br />

Advertiser Page<br />

APC 1<br />

Cisco 72-75<br />

Georgia State University 73<br />

IEEE Computer Society CV3, CV4<br />

ISADS 2011 12<br />

Stevens Institute of Technology 72<br />

University of Massachusetts 9<br />

University of Pittsbrugh 73<br />

Classified Advertising 72-75<br />

Advertising Personnel<br />

Marion Delaney<br />

IEEE Media, Advertising Dir.<br />

Phone: +1 415 863 4717<br />

Email: ____________<br />

md.ieeemedia@ieee.org<br />

Marian Anderson<br />

Sr. Advertising Coordinator<br />

Phone: +1 714 821 8380<br />

Fax: +1 714 821 4010<br />

Email: ______________<br />

manderson@computer.org<br />

Sandy Brown<br />

Sr. Business Development Mgr.<br />

Phone: +1 714 821 8380<br />

Fax: +1 714 821 4010<br />

Email: ____________<br />

sb.ieeemedia@ieee.org<br />

COMPUTER<br />

Entrust Truepass, Red Dot, PVCS, Win-<br />

Runner; Req MS Comp Sci, Eng or rel.<br />

Mail resumes to HR-National Computer<br />

Systems, 6-70 Towne Center Dr , North<br />

Brunswick, NJ 08902.<br />

HEWLETT-PACKARD COMPANY has an<br />

opportunity for the following position in<br />

Houston, TX. Engineering Project Manager:<br />

Reqs: Ability to use lab equipmt<br />

incl Oscilloscopes, DMMS (Digital Multimeters),<br />

Pwr Meters, Gain/Phase analyzers.<br />

Exp. w/impedance analyzers; Data<br />

acquisition systms. Also requires Bachelors<br />

degree in Elec. Engrng, or rel field<br />

of study and 3 yrs. exp in job offered or<br />

rel. Send resume & refer to Job# HOUK-<br />

MI2.: Please send resumes with job number<br />

to Hewlett-Packard Company, 19483<br />

Pruneridge Ave., MS 4206, Cupertino,<br />

CA 95014. No phone calls please. Must<br />

be legally authorized to work in the U.S.<br />

without sponsorship. EOE.<br />

HEWLETT-PACKARD COMPANY has an<br />

opportunity for the following position<br />

in Houston, TX. Systems/Software Engineer:<br />

Reqs: 7yrs s/w dvlpmt exp on Linux<br />

&/or UNIX; C/C++; SCSI, SES and SAS; FC,<br />

SATA & RAID storage; SMI-S & CIM; SM-<br />

BIOS & IPMI; UNIX make, shell scripts &<br />

Perl; version cntrl systems; OOAD, design<br />

COMPUTER<br />

Advertising Sales<br />

Representatives<br />

Recruitment:<br />

Mid Atlantic<br />

Lisa Rinaldo<br />

Phone: +1 732 772 0160<br />

Fax: +1 732 772 0164<br />

Email: _______<br />

lr.ieeemedia@<br />

ieee.org<br />

New England<br />

John Restchack<br />

Phone: +1 212 419 7578<br />

Fax: +1 212 419 7589<br />

Email: ______<br />

j.restchack@<br />

ieee.org<br />

Southeast<br />

Thomas M. Flynn<br />

Phone: +1 770 645 2944<br />

Fax: +1 770 993 4423<br />

Email: _____ flynntom@<br />

mindspring.com<br />

Midwest/Southwest<br />

Darcy Giovingo<br />

Phone: +1 847 498 4520<br />

Fax: +1 847 498 5911<br />

Email: _______<br />

dg.ieeemedia@<br />

ieee.org<br />

Northwest/Southern CA<br />

Tim Matteson<br />

Phone: +1 310 836 4064<br />

Fax: +1 310 836 4067<br />

Email: _______<br />

tm.ieeemedia@<br />

ieee.org<br />

Japan<br />

Tim Matteson<br />

Phone: +1 310 836 4064<br />

Fax: +1 310 836 4067<br />

Email: _______<br />

tm.ieeemedia@<br />

ieee.org<br />

Europe<br />

Heleen Vodegel<br />

Phone: +44 1875 825700<br />

Fax: +44 1875 825701<br />

Email: _____ impress@<br />

impressmedia.com<br />

patterns & UML; HP-UX internals; SOAP/<br />

XML; multi-threaded applctns; Java;<br />

storage bnchmrkng tools. Also requires<br />

Bach degree in CS, CE or rel & 7 yrs exp<br />

in job offered or rel. Send resume & refer<br />

to Job #HOUPPU2. Please send resumes<br />

with job number to Hewlett-Packard<br />

Company, 19483 Pruneridge Ave., MS<br />

4206, Cupertino, CA 95014. No phone<br />

calls please. Must be legally authorized<br />

to work in the U.S. without sponsorship.<br />

EOE.<br />

HP ENTERPRISE SERVICES, LLC is accepting<br />

resumes for the following positions:<br />

TECHNOLOGY CONSULTANT IN<br />

FARMINGTON HILLS, MI. (Ref. #HPESF-<br />

HVPA1). Create & implement standard<br />

deployment image for using Windows<br />

XP & Windows 7. Script solutions, independent<br />

of deployment tools used, to<br />

deploy standard image across globe.<br />

Requires Master’s or foreign degree<br />

equiv. in Electrical Engg, Comp Engg,<br />

Comp Sci, or related + 2 yrs experience<br />

in job offered, or as programmer analyst,<br />

intern, or related. Hewlett Packard<br />

Configuration Automation Enterprise;<br />

Visual Basic Scripting; Microsoft Windows<br />

Image Mgmt; Microsoft Windows<br />

Software Distribution; Microsoft Active<br />

<strong>Directory</strong>.<br />

Product:<br />

US East<br />

Dawn Becker<br />

Phone: +1 732 772 0160<br />

Fax: +1 732 772 0164<br />

Email: _______<br />

db.ieeemedia@<br />

ieee.org<br />

US Central<br />

Darcy Giovingo<br />

Phone: +1 847 498 4520<br />

Fax: +1 847 498 5911<br />

Email: ___________<br />

dg.ieeemedia@ieee.org<br />

US West<br />

Lynne Stickrod<br />

Phone: +1 415 931 9782<br />

Fax: +1 415 931 9782<br />

Email: ___________<br />

ls.ieeemedia@ieee.org<br />

Europe<br />

Sven Anacker<br />

Phone: +49 202 27169 11<br />

Fax: +49 202 27169 20<br />

Email: _____ sanacker@<br />

__________<br />

intermediapartners.de<br />

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BUSINESS CONSULTANT IN GREENS-<br />

BURG, PA. (Ref. #HPESSCH1). Interact<br />

with client face to face on daily basis. Innovate<br />

& formulate business solutions &<br />

“technology enabled” business models<br />

& new ways of doing business to create<br />

breakthrough positions in marketplace.<br />

Master’s or foreign degree equiv. in<br />

Comp. Sci, Comp. Engg., Electrical Engg,<br />

or related + 2 yrs of exp in job offered,<br />

or as SW consultant, SW engineer, or related.<br />

SAP Project Mgmt; SAP ABAP; SAP<br />

Netweaver XI; SAP EDI / ALE / IDOCS; SAP<br />

Scripts – Smartforms; SAP Workflow.<br />

Please mail resumes with reference #<br />

to: Ref. #, HP Enterprise Services; 19483,<br />

Pruneridge Avenue, MS 4206, 95014.<br />

No phone calls please. Must be legally<br />

authorized to work in the U.S. without<br />

sponsorship. EOE.<br />

SR. DEVELOPER - eCommerce Industries,<br />

Inc. (ECI) has an opening in Big Sandy,<br />

TX for Sr. Developer. Position involves<br />

designing & developing complex software<br />

applications. Design, plan, develop,<br />

test & document accounting & office<br />

products software, applying knowledge<br />

of programming techniques & computer<br />

systems. Analyze user request for new<br />

or modified functions for our financial/<br />

accounting system analyze & develop<br />

specifications for the new design, to determine<br />

feasibility, cost & time required<br />

compatibility with the current system<br />

& computer capabilities. Consult with<br />

end users to identify current operating<br />

procedures & clarifying program objectives.<br />

Study relevant manuals, periodicals<br />

& technical reports to learn ways to develop<br />

software that meet user requirements.<br />

Formulate plans outlining steps<br />

required to develop programs, using<br />

structured analysis, designing & object<br />

oriented methodology. Prepare flowcharts<br />

& class diagrams to illustrate the<br />

sequence of steps a program must follow<br />

& describing the logical operations<br />

involved. Convert project specifications,<br />

using flowcharts & class diagrams into a<br />

sequence of detailed instructions & logical<br />

steps for coding into office product<br />

software language which is written in<br />

C++, JAVA, Windows, UNIX, LINUX, SQL<br />

Server, .Net, Visual Basic, SQL, Web appli-<br />

cations development networking. Code &<br />

software module design. Write documentation<br />

to describe program development,<br />

logic, coding & corrections & rectifying<br />

bugs. Develop understanding of the project<br />

scope & requirements & question any<br />

areas that are unclear. Identify potential<br />

problem areas in software design. Participate<br />

in training of new members of the<br />

department. Assist Customer Support<br />

& Technical Support in providing a customer<br />

response or assume responsibility<br />

for calls that have been escalated to Software<br />

Development. Requires Bachelor’s<br />

in Computer Science or CIS & 3 yrs exp. in<br />

JAVA programming OR Master’s in Computer<br />

Science or CIS & 1 year exp. in industry<br />

or as a graduate research assistant<br />

in JAVA programming. Submit your resume<br />

to ___________________<br />

developmentjobs@ecisolutions.<br />

___ com. An EOE.<br />

PROGRAMMER - eCommerce Industries,<br />

Inc. (ECI) has an opening in Fort<br />

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COMPUTER<br />

AI REDUX<br />

Probabilistic Analysis<br />

of an Ancient<br />

Undeciphered Script<br />

Rajesh P.N. Rao, University of Washington<br />

Probabilistic methods for analyzing sequences are providing<br />

new insights into the 4,000-year-old undeciphered script of the<br />

Indus civilization.<br />

In the latter half of the 19th<br />

century, railway workers in<br />

British India found an almost<br />

inexhaustible supply of precisely<br />

cut baked bricks at Harappa,<br />

a small town located in present-day<br />

Pakistan. They proceeded to use the<br />

bricks as ballast for laying down 100<br />

miles of railroad track. Little did they<br />

know that these bricks were more<br />

than 4,000 years old, products of<br />

South Asia’s oldest urban civilization.<br />

The Indus civilization, so named<br />

because its first important sites were<br />

discovered along the Indus River,<br />

flourished from 2600 to 1900 BC. At<br />

its peak, it encompassed more than<br />

1 million square kilometers and was<br />

larger than the roughly contemporaneous<br />

Egyptian and Mesopotamian<br />

civilizations. Its cities were laid out<br />

in a grid-like pattern with a sophisticated<br />

water management and<br />

drainage system that would be the<br />

envy of many towns today. Citizens<br />

of the Indus civilization were highly<br />

enterprising, traveling to lands as far<br />

away as the Persian Gulf and Mesopotamia<br />

(present-day Iraq) to trade.<br />

Remarkably, there is no evidence<br />

that powerful kings or elites ruled the<br />

Indus cities, as in other Bronze Age<br />

civilizations. No extravagant royal<br />

palaces, pyramids, or ziggurats have<br />

been found. What archaeologists<br />

have unearthed in large numbers are<br />

tiny seals like those shown in Figure<br />

1a, most around 1” × 1” in size. Each<br />

typically depicts an expertly crafted<br />

animal, with a short text of signs<br />

at the top. These texts, which also<br />

appear on miniature tablets, copper<br />

plates, tools, weapons, and pottery,<br />

constitute the Indus script, one of the<br />

last remaining undeciphered scripts<br />

of the ancient world.<br />

THE INDUS SCRIPT<br />

Figure 1b shows a small subset of<br />

the approximately 400 signs in the<br />

Indus script. The number of signs<br />

is more than in purely alphabetic<br />

or syllabic scripts, which typically<br />

contain a few dozen signs, but less<br />

than in logographic scripts such<br />

as Chinese, which contain large<br />

numbers of signs representing<br />

entire words. Researchers have<br />

therefore suggested that, like other<br />

ancient scripts such as Sumerian<br />

and Mayan, the Indus script was<br />

logosyllabic in nature, each sign<br />

representing either a word or a<br />

syllable.<br />

What the Indus signs actually<br />

mean remains a mystery, although<br />

the number of books claiming to have<br />

deciphered the script could occupy<br />

several bookshelves. None of these<br />

claims have been widely accepted.<br />

The major impediments to decipherment<br />

include<br />

the brevity of existing Indus<br />

texts—the average text length is<br />

about five signs while the longest<br />

text consists of 17 signs;<br />

our almost complete lack of<br />

knowledge of the language<br />

spoken by the Indus people; and<br />

the lack of a bilingual document<br />

such as the Rosetta Stone,<br />

which was instrumental in<br />

deciphering the Egyptian hieroglyphic<br />

script.<br />

Given such formidable obstacles,<br />

efforts to decipher the script have<br />

ranged from inspired guesswork to<br />

ideology-driven speculation.<br />

An alternate, more objective<br />

approach is to first analyze the script’s<br />

syntactic structure, in the hope that<br />

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such an analysis could eventually lead<br />

to decipherment. Are the symbols in<br />

Indus texts randomly ordered or do<br />

they follow specific rules? Do particular<br />

symbols have particular positions<br />

within texts? How much flexibility<br />

does the script allow when composing<br />

a string of symbols? How do the<br />

Indus script’s syntactical properties<br />

compare with those of other ancient<br />

and modern languages and scripts?<br />

Researchers are investigating such<br />

questions using statistics, probabilistic<br />

reasoning, and machine learning.<br />

EARLY STATISTICAL<br />

ANALYSIS<br />

G.R. Hunter conducted the first<br />

rudimentary statistical analysis of the<br />

Indus script in the early 1930s. In the<br />

absence of computers, Hunter handenumerated<br />

frequently occurring<br />

clusters of signs, segmenting Indus<br />

texts into short “words” of two or<br />

more signs. This enabled him to infer<br />

important syntactic characteristics<br />

of the script such as the tendency of<br />

certain symbols and words to occur<br />

at specific positions within texts. For<br />

example, Hunter was among the first<br />

to note that the “jar” sign , which is<br />

the most frequently occurring sign<br />

in the texts, acts as a “word ender,”<br />

and that the “fish” signs frequently<br />

occur in pairs (such as and ),<br />

occupying the same relative position<br />

within texts.<br />

In the 1960s, the fact that sign clusters<br />

have particular positions within<br />

Indus texts was confirmed independently<br />

with the help of computers by a<br />

Finnish team led by Asko Parpola and<br />

a Soviet team led by Yuri Knorozov<br />

(who played a key role in deciphering<br />

the Mayan script). More recent work<br />

has demonstrated that the frequency<br />

of certain two-, three-, and four-sign<br />

combinations is much higher than<br />

would be expected by chance, and<br />

that a majority of the texts longer<br />

than five signs can be segmented into<br />

these smaller, frequently occurring<br />

sign combinations (N. Yadav et al.,<br />

“Segmentation of Indus Texts,” Int’l<br />

(a) (b)<br />

Figure 1. Indus script. (a) Three examples of square stamp seals, each with an<br />

Indus text at the top (image credit: J.M. Kenoyer/Harappa.com). Texts were usually<br />

written from right to left (inferred, for example, from writing on pottery where a<br />

sign is overwritten by another on its left) but this direction was reversed in seals<br />

(that is, left to right as in these images) to form correctly oriented impressions. (b)<br />

A small subset of the 400 or so signs in the Indus script (selected from Mahadevan’s<br />

concordance).<br />

J. Dravidian Linguistics, vol. 37, no.<br />

1, 2008, pp. 53-72). Such regularities<br />

point to the existence of distinctive<br />

syntactic rules underlying the Indus<br />

texts.<br />

MARKOV AND<br />

NfiGRAM MODELS<br />

The presence of statistically significant<br />

clusters of symbols with<br />

positional preferences suggests that<br />

there is sequential order in the Indus<br />

script. One way to capture such<br />

sequential order is to learn a Markov<br />

model for the script from available<br />

texts.<br />

The simplest (first-order) model<br />

estimates the transition probabilities<br />

P(s i |s j ) that sign i follows sign j. The<br />

obvious way of estimating P(s i |s j ) is<br />

to count the number of times sign i<br />

follows sign j, an approach equivalent<br />

to maximum likelihood estimation.<br />

However, given that there are approximately<br />

400 signs and only a few<br />

thousand texts, a large number of<br />

sign pairs will have a frequency of 0<br />

even though their actual probability<br />

may not necessarily be 0. This is a<br />

common problem in statistical language<br />

modeling and can be addressed<br />

using smoothing techniques.<br />

A prominent smoothing technique,<br />

the modified Kneser-Ney algorithm,<br />

was used to learn a first-order Markov<br />

model of the Indus script (R.P.N. Rao<br />

et al., “A Markov Model of the Indus<br />

Script,” Proc. National Academy of<br />

Sciences, vol. 106, no. 33, 2009, pp.<br />

13685-13690). The data for training<br />

the model came from Iravatham<br />

Mahadevan’s The Indus Script: Texts,<br />

Concordance and Tables (Archaeological<br />

Survey of India, 1977). Once trained,<br />

the Markov model can be used to<br />

generate new samples of Indus texts.<br />

This can reveal interesting subunits of<br />

grammatical structure and recurring<br />

patterns, as Figure 2a shows.<br />

There exist a large number of damaged<br />

Indus seals, tablets, and other<br />

artifacts that contain texts with one<br />

or more missing or illegible signs. A<br />

Markov model of the Indus texts can<br />

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COMPUTER<br />

Log likelihood<br />

AI REDUX<br />

0<br />

–10<br />

–20<br />

–30<br />

–40<br />

(a) (b)<br />

Indus A B C D<br />

(c)<br />

Figure 2. Markov model of the Indus script. (a) (Top) A new Indus text generated by<br />

the Markov model. (Below) Two closest matching texts in the training corpus. (b)<br />

(Left) Text from a damaged seal containing one or more missing signs (indicated<br />

by the shaded box). (Right) Three possible restorations predicted by the Markov<br />

model. The črst and third texts actually exist in the corpus. (c) Log likelihood under<br />

the Markov model for four texts (A through D) found in foreign lands compared to<br />

average log likelihood for a random set of 50 Indus region texts not included in the<br />

training data (error bar denotes +/- 1 standard error of mean). The 50 Indus region<br />

texts had the same average length as the foreign texts.<br />

be used to predict these missing or<br />

illegible signs. The first-order Markov<br />

model was found to be surprisingly<br />

good at predicting signs deliberately<br />

obliterated for testing purposes, performing<br />

at a 75 percent accuracy<br />

level in a fivefold cross-validation<br />

study. Figure 2b shows an example<br />

of restoration of an actual damaged<br />

Indus inscription from Mahadevan’s<br />

concordance, as suggested by the<br />

first-order Markov model.<br />

Several seals with Indus signs have<br />

been discovered outside the Indus<br />

region, as far away as Mesopotamia<br />

and the Persian Gulf. One can compute<br />

the likelihood of these “foreign”<br />

texts with respect to a Markov model<br />

trained only on texts from the Indus<br />

region. As Figure 2c shows, the likelihood<br />

values for many of these foreign<br />

texts are several orders of magnitude<br />

lower than those for Indus region<br />

texts, indicating their low probability<br />

of belonging to the same language.<br />

Indeed, an examination of these<br />

foreign texts reveals that although<br />

they contain commonly used Indus<br />

signs, the sequential order of the signs<br />

differs dramatically from that in texts<br />

originating in the Indus region—for<br />

example, the sequence in the foreign<br />

text C in Figure 2c never occurs<br />

on an Indus seal. This suggests that<br />

A<br />

B<br />

C<br />

D<br />

Indus traders in foreign lands may<br />

have used the script to represent different<br />

content, such as foreign names<br />

or goods, or an altogether different<br />

language.<br />

More recent work examined the<br />

utility of higher-order N-gram models.<br />

An N-gram model is essentially an<br />

(N 1)th-order Markov chain where<br />

the transition probability depends on<br />

the previous N 1 symbols instead<br />

of just the previous symbol. The<br />

results suggest that a bigram model<br />

(N = 2) captures a significant portion<br />

of the syntax, with trigrams and<br />

quadrigrams making more modest<br />

contributions (N. Yadav et al., “Statistical<br />

Analysis of the Indus Script<br />

Using N-Grams,” PLoS One, to appear<br />

in 2010).<br />

THE LANGUAGE QUESTION<br />

AND ENTROPIC ANALYSIS<br />

The brevity of existing Indus<br />

inscriptions and other attributes,<br />

such as the low frequency of many<br />

Indus signs, has prompted some<br />

to propose that the Indus script is<br />

not a script at all but instead is a<br />

collection of religious or political<br />

symbols. Adherents of the “nonscript”<br />

thesis have likened the Indus<br />

script to nonlinguistic systems such<br />

as traffic signs, medieval heraldry,<br />

markings on pottery in the Vinc a<br />

culture of southeastern Europe,<br />

and carvings of deities on boundary<br />

stones in Mesopotamia.<br />

Interestingly, this is not the first<br />

time that a script of a major ancient<br />

civilization has been deemed to be<br />

nonlinguistic. The Mayan script was<br />

long considered not to be a writing<br />

system at all until Knorozov and<br />

others finally worked out the rich<br />

phonetic underpinnings of the script<br />

in the 1950s and 1960s, revealing<br />

it to be a fully functional writing<br />

system.<br />

Several key features of the Indus<br />

script suggest that it represents<br />

language:<br />

the texts are usually linear, like<br />

the vast majority of linguistic<br />

scripts and unlike nonlinguistic<br />

systems such as heraldry or traffic<br />

signs;<br />

symbols are modified by the<br />

addition of specific sets of marks<br />

over, around, or inside a symbol,<br />

much like later Indian scripts<br />

that use such marks to modify<br />

the sound of a root consonant or<br />

vowel symbol;<br />

the script possesses rich syntactic<br />

structure, with particular<br />

signs or clusters of signs preferring<br />

particular positions<br />

within texts, similar to linguistic<br />

sequences;<br />

the script obeys the Zipf-<br />

Mandelbrot law, a power-law<br />

distribution on ranked data,<br />

which is often considered a necessary<br />

(though not sufficient)<br />

condition for language; and<br />

texts found in Mesopotamia and<br />

the Persian Gulf use the same<br />

signs as texts found in the Indus<br />

region but alter their ordering,<br />

suggesting that the script was<br />

versatile enough to represent<br />

different subject matter or a different<br />

language.<br />

Such attributes are hard to reconcile<br />

with the thesis that the script<br />

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merely represents religious or political<br />

symbols.<br />

Further evidence for the Indus<br />

script’s linguistic nature comes from<br />

quantitative studies comparing the<br />

entropy of the Indus texts with that<br />

of various languages. In some nonlinguistic<br />

systems, such as the Vinc a<br />

system, the signs do not seem to<br />

follow any order and appear to be<br />

juxtaposed randomly. Other nonlinguistic<br />

systems, such as deities<br />

carved on Mesopotamian boundary<br />

stones, exhibit a rigid order reflecting,<br />

for example, the hierarchical order of<br />

the deities.<br />

In languages, on the other hand,<br />

sequences of words and characters<br />

exhibit a degree of order intermediate<br />

between random and rigid. This<br />

intermediate degree of randomness<br />

arises from the grammatical rules<br />

and morphological structure of languages.<br />

The degree of randomness in<br />

a sequence can be measured quantitatively<br />

using entropy.<br />

The smoothed first-order Markov<br />

model can be used to compute conditional<br />

entropy, which measures the<br />

average flexibility allowed in choosing<br />

the next sign given a preceding<br />

sign. The conditional entropy of Indus<br />

texts has been shown to fall within the<br />

range of natural languages (R.P.N. Rao<br />

et al., “Entropic Evidence for Linguistic<br />

Structure in the Indus Script,” Science,<br />

vol. 324, no. 5931, 2009, p. 1165).<br />

A potential shortcoming of the<br />

conditional entropy result is that it<br />

only captures pairwise dependencies.<br />

Figure 3 shows new results<br />

(presented here for the first time)<br />

on higher-order entropies for blocks<br />

of up to six symbols. These block<br />

entropies were calculated using<br />

the state-of-the-art NSB estimator<br />

(I. Nemenman, F. Shafee, and<br />

W. Bialek, “Entropy and Inference,<br />

Revisited,” Advances in Neural Information<br />

Processing Systems 14, MIT<br />

Press, 2002, pp. 471-478), which has<br />

been shown to provide good estimates<br />

of entropy for undersampled<br />

discrete data.<br />

Normalized block entropy<br />

6<br />

5<br />

4<br />

3<br />

2<br />

1<br />

0<br />

1<br />

Indus<br />

Max Ent<br />

DNA<br />

Protein<br />

Tamil<br />

Eng chars<br />

Eng words<br />

Sansk<br />

Tagalog<br />

Sumer<br />

Fortran<br />

Min Ent<br />

The new results in Figure 3 extend<br />

the conditional entropy result to<br />

sequences of length up to six: The<br />

block entropies of the Indus texts<br />

remain close to those of a wide range<br />

of natural languages and far from<br />

the entropies for randomly and rigidly<br />

ordered sequences (Max Ent and<br />

Min Ent, respectively). Also shown in<br />

the plot for comparison are the entropies<br />

for a computer program written<br />

in Fortran and two sample biological<br />

sequences (DNA and proteins). The<br />

Fortran program and the biological<br />

sequences have noticeably lower and<br />

higher block entropies, respectively,<br />

than the Indus script and natural<br />

languages.<br />

Entropic similarity to natural languages<br />

by itself is not sufficient to<br />

prove that the Indus script is linguistic.<br />

However, given that it exhibits<br />

other key features of linguistic scripts<br />

as enumerated above, this similarity<br />

increases the probability in a<br />

Bayesian sense that the Indus script<br />

represents language.<br />

2 3<br />

4 5 6<br />

Sequence length (block size)<br />

Figure 3. Entropy of the Indus script compared to natural languages and other<br />

sequences. Symbols were signs for the Indus script; bases for DNA; amino acids for<br />

proteins; characters for English; words for English, Tagalog, and Fortran; symbols in<br />

abugida (alphasyllabic) scripts for Tamil and Sanskrit; and symbols in the cuneiform<br />

script for Sumerian. To compare sequences over dićerent alphabet sizes L, the<br />

logarithm in the entropy calculation was taken to base L: 417 for Indus, 4 for DNA,<br />

and so on. The resulting normalized block entropy is plotted as a function of block<br />

size. Error bars denote one standard deviation above/below mean entropy and are<br />

negligibly small except for block size 6.<br />

PROSPECTS FOR<br />

DECIPHERMENT<br />

Can the Indus script be deciphered<br />

without a bilingual artifact such as<br />

the Rosetta Stone? History suggests<br />

it could be: The Linear B script used<br />

in ancient Greece was deciphered in<br />

the 1950s without a bilingual artifact.<br />

The decipherment relied on several<br />

factors such as being able to identify<br />

common roots and suffixes, hypothesizing<br />

that the script was syllabic, and<br />

guessing the pronunciation of some<br />

symbols, which revealed the script<br />

to be a form of Greek. In the case of<br />

the Indus script, the short length of<br />

the available texts makes such an<br />

approach difficult. It may be possible,<br />

however, to obtain results by focusing<br />

on particular types of Indus texts and<br />

the contexts in which they are found.<br />

Most of the Indus texts found are<br />

on stamp seals, which were typically<br />

used in Bronze Age cultures for regulating<br />

trade. Seals were pressed onto<br />

clay tags affixed to packaged goods.<br />

The tags often listed the contents,<br />

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origin or destination, type or amount<br />

of goods being traded, name and title<br />

of the owner, or some combination of<br />

these. Numerous such clay tags have<br />

been found at various sites in the Indus<br />

civilization, bearing seal impressions<br />

on one side and impressions of woven<br />

cloth, reed matting, or other packing<br />

material on the other.<br />

If the Indus script was used for<br />

trade, as the evidence suggests, then<br />

we would expect to find signs representing<br />

numerical quantities and<br />

units of measure. Progress in this<br />

direction has recently been reported<br />

by Bryan Wells, who estimated the<br />

volumes of two pots, one bearing<br />

the inscription and the other the<br />

inscription . By showing that the<br />

estimated volume of the second pot<br />

was in fact twice that of the first,<br />

Wells was able to conclude that<br />

strokes such as and represent<br />

numbers, and the sign probably<br />

represents a unit of volume.<br />

Other efforts by Parpola and<br />

Mahadevan have assumed that at<br />

least some of the texts probably<br />

represent names. Phonetic values<br />

for specific signs can then be sug-<br />

gested by assuming an underlying<br />

language—for example, proto-Dravidian—and<br />

using the rebus principle<br />

to guess the pronunciation of pictorial<br />

signs such as “fish,” “jar,” and<br />

“arrow.” In English, for example,<br />

the rebus principle could be used to<br />

represent an abstract word such as<br />

“belief” with the picture of a bee followed<br />

by a picture of a leaf. Ancient<br />

scripts often used the rebus principle<br />

to represent language.<br />

Probabilistic models could<br />

help in this decipherment process<br />

in several ways. Recently proposed<br />

algorithms for probabilistic<br />

grammar induction could allow<br />

construction of a partial grammar<br />

for the Indus texts, facilitating the<br />

identification of root words, suffixes,<br />

prefixes, and other modifiers.<br />

This may facilitate the use of deciphering<br />

techniques similar to those<br />

applied to Linear B. Reconstructing<br />

a grammar would also allow<br />

comparison with the grammars of<br />

other languages, helping narrow<br />

down the set of candidate language<br />

families to consider when using the<br />

rebus principle.<br />

Silver Bullet Security Podcast<br />

COMPUTER<br />

AI REDUX<br />

In-depth interviews with security gurus. Hosted by Gary McGraw.<br />

www.computer.org/security/podcasts<br />

Sponsored by<br />

A site-by-site analysis of the Indus<br />

texts using probabilistic models could<br />

indicate whether different languages<br />

or dialects were spoken in different<br />

regions of the Indus civilization. Similarly,<br />

training probabilistic models<br />

on texts found on specific types of<br />

artifacts, such as seals versus tablets,<br />

could ascertain whether the content<br />

of the texts varies according to artifact<br />

type.<br />

In summary, the study of the<br />

Indus script has emerged as an<br />

exciting area of interdisciplinary<br />

research, offering a unique opportunity<br />

for probabilistic models to shed<br />

new light on one of the world’s oldest<br />

civilizations.<br />

Rajesh P.N. Rao is an associate professor<br />

in the Department of Computer<br />

Science & Engineering at the University<br />

of Washington. Contact him at<br />

rao@cs.washington.edu.<br />

________________<br />

Editor: Naren Ramakrishnan, Dept. of<br />

Computer Science, Virginia Tech, Blacksburg,<br />

VA; _________<br />

naren@cs.vt.edu<br />

_____________________________________________<br />

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SOFTWARE TECHNOLOGIES<br />

When TV Dies, Will<br />

It Go to the Cloud?<br />

Karin Breitman and Markus Endler, PUC-Rio, Brazil<br />

Rafael Pereira and Marcello Azambuja, Globo.com<br />

Coupled with the expected growth in bandwidth through the<br />

next decade, cloud <strong>computing</strong> will change the face of TV.<br />

The increasing popularity<br />

of videos on the<br />

Internet, allied to recent<br />

advances in network<br />

technology, are drastically changing<br />

television as we know it. In the past<br />

few decades we experienced a very<br />

clear role distinction: TV channels<br />

and independent companies produced<br />

video footage to be distributed<br />

by broadcasters and consumed by<br />

passive general audiences. Roles and<br />

responsibilities were clear down the<br />

line, and everyone was happy.<br />

A few years ago this “family<br />

around the TV set” scenario began to<br />

crack. Television faced several daunting<br />

challenges as cable multiplied the<br />

number of viewing choices and hardware<br />

prices let middle-class families<br />

own as many TV sets as there were<br />

members in the family.<br />

SEA CHANGE<br />

The Internet brought the potential<br />

to completely reinvent TV. First,<br />

it let users see what they wanted,<br />

when they wanted, while suppressing<br />

the need for additional hardware.<br />

Digital video recorders, notably the<br />

TiVo, popularized the concept of letting<br />

users choose more convenient<br />

times to watch their favorite programs.<br />

However, with the increase<br />

in bandwidth availability for the<br />

last mile—via cable and asymmetric<br />

digital subscriber line (ADSL) technol-<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

ogy—it makes more sense to stream<br />

the content directly from the Internet<br />

than record it for later use.<br />

Second, and more importantly, the<br />

Net removes the barrier that separates<br />

producers, distributors, and consumers.<br />

On the Internet, anyone can<br />

produce and distribute high-quality<br />

content. As a result, there is much<br />

more content available, making the<br />

competition for audiences tougher and<br />

changing viewing habits irreversibly.<br />

Third, the Internet allows mixing<br />

and matching of multisource content.<br />

It has become commonplace for networks<br />

to mix their own footage with<br />

user-generated content to provide a<br />

more holistic experience. Video production,<br />

distribution, and selection are<br />

no longer the privilege of a few. Users<br />

now have a front seat, forcing media<br />

giants to explore new business models.<br />

From a technical viewpoint, huge<br />

challenges remain, however, including<br />

the ability to process, index,<br />

store, and distribute nearly limitless<br />

amounts of data. This is why cloud<br />

<strong>computing</strong> will play a major role in<br />

redefining TV in the next few years.<br />

RAMPING UP<br />

Electronic devices that can be used<br />

to consume content on the Internet<br />

are proliferating at an increasing rate:<br />

PCs, tablet and laptop computers,<br />

PDAs, mobile phones, handheld video<br />

game consoles, and eBook readers,<br />

Published by the IEEE Computer Society<br />

not to mention router-type devices<br />

that let regular TV sets display Internet<br />

content.<br />

It seems our <strong>lives</strong> are driven by<br />

media displays, as Steve Jobs demonstrated<br />

with his recent unveiling<br />

of the iPad. It is easy to imagine a<br />

middle-class adult in the work force<br />

soon having access to two or more<br />

such displays on a regular basis.<br />

Displays can be organized in<br />

five strata, according to their evolution<br />

(B. Mazloff, Le 5éme écran<br />

– Les medias urbains dans la ville<br />

2.0 – editions Fyp - 2009), as Figure<br />

1 shows. Movie projection screens<br />

were the first to appear, in open<br />

public spaces. Then came the TV<br />

and PC—no longer public, but still<br />

collective. Mobile devices followed,<br />

for personal use in both private and<br />

public environments. More recently,<br />

public electronic displays on everything<br />

from billboards to bus stops are<br />

changing the urban landscape.<br />

Fifty years ago, video was produced<br />

in a single format since its<br />

consumption was restricted to some<br />

specific displays. Today, on the other<br />

hand, several different versions are<br />

required to enable access on PCs,<br />

iPhones, PDAs, game consoles,<br />

and other devices. This is a critical<br />

problem for broadcasters, as video<br />

processing is as computationally<br />

expensive as it is data intensive, consuming<br />

time and resources.<br />

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SOFTWARE TECHNOLOGIES<br />

Shared<br />

public<br />

spaces<br />

open<br />

access<br />

Besides the proliferation of different<br />

devices, it is not uncommon for<br />

the market to prefer particular platforms.<br />

A decade ago, RealNetworks’s<br />

RealVideo and RealMedia took the<br />

lead, followed by MS Windows Media<br />

and Adobe’s Flash, with the future<br />

looking toward HTML 5. Each of these<br />

technologies defined a set of associated<br />

formats, codecs, and transport<br />

protocols that everyone must follow.<br />

On top of that, the last mile is pushing<br />

the demand for high-quality content<br />

and high-definition videos that require<br />

many more computational resources.<br />

SPLIT AND MERGE<br />

Split and Merge is a cloud-based<br />

platform for distributed video<br />

encoding that can overcome these<br />

drawbacks. The basic idea is to use the<br />

cloud’s elasticity to engage resources<br />

dynamically, then distribute and parallelize<br />

the video-encoding processes.<br />

The Split and Merge platform, shown<br />

in Figure 2, was designed to reduce<br />

video-encoding times to fixed thresholds,<br />

independently of the input size<br />

of the video file, using only dynamic<br />

resource provisioning in the cloud.<br />

Split and Merge fragments every<br />

video received, processes the<br />

fragments in a distributed cloud<br />

environment, and merges partial<br />

results. As in most map-reduce implementations,<br />

it makes efficient use of<br />

available <strong>computing</strong> resources. It also<br />

allows for the customization of tech-<br />

COMPUTER<br />

Shared<br />

private<br />

space<br />

open<br />

access<br />

Shared<br />

private<br />

space<br />

restricted<br />

access<br />

Individual<br />

mobile<br />

very<br />

restricted<br />

access<br />

Shared<br />

public<br />

spaces<br />

open<br />

access<br />

Figure 1. Evolution of media display types. The Internet is enabling the rapid<br />

proliferation of electronic displays.<br />

niques used in the split, distribute,<br />

process, and merge steps as needed.<br />

This ensures flexibility, adaptation,<br />

extensibility, and the accommodation<br />

of different applications. In the<br />

case of video processing, allowing<br />

a choice among codecs, containers,<br />

audio streams, and different splitting<br />

techniques is paramount.<br />

Considering the growth of Internet<br />

video use along with the demand<br />

for higher-quality HD-level content,<br />

dealing efficiently with transcoding<br />

processes is a strategic priority. The<br />

cloud solution offers a competitive<br />

advantage by providing the unprecedented<br />

possibility of processing<br />

videos several hours long in the same<br />

time frame as those that run only a<br />

few minutes.<br />

DISTRIBUTION CHALLENGES<br />

Unlike TV signals, which are transmitted<br />

independently of the number<br />

of viewers, Internet media consumption<br />

is based on connectivity: Each<br />

user who wants to watch a video<br />

must open a separate connection.<br />

With unicast, the most popular distribution<br />

model, there is a separate<br />

connection for each user to the server<br />

responsible for content distribution.<br />

This limitation becomes increasingly<br />

evident when a variable volume of<br />

information must be processed to<br />

meet spikes in demand during, for<br />

example, popular sports competitions<br />

or public emergencies.<br />

No matter how resourceful the<br />

entity distributing the contents is,<br />

there will be peak times with excessive<br />

demand and other times of<br />

idleness. Given that service providers<br />

can build applications with an elastic<br />

infrastructure and adjust effectively<br />

to demand variations, the cloud has<br />

all the characteristics needed to deal<br />

with this type of content.<br />

In cases where there is a very<br />

large or seasonal demand, the use<br />

of public clouds for information processing<br />

and storage is emerging as an<br />

attractive alternative. The concept of<br />

hardware as a service (HaaS) relieves<br />

the necessity of making large infrastructure<br />

investments, while allowing<br />

on-the-fly resizing and adaptation to<br />

current needs.<br />

With a public cloud, users can<br />

quickly gauge the resources required<br />

to perform a particular task and pay<br />

only for those effectively used. A<br />

successful example of this is the registration<br />

system for the Big Brother<br />

Brasil reality TV show.<br />

The application process is open<br />

to any resident in the country, with<br />

contestants required to send a video<br />

of themselves in the format of their<br />

choice. Videos are encoded in the<br />

MPEG-2 standard to facilitate visualization<br />

by the jurors and spare them<br />

the hassle of dealing with a plethora<br />

of different codecs. The system is<br />

able to receive a very large number of<br />

videos during the three-month application<br />

process.<br />

The system in particular leverages<br />

the power of cloud <strong>computing</strong> to deal<br />

with uncertain storage and processing<br />

requirements, allocate resources<br />

needed during the application and<br />

selection processes, and scale up to<br />

rare but extreme high-peak situations—for<br />

example, during the last<br />

weekend, when 60 percent of the<br />

total submissions with about 200,000<br />

videos are expected.<br />

Applications with seasonal but<br />

very large demand are not rare.<br />

The Internet transmission of sports<br />

events such as FIFA’s World Cup and<br />

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the Olympics, and of breaking news<br />

such as Michael Jackson’s death,<br />

require a huge infrastructure for a<br />

very short time, making them killer<br />

cloud applications.<br />

CONSUMER CHALLENGES<br />

The new paradigm of video content<br />

consumption quickly became<br />

clear to major broadcasters, whose<br />

revenues had been falling consistently<br />

since 2005 and who had<br />

been forced to rethink their content<br />

distribution models. For example,<br />

NBC Universal partnered with News<br />

Corp. to launch Hulu.com in 2007,<br />

with Disney joining two years later.<br />

The popular website, which offers<br />

commercial-supported streaming<br />

video of TV shows and movies, aims<br />

to recover part of the lost revenue<br />

resulting from the decrease of traditional<br />

TV audiences.<br />

During the recent high-definition<br />

format war between HD-DVD (supported<br />

by Microsoft and Toshiba) and<br />

Blu-ray (supported by Sony) technologies,<br />

videogames played an important<br />

role. Sony pushed Blu-ray adoption,<br />

using the technology as the underlying<br />

basis for its PlayStation 3, which<br />

doubles as a Blu-ray disc player.<br />

Although Microsoft’s Xbox 360 console<br />

supported HD-DVD, a disc player<br />

sold as expansion hardware and was<br />

not required to play videogames.<br />

Shortly after Blu-ray emerged victorious<br />

in 2008 (http://news.bbc.co.uk/1/<br />

________________<br />

hi/business/7252172.stm), it become<br />

clear that Microsoft’s strategy was not<br />

focused on the disc formats but rather<br />

on the rising market for online video.<br />

In July 2008, less than six months<br />

after the end of the HD format wars,<br />

Microsoft announced its partnership<br />

with Netflix to stream movies and<br />

TV episodes using the XBox 360 console<br />

(www.microsoft.com/presspass/<br />

________________________<br />

press/2008/jul08/07-14instantstreampr.<br />

____ mspx). This constituted a shift from<br />

the paradigm of media discs, enabling<br />

console owners to rent movies with the<br />

press of a button. Apple offered a similar<br />

initiative with Apple TV, enabling<br />

chunk1 chunk2<br />

subscribers to download movies<br />

through its iTunes store.<br />

While the Internet offered new revenue<br />

possibilities, it also augmented<br />

the complexity of production and<br />

distribution business models. Hulu<br />

(www.fastcompany.com/magazine/<br />

_____________________<br />

140/the-unlikely-mogul.html), for<br />

example, preferred to follow a model<br />

similar to that used by TV, with<br />

commercial spots at intervals in the<br />

content. Even this simple model can<br />

be further refined, with Web technology<br />

easily identifying and addressing<br />

specific group campaigns such as<br />

gender, age, and location.<br />

Cable TV networks are pursuing<br />

a similar approach to avoid losing<br />

ground to Internet-based TV providers.<br />

Many have launched their own<br />

video sites, which offer added services<br />

to justify their value. For example,<br />

Comcast recently launched Xfinity<br />

(blogs.wsj.com/digits/2009/12/15/<br />

______________________<br />

comcast-opens-fancast-xfinity-tv), a<br />

service that lets users watch TV programming<br />

on the Internet anywhere.<br />

The popularity of online videos<br />

has also raised the interesting possibility<br />

of the Internet serving as a large<br />

and collaborative content producer,<br />

with user-generated content complementing<br />

TV programming.<br />

Tempo<br />

chunkN<br />

chunk1 chunk2 chunkN<br />

Full encoded video<br />

Figure 2. Split and Merge architecture. The system fragments every video received,<br />

processes the fragments in a distributed cloud environment, and merges partial<br />

results.<br />

Video production and distribution<br />

are no longer<br />

restricted to large broadcasters.<br />

Users now have the power<br />

to make, distribute, mix, and match<br />

their own content. Cloud <strong>computing</strong><br />

will play a decisive role in this<br />

extremely demanding scenario. The<br />

evolution of connectivity, coupled<br />

with the expected growth in bandwidth<br />

over the next decade, will<br />

indelibly change the face of TV.<br />

Karin Breitman is an assistant<br />

professor in the Departamento de<br />

Informática, PUC-Rio. Contact her at<br />

______________<br />

karin@inf.puc-rio.br.<br />

Markus Endler is an associate<br />

professor in the Departamento de<br />

Informática, PUC-Rio. Contact him at<br />

______________<br />

endler@inf.puc-rio.br.<br />

Rafael Pereira is a senior media engineer<br />

at Globo.com. Contact him at<br />

____________________<br />

rafael.pereira@corp.globo.com.<br />

Marcello Azambuja is a digital media<br />

manager at Globo.com. Contact him at<br />

azambuja@ieee.org.<br />

_____________<br />

Editor: Mike Hinchey, Lero—The Irish<br />

Software Engineering Research Centre;<br />

mike.hinchey@lero.ie<br />

____________<br />

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INVISIBLE COMPUTING<br />

Questioning Invisibility<br />

The invisibility of today’s<br />

technology is often a<br />

blessing. My laptop<br />

can be used as a word<br />

processor, TV, and stereo without<br />

COMPUTER<br />

Leah Buechley, MIT Media Lab<br />

Should invisibility be the guiding design goal for ubiquitous<br />

<strong>computing</strong>?<br />

A good tool is an invisible tool. By invisible, I mean that the tool does not intrude on your consciousness; you focus on the task,<br />

not the tool.<br />

– Mark Weiser<br />

changing shape, and I’m grateful<br />

that I don’t have to think about transistors,<br />

compilers, and operating<br />

systems while I use it. However, is<br />

invisibility always a good thing?<br />

Figure 1. Crashes and errors make the invisible technologies underlying our <strong>lives</strong><br />

alarmingly visible.<br />

Should it be the guiding design goal<br />

for ubiquitous <strong>computing</strong>?<br />

WHEN INVISIBILITY FAILS<br />

Benjamin Mako Hill has been<br />

examining instances where the invisibility<br />

of technology breaks down.<br />

His website, revealingerrors.com,<br />

documents occasions when a crash<br />

or error makes one of the invisible<br />

technologies underlying our <strong>lives</strong><br />

alarmingly visible, forcing us to confront<br />

its technological innards. Figure<br />

1 shows a few examples.<br />

The crashed ATM with its exposed<br />

Windows desktop and the GPS system<br />

that locates itself in the ocean are<br />

self-explanatory errors, but the third<br />

example requires some elucidation.<br />

The text at the top of the webpage<br />

should read “Gay eases into 100 final<br />

at Olympic trials,” Gay being the<br />

surname of athlete Tyson Gay. This<br />

strange headline reveals the fact that<br />

the website posting the news feed,<br />

a conservative network called One<br />

News Now, uses a program to adjust<br />

the language of AP news stories. Here<br />

we see that part of their program<br />

replaces instances of the word “gay”<br />

with the word “homosexual.”<br />

Hill argues that such breakdowns<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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Figure 2. The LilyPad Arduino toolkit consists of a set of sewable electronic modules that users can stitch together with electrically<br />

conductive thread to make interactive textile-based computers.<br />

aren’t necessarily bad. Though<br />

inconvenient and frustrating, they<br />

can reveal the inelegance, fragility,<br />

and questionable practices behind<br />

technological systems. I can use that<br />

information to make more informed<br />

decisions; I might very well change<br />

banks if I knew more about my favorite<br />

ATM’s operating system.<br />

Does this mean we should start<br />

designing error-prone systems? Of<br />

course not. But it does raise a question<br />

about the narrow design goal of<br />

invisibility. Systems that vanish into<br />

the background aren’t inherently<br />

good ones. The examples in Figure 1<br />

are troubling demonstrations of some<br />

of the things invisibility can hide.<br />

LEVERAGING VISIBILITY<br />

FOR EDUCATION<br />

The errors documented on Hill’s<br />

website are funny, fascinating, and<br />

enlightening; consequently, they<br />

provide wonderful opportunities for<br />

teaching and learning.<br />

Imagine the curiosity and delight<br />

that an encounter with one of these<br />

broken systems could inspire in a<br />

young person. There are two facets<br />

to this appeal. First, the errors are<br />

engaging—they surprise us and force<br />

us to notice technology we might<br />

have otherwise ignored. Second, they<br />

introduce legibility to technology—<br />

they reveal interesting information<br />

about how it works.<br />

In the research group I direct at<br />

the MIT Media Lab (hlt.media.mit.<br />

__________<br />

___ edu), we design educational technology<br />

that is deliberately engaging and<br />

legible. We exploit these properties<br />

to get students excited about technology.<br />

Our particular approach focuses<br />

on using new and unusual physical<br />

materials to create compelling and<br />

comprehensible systems.<br />

For example, during the past several<br />

years we have been working<br />

in the emerging field of electronic<br />

textiles, or “e-textiles,” integrating<br />

electronics, computers, and textiles.<br />

We began by tackling a fundamental<br />

engineering challenge: How do you<br />

attach computers to fabric? Once we<br />

had developed robust solutions to this<br />

problem, we focused on making the<br />

domain accessible to students.<br />

The result of our efforts was the<br />

LilyPad Arduino (L. Buechley et al.,<br />

“The LilyPad Arduino: Using Computational<br />

Textiles to Investigate<br />

Engagement, Aesthetics, and Diversity<br />

in Computer Science Education,” Proc.<br />

26th Ann. SIGCHI Conf. Human Factors<br />

in Computing Systems, ACM Press,<br />

2008, pp. 423-432). As the leftmost<br />

image in Figure 2 shows, this toolkit<br />

consists of a set of sewable electronic<br />

modules—similar in spirit to Lego<br />

Mindstorm modules—that users can<br />

stitch together with electrically conductive<br />

thread to make interactive<br />

textile-based computers.<br />

In a series of courses and workshops,<br />

we found that this very visible<br />

new technology could uniquely capture<br />

the imagination of teenagers<br />

and teach them the fundamentals of<br />

computer science and electrical engineering.<br />

Interestingly, young women<br />

were especially excited about this<br />

blend of textiles and <strong>computing</strong>. The<br />

other two images in Figure 2 show a<br />

young woman from one of our workshops<br />

first constructing and then<br />

modeling her course project, an interactive<br />

light-up jacket with an ambient<br />

thermometer.<br />

We’re now expanding this<br />

approach to another unusual material,<br />

paper—exploring how we can<br />

blend paper and paint with computers<br />

and electronics. We’ve designed a<br />

paper <strong>computing</strong> kit that consists of<br />

magnetic sensors, actuators, microcontrollers,<br />

and wireless devices;<br />

ferrous paper, to which the modules<br />

stick; and a jar of conductive paint,<br />

which is used to connect the modules<br />

across the paper. Students can<br />

use the kit to paint beautiful, functional<br />

electronic devices onto paper.<br />

Figure 3 shows images of a prototype<br />

kit and a construction example:<br />

an electronic pop-up book built by<br />

Jie Qi, an undergraduate researcher<br />

in our lab.<br />

We’ve just begun to hold workshops<br />

to explore how we might employ this<br />

kit to teach embedded <strong>computing</strong> (J. Qi<br />

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INVISIBLE COMPUTING<br />

Figure 3. Paper <strong>computing</strong> kit. Left: Prototype kit. Right: Electronic popables.<br />

and L. Buechley, “Electronic Popables:<br />

Exploring Paper-Based Computing<br />

through an Interactive Pop-up Book,”<br />

Proc. 4th Int’l Conf. Tangible, Embedded,<br />

and Embodied Interaction, ACM<br />

Press, pp. 121-128).<br />

Technologies like these—ones that,<br />

at their best, captivate, empower,<br />

and educate people—stand in direct<br />

opposition to ubicomp’s tenet of<br />

invisibility; the kits, and often the<br />

devices constructed with them as<br />

well, are intentionally visible objects<br />

that reveal the inner workings of technology<br />

and explicitly require users’<br />

time and attention.<br />

Other researchers have also noted<br />

this conflict between invisibility and<br />

education (M. Eisenberg et al., “Invisibility<br />

Considered Harmful: Revisiting<br />

Traditional Principles of Ubiquitous<br />

Computing in the Context of Education,”<br />

Proc. 4th IEEE Int’l Workshop<br />

Wireless, Mobile, and Ubiquitous Technology<br />

in Education, IEEE CS Press, pp.<br />

103-110; Y. Rogers, “Moving On from<br />

Weiser’s Vision of Calm Computing:<br />

Engaging UbiComp Experiences,”<br />

Proc. 8th Int’l Conf. Ubiquitous Computing,<br />

LNCS 4206, Springer, 2006, pp.<br />

404-421).<br />

INVISIBILITY, VISIBILITY,<br />

AND DESIGN<br />

In our <strong>lives</strong> there are objects we<br />

ignore and objects we treasure. Some<br />

vanish into the background and stay<br />

there and others please, amuse,<br />

COMPUTER<br />

and comfort us. There are the forgotten<br />

paper clips, printers, and<br />

towels, and the beloved dining room<br />

tables, sports uniforms, and jewelry.<br />

Why should ubicomp—or any<br />

other <strong>computing</strong> discipline, for that<br />

matter—consign itself to the ignored,<br />

invisible realm?<br />

Our research group strives to build<br />

systems that fit into people’s aesthetic<br />

and emotional <strong>lives</strong> as much as their<br />

technological ones. As Figures 2 and 3<br />

suggest, exploring the aesthetic possibilities<br />

of technology provides us with<br />

new and unusual ways to excite and<br />

engage students. We also investigate<br />

aesthetic and emotional dimensions<br />

when we develop systems that are<br />

less explicitly educational.<br />

A recent project along these lines<br />

is a unique piece of wallpaper that<br />

we constructed with our paper <strong>computing</strong><br />

kit. The Living Wall is a flat<br />

surface built out of ferrous paint,<br />

conductive paint, traditional paint,<br />

and electronics to which our paper<br />

<strong>computing</strong> modules can be attached.<br />

With its wide range of attachable<br />

components, the Living Wall can provide<br />

lighting, sense information about<br />

its environment, communicate with<br />

other devices like computers and<br />

phones, and act as a large-scale input<br />

device. The News Brief “Researchers<br />

Build a Wall That Acts Like a Remote<br />

Control” on p. 18 has more information<br />

on the system and an illustration<br />

of its use.<br />

The Living Wall is a flexible ubicomp<br />

system. However, it also<br />

functions as a decorative element<br />

in a home. Like the other examples<br />

mentioned here, it wasn’t designed<br />

to be invisible; it elicits and rewards<br />

attention.<br />

Invisibility is a narrow design<br />

goal. It’s not necessarily a bad<br />

one, but it doesn’t capture the<br />

full range of technological or creative<br />

possibilities. If we as computer scientists<br />

and engineers only strive to<br />

build invisible systems, we’ll neglect<br />

to build important technology that is<br />

educational, engaging, and beautiful.<br />

We should expand our focus and our<br />

rhetoric.<br />

Leah Buechley is an assistant professor<br />

and AT&T Career Development<br />

Professor of Media Arts and Sciences<br />

at MIT Media Lab, where she also<br />

directs the High-Low Tech research<br />

group. Contact her at leah@media.<br />

mit.edu.<br />

Editor: Albrecht Schmidt, Institute for<br />

Computer Science and Business Information<br />

Systems, University of Duisburg-Essen,<br />

Germany; albrecht.schmidt@gmail.com<br />

Selected CS articles and columns<br />

are available for free at<br />

http://ComputingNow.computer.org.<br />

Join the<br />

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Computer<br />

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EDUCATION<br />

Cutting Across<br />

the Disciplines<br />

Jim Vallino,<br />

Rochester Institute of Technology<br />

Engineering and <strong>computing</strong> educators must design curricula<br />

that require students to work outside their own domain.<br />

Multidisciplinary,<br />

interdisciplinary,<br />

transdisciplinary—<br />

these terms are<br />

all the buzz in engineering and<br />

<strong>computing</strong> curriculum design.<br />

Throughout their career, most<br />

graduates will work on project<br />

teams with people from multiple<br />

fields of expertise. Engineering and<br />

<strong>computing</strong> educators must accordingly<br />

design curricula that require<br />

students to work outside of their<br />

own domain. This opportunity can<br />

range from small-group collaboration<br />

in a single course to large-scale<br />

efforts that span every program at<br />

an institution.<br />

There is often resistance to incorporating<br />

multidisciplinary work into<br />

curricula. Academic institutions,<br />

like most other organizations, have<br />

administrative and management<br />

entities that can unintentionally construct<br />

impediments to cutting across<br />

entrenched boundaries. At colleges<br />

and universities, fingers usually point<br />

at the department as the main culprit.<br />

Typical impediments are joint sched-<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

uling of cross-listed courses, faculty<br />

teaching-load accounting, and support<br />

for shared facilities.<br />

One reaction to this is a push to<br />

eliminate administrative entities.<br />

However, this creates a new set of<br />

problems when program responsibility<br />

becomes ill-defined. At the core,<br />

what is required is a commitment<br />

to improve students’ education by<br />

promoting multidisciplinary teams<br />

and projects. The motivation may<br />

be provided top-down, especially<br />

for institute-wide programs, but<br />

in most cases it will be a limited<br />

effort led from the bottom up by a<br />

small number of individual faculty<br />

members.<br />

ACCREDITATION<br />

PROVIDES A MOTIVATION<br />

Whether you believe that multidisciplinary<br />

work will be the savior<br />

of engineering and <strong>computing</strong> education<br />

or is just another fad that<br />

will blend into the curriculum landscape,<br />

educators will see it in one<br />

form or another in the foreseeable<br />

future.<br />

Published by the IEEE Computer Society<br />

Programs accredited by the Engineering<br />

Accreditation Commission of<br />

ABET (www.abet.org) must demonstrate<br />

that students have<br />

“(c) an ability to design a system,<br />

component, or process to meet<br />

desired needs within realistic<br />

constraints such as economic,<br />

environmental, social, political,<br />

ethical, health and safety, manufacturability,<br />

and sustainability”;<br />

“(d) an ability to function on<br />

multidisciplinary teams”; and<br />

“(h) the broad education necessary<br />

to understand the impact of<br />

engineering solutions in a global,<br />

economic, environmental, and<br />

societal context.”<br />

All three of these program outcomes<br />

look beyond a traditional<br />

single-discipline curriculum. Because<br />

the program is responsible for demonstrating<br />

these outcomes, the<br />

experiences can’t be haphazardly<br />

inserted in the curriculum or based<br />

on elective coursework that students<br />

may or may not actually take.<br />

APRIL 2010<br />

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COMPUTER<br />

EDUCATION<br />

The Computing Accreditation<br />

Commission specifies similar criteria<br />

for the accreditation of <strong>computing</strong><br />

programs.<br />

The broad field of <strong>computing</strong> cuts<br />

across disciplines in unique ways.<br />

Computing typically has a domain<br />

presence as a necessary tool rather<br />

than an area of detailed study—<br />

students must learn the fundamentals<br />

of <strong>computing</strong> to successfully<br />

apply it in all their work. Perhaps<br />

more important, they also must<br />

learn when a project has a <strong>computing</strong><br />

component that requires deeper<br />

expertise. This becomes an opportunity<br />

for educators to blend programs<br />

in <strong>computing</strong>, engineering, and other<br />

disciplines across an institution.<br />

MULTIDISCIPLINARY<br />

IN THE SMALL<br />

There are conflicting definitions<br />

for the terms multidisciplinary, interdisciplinary,<br />

and transdisciplinary,<br />

but educators shouldn’t get stuck on<br />

what to call it. Any approach that<br />

gets students interacting with material<br />

and people outside their own<br />

technical discipline, or in ways that<br />

are atypical for their discipline, is<br />

beneficial.<br />

Those who want to experiment<br />

with a multidisciplinary approach<br />

should start small within one of their<br />

courses by assigning exercises to<br />

students that require them to think<br />

from unfamiliar perspectives. In one<br />

course, I ask students to capture their<br />

thoughts on aspects of the course<br />

material in Haiku poems. Here’s an<br />

example of one called “Basic Principles”<br />

from a software engineering<br />

design course:<br />

Coupling, Cohesion<br />

Antagonistic forces<br />

Tradeoffs to be made.<br />

In that same course, I have students<br />

ask themselves about the<br />

structure shown in M.C. Escher’s<br />

Waterfall (www.mcescher.com/<br />

_____________________<br />

Gallery/recogn-bmp/LW439.jpg). For<br />

each of those questions about this<br />

illusionary structure, I ask them<br />

to pose an analog question when<br />

studying the design of a software<br />

system.<br />

This exercise isn’t what most<br />

readers may have in mind when<br />

they think multidisciplinary, but on<br />

a small scale that a faculty member<br />

can do in any course, it requires students<br />

to think using paradigms from<br />

other disciplines.<br />

The next step would be to have students<br />

enrolled in courses in different<br />

The students as well as the instructor must commit<br />

to the multidisciplinary approach.<br />

disciplines collaborate on projects.<br />

Individual faculty can coordinate this<br />

with little administrative support. As<br />

in all such instances, the students as<br />

well as the instructor must commit<br />

to the multidisciplinary approach: A<br />

project that serves as an extracurricular<br />

or small-credit activity for some<br />

students but counts as significant<br />

coursework for others won’t be very<br />

effective.<br />

MULTIDISCIPLINARY<br />

BY DESIGN<br />

If educators intend the multidisciplinary<br />

experience to satisfy<br />

accreditation requirements, it’s preferable<br />

to carefully design it into a<br />

program.<br />

All ABET-accredited software engineering<br />

programs require students to<br />

be able to work in one or more major<br />

application domains. However, what<br />

constitutes an application domain<br />

varies widely across programs (D.<br />

Bagert, “The Role of Application<br />

Domain Tracks in Software Engineering<br />

Programs,” Proc. 2006 Ann.<br />

Conf. Am. Soc. for Eng. Education,<br />

ACEE, 2006; http://soa.asee.org/paper/<br />

_______________________<br />

conference/paper-view.cfm?id=2832).<br />

Our software engineering program<br />

at the Rochester Institute of<br />

Technology (RIT) uses application<br />

domains as a vehicle to expose students<br />

to uses of <strong>computing</strong> outside<br />

their comfort zones. Each domain<br />

requires three courses, at least two<br />

of which must be taken from colleges<br />

other than our College of Computing<br />

and Information Sciences. This<br />

prevents the application domain<br />

from being simply a set of <strong>computing</strong><br />

electives.<br />

A cross-curriculum multidisciplinary<br />

approach involves designing<br />

a course, or course cluster, with<br />

multi-disciplinary interaction as a<br />

basic course principle. Educators<br />

must make the course material<br />

interesting and accessible to students<br />

from all the disciplines expected to<br />

participate.<br />

This can be challenging. With a<br />

computer engineering colleague, I<br />

created a cluster of three courses<br />

in real-time and embedded systems<br />

at RIT (J. Vallino and R.S.<br />

Czerniskowski, “Interdisciplinary<br />

Teaming as an Effective Method to<br />

Teach Real-Time and Embedded Systems<br />

Courses,” Proc. 2008 Workshop<br />

Embedded Systems Education, 2008,<br />

pp. 25-32). Even with closely related<br />

disciplines like software engineering<br />

and computer engineering, it<br />

was more difficult than we originally<br />

thought to keep the course interest<br />

balanced between the two.<br />

Educators must carefully select<br />

course projects to ensure that all<br />

disciplines contribute in different<br />

but equivalent ways. Some registration<br />

controls may be needed to<br />

help maintain balance across all<br />

disciplines. Ideally, these courses<br />

are team taught, but unless an<br />

institution’s teaching-load accounting<br />

easily accommodates that<br />

arrangement, it may have to settle<br />

for more traditional single-instructor<br />

teaching.<br />

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Finally, what seems like it should<br />

be easy could require regular attention.<br />

Each term, we have to schedule<br />

multiple course listings at the same<br />

time, in the same room, and with a<br />

common final exam time.<br />

We’re currently applying lessons<br />

learned from the successful multidisciplinary<br />

real-time and embedded<br />

systems cluster to an applied cryptography<br />

cluster incorporating computer<br />

science, computer engineering, and<br />

software engineering.<br />

LARGEfiSCALE<br />

MULTIDISCIPLINARY<br />

EXPERIENCES<br />

More ambitious forays into multidisciplinary<br />

work require significantly<br />

more coordination and administrative<br />

support. RIT has implemented many<br />

such programs for seniors in its College<br />

of Engineering (P.H. Stiebitz, E.C.<br />

Hensel, and J.R. Mozrall, “Multidisciplinary<br />

Engineering Senior Design<br />

at RIT,” Proc. 2004 Ann. Conf. Am.<br />

Soc. for Eng. Education, ACEE, 2004;<br />

http://soa.asee.org/paper/conference/<br />

_________________<br />

paper-view.cfm?id=20471).<br />

Extended multidisciplinary<br />

efforts start with designing appropriate<br />

content and uniform assessment<br />

mechanisms for courses that encompass<br />

a wide range of projects. It’s<br />

usually necessary to designate a<br />

project coordinator to solicit sufficient<br />

cross-disciplinary content<br />

from internal and external sponsors.<br />

Faculty coaches or advisors must be<br />

assigned to every project along with<br />

a student team. To achieve faculty<br />

buy-in, it may be necessary to give<br />

teaching credit to those working<br />

with project teams.<br />

Accreditation requirements initially<br />

motivate many college-level<br />

multidisciplinary programs. Once<br />

the programs have overcome startup<br />

problems and are steadily operating,<br />

however, the benefits beyond accreditation<br />

become evident.<br />

Ultimately, educators may want to<br />

embrace a multidisciplinary culture<br />

that spans the entire institution—for<br />

example, including business, fine<br />

arts, and liberal arts as well as engineering<br />

and <strong>computing</strong>. This might<br />

be tied to initiatives requiring undergraduate<br />

students to have research or<br />

international study experience.<br />

Cutting across disciplines with<br />

diverse curriculum models adds new<br />

challenges to making multidisciplinary<br />

work a reality. There should<br />

be a way to define projects from any<br />

corner of the campus. Each project<br />

needs at least one faculty member as<br />

an advocate to specify the necessary<br />

team skills.<br />

Every program must offer students<br />

an opportunity for required or elective<br />

multidisciplinary project work.<br />

Students could search a project registration<br />

database for interesting<br />

projects, or the system could suggest<br />

projects based on students’ selfdefined<br />

skill sets.<br />

Some material, such as discussion<br />

of problem-solving techniques<br />

and how to be a good team player,<br />

should be common to all projects or<br />

integrated into prerequisite courses,<br />

perhaps hosted by multiple entities<br />

using different paradigms. Students<br />

could be required to, for example,<br />

take a problem-solving course appropriate<br />

for their home discipline and<br />

one from another area.<br />

To satisfy accreditation requirements,<br />

a faculty member in a<br />

student’s home discipline would<br />

need to review the student’s work<br />

to ensure that he or she has gained<br />

discipline-appropriate experience on<br />

the project.<br />

The pressure on engineering<br />

and <strong>computing</strong> curricula<br />

is to broaden programs<br />

(National Academy of Engineering,<br />

The Engineer of 2020: Vision of Engineering<br />

in the New Century, National<br />

Academies Press, 2004). Many educators<br />

view the current curriculum<br />

model for most programs as being<br />

too focused. I’ve been in meetings<br />

where a view was expressed that<br />

highly structured engineering programs<br />

are a primary impediment<br />

to creative and innovative thought.<br />

I certainly don’t subscribe to that<br />

view, but given the direction that<br />

engineering and <strong>computing</strong> education<br />

is headed, I have some concerns.<br />

Teams work best when they bring<br />

together people with individual depth<br />

in multiple disciplines who are open<br />

to cutting across the disciplines.<br />

Will a collection of broadly trained<br />

students be as effective as one of students<br />

who have depth in their own<br />

individual disciplines?<br />

One benefit of multidisciplinary<br />

projects is the presence of “low-hanging<br />

fruit” between the disciplines.<br />

As institutions broaden programs<br />

and students attain breadth across<br />

disciplines, will educators abandon<br />

individual disciplines themselves<br />

in pursuit of easy-to-pick fruit? Will<br />

students be able to tackle the hard<br />

problems in the individual disciplines<br />

or even in the multidisciplinary<br />

domain?<br />

When redesigning curricula to<br />

incorporate multidisciplinary activities,<br />

educators must be careful. To<br />

students’ potential employers, it could<br />

be a short curricular distance from<br />

“Your students need more breadth”<br />

to “Your students don’t know very<br />

much.”<br />

Jim Vallino is a professor in the<br />

Department of Software Engineering<br />

in the B. Thomas Golisano College of<br />

Computing and Information Sciences<br />

at Rochester Institute of Technology.<br />

Contact him at j.vallino@se.rit.edu.<br />

_____________<br />

Editor: Ann E.K. Sobel, Department of<br />

Computer Science and Software Engineering,<br />

Miami University; sobelae@muohio.edu<br />

____________<br />

Selected CS articles and columns<br />

are available for free at ____<br />

http://<br />

ComputingNow.computer.org.<br />

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COMPUTER<br />

SECURITY<br />

Integrating Legal<br />

and Policy Factors in<br />

Cyberpreparedness<br />

James Bret Michael, Naval Postgraduate School<br />

John F. Sarkesain, Aerospace Corp.<br />

Thomas C. Wingfield, George C. Marshall European<br />

Center for Security Studies<br />

Georgios Dementis, Hellenic Navy<br />

Gonçalo Nuno Baptista de Sousa, Portuguese Navy<br />

Cyberwarfare countermeasures must consider more than<br />

technological capabilities.<br />

Attacks in cyberspace<br />

are commonplace. The<br />

effects of such attacks<br />

can range from minor<br />

nuisances, such as defacing webpages<br />

or temporarily denying service<br />

to noncritical systems, to major disturbances<br />

that interrupt international<br />

commerce or threaten to destabilize<br />

a nation-state.<br />

Anyone can wage an attack in<br />

cyberspace: individual citizens,<br />

criminal syndicates, terrorist organizations,<br />

even entire nations. Such<br />

attacks can be extremely sophisticated<br />

and involve many actors. The<br />

cyberattacks on Estonia in 2007 by<br />

so-called “patriotic hackers,” criminal<br />

elements that leased out botnets,<br />

and alleged state-sponsored information<br />

warriors combined some<br />

of the characteristics of a military<br />

campaign with those of a covert<br />

operation (www.economist.com/<br />

________________________<br />

world/international/displaystory.<br />

cfm?story_id=E1_JNNRSVS).<br />

__________________<br />

CYBERPREPAREDNESS<br />

Regardless of who perpetrates<br />

a cyberattack, defenders of the<br />

attacked systems must be prepared<br />

to respond, even if only to mitigate<br />

the attack’s effects. Cyberpreparedness<br />

can be said to have three<br />

dimensions (E. Tikk and T. Wingfield,<br />

“Frameworks for International Cyber<br />

Security: The Cube, the Pyramid, and<br />

the Screen,” presentation, Int’l Cyber<br />

Conflict Legal and Policy Conf., 2009):<br />

technical feasibility—the<br />

“possible”;<br />

legal—the “permissible”; and<br />

policy—the “preferable.”<br />

From a technical vantage, a<br />

defender could use a computerbased<br />

tool such as NetSPA to assess<br />

a computer network’s vulnerability<br />

to attack and develop appropriate<br />

countermeasures (K. Ingols et al.,<br />

“Modeling Modern Network Attacks<br />

and Countermeasures Using Attack<br />

Graphs,” Proc. Ann. Comp. Security<br />

Applications Conf., IEEE, 2009, pp. 117-<br />

126). However, a defender also needs<br />

a distributed command, control, and<br />

battle management (C2/BM) system<br />

to maintain situational awareness of<br />

and respond to cyberattacks in nearreal<br />

time (N. Howes, M. Mezzino,<br />

and J. Sarkesain, “On Cyber Warfare<br />

Command and Control Systems,”<br />

Proc. 9th Ann. Int’l Command and Control<br />

Research and Technology Symp.,<br />

2004; www.dodccrp.org/events/9th_<br />

____________________<br />

ICCRTS/CD/papers/118.pdf).<br />

_________________<br />

LAW AND POLICY<br />

Turning now to the “permissible”<br />

and “preferable,” the customary<br />

guiding principles of jus in bello,<br />

“customary legal standards for the<br />

conduct of war”—discrimination,<br />

necessity, proportionality, and chivalry—also<br />

apply to cyberwarfare,<br />

as does the jus ad bellum, “law governing<br />

the transition from peace to<br />

war” (J.B. Michael, “On the Response<br />

Policy of Software Decoys: Conducting<br />

Software-Based Deception in<br />

the Cyber Battlespace,” Proc. 26th<br />

Ann. Int’l Computer Software and<br />

Apps. Conf., IEEE, 2002, pp. 957-962).<br />

Cyberattacks can have the equivalent<br />

effects of attacks waged with kinetic<br />

weapons, rising to the level of a “use<br />

of force” under international law (J.B.<br />

Michael, T. Wingfield, and D. Wijesekera,<br />

“Measured Responses to Cyber<br />

Attacks Using Schmitt Analysis: A<br />

Case Study of Attack Scenarios for<br />

a Software-Intensive System,” Proc.<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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26th Ann. Int’l Computer Software<br />

and Applications Conf., IEEE, 2003,<br />

pp. 622-627).<br />

Thus, regardless of the technical<br />

measures used, law and policy must<br />

be in place to guide defenders as<br />

they craft responses to cyberattacks.<br />

Although a response might be legal,<br />

policy dictates the latitude in applying<br />

the law, taking into consideration<br />

such factors as the impact on society,<br />

diplomatic relations, and even<br />

privacy concerns, such as a given<br />

response’s level of intrusiveness. The<br />

currency of the topic of cyberpreparedness<br />

is evidenced by the recent<br />

front-page news account of the legal<br />

and policy discussions that ensued<br />

prior to the cyberattack sponsored<br />

by the US Department of Defense to<br />

dismantle an online forum used by<br />

terrorists to plan kinetic attacks on<br />

US troops (E. Nakashima, “For Cyberwarriors<br />

Murky Terrain; Dismantling<br />

of Saudi-CIA Web Site Illustrates need<br />

for Clearer Cyberwar Policies,” The<br />

Washington Post, 19 March 2010, pp.<br />

A1 and A16). Policy issues included<br />

the impact on US-Saudi relations and<br />

whether the response should be conducted<br />

as an intelligence or military<br />

operation.<br />

In addition, techniques for conducting<br />

principled analyses must be<br />

ready to help minimize legal uncertainty<br />

about cyberincidents and allow<br />

the most complete range of effective<br />

responses. Whether the response is<br />

conducted via kinetic or cyber means,<br />

it must be lawful (T. Wingfield, The<br />

Law of Information Confiict: National<br />

Security Law in Cyberspace, Aegis<br />

Research Corp., 2000).<br />

LEVERAGING THE<br />

LEGAL CELL<br />

We propose merging the three<br />

dimensions of cyberpreparedness<br />

by adding a new type of virtual cell<br />

to cybersystems: the legal cell.<br />

Virtual cells within such systems<br />

serve as dynamic virtual<br />

communities in which cyberopera-<br />

tors can interact in support of making<br />

informed decisions. Cyberoperators<br />

encompass subject-matter experts<br />

in cyberoperations along with the<br />

related communities of the diplomatic<br />

corps, intelligence analysts, the<br />

military, politicians, legal authorities,<br />

law-enforcement agents, economists,<br />

and those responsible for creating<br />

and maintaining the national critical<br />

infrastructure. Cyberoperators can<br />

create, join, leave, and even dissolve<br />

cell instantiations.<br />

The legal cell provides cyberoperators<br />

with the means to obtain<br />

advice from experts in information<br />

operations (IO) law. Within cyber C2/<br />

BM systems, cells subscribe to infor-<br />

We propose merging<br />

the three dimensions<br />

of cyberpreparedness<br />

by adding a new type<br />

of virtual cell to cybersystems:<br />

the legal cell.<br />

mation and the system publishes it<br />

continuously in a digestible format.<br />

This differs from the information-pull<br />

approach incorporated into most of<br />

today’s C2/BM systems when used in<br />

conjunction with kinetic warfare.<br />

Through the legal cell, IO experts<br />

can maintain a current picture of the<br />

cyberspace situation and provide<br />

advice as needed. This is an important<br />

capability, given the rapid tempo<br />

of cyberbattles and the high degree<br />

of space compression, which asserts<br />

that the physical distance from a<br />

target does not matter as it would<br />

with kinetic weapons and that a<br />

flattened command structure is necessary<br />

for conducting cyberwarfare.<br />

On instantiation of a legal cell, the<br />

system populates it with presumptions<br />

and algorithms. In this context,<br />

presumptions follow black-and-white<br />

if-then rules automatically enacted by<br />

mobile agents, whereas algorithms<br />

involve more complex data processing<br />

than with production rules but,<br />

like presumptions, are processed<br />

without human intervention and<br />

whose results trigger a course of<br />

action.<br />

These three elements—the law,<br />

presumptions, and algorithms—are<br />

what Tikk and Wingfield refer to as<br />

the “pyramid,” representing decision<br />

making along a continuum of<br />

operational speed and the inherent<br />

limitations on what types of problems<br />

computers solve in support of decision<br />

making.<br />

ATTACK RESOLUTION<br />

Given the unpredictability and<br />

quickness of cyberattacks, a rapid<br />

response is critical, necessitating<br />

use of at least some autonomic<br />

systems. According to a report by<br />

the National Institute of Standards<br />

and Technology (NIST) outlining a<br />

smart grid cybersecurity strategy<br />

and requirements (http://csrc.nist.<br />

gov/publications/drafts/nistir-7628/<br />

draft-nistir-7628_2nd-public-draft.<br />

__<br />

pdf).<br />

Ultimately, the cyberoperation<br />

leader will ascertain the effect of<br />

the attack’s automated response,<br />

particularly in the military because<br />

a commander cannot delegate<br />

responsibility for the actions of their<br />

command. While a commander may<br />

delegate the authority to execute<br />

certain actions on to a subordinate<br />

within the command, the commander<br />

still retains full and complete responsibility<br />

for the outcome of those<br />

delegated actions, for good or bad.<br />

Some defensive systems that involve<br />

using kinetic weapons require extensive<br />

automation, such as those used<br />

for ballistic missile defense, in which<br />

the duty cycle for core functions of<br />

the so-called “kill chain”—detect,<br />

track, assign weapons, engage, and<br />

assess outcome—cannot be performed<br />

by humans swiftly enough to<br />

achieve the desired levels of operational<br />

effectiveness.<br />

APRIL 2010<br />

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92<br />

COMPUTER<br />

SECURITY<br />

An example of a presumption in<br />

this context is: “If a tracked object<br />

enters a restricted airspace, then<br />

assign a weapon to that object and<br />

engage.” An instance of engaging<br />

the human operator would occur if,<br />

for example, the US were to have a<br />

chance to intercept missiles over<br />

another country. In this case, intercepting<br />

the missiles would be lawful<br />

but the potential consequences—<br />

such as residual debris from the<br />

missiles’ chemical, nuclear, or biological<br />

payloads landing on the other<br />

country’s territory—would need to be<br />

weighed against the risk of the missiles<br />

reaching their targets.<br />

Other aspects of preparedness<br />

could be incorporated into cyber<br />

C2/BM systems, such as a brokering<br />

capability to facilitate controlled dissemination<br />

of information among<br />

cyberoperators from different<br />

administrative domains who are collaborating<br />

in an ad hoc but formal<br />

coalition, or persistent operations to<br />

defend assets through their combined<br />

cyberwarfare resources.<br />

For example, a legal advisor might<br />

need to subscribe to certain data<br />

feeds to pull together the information<br />

required to make a legal determination,<br />

but he or she might not have a<br />

need to know about where the data<br />

originated or related information.<br />

That is, the brokering capability provides<br />

a means for enabling the sharing<br />

of information by protecting the anonymity<br />

of the information sources<br />

and their methods of collection, only<br />

sharing what cyberoperators playing<br />

particular roles are entitled to access.<br />

Such an information-sharing capability<br />

would have been useful to the<br />

informal assembly of private- and<br />

public-sector organizations that came<br />

to the aid of Estonia in 2007.<br />

Systems have become increasingly<br />

interconnected through trends such<br />

as the adoption of cloud <strong>computing</strong><br />

and the creation of systems of systems.<br />

These compositions provide<br />

one or more value-added capabilities<br />

that none of the individual systems<br />

can deliver on their own. Preparedness<br />

for cyberattacks will entail<br />

cooperation between the many stakeholders<br />

in these systems, even with<br />

sound mechanisms for containment<br />

of behavior between systems.<br />

Efforts at achieving cyberpreparedness,<br />

such as that by NIST, are<br />

a step in the right direction, as the<br />

NIST report on the smart grid shows:<br />

Some of the responses [to cyber<br />

attacks] must be autonomic—timely<br />

response is a critical requirement for<br />

grid reliability. However, for a quick<br />

response to treat the symptom locally<br />

and effectively, the scope and extent<br />

of the impact of the failure needs to be<br />

quickly determined. Not all responses<br />

are autonomic however. New research<br />

is needed to measure and identify<br />

the scope of a cyber attack and the<br />

dynamic cyber threat response options<br />

available in a way that can serve as a<br />

decision support tool for the human<br />

operators.<br />

We believe that our<br />

research is on target<br />

regarding support for<br />

cyber command-and-control understanding,<br />

planning, and decision<br />

activities. Preparation must include<br />

provision of integrated full-spectrum<br />

capabilities in cyber C2/BM systems<br />

along with specialized dynamic virtual<br />

cells like the proposed legal cell<br />

enabling collaboration among cyberoperators<br />

proactively.<br />

James Bret Michael is a professor in<br />

the Department of Computer Science<br />

and a member of the Center for Cyber<br />

Warfare at the Naval Postgraduate<br />

School. Contact him at bmichael@<br />

nps.edu.<br />

_____<br />

John F. Sarkesain is a senior engineer<br />

with the Aerospace Corporation. Contact<br />

him at john.f.sarkesain@aero.org.<br />

Thomas C. Wing eld is a professor<br />

at the George C. Marshall European<br />

Center for Security Studies. Contact<br />

him at ____________________<br />

thomas.c.wing eld@marshallcenter.org.<br />

_______<br />

Georgios Dementis is a lieutenant<br />

in the Hellenic Navy. Contact him at<br />

ydementis@gmail.com.<br />

_______________<br />

Gonçalo Nuno Baptista de Sousa is<br />

a lieutenant in the Portuguese Navy.<br />

Contact him at _______________<br />

goncalobsousa@gmail.<br />

___ com.<br />

Editor: Jeffrey Voas, National Institute<br />

of Standards and Technology;<br />

j.voas@ieee.org<br />

_________<br />

________<br />

_________________<br />

Disclaimer<br />

The views and conclusions<br />

contained herein are those<br />

of the authors and should not<br />

be interpreted as necessarily<br />

representing the official policies<br />

or endorsements of the US<br />

Government.<br />

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BOOKSHELF<br />

Topology for Computing, Afra<br />

J. Zomorodian. This emerging<br />

field utilizes theory from<br />

topology and the power of <strong>computing</strong><br />

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Recent applications include computer<br />

graphics, CAD, and structural<br />

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the intrinsic shape of some<br />

real or abstract space. The author<br />

strives to present basic concepts<br />

from topology and Morse theory so<br />

that nonspecialists can grasp and<br />

participate in current research in<br />

computational topology.<br />

This book’s self-contained presentation<br />

of mathematical concepts<br />

from a computer scientist’s viewpoint<br />

combines point set and algebraic<br />

topologies, group theory, differential<br />

manifolds, and Morse theory. The<br />

author also presents some recent<br />

advances in the area, including topological<br />

persistence and hierarchical<br />

Morse complexes. Throughout, the<br />

focus is on computational challenges<br />

and presenting algorithms and data<br />

structures when appropriate.<br />

Cambridge University Press; ____ www.<br />

cambridge.org; ISBN-978-0-521-<br />

13609-9, 258 pp.<br />

Symbolic Dynamics and Geometry<br />

Using D* in Graphics and Game<br />

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The symbolic-differentiation capabilities<br />

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Many applications of D* are covered,<br />

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simulation and procedural 3D<br />

0018-9162/10/$26.00 © 2010 IEEE<br />

geometric modeling—are developed<br />

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A K Peters, Ltd; www.akpeters.<br />

___ com; ISBN-978-1-56881-280-9,<br />

250 pp.<br />

Leading the Virtual Workforce:<br />

How Great Leaders Transform<br />

Organizations in the 21st Century,<br />

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ago, going to work meant driving<br />

to a physical location to interact<br />

face-to-face with a boss and coworkers.<br />

Today, this might only require<br />

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office or joining a videoconference.<br />

According to the author, the implications<br />

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and require a whole new leadership<br />

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workers set to become 73 percent of<br />

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According to Lojeski, physical separation,<br />

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When virtual distance is relatively<br />

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Wiley; www.wiley.com; 978-0-470-<br />

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Touch of Class: Learning to Program<br />

Well with Objects and<br />

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Springer; www.springer.com; 978-<br />

3-540-92144-8; 876 pp.<br />

Inside Larry and Sergey’s Brain,<br />

Richard L. Brandt. This book<br />

focuses on what drives these two<br />

men and where they will take Google.<br />

Looking at this brainchild of two brilliant<br />

minds, the author examines<br />

Google’s business decisions in light<br />

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Larry is the main strategist, while<br />

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Send book announcements to<br />

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APRIL 2010 93<br />

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94<br />

COMPUTER<br />

THE PROFESSION<br />

Currently, it has taken the form of an<br />

eBook reader with an easy-to-read<br />

display. However, even when we leverage<br />

an innovative distribution system<br />

using wireless technology, presenting<br />

static books falls short of employing<br />

the computer to full advantage.<br />

With larger displays, fiexible and<br />

lightweight units, and full color we<br />

may see more dramatic changes.<br />

Will eInk replace printed paper in<br />

all domains or be the savior of traditional<br />

newspapers? If the technology<br />

matures the consequences will be<br />

dramatic for many industries. But this<br />

particular if entails speculation.<br />

Instead of focusing on possible<br />

advances in new technologies, we<br />

observe that change may also come<br />

based on ingredients that have been<br />

present for some time. Email and TCP/<br />

IP provide good examples. It took<br />

many years from when the technology<br />

and standards emerged to when<br />

they saturated society and made a<br />

major impact.<br />

POS<br />

The technology that provides<br />

our case study here is the simple<br />

point-of-sale (POS) terminal. This<br />

technology was not developed to<br />

change the world, but simply to<br />

make monetary transactions easier.<br />

By using a credit or cash card, the<br />

terminal lets us perform an alldigital<br />

transaction with no cash<br />

involved. The advantages of this<br />

are so substantial that in many<br />

countries a large percentage of all<br />

monetary transactions are digital,<br />

based on POS terminals or using<br />

credit cards over the Internet. Data<br />

is captured automatically and can be<br />

transferred at almost no cost.<br />

At the same time, this information<br />

can be used directly for inventory<br />

Continued from page 96<br />

control, accounting, and statistics.<br />

In my home country, Norway, people<br />

can avoid cash altogether, because<br />

all shops, hotels, restaurants, gas stations,<br />

cabs, and many buses allow<br />

digital payment. Most banks offer free<br />

service, and cards are used also for<br />

very small amounts. Even the pizza<br />

boy brings along a wireless POS terminal.<br />

Looking at value, 98 percent of<br />

all monetary transactions in Norway<br />

are digital. In Stockholm, people can<br />

even pay their bus fare by cell phone.<br />

Small countries have an advantage<br />

and can often offer high dissemination<br />

numbers for new technologies.<br />

National standards are easier to<br />

implement in a small country than in<br />

a large one. Fewer installations make<br />

it easier to update equipment, while<br />

a homogeneous population makes it<br />

Small countries have an advantage and can often offer<br />

high dissemination numbers for new technologies.<br />

simpler for people to accept new services.<br />

However, larger countries are<br />

following suit in the digital economy.<br />

A few years ago travelers needed<br />

cash when in cities such as Rome and<br />

Madrid. Today nearly all businesses<br />

accept a card.<br />

CASHfiFREE SOCIETY<br />

When only a small fraction of<br />

transactions are in cash an interesting<br />

question arises: Can we remove<br />

cash altogether? Money, in the form<br />

of coins, has been in use for nearly<br />

three thousand years. Paper bills<br />

have been used in Europe for nearly<br />

four hundred years, and much longer<br />

than that in China. It seems dramatic<br />

to convert to a true digital economy.<br />

There are, however, many advantages<br />

to going digital. Great savings<br />

can be achieved for businesses if we<br />

avoid storing, counting, handling, and<br />

transporting cash.<br />

The advantages for society<br />

as a whole may be even greater,<br />

especially if cash is removed altogether.<br />

As we learn from the news<br />

every day, cash encourages crime.<br />

The public may experience that a<br />

wallet is stolen from a pocket, or<br />

more severely, become the victim<br />

of armed robbery. Institutions such<br />

as banks and security transports<br />

must spend signiflcant resources to<br />

thwart criminals and sometimes still<br />

fail to deter them. Death and both<br />

physical and psychological injuries<br />

can be the consequences of holding<br />

all this “bait” in the form of cash.<br />

It would be naive to expect crime<br />

to disappear in a digital economy.<br />

Credit card fraud is already a daily<br />

occurrence. However, today it is stimulated<br />

by the possibility of retrieving<br />

the stolen money in cash from ATMs.<br />

Without cash it will be much easier to<br />

follow the transactions.<br />

We can, however, realistically<br />

hope to make being a criminal less<br />

convenient. A monetary economy is<br />

much more effective than bartering.<br />

People understood this thousands<br />

of years ago. It was easier then to<br />

sell a horse for money that could be<br />

spent freely than to trade it for a cow<br />

and some chickens on the side. The<br />

seller might not need chickens, or the<br />

potential horse buyer might not have<br />

a cow for sale.<br />

What we could expect by going<br />

digital is to enjoy the advantages of<br />

the monetary system without being<br />

threatened by criminals. The pusher<br />

down the street, for example, would<br />

have problems if customers no longer<br />

had anonymous cash handy for their<br />

transactions. They would be forced to<br />

accept gold, PCs, TVs, and refrigerators<br />

instead, thereby confronting all<br />

the hassles of a barter economy.<br />

DIGITAL CRIME<br />

Criminals can also go digital,<br />

although this requires <strong>computing</strong><br />

competence. Today, with improved<br />

information security systems, successful<br />

cybercrime implies a fairly<br />

high level of competence. Such skill<br />

can also be sold in the open economy<br />

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at lucrative prices, and digital criminals<br />

can be thwarted by digital police.<br />

Some tasks, such as detecting whitewashing,<br />

might even be performed<br />

automatically.<br />

Do we see big brother here? Cash<br />

is anonymous while digital money<br />

can be tracked. For ordinary lawabiding<br />

citizens this should not<br />

be considered a threat as long as<br />

good laws to protect public privacy<br />

remain in place. However,<br />

tax authorities now have a weapon<br />

against the black market economy.<br />

For example, it won’t be so easy to<br />

pay the carpenter, off-the-record,<br />

without cash. Some might view this<br />

as a disadvantage, but we will gain<br />

instead a more fair tax system and<br />

increased state income.<br />

Willing or not, we are moving<br />

slowly but smoothly into a cashfree<br />

society. Today the $100 bill is<br />

the highest denomination in circulation,<br />

with $500, $1,000, $5,000,<br />

and $10,000 bills no longer used.<br />

As inflation takes a percentage of<br />

the real value of the $100 bill every<br />

year, we will soon only have cash<br />

as small change. On the fiip side, it<br />

is interesting to note that the US still<br />

has a one-cent coin. In Norway, the<br />

lowest valued coin is now flfty øre or<br />

approximately nine cents, up from<br />

the one øre that was removed from<br />

circulation in 1972.<br />

The process toward a cash-free<br />

society will be accelerated when the<br />

real costs of using cash are placed on<br />

the individual cash-paying customer,<br />

not shared among all customers. The<br />

growth of true Internet banks, where<br />

all transactions are digital, poses a<br />

severe threat to banks that still have<br />

high cash handling costs. It might<br />

also become more awkward to use<br />

cash. Many countries now require a<br />

national bank notiflcation whenever<br />

large sums are withdrawn or deposited<br />

as cash. We could go further,<br />

perhaps placing a risk tax on the<br />

use of cash to compensate for public<br />

injury and other expenses that follow<br />

from robberies.<br />

RISK<br />

Computing professionals must<br />

be concerned about the risk of getting<br />

into a situation where people<br />

no longer have cash as a backup.<br />

Truthfully, though, we have already<br />

reached this stage. Look into your<br />

wallet and count the bills. Is that<br />

amount sufflcient for food, rent, gas,<br />

and all other expenses? For how long?<br />

While there have been incidents of<br />

credit card and banking system hacking,<br />

computer security is steadily<br />

improving. As with cars, safety only<br />

became an issue late in the technology’s<br />

development. First we had to<br />

solve the “important” problems: getting<br />

the systems to run, making their<br />

services affordable, adding core functionality,<br />

and offering a commercially<br />

aesthetic design.<br />

Most likely, one of the small countries<br />

will flrst take the leap toward<br />

an all-digital economy. As I have<br />

noted, it is easier to get the necessary<br />

infrastructure in place. This<br />

may be done to issue cash cards<br />

to persons who do not qualify for<br />

commercial banking services, or to<br />

implement improved ID systems and<br />

other safeguards. It is also easier to<br />

remove cash from a currency in use<br />

on a national level only, unlike the<br />

dollar and euro, which already have<br />

widespread acceptance.<br />

Given that there are clear<br />

advantages to being the<br />

flrst country to go all digi-<br />

IEEE<br />

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tal, we can expect this development<br />

to happen sooner rather than later.<br />

Crimes will be averted, and national<br />

industry and service providers will<br />

have a home market for technologies<br />

that might be in widespread use in<br />

just a few years.<br />

This transition to a digital economy<br />

can be performed in measured<br />

steps, starting with removing the<br />

high-denomination bills and placing<br />

cash-handling costs on the<br />

shoulders of cash-paying customers.<br />

This process could persist until the<br />

economy is fully digital, or banks<br />

might see a beneflt in keeping smalldenomination<br />

bills and coins in circulation.<br />

As <strong>computing</strong> professionals,<br />

we are privileged to take part in these<br />

dramatic historic developments.<br />

Ultimately, we should consider it an<br />

improvement if bandits replace guns<br />

with keyboards—there will at least<br />

be fewer injuries.<br />

Kai A. Olsen is a professor at Molde<br />

College and the University of Bergen,<br />

and is an adjunct professor at the University<br />

of Pittsburgh. Contact him at<br />

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and Information Systems, University of<br />

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96<br />

COMPUTER<br />

THE PROFESSION<br />

Computing a<br />

Better World<br />

Kai A. Olsen,<br />

Molde College and University of Bergen, Norway<br />

While government leaders struggle to implement significant<br />

change, <strong>computing</strong> professionals increasingly achieve this goal<br />

as a side-effect.<br />

As <strong>computing</strong> professionals<br />

we have been<br />

involved in many projects.<br />

Most have had a<br />

limited scope, duration, and budget.<br />

These milestones span decades, from<br />

developing a system for sending text<br />

messages between universities and<br />

research centers in 1969, to manufacturing<br />

a chip for a calculator in<br />

1971, to setting standards for electronic<br />

communication in 1974, to<br />

designing a computer system that<br />

offers an improved user experience<br />

in 1981, to simplifying access to scientiflc<br />

papers in 1990, to developing<br />

new technologies for ranking Web<br />

pages in 1996, and to creating an<br />

online student directory with photos<br />

in 2003.<br />

I suspect few people involved in<br />

these projects had any idea they were<br />

changing the world. Yet, in retrospect,<br />

we see this is what really happened.<br />

The Arpanet project gave us the flrst<br />

e-mail system in 1969, Intel developed<br />

the microprocessor in 1971, and an<br />

international effort gave us the TCP/<br />

IP standard for data communication<br />

in 1974. Then, in 1981, researchers<br />

at Xerox Parc designed the flrst<br />

complete graphical workstation; Tim<br />

Berners Lee deflned the basis for the<br />

World Wide Web at CERN in 1990,<br />

Larry Page and Sergey Brin created<br />

the foundations for Google in 1996,<br />

and Mark Zuckerberg created Facebook<br />

in 2003.<br />

CHANGING LIVES<br />

Combined, these <strong>computing</strong><br />

advances have changed the <strong>lives</strong> of<br />

millions throughout the world. In the<br />

industrial countries we work, shop,<br />

play, and socialize using a computer.<br />

Whole business areas are experiencing<br />

this revolution. Music, movies,<br />

and books are now separated from<br />

their physical representation, with<br />

a consequently huge impact on the<br />

industry. Photography has gone<br />

digital. Analog products, such as<br />

fllm, cameras, and their connected<br />

services—are now disappearing.<br />

Newspapers that have existed for<br />

more than 200 years are in danger<br />

of closing down as the competition<br />

from the net becomes overwhelming.<br />

Meanwhile, TV is losing viewers to the<br />

Internet and sites like YouTube.<br />

Physical libraries, with collections<br />

in the form of clay tablets, papyrus,<br />

or books, have been an integral<br />

part of educational institutions for<br />

thousands of years. Today digital<br />

collections are taking over and the<br />

physical library has an uncertain<br />

future in many domains. Companies<br />

that hardly existed flve to ten years<br />

ago—such as Google, Facebook, and<br />

Twitter—are today known by everybody.<br />

New services and applications<br />

are offered every day to make our<br />

<strong>lives</strong> more effective and, perhaps,<br />

more interesting. It is tempting to<br />

compare these trends with politics.<br />

While many state leaders struggle to<br />

implement signiflcant change, <strong>computing</strong><br />

professionals increasingly<br />

achieve this as a side-effect.<br />

CATALYST<br />

Clearly, the <strong>computing</strong> industry<br />

is today’s main catalyst for change.<br />

No other industry has a comparable<br />

impact and none is as dynamic. As<br />

professionals in this area we are<br />

truly shaping the world into something<br />

better—or so we hope. Some<br />

argue that <strong>computing</strong> has become<br />

a commodity, like electricity, something<br />

you still need but that has lost<br />

its competitive advantage. However,<br />

the Googles, YouTubes, Wikipedias,<br />

and Twitters show that the pace has,<br />

if anything, accelerated. So what can<br />

we expect in the next decennium?<br />

eInk offers one new technology<br />

that flows from <strong>computing</strong>. In the<br />

past 10 years it has moved from the<br />

labs to commercial product status.<br />

Continued on page 94<br />

Published by the IEEE Computer Society 0018-9162/10/$26.00 © 2010 IEEE<br />

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