OR/MS TOMORROW
The INFORMS Student Newsletter
Volume 15, Number 1, Winter 1998
Our first article is by Laxminarayan Das, who takes us into a world of matrices in his articles, "Application of solid matrix in LP modeling." The author defines a matrix as one with row, column and height that is called a solid or space matrix. In this article, such a matrix is applied to model a linear programming problem. This method has applications to other OR problems such as complementary problems and optimization problems.
Weidong Zhou, our next author, has research interests in Tabu search, machine layout problems and assembly line balancing problems. Weidong's current work looks at the parallel processing problem. The author is still in the process of completing this work but has submitted an abstract titled "Application of Client/Server Technology in the Operations Research"
The Montreal Conference is rapidly approaching. For all people planning to attend who may not have time to gather information about the area, we have put together our own helpful list. It includes some of the more popular sights and scenes of Montreal. One of our favorite places to visit is the underground city.
There will be a special session at the Montreal conference designed for Masters and Doctoral students considering a career in industry. See the announcement advertized later in this issue. We have also included a short list of all the up coming INFORMS events.
Finally, tease your brain with SQL commands contained in newsletters Puzzlemaster section. Type in the commands to figure out the solutions to the jumbled up letters. GOOD LUCK!
Matthew Swinarski
and Naima Chaudhry
Laxminarayan Das†
Department of Computer Science
Texas A& M University, CollegeStation, TX.
Abstract
Key words and phrases: Solid matrix, H-layer, SN-layer WE-layer, Row-WE-line vector, Height-SN-line vector
1 Introduction
The common convention of matrix is an array of numbers, that associated with certain rows and columns. The rows and columns are perpendicular to each other and lie in one plane. Therefore this type of matrices can be called as plane or two dimensional matrix. If a particular matrix is constituted by the number of plane matrices placing one above another, then a new dimension arises, which is called height and that matrix is called a solid or three dimensional matrix. Thus a solid matrix has three dimensions, named as row, column and height. Although the dimensions, row and column of this matrix are similar to the concepts of row and column of a plane matrix, but their orientations are different. In the case of solid matrix, a row is a plane matrix that lies parallel to the base, we rename it H-layer and the column is a plane matrix vertical to the row and extends from West to East, we call it WE-layer. The plane matrix, vertical to both H-layer and WE-layer is called SN-layer.
1.1 Symbolic representation of solid matrix
The matrix Am×n×k [aijl], for i {1,2,,m}, j {1,2,,n} and l {1,2,,k} and is a solid matrix of m number of H-layers, n number of WE-layers and k number of SN-layers. The indices i, j and l of the element , denote its position in i-th H-layer, j-th WE-layer and l-th SN-layer. The initial position (1, 1, 1) is considered as South-West corner element of the top most H-layer, because counting of H-layer starts from the top. Similarly the positions of West-North. North-East, and East-South corners of the top most layer are (1,n,1), (1,n,k) and (1,1,k) respectively. The bottom most layer is numbered as m-th H-layer. The positions of the corresponding corners are (m,1,1), (m,n,1), (m,n,k) and (m,1,k) respectively. It may be noted that each element in i-th H-layer, has the same i subscripts. Similarly, each element of j-th WE- or l-th SN-layer has the same j or l subscripts.
As the solid matrix can not be shown in the plane of the paper, we use the following notations for its represention. The solid matrix Am×n×k can be represented by
The i-th H-layer, j-th WE-layer and l-th SN-layer of the above solid matrix Am×n×k are the plane matrices
and 
respectively.
2 Applications
The solid matrix has a number of applications in various fields. Here we illustrate an example of such application in modeling an Linear programing problem.
A manufacture produces three types of chairs and three types of tables using definite volume of material and definite machine jobs for each type of table and chair. The quantity of material and machine jobs required to manufacture chairs and tables are mentioned in the first table. In the second table the information of availability of maximum unit of materials and machine jobs to each type of chair and table is given. If he expects profits c1, c2, c3 and t1, t2, t3 from first, second and third types of chair and table respectively, then how many numbers of each he should produce so that the profit should be maximum?
| Type | chairs | tables | ||
| material | machine job | material | machine job | |
| Type-1 |  |
 |
 |
 |
| Type-2 |  |
 |
 |
 |
| Type-3 |  |
 |
 |
 |
/each type /each type jwh2 It is important that the manufacturer has to notice the production of equal numbers of chairs and tables.
Thus, we can not assume the variables required to model a LPP are scalars, rather they are vectors with two
components and we model this problem to a LPP in a special manner. We can obtain solid matrices A and B from the first and second tables respectively.
Type
Total material available
Total material job available
Type-1
Type-2
Type-3
The 1st WE-layer of solid matrix A3×2×2 represent the unit of materials required to manufacture each type of chair and table. The 2nd WE-layer of the same solid matrix represent the unit of required machine jobs for manufacturing each type of table and chair. The 1st H-layer of the above solid matrix A3×2×2 consists of the unit of materials and jobs for manufacturing first type chair and first type of table. Similarly the elements of the 2nd H-layer and the 3rd H-layer of the solid matrix A3×2×2 represent the unit of materials and machine jobs for the second and the third types of chairs and tables. The 1st SN-layer of A3×2×2 represents the unit of materials and machine jobs to manufacture three types of chair and the 2nd SN-layers of the same matrix represent the unit of materials and machine jobs to manufacture three types of table.
If 1st and 2nd WE-layers of B represent the availability of maximum units of materials and machine jobs respectively, then 1st, 2nd, and 3rd H-layers of B represent the same for the first, second and the third types of chair and table respectively.
The following Linear Programming Problem can be designed from the above problem;
Where xi and yi for i {1,2,3} are the number of chairs and tables to be manufactured.
References
† BOYSCAST Fellow, Department of Computer Science, Texas A& M University, CollegeStation, TX.
Research In Progress
Weidong Zhou
Quality Management and Management Information Systems Department
University of Tulsa
Client/server technology evolved from the changing patterns of computer usage in the business world. Organizations expect an architecture which enables distributed computing resources on a network to share common resources among groups of users. The advantages of client/server computing are listed as follows: (1) Adaptability: client/server architecture provides the ability to easily upsize/downsize computing resources to match the changing computing environment. (2) Platform independence: the virtual computer resource can be organized based on different hardware and software environments. The objective is to grow in stages and take advantage of the latest computational and network technologies. (3) Better utilization of computing power: To avoid the overload situation for mainframe environment, the computation in client/server environment spread out across the entire network. (4) Reliable environment: compared with the centralized systems, there is the minimal disruption in the client/server environment because the shutdown of one computer does not influence other computers' performance. The popular adoption of client/server technology in the business world also has important significance in the operation research.
Most of the OR literatures employ the Sequential Processing Architecture (SPA) which includes several approaches. Each approach has its own strength and weakness. Whenever one approach can not generate satisfactory results, another approach is used in order to improve the performance. Only one approach can be running at a certain time. The Parallel Processing Architecture (PPA) intends to focus on the improvement of more approaches running at the same time. Many literatures suggested a master-slave organization in parallel processing. The available methods include the generation of child process as slave, or the application of multi-processor, or the utilization of multi threads. These methods generally focus on the environment of a computer with one or many processors and do not fully utilize the available computing resource in the network environment. To add the features for the network environment, client/server technology is introduced to provide the communication for the parallel processing. The client refers to the available approach while the server is a host that monitors, instructs, and coordinates the progress among the clients. Every client approach can join or exit the computation at any time. Since one approach may run faster than another one, the key here is how to balance the workload for each client in order to minimize the waiting time for the faster approaches. To evaluate the efficiency, I used the U-line assembly line balancing problem to compare the difference between SPA and PPA. An algorithm is developed for the host program to coordinate the process among the client approaches. Currently, the program is developed in C++ and I hope it finally can be run in a heterogeneous network environment, including mainframe, mid-range, workstation and personal computer. The possible applications of the client/server technology can also extend to the job schedule problem in the airline industry, the vehicle routing problem in the transportation industry, and many more.
Finally, I would like to thank my advisor Dr. Chiang who constantly gave me encouragement and support. He initially suggested me to focus on this topic for my independent study and continues to provide helpful suggestions to my work.
Naima Chaudhry
Department of Management Science and Systems
State University at Buffalo, Amherst, NY
The Institute of Operations Research and Management Sciences (INFORMS) announces the third Joint Conference on Information Systems and Technology to be held in conjunction with the INFORMS Spring Meeting in Montreal, Canada April 26-29, 1998. The conference is sponsored by the College on Information Systems and the College on Artificial Intelligence. The conference will provide a forum for all groups related to information systems and information technology to present and discuss their views, issues, and research results.
WHAT INFORMS National Meeting
WHERE Montreal Bonaventure Hilton and Queen Elizabeth Hotel, Montreal, Quebec
WHEN April 26-29, 1998
WHY MONTREAL?
Montreal (As taken from www.tourism-montreal.org)
Montreal has a warm and welcoming hospitality with a definite French flavor as described on the Montreal web page. Joie de vivre expresses the unique spirit and Latin ambiance that permeate the fabric of Montreal. The conference hotels, the Queen Elizabeth and the Bonaventure Hilton Regency, are located at the heart of it all! Everything is within walking distance or a short Metro ride away. Between conference sessions, visit the Montreal Museum of Fine Arts, the Muse d'art contemporain de Montreal, or one of the city's many other museums. Take in the theater, dance, opera, or the symphony at Place des Arts or at other numerous performing arts venues. Try your luck at the elegant Casino housed in Expo '67's former French Pavilion. Enjoy world-class shopping at some of the city's many fine boutiques. If you are a sports fan, check out an Expos baseball game at the Olympic Stadium or a Canadiens hockey game at the Molson Center. Hail a horse-drawn calche and ride along the cobblestone streets of the historic Old Montreal district. While there, see the mighty St. Lawrence River at the Old Port and enjoy some of the many activities going on. Take a romantic stroll on Mount Royal (for which the city is named) and enjoy some of the spectacular views of the surrounding areas from the park's several lookouts.
But Montreal is best known for its restaurants and nightlife. When it comes to pure dining pleasure, it can hold its own against any European city. Sidewalk cafes, quaint bistros, chic dining rooms and restaurants offer a smorgasbord of the most tantalizing local and ethnic specialties. Bars and nightclubs around town serve up live entertainment for every taste. From comedy clubs and piano bars to rhythm and blues clubs, jazz bars, salsa and tango clubs, Montreal moves to different beats into the wee hours!
A major urban center and one of the world's greatest cities, Montreal is the venue of choice for both pleasure and business. The Montreal INFORMS Committee welcomes you and invites you to experience our city.
Bridging Continents and Cultures
In spite of its location - a mountain in the middle of an island in the center of a river flowing out to the Atlantic Ocean (more than 1,500 kilometers away) - Montreal is one of the world's major international ports. Geographically, it has a little bit of everything, a trait that extends to cultural matters as well. Solidly rooted in North America, Montreal has retained a strong European flavor and draws its strength from that duality. As such, this reinforces the theme of the Spring '98 INFORMS conference: Bridging Continents and Cultures. Strong international participation has been encouraged for this meeting so that we can introduce and be introduced to various research perspectives and approaches in the fields of Operations Research and the Management Sciences.
In fact, Montreal is the site of four universities and two world-renowned O.R. research centers where people from many countries bridge continents and cultures on a daily basis.
The increasingly global nature of trade and manufacturing makes it important for us to widen the scope of international understanding in our areas of research. The local committee of the Montreal '98 meeting invites you to our island to help bridge continents and cultures.
MUST SEE PLACES IN MONTREAL
Some of Montreal's most impressive tourist attractions are as follows, all of which attest to the creative and avant-garde spirit of Montrealers. These facilities are located to the north of the Maisonneuve district which, until the early days of this century, was an independent, highly-industrialized city. The neighborhood has retained a number of beautiful public buildings from that era, as well as a rich industrial heritage. In all, a total of 188 hectares is devoted to leisure activities for Montrealers, making it one of the primary tourist destinations in Quebec. This concentration of so many first-rate installations onto one site has given the city of Montreal a tourist center of truly international caliber.
The Montreal Tower.
This tower is one of the world's tallest leaning tower! Site of the 1976 Olympic Games, the Olympic Park is a world-class tourist attraction as well as a peerless architectural complex.
Montreal Botanical Garden and Insectarium
A Garden of Earthly Delights Created in 1931, the Montreal Botanical Garden is now one of the largest of its kind in the world. Come explore 10 exhibition greenhouses and more than 30 outdoor gardens and experience the colors and fragrances of the world. Let yourself be carried away by the exotic charm of the Chinese and Japanese gardens. Open the doors of the Tree House and become acquainted with the richness of Quebec's forests. Learn about the important contribution of trees to the urban environment. Venture into the mysterious world of insects at the Montreal Insectarium. Take the shuttle to escape to remote secret gardens or simply to get to your favorite site faster. Throughout the year, the Botanical Garden puts on approximately 30 astonishing exhibitions of a horticultural, artistic or cultural nature.
Open: daily year-round, from 9 a.m. to 5 p.m. and until 7 p.m. from June 21 to September 1.
401 Sherbrooke Street East - Tel.: (514) 872-1400
The Muse d'art contemporain de Montreal
Located right next to Place des Arts, the Muse d'art contemporain de Montreal moves to the rhythm of the summer's festivals and cultural events. Jazzy atmosphere, terrace filled with music, sculpture garden in full bloom, design items at your fingertips C the Muse promises many enjoyable, refreshing moments. Step into the world of today's art and discover some amazing, maybe even provocative works.
Open: From Tuesday to Sunday 11 a.m. to 6 p.m., Wednesdays 11 a.m. to 9 p.m..
1379-1380 Sherbrooke Street West Tel.: (514) 285-2000
Underground City
A booming international metropolis where temperatures plummet or soar dramatically from one season to the next, Montreal has tamed the climate with a weatherproof, underground city which gives priority to the pedestrian. It is an innovation which has made Montreal a pleasant place to live in or to visit, rain or shine - the prototype of the city of the future, based on an idea by Leonardo Da Vinci. In winter, the underground city allows you to shop where it is dry and cozy. During the blazing heat of summer, you'll enjoy strolling through the spacious, air-conditioned underground passageways. The broad, colorful concourses are lined with boutiques, restaurants and numerous retail outlets which are the joy of the downtown area. It began in the early '60s with construction of new downtown buildings. With the inauguration of Montreal's first major skyscraper, Place Ville-Marie with its striking cruciform architecture, it was destined to become the heart of the new city as well as the initiator of a spectacular renaissance of the downtown area. The excitement of the mid-'60s included construction of a major cultural center, Place des Arts and a sophisticated metro system. Now, 29 kilometers of underground passages give pedestrians access to virtually every type of facility without ever getting soaked in a downpour or frozen in the cold. Sports fans, theater-goers, gourmets, all are whisked smoothly by the subway to their destinations in underground Montreal.
Announcing:
The Student Affairs Committee of INFORMS announces three special sessions to be held on the Sunday of the Montreal conference (April 26,1998). These sessions are designed for the Masters and Doctoral students who are considering a career in industry. Two of these sessions will be panel presentations and discussions centering on issues in careers in management consulting and operations research practice. The other session will be a catered luncheon where we will brainstorm ideas for future meetings of this type. The idea is to have a meeting that parallels the successful Fall Doctoral Colloquium but which is aimed at both masters and doctoral students who are interested in industrial careers. We need input to design such a program and hope to get it at this luncheon.
The schedule for April 26th will be:
| 10:30 a.m. - 12:00 noon | HOW TO SUCCEED IN BUSINESS - TIPS FOR SUCCESS IN INDUSTRY AND CONSULTING |
| 12 noon - 1:30 p.m. | CATERED LUNCHEON - BRAINSTORMING FUTURE SPRING CONSORTIA FOR STUDENTS |
| 1:30 p.m. - 3:00 p.m. | WHAT EVERY MANAGEMENT CONSULTANT NEEDS TO KNOW ABOUT OPERATIONS RESEARCH/WHAT EVERY OPERATIONS RESEARCH PRACTITIONER NEEDS TO KNOW ABOUT MANAGEMENT |
All graduate students who are nearing the end of their current degree and are interested in participating are welcome. We need to know how many to plan for the luncheon, so please RSVP if you intend to attend. Send your name, your institution, your e-mail address (if you have one), your snail mail address, your phone number, and any dietary and/or access restrictions to:
Dr. Donna C. Llewellyn
ISyE
Georgia Tech
Atlanta, GA 30332-0205
phone: 404-894-2340
fax: 404-894-2301
e-mail: donna.llewellyn@isye.gatech.edu
International Meetings
General Chairs: Jacob Hornik and Ben Lev.
National Meetings
Subdivision and Specialized Meetings
Meetings of Associated Societies
Naima Chaudhry
Department of Management Science and Systems
State University at Buffalo, Amherst, NY
The INFORMS Student Union aims to be the preeminent Web site for students and recent graduates in OR/MS and related fields. It seeks to fill their most important needs insofar as that can be done on-line. Some of the information available to students through easy access of this site are:
The Student Union (http://www.informs.org/student_union/) is an informative site for students provided by INFORMS. INFORMS is governed by an elected board of directors consisting of a president (currently Art Geoffrion), a president-elect, a secretary, a treasurer, a past president, six vice presidents (Information Technology, International Activities, Meetings, Practice Activities, Publications, and Subdivisions [currently John Birge]), two directors-at-large, one of whom must reside outside the United States, and five division directors representing clusters of subdivisions. Professional staff exists at our two business office locations, one at Linthicum, Maryland (between Baltimore and Washington) and the other in Providence, Rhode Island.
What does INFORMS provide? Among the major items are:
The latest happenings in research and practice
Job placement opportunities
Networking
Education
More information on INFORMS On Line [IOL] is available on the Web at http://www.informs.org/ and http://www.informs.org/subdiv/subdiv.html.
So, get involved and stay involved. Attend local geographic chapter meetings if available in your locale. Volunteer to write an article for this newsletter. Be active in your student chapter, or help form one if there isn't any. And by all means, when you graduate, make sure you convert your student membership to full membership!
Naima Chaudhry
Department of Management Science and Systems
State University at Buffalo, Amherst, NY
WHAT WOULD THE FOLLOWING SQL COMMAND PRODUCE?
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Answer to Last Edition's Puzzle:
Problem 1: 2520 is the lowest number into which all the digits from 1 to 10 will divide
Problem 2: 41, 80, 320
Problem 3: Mary is 27½ years old
The OR/MS Tomorrow staff is currently accepting articles for the Spring 1998 issue due out by the end of April. We are currently expanding the scope of the newsletter to include the following new sections:
| Section | Description |
| Chapter Reports: | A short ½ to 1 page article about your student chapter's current project, upcoming events or previous awards. We hope this section will stimulate a more community atmosphere amongst INFORMS chapters |
| The Job Report: | A ½ article recapping your own personal job hunting experiences |
| Colloquium Report: | Roughly a 1 page article about your experience at the colloquium, what you liked or didn't like about the colloquium and/or the city in which it was held |
We are still accepting articles for the current newsletter sections. You may write an article about your current research, summit a puzzle, or popular site of the next colloquium city. We are particularly interested in an article about the sights and night life in Seattle form anyone currently or formally living there. All article should be submitted by e-mail to the following address: mes2@acsu.buffalo.edu as an attachment in either ASCII, Word or WordPerfect format. Articles should be no more than 3 pages double spaced. Please include your name, as you wish it to appear in the newsletter, the institution you are affiliated with and your current mailing address.
Deadline Date for articles for the Spring 1998 issue is April 1st 1998.
Janauary 7-9 INFORMS Computer Monterey, Calif.
Science Technical Section Conference
March 8-11 INFORMS Telecommunications Sheraton Boca Raton
Conference Boca Raton, Fla.
April 26-29 INFORMS/CORS Montreal Queen Elizabeth
Spring 1998 Meeting Bonaventure Hilton Montreal, Canada
June 28-July 1 INFORMS Israel Israel
International 1998
October 25-28 INFORMS Seattle Seattle, Washington
Fall 1998
ADDRESSES OF INTEREST
Editors:
Matthew Swinarski and Niama Chaudhry
e-mail: mes2@acsu.buffalo.edu
Staff:
Douglas G Taylor, Tami Topol, and Elizabeth Yuen
State University of New York at Buffalo
Faculty Advisors:
Ram Ramesh and Stan Zionts
Department of Management Science and Systems
Buffalo, New York 14260-4000
Phone: (716) 645-3281
Fax: (716) 645-6117
Student Affairs Committee Chair:
Professor James B. Orlin
MIT e53-357
Cambridge, MA 02139
e-mail: jorlin@MIT.EDU
ADDRESS CHANGES SHOULD BE SENT TO:
INFORMS
290 Westminster Street
Providence, RI 02903-3432
SUNY at Buffalo
Department of Management Science and Systems
Jacobs Management Center
Buffalo, NY 14260-4000
First Class