Melbourne Chapter

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2001 Program

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Lecture TITLE ORMS in the Networked Economy SPEAKER Jay Horton, PricewaterhouseCoopers WHEN 6:30-7:30PM, Wednesday, March 21, 2001 WHERE Room 8:9:66, RMIT ABSTRACT The presenter will describe the opportunities for ORMS in the emerging on-line, networked economy. In many ways the major structural changes now underway in industry and commerce play to the strengths of ORMS. Decision makers are now applying more ORMS, not less - to deal with the complexities, dynamics and uncertainties of Australia's changing economy. The presenter will draw on case studies in delivering the benefits of ORMS for strategic and tactical business planning. In particular he will demonstrate new "web-based" decision support application services, and describe the advantages they offer over traditional methods. Profile of Jay Horton Jay Horton is a Partner within PricewaterhouseCoopers and leads PwC's Applied Decision Analysis practice in the Asia-Pacific. Jay has over 25 years experience in strategic OR/MS consulting, most recently with his own firm Operations Research Group which was acquired by PricewaterhouseCoopers in 1999. Previously Jay was with McKinsey & Company. He advises business leaders in Australia, New Zealand and Asia in a wide range of corporations in energy and mining, telecommunications, and the consumer and industrial products sectors. CONTACT Paul Lockert, E-mail: paul.lochert@sci.monash.edu.au

Lecture TITLE Using Fuzzy Logic in Organizing Construction Industry Activities SPEAKER Sonja Petrovic-Lazarevic, Monash University WHEN 6:00PM, Wednesday, April 18, 2001 WHERE Room 8:9:66, RMIT ABSTRACT Construction industry activities are characterised by having mobile assets and a mobile work force relative to many other industriesí activities. Organising construction industry activities may be based on sound judgement and common sense. This implies imprecise and vague decisions. Decision processes of organising construction industry activities, therefore, could be explained by fuzzy multiple objective decision methods. The purpose of the talk is to point to the usefulness of applying a linear mathematical formulation of fuzzy multiple criteria objective decision methods in organising construction industry activities. In this respect fuzzy parameters of linear programming are modelled by preference-based membership functions. The membership functions represent subjective degrees of satisfaction within given tolerance. The results of the applied models point to insignificant difference between nonfuzzy and fuzzy objective functions for the optimal solution. This is the core of Sonja's presentation. However, for such as myself who have a vague grasp of the Fuzzy approach, Sonja will be spending some additional time in outlining the main ideas in Fuzzy logic. CONTACT Paul Lockert, E-mail: paul.lochert@sci.monash.edu.au

Lecture TITLE Modelling and Optimisation: Practical Approaches in Road Transport SPEAKER Tim Martin, ARRB Transport Research Ltd WHEN 6:00-7:300PM, Wednesday, May 16, 2001 WHERE Room 8:9:66, RMIT ABSTRACT In this talk I shall demonstrate the use of a commercially available genetic algorithm (Evolver by Palisades) to find the lowest possible life-cycle cost (optimal solution) in the maintenance and rehabilitation of Australia's national highway road network. Evolver is capable of running and optimising with constraints (in this case annual budgets and road conditions) either separately or simultaneously. These constraints also allow confirmation of the search for the unconstrained optimal solution. Evolver is used in conjunction with other software to undertake the life-cycle costing analysis. The above analyses are highly deterministic (one answer only) for given set of parameters. Input parameters can vary considerably because roads are highly variable in terms of condition, use, climatic influences and so on and how they are modelled as a network. An analysis was undertaken by adopting probabilistic distributions for some of the input variables that influence the outcome for optimisation. The software used was risk analysis (@RISK by Palisades) to estimate how much the output will vary with the probabilistic distributions used for the input parameters with different network model simulations. The risk analysis generates random values of each of the parameters within their defined distribution (Monte Carlo simulation or similar) to estimate the resulting output probability distribution. The risk analysis software was also used to estimate the accuracy of the maintenance and rehabilitation costs (which was the actual aim of the work for the client - the Federal Department of Transport). I propose to use a powerpoint demonstration and simple examples of the software to explain their use and application. CONTACT Paul Lockert, E-mail: paul.lochert@sci.monash.edu.au

Lecture TITLE Stochastic Optimisation and Statistical Inference of Simulation Based Optimisation Models SPEAKER Reuven Rubinstein, Technion, Israel WHEN 6:00PM, Wednesday, July 16, 2001 WHERE Room 8:9:66, RMIT ABSTRACT We consider optimization problems where the objective function is not given explicitly and should be estimated, say, by a Monte Carlo simulation. We present the so-called "stochastic counterpart" approach for stochastic optimization and discuss its convergence properties and statistical inference. Stochastic counterpart approach is based on generation of stochastic approximation of the "true" program via simulation and on subsequent solution using deterministic methods of nonlinear programming. The required "stochastic counterpart" approximation can be constructed, for example, by the likelihood ratio-score function techniques. We discuss relative efficiency of the stochastic counterpart and stochastic approximation methods. Different applications of "stochastic counterpart" approach for stochastic optimization will be presented. CONTACT Paul Lockert, E-mail: paul.lochert@sci.monash.edu.au

Lecture TITLE Modelling and Analysis of Protean Operating Systems SPEAKER Santosh Kumar, Victoria University WHEN 6:00PM, Wednesday, August 22, 2001 WHERE Room 8:9:66, RMIT ABSTRACT In this talk first we briefly explain protean systems and apply those concepts to some problems arising in operating systems. It is the belief of the author, that mathematical modelling and analysis becomes robust and meaningful for applications in real life situation. Necessary concepts have been explained by giving examples. We illustrate how input information can change in a given situation and how to cope with modelling and analysis in that changing environment. Although examples used in this talk are from the field of Operations Research, concepts discussed are general and independent of any prerequisite background or area for application. The protean system methodology is not a technique but an approach to problem solving which may be useful to any person interested in modelling and analysis of problems arising in real life operating systems. CONTACT Paul Lockert, E-mail: paul.lochert@sci.monash.edu.au

Seminar TITLE Operations Research Approaches to the Multi-Leaf Collimator Problem in Cancer Radiation Therapy SPEAKERS Natashia Boland WHEN 4:30PM, Wed, Oct 24, 2001 WHERE Medley Theatre, Redmond Barry Building, University of Melbourne, The University of Melbourne Abstract A multi-leaf collimator (MLC) is a piece of equipment used to beam radiation at a tumour site, in the treatment of cancer. The MLC delivers the radiation in a pattern determined by the positions of leaves, which are used to block some parts of the radiation. The leaves are arranged in rows, with a left- and right-hand leaf in each row. Moving the left leaf to the right reduces the area irradiated in that row, as does moving the right leaf to the left. The area to be irradiated can be modelled as a matrix, called the intensity matrix, with entries giving the number of seconds which each of the corresponding areas should be irradiated for. Once the leaves have been positioned, the resulting pattern can be modelled as a binary matrix. The beam can be turned on with this pattern for some period of time, leading to all exposed areas receiving irradiation for that period. By changing the positions of the leaves, and turning the beam on for different periods for each position, it is possible to ensure that the radiation accumulated in each area is the needed amount as indicated by the intensity matrix. In fact, many combinations of patterns and corresponding irradiation times may yield the same delivered intensities. The MLC problem is to determine the combination which minimizes the time needed to complete the exercise, which includes both total irradiation time and various overhead times. The problem will be described, and Operations Research approaches to it discussed. It will be shown that under some practical simplifications, the problem of minimizing the total irradiation time (ignoring overheads) can be solved very efficiently, in time polynomial in the length of the input data. Results of some exact and heuristic approaches to the problem with overheads will also be presented. CONTACT Natashia Boland, E-mail: n.boland@ms.unimelb.edu.au

Conference TITLE Recent Advances in OR SPEAKERS You! WHEN 9-5, Tue, Nov 13, 2001 WHERE Room 8:9:66, RMIT Call for Papers and Participation The annual one day conference/forum is on again. This one day forum was designed to give members the opportunity to exchange ideas and promote growth and activity in the OR community. Both recent interesting and/or novel applied work along with research activities are sought for this day. Abstracts: All abstracts submitted by November9 2001 will be published for distribution at the conference. This is the final call for abstracts, please submit electronically (preferably as a WORD file, but I can cope with most others) to p.lochert@sci.monash.edu.au or post paper copy to Paul Lochert 11 Laura Gve Mt Waverley VIC 3149 Cost: The registration fee of $50 is to cover the cost of lunch, morning and afternoon tea plus the printing of abstracts and other administrative costs. Retirees and students $20 CONTACT Paul Lockert, E-mail: paul.lochert@sci.monash.edu.au

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EXECUTIVE COMMITTEE 2001/02

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Chairperson:	Moshe Sniedovich (Dr) Department of Mathematics and Statistics University of Melbourne Parkville 3052	E-mail: m.sniedovich@ms.unimelb.edu.au Phone: (w) +613 9344 5559 Fax: +613 9344 4599
Vice Chairperson:	Gavin Cole Department of Mathematics and Statistics University of Melbourne Parkville 3052	E-mail: gecole@ms.unimelb.edu.au Phone: +613 9885-1249
Secretary:	Patrick Tobin (Mr) School of Mathematical Sciences Swinburne University of Technology P O Box 218 HAWTHORN 3121	E-mail: ptobin@swin.edu.au Phone: (w) +613 9214 8013 Fax: +613 9819 0821
Treasurer:	Paul Lochert (Assoc Prof) Department of Mathematics Monash University P.O. Box 197 CAULFIELD EAST 3145	E-mail: P.Lochert@sci.monash.edu.au Phone: (w) +613 9903 2647 Fax: +613 9903 2227
Committee:	Lutfar Khan (Dr) Department of Computer and Mathematical Sciences Victoria University of Technology P O Box 14428, MCMC MELBOURNE 8001	E-mail: Khan@matilda.vut.edu.au Phone: (w) +613 9688 4687 Fax: +613 9688 4050
	Angie Byrne (Dr) Department of Mathematics and Statistics The Uniuversity of Melbourne Parkville VIC 3052	E-mail: a.byrne@ms.unimelb.edu.au Phone: (w) +613 8b344 5558 Fax: +613 8344 4599
	Natashia Boland (Dr) Department of Mathematics and Statistics The Uniuversity of Melbourne Parkville VIC 3052	E-mail: n.boland@ms.unimelb.edu.au Phone: (w) +613 8b344 5547 Fax: +613 8344 4599
	Dudley Foster (Mr) 23 Wolseley Crescent BLACKBURN 3130	E-mail: dudley@ozemail.com.au Phone: (w) +613 9894 0355 Fax: +613 9894 0244 Mobile: 0417 342 272
	Kaye E. Marion (Ms) Department of Statistics & OR RMIT 360 Swanston Street MELBOURNE 3000	E-mail: K.Marion@rmit.edu.au Phone: (w) +613 9925 3162 Fax: +613 9925 2454
	Leonid Churilov (Dr) School of Business Systems Monash University CLAYTON 3168	E-mail: Leonid.Churilov@fcit.monash.edu.au Phone: (w) +613 9905 5802 Fax: +613 9905 5159
Editor:	Harry Gielewski	E-mail: harrygie@ozemail.com.au
Office Manager:	Kaye E. Marion (Ms) Department of Statistics & OR RMIT 360 Swanston Street MELBOURNE 3000	E-mail: K.Marion@rmit.edu.au Phone: (w) +613 9925 3162 Fax: +613 9925 2454
Ex-Officio::	Harry Gielewski (Mr) 28 Kennedy Street RESERVOIR 3073	E-mail: harrygie@ozemail.com.au Phone: (w) +613 9350 4726 Mobile Phone: 0414 650 110