IFORS 2011

July 10-15, 2011

Australian Society for Operations Research
Melbourne Chapter


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2011 Program

The default venue for the monthly lectures is
RMIT, Access Grid Room. 8.9.66
Melbourne time

Scheduled Events for 2011
November 16 (full day) see full program Recent Advances in Operatons Research
October 19, 6:00PM Leorey Marquez Development of a Fruit & Vegetable Supply Chain Emissions Model for Victoria
September 21, 6:00PM Luke Reedman The Energy Sector Model
August 17, 6:00PM Mindi Nath A perspective on stock returns and idiosyncratic volatility relationship
May 18, 6:00PM Leo Lopes Implementing Commercial Maths: Lessons and examples
March 16, 5:30PM AGM
March 16, 6:00PM Joe Forbes Implementing Commercial Maths: Lessons and examples
Feb 16, 6:00PM Olena GavrilioukApplying capacitated assignment problem to interviewer allocation problem at the Australian Bureau of Statistics


Recent Advances in Operations Research

Venue: RMIT Access Grid Room, 8.9.66 (Building 8, level 9, room 66)

Time: Full day, Wed November 16, 2011

Program: Short presentations by OR scholars/analysts

Topics: TBA

Registration fee:
Member $65
Non-Member  $70

Registration and submission of abstracts via e-mail: contact Paul Lochert plochert@bigpond.net.au.

Note: The registration fee can be paid on the day of the mini-conference. However, for catering purposes, it is essential that you provide Paul your personal details (full name, title, address, phone, e-mail, dietary preferences e.g. vegetarian) well ahead of time.

Below is some information that should wet your appetite.


8:45 to 9:15 Registration.

9:15 -- 10:45 From RMIT
Tristan Barnett: Automating Online Video Poker for Profit
Andrey Kostenko: On forecasting counts with exponential smoothing **
Andreas Ernst: Parallel Ant Colony Optimisation for a Resource Constrained

10:45 -- 11:00 Morning Tea

11:00- 12:30 From Newcastle
Kristian Krabbenhoft: Variational Mechanics using Mathematical Programming Methods
Martin Savelsbergh: Network Infrastructure Optimization: The Incremental Shortest Path Problem
Sebastian Ruther: Integrating Aircraft Routing with Crew Pairing and Tail Number Assignment

12:30 -- 01:30 Lunch

1:30 -- 2:30 From Newcastle
Natashia Boland: Turbo-charging the Feasibility Pump
Fatemeh Charkhsaz: Single Period Production Problem with Scrap and Rework **

2:30 -- 2:45 Afternoon tea

2:45 -- 4:45 From Melbourne
Bizhan Jamshidnezhad: An Agent-Based Simulation of the Relationship between Quality Management and Productivity **
Moshe Sniedovich: On the Power of the Written (and peer-reviewed) Word
Mohsen Jafari Songhori: Imperfect competency and coordination in complex systems **
Rodolfo Garcia-Flores: A comparison of methods for solving the sensor location problem.

** Student paper.


*Title: Automating Online Video Poker for Profit*

*Speaker:* Tristan Barnett, Strategic Games, strategicgames.com.au


The arrival of online casinos in 1996 brought games that you would find at land-based casinos to the computer screens of gamblers all over the world. A major benefit in online casinos is in the automation of systems across several computers for favourable games; as this has the potential to make a significant amount of profit. This article applies this concept to online progressive video poker games. By establishing a set of characteristics to compare different games, analyses are carried out to identify which game should be the starting point for building an automated system. Bankroll management and playing strategies are also analyzed in this article, and are shown to be important components if profiting from online gambling is going to be a long term business.

*Title*: *On forecasting counts with exponential smoothing *

*Speaker*: Andrey Kostenko


Within the topic of model-based forecasting with exponential smoothing, this paper seeks to contribute to the understanding of the property of certain stochastic processes to converge almost surely to a constant. It provides a critical discussion of the related views and ideas found in the recent forecasting literature and aims at elucidating the present confusion by review and study of the classical and less known theorems of probability theory and random processes. The paper then argues that a useful role of exponential smoothing for modelling and forecasting sequential count data is limited and methods that are either not based on exponential smoothing or use exponential smoothing in a more flexible way are worthy of exploration. An approach to forecasting such data based on applying exponential smoothing to the probabilities of each count outcome is thus introduced and its merits are discussed in the context of pertinent statistical literature.

*Title: Parallel Ant Colony Optimisation for a Resource Constrained Scheduling Problem*

*Authors:*  Andreas Ernst, Gaurav Singh, Dhananjay Thiruvady


In this talk we consider a problem of scheduling several jobs on multiple machines satisfying precedence and resource constraints. Each job has a due date and the objective is to minimize the cumulative weighted tardiness across all jobs. We investigate how to efficiently obtain heuristic solutions on multi-core computers using an Ant Colony Systems framework for the optimisation. The talk will discuss some of the challenges that arise in designing a multi-threaded heuristic and provided computational results for some alternative algorithm variants. The results showing that the ACS heuristic is more effective particularly for large problem instances than other methods developed to date.

*Title: Variational Mechanics using Mathematical Programming Methods*

*Speaker*:Kristian Krabbenhoft


The relation between mechanics and optimization goes back at least to Euler and was further strengthened by the Lagrangian and Hamiltonian formulations of Newtonian mechanics. Since then, numerous variational formulations of mechanical phenomena have been proposed and although the link to optimization often has been somewhat obscured in the subsequent development of numerical methods, it is in fact as strong as ever. In this talk, I will summarize some of the recent developments in the application of modern mathematical programming methods to problems involving the simulation mechanical phenomena. While the methodology is quite general, emphasis will be on the static and dynamic deformation processes in civil engineering, geomechanics and the earth sciences.

*Title:Turbo-charging the Feasibility Pump*

*Speaker:*Natashia Boland


The Feasibility Pump (FP) has proved to be an effective method for finding feasible solutions to Mixed-Integer Programming problems. We investigate the benefits of replacing the rounding procedure with a more sophisticated integer line search that efficiently explores a larger set of integer points with the aim of obtaining an integer feasible solution close to an FP iterate. An extensive computational study on 1000+ benchmark instances demonstrates the effectiveness of the proposed approach.

*Title:Integrating Aircraft Routing with Crew Pairing and Tail Number Assignment*

*Speaker:*Sebastian Ruther


A common issue when integrating airline planning processes is the long planning horizon of the crew pairing problem. We propose a new approach to the crew pairing problem through which we retain a significant amount of flexibility. This allows us to solve an integrated aircraft routing, crew pairing, and tail number assignment problem only few days before the day of operations and with a rolling planning horizon. The model simultaneously schedules appropriate rest periods for all crews and maintenance checks for all tail numbers. A Branch-and-Price method is proposed in which each tail number and each 'crew block' is formulated as a subproblem.

*Title: Network Infrastructure Optimization: The Incremental Shortest Path Problem*

*Speaker: *Martin Savelsbergh


A water and sewage system, a power grid, a telecommunication network, are all examples of network infrastructures. Network infrastructures are a common phenomenon in many industries. A network infrastructure is characterized by physical links and connection points. Examples of physical links are pipes (water and sewage system), fiber optic cables (telecommunication network), power lines (power grid), and tracks (rail network). Such network infrastructures have to be maintained and, often, have to be upgraded or expanded. Network upgrades and expansions typically occur over a period of time due to budget constraints and other considerations. Therefore, it becomes important to determine both when and where network upgrades and expansions should take place so as to minimize the infrastructure investment as well as current and future operational costs. We introduce a class of multi-period network infrastructure expansion problems that allow us to study the key issues related to the choice and timing of infrastructure expansions and their impact on the costs of the activities performed on that infrastructure. We focus on the simplest variant, an incremental shortest path problem (ISPP). We show that even ISPP is NP-hard, we introduce a special case that is polynomially solvable, we derive structural solution properties, we present an integer programming formulation and classes of valid inequalities, and discuss the results of a computational study.

*Title:Single Period Production Problem with Scrap and Rework*

*Speaker:*Fatemeh Charkhsaz


The classical single period problem (SPP) has wide applicability especially in service industries which dominates the economy. In this paper a single period production problem, is considered, as a specific type of SPP. The SPPmodel is extended by considering the probability of scrap and rework in production at the beginning and during the period. The optimal solution which maximizes the expected value of total profit obtained. In the case of producing the scrap items and defective items which should rework, the optimal profit of system in comparison to ideal production system reduces. Also, the reduction of profit is more sensitive by increasing the probability of producing scrap items in comparison with the probability of producing defective items. These results would help the managers in order to make the right decision about changing or revising machines or technologies.

*Title: On the Power of the Written (and peer-reviewed) Word

Speaker*: Moshe Sniedovich, Department of Mathematics and Statistics, The University of Melbourne


In this presentation I briefly discuss practical and philosophical issues related to the role of the peer-review process in maintaining the quality of scientific publications. The discussion is based on, among other things, my experience over the past eight years in containing the spread of voodoo decision theories in Australia. To motivate the discussion, I ask: how do you justify the use a model of local robustness (operating in the neighborhood of a wild guess) to manage Black Swans and Unknown Unknowns?

*Title: Imperfect competency and coordination in complex systems *

*Authors*: Mohsen Jafari Songhori, Alan Smith, Department of Mechanical Engineering, The Universityof Melbourne

Design of a complex system needs both micro and macro level competencies to capture the underlying structure of complex problem satisfying convergence to good solution point. Systems such as complex organizations, complex New Product Development (NPD) and complex network of firms (Supply Chains or SC) require competencies at both macro (coordination and integration) and micro (capable designers, teams for NPD and capable firms in SC) entities. Given high complexity in such problems at both macro and micro levels, a couple of different errors can happen at each: 1) Either acceptance of a wrong solution or rejection of a right solution at micro level. 2) Either coordination of a couple of entities that do not need any coordination [e.g. teams or designers working in NPD might put too much time in meetings and firms in SC might lose their flexibility due to limitations from powerful and leader firms in SC] or lack of deployed resources for entities that need coordination [e.g. inconsistencies in decisions made in decentralized systems such as NPD and SC]. In this paper a simple and parsimonious Agent Based Model (ABM) of NK type is build and simulated to study these complex interactive systems. The results of simulations provide some insights on imperfect management of above mentioned complex systems. For instance, we found that asymmetry in any of the above mentioned errors favours a particular policy in management of these systems.

*Title: A comparison of methods for solving the sensor location problem.*

*Speaker*: Rodolfo Garcia-Flores, Research Scientist, Operations Research, CSIRO Mathematics, Informatics and Statistics

A problem that frequently arises in environmental surveillance is where to place a set of sensors in order to maximise collected information. In this article we compare four methods for solving this problem: a discrete approach based on the classical k-median location model, a continuous approach based on the minimisation of the prediction error variance, an entropy-based algorithm, and simulated annealing. The methods are tested on artificial data and data collected from a network of sensors installed in the Springbrook National Park in Queensland, Australia, for the purpose of tracking the restoration of biodiversity. We present an overview of these methods and a comparison of results

Venue: RMIT Access Grid Room, 8.9.66 (Building 8, level 9, room 66)

Time: 6:00PM, Wed October 19, 2011

Program: Lecture by Leorey Marquez CSIRO

Topic:: Development of a Fruit & Vegetable Supply Chain Emissions Model for Victoria

To enable a more sustainable and resilient fruit and vegetable (F&V) distribution system, a freight study to map current value chains for F&V movements in the state of Victoria was undertaken. This presentation describes two complementary approaches used in the development of an emissions model for retail and greengrocer supply chains. The first is a deterministic approach, used to identify and assign suitable values (observed or estimated) for components of the supply chain to enable calculation of summary values and overall measures of efficiency in the system. The deterministic approach was implemented via a Supply Chain Database Tool (SCDT), an Access-based model simulating transport flows of fruits and vegetables and calculating the associated emissions. The tool provides relative (instead of absolute) measures of emissions, which are indicative of the efficiencies that can be obtained from a base scenario with the application of various food transport and distribution policies and strategies. To include the effect of data uncertainty observed in the deterministic approach, a stochastic analysis tool employing Monte Carlo simulation was developed, to extend the sensitivity analysis of greenhouse gas emissions to a wider range of variables. A case study on the impact of transport segments on emissions is used to present and discuss the results of analyses from the two models.

Venue: RMIT Access Grid Room, 8.9.66 (Building 8, level 9, room 66)

Time: 6:00PM, Wed September 21, 2011

Program: Lecture by Luke Reedman, CSIRO

Topic:: The Energy Sector Model

Luke will present on the development of CSIRO's Energy Sector Model (ESM). ESM is a techno-economic bottom-up model of the Australian energy sector. It integrates the centralised and decentralised electricity generation sector and the transport sector in a single modelling package. ESM can be used to predict and understand major technological and market changes in the way Australia produces and uses energy. ESM can determine the impact of various potential future events, policies and technology breakthroughs on:

  • the uptake of new technologies in electricity generation and road transport
  • the contribution of the energy sector to greenhouse gas emissions or, alternatively, the price of carbon needed to reach a particular greenhouse gas emission reduction path
  • the price of electricity in the wholesale market as well as for households and businesses
  • the costs of road transport per kilometre for individuals and businesses.
ESM is primarily a linear programming model. Luke will discuss how this model has developed, some of the challenges along the way, as well as touch on some possible future directions.

Venue: RMIT Access Grid Room, 8.9.66 (Building 8, level 9, room 66)

Time: 6:00PM, Wed August 17, 2011

Program: Lecture by Mindi Nath, Monash University

Topic:: A perspective on stock returns and idiosyncratic volatility relationship

In finance literature, the relationship between stock returns and idiosyncratic volatility has been referred to as a puzzle by many researchers. There have been numerous research papers published in the past two decades that attempt to explain this association. Some researchers find the relation to be positive while others quote it as negative. Most of these studies form portfolios of returns on one or more explanatory variables, apply the least squares method and use a variety of explanatory variables in numerous aggregate settings involving time series and/or cross sectional models. Thus, the conclusions of researchers about the stock returns and idiosyncratic volatility relation apply only at the mean level. We evaluate the relationship at various quantiles of the conditional distribution of returns that allows parameter heterogeneity across different levels of stock returns. Our findings suggest that the stock returns and idiosyncratic volatility relation is indeed dynamic, of parabolic nature and depends on the quantile of the conditional distribution being estimated.

Venue: RMIT Access Grid Room, 8.9.66 (Building 8, level 9, room 66)

Time: 6:00PM, Wed May 18, 2011

Program: Lecture by Leo Lopes and Kate Smith-Miles, Monash University

Topic:: Generating Applicable Synthetic Instances for Branch Problems

Generating valid synthetic instances for branch problems -- those that contain a core problem like Knapsack or Graph Coloring, but add several complications -- is hard. It is even harder to generate instances that are applicable to the specific goals of an experiment and help to support the claims made. This paper presents a methodology for tuning instance generators of branch problems so that synthetic instances are similar to real ones and are capable of eliciting different behaviors from solvers. It also presents a statistic that can be used to summarize the applicability of the instances for drawing a valid conclusion. We demonstrate the methodology by generating instances for the Udine Timetabling problem. Examples and the necessary cyberinfrastructure are available as a project from Coin-OR.

Key words: Instance generation; Data mining; Optimization; timetabling

Venue: RMIT Access Grid Room, 8.9.66 (Building 8, level 9, room 66)

Time: 6:00PM, Wed March 16, 2011

Program: Lecture by Joe Forbes

Topic:: Implementing Commercial Maths: Lessons and examples

In the past operations research has struggled to make itself valued by the broader business community. In part this has been due to the difficulty that OR professionals have in both communicating and delivering the benefits of optimisation. For OR to make some space amongst the 'softer' and more favoured commercial improvement disciplines practitioners need to make optimisation easier for business to access. This presentation will examine how to successfully bring the power of mathematics to bear on business and explore some relevant examples. The following topics will be covered:

    Frame, formulate, code and use
  • Solve the right problem
  • The value of point solutions
  • Low Fi vs Hi Fi
  • Do the maths before the IT
  • Make OR accesible
  • Two recent examples from the real world: One old and one new.
  • The future: Riding the Business Analytics bandwagon
Joe Forbes, Director and Co-founder, Biarri

Joe set up Biarri, a commercial mathematics company, in January 2009 with Co-founder and Director, Ashley Nelson. Joe has been involved with optimisation companies for the last ten years primarily managing sales and marketing functions, a role he sees as being the 'translator' between mathematicians and business people.

Joe has held roles at Opcom, Carmen Systems and Boeing. Prior to becoming involved in corporate mathematics, Joe worked as a management consultant in Australia, Asia, the UK and the US. He has also worked as a transport manager with the United Nations and was an officer in the Australian Army. Joe holds a Bachelor of Arts Degree from the University of New South Wales and an MBA from the University of Western Australia. Joe is also a keen Rugby Union fan. He is married with three children.

Venue: RMIT Access Grid Room, 8.9.66 (Building 8, level 9, room 66)

Time: 6:00PM, Wed Feb 16, 2011

Program: Lectures by Olena Gavriliouk

Topic:: Applying capacitated assignment problem to interviewer allocation problem at the Australian Bureau of Statistics

In this presentation we address the workload allocation model (WAM) which arises in the process of coordinating work assignment to interviewers employed by the Australian Bureau of Statistics (ABS) for data collection in household surveys. WAM appears to be an assignment problem with different types of capacity constraints and hence not easy to solve. Also the size of WAM grows very quickly due to: (1) the number of surveys being conducted at any one time, and (2) length of the data collection periods. We show how WAM is being used at the ABS to assign work to interviewers.

The previous big event

IFORS 2011 Conference
July 10-15, 2011, Melbourne, Australia