Detailed schedule

Thursday 7 February:

• Testing Rationality of Collective Household Consumption (PDF)
  Fabrice Talla Nobibon (KU Leuven)
  Co-authors: L. Cherchye, Y. Crama, T. Demuynck, B. De Rock, and F.C.R. Spieksma
  
• On the statistical analysis of overlapping observations in large networks (PDF)
  Yuyi Wang (KULeuven)
  Co-authors: Jan Ramon
  
• Dantzig-Wolfe Reformulation for the Network Pricing Problem with Connected Toll Arcs (PDF)
  Alessia Violin (Université Libre de Bruxelles)
  Co-authors: Bernard Fortz, Martine Labbé
  

• Dynamic Product Portfolio Management with Life Cycle Considerations (PDF)
  Jean-sébastien Tancrez (Louvain School of Management, Université catholique de Louvain)
  Co-authors: A.C. Zeballos, R.W. Seifert
  Abstract:
  In order to be profitable, companies have to continuously manage their portfolio of product lines. At the same time, demand for products varies across different life cycle stages. Disregarding these variations may result in high operational costs due to inadequate ordering decisions and revenue shortfalls. In a portfolio of product lines, the product life cycle acquires even more relevance because the upper and lower extremes of demand and revenue may occur simultaneously in multiple product lines and thus be magnified. Therefore, companies may want to smooth the overall levels of demand and revenue by actively managing their portfolio, properly timing product upgrade launches and adequately choosing the amount and timing of marketing support. This is particularly true for products with short life cycles such as high technology goods, consumer electronics, and fashion apparel, for which the life cycle is the main source of demand dynamics. When firms are financially constrained in making needed investments yet still have to manage multiple products through various life cycle stages, achieving optimal inventory, product launch and marketing support decisions becomes complex. In this research, to understand how a company should combine these decisions to successfully coordinate its operations and finances, we propose a stylized model that combines three subjects: product portfolio management, product life cycle and financial constraints. The model aims to help dynamically manage a portfolio of product lines that probabilistically transition through various life cycle stages (introduction, growth, maturity, decline and end-of-life). For this, we develop a Markov decision process to find the optimal decisions depending on the actual composition of the portfolio. Products are characterized by varying operational cost parameters (procurement, holding, and lost sales) and can have specific life cycle characteristics. The evolution through the life cycle stages is impacted by both marketing support and product launch decisions. These decisions involve costs and impact the life cycle stages transitions. The inventory, launching and marketing decisions and the related portfolio expenditures are bound by a financial constraint in the form of restricted working capital. The working capital is a constant level of cash and inventory held by the company, which is supposed to be decided a priori by the company. Therefore, in our model, companies can, within limits, actively manage their product portfolio to achieve more favorable demand realizations. In fact, product life cycle management acquires real meaning at the product portfolio level since harmonizing decisions can be made to smooth aggregated demand and thus income. Applying our tool, several managerial insights can be provided. Firstly, the decisions regarding the launch timing, the marketing support and the WC level are complex and dynamic, justifying the use of a comprehensive model, including the complex and multiple trade-offs involved. Cautious and greedy policies lead to much lower profit. Secondly, product portfolios benefit greatly from joint management, which reduces the amount of WC used per product and increases the benefits per allocated WC. Thirdly, the optimal policy aims to reach a stable aggregate demand level and thus stable resource requirements, rather than temporarily reaching the highest aggregate demand level. Optimal decisions smooth not only aggregated demand levels but also cash flows and the length of time in and outside the market. This is important to ensure optimal use of resources and avoid high costs. Finally, portfolio composition is a strategic decision that can also be made with the help of the proposed portfolio management tool. The optimal composition depends closely on the characteristics of admitted product types.
  
• Energy-Neutral Demand Response from a Large Population of batch-process loads (PDF)
  Arnaud Latiers (UCL Louvain-la-Neuve)
  Co-authors: Francois Glineur, Emmanuel De Jaeger
  
• Measuring Complexity in Mixed-Model Assembly Workstations (PDF)
  Luiza Zeltzer (Department of Industrial Management Faculty of Engineering and Architecture Ghent University Ghent, Belgium)
  Co-authors: Luiza Zeltzer, Veronique Limère, El-Houssaine Aghezzaf, Hendrik Van Landeghem
  

• On jet-convex functions and their tensor products (PDF)
  Vladimir Shikhman (Université Catholique de Louvain)
  Co-authors: O. Stein
  
• Hybrid approach for generating laser cutting tool paths (PDF)
  Reginald Dewil (Katholieke Universiteit Leuven)
  Co-authors: Pieter Vansteenwegen, Dirk Cattrysse
  
• Optimal group sizes for dynamic group screening (PDF)
  Dieter Claeys (Ghent University)
  Co-authors: Joris Walraevens, Bart Steyaert, Herwig Bruneel
  

• Intermodal network design for freight transportation in Belgium - location of rail/road and road/inland waterway terminals (PDF)
  Martine Mostert (University of Liege)
  Co-authors: Sabine LIMBOURG
  
• Using Contraction Hierarchies to Find Dissimilar Paths in Transportation Networks (PDF)
  Sofie Demeyer (Ghent University)
  Co-authors: Maarten Houbraken, Thijs Walcarius, Pieter Audenaert, Didier Colle, Mario Pickavet
  
• Analysis of different cost allocation methods in a collaborative transport setting (PDF)
  Christine Vanovermeire (University of Antwerp)
  Co-authors: Dries Vercruysse, Kenneth Sörensen
  

• Planning the caregivers at Landelijke Thuiszorg (PDF)
  Marco Castro (University of Antwerp)
  Co-authors: Pablo Maya, Kenneth Sorensen, Peter Goos
  
• Automatic Constraint Weight Extraction for Nurse Rostering: A Case Study (PDF)
  Mihail Mihaylov (CODeS, KAHO Sint-Lieven)
  Co-authors: Pieter Smet, Greet Vanden Berghe
  
• The overlapping case in an integrated staffing and rostering formulation (PDF)
  Komar Komarudin (Vrije Universiteit Brussel)
  Co-authors: M.-A. Guerry, G. Vanden Berghe and T. De Feyter
  
• Hardness analysis and a new approach for the shift minimisation personnel task scheduling problem (PDF)
  Pieter Smet (CODeS, KAHO Sint-Lieven)
  Co-authors: Tony Wauters, Greet Vanden Berghe
  

• Elementary shortest path problems for a multiple-trip vehicle routing problem (PDF)
  Hande KÜÇÜkaydin (University of Liège)
  Co-authors: Yasemin Arda, Yves Crama
  
• State of the art of vehicle routing problems with loading constraints (PDF)
  Hanne Pollaris (Hasselt University)
  Co-authors: Kris Braekers, An Caris, Katrien Ramaekers, Gerrit K. Janssens
  
• The eect of customer characteristics on coalition gains in collaborative vehicle routing (PDF)
  Christof Defryn (University of Antwerp)
  Co-authors: C.Vanovermeire, K.Sörensen
  
• A time-dependent vehicle routing problem in the service area of intermodal terminals (PDF)
  Kris Braekers (Universiteit Hasselt)
  Co-authors: An Caris, Gerrit K. Janssens
  

• Multi-Objective Large Neighborhood Search (PDF)
  Renaud Hartert (Université Catholique de Louvain)
  Co-authors: Pierre Schaus
  
• OscaR.cbls: an open source framework for constraint-based local search (PDF)
  Renaud De Landtsheer (CETIC)
  Co-authors: Christophe Ponsard
  
• The Budget-Constrained Min Cost Flow Problem (PDF)
  Sofie Coene (KULeuven)
  Co-authors: P. Maya, K. Sörensen, P. Goos, F.C.R. Spieksma
  
• A Memetic Algorithm for the Orienteering Problem with Intermediate Facilities (PDF)
  Ali Divsalar (KU Leuven)
  Co-authors: Pieter Vansteenwegen, Dirk Cattrysse
  

• Optimisation model for empty container repositioning. (PDF)
  Frederic Salmon (HEC-ULg QuantOM)
  Co-authors: S.Limbourg
  
• The Red-Blue Transportation Problem (PDF)
  Wim Vancroonenburg (KU Leuven - KAHO Sint-Lieven)
  Co-authors: Federico Della Croce, Dries Goossens, Frits Spieksma
  
• The ship placement problem: Decision support through exact decomposition (PDF)
  Jannes Verstichel (KU Leuven - KAHO Sint-Lieven)
  Co-authors: Patrick De Causmaecker, Greet Vanden Berghe
  
• The lockmaster's problem: a computational study (PDF)
  Ward Passchyn (KU Leuven)
  Co-authors: S. Coene; F. C. R. Spieksma; G. Vanden Berghe; D. Briskorn; J. L. Hurink
  

• An Adaptive Large Neighborhood Search for a Vehicle Routing Problem with Multiple Trips and Driver Shifts (PDF)
  Véronique François (HEC-Management School of the University of Liège)
  Co-authors: Yasemin Arda and Yves Crama
  
• New Metaheuristics for the Risk Constraint Cash-in-Transit Vehicle Routing Problem (PDF)
  Luca Talarico (University of Antwerp)
  Co-authors: K. Sörensen and J. Springael
  
• Routing for couriers: a multi-objective tabu search method to rebalance a tactical route plan with microzones (PDF)
  Jochen Janssens (University of Antwerp)
  Co-authors: Joos Van Den Bergh
  

• A Set-Based Approach to the Decomposition of Linear Mixtures Using Quasi-Convex Programming (PDF)
  Jan Verwaeren (Ghent University)
  Co-authors: Michael Rademaker, Bernard De Baets
  
• Dice representability of reciprocal relations (PDF)
  Karel De Loof (Universiteit Gent)
  Co-authors: K. De Loof, B. De Baets and H. De Meyer
  
• Using a natural monotonicity constraint as the basis of a ranking procedure (PDF)
  Michael Rademaker (UGent)
  Co-authors: Bernard De Baets
  

• Automatic Aircraft Cargo Load Planning with Pick-up and Deliveries (PDF)
  Virginie Lurkin (HEC- Université de Liège)
  Co-authors: Lurkin Virginie and Schyns Michael
  
• A tabu-embedded simulated annealing algorithm for a selective pickup and delivery problem (PDF)
  Tabitha Maes (Hasselt University)
  Co-authors: An Caris, Katrien Ramaekers, Gerrit K. Janssens
  
• An insertion-based heuristic for the constrained pickup and delivery problem (PDF)
  Maarten Houbraken (UGent)
  Co-authors: T. Walcarius, S. Demeyer, P. Audenaert, D. Colle, M. Pickavet
  

• The cooperative facility location problem (PDF)
  Lotte Verdonck (Hasselt University, Research Foundation Flanders (FWO))
  Co-authors: Patrick Beullens, An Caris, Katrien Ramaekers, Gerrit K. Janssens
  
• Two- and three-dimensional strip packing: a shaking procedure (PDF)
  Tony Wauters (CODeS, KAHO Sint-Lieven)
  Co-authors: Jannes Verstichel, Greet Vanden Berghe
  
• Multiperiod vehicle loading with stochastic release dates (PDF)
  Thierry Pironet (University of Liège)
  Co-authors: Y. Arda, Y. Crama, D. Kronus, Th. Pironet, P. Van Hentenryck
  

• Lexicographic optimization of a bi-objective permutation flow shop with time lags (PDF)
  Jacques Teghem (Faculté Polytechnique de Mons)
  Co-authors: E.Dhouib;D.Tuyttens;T.Loukil
  
• general lotsizing problem in a closed-loop supply chain with uncertain returns (PDF)
  Guillaume Amand (University of Liège)
  Co-authors: Yasemin Arda
  
• A branch and bound algorithm for a lexicographic optimization of a bi-objective permutation flowshop with time lags (PDF)
  Arnaud Vandaele (UMONS, Faculté Polytechnique)
  Co-authors: Daniel Tuyttens
  

• The characterization of affine maximizers when there are only two alternatives\,: A technical note (PDF)
  Thierry Marchant (Ghent University)
  Co-authors: Debasis Mishra
  
• Covering Linear Programs with Violations (PDF)
  Laurence Wolsey (CORE, UCL)
  Co-authors: Feng Qiu, Shabbir Ahmed, Santanu S. Dey
  
• Approximation Algorithms for Multi-Dimensional Vector Assignment problems (PDF)
  Trivikram Dokka (K U Leuven)
  Co-authors: Yves Crama, Frits Spieksma
  

• From Grammars to Parameters: Automatic Design of Iterated Greedy Algorithms (PDF)
  Manuel LÓpez-ibaÑez (Université Libre de Bruxelles)
  Co-authors: Franco Mascia, Jérémie Dubois-Lacoste and Thomas Stützle
  
• Automatic algorithm selection for multi-mode resource-constrained project scheduling problems (PDF)
  Tommy Messelis (KU Leuven kulak)
  Co-authors: Patrick De Causmaecker
  
• Predicting parameter configurations for tuning effective algorithms on very large instances (PDF)
  Franco Mascia (Université Libre de Bruxelles (ULB))
  Co-authors: Mauro Birattari and Thomas Stützle
  
• An Approach to the Automatic Configuration of a Generalized Metaheuristic Structures (PDF)
  Marie-eléonore Marmion (Université Libre de Bruxelles)
  Co-authors: Franco Mascia, Manuel López-Ibáñez, Thomas Stützle
  

• SIMEDIS disaster management simulator: major road traffic accident (PDF)
  Christophe Ullrich (Royal Military Academy)
  Co-authors: F. Van Utterbeeck, M. Debacker, E. Dhondt
  
• Two-stage stochastic integer programming models for strategic disaster preparedness (PDF)
  Alper Döyen (University of Liege)
  Co-authors: Necati Aras,Yasemin Arda
  
• Generation of synthetic water distribution networks (PDF)
  Annelies De Corte (University of Antwerp)
  Co-authors: Kenneth Sörensen
  
• A Class Representative Model for Pure Parsimony Haplotyping under Uncertain Data (PDF)
  Luciano Porretta (Université Libre de Bruxelles)
  Co-authors: D. Catanzaro, M. Labbe
  

• Progressive multi-objective optimization (PDF)
  Kenneth Sörensen (Universiteit Antwerpen)
  Co-authors: Johan Springael
  
• Elicitation procedures for the comparison of decisional maps (PDF)
  Valérie Brison (UMONS, Faculté Polytechnique)
  Co-authors: Marc Pirlot
  
• Designing a combinatorial auction for Solids (PDF)
  Dries Goossens (KU Leuven)
  Co-authors: Frits Spieksma, Sander Onderstal, Jan Pijnacker
  
• On a queue with customer deadlines (PDF)
  Tom Maertens (Ghent University)
  Co-authors: Herwig Bruneel