ORBEL 28

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Detailed schedule

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Thursday 30 January:

9:00-9:30Registration (Hall of Vesale Building)
9:30-10:45Plenary session (Room Vesale 023)
Welcome
Invited speaker: Gerhard Woeginger
Optimization at the second level
10:45-11:15Coffee break
11:15-12:30Parallel sessions
  TA-1: COMEX - Optimization 1
Chair: M. Schyns
Room: Vesale 023
TA-2: Software and Implementation
Chair: M. Mezmaz
Room: Vesale 020
TA-3: COMEX - Smart mobility
Chair: A. Caris
Room: Vesale 025
TA-4: Systems
Chair: P. Kunsch
Room: Pentagone 0A11
12:30-14:00Lunch (First floor of the Restaurant building)
13:30-General Assembly
14:00-15:40Parallel sessions
  TB-1: Data Analysis 1
Chair: X.Siebert
Room: Vesale 023
TB-2: Multiple Objectives
Chair: Y. de Smet
Room: Vesale 020
TB-3: Logistics
Chair: D. De Wolf
Room: Vesale 025
TB-4: COMEX - Applications to Economy
Chair: W. Brauers
Room: Pentagone 0A11
TB-5: Networks
Chair: B. Fortz
Room: Pentagone 0A07
15:40-16:10Coffee break
16:10-17:25Parallel sessions
  TC-1: Mixed-integer nonlinear programming
Chair: Y. Crama
Room: Vesale 023
TC-2: Decision Analysis 1
Chair: S. Eppe
Room: Vesale 020
TC-3: Routing
Chair: K. Sörensen
Room: Vesale 025
TC-4: Graphs
Chair: H. Mélot
Room: Pentagone 0A11
TC-5: Scheduling
Chair: S. Hanafi
Room: Pentagone 0A07
 
17:30-General Assembly (if quota not reached at 13:30)
19:30-Conference dinner

Friday 31 January
9:00-10:15Parallel sessions
  FA-1: Queuing
Chair: S. Wittevrongel
Room: Vesale 023
FA-2: Decision Analysis 2
Chair: R. Bisdorff
Room: Vesale 020
FA-3: COMEX - Optimization 2
Chair: M. Labbé
Room: Vesale 025
FA-4: Production
Chair: D. Tuyttens
Room: Pentagone 0A11
 
10:15-10:40Coffee break
10:40-12:40Plenary session (Room Vesale 023)
Invited speaker: Matthias Ehrgott
From routeplanning to scheduling and policy decisions: Applications of multiobjective optimization in transportation
ORBEL Award
Wolsey award announcement
12:40-14:00Lunch (First floor of the Restaurant building)
14:00-15:40Parallel sessions
  FB-1: Data Analysis 2
Chair: P. Fortemps
Room: Vesale 023
FB-2: Heuristics
Chair: T. Stützle
Room: Vesale 020
FB-3: COMEX - Transportation
Chair: F. Spieksma
Room: Vesale 025
FB-4: Health
Chair: G. Vanden Berghe
Room: Pentagone 0A11
 
15:40-17:00Closing: Coffee, beers and wine


Thursday 11:15-12:30 TA-1: COMEX - Optimization 1
Room Vesale 023 - Chair: M. Schyns

Thursday 11:15-12:30 TA-2: Software and Implementation
Room Vesale 020 - Chair: M. Mezmaz

Thursday 11:15-12:30 TA-3: COMEX - Smart mobility
Room Vesale 025 - Chair: A. Caris

Thursday 11:15-12:30 TA-4: Systems
Room Pentagone 0A11 - Chair: P. Kunsch

Thursday 14:00-15:40 TB-1: Data Analysis 1
Room Vesale 023 - Chair: X.Siebert

Thursday 14:00-15:40 TB-2: Multiple Objectives
Room Vesale 020 - Chair: Y. de Smet

Thursday 14:00-15:40 TB-3: Logistics
Room Vesale 025 - Chair: D. De Wolf

Thursday 14:00-15:40 TB-4: COMEX - Applications to Economy
Room Pentagone 0A11 - Chair: W. Brauers

Thursday 14:00-15:40 TB-5: Networks
Room Pentagone 0A07 - Chair: B. Fortz

Thursday 16:10-17:25 TC-1: Mixed-integer nonlinear programming
Room Vesale 023 - Chair: Y. Crama

Thursday 16:10-17:25 TC-2: Decision Analysis 1
Room Vesale 020 - Chair: S. Eppe

Thursday 16:10-17:25 TC-3: Routing
Room Vesale 025 - Chair: K. Sörensen

Thursday 16:10-17:25 TC-4: Graphs
Room Pentagone 0A11 - Chair: H. Mélot

Thursday 16:10-17:25 TC-5: Scheduling
Room Pentagone 0A07 - Chair: S. Hanafi

Friday 9:00-10:15 FA-1: Queuing
Room Vesale 023 - Chair: S. Wittevrongel

Friday 9:00-10:15 FA-2: Decision Analysis 2
Room Vesale 020 - Chair: R. Bisdorff

Friday 9:00-10:15 FA-3: COMEX - Optimization 2
Room Vesale 025 - Chair: M. Labbé

Friday 9:00-10:15 FA-4: Production
Room Pentagone 0A11 - Chair: D. Tuyttens
  • CP Approach for the Multi-Item Discrete Lot-Sizing Problem with Sequence-Dependent Changeover Costs
    Vinasetan Houndji (Université Catholique de Louvain)
    Co-authors: Pierre Schaus, Laurence Wolsey
    Abstract:
    The Discrete Lot Sizing and Scheduling Problem (DLSP) is a production planning problem which involves determining a minimal cost production schedule in which the machine capacity restrictions are not violated, and the demand for all products is satisfied. The planning horizon is discrete and finite. The variant considered here, called the Pigment Sequencing Problem [1], is a multi-item, single machine problem with production capacity limited to one item per period. There are storage costs and sequence-dependent changeover costs satisfying the triangle inequality. Without loss of generality, we can assume that demands are normalized and so are binary. Pigment Sequencing Problem is an NP-Hard combinatorial optimization problem for which medium-sized instances can be solved effectively using an appropriate Mixed Integer Program formulation (such as those introduced in [1]). However, as far as we know, no CP model have been proposed for it. We propose two CP models for the problem: - the first mainly uses a global cardinality constraint [2] to enforce the production of all items required and some "atleast" constraints so as to respect each demand deadline ; - the second is similar to the successor CP model for the Traveling Salesman Problem (TSP) where the cities to be visited represent the different demands and the distance between them are the corresponding transition (changeover) costs. The distinction with the classical TSP lies in the storage costs which must be taken into account. We use Large Neighborhood Search (LNS) [3] with some variants of relaxation procedures and heuristic search in order to quickly discover close to optimal solutions. The results show that Constraint Programming is potentially an effective approach for tackling Discrete Lot Sizing Problems. References [1] Pochet, Y, Wolsey, L. : Production Planning by Mixed Integer Programming. Springer, New York (2005) [2] Régin, J-C. : Generalized arc consistency for global cardinality constraint. Proceedings of Association for the Advancement of Artificial Intelligence (AAAI) conference on Artificial Intelligence, Portland, USA. 209--215 (1996) [3] Shaw, P. : Using constraint programming and local search methods to solve vehicle routing problems. Proceedings of Principles and Practice of Constraint Programming conference, Pisa, Italy. 417--431 (1998)
  • Local search approaches for 2D nesting problems
    Tony Wauters (KU Leuven, Department of Computer Science, CODeS - iMinds-ITEC)
    Co-authors: Sam Van Malderen, Greet Vanden Berghe
  • Exact resolution of the Cover Printing Problem
    Arnaud Vandaele (UMONS, Faculté Polytechnique)
    Co-authors: Daniel Tuyttens

Friday 14:00-15:40 FB-1: Data Analysis 2
Room Vesale 023 - Chair: P. Fortemps

Friday 14:00-15:40 FB-2: Heuristics
Room Vesale 020 - Chair: T. Stützle

Friday 14:00-15:40 FB-3: COMEX - Transportation
Room Vesale 025 - Chair: F. Spieksma

Friday 14:00-15:40 FB-4: Health
Room Pentagone 0A11 - Chair: G. Vanden Berghe

 
 
  SOGESCI/ORBEL - Conference chair: Prof. M. Pirlot - Platform: Prof. M. Schyns