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
  • A Branch-and-Price Algorithm for the Network Pricing Problem with Connected Toll Arcs
    Alessia Violin (Université Libre de Bruxelles)
    Co-authors: Bernard Fortz, Martine Labbé
  • Maximizing User Benefits by Changes in Incomplete Networks
    Corrinne Luteyn (KU Leuven)
    Co-authors: Pieter Vansteenwegen
  • Models for traffic engineering with multiple spanning tree protocols
    Martim Moniz (Université Libre de Bruxelles)
    Co-authors: Bernard Fortz; Luís Gouveia
    Abstract:
    With the increasing demand for Internet and cloud computing services, the need for large scale data centers has become paramount. This emphasizes the critical necessity of improving the performance of these telecommunication networks. In these data centers, switched Ethernet networks are becoming popular, as they are more effective in the management of traffic. Loops in the network's topology can result in broadcast radiation. As such, Ethernet networks only activate, at a given time, a cycle-free subset of the existing links. To ensure this, these networks implement the IEEE 802.1d standard which defines the topology of the network as a spanning tree. One of the drawbacks of this protocol is that the network only ends up using a small number of the existing links (#nodes-1). To overcome this drawback, Ethernet networks began using the Multiple Spanning Tree Protocol, which maintains a set of spanning trees that are used for routing the demands in the network. Each spanning tree is allocated to a pre-defined set of demands. This is highly advantageous for the traffic performances of Ethernet networks, as the traffic can be spread throughout a bigger number of links. We present two mixed integer programming models for the Traffic Engineering problem of optimally designing a network implementing the Multiple Spanning Tree Protocol, such that link utilization is minimized. Although some variants of this problem have been treated in the literature, this is the first approach that focuses on using exact methods. Both formulations are based on models that have been previously used for the design of single spanning trees. The Multi-commodity Flow Formulation (MFF) makes use of flows to design the spanning trees, while the Rooted Directed Formulation (RDF) uses variables to orient the edges into arborescences rooted at each node of a VLAN. We present tests in order to compare the two formulations, in terms of linear relaxation strength and computing time. We also propose a binary search algorithm that has proven to be efficient in obtaining quasi-optimal solutions for this problem.
  • Optimal capacitated ring trees
    Alessandro Hill (University of Antwerp)
    Co-authors: Stefan Voss

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

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