ORBEL 32

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Schedule

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Thursday, February 1
08:30-09:15Welcome
09:15-09:30Opening session
09:30-10:30Plenary session - Dominique Feillet (Chair: Yasemin Arda)
10:30-11:00Coffee break
11:00-12:20Parallel sessions
  Routing Problems
Chair: Pieter Vansteenwegen
Room: 138
Emergency operations scheduling
Chair: El-Houssaine Aghezzaf
Room: 130
Algorithm design
Chair: Gerrit Janssens
Room: 126
Multiple Objectives
Chair: Filip Van Utterbeeck
Room: 120
12:20-13:30Lunch
12:25-13:25ORBEL board meeting
13:30-14:50Parallel sessions
  Integrated logistics
Chair: Kris Braekers
Room: 138
Person transportation
Chair: Célia Paquay
Room: 130
Continuous models
Chair: Nicolas Gillis
Room: 126
Integer programming
Chair: Bernard Fortz
Room: 120
14:50-15:20Coffee break
15:20-16:20Parallel sessions
  Material handling and warehousing 1
Chair: Greet Vanden Berghe
Room: 138
Operations management
Chair: Roel Leus
Room: 130
Matrix factorization
Chair: Pierre Kunsch
Room: 126
 
16:30-17:10Parallel sessions
  Material handling and warehousing 2
Chair: Katrien Ramaekers
Room: 138
Routing and local search
Chair: An Caris
Room: 130
Traffic management
Chair: Joris Walraevens
Room: 126
Pharmaceutical supply chains
Chair: Bart Smeulders
Room: 120
17:15-18:15ORBEL general assembly
18:30-...Conference dinner

Friday, February 2
09:30-10:30Plenary session - Martin Savelsbergh (Chair: Yves Crama)
10:30-10:50Coffee break
10:50-12:10Parallel sessions
  Optimization in health care
Chair: Jeroen Beliën
Room: 138
Network design
Chair: Jean-Sébastien Tancrez
Room: 130
Local search methodology
Chair: Patrick De Causmaecker
Room: 126
ORBEL Award
Chair: Frits Spieksma
Room: 120
12:10-13:00Lunch
13:00-14:00Parallel sessions
  Production and inventory management
Chair: Tony Wauters
Room: 138
Logistics 4.0
Chair: Thierry Pironet
Room: 130
Data clustering
Chair: Yves De Smet
Room: 126
Collective decision making
Chair: Bernard De Baets
Room: 120
14:10-15:10Parallel sessions
  Sport scheduling
Chair: Dries Goossens
Room: 138
Discrete choice modeling
Chair: Virginie Lurkin
Room: 130
Data classification
Chair: Ashwin Ittoo
Room: 126
 
15:10-15:30Coffee break
15:30- 16:30Plenary session - Michel Bierlaire (Chair: Michaël Schyns)
16:30- 16:45ORBEL award and closing session
16:45-18:00Closing cocktail

Thursday 11:00 - 12:20 Routing Problems
Room 138 - Chair: Pieter Vansteenwegen

Thursday 11:00 - 12:20 Emergency operations scheduling
Room 130 - Chair: El-Houssaine Aghezzaf

Thursday 11:00 - 12:20 Algorithm design
Room 126 - Chair: Gerrit Janssens

Thursday 11:00 - 12:20 Multiple Objectives
Room 120 - Chair: Filip Van Utterbeeck

Thursday 13:30 - 14:50 Integrated logistics
Room 138 - Chair: Kris Braekers

Thursday 13:30 - 14:50 Person transportation
Room 130 - Chair: Célia Paquay

Thursday 13:30 - 14:50 Continuous models
Room 126 - Chair: Nicolas Gillis
  • On computing the distances to stability for matrices
    Punit Sharma (University of Mons)
    Co-authors: Nicolas Gillis
    Abstract:
    The stability of a continuous linear time-invariant (LTI) system dx/dt = Ax+Bu, where A is a real matrix of size nxn and B is a real matrix of size nxm, solely depends on the eigenvalues of the stable matrix $A$. Such a system is stable if all eigenvalues of A are in the closed left half of the complex plane and all eigenvalues on the imaginary axis are semisimple. It is important to know that when an unstable LTI system becomes stable, i.e. when it has all eigenvalues in the stability region, or how much it has to be perturbed to be on this boundary. For control systems this distance to stability is well-understood. This is the converse problem of the distance to instability, where a stable matrix A is given and one looks for the smallest perturbation that moves an eigenvalue outside the stability region. In this talk, I will talk about the distance to stability problem for LTI control systems. Motivated by the structure of dissipative-Hamiltonian systems, we define the DH matrix: a matrix A of size nxn is said to be a DH matrix if A=(J-R)Q for some real nxn matrices J, R, Q such that J is skew-symmetric, R is symmetric positive semidefinite and Q is symmetric positive definite. We will show that a system is stable if and only if its state matrix is a DH matrix. This results in an equivalent optimization problem with a simple convex feasible set. We propose a new very efficient algorithm to solve this problem using a fast gradient method. We show the effectiveness of this method compared to other approaches such as the block coordinate descent method and to several state-of-the-art algorithms. For more details, this work has been published as [1]. [1] N. Gillis and P. Sharma, On computing the distance to stability for matrices using linear dissipative Hamiltonian systems. Automatica, 85, pp. 113-121, 2017.
  • Low-Rank Matrix Approximation in the Infinity Norm
    Nicolas Gillis (University of Mons)
    Co-authors: Yaroslav Shitov
  • Benchmarking some iterative linear systems solvers for deformable 3D images registration
    Justin Buhendwa Nyenyezi (Université de Namur)
  • Spectral Unmixing with Multiple Dictionaries
    Jérémy Cohen (UMONS/FNRS)
    Co-authors: Nicolas Gillis

Thursday 13:30 - 14:50 Integer programming
Room 120 - Chair: Bernard Fortz

Thursday 15:20 - 16:20 Material handling and warehousing 1
Room 138 - Chair: Greet Vanden Berghe

Thursday 15:20 - 16:20 Operations management
Room 130 - Chair: Roel Leus

Thursday 15:20 - 16:20 Matrix factorization
Room 126 - Chair: Pierre Kunsch

Thursday 16:30 - 17:10 Material handling and warehousing 2
Room 138 - Chair: Katrien Ramaekers

Thursday 16:30 - 17:10 Routing and local search
Room 130 - Chair: An Caris

Thursday 16:30 - 17:10 Traffic management
Room 126 - Chair: Joris Walraevens

Thursday 16:30 - 17:10 Pharmaceutical supply chains
Room 120 - Chair: Bart Smeulders

Friday 10:50 - 12:10 Optimization in health care
Room 138 - Chair: Jeroen Beliën

Friday 10:50 - 12:10 Network design
Room 130 - Chair: Jean-Sébastien Tancrez

Friday 10:50 - 12:10 Local search methodology
Room 126 - Chair: Patrick De Causmaecker

Friday 10:50 - 12:10 ORBEL Award
Room 120 - Chair: Frits Spieksma

    Friday 13:00 - 14:00 Production and inventory management
    Room 138 - Chair: Tony Wauters

    Friday 13:00 - 14:00 Logistics 4.0
    Room 130 - Chair: Thierry Pironet

    Friday 13:00 - 14:00 Data clustering
    Room 126 - Chair: Yves De Smet

    Friday 13:00 - 14:00 Collective decision making
    Room 120 - Chair: Bernard De Baets

    Friday 14:10 - 15:10 Sport scheduling
    Room 138 - Chair: Dries Goossens

    Friday 14:10 - 15:10 Discrete choice modeling
    Room 130 - Chair: Virginie Lurkin

    Friday 14:10 - 15:10 Data classification
    Room 126 - Chair: Ashwin Ittoo

     
     
      ORBEL - Conference chair: Prof. A. Arda - Platform: Prof. M. Schyns.