ORBEL 27

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Detailed schedule

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Thursday 7 February:

9:00-9:30Registration (Room Spina)
9:30-10:45Plenary session
Welcome
Invited speaker: El-Ghazali Talbi
Metaheuristics for multi-objective optimization - A unified view
10:45-11:15Coffee break
11:15-12:30Parallel sessions
  TA-1: COMEX Decision Making
Chair: B. Fortz
Room: C.611
TA-2: Production 1
Chair: E.h. AGhezzaf
Room: C.601
TA-3: Global Optimization
Chair: D. Claeys
Room: C.602
TA-4: Transportation 1
Chair: C. Vanovermeire
Room: C.603
12:30-14:00Lunch
14:00-15:40Parallel sessions
  TB-1: COMEX Health
Chair: G. Vanden Berghe
Room: C.611
TB-2: Routing
Chair: G.K. Janssens
Room: C.601
TB-3: Meta-Heuristics
Chair: P. Vansteenwegen
Room: C.602
TB-4: Transportation 2
Chair: F.C.R Spieksma
Room: C.603
15:40-16:10Coffee break
16:10-17:25Parallel sessions
  TC-1: COMEX Routing
Chair: K. Sôrensen
Room: C.611
TC-2: Sets, Relations and Rankings
Chair: B. De Baets
Room: C.601
TC-3: Logistics
Chair: S. Demeyer
Room: C.602
 
17:30-General Assembly (Room C.611)
19:30-Conference dinner (Carlton)

Friday 8 February
9:00-10:15Parallel sessions
  FA-1: COMEX Logistics
Chair: Y. Crama
Room: C.611
FA2: Production 2
Chair: D. Tuyttens
Room: C.611
FA-3: MIP
Chair: T. Dokka
Room: C.603
 
10:15-10:40Coffee break
10:40-12:40Plenary session
ORBEL Award
Wolsey award announcement
Invited speaker: Andrea Schaerf
Educational Timetabling: Problems, Benchmarks, Algorithms, Software Tools, and Practical Issues
12:40-14:00Lunch
14:00-14:30IMinds Information Session (Room C.611)
14:30-16:10Parallel sessions
  FB-1: COMEX automatic tuning and organization
Chair: T. Stützle
Room: C.611
FB2: Disaster, Water and Biology
Chair: L. Porretta
Room: C.602
FB-3: Decision Making
Chair: D. Goossens
Room: C.603
 
16:10-16:40Coffee break


Thursday 11:15-12:30 TA-1: COMEX Decision Making
Room C.611 - Chair: B. Fortz

Thursday 11:15-12:30 TA-2: Production 1
Room C.601 - Chair: E.h. AGhezzaf

Thursday 11:15-12:30 TA-3: Global Optimization
Room C.602 - Chair: D. Claeys

Thursday 11:15-12:30 TA-4: Transportation 1
Room C.603 - Chair: C. Vanovermeire

Thursday 14:00-15:40 TB-1: COMEX Health
Room C.611 - Chair: G. Vanden Berghe

Thursday 14:00-15:40 TB-2: Routing
Room C.601 - Chair: G.K. Janssens

Thursday 14:00-15:40 TB-3: Meta-Heuristics
Room C.602 - Chair: P. Vansteenwegen

Thursday 14:00-15:40 TB-4: Transportation 2
Room C.603 - Chair: F.C.R Spieksma

Thursday 16:10-17:25 TC-1: COMEX Routing
Room C.611 - Chair: K. Sôrensen

Thursday 16:10-17:25 TC-2: Sets, Relations and Rankings
Room C.601 - Chair: B. De Baets

Thursday 16:10-17:25 TC-3: Logistics
Room C.602 - Chair: S. Demeyer

Friday 9:00-10:15 FA-1: COMEX Logistics
Room C.611 - Chair: Y. Crama

Friday 9:00-10:15 FA2: Production 2
Room C.611 - Chair: D. Tuyttens
  • 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
    Abstract:
    Lexicographic optimization of a bi-objective permutation flow shop with time-lags. E.Dhouib (*); D.Tuyttens(**); J.Teghem (**); T.Loukil (*) (*) Laboratory LOGIQ, University of Sfax (Tunisia). [email protected]; [email protected] (**) Laboratory MathRO, University of Mons (Belgium) [email protected]; [email protected] ABSTRACT. We consider a permutation flow shop with time lags constraints. These constraints consist to impose some restrictions on the time elapsed between two successive operations of a same job. In the considered model there exist minimal and maximal time-lags which are respectively lower and upper bounds of the delay between the end of the operation on one machine and the beginning of the operation on the following machine. At each job is associated a due date. Two criteria are taken into consideration in a lexicographical manner: the primary objective is the number of tardy jobs; the secondary one is the makespan. So the aim is to find the schedule within the minimal total completion time among the schedules with the minimal number of tardy jobs. In a first step a mixed integer linear programming formulation is proposed and solved with CPLEX. It quickly appears that only small instances can be solved in a time limit of 5.000 seconds (experiments are made with 20 jobs and 3 or 5 machines).In a second step two local search metaheuristics are adapted to tackle the problem. The first one is a Simulated Annealing (SA) based algorithm with some additional elements in regard with the classical SA scheme: - Several solutions are generated randomly in the neighborhood and the best one is selected; - Two acceptance tests of this solution are analyzed in regard of the lexicographical optimization; - Several variants of a greedy heuristic are proposed to optimize the partial schedule of the tardy jobs, each time the first objective is improved; - At the end of the SA procedure, an improvement scheme is applied to still trying to improve the final schedule. The second metaheuristic is a GRASP algorithm. An iteration is composed of two phases: - A greedy randomized search procedure is proposed to build a schedule taking into account the lexicographic optimization. At each step a list of possible jobs to schedule is based on the due date of the job and the generated total idle time of the machines. - A local search to improve the schedule. Extensive numerical experiments are made to compare both methods on instances with 60 or 80 jobs and 8 machines, and with 100 jobs and 5 machines. The aim of these experiments is not only to compare the performances of the two metaheuristics but also to analyze the impact of the respective values of the due dates and the time lags.
  • 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

Friday 9:00-10:15 FA-3: MIP
Room C.603 - Chair: T. Dokka

Friday 14:00-15:40 FB-1: COMEX automatic tuning and organization
Room C.611 - Chair: T. Stützle

Friday 14:00-15:40 FB2: Disaster, Water and Biology
Room C.602 - Chair: L. Porretta

Friday 14:00-15:40 FB-3: Decision Making
Room C.603 - Chair: D. Goossens

 
 
  SOGESCI/ORBEL - Conference chair: Prof. P. De Causmaecker - Platform: Prof. M. Schyns