SÉMINAIRE / SEMINAR

LUNDI / MONDAY7 décembre 2009 / December 7, 2009

10h30Salle / Room 5441

Pavillon André-AisenstadtUniversité de Montréal

Bienvenue à tous / Welcome to all

Luis GouveiaUniversité de Lisbonne/University of Lisboa, Portugal

Responsable/Organizer : Bernard Gendron

Information : Pierre MarchandResponsable des communications du CIRRELT pierre.marchand@cirrelt.ulaval.ca

NoteLuis Gouveia est/is professeur agrégé/Associate Professor au/at the Department of Statistics and Operations Research, Faculty of Sciences, University of Lisboa, Portugal. legouveia@fc.ul.pt

Résumé / AbstractConsider a graph G=(V,E) where V is the set of nodes and E is the set of edges with non-negative costs associated. We also consider a concave cost function on the degree of each node and a constraint on the degree of each node. These considerations are mainly motivated in the telecommunications field where specific technology must be installed on each node with a degree greater than 1. We consider this variant on the classical Spanning Tree Problem and on the Prize-collecting Steiner Tree Problem. Several integer linear programming problems based on reformulation techniques such as "discretrization" and "knapsack/shortest path" are presented and their linear programming relaxations are compared using a set of instances with up to 100 nodes.

« Tree Problems with Node Dependent Costs »