Décembre 2013


Retour à la vue des calendrier
Mardi 3 Décembre
Heure: 12:00 - 13:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: A branch-and-bound method for box constrained integer polynomial optimization
Description: Claudia D'Ambrosio We consider the problem of minimizing an arbitrary polynomial subject to
box and integrality constraints. We propose a new class of
under-estimators composed of separable functions of the original variables
and use it within a branch-and-bound scheme to easily and quickly compute
lower bounds. Computational results on randomly generated instances show
good performance with respect to the ones of different open-source solvers
like Couenne, Gloptipoly , and SCIP.
Moreover, the second part of the talk will be devoted to present a
different perspective on partially separable problems. In particula, an
exact algorithm for mixed integer non-linear programming problems with
separable non-convexities will be presented.
Mardi 17 Décembre
Heure: 12:00 - 13:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Konig's edge-colouring theorem for all graphs
Description: Denis Cornaz We show that the maximum degree of a
graph G is equal to the minimum number of ocm sets covering G,
where an ocm set is the vertex-disjoint union of elementary odd
cycles and one matching, and a collection of ocm sets covers G if
every edge is in the matching of an ocm set or in some odd cycle
of at least two ocm sets.
This min-max relation gives a linear description of the star
polytope with a minimal TDI-system.
Joint work with V. H. Nguyen from LIP6.