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. |
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