Column generation is one of the most successful approaches for solving large scale linear programming problems. However, degeneracy difficulties and long-ta...

Column generation has become a powerful tool in solving large scale integer programs. It is well known that most of the often reported compatibility issues ...

Several upper bounds on the largest Laplacian eigenvalue of a graph <i>G</i>, in terms of degree and average degree of neighbors of its vertices, have been ...

This paper considers a shift scheduling problem that includes different forms of flexibility in terms of shift starting times, break lengths and break plac...

Une étude du transport de roses coupées, en collaboration avec la plantation Mira- flores évalue l’exportation de Bogotá (Colombie) vers Miami (USA), port d...

La localisation d'un site d'approvisionnement pour minimiser les coûts d'opérations est une problématique industrielle courante. Les variables classiques co...

Several variants and generalizations of the Or-opt heuristic for the <i>Symmetric Traveling Salesman Problem</i> are developed and compared on random and pla...

The continuous location-allocation problem requires finding sites for <i>m</i> new facilities in the plane in order to serve <i>n</i> users such that the to...

Variable Neighborhood Search (VNS) is a recent and effective metaheuristic for solving combinatorial and global optimization problems. It is capable of esca...

This paper introduces the first exact approach for constructing aircrew member personalized monthly work schedules when a preferential bidding system (PBS) ...

The global <i>k</i>-means heuristic is a recently proposed (Likas et al. 2003) incremental approach for minimum sum-of-squares clustering of a set <i>X</i> ...

In this paper we develop a Variable neighborhood search (VNS) heuristic for solving Mixed-Integer Programs (MIP’s). It uses CPLEX, the general-purpose MIP s...

An upper bound is given on the variance of degrees of graphs with <i>n</i> vertices, <i>m</i> edges and maximum degree &Delta;. Particular cases of chemical...

The fractional aircraft market is the fastest growing segment of the business aircraft industry. A fractional aircraft operation is complex - essentially an...

The algebraic connectivity <i>a(G)</i> of a graph <i>G = (V,E)</i> is the second smallest eigenvalue of its Laplacian matrix. Using the AutoGraphiX (AGX) sys...

Ce document présente un modèle intégrateur de la logistique inverse. Le modèle est générique et peut servir à différents types d’entreprises. Le contexte du...

Column Generation (CG) algorithms are instrumental in many areas of applied optimization, where Linear Programs with an enormous number of columns need to ...

We describe an approach that computes an optimal primal basic solution given an optimal vector of dual multipliers. It consists in restricting the dual prob...

This article presents a formulation for the job shop problem based on the Dantzig- Wolfe decomposition with a subproblem for each machine. Each subproblem i...

In most vehicle routing and crew scheduling applications solved by column generation, the subproblem corresponds to a shortest path problem with resource con...