Stéphane Nègre

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The notion of treewidth is of considerable interest in relation to NP-hard problems. Indeed, several studies have shown that the tree-decomposition method can be used to solve many basic optimization problems in polynomial time when treewidth is bounded, even if, for arbitrary graphs, computing the treewidth is NP-hard. Several papers present heuristics(More)
In this paper, we discuss the circular open dimension problem (CODP); that is a problem of the cutting/packing family. In CODP, we are given an initial strip of fixed width W and unlimited length, as well as a finite set N of n circular pieces C<inf>i</inf> of known radius r<inf>i</inf>, i &#x2208; N. The objective is to find a global optimum corresponding(More)
In this paper we consider the three-dimensional bin packing problem (3D-BPP), when the bins are identical with the aim of minimizing the number of the used bins. We introduce a mixed-integer linear programming formulation (MILP1). Some special valid inequalities will be presented in order to improve the relaxed lower bound of MILP1. A large set of(More)
This paper proposes a parallel large neighborhood search-based heuristic for solving the Disjunctively Constrained Knapsack Problem (DCKP), which has an important impact on the transportation issues. The proposed approach is designed using Message Passing Interface (MPI). The effectiveness of MPI's allows us to build a flexible message passing model of(More)
In this paper, we propose to solve large-scale disjunctively constrained knapsack problem. We investigate the use of the rounding solution procedure and an effective local branching. The method can be viewed as a combination of two complementary stages: (i) a rounding solution stage and (ii) a restricted exact solution procedure. The method is analyzed(More)