Djamal Habet

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We present a general approach for solving Constraint Optimization Problems. A Tabu Search is performed on a well-designed Consistent Neighbourhood built using Constraint Programming. After each variable assignment, the conflicting variables are deleted to maintain the consistency of the instantiated constraints. Hence, instead of allowing infeasible moves(More)
One of the most critical components of Branch & Bound (BnB) solvers for Max-SAT is the estimation of the lower bound. At each node of the search tree, they detect inconsistent subsets (IS) of the formula by unit propagation based methods and apply a treatment on them. Depending on the structure of the IS, current best performing BnB solvers transform(More)
The queen graph coloring problem consists in covering a n × n chessboard with n queens, so that two queens of the same color cannot attack each other. When the size, n, of the chessboard is a multiple of 2 or 3, it is hard to color the queen graph with only n colors. We have developed an exact algorithm which is able to solve exhaustively this problem for(More)
The mission of an Agile Earth Observing Satellite (AEOS) is to acquire photographs on the Earth surface, in response to observation requests. The management problem of an AEOS is to select and schedule a subset of weighted images among a set of candidate ones which must satisfy imperative constraints and at the same time maximize a given profit function.(More)
The main purpose of the paper is to solve structured instances of the satisfiability problem. The structure of a SAT instance is represented by an hypergraph, whose vertices correspond to the variables and the hyper-edges to the clauses. The proposed method is based on a tree decomposition of this hyper-graph which guides the enumeration process of a(More)
In the last years, many advances were accomplished in the exact solving of the Max-SAT problem, especially by the definition of new inference rules and a better estimation of lower bounds in branch and bound based methods. However, and oppositely to the SAT problem, fewer works exist on approximate methods for Max-SAT, mainly local search ones which have(More)