Constraint satisfaction as global optimization

We present an optimization formulation for discrete binary CSP, based on the construction of a continuous function A(P) whose global maximum represents the best possible solution for that problem. By the best possible solution we mean either (i) a solution of the problem, if it is solvable, or (ii)...

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Detalles Bibliográficos
Autores: Meseguer González, Pedro, Larrosa Bondia, Francisco Javier|||0000-0002-8322-0505
Tipo de recurso: informe técnico
Fecha de publicación:1995
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/96820
Acceso en línea:https://hdl.handle.net/2117/96820
Access Level:acceso abierto
Palabra clave:Discrete binary CSP
Constraint satisfaction
Global optimization
Àrees temàtiques de la UPC::Informàtica::Informàtica teòrica
Descripción
Sumario:We present an optimization formulation for discrete binary CSP, based on the construction of a continuous function A(P) whose global maximum represents the best possible solution for that problem. By the best possible solution we mean either (i) a solution of the problem, if it is solvable, or (ii) a partial solution violating a minimal number of constraints, if the problem is unsolvable. This approach is based on relaxation labeling techniques used to enforce consistency in image interpretation. We have used a projected gradient ascent algorithm to maximize A(P) on the n-queens problem obtaining good results but with a high computational costs. To elude this problem, we have developed a heuristic for variable and value selection inspired in the direction in which A(P) is maximized. We have tested this heuristic with forward checking on several classes of CSP.