Exploiting the use of DAC in MAX-CSP
Following the work of Wallace, who introduced the use of directed arc-consistency in MAX-CSP algorithms using DAC counts, we present a number of improvements of DAC usage for the P-EFC3 algorithm. These improvements include: (i) a better detection of dead-ends, (ii) a more effective form for value pruning, and (iii) a different heuristic criterion for value ordering. Considering the new DAC usage, we have analyzed some static variable ordering heuristics previously suggested, and we propose new ones which have been shown effective. The benefits of our proposal has been assessed empirically solving random CSP instances, showing a clear performance gain with respect to previous approaches.
Unable to display preview. Download preview PDF.
- Bakker R., Dikker F., Tempelman F. and Wognum P. (1993). Diagnosing and solving overdetermined constraint satisfaction problems Proceedings of IJCAI-93, 276–281.Google Scholar
- Dechter R. and Pearl J. (1988). Network-based heuristics for constraint satisfaction problems, Artificial Intelligence, 34, 1–38.Google Scholar
- Feldman R. and Golumbic M. C. (1990). Optimization algorithms for student scheduling via constraint satisfiability, Computer Journal, vol. 33, 356–364.Google Scholar
- Fox M. (1987). Constraint-directed Search: A Case Study on Jop-Shop Scheduling. Morgan-Kauffman.Google Scholar
- Freuder E. C. and Wallace R. J. (1992). Partial constraint satisfaction, Artificial Intelligence, 58:21–70.Google Scholar
- Larrosa J. and Meseguer P. (1995). Optimization-based Heuristics for Maximal Constraint Satisfaction, Proceedings of CP-95, 103–120.Google Scholar
- Larrosa J. and Meseguer P. (1996). Phase Transition in MAX-CSP, Proceedings of ECAI-96, 190–194.Google Scholar
- Prosser P. (1994). Binary constraint satisfaction problems: some are harder than others, Proceedings of ECAI-94, 95–99.Google Scholar
- Smith B. M. (1994). Phase thansition and the mushy region in constraint satisfaction problems, Proceedings of ECAI-94, 100–104.Google Scholar
- Wallace R. J. and Freuder E. C. (1993). Conjunctive width heuristics for maximal constraint satisfaction, Proceedings of AAAI-93, 762–778.Google Scholar
- Wallace R. J. (1994).Directed Arc Consistency Preprocessing as a Strategy for Maximal Constraint Satisfaction, ECAI94 Workshop on Constraint Processing, M. Meyer editor, 69–77.Google Scholar