A Multi-level Memetic/Exact Hybrid Algorithm for the Still Life Problem
Bucket elimination (BE) is an exact technique based on variable elimination. It has been recently used with encouraging results as a mechanism for recombining solutions in a memetic algorithm (MA) for the still life problem, a hard constraint optimization problem based on Conway’s game of life. This paper studies expanded multi-level models in which this exact/metaheuristic hybrid is further hybridized with branch-and-bound techniques. A novel variable clustering based recombination operator is also explored, with the aim of reducing the inherent time complexity of BE. Multi-parent recombination issues are analyzed as well. The obtained results are of higher quality than any previous metaheuristic approach, with large instances being solved to optimality.
KeywordsHybrid Algorithm Constraint Programming Constraint Satisfaction Problem Memetic Algorithm Variable Cluster
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