We propose a new switching criterion, namely the evenness or unevenness of the distribution of variable weights, and use this criterion to combine intensification and diversification in local search for SAT. We refer to the ways in which state-of-the-art local search algorithms adaptG 2 W SAT P and V W select a variable to flip, as heuristic adaptG 2 W SAT P and heuristic V W , respectively. To evaluate the effectiveness of this criterion, we apply it to heuristic adaptG 2 W SAT P and heuristic V W , in which the former intensifies the search better than the latter, and the latter diversifies the search better than the former. The resulting local search algorithm, which switches between heuristic adaptG 2 W SAT P and heuristic V W in every step according to this criterion, is called Hybrid. Our experimental results show that, on a broad range of SAT instances presented in this paper, Hybrid inherits the strengths of adaptG 2 W SAT P and V W , and exhibits generally better performance than adaptG 2 W SAT P and V W . In addition, Hybrid compares favorably with state-of-the-art local search algorithm R+adaptN ovelty+ on these instances. Furthermore, without any manual tuning parameters, Hybrid solves each of these instances in a reasonable time, while adaptG 2 W SAT P , V W , and R+adaptN ovelty+ have difficulty on some of these instances.
In REF a new switching criterion based on the evenness or unevenness of the distribution of variable weights is presented.
A Switching Criterion for Intensification and Diversification in Local Search for SAT
J. Satisf. Boolean Model. Comput.
J. Satisf. Boolean Model. Comput.
Computer Science Mathematics