When searching for prey, many predator species exhibit a remarkable behavior: after prey capture, the predators promptly engage in `area-restricted search', probing for consecutive captures nearby. Biologists have been surprised with the efficiency and adaptability of this search strategy to a great number of habitats and prey distributions. We propose to synthesize a similar search strategy for the massively multimodal problems of combinatorial optimization. The predatory search strategy restricts the search to a small area after each new improving solution is found. Subsequent improvements are often found during area-restricted search. Results of this approach to Gate Matrix Layout, an important problem arising in VLSI architectures, are presented. Compared to established methods over a set of benchmark circuits, predatory search is able to either match or outperform the best known layouts. Additional remarks address the relation of predatory search to the `big-valley' hypothesis and...

Abstract not found

This article describes applications of modern heuristic search methods to pattern sequencing problems, i.e., problems seeking for a permutation of the rows of a given matrix with respect to some given objective function. We consider two di#erent objectives: Minimization of the number of simultaneously open stacks and minimization of the average order spread. Both objectives require the adaptive evaluation of changed solutions to allow an e#cient application of neighbourhood search techniques.