Multi-layer local optima networks for the analysis of advanced local search-based algorithms

Author(s): Marcella Scoczynski Ribeiro Martins, Mohamed El Yafrani, Myriam Delgado, Ricardo Luders
Venue: Proceedings of the 2020 Genetic and Evolutionary Computation Conference
Year: 2020

Paper: https://dl.acm.org/doi/10.1145/3377930.3390179

Abstract

A Local Optima Network (LON) is a graph model that compresses the fitness landscape of a particular combinatorial optimization problem based on a specific neighborhood operator and a local search algorithm. Determining which and how landscape features affect the effectiveness of search algorithms is relevant for both predicting their performance and improving the design process. This paper proposes the concept of multi-layer LONs as well as a methodology to explore these models aiming at extracting metrics for fitness landscape analysis. Constructing such models, extracting and analyzing their metrics are the preliminary steps into the direction of extending the study on single neighborhood operator heuristics to more sophisticated ones that use multiple operators. Therefore, in the present paper we investigate a two-layer LON obtained from instances of a combinatorial problem using bit-flip and swap operators. First, we enumerate instances of NK-landscape model and use the hill climbing heuristic to build the corresponding LONs. Then, using LON metrics, we analyze how efficiently the search might be when combining both strategies. The experiments show promising results and demonstrate the ability of multi-layer LONs to provide useful information that could be used for in metaheuristics based on multiple operators such as Variable Neighborhood Search.

Additional information

If you can’t access the paper at the link above, you can also get it from arXiv.