Graph coloring is a well known problem from graph theory that, when solving it with local search algorithms, is typically treated as a series of constraint satisfaction problems: for a given number of colors k, one has to find a feasible coloring; once such a coloring is found, the number of colors is decreased and the local search starts again. In this article we explore the application of Ite...

Graph coloring is a well known problem from graph theory that, when solving it with local search algorithms, is typically treated as a series of constraint satisfaction problems: for a given number of colors k, one has to find a feasible coloring; once such a coloring is found, the number of colors is decreased and the local search starts again. Here we explore the application of Iterated Local...

This paper proposes an evolutionary-based iterative local search hyper-heuristic approach called Iterated Search Driven by Evolutionary Algorithm Hyper-Heuristic (ISEA). Two versions of this algorithm, ISEAchesc and ISEA-adaptive, that differ in the re-initialization scheme are presented. The performance of the two algorithms was experimentally evaluated on six hard optimization problems using ...

Although a large number of evolutionary algorithms have been proposed to efficiently treat multimodal problems, it is currently unclear under what conditions they can be faster than iterated local search algorithms. We tackle this question, assuming we had means to efficiently and errorlessly determine the corresponding basin of attraction for each individual (basin identification) by employing...

The colored traveling salesmen problem (CTSP) is a generalization of the popular salesman with multiple salesmen. In CTSP, cities are divided into m exclusive city sets ( number salesmen) and one shared set. goal CTSP to determine shortest Hamiltonian circuit (also called route or tour) for each satisfying that (1) includes all an set some (or all) set, (2) included in unique route. relevant mo...

The irregular strip packing problem asks to place a set of polygons within a rectangular strip of fixed height without overlap, so as to minimize the strip width required. We consider an overlap minimization problem which minimizes the amount of overlap penalty for all pairs of polygons within a given bound of strip width. We propose a local search algorithm which translates a polygon in horizo...

Iterated local search (ILS) is a general and powerful metaheuristic which provides an easily implementable way of improving the performance of local search algorithms. In this article we consider the application of ILS to the permutation flow shop problem (FSP), a strongly studied problem in machine scheduling. We experimentally investigate the effect of specific implementation choices in our I...

The Graph Colouring Problem (GCP) is a well known -hard problem with many theoretical and practical applications. In this paper we introduce a new local search algorithm based on a very large scale neighbourhood. We provide an extensive numerical comparison between this method and several other local search techniques considering also the embedding of the local search into more complex schemes ...

This paper studies the customer order scheduling problem in context of additive manufacturing. The study discusses an integrated involving nesting parts as well batches nested onto unrelated parallel machines. A mixed-integer programming model is presented, based on existing formulations from literature, that integrates different materials and sequence-dependent setup times. Additionally, a met...