This paper presents ACO_GLS, a hybrid ant colony optimization approach coupled with a guided local search, applied to a layout problem. ACO_GLS is applied to an industrial case, in a train maintenance facility of the French railway system (SNCF). Results show that an improvement of near 20% is achieved with respect to the actual layout. Since the problem is modeled as a quadratic assignment pro...

Abstract. The quadratic assignment problem (QAP) is a very difficult and practically relevant combinatorial optimization problem which has attracted much research effort. Local search (LS) moves can be quickly evaluated on the QAP, and hence favoured methods tend to be hybrids of global optimization schemes and LS. Here we introduce the multiobjective QAP (mQAP) where distinct QAPs must be mini...

This paper presents several optimization problems occurring in VLSI interconnect, Networks on Chip (NoC) design and 3D VLSI integration, all possessing closed-form solutions obtained by well-solvable Quadratic Assignment Problems (QAP). The first type of problems deals with the optimal ordering of signals in a bus bundle such that the switching power, delay and noise interference areminimized.W...

The bilinear assignment problem (BAP) is a generalization of the well-known quadratic assignment problem (QAP). In this paper, we study the problem from the computational analysis point of view. Several classes of neigborhood structures are introduced for the problem along with some theoretical analysis. These neighborhoods are then explored within a local search and a variable neighborhood sea...

Since 2004, the Computational Optimization and Applications (COAP) editorial board has selected a paper from the preceding year’s COAP publications for the “Best Paper Award.” The award competition among papers published in 2008 culminated in a tie between two papers. This article concerns the award winning work of Peter Hahn, Bum-Jin Kim, Monique Guignard-Spielberg and Yi-Rong Zhu at the Unive...

We consider a new semidefinite programming (SDP) relaxation of the symmetric traveling salesman problem (TSP), that may be obtained via an SDP relaxation of the more general quadratic assignment problem (QAP). We show that the new relaxation dominates the one in the paper: [D. Cvetković, M. Cangalović and V. Kovačević-Vujčić. Semidefinite Programming Methods for the Symmetric Traveling Salesman...

The population-based ant colony optimization algorithm (PACO) uses a very different pheromone update when compared to other ACO algorithms. In this work, we study P-ACO’s behavior for solving the traveling salesman problem (TSP) and the quadratic assignment problem (QAP). In particular, we investigate the impact of a local search on P-ACO parameters and performance. The results clearly show tha...

The Bacterial Foraging Optimization (BFO) is one of the metaheuristics algorithms that most widely used to solve optimization problems. The BFO is imitated from the behavior of the foraging bacteria group such as Ecoli. The main aim of algorithm is to eliminate those bacteria that have weak foraging methods and maintaining those bacteria that have strong foraging methods. In this extent, each b...

THE quadratic assignement problem (QAP) can be described as an optimizing the assignment a set of facilities to a set of locations with given costs between the locations and given flows between the facilities in order to minimize the sum of the product between flows and distances. A concrete example, would be a hospital planning optimization the location of various medical facilities in order t...

Generating diverse populations of high-quality solutions has gained interest as a promising extension to the traditional optimization tasks. This work contributes this line research with an investigation on evolutionary diversity for three most well-studied permutation problems: Traveling Salesperson Problem (TSP), both symmetric and asymmetric variants, Quadratic Assignment (QAP). It includes ...