The Cutwidth Minimization Problem, also known as the Minimum Cut Linear Arrangement consists of finding an arrangement of the vertices of a graph on a line, in such a way that the maximum number of edges between each pair of consecutive vertices is minimized. This problem has practical applications in VLSI Design, Network Migration and Graph Drawing, among others. In this paper we propose sever...

† Département d’informatique et recherche opérationnelle and Centre de recherche sur les transports, Université de Montréal Email: {hoeb, michelg}@crt.umontreal.ca ‡ GERAD and École des Hautes Etudes Commerciales 3000 ch. de la Côte-Sainte-Catherine, Montréal H3T 1V6, Canada Email: {pierreh, nenad}@crt.umontreal.ca § Matematički Institut, SANU Knez Mihajlova 35, Beograd, Yugoslavia Email: nenad...

Although there has been a rapid development of technology and increase of computation speeds, most of the real-world optimization problems still cannot be solved in a reasonable time. Some times it is impossible for them to be optimally solved, as there are many instances of real problems which cannot be addressed by computers at their present speed. In such cases, the heuristic approach can be...

The application of transmission line surge arresters (TLSAs) is one the main approaches found to boost performance overhead lines (OHTLs) against atmospheric discharges. Thus, this work proposes a methodology for optimal placement TLSAs in OHTLs based on combination an optimization algorithm - inspired by General Variable Neighbourhood Search and Genetic Algorithm ATP (Alternative Transient Pro...

We report on the theory and implementation of a global optimization solver for general constrained nonlinear programming problems based on Variable Neighbourhood Search, and we give comparative computational results on several instances of continuous nonconvex problems. Compared to an efficient multi-start global optimization solver, the VNS solver proposed appears to be significantly faster.

We present a study on heuristic solution approaches to the minimum labelling Steiner tree problem, an NP-hard graph problem related to the minimum labelling spanning tree problem. Given an undirected labelled connected graph, the aim is to find a spanning tree covering a given subset of nodes of the graph, whose edges have the smallest number of distinct labels. Such a model may be used to repr...

Variable Neighborhood Search (VNS) is a relatively new metaheuristic for solving hard combinatorial optimisation problems. One such optimisation problem is the Car Sequencing Problem (CarSP), where a sequence of cars along the assembly line with minimum production costs has to be found. Although VNS is a successful metaheuristic, it takes a long time until a suitable solution is found for real-...

The Service Network Design Problem (SNDP) is generally considered as a fundamental problem in transportation logistics and involves the determination of an efficient transportation network and corresponding schedules. The problem is extremely challenging due to the complexity of the constraints and the scale of real-world applications. Therefore, efficient solution methods for this problem are ...

In this paper we consider the single machine earliness/tardiness scheduling problem with no idle time. We present heuristic algorithms based on the filtered and recovering beam search techniques and compare them with existing neighbourhood search and dispatch rule heuristics. Filtering procedures using both priority evaluation functions and problem-specific properties have been considered. Exte...

In the past several years, it has amply been demonstrated that metaheuristics, such as simulated annealing, tabu search, genetic algorithms and ant colony are simple, adaptable and computationally efficient to solve a large range of combinatorial problems including hard single objective industrial. In this paper, we propose a formalisation of the search process for finding compromise solutions ...