The purpose of this paper is to improve the simulated annealing method with a variable neighborhood search to solve the resource-constrained scheduling problem. We also compare numerically this method with other neighborhood search (local search) techniques: threshold accepting methods and tabu search. Furthermore, we combine these techniques with multistart diversification strategies and with ...

Local search algorithms operate by making small changes to candidate solutions with the aim of reaching new and improved solutions. The problem is that often the search will become trapped at sub optimal states from where there are no improving neighbours. Much research has gone into creating schemes to avoid these local optima and various strategies exist mainly based around altering the accep...

A novel nurse rostering model is developed to represent real world problem instances more accurately. The proposed model is generic in a way that different problem instances can be successfully represented. Novel local search neighbourhoods are developed to take advantage of the problem properties represented by the model. These neighbourhoods are utilised within a variable neighbourhood search...

A Variable Neighbourhood Search algorithm that employs new neighbourhoods is proposed for solving a task allocation problem whose main characteristics are: (i) each task requires a certain amount of resources and each processor has a capacity constraint which limits the total resource of the tasks that are assigned to it; (ii) the cost of solution includes fixed costs when using processors, tas...

In a Proportional Representation (PR) electoral system it is assumed that seats are apportioned to the different electoral districts/states according to the corresponding voters’ distribution. In a previous paper we proposed a MILP (Mixed Integer Linear Programming) model to apportion the seats in the European Parliament (EP). Since the exact solution to the problem is not computationally effic...

We consider a location-distribution problem motivated by a case study for a multi-channel retailing company, which sells a wide variety of products via Internet, mail order catalogs, and stores. Since most items to deliver are small or medium-size parcels, consolidation is a major concern which is addressed by designing a multi-echelon distribution system. This system is adaptive, in the sense ...

In this research a variable neighborhood search (VNS) algorithm is developed that can generate musical fragments of arbitrary length. The objective function of the algorithm is based on a quantification of existing fifth species counterpoint rules. A thorough parametric analysis of the VNS reveals the significance of the algorithm’s parameters on the quality of the composed fragment, as well as...

Variable neighborhood search (VNS) is a metaheuristic, or framework for building heuristics, based upon systematic change of neighborhoods both in a decent phase to find a local minimum, and in a perturbation phase to get out of the corresponding valley. It was first proposed in 1997 and since has rapidly developed both in its methods and its applications. Both of these aspects are thouroughly ...