We discuss the geometrical interpretation of a well-known smoothing operator applied to the Molecular Distance Geometry Problem, and we then describe a heuristic approach based on Variable Neighbourhood Search on the smoothed and original problem. This algorithm often manages to find solutions having higher accuracy than other methods. This is important as small differences in the objective fun...

In this paper we present effective new local and variable neighbourhood search heuristics for the asymmetric Travelling Salesman Problem. Our local search approach, HyperOpt, is inspired by a heuristic developed for a sequencing problem arising in the manufacture of printed circuit boards. In our approach we embed an exact algorithm into a local search heuristic in order to exhaustively search ...

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...

We introduce a new approach to traffic locality then use it to develop a new route discovery algorithm. The algorithm, we named Traffic LocalityExpanding Ring Search (TL-ERS), improves the route discovery process for MANETs that exhibit traffic locality by establishing a neighbourhood that includes the most likely destinations for a particular source, then broadcasting route requests using this...

All commercial packages for vehicle routing that the authors are aware of use some form of variable neighbourhood search. This paper attempts to answer the question why this is the case. As we will show, variable neighbourhood search can be considered to be a very adaptable metaheuristic, which makes it especially suitable for the practical problems encountered in real life. We also point out t...

A recent trend in local search concerns the exploitation of several different neighbourhood functions so as to increase the ability of the algorithm to navigate the search space. In this work we investigate the use of local search techniques based on various combinations of neighbourhood functions, and we apply it to a timetabling problem. In particular, we propose a set of generic operators th...

This paper proposes an Iterated Local Search (ILS) procedure and an Iterated Greedy (IG) algorithm, which are both combined with a variable neighbourhood search (VNS), for dealing with the flow shop problem with blocking, in order to minimize the total tardiness of jobs. The structure of both algorithms is very similar, but they differ in the way that the search is diversified in the space of s...

A variety of neighbourhood operators have been used in local search and metaheuristic approaches to solving nurse rostering problems. We test and analyse the efficiency of these neighbourhoods on benchmark problems taken from real world scenarios. A variable depth search is then developed based on the results of this investigation. The algorithm heuristically chains together moves and swaps whi...

This paper describes an incremental neighbourhood tabu search heuristic for the generalized vehicle routing problem with time windows. The purpose of this work is to offer a general tool that can successfully be applied to a large variety of specific problems. The algorithm builds upon a previously developed tabu search heuristic by replacing its neighbourhood structure. The new neighbourhood i...