Variable Neighbourhood Search

Constraint Directed Variable Neighbourhood Search

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...

Variable neighbourhood search: methods and applications

Variable neighbourhood search (VNS) is a metaheuristic, or a framework for building heuristics, based upon systematic changes of neighbourhoods both in descent phase, to find a local minimum, and in perturbation phase to emerge from the corresponding valley. It was first proposed in 1997 and has since then rapidly developed both in its methods and its applications. In the present paper, these t...

Variable Neighbourhood Search for Nurse Rostering Problems

Nurse rostering problems consist of assigning varying tasks, represented as shift types, to hospital personnel with different skills and work regulations. We want to satisfy as many constraints and personal preferences as possible while constructing a schedule which meets the personnel requirements of the hospital over a predefined planning period. Real world situations are often so constrained...

Some applications of continuous variable neighbourhood search metaheuristic (mathematical modelling)

In the real world, many problems are continuous in nature. In some cases, finding the global solutions for these problems is difficult. The reason is that the problem’s objective function is non convex, nor concave and even not differentiable. Tackling these problems is often computationally too expensive. Although the development in computer technologies are increasing the speed of computation...

Composing first species counterpoint with a variable neighbourhood search algorithm