4 research outputs found

    Harmonious personnel scheduling

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    The area of personnel scheduling is very broad. Here we focus on the ‘shift assignment problem’. Our aim is to discuss how ORTEC HARMONY handles this planning problem. In particular we go into the structure of the optimization engine in ORTEC HARMONY, which uses techniques from genetic algorithms, local optimization algorithms and variable neighborhood search. We will describe the result on an artificial test set.\u

    Progress Control in Variable Neighbourhood

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    Introduction The methods of intensification and diversification are indispensable in successful meta heuristics for local search. Intensification corresponds in some sense to local optimisation; the neighbourhood of a solution is searched intensively for solutions which are better or have better opportunities. On the other hand, diversification tries to escape from (relatively small) neighbourhoods to solutions which might lead to better final results. A heuristic that is well aware of the intensification versus diversification problems, is the Variable Neighbourhood Search (VNS), see [2]. In this method, more than one neighbourhood structure is considered. After finishing intensification with respect to one neighbourhood, the heuristic diversifies to another neighbourhood. In this way one hopes to escape from poor local optima. In this work we introduce a model to predict the quality of a neighbourhood. We use this model to identify `bad' neighbourhoods and avoid searching them. W
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