عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this paper, a mathematical modeling of nested hierarchical p-center problem is presented. In this model there are two levels of hierarchies and the first one should be passed to achieve the second level . The second level facility can provide both services of the first and the second level. This model is a linear integer mathematical programming model. To provide an application of the model, some simulated cases are investigated and resolved, the results show that using this model reduces the initial construction cost while the main objective which is maximum servicing distance will not be changed basically.for the large size problem using of metaheuristic algorithms is necessary so in this paper an algorithm based on the Particle swarm intelligence is proposed to solve the problem. Numerical results confirm efficiency of the algorithm.
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