Thousands of victims and millions of affected people are hurt by natural disasters every year. Therefore, it is essential to prepare proper response programs that consider early activities of disaster management. In this paper, a multiobjective model for distribution centers which are located and allocated periodically to the damaged areas in order to distribute relief commodities is offered. The main objectives of this model are minimizing the total costs and maximizing the least rate of the satisfaction in the sense of being fair while distributing the items. The model simultaneously determines the location of relief distribution centers and the allocation of affected areas to relief distribution centers. Furthermore, an efficient solution approach based on genetic algorithm has been developed in order to solve the proposed mathematical model. The results of genetic algorithm are compared with the results provided by simulated annealing algorithm and LINGO software. The computational results show that the proposed genetic algorithm provides relatively good solutions in a reasonable time.

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Administration of an access control model deals with the question of who is authorized to update policies defined on the basis of that model. One of the models whose administration has absorbed relatively large research is the Role-Based Access Control (RBAC) model. All the existing role-based administrative models fall into the category of administratorbased decentralized approach. In such an approach, a group of administrators are given firstly, the authority of updating authorizations for operative roles and secondly, the authority of delegating the previous right to other lower-level administrators. However, in organizations with informal and flexible structure, like academic and research-oriented organizations such a sharp distinction between administrative roles and operative roles might not exist. Here, each role may take part in both operative and administrative decisions such that more mission-oriented decisions are made by senior roles and more specialized-level decisions are made by junior roles. In this paper, we study a new class of access control model called Owner-Based Role-Based Access Control (OB-RBAC) which is suitable for such environments. The OB-RBAC model utilizes the advantages of both Discretionary Access Control (DAC) and RBAC. In particular, the OB-RBAC model builds a policy model which not only fulfills the organizational restrictions but enjoys the flexible administration of the DAC model.