This paper discusses the fixed-hub single allocation problem (FHSAP). In this problem, a network consists of hub nodes and terminal nodes. Hubs are fixed and fully connected; each terminal node is connected to a single hub which routes all its traffic. The goal is to minimize the cost of routing the traffic in the network. In this paper, we propose a linear programming (LP)-based rounding algor...

The hierarchical hub covering facility location problems are applied to distribution systems, transportation, waste disposal, treatment services, emergency services and remote communication. The problems attempt to determine the location of service providers' facilities at different levels and specify their linking directions in order to reduce costs and to establish an appropriate condition in...

Hub location problems, with the hub-and-spoke network structure, involve locating hub facilities, allocating the non-hubs (spokes) to the hubs, and determining the path for each origin-destination pair. In a pure hub-and-spoke network, all hubs, which act as intermediate switching or transshipment points for internodal flows, are fully interconnected and none of the non-hubs are directly connec...

This paper presents a new mathematical model, in which the location of hubs is fixed and their capacity is determined based on facilities and factories allocated to it. In order to feed the client's nodes, different types of vehicles of different capacities are considered, in which the clients are allocated to hubs, and types and numbers of vehicles are allocated to the factory's facilities. To...

As the sizes of realistic hub location problems increase as time goes on (reaching thousands nodes currently) this makes such difficult to solve in a reasonable using conventional computers. This study aims show that may be solved short computing and with high-quality solutions computational power GPU (actually available most personal computers). So, we present GPU-based approach for uncapacita...

In this paper, we introduce a new hub-and-spoke structure for service networks based on round-trips as practiced by some transport providers. This problem is variant of Uncapacitated Hub Location Problem wherein the spoke nodes allocated to hub node form (cycles) starting from and ending node. motivated two real-life practices in logistics runaway connections with their associated economies sca...

The main advantage of heuristic or metaheuristic algorithms compared to exact optimization methods is their ability in handling large-scale instances within a reasonable time, albeit at the expense of losing a guarantee for achieving the optimal solution. Therefore, metaheuristic techniques are appropriate choices for solving NP-hard problems to near optimality. Since the parameters of heuristi...

hub location problems are among the extensions ofclassical location problems that have numerous applications in designingtransportation, postal, and telecommunication networks. despite the evidentattention of researchers to these problems, there are few studies on designinghub networks under uncertainty and disruption. in this study, the capacitatedsingle allocation hub location problem under d...