Available online 9 December 2008

We study the computational aspects of the single-assignment p-hub center problem on the basis of a basic model and a new model. The new model's performance is substantially better in CPU time than di€erent linearizations of the basic model. We also prove the NP-Hardness of the problem. Ó 2000 Elsevier Science B.V. All rights reserved.

the biggest challenges faced in big cities are greenhouse gas emission and growing energy needs. efficient utilization of existing infrastructures has a prominent role in response to the challenges. energy hub approach embraces performance of different energy networks. energy hub is defined as a super node in electrical system receiving distinctive energy carriers such as gas and electricity in...

The p-median problem is one of choosing p facilities from a set of candidates to satisfy the demands of n clients such that the overall cost is minimised. In this paper, PBS, a population based hybrid search algorithm for the p-median problem is introduced. The PBS algorithm uses a genetic algorithm based meta-heuristic, primarily based on cut and paste crossover operators, to generate new star...

Web Services (WS) have emerged as an industry standard attracting the attention of the scientific community as technological alternative for implementing computational portals. Using the OpenCF computational framework, we develop the p-hub Web Service Portal (p-HubWSP) to provide a platform with capabilities for the efficient execution of metaheuristics for p-hub problems through the Internet. ...

health care is considered a universal human right greatly emphasized in social welfare development in most countries. in this regard, public health care with its pervasive effects on the general level of communities' health is a top priority drawing the attention of planners and decision-makers a like. unequal and inharmonious distribution of such services leads to unequal accessibility ca...

Hub facilities serve as switching and transshipment points in transportation and communication networks as well as in logistic systems. Hub networks have an influence on flows on the hub-to-hub links and ensure benefit from economies of scale in inter-hub transportation. The key factors for designing a successful hub-and-spoke network are to determine the optimal number of hubs, to properly loc...

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...