An extended star is a tree which has only one vertex with degree larger than two. The -center problem in a graph  asks to find a subset  of the vertices of  of cardinality  such that the maximum weighted distances from  to all vertices is minimized. In this paper we consider the -center problem on the unweighted extended stars, and present some properties to find solution.

Facility location decisions play a prominent role in strategic planning of many firms, companies and governmental organizations. Since in many real-world facility location problems, the data are subject to uncertainty, in this paper, we consider the P-center problem under uncertainty of demands. Using Bertsimas and Sim approach, we develop a robust model of the problem as an integer programming...

centralizing and using proper transportation facilities cut down costs and traffic. hub facilities concentrate on flows to cause economic advantage of scale and multimodal transportation helps use the advantage of another transporter. a distinctive feature of this paper is proposing a new mathematical formulation for a three-stage p-hub location routing problem with simultaneous pick-ups and de...

In this paper we consider an extended version of the classical capacitated single allocation hub location problem in which the size of the hubs must be chosen from a finite and discrete set of allowable capacities. We develop a Lagrangian relaxation approach that exploits the problem structure and decomposes the problem into a set of smaller subproblems that can be solved efficiently. Upper bou...

Facility location decisions play a prominent role in strategic planning of many firms, companies and governmental organizations. Since in many real-world facility location problems, the data are subject to uncertainty, in this paper, we consider the P-center problem under uncertainty of demands. Using Bertsimas and Sim approach, we develop a robust model of the problem as an integer programming...

This paper determines the optimal location of K connections in the plane, where a connection links pairs of existing facilities. Both uncapacitated and capacitated versions of the problem are considered. Discretization results for general polyhedral gauges and other properties are established. Two heuristic algorithms are developed for each case using the concept of a shortest path flow set cou...

The aim of this study is to present a Genetic Algorithm (GA) for solving the Capacitated Single Allocation Hub Location Problem (CSAHLP) and to demonstrate its robustness and effectiveness for solving this problem. The appropriate objective function is correcting infeasible individuals to be feasible. These corrections are frequent in the initial population, so that in the subsequent generation...

Article history: Received 28 June 2011 Received in revised form 5 June 2012 Accepted 3 July 2012 Available online 16 August 2012

The goal of this paper is to study a profit-maximization location-inventory problem in a multicommodity supply chain distribution network with price-sensitive demands. The problem determines location, allocation, price and order-size decisions in order to maximize the total profit of serving the customers. The problem is formulated as a mixed-integer nonlinear programming model and solved using...