This paper deals with a capacitated hub location problem arising in the design of telecommunications networks. The problem is different from the classical hub location problem in two ways: the cost of using an edge is not linear but stepwise and the capacity of a hub restricts the amount of traffic transiting through the hub rather than the incoming traffic. In this paper both an exact and a he...

The metric capacitated facility location is a well-studied problem for which, while constant factor approximations are known, no efficient relaxation with constant integrality gap is known. The question whether there is such a relaxation is among the most important open problems of approximation algorithms [14]. In this paper we show that, if one is restricted to linear programs that use the na...

This paper develops a new mathematical model to study location-routing problem with simultaneous pickup and delivery under the risk of disruption. A remarkable number previous studies have assumed that network components ( e.g. , routes, production factories, depots, etc.) are always available can permanently serve customers. assumption is no longer valid when faces disruptions such as flood, e...

In this paper, we propose a new hybrid heuristic to solve the Location Routing Problem with capacitated depots and capacitated vehicles. The heuristic combines a Greedy Randomized Adaptive Search Procedure to determine the depot locations to be established and a Variable Neighborhood Search to optimize the vehicle routes originating at the opened depots. Furthermore, we enhance the heuristic by...

We present a novel hybrid method, swarm intelligence based sample average approximation (SIBSAA), for solving the capacitated reliable facility location problem (CRFLP). The CRFLP extends the wellknown capacitated fixed-cost facility problem by accounting for the unreliability of facilities. The standard SAA procedure, while effectively used in many applications, can lead to poor solution quali...

The aim of this study is to present a hybrid algorithm based on two meta-heuristic algorithms named Vibration Damping Optimization (VDO) algorithm and Genetic Algorithm (GA) for solving the stochastic capacitated location-allocation problem. For solving the model more efficiently, the simplex algorithm, stochastic simulation and the proposed hybrid algorithm are integrated to design a powerful ...

Given facilities with capacities and clients with penalties and demands, the transportation problem with market choice consists in finding the minimum-cost way to partition the clients into unserved clients, paying the penalties, and into served clients, paying the transportation cost to serve them. We give polynomial-time reductions from this problem and variants to the (un)capacitated facilit...

The main purpose of any facility location is to select the optimal places that satisfy project's goals. In location problems, the object is usually to optimize a function objective function that defines the problem conditions and efficient decision parameters. Numerous methods are proposed to challenge the location facility issues. In this paper, we consider a class of location/allocation probl...

In this paper a capacitated dynamic location problem with opening, closure and reopening of facilities is formulated and a primal-dual heuristic that can solve this problem is described. The problem formulated considers the situation where a facility is open (or reopens) with a certain maximum capacity that decreases as clients are assigned to that facility during its operating periods. This pr...