In this article, particle swarm optimization (PSO) is adopted to solve capacitated vehicle routing problems (CVRPs). In order to obtain high quality and diverse initial solutions to facilitate the subsequent search for optimal solutions by PSO, a sweep algorithm is combined with greedy randomized adaptive search procedure (GRASP) to produce high quality initial solutions, and an initial heurist...

We present and study a mixed integer programming model that arises as a substructure in many industrial applications. This model provides a relaxation of various capacitated production planning problems, more general fixed charge network flow problems, and other structured mixed integer programs. After distinguishing the general case, which is NP–hard, from a polynomially solvable case, we anal...

In this paper we consider a capacitated single allocation p-hub median problem (CSApHMP) which is to determine the location of p hubs, the allocation of non-hub nodes to hubs in the logistics network. This problem is formulated as an integer programming model with the objective of minimizing the sum of total transportation cost and fixed cost of the selected p hubs. Since the CSApHMP is NP-hard...

We address the algorithmic complexity of a profit maximization problem in capacitated, undirected networks. We are asked to price a set of m capacitated network links to serve a set of n potential customers. Each customer is interested in purchasing a network connection that is specified by a simple path in the network and has a maximum budget that we assume to be known to the seller. The goal ...

The Multiple Capacitated Facility Location Problem (MCFLP) is well-known and studied in the international literature optimization problem. The geographical information data of the enterprises’ locations are usually either ignored by the modeler or entered manually in these systems. In this paper, a spatial Decision Support System (DSS) is designed and implemented enabling co-located collaborati...

We study the Capacitated k-Median problem for which existing constant-factor approximation algorithms are all pseudo-approximations that violate either the capacities or the upper bound k on the number of open facilities. Using the natural LP relaxation for the problem, one can only hope to get the violation factor down to 2. Li [SODA’16] introduced a novel LP to go beyond the limit of 2 and ga...

In this paper we give a constant factor approximation algorithm for the capacitated k-median problem. Our algorithm produces a solution where capacities are exceeded by at most a constant factor, while the number of open facilities is at most k. This problem resisted attempts to apply the plethora of methods designed for the uncapacitated case. Our algorithm is based on adding some new ingredie...