The recent Variable Neighborhood Search (VNS) metaheuristic combines local search with systematic changes of neighborhood in the descent and escape from local optimum phases. When solving large… (More)

The problem of reducing the bandwidth of a matrix consists of finding a permutation of rows and columns of a given matrix which keeps the non-zero elements in a band as close as possible to the main… (More)

Given a matrix of weights, the Linear Ordering Problem (LOP) consists of finding a permutation of the columns and rows in order to maximize the sum of the weights in the upper triangle. This… (More)

A Systematic change of Neighborhood within a possibly randomized local search algorithm yields a simple and effective metaheuristic for combinatorial and global optimization. In this paper we present… (More)

A p-facility location problems on a network N consist of locating p new facilities on N such that some function of distances among them and vertices of N is minimum. We consider a class of such… (More)

This paper describes an O(n log n) algorithm for 2nding the optimal location of a tree shaped facility of a speci2ed size in a tree network with n nodes, using the centdian criterion: a convex… (More)