A solution to the hub center problem via a single-relocation algorithm with tabu search

Abstract

Network designers for many transportation or telecommunication applications need to minimize the maximum (weighted) interaction time or distance in the networks, i.e., to solve the p-hub center problems. This study addresses the p-hub center problem. A single-relocation heuristic is proposed as a means of generating location-allocation strategies in a reasonable amount of time, and tabu search is superimposed on the underlying algorithm, so as to decrease the possibility of being trapped by local optima. Two single-allocation schemes are adapted from the literature, and a further one is developed specifically for the minimax objective function, for use in the evaluation phase of the algorithm. A greedy local search is employed to improve the resulting allocations. A number of strategies for choosing the initial hub locations are discussed and initial strategy - allocation scheme combinations are compared in terms of solution quality and pragmatic efficiency.