In contrast to p-hub problems with a summation objective (p-hub median), minmax hub problems (p-hub center) have not attained much attention in the literature. In this paper, we give a polyhedral analysis of the uncapacitated single allocation p-hub center problem (USApHCP). The analysis will be based on a radius formulation which currently yields the most efficient solution procedures. We show...

Given a connected graph G, the vertex and edge sets and their cardinalities are denoted by V(G), E(G), n and m, respectively. It is assumed that every vertex o is assigned a non-negative real number w(o), called the weight of o, and every edge uv is assigned a positive real number a(uo), the length of uo. The lengths determine the distance d(u, o) between any two vertices u and o as the minimal...

The p-center problem is one of the location problems that have been studied in operations research and computational geometry. This paper describes a compatible discrete space version of the heuristic Voronoi diagram algorithm. Since the algorithm gets stuck in local optimums in some cases, we apply a number of changes in the body of the algorithm with regard to the geometry of the problem, in ...

Problems associated with nding strings that are within a speci ed Hamming distance of a given set of strings occur in several disciplines. All of the problems investigated are NP -hard and have varying levels of approximability. In this paper, we use techniques from parameterized computational complexity to assess non-polynomial time algorithmic options for three of these problems, namely p-exa...

An O(n log3 n) algorithm for the continuous p-center problem on a tree is presented. Following a sequence of previous algorithms, ours is the first one whose time bound in uniform in p and less than quadratic in n. We also present an O(n log2 n log log n) algorithm for a weighted discrete p-center problem. 1. Introduction. The p-center problems are defined on a weighted undirected graph G = (V,...

In speech rhythm analysis, it is important to localize the perceptual center (P-center) of syllables in order to establish a basis for measuring syllabic duration. P-center research has focused primarily on Germanic languages, for which syllables tend to begin with multiple consonants. In Cantonese, the syllable-initial position contains no more than one consonant, making it less prone to durat...

The objective of the p-center problem is to locate p-centers on a network such that the maximum of the distances from each node to its nearest center is minimized. The artificial bee colony algorithm is a swarm-based meta-heuristic algorithm that mimics the foraging behavior of honey bee colonies. This study proposes a modified ABC algorithm that benefits from a variety of search strategies to ...

We study the computational aspects of the single-assignment p-hub center problem on the basis of a basic model and a new model. The new model's performance is substantially better in CPU time than di€erent linearizations of the basic model. We also prove the NP-Hardness of the problem. Ó 2000 Elsevier Science B.V. All rights reserved.

The hub median problem is to locate hub facilities in a network and to allocate non-hub nodes to hub nodes such that the total transportation cost is minimized. In the hub center problem, the main objective is one of minimizing the maximum distance/cost between origin destination pairs. In this paper, we study uncapacitated hub center problems with either single or multiple allocation. Both pro...

We give a review of existing methods for solving the absolute and vertex restricted p-center problems on networks and propose a new integer programming formulation, a tightened version of this formulation and a new method based on successive restrictions of the new formulation. A specialization of the new method with two-element restrictions obtains the optimal p-center solution by solving a se...