This paper addresses the 1-center location problem on a 2-dimensional plane having arbitrarily shaped barriers and using Manhattan metric distances. Barriers commonly occur in practical location and layout problems and are regions where neither travel through nor location of the new facility is permitted. Along the lines of Larson and Sadiq (1983) we divide the feasible location region into cel...

We point out a relation between the minimum diameter spanning tree of a graph and its absolute 1-center. We use this relation to solve the diameter problem and an extension of it eeciently.

Higher working memory capacity (WMC) supports performance on a wide variety of complex cognitive and academic activities (Barret, Tugade, & Engle, 2004). However, a growing body of research demonstrates that higher WMC can have disadvantages—leading individuals to employ complex performance strategies that are less optimal for a given task (cf. DeCaro & Beilock, 2010). We examine this possibili...

We study the capacitated k-center problem with vertex weights. It is a generalization of the well known k-center problem. In this variant each vertex has a weight and a capacity. The assignment cost of a vertex to a center is given by the product of the weight of the vertex and its distance to the center. The distances are assumed to form a metric. Each center can only serve as many vertices as...

The p-hub center problem is to locate p hubs and to allocate non-hub nodes to hub nodes such that the maximum travel time (or distance) between any origin–destination pair is minimized. We address the p-hub center allocation problem, a subproblem of the location problem, where hub locations are given. We present complexity results and IP formulations for several versions of the problem. We esta...