Least-cost modelling and circuit theory are common analogs used in ecology and evolution to model gene flow or animal movement across landscapes. Least-cost modelling estimates the least-cost distance, whereas circuit theory estimates resistance distance. The bias added in choosing one method over the other has not been well documented. We designed an experiment to test whether both methods wer...

A free-hand diagram editor allows the user to place diagram components on the pane without any restrictions. This increase in flexibility often comes at the cost of editing performance, though. In particular it is tedious to manually establish the spatial relations between diagram components that are required by the visual language. Even worse are certain graph-like languages where it is a quit...

This study deals with the topology discovery for the capacitated minimum spanning tree network. The problem is composed of finding the best way to link nodes to a source node and, in graph-theoretical terms, it is to determine a minimal spanning tree with a capacity constraint. In this paper, a heuristic algorithm with two phases is presented. Computational complexity analysis and simulation co...

New technologies and the deployment of mobile and nomadic services are driving the emergence of complex communications networks, that have a highly dynamic behavior. This naturally engenders new route-discovery problems under changing conditions over these networks. In this paper, we use and extend a recently proposed graph theoretic model, which helps capture the evolving characteristic of suc...

OBP, for the attention of Dr M. Armitage. Opinions expressed in The Computer Journal are those of the authors and do not necessarily represent the views of The British Computer Society, the publisher or the organizations by which the authors are employed. The code and the copyright notice appearing at the bottom of the first page of an article in this journal indicates the copyright owner's con...

Mathematical equations represented in markup languages such as LaTeX and MathML are difficult to parse because the particular mathematical notation may not be known in advance. Parsing would be, for example, the first step before translation to another word processing format. A promising approach is to specify the equation language with an ambiguous grammar whose rules have associated cost expr...

This paper develops a recursive algorithm for estimating the least-cost planning sequence in a manufacturing system that is modeled by a labeled Petri net. We consider a setting where we are given a sequence of labels that represents a sequence of tasks that need to be executed during a manufacturing process, and we assume that each label (task) can potentially be accomplished by a number of di...

Private branch exchanges offer a constantly increasing number of features which are traditionally implemented on an embedded processor within the PBX. With the advent of computer telephone integration they now offer methods to communicate with the outside world and let certain features be implemented on external workstations. In this paper we describe how Jini can be used to make legacy PBXs re...

Theories of cognition that posit complementary dual-route processes afford better fits to the data when each route explains a part of the data not explained by the other route. However, such theories must also explain why each route is invoked, lest one can fit any data set with enough alternatives. One possible explanation is that route selection is based on a least-cost principle: the route t...