James A. Malcolm

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— Researchers have used extensive simulation and experimental studies to understand TCP performance in adhoc wireless networks. In contrast, the objective of this paper is to theoretically analyze TCP performance in this environment. By examining the case of running one TCP session over a string topology, a system model for analyzing TCP performance in(More)
Over the past few years, several local search algorithms have been proposed for various problems related to multicast routing in the off-line mode. We describe a population-based search algorithm for cost minimisation of multicast routing. The algorithm utilises the partially mixed crossover operation (PMX) under the elitist model: for each element of the(More)
Text-based approaches to the analysis of software evolution are attractive because of the fine-grained, token-level comparisons they can generate. The use of such approaches has, however, been constrained by the lack of an efficient implementation. In this paper we demonstrate the ability of Ferret, which uses n-grams of 3 tokens, to characterise the(More)
The unique characteristics of a mobile ad hoc network (MANET), such as dynamic topology, shared wireless medium and open peer-to-peer network architecture, pose various security challenges. This paper compares three routing protocols, DSDV, DSR, and AODV under security attack where two types of node misbehaviour have been investigated. Network performance(More)
Public key cryptography is often used to verify the integrity of a piece of data, or more generally to ensure that operations which modify the data have been requested and carried out by principals who are authorized to do so. This requires keys to be bound to principals in an unforgeably veriiable manner. Cryptographic bit patterns such as electronic key(More)
We describe a population-based search algorithm for cost minimization of multicast routing. The algorithm utilizes the partially mixed crossover operation (PMX) and a landscape analysis in a pre-processing step. The aim of the landscape analysis is to estimate the depth Γ of the deepest local minima in the landscape generated by the routing tasks and(More)
Wireless sensor networks (WSNs) have attracted considerable interest in the research community, because of their wide range of applications. However, due to the distributed nature of WSNs and their deployment in remote areas, these networks are vulnerable to numerous security threats that can adversely affect their proper functioning. Resource constraints(More)
— Conventional entity authentication is not enough to build a secure pervasive computing environment. Being sure that you are talking to the expected entity does not guarantee it is going to do what you expect him to do, and only that. This paper introduces a concept of " trustworthy authentication " in pervasive computing which is defined as entity(More)