In this paper, we study the call admission control (CAC) and routing issue in multi-service networks. Two categories of calls are considered: a narrow-band with blocked calls cleared and a wide-band with blocked calls delayed. The optimisation is subject to several quality of service (QoS) constraints, either on the packet or call level. The objective function is formulated as reward maximisati...

In this paper, we propose a novel and fast method to localize and track needles during image-guided interventions. Our proposed method is comprised of framework of needle detection and tracking in highly noisy ultrasound images via level set and PDE (partial differential equation) based methods. Major advantages of the method are: (1) efficiency, the entire numerical procedure can be finished i...

The wireless mesh networksare considered as one of the vital elements in today’s converged networks,providing high bandwidth and connectivity over large geographical areas. Mesh routers equipped with multiple radios can significantly overcome the capacity problem and increase the aggregate throughput of the network where single radio nodessuffer from performancedegradation. Moreover, the market...

Behavioral decomposition is a classical modeling ap proach for performability analysis typically resulting in Markov reward models in which the states represent system con gurations and the rewards represent per formance given the system con guration In this report we experimentally investigate ways of obtaining rewards from a performance model We discuss four candidate metrics to determine rew...

Software rejuvenation is a preventive maintenance technique that has been extensively studied in recent literature. In this paper, we extend the classical result by Huang et al. (1995), and in addition propose a modified stochastic model to generate the software rejuvenation schedule. More precisely, the software rejuvenation models are formulated via the semi-Markov reward process, and the opt...

In this paper, we propose a single sample path based algorithm with state aggregation to optimize the average rewards of singularly perturbed Markov reward processes (SPMRPs) with a large scale state spaces. It is assumed that such a reward process depend on a set of parameters. Differing from the other kinds of Markov chain, SPMRPs have their own hierarchical structure. Based on this special s...

DEGAN ZHANG†, YANAN ZHU‡, SI LIU, XIAODAN ZHANG AND JINJIE SONG Key Laboratory of Computer Vision and System Ministry of Education, Tianjin Tianjin Key Lab of Intelligent Computing and Novel Software Technology Tianjin University of Technology Tianjin, 300384 P.R. China School of Electrical and Information Engineering The University of Sydney Sydney, NSW 2006, Australia Institute of Scientific ...

Cognitive radio (CR) has emerged as a promising technology to improve spectrum utilization. Capacity analysis is very useful in investigating the ultimate performance limits for wireless networks. Meanwhile, with increasing potential future applications for the CR systems, it is necessary to explore the limitations on their capacity in a dynamic spectrum access environment. However, due to spec...

We present a non-equilibrium analysis and control approach for the Active Queue Management (AQM) problem in communication networks. Using simplified fluid models, we carry out a bifurcation study of the complex dynamic queue behavior to show that non-equilibrium methods are essential for analysis and optimization in the AQM problem. We investigate an ergodic theoretic framework for stochastic m...