Performance Analysis of Hierarchical Routing Protocols in Wireless Sensor Networks

This work focusses on analyzing the optimization strategies of routing protocols with respect to energy utilization of sensor nodes in Wireless Sensor Network (WSNs). Different routing mechanisms have been proposed to address energy optimization problem in sensor nodes. Clustering mechanism is one of the popular WSNs routing mechanisms. In this paper, we first address energy limitation constraints with respect to maximizing network life time using linear programming formulation technique. To check the efficiency of different clustering scheme against modeled constraints, we select four cluster based routing protocols; Low Energy Adaptive Clustering Hierarchy (LEACH), Threshold Sensitive Energy Efficient sensor Network (TEEN), Stable Election Protocol (SEP), and Distributed Energy Efficient Clustering (DEEC). To validate our mathematical framework, we perform analytical simulations in MATLAB by choosing number of alive nodes, number of dead nodes, number of packets and number of CHs, as performance metrics.Comment: NGWMN with 7th IEEE International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA 2012), Victoria, Canada, 201

Dynamic orchestration of distributed services on interactive community displays: the ALIVE approach

Interconnected service providers constitute a highly dynamic, complex, distributed environment. Multi-agent system design-methodologies have been try-ing to address this kind of environments for a long time. The European project ALIVE presents a framework of three interconnected levels that tackles this issue relying on organisation and coordination techniques, as well as on developments in the Web-services world. This paper presents initial results focused on a high-tech, real use case: interactive community displays with touristic information and services, dynamically personalized according to user preferences and local laws.Peer ReviewedPreprin

Long-term (25-year) survival after renal homotransplantation - The world experience

A follow-up is provided for 64 patients treated with renal transplantation at the University of Colorado before 31 March 1964. The 25-year survival was 15/64 (23.4%) and 14 patients (22%) are still alive after 25 1/2 to 27 years. There are 9 other survivors in the world from this era, distributed in 4 American and 2 European centers. All of the 25-year survivors received their grafts from living related donors

Adding Policy-based Control to Mobile Hosts Switching between Streaming Proxies

We add a simple policy-based control component to mobile hosts that enables them to control the continuous reception of live multimedia content (e.g. a TV broadcast) while they switch between different distributors of that content. Policy-based control provides a flexible means to automate the switching behavior of mobile hosts. The policies react to changes in the mobile host's environment (e.g. when a hotspot network appears) and determine when and how to invoke an earlier developed application-level protocol to discover the capabilities (e.g. supported encodings) of the content distributors and to execute the switches. The design of the control component is based on the IETF policy model, but extended and applied at the application-level instead of at the network-level. We implemented the system and deployed it in a small-scale test bed

Probabilistically safe vehicle control in a hostile environment

In this paper we present an approach to control a vehicle in a hostile environment with static obstacles and moving adversaries. The vehicle is required to satisfy a mission objective expressed as a temporal logic specification over a set of properties satisfied at regions of a partitioned environment. We model the movements of adversaries in between regions of the environment as Poisson processes. Furthermore, we assume that the time it takes for the vehicle to traverse in between two facets of each region is exponentially distributed, and we obtain the rate of this exponential distribution from a simulator of the environment. We capture the motion of the vehicle and the vehicle updates of adversaries distributions as a Markov Decision Process. Using tools in Probabilistic Computational Tree Logic, we find a control strategy for the vehicle that maximizes the probability of accomplishing the mission objective. We demonstrate our approach with illustrative case studies

An investigation of the efficient implementation of Cellular Automata on multi-core CPU and GPU hardware

Copyright © 2015 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Parallel and Distributed Computing . Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Parallel and Distributed Computing Vol. 77 (2015), DOI: 10.1016/j.jpdc.2014.10.011Cellular automata (CA) have proven to be excellent tools for the simulation of a wide variety of phenomena in the natural world. They are ideal candidates for acceleration with modern general purpose-graphical processing units (GPU/GPGPU) hardware that consists of large numbers of small, tightly-coupled processors. In this study the potential for speeding up CA execution using multi-core CPUs and GPUs is investigated and the scalability of doing so with respect to standard CA parameters such as lattice and neighbourhood sizes, number of states and generations is determined. Additionally the impact of ‘Activity’ (the number of ‘alive’ cells) within a given CA simulation is investigated in terms of both varying the random initial distribution levels of ‘alive’ cells, and via the use of novel state transition rules; where a change in the dynamics of these rules (i.e. the number of states) allows for the investigation of the variable complexity within.Engineering and Physical Sciences Research Council (EPSRC