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Proceedings of the twentieth annual symposium on Parallelism in algorithms and architectures

作者： Yongwook Choi Maleq Khan V.S. Anil Kumar Gopal Pandurangan Purdue University West Lafayette IN USA Virginia Tech Blacksburg VA USA

ISBN: (纸本)9781595939739

Traditionally, the performance of distributed algorithms has been measured in terms of time and message complexity. Message complexity concerns the number of messages transmitted over all the edges during the course of the algorithm. However, in energy-constraint radio or wireless networks (e.g., sensor networks), energy is a critical factor in measuring the efficiency of a distributed algorithm. Transmitting a message between two nodes has an associated cost (energy) and moreover this cost can depend on the two nodes (e.g., the distance between them among other things). Thus in addition to the time and message complexity, it is important to consider energy complexity that accounts for the total energy associated with the messages exchanged among the nodes in a distributed algorithm, and design energy-efficient distributed algorithms for energy-constraint *** paper addresses the minimum spanning tree (MST) problem, an important problem in distributed computing. We study energy-efficient distributed algorithms for the Euclidean MST problem assuming random distribution of nodes. We show a non-trivial lower bound of Ω(log n) on the energy complexity of any distributed MST algorithm. We then give a distributed algorithm that constructs an optimal MST with energy complexity O(logn) on average and O(log n log log n) with high probability. This is an improvement over the previous best known bound on the average energy complexity of Ω(log2 n). All the above results assume that nodes do not know their geometric coordinates. If the nodes know their own coordinates, then we give an algorithm with O(1) energy complexity (which is the best possible) that gives an O(1) approximation to the MST.

关键词： energy-efficient distributed algorithm minimum spanning tree distributed approximation algorithm

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distributed chasing of network intruders

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THEORETICAL COMPUTER SCIENCE 2008年第1-2期399卷 12-37页

作者： Blina, Lelia Fraigniaud, Pierre Nisse, Nicolas Vial, Sandrine Univ Evry IBISC Evry France Univ Paris 07 CNRS Paris France Univ Chile DIM Santiago Chile Univ Versailles PRiSM F-78000 Versailles France

Graph searching is one of the most popular tools for analyzing the chase for a powerful and hostile software agent (called the "intruder"), by a set of software agents (called the "searchers") in a network. The existing solutions for the graph searching problem suffer however from a serious drawback: they are mostly centralized and assume a global synchronization mechanism for the searchers. In particular: (1) the search strategy for every network is computed based on the knowledge of the entire topology of the network, and (2) the moves of the searchers are controlled by a centralized mechanism that decides at every step which searcher has to move, and what movement it has to perform. This paper addresses the graph searching problem in a distributed setting. We describe a distributed protocol that enables searchers with logarithmic size memory to clear any network, in a fully decentralized manner. The search strategy for the network in which the searchers are launched is computed online by the searchers themselves without knowing the topology of the network in advance. It performs in an asynchronous environment, i.e., it implements the necessary synchronization mechanism in a decentralized manner. In every network, our protocol performs a connected strategy using at most k + 1 searchers, where k is the minimum number of searchers required to clear the network in a monotone connected way using a strategy computed in the centralized and synchronous setting. (C) 2008 Elsevier B.V. All rights reserved.

关键词： graph searching distributed algorithm network security

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A Learning Based Method for Topology Control in Wireless Sensor Networks

A Learning Based Method for Topology Control in Wireless Sen...

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International Conference on Autonomic and Autonomous Systems (ICAS)

作者： Seyed Hossein Khasteh Saeed Bagheri Shouraki Department of Computer Engineering Sharif University of Technology Tehran Iran Department of Electrical Engineering Sharif University of Technology Tehran Iran

Topology Control (TC) is one of the most important techniques used in wireless ad hoc and sensor networks to reduce energy consumption and radio interference, The goal of this technique is to control the topology of the graph representing the communication links between network nodes with the purpose of maintaining some global graph property (e.g., connectivity), while reducing energy consumption and/or interference that are strictly related to the nodes' transmitting range. In this paper we present a new distributed learning based method to choose nodes transmitting range, in this method we run a range adjustment mechanism periodically to choose a near optimal transmitting range, we don't need any information about location of nodes or distance between nodes or received signal strength, the communication overhead of this method is very low, performance evaluation results show that this method decrease the energy consumption and overcome other existing methods in some scenarios.

关键词： Sensor Network Topology Control Machine Learning distributed algorithm Transmitting Range

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Double Barrier Coverage in Dense Sensor Networks

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Journal of Computer Science & Technology 2008年第1期23卷 154-164,F0003页

作者：蒋承东陈国良 Department of Computer Science and Technology University of Science and Technology of China

When a sensor network is deployed to detect objects penetrating a protected region, it is not necessary to have every point in the deployment region covered by a sensor. It is enough if the penetrating objects are detected at some point in their trajectory. If a sensor network guarantees that every penetrating object will be detected by two distinct sensors at the same time somewhere in this area, we say that the network provides double barrier coverage （DBC）. In this paper, we propose a new planar structure of Sparse Delaunay Triangulation （SparseDT）, and prove some elaborate attributes of it. We develop theoretical foundations for double barrier coverage, and propose efficient algorithms with NS2 simulator using which one can activate the necessary sensors to guarantee double barrier coverage while the other sensors go to sleep. The upper and lower bounds of number of active nodes are determined, and we show that high-speed target will be detected efficiently with this configuration.

关键词： wireless sensor network barrier coverage Delaunay triangulation distributed algorithm

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Anti-jam distributed MIMO decoding using wireless sensor networks

Anti-jam distributed MIMO decoding using wireless sensor net...

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33rd IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Farahmand, Shahrokh Cano, Alfonso Giannakis, Georgios B. Univ Minnesota Dept ECE 200 Union St SE Minneapolis MN 55455 USA

ISBN: (纸本)9781424414833

Consider a set of sensors that wish to consent on the message broadcasted by a multi-antenna transmitter in the presence of white-noise jamming. The jammer's interference introduces correlation across receivers and destroys the decomposable form of the maximum-likelihood decoder, thus preventing direct application of known distributed detection algorithms. This paper develops distributed detectors that circumvent this problem. Treating the jammer signal as deterministic, we develop two distributed estimation-decoding algorithms. The first algorithm relies on the generalized likelihood ratio test, whereas the second algorithm relies on semi-definite relaxation techniques and is suitable for large alphabet sizes. Both algorithms feature: (i) distributed implementation requiring only single-hop communications;(ii) no constraints on the network topology so long as it is connected;and (iii) performance close to the optimum centralized detector in the presence of severe jamming.

关键词： consensus jamming generalized likelihood ratio test semi-definite relaxation distributed algorithm

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Binary power allocation for cognitive radio networks with centralized and distributed user selection strategies

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Physical Communication 2008年第3期1卷 183-193页

作者： Zayen, Bassem Haddad, Majed Hayar, Aawatif Øien, Geir E. Mobile Communications Group Institut Eurecom 06904 Sophia Antipolis 2229 Route des Cretes B.P. 193 France Department of Electronics and Telecom Norwegian University of Science and Technology 7491 Trondheim Norway

Motivated by the desire for efficient spectral utilization, we present a novel algorithm based on binary power allocation for sum rate maximization in Cognitive Radio Networks (CRN). At the core lies the idea of combining multi-user diversity gains with spectral sharing techniques and consequently maximizing the secondary user sum rate while maintaining a guaranteed quality of service (QoS) to the primary system. We consider a cognitive radio network consisting of multiple secondary transmitters and receivers communicating simultaneously in the presence of the primary system. Our analysis treats both uplink and downlink scenarios. We first present a distributed power allocation algorithm that attempts to maximize the throughput of the CRN. The algorithm is simple to implement, since a secondary user can decide to either transmit data or stay silent over the channel coherence time depending on a specified threshold, without affecting the primary users' QoS. We then address the problem of user selection strategy in the context of CRN. Both centralized and distributed solutions are presented. Simulation results carried out based on a realistic network setting show promising results. © 2008 Elsevier B.V. All rights reserved.

关键词： Binary power allocation Capacity Cognitive radio network distributed algorithm Outage probability QoS Scheduling

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Fast convergence of distributed joint spreading sequence and power control algorithms

Fast convergence of distributed joint spreading sequence and...

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IEEE Radio and Wireless Symposium

作者： Lacatus, Catalin Akopian, David Shadaram, Mehdi Univ Texas San Antonio Dept Elect & Comp Engn San Antonio TX 78249 USA

ISBN: (纸本)9781424414628

In this paper a distributed iterative algorithm is developed for joint spreading sequence design and power control in the uplink of CDMA systems. Simultaneous iterations are implemented using gradient approaches for convex cost functions with nonlinear QoS constraints. Performing parallel iterations instead of round robin iterations, the algorithm convergence speed is significantly increased. Different from conventional approaches the algorithm convergence speed will not explicitly depend on the number of active users. Moreover, the efficiency of our method increases by increasing the number of active users.

关键词： constrained optimization CDMA spreading sequence power control distributed algorithm

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distributed chasing of network intruders

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13th International Colloquium on Structural Information and Communication Complexity (SIROCCO 2006)

ISBN: (纸本)3540354743

关键词： graph searching distributed algorithm network security

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Grid implementation of a parallel multiobjective genetic algorithm for optimized allocation of chlorination stations in drinking water distribution systems: Chojnice case study

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IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART C-APPLICATIONS AND REVIEWS 2008年第4期38卷 497-509页

作者： Ewald, Grzegorz Kurek, Wojciech Brdys, Mietek A. Gdansk Univ Technol Fac Elect & Control Engn PL-80952 Gdansk Poland Univ Birmingham Sch Elect Elect & Comp Engn Birmingham B15 2TT W Midlands England

Solving multiobjective optimization problems requires suitable algorithms to find a satisfactory approximation of a globally optimal Pareto front. Furthermore, it is a computationally demanding task. In this paper, the grid implementation of a distributed multiobjective genetic algorithm is presented. The distributed version of the algorithm is based on the island algorithm with forgetting island elitism used instead of a genetic data exchange. The algorithm is applied to the allocation of booster stations in a drinking water distribution system. First, a multiobjective formulation of the allocation problem is further enhanced in order to handle multiple water demand scenarios and to integrate controller design into the allocation problem formulation. Next, the new grid-based algorithm is applied to a case study system. The results are compared with a nondistributed version of the algorithm.

关键词： booster station allocation computer grid distributed algorithm genetic algorithm (GA) multiobjective optimization (MOO) water quality

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Spatial Partitioning in Self-Organizing Smart Camera Systems

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IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING 2008年第4期2卷 480-492页

作者： Hoffmann, Martin Wittke, Michael Haehner, Joerg Mueller-Schloer, Christian Leibniz Univ Hannover Dept Elect Engn & Comp Sci D-30167 Hannover Germany

We propose a decentralized, self-organizing system architecture for wireless networked smart cameras (SCs) with pan, tilt, and zoom abilities. Each SC communicates with its neighbors and independently calculates the optimal position for its field of view. Thereby, SCs autonomously organize themselves and spatially partition the area they observe. This is achieved by a decentralized algorithm that makes way for self-organization in SC systems. The system quickly adapts to new situations caused by joining and failing nodes. Simulations with hundreds of cameras show that scalability and reliability are achieved. We analyze the performance of different camera densities and show that optimal surveillance coverage is achieved in a short time (20 s) while maintaining low communication traffic using a simulated 350-node outdoor SC system.

关键词： Camera calibration distributed algorithm self-organizing smart camera networks spatial partitioning of area under surveillance

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