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Consistency-based on-line localization in sensor networks

2nd ieee international conference on distributed computing in sensor systems

作者： Feng, Jessica Girod, Lewis Potkonjak, Miodrag 4821 Boelter Hall Los Angeles CA 90034 USA

ISBN: (纸本)3540352279

We have developed a new on-line error modeling and optimization-based localization approach for sensor networks in the presence of distance measurement noise. The approach is solely based on the concept of consistency, and is developed specifically for the case of on-line localization, which refers to the situation when references are not available a priori. The localization problem is formulated as the task of maximizing the consistency between measurements and calculated distances. In addition, we also present a localized localization algorithm where a specified communication cost or the location accuracy is guaranteed while optimizing the other. We evaluated the approach in (i) both GPS-based and GPS-less scenarios;(ii) 1-D, 2-D and 3-D spaces, on sets of acoustic ranging-based distance measurements recorded by deployed sensor networks. The experimental evaluation indicates that localization of only a few centimeters is consistently achieved when the average and median distance measurement errors are more than a meter, even when the nodes have only a few distance measurements. The relative performance in terms of location accuracy compares favorably with respect to several state-of-the-art localization approaches. Finally, several insightful observations about the required conditions for accurate location discovery are deduced by analyzing the experimental results. © Springer-Verlag Berlin Heidelberg 2006.

关键词： consistency location discovery statistical modeling

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A WEIGHTED K-SUBSET LOAD BALANCING ALGORITHM FOR distributed SLEE IN NEXT GENERATION NETWORK

A WEIGHTED K-SUBSET LOAD BALANCING ALGORITHM FOR DISTRIBUTED...

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1st international conference on Communications and Networking in China

作者： Zhao, Yao Yang, Fangchun Bai, Dongwei Beijing Univ Posts & Telecommun State Key Lab Networking & Switching Technol Beijing Peoples R China

ISBN: (纸本)1424404630

Load balancing with stale information is becoming an increasingly important problem for distributed systems. And k-subset algorithm is promising to address this problem. In this paper, the load balancing problem for distributed SLEE in NGN is studied. Considering the heterogeneity of the clustering system, a load model is designed, and a weighted k-subset (WK) algorithm is proposed. WK improves k-subset algorithm with a weight defined on the process capabilities and the resource capacities of the nodes. Experiments show that WK balances system load effectively, and outperforms k-subset in every situation by about 10%.

关键词： NGN distributed system load balancing k-subset algorithm stale information

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A distributed topic map architecture for enterprise knowledge management

A distributed topic map architecture for enterprise knowledg...

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5th ieee/ACIS international conference on Computer and Information Science, ICIS 2006. In conjunction with 1st ieee/ACIS international Workshop on Component-Based Software Engineering, Software Architecture and Reuse, COMSAR 2006

作者： Korthaus, Axel Henke, stefan Aleksy, Markus Schader, Martin University of Mannheim Department of Information Systems

ISBN: (纸本)0769526136

Topic Maps offer a powerful foundation for knowledge representation and the implementation of knowledge management applications. Using ontologies to model knowledge structures, they offer concepts to link these knowledge structures with unstructured data stored in files, external documents etc. This paper presents the architecture and prototypical implementation of a Topic Map application infrastructure (called "Topic Grid" in the following) allowing transparent access to different Topic Maps distributed in a network. To a client of the Topic Grid, it appears as if access to a single virtual Topic Map is provided. The Topic Grid architecture is designed as a multi-protocol layered model in order to enhance its reusability. © 2006 ieee.

关键词： Computer architecture

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MotePlat: A monitoring and control platform for wireless sensor networks

MotePlat: A monitoring and control platform for wireless sen...

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5th international conference on Grid and Cooperative computing (GCC 2006)

作者： Sun, Limin Sun, Yuyan Shu, Jian He, Qingwei Chinese Acad Sci Inst Software POB 8718 Beijing 100080 Peoples R China Chinese Acad Sci Grad Univ Beijing 100080 Peoples R China Nanchang Inst Aeronaut Technol Fac Comp Nanchang 330063 Jiangxi Peoples R China

ISBN: (纸本)0769526950

With the wide application of Wireless sensor networks, the surveillance of wireless sensor networks itself has drawn more and more attention in recent years. Based on sensor nodes under TinyOS, we develop a monitoring and control platform called MotePlat (1) to facilitate our development of WSN application systems. MotePlat employs a three-tier application framework and adopts an agent mechanism in the software architecture of sensor nodes and sink nodes. Users can remotely acquire node status information, such as its residual energy, a list of its neighbor nodes and link quality to each neighbor through this platform. They can also adjust configuration of sensor nodes, control the network to accomplish various tasks,, debug software modules of sensor nodes and test the network performance. In this paper, we describe some key technologies in MotePlat including node status information acquisition and network controlling mechanism, nodes' software architecture, and the workflow in the process of monitoring, control, debug and test.

关键词： Wireless sensor networks

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Designing power-aware overlays in heterogeneous wireless sensor networks

Designing power-aware overlays in heterogeneous wireless sen...

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ieee international conference on sensor Networks, Ubiquitous, and Trustworthy computing

作者： Ou, Si-Yu Hsiao, Hung-Chang Chiang, Chi-Kuo King, Chung-Ta Natl Tsing Hua Univ Dept Comp Sci Hsinchu 300 Taiwan Natl Tsing Hua Univ Dept Comp Sci & Informat Engn Hsinchu 300 Taiwan

ISBN: (纸本)0769525539

As more and more innovative applications of wireless sensor networks emerge, the need for deploying heterogeneous sensors with different functionalities and capabilities rise rapidly. In this study, we consider a heterogeneous sensor network containing at least two types of sensors: powerful sensors and normal sensors. Powerful sensors have higher energy and computing capacities, and can communicate with normal senors using the same network interface. Communications between powerful sensors may thus be facilitated by building an overlay on top of the normal sensors. The topology of the overlay is critical. The overlay must have a low diameter to efficiently support upper layer applications such as resource discovery. It must also consider the energy consumption of the relaying normal sensors. In this paper, we propose a distributed overlay formation protocol to achieve the above goals. Through simulation, we compare our protocol with two overlay formation protocols, fully connected graph and minimum spanning tree. The results show that our proposed protocol can achieve better performance both in message latency and energy consumption.

关键词： Wireless telecommunication systems

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A probabilistic algorithm for efficient and robust data propagation in wireless sensor networks

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Ad Hoc Networks 2006年第5期4卷 621-635页

作者： Chatzigiannakis, Ioannis Dimitriou, Tassos Nikoletseas, Sotiris Spirakis, Paul Patras University P.O. Box 1122 261 10 Patras Greece Athens Greece

We study the problem of data propagation in sensor networks, comprised of a large number of very small and low-cost nodes, capable of sensing, communicating and computing. The distributed co-operation of such nodes may lead to the accomplishment of large sensing tasks, having useful applications in practice. We present a new protocol for data propagation towards a control center ("sink") that avoids flooding by probabilistically favoring certain ("close to optimal") data transmissions. Motivated by certain applications (see [I.F. Akyildiz, W. Su, Y. Sankarasubramaniam, E. Cayirci, Wireless sensor networks: a survey, Journal of Computer Networks 38 (2002) 393-422], [C. Intanagonwiwat, R. Govindan, D. Estrin, Directed diffusion: a scalable and robust communication paradigm for sensor networks, in: 6th ACM/ieee Annual international conference on Mobile computing (MOBICOM 2000), 2000, pp. 56-67]) and also as a starting point for a rigorous analysis, we study here lattice-shaped sensor networks. We however show that this lattice shape emerges even in randomly deployed sensor networks of sufficient sensor density. Our work is inspired and builds upon the directed diffusion paradigm of [C. Intanagonwiwat, R. Govindan, D. Estrin, Directed diffusion: a scalable and robust communication paradigm for sensor networks, in: 6th ACM/ieee Annual international conference on Mobile computing (MOBICOM 2000), 2000, pp. 56-67]. This protocol is very simple to implement in sensor devices, uses only local information and operates under total absence of co-ordination between sensors. We consider a network model of randomly deployed sensors of sufficient density. As shown by a geometry analysis, the protocol is correct, since it always propagates data to the sink, under ideal network conditions (no failures). Using stochastic processes, we show that the protocol is very energy efficient. Also, when part of the network is inoperative, the protocol manages to propagate data very close to the

关键词： Wireless telecommunication systems

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An attitude compensation technique for a MEMS motion sensor based digital writing instrument

An attitude compensation technique for a MEMS motion sensor ...

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ieee international conference of Nano/Micro Engineered and Molecular systems

作者： Luo, Yilun Tsang, Chi Chiu Zhang, Guanglie Dong, Zhuxin Shi, Guangyi Kwok, Sze Yin Li, Wen J. Leong, Philip H. W. Wong, Ming Yiu Chinese Univ Hong Kong Ctr Micro & Nano Syst Hong Kong Hong Kong Peoples R China Chinese Univ Hong Kong Dept Comp Sci & Engn Hong Kong Hong Kong Peoples R China DAKA Dev Ltd Kowloon Hong Kong Peoples R China

ISBN: (纸本)9781424401390

A MAG-mu IMU which is based on MEMS gyroscopes, accelerometers, and magnetometers is developed for real-time estimation of human hand motions. Appropriate filtering, transformation and sensor fusion techniques are combined in the Ubiquitous Digital Writing Instrument to record handwriting on any surface. In this paper, we discuss the design of an extended Kalman filter based on MAG-mu IMU (Micro Inertial Measurement Unit with Magnetometers) for real-time attitude tracking. The filter utilizes the gyroscope propagation for transient updates and correction by reference field sensors, such as gravity sensors, magnetometers or star trackers. A process model is derived to separate sensor bias and to minimize wideband noise. The attitude calculation is based on quaternion which, when compared to Euler angles, has no singularity problem. Testing with synthetic data and actual sensor data proved the filter will converge and accurately track the attitude of a rigid body. Our goal is to implement this algorithm for motion recognition of a 3D ubiquitous digital pen.

关键词： MEMS MAG-mu IMU human motion sensing extended kalman filter digital writing system wireless sensing

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Efficient and authenticated key agreement mechanism in low-rate WPAN environment

Efficient and authenticated key agreement mechanism in low-r...

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1st international Symposium on Wireless Pervasive computing

作者： Heo, Joon Hong, Choong Seon Kyung Hee Univ Dept Comp Engn 1 Seochun Gyeonggi 449701 South Korea

ISBN: (纸本)0780394100

Generally sensor network and wireless ad hoe network use a symmetric key agreement scheme, although this mechanism has some problems, such as key management, complex network deployment and configuration. This is because the devices of sensor network have limitations such as power, memory, processor speed and implementation cost. The public key algorithms are considered to be too expensive in term of memory and processing requirements. In Low-Rate Wireless Personal Area Network (WAN), we propose a new key agreement mechanism using the Security Manager (SM) for public key management based on the EC-MQV algorithm. And also, we define two security levels by means of device's power and security policies in the network. We have measured the performance of this mechanism and at the same time meeting the low implementation cost and low power.

关键词： Cryptography

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Carbon Nanotube-SnO₂ composite gas sensor prepared by electron beam evaporation

Carbon Nanotube-SnO<sub>2</sub> composite gas sensor prepare...

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ieee international conference of Nano/Micro Engineered and Molecular systems

作者： Wisitsoraat, A. Tuantranont, A. Thanachayanont, C. Singjai, P. Natl Elect & Comp Technol Ctr 112 Thailand Sci PkPahol Yothin Rd Klong Laung 12120 Pathumthani Thailand Natl Met & Mat Technol Ctr Pathum Thani Thailand Chiang Mai Univ Fac Sci Chiang Mai Thailand

ISBN: (纸本)9781424401390

Carbon nanotube (CNT) is a useful material for gassensing applications because of its high surface to volume ratio structure. In this work, multi-wall CNTs are incorporated into tin oxide thin film by the means of powder mixing and electron beam evaporation and the enhancement of gas-sensing properties is presented. The CNTs were combined with SnO2 powder with varying concentration in the range of 0.25-5% by weight and electron beam evaporated onto glass substrates. From AFM and TEM characterization, CNT inclusion in SnO2 thin film results in the production of circular cone protrusions of CNT clusters or single tube coated with SnO2 layer. Experimental results indicate that the sensitivity to ethanol of SnO2 thin film increases by the factors of 3-6. However, if the CNT concentration is too high, the sensitivity is decreased. Moreover, the CNT doped film can operate with good sensitivity and stability at a relatively low temperature of 250300 degrees C. The improved gas-sensing properties should The attributed to the increasing of metal oxide surface adsorption area produced by CNT protrusion.

关键词： Evaporation

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Fully pre-splicing TCP for web switches

Fully pre-splicing TCP for web switches

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1st international conference on Innovative computing, Information and Control (ICICIC 2006)

作者： Chang, Yeim-Kuan Cheng, Wen-Hsin Young, Chung-Ping Natl Cheng Kung Univ Dept Comp Sci & Informat Engn Tainan 70101 Taiwan

ISBN: (纸本)0769526160

Fully pre-splicing (FPS) is an extension of TCP splicing which is content-blind that prevents the switches from using application layer information for forwarding decisions. FPS extends TCP splicing to support content-aware load balancing algorithms and pre-splices the client's connections to web servers. In addition, FPS extracts the application-information in kernel-space for eliminating the cost of moving data twice through user/kernel protection boundaries and the latency of scheduling the processes. To achieve our design, we extended the TCPSP project of LVS using Linux Netfilter which defines specific hooks to provide a verdict for the packet. On the performance results, FPS improves the TCPSP throughput dramatically.

关键词： fully pre-splicing FPS TCP splicing TCP handoff layer-7 web switch content switch pre-fork connection distributed web server

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