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Dimensioning of time-critical WSNs -theory, implementation and evaluation

Journal of Communications 2011年第5期6卷 360-369页

作者： Suriyachai, Petcharat Roedig, Utz Scott, Andrew Gollan, Nicos Schmitt, Jens Department of Computer Engineering Faculty of Engineering Prince of Songkla University Thailand InfoLab21 Lancaster University United Kingdom Distributed Computer Systems Lab University of Kaiserslautern Germany

It is difficult to design and operate a Wireless Sensor Network (WSN) that ensures timely data delivery. Hence, few time-critical WSNs are nowadays in operation despite numerous application scenarios that would benefit from such a system. This paper presents a novel dimensioning framework that can be used to efficiently construct WSNs for time-critical applications. The framework employs the Sensor Network Calculus (SNC) as an analytical method for network dimensioning. A medium access control (MAC) protocol called SNC-MAC is used to ensure that this dimensioning process is reflected accurately in a subsequent deployment. The proposed framework is evaluated using both simulations and measurements in an experimental WSN deployment. The evaluation shows that observed message transfer delays in the deployment never exceed delay bounds determined during network dimensioning. Therefore, the framework can be used to implement WSNs requiring transmission delay guarantees. © 2011 ACADEMY PUBLISHER.

关键词： Medium access control

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A comparison of Wireless Fidelity (Wi-Fi) fingerprinting techniques

A comparison of Wireless Fidelity (Wi-Fi) fingerprinting tec...

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International Conference on Information and Communication Technology Convergence (ICTC)

作者： Lersan B. Del Mundo Rafael Lean D. Ansay Cedric Angelo M. Festin Roel M. Ocampo Networks and Distributed Systems Laboratory Department of Computer Science University of the Philippines Diliman Quezon Philippines Computer Networks Lab Electrical and Electronics Engineering Institute University of the Philippines Diliman Quezon Philippines

Among several techniques proposed for indoor positioning using IEEE 802.11 Wireless Fidelity (Wi-Fi) based networks, those that rely on fingerprinting have been demonstrated to outperform those based on lateration, angulation, and cell of origin in terms of accuracy. We compare and evaluate three Wi-Fi fingerprinting techniques that use the K-Nearest Neighbor (k-NN), Naive Bayes Classifier (NBC) and Support Vector Machine (SVM) algorithms. Our experiments show that SVM-based fingerprinting outperformed both k-NN and NBC-based fingerprinting, achieving accuracies of 2 meters or better within our testbed.

关键词： Accuracy Support vector machines IEEE 802.11 Standards Vectors Databases Fingerprint recognition Kernel

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Persistent Ocean Monitoring with Underwater Gliders: Towards Accurate Reconstruction of Dynamic Ocean Processes

Persistent Ocean Monitoring with Underwater Gliders: Towards...

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2011 IEEE International Conference on Robotics and Automation(2011年IEEE世界机器人与自动化大会 ICRA 2011)

作者： Ryan N. Smith Mac Schwager Daniela Rus Stephen L. Smith Gaurav S. Sukhatme School of Engineering Systems at the Queensland University of Technology BrisbaneQLD4000 Australia GRASP Lab University of PennsylvaniaPhiladelphiaPA 19104USA Distributed Robotics Lab Computer Science and Artificial Intelligence LaboratoryMassachusetts Insti Robotic Embedded Systems Laboratory Department of Computer ScienceUniversity of Southern California

This paper proposes a path planning algorithm and a velocity control algorithm for underwater gliders to persistently monitor a patch of ocean. The algorithms address a pressing need among ocean scientists to collect high-value data for studying ocean events of scientific and environmental interest, such as the occurrence of harmful algal blooms. The path planner optimizes a cost function that blends two competing factors: it maximizes the information value of the path, while minimizing the deviation from the path due to ocean currents. The speed control algorithm then optimizes the speed along the planned path so that higher resolution samples are collected in areas of higher information value. The resulting paths are closed circuits that can be repeatedly traversed to collect long term ocean data in dynamic environments. The algorithms were tested during sea trials on an underwater glider operating off the coast of southern California over the course of several weeks. The results show significant improvements in data resolution and path reliability compared to a sampling path that is typically used in the region.

关键词： Oceans Heuristic algorithms Vehicles Monitoring Sea measurements Vehicle dynamics Read only memory

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Improving range query performance on historic web page data

Improving range query performance on historic web page data

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5th Annual ChinaGrid Conference, ChinaGrid 2010

作者： Li, Geng Peng, Bo Lab. of Computer Networks and Distributed Systems Peking University Beijing China

ISBN: (纸本)9780769541068

This paper is about the performance of range queries on historic web page data set, i.e. requests into a data set of web pages that keeps record of historic versions of HTML data of URLs on the web for a subset of data, the URLs and the timestamps of which satisfy the query conditions. To keep track of all versions of every web URL, the data set could easily scale up to terabytes. Hence, systems providing query services to such a data set would require much computing resource. We show that in this scenario data storage layout has significant impact on query performance and propose storage design principles for performance improvement through quantitative approaches. © 2010 IEEE.

关键词： Websites

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A bandwidth reservation strategy for multiprocessor real-time scheduling

A bandwidth reservation strategy for multiprocessor real-tim...

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16th IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS 2010

作者： Massa, Ernesto Lima, George Department of Computer Science Distributed Systems Lab. UFBA - Federal University of Bahia Salvador Brazil

ISBN: (纸本)9780769540016

The problem of scheduling a set of tasks on a multiprocessor architecture is addressed. Tasks are assumed to be sporadic with arbitrary deadlines and may migrate between processors. The execution of migrating tasks is controlled by a bandwidth reservation scheme so that schedulability is guaranteed by EDF. Task migration costs are taken into consideration. Results from experiments indicate that the proposed approach performs well in terms of schedulability. © 2010 IEEE.

关键词： Scheduling

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SUDOKU: Secure and usable deployment of keys on wireless sensors

SUDOKU: Secure and usable deployment of keys on wireless sen...

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2010 6th IEEE Workshop on Secure Network Protocols, NPSec 2010

作者： Wilhelm, Matthias Martinovic, Ivan Uzun, Ersin Schmitt, Jens B. Disco / Distributed Computer Systems Lab. TU Kaiserslautern Germany Computer Science Department University of California Irvine CA United States

ISBN: (纸本)9781424489152

Initial deployment of secrets plays a crucial role in any security design, but especially in hardware constrained wireless sensor networks. Many key management schemes assume either manually pre-installed shared secrets or keys authenticated with the aid of out-of-band channels. While manually installing secret keys affects the practicability of the key deployment, out-of-band channels require additional interfaces of already hardware-limited wireless sensor nodes. In this work, we present a key deployment protocol that uses pair-wise ephemeral keys generated from physical layer information which subsequently enables an authenticated exchange of public keys. Hence, this work presents an elegant solution to the key deployment problem without requiring more capabilities than already available on common low-cost devices. To justify the feasibility of this solution, we implement and experimentally evaluate the proposed key deployment protocol using commodity wireless sensor motes. ©2010 IEEE.

关键词： Network layers

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Statistical response time bounds in randomly deployed wireless sensor networks

Statistical response time bounds in randomly deployed wirele...

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Conference on Local computer Networks (LCN)

作者： Steffen Bondorf B. Schmitt Jens disco | Distributed Computer Systems Lab University of Kaiserslautern Germany Distributed Computer Systems Lab University of Kaiserslautern Germany

Response time bounds are important for many application scenarios of wireless sensor networks (WSN). Often, during the planning phase of a WSN its topology is not known. It rather results from a deployment process. This makes the provision of deterministic response time bounds difficult. In this paper, we strive for statistical response time bounds in WSNs that take the stochastic nature of the deployment process into account. Based on a Monte Carlo method we derive estimates for quantiles of the maximum response time distribution under uncertainty about the topology. In numerical experiments we show that the long but light tail of this distribution causes considerably lower bounds compared to the deterministic one even under small violation probabilities and, yet, on the other hand compare favourably with the median of the distribution.

关键词： Time factors Topology Wireless sensor networks Network topology Calculus Uncertainty Delay

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Improving Range Query Performance on Historic Web Page Data

Improving Range Query Performance on Historic Web Page Data

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ChinaGrid Annual Conference (ChinaGrid)

作者： Geng Li Bo Peng Lab of Computer Networks and Distributed Systems Peking University Beijing China

关键词： Web pages distributed databases Indexing Hard disks Optimization

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Wide area distributed file systems-A scalability and performance survey

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Scalable Computing 2010年第3期11卷 305-326页

作者： Ponnavaikko, Kovendhan Dharanipragada, Janakiram Distributed and Object Systems Lab Department of Computer Science and Engineering Indian Institute of Technology Madras Chennai India

Recent decades have witnessed an explosive growth in the amounts of digital data in various fields of arts, science and engineering. Such data is generally of interest to a large number of people spread over wide geographical areas. Over the years, several distributed File systems (DFS) have, to varying degrees, addressed this requirement of sharing large amounts of data, stored in the form of files, among several users and applications. Scalability and performance are two important measures that determine the suitability of a file system for the applications executing over them. We perform a detailed comparative analysis of popular distributed file systems in terms of these measures in our survey. © 2010 SCPE.

关键词： Surveys

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SUDOKU: Secure and usable deployment of keys on wireless sensors

SUDOKU: Secure and usable deployment of keys on wireless sen...

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IEEE Workshop on Secure Network Protocols (NPSec)

作者： Matthias Wilhelm Ivan Martinovic Ersin Uzun Jens B. Schmitt Disco / Distributed Computer Systems Lab TU Kaiserslautern Germany Computer Science Department University of California Irvine USA

关键词： Sensors Protocols Wireless sensor networks Wireless communication Communication system security Base stations Cryptography

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