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Introduction to Model-based Reliability Evaluation of Wireless Sensor networks

IFAC Proceedings Volumes 2009年第5期42卷 134-139页

作者： C. Jäggle J. Neidig T. Grosch F. Dressler Siemens AG Industry Sector Nuremberg Germany Computer Networks and Communication Systems Dept. of Computer Science University of Erlangen Germany

A high level of reliability is a significant requirement for using wireless sensor networks in industrial environments. Model-based evaluation is usually applied in conventional systems to estimate the reliability. In contrast, for analyzing sensor networks, these methods are hardly tested and proven due to the unique properties of that kind of network. This paper presents a first model-based approach to quantitatively assess the reliability of sensor networks. Based on an abstract model of a sensor network, the degree of detail with respect to the characteristic aspects of sensor networks is increased in a stepwise manner. If network topologies are taken into account, analytical methods fail and the assessment of reliability measures has to be done numerically. Finally, a Monte Carlo Simulation is conducted to also cover dynamics in the topology. In conclusion, this paper shows that, by knowledge of link probabilities and lifetime distributions of single sensor nodes, model-based analysis may be used to estimate reliability measures of sensor networks.

关键词： Network reliability Sensor networks Stochastic modeling Monte Carlo Simulation

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Microring resonator for glucose sensing applications

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Frontiers of Optoelectronics 2009年第3期2卷 304-307页

作者： Yao CHEN Zhengyu LI Huaxiang YI Zhiping ZHOU Jun YU Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology State Key Laboratory on Advanced Optical Communication Systems and Networks Peking University School of Electrical and Computer Engineering Georgia Institute of Technology

Silicon nitride microring resonators were demonstrated as chemical sensors. The microring devices,with diameter of 100 μm, were fabricated using complementary metal oxide semiconductor（CMOS）-compatible technology, and a high Q factor of 15000 was realized with free spectrum range（FSR） of 2 nm. The structures were further packaged to perform as chemical sensors, and their functionality was proved using deionized water（DI water）and ethanol as detecting mediums. Lastly, the packaged chips were used to detect glucose solutions with various concentrations, and a detection capability of refractive index change of 10–3refractive index unit（RIU） was obtained.

关键词： chemical sensor glucose sensing microring resonator Q factor refractive index unit (RIU)

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A novel ellipse model for optically injection-locked VCSELs

A novel ellipse model for optically injection-locked VCSELs

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Frontiers in Optics, FiO 2009

作者： Guo, Peng Yang, Weijian Parekh, Devang Chang-Hasnain, Connie J. Department of Electrical Engineering and Computer Sciences University of California Berkeley CA 94720 United States State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University Beijing 100871 China

A novel ellipse graphic tool is established based on injection-locked rate equations to analyze the cavity mode behavior of injection-locked vertical-cavity surface-emitting lasers. Calculation based on this model sho... 详细信息

ISBN: (纸本)9781557528780

关键词： Surface emitting lasers

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Tunable group velocity of light propagation and its application

Tunable group velocity of light propagation and its applicat...

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2009 Symposium on Photonics and Optoelectronics, SOPO 2009

作者： Yonglan, Hou Chao, Peng Lei, Jia Lixin, Zhu Zhengbin, Li State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University Beijing China State Key Joint Laboratory of Integrated Optoelectronics Beijing China

ISBN: (纸本)9781424444113

In this paper, we proposed a novel approach to demonstrate optically controllable pulse group velocity at telecommunication wavelengths in EDF due to CPO. First we reviewed recent advances in slow-light-based optical signal processing, then we study slow and fast light propagation in erbium doped fiber abstractly based on theory and simulation model. It is revealed though the research that the time delay and advancement depends greatly on the pump power, influence of the ion density on the group velocity of light propagation is also studied. Based on our discussion, the optimization parameters should be selected in order to obtain more appropriate time delay and the slowdown of group velocity, which is of great importance to the communication industry. ©2009 IEEE.

关键词： Light velocity

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A simulation approach for the design of safety-relevant automotive multi-ECU systems

A simulation approach for the design of safety-relevant auto...

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IEEE International Conference on System of Systems Engineering (SoSE)

作者： Thomas Herpel Reinhard German Department of Computer Science 7-Computer Networks and Communication Systems University Erlangen-Nuünberg Erlangen Germany

Modern cars comprise tens of electronic control units, interconnected via automotive bus systems towards a specific system-of-systems inside the vehicle. Safety-relevant applications which are realized by these networked embedded controllers require a sophisticated process of system design. The appropriate choice of communication infrastructure and parameters at an early stage of system development significantly influences the overall application performance and reliability. Therefore, we propose the employment of distinct, well-proven system modeling techniques, using discrete event simulation and the Unified Modeling Language with real-time extensions. Our approach allows modeling the relevant aspects of in-car communication even before the first prototype vehicle is built up. Various design alternatives can easily be investigated without time- and manpower-consuming real-world system tests, yielding trustworthy results for a broad variety of aspects of automotive in-car communication. In cooperation with the German car manufacturer Audi, we applied our methodology for design of a networked airbag control system.

关键词： Automotive engineering communication system control Control systems Vehicles Telecommunication network reliability Employment Discrete event simulation Unified modeling language Real time systems Prototypes

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A Novel Peer Relay Lookup Scheme for SIP+P2P VoIP System

A Novel Peer Relay Lookup Scheme for SIP+P2P VoIP System

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International Conference on Wireless communications, Networking and Mobile Computing (WiCom)

作者： Xiuwu Zhang Weimin Lei Peipei Chen Department of Computer Science and Technology University of Science and Technology Hefei China Networks and Communication Laboratory Shenyang Institute of Computer Technology Shenyang China

Because of the best-effort service in Internet, direct routing path may not always meet the VoIP quality requirements. Thus, most VoIP systems such as SIP+P2P system use application-layer routing scheme to achieve better QoS performance, which is to use relay node to relay RTP stream from the source node to the destination node. The key of this scheme is how to lookup the appropriate relay nodes, which we call relay lookup problem. This paper presents a novel peer relay lookup scheme based on SIP+P2P system. The main idea is to use topology-aware to optimize relay selection. We introduce the mechanism in detail, and then evaluate this mechanism in NS2 network simulation environment. The results show that our scheme is scalable and can get high relay hit ratio, which confirm the feasibility of a real system. We also make comparison with traditional schemes and the results show that our scheme has good path quality.

关键词： Relays Peer to peer computing Routing Quality of service Web and internet services IP networks Network topology computer science Laboratories computer networks

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An inter-MAC architecture for heterogeneous Gigabit home networks

An inter-MAC architecture for heterogeneous Gigabit home net...

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2009 IEEE 20th Personal, Indoor and Mobile Radio communications Symposium, PIMRC 2009

作者： Meyer, Torsten Suraci, Vincenzo Langendörfer, Peter Nowak, Stefan Bahr, Michael Jennen, Ralf Information and Communications Siemens AG Corporate Technology Munich Germany Department of System and Computer Science University of Rome La Sapienza Rome Italy Germany Communication Technology Institute Dortmund University of Technology Dortmund Germany Department of Communication Networks RWTH Aachen University Faculty 6 Aachen Germany

ISBN: (纸本)9781424451234

The home network of the near future will be a heterogeneous broadband network supporting the use of wired as well as wireless transmission technologies. The variety of services will range from HDTV via gaming to emergency services in the telemedicine area. In this paper, we introduce a technology-independent protocol layer called Inter-MAC which provides a common infrastructure to all home networking devices. The Inter-MAC can establish a connection via different transmission technologies while ensuring appropriate QoS. Key to this is the capability to correctly interpret technology-dependent PHY and MAC parameters for determining QoS when selecting initial and alternative paths, as well as the feature of admission control. Our simulations indicate clearly that the Inter-MAC approach can cope with varying loads, for instance, the time the jitter needed to stabilize was as short as 4 s. The reduced QoS was not noticeable by the user since the jitter introduced by handling additional HDTV flows was less than 0.2 ms for the existing and less than 0.7 ms for the new flow. ©2009 IEEE.

关键词： Jitter

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Effect of the dipole-dipole interaction for two atoms with different couplings in a non-Markovian environment

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Physical Review A 2009年第1期79卷 012309-012309页

作者： Yang Li Jiang Zhou Hong Guo State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) School of Electronics Engineering and Computer Science Peking University Beijing 100871 China

Using a nonperturbative method, we study the exact entanglement dynamics of two two-level dipole-dipole interacting atoms coupled to a common non-Markovian reservoir with different coupling strengths. Besides analyzing the conditions for the existence of a steady state, we find that, although the dipole-dipole interaction could destroy the stationary entanglement, a relatively strong dipole-dipole interaction does suppress disentanglement in the initial period of time. These results are helpful for the practical engineering of entanglement in the future.

关键词： Dipole moment

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Estimation of rain attenuation characteristics of satellite communication links using X-band meteorological radars

Estimation of rain attenuation characteristics of satellite ...

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ICROS-SICE International Joint Conference 2009, ICCAS-SICE 2009

作者： Maekawa, Yasuyuki Miyamoto, Shosuke Sawai, Koichi Shibagaki, Yoshiaki Sato, Toru Yamamoto, Mamoru Hashiguchi, Hiroyuki Fukao, Shoichiro Department of Telecommunications and Computer Networks Osaka Electro-Communication University Osaka Japan Department of Communications and Computer Engineering Kyoto University Kyoto Japan Research Institute for Sustainable Humanosphere Kyoto University Kyoto Japan Department of Space Information Science and Technology Fukui University of Technology Fukui Japan

ISBN: (纸本)9784907764333

Rain attenuation characteristics of the Ku-band up-link satellite signals are presented for the past four years of 2003-2006 in Japan and Indonesia, using Japan's domestic communication satellite Superbird C that connects Research Institute for Sustainable Humanosphere of Kyoto University (RISH) to Equatorial Atmosphere Radar Observatory (EAR). Compared with the rainfall rates with the same time percentages, equivalent path lengths of the satellite signal against the rain area are shown to be reduced down to 2 km at EAR, which is remarkably shorter than those at RISH in Japan. The almost same attenuation values and annual statistics are, however, obtained from the X-band radar observations simultaneously conducted at EAR. This suggests that long-term radar observations of convective clouds are effective to estimate rain attenuation statistics of the satellite signals in the tropical regions. © 2009 SICE.

关键词： Meteorological radar

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Inheritance growth: A biology inspired method to build structures in P2P

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World Academy of science, Engineering and Technology 2009年 35卷 339-343页

作者： Sukjit, Panchalee Unger, Herwig Dpt. of Communication Networks Faculty of Mathematics and Computer Science Fernuniversität Universitätsstrasse 27 - PRG 58084 Hagen Germany

IT infrastructures are becoming more and more difficult. Therefore, in the first industrial IT systems, the P2P paradigm has replaced the traditional client server and methods of self-organization are gaining more and more importance. From the past it is known that especially regular structures like grids may significantly improve the system behavior and performance. This contribution introduces a new algorithm based on a biologic analogue, which may provide the growth of several regular structures on top of anarchic grown P2P- or social network structures.

关键词： Peer to peer networks

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