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24th AIAA International communications Satellite systems conference, ICSSC

作者： Hui, Zeng Roy-Chowdhury, Ayan Rentz, Nicolas Hadjitheodosiou, Michael Baras, John S. HyNet Center Institute of Systems Research University of Maryland College Pork MD 20742 United States HyNet University of Maryland College Park HyNet Institute for Systems Research University of Maryland AIAA ECE Department Institute for Systems Research University of Maryland

ISBN: (纸本)1563478161

We present work related to designing a communication network for lunar exploration. We discuss the important requirements for future space missions that influence the design of this network. We list some characteristics of the network, and highlight important issues and constraints related to performance, cost, and future network evolution. We address issues related to efficiency, fairness, end-to-end delay minimization and Quality-of-Service (QoS) framework in order to enable a flexible access and dynamic mission operation. To provide optimal or near-optimal efficient utilization and fair allocation of bandwidth of the downlink channel while guaranteeing specific QoS requirements for different service classes, we propose two-level (long-term static and short-term dynamic) sharing of a slotted high data rate satellite communication link The long-term optimal bandwidth allocation is implemented to provide per-stream/per-user QoS guarantee and give the inputs to the next level, short-term dynamic bandwidth allocation. In our time-varying short-term bandwidth allocation with threshold regulation, a small portion of bandwidth is still assigned to all active spacecrafts in advance, but most bandwidth is dynamically allocated by the requests from them, per frame, by solving an optimal timeslot scheduling problem. Copyright © 2006 by HYNET.

关键词： Lunar missions

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Data-base architectures: Current trends and their relationships to environmental data management

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ENVIRONMENTAL MODELLING & SOFTWARE 2006年第11期21卷 1579-1586页

作者： Pokorny, Jaroslav Charles Univ Prague Fac Math & Phys Dept Software Engn CR-11800 Prague Czech Republic

Ever increasing environmental information demands from customers, authorities, and governmental organizations as well as new business control functions are implemented and integrated to environmental information management systems (EIMSs). These systems are often based on traditional file techniques or, more recently, on commercial database management systems (DBMSs). With a production of huge data sets and their processing in real-time applications, the needs for environmental data management have grown significantly. Numerous examples from practice of EIMSs prove that the architecture of DBMS should be open for a permanent evolution. Current trends in database development and an associated research meet these challenges. New information and communication technologies and techniques influence today's DBMSs. They include, among other things, sensor networks, stream processing, processing uncertain and imprecise data, knowledge discovery and intelligent data analysis, as well as wireless broadcast and mobile computing. Both research and practice indicate that the traditional universal DBMS architecture hardly satisfies these trends and new solutions are needed. Rather separate specialized engines connected into networks are beneficial. The paper discusses recent advances in database technologies and attempts to highlight them with respect to requirements of EIMSs. (c) 2006 Elsevier Ltd. all rights reserved.

关键词： environmental management system database management system sensor sensor network stream processing uncertain and imprecise data knowledge discovery and intelligent data analysis wireless broadcast mobile computing

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A network based, delay-tolerant, integrated navigation system for a differential drive UGV using harmonic potential field

A network based, delay-tolerant, integrated navigation syste...

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45th IEEE conference on Decision and control

作者： Gupta, Rachana Ashok Masoud, Ahmad A. Chow, Mo-Yuen North Carolina State Univ Dept Elect & Comp Engn Raleigh NC 27606 USA King Fahd Univ Petr & Minerals Dept Elect Engn Dhahran 31261 Saudi Arabia

ISBN: (纸本)9781424401703

network based integrated navigation systems are a multidisciplinary effort whose aim is to produce a network structure and components that are capable of integrating sensors, actuators, communication, and control algorithms in a manner to suit real-time navigation and/or obstacle avoidance. There are many challenges to be overcome in order to put such a distributed and heterogeneous system together. This paper deals with some of these issues, i.e. the adverse effect of processing delays on the system And efficient integration of different modules. This paper describes a delay-resistant sensory-motor module for navigating a differential drive unmanned ground vehicle (UGV) in an indoor cluttered environment. The module consists of an early vision edge detection stage, a harmonic potential field (HPF) planner;a network based quadratic curve fitting controller and gain schedule middleware, (GSM). Though the different techniques and algorithms used to implement the navigation system have been previously well-studied algorithms, the novel contribution in this paper is the way all these different modules are integrated together for the first time to create an efficient structure for a network based integrated navigation system making it easy to implement and realize for many different applications. The structure of this module and its components are described. Thorough experimental results along with performance assessment comparing to the previous implementation are also provided to illustrate the effectiveness of the new integrated navigation structure.

关键词： Navigation systems

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Intelligent PV module for grid-connected, PV systems

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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2006年第4期53卷 1066-1073页

作者： Roman, Eduardo Alonso, Ricardo Ibanez, Pedro Elorduizapatarietxe, Sabino Goitia, Damian ROBOTIKER TECNALIA Res Ctr Energy Unit Zamudio 48170 Spain

Most issues carried out about building integrated photovoltaic (PV) system performance show average losses of about 20%-25% in electricity production. The causes are varied, e.g., mismatching losses, partial shadows, variations in current-voltage (I-V) characteristics of PV modules due to manufacturing processes, differences in the orientations and inclinations of solar surfaces, and temperature effects. These losses can be decreased by means of suitable electronics. This paper presents the intelligent PV module concept, a low-cost high-efficiency dc-dc converter with maximum power point tracking (MPPT) functions, control, and power line communications (PLC). In addition, this paper analyses the alternatives for the architecture of grid-connected PV systems: centralized,. string, and modular topologies. The proposed system, i.e., the intelligent PV module, fits within this last group. Its principles of operation, as well as the topology of boost dc-dc converter, are analyzed. Besides, a comparison of MPPT methods is performed, which shows the best results for the incremental conductance method. Regarding communications, PLC in every PV module and its feasibility for grid-connected PV plants are considered and analyzed in this paper. After developing an intelligent PV module (with dc-dc converter) prototype, its optimal performance has been experimentally confirmed by means of the PV system test platform. This paper describes this powerful tool especially designed to evaluate all kinds of PV systems.

关键词： communication system fault diagnosis dc-dc power conversion frequency-shift keying (FSK) photovoltaic (PV) power systems pulsewidth-modulated (PWM) power converters

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Scalable communication security in video sensor networks

Scalable communication security in video sensor networks

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3rd International conference on Cybernetics and Information Technologies, systems and Applications/4th International conference on Computing, communications and control Technologies

作者： Dong, Decun Zhang, Shujing Hu, Fei Madigan, Justin Tongji Univ Multimedia Signal Proc Inst Shanghai 200331 Peoples R China

ISBN: (纸本)9789806560833

Wireless Video Sensor networks (WiSe) has attracted wide attention since it could utilize large amount of low-cost, wireless interconnected, battery-driven camera sensors to monitor the object changes in harsh or remote environments. It is very important to make sure that the video transmission in such a distributed sensor network can countermeasure all types of network attacks such as inserted fake video clips, Sybil attacks (using faked sensor IDs), wormhole attacks (through setting up a better route to attract packets), etc. This paper will propose a light-weight security approach that can prevent typical WiSe network attacks however does not add much overhead to the wireless sensor communications. We have also conducted experimental analysis to verify the energy-efficiency of our WiSe security scheme. Our security proposal is based on a cluster-ripple WiSe routing architecture that is scalable to large network cases.

关键词： wireless video sensor networks (WiSe) multimedia wireless video transmission video security key management

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A delay-tolerant, potential field-based, network implementation of an integrated navigation system

A delay-tolerant, potential field-based, network implementat...

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IEEE/RSJ International conference on Intelligent Robots and systems

作者： Gupta, Rachana Ashok Masoud, Ahmad A. Chow, Mo-Yuen N Carolina State Univ Dept Elect & Comp Engn Raleigh NC 27695 USA King Fahd Univ Petr & Minerals Dept Elect Engn Dhahran 31261 Saudi Arabia

ISBN: (纸本)9781424402588

Intelligent space (iSpace) is a large scale mechatronics system. It is a multidisciplinary effort whose aim is to produce a network structure and components that are capable of integrating sensors, actuators, DSP, communication, and control algorithms in a manner that suits time-sensitive applications including real-time navigation and/or obstacle avoidance. There are many challenges that must be overcome in order to put such a distributed, heterogeneous system together. This paper deals with one of these issues, i.e. the adverse effect of network and processing delays on the system. Here a delay-resistant sensory-motor module for navigating a differential drive unmanned ground vehicle (UGV) in a cluttered environment is suggested. The module consists of an early vision edge detection stage, a harmonic potential field (HPF) planner, a network based quadratic curve fitting controller and gain schedule middleware, (GSM). Though the different techniques used to implement the navigation system have been well-studied as independent modules, the contribution in this paper is the way all these different modules are integrated together for the first time to create an efficient structure for a network based integrated navigation system. The structure of this module and its components are described. Thorough experimental results along with performance assessment comparing the suggested structure to a previous implementation of iSpace are also provided.

关键词： Mechatronics

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Security Enhancements for a User-controlled Lightpath Provisioning System

Security Enhancements for a User-Controlled Lightpath Provis...

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International conference on Computing and Informatics

作者： Wu, Jing Savoie, Michel Zhang, Hanxi Campbell, Scott Commun Res Ctr 3701 Carling Ave Ottawa ON K2H 8S2 Canada

ISBN: (纸本)9781424402199

User owned and managed optical networks offer new benefits compared to carrier networks. There are basically two types of user owned and managed optical networks: metro dark fibre networks and long-haul wavelength networks. A user-controlled lightpath provisioning system is designed to address the network management challenges, where only the customer has complete visibility of its own network and no provider can see all the network elements. The prototyped management software has a service-oriented architecture and uses the Jini and JavaSpaces technologies. Within one management system for a federation, there are six key components: a Jini Lookup Service, an instance of JavaSpaces;for storage of Light Path Objects (LPOs), a Jini Service Access Point (SAP), an LPO service, an instance of switch communication service for each switch in the transport layer and a Grid SAP. Since the new management system is a distributed system and the new management system may be deployed over a public Internet infrastructure, secure access to the management modules is required. The application of existing system security technologies to the new management system is analyzed. To securely transfer objects across a network, SSL is used to encrypt RMI data streams and thus data streams between Jini services. To securely execute a dynamically downloaded Java class, Jini adopts the Java security model. To securely use a dynamically downloaded proxy to communicate to a remote service, Jini Extensible Remote Invocation is implemented to support security features such as invocation constraints, remote method control, and the trust verification model.

关键词： network Management Software Distributed Software Security User-controlled Lightpath Provisioning

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A Novel Framework for Guaranteed Serivice Provisioning in optical network

A Novel Framework for Guaranteed Serivice Provisioning in Op...

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International conference on communication systems

作者： Chee Kheong Siew Daojun Xue Yang Qin Jens Schmitt Nanyang Technological University Singapore University of Kaiserslautern Germany

This paper proposes a novel framework for the provisioning of guaranteed services in slot-based optical networks. We use the time-domain wavelength interleaved network (TWIN) architecture for the proof of concept. In this paper, we propose a framework comprising a control plane and a data plane. While the main functions of the control plane include admission control and capacity allocation to source-destination node pairs, the data plane functions settle operational issues such as traffic aggregation, buffering, and scheduling. We present a simple slot collision-resolution algorithm in the control plane and conduct extensive simulations to show the performance of the algorithm. In the data plane we show by means of the service curve theory that the aggregation and scheduling mechanism is able to provide an efficient per-flow guarantee

关键词： optical fiber networks optical buffering Quality of service Delay optical packet switching Traffic control Job shop scheduling Wavelength division multiplexing WDM networks Ultrafast optics

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communication protocol conformance testing - Example LIN

Communication protocol conformance testing - Example LIN

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IEEE International conference on Vehicular Electronics and Safety

作者： Lawrenz, Wolfhard Univ Appl Sci Wolfenbuttel Germany

ISBN: (纸本)9781424407583

Current automobiles have made significant progress in increased safety and comfort, higher fuel efficiency, less pollution, easier handling, etc. all this is due to the tremendous evolution in electronics, which offer higher performance at lower cost at a very rapid pace. As such vehicle electronics have become very large and complex distributed systems, comprising up to 100 networked electronic control units - ECUs. Guaranteeing a high quality of these very complex systems is an urging requirement of current and future highly complex systems. This can be achieved by introducing more and more standard modules in hardware and/or software - AutoSar worldwide standardization efforts are showing the way. As these standard modules typically will be supplied by different suppliers - this will lead to additional cost cut - the problem of guaranteeing interoperability between networked ECUs, containing mixed suppliers standard sub-modules. Experience shows that the specification of standard modules in most cases is not sufficiently precise. Therefore the interoperability of distributed ECUs is endangered. A proven means to reduce the risk of lacking interoperability of standard modules in cooperating ECUs are conformance tests. This paper discusses the interoperability problem referring to example of LIN network standard hardware/software modules. The typical specification process for related conformance tests, the implementation architecture and some test experience is described.

关键词： Interoperability

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QoS for IP-based satellite network: Cross layer design

QoS for IP-based satellite network: Cross layer design

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24th AIAA International communications Satellite systems conference, ICSSC

作者： Kota, Sastri L. Giambene, Giovanni AIAA Harris Corporation GCSD 1134 E. Arques Avenue Sunnyvale CA 94085 Universita degli Studi di Siena Italy Dipartimento di Ingegneria dell'Informazione Via Roma 56 53100 Siena Italy

ISBN: (纸本)1563478161

As demand for communication connectivity "anytime, anywhere, and any way" increases, heterogeneous network design trend will grow faster supporting seamless integration of satellite/wired and wireless networks. Satellite communication plays a significant role in supporting next generation IP-based communication network through heterogeneous infrastructure for broadband and mobile applications. To deploy state-of-the-art satellite technologies and supporting media rich applications provisioning an end-to-end Quality of Service (QoS) and mobility must be addressed. Study of satellite communications constraints like attenuation, propagation delays, fading is very critical to support user service level agreements. Adaptive resource management, advanced modulation and coding techniques and congestion control algorithms must be developed. Transport protocols need to address the impact on end-to-end system performance due to lower layer protocols and their interaction. End-to-end QoS models and cross-layer protocol optimization must be investigated. In this paper we propose an end-to-end QoS protocol model emphasizing cross-layer optimization. In particular, we consider joint optimization of TCP and lower layer in geostationary network architecture assuming transport protocol enhancements such as TCP Reno, SACK, Westwood, and Hybla. At the physical layer modulations and coding considered include BPSK and QPSK;and Convolution Coder/Viterbi decoder. Our simulation results demonstrate that the interaction/adaptation at the physical layer improve the TCP goodput at the transport layer. Future research includes impact analysis of multimedia applications performance due to lower layer protocol selections. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. all rights reserved.

关键词： Satellite communication systems

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