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Optical transmitter bandwidth requirements for POF telecom links

WSEAS Transactions on Circuits and Systems 2005年第11期4卷 1608-1613页

作者： Louvros, S. Ioannou, K. Vassiliadis, B. Drossos, L. Kotsopoulos, S. Wireless Telecommunication Laboratory Department of Electrical and Computer Engineering University of Patras Rion 26500 Patras Greece Computer Science Hellenic Open University 13-15 Tsamadou st. GR-26222 Patras Greece Department of Applied Informatics in Management and Economy Technical Education Institute of Messologi Messologi Greece

Light emitting diodes (LED) are usually the alternative optoelectronic devices for optical communications with moderate bandwidth efficiency and bit rates, compared to semiconductor lasers. Laser applications dominate the long distance communication networks. However LED seems to be a very good solution, especially in very short distance communication networks, where Plastic Optical Fibers, (POF) are used as the optical transmission medium. This paper investigates a qualitative technique of calculating the bandwidth, based on first principles of semiconductor physics. This technique is more convenient for a first approach of the subject on optical communication networks and its simplicity provides a very useful analytical tool. Finally these results are compared with the existing experimental ones.

关键词： Optical links

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ONE-TO-ONE TECHNOLOGY-ENHANCED LEARNING: AN OPPORTUNITY FOR GLOBAL RESEARCH COLLABORATION

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Research and Practice in Technology Enhanced Learning 2006年第1期1卷 3-29页

作者： TAK-WAI CHAN JEREMY ROSCHELLE SHERRY HSI KINSHUK MIKE SHARPLES TOM BROWN CHARLES PATTON JOHN CHERNIAVSKY ROY PEA CATHIE NORRIS ELLIOT SOLOWAY NICOLAS BALACHEFF MARLENE SCARDAMALIA PIERRE DILLENBOURG CHEE-KIT LOOI MARCELO MILRAD ULRICH HOPPE Research Center for Science and Technology for Learning National Central University 300 Jhongda Road Jhongli City 32001 Taiwan ROC Center for Technology in Learning SRI International 333 Ravenswood Ave BN-376 Menlo Park California 94025 USA Center for Learning and Teaching The Exploratorium 3601 Lyon Street San Francisco California 94123 USA Advanced Learning Technologies Research Centre Massey University Private Bag 11-222 Palmerston North New Zealand Learning Sciences Research Institute Nottingham University Jubilee Campus Wollaton Road Nottingham NG8 1BB UK University of Pretoria Telematic Learning & Education Innovation Lynnwood Road Hillcrest Pretoria South Africa 0002 South Africa National Science Foundation 4201 Wilson Boulevard Arlington Virginia 22230 USA Stanford Center for Innovations in Learning Stanford University Wallenberg Hall Building 160 450 Serra Mall Stanford CA 94305-205 USA Department of Cognition and Technology University of North Texas Matthews Hall 316-D PO Box 311337 Denton TX 76203-1337 USA Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI 48109 USA Laboratoire Leibniz 46 Avenue Félix Viallet 38031 Grenoble Cedex France Institute for Knowledge Innovation and Technology OISE/University of Toronto 252 Bloor Street West Toronto Ontario M5S 1V6 Canada Swiss Federal Institute of Technology Ecole Polytechnique Fédérale de Lausanne 1015 Lausanne Switzerland Learning Sciences Lab National Institute of Education Nanyang Technological University 1 Nanyang Walk Singapore 637616 Singapore Center for Learning and Knowledge Technologies Växjö University MSI Växjö University Vejdes plats 6 och 7 351 95 Växjö Sweden Institute for Computer Science and Interactive Systems University Duisburg-Essen Building LF Lotharstr. 63/65 47048 Duisburg Germany

Over the next 10 years, we anticipate that personal, portable, wirelessly-networked technologies will become ubiquitous in the lives of learners — indeed, in many countries, this is already a reality. We see that ready-to-hand access creates the potential for a new phase in the evolution of technology-enhanced learning (TEL), characterized by "seamless learning spaces" and marked by continuity of the learning experience across different scenarios (or environments), and emerging from the availability of one device or more per student ("one-to-one"). One-to-one TEL has the potential to "cross the chasm" from early adopters conducting isolated design studies to adoption-based research and widespread implementation, with the help of research and evaluation that gives attention to the digital divide and other potentially negative consequences of pervasive computing. We describe technology-enhanced learning and the affordances of one-to-one computing and outline a research agenda, including the risks and challenges of reaching scale. We reflect upon how this compares with prior patterns of technology innovation and diffusion. We also introduce a community, called "G1:1," that brings together leaders of major research laboratories and one-to-one TEL projects. We share a vision of global research, inviting other research groups to collaborate in ongoing activities.

关键词： Technology-enhanced learning research collaboration pervasive computing wireless technologies

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Minimum disc cover set construction in mobile ad hoc networks

Minimum disc cover set construction in mobile ad hoc network...

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Third International Conference on computer Network and Mobile Computing, ICCNMC 2005

作者： Sun, Min-Te Ma, Xiaoli Yi, Chih-Wei Yang, Chuan-Kai Lai, Ten H. Wireless Engineering Research and Education Center Auburn University United States Department of Computer Information Science National Chiao Tung University Taiwan Department of Information Management National Taiwan University of Science and Technology Taiwan Department of Computer Science and Engineering Ohio State University United States

The minimum disc cover set can be used to construct the dominating set on the fly for energy-efficient communications in mobile ad hoc networks. The approach used to compute the minimum disc cover set proposed in previous study has been considered too expensive. In this paper, we show that the disc cover set problem is in fact a special case of the general α-hull problem. In addition, we prove that the disc cover set problem is not any easier than the α-hull problem by linearly reducing the element uniqueness problem to the disc cover set problem. In addition to the known α-hull approach, we provide an optimal divide-and-conquer algorithm that constructs the minimum disc cover set for arbitrary cases, including the degenerate ones where the traditional α-hull algorithm incapable of handling. © Springer-Verlag Berlin Heidelberg 2005.

关键词： Telecommunication networks

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Abstracts from the 6th International Conference on the Engineering of Sport, 10-14 July 2006, Olympic Hall, Munich, Germany Abstracts

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SPORTS ENGINEERING 2006年第4期9卷 229-249页

作者： [Anonymous] TNO Netherlands Delcam plc UK Technological Institute of Toys AIJU Spain Technische Universitaet Muenchen Germany Hochschule für Gestaltung und Kunst Zuerich Germany Otto-v.-Guericke-University Magdeburg Germany AISTS-International Academy of Sports Science and Technology Lausanne Switzerland CSEM-Swiss Center for Electronics and Microtechnology Neuchâtel Swizerland University of Illinois at Urbana-Champaign USA Delft University of Technology Netherlands Faculty of Education Art and Science Yamagata University Japan Department of Mathematical Modelling Perm State Technical University Russia Department of Theoretical Mechanics Perm State Technical University Russia Department of Computational Fluid Dynamics JSC Aviadvigatel Perm Motors Russia Mechanical and Automotive Engineering RMIT University Japan Fluent Europe Ltd Sheffield UK SportKreativWerkstatt GmbH München Germany Sports Technology Research Group Loughborough University UK Department of Mechanical Engineering University of Bath UK Instituto de Biomecánica de Valencia (IBV) Spain University Augsburg UK Sports Engineering Research Group University of Sheffield England Sports-Equipment Technology Technikum Wien Austria Fischer GmbH Germany Biocompatible Materials and Process Engineering TU Munich Germany The University of Waikato New Zealand Sandvik Materials Technology Sweden Institute for Machine Tools and Industrial Management TU Munich Germany Institut fuer Verbundwerkstoffe GmbH Canada Sports Engineering Centre for Sports and Exercise Science Sheffield Hallam University England University of Glamorgan UK Department of Information Science and Engineering Tokyo Institute of Technology Tokyo Japan Toyota Motor Co. Aichi Japan Iowa Univeristy Iowa USA Simbex Lebanon USA Japan Institute of Sports Sciences Tokyo Japan University of Vienna Austria Technische Universität München Germany Department of Econometrics University of Groningen The Netherlands Department of Physical Education and Sport

A radical change (Feenstra, Holmer, Tromans, Moos and Mieritz 2003) in manufacturing is starting to occur. The Rapid Manufacturing, which can be defined as "the use of an additive manufacturing process to construct parts that are used directly as finished products or components", is set to supersede many current uses of moulds and dies. Rapid Manufacturing (Wohlers 2003) is based on new additive manufacturing techniques that produce fully functional parts directly from a 3D CAD model without the use of tooling. The ambitious scope of the European Initiative CUSTOM-FIT, a Framework 6 Integrated Project, is to create a fully integrated system for the design, production and supply of individualized custom-products. Within the cases under study there are strong connections to sporting articles. This project is being funded by the European Commission over the next four years and a half and will become central to European research concerning Rapid Manufacturing (RM).

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A low overhead Ad Hoc routing protocol with route recovery

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1st International Conference on Mobile Ad-hoc and Sensor Networks, MSN 2005

作者： Yu, Chang Wu Wu, Tung-Kuang Cheng, Rei Heng Chen, Po Tsang Department of Computer Science and Information Engineering Chung Hua University Hsin-Chu Taiwan Department of Information Management National Changhua University of Education Changhua Taiwan Department of Information Management Hsuan Chuang University Hsin-Chu Taiwan

ISBN: (纸本)3540308563

Many routing protocols have been designed for Ad Hoc networks. However, most of these kinds of protocols are not able to react fast enough to maintain routing. In the paper, we propose a new protocol that repairs the broken route by using information provided by nodes overhearing the main route communication. When links go down, our protocol intelligently replaces these failed links or nodes with backup ones that are adjacent to the main route. Experimental results show that our protocol finds a backup route around 50% of cases and achieve better (or as good) in term of the packet delivery rate than the major Ad Hoc routing protocols, but with much less overhead. © Springer-Verlag Berlin Heidelberg 2005.

关键词： computer networks

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The analysis of learning records and learning effect in blended e-learning

The analysis of learning records and learning effect in blen...

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作者： Yeh, Dowming Lee, Chun-Hsiung Sun, Pei-Chen Institute of Computer and Information Education National Kaohsiung Normal University Kaohsiung 802 Taiwan Department of Information Management National Taiwan University of Science and Technology Taipei 106 Taiwan Institute of Information and Computer Education National Kaohsiung Normal University IEEE ACM Department of Information Management National Taiwan University of Science and Technology National Kaohsiung Normal University Phi-Tau-Phi Scholastic Honor Society

Some teachers adopt a blended learning model that combines traditional classroom teaching and an e-learning system. In this model, a teacher may teach the first few sessions in a classroom. After the students have established a general idea of the course, they can then proceed to on-line learning and interaction. This study aimed to discover the relationship between learning records and the learning effect in a blended e-learning environment through multiple regression analysis. The learning records considered included the grades for online assignments, reading time, the total number of login times, and the total number of online discussions. The learning effect was defined as the total grade for two monthly exams and one final exam. To collect learning record data, an e-learning system was designed that integrates the data collection functionality of learning activities with a teaching material managing module so that the learning records of all the learners are recorded automatically. With this system, an experiment was conducted on a program design course in a local high school. The results differed from those obtained in a 'pure' e-learning setting, and the online homework performance was the only item that significantly accounted for the learning effect, which is a natural result of learning procedural knowledge.

关键词： Learning systems

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Better than the real thing? Iterative pseudo-query processing using cluster-based language models

Better than the real thing? Iterative pseudo-query processin...

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28th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, SIGIR 2005

作者： Kurland, Oren Lee, Lillian Domshlak, Carmel Computer Science Department Cornell University Ithaca NY 14853 United States Language Technologies Institute Carnegie Mellon University Pittsburgh PA 15213 United States Computer Science Department Carnegie Mellon University Pittsburgh PA 15213 United States William Davidson Faculty of Industrial Engineering and Management Technion Haifa 32000 Israel

ISBN: (纸本)1595930345

We present a novel approach to pseudo-feedback-based ad hoc retrieval that uses language models induced from both documents and clusters. First, we treat the pseudo-feedback documents produced in response to the original query as a set of pseudo-query that themselves can serve as input to the retrieval process. Observing that the documents returned in response to the pseudo-query can then act as pseudo-query for subsequent rounds, we arrive at a formulation of pseudo-query-based retrieval as an iterative process. Experiments show that several concrete instantiations of this idea, when applied in conjunction with techniques designed to heighten precision, yield performance results rivaling those of a number of previously-proposed algorithms, including the standard language-modeling approach. The use of cluster-based language models is a key contributing factor to our algorithms' success. © 2005 ACM.

关键词： Iterative methods

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Neural network prediction model based on data parallelism

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Jisuanji Gongcheng/computer Engineering 2005年第11期31卷 162-164页

作者： Hu, Haomin Ma, Deyun Computer Center Shanghai University of Engineering Science Shanghai 200336 China Department of Physical Management Shanghai Institute of Physical Education Shanghai 200438 China

The paper analyzes the requirement of performance, mainly including validity, flexibility and parallelism of algorithm in data mining. Based on the idea of data parallelism, a parallel training model for RBF (radial basis function) neural network in time-series prediction to improve the training speed is proposed. This model has good expansibility can cope with large training set, and is a kind of coarse granular parallel and suitable to data mining on parallel system such as cluster. Also the algorithm is described and the training speed is tested.

关键词： Data mining Data prediction Neural network Parallel computing

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Platform-based synthesis design methodology for system-on-chips

Platform-based synthesis design methodology for system-on-ch...

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International Conference on (ICEPT) Electronic Packaging Technology

作者： Wen Quan Liu Bo He Jianmin Department of Computer Science and Technologies Second Northwest University for Nationalities Yinchuan China Department of Management Science and Engineering South-East University Nanjing China Department of Computer Science and Engineering South-East University Nanjing China

Platform-based design for system-on-chips (SoCs) uses existing designs as starting points for new system implementations and put more stress on system level reuse. Synthesis methods are important elements in platform-based design methodologies. This paper takes hardware/software (HW/SW) co-design and high level design reuse as keys to SoC design. First, it introduces a system level co-exploration methodology and presents a typical platform-based design flow. Then it emphasizes performance analysis; considering a problem called the first-generation dilemma, proposes a revised platform-based design flow. To support design technology innovations, several synthesis issues are discussed, such as platform reuse, configurable architecture, and system level verification. In addition, it adopts market-oriented views and synthesis tools such as Cadence VCC to make the design practical.

关键词： Design methodology System-on-a-chip System-level design computer architecture Hardware Design engineering computer science Application specific integrated circuits Space technology Field programmable gate arrays

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An application based on spatial-relationship to basketball defensive strategies

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EUC 2005 Workshops: UISW, NCUS, SecUbiq, USN, and TAUES

作者： Chin, Su-Li Huang, Chun-Hong Tang, Chia-Tong Hung, Jason C. Dept. of Physical Education Tamkang University Tamsui Taipei Hsien 251 Taiwan Dept. of Computer Science and Information Engineering Tamkang University Tamsui Taipei Hsien 251 Taiwan Department of Information Management Northern Taiwan Institute of Science and Technology Peitou Taipei 112 Taiwan

ISBN: (纸本)3540308032

This paper aims to develop a simulated system used for teaching and training basketball defensive strategies. Respectively, defensive strategies can be described within one method by editing video recorded from basketball games into desired clips for analysis and storing them into the database. In this paper, we used Spatial-Temporal Relationships to describe the local defensive movements by the basketball players in a game. The system will automatically capture tracks of defensive movements by the basketball players in the video clips, from which basketball coaches and players can learn various defensive strategies within the shortest period of time. The simulated system is expected to become a computerized educational aid to basketball teaching and training and to replace the unscientific and stereotyped system of basketball teaching and training. © IFIP International Federation for Information Processing 2005.

关键词： Learning systems

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