检索结果-内蒙古大学图书馆

8th International e-VLBI Workshop, EXPReS 2009

作者： Sekido, M. Kawaguchi, N. Koyama, Y. Kimura, M. Kondo, T. Takiguchi, H. Hobiger, T. Takefuji, K. Harai, H. Ikeda, T. Shimojo, S. Oyama, T. Hara, T. Kono, Y. Kurihara, S. Kokado, K. Tanimoto, D. Nozawa, K. Takeuchi, H. Uose, H. Fujisawa, K. Takaba, H. Kashima Space Research Center National Institute of Information and Communications Technology 893-1 Hirai Kashima Ibaraki 314-8501 Japan National Astronomical Observatory 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Next Generation Network Research Center National Institute of Information and Communications Technology 4-2-1 Nukui-Kitamachi Koganei Tokyo184-8795 Japan Ajou University Paldai Hall 901 Worcheon-Dong Yeongtong-Gu Suwon442-749 Korea Republic of Geographical Survey Institute 1Kitasato Tsukuba 305-0811 Japan Japan Aerospace Exploration Agency/Institute of Space and Astronautical Science 3-1-1 Yoshinodai Sagamihara Kanagawa229-8510 Japan Nippon Telegraph and Telephone Corporation Musashino Research and Development Center 3-9-11 Midori-cho Musashino-shi Tokyo180-8585 Japan Yamaguchi University 1677-1 Yoshida Yamaguchi Yamaguchi753-8511 Japan Gufu University 1-1 Yanagito Gifu Gifu501-1193 Japan

Recent Japanese e-VLBI activities are reported in this paper. Offline data transfer though the network has been regularly performed for geodetic VLBI experiments. Besides these offline transfers, real-Time eVLBI experiments for ultra-rapid UT1 measurements have been performed among Onsala, Metsähovi, Tsukuba, and Kashima stations in a pilot project. In the field of astronomy, a real-Time e-VLBI demonstration session organized by the ATNF in 2008 was the first occasion for Kashima to transmit VLBI data obtained by the K5 system to a foreign correlator in real-Time. The global e-VLBI observation session organized by JIVE for the opening event of International Year of Astronomy in January 2009 was the first participation for a Japanese station in a global real-Time e-VLBI session. Overview of the K5 DAS systems (K5/VSSP, and K5/VSI) used for the e-VLBI is described. Optically linked e-VLBI observations with domestic VLBI stations have been conducted by the NAOJ. Also the NAOJ has developed a high speed VLBI data sender/reciver equipment named VOA-200 and a high speed hardware correlator (2Gbps × 6 baselines). A test observation of 8 Gbps real-Time VLBI was successfully achieved by using the VOA-200 and the hardware correlator in 2008. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.

关键词： Data transfer

来源：评论

学校读者我要写书评

暂无评论

On the optimal number of hops in linear wireless ad hoc networks with hybrid ARQ

On the optimal number of hops in linear wireless ad hoc netw...

引用

International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)

作者： Igor Stanojev Osvaldo Simeone Yeheskel Bar-Ness Myeon-gyun Cho Center for Wireless Communications and Signal Processing New Jersey Institute of Technology Newark NJ USA Next Generation System Research Team Telecommunication Research & Development Center Samsung Electronics Company Limited Suwon South Korea

In this paper, we study the optimal design of a linear wireless multihop network that employs Hybrid Automatic Repeat reQuest (HARQ) protocols in a quasi-static fading environment. Data transmission is assumed to be delay-tolerant up to a certain predefined maximum delay (in transmission slots) that is larger or equal to the number of hops. Multihop routing is implemented through a time-division scheduling and decode-and-forward relaying. Excess time is exploited for retransmissions using either HARQ Type I or Chase Combining protocols on the hops that result in link-outage. Relying on analysis and numerical optimization, we seek answer to the following question: given the maximum allowed delay and signal-to-noise ratio, what is the optimal number of hops that maximizes the end-to-end throughput?

关键词： Mobile ad hoc networks Automatic repeat request Delay Spread spectrum communication Wireless application protocol Fading Data communication Routing Decoding Relays

来源：评论

学校读者我要写书评

暂无评论

Cooperative Coding using Cyclic Delay for Multiuser OFDM Systems

Cooperative Coding using Cyclic Delay for Multiuser OFDM Sys...

引用

IEEE Conference on Vehicular Technology (VTC)

作者： Dongwoo Lee Young Seok Jung Jae Hong Lee Byung Jang Jeong Taegyun Noh School of Electrical Engineering and INMC Seoul National University Seoul South Korea Wireless Device Laboratory2 Telecommunication Research and Development Center Samsung Electronics Company Limited Suwon South Korea Next Generation Radio Transmission Research Team Mobile Telecommunication Research Division Electronics and Telecommnications Research Institute Daejeon South Korea

In this paper, the cooperative coding using cyclic delay diversity (CDD) for multiuser OFDM systems is introduced. In proposed scheme, multiple terminals with a single antenna share their resources and exploit spatial diversity. Also, in order to increase frequency selectivity in the relay channel, different cyclic time delay is used at the relays. Analysis of frame error probability (FEP) for proposed cooperative coding using CDD is shown. Simulation results show the frame error rate (FER) for various consideration. The proposed scheme provides the diversity gain according to the number of relays and cyclic delay.

关键词： OFDM Relays MIMO Delay effects Error analysis Error probability Diversity methods Wireless communication Fading Wireless networks

来源：评论

学校读者我要写书评

暂无评论

RoF System for TDD-based 4×4 MIMO OFDMA Wireless Communication Systems

RoF System for TDD-based 4×4 MIMO OFDMA Wireless Communicat...

引用

IEEE Photonics Conference (IPC)

作者： Seongtaek Hwang Hoon Kim B. Kim J. Lee H. Lee S. Kim K. Song J. Cho Y. Oh Telecommunication Research and Development Center Next Generation Technology Team Samsung Electronics Company Limited Suwon Gyeonggi South Korea

We demonstrate a fiber-optic transport system for next generation wireless communication systems utilizing time division duplex-based 4times4 multiple-input multiple-output orthogonal frequency division multiple acces... 详细信息

关键词： MIMO Wireless communication RF signals Propagation delay Mobile handsets Delay effects Radio frequency Radiofrequency amplifiers Frequency conversion Optical fibers

来源：评论

学校读者我要写书评

暂无评论

An Enhanced V-BLAST System for Reduced-Complexity Tree Searching

An Enhanced V-BLAST System for Reduced-Complexity Tree Searc...

引用

IEEE Conference on Wireless Communications and Networking

作者： Hyounkuk Kim Kihwan Jeon Sungsoo Hwang Hyuncheol Park School of Engineering Information and Communications University Daejeon South Korea Next Generation System Team Telecommunication Research and Development center Samsung Electronics Company Limited Suwon Gyeonggi South Korea

This paper presents a new vertical Bell labs layered space-time (V-BLAST) transmission scheme for developing reduced-complexity receiver. It can significantly alleviate the receiver complexity in sense of tree searching of the QRD-M algorithm. The new V-BLAST system is designed by two criteria: minimum performance loss and maximum complexity reduction. In a 4 times 4 V-BLAST system with 16 bps/Hz, the former can lessen about 51% metric computations with 1.0 dB performance degradation, compared with the conventional V-BLAST system with the QRD-M algorithm. The latter can achieve approximately 65% complexity reduction at the expense of 3.0 dB performance penalty.

关键词： Decision trees Receiving antennas Electronic mail Performance loss Degradation Detectors Transmitting antennas Decoding Communications Society research and development

来源：评论

学校读者我要写书评

暂无评论

Mutiple-view object tracking using metadata

Mutiple-view object tracking using metadata

引用

International Conference on Wavelet Analysis and Pattern Recognition (ICWAPR)

作者： Inho Paek Changhan Park Myeongsuk Ki Kyoungju Park Joonki Paik Image Processing and Intelligent System Laboratory Department of Image Engineering Chung-Ang University Seoul South Korea Advanced Technology Research & Development Center Samsung Thales Company Limited Yongin si Gyeonggi South Korea Digital Broadcasting Research Division ETRI Electronics and Telecommunication Research Institute Daejeon South Korea Next Generation Imaging Contents Laboratory Department of Image Engineering Chung-Ang University Seoul South Korea

In this paper we present a moving object tracking method in a multiple camera tracking system using meta-data. The proposed method acquires image sequences from multiple fixed cameras without a priori camera calibration. The tracking is performed based on object's robust characteristics, such as motion, shape, color, and etc. Elements of meta-data and the optimal tracking method are selected at each frame. Because object's characteristics are affected by camera position and environmental condition, tracking method between individual cameras is selected by optimal metadata. Tracking in a single view can be divided into three classes, such as; optical flow-based moving object detector, active shape model (ASM), color correlation based detector. The proposed method matches objects to most similar object color information, by comparing meta-data and ASM. In the experiment, the proposed multi-camera tracking system is show to be robust for non-rigid objects.

关键词： Cameras Tracking Robot vision systems Surveillance Humans Biological system modeling Image analysis Robustness Object detection Active shape model

来源：评论

学校读者我要写书评

暂无评论

development of MEA for automotive fuel cell at honda

Development of MEA for automotive fuel cell at honda

引用

22nd International Battery, Hybrid and Fuel Cell Electric Vehicle Symposium and Exposition, EVS 2006

作者： Fukuda, Kaoru Automobile R and D Center Research Department Development of MEA for Next Generation Automotive Fuel Cells Honda Honda R and D Co. Ltd 1 4630 Shimotakanezawa Hga-machi Haga-gun Tochigi Japan

As the next generation fuel cell to be mounted in the Honda FCX, a Membrane Electrode Assembly (MEA), which uses an aromatic electrolyte membrane, a new technology that has excellent proton conductivity and high temperature durability, has been adopted. As a result of the use of this MEA, it was possible to obtain high output and power generation between -20°C and +95°C. Compared to the conventional fluorine electrolyte membrane, the aromatic electrolyte membrane has better characteristics, including greater shape retention in the high temperature region and lower membrane resistance in the low temperature region. In this paper, a description is given of the element technology of the fuel cell MEA that uses this new aromatic electrolyte membrane. © EVS-22 Yokohama, Japan.

关键词： Aromatic compounds

来源：评论

学校读者我要写书评

暂无评论

Flexible scheduling of system information for evolved UMTS radio access

Flexible scheduling of system information for evolved UMTS r...

引用

7th World Wireless Congress, WWC

作者： Petrovic, Dragan Seidel, Eiko Aoyama, Takahisa Suzuki, Hidetoshi Panasonic Frankfurt Laboratory Panasonic R and D Center Germany GmbH Langen/Frankfurt Germany Next-Generation Mobile Development Center Matsushita Electric Industrial Co. Ltd. Kanagawa Japan Communication System Development Center Panasonic Mobile Communications Co. Ltd. Kanagawa Japan NOMOR Research GmbH Munich Germany

Deficiencies of a conventional scheme for temporally sequential fixed-rate transmission of system information in evolved UMTS Radio Access are investigated. These deficiencies include less flexible allocation of resources for deployment options having different sizes of spectrum allocations, different capacity requirements of broadcast channel for various deployment options and suboptimal reception of system information originating from source or neighbouring cell. A new method for flexible scheduling of system information including temporally parallel variable rate transmission wherein part of system information is mapped on Downlink Shared Channel is proposed to alleviate identified shortcomings.

关键词： Scheduling

来源：评论

学校读者我要写书评

暂无评论

Performance assessment of the new rapid-static module of the online positioning user service - OPUS-RS

Performance assessment of the new rapid-static module of the...

引用

18th International Technical Meeting of the Satellite Division of The Institute of Navigation, ION GNSS 2005

作者： Grejner-Brzezinska, Dorota A. Wielgosz, Pawel Kashani, Israel Mader, Gerald L. Smith, Dru Robertson, Doug Komjathy, Attila Lab. Ohio State University National Geodetic Survey NOS NOAA NASA JPL Pasadena ION Council IAG SC-4.1 Multi-sensor Systems IAG Special Commission 4 WG-5 Pseudolite Applications in Engineering Geodesy Task Force 5.3.1 Mobile Mapping Systems FIG WG-5.3 Poland OSU IGS Ionosphere Working Group IAG Sub-Commission SC-4.3 GNSS Measurement of the Atmosphere IAG Sub-Commission SC-4.5 Next Generation RTK IAG Working Group WG-4.5.2 Carrier Phase-Based Precise Point Positioning ION IAG Working Group WG-4.5.1 Network RTK OPUS - the On-line Positioning User Service NOAA's National Geodetic Survey Interageney GPS Executive Board American Geophysical Union International Association of Geodesy Institute of Navigation American Association for Geodetic Surveying Department of Geological Sciences Cooperative Institute for Research in Environmental Sciences Colorado Center for Chaos and Complexity University of Colorado Boulder Group Tracking Systems and Applications Section

The National Geodetic Survey (NGS) operates the Online Positioning User Service (OPUS) as means to provide the GPS users' with easier access to the National Spatial Reference System (NSRS). OPUS allows the users to submit their GPS data files to NGS, where the data are processed to determine position coordinates using the NGS computers and software. OPUS is completely automatic, and the results are e-mailed back to the user, usually within a few minutes. OPUS is intended for the use in the conterminous U.S. and most territories. Currently, OPUS accepts a minimum of two hours of GPS data, with a recommendation of submitting at least four hours in order to obtain the best possible solution (http://***/OPUS/). To extend the number of OPUS users to those, who normally collect shorter data spans, the effort, sponsored by NGS, and performed in collaboration with the Satellite Positioning and Inertial Navigation (SPIN) group at The Ohio State University (OSU), resulted in the development of a rapidstatic module (OPUS-RS), as an extension of the currently used OPUS model. In this paper, the performance analysis of the OPUS-RS module, based on the stations of the CORS (Continuously Operating Reference Station) network is presented. Selected sub-network with ∼250-300 km station separation is used to produce the ionospheric and tropospheric corrections that are tested in the rover positioning solution in multi-baseline mode, simulating the expected reference network and user geometry. One of the CORS stations is considered a user receiver with known coordinates, providing the ground truth to our tests. The data processing is performed in the post-mission mode. Even though the OPUS-RS module is designed to estimate the ionospheric correction internally, additional tests of the positioning module accuracy and reliability were performed using the external ionospheric models. Four external ionospheric models were tested for their accuracy and applicability to support

关键词： Global positioning system

来源：评论

学校读者我要写书评

暂无评论

ASYNCHRONOUS TRANSFER MODE (ATM) OPERATION VIA SATELLITE - ISSUES, CHALLENGES AND RESOLUTIONS

引用

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 211-222页

作者： CHITRE, DM GOKHALE, DS HENDERSON, T LUNSFORD, JL MATHEWS, N COMSAT Laboratories 22300 Comsat Drive Clarksburg MD 20871 USA. Received his B.Sc. from the University of Bombay India an M.A. in mathematics from the University of Cambridge U.K. and a Ph.D. in physics from the University of Maryland. He is currently an Associate Executive Director of the Network Technology Division at COMSAT Laboratories. He has been involved in research and development activities in ISDN VSAT networks data communications and network systems and architectures. Prior to his current positions Dr. Chitre was a Principal Scientist in the Network Technology Division at COMSAT Laboratories. Dr. Chitre joined COMSAT Laboratories in 1980. He has made major contributions to the analysis and architecture of data communication ISDN and BISDN via satellite. Dr. Chitre directs and participates in the international and national standards activities in ISDN BISDN and data communication as they apply to satellite communication. He was Chairman of the Working Group on Protocols and Network Timing Function of the CCIR/CCITT Joint Ad Hoc Group on ISDN-Satellite Matters during 1990–1992. Currently he is the Chairman of the Working Group on New Technologies in the ITU Intersector Coordinating Group (ICG) on Satellite Matters. Dr. Chitre was a programme manager during 1990 and 1991 on a contract from INTELSAT on systems studies on satellite communications systems architectures for ISDN and broadband ISDN systems. Currently he is the technical manager of the DoD Contract on ATM via satellite demonstration and the programme manager for the INTELSAT contract on analysis and top-level specification of INTELSAT ISDN subnetworks and SDH compatible transport network. Department manager for ISDN/Data Communications in the Network Technology Division of COMSAT Laboratories. His responsibilities include managing the implementation of next generation telecommunication systems for fixed and mobile satellite systems. Current projects include the development of a high data rate gateway switch that provides for the

Key issues regarding the operation of the broadband integrated services digital network (BISDN) via satellite are presented herein. The specific issues, challenges, and their resolutions are detailed. In particular, the impact of error characteristics and propagation delay on the operation of BISDN via satellite is discussed. Solutions are presented for removing adverse effects and providing high-quality service to users of BISDN via satellite.

关键词： ATM BISDN

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：