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Low-complexity distributed differential spacetime coding scheme for amplify-and-forward cooperative networks

Science in China(Series F) 2009年第8期52卷 1418-1427页

作者： YU XiangBin1,2, BI GuangGuo3.& XU WeiYe4 1 College of Information Science and technology, nanjing University of Aeronautics and Astronautics, nanjing 210016, China 2 {3. of Electronic engineering, City University of Hong Kong, Hong Kong, China 3.National Mobile communications Research Laboratory, Southeast University, nanjing 210096, China 4 department of communication engineering, nanjing institute of technology, nanjing 211167, China College of Information Science and technology Nanjing University of Aeronautics and Astronautics department of Electronic engineering City University of Hong Kong National Mobile communications Research Laboratory Southeast University department of

By introducing a space-time coding scheme based on amicable orthogonality, we develop a distributed differential space-time coding scheme with the amplify-and-forward （AF） method for wireless cooperative networks. The scheme requires no knowledge of the channel state information at both transmitters and receivers, and effectively decreases the realization complexity due to no channel estimation. Moreover, it has lower decoding complexity and higher coding advantage than the existing scheme, thus avoiding the shortcoming of exponential decoding complexity of some existing schemes. According to the pairwise error probability （PEP） analysis of the system, the power allocations of source and relay terminals are jointly optimized, and as a result, the PEP is minimized, which will provide a helpful guideline for system design. Numerical calculation and simulation results show that the developed scheme is superior to the existing scheme. Moreover, the scheme with optimal power allocation yields obvious performance improvement over that with equal power allocation.

关键词： differential space-time coding cooperative communication amplify-and-forward method power allocation

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Quantitative Evaluation for Drawability of Sheet Metal

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Journal of Materials Science & technology 2005年第5期21卷 763-766页

作者： Zhiqing XIONG and Xuemei YANGdepartment of Mechanical engineering, nanjing institute of technology, {3. 210013. China department of Mechanical engineering Nanjing Institute of Technology Nanjing 210013 China

The theoretical evaluating method is given for the drawability of the sheet with normal anisotropy. The general solution on the cracking load of deep-drawing is deduced, which is based on three kinds of hardening curve of materials most in use. The distributions of stress and strain in the deformed region and the drawing force are obtained by the numerical method. The limiting drawing ratio is calculated through computer-aided simulating test. The experiments of deep-drawing to four kinds of sheet metals express that the relative errors between the predictive and the experimental results about the cracking load and the limiting drawing ratio are within 5%. The drawability of common sheet metals can be quantitatively evaluated in precise terms by means of the theory and the method advanced in this paper.

关键词： Sheet forming Deep-drawing Formability Drawability

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A novel multicluster V-MIMO PCR scheme in large-scale Ad Hoc networks

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Science China(Information Sciences) 2010年第10期53卷 2097-2105页

作者： ZHOU Yao, CAI YueMing & PAN ChengKang department of Wireless communication, institute of communications engineering, PLA University of Science and technology, nanjing 210007, China department of Wireless communication Institute of Communications Engineering PLA University of Science and Technology

A multicluster packet collision resolution (PCR) scheme is a kind of recently proposed virtualMIMO techniques. In existing multicluster PCR schemes, a large-scale wireless Ad Hoc network is divided into clusters and the single cluster PCR scheme is applied independently to resolve collisions in each cluster. However, there are still some flaws in existing multicluster PCR schemes. In this paper, by presenting a concise theoretical analysis model and a new CNS algorithm, a novel multicluster PCR scheme is proposed. Analysis and simulation results show that the proposed scheme can obtain high performance gain with low complexity. The proposed scheme is more robust and applicable than existing schemes.

关键词： packet collision resolution virtual-MIMO cooperative communication cooperative nodes selection

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A new sequential learning algorithm for RBF neural networks

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Science China(Technological Sciences) 2004年第4期47卷 447-460页

作者： YANG Ge1, LV Jianhong1 & LIU Zhiyuan2 1. department of Power engineering, Southeast University, nanjing 210096, China 2. department of Power engineering, nanjing institute of technology, nanjing 210013. China department of Power engineering Southeast University department of Power engineering Nanjing Institute of Technology

Due to their inherent imperfections, it is hard to use the static neural networks for nonlinear time-varying process modeling and prediction, and the minimal resource allocation network (MRAN) is difficult to be realized for its too many regulation parameters. A new sequential learning algorithm for radial basis function (RBF) neural networks based on local projection named Local Projection Network (LPN) is proposed in this paper. The results of validation for several benchmark problems with the new algorithm show that the presented LPN not only has the same level as M-RAN in network size and precision of the outputs, but also has fewer regulation parameters and is more predictable.

关键词： radial basis functions, local projection network, minimal resource allocation network, learning algorithm.

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Early Hydration of Composite Cement with Thermal Activated Coal Gangue

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Journal of Wuhan University of technology(Materials Science) 2010年第1期25卷 162-166页

作者：郭伟 department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca（OH）2 content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis （TG-DSC）, X-ray diffraction（XRD）, scanning electronic microscopy （SEM） and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. The early hydrated products of the cement are C-S-H gel, Ca（OH）2 and AFt. The cement with 3.% （in mass） the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 ℃ displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.

关键词： blended cement hydration microstructure hydration product

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A Feedback-Based Web Search Engine

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Wuhan University Journal of Natural Sciences 2004年第5期9卷 561-568页

作者： ZHANG Wei-feng 1,2,3., XU Bao-wen 2,3.4 , ZHOU Xiao-yu 2,3.4 1. department of Computer Science and engineering, nanjing University of Posts and Tele{3.s, nanjing 210003. Jiangsu, China 2. department of Computer Science and engineering, Southeast University, nanjing 210096, Jiangsu, China 3. Jiangsu institute of Software Quality, nanjing 210096 Jiangsu, China 4. The State Key Laboratory of Software engineering, Wuhan University, Wuhan 43.072, Hubei, China department of Computer Science and engineering Nanjing University of Posts and Telecommunications Nanjing Jiangsu China department of Computer Science and engineering Southeast University Najing Jiangsu China Jiangsu institute of Software Quality Nanjing Jiangsu China The State Key Laboratory of Software engineering Wuhan University Wuhan Hubei China

Web search engines are very useful information service tools in the Internet. The current web search engines produce search results relating to the search terms and the actual information collected by them. Since the selections of the search results cannot affect the future ones, they may not cover most people’s interests. In this paper, feedback information produced by the user’s accessing lists will be represented by the rough set and can reconstruct the query string and influence the search results. And thus the search engines can provide self-adaptability. Key words WWW - search engine - query reconstruction - feedback CLC number TP 3.1. 13..4 Foundation item: Supported by the National Natural Science Fundation of China (603.3.66). National Grand Fundamental Research 973.Program of China (2002CB3.200). Opening Foundation of State Key Laboratory of Software engineering in Wuhan University, Opening Foundation of Jiangsu Key Laboratory of Computer Information Processing technology in Soochow UniversityBiography: ZHANG Wei-feng (1975-), male, Ph.D. research direction: artificial intelligence, search engine, data mining, network language.

关键词： WWW search engine query reconstruction feedback

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Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

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Science China(Information Sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2 & FENG GuangZeng3.1department of Electronic and Information engineering, Zhejiang institute of Media and {3.s, Hangzhou 3.0018, China 2department of Information engineering, Jiangsu City Vocation College, nanjing 21003., China 3.ollege of {3. and Information engineering, nanjing University of Posts and Tele{3.s, nanjing 210003. China department of Electronic and Information engineering Zhejiang Institute of Media and Communications department of Information engineering Jiangsu City Vocation College College of communication and Information engineering Nanjing University of Posts a

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding

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Game model of safety monitoring for arch dam deformation

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Science China(Technological Sciences) 2008年第S2期51卷 76-81页

作者： SU HuaiZhi1,2,WU ZhongRu1,2,GU YanChang1,2,HU Jiang1 & WEN ZhiPing3.1 College of Water Conservancy and Hydropower engineering,Hohai University,nanjing 210098,China 2 National engineering Research Center of Water Resources Efficient Utilization and engineering Safety,nanjing 210098,China 3.department of Computer engineering,nanjing institute of technology,nanjing 210013.China College of Water Conservancy and Hydropower engineering Hohai University Nanjing China National engineering Research Center of Water Resources Efficient Utilization and engineering Safety Nanjing China department of Computer engineering Nanjing Institute of Technology Nanjing China

Arch dam deformation is comprehensively affected by water pressure,temperature,dam's structural behavior and material properties as well as other *** them the water pressure and temperature are external factors(source factors) that cause dam deformation,and dam's structural behavior and material properties are the internal factors of deformation(resistance factors).The dam deformation is the result of the mutual game playing between source factors and resistance ***,resistance factors of structure and materials that reflect resistance character of arch dam structure are introduced into the traditional model,where structure factor is embodied by the flexibility coefficient of dam body and the maximum dam height,and material property is embodied by the elastic modulus of *** the basis of analyzing the correlation between dam deformation and resistance factors,the game model of safety monitoring for arch dam deformation is put forward.

关键词： arch dam deformation monitoring model flexibility coefficient game theory

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Structure and Pozzolanic Activity of Calcined Coal Gangue during the Process of Mechanical Activation

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Journal of Wuhan University of technology(Materials Science) 2009年第2期24卷 326-329页

作者：郭伟 department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

On the basis of analyzing coal gangue＇s chemical and mineral compositions, the structure change of coal gangue during the mechanical activation was investigated by XRD, FTIR, NMR, and the mechanical strength of the cement doped coal gangue with various specific surface area was tested. The experimental results indicate that, the lattice structure of metakaolin in coal gangue samples calcined at 700 ℃ disorganizes gradually and becomes disordered, and the lattice structure of α-quartz is distorted slightly. The pozzolanic activity of the coal gangue increases obviously with its structural disorganization.

关键词： coal gangue mechanical activation structure NMR tetrahedron

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Thermal Insulation and Strength of Autoclaved Light Concrete

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Journal of Wuhan University of technology(Materials Science) 2011年第1期26卷 132-136页

作者：杨若冲吴智深 School of Transportation Southeast University institute of Urban engineering Science & technology Southeast University

The primary objective of this study was to develop an autoclaved light concrete （ALC） material with ultra-thermal insulation property and to investigate the relationship between its physical characteristics and mechanical properties. Through tests of dry bulk density and compressive strength, relationship of physical characteristics and mechanical properties of samples were studied, resulting in a material with ultra-thermal insulation property. Scanning electron microscope （SEM） and energy-dispersive X-ray spectroscopy （EDX） were applied to analyze the micro-morphology and elemental composition of samples. To identify the product phases, X-ray diffraction （XRD） was engaged. The test results showed that compressive strength and thermal coefficient were reduced with the increasing of aluminum powder within the mixtures. As a result the optimal thermal coefficient and compressive strength of samples were improved to 0.061 W/（m·k） and 1.2 MPa, respectively. SEM, EDX and XRD analyses showed that calcium silicate hydrate and tobermorite crystal were main resultant phases.

关键词： autoclaved light concrete ultra-thermal insulation microscopic appearance and phase analysis tobermorite crystal

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