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Self-dual Codes Defined on Factor Graphs

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Journal of Shanghai Jiaotong university(Science) 2007年第4期12卷 433-436页

作者：汪辉松汪隽杜群曾贵华 dept.of Electronic Eng. Shanghai Jiaotong Univ. Central-South Architectural design Institute

A definition of a self-dual code on graph and a procedure based on factor graphs to judge a self-dual code were presented. Three contributions of this paper were described as follows. To begin with, transform T_ R→L were defined, which was the basis of self-dual codes defined on graphs and played a key role in the paper. The second were that a self-dual code could be defined on factor graph, which was much different from conventional algebraic method. The third was that a factor graph approach to judge a self-dual code was illustrated, which took advantage of duality properties of factor graphs and our proposed transform T_ R→L to offer a convenient and geometrically intuitive process to judge a self-dual code.

关键词： factor graph self-dual code dual property error-correcting code

HEST: A Hybrid-Language-Based Expert System Tool

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Journal of Systems Engineering and Electronics 1995年第3期6卷 25-30页

作者： Huang Houkuan Hao Jigang Wang Zhaoqi & Gao Feng( dept. of Computer Set., Northern Jiaotong University, Beijing 100044, China)( dept. of Computer Set., Tsinghua University, Beijing 100084, China)( Computer Center, Research Institute No.701, Shanghai 201 dept. of Computer Sci. Northern Jiaotong University Beijing 100044 China dept. of Computer Sci. Tsinghua University Beijing 100084 China Computer Center Research Institute No.701 Shanghai 201103 China dept. of Computer Sci Harbin Engineering University Harbin 150001 China

HEST is a practical integrated expert system tool. Its basis is a knowledge programming language FFLL, characterized by a combination of fuzzy logic and function paradigms. The tool integrates alot of important knowledge processing capabilities such as fuzzy reasoning, function computation, knowledge compilation and explanation, knowledge base maintenance, as well as practical programming functions, e.g., editing, filing, compiling, module imbedding, etc., constructing, a user--friendly knowledge application environment, HEST can enable expert system development in various domaills quickly and *** paper gives an outline of the design and implementation of HEST.

关键词： Expert system tool Fuzzy logic Function paradigm Warren abstract machine

Buildup and simulation of a truck model with rear air suspension using leaf spring as guiding rod

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Journal of Harbin Institute of Technology(New Series) 2006年第6期13卷 654-657页

作者：姜立标王登峰谢东倪强郎锡择 College of Automotive Engineering Jilin University dept. of Automotive EngineeringHarbin Institute of Technology at Weihai Weihai 264209 China School of Mechanical Engineering Shanghai Jiaotong University dept. of Automotive EngineeringHarbin Institute of Technology at Weihai

A new kind of commercial truck is presented, which has rear air suspension using leaf spring as guiding rod instead of original leaf spring. ADAMS/Car is used as a tool to build the whole truck model. The designed truck＇s constant-radius cornering analysis and its ride performance simulation analysis under B class random road condition are carried out according to national experimental method standards. Compared the simulation results with the field test results indicate that performance index of the designed air suspension truck＇ s constant-radius cornering and its ride performance meets the design requirements and reaches its prospective target. And resuhs from simulation are similar to those from tests in value and trend, which indicates the virtual prototype is correct. The model can be used further to opti,nize suspension parameters and do some design work on the control system of air suspension.

关键词： air suspension commercial truck simulation virtual prototype

The design and simulation of TCR(thyristor control reactor) reactive power compensation system based on Arene

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Journal of Coal Science & Engineering(China) 2004年第2期10卷 101-104页

作者：王淑芳张丽姜建国王汝琳 dept. of Information and Electronic Engineering China University of Mining and Technology Beijing 100083China

Inevitably, the question of reactive power compensation was aroused by applied of power electronics. Based on the study of the instantaneous reactive power theory, the designs of TCR(thyristor control reactor) thyristor control reactor reac- tive power compensation system and TCR single closed loop strategy was pro- posed. In addition, as digital simulation software, Arene was applied to simulate the Jining coal mine No.2 system. The simulation results validate that the design is effective to improve power factor and stabilization of the system.

关键词： TCR reactive power compensation instantaneous reactive power

On the Basis of the Singular Perturbation Approach to Control a Two-link Constrained Flexible Manipulator

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High Technology Letters 2001年第3期7卷 90-92页

作者：李元春 dept. of Contr. Sci. and Engineering JiLin University Changchun 130025 China

On the basis of singular perturbation theory, a composite control approach is proposed for constrained flexible manipulators in this paper. The dynamics equation of a constrained two link flexible manipulator is divided into slow subsystem and fast subsystem. Based on the adaptive theory, the slow controller is designed. For the fast subsystem, a robust optimal controller is presented. Under the slow time scale and the fast time scale, a composite control strategy is constructed. Some results of numerical simulations are presented to show the effectiveness of this design procedure.

关键词： Constrained flexible manipulator Singular perturbation approach Composite control

Performance Evaluation of List Sphere Detector

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Journal of Shanghai Jiaotong university(Science) 2005年第4期10卷 344-348页

作者： HE Xiang（贺翔） LUO Han-wen（罗汉文） YI Yang（易洋） dept. of Electrical Eng. Shanghai Jiaotong Univ. Shanghai 200030 China

A list sphere detector can use a smaller list than commonly believed by employing an appropriate soft output approximation method. Its effect on the ＂quality＂ of detector＇s soft output value is evaluated by measuring mutual information under ergodic channel. The result shows a length 40 list is adequate for a 4×4 16QAM MIMO system without system-level iteration. For the ergodic channel, the gain of a sphere detector over the linear MMSE detector is dependent on channel coding rate, which answers an important question when sphere detector should he used in system level design. All these theoretical results are then verified by Monte Carlo simulation.

关键词： multiple-input multiple-output (MIMO) list sphere detector mutual information

An Improved Group Space-Time Block Code Through Constellation Rotation

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Journal of Shanghai Jiaotong university(Science) 2005年第4期10卷 349-353页

作者： ZHANG Hong-wei（张红伟） ZHANG Hai-bin（张海滨） SONG Wen-tao（宋文涛） LUO Han-wen（罗汉文） LIU Xing-zhao（刘兴钊） dept. of Electronic Eng. Shanghai Jiaotong Univ. Shanghai 200030 China

A new improved group space-time block code (G-STBC) based on constellation rotation for four transmit antennas was proposed. In comparison with the traditional G-STBC coding scheme, the proposed space-time code has longer code length and adopts proper rotation-based symbols, which can increase the minimum distance of space-time codes and thereby improve code gain and achieve full diversity performance. The simulation results verify that the proposed group space-time code can achieve better bit error performance than both the traditional group space-time code and other quasi-orthogonal space-time codes. Compared with Ma’s full diversity full rate (FDFR) codes, the proposed space-time code also can achieve the same excellent error performance. Furthermore, the design of the new space-time code gives another new and simple method to construct space-time codes with full diversity and high rate in case that it is not easy to design the traditional FDFR space-time codes.

关键词： group space-time block code constellation rotation multiple-input multiple-output (MIMO) full diversity full rate

Pressure characteristics of a hydrocyclone for fine particle separation

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Journal of Harbin Institute of Technology(New Series) 2006年第3期13卷 294-298页

作者：赵立新蒋明虎孙德智 BELAIDI A THEW M Mechanical Science and Engineering College Daqing Petroleum Institute Daqing 163318 China dept. of Environmental Engineering Harbin Institute of Technology Harbin 150090 China School of Engineering Design and Technology University of Bradford Bradford West Yorkshire BD7 1DP UK

Solid-liquid hydrocyclones are mainly used to separate large particles, such as the particles of drilling fluid in petroleum industry, and large mineral particles. Till now the hydrocyclonic separation for fine particles is still a big problem. Basic separation principle of hydrocyclones and experimental research facility are simply introduced. The difficulty of separating fine particle is analyzed. Based on a solid-liquid hydrocyclone used for separating fine particles, relationships of dimensionless pressure characteristic parameters, i.e. Euler number and pressure drop ratio, with several main dimensionless parameters, such as split ratio, swirl number and gas-liquid ratio, were experimentally studied in detail. The research was carried out by using the hydrocyclonic separation experimental rig at the University of Bradford. It is shown that the less the size of particle, the less the value of radius of the balance orbit occupied by the particle, and then the more difficult for the particle to be separated. Experiments indicate that Euler number of the tested hydrocyclone increases with the rise of Reynolds number, split ratio, swirl number and gas-liquid ratio respectively, and the pressure drop ratio falls with the increase of Reynolds number, split ratio and swirl number respectively. It is concluded that the most effective way to decrease the unit energy dissipation of hydrocyclone is to reduce swirl number or gas-liquid ratio of the mixed media.

关键词： water treatment separation technology hydrocyclone pressure

Application of orthogonal design in the experiment of plasma arc powder surfacing technology

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China Welding 2001年第2期10卷 57-61页

作者：张德勤杜则裕云绍辉 dept. of Mech. and Electronic Eng. University of Petroleum Dongying 257061 China

In this paper, the influence of plasma arc powder surfacing technical parameters on the property of layer is defined using the orthogonal design. By the orthogonal polynomial regression, when plasma arc powder surfacing is used on the surface of the X65 steel plate with the Fe-07 alloy powder, the optimum technical parameters are the following: I=180～190 A , G=41.5 g/min , v=102 mm/min , T_0=350 ℃ , Q_l=280 L/h , Q_s=400 L/h . Further, analysis of the cracking test data showed that the cracking preheat temperature is 350 ℃ .

关键词： orthogonal design plasma arc powder surfacing orthogonal polynomial regression optimum technical parameters cracking test