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2001 Vol. 27, No. 2

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Cycling Oxidation Behavior of Nb-ion Implanted γ-TiAl
WANG Wei, SHI Jing-yu, ZHANG Yong-gang, ZHANG Tong-he
2001, 27(2): 125-128.
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The thermal cycling oxidation behaviors of Nb-ion implanted γ-TiAl in air were studied in the temperature range of 1123~1173K. The microstructures of the oxide scales were examined by SEM equipped with EDS. Nb distribution and depth profiles of elements were analyzed by AES. The results indicated th...
Research of Gray Model Applied in the Prior Corrosion and Fatigue of Aluminum Alloys
LIU Yan-li, ZHONG Qun-peng, WANG Yu-kui
2001, 27(2): 129-132.
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The effect of corrosion temperature and time on properties of the prior-corroded aluminum alloys was discussed tentatively, and gray model was introduced in the research of the simulating accelerated corrosion test for aluminum alloys. The non-linear relationship between mass loss,maximum corrosion ...
Study of Sol-gel/Microcapsule Compound Coating on Stainless Steel
ZHU Li-qun, LIU Chen-min, LI Xue-yuan
2001, 27(2): 133-136.
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A method for applying compound coating using a sol-gel/microcapsule method is described. Orhanosilicon resin having been made into microcapsule was added to zirconia sol. The microcapsulation technique was applied to the preparation of compound coatings. Through a lot of experiments and tests, a kin...
ATS Telegraph Pattern Recognition Using a Neural Network
ZHANG Xue-jun, ZHANG Qi-shan
2001, 27(2): 137-141.
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The air traffic service (ATS) telegraphs are composed of fixed information groups. The transmission errors and artificial factors lead to the nonstandard contents of telegraphs, which make the difficulties for the computer to process. In order to solve the problem, pattern recognition and neural net...
Design of Log-periodic Dipole Antenna Using Genetic Algorithms
LI Chao-wei
2001, 27(2): 142-145.
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The history of the development in theory of log-periodic dipole antenna (LPDA) and the basic design method used here are briefly presented.After showing steps in the optimization using the genetic algorithm (GA) in details,the application of designing LPDA with genetic algorithm is discussed.The app...
Smoothed-unit HMM Algorithm in Mandarin Speech Recognition
HE Qiang, MAO Shi-yi, ZHANG You-wei
2001, 27(2): 146-149.
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The base unit in mandarin speech recognition is phoneme, semi-syllable or syllable. Semi-syllable system has fewer HMM models and needs less computation, thus it's suitable for real-time systems. But due to poor description for the acoustic properties of the speech signal, it generally shows a low p...
Curve Simulation for Nonlinearity in Frequency Sweep in ISAR Imaging
LI Yu-xing, WANG Zhen-rong, LU Xu-dong
2001, 27(2): 150-152.
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LFM is one of widely used methods of ISAR. Nonlinearity in frequency sweep has some effects on the quality of imaging. Especially in the high-frequency, broad-band and short-tune frequency sweep, frequency swept nonlineatity of LFM curve can hardly distribute it. Based on the theory of ISAR, using s...
Study of GPS/MM Integrated Navigation System for Vehicle Positioning Based on D-S Evidence Reasoning
HU Hong-jie, ER Lian-jie, LIU Qiang, CHEN Jing-quan
2001, 27(2): 153-156.
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Classic PID control method which is based on precise mathematical model has poor adaptivity and is not adaptive to nonlinear and time-variant plants.Conventional neural network is always complicated and its stability often suffers from the effect of initial weight value selecting.A simple stable dir...
Study of GPS/MM Integrated Navigation System for Vehicle Positioning Based on D-S Evidence Reasoning
MM Integrated, S Evidence, SU Hui-min
2001, 27(2): 157-160.
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General principles of map matching are investigated according to segmentation and feature extraction, and an algorithm based on D-S evidence reasoning for GPS/MM integrated navigation system is proposed. The single point positioning accuracy of GPS is improved. Finally, a simulation example demonstr...
General RAIM Algorithm Based on Aiding of Receiver Clock Bias
HUANG Ji-xun, ZHOU Li-xian, FAN Yue-zu
2001, 27(2): 161-163.
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The characters of least-squares-residuals method belonging to receiver autonomous integrity monitoring(RAIM) were analyzed. After the receiver clock bias behavior was accurately modeled using global positioning system(GPS) measurements, a new algorithm for RAIM was developed based on the least-squar...
New Approach to GPS Integrity Monitoring Based on SINS
GENG Yan-rui, ZHANG Wei-wei, CUI Zhong-xing
2001, 27(2): 164-166.
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A new approach of GPS integrity based on SINS is studied by means of the Chebyshev-s law of great numbers. The magnitude of pseudoranges can be estimated and that which satellite is in trouble can be determined by using only a Kalman filter. A example is given in the case of step-type pseudorange er...
Bend/Twist Coupling Effects of Unsymmetric and Unbalanced Laminate
XU De-wei, LI Zheng-neng, CUI De-gang
2001, 27(2): 167-170.
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In order to obtain particular twist angle of composite structure, utilizing the coupling effects of unsymmetric&unbalanced laminate is a considerable approach. An unsymmetric&unbalanced laminate is formed by adding a sub-laminate into the symmetric laminate. How to lay the sub-laminate and w...
Research of Mass Transfer of Living Skin
DING Li, YUAN Xiu-gan, ZHAO Yu-zhen
2001, 27(2): 171-174.
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Based on characteristics that different layers of skin mainly consist of cells and liquid between cells,a feasible three-layer physical model,which had used methods of porous medium,was put forward. Mathematic equations about conversation of consistency and energy were founded according to peculiari...
Synthetical Evaluation of Ergonomics Study in Visual Information Flow System of Pilots
LIU Wei, YUAN Xiu-gan, LIN Hai-yan
2001, 27(2): 175-177.
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Based on the study of visual area, main pathways of visual flow, ergonomics factors and the judgement of visual ergonomics, a synthetical evaluation of ergonomics study in visual information flow system of pilots has been built. Primary results reveal that there exists optimal, good and limit visual...
Research and Implementation of Role Based Access Control System
YANG Ya-ping, LI Wei-qin, LIU Huai-yu
2001, 27(2): 178-181.
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First, a theory of access control—role based access control was analyzed, and the characters and advantages of RBAC were discussed. Then, the infrastructure and implementary techniques of our own access control system based on this theory were given. This system can provide access control service fo...
Undeniable Cryptographic Protocol for Both Sender and Receiver and Its Applications
LI Xian-xian, HUAI Jin-peng
2001, 27(2): 182-185.
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In data communications, digital signature schemes have been used to ensure non-repudiation of sending data and the integrality of data, and non-repudiation of receiving data is also very important in the secure communication. In the past years, this kind of cryptographic protocols was mainly impleme...
Research on Modeling Based on STEP/AP
YANG Zhan-yong, CHEN Ming, ZHAO Yong-shun, DENG Jia-ti
2001, 27(2): 186-189.
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In the implementing of STEP, the application protocol(AP) provides share model for specific domain, but it limits to operate each other.It is difficult to ensure its conformance and augmentability. By reference of AP214, it is concerned with describing an approach of modeling based on STEP/AP. It de...
Numerical Control System for Virtual Axis Tool Grinders and Conventional Tool Grinders
CHEN You-dong, CHEN Wu-yi, FAN Rui, CHEN Ding-chang
2001, 27(2): 190-193.
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A PC-based open computer numerical control system is described. This system can be used both for virtual axis tool grinders and for conventional tool grinders. The hardware setup and software structure are presented. The machine controller consists of two major elements: a PC and an IN/OUT board (in...
Numerical Simulation of Springback in Sheet Metal Forming
XU Bing-kun, SHI Fa-zhong
2001, 27(2): 194-197.
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Springback is an inevitable phenomenon in sheet metal forming process. As an effective method to solve springback problem, numerical simulation is receiving increasing attention throughout industry and academic world. Integrated springback simulation can be divided into two steps, that is punch load...
Research on Automatic Resonating for Ultrasonic Vibration Cutting
ZHOU Zheng-gan, WANG Chun-sheng, ZHANG Bo, ZHANG De-y
2001, 27(2): 198-201.
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In the process of ultrasonic vibration cutting (UVC), the resonant frequency of mechanical syntonic system varies in a wide range because of system's heating up and variable loads. If the ultrasonic power doesn't work at the resonant frequency of mechanical syntonic system, UVC is not able to go alo...
Product Requirement Acquisition and Definition for Creativity
WULAN Mu, WU Bin, DENG Jia
2001, 27(2): 202-205.
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Imitative creation is one way for Chinese enterprises to achieve innovation and development. Meeting market demands is the first step of product creation. If the market requirements are translated to the operable specification which directs product design, it needs the integration of semantic expres...
Study on Mechanism of Electro-friction Effect
ZHU Run-sheng, CHI Chang-qing, ZHANG Jian-bin
2001, 27(2): 206-208.
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The friction coefficient of ferromagnetic flow under boundary lubrication exhibits regular change in the presence of applied direct electric fields. The diverse effect of electric potential and magnetic field generated by direct electric current on the friction of ferromagnetic flow under boundary l...
Algorithm for Mixed Meshing Multiple Trimmed ParametricSurfaces for Finite Element Analysis
OUYANG Xing, SHI Fa-zhong
2001, 27(2): 209-212.
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According to the character of die shape, based on the mathematical model of multiple trimmed parametric surfaces, which is created by CAD/CAM system, an algorithm for generate mixed mesh of triangles and quadrilaterals for finite element analysis is presented. The trimmed parametric surfaces are dis...
Virtual Reality Simulation and Its Application on Aircraft Assembling
WANG Fei, YANG Xiang-long, FENG Yun-cheng
2001, 27(2): 213-216.
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The mechanism of virtual reality simulation is deeply discussed. By means of the popular VRML 3D constructing language to build virtual reality scene and objects, and Java general programming language to code the mobile engine, which not only can complete the normal numeric simulation but also drive...
Existence and Multiplicity of Positive Entire Solutions fora Class of Quasilinear Elliptic Equation
YANG Zuo-dong, LU Qi-shao
2001, 27(2): 217-220.
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With the Schauder-Tychonoff fixed point theorems as the principal tool, the theorems of existence and multiplicity of bounded positive entire solutions for a class quasilinear elliptic equations are established.In many articles, the theorems of existence and multiplicity of bounded positive entire s...
Application of Wavelet Transform to　Ground Echo-s Noise Processing
LI He-sheng, MAO Jian-qin, HAN Yu
2001, 27(2): 221-225.
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Based on the wavelet transform and its multiscale decompositions, it is possible to grasp the slight changes of characteristic information carried by image's edge on every scale. The laws have been analysed, which are followed by local maximal of wavelet transform modulus of white noise and continuo...
Design Method of a New Adaptive Fuzzy Controller
WANG Sheng-yuan, HUO Wei
2001, 27(2): 226-229.
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Based on analyzing disadvantages of the existing adaptive fuzzy control approach, a new design method of adaptive fuzzy controller(AFC) for a class of nonlinear systems is proposed. In order to ensure the consistency of the closed-loop system performances, before the AFC is applied, a supervisory co...
Numerical Algorithm for Calculating Lyapunov Exponents of Multibody Hamilton Systems with Topological Tree Configuration
JIN Li, WANG Qi, LU Qi-shao
2001, 27(2): 230-232.
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A numerical algorithm for calculating Lyapunov exponents of Hamiltonian multibody systems with topological tree configuration is studied. The algorithms for Lyapunov exponents of Hamiltonian multibody systems using the canonical equations of the system and symplectic algorithm for ordinary different...
Stability of Spinning Top Filled with Non-fully Rotating Liquid
WANG Shi-min, LI Lei
2001, 27(2): 233-236.
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In some liquid-filled spinning systems, although top stability conditions of frozen-liquid are satisfied theoretically, and the top nutation is not of resonant instability due to liquid inertia wave, angular motion of the rotating liquid-filled system is not stable in experiments. This phenomena can...
Early Software Reliability Prediction: an Approach Based on Fuzzy Neural Network
LIU Bin, LU Min-yan, RUAN Lian
2001, 27(2): 237-240.
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Based on the fuzzy neural network, an approach to early software reliability prediction is proposed. The reason of the software defects generated is analyzed and the factors which introduce the defects during software creation are presented. It is pointed out that fuzzy and using experience are the ...
Study on Software Reliability Parameters
LU Min-yan
2001, 27(2): 241-244.
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Abstract:

It is the first task in software reliability engineering to specify quantitative software reliability requirements. The meaning and properties of quantitative software reliability requirements are discussed. Based on the analysis of the general software reliability parameters, the software reliabili...
Study on Delay Model of Data Processingin Real Time for UCAV
JING Hua, QIU Xiao-hong
2001, 27(2): 245-248.
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The uninhabited combat aerial vehicles(UCAVs) is gradually becoming the research object in the area of aeronautics, the effectiveness and progressing of which depend on the method of its real-time management and control. A delay model of communication in the real-time mission planning of UCAVs is pr...

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