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2004 Vol. 30, No. 08

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Investigation of separation mechanism for airfoil leading edge flow at low Reynolds number
Ye Jian, Zou Zhengping, Lu Lipeng, Yang Lin
2004, 30(08): 693-697.
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Abstract:
A direct numerical simulation (DNS) around a 2-D airfoil was carried out through high order finite difference scheme, the Reynolds number based on chord is 1.0×104, the angle of attack is 3°. Via analyzing the quasi-periodic numerical solutions, the separation mechanism of leading edge flow at low R...
X-ray flat-panel-detector-based digital radiography and its image calibration
Zhou Zhenggan, Teng Shenghua, Jiang Wei, An Zhengang
2004, 30(08): 698-701.
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Abstract:
To improve imaging quality of X-ray digital radiography system, an X-ray flat-panel-detector-based digital radiography system was investigated. Four factors of flat panel detector which degrade image quality, such as random noise, offset, response nonuniformity and defective pixels, were introduced....
Analysis of vibration error in digital closed-loop fiber optic gyroscope
Song Ningfang, Zhang Chunxi, Li Lijing, Lin Heng
2004, 30(08): 702-704.
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Abstract:
Vibration error of fiber optic gyro affect its application performance directly. In order to solve the problem, the main causes of vibration error were analyzed. The expression between the closed-loop gyro output and optical power was conducted, The conclusion is that The inner stress of the fiber c...
Research on the pneumatic position servo system for climbing robot
Zhang Houxiang, Liu Rong, Wang Wei, Zong Guanghua
2004, 30(08): 705-708.
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Abstract:
To meet the requirements of glass-wall cleaning for high-rise buildings, a pneumatically actuated climbing robot has been developed. However, the characteristics of low-stiffness and nonlinearity in pneumatic system make accuratecylinder position control difficulty. To solve this problem, a new bang...
Aeroservoelastic stability on roll loop of a missile
Wang Jingyan, Yang Chao, Wu Zhigang
2004, 30(08): 709-712.
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Abstract:
Flexible air vehicles may encounter aeroservoelastic instability which is induced by the adverse coupling between structure, aerodynamics and controllers. Aeroservoelastic stability on roll loop of a missile with differential rudders and control system is analyzed. The generalized unsteady aerodynam...
Experimental investigations on improvement of AO-resistant of epoxy resin by filled with superfine cenospheres
Wang Mingzhu, Zhao Xiaohu, Shen Zhigang, Xing Yushan
2004, 30(08): 713-717.
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Abstract:
A new method of improving AO-resistant characteristics of spacecraft resins is proposed. The superfine particles, which are stable in AO environment, are filled in the spacecraft resin in order to improve the AO-resistant characteristics of the composite. The emphasis of this paper is filling superf...
Auto-correlation function based estimation of the fractal dimension of natural texture images
Wang Hua, Wang Qi, Sun Jinwei
2004, 30(08): 718-722.
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Abstract:
A novel method for estimating the fractal dimension has been proposed and the method has been applied to estimate the fractal dimension in natural texture images. Fractal dimension is an important parameter to characterize roughness in an image. Extending the basic theory of fractional Brownian moti...
Research on integrated control and supervision of engineering vehicles based on Agent
Yuan Haibin, Li Yunhua, Yang Liman
2004, 30(08): 723-726.
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Abstract:
An Agent-based distributed network control system was proposed, aiming at the requirement of control and supervision for undertaking complex and mission-critic workload in engineering vehicles and construct machinery. The system architecture, component, functionality of Agent-based integrated intell...
Visco-plastic constitutive modeling of inelastic deformation of Udimet 720 Li at high temperature
Shi Duoqi, Yang Xiaoguang, Wang Yanrong
2004, 30(08): 727-731.
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Abstract:
The mechanical deformations of a Nickel-based superalloy Udimet 720 Li was modeled simultaneously by the Chaboche unified viscoplastic constitutive theory under tensile, cyclic and creep loading conditions at 700℃. To describing the phenomena of cyclic relaxation of mean stress under strain controll...
Performance of smart antenna when coupling and excitation error are considered
Li Miao, Lü Shanwei, Xue Minghua, Zhang Lei
2004, 30(08): 732-734.
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Abstract:
The performance of smart antenna in DS/CDMA(direct sequence/code division multiple access) systems is investigated when there are mutual coupling and/or excitation error which is compared with that in ideal situations. As an example, it is shown from the simulation that for adaptive arrays with half...
Fuzzy adaptive Kalman filtering for spacecraft celestial navigation
Zhang Yu, Fang Jiancheng
2004, 30(08): 735-738.
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Abstract:
High positioning precision can be obtained by autonomous navigation method based on indirectly sensing horizon by stellar atmospheric refraction. Because of the limited resolution of the atmosphere density model, large instantaneous error would occur in the horizon sensed by this method. In this cas...
Experimental study on single-phase flow and heat transfer for FC-72 in rectangular microchannels
Xie Yongqi, Yu Jianzu, Zhao Zenghui, Qin Yan
2004, 30(08): 739-743.
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Abstract:
The microchannel heat sink provides an efficient method to solve thermal control problems of the aviation electronic components. The experiment of single-phaseflow and forced convective heat transfer was carried out with FC-72 which was agood prospective electronic cooling fluid. Four rectangular mi...
Error block performance analysis for SDH based on background noise or impulse disturbing
Liu Xingchun, Li Zheng
2004, 30(08): 744-747.
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Abstract:
The error code performance is one of the most important transmission performances for optical fiber digital transmission system. And for synchronous digital hierarchy(SDH), the error block performance is usually used to describe error code performance. The error block performance under the inference...
Multi-model Kalman filter algorism based on GA
Wang Ziliang, Fang Jiancheng, Quan Wei
2004, 30(08): 748-752.
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Abstract:
A multi-model Kalman filter based on GA(genetic algorism) was designed. When the parameter is imprecise, estimation results of Kalman filter are false.Method used in this paper can estimate the best parameters on line,so as to get true estimation results.At the end of this paper the application to i...
Evaluation of fatigue lives for civil aircraft structures under corrosive condition
Liu Wen, Yang Hongyuan, He Xiaofan
2004, 30(08): 753-756.
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Abstract:
A method evaluating fatigue lives for civil aircraft structures under corrosive environment was presented. The service process of civil aircraft structures was simplified to two independent parts: pre-corrosion on the ground and in the air environment, corrosion fatigue in the air. All these effect ...
Application of predictive Fuzzy-PID in center air adjusting control system
Pang Liping, Wang Jun, Liu Wangkai
2004, 30(08): 757-761.
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Abstract:
The electrical heating element is often used in center air adjusting system. It is installed in the end of air supply duct system and can improve the control precision of temperature by combining with other elements in center air adjusting system. The temperature control method of electrical heating...
Study on GPS timing and frequency calibration method and the test results
Zhao Junxiang, Li Jianhui, Chang Qing, Zhang Qishan
2004, 30(08): 762-766.
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Abstract:
To solve the problem of time synchronization and frequency calibration among different stations in an integrated multi-target tracking system, two methods using global positioning system(GPS) through observing one or more GPS satellites in common view are put forward. Calculation formulas are derive...
Application of boundary-tracing and Freeman code in quantitative metallography
Yu Yang, Liu Erli, Zhou Tietao, Liu Peiying
2004, 30(08): 767-770.
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Abstract:
The grainy second phase of multi-phase alloy was processed by various image pretreatments according to different conditions to obtain binary image of the discreet multi-object. These image pretreatments include two-value transformation, grain segmentation, hole-filling and filtering. To analyze the ...
Ecological organizational model on workflow system
Wan Liangjun, Huai Jinpeng
2004, 30(08): 771-776.
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Abstract:
In order to solve the problem of lacking structure flexibility and changing initiative in traditional organizational models, the weaknesses in existing researching works was summarized and an ecological organizational model was put forward. Essential factors of ecological organizational model was in...
Research of new conceptive rotated ramjet
Wang Yun, Zhao Xiaolu, Xu Jianzhong, Ang Haisong
2004, 30(08): 777-782.
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Abstract:
To solve the problems which the performance and cost of the gas turbine are restricted by structure and material and the ramjet can not be used independently and can be used on ground, a new conceptive rotated ramjet based on the ram-compressed technology was presented by analyzed the structures of ...
Effects of defects on the tensile strength of rigid polyurethane foamed plastics
Lu Zixing, Shi Shanglu, Wang Jianhua
2004, 30(08): 783-786.
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Abstract:
The tensile tests have been done for different densities polyurethane rigid foam (PURF) specimens with and without defects. On the basis of experiments, the strength of PURF is investigated and the effects of defect with different kind and different size on the ultimate strength of PURF are discusse...
Study on the simulation of the temperature field of sintering complex ceramics parts
Wang Su, Chen Jia, Li Jianming
2004, 30(08): 787-790.
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Abstract:
As the applied fields of ceramics enlarged, the quality of the ceramics parts was needed higher and higher. However, the designing and the manufacturing of the ceramics parts were separated, and the designing resolution had to be amended many times before it became the final resolution. In order to ...
Synthesizing algorithm for mining composite-frequent item sets
Li Guohe, Zhao Qinping, Wang Xi
2004, 30(08): 791-796.
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Abstract:
It is very important to get the frequent item set in the associate rule mining. In order to fast obtain the frequent item set from a database that includes multiple values, the definition of transaction database was extended. And then by the tree concept, a special tree was built in which every node...
Process model for software testing based on game theory
Cui Xiaole, Wang Yichen, Ruan Lian
2004, 30(08): 797-802.
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Abstract:
To analysis the dynamic process of software testing and the relationship of relevant factors in it, a new method on modeling and analysis of software testing process with the game theory was provided. A game model of software testing process was established and a series of analysis were made on deci...

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