2008 Vol. 34, No. 09

Display Method:
Bionic design of column structure of machine tool for high specific stiffness
Yang Yongbin, Chen Wuyi, Zhao Dahai
2008, 34(09): 991-994.
Abstract:
Improving the specific stiffness of moving structure is important for the improvement of the machining accuracy and dynamic performance of high speed machine tools. Based on structural bionic theory, through study on the contribution of biologic skeleton to organism stiffness and the concept that bi...
Data analysis of reliability growth test for electronic equipments based on Fiducial inference
Yang Jun, Zhao Yu, Yu Dan
2008, 34(09): 995-998.
Abstract:
Reliability growth is an important part of reliability engineering, but for the problem that small samples are often occurred during reliability growth test, there is almost no effective method so far. To solve this problem, fiducial inference with restricted parameter space was studied, for non-loc...
Identification method for the material parameters of Al alloy under the condition of hypervelocity impact
Hu Zhendong, Huang Hai, Jia Guanghui
2008, 34(09): 999-1002.
Abstract:
In the research of hypervelocity impact, how to identify the metallic material’s parameters under the extreme distortions and high strain rate is a key problem. Steinberg strength model and Gruneisen equation of state were selected to describe the characteristics of Al6061 under the condition of hyp...
Detection and control of non-linear errors in 5-axis machining
Wang Dan, Chen Zhitong, Chen Wuyi
2008, 34(09): 1003-1006.
Abstract:
Non-linear error is an important source of the machining error in multi-axis numerical controlled machining and it is unavoidable. A new strategy to deal with the non-linear error was proposed based on the analysis of former work. In the new strategy the tool positions with large non-linear errors w...
Principle and application of vibration suction method
Nashun Buhe, Liu Rong, Yang Hao
2008, 34(09): 1007-1011.
Abstract:
Vibration suction is a kind of suction method for robots which was newly introduced by researchers. A new mathematical model of vibration suction was brought forward and a testing device was designed to measure the air pressure of the inner chamber of the suction cup. Experiments under different vib...
Application of improved PCA to thermal wave image processing
Sun Yanchun, Ma Qishuang, Liu Yueming, Yao Hongyu
2008, 34(09): 1012-1015.
Abstract:
To solve the problems less valid data in thermal infrared imager, uneasy dipartite corrosion area in image and lower the signal to noise ratio which happened in detection of structure parts- hidden corrosion by thermal wave imaging, the improved PCA (principal component analysis) based on the wavele...
Distortion correction for small-field space image based on star map matching
Zhang Chun, Qin Shiyin, Zhao Danpei, Liu Zunyan
2008, 34(09): 1016-1019.
Abstract:
Due to the impacts from launching vibrations and complex space environment, it is inevitable to generate some distortions in images by the small-field space imaging, moreover, the distortion model and parameters may also change sometimes. In fact, there would be a few or a sparse stars in a single s...
8mm band 2-dimensional synthetic aperture microwave radiometer (BHU-2D)
Xue Yong, Miao Jungang, Wan Guolong
2008, 34(09): 1020-1023.
Abstract:
The imaging principle, system structure and characteristics, calibration approach, several imaging experiments and imaging results of 2-dimensional synthetic aperture microwave radiometer BHU-2D (BeiHang University 2-Dimensional) were presented. BHU-2D operates at 8mm wave band and has 10 receiving...
Carrier synchronization method for digital terrestrial television system
Zhang Chao, Zhang Xiaolin, Zhang Shuai
2008, 34(09): 1024-1027.
Abstract:
According to the technique characteristic and frame structure of the China national standard for digital television terrestrial broadcasting system, a carrier synchronization scheme based on the pseudo noise (PN) frame header was presented. After the acquisition of PN frame header, the same PN seque...
Solution to switching angles for selective harmonic elimination inverter
Wu Jianwen, Wang Feng
2008, 34(09): 1028-1031.
Abstract:
Since the solution to switching angles for selective harmonic elimination inverter is difficult, a method of solution to switching angles based on complex optimal method with constrain conditions was presented,and the design method of objective function and constrain conditions was analyzed.This met...
Performance analysis and improvement on acutely defocused scenes
Sun Minglei, Shi Jingxin, Dong Dai, Zong Guanghua
2008, 34(09): 1032-1036.
Abstract:
Some classic focusing measures such as gradient function, Brenner function and entropy function, et al, show poor performance in computing high frequency energy in acutely defocused images. Their focusing curves away from the focus show serious nonmonotonicity. The Fourier transform method for image...
Improvement of remote user authentication schemes using passwords
Hu Ronglei, Liu Jianwei, Zhang Qishan
2008, 34(09): 1037-1040.
Abstract:
Password authentication scheme is a promising and practical solution to remote user authentication. The security of an authentication scheme using strong graphical passwords basing on hash function was analyzed. The scheme can not resist to stolen-verifier attack. The adversary can pretend to be a s...
Phase structure and magnetic properties of SmCo x-0.4 Ti0.4 ribbons
Zhang Yu, Yao Zan, Jiang Chengbao
2008, 34(09): 1041-1044.
Abstract:
SmCox-0.4Ti0.4(x=5.0,5.5,6.5 and 7.0) ribbons were prepared by melt-spinning at a wheel speed of 42m/s, followed by annealing at 750℃ for 2 h.The phase structure and magnetic properties were measured for two types of ribbons, the as-spun and the as-spun/annealed. It was found that the phase struct...
Discussion of a data integration mechanism with data integrality
Yang Yongqiang, Ma Shilong, Jin Wen
2008, 34(09): 1045-1048.
Abstract:
At present, the enterprise data is often scattered in various independent business systems, therefore the unified data management and integration is not well realized. Based on the analysis of the distributed and heterogeneous data characteristics, a data integration system with data integrality was...
Simulation on bistatic RCS measurement method in anechoic chamber
Li Zhiping, He Guoyu
2008, 34(09): 1049-1052.
Abstract:
An method was presented to measure bistatic RCS in anechoic chamber. The target was illuminated by compact antenna test range (CATR), and the scattered field was probed in near-field. The transformation from near-field to far-field (N2F) was analyzed by antennas coupling equation, plane wave synthes...
Quantitative evaluation on characteristic index of post-stall maneuvers fighter
Zhang Li, Wang Lixin, Fu Yang
2008, 34(09): 1053-1056.
Abstract:
The post-stall maneuver can effectively improve the fighter-s ability of air-combat and survival. The dynamic equations of high angle of attack with thrust vector using quaternion method were built. According to the purpose of post-stall maneuver -changing nose pointing, and combining maneuverabilit...
Decentralized optimal control of coordination target awareness with multiple vehicles
Wu Wenman, Zhou Rui
2008, 34(09): 1057-1060.
Abstract:
The centralized coordination control of multiple vehicles was difficult to implement since the highly distributed information and computation, the vehicles motion, and the changing information networks topology. The decentralized coordination control was scalable, heterogeneous, reconfigurable, and ...
Tetrahedron-based constructing 3D_streamlines in visualization
Yang Guang, Cheng Shiming
2008, 34(09): 1061-1064.
Abstract:
Streamline is an important technique in computational fluid dynamics for vector visualization. This algorithm is based on tetrahedron cells. Firstly, hexahedron cells in data field of point cloud were divided into tetrahedron cells. Tetrahedron relations between the adjacent tetrahedron were stored,...
Directional adaptive diamond search for motion estimation
Li Rong, Zhang Qishan, Yang Dongkai
2008, 34(09): 1065-1069.
Abstract:
Based on the research of motion vector distribution, a novel directional adaptive diamond search (DADS) algorithm was proposed. This algorithm adopted three strategies: the initial search point prediction strategy, the early search termination strategy, and the directional adaptive diamond search st...
Error-predictable adaptive dead reckoning algorithm
Zhou Zhong, Wei Sheng, Zhang Guofeng, Wu Wei
2008, 34(09): 1070-1075.
Abstract:
A dead reckoning algorithm was presented which is suitable for first-person shooting games. Avatars- moving directions change frequently and their traces consist of continuous broken lines. According to the features, first order derivative polynomial and linear convergence algorithms were selected f...
Gust load alleviation control of aircraft with large ratio flying wing configuration
Gao Jie, Wang Lixin, Zhou Kun
2008, 34(09): 1076-1079.
Abstract:
The configuration of flying wing aircraft with large aspect ratio is advantageous on the characteristic of aerodynamics and stealth, but due to lack of conventional elevator and rudder, gust load alleviation control method for the aircraft with conventional configuration is not suitable anymore. The...
Low hysteresis brush seal numerical simulations
Wang Zhili, Liang Xiaofeng, Song Fei, Huang Qiwu
2008, 34(09): 1080-1083.
Abstract:
In order to establish the calculation model of low hysteresis, an anisotropic porous model contained with the bristles bending deflections was employed based on the physical structure of low hysteresis brush seal. The effect of the bristles in the seal was considered a resistance force and was added...
Time management of RTI based on negotiation group
Lü Fang, Fang Zhou, Zhong Wei, Sheng Wu
2008, 34(09): 1084-1087.
Abstract:
Aimed at the problems existed in the time management of run-time infrastructure(RTI) at the present time, a method of time management of RTI based on negotiation group was brought forward and applied in the time management service of BH RTI 2.3, which was conducted to solve the problems such as low ...
Simulation analysis of plastic deformation and residual stress distribution of radial ring rolling
Zhao Xiaoci, Zhang Yidu, Zhang Hongwei
2008, 34(09): 1088-1091.
Abstract:
To eliminate the residual stress formed during the process of ring rolling, the radial ring rolling was simulated by elas-plastics large deformation finite element analysis. Al alloy rings with rectangular cross-section were adopted as workpieces and total depressing amounts of mandrel with differen...
Multi-phase trajectory collaborative optimization for a hypersonic vehicle
Zhou Hao, Chen Wanchun, Yin Xingliang
2008, 34(09): 1092-1095.
Abstract:
A approach was proposed to solve multi-phase trajectory optimization problem. The approach allowed the trajectory for hypersonic vehicle in vertical plane dividing into several phase, then obtained the multi-phase trajectory optimal value by collaborative optimization method. Only the transitional p...
Double gimbal control moment gyroscopes singularity analysis
Lu Songtao, Wang Lei, Zhao Yushan
2008, 34(09): 1096-1100.
Abstract:
Aimed at analyzing the singularity of double gimbal control moment gyroscopes(DGCMGs), a gimbal reference frame, an ε-δ definition of apparent and concealed singular points, three sorts of singular points, system momentum taylor series expanded formula at singular point and a determination of null m...
Measures of effectiveness for blinking jamming under airborne self-protection operations
Gao Bin, Han Ke
2008, 34(09): 1101-1104.
Abstract:
According to blinking jamming on analysis and modeling about operation procedure of blinking jamming, the measures of effectiveness for blinking jamming against angle guided missiles using radar seekers were evaluated by relational index. Firstly, the basic principle of blinking jamming was obtained...
Application of unified hardening model under complex loading
Hou Wei, Yao Yangping
2008, 34(09): 1105-1108.
Abstract:
The overconsolidated clay model, a simple and applied model, can describe many characteristics of overconsolidated clays well, including stress-strain relationships, stress dilatancy, strain hardening and softening, and path dependency behaviour. Compared with the Cam-clay model, the overconsolidate...
Novel technique to manufacture short millimeter wave band corrugated horn antenna
Bai Bing, Miao Jungang, Cui Yanjun
2008, 34(09): 1109-1112.
Abstract:
In short-millimeter band quasi-optical network, it is a difficult problem to design and manufacture corrugated horn antennas acting as Gaussian feeds because of the accuracy of classical manufacture methods. The dimension design methods for corrugated horns were presented in term of the expected Gau...
Video vehicle detection algorithm based on edge symmetry
Gao Lei, Li Chao, Zhu Chengjun, Xiong Zhang
2008, 34(09): 1113-1116.
Abstract:
The existing vehicle detection algorithms are subject to many environmental influences, such as different lighting conditions, shadows. To solve these problems, a novel vehicle detection algorithm was proposed. Different from traditional methods, which use motion features to detect vehicles, the pro...