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2006 Vol. 32, No. 04

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Volterra series based transonic unsteady aerodynamics modeling
Wu Zhigang, Yang Chao
2006, 32(04): 373-376.
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To implement aeroservoelastic analysis and synthesis in transonic flow, an approach for transonic unsteady aerodynamics modeling by applying Volterra series theory is presented. Based on the assumption of small perturbation, transonic unsteady aerodynamics can be expressed approximately as one-order...
IPACS modeling and dynamical analysis of a flexible spacecraft
Zhang Jun, Xu Shijie
2006, 32(04): 377-381.
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The dynamical equations of a flexible spacecraft with VSCMGs (variable speed control moment gyroscopes) are established via the Lagrange equations in terms of quasi-coordinates and the momentum theorem. The equations are suitable for both attitude control law design and VSCMGs steering law design. S...
Particle simulation of ion thruster optical system based on PIC method
Liu Chang, Tang Haibin, Gu Zuo, Jiang Haocheng
2006, 32(04): 382-386.
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The plasma particle simulation of ion thruster optical system was carried out by the PIC (particle-in-cell) method. PIC method is an efficient method in plasma particle simulation, in which the SOR(successive over relaxation) method was adopted to calculate the electric field and the leap-frog metho...
Adaptive local time step method for DSMC code
Du Yongle, Yan Chao
2006, 32(04): 387-390.
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Theoretic analysis reveals that, ALTS(adaptive local time step) method offered by Laux, although greatly reducing the execution CPU time needed for the flow to reach to a steady state and thus leading to high simulation efficiency of DSMC(direct simulation of Monte Carlo) method codes, has some draw...
New algorithm of processing multi occultation and its application in infrared radiation calculation of military helicopter
Chen Haitao, Bian Enrong
2006, 32(04): 391-394.
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To solve the problem of calculating visible net area under any direction in infrared radiation calculation for military helicopter, a new algorithm based on stochastic simulation was proposed. By using surface modeling method, the helicopter's three-dimensional model was constructed and discretilize...
Noise density research in the system-modeling of RF receivers
Wang Qiong, Su Donglin, Xie Shuguo, Dai Fei
2006, 32(04): 395-398.
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A new method of noise analysis in RF (radio frequency) receivers is provided when the system modeling is required while only some limited parameters of the whole RF system are known. The analysis procedure of AWGN(additive white Gaussian noise) through noisy linear circuits is given in detail using ...
Series microscopy images fusion based on area wavelet transform
Jiang Zhiguo, Han Dongbing, Xue Bindang, Zhou Xiaokua
2006, 32(04): 399-403.
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Digital image fusion technique based on multi-focus series microscopy images is an effective method to extend the depth of focus. In order to avoid the blocking effect of fused image by spatial domain fusion algorithm when large focusing step is chosen or the image samples are transparent, a series ...
Product spectrum based target recognition using high resolution radar range profiles
Guo Zunhua, Li Shaohong
2006, 32(04): 404-406.
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To solve the problem of classifying the aircrafts using high resolution radar range profiles, the product spectrum which was used in the speech signal processing community was introduced to the radar target recognition community. The product spectrum was defined as the product of the power spectrum ...
Analysis of frequency stability of atomic clock under sinusoidal vibration
Cao Yu, Lü Shanwei, Feng Keming, Dang Qun
2006, 32(04): 407-411.
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Vibration effects on the atomic clock(atomic frequency standard) could be divided into three parts: atomic resonance effects, crystal oscillator effects and servo-loop effects. Within the vibration frequency, the phase noise of crystal oscillator under sinusoidal vibration was only related to accele...
Application of periodical structure in millimeter waveguide coaxial connecter
Zhou Yan, Su Donglin
2006, 32(04): 412-416.
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Waveguide coaxial connecter has been playing a very important role in microwave & millimeter-wave communications and tests. On the basis of the effects of PBG(photonic band-gap) structure and step impedance conversion structure in transmitting electromagnetic wave system, a novel waveguide coaxi...
Novel autofocus algorithm based on DCT for SAR images
Ma Lun, Liao Guisheng
2006, 32(04): 417-420.
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A novel autofocus algorithm for SAR(synthetic aperture radar) images is presented, which is based on DCT(discrete cosine transform). The method, which starts with complex phase-degraded SAR image, after phase errors model is introduced into the range-compressed phase-history domain, carries out phas...
Filter wheel device in solar X-EUV image telescope
Zhang Xin, Su Donglin, Li Baoquan, Wei Fei
2006, 32(04): 421-425.
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The solar X-EUV(X rays-extreme ultraviolet) imaging telescope is a solar shortwave imaging instrument, which can be used to monitor the solar activities and predict space weather. The solar X-EUV imaging telescope operates in the 0.4~10 nm X-ray waveband and the 19.5 nm EUV wavelength, and it can pr...
Microwave imaging by scattering
Li Liang, Miao Jungang, Jiang Yuesong, Li Zhiping
2006, 32(04): 426-429.
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A microwave imaging method, which can be applied in detection of concealed weapons and contraband and security in public situations, is presented. In the method, the radar scans on a rectangular plane, i.e. synthesizing a rectangular planar aperture.Synthetic aperture processing for radar data can i...
Fault injection system design based on BIT
Zhang Xiaojie, Wang Xiaofeng, Jin Man
2006, 32(04): 430-434.
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With the deep research and comprehensive application of BIT(built-in test), exigent demands for the validation and estimate have been brought forward, and this field becomes a new focus on research. Testing the performance of BIT through fault-injection is an effective method to validate its testing...
SAR imaging formation and geometric correction method based on diving model
Sun Bing, Zhou Yinqing, Chen Jie, Li Chunsheng
2006, 32(04): 435-439.
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The squint SAR(synthetic aperture radar) high resolution imaging formation and geometric correction method based on the diving model were studied. The general three-dimensional geometric model was founded based on the SAR movement mode. The equivalent squint range model was derived from this general...
Multi-channel Chirp Scaling algorithm for high-resolution multi-channel antenna space-borne SAR imaging
Wang Pengbo, Zhou Yinqing, Chen Jie, Li Chunshen
2006, 32(04): 440-444.
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Based on the analysis of the limitation that exists in the traditional imaging algorithms when processing the echo of high resolution multi-channel antenna space-borne SAR(Synthetic Aperture Radar), a novel MCCS(multi-channel Chirp Scaling algorithm) for high resolution multi-channel antenna space-b...
Quick method of distributed small satellite synthetic aperture radar single-look complex image simulation
Xu Huaping, Chen Jie, Wang Baofa, Zhou Yinqing
2006, 32(04): 445-449.
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The basic requirements for echo simulation of DSS-SAR(distributed small satellite synthetic aperture radar) were concluded. The geometry model and signal model of DSS-SAR were presented. Hill equation was employed to illustrate the configuration of small satellites. Single-look complex image signal ...
Investigation of probability failure assessing curve of steel used as pressure vessel material produced in China
Luo Hongyun, Zhang Yubo, Zhong Qunpeng
2006, 32(04): 450-454.
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Along with the development of the theory and the technology of PSA(probabilistic safety assessment),the theory and the technology has been used on the engineering field. But there are many problems that are not clear both in theory and technology of PSA. Probabilize of failure assessment curve is on...
Elastic properties for 3 dimensional and 5 directional braided composites
Lu Zixing, Liu Zixian
2006, 32(04): 455-460.
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According to actual braiding process and the micro-structural model of braiding preform, using stiffness averaging method, the stiffness matrix of 3D&5D(3 dimensional and 5 directional) braided composites is deduced and their elastic properties are calculated. On the basis of calculation,the cha...
Packing density of powder in paste with continuous grain size distribution
Huang Xin, Zhu Baolin, Guo Ye, Ma Baoguo
2006, 32(04): 461-465.
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The experimental result of measuring water requirements in paste under the same fluidity showed that there existed noticeable difference in packing density among the slag powders with different particle size distribution. By regarding the powder particles with the water film wrapping them as compoun...
Application of improved threshold denoising based on wavelet transform to ultrasonic signal processing
Chen Yi, Li Shu
2006, 32(04): 466-470.
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The signal to noise ratio of ultrasonic echoes signal was low, the echoes signal was submerged easily in ultrasonic testing, and wavelet transforms was an effective method by which the flaw echoes can be extracted. The mathematics model of ultrasonic echoes signal was established, including the flaw...
Embedded CNC system with the μc/os-Ⅱ OS
Wang Tianmiao, Chen Youdong, Sun Kai, Wei Hongxing
2006, 32(04): 471-474.
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An embedded CNC(computer numerical control) system and its hardware and software platform are presented. The system hardware consists of microcontroller ARM(advanced RISC machines) and FPGA(field programmable gate arrays). The CNC system application runs on the ARM, while FPGA is used to connect IO ...
Process parameters and limits in tube hydro-forming with axial feeding
Li Xinjun, Zhou Xianbin, Lang Lihui
2006, 32(04): 475-480.
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By using the viscous media, tube hydro forming with axial feeding was investigated. Based on the diffusion instability and plasticity theory, the distribution rules of the internal pressure were indicated and the relationship between the internal pressure and the axial loading were obtained with axi...
Numerical simulation of influence of two different hand-figures on swim propulsive efficiency
Kang Honglin, Yuan Wu, Gao Ruize, Yan Chao
2006, 32(04): 481-483.
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In order to find which hand-figures could provide higher propulsive efficiency for swimming, two different 3D unstructured grid models of a native woman swimmer’s hand and forearm were generated based on two hand-figures-fingers splaying and fingers holding together. The numerical technique of compu...
Research and implement of a grid job manager
Wang Yong, Xia Xianbo, Wan Yu, Hu Chunming
2006, 32(04): 484-488.
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With the development of grid and grid applications, more and more flow jobs have appeared. Definition, execution and management of jobs need the support of software system and the job manager is the core component. The job manager interprets the job definition and provides the monitor function. A jo...
Fast algorithm for pseudo random number generation in Linux user space
Gao Xiaopeng, Zhang Zhe, Liu Guoliang, Long Xiang
2006, 32(04): 489-493.
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RNGs(random number generators) are important building blocks for algorithms in security applications. They are paramount in construction of encryption keys. For security applications with key exchange in high frequency, the two RNGs provided by Linux kernel are not acceptable because of their low ef...
User oriented availability model of ethernet
Shi Jian, Wang Shaoping, Wei Zhenjin
2006, 32(04): 494-498.
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Carrier sensing random multiple access with collision detection protocol (CSMA/CD) can solve competition effectively and provide high throughput and low delay, so it has become an attractive protocol to the designers of local area net (LAN). Based on LAN’s CSMA/CD protocol analysis, the user oriente...

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