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2009 Vol. 35, No. 5

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Influence of wing location on rotor-wing interaction of compound helicopter
Wan Jia, Chen Ming
2009, 35(5): 519-522.
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The compound helicopter has gained more and more attentions so far, but the analysis method available is limited. Employing the free-wake arithmetic and vortex lattice method(VLM), a program for compound helicopter aerodynamic computation was developed. Using this program, interactions between the r...
Way to study one-dimensional numerical simulation of aero engine
Chang Zhonghong, Zhu Zhili, Tang Hailong
2009, 35(5): 523-526.
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One-dimensional aerodynamic thermodynamic mathematic models for each component of aero engine were formulated. This model can be used to estimate the components and full engine system-s performance. A full engine flow simulation was done by applying this model. Viscous effects of the gas and seconda...
Cooling structure on double-web turbine disk with equal mass scheme
Zhao Xi, Xu Guoqiang, Luo Xiang, Deng Hongwu
2009, 35(5): 527-531.
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Numeration analysis was made to simulate the flow and heat transfer in the double-web turbine disk. Several cooling structures of double-web turbine disk with different radial inlet position were proposed based on the same weight as a simplified solid disk. The calculated results present that: struc...
Approximation model for reliability analysis based on GA-BP Bayesian algorithm
Ren Yuan, Bai Guangchen
2009, 35(5): 532-535.
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The usefulness of genetic algorithm-backpropagation(GA-BP) Bayesian algorithm was studied and evaluated for reliability simulation. GA-BP Bayesian algorithm is a algorithm to train feedforward neural networks, and it is based on GA, L-M (Levenberg-Marquardt) BP, and Bayesian method. The algorithm tr...
Numerical simulation of pulverized-coal combustion
Zhang Hongbo, Qin Guotong, Ji Renshan, Wang Naiji
2009, 35(5): 536-539.
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The comparative study between CFD numerical results of pulverized coal combustion process and the experimental data is becoming an important measure for validating mathematical models and direct engineering practice. The CFD commercial software, FLUENT, was used to simulate the pulverized coal flow ...
Effects of rare-earth (RE) elements on crystallization behavior of Al-Ni-Gd-Y amorphous alloy
Song Honghai, Duan Huiping, Ma Chaoli, Zhang Tao
2009, 35(5): 540-543.
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The effects of rare-earth (RE) elements on the crystallization behavior of Al-Ni-Gd-Y amorphous alloy were investigated by differential scanning calorimetry(DSC), X-ray diffraction(XRD) and transmission electron microscopy(TEM). The first crystallization temperature of Al-Ni-Gd-Y amorphous alloy inc...
Unsupervised classification approach based on graph-segment for multispectral remote sensing images
Liu Nana, Li Jingwen, Li Ning
2009, 35(5): 544-546.
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To solving the noisy points and high cost problems of pixel-based multispectral image classification, a hybrid unsupervised approach with graph-based segment and fuzzy c-means clustering was presented. First, based on the relationships among neighboring pixels, image was segmented into groups of sub...
Optimization of near-space aerocraft track for regional coverage based on greedy algorithm
Chen Rongguang, Li Chunsheng, Chen Jie, Yu Ze
2009, 35(5): 547-550.
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In order to covering any discretionary polygonal region,a novel method was proposed based on set covering problem model, which is a NP-hard problem. Random greedy algorithm strategy was applied in the method to achieve 100% regional coverage with minimum aerocrafts by designing and optimizing each a...
Modeling of GPS multi-path signals and receiver testing
Yang Wei, Zhao Yun, Kou Yanhong, Huang Zhigang
2009, 35(5): 551-554.
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The multi-path effect is one of the most important sources of positioning errors for global positioning system (GPS) and other satellite navigational systems. Multi-path signal modeling and its mitigation techniques have always been hot spots in the satellite navigation research direction. According...
Design and implementation of IF signal modulator for GNSS signal simulator
Zhang Shuo, Kou Yanhong
2009, 35(5): 555-558.
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Global navigation satellite system(GNSS) signal simulator can simulate satellite signals received by target receivers in high fidelity according to the signal structure, dynamics of the receiver and environmental parameters defined by users, which provides an effective way for both GNSS system-level...
Novel chaotic frequency modulation circuit for class-D amplifier
Feng Wei, Li Hongge, Zhang Youguang
2009, 35(5): 559-562.
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The easy to be integrated chaotic frequency modulation circuit for class-D amplifier was proposed to solve electromagnetic interference(EMI) issue. In the circuit, an improved chaotic sequence generator was designed and its chaotic behavior was modeled by stroboscopic map. The proposed circuit only ...
3D laser scanning algorithm with humanoid-eye function
Chen Weihai, Song Weiyang, Rong Lixia, Liu Jingmeng
2009, 35(5): 563-566.
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Aiming at the scanning efficiency of three dimensional (3D) laser scanning system for mobile robot all over the world, a humanoid-eye 3D laser scanning algorithm was proposed. Imitating the scanning function of human eyes from bionics, this algorithm divides the scanning process into two steps: acco...
Design and realization of a prototype of software GPS receiver
Liu Jie, Fu Li, Wang Linlin
2009, 35(5): 567-571.
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A prototype of software global positioning system(GPS) receiver based on software defined radio techniques to design a flexible and reconfigurable receiver with a wide range of applications was discussed. Compared with hardware GPS receiver, there is a need for a unified platform that allows softwar...
Quadric error metrics for mesh simplification based on feature matrix
Chen Weihai, Xu Lihong, Liu Jingmeng, Wang Jianhua
2009, 35(5): 572-575.
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Contraposing the some deficiencies from the algorithm based on quadric error metrics (QEM), such as neglect of some cusp features and excessive simplification in some parts of the model, a QEM based on eigenmatrix was proposed for mesh simplification. Through introducing the curvature and edge lengt...
Model of stepped leader current for simulation of lightning
Liu Ning, Xiao Chunyan
2009, 35(5): 576-579.
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Model of stepped leader current is the basis of lightning movement simulation and strike analysis, and it is indispensable for lightning protection design, theoretical research of shielding failure for transmission lines, etc.. Physical model of stepped leader was given, which includes a main channe...
Instrumentation in flight-control software testing
Li Yuefei, Guo Junhong, Bai Chenggang, Cai Kaiyuan
2009, 35(5): 580-583.
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Instrumentation is one of the important techniques in the software testing. When instrumentation was applied in the flight-control software testing, the real-time performance of the original software becomes bad even lead to failure of the software, due to the extra spending on the instrumentations....
Fuzzy guidance law for wire-guidance torpedo under condition of incomplete information
Zhang Xiaogong, Ren Zhang, Wang Xinyuan
2009, 35(5): 584-587.
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A fuzzy guidance technique under the condition of incomplete information was proposed to solve the problem that the commonly used guidance methods can not provide very good solution for the incomplete information of targets.Based on the deeply analysis of the function on artificial-intelligence(AI) ...
Numerical aerodynamic computation of unmanned aerial vehicle
Zhao Guochen, Wang Chaozhi
2009, 35(5): 588-590.
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Numerical simulation of an unmanned aerial vehicle (UAV) was carried out by 3D modeling and computational fluid dynamics (CFD) software, and then the coefficients of lift, drag and moment with a small angle of attack (AoA) variety as well as the distribution of pressure,density and velocity on the s...
Numerical simulation of three dimension viscous flow of combustion-heater used for scramjet test
Chen Chaoqun, Wei Baoxi, Zhang Chengliang, Xu Xu
2009, 35(5): 591-595.
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The combustion-heater was used to get high enthalpy, high mach number flow field in scramjet test. The injection is very important for the uniformity of the out-flow field. A three dimension numerical simulation software named Fluent was used to calculate the two injection. By examining the injectio...
Lambert transfer based on ant colony algorithm and Powell-s method
Gao Xiaobo, Dong Yunfeng, Su Jianmin
2009, 35(5): 596-599.
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The optimization of Lambert two-impulse orbital transfer with unfixed two impulses time was studied. The goal was to find the optimal two impulses time to minimize the weighted sum of consumed fuel and transfer time. Because traditional optimization algorithms were difficult to get global optimal re...
Constitutive equations of high strength aluminum alloy sheet 7B04-T6 under warm tension
Zhang Zhi, Lang Lihui, Li Tao, Liu Hejun
2009, 35(5): 600-603.
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Warm tensile tests for high strength aluminum alloy 7B04-T6 sheet were held at condition of elevated temperature and different strain rates. The range of temperature is 293~573K and the strain rate is 0.0006~0.06s-1. The warm tensile properties, relation between temperature, strain rate and the f...
Experiment and analysis on sound absorption characteristics of metal rubber
Ma Yanhong, Li Haoyu, Li Yifeng, Hong Jie
2009, 35(5): 604-607.
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According to the established sound absorption model of metal rubber(MR), the measurement and research for the coefficient and acoustic impedance of MR, which is of different parameters, were carried. The influencing laws of MR-s structural parameters (such as wire diameter, thickness, porosity, cavi...
Key factors analysis of wall-climbing robot
Liu Rong, Tian Lin
2009, 35(5): 608-611.
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A kind of negative pressure wall-climbing robot was proposed. Analysis the relationship between speed of vacuum motor and negative pressure which based on courses of pressure form and pressure keep, and found that interspace height between airproof gasbag and wall was the key factor influencing on t...
Site measuring accuracy testing of laser tracker
Gan Lin, Li Xiaoxing
2009, 35(5): 612-614.
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Laser tracker has the advantages of high precision, real-time, dynamic and easy to be moved etc. The site calibration and accuracy testing of the laser tracker are very necessary in actual measurement. The error of fixed points and the plane error of standard granite set square was measured by the L...
Optimal design of shell-and-tube heat exchanger
Yang Ming, Meng Xiaofeng, Zhang Weijun
2009, 35(5): 615-617.
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The optimal design of the heat exchanger structure is a coupling problem with several parameters. Exchanger cubage and the pressure loss of the exchanger performance factors was selected as the optimal object. In the condition of moist air and water heat exchange, the heat transfer and pressure loss...
Sensing theory of fiber optic intrusion sensor based on multimode fiber intensity modulation
Li Chenguang, Yang Dewei, Luo Guangming, Li Chen
2009, 35(5): 618-622.
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An intrusion sensor adopting a "single-mode multimode single-mode" (SMS)structure was introduced. The actual sensor element was the multimode fiber spliced to two single-mode fibers on its two ends. In order to improve the sensing sensitivity, the theory of intensity modulation was researched. High ...
Algorithm for video shot clustering based on spectral division
Zhong Lin, Li Chao, Xue Ling, Xiong Zhang
2009, 35(5): 623-626.
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A spectral-division unsupervised shot-clustering algorithm (SDUSC) was proposed. First, the keyframes were picked out to represent the shots, and the color features of keyframes were extracted to describe the video shots. In order to characterize shots optimally, a spherical gaussian model (SGM) was...
Method of processor resources virtualization on cluster
Liu Zhonglin, Xiao Limin, Hao Qinfen, Zhu Mingfa
2009, 35(5): 627-630.
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In order to make the processor resources in multiple servers of cluster be utilized to operating system transparently, the processor resources virtualization scheme in distributed virtual machine monitor was proposed. That is to make each server provide a certain amount of virtual processors based o...
Coverage quality problem in wireless sensor networks
Zhang Shuo, Pu Juhua, Liu Yuheng, Xiong Zhang
2009, 35(5): 631-635.
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Extending lifetime by scheduling node state and maintaining the coverage quality are two important aspects in wireless sensor networks (WSNs). It was presented a mathematical model to compute minimum number of nodes under any given required coverage quality. Simulation results demonstrate that our a...
Adaptive aberrant network traffic detection algorithm based on time series forecast
Lü Junhui, Zhou Gang, Jin Yi
2009, 35(5): 636-639.
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The traditional network management tools usually detect aberrant network traffic according to the preset threshold. This method is straightforward, but it has poor adaptability. Therefore, A mature aberrant detection method called Holt-Winters based on the time series forecast was described. But it ...
Effective algorithm for mining compressed frequent patterns
Tong Yongxin, Ma Shilong, Li Yu
2009, 35(5): 640-643.
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Researches of frequent-pattern mining have recently focused on discovering representative patterns to compress a large of results within a reasonable tolerance bound. A novel heuristic algorithm, approximating mining based simulated annealing (AMSA), was proposed. The algorithm uses a method based s...
Performance reliability assessment for products based on time series analysis
You Qi, Zhao Yu, Ma Xiaobing
2009, 35(5): 644-648.
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Time series model has the advantage of strong self-adjustment for stochastic process and high precision for prediction. For the high-reliability and long-life products in the field of aeronautics and astronautics, two methods based on time series model were proposed to evaluate reliability and predi...
Trafficability of rigid wheel on moon by model experiment
Gong Yongtao, Gao Feng, Li Wen, Sun Peng
2009, 35(5): 649-652.
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Based on a tractive performance test-bed for planetary rover wheel, remodeled lunar simulant as a medium, the interaction between the rigid lugged wheel of lunar rover vehicle and lunar simulant was studied. The influence on trafficability which are brought by rotating speed and wheel load, was anal...
Theoretical analysis on sound absorption characteristics of metal rubber
Ma Yanhong, Hong Jie, Li Haoyu, Li Yifeng
2009, 35(5): 653-656.
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The theoretical research on sound absorption characteristic of metal rubber (MR) was performed. On the basis of Rayleigh model and according to the sound propagation theory in pipe and the principle of Helmholtz, the acoustic model of MR was established, and formula of absorption coefficient was der...

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