2001 Vol.19

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Synchronizing Chaos via APD and Activeoccasional Coupling LI Guo-hui, XU De-ming, ZHOU Shi-ping, LAI Jian-wen Journal of Applied Sciences    2001, 19 (1): 1-4.   Abstract （321）      PDF（pc） （181KB）（87）       Knowledge map    Save We have realized Henon synchronization via APD synchronization, in which we acquired synchronization of identical systems. The nonsynchronization of unidentical systems makes the method potentially useful in secure communication. Because chaos synchronization by coupling continuously is not easy, we realized Henon synchronization by occasional coupling synchronization. As long as the synchronization phases exceed the critical value, synchronizing Henon mapping by occasional coupling can be obtained. The same results have also been achieved by synchronizing Henon-like. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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MQAM Digital Communication Adaptive Equalizers Using Wavelet Networks ZHANG Guo-an, ZHANG Xiao-dong, BI Guang-guo Journal of Applied Sciences    2001, 19 (1): 5-9.   Abstract （323）      PDF（pc） （218KB）（130）       Knowledge map    Save In this paper, a novel wavelet network based adaptive equalizer (WNBAE) is presented. The structure and stochastic gradient learning algorithm of the WNBAE is given. In the MQAM digital communication reception systems over nonlinear channels the proposed WNBAE has better performance than that of the conventional linear transversal equalizer based on the LMS or the RLS algorithms, as well as that of the decision feedback equalizer based on the RLS algorithm. It outperforms slightly the back propagation network based adaptive equalizer. Several simulations are performed to evaluate the behavior of the WNBAE. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Transmission Characteristics of Taper TEM Cell CUI Fu-rong, LAI Sheng-li, JI Fei, HU Bing-jie Journal of Applied Sciences    2001, 19 (1): 10-13.   Abstract （302）      PDF（pc） （174KB）（110）       Knowledge map    Save This paper analyzes a new type of taper TEM cell using FDTD method in the spherical coordinate. The field distribution, field uniform and the upper work frequency have been analyzed. The results prove very important to the design and application of taper TEM cell. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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A Trial Research on the Design and Decision Expert System of Land Rational Use FU Wei Journal of Applied Sciences    2001, 19 (1): 14-19.   Abstract （272）      PDF（pc） （249KB）（80）       Knowledge map    Save This paper presents the approaches and principles for building design and decision expert system of land rational use (DDES). The system can be used to evaluate and decide the plan on the geo expert level for the rational use of land. Furthermore, several practical suggestions can be obtained by consulting the system, so that the users can select an effective plan for utilizing the land. By citing the formulation of the DDES of the Urumqi River basin as an example, the author expounds the method to express expert knowledge of planning and decision for rational use of the land in the basin as well as the basic rules to express the knowledge contained in the expert system and the organization modes of expert knowledge in the knowledge base. In addition, the author discusses the design principles and organization method of inference rules and the inference algorithms. Related Articles | Metrics | Comments（0） Cited: Baidu(7)

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An All-digital Receiver for Mobile Satellite Burst Communication CHEN Yin-jian, LI Li, Li Guo-tong, LIANG Xu-wen, YANG Gen-qing Journal of Applied Sciences    2001, 19 (1): 20-23.   Abstract （258）      PDF（pc） （183KB）（167）       Knowledge map    Save Mobile satellite burst communication operates under severe noise conditions, large Doppler offset, fast Doppler frequency shifts, and multi-path fading, so synchronization in receiver becomes very difficult, especially when the burst frame is too short. This paper proposes a new all-digital receiver structure, which relies on FFT-based burst acquisition and non-coherent detection. Simulation results demonstrate that the receiver can work under large frequency offset and have short acquisition time, so that can be used in mobile satellite burst communication. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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A New Kind of Absorbing Boundary Condition and Its Application for 3-D TLM Method SHAO Zhen-hai, ZHU Chen-dong, HONG Wei, HE Li-quan Journal of Applied Sciences    2001, 19 (1): 24-28.   Abstract （294）      PDF（pc） （214KB）（88）       Knowledge map    Save A new kind of absorbing boundary conditions based on the theory of generalized Z-domain absorbing boundary conditions (Z-ABCs) for the 3D TLM SCN method is presented. The results indicate that the Z-ABCs show better performance than Higdon's ABC in suppressing instability caused by spurious modes. The different order coefficients of this new Z-ABCs can be given by a recurrence formula. Related Articles | Metrics | Comments（0）

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The Learning Algorithm of the Second Order HMM and Its Relationship with the First Order HMM SHI Xiao-xing, WANG Tai-jun, HE Zhen-ya Journal of Applied Sciences    2001, 19 (1): 29-32.   Abstract （385）      PDF（pc） （169KB）（99）       Knowledge map    Save In this paper, we investigate the learning algorithm of the second order HMM (HMM2), which includes the forward variable algorithm, backward variable algorithm, Viterbi algorithm and Baum-Welch algorithm. Meanwhile, we study the relationship between the HMM2 and the first order HMM (HMM1), and find that for any HMM2 there always exists a HMM1 which is equal to the HMM2. We propose and prove the equivalent theorem of the HMM2 and HMM1. Related Articles | Metrics | Comments（0） Cited: Baidu(16)

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Paramatric Adaptive Decomposition Based on Gaussian Elementary Functions and Related Adaptive Time-frequency Distribution MA Shi-wei, DEN Jia-mei, CAO Jia-lin Journal of Applied Sciences    2001, 19 (1): 33-36.   Abstract （458）      PDF（pc） （177KB）（97）       Knowledge map    Save We propose a method of adaptive signal decomposition based on the linear frequency modulated Gaussian elementary functions and the related adaptive time-frequency distribution that is positive, cross-term interference free and with better time and frequency resolution. The set of the elementary functions is obtained by the successive matching of the signal local nature with the single prototype Gaussian function through regulating its variance, sweep rate, translation and modulation in an adaptive manner. The matched coefficients and the parameters contain all the information of the signal and can be used for the further processing of the signal. The effectiveness of the method has been proved by simulation results. Related Articles | Metrics | Comments（0）

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The Decoupling Problem of a Class of Time-delay Nonlinear Systems FU Yu-sun, TIAN Zuo-hua, SHI Song-jiao Journal of Applied Sciences    2001, 19 (1): 37-39.   Abstract （365）      PDF（pc） （131KB）（85）       Knowledge map    Save This paper is concerned with the decoupling problem of a class of time-delay nonlinear systems. A controller is used so that the output is decoupled from the delayed state and disturbance. Related Articles | Metrics | Comments（0）

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The Study and Development of a New Omni-directional Vehicle Applied in the Wall-climbing Robot TAN Shi-li, ZHANG Hai-hong, GONG Zhen-bang Journal of Applied Sciences    2001, 19 (1): 40-43.   Abstract （324）      PDF（pc） （171KB）（83）       Knowledge map    Save Considering the special requirements for wall-climbing cleaning robot, a new type of omni-directional mechanism which can cross obstacles has been developed. This omni-directional mechanism can make the wall-climbing robot not only move in all directions on the wall without changing its pose or rotate at any angle at its original place but also overstep the obstacles such as the window frame in its routing. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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Discriminating the Existence of Inverse Kinematics Solution of Underfreedom-robot by Neural Network CHONG Kai, KE Xian-xin Journal of Applied Sciences    2001, 19 (1): 44-47.   Abstract （314）      PDF（pc） （168KB）（83）       Knowledge map    Save For solving the solvability problem within the work space of underfreedom-robot, a virtual joint method is proposed and BP neural network is used to distinguish the solvable and unsolvable posture space and to determine whether there exists an inverse kinematics solution. The result is proved ideal. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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A Study on the Optimization Design of the Grinding Wheel Topography for the High Efficiency Grinding FU Yu-can, XU Hong-jun Journal of Applied Sciences    2001, 19 (1): 48-52.   Abstract （302）      PDF（pc） （206KB）（93）       Knowledge map    Save In view of the limitation of the traditional thinking in modeling and simulation of the grinding processes, a new idea is put forward. It is the optimization of the topography in accordance with machining demands and grinding parameters and the optimization of grinding parameters in accordance with the topography and machining demands. In this way, not only the study of modeling and simulation can be realized but also the optimization of the processes can be carried out. Furthermore, a superabrasive slotted grinding wheel is designed as a practical application of the optimization model. Related Articles | Metrics | Comments（0） Cited: Baidu(8)

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The Application of Random Displacement Method in the Static Buckling of Frame Structure YANG Ji-xin, CHEN Ding-fang Journal of Applied Sciences    2001, 19 (1): 53-56.   Abstract （284）      PDF（pc） （169KB）（75）       Knowledge map    Save A new mechanical method, random displacement method, was used to analyse static buckling of frame structure. The basic idea was to discrete the structure and find the load function according to the energy criterion of buckling and the principle of random displacement method. As the critical load is the minimum of the load function, a problem of frame buckling can be transformed into an optimization problem. Therefore, the critical load can be found through solving the optimization problem. The feasibility of the method is discussed on the basis of numerical computing instances. Related Articles | Metrics | Comments（0）

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Structural Design for the Elastic Body of a High Performance Six-axis Wrist Force Sensor LIU Zheng-shi, LU Yi-min, CHEN Xiao-dong, WANG Guo-tai, GE Yun-jian Journal of Applied Sciences    2001, 19 (1): 57-61.   Abstract （337）      PDF（pc） （209KB）（150）       Knowledge map    Save A model of static and dynamic characteristics of the elastic body of a wrist force sensor used in space robot is built with finite element method. The stress distribution pattern in various load cases, natural frequencies and vibration shapes of the elastic body are analyzed. The influence of main structure parameters on static and dynamic characteristics is investigated comprehensively by using orthogonal test design. The regression equations between the structure parameters and performances of the sensor are obtained by using step regression analysis on numerical results. And the optimization design of elastic body for the wrist force sensor has been carried out. Related Articles | Metrics | Comments（0） Cited: Baidu(23)

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Tool-path Generation in the NC Machining of Compound Surfaces CHEN Tao, CHEN Gang, TANG Jin, ZHONG Yi-fang, ZHOU Ji Journal of Applied Sciences    2001, 19 (1): 62-65.   Abstract （377）      PDF（pc） （176KB）（77）       Knowledge map    Save An algorithm for tool-path generation in the NC machining of compound surfaces is presented:The compound surfaces are approximated by triangular meshes. The vertices of triangular meshes are offset along the normal direction at the vertices. All offset vertices are then connected to form an offset triangular mesh surface which is sliced by a series of vertical planes to obtain parallel tool-paths. The experimental NC machining results demonstrate the feasibility of the algorithm. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Research on Displacement Flow of Internal Moisture in Porous Media During Rapid Drying Process WANG Xin, WANG Hai, SHI Ming-heng, YU Wei-ping Journal of Applied Sciences    2001, 19 (1): 66-69.   Abstract （363）      PDF（pc） （176KB）（95）       Knowledge map    Save In this paper, the authors put forward the idea that the displacement flow in capillary structure under pressure gradient is the main mechanism of high intense and rapid drying process. In this paper, both analytical and experimental studies are carried out to clarify the displacement process and its characteristic. A simplified displacement flow model is proposed and the time of the moisture migration is calculated. A one-dimentional displacement flow test device is built up and a set of experiments under different pressure gradients and temperatures are conducted. Glass beads of 0. 8mm diameter are used as the porous material. The experiment results show that under a constant temperature, as the pressure gradient is getting greater, the time for moisture to reach the external surface from the internal is getting smaller and the range of time reducing is getting smaller too. On the other hand, under the same pressure gradient, as the liquid temperature increases, the time for moisture from the internal to the external surface decreases. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Experiment on the Shrinkable Character of Material During Convective Drying Process CAI Liang, YU Wei-ping, SHI Ming-heng Journal of Applied Sciences    2001, 19 (1): 70-72.   Abstract （265）      PDF（pc） （136KB）（82）       Knowledge map    Save Some material, especially biomaterial, will shrink during the drying process. In the experiment, drying curve and shrinkable curve of fresh pea is measured. Volumetric shrinkable coefficient is also introduced and measured. Related Articles | Metrics | Comments（0） Cited: Baidu(10)

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Models for the Critical Volume Content of the Reinforcement Phase in Ceramic Materials Based on the Toughening Mechanism of Residual Thermal Stress and Their Applications XU Chong-hai, DING Wen-lia ng, HUANG Chuan-zhen, DENG Jian-xin, AI Xing Journal of Applied Sciences    2001, 19 (1): 73-76.   Abstract （310）      PDF（pc） （179KB）（76）       Knowledge map    Save Based on the toughening mechanism of residual thermal-stresses, a model is built for the calculation of the critical volume content of the reinforcement phase in ceramic materials when TP> Tm. The model has been proved valid through its applications in SiC/TiB2 ceramic material. Next, two models are established for the determination of the critical volume content of the reinforcement phase when the particle size of the matrix and the ratio of the particle size of the reinforcement phase and the matrix are considered. Models built here will find a practically application in the composition designing and the micro-structural designing of ceramic materials. Related Articles | Metrics | Comments（0）

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A Study on Ni3Al(Cr)-base in-situ Composite Microcrystalline Alloy LIN Yi-jian Journal of Applied Sciences    2001, 19 (1): 77-80.   Abstract （313）      PDF（pc） （179KB）（74）       Knowledge map    Save It was proposed that fabricating intermetallics with the rapid-solidification technique for micro-crystalline alloys would be a promising way to develop high-performance materials. A Ni3Al(Cr) base micro-crystalline alloy, strengthened and stabilized by M3B2 boride particles, was designed and prepared. The alloy has a uniform sub-micron-scale refined micro-structure, which is stable without coarsening even after 1000℃ anneal when subjected to high temperature. It retains a high hardness of HV≈580 from room temperature up to at least 650℃, which is related to the characteristic high temperature strength of Ni3Al phase and the strengthening effect of M3B2 particles. Related Articles | Metrics | Comments（0）

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Research of Numerical Prediction in the Course of the Hyperthermia Treatment of Tumor HUANG Zhen-kan, GENG Mei-ying, LI Qin-fu Journal of Applied Sciences    2001, 19 (1): 81-84.   Abstract （301）      PDF（pc） （175KB）（75）       Knowledge map    Save Time series prediction approach is utilized in this paper to predict and analyze the law governing the change of temperature somewhere inside the tumor. The radial power and the marginal temperature of the interface between the probe and the tumor are modified, and the temperature of the body of tumor is controlled according to the result of the prediction in order to achieve the desired curative effect. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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A Characterization of Two-heat-source Refrigerators YANG Hui-shan, YAN Zi-jun Journal of Applied Sciences    2001, 19 (1): 85-88.   Abstract （343）      PDF（pc） （161KB）（72）       Knowledge map    Save By using finite-time thermodynamic theory, unified description a characterization is made of a class of two-heat-source refrigerators using an ideal gas as working fluid is achieved. The fundamental optimal relation of the refrigerators is derived, and the effect of regenerative loss and regenerative time on the cooling rate and coefficient of performance is discussed. The results obtained here have general significance. They may provide some new theoretical guidance for the manufacture and the optimal design of a class of two-heat-source refrigerators, such as Carnot refrigerators, Stirling refrigerators, Ericsson refrigerators, and so on. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Analysis of the Stabilizability of Two Stabilizers for Plants YUAN Xiang-yang, SHI Song-jiao, IKEDA Masao Journal of Applied Sciences    2001, 19 (1): 89-91.   Abstract （389）      PDF（pc） （133KB）（65）       Knowledge map    Save For a linear SISO plant with variable operating condition, whose dynamics is described by a linear interpolation of proper stable coprime factorizations of the transfer functions at two representative operating points, a fixed stabilizer is proposed in[1,2]while an interpolated stabilizer is proposed in[3]. It is demonstrated in this paper that the class of stabilizable plants via the stabilizer proposed in[3]is larger than that via the fixed controllers proposed in[1,2]. Related Articles | Metrics | Comments（0）

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A Study on the Bubbling of the Anti-stickiness Coating on ZL102 Casting Al Alloy for Cooking Utensils HUANG Xu-qiang, LU Chao-yang Journal of Applied Sciences    2001, 19 (1): 92-94.   Abstract （440）      PDF（pc） （159KB）（79）       Knowledge map    Save The cause of the bubbling of anti stickiness coating on ZL102 casting Al alloy cooking utensils is discussed. By metalloscope and electronic probe, it is found that the bubbling may result from the impurities which remain in the flaws (such as bubbles loose structures etc.) if refiring and modification are inadequate, when cooking utensils are used at high temperature a pressure leading to the formation of bubbles will be produced with the impurities diffusing from inside to the surface. Related Articles | Metrics | Comments（0）

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“Instantaneous Thin layer” Model for Non-Fick Mass Transfer JIANG Fang-ming, LIU Deng-ying Journal of Applied Sciences    2001, 19 (2): 95-99.   Abstract （307）      PDF（pc） （210KB）（98）       Knowledge map    Save An "instantaneous thin layer" model for transnormal mass transfer is brought forward in this paper. In transnormal mass transfer,there is an interface existing in the medium,which divides the object into two parts:the "instantaneous thin layer",which is a thin layer region around the mass disturbance position,and the other part of the object. Mass transfer in the "thin layer" is governed by non-Fick law, while that in the other part still complies with the Fick's law approximatively. Mass transfer on the boundary surface of the "thin layer" region satisfies the continuous boundary conditions (i.e.the fourth kind of boundary conditions). An example of one-dimensional transnormal mass transfer, resulting from a pulsed mass disturbance source,is presented in this paper,too. The hyperbolic non-Fick mass transfer equation,which is similar to the hyperbolic non Fourier heat conduction equation,is used to describe this transnormal mass transfer,and the finite-difference method(FDM) combined with MacCormack's predictor-corrector schems is used to solve it. Ultimately the correlativity of the thickness of the "instantaneous thin layer" to the mass relaxation time, mass diffusivity and the mass disturbing source is obtained. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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Multipole Theory Analysis of the Higher Order Modal Characteristics of Circular-rectangular Coaxial Waveguide ZHENG Qin-hong, ZENG Hua, XIE Fu-yao Journal of Applied Sciences    2001, 19 (2): 100-102.   Abstract （376）      PDF（pc） （146KB）（69）       Knowledge map    Save A new method, the multipole theory (MT) method, is presented for calculating the higher order modal characteristics of circular-rectangular coaxial waveguides. The results obtained by the MT method are compared with the exact data reported in the literature. It is shown that the MT method is an accurate and reliable approach for analyzing the higher order modal characteristics of circular-rectangular (C-R) coaxial waveguide. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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A Theoretical Study of Rock Strength Conditions LI Chuan-liang, KONG Xiang-yan Journal of Applied Sciences    2001, 19 (2): 103-106.   Abstract （286）      PDF（pc） （168KB）（83）       Knowledge map    Save Effective stresses should be used instead of normal-stresses in the analysis of rock strength. Terzaghi effective stress is the approximation of structural effective stress. Terzaghi equation is only applicable to porous media like soil. Tight media like rock must adopt the structural effective stress,otherwise error will inevitably occur. Normal-stress analysis overestimates the strength of rock, and Terzaghi effective stress underestimates the strength of rock. Only the structural effective stress can provide the correct answer. Related Articles | Metrics | Comments（0） Cited: Baidu(6)

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Low Frequency Ultrasonic Multi-mode Lamb-like Wave Method for Characterizing the Ultra-thin Bonding Composite ZHANG Rui, WAN Ming-xi, CAO Wen-wu Journal of Applied Sciences    2001, 19 (2): 107-112.   Abstract （257）      PDF（pc） （256KB）（84）       Knowledge map    Save A low-frequency ultrasonic Lamb-like wave method suitable for characterizing the thickness, density, shear and longitudinal wave velocities of the ultra-thin bonding composite is presented. The dispersion property of the low-frequency Lamb-like wave propagating along the ultra-thin bonding composite is derived, which is the basis of the characterization method. In conjunction with the method of the least square, the secant algorithm is used to estimate each layer's parameters of the ultra-thin bonding composite. The reasons for evaluation error of the parameters and the sensitivity of the method for different parameters are analyzed. Using the ultrasound coupler and a pair of broadband longitudinal wave transducers with 1MHz center frequency, we can successfully estimate the parameters of the ultra-thin bonding layer (with h of each layer smaller than 0.05λ) of the steel/brass composite by employing the leaky guided wave frequency-domain analysis method. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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Reliability Synthesis Assessment Based on the Information Theory for Sophisticated Products SUN You-chao Journal of Applied Sciences    2001, 19 (2): 113-116.   Abstract （231）      PDF（pc） （169KB）（81）       Knowledge map    Save An effective reliability synthesis assessment method based on the information theory for sophisticated products is presented. The general conversion models are established according to the equivalent principle of information quantity,and the calculating formulae of the first and second approximate lower limits of the system reliability are given. The applications of this method are demonstrated by examples. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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Measurement of Mode Shapes of Vibration for Plates and Shells ZHOU Xing-de, WANG Feng-quan Journal of Applied Sciences    2001, 19 (2): 117-120.   Abstract （262）      PDF（pc） （188KB）（90）       Knowledge map    Save In this paper, A new method of optically dynamic measurement is presented. The method applies the linear integral imaging mechanism of the CCD image sensor and combines time-average image method with digital image processing techniques. By using the method,the information of mode shapes of vibration for plates and shells can be reconstructed from their sta tic reference images and its time-average images under resonance state. The method is easy and needs only simple equipment. Related Articles | Metrics | Comments（0）

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Chinese Tone Extraction in Extremely Noisy Background DAI Ming-yang, YU Kai, XU Bo-ling, YU Chong-zhi Journal of Applied Sciences    2001, 19 (2): 121-126.   Abstract （286）      PDF（pc） （257KB）（93）       Knowledge map    Save This paper proposes a robust Chinese tone extraction algorithm based on the human auditory mechanism and short-term stationary of Chinese speech. In this method, we use the pooled correlogram based on human auditory model to extract the pitch of speech. An unsupervised lateral inhibitory network is used to get the peak position, which simulates the lateral inhibitory phenomenon in human auditory system. The pitch restriction between successive frames of speech is imposed to get rid of misjudgement in the output of lateral inhibitory network. As shown in the experiments, the method can extract Chinese tone quite well even in rather low SNR cases. It can separate the individual tone clearly as two speakers talk simultaneously. Related Articles | Metrics | Comments（0） Cited: Baidu(6)

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Video Transcoding Based on the Model of Resolution Reduction LI Xiao hui Journal of Applied Sciences    2001, 19 (2): 127-130.   Abstract （256）      PDF（pc） （167KB）（70）       Knowledge map    Save The motion vectors and macroblock type during video transcoding based on resolution reduction are refined in this paper. A model of adaptive motion vectors is proposed based on the sum of the differential quantization errors, thus to reduced the search area. It is possible to achieve fast motion estimation for near-optimal outgoing motion vectors. This method may improve the computational complexity without significant losing in quality. Related Articles | Metrics | Comments（0）

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The Effects of Pumping Perturbation on the Stability of Er-doped Fiber Laser YAN Sen-lin, WU Shi-bao, SUN Xiao-han, ZHANG Ming-de Journal of Applied Sciences    2001, 19 (2): 131-134.   Abstract （261）      PDF（pc） （175KB）（77）       Knowledge map    Save In this paper, the effects of instantaneous state of Er-doped fiber laser are studied. The expressions in dicating the photon population density perturbations with time in Er-doped fiber laser are given. The fluctuation functions of photon population density under pumping perturbations are solved at the first order approximation. Furthermore, the properties of the white noise and the resonance effects are discussed in detail. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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The Domain Decomposition Method for EM Scattering Analysis of Arbitrary Finite Dielectric Cylinders WANG Jie, HONG Wei Journal of Applied Sciences    2001, 19 (2): 135-139.   Abstract （242）      PDF（pc） （219KB）（67）       Knowledge map    Save In this paper the domain decomposition method (DDM) is used to analyze the EM scattering problems from inhomogeneous and anisotropic dielectric 3-D objects. In DDM, the original large domain is divided into several sub-domains. It is therefore very suitable for solving 3-D electrically large electromagnetic problems. A relaxed iterative procedure is presented for accelerating the iterative procedure. Good agreement between the results calculated by DDM and those from other literatures verifies the accuracy of DDM. Finally, the DDM is also applied to calculate the specific absorption rate (SAR) distribution in human body illuminated by electromagnetic waves. The conclusions drawn from this paper are consistent with those from other papers. Related Articles | Metrics | Comments（0）

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A Efficient Method for Increasing the Capacities of WDM Star Single-hop Networks GAN Chao-qin, LIU Xue-ming, XIE Bin, SUN Xiao-han, ZHANG Ming-de Journal of Applied Sciences    2001, 19 (2): 140-144.   Abstract （336）      PDF（pc） （204KB）（64）       Knowledge map    Save In this paper, a novel networking scheme with two star couplers in parallel is presented to solve the capacity problem of WDM star single-hop network. The network structure is introduced; communicatioms between nodes are analyzed, and the network capacity is computed and analyzed. Related Articles | Metrics | Comments（0）

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Application of Preconditioned Conjugate Gradient Method to the RCS Analysis of Dipole-array Antennas ZHOU Hou-xing, TONG Chuang-ming, HONG Wei Journal of Applied Sciences    2001, 19 (2): 145-148.   Abstract （323）      PDF（pc） （175KB）（83）       Knowledge map    Save To obtain the RCS of dipole-array antennas, the system of electric field integral equations is turned into a linear algebra system whose coefficient matrix is a symmetric block Toeplitz complex matrix by using Calerkin method with pulse basis functions. The linear algebra system is solved by a combination of the preconditioned conjugate gradient method (PCG) with the fast Fourier transform (FFT), where T. Chan optimal circulant preconditioner is used. The above method reduces the need for computer memory, speeds the iteration and enhances the convergence. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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A Self-organizing Fuzzy Neuron Network Model for Data Fusion of Radar Net ZHANG You-sai, LIU Wei-ting Journal of Applied Sciences    2001, 19 (2): 149-152.   Abstract （236）      PDF（pc） （170KB）（77）       Knowledge map    Save A self-organizing fuzzy neuron network model for the data fusion of radar net is presented. The self-organizing feature of the model and WTA competition mechanism for maximizing the fussy membership function in the neuron's receptive field is analyzed. Its validity is demonstrated by the simulation of 2-D ships' track fusion. Related Articles | Metrics | Comments（0）

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The Study on Indirect Multi-mode Control Method for Ship Track-keeping Autopilot CHENG Qi-ming Journal of Applied Sciences    2001, 19 (2): 153-156.   Abstract （277）      PDF（pc） （177KB）（83）       Knowledge map    Save The track control strategies include direct approach and indirect approach. In this paper, the indirect multi-mode control method for ship track-keeping autopilot is discussed. The track autopilot works properly, its performance is satisfactory. The controller can capture current way point automatically, and keep the trajectory precisely on the planned route. When the ship approaches a way point, it can turn to the new course swiftly and smoothly. Related Articles | Metrics | Comments（0） Cited: Baidu(6)

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Time-delay Filter Anti-sway Control of Cranes with Load LIANG Chun-yan, JIA Qing, XIE Jian-ying Journal of Applied Sciences    2001, 19 (2): 157-160.   Abstract （318）      PDF（pc） （175KB）（89）       Knowledge map    Save In this paper, time-delay filter technique is applied to the anti-sway control of cranes with load and is shown to significantly eliminate load residual sway. As a feed forward unit, time-delay filter does not require the measurement of swing angel of the load. It can eliminate load residual swing by merely shaping the acceleration control signal. It is a simple and easy method to be implemented in the microcomputer. Related Articles | Metrics | Comments（0） Cited: Baidu(6)

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An Interpolation Fuzzy Reasoning Approach Based on Vague Sets LI Fan, XU Zhang-yan, LU An Journal of Applied Sciences    2001, 19 (2): 161-164.   Abstract （310）      PDF（pc） （168KB）（74）       Knowledge map    Save When the membership functions (represented by vague sets) of fuzzy terms are continuous functions, we give a one-to-one mapping between the universe of discourse of fuzzy terms in the antecedent of the rule and that in the consequent of the rule. In this way, we are able to find a method of interpolation fuzzy reasoning based on vague sets. When the membership functions of vague sets are discrete functions, after giving one-to-one mapping between the universe of discourse of fuzzy terms in the antecedent of the rule and that in the consequent of the rule, we carry out linear interpolation in the true/false membership functions of vague sets in the antecedent of the rule and fact, to turn them in to continuous functions. we are thus able to develop a method of interpolation fuzzy reasoning based on vague sets. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Study of n-dimensional Extension Set CAI Guo-liang, DING Zhan-wen Journal of Applied Sciences    2001, 19 (2): 165-169.   Abstract （253）      PDF（pc） （210KB）（77）       Knowledge map    Save In this paper, the definitions of the n-dimensional extension set and its extension field were first given. Then the operations and properties of the n-dimensional extension set were discussed. The concept of the m-dimensional positive field was given finally. The results obtained may enrich the theory of the n-dimensional extension set. Related Articles | Metrics | Comments（0）

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