2002 Vol.20

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An Experimental Study on the Factors Influencing Ebullient Tests of Highly-wetting Liquids HOU Ding-wei, MA Chong-fang, LIU Deng-ying Journal of Applied Sciences    2002, 20 (1): 1-5.   Abstract （354）      PDF（pc） （206KB）（112）       Knowledge map    Save An experimental and mechanismic study was conducted to investigate the factors effecting boiling tests of highly-wetting liquids. The results showed that only the experimental data obtained through a rigorous test procedure could be compared with each other. Related Articles | Metrics | Comments（0）

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A Fine Needle Probe for Determining the Thermal Conductivity of Penetrable Materials XIE Hua-qing, WANG Jin-chang, CHENG Shu-xia, LIU Yan Journal of Applied Sciences    2002, 20 (1): 6-9.   Abstract （503）      PDF（pc） （183KB）（245）       Knowledge map    Save A fine needle probe for determining the thermal conductivity of penetrable materials such as fluids, fruit, animal fresh has been developed. The present probe is constructed by inserting twenty strands of copper wire with electrical insulation coating into a fine stainless steel needle. The copper wire serves both as a heating unit and as an electrical resistance thermometer. The effects on the thermal conductivity measurement caused by the thin needle wall has been analyzed. It is found that the effects can be negligibly small if the instruments and the measurement procedure is adequately designed. The usability of the as-constructed apparatus for the penetrable materials has been tested to measure the thermal conductivity of liquid, fruit and animal fresh. The accuracy of the measurement was estimated to be ±3%. Related Articles | Metrics | Comments（0）

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A Research on the Framework of Organization of Brazed Mono-layer Diamond Grinding Wheel with Ni-Cr Alloy WU Zhi-bin, XU Hong-jun, YAO-Zheng-jun, XIAO Bing, FU Yu-can Journal of Applied Sciences    2002, 20 (1): 10-13.   Abstract （393）      PDF（pc） （268KB）（151）       Knowledge map    Save We have successfully developed a brazed mono-layer diamond grinding wheel with Ni-Cr alloy under Ar atmosphere. SEM-EDS microanalyses have shown that during brazing the chromium present in the alloy segregated preferentially to the surface of the diamond to form a chromium-rich reaction product. X-ray diffraction revealed that the wetting and bonding behavior on the diamond surface by Ni-Cr alloy melt is realized through Cr7C3 which is produced by interaction between Cr atoms of Ni-Cr alloy and C atoms of the diamond surface at elevated temperatures.The analyses also revealed that the bond between the alloy and the steel substrate was established through a cross-diffusion of iron and chromium and the formation of (Fex Cry) C-type carbides.Finally a grinding test show ed that the wear modes of such a brazed grinding wheel were mainly grit fracture and attrition rather than grit dislodgment from the bond. Related Articles | Metrics | Comments（0）

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A Research on the Characteristics of Attenuating Vibration of a Multi-medium Coupling Shock Absorber for Precision Equipment YANG Ping Journal of Applied Sciences    2002, 20 (1): 14-20.   Abstract （313）      PDF（pc） （272KB）（123）       Knowledge map    Save A multi-medium coupling shock absorber is designed by ingeniously coupling the air, oil, rubber and metallic elastic component to meet the requirement of resisting violent impact and attenuating vibration in the vibration-impact-safety device of electronic-information equipment. The model machine shows strong nonlinear dynamic characteristics in the multi-parameter coupling dynamic test. Based on this, the nonlinear dynamic characteristics model is established by combining the theoretical analysis and the actual structural parameters applied in modeling. The analytic result shows that the multi-medium coupling shock absorber has a good dynamic performance and controllable design-capability. The modeling method is applicable to the research and design of other shock absorbers Related Articles | Metrics | Comments（0）

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Characteristics Analysis of Noise Transfer of Wavelength Converters Based on Cross-gain Modulation WU Shi-bao, YAN Sen-lin, LIU Xiao-fei, SUN Xiao-han, ZHANG Ming-de Journal of Applied Sciences    2002, 20 (1): 21-24.   Abstract （307）      PDF（pc） （178KB）（110）       Knowledge map    Save A theoretical model describing the noise conversion characteristics of wavelength converters based on XGM in SOA is established in this paper. The numerical simulation results show that the input pump power and probe power have direct influences on the noise conversion. In an appropriate range of input power, the noise can be effectively suppressed and the quality of the converted signal is improved. Related Articles | Metrics | Comments（0）

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Intra band Crosstalk in an OXC Based on Demultiplexers Using FBG HE Jin-lin, SUN Xiao-han, ZHANG Ming-de, DING Dong Journal of Applied Sciences    2002, 20 (1): 25-29.   Abstract （397）      PDF（pc） （213KB）（120）       Knowledge map    Save Basing on the reflection spectrum of a FBG filter, the impacts of intraband coherent crosstalk and intraband incoherent crosstalk in an OXC based on demultiplexers using fiber Bragg grating (FBG) filters, deduces the system power penalty and discusses in detail the dependence of system degradation on the coupling coefficient, grating length and polarization matching factor, etc. Related Articles | Metrics | Comments（0）

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The Implementation of Q Factor On-line Detection Based on DSP Technology in Optical Fiber LANs LI Jin-hui, SUN Xiao-han, ZHANG Ming-de, DING dong Journal of Applied Sciences    2002, 20 (1): 30-34.   Abstract （343）      PDF（pc） （201KB）（100）       Knowledge map    Save In view of the characteristics of PHY(physical layer) in optical LAN(local area network), an on-line method for Q factor detection based on DSP(digital signal processor) technology is put forward and its mathematical physical model is discussed. A series of simulative tests indicate that the method is valid, feasible, and convenient. Related Articles | Metrics | Comments（0）

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A Projective Method for Solving the Boundary Value Problems of the Electromagnetic Field in Special Domains SUN Lian-you, HONG Wei Journal of Applied Sciences    2002, 20 (1): 35-37.   Abstract （339）      PDF（pc） （135KB）（119）       Knowledge map    Save An algorithm is presented for solving electromagnetic problems in special domains with many branches. According to the geometric shape of domains the large matrix is divided into several small ones. The convergence rate of iterative solution is geometrical. The method is applied to the reflecting parameter and phase analysis of the slotting slow wave guide. Then we find the main factors of affecting the above parameter and phase, finally give them the relation curves. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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An Analysis of the Inter leavers for Turbo Codes ZHAO Guang-ling, WU Le-nan Journal of Applied Sciences    2002, 20 (1): 38-41.   Abstract （516）      PDF（pc） （183KB）（187）       Knowledge map    Save Several interleavers are applied to Turbo codes and simulated respectively. The performances are compared with each other. A new interleaving scheme is put forward by this paper that combines two different types of interleaver into a new interleaver. Since there is a strong correlation in time between information bits and check bits produced by the first constituent encoder not being interleavered, an additional symbol interleaver is added to the multiplexer to reduce the bit error rate ulteriorly in the flat Rayleigh fading channel. Related Articles | Metrics | Comments（0） Cited: Baidu(7)

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A New Algorithm for Displacement Field Estimate Based on Joint Luminance and Motion Segmentation TANG Li, ZHANG Zhao-Yang Journal of Applied Sciences    2002, 20 (1): 42-46.   Abstract （375）      PDF（pc） （238KB）（125）       Knowledge map    Save Motion estimate is a key technology in computer vision and video signal processing. It is widely used in international standards for video communication. Due to the difference between real motion and apparent motion and the existence of the aperture and the occlusion problem, it seems difficult to obtain the precise motion field. In this paper, we present a displacement field estimate algorithm based on joint luminance and motion segmentation to obtain a satisfactory result. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Low-complexity Blind Multiuser Detection of CDMA Signals in Fading Channels LIN Zhi-qiang, YOU Xiao-hu, WANG Yong Journal of Applied Sciences    2002, 20 (1): 47-50.   Abstract （400）      PDF（pc） （181KB）（106）       Knowledge map    Save The problem of blind multiuser detection of CDMA signals in fading channels is considered. It is noted that the minimum-mean-square-error (MMSE) detector often loses phase to lock a desired signal when the desired signal dips into a deep fade. This paper proposes a suboptimal blind MMSE detector that is incorporated into the desired user's signature waveform and the auxiliary vector to achieve low-complexity. It decouples the signal phase, and fits into realistic fading channels. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Simultaneous Extrapolation of Electromagnetic Scattering of Multi-wires in Time and Frequency Domains Based on Hermite Expansion TONG Chuang-ming, HONG Wei, ZHOU Hou-xing Journal of Applied Sciences    2002, 20 (1): 51-54.   Abstract （384）      PDF（pc） （172KB）（129）       Knowledge map    Save The entirety responses of the induced currents on the wires in both time and frequency domains can be obtained at the same time by simultaneous extrapolation computation using both the early-time response and the low-frequency information of the induced currents. The time-domain response of the induced currents on a scattering object irradiated by a plane wave with a Gaussian pulse in time is expanded as an associate Hermite series. Using the isomorphism of the associate Hermite function and its Fourier transform, the frequency-domain information can also be obtained. According to the corresponding relation between time-domain analysis and frequency-domain analysis, and using the early-time response and the low-frequency information of the induced currents, the non known coefficients in the expansion series can be determined. Electromagnetic scattering of multi-wires are calculated and analyzed based on this extrapolation method recommended in this paper. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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A Study and Discussion on a Controller for Radial Four-degree Freedom Active Magnetic Bearing ZHU Huang-qiu, XU Long-xiang Journal of Applied Sciences    2002, 20 (1): 55-60.   Abstract （537）      PDF（pc） （254KB）（201）       Knowledge map    Save This paper, basing on the state equation of a radial four degree freedom magnetic bearing, presents the steps in using the linear quadratic method of the optimal control theory to design a centralized and decentralized parameters control system. Matlab language is also used to carry out simulation comparison, which proves that the difference is small. In this paper, the structure of hardware and software based on the digital signal processor, the method of debugging and the experimentation result are presented in brief. The vibration amplitude of rotor is about 20μm when the speed of rotor runs between 0 to 60000r/min. The experiment shows that the decentralized controller based on the linear quadratic method meets the demands of active magnetic bearing system. This method may be used for reference in the study and designing of controllers for active magnetic bearing. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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Computer Simulation of the Production System of Factory Agriculture GU Ji-nan Journal of Applied Sciences    2002, 20 (1): 61-65.   Abstract （362）      PDF（pc） （202KB）（105）       Knowledge map    Save This is the first time a research that includes the growth of plants, environmental control and economic analysis of the production system of factory agriculture in a single large scale system has been carried out. We build three separate sub-models of the velocity of photosynthetic, environmental control and cost control. Next we construct a comprehensive dynamic model on the basis of three sub-models and the relations between them, and carries out simulation research in this way we obtain the optimum mode of comprehensive environmental control to simultaneously meets the two requirements of better control and lower cost under different external weather conditions. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Indirect Adaptive Decentralized Neurcontrol for a Kind of Nonlinear Large Scale System HU Shou-song, ZHANG Rui Journal of Applied Sciences    2002, 20 (1): 66-69.   Abstract （363）      PDF（pc） （180KB）（96）       Knowledge map    Save An indirect adaptive decentralized neurcontrol is proposed for a kind of nonlinear large scale systems by adopting a decentralized control mode. Fuzzy neural network is used to identify the subsystem for building NARMA model and adjusting the parameter of the controller. Besides, the adaptive control and sliding-model-control method is used to extinguish nonlinear interconnection between each subsystems and disturbances with unknown bounds. The indirect adaptive decentralized neurcontrol controller is verified by its application to a double inverted pendulum system, the results of simulation confirm the effectiveness of the proposed algorithm. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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An Algorithm of Make span Scheduling for Hybrid Production in Dynamic Environment XU Zhi, XI Yu-geng, HAN Bing Journal of Applied Sciences    2002, 20 (1): 70-76.   Abstract （413）      PDF（pc） （282KB）（116）       Knowledge map    Save To solve the problem of the optimal production time scheduling for a class of hybrid production process in dynamic environment, we use the rolling optimization method in accordance with the basic principle of predictive control and put forward the concept of available operation set. The scheduling problem in dynamic environment is reasonably divided and the sub-questions are standardized. An optimized algorithm based on MILP is given for low dimension and a heuristic algorithm for high dimension is proposed. The emulation of an actual example indicates that the algorithm is practicable. Related Articles | Metrics | Comments（0）

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The Confidence Intervals of the Nonparametric Regression Function XUE Liu-gen Journal of Applied Sciences    2002, 20 (1): 77-79.   Abstract （447）      PDF（pc） （136KB）（137）       Knowledge map    Save In the paper, we apply random weighting methods to construct random weighting statistic for the unknown regression function m(x) and prove that the random weighting approximation can attain the accuracy of o(n-1/(d+2) lnnMn),where 0< Mn→∞. The confidence intervals of m(x) can be constructed by this result. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Ecological Optimal Performance of a Ferroelectric Ericsson Refrigerator YANG Hui-shan Journal of Applied Sciences    2002, 20 (1): 80-83.   Abstract （373）      PDF（pc） （173KB）（120）       Knowledge map    Save By utilizing the finite time thermodynamics and the thermodynamic properties of a ferroelectric, the ecological optimal performance of a class of ferroelectric Ericsson refrigerators with thermal resistance and nonperfect regeneration is studied. Some new performance parameters are obtained. The conclusions obtained here may provide some new theoretical guidance for the development and optimal design of ferroelectric Ericsson refrigerators. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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A Generalized Post-processing Algorithm to Compensate Geometric Errors of Multi-axis NC Machine Tools with Arbitrary Configuration HE Yao-xiong, ZHOU Yun-fei, ZHOU Ji Journal of Applied Sciences    2002, 20 (1): 84-89.   Abstract （393）      PDF（pc） （241KB）（145）       Knowledge map    Save The multi-axis NC machine tool typically consists of two open kinematics chains:workpiece chain and cutter chain. According to this principle, the kinematics model and error model of multi-axis NC machine tools have been analyzed and set up, and then a generalized algorithm for post-processing of multi-axis NC machine tools is presented in this paper. The algorithm can be used to generate the coordinated motion value for all types of multi-axis NC machine with all sorts of errors according to the tool-path generated by the CAM system. Related Articles | Metrics | Comments（0） Cited: Baidu(25)

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Optimal Disposition of Actuators in Intelligent Frame Structures Based on Genetic Algorithm ZHOU Xing-de, WANG Feng-quan Journal of Applied Sciences    2002, 20 (1): 90-93.   Abstract （357）      PDF（pc） （174KB）（136）       Knowledge map    Save This paper is based on the modal degree of controllability and the least cost function with a view to overcoming the difficulties faced arising out of the application of combined optimization to disposition actuators. In the paper, the genetic algorithm is used to solve the optimal disposition in active vibration control. The introduction of constraint condition in to conventional genetic algorithm is improved to fit into the solution of frame structures. Finally, a numerical example is presented to show the effectiveness of the method. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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A Study on the Uncertainty lnference in Fuzzy Rule XIAO Wei-yue Journal of Applied Sciences    2002, 20 (1): 94-98.   Abstract （489）      PDF（pc） （196KB）（115）       Knowledge map    Save In this paper, the uncertainty problems with regard to fuzzy truth value in fuzzy rules are investigated in depth. First, the different meaning of six propositions is completely analyzed. Next, a new logic combination relation, the generalized logic relation, is proposed in accordance with actual conditions of fuzzy rule application. Finally, the fuzzy sets matching degree and the fuzzy rule matching degree are defined and the inference algorithm of condition truth value and result truth value is presented, and the generalized uncertainty inference model is formed. Related Articles | Metrics | Comments（0） Cited: Baidu(7)

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A New Technology Based on RBFNN and GA for Resolving Overlapped Peaks LI Yi-bo, HUANG Xiao-yuan Journal of Applied Sciences    2002, 20 (1): 99-103.   Abstract （430）      PDF（pc） （205KB）（133）       Knowledge map    Save Radial basis function neural network (RBFNN) based on chromatographic peakshape functions and spectral lineshape functions has been constructed. A genetic algorithm based on feasible field constraint and shared niche technique is introduced to enable this RBFNN to acquire the ability of reconstruction. Next the RBFNN was introduced into the resolution of overlapped peaks of spectrum. This paper tries to build up a integrative frame suited to the resolution of spectrum and chromatogram, and partial results have been obtained. Related Articles | Metrics | Comments（0） Cited: Baidu(16)

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Phase-locked Loops Used with Atomic Hydrogen Frequency Standard ZHANG Wei-qun, ZHANG Yi-ping, WANG Guan-zhong, YU Shuang-lin Journal of Applied Sciences    2002, 20 (1): 104-108.   Abstract （403）      PDF（pc） （206KB）（128）       Knowledge map    Save Active atomic frequency standards, such as hydrogen maser, are characterized by a very good frequency stability. However, they deliver a signal at a power level and at a frequency that are not practical to the users. This paper descries the techniques used to phase lock to the hydrogen maser a standard crystal oscillator at a cardinal frequency. Related Articles | Metrics | Comments（0）

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Accurate Measurement of the Coefficient of Thermal Deformation for Metal HUANG Qi-sheng, FEI Ye-tai, ZHANG Yong, HU Peng-hao Journal of Applied Sciences    2002, 20 (1): 109-110.   Abstract （477）      PDF（pc） （96KB）（204）       Knowledge map    Save This paper analyzes the change of the forced deformation that occurs along with thermal expansion of material at rising temperature. The change of the forced deformation must be taken into account in the accurate measurement of thermal deformation of metal. The concepts of the thermal deformation coefficient and the relation between the coefficient of thermal deformation and that of thermal expansion are discussed. Related Articles | Metrics | Comments（0） Cited: Baidu(6)

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Multiple Fault Detection for Easily Testable Realizations of Logic Functions PAN Zhong-liang Journal of Applied Sciences    2002, 20 (2): 111-115.   Abstract （332）      PDF（pc） （212KB）（103）       Knowledge map    Save The EXOR-sum-of-products (ESOP) is the most general form of 2-level AND-EXOR networks, it usually requires fewer products than Reed-Muller canonic expressions. A new method of design for testability (DFT) is presented in the paper, which employs AND gates and XOR gates tree to realize the ESOP expression of arbitrary logic functions. The method is able to reduce the delay in the circuits as compared with the approaches using XOR gates cascade. A universal test set which detects multiple faults in the circuit realization is given, it can be generated easily and is independent of the logic function realized. The results have considerable significance on the detection and testable design of multiple faults in the digital circuits. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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An Inter leaver with Reduced Storage Memory Requirement for Turbo Codes ZHAO Guang-ling, WU Le-nan Journal of Applied Sciences    2002, 20 (2): 116-118.   Abstract （419）      PDF（pc） （138KB）（85）       Knowledge map    Save This paper presents a new structure of interleaver that saves 50% memories relative to conventional ones. By swapping the odd and even positions, the interleaver has the property of symmetry, and the constraints on the mapping didn't deteriorate the performance of the interleaver. This is important in hardware implementation. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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A Study of Turbo Space-time Block Codes LI Guang-sen, HU Yan-ping, ZHOU Liang-zhu Journal of Applied Sciences    2002, 20 (2): 119-122.   Abstract （372）      PDF（pc） （179KB）（78）       Knowledge map    Save Space-time block codes are code technologies which provide a new paradigm for transmit ting over Rayleigh fading channels using multiple antennas. An overview of the space-time codes is made in terms of the system model, encoding and decoding algorithm, design criterion, concatenation of space-time codes and outer codes. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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A New Large-scale All-optical Star Coupler for Bidirectional WDM Systems GAN Chao-qin, SUN Xiao-han, ZHANG Ming-de Journal of Applied Sciences    2002, 20 (2): 123-128.   Abstract （453）      PDF（pc） （243KB）（74）       Knowledge map    Save In this paper, a novel large-scale star coupler is presented for the first time. This star coupler can provide a large number of ports for very large-scale single-fiber bidirectional WDM network system in future. The WDM star network composed of star couplers has great flexibility of networking. Its size can be increased conveniently and smoothly on-line by a factor of m. At the same time, the star coupler is still adapted to the single-fiber unidirectional WDM network system being extensively applied nowadays. It provides a good selection for WDM star networks. Related Articles | Metrics | Comments（0）

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Optimized Performance Criterion for STTC and the Serially Concatenated Convolution ally Coded STTC CHENG Jian, CHEN Ming, CHENG Shi-xin Journal of Applied Sciences    2002, 20 (2): 129-134.   Abstract （413）      PDF（pc） （273KB）（96）       Knowledge map    Save In this paper, an improved criterion for STTC construction is discussed. Next a new kind of STTC construction using serially concatenated convolutionally coded modulation with QPSK with Gray mapping is proposed. Simulation shows that Gray mapping is much better than direct mapping, and the serially concatenated convolutionally coded STTCs with Gray mapping outperform the classical STTC proposed by Tarokh or the improved ones proposed by Bäro. The serially concatenated convolutionally coded STTC has good performance and is easy to construct. Related Articles | Metrics | Comments（0）

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A Multi-level DAPSK Performance with Punctured Convolutional Coding SAYHOOD Khalid Hassan, WU Le-nan Journal of Applied Sciences    2002, 20 (2): 135-140.   Abstract （473）      PDF（pc） （273KB）（92）       Knowledge map    Save Punctured convolutional coding with an 8, 16 and 32differential amplitude and phase shift keying (DAPSK) modulation is considered. The performance with an additive white Gaussian noise (AWGN) and Rayleigh fading channels are compared to a coherent 16-quadrature amplitude modulation (QAM). DAPSK modulation parameter such as ring ratio has been optimized for a number of fading conditions. With punctured convolutional coding, the performance of noncoherent 8-DAPSK modulation in an AWGN and Rayleigh fading channels is about 1 dB less than a comparable 16-QAM with a code rate of 8/16 (or 8/24). Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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Optimization of GMM Based on Hybrid Evolutionary Algorithm and Its Application in Speaker Identification CUI Yu-hong, HU Guang-rui, HE Xu-ming Journal of Applied Sciences    2002, 20 (2): 141-144.   Abstract （498）      PDF（pc） （173KB）（173）       Knowledge map    Save When training data is limited, the performances of speaker identification (SI) system deteriorate owing to the weak generalization of GMM trained by EM algorithm. This paper presents a solution of this problem by using a evolutionary Gaussian mixture model (EGMM) as a modeling method of SI system. Based on evolutionary algorithm, EGMM optimizes both the structure and the parameters of a GMM to better its generalization ability. Also, other speakers' discriminative information is integrated into objective function to increase the accuracy of classification. According to the characteristics of GMM, we design two special evolutionary operators and present a new hybrid evolutionary algorithm using genetic algorithms and evolutionary programming. The preliminary experimental results show that the speaker models based on EGMM have more generalization ability. Compared with traditional GMM, the correct recognition rate of SI system based on EGMM increases by approximate 3%. Furthermore, the GMMS in new system have smaller average size. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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A Study of Hi-Bi-NLCFBG Used to Compensate PMD FENG Xian-jie Journal of Applied Sciences    2002, 20 (2): 145-149.   Abstract （395）      PDF（pc） （223KB）（95）       Knowledge map    Save We make a study of a tuning high birefringence nonlinearly chirped fiber Bragg gratings (Hi-Bi-NLCFBG) used to compensate the polarization mode dispersion (PMD) of the high-speed optical fiber communication system and analyze the spectrum characteristics and time-delay for the first time. A method for tuning the Hi Bi NLCFBG by means of PZT is suggested. Finally, we advance a scheme to compensate PMD by a self-adaptive method. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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The I-V Character of Tunnel Junction Constituted by Ferroelectric Thin Film PbSrTiO3 CHEN Hong-wei, MIAO Jiang-ping, ZHAI Ya, WU Zong-han, SUN Cheng-xiu, SUN Ping Journal of Applied Sciences    2002, 20 (2): 150-152.   Abstract （470）      PDF（pc） （136KB）（161）       Knowledge map    Save The ferroelectric thin film PbSrTiO 3 is a typical ferroelectric film with wide application. In this paper, the measurement of the I-V characteristics of this thin ferroelectric system, which was prepared by RF magnetron spattering method is reported. We found, for the first time, the negative resistance phenomenon, and interpreted it through the application of the theory of surface plasmon polariton (SPP) and polarized-wave. Related Articles | Metrics | Comments（0）

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The Faulty Systems State Observer and Its Application to Fault Diagnosis in a Class of Nonlinear Systems CHEN Yu-dong, SHI Song-jiao, WENG Zheng-xin Journal of Applied Sciences    2002, 20 (2): 153-159.   Abstract （397）      PDF（pc） （277KB）（91）       Knowledge map    Save The concept of faulty systems state observer (FSSO) is presented for the first time. The difference between FSSO and the traditional observer is analysed, and two possible structures for FSSO are pointed out. A new robust fault diagnosis method based on FSSO for a class of nonlinear systems with bounded uncertainties satisfying Lipschitz condition is proposed and its robustness and sensitivity are also analysed. This method can detect and isolate faults. It can also estimate the characteristics of the fault signal which varies with time. The result of the simulation indicates its validity. Related Articles | Metrics | Comments（0）

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A Study of Chaos Identification Via an On line Training RBF Neural Network YANG Tao, WANG Xue-lei, SHAO Hui-he Journal of Applied Sciences    2002, 20 (2): 160-164.   Abstract （426）      PDF（pc） （215KB）（126）       Knowledge map    Save In this paper, we discuss the online identification of the chaotic system. A novel online training algorithm for RBF neural network is presented. Some problems related to the algorithm are discussed in detail. Simulations show that the algorithm is very effective and can overcome the shortcomings existing in the so-called offline algorithm, We also use this online neural network to identify chaotic systems with good results. Related Articles | Metrics | Comments（0）

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A Design of Object-oriented Data Warehouse Using Snow-star Schema: Its Application in the Power System of Bao Steel Group ZHENG Bin-xia ng, XI Yu-geng, DU Xiu-hua Journal of Applied Sciences    2002, 20 (2): 165-168.   Abstract （448）      PDF（pc） （177KB）（92）       Knowledge map    Save This paper uses the power system of Bao Steel Group as an example and introduces the concepts and characters of the data warehouse. The designing method of data warehouse is given. An OOP data schema based on snowflake schema is given. This paper explains the way of the gathering and visualization of the data. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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A Numerical and Experimental Study of the Ventilation of Light-duty Bus CHEN Jiang-ping, SUN Zhao-pu, QUE Xiong-cai, CHEN Zhi-jiu Journal of Applied Sciences    2002, 20 (2): 169-172.   Abstract （395）      PDF（pc） （191KB）（140）       Knowledge map    Save A 3-dimensional ventilation model of a light-duty bus is established by taking the duct into account. The air velocity and temperature inside the passenger compartment are analyzed numerically and experimentally. Both results show that the cooled air flux of discharges are decided by the steady pressure distribution in duct interior. The uniformity of discharge-air can be improved by enlarging the flow area of the duct or using the contractive duct. To simplify the technological process a new duct with 40% flow area enlarged are recommended for the vehicle under study. Related Articles | Metrics | Comments（0） Cited: Baidu(12)

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B-spline Surface Reconstruction Based on Digitized Section Data ZHANG Li-yan, ZHOU Lai-shui, CAI Wei-bin, ZHOU Ru-rong Journal of Applied Sciences    2002, 20 (2): 173-177.   Abstract （363）      PDF（pc） （236KB）（104）       Knowledge map    Save Digital model reconstruction based on coordinate measuring of existing physical objects is widely used in a variety of situations. The data obtained through popular measuring machines, such as laser scanners, are mostly digitized data organized in sections. In this paper, the problem of B-spline surface fitting based on digitized section data is addressed. An algorithm, which combined bisection and least square method, is put forward. The algorithm can greatly compress the digitized points and generate compact-surface representation while satisfying the given tolerance. Examples in the paper show that the algorithm is effective and practical. Related Articles | Metrics | Comments（0） Cited: Baidu(9)

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Fuzzy Reasoning Based on Similarity Measure Between the Elements of Vague Sets LI Fan, XU Zhang-yan, CAI Li-jing Journal of Applied Sciences    2002, 20 (2): 178-182.   Abstract （423）      PDF（pc） （202KB）（127）       Knowledge map    Save In this paper, we give a method of similarity measure between the elements of vague sets. 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 rule and that in the consequent of rule. We also give a method of approximate reasoning based on similarity measure between the elements of vague sets. When the membership functions of vague set are discrete functions, after giving one-to-one mapping between the universe of discourse of fuzzy terms in the antecedent of rule and that in the consequent of rule, we present a method of linear interpolation into the true/false membership functions of the vague sets for the antecedent of rule and fact, converting them into continuous functions. Finally, we provide a method of approximate reasoning based on similarity measure between the elements of vague sets. Related Articles | Metrics | Comments（0） Cited: Baidu(11)

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Correlation Function of the Highest Lever Sequences of Primitive Sequences over Z4 LI Chao, FENG Ke-qin, FENG Guo-zhu Journal of Applied Sciences    2002, 20 (2): 183-187.   Abstract （451）      PDF（pc） （218KB）（99）       Knowledge map    Save In this paper, possible values of the correlation function of the highest lever sequences of primitive sequences over Z4 are determined. Related Articles | Metrics | Comments（0）

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