Showing papers in "Journal of Electronics (china) in 1998"
TL;DR: A queue model of the polling system with limited service (K=1) in discrete time is analyzed by the imbedded Markov chain theory and the probability generating function method and the mean values of queue length and message waiting time are explicitly obtained.
Abstract: This paper analyzes a queue model of the polling system with limited service (K=1) in discrete time. By the imbedded Markov chain theory and the probability generating function method, the mean values of queue length and message waiting time are explicitly obtained. Also, we give the simulation results. The results obtained by H. Tagai (1985) are revised.
20 citations
TL;DR: It is seen that greater ratio of pulse compression and suppression of range sidelobe in SIAR can be obtained, and its effective range and range resolution is increased as well.
Abstract: Sparse-array Synthetic Impulse and Aperture Radar (SIAR) can isotropically radiate by employing multiple frequencies (synthetic pulse) and multiple antennas (synthetic antenna). According to Ambiguity Function(AF), its range resolution depends only on bandwidth of transmitted signals, however, the distance grating lobes emerge when increasing the time-bandwidth product of transmitted signals. The performance of pulse compression is analyzed with the transmitted signals modulated by phase-coded sequences. It is seen that greater ratio of pulse compression and suppression of range sidelobe in SIAR can be obtained, and its effective range and range resolution is increased as well.
10 citations
TL;DR: The proposed neural network can be used to solve the analog diagnosis L1 problem and the fault location L1 method can be solved with less computing time through only one optimization processing.
Abstract: Based on exact penalty function, a new neural network for solving the L1-norm optimization problem is proposed. In comparison with Kennedy and Chua’s network(1988), it has better properties.Based on Bandler’s fault location method(1982), a new nonlinearly constrained L1-norm problem is developed. It can be solved with less computing time through only one optimization processing. The proposed neural network can be used to solve the analog diagnosis L1 problem. The validity of the proposed neural networks and the fault location L1 method are illustrated by extensive computer simulations.
6 citations
TL;DR: The sufficient conditions of existence, uniqueness, and globally asymptotic stability of the equilibrum position are given and two interesting examples to illustrate the theory are given.
Abstract: In this paper the globally asymptotic stability of more general two-layer nonlinear feedback associative memory neural networks with time delays is examined. The sufficient conditions of existence, uniqueness and globally asymptotic stability of the equilibrum position are given. Finally, two interesting examples to illustrate the theory are given.
6 citations
TL;DR: The global exponential stability of an equilibrium position for general bidirectional associative memory neural networks are studied and the sufficient conditions and uniqueness of the equilibrium position are given.
Abstract: In this paper, the global exponential stability of an equilibrium position for general bidirectional associative memory neural networks are studied. The sufficient conditions of existence and uniqueness of the equilibrium position are given. The method of energy function is examined. Two examples are given to illustrate the theory.
5 citations
TL;DR: By using the theory of clipping voltage-switches, two kinds of master/slave nMOS quaternary flip-flops are designed that have the capability of two-input presetting and double-rail complementary outputs.
Abstract: By using the theory of clipping voltage-switches, two kinds of master/slave nMOS quaternary flip-flops are designed. These flip-flops have the capability of two-input presetting and double-rail complementary outputs. It is shown that these flip-flops are effectively suitable to design nMOS quaternary sequential circuits by designing two examples of hexadecimal up-counter and decimal up-counter.
3 citations
TL;DR: The simulation results show that the new proposed detector has the best detection performance in homogeneous as well as nonhomogeneous background conditions, while TGS procedure is better than the GS detector in distinguishing the primary target from the secondary interfering ones.
Abstract: This paper is devoted to the performance evaluation of the Generalized Sign(GS), Trimmed Generalized Sign(TGS), Modified Savage(MS), Mann-Whitney(MW) and a new proposed detector in multiple target situations. The analysis is carried out for both fluctuating and nonfluctuating received signals. The simulation results show that the new proposed detector has the best detection performance in homogeneous as well as nonhomogeneous background conditions, while TGS procedure is better than the GS detector in distinguishing the primary target from the secondary interfering ones.
3 citations
TL;DR: A new nonparametric detection method, which not only does less computation, but also is able to detect multiple extended targets radially distributed along distance “corridor” based on the position (range) correlation information of one-dimensional range images of high resolution radar targets.
Abstract: This paper studies a detection method of targets of high resolution radar operating at the band of millimeter-wave(32∼38GHz) under the background of the clutters, and proposes a new nonparametric detection method, which not only does less computation, but also is able to detect multiple extended targets radially distributed along distance “corridor”, based on the position (range) correlation information of one-dimensional range images(or called range profiles) of high resolution radar targets. The experimental results, on the real echo data of tank illuminated by the millimeter-wave stepped frequency high resolution radar, have certified that such a method presented in this paper is a very effective detection method for multiple extended targets.
3 citations
TL;DR: This work uses a fuzzy estimator to evaluate the fitness of chromosomes in a genetic algorithm and adaptively training it in the evolutionary process to reduce the computation time of the algorithm.
Abstract: Using a fuzzy estimator to evaluate the fitness of chromosomes in a genetic algorithm and adaptively training it in the evolutionary process, the genetic algorithm with fuzzy fitness evaluation is proposed to reduce the computation time of the algorithm. An analysis on the optimization performance of the proposed algorithm shows that it maintains good performance with its computation time saved. Finally, simulation results on design of a fuzzy controller are presented.
3 citations
TL;DR: In this paper, the analysis of open microstrip structures by using diakoptic method of lines (ML) combined with periodic boundary conditions (PBC) was presented, where the parameters of microstrip patch are obtained from patch current excited by plane wave.
Abstract: This paper presents the analysis of open microstrip structures by using diakoptic method of lines (ML) combined with periodic boundary conditions (PBC). The parameters of microstrip patch are obtained from patch current excited by plane wave. Impedance matrix elements are computed by using fast Fourier transform(FFT), and reduced equation is solved by using diakoptic technique. Consequently, the computing time is reduced significantly. The convergence property of simulating open structure by using PBC and the comparison of the computer time between using PBC and usual absorbing boundary condition (ABC) show the validity of the method proposed in this paper. Finally, the resonant frequency of a microstrip patch is computed. The numerical results obtained are in good agreement with those published.
2 citations
TL;DR: In this article, a generalization of the notations and properties of 2-band wavelet packets to that of M-band Wavelet packets is made and corresponding proofs are given.
Abstract: In recent years, M-band orthonormal wavelet bases, due to their good characteristics, have attracted much attention. The ability of 2-band wavelet packets to decompose high frequency channels can be employed to improve the performance of wavelets for time-frequency localization, which makes more kinds of signals for analyzing by wavelets. Similar to the notations from the extension of 2-band wavelets to 2-band wavelet packets, the theoretic framework of M-band wavelet packets is developed, a generalization of the notations and properties of 2-band wavelet packets to that of M-band wavelet packets is made and the corresponding proofs are given.
TL;DR: Experimental results show that the proposed genetic algorithm is an efficient global optimization algorithm and hybrid algorithm which takes the BP algorithm as a mutation operator is used to train a neural network for image recognition.
Abstract: A new genetic algorithm is proposed for the optimization problem of real-valued variable functions. A new robust and adaptive fitness scaling is presented by introducing the median of the population in exponential transformation. For float-point represented chromosomes, crossover and mutation operators are given. Convergence of the algorithm is proved. The performance is tested by two generally used functions. Hybrid algorithm which takes the BP algorithm as a mutation operator is used to train a neural network for image recognition. Experimental results show that the proposed algorithm is an efficient global optimization algorithm.
TL;DR: A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using a generalized spectral Green’s function formulation of N-layer substrate structure with three dimension sources.
Abstract: A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using the above spectral Green’s function. The unknown surface current density on the microstrip patch for such structure is found as a solution of an integral equation. The input VSWR and radiation patterns of the antenna are also obtained. The numerical results have been verified by the experimental results.
TL;DR: In this paper, modifications to the finite-difference time-domain (FD-TD) method for modeling microwave pulse coupling into a slot, which is much narrower than one conventional FD-TD cell, are discussed.
Abstract: In this paper, modifications to the finite-difference time-domain(FD-TD) method for modeling microwave pulse coupling into a slot, which is much narrower than one conventional FD-TD cell, are discussed. The coupling process of microwave pulse into a slot is studied by using the modified FD-TD method, and the dependence of microwave coupling on slot sizes, the carrier frequencies and the polarization directions of the incident waves is analysed. Resonant and enhancement effects which occur in this process are observed. The condition at which the resonant effect takes place is also presented.
TL;DR: A multisensor distributed extended Kalman filtering algorithm is presented for nonlinear system, in which the dynamic equation of the system and the equations of sensor’s measurements are linearized in the global estimate and global prediction respectively and the suboptimal global estimate can be reconstructed from the estimates computed by local sensors based solely on their own local information.
Abstract: A multisensor distributed extended Kalman filtering algorithm is presented for nonlinear system, in which the dynamic equation of the system and the equations of sensor’s measurements are linearized in the global estimate and global prediction respectively and the suboptimal global estimate based on all available information can be reconstructed from the estimates computed by local sensors based solely on their own local information and transmitted to the data fusion center. An analysis of the properties of the algorithm presented here shows that the global estimate has higher precision than the local one and smaller linearization error than the existing method. Finally, an application of the algorithm to radar/IR tracking of a maneuvering target is illustrated. Simulation results show the effectiveness of the algorithm.
TL;DR: The paper presents a complete composite gate turn-off thyristor (GTO) model, which is based on the combination of the p-n-p and n-p-n transistor models, and calculated results show that it corresponds statically and dynamically with the practical device.
Abstract: The paper presents a complete composite gate turn-off thyristor (GTO) model, which is based on the combination of the p-n-p and n-p-n transistor models. PSpice simulations and parametric sensitive analysis are performed with the complete composite model and calculated results are given, which show that it corresponds statically and dynamically with the practical device. In particular, the GTO gate dynamical characteristics in practical circuits are discussed and experimental results are included.
TL;DR: In this paper, a large class of linear structural functions satisfying the condition of correlational immunity of order one are constructed by studying the linear structural Boolean functions, and the known enumeration bounds of correlation-immune functions are greatly improved.
Abstract: A large class of linear structural functions(LSF) satisfying the condition of correlational immunity of order one are constructed by studying the linear structural Boolean functions. With these new founded functions, the known enumeration bounds of correlation-immune functions of order one are greatly improved. In fact, the best, up to now, lower bound is found.
TL;DR: In this paper, a rotational invariance technique for blind estimates of direction of arrival (DOA) and Doppler frequency with unknown array manifold due to array sensor uncertainties is proposed.
Abstract: A novel rotational invariance technique for blind estimates of direction of arrival (DOA) and Doppler frequency with unknown array manifold due to array sensor uncertainties is proposed, taking Doppler frequency difference between a successive pulses as rotational parameter. The effectiveness of the new method is confirmed by computer simulation. Compared with the existing 2-D DOA-frequency estimate techniques, the computation load of the proposed method can be saved greatly.
TL;DR: In this article, a styrofoam layer is introduced to the cryogenic calibration load for microwave radiometers in order to keep the antenna at ambient temperature while calibrating Obviously the insulation layer has nonuniform temperature profile.
Abstract: A styrofoam layer is introduced to the cryogenic calibration load for microwave radiometers in order to keep the antenna at ambient temperature while calibrating Obviously the insulation layer has nonuniform temperature profile A novel approach based on the transmission-line theory is presented to calculate the emission from the load According to the sample calculation through this new approach, the contribution of the insulation layer to the load radiation can not be neglected
TL;DR: In this paper, numerical simulations were developed and applied to polarized scattering from random clusters of spatially-oriented, non-spherical particles, and the functional dependence on particle shape, size, spatial distribution and orientation, and other physical parameters.
Abstract: Employing multiple scattering formulation of T-matrix method, numerical simulations are developed and applied to polarized scattering from random clusters of spatially-oriented, non-spherical particles. Polarized scattering is numerically presented for the functional dependence on particle shape, size, spatial distribution and orientation, and other physical parameters. Numerical calculations of backscattering from randomly clustered particles are well compared with that from independent particles and clusters. It can be seen that spatial distribution and orientation of non-spherical particles can have significant effect on scattering.
TL;DR: The Perfectly Matched Layer (PML) technique as discussed by the authors yields a robust Absorbing Boundary Condition (ABC) independent of the angle of incidence and the frequency of outgoing waves.
Abstract: The key problem of finite-difference time-domain (FD-TD) method is the skillful application of special conditions on the boundaries of the computational domain. A new technique named Perfectly Matched Layer(PML) yields a robust Absorbing Boundary Condition(ABC) independent of the angle of incidence and the frequency of outgoing waves. In this paper, the principle of the PML technique is briefly presented. Then some problems in the application and their settlements are discussed emphatically. Finally three numerical tests and a measured result are devoted to examine the accuracy and effectiveness of this approach.
TL;DR: For full response linear modulation signal, a interpolation criterion is proposed and an interpolation formula is presented on bandwidth-limited transmission signal, using the raised cosine roll off function as the system pulse response.
Abstract: All digital implementation of receiver is a main topic on digital communication recently. The design of interpolation filter is one of the important problems for all digital implementation of receiver. In this paper, for full response linear modulation signal, a interpolation criterion is proposed. An interpolation formula is presented on bandwidth-limited transmission signal. For example, using the raised cosine roll off function as the system pulse response, the feasibility and effectiveness on the interpolation formula are certified by theoretical and numerical analysis. The computer simulation result on 16-QAM signal is given.
TL;DR: The new method is improved further in DCT domain and coding results show the advantage of the new method.
Abstract: Some shortcomings of common fractal image coding methods are studied, then they are corrected with a new method. The new method is improved further in DCT domain. Coding results show the advantage of the new method.
TL;DR: In this article, the authors studied the almost sure convergence of the third and fourth-order moment and cumulant estimates of stationary processes under certain conditions, and showed that the convergence rate of these estimates is asymptotic normal.
Abstract: The sample estimates of higher-order statistics are studied. Under certain conditions, the almost sure convergence of the third- and fourth-order moment and cumulant estimates of stationary processes is established. The rate of almost sure convergence is obtained for the sample estimates of third- and fourth-order moment and cumulant. Additionally, it is shown that the third- and fourth-order moment and cumulant estimates are asymptotic normal.
TL;DR: In this paper, a new maximum likelihood (ML) classification algorithm is proposed to classify the multi-look polarimetric synthetic aperture radar (SAR) imagery, which is used for terrain type classification.
Abstract: In this paper, a new maximum likelihood (ML) classification algorithm is proposed to classify the multi-look polarimetric synthetic aperture radar (SAR) imagery. Experimental results with the NASA/JPL airborne L-band polarimetric SAR data demonstrate the effectiveness of the new algorithm. Furthermore, when using the algorithm in the classifications with subsets of the multi-look polarimetric SAR data, the polarization-channel optimization for the terrain type classification is implemented.
TL;DR: A novel estimating multiple frequencies approach of signal with sampling rate which is least Nyquist sampling rate is presented and with choosing delay time properly, the estimated frequencies are unambiguous.
Abstract: Based on time delay technology and MUSIC algorithm, a novel estimating multiple frequencies approach of signal with sampling rate which is least Nyquist sampling rate is presented in this paper. With choosing delay time properly, the estimated frequencies are unambiguous. Computer simulation confirms its availability.
TL;DR: This paper gives the best ideal sets (i. e. the best biphase code sets whose maximal sidelobe not more than 2) for all code length N≤12, which have been obtained from binary sequences by means of the best codes sieving method suggested by Yang Guangzheng, et al.
Abstract: A canceling range sidelobes scheme has been suggested by Yang Guangzheng, et al.,(1997) this technology is based on the fact that all sidelobe of group correlation function of ideal sets are zero. At first, this paper gives the best ideal sets (i. e. the best biphase code sets whose maximal sidelobe not more than 2) for all code length N≤12, which have been obtained from binary sequences by means of the best codes sieving method suggested by Yang Guangzheng, et al.(1997) Computer simulation for group correlation property of best ideal sets for code length N=12 on various conditions is made. Simulation result shows that the sidelobe level of best ideal set with no weighting is zero, under condition of zero-Doppler shift and has ultra-low sidelobe on Doppler up to 5kHz with no weighting and whose tolerance of phase and amplitude distortion is bigger too.
TL;DR: Based on scalar diffraction optics theory, a new type of mm-wave antenna(diffraction antenna) phase-correcting Fresnel zone plate with continuous structure is described in this paper.
Abstract: Based on scalar diffraction optics theory, a new type of mm-wave antenna(diffraction antenna) phase-correcting Fresnel zone plate with continuous structure is described in this paper. It has the advantages of thinner thickness, lighter weight and design flexibility. The design theory and space shadow are discussed in details, and the measured results are presented. The results show that the properties of this kind of antenna is closed to paraboloid reflector.
TL;DR: The loss rates of the cells with different priorities in an ATM Mux are analyzed by approximating the actual input process with two-state MMDP and fluid flow technique, and the analytical expressions of the relation between the loss rates and the buffer size are obtained.
Abstract: The analysis of cell loss rates in an ATM Mux with loss priorities is an important problem in the study of traffic control in ATM networks. In this paper, the loss rates of the cells with different priorities in an ATM Mux are analyzed by approximating the actual input process with two-state MMDP and fluid flow technique, and the analytical expressions of the relation between the loss rates and the buffer size are obtained. Simulation shows that the approach is sufficiently accurate for applications.
TL;DR: A kind of Chinese combined language model that takes into account POS(part of speech) information in a trigram-based statistical language model, that is superior to trigram model in dependence on testing text domain is presented.
Abstract: A kind of Chinese combined language model, that takes into account POS(part of speech) information in a trigram-based statistical language model, is presented in the paper. The theoretical analysis and experiments all show that the model not only is lower than trigram model in PP(perplexity), but also is superior to trigram model in dependence on testing text domain.