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1992 Vol. 14, No. 1
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1992, 14(1): 1-6.
Abstract:
A new method for analysing dynamics of continuous competitive neuralnetworks has been proposed, and the necessary convergence conditions for a class of associative networks has been obtained. Based on the stability criterion and the equations of equilibrium set of the network, synthesis of a class of associative neural networks has been given. The stability control model of asymmetric unstable networks has been suggested, which is also a valid way for optimization and dynamic control of the stable neural n...
A new method for analysing dynamics of continuous competitive neuralnetworks has been proposed, and the necessary convergence conditions for a class of associative networks has been obtained. Based on the stability criterion and the equations of equilibrium set of the network, synthesis of a class of associative neural networks has been given. The stability control model of asymmetric unstable networks has been suggested, which is also a valid way for optimization and dynamic control of the stable neural n...
1992, 14(1): 7-14.
Abstract:
A new auditory system model based on a combination of physiological andpsychological acoustic data has been proposed. This model consists of a bank of nonuniform bandpass filters, detectors and main-frequency choosing mechanisms, they act as basilar membranes, inner hair cells and nerve fibers, respectively. Combining with the improved critical bandwidth parameters, the input to this model is analogous to the pressure at the eardrum, and the output of this model simulates various features of the firing patterns. The synthesizer obtains the resultant speech by use of the simple adding method. Computer simulations show that the resultant speech is highly intelligible and natural. The proposed model is correct, and the improvement of the critical bandwidth parameters is effective.
A new auditory system model based on a combination of physiological andpsychological acoustic data has been proposed. This model consists of a bank of nonuniform bandpass filters, detectors and main-frequency choosing mechanisms, they act as basilar membranes, inner hair cells and nerve fibers, respectively. Combining with the improved critical bandwidth parameters, the input to this model is analogous to the pressure at the eardrum, and the output of this model simulates various features of the firing patterns. The synthesizer obtains the resultant speech by use of the simple adding method. Computer simulations show that the resultant speech is highly intelligible and natural. The proposed model is correct, and the improvement of the critical bandwidth parameters is effective.
1992, 14(1): 15-20.
Abstract:
constructing method for n-terminal equivalent subnetwork is developed, and a transformation of voltage equations for transposing reference nodes is given. These should have not only theoretical but also practical significance. And the computing speed can be increased, the memory space can be saved.
constructing method for n-terminal equivalent subnetwork is developed, and a transformation of voltage equations for transposing reference nodes is given. These should have not only theoretical but also practical significance. And the computing speed can be increased, the memory space can be saved.
1992, 14(1): 21-28.
Abstract:
A decomposition approach of logic functiony is discussed. The design method, by which the minimization or near minimization of tree-type logic networks can be obtained, is presented when multiple variables combinational logic function is implemented by using multiplexers. Using the method, the automatic synthesis of the logic function can easily be accomplished on conputers.
A decomposition approach of logic functiony is discussed. The design method, by which the minimization or near minimization of tree-type logic networks can be obtained, is presented when multiple variables combinational logic function is implemented by using multiplexers. Using the method, the automatic synthesis of the logic function can easily be accomplished on conputers.
1992, 14(1): 29-34.
Abstract:
How to start oscillation and how to stabilize amplitude in SC oscillators are discussed. New methods for start-oscillation and amplitude-stabilization of SC oscillators are presented. The control circuitry with good stability for amplitude-stabilization is given. It is shown that the complexity of the amplitude-stabilization circuitry does not increase as the number of oscillator phases in the multiphase oscillator increases. The experimental results are in agreement with the presented theory.
How to start oscillation and how to stabilize amplitude in SC oscillators are discussed. New methods for start-oscillation and amplitude-stabilization of SC oscillators are presented. The control circuitry with good stability for amplitude-stabilization is given. It is shown that the complexity of the amplitude-stabilization circuitry does not increase as the number of oscillator phases in the multiphase oscillator increases. The experimental results are in agreement with the presented theory.
1992, 14(1): 35-40.
Abstract:
A novel algorithm based on the spatial third-order cumulants is presented. This algorithm is independent of the coherence of signals and the correlaton of the additive noises with high resolution. The simulation results demonstrate the effectiveness of this scheme.
A novel algorithm based on the spatial third-order cumulants is presented. This algorithm is independent of the coherence of signals and the correlaton of the additive noises with high resolution. The simulation results demonstrate the effectiveness of this scheme.
1992, 14(1): 41-49.
Abstract:
A large-signal model for GaAs FET is derived based on its small-signal S parmeter and DC characteristics. The harmonic balance algorithm is applied to analyze and optimize the FET fundamental and harmonic oscillators, and the values of steady current are obtained. In the solving process, a simplified CAD approach is used to obtained the parameters of matching network when the output power is maximum. Finally, a fundamental oscillator and a harmonic oscillator of Q-band are fabricated. The measurements show that the theoratical analysis and experimental results are in good agreement.
A large-signal model for GaAs FET is derived based on its small-signal S parmeter and DC characteristics. The harmonic balance algorithm is applied to analyze and optimize the FET fundamental and harmonic oscillators, and the values of steady current are obtained. In the solving process, a simplified CAD approach is used to obtained the parameters of matching network when the output power is maximum. Finally, a fundamental oscillator and a harmonic oscillator of Q-band are fabricated. The measurements show that the theoratical analysis and experimental results are in good agreement.
1992, 14(1): 50-60.
Abstract:
By applying hypergraph theory, algorithm RFCMHGT is presented fordetermining the realizability of a given directed fundamental cutset matrix Qf and synthesizing its corresponding directed graph G layer by layer from its tree path submatrix Qfp. Its principle is intuitive and its computational complexity is O(nl2). where n and l are the numbers of rows and columns of Qfp. Example 2 shows that Tutte s condition is not the sufficient condition for Qf to be realizable.
By applying hypergraph theory, algorithm RFCMHGT is presented fordetermining the realizability of a given directed fundamental cutset matrix Qf and synthesizing its corresponding directed graph G layer by layer from its tree path submatrix Qfp. Its principle is intuitive and its computational complexity is O(nl2). where n and l are the numbers of rows and columns of Qfp. Example 2 shows that Tutte s condition is not the sufficient condition for Qf to be realizable.
1992, 14(1): 61-70.
Abstract:
The mathematical model of spaceborne SAR systems and its computer simulations are described. Results of computer simulations about range migration, range migration correction, azimuth weighting and azimuth signal generation/processing are given. This software can be used to simulate the dynamical process in spaceborne SAR system, to develop new signal processing technique and to evaluate the performance of the designed system.
The mathematical model of spaceborne SAR systems and its computer simulations are described. Results of computer simulations about range migration, range migration correction, azimuth weighting and azimuth signal generation/processing are given. This software can be used to simulate the dynamical process in spaceborne SAR system, to develop new signal processing technique and to evaluate the performance of the designed system.
1992, 14(1): 71-75.
Abstract:
A new method, panel method, for Radar Cross-Section (RCS) computations of arbitrarily complicated objects is put forward based on the work by D. Klement et al. (1988). The method has a high speed for calculation, and is convenient for application. By the method, the RCS of classic scatterers, for example, cones and cylinders, are computed, and the calculated results agree with the experimental ones. Then, the RCS of a aircraft model at various attitudes are computed, the obtained results agree with the experimental ones. Then, the RCS of a aircraft model at various attitudes are computed, the obtained results agree with the experimental ones also.
A new method, panel method, for Radar Cross-Section (RCS) computations of arbitrarily complicated objects is put forward based on the work by D. Klement et al. (1988). The method has a high speed for calculation, and is convenient for application. By the method, the RCS of classic scatterers, for example, cones and cylinders, are computed, and the calculated results agree with the experimental ones. Then, the RCS of a aircraft model at various attitudes are computed, the obtained results agree with the experimental ones. Then, the RCS of a aircraft model at various attitudes are computed, the obtained results agree with the experimental ones also.
1992, 14(1): 76-80.
Abstract:
Monte Carlo method is used to simulate the whole courses of electronictransportation, collision and secondary emission in a single channel of MCP. The energy distribution formula of secondary electron of MCP is derived. Each parameter of a single channel in MCP is calculated and discussed.
Monte Carlo method is used to simulate the whole courses of electronictransportation, collision and secondary emission in a single channel of MCP. The energy distribution formula of secondary electron of MCP is derived. Each parameter of a single channel in MCP is calculated and discussed.
1992, 14(1): 81-85.
Abstract:
A new iterative method for signal restoration has been presented. Anestimate operator Wk that is related to error operator Bk in the restoration process is introduced to decrease the estimate error and increase the convergence rate. The effect of noise on the estimate process has been described. Finally, the method has been applied to the deconvolu-tion of a blurred signal, the results of which validate the theory. The comparison between presented method and general method has also been given.
A new iterative method for signal restoration has been presented. Anestimate operator Wk that is related to error operator Bk in the restoration process is introduced to decrease the estimate error and increase the convergence rate. The effect of noise on the estimate process has been described. Finally, the method has been applied to the deconvolu-tion of a blurred signal, the results of which validate the theory. The comparison between presented method and general method has also been given.
1992, 14(1): 86-91.
Abstract:
The matrix direct product is generalized and two kinds of direct products are given by Wang Zhongde (1989). These two kinds of direct products are applied to the construction of orthogonal transforms. In this paper, Wang Zhongde s work is generalized further, and a kind of direct product of matrix block is given. It is also used to construct the orthogonal transforms.
The matrix direct product is generalized and two kinds of direct products are given by Wang Zhongde (1989). These two kinds of direct products are applied to the construction of orthogonal transforms. In this paper, Wang Zhongde s work is generalized further, and a kind of direct product of matrix block is given. It is also used to construct the orthogonal transforms.
1992, 14(1): 92-95.
Abstract:
A new 8 mm high-performance sum-frequency upconverter is described. Ttsconversion loss is 2.9 dB; its output power is 1.34mW at 1 dB compression point. As the power of sum-frequency signal below 1mW, the upconverter shows a very good linearity. Sum-frequency signal is 30 dB higher than stray spectrum. The isolation of each port is over 40 dB.
A new 8 mm high-performance sum-frequency upconverter is described. Ttsconversion loss is 2.9 dB; its output power is 1.34mW at 1 dB compression point. As the power of sum-frequency signal below 1mW, the upconverter shows a very good linearity. Sum-frequency signal is 30 dB higher than stray spectrum. The isolation of each port is over 40 dB.
1992, 14(1): 96-100.
Abstract:
Continuously tunable 75-110 GHz Gunn Oscillators have been developedwith WT 57 GaAs diodes. In most cases, the oscillators can offer 10-20 mW output power over a bandwidth of 10-15 GHz. The characteristics of bias electronic tuning are tested using the bias sweep method.
Continuously tunable 75-110 GHz Gunn Oscillators have been developedwith WT 57 GaAs diodes. In most cases, the oscillators can offer 10-20 mW output power over a bandwidth of 10-15 GHz. The characteristics of bias electronic tuning are tested using the bias sweep method.
1992, 14(1): 101-105.
Abstract:
A novel two way rotary junctor is presented. One way of the rotarv junctor is designed at S band, and another way is designed at P band. The VSWR for S band rotary junctor is less than 1.2 in the 1.2-4.4 GHz frequency range. A reentrant resonant cavity is used for the design of the P band roiary junctor in order to reduce the length of the rotary junctor. The total length of two way rotary junctor is /4 approximately. It satisfies the needs for the especially small size.
A novel two way rotary junctor is presented. One way of the rotarv junctor is designed at S band, and another way is designed at P band. The VSWR for S band rotary junctor is less than 1.2 in the 1.2-4.4 GHz frequency range. A reentrant resonant cavity is used for the design of the P band roiary junctor in order to reduce the length of the rotary junctor. The total length of two way rotary junctor is /4 approximately. It satisfies the needs for the especially small size.
1992, 14(1): 106-109.
Abstract:
A fast computing scheme for the mement method with entire domain bases used for solving integral equations arisen in antenna radiation and scattering is proposed. By using this scheme, the computing time required to evaluate the generalized impedance matrix can he reduced to a very small portion of that of the conventional scheme. Because fewer bases are needed when using the entire domain bases, this scheme will certainly decrease the total comput-ing time significantly. Its effectiveness is confirmed by the numerical examples. For long an- tenna or bent antenna, a kind of subsectional entire domain bases is proposed in order that the fast computing scheme can be used and the accumulatidn of the numerical errors can be re- duced.
A fast computing scheme for the mement method with entire domain bases used for solving integral equations arisen in antenna radiation and scattering is proposed. By using this scheme, the computing time required to evaluate the generalized impedance matrix can he reduced to a very small portion of that of the conventional scheme. Because fewer bases are needed when using the entire domain bases, this scheme will certainly decrease the total comput-ing time significantly. Its effectiveness is confirmed by the numerical examples. For long an- tenna or bent antenna, a kind of subsectional entire domain bases is proposed in order that the fast computing scheme can be used and the accumulatidn of the numerical errors can be re- duced.
1992, 14(1): 110-112.
Abstract:
A new single-amplifier switcbed-cap acitor filter using unity-gain amplifier is presented. When used for the relation of high Q bandpass characteristic, the circuit can obtain much less capacitor spread, and its capacitor spread, compared with other circuits given by literatures, is reduced significantly.
A new single-amplifier switcbed-cap acitor filter using unity-gain amplifier is presented. When used for the relation of high Q bandpass characteristic, the circuit can obtain much less capacitor spread, and its capacitor spread, compared with other circuits given by literatures, is reduced significantly.
