ISSN 
1998 Vol. 27, No. 3
1998, 27(3): 225-230.
Abstract:
Phase unwrapping is an important step in interferometric synthetic aperture radar(INSAR).By using local Radon transform,this paper put forwards a kind of method for phase unwrapping of INSAR which based on the same phase path searching.A method for phase correcting by setting reference phase of the ground is also given.The method given in this paper has the advantages of stability and less error,which is very useful and realistic in phase unwrapping.By using the L band data of SIR-C of the Three-Gorgess area of China,the local DEM(digital elevation map) is obtained.
Phase unwrapping is an important step in interferometric synthetic aperture radar(INSAR).By using local Radon transform,this paper put forwards a kind of method for phase unwrapping of INSAR which based on the same phase path searching.A method for phase correcting by setting reference phase of the ground is also given.The method given in this paper has the advantages of stability and less error,which is very useful and realistic in phase unwrapping.By using the L band data of SIR-C of the Three-Gorgess area of China,the local DEM(digital elevation map) is obtained.
1998, 27(3): 231-235.
Abstract:
In the ressearch of multiresolution data fusion algorithm, the quadrature mirrorfilter (QMF) and B-spline wavelet with linear phase are designed and used to decompose and reconstruct signals in this paper. The result shows that the performance of reconstruction is excellent.
In the ressearch of multiresolution data fusion algorithm, the quadrature mirrorfilter (QMF) and B-spline wavelet with linear phase are designed and used to decompose and reconstruct signals in this paper. The result shows that the performance of reconstruction is excellent.
1998, 27(3): 236-240.
Abstract:
A multiresolution 64-level QAM (quadrature amplitude modulation) for application of terrestrial digital HDTV broadcating is investigated in this paper.The bit error rate (BER) performance of MR-64QAM in the presence of additive Gaussian noise and Rayleigh fading is derived and simulated with computer.The results indicate the evaluated BER performace coincide with the simulation results.In order to improve the BER performance of MR-64QAM in the presence of Rayleigh fading,a concatenated coded modulation must be required.
A multiresolution 64-level QAM (quadrature amplitude modulation) for application of terrestrial digital HDTV broadcating is investigated in this paper.The bit error rate (BER) performance of MR-64QAM in the presence of additive Gaussian noise and Rayleigh fading is derived and simulated with computer.The results indicate the evaluated BER performace coincide with the simulation results.In order to improve the BER performance of MR-64QAM in the presence of Rayleigh fading,a concatenated coded modulation must be required.
1998, 27(3): 241-245.
Abstract:
Based on a uniform linear L-typical signal received array and ESPRIT algorithm,a new separable method for estimating two dimensional(2 D) directions of arrival of multiple narrow-band spatial signals simultaneously is proposed in this paper.A paring method of azimuth and elevation of signals is given as well.Since the estimation of azimuth has the same architecture as the estimation of elevation of signals,it can be realized in parallel way.The simulation results on computer confirm its availability.
Based on a uniform linear L-typical signal received array and ESPRIT algorithm,a new separable method for estimating two dimensional(2 D) directions of arrival of multiple narrow-band spatial signals simultaneously is proposed in this paper.A paring method of azimuth and elevation of signals is given as well.Since the estimation of azimuth has the same architecture as the estimation of elevation of signals,it can be realized in parallel way.The simulation results on computer confirm its availability.
1998, 27(3): 246-250.
Abstract:
The information of low probability interception (LPI) signals is useful in practice,but LPI signals are often hided or put in jammer,which show more difficulty in direction-finding.This paper exploits the characters of signals and uses spectral correlation theory in direction-finding of LPI signals in jammer.The simulation results show that the combination of array direction-finding and spectral correlation theory can get better results than the method of MUSIC in direction-finding of LPI signals.
The information of low probability interception (LPI) signals is useful in practice,but LPI signals are often hided or put in jammer,which show more difficulty in direction-finding.This paper exploits the characters of signals and uses spectral correlation theory in direction-finding of LPI signals in jammer.The simulation results show that the combination of array direction-finding and spectral correlation theory can get better results than the method of MUSIC in direction-finding of LPI signals.
1998, 27(3): 251-255.
Abstract:
Recently,neural network optimization (NNO) technique has been proved to be an efficient approach for designing FIR filters.This paper makes an attemp to generalize the NNO technique to design ⅡR digital filters.For this aim a high order neural network (HONN) is used to form the Lyapunov function which corresponds to the MSE in designing the ⅡR.The convergency of the algorithm is addressed and an LP ⅡR simulation example is given to verify the effectiveness of the NNO design technique.
Recently,neural network optimization (NNO) technique has been proved to be an efficient approach for designing FIR filters.This paper makes an attemp to generalize the NNO technique to design ⅡR digital filters.For this aim a high order neural network (HONN) is used to form the Lyapunov function which corresponds to the MSE in designing the ⅡR.The convergency of the algorithm is addressed and an LP ⅡR simulation example is given to verify the effectiveness of the NNO design technique.
1998, 27(3): 256-260.
Abstract:
Nowadays,the WDM network can not hold more than tens of channels,and the broad-band network normally need support a lot of nodes.This paper,proposes a distribution method of the network channels based on the condition that the node number is bigger than the channel number.Some of the network properties are analyzed through mathematical method,based on the distrbution methed.This paper also find a new method to utilized the limited channel resource.Moreover,the optimal number of data slat is studied.
Nowadays,the WDM network can not hold more than tens of channels,and the broad-band network normally need support a lot of nodes.This paper,proposes a distribution method of the network channels based on the condition that the node number is bigger than the channel number.Some of the network properties are analyzed through mathematical method,based on the distrbution methed.This paper also find a new method to utilized the limited channel resource.Moreover,the optimal number of data slat is studied.
1998, 27(3): 261-264.
Abstract:
In this paper,the typical architecture of free-space optical communication systems is introduced.In order to generate high laser output power and acquire high receiver sensitivity,a model of optical transmitter and receiver is presented,which is based on long-range inter-satellite links.The power budget of 622 Mb/s system is put forward.The analysis shows that the model is easily achieved.
In this paper,the typical architecture of free-space optical communication systems is introduced.In order to generate high laser output power and acquire high receiver sensitivity,a model of optical transmitter and receiver is presented,which is based on long-range inter-satellite links.The power budget of 622 Mb/s system is put forward.The analysis shows that the model is easily achieved.
1998, 27(3): 265-268.
Abstract:
A hybrid approach based on changing the activation function and using a robust error estimator for improving the learning speed of BP network is suggested in this paper.The activation function used in this paper is a non-differentiable piecewise linear function and its derivative function is re-defined as a new continuous one.The network learning is proceeding under new error function.Significant improvement is observed in the simulations of the XOR and encoder/decode examples.
A hybrid approach based on changing the activation function and using a robust error estimator for improving the learning speed of BP network is suggested in this paper.The activation function used in this paper is a non-differentiable piecewise linear function and its derivative function is re-defined as a new continuous one.The network learning is proceeding under new error function.Significant improvement is observed in the simulations of the XOR and encoder/decode examples.
1998, 27(3): 269-273.
Abstract:
The design and study of the high-speed CCD video camera are introduced in accordance with the television measurement system with spacious field-of-view,high frame rate and multi-target.The generation of the high-speed CCD video signal is discussed and the design of correspondent circuit is presented.The signal transformation model is built and analyzed.Based on the circuit designed for the signal transformation,the high-speed CCD video camera can be used in combination with standard TV-monitors and videocorders to display and record high-speed CCD video signal without needing additional expensive equipment.The experimental results show that the high-speed CCD video camera in this paper is applicable.
The design and study of the high-speed CCD video camera are introduced in accordance with the television measurement system with spacious field-of-view,high frame rate and multi-target.The generation of the high-speed CCD video signal is discussed and the design of correspondent circuit is presented.The signal transformation model is built and analyzed.Based on the circuit designed for the signal transformation,the high-speed CCD video camera can be used in combination with standard TV-monitors and videocorders to display and record high-speed CCD video signal without needing additional expensive equipment.The experimental results show that the high-speed CCD video camera in this paper is applicable.
1998, 27(3): 274-279.
Abstract:
This paper study the propagation characteristics of surface wave along a coated broad surface by using a RAM coated plane model.The complex propagation constants are formulated with eigenvalue function,which may be solved by iterative method.To explane in which manner the attenuation constant is depended upon the EM parameters of the material,a precise formula of attenuation is also derived and analyzed in detail.Finally,an efficient method for design wideband thin coated layer is presented which my be useful for practical purpose applications.
This paper study the propagation characteristics of surface wave along a coated broad surface by using a RAM coated plane model.The complex propagation constants are formulated with eigenvalue function,which may be solved by iterative method.To explane in which manner the attenuation constant is depended upon the EM parameters of the material,a precise formula of attenuation is also derived and analyzed in detail.Finally,an efficient method for design wideband thin coated layer is presented which my be useful for practical purpose applications.
1998, 27(3): 280-283.
Abstract:
A method for pre-estimating the equivalent electromagnetic parameters of absorbing fiber cloth sheet which has been widely used in fabricating stealth vehicles is presented.The equivalent EM parameters(i.e., permittivity and permeability)are the most important data in design.With the anisotropic property structure of the mixed media,based on the strong fluctuation theory,a set of complex integral equations for EM parameters are formulated.With Fortran 5.1,a system software is set up to search out these unknown parameters by iterative way.Some pre estimating EM parameters examples are listed.
A method for pre-estimating the equivalent electromagnetic parameters of absorbing fiber cloth sheet which has been widely used in fabricating stealth vehicles is presented.The equivalent EM parameters(i.e., permittivity and permeability)are the most important data in design.With the anisotropic property structure of the mixed media,based on the strong fluctuation theory,a set of complex integral equations for EM parameters are formulated.With Fortran 5.1,a system software is set up to search out these unknown parameters by iterative way.Some pre estimating EM parameters examples are listed.
1998, 27(3): 284-287.
Abstract:
In this paper,a multi-linear system in arbitrary shape and arbitrary location is analyzed by using spatial decompositon method(SDM) and the general software is programmed with object-oriented method.With the software,such antenna characteristics as coupling between elements and field pattern can be calculated.Given basic parameters of linear antenna system,the optimum project of antenna distribution can be obtained by adding special program.
In this paper,a multi-linear system in arbitrary shape and arbitrary location is analyzed by using spatial decompositon method(SDM) and the general software is programmed with object-oriented method.With the software,such antenna characteristics as coupling between elements and field pattern can be calculated.Given basic parameters of linear antenna system,the optimum project of antenna distribution can be obtained by adding special program.
1998, 27(3): 288-292.
Abstract:
The equation of electron trajectory in drifting tube filled with plasma is given in this paper.The space is divided into two areas (α and β),the equation is solved and focus properties are studied and some parameters affecting the focus properties are discussed carefully.The study shows that after the tube is filled with plasma,the beam is focused obviously,and the design of drifting tube and adjustment of beam transmission pattern are more convenient.
The equation of electron trajectory in drifting tube filled with plasma is given in this paper.The space is divided into two areas (α and β),the equation is solved and focus properties are studied and some parameters affecting the focus properties are discussed carefully.The study shows that after the tube is filled with plasma,the beam is focused obviously,and the design of drifting tube and adjustment of beam transmission pattern are more convenient.
1998, 27(3): 293-295.
Abstract:
Following the demands of the optical antenna of the wide-band digital communication lightwave system (WDCLS) and detailed computation,an off-axis catadioptrical optical antenna with the features of combined transmitting and receiving,auto-acquiring,tracking and pointing is designed.The method and experience of tuning the optical system and the results of the practical field experiments are also presented.The results of the experiments showed that the optical antenna operates very well.
Following the demands of the optical antenna of the wide-band digital communication lightwave system (WDCLS) and detailed computation,an off-axis catadioptrical optical antenna with the features of combined transmitting and receiving,auto-acquiring,tracking and pointing is designed.The method and experience of tuning the optical system and the results of the practical field experiments are also presented.The results of the experiments showed that the optical antenna operates very well.
1998, 27(3): 296-299.
Abstract:
In this paper,an improvement is made on the novel quasi-parallel resonant DC link inverter.The individual inverter IGBT get its own local snub by shifting the resonant capacitors on its own.Its principle of operation and design methodology is discussed in detail.An optimal space voltage modulation is applied to the IQPRDCL inverter.The soft switching character is proved by the simulation and experiment.
In this paper,an improvement is made on the novel quasi-parallel resonant DC link inverter.The individual inverter IGBT get its own local snub by shifting the resonant capacitors on its own.Its principle of operation and design methodology is discussed in detail.An optimal space voltage modulation is applied to the IQPRDCL inverter.The soft switching character is proved by the simulation and experiment.
1998, 27(3): 300-304.
Abstract:
A method measuring micro-hole diameter is presented in this paper.To perform measurement,a measuring system is developed,which consists of laser sensor head,2D-table,driven by step motors,driven and control circuits based on single chip microcomputer etc.The laser sensor head focus the beam on the measured piece.The reflected light is passed through the optical components before reaching four phase photodiode.The photodiode converts the light into current.The current is different between micro-hole and surface on the piece,and would be processed and controlled through interface and single chip microcomputer.The experiment showed the reliability to obtain the accurate diameter of micro-hole.
A method measuring micro-hole diameter is presented in this paper.To perform measurement,a measuring system is developed,which consists of laser sensor head,2D-table,driven by step motors,driven and control circuits based on single chip microcomputer etc.The laser sensor head focus the beam on the measured piece.The reflected light is passed through the optical components before reaching four phase photodiode.The photodiode converts the light into current.The current is different between micro-hole and surface on the piece,and would be processed and controlled through interface and single chip microcomputer.The experiment showed the reliability to obtain the accurate diameter of micro-hole.
1998, 27(3): 305-309.
Abstract:
In this paper,the shortcomings of the energy functions for delay testing in Ref.[1] are discussed.That is the test patterns generated by using the energy functions may be invalid and the expressions of the energy functions are rather complex.On the basis of the discussion,new energy functions for delay testing are presented,which overcome the shortcomings of the energy funtions for delay testing in the Ref.[1].
In this paper,the shortcomings of the energy functions for delay testing in Ref.[1] are discussed.That is the test patterns generated by using the energy functions may be invalid and the expressions of the energy functions are rather complex.On the basis of the discussion,new energy functions for delay testing are presented,which overcome the shortcomings of the energy funtions for delay testing in the Ref.[1].
1998, 27(3): 310-315.
Abstract:
This paper deals with manipulator inverse kinematics.A parameter disturbing algorithm of neural networks which can overcome the local minima porblem of Hopfield network is proposed.Its performance is analyzed in terms of digital simulations in detail.The algorithm is successfully applied to the inverse kinematics problem of manipulator control.It is shown by simulations that the proposed neural network controlling method not only has fast control speed but also raise the control accuracy of manipulator.
This paper deals with manipulator inverse kinematics.A parameter disturbing algorithm of neural networks which can overcome the local minima porblem of Hopfield network is proposed.Its performance is analyzed in terms of digital simulations in detail.The algorithm is successfully applied to the inverse kinematics problem of manipulator control.It is shown by simulations that the proposed neural network controlling method not only has fast control speed but also raise the control accuracy of manipulator.
1998, 27(3): 316-320.
Abstract:
This paper presents the structure and main functions of an optimal production scheduling system with multi-goals.How the system combines a multi-goals optimal heuristic algorithm with a simulation model and workingday assignment procedure to implement establishing,modifying and resequening of an optimal production schedule plan dynamically and rapidly is also analyzed in this paper.
This paper presents the structure and main functions of an optimal production scheduling system with multi-goals.How the system combines a multi-goals optimal heuristic algorithm with a simulation model and workingday assignment procedure to implement establishing,modifying and resequening of an optimal production schedule plan dynamically and rapidly is also analyzed in this paper.
1998, 27(3): 321-325.
Abstract:
This paper adopts AHP method to design an appraise model and algorithms for technician system and presents an model structure and standards of appraisal.The standards of appraisal are defined,and their relations are presented by appraising relational digraph.The algorithms are given in this paper.The model is adopt by Railway Ministry technicain decision support system which can be used by personnel management as a reference.
This paper adopts AHP method to design an appraise model and algorithms for technician system and presents an model structure and standards of appraisal.The standards of appraisal are defined,and their relations are presented by appraising relational digraph.The algorithms are given in this paper.The model is adopt by Railway Ministry technicain decision support system which can be used by personnel management as a reference.
1998, 27(3): 326-331.
Abstract:
Capital budgeting models are important to project selection and combination from multiple alternatives when there are budget and borrowing limits imposed during several time periods,and difference between the interest rates for lending and borrowing.In this paper,Murga's capital budgeting model that considers dividends and terminal wealth is revised to consider the steadiness of the dividend stream better.The shadow prices of the revised models are analyzed and their importance in determining the project acceptance conditions and captital cost and in regulating the dividend stream and the terminal wealth is pointed out based on Kuhn-Tucker condition and the economic interpretation of Kuhn-Tucker multipliers.
Capital budgeting models are important to project selection and combination from multiple alternatives when there are budget and borrowing limits imposed during several time periods,and difference between the interest rates for lending and borrowing.In this paper,Murga's capital budgeting model that considers dividends and terminal wealth is revised to consider the steadiness of the dividend stream better.The shadow prices of the revised models are analyzed and their importance in determining the project acceptance conditions and captital cost and in regulating the dividend stream and the terminal wealth is pointed out based on Kuhn-Tucker condition and the economic interpretation of Kuhn-Tucker multipliers.
1998, 27(3): 332-336.
Abstract:
Some relationships between two kinds of linear permutation counting problems exist in the set of m level digital sequences of length n whose maximal run length and minimal run length satisfy some constrains respectively.In this paper,some unified formulas are given which solve the above problems.A combinatorial identical relation is also obtained.
Some relationships between two kinds of linear permutation counting problems exist in the set of m level digital sequences of length n whose maximal run length and minimal run length satisfy some constrains respectively.In this paper,some unified formulas are given which solve the above problems.A combinatorial identical relation is also obtained.
