ISSN 
1998 Vol. 27, No. 1
1998, 27(1): 1-4.
Abstract:
An efficient parallel algorithm for synthetic aperture radar(SAR) imaging is presented in this paper.The parallel algorithm is available for implementation the range compression,azimuth and Compression of SAR imaging.So it is efficient for SAR imaging by the parallel alagrithm.Theoretical analysis and experimental results on computer network indicate that the parallel algorithm is significant.
An efficient parallel algorithm for synthetic aperture radar(SAR) imaging is presented in this paper.The parallel algorithm is available for implementation the range compression,azimuth and Compression of SAR imaging.So it is efficient for SAR imaging by the parallel alagrithm.Theoretical analysis and experimental results on computer network indicate that the parallel algorithm is significant.
1998, 27(1): 5-9.
Abstract:
In this paper,the cell loss rate of an internal nonblocking backpressure input and output ATM switch due to backpressure signal delay is investigated.An output extra buffering algorithm to reduce the cell loss rate at output ports is proposed.The conclusions of this paper give contribution to the realization of an input/output ATM switch.
In this paper,the cell loss rate of an internal nonblocking backpressure input and output ATM switch due to backpressure signal delay is investigated.An output extra buffering algorithm to reduce the cell loss rate at output ports is proposed.The conclusions of this paper give contribution to the realization of an input/output ATM switch.
1998, 27(1): 17-20.
Abstract:
A fast extraction technology for image object in led tracking system is studied.The image object model of the system is described.The possibility of extraction for image object's characteristic graph is analysed aceording to the defin itions of condensation degree and recognition degree presented.The method to produce the result with maintained character,which is used to extract system's image object is introduced through statistic studies and theoretical analysis for a large number of real images by means of histogram.Finally,some experimental results for real images show that the method in this paper is applicable.
A fast extraction technology for image object in led tracking system is studied.The image object model of the system is described.The possibility of extraction for image object's characteristic graph is analysed aceording to the defin itions of condensation degree and recognition degree presented.The method to produce the result with maintained character,which is used to extract system's image object is introduced through statistic studies and theoretical analysis for a large number of real images by means of histogram.Finally,some experimental results for real images show that the method in this paper is applicable.
1998, 27(1): 21-24.
Abstract:
In this paper,the combination of an adaptive array antenna and traditional detection for interference suppression in CDMA system is discussed.A new combined method is proposed,and its improvement of performance for multiple Access Interference (MAI) suppression is analyzed and proved in theory and in practice.It is proved that the MAI suppression performance of the new method achieves a greater improvement than the traditional detection only.
In this paper,the combination of an adaptive array antenna and traditional detection for interference suppression in CDMA system is discussed.A new combined method is proposed,and its improvement of performance for multiple Access Interference (MAI) suppression is analyzed and proved in theory and in practice.It is proved that the MAI suppression performance of the new method achieves a greater improvement than the traditional detection only.
1998, 27(1): 25-28.
Abstract:
According to the equivalent expression theorem about the orthogonality of wavelets and the equivalent expression theorem about the Riesz bounds of integral shifting basis of a function inL2(R),the orthogonality condition of Bubble wavelets is analysed and discussed systematically from three respects.The results show that the orthogonal and almost orthogonal Bubble wavelet can be constructed by selecting appropriately the shape parameter of Bubble functions,but the Mexican hat wavelet (a special Bubble wavelet) can not be regarded as an almost orthogonal wavelets.
According to the equivalent expression theorem about the orthogonality of wavelets and the equivalent expression theorem about the Riesz bounds of integral shifting basis of a function inL2(R),the orthogonality condition of Bubble wavelets is analysed and discussed systematically from three respects.The results show that the orthogonal and almost orthogonal Bubble wavelet can be constructed by selecting appropriately the shape parameter of Bubble functions,but the Mexican hat wavelet (a special Bubble wavelet) can not be regarded as an almost orthogonal wavelets.
1998, 27(1): 29-32.
Abstract:
The CORDIC algorithm is well known as an efficient method for the computation of trigonometric/hyperbolic functions and vector rotations.The CORDIC iteration is directed by the rotation direction factor σi.Therefore the fast determination of σi is important to accelerate the speed of CORDIC processors.σi determination in redundant number system is not straightforword because an exact sign detection is not possible efficiently.Therefore,an predict algorithm of the original CORDIC is proposed which parallelize the σi determination and reduce the latency time of CORDIC algorithm considerably.
The CORDIC algorithm is well known as an efficient method for the computation of trigonometric/hyperbolic functions and vector rotations.The CORDIC iteration is directed by the rotation direction factor σi.Therefore the fast determination of σi is important to accelerate the speed of CORDIC processors.σi determination in redundant number system is not straightforword because an exact sign detection is not possible efficiently.Therefore,an predict algorithm of the original CORDIC is proposed which parallelize the σi determination and reduce the latency time of CORDIC algorithm considerably.
1998, 27(1): 33-38.
Abstract:
In this paper,the DOA(direction of arrival) estimation methods based on fourth-order cumulant are investigated,and the algorithms MUSIC and ESPRIT based on fourth-order cumulant are presented.The fourth-order MUSIC has the ability of array extension,and the fourth-order ESPRIT is robust to the channel uncertainty model errors.The results are verified by the simulation experiments.
In this paper,the DOA(direction of arrival) estimation methods based on fourth-order cumulant are investigated,and the algorithms MUSIC and ESPRIT based on fourth-order cumulant are presented.The fourth-order MUSIC has the ability of array extension,and the fourth-order ESPRIT is robust to the channel uncertainty model errors.The results are verified by the simulation experiments.
1998, 27(1): 39-42.
Abstract:
Based on the simulation of linear PLL,this paper puts forward an improved method to analyze and simulate the nonlinear performance of PLL.Some PC-based circuit CAD programs (such as IsSpice,Pspice,etc.)can be used to model the nonlinear PLL,as a illustration,one instance with sine PD and step frequency hopping is simulated with this method,from it we can watch the locking process of a PLL circuit which is impossible for a linear PLL model analyses,further more,a magic phenomenon can be found to determine whether it will lock out.
Based on the simulation of linear PLL,this paper puts forward an improved method to analyze and simulate the nonlinear performance of PLL.Some PC-based circuit CAD programs (such as IsSpice,Pspice,etc.)can be used to model the nonlinear PLL,as a illustration,one instance with sine PD and step frequency hopping is simulated with this method,from it we can watch the locking process of a PLL circuit which is impossible for a linear PLL model analyses,further more,a magic phenomenon can be found to determine whether it will lock out.
1998, 27(1): 43-46.
Abstract:
A new source which has a rectangular spectrum is proposed for the FDTD analysis of waveguide discontinuity.The source has high excitation efficiency and can filter out all undesired frequency components which are under the cut off frequency of the dominant mode and makes the calculation operating on a single dominant mode condition.Compared with the convention Gaussian pulse excitation,a practical calculation shows that both the CPU time and the memory requirement is greatly saved.
A new source which has a rectangular spectrum is proposed for the FDTD analysis of waveguide discontinuity.The source has high excitation efficiency and can filter out all undesired frequency components which are under the cut off frequency of the dominant mode and makes the calculation operating on a single dominant mode condition.Compared with the convention Gaussian pulse excitation,a practical calculation shows that both the CPU time and the memory requirement is greatly saved.
1998, 27(1): 47-50.
Abstract:
The resistivity-temperature characteristics of polysilicon films heavily doped with B, which is deposited on the AlN substrate are studied. It is found that the R-T characteristics show a U type curve within a wide temperature from 25℃~450℃, and the criterion depends on the processing techniques. The theroetical analysis shows that the minium of resistivity exists due to the interface barrier,and the result can be used to adjust the criterion and TCR.
The resistivity-temperature characteristics of polysilicon films heavily doped with B, which is deposited on the AlN substrate are studied. It is found that the R-T characteristics show a U type curve within a wide temperature from 25℃~450℃, and the criterion depends on the processing techniques. The theroetical analysis shows that the minium of resistivity exists due to the interface barrier,and the result can be used to adjust the criterion and TCR.
1998, 27(1): 51-56.
Abstract:
A mechanical system with fast automatic precision location function is studied and analyzed.A mathematical model of the system is given in this paper.Using the model,the dynamic analysis about the system is made and the dynamics of the system is gained.According to the results,the control closed system is finished.The experiment of the system is proved to be good and it is shown that the system can satisfy the requirement,which is a good example for combining machinery with electronics.The method of the device has significance for the system of precision location.
A mechanical system with fast automatic precision location function is studied and analyzed.A mathematical model of the system is given in this paper.Using the model,the dynamic analysis about the system is made and the dynamics of the system is gained.According to the results,the control closed system is finished.The experiment of the system is proved to be good and it is shown that the system can satisfy the requirement,which is a good example for combining machinery with electronics.The method of the device has significance for the system of precision location.
1998, 27(1): 57-62.
Abstract:
The principle and method of bilinear transformation in engineering applications is presented.The characteristics of the method are simple and fast,which can be conveniently applied to the digital control system and the digital filter design.Its correctness is shown by a numerial example both in theory and in practice.
The principle and method of bilinear transformation in engineering applications is presented.The characteristics of the method are simple and fast,which can be conveniently applied to the digital control system and the digital filter design.Its correctness is shown by a numerial example both in theory and in practice.
1998, 27(1): 63-67.
Abstract:
A physical model about relativistic backward wave oscillator,based on the experimental system built in University of Electronic Science and Technology of China is supposed.The model includes a slow-wave structure consisting of an axially symmetric,cylindrical waveguide with sinusoidally rippled wall,and an annular electron beam of finite thickness going through the waveguide.The dispersion equation is derived.By numerical computation,BWO's bandwidth,growth rate and electron tuning ability affected by geometry parameters of slow wave structure,such as ripple's depth and length of ripple's period are analyzed.Some useful results for designing BWO are achieved.
A physical model about relativistic backward wave oscillator,based on the experimental system built in University of Electronic Science and Technology of China is supposed.The model includes a slow-wave structure consisting of an axially symmetric,cylindrical waveguide with sinusoidally rippled wall,and an annular electron beam of finite thickness going through the waveguide.The dispersion equation is derived.By numerical computation,BWO's bandwidth,growth rate and electron tuning ability affected by geometry parameters of slow wave structure,such as ripple's depth and length of ripple's period are analyzed.Some useful results for designing BWO are achieved.
1998, 27(1): 68-72.
Abstract:
946 nm light oscilation is operated with a diode end pumpde Nd:YAG laser Puting.a KNbO3 crystal into the laser cavity,a stabilized CW 473 nm blue laser is abtained at room temperature.The output power reaches 1 mW.
946 nm light oscilation is operated with a diode end pumpde Nd:YAG laser Puting.a KNbO3 crystal into the laser cavity,a stabilized CW 473 nm blue laser is abtained at room temperature.The output power reaches 1 mW.
1998, 27(1): 73-77.
Abstract:
An experimental beam correcting optical system for laser diode is established for compensating astigmation and circulating the elliptical beam.The system is combined by two prisms,a cylindrical lens and a collimating lens.The results show that the divergence angle of the laser beam can be corrected to less than l mrad,and even reach diffraction limited.This system possesses the advantages of low cost,low power loss,simple structure,and it is convenient to operate.
An experimental beam correcting optical system for laser diode is established for compensating astigmation and circulating the elliptical beam.The system is combined by two prisms,a cylindrical lens and a collimating lens.The results show that the divergence angle of the laser beam can be corrected to less than l mrad,and even reach diffraction limited.This system possesses the advantages of low cost,low power loss,simple structure,and it is convenient to operate.
1998, 27(1): 78-82.
Abstract:
Adding multi-media function for chinese open operation system COSIX1.1 is a new project.This paper describes many key techniques for its realization,including the soundblaster device driver,the kernel rebuild,and the format of device file.
Adding multi-media function for chinese open operation system COSIX1.1 is a new project.This paper describes many key techniques for its realization,including the soundblaster device driver,the kernel rebuild,and the format of device file.
1998, 27(1): 83-89.
Abstract:
Massively parallel processing system using crossbar switches to interconnect nodes & introducing programmable cut-through communication between nodes has better performance as compared with store-&-forward,virtual cut-through,wormhole routing and circuit switching.Presented in this paper are speed up ratio,efficiency,delay & bandwidth of the computer system based on the programmable crossbar switches cut-through communication.The result shows that the communication is an attractive communication technology for nodes of the massively parallel processing system.
Massively parallel processing system using crossbar switches to interconnect nodes & introducing programmable cut-through communication between nodes has better performance as compared with store-&-forward,virtual cut-through,wormhole routing and circuit switching.Presented in this paper are speed up ratio,efficiency,delay & bandwidth of the computer system based on the programmable crossbar switches cut-through communication.The result shows that the communication is an attractive communication technology for nodes of the massively parallel processing system.
1998, 27(1): 90-94.
Abstract:
In IT area,object-oriented interoperability technology is going to be mainstream over next few years.The reason that the object-oriented interoperability technology appeared and its usefulness in IT area are analyzed.The main components that provide interoperability in CORBA 2.0 are clearly described.Those are CORBA architecture,IDL language,dynamic invocation,object adapter and the interoperability between ORB.
In IT area,object-oriented interoperability technology is going to be mainstream over next few years.The reason that the object-oriented interoperability technology appeared and its usefulness in IT area are analyzed.The main components that provide interoperability in CORBA 2.0 are clearly described.Those are CORBA architecture,IDL language,dynamic invocation,object adapter and the interoperability between ORB.
1998, 27(1): 95-98.
Abstract:
The backbone company integrates products relying on technology as investment is one of the way innovating enterprise's system.The proper technology price is the base of integrating products.This paper gives quantitative analyses of the key parameters of technology price,such as discount rate,licensor's share licensee's profit.
The backbone company integrates products relying on technology as investment is one of the way innovating enterprise's system.The proper technology price is the base of integrating products.This paper gives quantitative analyses of the key parameters of technology price,such as discount rate,licensor's share licensee's profit.
1998, 27(1): 99-104.
Abstract:
In this paper,two useful models that optimizt linear combination forecasting model are analysed and conpared in order to provide theory for a designer of combination forecasting model in practical application.It is meanimgful to both theory and practice of combinatel forecasting.
In this paper,two useful models that optimizt linear combination forecasting model are analysed and conpared in order to provide theory for a designer of combination forecasting model in practical application.It is meanimgful to both theory and practice of combinatel forecasting.
1998, 27(1): 105-108.
Abstract:
In this paper the definition of generalized S-A-proper mappings and their topological degree is estabilshed.The properties and applications of the degree are studied,in which some fixed point results about the generalized P1-compact mappings are proved by the degree theory.
In this paper the definition of generalized S-A-proper mappings and their topological degree is estabilshed.The properties and applications of the degree are studied,in which some fixed point results about the generalized P1-compact mappings are proved by the degree theory.
1998, 27(1): 109-112.
Abstract:
In this paper,a method for raise of entropic function and its defining equation are proposed.The method exposes the physical meaning of entropic function and drows its computational equation and entropic criterion.The method is universal which is good for strengthened understand of entropic function and entropic criterion.The method is also helpful for understanding of the relationship among Boltzmann's entropic equation and Clausius's entropic equation.
In this paper,a method for raise of entropic function and its defining equation are proposed.The method exposes the physical meaning of entropic function and drows its computational equation and entropic criterion.The method is universal which is good for strengthened understand of entropic function and entropic criterion.The method is also helpful for understanding of the relationship among Boltzmann's entropic equation and Clausius's entropic equation.
