最新刊期
卷 ， 期 9 ， 1999
- 摘要：In this paper,it is investigated that the polarization of the echo tends to the pseudo eigen polarization in the optics region,on the basis of polarimetric and high resolution radar system.That property is described by means of exponential function fitting.Furthermore,the recognition of four kinds of aircraft targets is investigated and good results are achieved.关键词：polarization;target recognition;Pseudo eigen polarization;Fit2|120|11更新时间：2025-12-08
- 摘要：Perfectly Matched Layer （PML） is one of the most efficient absorbing boundary condition recently developed in the world.In this paper,the unsplit PML method was further extended to the lossy media,and was applied to object detecting problems together with the FDTD method.The computing model,the loading of the antennas,and the selection of the PML coefficients were discussed.Also,the coupling between the transmitting and receiving antennas and the lossy medium was analyzed in detail.Finally,some examples were given,in which the antennas were scanning on the medium surface and there are arr cavity and metallic pipes existing in the lossy medium.The method and model presented in this paper are more close to realistic problems,and can be used to establish the data library of object detecting of lossy media,which is very useful to realistic applications.关键词：absorbing boundary condition;Lossy media;Object detection;antenna;scattering2|132|5更新时间：2025-12-08
- 摘要：In this paper a new time integrating acousto optical correlator is discussed.With the example of the correlating experimental system,the characteristics of the system are discussed and a new method for correlating speak extraction is presented.At the end,the experimental result is given.关键词：Time integrate;Acousto optical correlation;Extraction of correlating peak2|56|4更新时间：2025-12-08
- 摘要：In this paper,we analyze the Radar Cross Section（RCS） sequence while target is moving,then propose that it is composed by Certain Variation Sequence （CVS） and Random Variation Sequence （RVS）.We can testify that they have the fractal features,and as a result a fractal filter based on Iterate Function System （IFS） is presented.The result shows the decomposition is better than band passed filter.关键词：Radar cross section （RCS）;Iterate function system（IFS）;Decomposed2|75|6更新时间：2025-12-08
- 摘要：Based on the common compactly supported synthesis scaling function,a novel adaptive wavelet prefilter is designed in this paper,and the theoretical analysis and simulation results show that the approximation accuracy and convergence speed of the prefiltering algorithm are satisfactory.关键词：Adaptive wavelet prefilter;approximation accuracy;scaling funciton2|59|1更新时间：2025-12-08
- 摘要：An analysis of the slot coupled gridded patch antenna is presented by using the spectral domain dyadic Green′s function approach.Effects of various antenna parameters on the input impedance and resonant frequency are studied by means of numerical analysis.These results are important for practical antenna design.关键词：Dyadic Green’s function;microstrip antenna;input impedance2|171|0更新时间：2025-12-08
- 摘要：Digital auto gain compensative microwave radiometer is a new type of microwave radiometer.It can compensate gain very well and raises efficiently the properties of microwave radiometer.So it is more suited to spaceborne microwae remote sensing.In this paper,simulation of the digital auto gain compensative microwave radiometer based on the total power microwave radiometer has been done.The specificity of the total power microwave radiometer is analyzed.On the basis of that,a method of realizing system frequency region simulation is suggested when the span of frequency range is very large.It is proved by simulative results that this method is effective,and it gives an important reference to optimizing system design.Also it lays a foundation for the advancement of realizing spaceborne environment debugging.关键词：microwave radiometer;Digital auto gain compensative micrwoave radiometer;computer simulation2|104|1更新时间：2025-12-08
- 摘要：In this paper,we introduce a new method of improving GPS （Global Positioning System） positioning precision.This method is based on a modified ARMA on line and real time model building and prediction algorithm.By the algorithm and an adaptive filtering algorithm based on the modeling and prediction,GPS positioning precision will be improved 3 to 5 times.The tests on a fixed point have proved that the method is correct.This method is of practical value for vessel optimum control and especially for military users.关键词：Positioning precision;Real time and on line data processing;Model building and prediction method2|265|4更新时间：2025-12-08
- 摘要：A new highly efficient algorithm for solving monostatic RCS——Method of Basic Waves Exciting is presented.In this method,a basic wave functions set is selected at first.Using these basic waves of the set as the basic exciting fields of an object,we can calculate the subelectric currents on the object’s surface excited by them.Then,an arbitrary directional incident field is expanded by these basic wave functions and the expansion coefficients are obtained.It is proved that the surface current excited by the incident field equals to the weighted sum of all of the sub electric currents excited by the basic wave functions,and the weighting factors are the expansion coefficients exactly.So,we can use the surface current obtained to solve the monostatic RCS of this object.In the RCS analysis of electrical large object,compared to traditional solvers,the method has advantages of higher efficiency in solving matrix equations and saving storage of computer etc.关键词：Monostatic RCS;Incident field;Basic waves exciting2|166|1更新时间：2025-12-08
- 摘要：This paper theoretically analyzes the propagation characteristics of magnetostatic waves （MSWs） in magnetic film under normal nonuniform bias field.The dynamic magnetization of MSWs under the nonuniform field of parabolic profile is calculated in detail.Calculation results indicate that,under nonuniform bias field of appropriate profile,MSW amplitude can be increased by comparison with the case of uniform bias magnetic field,thereby,the diffraction effect of guided optical waves from the MSWs is also enhanced.关键词：Nonuniform magnetic field;Magnetostatic waves;Magnetic film2|59|1更新时间：2025-12-08
- 摘要：In this paper we present the first order reflection approximation （FRA） method for half space backscattering problem.Further use of the reciprocity theorem and an equivalent dipole model may notably simplify the computation.Numerical results show the feasibility of presented scheme.This method can be applied for the analysis of scattering problem of a target above the sea surface for HF over the horizon radar.关键词：Half space scattering problem.;Approximate method;HF over the horizon radar2|65|1更新时间：2025-12-08
- 摘要：This paper presents a novel method of calculating discrete Green’s function in time domain Parallcl Time Domain Diakoptics.A complicated circuit is divided into several sub circuits that could be calculated by finite diiference time domain（FDTD） method independently.The parallel time domain Diakoptics algorithm is employed to analyze coupling between sub circuits and to obtain the discrete time domain Green’s functions of the circuit.As a comparison to conventional Mode Matching method and FDTD,the method in this paper is more accurate and efficient for simulations of complicated structures.关键词：Finite difference time domain（FDTD）;Diakoptics;Time domain method;Green’s function;Microwave circuits （MC）2|110|1更新时间：2025-12-08
- 摘要：The paper presents a practical method for high frequency electromagnetic scattering modeling used in wideband radar signals prediction and analysis,which is beyond the capability of the narrowband RCS modeling.This method is capable of range profile computation,ISAR imaging.In particular,the electromagnetic scattering mechanism of each scattering center on complex objects can be determined in wideband radar scattering time frequency analysis.Some typical scattering computation results of an aircraft,such as RCSs,range profile,ISAR image,are given.This modeling method shows the validation in comparing with the measured data.关键词：Wideband Electromagnetic Scattering;theory modeling;RCS;Radar Signatures2|473|6更新时间：2025-12-08
- 摘要：A coaxial cavity with inner and outer conductors interleaved disk loaded is proposed,and a kind of analysis technique for this type of cavity is obtained by applying the network method to the radial transmission line.This type of cavity has compact volume due to the interleaving of the disks.The results show that the length of an interleaved disk loaded coaxial cavity is nearly one seventh that of a TEM mode cavity,by assuming that both cavities have same size of the cross section and work at same frequency.关键词：coaxial cavity;Interleaved disk loaded;Network method2|44|0更新时间：2025-12-08
- 摘要：Electromagnetic scattering from the trees above a tilted rough ground plane generated by the stochastic Lidenmayer system is studied by Monte Carlo simulations in this paper.The scattering coefficients are calculated in three methods:coherent addition approximation,tree independent scattering,and independent scattering.It shows that the results of the tree independent scattering agree well with that of coherent addition approximation for high frequency.However,independent scattering is not a good approximation except for very high frequency.The ground tilted generated the cross polarization in the scattered signal and reduced the co polarized signal.关键词：electromagnetic scattering;Fractal tree;L system;Monte Carlo simulation2|95|9更新时间：2025-12-08
- 摘要：Based on a cascaded fibre link model,transmission of quasi soliton is studied,and the best method of the quasi soliton transmission of 10000km is obtained with numerical simulation.The stability studies of this system under different initial conditons（initial peak power,initial pulse width and initial chirp） are given.关键词：optical communication;Cascaded fibre link;Quasi soliton2|37|1更新时间：2025-12-08
- 摘要：In this paper,a new space time adaptive processing（STAP） approach has been proposed,which is very much suitable for the non homogeneous clutter environments.It is characterized by low degrees of freedom of system,strong robust to error,good performance of detecting the slow target and convenient implementation in real time.Comparison with the local domain joint processing approach and the sigma and delta （∑ Δ） approach,it has a better performance in the practical airborne surveillance radar system.关键词：airborne radar;Space time adaptive processing;clutter suppression2|497|7更新时间：2025-12-08
- 摘要：Using the characteristic line theory of hyperbolic partial differential equations,relations between the reflected signals and the dielectric parameters of the stratified media are analyzed.Studies about the discretized model of marching on in time parameter inversion show the impossibility of simultaneous inversion of the permittivity and conductivity.Numerical simulation shows the validity of the theoretical analysis result.关键词：Stratified media;parameter;inversion2|97|7更新时间：2025-12-08
- 摘要：Graphical Electromagnetic Computing （GRECO） is recognized as one of the most valuable methods of the RCS （Radar Cross Section） computation for the high frequency region.This paper shows satisfied results of computing monostatic and bistatic RCS in the high frequency region by using the hybrid method of GRECO and Monostatic bistatic Equivalence Theorem.At the same time,it gives monostatic and bistatic RCS curves of standard body and a complex target for a practical virtual reality,which satisfied the meausred results.The results have practical engineering value.关键词：electromagnetic wave scattering;radar cross section;Monostatic bistatic equivalence theorem;virtual reality2|137|1更新时间：2025-12-08
- 摘要：A new symplectic geometrical method for solving the propagation of electromagnetic wave in the inhomogeneous media is presented in this paper.,The new vectors are introduced first.The vectors and former physical vectors form a symplectic space.The propagating problem in the physical space is promoted to Lagrange manifold in the symplectic space.With proper projection transform,the propagating caustic problem of the electromagnetic wave in the inhomogeneous media can be solved.关键词：symplectic geometrical theory;Wave equation;Inhomogeneous media;Caustic2|134|1更新时间：2025-12-08
- 摘要：A simple method,MVA,is put forward in this paper and is used to solve the complicated problem of the polarization tilt angle calculation.An universal formula in form of vector is given.And six practical and analytical formulae,which can meet all polarization cases,and two contour maps are also presented.关键词：polarization tilt angle;MVA;broadcasting satellite;antenna beam center2|45|2更新时间：2025-12-08
- 摘要：This paper proposes a new method for designing quadriphase spread spectrum sequences,which is based on Chebyshev Map.The correlation distribution of the generalized odd correlation of such sequences is analyzed.And the sequences is compared with other quadriphase spread spectrum sequences with respect to the correlation properties such as the correlation peak and the correlation mean square.Theoretical analyses and the results of simulation show that the quadriphase spread spectrum sequences generated by the method proposed in the paper has good correlation properties,and it will be used in CDMA in future.关键词：Chebyshev Map;quadriphase spread spectrum sequences;generalized odd correlation;multiple access interference;DS/CDMA2|92|7更新时间：2025-12-08
- 摘要：The filtering properties of parallel transmission lines with two types of specified length are analyzed in this paper.The lowpass filter and broadband bandpass filter with fine characteristics can be composed of it.Its configuration is simple,so employing it in MIC′s modules is suitable.关键词：MIC;Parallel transmission line;Filtering properties2|83|1更新时间：2025-12-08
- 摘要：A continuous speech recognition model integrated by multi module RBF Gamma neural networks and HMMs is proposed in this paper.In this model,the abilities of RBF Gamma nets that effectively represent the space of speech units and synthesize the temporal correlation information of speech sequence are combined with the abilities of HMMs that integrate and expand the speech units in time domain.They are mutually complementary in function and improve the recognition accuracy obviously.A speaker dependent continuous digits recognition system is realized according to this model and using the learning algorithms proposed in this paper for improving classification performance.The tested digit accuracy is 98.9% and the string accuracy is 94.8%.关键词：continuous speech recognition;Gamma neural network;hidden Markov model;Combined model2|106|1更新时间：2025-12-08
- 摘要：In this paper,we propose a modified SC SSF（spectral correlation signal subspace fitting）method to estimate DOA of coherent narrow band or wide band signals,while the advantage of SC SSF method still rematins.Monte Carlo trials demonstrate that the noise suppression of this method is superior to that of SC SSF,and can be used to multi cyclic correlated signals with same cyclic frequency.关键词：cyclostationarity;Cyclic cross correlation;DOA2|315|3更新时间：2025-12-08
- 摘要：The radio channel and temporal or spatial processing are summarized for antenna array CDMA cellular radio communications.And the space time processing or vector equalization is overviewed in terms of the system model,structural properties of space time oversampling signals,and processing schemes based on these properties and some optimization criteria so as to demonstrate the feasibility of embedding space time processing into IMT 2000.关键词：Antenna array CDMA;Space time processing;Vector processing gain;IMT 20002|89|11更新时间：2025-12-08
- 摘要：For airborne early warning （AEW） radars with a side looking rectangular plannar phased array,if the elements in each column are combined into a subarray at the microwave level first,the random amplitude and phase errors existing inevitably in the array elements would give rise to much differeme in column subarray patterns in elevation,especially in sidelobearea,and result in the received clutter with nonstationary characteristics.It is highly desirable that the weight vectors of space time adaptive processing （STAP） be able to adapt the nonstationary characteristics in time.For this purpose,a fast recursive algorithm is presented based on an inverse QR decomposition in this paper.The computer simulation results show that the weight vectors obtained by the proposed algorithm allow the space time adaptive processor outperform the Capon adaptive processor for the rejection of the clutter with nonstationary characteristics.关键词：airborne radar;Space time adaptive processing （STAP）;clutter suppression;Inverse QR decomposition2|276|1更新时间：2025-12-08
- 摘要：This paper presents a simple method of the direction of arrival （DOA） estimation for the nonuniform linear array,which uses the spatial smoothing MUSIC technique.In the case of the same sensor number,this method which adopts appropriate array geometry arrangement can improve the resolvability of DOA estimation more obviously than the uniform linear array.It also overcomes the shortcoming of the ambiguity of DOA estimation and the poor quality of de correlation in the conventional nonuniform linear array.关键词：Estimation of DOA;array signal processing2|434|11更新时间：2025-12-08
- 摘要：This paper describes a multisensor data fusion method based on Dempster shafer evidential reasoning.Using this method,we developed an object recognition system.As an applied instance,a test is made for object assortment on the fusion of robot force sensor and thermal sensor.At the end of the paper,test results and conclusion are given.关键词：robot;sensor;data fusion;recognition2|1124|29更新时间：2025-12-08
- 摘要：Linear frequency modulation continuous wave （LFMCW） radar has high theoretical range precision and range resolution,but its practical range precision and range resolution will decrease because of its inherent nonlinearity in frequency sweep.This paper analyses theoretically the effects of the nonlinearity on the range precision and range resolution of LFMCW radar according to its echo power spectrum,and gives accurately theoretical grounds for outside correction of the nonlinearity of LFMCW radar.关键词：LFMCW radar;Sweep nonlinearity;Nonlinearity correction;range resolution2|706|12更新时间：2025-12-08
- 摘要：Space feed array is an important part of phased array radar antenna,and array error calibration is very important for many array signal processing algorithms.Based on a multi feed array model,by using the phase shifter of the main array plane,we present an error calibration method.The efficiency of the method is confirmed by computer simulation.关键词：Space feed array;Error calibration;phased array radar2|163|3更新时间：2025-12-08
- 摘要：A hybrid technique to calculate the scattering of two dimensional large bodies with cracks is developed by combining high frequency approximation method and a numerical method.Using the equivalence theorem,the technique divides the total scattered field into two parts,and employs iterative physical optical method （IPO） for the scattering from the large bodies with the cracks filled with perfect conductors and the moment methods （MoM） to characterize the cracks.The generalized network principle is then used to deal with the coupling across the opening of the aperture.Some numerical results have been obtained,showing the feasibility of proposed method.关键词：hybrid method;Iterative physical optical method;moment method;Electro magnetic scattering2|139|4更新时间：2025-12-08
- 摘要：In this paper,a method of solution for the shielding equation of a rotating thin spherical shell in a low frequency magnetic field is presented.On the basis of averaged boundary conditions,the solution of the boundaryvalue problem for the shielding of the rotating thin spherical shell is derived.Later the formula for the transmission coefficient in the centre of the thin spherical shell is achieved.A computer program for the shielding shell is also offered.A relation of the magnetic field frequency,rotating velocity and transmission coefficient as well as other important shielding properties are found out.关键词：Low frequency magnetic field;Thin spherical shell;Rotating velocity;averaged boundary condition;shield;Transmission coefficient2|89|1更新时间：2025-12-08
- 摘要：In this paper a practical tape shape helix slow wave structure is calculated for coupling impedance with a new developed coordinates helical coordinates.Particularly the electromagnetic field solution in the gap between the helix is given,the propagation power within this area and its effects on coupling impedance has been calculated and discussed more rigorously than by previous researchers.关键词：Helical coordinate system;helix;Coupling impedance2|110|8更新时间：2025-12-08
- 摘要：In this paper,an efficient scheme of motion estimation for MPEG 2 video coding is proposed.According to the correlation of different types of motion vectors in a macroblock,the scheme is divided into two stages.Analysis shows t hat the proposed scheme can reduce about 17% of the computation employed by MPEG 2 Test Model 5（TM5）.Simulation results show that the scheme achieves nearly the same MSE and PSNR performance as TM5.Due to adopting full search strategy in the two stages,the proposed scheme can be implemented easily in parallel.It provides a way for the implement ation of MPEG 2 video coding motion estimation in real time,which has low complexity.关键词：MPEG 2;video coding;motion estimation;Test model 52|77|2更新时间：2025-12-08
- 摘要：Rectangular waveguide finite phased arrays are analysed using moment method.According to equivalent principle and magnetic field boundary condition,integral equation for solving waveguide end face magnetic currents is given.Center unit′s reflection coefficient as a function of scan angle has been investigated in detial.关键词：phased arrays;Rectangular waveguide;moment method;Reflection coefficient2|136|4更新时间：2025-12-08
- 摘要：The goal of this research was to present an approach which address both de noising and contrast enhancement.1)2D wavelet transform （WT）.2)At finer scales,wavelet phase filter was used in WT domain to reduce noise and at coarse scales,and semisoft wavelet shrinkage technique was used to furtrher reduce noise.3)Based on human visual properties,the coefficients of 2D WT of image were emphasized by a generalized adaptive gain nonlinear operator.4)Image reconstruction.Preliminary results show that the proposed approach can make unseen or barely seen features of an image more obvious without generating artifacts and enhance the contrast of region of interest in images while reducing the enhancement of noise.关键词：wavelet transform;Human visual properties;image enhancement2|311|15更新时间：2025-12-08
- 摘要：This paper presents a fast algorithm based on the measured equation of invariance （Fast MEI）.Conformal meshes are made along the surface of two dimensional scatterer.Renumbering of nodes changed the original sparse matrix into band one,and the consumption of computer memory and CPU time decrease from O（N 2） to O（N） .Via this new algorithm,electrically large problem can now be rapidly solved.The scattering fields are computed on several 2 D cylinders with the maximum perimeter of 10,000 wave length.The results are then compared with that got by MOM and MEI.关键词：Measured equation of invariance;Finite difference equation;Cylinder scattering;Band matrix;Sparse matrix2|75|1更新时间：2025-12-08
- 摘要：Pricing is a recently proposed mechanism for congestion control and resource allocation in computer networks.A novel feature of pricing policies is that they provide an incentive for users to utilize network resources more efficiently.This paper presents a market based approach to allocate bandwidth under wide area network environment.The market based approach to allocate bandwidth under wide area network environment.The market price of the bandwidth is calculated based on the bandwidth demand of users （i.e.,applications or flows） and the bandwidth usage of the network system,which is used together with users’ price parameters to regulate bandwidth allocation along their routes.Then a bandwidth allocation algorithm by employing users’ price parameters is proposed.We prove its effectiveness in improving users’ satisfaction and the system’s utilization through analysis.关键词：computer networks;congestion control;pricing;Bbandwidth allocation2|277|13更新时间：2025-12-08
- 摘要：Identical parallel machine scheduling problem of minimizing the number of tardy jobs is studied,a genetic algorithm based on knowledge is proposed,and researches are made in these aspects such as problem formulation,coding,generation of initial population,crossover and mutating of genetic algorithm.Numerical computational results of different scale problem show that the genetic algorithm based on knowledge has advantage over so far best heuristic procedure and common genetic algorithm and is fit for larger scale identical parallel machine scheduling problem.关键词：Identical parallel machine;genetic algorithm;combinatorial optimization;scheduling problem2|376|4更新时间：2025-12-08
- 摘要：Based on multithreading,no -break pipeline is put out combining optimization compiler with hardware and a kind of no -break pipeline is designed （called MTNB -PIPELINE）.By this pipeline,branch overhead is cut off by thread switching beforehand and more parallelism among threads is explored.Performance evaluation to MTNB -PIPELINE indicates that speedup can increase by this pipeline.关键词：pipeline;ILP;Optimization compiler;Multithreaded architecture2|67|0更新时间：2025-12-08
- 摘要：This paper advances a scheme using the TMS320C62x to realize a digital pulse compression system which waveform is linear FM signal.The finite register effects in the system are discussed.The word length errors using truncation of sign magnitude code are analyzed.And the computer simulations which uses truncation and ronding of sign magnitude code and complementary code are given.The improvement of finite register length effects by noise is discussed.The paper also raises an effective method to solve the word length error′s problem.关键词：Linear FM signal;digital pulse compression;Finite register length effects2|208|2更新时间：2025-12-08
- 摘要：CEVA Cumulant based Eigen Vector Approach to 2 D DOA estimation is proposed.New algorithm determines elevation and azimuth at the same time.Spatial smoothed cumulants increase the insensibility to spatial correlated Gaussian noises.It is also proven that particular chosen cumulants make proposed algorithm even insensitive to spatial white non Gaussian noises.Simulation results show the remarkable higher performance with comparison to those obtained from MUSIC method.关键词：Cumulant;2 D DOA estimation;spatial smoothing2|193|1更新时间：2025-12-08
- 摘要：In this paper,we compare our proposed approach of missile borne radar target recognition based on envelope of Doppler echo with the one dimensional range profile based target recognition appproach using the direct averaging technique.We emphatically analyzed the effect of swept frequency linearity.Simulation results demonstrate that our approach achieves better recognizability even in the case of worse swept frequency linearity.关键词：target recognition;Doppler envelope;range profile3|117|2更新时间：2025-12-08
- 摘要：This paper proposes the method of processing using compensation for MTI data of randomly pulsed phase signal,and gives and discusses the analyses of the theory and the functions of the compensation.In the end of the paper,the experiment of simulation is given.It is shown that the theory is right.关键词：randomly pulsed phase signal;MTI;compensation function;resolution targets.2|111|2更新时间：2025-12-08
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