最新刊期
卷 32 ， 期 9 ， 2004
- 摘要：A new 3-dimensional joint estimation method is presented.With a single echo wave,bearings,frequencies,and time-delays of multiple reflectors are estimated jointly.We construct 2 sub-arrays like ESPRIT,and then make a generalized eigen-decomposition on their auto-correlation matrix and cross-correlation matrix.Bearing parameters can be estimated from eigenvalues,while frequency parameters can be obtained from corresponding eigenvectors.Having modified the time-delay vectors of enveloping with estimated frequencies,we can get the time-delay parameters simultaneously.Computer simulations show that the proposed method can carry out the 3-dimensional joint estimation without additional pairing algorithm in the case of lower SNR.Preferable results are also obtained in water tank experiments,indicating the method is robust for sensor array errors,and showing good potential in applications.关键词：DOA estimation;time-delay estimation;frequency estimation;joint parameter estimation;ESPRIT2|1054|4更新时间：2025-07-16
- 摘要：For non-uniformly periodically sampled multirate systems,we derive the corresponding lifted state-space models by using the lifting technique.Furthermore,for multirate systems whose states are measurable,an identification method to estimate the lifted system parameter matrices is given by using the least squares principle;for multirate systems whose states are unmeasurable,the lifted multirate systems are decomposed into some subsystems according to the hierarchical identification principle,and the hierarchical state-space model identification methods are developed,which take causality constraints into consideration.The simulation results indicate that the proposed algorithms are effective.关键词：multirate systems;state-space models;hierarchical identification;parameter estimation2|1023|21更新时间：2025-07-16
- 摘要：Based on Doppler distributed clutter (DDC) model,this paper gives the performance analysis for Doppler parameter estimation of airborne radar.Furthermore,a fast nonlinear operator (NLOP) method is also proposed to estimate clutter Doppler parameters for DDC model with modestly small Doppler angular spread.The proposed method directly gives the closed-form expressions for estimating parameters,and it may remarkably reduce the calculation amount and satisfy the real application of airborne radar.关键词：airborne radar;Doppler Distributed Clutter (DDC) model;Doppler parameter;nonlinear operator (NLOP)2|885|2更新时间：2025-07-16
- 摘要：GPS sometimes can not be used in positioning of ad hoc networks due to limits of landform or special applications. For such situations,we propose a GPS-free position system ANGEPS (Ad hoc Networks Gps-frEe 3d Position System).ANGEPS's architecture and local positioning method are described in detail.Under given physical models,a local 3d coordinate system building and positioning approach is introduced and proved mathematically.Simulation results by ns-2 simulator prove that our method is effective.关键词：Ad Hoc networks;ANGEPS positioning system;GPS-free;the simplest basal graph;local node2|910|1更新时间：2025-07-16
- 摘要：After analyzing the characteristics of multi-aperture moving targets detecting and imaging,the paper improves the classical displaced phase center antenna (DPCA) measurements.The improved algorithm detects moving targets through pictures interpolation and pictures registering when using two apertures.Moving targets parameters can be estimated and at the same time moving targets images can be obtained if aperture number is increased.The blind speeds can also be removed.In the last,some typical computer simulation results are presented which illustrate the methods' validities.关键词：displaced phase center antenna (DPCA);multi-aperture;moving targets detecting and imaging;pictures interpolation and registering2|1212|20更新时间：2025-07-16
- 摘要：Fuzzy integral is an effective decision level fusion method for target recognition.The core problem in using fuzzy integral is to determine the fuzzy densities which can reflect the importance of the sensors.Presently,the main methods of determining fuzzy densities include using confusion matrix or genetic algorithm.These methods only use the a priori static information of the training samples to determine the fuzzy densities.A new method of determining fuzzy densities adaptively is presented in this paper,which uses the a priori static information of the training samples and the dynamic information contained in each sensor's decision.The simulation experiment shows that better fusion result can be obtained by using this method.关键词：decision level fusion;fuzzy integral;target recognition2|1179|13更新时间：2025-07-16
- 摘要：The principle of displaced phase centers multiple azimuth beam is introduced,the cause and effect to imaging of the errors induced by the method are analyzed,and computer simulation results are presented.The paper provides the reference for system design and further studying on imaging algorithm of displaced phase centers multiple azimuth beam SAR.关键词：Spaceborne SAR;high resolution wide swath;multiple azimuth beam(MAB);displaced phase centers antenna(DPCA);error analysis4|1738|5更新时间：2025-07-16
- 摘要：This paper presents DPCNN(Delay Pulse Coupled Neural Network) based on PCNN and uses DPCNN to find the shortest path successfully.Meanwhile,the algorithm of finding the shortest path based on DPCNN is described.Caulfield and Kinser introduced the PCNN method to solve the maze problem and although their method also can be used to find the shortest path,a large quantity of neurons are needed.However,the approach proposed in this paper needed very fewer neurons than proposed by Caulfield and Kinser.In the meantime,due to the pulse parallel transmission characteristic of DPCNN,the approach proposed can find the shortest path quickly.The computational complexity of our approach is only related to the length of the shortest path, and independent to the path graph complexity and the number of existing paths in the graph.The results of computer simulations show that by using the approach proposed in this paper,we can use a small quantity of neurons to find the shortest path quickly.关键词：DPCNN;shortest path;PCNN2|1217|9更新时间：2025-07-16
- 摘要：This paper presents a novel data hiding method for concealing a piece of critical information in a host message.Given a host data stream of n bits size,the proposed method can embed as many as bits of data by changing,at most,one bit in host data stream.The matrix H for embedding and extracting data can also be used as a secret user key,which provides a higher security of the hidden data.With the proposed method,we gain satisfactory simulation results on PC.关键词：data hiding;embedding-extracting matrix;encrypt;multimedia2|1099|18更新时间：2025-07-16
- 摘要：The applicability of biomimetic pattern recognition to information processing of abstract objects is studied,and then a DOA estimation method based on biomimetic pattern recognition and PCA/ICA is advanced.In this method,the output signals of antenna array are collected in practical conditions and expressed as feature vectors by using PCA/ICA.These feature vectors are studied with the method of high dimensional geometry and the principle of biomimetic pattern recognition.By using the feature vectors as training samples ANN models are constructed.In our experiments,when SNR is 20dB or 0dB,the correct estimation rate is 100%;when SNR is -20dB,the correct estimation rate is 83%;The experimental results show that the proposed method has the great advantage of preferable robustness and fast computation.关键词：DOA estimation;biomimetic pattern recognition;neural networks;PCA;ICA2|893|7更新时间：2025-07-16
- 摘要：We have investigated a location precision model based on the separated error of TDOA from that of station site by analyzing the principle of tri-station united TDOA location towards emitters.The scale of 2-D location error caused by target height is estimated as well.With the help of computer simulation,we have made some useful conclusions about the distribution of location error and station deployment.Then a location precision reckoning model is proposed.关键词：passive location;time difference of arrival;reckon2|1801|18更新时间：2025-07-16
- 摘要：We have investigated the indoor geolocation based on signal strength modeling.Linear,compensated linear,and multiple regression methods have been applied to set up signal strength models by using simulated data.We have also analyzed this modeling method to better understand the relation between the location error and the signal strength error.Some important results have been obtained to help us determine proper placement of Access Points (AP) and evaluate the range of location error.A simulation experiment has been conducted based on typical parameters of IEEE802.11b MAC.关键词：WLAN;geolocation;signal strength;IEEE802.11b2|3200|20更新时间：2025-07-16
- 摘要：The discovery of scaling behavior in network has provided hope that mathematical models can be used to describe the nature of the traffic.A joint multifractal (JMF) model for network traffic is proposed based on the combination of multiplicative cascade process and independent K distributed process.The model focuses on both the scaling function and moment factor as the key for unraveling the multifractal characteristics of the network traffic.JMF model is objective and simple enough to describe the short-term fractal behavior as well as the long-term self-similar behavior of network traffic simultaneously,which is proved by theoretical analysis and simulated results from several real traffic data sets.The influence on the traffic characteristics due to timescale is expressed by scaling function,and traffic burstiness variation in a specified timescale is illuminated by moment factor.The combination of scaling function and moment factor describes the short-term behavior of network traffic,and the statistical properties of JMF model describe the traffic long-term behavior characteristics.关键词：internet;network traffic;multifraction;K distribution2|1403|5更新时间：2025-07-16
- 摘要：This paper proposes a novel method for the optimal filtering of linear FM signal based on the fractional Fourier transform.First,an optimal filtering operator on the continuous fractional Fourier domain is provided according to the orthogonality principle about the linear minimum mean square error (MSE) estimation,and then,a discrete algorithm of the filtering operator is further proposed.Theoretical analysis and simulation results show that the performance of the proposed filtering algorithm is very close to that of the Wiener filtering,and also,this filtering algorithm is simple in computation and easy in implementation.关键词：LFM signal;optimal filtering;fractional Fourier transform2|1198|5更新时间：2025-07-16
- 摘要：The detection and location method of GPR targets presented in this paper has two steps.First,based on the analysis of GPR A-scan signal's statistical features,a windowed statistical method is introduced to efficiently extract the range of interest (ROI) from a large amount of data.Second,according to the hyperbola feature of GPR B-scan signal,a modified Hough transform is used to detect the hyperbola from the ROI data that after being segmented,aims to get rid of the false targets and locate the targets accurately.The method had been employed to find and locate targets from GPR data.The results show that all targets are detected correctly,and the depth and horizontal location errors are less than 1cm.Moreover,the signal-to-clutter ratio (SCR) of ROI data can be down to about 2dB.关键词：GPR;detection;location;Hough transform2|1389|11更新时间：2025-07-16
- 摘要：The method of shift-copy generating sequence by hybrid code copy information is presented.The cross correlation function and property of sequence are also discussed.The condition that cross correlation function of two generating sequence is always zero is given.At last,the selection criteria of copy information are given,according to which a sequence family can be found where cross correlation function is always zero.关键词：sequence;correlation function;copy generation;hybrid code2|964|0更新时间：2025-07-16
- 摘要：The near-far resistant receiver for navigation system is studied in the paper.2Firstly,the structure of the receiver is given.2Then methods of determining the near-far effect are given.2Finally,the cancellation method for the near-far effect is studied.2Simulation results indicate that the receiver demonstrates the near-far resistant performance,so it suits to navigation system adopting DS-SS technique.关键词：navigation;Near-far effect;DS-SS;Receiver2|1118|4更新时间：2025-07-16
- 摘要：Based on the gene expression profiles of multiple myeloma,a method was proposed for knowledge discovery using data mining and machine learning methods.We used the information gain as the criterion of each gene for classification,and got a set of informative genes using artificial neural networks.Identified by decision tree algorithm,production rules were discovered as references for biomedical researchers.The effectiveness of the method we proposed is proved by experimental results.The method can also be used as a tool for gene expression analysis in the research of biomedicine and biotechnology.关键词：DNA chip;gene expression;data mining;neural networks;multiple myeloma2|1032|9更新时间：2025-07-16
- 摘要：For coded-division multiple access (CDMA) mobile communication receiving systems,a new space-time 2-dimension signal processing framework is presented in this paper,which is a kind of parallel interconnection of smart antenna and RAKE receiver (PI-SA&RR).Based on this framework the space-time 2-dimension adaptive digital-beamforming (ST2-DADBF) algorithm is given.Comparing with the 2-dimension RAKE receiver (2-DRR),the ST2-DADBF algorithm can implement optimal outputs of joint space- and time-domain without estimating delay-DOA's (Directions of Arrival).Comparing with the pilot symbol-assisted coherent adaptive antenna array diversity receiver (PSA-CAAADR),the ST2-DADBF algorithm is a genuine 2-dimension adaptive algorithm,which can combine smart antenna and RAKE receiver to perform adaptive algorithm without estimating parameters of RAKE fingers.Considering both effects of time-delay-dispersion and space-angle-dispersion of the channel,we present a general signal model for multiple-subscriber mobile communication system.Based on this model the computational simulations of the ST2-DADBF algorithm are done.Simulating results imply that the ST2-DADBF algorithm can catch each of the multi-path components of the interested user in 2-D space-time domain,and combine these components coherently and simultaneously,while suppress interferences caused by other users in time- and space-domain,hence improve bit error rate (BER) performance of the system.关键词：space-time parallel interconnection;smart antennas;RAKE receiver;2-D adaptive digital-beamforming algorithm;optimal space-time radio pattern2|814|0更新时间：2025-07-16
- 摘要：Wide-band direction finding is a difficult topic of research in signal processing domain.This paper generalizes weighted sub-space fitting direction finding algorithm to the wideband situation,and so constructs an aim function,then applies genetic algorithm for nonlinear global optimization.Direction of arrival is estimated without preprocessing.The algorithm is applied on uniform linear array and extensive simulation results demonstrate that the algorithm has good performance.关键词：wide-band direction finding;weighted sub-space fitting;genetic algorithm2|967|3更新时间：2025-07-16
- 摘要：Millimeter wave characteristics differ from those of microwaves,infrared or optical,as well.It has some distinct advantages over microwave,infrared,or optical system.There are many significant applications and exciting developments in millimeter wave system. To calculate the brightness temperature distribution from the measured antenna temperature,a Fredholm integral equation of the first kind must be solved.This equation is ill-posed.DFP is applied to recovery of the armour target's brightness temperatures from the scanning millimeter wave radiometer data.关键词：millimeter wave radiometer;antenna temperature;Fredholm integral equation of the first kind;inversion2|698|3更新时间：2025-07-16
- 摘要：Normal methods of polarization filter change the phases of the target signal,and the difference of phase-shift,which is affected by the difference of the filter parameters produces the phase distortion.Based on the normal single notch and multi-notch logical product polarization filter,a new type of polarization filter named Null Phase-Shift Instantaneous Polarization (NPSIP) filter is proposed to avoid the phase distortion.The real phase (and amplitude) is kept through Linear Polarization Translation (LPT),normal polarization filter and the compensation of the phase (and the amplitude).It is indicated from the experimentally derived data that the improvement of the signal to interference ratio (SIR) achieved more than 27dB in the experiment of HF radar for suppressing the radio interference.关键词：signal processing;polarization;filtering;high frequency radar (HF radar)2|1027|8更新时间：2025-07-16
- 摘要：This paper presents an alternating direction implicit FDTD (ADI-FDTD) algorithm without the Courant-Friedrich-Levy condition restraint for obtaining the solution of the three dimensional scattering problem.The perfectly matched layers are adopted to simulate the infinite space.The modified formulations of the connective boundaries are also given in detail.Compared with the conventional FDTD,the timestep increment is free from the CFL condition.So the total timestep is decreased significantly and the new algorithm is more efficient than traditional FDTD in terms of CPU time.Finally,some numerical results are given to demonstrate the accuracy and the high efficiency of ADI-FDTD.关键词：CFL stability condition;ADI-FDTD;electromagnetic scattering2|1123|3更新时间：2025-07-16
- 摘要：To keep the stability,the time step length of traditional equal-time-step non-uniform finite-difference time-domain (ETS-FDTD) method is determined by the minimized grid size,which results in a long computational time.A multi-time-step finite-difference time-domain (MTS-FDTD) method is presented,which uses different time step lengths in different grid regions to reduce computational time.Numerical results demonstrate that MTS-FDTD method reduces more than 42 percent of computational time than ETS-FDTD method.关键词：non-uniform grid;multi-time-step;FDTD method2|931|2更新时间：2025-07-16
- 摘要：A novel blind video watermarking scheme is proposed.In this scheme,independent component analysis (ICA) is used to extract the motion component between the consecutive frames and the watermark is embedded into the wavelet coefficients of the motion component according to the mean of the neighboring wavelet coefficients.Motion component is important to the video,but it is not obviously affected by compression.So,the robustness is improved by embedding the watermark into the motion components.Frame-based motion extraction avoids the repeat operations of block-based extraction and reduces the complexity.Embedding watermark in wavelet domain disperses the effects caused by watermark to the whole frame.Better invisibility can be achieved.The simulation results show that the proposed scheme can preserve high video quality.The watermark can be extracted blindly and is robust to common video processing with little probability of false positive.关键词：digital watermark;video watermark;blind detection;independent component analysis (ICA)2|934|2更新时间：2025-07-16
- 摘要：The quasi-periodic boundary conditions in the computer code MAFIA is used to determine the effect on dispersion and on-axis interaction impedance of helical slow-wave structure parameter variations ,including width,thickness and relative dielectric constant of the support rods.This is a difficult problem in theory now.The result is that,with the variations of axial width and height of the helical tape,only a slight decrease in the phase velocity,but more decrease in the interaction impedance .There is an optimum size on both axial width and height of the helical tape for the interaction impedance of a helical slow-wave structure.关键词：traveling-wave tube;helical slow-wave structure;dispersion;interaction impedance2|1131|3更新时间：2025-07-16
- 摘要：A kind of novel tape helical slow wave structure (SWS) is supported by wedge-shaped discontinuous dielectric pillars and brazed with the helix and metal envelope through two metal connectors.The dielectric pillars exist only at the tape helix in each pitch.It has higher power capacity and broader bandwidth.The hybrid model for analyzing the tape helix is developed in this paper.In this model,by expanding the surface currents on the tape helix in a series of Chebyshev polynomials,simulating the helical radial thickness with vacuum layer,equalizing the discontinuous dielectric pillars with multiple azimuthally symmetric layers,assuming an infinite number of infinitely thin radial vanes and considering the metal connectors,the dispersion equation and interaction impedance of the novel helical SWS are obtained.In the meantime,the tape helical SWS is simulated by HFSS.The calculated results using the model presented in the paper show good agreements with HFSS simulation results.The theory presented here can provide a strong basis for designing the tape helical SWS.关键词：helix radial thickness;novel discontinuous dielectric pillar;metal connector;dispersion characteristic;interaction impedance;traveling wave tube2|968|2更新时间：2025-07-16
- 摘要：Based on the temporal-spatial sequential Maximum Likelihood(ML) algorithm,a new algorithm for estimating the elevation angle of a target in radar low-angle tracking environment is presented.According to the range of the target and the height of the antenna,the new algorithm first gets the relation of the direct and specular signals in elevation.Then a one-dimensional search are done on the likelihood function.Compared to the temporal-spatial sequential ML algorithm,the new algorithm not only has a low computation complexity,but also has a good performance.The theoretical analysis and computer simulation results demonstrate the merits of the new algorithm.关键词：maximum likelihood estimation;direction-of-arrival;low-angle tracking2|2276|23更新时间：2025-07-16
- 摘要：The real-time detection algorithm for dim moving point target in image sequences is one of the key algorithms in precise guidance system.This paper presents a thorough analysis of a point-track detection algorithm based on Linear Least Square Predictor after a brief discussion of the current algorithms for moving point target in image sequences.With the result of simulation test,it can be shown that the introduced algorithm can effectively detect moving point target trajectory in image sequences than previously developed algorithm.关键词：point target;least square linear predictor;trajectory detection4|1497|14更新时间：2025-07-16
- 摘要：A new method to design and analyse a wideband splitter is presented.Two ways are put forward:one is using continuously tapered line instead of an excessive impedance convertor,the other is using parallel coupled-strip line to design the wide band splitter.At the same time the scatter matrix of the wide band splitter is simulated by the finite element method and tested.The experimental results show that the performances of the frequency range from 2GHz to 18GHz of this wide band splitter are satisfactory.The splitters with asymmetrical magnitude are designed using this method and their scatter matrixes are simulated by the finite element method.The results show that this method realizes the wide band splitters of the superior coherence in equiphase with the magnitude of asymmetrical power division.关键词：coupled-strip line;splitter;wide band;tapered-line2|2218|2更新时间：2025-07-16
- 摘要：A fractal microstrip patch antenna is illustrated for antenna Radar Cross Section (RCS) reduction.Fractal structure has the special ability of space filling which can be explored for antenna RCS reduction.The characters of the designed fractal microstrip patch antenna are compared with those of traditional patch antenna.The results show that fractal antenna retains the radiation character and also has RCS reduction to some extent,which is helpful to the antenna RCS reduction.关键词：fractal antenna;RCS;microstrip patch antenna6|1225|2更新时间：2025-07-16
- 摘要：Approximate conformal mapping technique has been employed to analyze the effect of finite metellization thickness of CPW theoretically,therefore numerical computations and some corresponding numerical processes are carried out.As a result,a new accurate correction formula of strip width is presented.In addition,the closed form formulas of characteristic impedance and attenuation are derived from it.Finally,the computation results based on these new formulas are compared with those of K.C.Gupta formula's and experimental values.It shows that the errors of new formulas are dramatically decreased,which are only 13.0~31.3% of K.C.Gupta formula's.This results suggest that the new formulas will play an important role in characterizing CPW precisely instead of K.C.Gupta formula.关键词：coplanar waveguide;correction width of strip;characteristic impedance;loss2|1549|0更新时间：2025-07-16
- 摘要：Two admission control algorithms are proposed for TD-SCDMA system.The successful admission probability,the lost call probability and the quality of service etc.are analyzed by the means of simulation.One of the above is used in the current development of the product by considering many factors.关键词：TD-SCDMA;admission control;Quality of Service2|814|2更新时间：2025-07-16
- 摘要：The theoretical analysis of abrupt structure loaded with lossy material on both sides has been described.Dispersion equations of waveguides and field matching equations of hybrid modes (HEM) for abrupt structures with absorber are derived.Further,numerical solution of the equations has been used to analyze the field of different modes in each region and study the properties of waveguides and abrupt cavities loaded with lossy material.The theoretical analysis and calculation code are used to design and study the low Q cavities for gyroklystrons.关键词：lossy material;hybrid mode;abrupt structure;resonant cavity;gyroklystron amplifier;high power millimeter waves2|927|1更新时间：2025-07-16
- 摘要：A fast VQ encoding algorithm,Hadamard transform (HT) based equal-average equal-variance nearest neighbor codeword search algorithm (HTEENNS),is presented.Before the search process,all codewords in the codebook are Hadamard-transformed and sorted in the ascending order of their first elements.During the search process,we firstly perform the HT on the input vector and calculate its variance,and initialize the current closest codeword of the input vector to be the codeword whose Hardamard-transformed first element is nearest to the input vector's,and secondly two efficient elimination criteria are used to find the nearest codeword to the input vector using the up-down search mechanism near the initial best-match codeword.Experimental results demonstrate that the performance of the proposed algorithm is much better than that of the ENNS,EENNS,and Hadamard transform based PDS algorithms.关键词：vector quantization;codeword search;fast encoding;Hadamard transform2|1036|8更新时间：2025-07-16
- 摘要：Radio frequency interference (RFI) often causes great trouble to HF radars.We propose a novel method for RFI suppression based on the discrepancies of the time-frequency distributions of the RFI and the target signals.The method suppresses RFI effectively while hardly brings any loss to the target signals so that the qualities of the echo range-Doppler spectra are greatly improved and the anti-jamming abilities of the HF radars are greatly enhanced.The method can also be regarded as a soft realization of the real time radar frequency selection.关键词：HF radar;radio frequency interference;time-frequency analysis;chirp4|1176|7更新时间：2025-07-16
- 摘要：The paper investigates the ambiguity resolution problem in the field of GPS.By utilizing Z-transformation and baseline constraint,it improves the conventional FASF.At last,the paper gives the result of experiment.The result indicates that the method that the paper gave can reduce the state range of potential ambiguity relative to the conventional FASF.So the computing time can be reduced.It is suited to the real-time application in the dynamic condition.关键词：GPS;Kalman filter;FASF;baseline constraint2|1063|1更新时间：2025-07-16
- 摘要：A new multistage joint adaptive array and successive interference cancellation (AA-SIC) structure for a direct sequence code division multiple access (DS/CDMA) system are proposed.In the structure of the system,space,time processing and multiuser detection to improve the performance are utilized.Most structure needs RAKE combiner to capture the multipath,but the proposed structure needs no RAKE combiner and its adaptive algorithm has the function of RAKE combiner.关键词：DS/CDMA;smart antenna;multiuser detector2|776|1更新时间：2025-07-16
- 摘要：A novel power allocation and adaptive modulation algorithm for MIMO systems over time-varying fading channel is proposed.Using water-filling theory in space domains,the optimal power allocation and adaptive MQAM by singular values of the channel transfer matrix with average transmit power constraint is obtained.The spectral efficiency is analysed.The effect of the channel estimation error and feedback delays on the algorithm is investigated.The theoretic analysis and simulation results show that the novel algorithm is robust and easy to implement,and the spectral efficiency of the algorithm is greater than that of early-proposed algorithm with total power constraint.关键词：MIMO;adaptive modulation;spectral efficiency;QAM2|1138|5更新时间：2025-07-16
- 摘要：Complicated characters of noise in dynamical measure data are discussed in this paper.The analysis results show that the complicated characters of noise comes from two essential properties of model error.One is complex error,which cannot be described by general statistics model,and another is uncertainty of systematic error.It is built that the mathematic model of including complex error described by optimal knot spline function and time varying AR noise.The model can separate accurately not only the error with secondary low frequency but also the time varying stochastic error from complex error data.Furthermore,data fusion model with systematic error state is presented and precision discount factor method based on the uncertainty of systematic error state is also realized.At last,the precision integrate evaluation process is given.Computing results show the method is adaptive to actual engineering situation well.关键词：data fusion;error;precision2|980|1更新时间：2025-07-16
- 摘要：To correct the fixture effect on the device used in high speed eye diagram measurement at high bit rates above Gb/s,a correction method based on time domain measurement,frequency domain measurement and fast Fourier transforms has been proposed.Under the guidance of the proposed method,experiments were designed and performed.It is found that the corrected eye diagram fits the directly measured eye diagram very well and the corrected parameters,such as eye height,Q factor,rise time,fall time and peak-to-peak jitter,are very different from the uncorrected parameters.关键词：eye diagram;fixture;fast Fourier fransforms;transfer function2|1378|1更新时间：2025-07-16
- 摘要：Transformers are the main devices in electrical isolation and signal and energy transfer.Based on the analysis of coreless PCB transformers structure,an improved approach to compute the self and mutual impedances in coreless PCB transformers is given.The experiment proved that the proposed approach is coincident with the testing results.关键词：coreless printed circuit board (PCB) transformers;spiral coils;film inductor2|1336|0更新时间：2025-07-16
- 摘要：We discuss the design of clock distribution circuits for VLSI chips operating at GHz frequency.Clock tree uses balanced planar tree routing to eliminate the clock skew;and dynamically optimize clock circuit by inserting buffers.Finally we evaluate the clock circuit performance by simulator.The method realizes the optimization of clock circuit in the frequent domain,and dramatically improve simulating time compared with previous work.关键词：moment matching method;clock circuit;transmission line2|827|0更新时间：2025-07-16
- 摘要：This paper proposes a structure-improving particle swarm optimization (SPSO) algorithm for training artificial neural network (ANN).The algorithm is successfully applied to pattern classification problems including Iris,ionosphere and breast cancer.By tuning the structure and connection weights of ANN simultaneously,the proposed algorithm generates optimized ANN with problem-matched capacity for processing classification information.By doing this,it also eliminates some ill effects introduced by redundant input features and the corresponding structure of ANN.Compared with BP and GA based training techniques,SPSO can improve the classification accuracy while speeding up the convergence process.Simulation results show that SPSO is a potentially robust learning algorithm and could be extended to real world applications.关键词：particle swarm optimization;artificial neural network;genetic algorithm;pattern classification2|3118|50更新时间：2025-07-16
- 摘要：H.264 supports a so-called multi-reference-frame prediction technique.We adjust its three relevant parameters (the number of previous reference frames,the number of skipped frames,and the number of B-frames),and use their different combinations to encode various test video sequences respectively.Experimental results show that multi-reference-frame prediction does not improve coding performance but involve heavy computing cost in most cases.We propose that the advantage of this technique depends on a sort of video content self-similarity,which seldom occurs in practice.We then suggest not to use the multi-reference-frame prediction technique in most applications.关键词：video coding;H.264;multi-reference-frame;prediction2|909|1更新时间：2025-07-16
- 摘要：Emergint is a P2P routing algorithm which aims at the issue of P2P network dynamic construction.Emergint has 3 characteristics:(1) autonomy:node insert or delete does not need the control of central coordinator;(2) dynamicity:node insert or delete does not affect the correctness of the ongoing routing process of other nodes;(3) concurrency:multiple nodes can join or leave the system at the same time without any interference with each other.We examined the performance of Emergint by network simulation.Examination result shows:The RDP of Emergint is approximately 1.5.The overhead of node insert or delete is O(logN).2|828|2更新时间：2025-07-16
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