最新刊期
卷 29 ， 期 S1 ， 2001
- 摘要：To understand the function genome and proteome is the main task of post genome era.Biosome is somewhat a complex,ordinal system which is excited both by genetic and environmental information.Genome has contained all the genetic information needed,including its products and regulation information.In nature,genome is an information system,which obeys the same regulation law as a general information system does.Consequently,we have to understand the function genome from the information system point of view,and treat biological signal as the core content of this scheme.关键词：genome;proteome;complexity;information structure;information system2|1059|0更新时间：2025-07-16
- 摘要：With the completion of Human Genome draft,bioinformatic research has entered the post-genomic era.Studying of the control of gene expression and function using computational methods has gradually become the mainstream of research.For its special role in the control of eukaryotic gene expression,alternative splicing has become an important topic in genomic research.In this study,we analyzed alternative splicing of human genes based on complete coding sequences(cds) of alternatively spliced genes.As reported previously we have set up a database AsMamDB.Transcripts probably belonging to one gene were put into a single cluster.We also developed a new multi-alignment tool,ASALIGN,aiming to reveal alternative splicing patterns of transcripts belonging to a same gene and identify their alternative and non-alternative regions.Here,through filtering we chose 371 genes that have two or more different cds.Using Asalign we have identified all alternatively spliced regions in the cds of selected genes.We also studied lengths,positions of alternatively spliced regions,shifting of reading frames due to alternative splicing,as well as codon frequencies of non-alternative,alternatively spliced regions and their boundaries,and ended with some interesting results.Our study may provide important in-sights into the alternative splicing phenomenon and clues for prediction of alternative splicing.关键词：alternative splicing;multiple alignment;gene structure;splice pattern2|3322|0更新时间：2025-07-16
- 摘要：Electronic cell or E-cell simulates and reveals life activities around cell internally and externally by using advanced tools of computer science,electronic information technology and others.It can be used as a new powerful tool to explore the potential nature laws of cell life.E-cell represents the frontier of life science and information science.It is a type of artificial life and a very complex system.This paper gives survey on the history and cause of E-cell research and development.And briefly presents its research contents,two real examples,other scientific areas closely related to it,and its functions and great significance.Finally,we address its future prospects and some suggestions on its research progress.2|1475|0更新时间：2025-07-16
- 摘要：An accurate automatic personal identification is critical to our highly inter-connected information society.Biometrics refers to automatic identification of an individual based on her/his physiological or behavioral traits.Though biometrics is not an identi-fication panacea,it is beginning to provide very powerful tools for problems requiring positive identification.This paper attempts to summarize important research issues in biometrics.62|8030|0更新时间：2025-07-16
- 摘要：The olfactory analogue is a newly rising technology developed in the last ten years,and its development closely de pends upon such research fields as new material,precision manufacture technology,multi sensor mixture,computer,pattern recognition,applied methematics,and relative application ones as well.Therefore,its study has very important theoretical significance.The ol factory analogue technology has widely application prospects in quality evaluations of such odorous products as foods,and in environ mental supervision,chemical industry,transportation,medical treatments and the others.This paper goes into details the basic principle of the technology,introduces its history,state-of-the art work and future development,points out some problems in its applications that remain unsolved.And furthermore,this paper elaborates with an emphasis on its widely application prospects in qualitatively evaluating the odor qualities of performs,cigarettes,alcoholic dr inks as well as other aromatic materials in the light industry.This paper goes into details the basic principle of olfactory analogue technology,introduces its history,state-of-the art work and future development,points out some problems in its applications that remain unsolved.And furthermore,this paper elaborates with an emphasis on its widely ap plication prospects in qualitatively evaluating the odor qualities of performs,cigarettes,alcoholic drinks as well as other aromatic mate rials in the light industry.关键词：olfactory analogue;odor Sensor array;data processing methods;evaluation of odors3|1095|0更新时间：2025-07-16
- 摘要：Based on tetranucleotide parameters,a statistical mechanical model was suggested to analyze the flexibility of the Escherichia coli genome.The terminus region of replication displayed a low level of flexibility.A strong correlation between G+C content and flexibility can be seen.Average flexibilities in coding regions were found to be significantly larger than those in non-coding regions.The flexible characteristics in three class sigma promoter sequences in the Escherichia coli genome were also analyzed.关键词：non-neighbor base-pair interaction;statistical mechanical model;DNA flexibility;whole-genome analysis2|954|0更新时间：2025-07-16
- 摘要：The serine protease superfamily is a subgroup of the hydrolases,whose name comes from the conserved Se-r195 cat alyzing the substrates.Serine proteases maintain a common fold over a very long evolutionary span,in spite of divergent sequences.This class of enzymes has developed a wide variety of important biological functions.However,strongly divergent protein sequences and a mass of gene duplications make it very difficult to perform evolution analysis on the whole superfamily.In the present work,structure based evolution analysis was performed on the serine proteases superfamily using SSAP algorithm,and the structure and function evolution were analyzed,especially the effect on functions by structure evolution of the serine proteases.The research would have certain guiding significance on the relationships between protein structures and functions and the molecular design.关键词：serine protease superfamily;molecular evolution analysis;strcture alignment;SSAP2|2012|0更新时间：2025-07-16
- 摘要：Fast speaker adaptation is very important in application of speaker independent continuous speech recognition.Recently speaker adaptation methods almost just update mean vector.A new adaptation algorithm proposed in this paper can adapt covariance matrixes rapidly.Gaussian similarity is used for measuring the distance of different covariance.A binary decision tree is constructed with this measure.And each middle node includes a covariance matrix of cluster center.Lots of covariance matrixes corresponding to speaker dependent model are trained based on this tree.During adaptation,covariance matrixes are updated through linear interpolating those covariances of cluster center.It can be shown from the experiments that error rate is descended from 29.49% to 27.55% in case of just one adapted sentence.关键词：continuous speech recognition;rapid speaker adaptation;Gaussian similarity analysis2|1214|0更新时间：2025-07-16
- 摘要：Tongue Diagnosis is one of the essential methods of traditional Chinese medical diagnosis.The accuracy of tongue diagnosis can be improved by tongue characterizaton.This paper investigates the use of image analysis techniques for tongue characterization by evaluating visual features obtained from images.Several algorithms are presented for color calibration,tongue area segmentation,feature analysis for the tongue and its coating and quantification of the cracks of the tongue.The clinical application shows the effectiveness of the algorithms.关键词：tongue characterization;image analysis;color calibration;tongue segmentation;tongue analysis;tongue coating analysis;tongue crack analysis55|10269|0更新时间：2025-07-16
- 摘要：A typical problem in array processing and data analysis is to recover the unobserved source signals from their mixtures.Blind source separation(BSS) is a powerful methodology for solving this problem.In recent years,the BSS has received considerable attention from the signal processing community and the neural network community.This paper presents a survey and review on the BSS,focusing on the independent component analysis(ICA) and the principal component analysis(PCA).关键词：source separation;neural network;independent component analysis;principal component analysis4|6315|0更新时间：2025-07-16
- 摘要：This paper summarizes various fast codeword search algorithms for vector quantization.These algorithms are classified into several classes according to their characteristics.Simulation,comparisons and analysis are done for various fast algorithms in terms of encoding time,average calculations,extra memory and off-line computation.Some modified algorithms or trains of thoughts are also presented in this paper.关键词：vector quantization;codeword search2|1147|0更新时间：2025-07-16
- 摘要：In this paper,an adaptive color image-watermarking algorithm based on 3D-DCT(Three Dimensional-Discrete Cosine Transform) is proposed.The algorithm demonstrates that 3D-DCT outperforms 2D-DCT in terms of energy concentration.Since the 3D-DCT coefficients of a color image have larger magnitudes than that of the 2D-DCT coefficients,the 3D-DCT coefficients have larger perceptual capacity and then allow to embed stronger watermark signal.Based on 3D-DCT,we propose to change the watermark strength adaptively by taking account of the perceptual feature of human visual system.The experimental results show that the proposed algorithm can trade-off the conflict of transparency and robustness of invisible watermark well,the thus generated watermark can with-stand under the common attacks,such as JPEG compression,additive noise,image filtering,color and luminance/contrast alteration very well.关键词：color image watermarking;3D-DCT;color visual characteristic;adaptive watermarking;robustness2|1027|0更新时间：2025-07-16
- 摘要：This paper proposes a novel digital watermark embedding algorithm for still images.A gray-level image with rich details is used as a watermark and embedded in vector transform domain,more than scalar transform domain used traditionally(such as discrete cosine transform domain,etc.).The better robustness of the proposed algorithm is demonstrated by experimental results.关键词：vector transform;digital watermark;copy protection;image processing2|915|0更新时间：2025-07-16
- 摘要：Attitude stability is a very important parameter for the platform design of Synthetic Aperture Radar(SAR) satellite. The mathematical expression of spaceborne SAR impulse response function with attitude jitter is studied using paired echo theory.The effect of attitude jitter on spaceborne SAR image qualities is summarized based on the theoretical analysis and computer simulation.The analytical mathematical expression is deduced,which is useful in analysis of attitude stability and SAR image qualities.A method for quantificationally analyzing attitude stability is proposed in this paper basing on the characteristics of SAR satellite.The conclusion is validated by large quantities of computer simulation according to the L,C and X-band SAR satellite parameters.It provides theoretical foundation for SAR satellite system analysis and design.关键词：spaceborne synthetic aperture radar;radar echo;satellite attitude2|1507|0更新时间：2025-07-16
- 摘要：Based on the residue theorem of Interferometric SAR,in depth analysis and detailed description of Branch Cut algorithm,one of the most popular In SAR phase unwrapping approaches,has been given in this paper.Many wrong implementations and premature conclusions about Branch Cut method caused by the over brief description of Goldstein's orig inal algorithm and not enough understanding of the residue phenomenon have been clarified and rectified totally.Besides,grounding process and dipole remover preprocessor are introduced in Goldstein's Branch Cut algorithm to get tremendously length reduced branch cuts and more continuous unwrapped phase surface.Finally,the performance and character of Branch Cut method are discussed and branch cut is stated as an essential factor for all the phase unwrapping approaches,either existed or under developed,for its nature of isolating the residue effect.X-SAR data based experimental results are presented as the proof of the paper.关键词：interferometric SAR;phase unwrapping;branch cut algorithm;residue2|972|0更新时间：2025-07-16
- 摘要：Motion is an important clue to describe the content of a video sequence.This paper presents a global motion information based video retrieval system.In this system,video sequences have undergone a short-term global motion analysis,which will accurately extract the bilinear motion model of the global camera motion.The extracted model parameters are used as motion features for retrieval,and the retrieval scheme is based on the feature point sequential match technique and the calculation of square sum of global motion vector distance.Experimental results show that in certain application domain,such as sports video,our retrieval scheme could achieve a near-semantic content retrieval,and it provides new functionalities that other image based features cannot achieve.关键词：video retrieval;motion information;global motion;motion model2|1281|0更新时间：2025-07-16
- 摘要：In DS-CDMA channels with multipath and multiple access interference,this paper estimates blindly the user-channel with extended space-time channel model to process the blind MMSE detection.Moreover,using the concept in radar,this paper proposes a kind of reduced-rank processing which outperforms the subspace method by maximizing the output signal-to-interference and noiseratio(SINR).Simulation results demonstrate the good performances of those methods.关键词：space-time adaptive processing;multiuser detection;CDMA2|819|0更新时间：2025-07-16
- 摘要：This paper proposes a new methodology of joint optimization among source coding,channel coding and error concealment for wireless video transmission.Specifically,a generalized rate distortion function,which reflects the distortion-rate due to sourcecoding,channel coding,and error concealment,is established for optimal bits-allocation,resulting an effective transmission of video data.Simulations confirm that the proposed scheme outperforms the conventional joint source-channel coding schemes.关键词：generalized distortion-rate function;joint source-channel coding;rate allocation2|1015|0更新时间：2025-07-16
- 摘要：Range alignment is usually based on the correlation of range profile in ISAR imaging.According to the point scatterer model of target,this paper shows that the range profiles have strong correlation within the aspect change 0.1°,but with the increase of aspect change the correlation will decrease greatly due to cross-term,which also shows that drift error will be caused when conventional neighbor amplitude correlation method is used to align the envelope.It is shown that by averaging over ten range profiles selected from the imaging needed range profiles with equal aspect change,the cross-term can be restrained,and the stable average range profile can be obtained.The average range profile has strong correlation with all range profiles,and if it is used as template,then the accuracy of range alignment can be enhanced.An iterative correlation alignment method for range alignment is proposed by using global optimization criterion.Real data validate its effectiveness.关键词：ISAR;range alignment2|1720|0更新时间：2025-07-16
- 摘要：In this paper,an error concealment scheme is developed to enhance the robustness of digital terrestrial TV broad-casting(DTTB).This scheme includes a low complexity error concealment algorithm,an effective reception for isolated I-pictures,and an efficient detection of spatial/temporal activity.Specifically,the error concealment algorithm combines temporal motion compensation with block matching methodology to achieve effective concealment while keeping low complexity with small size of search-window for block matching.Extensive simulations have verified that,even with high packet error rate,the proposed scheme may achieve efficient and robust video broadcasting over DTTB systems.关键词：error concealment;MPEG-2;DTTB2|955|0更新时间：2025-07-16
- 摘要：Based on the basic principles of the Dual Star position and navigation system,this paper gives a new scheme of position and navigation,which can be applied for the ICAO's CNS/ATM system in the future.From the epicheirema error,propagation error,station address error,equipments error and the satellite clock error,the authors analyze the new system's precision if the distribution of the stations is satisfied,and forecast the potential application in CNS/ATM system.关键词：CNS/ATM;navigation;precision of position1|1309|0更新时间：2025-07-16
- 摘要：A target classification algorithm in high resolution and single polarimetric SAR image is presented in this paper. Firstly,a new RCS reconstruction filter based on the modified correlated neighborhood model is used for target and shadow detection. By nonlinear iterated process,the whole image can be classified to "background","shadow" and "targets".Secondly,a series of mor-phological operators are used to terrain filtering and edge extraction,and then through modified Hough Transform technology and the measure of slimming lines,line structures of man-made clutters in "target" class are linked and grouped.Finally,with special association model,the targets we are interested in are classified.关键词：SAR;RCS reconstruction;Target Detection;segment;extended terrain classification2|1565|0更新时间：2025-07-16
- 摘要：Motion compensation is the key step of SAR imaging,especially for high resolution SAR imaging.The motion parameter can be measured by navigational instrument,and also can be estimated from data.These two methods usually need to be combined.Although there are many studies about motion parameter estimation,and many estimation and compensation methods have been proposed,how to select a proper method according to real situation is still problem.This paper proposes algorithms for estimating the motion parameter and SAR imaging for a given radar and motion state,which can obtain a good SAR image with reduced computation load.关键词：SAR;Doppler centroid;Doppler rate;Chirp Scaling2|1515|0更新时间：2025-07-16
- 摘要：We present a new method for noisy speech recognition,which combines multiple timescale analysis with sub-band method.In the new method,sub-band features and full band features are extracted in different timescales,then combined at probabilistic layer.The method has robustness of both multiple timescale method and sub band method.Differential method is also introduced to further enhance the robustness of the features.Evaluated by a task on E-SET database under white noise from NoiseX92 noise database,the new method has higher recognition accuracy than conventional multiple timescale method on both noisy speech and clean speech.关键词：speech recognition;noise;sub band;multiple timescale4|863|0更新时间：2025-07-16
- 摘要：It is a great contribution that introduces hidden Markov model(HMM)in speech recognition.But the assumption of the traditional HMM that state transition probabilities aij(#em/em#≠j)are independent of self-trainsiton probabilty aij leads to disharmomy to the model.In fact,duration distribution probability and transition probability are dependent and one can be determined by another. From the viewpoint of duration distribution probabilty,this paper shows that the aussumption of independence of transition probability is unreasonable.And a new re-estimation algorithm of transition probability is deduced.The new algorithm performs better than the Baum-Welch algorithm.The average error reduction is about 5%.关键词：speech recogonition;hidden Markov model(HMM);transition probability2|1303|0更新时间：2025-07-16
- 摘要：Detailed measurement results for Web traffic provide the foundations of analysis in both large-scale user's access patterns and performance evaluation of Web servers and Web caches.This paper proposes a distributed online measurement system, which generates rich logs by packet monitoring for Web analysis in the cluster environment.The system gains high throughput and availability by adopting distributed processing technologies.Some new techniques,such as online reconstruction in memory and kernel packet filter,are also adopted to improve the system performance.关键词：Web information;distributed processing;network monitoring;performance evaluation2|885|0更新时间：2025-07-16
- 摘要：The performance of STAP degrades severely when the training samples are not independently and identically distributed(iid).The iid assumption is violated not only by the nonhomogeneity of the ground and the inner moving of the scatterer but also by the targets and other interferences.In some cases,the sample contaminated by a target will affect the estimation of the weight vector effectively and the output SCNR of STAP degrades evidently.In this paper,the target effect on the generalized sidelobe cancellor(GSC) is analysed.It seems that the blocking matrix and the secondary data training can not avoid the effect effectively.And the existing nonhomogeneity detectors can not select the contaminated sample exactly also.So a new NHD criterion and two new NHD methods are proposed.The computer simulation results show good performance can be obtained.Moreover,one of them is computationally easy and suits applications.关键词：STAP(Space Time Adaptive Processing);clutter suppression;NHD(nonhomogeneity detector)2|1054|0更新时间：2025-07-16
- 摘要：The performance of a smart antenna system is deteriorated markedly by the mismatch among antenna element channels.To combat this,an equalizer is usually used,but the detection of useful signals for active users is degraded since the additional signal is required in equalization.A new calibration method is proposed in this paper,which can mitigate the additional signal.Simulation results are presented to demonstrate its effectiveness,and the relationship between the performance and some key parameters is also discussed.关键词：smart antenna;Adaptive equalizer;adaptive interference suppression;calibration2|1160|0更新时间：2025-07-16
- 摘要：This paper proposes a total least mean lp-norm algorithm for adaptive filtering and system identification in α-stable noise environments,which is an extension of the total least mean squares algorithm.In the paper,both least lp-norm error and the lp-norm distance are defined.Computer simulations are presented to compare the relative performance of TLMP and LMP algorihms.关键词：adaptive filtering;system identification;α-stable noise;lp-norm distant;TLMP algorithm2|1010|0更新时间：2025-07-16
- 摘要：Within the framework of Dempster-Shafer theory of evidence,a combination rule based on proportional belief assignment is presented in order to solve conflict evidence combination in identification fusion.The order of combination is defined based on comparability.Comparison of our method with the existing algorithms demonstrates that our algorithm is superior to the existing approaches in terms of robustness via several simulations.关键词：Dempster rule;proportional belief assignment;conflict evidence combination2|1141|0更新时间：2025-07-16
- 摘要：Low probability detection(LPD) is an approach for hyperspectral imagery analysis;it use the eigenvectors of the imagery's correlation matrix in detecting small targets.Unfortunately,bacause of noise and the orthogonality constraints among the eigen vectors,the results of detection are non ideal.In this paper,we use the method of Convex Cone Analysis(CCA) to improve the detectability of LPD and to eliminate the stripe noise.The experimental results are given by applying the method to the data from Operative Modulor Imaging Spectrometer(OMIS) system.关键词：hyperspectral;low probability detection;convex cone analysis2|919|0更新时间：2025-07-16
- 摘要：This paper concentrates on the implementation of spaceborne SCANSAR mode which is developed in the stripmap spaceborne SAR system with variable look angle.SCANSAR signal parameters are determined and imaging algorithm for SCANSAR data with the large range migration is presented.Several SCANSAR performance parameters are analyzed and particular attention is given to ambiguity and noise equivalent σ0.With the requirement of spatial resolution,SCANSAR mode is designed in a large range migration spaceborne SAR system,the SCANSAR echo data is simulated and image is obtained.关键词：spaceborne SCANSAR;mode;implementation;simulating2|1053|0更新时间：2025-07-16
- 摘要：When hybrid coded video with motion compensated prediction(MCP) is transmitted over unreliable channels there exists the annoying problem of error propagation.In this paper we analyze the performance of coding efficiency and the distortion caused by propagation error,i.e.,propagation distortion,in multi hypothesis MCP,and give its theoretical performance limit.Then the numerical results under some assumptions are given.Both the theoretical performance and the simulation results of some specific multi-hypothesis MCP schemes under the typical packet loss environment of Internet show that with multi hypothesis MCP both the propagation distortion can be attenuated and the coding efficiency can be improved.关键词：multi-hypothesis motion compensated prediction;propagation distortion;coding efficiency2|728|0更新时间：2025-07-16
- 摘要：A novel clustering algorithm is developed by using immune evolutionary method after analyzing the advantages and disadvantages of the classical clustering algorithm and the GA-based clustering algorithm.It not only avoids the local optima and is robust to initialization,but also evidently restrains the degenerating phenomenon during the evolutionary process.The experimental results show that the correct ratio of our algorithm is higher than GA-based clustering algorithm by 8～16 percent.关键词：clustering analysis;FCM;genetic algorithm;immune evolutionary algorithm(IEA)2|1695|0更新时间：2025-07-16
- 摘要：In this paper,a novel kind of algorithm,the quantum evolutionary strategies-QES,is proposed based on the combination of quantum theory and evolutionary theory.It is a kind of evolutionary strategies with the form of quantum chromosome,whose core lies on the concept and principles of quantum computing,such as qubits and superposition of states.By using qubit mutation,we can make full use of the information of the currently best individual to perform the next search,and use whole interference to avoid prematurity,so it has rapid convergence and good global search capacity.The paper not only proves the global convergence of the QES,but some simulated experimentats are given to prove its superiority to other algorithms.4|1732|0更新时间：2025-07-16
- 摘要：The classifiable function of the wavelet neural network(WNN) is studied in this paper,and an integration of the immune evolutionary algorithm and WNN is proposed,based on the model of the immune evolutionary wavelet neural network(IEWNN). In this model,the immune evolutionary algorithm(IEA) used for training the network is a globally parallel algorithm which integrates the immune and the evolutionary mechanisms.The IEA is conducive to alleviating the undulating phenomenon produced by the blind fold behaviors of the original operators in the existent evolutionary algorithms through adaptively learning form the evolutionary environment.The analysis in theory and simulations show that WNN based on IEA is not only feasible but also effective.Because IEA has the parallel operation rules,the intelligent searching behavior and the criterion based on probability,it is conducive to relaxing the conditions of applying WNN and improving the ability of association memory and information processing.关键词：evolutionary algorithm;artificial neural network;wavelet;immunity;twin spiral problem2|997|0更新时间：2025-07-16
- 摘要：There are random row-noises in output digital image of near-field optical scanning microscopy because of the scanning way.To adhibit traditional method of filtering the waves cannot effictively wipe off such row-noises.This paper presents a method which combines adaptive iterration and wavelet analysis to filter row-noises.The method of subsectional linearity pseudo-color transformation is presented for emboldening image.The fitting of curve surface is adopted for filtering slowly change row-noises added in signal.关键词：row-noise;self-adapt;wavelet-analysis;pseudo-color;fit of curve surface2|1240|0更新时间：2025-07-16
- 摘要：To classify modulations blindly,this paper employs autoregressive models to generate feature parameters and the knearest-neighbour method to classify modulation types.Simulation results indicate that this method can classify modulations in a very low SNR environment such as -1dB,and be robust to the frequency offset and the dynamic change of sample frequency.关键词：modulation recognition;blind recognition;autoregressive model;software radio2|1251|0更新时间：2025-07-16
- 摘要：Based on correlative sequence determined by two neighbouring symbols,a new method of blind beamforming is proposed in this paper.Mitigating interference and making full use of the multipath signals,the new method utilizes the total energy of the desired user and does not require the channel parameters and training sequence.It is not restricted by the correlative value corresponding to nonzero time lag.It is characterized by identifying the multipath signals of the desired user and requiring less symbols for beam-forming.关键词：correlative sequence;blind beamforming;space-time processing2|936|0更新时间：2025-07-16
- 摘要：With the correlation of truncated chaotic sequences,the correlated demodulation for asynchronous DS-CDMA system in chaotic sequence is derived in the paper.It is shown that the system has multiple access and is robust by the theoretical analysis and computer simulations.Finally an optimization method of the chaotic spreading sequences is proposed.关键词：chaotic sequences;correlated demodulation;code division multiple access;multiuser interference2|941|0更新时间：2025-07-16
- 摘要：In this paper,the method of using open loop transmit diversity in a multi user DS-CDMA system operating in a frequency selective fading environment is considered.A novel approach is proposed for linear multi user detection in conjunction with transmit diversity to combat channel fading,multi user interference and inter symbol interference.By assigning spreading codes,blind and semi blind algorithms are developed for channel estimation and detection.Simulation results demonstrate that the proposed tech nique offers substantial performance over the RAKE receiver based on space time block codes,especially in a near-far situation.关键词：ransmit diversity;multi-user detection;space time coding;CDMA receiver2|957|0更新时间：2025-07-16
- 摘要：Multi-carrier code division multiple access(MC-CDMA)technology,which combines both advantages of OFDM(Orthogonal frequency division multiplex ing)and CDMA,has superior performance when transmitting high rate data in wireless fading channels.However,synchronization performance plays a key role on MC-CDMA systems.Based on the analysis of existing synchronization algorithms,a new synchronization algorithm is proposed in this paper.Theoretical analysis and computer simulation show that this algorithm has superior synchronization performance and less system complexity.关键词：MC-CDMA;Multicarrier transmission;synchronization4|1127|0更新时间：2025-07-16
- 摘要：Rough neural network can be used to process not only definite input but also semantic input which conventional neural network can not process.This paper proposes a new training method based on tabu search algorithm.Experimental results illustrate that the new training algorithm improves in convergence speed and network performance.关键词：rough neural network;tabu search algorithm;genetic algorithm2|1057|0更新时间：2025-07-16
- 摘要：An inclined aperture antenna based on an open-ended rectangular waveguide was analyzed using FDTD method in conjunction with the time-domain near zone to far zone transformation.The antenna is tapered at the opening on both narrow sides of a rectangular waveguide,while the wide sides are maintained.The deffraction field of the fringe is calculated using FDTD and the field pattern excited by the dominant mode is validated.关键词：aperture antenna;FDTD;waveguide;Antenna pattern2|1447|0更新时间：2025-07-16
- 摘要：With the rapid increase of dig itized medical image and wide application of PACS,efficient lossless medical image compression method has been highly desired.In this paper,a lossless compression method,based on adaptive prediction,is presented. This method uses neural network model to modify the prediction weight.As a result,the algorithm can remove the redundancy of X-ray medical images adaptively.In addition,it can simultaneously exploit the spatial and spectral correlation of colored medical images.Experimental results have proven the effectiveness and efficiency of this algorithm.关键词：medical image;lossless compression;neural network;adaptive coding2|1061|0更新时间：2025-07-16
- 摘要：In this paper a fast algorithm is proposed to detect and classify human faces.Querying the color table,the system firstly selects out the face area from the image.During the pose elassification each eigenspace is compressed individually to reduce the computation of training and classification of faces.Experiments testify the good performance of detection and classification.关键词：face detection;color model;eigenface;view classification2|950|0更新时间：2025-07-16
- 摘要：An adaptive Fourier estimation for automatic monitoring and analysis of EEG signal characters during anesthesia is described.The characteristic of evoked potential signals can be represented and traced with the Fourier coefficients,and the coefficients are classified with a neural network for estimating anesthetic depth.Computer simulation results show the validity of the method.关键词：EEG analysis;anesthetic depth;Fourier estimation;neural network4|959|0更新时间：2025-07-16
- 摘要：Affective information processing is a new subject of research in several developed countries such as Japan and U.S.A.Affective information of image is the subject studied in this paper.A model of two-dimensional 1/f fluctuation is proposed,then analyses are made on the fluctuation characteristics of image by way of this model,and a new algorithm is presented.At the same time psychological measuring method of SD is carried on toward three classes of image having different typical characteristics of fluctuation, and then remarkable difference of psychological measurement is verified by way of variance analysis method.A conclusion is made that the image with 1/f fluctuation characteristics is harmonious and beautiful.关键词：affective information of image;1/f fluctuation;power spectral density;SD;harmonious feeling3|1534|0更新时间：2025-07-16
- 摘要：This paper studied and accomplished a Synthetic Aperture Radar(SAR) real time processor with good performance. The high speed vector processor,which is the core element of the real time processor is introduced first.The vector processor could be applied to any other field which has massive data to be processed.The study uses 2DFFT to complement CS algorithm,which can remove corner turn and reduce processing overhead.The paper analyzes the precision and processing time of the vector processor and gives a satisfactory image produced by the processor.关键词：FFT;real time;CS algorithm2|900|0更新时间：2025-07-16
- 摘要：This paper studies several reduced rank partially space-time adaptive processing(STAP) approaches in beam-Doppler domain for airborne phased array radar,which includes the Auxiliary Channel Receiver(ACR),the Joint Domain Localized(JDL) approach and the Space-Time Multiple-Beam(STMB) approach.A comparative analysis is performed.Several selections of beam number and position are also investigated in detail based on improvement factor,adaptive weights and space-time two-dimensional response characteristics.Theoretical analysis and computer simulation further illustrate that the STMB approach has very low system degrees of freedom(DOFs) and good performance.It is robust to array element error and nonhomogeneous clutter,and therefore feasible and available for airborne phased array radar applications in nonhomogeneous clutter environments.关键词：airborne phased array radar;clutter rejection;space time adaptive processing2|1198|0更新时间：2025-07-16
- 摘要：In this paper,clutter suppression for bistatic airborne early warning(AEW) radar is studied farther by space-time adaptive processing(STAP) based on the clutter model presented in[1].The range-Doppler clutter characteristics are analyzed in detail in this paper.In the case of LPRF,a novel space-time adaptive processing approach based on range-Doppler compensation is proposed to suppress the clutter for bistatic AEW radar.The validity of the approach is illustrated by theoretical analysis and computer simulation.关键词：bistatic airborne early warning(AEW)radar;space-time adaptive processing(STAP);clutter suppression2|1243|0更新时间：2025-07-16
- 摘要：This paper sets up a two-dimensional space time clutter model for bistatic airborne early warning(AEW) radar.The impact on clutter spectrum of the practical factors such as the geometric configurations of bistatic radar,the parameters of radar system,range ambiguity and all kinds of errors etc.is considered in the model.The clutter characteristics is analyzed based on this model. The rationality of the clutter model is illustrated by computing two dimensional space-time likelihood spectra.This model can be used for studying the clutter suppression and STAP techniques for bistatic AEW radar.关键词：bistatic airborne early warning(AEW)radar;space time adaptive processing(STAP);clutter2|1240|0更新时间：2025-07-16
- 摘要：A method is presented in this paper which extends the copy theory of Walsh function from binary and multi-system to hybrid carry system.The copy theory of generalized Walsh function for hybrid carry system is first discussed in detail,and then analyzed mathematically.It is of importance for deep research of signal copy theory.关键词：generalized Walsh function for hybrid carry system;generalized shift copy;mathematical analysis2|1039|0更新时间：2025-07-16
- 摘要：A number of frequency domain deconvolution filters,which are applied successfully in modern tine domain measurement are introduced in this paper at first,and we illustrate that these deconvolution filters are noncausal totally.Obviously,the non-causal character of the filters will effect the estimation of deconvolution,so it is necessary to make the filters causality.And then,the theory and method to make these deconvolution filters causal are given,we get the flow charts also.Finally,the performance of general non-causal and causal deconvolution filters is investigated by computer simulation.The filtering results of them show that causal filter can refine deconvoltuion estimation.关键词：deconvolution;filter;causality2|1599|0更新时间：2025-07-16
- 摘要：In this paper,a neural network group is defined for BP-NN based classification systems.Then an adaptive algorithm for system growth is brought out,with which the system structure can be adjusted adaptively when new target class is added to the system.The experimental results have shown that when adding a new target class,the proposed method can simplify the adjustment of the system structure,shorten the time needed for system re-training,and thus improve the system training efficiency.关键词：BP neural network;pattern classification;automatic target recognition;neural network group2|1791|0更新时间：2025-07-16
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