最新刊期
卷 ， 期 1 ， 1998
- 摘要：This paper indicates that non-linear prediction technique should be one of more efficient tools for signal prmessing, because some non-linear correlation exists between adjacent saxnples of various signals. Ex periments based on both linear and non-linear predictions of speech signals are given. Finally, we apply non-lin ear technique to speech coding.关键词：语音信号处理;编码;预测;神经网络2|112|1更新时间：2025-12-08
- 摘要：A motion compensation interpolation method based on inteforing direct interpolation is presented in this paper, this method of HDTV display eliminating flicker motion compensation direct inierpolation is different from the other interpolation method which must be interpolated on progressive picture using motion compensation method. The motion compensation direct interpolation method has been simulated through computer.The result indicates that this method has a better effect.关键词：High-definition Television;Flicker free display;motion compensation;Direct interpolation2|74|1更新时间：2025-12-08
- 摘要：A moving target segmentation method using Genetic Algorithms（GAs）of multiple parameters is presented in the paper. First we describe the principles of GAs, next the method of segmenting a image by GAs is discussed .Then we developed a moving target segmentation methed by GAs of multiple parameters, including gray level, size, length, moving velocity, etc. Finally the devefoped method is experimented on several images.The results show that our method has better segmentation qualities.关键词：genetic algorithms;fitness function;Image segmentation2|73|2更新时间：2025-12-08
- 摘要：This paper addresses the problem of LMS motion estimation, in the presence of feature point uncertainties. Optimal motion estimation is substantially a nonlinear problem with 6 depees of freedom. In this paper a modified centroid coincidence theorem and a motion parameter decomposition theerem are introduced,which degenerate it into a pure rotation problem with only 3 degrees of freedom. We propose a linear algorithm as well as an iterative algorithm, both providing optimal estimations. The linear one can be implemented in realtime,however the iterative one has better convergence abilities.关键词：computer vision;Optimal motion estimation;Linear algorithm;iterative algorithm2|68|1更新时间：2025-12-08
- 摘要：A still picture hierarchical coding scheme based on wavelet analysis was proposed .The image was decomposed by discrete wavelet traneform, the transformed subimage was encoded by classified vector quanhzation, the class informahon was self-generated accortling to similarity between subimages. Experiments proved that this new scheme performs better than published schemes in the aspects of high compression ratio and high image quantization.关键词：wavelet analysis;image compression;vector quantization;hybrid coding2|115|1更新时间：2025-12-08
- 摘要：In this paper, a novel class of neural networks for nonlinear programming is presented to overcome the deficiences in [1]. The convergence and stability of these ed networks are analyzed,and the implementaion of their cirouits is discussed. Simulation demonstrates tha these neural networks can detively solvnonlinear programming problems.关键词：Nonlinear pmgramming;Lagrange multipler;neural network;Lyapunov function2|336|4更新时间：2025-12-08
- 摘要：This paper studies the real-time measarement of slow fading signal in the wideband fadingcbannel. With the description of the measurement error as Gaussian random variable, the error of real-time measurement of slow fading signal with the RAKE receiver is analyzed. The results indicate that the measurement precision can be improved significantly with the RAKE receiver. At the same time, the design of the measurement filter under eiferent conditions is discussed.关键词：Wideband fading;RAKE receiver;Slow fading2|95|2更新时间：2025-12-08
- 摘要：The diversity of VP bandwidths and the large number of VP connections bring about the difficulty which isn’ t met in SDH self-healing networks. Without a fast and effective VP-packing algorithm, both the restoration speed and restoration ratio may reduce. The optimal VP-packing algorithm is discovered unpractical due to its exponential computation complexity. Therefore an efficient VP-packing algorithm is proposed, which has a polynomial computation complexity and comes to an end in short time. Both theoretical analysis and computer simulation show that the difference between its packing ratio and the maximum packing ratio is slight in general.关键词：ATM network;VP-packing algorithm;Computation complexity;Packing ratio2|19|1更新时间：2025-12-08
- 摘要：In this paper, the window access schemes for input-buffered ATM switching fabrics are studied. The maximum switch throughput with a haditional Dependent Window Access （DWA） scheme is analyzed;An Independent Window Access （IWA） scheme is proposed, and the performances of an input-buffered ATM switching fabric with the IWA scheme, including the average cell delay and the maximum throughput are analyzed by means of a probability generating functions approach. The analytical results show that the IWA scheme makes the switching fabric have better performances than the DWA scheme, and improvements of the performance are more significant for smaller Window size. Finally, the accuracy of the calculated results is verified by computer simulations.关键词：Input-buffered ATM switching fabric;Window-access scheme2|23|1更新时间：2025-12-08
- 摘要：This paper provides a generalized data link model in which the effect of acknowledgement frame is considered. We use an iterative algorithm of direct calculation to find the equilibrium probability distribution of the queueing system, thus its performance is calculated. Simulations are presented to verify the analytc results. Finally, how to choose the parameters to obtain better performance is discussed.关键词：Link protocols;iterative algorithm;queueing system2|110|1更新时间：2025-12-08
- 摘要：ATM can support various services in a universal format. The transport of CBR services is an important feature of ATM, and is referred to as circnit emulation .The recovery of soaree clock hequency is one of the critical issues due to packet oriented technology. There are two classes of generic approaches to ATM timing recovery, namely, non-syncbonous methods and syncbonous methods. SFET, TS and SRTS are three main synchronous methods,among them SRTh has been accepted by ITU-T as the timing recovery standard for AALl.However it will introduce up to lUI waiting time jitter at some values of souree clock frequency. An improvement method, namely Synchronous Filtered Residual Time Stamp（SFRTh）, is proposed in this paper. It is based on 2-stage Sigma-Delta quantization and reduces the waiting time jitter below 0.02UI so that it greaily improves timing quality in ATM.关键词：电路仿真;定时恢复;抖动2|31|2更新时间：2025-12-08
- 摘要：A spread spectrum PRMA（SSPRMA）with randomized arrival time is proposed in this paper.We analyze its channel utilization and the probability of voice packet being dropped（Pdrop） by Markov chain analysis. We derive a formula that can be used in the calculation of the Pdrop of SSPRMA. It can also be used in the calculation of the Pdrop of PRMA if the number of address codes of each slot is 1. This problem is not solved in Reference[4]. We exploit the delay cape phenomenon to improve the performance of this protocol. Packet transmission errors are taken into account in the simulation and the Markov chain analysis. Numerical results prove that delay capture phnomenon improves the performace of SSPRMA.关键词：PRMA;spread spectrum communication;CDMA2|41|0更新时间：2025-12-08
- 摘要：In this pape,the equalizrs based on complex radial basis function networks（CRBFN）were invcestigated and two new adaptive equalizers based on CRBFN（which are orthogonal CRBFN equalizer and asymmetric CRBFN equalizer） were also proposed which are different from those in Refs. [2,5]. Based on both the new CRBFNs, the training algorithm that adapts all be parameters of the network was presented. Computer simulation results show both the new CRBFN equalizers have better performanve than those in Refs. [2,5] when the channel is linear or nonlinear.关键词：Complex radial basis functions networks;equalizer2|100|1更新时间：2025-12-08
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- 摘要：Based on the decorrelating linear multiuser detection （DCLMUD） scheme, a new coherent CDMA multiuser scheme is pmposed. It introduces aided continuous pilot to implement the coherent estimation and timing recovery. In addition, auto time delay control is inedced and the cedation time is rcduced to make the correlation independent on the past and future sndls. By adapting voice activation, the order of decorrelating matrix is reduced by 65 %, computahon complexity is reduced by 95 .71%. The theoretical analysis and simulation results prove that not only the complexity of the proposed scheme is reduced significantly, but also its performance is improved.关键词：Linear decorrelating;multiuser detection;CDMA;Voice activation2|65|1更新时间：2025-12-08
- 摘要：The availability of a repairable system represents a basic and elementary measure within reliability engineering. But the mean time between failures （MTBF）and the mean time to repair （MTTR）,which are commonly difficult to know, are by themselves quantities of practical interest, and can be even more important than system availability. This paper presents a method to determine the MTBF and MTFR of a repairable system with unlimited repair and exponential inter-failure and repair time at component level.关键词：MTBF;MTTR;Markov process;state transition2|445|2更新时间：2025-12-08
- 摘要：Based on the En-In noise model of cascade circuits, not only the limitation of Friis theorem is analysed,but also the En-ln noise mathematical model for the cascade cireuits is developed. This model with simple formulas and easy parameter’s extraction will facilitate the implementation of the model into the simulation programs for the circuit noise. The analsis also focuses on the minimum noise conditions for the cascade precucuits. Because the correlativity between the En and In is considered, the pnyision of noise calculation for the cascade circuits can be guaranteed effectively.关键词：Cascade circuits;En-In noise;power spectrum2|72|2更新时间：2025-12-08
- 摘要：In the dense signal environment, signal deinterleaving is a tedious problem by using traditional technique.This paper presents a new method──Plane Transformation. With this technique, the interleaved pulse trains were cut into many paxts and shown line by line as a plane fipe. By changing the width of the plane,various characteristic curves,representing the signals, can be seen. They are actually the result of the accumulation of the signal’ s"modulation" substracting the corresponding average value, which can be used to deinterleave signals with less difficulty by other means.关键词：Deinterleaving;Plane transformation;Accumulate transformation;Characteristic curve3|336|18更新时间：2025-12-08
- 摘要：In this paper, a kind of orthogonal transforms associated with orthogonal bases in libary ofHaar wavelet packets is studied to process random digital signals. A coding method for the bases in a libare of wavelet packets is proposed. The performance of these orthogonal transforms in data compression, generalized Wiener filtering and transform coding is compared using variance distribution, mean squared error and rate distortion function. In the end, the laws are summarized.关键词：orthogonal transform;Wavelet packet transforms;Random signal analysis2|105|1更新时间：2025-12-08
- 摘要：Further analysis of cryptographic propenies of exponential functions given in [1] is made.Emphasis is put on its enumeration,fixed points and cyclic sthecture. The results obtalned provide some cryptographic principles for the design of secare S boxes based on such functions.关键词：Exponential function;Exponntial permutahon;fixed point;Cyclic period;S box2|77|3更新时间：2025-12-08
- 摘要：Based on KzyptoKnight[6], this paper presents a light-weight authentication and key distribution protocol for PCS （permnal conununication system）. The results show that the protocol is secare and efficient,thus it can be used as low-layer network proocol in the PCS mobile envbonment.关键词：Personal communication system;authentication;key distribution;Hash function2|60|3更新时间：2025-12-08
- 摘要：In this paper,a class of multiple-iterated chaotic system is used to design nonlinear feed forward stream cipher. When analogue chaotic system is considered,the chaotic stream cipher is proved to be balanced and very sensitive to its parameter and the drive signal. The finite precision problem is also investigated and two resolving methods are proposed.关键词：Chaotic inverse system;Frobenius-Permn calculator;linear complexity;Nonlinear complexity2|265|27更新时间：2025-12-08
- 摘要：An efficient method has been presented to construct the authenticated key distribution scheme and secure broadcast scheme with the capability to correct errors, only using error-correcting codes technique instead of conventional encryption technique. The two schemes, constructed by means of the above method, are secure against attaks from inside and outside attackers and can improve the reliability of communicahon.关键词：error-correcting codes;authentication;key distribution2|45|2更新时间：2025-12-08
- 摘要：An M-ary Orthognal Coded Spread Spectrum（OCSS） system with 2.4Kbps and 16Kbps data rate is realized. The ereieved signal can be despreaded under low SNR. Firstly, the methods for spreading and despreading are discussed. Secondly, formulations for estimating the carrier and the sampling timing initial phase offset of MSK spread spectrum signal are derived. Thirdly, Q-channel correlation method for phase tracing is proposed. Finally, the bit error rate is measured.关键词：Orthogonal coded spread spectrum;despreading;Phase tracting2|381|10更新时间：2025-12-08
- 摘要：Based on the performance analysis of detector with fixed threshold, an adaptive boshold decision （ATD）scheme is proposed, and the experiment and analysis on it are also made. As a result, ATD technique has wider dynndc range and better performance. Combined with other techniques, such as diversity, it is a good way for high-speed and burst communication.关键词：High-speed;Burst;Adaptive;Threshold decision2|303|5更新时间：2025-12-08
- 摘要：In this paper we detailed describled the signal processing algorithms which use wavelet transform theory.Then a method to select threshold for hard-threshold filter （C-D filter） was developed. The threshold selection method for C-D filter brings the algorithm to completion. The simulahon shows that the new method is better than C-D filter the new theshold.关键词：Wavelet transfrm;Multiscale analysis;Thrshold2|412|29更新时间：2025-12-08
- 摘要：This paper addresses the improvement of the classification capability of network by using quadraic sigmoidal neurons. The results indicate that the degree on the improvement on the classification capability of network by using quadratic sigmoidal neurons is 3.关键词：Neuron model;Dichotomy;threshold;Classification capability2|48|1更新时间：2025-12-08
- 摘要：Based on the ideas of the multiobjechve optindzation, the pape analyzes the cause that convergence-rate of the standard BP（Back-Propagation） algorithm is low in the optindzaion of netal network which is used for classilication of imbalanced-exemplar patterns. We present the improved optindzation algorithms. Using the algorithms,we have been able to accelerate the rate of learning for two kinds of dsanced-exemplarpattem classification problems. The results indicate that the impmved algorithms can efficiently increase the convereence-rate of neural network optimizahon.关键词：neural network;pattern recognition;multiobjective optimization;Imbalanced exemplar patterns2|71|1更新时间：2025-12-08
- 摘要：The construction of a provable hash algorithm is developed based on the operations from various groups, also, a safety message authentication code is presented by the result.关键词：Cryptographic secure hash algorithm;Universal hash function;message authentication code2|187|2更新时间：2025-12-08
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