最新刊期
卷 ， 期 7 ， 1999
- 摘要：Pointer adjustment in SDH network will induce large jitter in the recovered tributaries.Based on the traditional pointer leaking techniques,a novel method named Smooth Phase Leaking is presented in the paper for the cancellation of pointer adjustment jitter.It greatly reduces the quantization jitter in pointer leaking and also the complexity of leaking control.The paper compares the performance of this method with that of an ideal filter through theoretical analysis and simulation.Performance of the method on those pointer testing patterns is also given.关键词：Pointer leaking;jitter;SDH2|45|3更新时间：2025-12-08
- 摘要：In this paper,the mathematical expression of the MAI as well as the definition of the crossinterference k,i between two users are developed.The results from the computer calculation show that:when the length of a PN code P with good pseudorandomness is greater than the spreading ratio N,no matter whether using the WHm/M concatenated sequences good pseudorandomness isgreater than the spreading ration N,no mather whether using the WHm/M concatenated sequencesor the m （or M） sequence as the spreading sequences,their crossinterference are all accordant with Gaussian distributions with equal moments characteristics;and when P is equal to N,k,i is not accordant with Gaussian distribution.This conclusion leads to no need for large spreading ratio and is applied to both synchronous and asynchronous DSCDMA systems.关键词：DSCDMA;WH sequence;m sequence;Crossinterference factor2|87|11更新时间：2025-12-08
- 摘要：Recently,the congestion control for ABR（Available Bit Rate）service is studied extensively.This paper analyzes the performance of the ABR congestion mechanism in the presence of VBR （Variable Bit Rate） traffic,then applies the analysis model obtained to the analysis of the queuing performance of ER switches.Finally,this paper studies the characteristics of congestion when TCP is over ABR service in ATM networks.关键词：ABR traffic;congestion control;VBR traffic;TCP2|28|6更新时间：2025-12-08
- 摘要：As a major element of services in ATM networks,realtime services have more stringent requirments for quality of service （QoS） than nonrealtime services.A good scheduling method is crucial for guaranteeing the QoS of realtime services.In the paper,a new scheduling technique for realtime services is proposed.Exact schedulability condition is also presented.The new method can reduce the workload of scheduler and provide high utilization of frequence resources.关键词：ATM;delay;Realtime service;SRPQ scheduling method2|30|0更新时间：2025-12-08
- 摘要：A problem in sending TCP traffic over ATM network is that the loss of even one ATM cell will corrupt the whole TCP packet.In order to resolve such a problem,it has been proposed that an ATM switch is used to intelligently discard selective cells when congested.Intelligent discarding policies such as EPD can improve the performance of TCP over ATM network with limited buffer.To analyze its performance,a fluid flow model has been introduced in this paper.The joint distribution of aggregate source state and buffer occupancy is obtained.Based on these results,upper and lower bounds of packet loss probability in an EPD system are derived.The analytical comparison between EPD and oncontrol case has shown that the performance of an EPD system with the threshold set at the buffer size is better than or at least equal to the performance of an uncontrolled system.关键词：ATM;EPD;Joint distribution;Packet loss probability2|25|0更新时间：2025-12-08
- 摘要：This paper proposes a method that applies adaptive optimal routing algorithm to adjust the distribution of traffics and may decrease congesting probability in ATM networks,where a new type of collision function is used as distance measurement.The analytical model is established in multirate’s traffics and analytical formula are given for several routing ports.It is showed by the analysis that congestion can be improved to a very large extent and the congesting probability can be largely decreased with the adaptive optimal congestion control method for distributing traffics in the ATM networks.关键词：Congestion analysis;ATM;routing optimization;Congestion control2|51|1更新时间：2025-12-08
- 摘要：The digitalization of a receiver is a hot spot in the current radio communications field.The key to an HF digital receiver with higher performance at lower cost lies in the effective DSP algorithms.This paper discusses the construction,researches on DSP algorithms,DSP implementation as well as experimental results of the HF digital receiver.关键词：shortwave communication;HF digital receiver2|386|52更新时间：2025-12-08
- 摘要：The use of optical PPM communication is bright.The synchronization is a crucial problem in PPM.In this paper,maximumlikelihood algorithms are derived for block and frame synchronization in all digital receiver of optical PPM communication and two approximations are identified.Further,the problem of PPM synchcode sequence designing based on aperiodic correlation is studied.The performances of the algorithms are discussed through computer simulations.关键词：Optical PPM communication;All digital receiver;Block and frame synchronization;Maximumlikelihood algorithms2|170|6更新时间：2025-12-08
- 摘要：A 3D wavelet transform and hierarchical 3D zerotree hybrid video coding algorithm is investigated in this paper.After 22band pyramid spatialtemporal wavelet decomposition,4band spatial decomposition for the lowest frequency band is carried out.For this special 3D structure of wavelet decomposition,zerotree conception is extended.The wavelet coefficients are quantized using a HVS quantization model.The hierarchical 3D zerotree represents the quantized 25band wavelet coefficients.This scheme reduces about 6% bitrates compared with singlelevel zerotree and realizes the spatialtemporal scalability coding stream.关键词：wavelet transform;zerotree;video coding2|76|12更新时间：2025-12-08
- 摘要：An effective scaleadaptive phasebased stereo matching algorithm is presented in this paper.Phasebased stereo matching algorithms are the stateoftheart stereo techniques,which have the advantage of high accuracy,good robustness and parallel computing structure.As to the usual phase wraparound problem in phasebased method,coarsetofine strategy is often utilized.But because of the instability of the phase signal in some regions,coarsetofine strategy sometimes fails.Scaleadaptive method may be a good solution.We put forward a kind of filter frequency selective constructing rule which is based on correlation of filter’s frequency response integration,and took a prime sequence as Gabor filter bank’s wavelengths.As a result,we realized a novel effective scaleadaptive algorithm,which could effectively achieve high accuracy and wide disparity range.关键词：stereo matching;multiscale decomposition;Gabor filters;Phase;disparity2|433|124更新时间：2025-12-08
- 摘要：The RTIPPOS （Realtime image processing parallel operating system） microkernel was specifically designed and implemented to support realtime intermediate and high level image processing on the Parallel DSP Array.The kernel provides a tasking model for program decomposition and supports message passing,synchronization,designs fast shared memory message passing,as well as other ancillary services.The kernel primitives supported POSIX system call interface to the C language and were designed to provide users binding of level abstraction,yet perform efficiently and behave predictably.This paper is overview of RTIPPOS microkernel design.关键词：embedded system;image processing;Parallel system;operating system;Microkernel;DSP2|212|18更新时间：2025-12-08
- 摘要：This paper proposes a class of new mappings called piecewisesquareroot mappings to design feedback stream ciphers.Such mappings can generate chaotic analogue signals that have uniform distribution function,like autocorrelation function,and can be further quantized into 01 sequence with secure statistical properties by a class of special transofrmation.Compared with Zhou & Lings piecewiselinear mappings,piecewisesquareroot mappings provide enhanced security in that they can maintain the original perfect statistical properties,as well as overcome the defect of piecewiselinearity and expand the key space.关键词：cryptography;chaos;stream cipher;msequences;linear complexity2|275|121更新时间：2025-12-08
- 摘要：The requirements of UPT system on authentication and key management are analyzed in this papper.Taking into account the personal mobility and network transparency of UPT users,Variable Authentication Code protocol,which is recommended by ETSI,is extended to include a trusted third party.Furthermore,a key distribution protocol is given in detail.关键词：UPT;security;Authentication;key management2|35|4更新时间：2025-12-08
- 摘要：A new structural adapting selforganizing network model SASONN,which can be thought as an extension of Kohonen’s SOFM,is presented in this paper.We proved that,if each neuron in the network have equal winning frequency in stationary status,the density of neuron is proportional of the p.d.f of sample set instead of its 2/3 power.The essence of evolutionary commputing is introduced to network optimization.We treat each neuron as individual of the evolutionary population and construct rules of neuron growing and pruning.Some deffects in SOFM,such as incorrect mapping,neuron underuse and boundary effect can be overcomed in SASONN.关键词：Selforganizing feature mapping network（SOFM）;Structural adaptation;Evolutionary computing2|291|29更新时间：2025-12-08
- 摘要：The paper investigates the learning of the complex neural network （NN） from the point of the statistics.With the help of linear approximation of the activation function,a new method to estimate the supervised signal （hidden or missing data） of each hidden unit of the complex NN is proposed.By virtue of the supervised signal estimation of hidden unit,the learning of the complex NN is decomposed into the learning of a set of single neural neurons,and the complicated problem of NN learning is solved through the simple learning of a set of single neural neurons.关键词：Multiplelayer FNN;hidden variables;Simple and fast learning algorithm2|53|0更新时间：2025-12-08
- 摘要：In the future asynchronous transfer mode （ATM） networks,an efficient virtual path（VP） control strategy should be developed to improve the utilization of network resources.Many advantages can be taken using the multistage VP control method which is designed to execute the adjustment of VPs in three stages with specific tasks for each stage.The VP topology optimization （VPTO） problem in this method is of great importance since it is a critical issue in both the first and third stages.In this paper,we first present the mathematical formulation of this problem with a liner objective fuction in which the tradeoff between the network throughput and processing costs is considered,and then propose a neural network（NN） approach to solve it.The numerical results demonstrate our algorithm can yield optimal or near optimal solutions with high stability and validity.关键词：ATM;虚通道;神经网络2|39|0更新时间：2025-12-08
- 摘要：This paper provides an Improved Fuzzy Leaky Bucket （IFLB） for policing traffic in ATM networks.Simulations on ON/OFF and VBR video AR traffic show that the performance of IFLB is better than that of conventional leaky bucket.That is to say,its response speed of policing illegal traffic is much faster with great amplitude,and its count resource requirement of legal traffic is less in comparison.关键词：Leaky bucket;IFLB;UPC2|28|1更新时间：2025-12-08
- 摘要：There are strong distribution effects in very small MOSFET’s.Their some characteristics should be described by twodimensional models.In this paper,twodimensional analytic distribution models of drain and substrate currents are built by use of flow function equations on y crosssection.The models are dependent on vertical electrical field Ex（y） and horizontal electrical field Ey（y）,and include much more physical processes,and show basically the exact distributions of the current densities.These two analytic models can be used in studying the characteristics dependent on current lines,especially,in the field of gate current distribution modeling in MOS’s hotcarrier reliability electronics.Using models of Ex（y）,Ey（y）,IDS and so on in deep submicron MOSFET’s,the distribution models in the paper can be applied in these devices.关键词：Twodimensional analytic distribution models;Flow function equations;MOS hotcarrier reliability electronics2|91|2更新时间：2025-12-08
- 摘要：The model for temperature of electronic components in electronic board is given.Complete implicit iterated method is used to solve the finite difference equation,which could avoid being limicit by time step;in conjunction with Simulated annealing algorithm to design optimally placement of electronic components in such a way as to decrease the maximal temperature of the system and to increase reliability of military equipment.Also one example is given to prove it.关键词：Simulated annealing algorithm;Finite difference equation;Complete implicit iterated method;optimal;reliability2|175|13更新时间：2025-12-08
- 摘要：In this paper a novel triple pulse laser crystallization method to enlarge grain size of polySi was proposed.The laser annealing computer model was used to simulate transient temperature profile,melt depth,solidification velocity of Si film under the novel laser annealing.All of them were compared with those of single pulse and double pulse laser annealing.The simulation results showed the novel method can reduce solidification velocity to 027m/s when energy density and delay time were optimized.The substrate heating experiments demonstrated that the method could enlarge grain size effectively.关键词：Laser crystallization;Solidification velocity;grain size;Triple pulse laser crystallization method2|61|0更新时间：2025-12-08
- 摘要：A detail analysis about the alignment signal of wafer phase grating in the projection lithography processes has been investigated.Based on Fourier optics and matrix optics the model discussed here considers that the reflectivity is various over the wafer phase grating with processes layers and resist layer.The alignment structure of resist grating over bare wafer is also described with similar considerations.The calculated results are compared with the experiment data published by others,they are closer each other.The computer program here is also suitable for the analysis of the alignment signal in the lithography with chemical mechanical polish or with antireflective coating.关键词：Semiconductor lithography;Phase grating;Multiple thin films;Fourier optics2|128|7更新时间：2025-12-08
- 摘要：A method （VPPRMA） based on the user’s demand to improve the performance of voice service in Packet Reservation Multiple Access （PRMA） system is proposed.After the analysis of PRMA,the new mothod,using variable contending probability according to the actual condition,is presented.According to the simulation,the probability of packet dropping is reduced.关键词：PRMA;multiple access control;wireless communication2|29|0更新时间：2025-12-08
- 摘要：In this paper,a method of fast detection and recognition of DS/SS signal is proposed and analyzed.The frequency and phase of DS/SS signal,the period,length and structure of spreading sequence could be detected and recognized by proposed method.Finally,the result of testing under this method is given.关键词：Direct sequence spread spectrum communication;Detection of spread spectrum signal;Recognition of spread spectrum signal2|458|76更新时间：2025-12-08
- 摘要：This paper studies briefly measures for objective quality evaluation using perceptuallybased features.We used 3 sorts of perceptuallybased features for objective quality measures of spectral distortion and spectral envelop distortion.The experimental results show that the correspondence between spectral distortion measure of perceptuallybased features and the subjective quality evaluation （MOS） is better compared with general spectral distortion measure.The predeictive order of spectral envelop distortion used perceptuallybased features is reduced from 8 to 4,and the correlation coefficients between 2 objective measures and the subjective quality are the same.关键词：Objective speech quality evaluation;Perceptuallybased feature;Spectral distortion measure;Spectral envelop distortion measure2|325|35更新时间：2025-12-08
- 摘要：Histogram is the most commonly used method to illustrate the grayscale statistical distribution of an image.2D histograms include cooccurrence matrix,（graylevel,edgevalue） scatter plot（graylevel,local average graylevel） scatter plot etc.In this paper,we present an image segmentation algorithm which uses SEM algorithm to implement parameters estimation of the hypothesis of 2D normal distribution about （graylevel,local average graylevel）scatter plot,and uses MAP criterion to achieve unsupervised pixel clustering.Compared with other thresholding methods based on scatter plot by applying them to various test images,our proposed algorithm demonstrates better performance,especially for the low quality images with low contrast,shading and heavy noise.关键词：Pixel clustering;Image thresholding;2D histogram;SEM algorithm;MAP2|149|11更新时间：2025-12-08
- 摘要：This paper presents an image compression approach by combining gradematch fractal image coding and fractal interpolation,which is developed from blockbased ones.Experimental results show that this new approach reduces the computation time greatly with no apparent degradation on the quality of the reconstructed image.关键词：fractal;image coding;Gradematch;Fractal attractor2|81|2更新时间：2025-12-08
- 摘要：Runlength Smearing algorithm is used at the beginning of document segmentation here.After the Runlength Smearing,the document image is divided into many small blocks called connected compoments.How to classify and combine those compoments correctly is the most import thing in document segmentation.A set of algrithms including Runlength smearing,how to select the smearing parameters,the classification of the connected compoments and the combination of the text blocks etc.are presented.关键词：Runlength smearing;Document segmentation;English document2|226|28更新时间：2025-12-08
- 摘要：This paper presents an online identification scheme for continuous nonlinear dynamic systems by combining the growing wavelet series model with Lyapunov synthesis approach.The introducing of growing model overcomes the problem of overdetermined or underdetermined model structure brought by choosing model structure a priori.The stability and convergence of the overall identification scheme are guaranteed by parameter adjustment laws developed by using the Lyapunov synthesis approach.关键词：Wavelet series;Continuous nonlinear dynamic system;Online identification;Lyapunov synthesis approach2|44|1更新时间：2025-12-08
- 摘要：Higher nonlinearity is an important cryptographic property of Boolean functions.There is trade off among the property and others,such as algebraic degree and correlation immunity.In this paper,constructions for Boolean functions with higher nonlinearity are presented.The tradeoff among the nonlinearity and the other cryptographic properties is discussed.Some methods of constructing Boolean functions with higher nonlinearity and higher algebraic degree,higher nonlinearity and propagation,higher nonlinearity and correlationimmunity are given respectively.关键词：nonlinearity;Correlationimmune;Propagation;Bent functions3|124|5更新时间：2025-12-08
- 摘要：The numeration and distribution of generalized Hamming weights for binary ] linear codear codes have been discussed.关键词：linear codes;Generalized hamming weights2|103|5更新时间：2025-12-08
- 摘要：In this paper,we generalize a method in for constructing resilient functions and obtain a general result for constructing new resilient functions from old ones.Furthermore,the nonlinearity of the new constructed resilient functions is also discussed.关键词：Resilient Function;nonlinearity2|40|0更新时间：2025-12-08
- 摘要：A decomposition formula of joint distribution of mvalued random variables is discussed and a decomposition formula of Chrestenson spectrum of a class of mvalued logical functions is investigated.On the basis of the formula,some new methods for construction of correlationimmune mvalued logical functions are given.关键词：mvalued logical function;Chrestenson spectrum;Correlationimmunity.2|23|1更新时间：2025-12-08
- 摘要：The sufficient and necessary condition for bidirectional continuoustime associate memory neural networks to be locally exponentially stable is obtained,and a characteristic function is defined for quantitatively study attractive domain of equilibrium point.关键词：Bidirectional associate memory neural network;Domain of attraction;Local exponential stability2|54|9更新时间：2025-12-08
- 摘要：The error measurement for soliton communication is successfully achieved in China for the first time.25 Gb/s soliton is successfully transmitted over 52km,and there is no error within two hours.关键词：Optical soliton communication;Error measurement;Ultrashort optical pulse;External modulation2|38|0更新时间：2025-12-08
- 摘要：In this paper,a computer controlled MOCVD circuit is designed,and the circuit can be controlled not only by control board manually,but also by computer automatically.Applying this circuit to MOCVD system,TiO2 nanosized ultra fine powders with average grain size about 74152nm are prepared from 500 to 1000.关键词：MOCVD;control circuit;Nanosized ultra fine powder;TiO22|64|4更新时间：2025-12-08
- 摘要：A parallel optoelectronic shape recognition system based on Hough transform （HT） is introduced in this article.Feature extraction is obtained by using Hough transform （HT） and the features are invariant in position and scale.We use optical system to reduce memory required and time in calculation.Parallel and realtime is the feature of this system.It can be used in online sense of pipeline and traffic sign recognition etc.关键词：Hough transform;shape recognition;Microlens4|108|24更新时间：2025-12-08
- 摘要：A new equvialent expression of the electromagnetic field in a conical waveguide is presented,by which the deviations of the calculated propagation constant and wave impedance from the exact values,the field components from the asympotic solution,are improved.It is especially of advantage for the prediction of the phase shift and the field charicteristics in the region of near cutoff of higher order modes,by which the problem of unintegral eigenvalues confronted in engineening design can be solved.关键词：Equivalent expression;Conical waveguide;Propagation constant;Wave impedance;Field component2|80|2更新时间：2025-12-08
- 摘要：Studying job shop scheduling problem has become increasingly important with the development of CIMS.Identical parallel machine scheduling problem of minimizing the number of tardy jobs is a kind of important job shop scheduling problem,but there have been many difficulties in the course of solving large scale identical parallel machine scheduling problem with too many jobs and machines so far.Evolutionary programming method is an important evolutionary computation method as genetic algorithm,and its many advantages such as simple description,flexible usage,efficient running,good robustness,and less restriction from initial conditions,make it have great practical value.But compared with genetic algorithm,the application of evolutionary programming has just begun,and papers about the application of evolutionary programming in the field of production scheduling in particular are much fewer,so it is very worth while to develop further application fields of evolutionary programming method.In this paper,evolutionary programming method is applied to identical paallel machine scheduling problem of minimizing the number of tardy jobs for the first time.Researches are made in these aspects such as problem formulation,expression of feasible solution,mutation method of evolutionary programming and so on.Computational results of different scale problems justify the efficacy of the evolutionary programming algorithm,and that it is fit for solving larger scale identical parallel machine scheduling problem,and that the quality of its solution is superior to heuristic procedure.关键词：identical parallel machine;evolutionary programming;combinatorial optimization;scheduling problem2|176|10更新时间：2025-12-08
- 摘要：Based on the basic principle of wavelet analysis,multiresolution analysis of signal in atomic clock is made.The coefficients of wavelet transform for synthesis atomic time,which are weighed and averaged at different wavelet scales,are obtained.Then according to reconstruction theorem,multiresolution synthesis time scale can be reconstructed.Since the signal of atomic clock has been analysed by multiresolution,we can use wavelet variance at different scales to weight and average the coefficients.Thus either the difference in stability of different clock or the varying characteristic of the same clock at the different scale are all considered.Finaly,this method is checked by the measured data from National Timing Serve Center of Shaanxi Astronomy Observatory.It confirmed that this technique,which is simple and practicable,is a new method of multiresolution.From this method,the common characteristic of different clocks can be extracted.The stability of multiresolution synthesis atomic time scale is obviously superior to that of other methods.关键词：time scale;Synthesis atomic time;Wavelet theory2|173|14更新时间：2025-12-08
- 摘要：An excitation method setting up a necessary connecting boundary and choosing appropriate incident waveforms in waveguide circuits is presented for FDTD algorithm.Numerical results show its significance by considerably saving computational domain and time.关键词：FDTD方法;波导;散射参数;激励;连接边界2|119|12更新时间：2025-12-08
- 摘要：In this paper,a new method to construct Acodes starting from error correcting codes and Acodes for large sources are given with some parameters proposed.关键词：Errorcorrecting codes;Authentication codes2|66|8更新时间：2025-12-08
- 摘要：In this paper,Marple algorithm and learning algorithm are introduced to develop two novel fast FDTD analysis algorithms.The difference among the three algorithms including the extant MUSIC algorithm is presented.With the three algorithms,a complicated microwave structure is analyzed.Compared with the result without signal processing,a great improvement of the efficiency and precision of FDTD method is achieved.关键词：digital signal processing;Microwave dielectric resonator;neural network2|101|0更新时间：2025-12-08
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