最新刊期
卷 29 ， 期 5 ， 2001
- 摘要：Based on the introduction of the traditional mathematical model of neurons in general-purpose neural network hardware realization,a novel all-purpose mathematical model has been proposed,which can simulate all kinds of neuron architecture,including RBF and BP models,etc.At the same time this model has been realized using hardware and implemented in the new CASSANDRA-Ⅱ neurocomputer that can be used to form many neural networks with multiple mathematical models of neurons.In this paper the flexibility of the new neurons has also been discussed in constructing neural networks.关键词：neural network;neurocomputer;mathematical model of neurons2|2661|28更新时间：2025-07-16
- 摘要：Based on the practice of Jade Bird software production line,we propose a software architectural style based on hierarchical message bus named JB/HMB,and design a corresponding architecture description language JB/SADL.JB/SADL describes a component from aspects of interface,static structure and dynamic behavior.Using JB/SADL,we can construct,refine and verify the software architecture conveniently,which provides basis for the dynamic simulating execution,automatic generation of code framework and run-time evolution.关键词：software architecture;hierarchical message bus;architecture description language2|1793|10更新时间：2025-07-16
- 摘要：Interval valued (i-v) fuzzy sets and vague sets are two new theories representing inexact knowledge.They have been widely applied to describe the uncertain data in decision systems.In this paper,the notions of i-v vague sets are first introduced by putting the two theories together.Then,the properties of i-v vague sets are discussed in detail.Finally,by a decision system and the operators of containment and intersection defined on it,we analyse the strategies of rule generation.In comparison with the method of using rough set theory,the two results are proved to be consistent.However,our new method behaves much flexibly in representing uncertainty.关键词：i-v vague sets;decision system;rough sets;uncertainty2|1216|12更新时间：2025-07-16
- 摘要：Some geometry of Support Vector Machines for classification and regression is described and proven.And then the generalization performance of SVMs on newly-added samples is discussed.Through the analysis of the property of newly-added samples and the effect of them on support vectors and non-support vectors,some valuable results are presented.These enable us to conclude that SVM has a good compatibility,adaptability and generalization performance for newly-added samples and is a hereditable learning model.关键词：support vector classification;support vector regression;learning machines;KKT conditions;hereditability2|1126|31更新时间：2025-07-16
- 摘要：A high performance mandarin digit string speaker-independent speech recognition system is given.The acoustic model is based on the Mel Frequency Cepstrum Coefficient and the continuous hidden Markov model (HMM).The multi-candidate frame synchronous search algorithm is adopted in the recognition stage with the MCE algorithm as the training approach.Experiments demonstrate that the correct recognition rate of the system is 94.8% (unknown length) and 96.8% (known length).In order to enhance the flexibility of the system,this paper also conduct research on the maximum a posteriori (MAP) based speaker adaptation and confidence measure based rejection.More than 40% recognition errors can be removed after adaptation and the recognition rate can be improved to 96.9% (unknown length) and 98.7% (known length) when 5% of the correct results are rejected.关键词：mandarin digit string;speech recognition;speaker adaptation;confidence measure2|1976|4更新时间：2025-07-16
- 摘要：Vector transform of sampled image data plays an important role in image vector coding.To counter the drawback that the dimension of matrix composed by vectors is not equal to the one of transform kernel matrix in vector transform algorithm,this paper presents a novel vector transform algorithm.The capabilities of decorrelation and energy compression of the proposed algorithm are statistically analyzed.The experimental results show that the algorithm can greatly increase computation efficiency.关键词：vector transform;image coding;decorrelation;energy compression2|833|0更新时间：2025-07-16
- 摘要：This paper studies hybrid suspended gate FET(HSGFET)ozone sensor with dual sensitive layer for detecting ozone in ppb range at room temperature.From the results of our experiments for the four solid HSGFET ozone sensors,we found the sensor with structure has excellent response to ozone.Results obtained by the HSGFET correspond to those obtained by the Kevin probe.关键词：hybrid suspended gate FET;work-function;dual sensitive layer;ozone sensor2|886|0更新时间：2025-07-16
- 摘要：The Discrete Wavelet Transform (DWT),which has good spatial-frequency characteristics,is widely used in lossy image and video compression schemes such as JPEG2000 and MPEG4.In this paper,we introduce orthogonal wavelet bases to decompose images,then reorganize wavelet image coefficients to form wavelet blocks.Finally we propose an efficient algorithm for constructing wavelet block quantization tables with optimal bit allocations for a given image.The algorithm uses wavelet coefficient distribution statistics in a novel way,and pays attention to the traits of Human Visual System (HVS),and uses a dynamic programming strategy to produce optimal quantization tables over a wide range of bit rates.关键词：wavelet block;quantization table;dynamic programming strategy;optimal bit allocation2|761|0更新时间：2025-07-16
- 摘要：This paper provides a new method to regulate the step length of FWCM by nonlinear companding in time domain,so that the error distribution can be controlled in circuit simulation.Because the technology of domain transform is used,the step length of FWCM can be modulated continuously.Furthermore,the methodology of error distribution control is applied in time domain simulation for lightly damped nonlinear dynamic circuit and results in high efficiency.Some simulation results prove the proposed method for error distribution control to be an effective one.关键词：FWCM;time domain companding;error distribution control;circuit simulation2|865|1更新时间：2025-07-16
- 摘要：Reference is not only one of the important modeling mechanism,but also beneficial to the design and implementations of join algorithms.Based on the features of ORDM(Object-Relational Data Model) and the query language,a new reference based join algorithm Sort-Loops is represented.Sort-Loops attempts to read most of the outer table as possible in one pass,and then sorts the tuples according to their reference's PID.By the sorting techniques,there is no duplicate read of the same page in a pass,and the performance is further improved by reading the inner table in order of its physical address.Sort-Loops is a useful and high performance join algorithm.It is further validated by the analysis and comparison with other algorithms.关键词：join algorithm;ORDB;algorithm analysis2|719|0更新时间：2025-07-16
- 摘要：A new algorithm is presented to estimate the azimuths,elevations and Doppler frequencies of uncorrelated signals incident on a uniform circular array (UCA).Firstly,the mode excitation method is used to transform the manifold matrix of UCA into one with a form similar to that of a uniform linear array (ULA).The estimation of Doppler frequencies and DOA can be obtained from the eigenvalues and the corresponding eigenvectors of the DOA matrix respectively.This method is computationally efficient with comparatively high resolution,with the azimuths,elevations and Doppler frequencies of incident signals easily obtained and automatically combined without spectral search.The performance of this method is demonstrated by simulations.关键词：uniform circular array;mode excitation method;array manifold;direction of arrival (DOA) matrix2|1971|9更新时间：2025-07-16
- 摘要：This paper presents a tabu search algorithm with varying neighborhood for Job Shop scheduling problem of minimizing the makespan.The neighborhood used can be changed with the process of the algorithm,and the scale of the neighborhood is not only small,but also the reachability can be kept.The computational results of different scale problems show that the efficiency of the algorithm is high ,and that the influence of the initial solution on the algorithm is small.关键词：scheduling;job shop;local search;Tabu search;neighborhood2|1658|6更新时间：2025-07-16
- 摘要：Global attractivity of Cellular Networks with infinite delay is investigated.By making use of the method of variation of parameters and the method of inequality analysis,the conditions for attractivity are given to work out the sets of attractions when the systems do not have equilibria.If the equilibria exist,conditions for the equilibria to be global attractors are presented.The conditions are obtained by extending the results of paper .关键词：cellular networks;global attactivity;infinite delay;stability2|985|4更新时间：2025-07-16
- 摘要：Estimation of maximum power dissipation is important in designing highly reliable VLSI systems.However,maximum power estimation for CMOS circuits is essentially a combination optimization problem,which has exponential complexity in the worst case.In this paper,we propose a novel approach to obtain a lower bound of the maximum power dissipation using Genetic Algorithm (GA).Experiments with ISCAS-85 and ISCAS-89 benchmark circuits show that our approach generates the lower bound with the quality which cannot be achieved using simulation-based techniques.In addition,a statistics based technique is realized to serve as a comparison version for our GA approach and to generate a metric to measure the equality of a lower bound from a statistical point of view.关键词：CMOS sequential circuits;dissipation estimation;genetic algorithm;logic simulation2|1210|0更新时间：2025-07-16
- 摘要：This paper proposes a new type of buffer management mechanisms,called"Additional Buffer Block Allocation on demand"(ABBA) scheme,suited for packet switches and routers.With the essntial of the proposed mechanism presented,we establish the associated queuing model,denoted by "M/M/1/K(2K)",and then derive the steady-state probability distribution and related packet loss probability.By both analysis and simulations,we evaluate the performance of the proposed ABBA scheme in terms of the packet loss probability and the equivalent buffer size Ke in comparison with typical schemes with static buffer allocation.Finally provided in this paper are some key factors used to determine whether an additional-buffer-block application is approved or not by a decision-making process,which is described in an algorithm form.关键词：packet switching;ATM;QoS;buffer management;queuing model2|791|0更新时间：2025-07-16
- 摘要：A new large-signal average circuit model for Boost converter is set up and a new simple control of power factor correction is proposed to realize the objective of high power factor and fast response.Computer simulation and experiment show excellent property of the new method.关键词：simple control;dynamical circuit relations;power factor correction2|1021|0更新时间：2025-07-16
- 摘要：We investigated integrated dynamic radio resource management using Euclidean distance metric as a decision criterion for handoff and admission control,considering five resource management tasks in an integrated way.The Euclidean distance (ED) metric,associated with the decoded information sequence,is used as an accurate and consistent channel quality measure.Simulation results show that within specified quality constraints integrated radio resource management can increase system capacity and offer better overall performance by selecting appropriate thresholds and algorithms or making the necessary tradeoffs between the individual goals.关键词：handoff;resource management;euclidean distance;power control2|943|0更新时间：2025-07-16
- 摘要：Fractal characteristic of multipath fading signal is studied in the paper which shows that multifractal dimension is a key parameter for describing the signal propagation in wireless channels.The multifractal dimension and fractal parameter are calculated.Then a novel channel model is proposed and fractal interpolation is applied to reconstruct the signals.Simulation results show that the new model outperforms the conventional statistic models in both effectiveness and accuracy.关键词：multipath fading signal;channel model;multifractal;fractal interpolation2|1281|2更新时间：2025-07-16
- 摘要：From an engineering point of view,a novel large-signal modeling method is proposed for dc-dc converters in this paper.Based on this model,a robust control strategy of linear uncertainty systems with time-varying uncertainty is applied to control of dc-dc converters.The modeling method and control strategy is simple and applicable to all four basic PWM converters.The results of computer simulations and experiments prove that the controller designed in this paper is robust to disturbances of input voltage and linear resistive load.关键词：DC-DC converters;large-signal modeling;linear time-varying uncertainty;robust control2|1646|8更新时间：2025-07-16
- 摘要：Simulated evolution and simulated annealing are two stochastic search algorithms for solving the global optimization problems.They have been widely used in different engineering areas.An evolutionary simulated annealing algorithm has been proposed in this paper which combines simulated evolution with simulated annealing to solve the codebook design problems of vector quantization for image coding.The simulation results show the algorithm has fast convergence rate and excellent performance for codebook.关键词：simulated evolution;simulated annealing;vector quantization;image coding2|1184|11更新时间：2025-07-16
- 摘要：Based on the calculation for capacities of equivalent channels[1],the performance of MLC(Multilevel coding)/MSD scheme with three different set partitioning strategies in AWGN and Rayleigh fading channels is simulated.In which BCH codes with different code lengths are chosen as component codes,and 8ASK modulation is used.Simulation results show that UP (Ungerboeck partitioning) set partitioning has the best performance in AWGN channels and BP (Block partitioning) is the best set partitioning strategy in fading channels.According to "capacity rule",BP is of good robustness in both kinds of channels to realize an optimum MLC system.关键词：fading channel;multilevel coding;set partitioning strategies2|943|0更新时间：2025-07-16
- 摘要：G function arithmetic of a HF high speed FH CHESS radio produced in U.S.is deeply studied in this paper,which involves FH pattern and the modulation and demodulation etc.The performance of G function FH pattern is analyzed and tested based on introducing the principle of G function arithmetic.Lastly some beneficial conclusions are derived,and improving points are put forward.关键词：HF frequency hopping;CHESS radio;FH pattern2|1615|25更新时间：2025-07-16
- 摘要：This paper considers a simple model for hard-decision multistage parallel interference cancellation within a codedivision multiple-access(CDMA)system.Previous work in this area has relied heavily on simulation techniques.[5]analyzes the effects of timing errors,obtaining a closed form result for bit-error rate after an arbitrary number of stages of cancellation in an additive white Gaussian noise(AWGN)channel.By analyzing statistical characteristics of residual multiple access interfrence,we obtained an analytical expression for the probability of bit error in hard-decision parallel interference cancellation.Calculation results are compared with simulation results.关键词：CDMA;parallel interference cancellation;gaussian approximation;timing errors2|775|0更新时间：2025-07-16
- 摘要：This paper introduces one method for digital video transmitting over CATV (HFC).We discussed the implementation of CU (Coding assigning Unit) applied in a transmission system.The design of the MPEG-2 TS Card is introduced,including its main functions,circuit configuration,hardware and software design.The implementation of the key signals and the result of its numerical simulation as well as the process of the state transition of the card are given.Finally,a practical system applying the card is described briefly.As a result that the card can work reliably and stably,to achieve satisfactory transmission of MPEG-2 TS.关键词：MPEG-2 TS;CATV(HFC);PCI Bus;data transmission2|833|2更新时间：2025-07-16
- 摘要：In this paper,it is directly and constructively proved that the orthogonal compactly supported wavelet (packets) Transform operator of a finite discrete signal with a length as 2's integer power can be represented by an orthogonal matrix with the same size.The general construction method and laws of these matrices are also given.关键词：orthogonal transform;wavelet transform;wavelet packets transform2|1666|1更新时间：2025-07-16
- 摘要：An associative memory network with spatiotemporal chaos control is investigated in this paper.Experimental results show that initial input with the knowledge of only a part of the target information can successfully complete associative memory by spatiotemporal chaos parameter control.By means of our proposed algorithm,memory search performance and memory capacity possess more powerful improvement compared with the Hopfield model.Meanwhile we find that success rate of associative memory depends on reinforcement factor,sampling number,information quantity,training threshold value and initial chaos parameters.关键词：spatiotemporal chaos control;associative memory network;success rate;reinforcement factor;training threshold value;initial chaos parameters2|950|4更新时间：2025-07-16
- 摘要：Redundancy on hidden-layer neurons has been proven useful in the fault tolerance of neural networks.This approach has been applied successfully in the fault tolerance design of classification neural networks,thus the complete single-fault tolerance can be gained.But this approach can only be applied to the feed forward networks which has hard-limit activation functions in output layer.And it is proved that this approach is valid only to single-fault.There are universal faults of neurons and weights in actual applications,so we evaluated this approach under universal faults in feed forward networks.We proved that the global fault-rate is reduced though the redundancy on hidden-layer neurons.And we presented a practical and valid method of redundancy of hidden-layer neurons to gain fault tolerance.关键词：neural networks;fault tolerance;redundancy2|888|0更新时间：2025-07-16
- 摘要：The fluctuation of incoming and outcoming data streams of MSA(Multiplex Section Adaptation Function) in SDH is analyzed and an algorithm to generate data-monitoring signals in FIFO(First-in-First-out memory) is put forward in this paper.A MSA function ASIC design of this algorithm has been accomplished and realized by sub-micrometer process.The chip was proved to have achieved the requirements of ITU-T and have very good consequence in the simulation.关键词：optical fiber communication;ASIC;MSA;FIFO2|1010|0更新时间：2025-07-16
- 摘要：Calculation of punch-through limited breakdown voltage for parallel-plane junction has been examined in this paper.The solution of impact ionization integral for the punch-through limited breakdown voltage has been proposed in the polynomial fit function for the first time.The results of three different models have been compared.It has been shown that the revised critical electrical field model solution coincides with the numerical solution of impact ionization integral,and the classic critical electrical field model introduces significant inaccuracies.关键词：punch-through junction;breakdown voltage;critical field model;revised critical field model;solution of impact ionization integral2|1922|0更新时间：2025-07-16
- 摘要：On the basis of theory of electron interference,it is pointed out that there are a series of separate weak interference non-localized state above barrier for multiquantum well (MQW) structure.When photoexcitation occurs,the electrons on ground state in quantum well can be excited to the weak interference non-locaized state above barrier forming absorption peak.The calculated positions of absorption peak are in good agreement with experimental results and estimated strength of several absorption peaks is in agreement with experimental results.关键词：GaAs;multiquantum well;electron interference2|1023|1更新时间：2025-07-16
- 摘要：A request-permit procedure based bandwidth allocation algorithm for non-real time stream is presented,which suits for SuperPON with large round-trip-delay and multi-customer.It requests slot switches dynamically between fixed allocation and random access,which adapts to the load situations.The delay performance is investigated with the help of the computer simulations,which prove that the algorithm assures low delay at light load and high throughput at heavy load,and then improves the performance of best effort services.关键词：passive optical network (PON);superPON;access network;asynchronous transfer mode (ATM);medium access control (MAC) protocol;access delay2|889|0更新时间：2025-07-16
- 摘要：By using of the multi-peak grating to select the wavelengths,we fabricated σ-shaped fiber lasers with 8 wavelengths simultaneous lasing.The spacing of output wavelength accords with the WDM wavelength standard proposed by ITU-T.The dispersion compensation for the 8-wavelength mode-locked pulses after 100km SMF transmission using the chirped grating is also implemented.关键词：fiber grating;fiber laser;active mode-locking2|1126|0更新时间：2025-07-16
- 摘要：A circuit system of programmable BP on-chip learning neural network with learning rate adaptation is designed.The whole system comprises feedforward network and error back-propagation network.A novel programmable generator of sigmoidal function and its derivation is proposed.Its outputs include the sigmoidal function to realize I－V nonlinear transfer and its derivative using the forward differential method.Both functions fit well with the ideal functions.Moreover, the threshold and the gain factor can be easily programmable.Learning rate adaptation circuit is also presented to accelerate the convergent speed.Using a standard 1.2μm CMOS process, experiments such as sin(x) function fitness are done to the whole system.These experiments verify the superior performance of this on-chip learning BP neural network.关键词：neural networks;CMOS analogue integrated circuits;programmable;adaptation2|1328|1更新时间：2025-07-16
- 摘要：First,the decorrelation method based on the object reflection properties of the same object was used to reduce the spectral correlation.The S+P transform was then applied to the difference image to realize spatial decorrelation.Finally,the improved SPIHT was used to realize high-performance lossless encoding.Experimental results showed obvious effects and also its potential in remote sensing image compression.关键词：remote sensing image compression;S+P transform;improved SPIHT;lossless image compression2|907|1更新时间：2025-07-16
- 摘要：54-parameter edge-element,"boundary-marching"and Galerkin method are combined to analyze the scattering characteristics of waveguide loaded with anisotropic dielectric.With the present method,the calculating accuracy and efficiency are effectively improved,and the requirement to the computer memory is tremendously reduced.Also no spurious solution is found.Some calculating results are given in the paper to verify the advantages of the method.关键词：54-parameter edge-element;anisotropic dielectric;waveguide discontinuity2|903|3更新时间：2025-07-16
- 摘要：Coupling equation of counter cross-phase modulation (XPM) is proposed.In nonlinear optical loop mirror (NOLM),nonlinear phase shift difference between the co-propagating and the counter-propagating signal in transmission process is gotten.The switching characteristics on Gaussian pulse,the effect of XPM on de-multiplexer which adopts NOLM and the progression without amplifier in an experiment adopting NOLM in all optical routing are analyzed.In the end,we discuss the switching characteristics on non-return zero (NRZ) codes.关键词：NOLM;counter XPM;nonlinear phase shift;de-multiplex;all optical routing;NRZ code2|873|1更新时间：2025-07-16
- 摘要：A new gray level thresholding approach to image segmentation based on a fuzzy ART neural network is presented,which can determine automatically the number of classes of and suppress effectively the noise in the given image.Segmentation results on manual and real images demonstrate the effectiveness of the proposed method.关键词：fuzzy ART;gray level thresholding;image segmentation2|943|9更新时间：2025-07-16
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