最新刊期
卷 ， 期 7 ， 1998
- 摘要：To celebrate the 50th anniversary of Shannon Information Theory, a survey of the outstanding achievements of this theory and its epoch-making contributions to the mankind is given in the paper while the unavoidable limitations of this theory due to the time factor are also pointed out. The most important progress achieved throughout the world in information science since then is stressed with the emphasis on the great revolution in this field-from statistical information theory to comprehensive information theory, from information transmission to information cognition, and from communication theory to intelligence science. An appeal is thus given from the author to the public that many efforts should be made so as to be ready for the forthcoming era-the intelligence science era, an advanced stage of information age.关键词：Shannon information theory;comprehensive information theory;Information science;Intelligence science3|250|5更新时间：2025-12-08
- 摘要：This paper gives a survey for the recent development and research problems of information theoretic cryyptography . The content includes recent results and open problems on cryptosystems of Shannon’s model and of new models hased on infonnation theory, some research work of the authors is also included. In the end, a brief discussion on the prospect of information theoretic eryptography in the future is given.关键词：信息理论密码学;流密码;迭代分组密码;窃密信道;认证理论;密钥共享2|611|3更新时间：2025-12-08
- 摘要：We summarize the results on the soft decision decoding of block codes, discuss certain prelms in the design of decoding algorithms, and propose some problems which remain to be studied. The paper consists of four parts. the first part brtiefly describes the main results on constructing Shannon codes, the basic methods of decoding linear block codes are presented in the second part, and in the third part,we discuss both the trellis structures and the corresponding decoding algorithms of linear block codes, finally, we introduce the current situation and trend for studying bob the turbo codes and their iterative feed back soft decision decoding algorithms.关键词：information theory;error-correcting code;Soft decision decoding2|627|4更新时间：2025-12-08
- 摘要：In this paper, we give a survey of some important developments in shannon’stheory of information secrecy and authentication in the last few years.关键词：information theory;Cryptology;Authentication theory;Multiuser information theory2|211|1更新时间：2025-12-08
- 摘要：An overview of the advances and trend in the channel coding is made under the Shannon’s Coding Theory. The hovel structures and astonishing Performance of the Turbo codes are analyzed comprehen comprehensively and systematically. A useful direction and prediction of some hot topics on this area that are of both theoretical and practical interests are pointed out.关键词：channel coding;Turbo codes;Concatenated codes;iterative decoding2|671|18更新时间：2025-12-08
- 摘要：This paper introduces the basic structures and new research developments of turbo codes.关键词：Turbo code;Convolutionary code;Vitervi decoding;Bahl decoding;Soft decision decoding2|232|5更新时间：2025-12-08
- 摘要：ATM switching technique is one of main techniques in B-ISDN. As the key part of an ATM exchange, ATM switching fadrics have been studied extensively. In this paper, we present a descriptive survey of unicast and multicast ATM switching fabrics, with emphasis on structures and performances, based on buffering concept. foe performances arid implementation complexity of various kinds of buffering ATM switching fabrics are also compared with each other.关键词：ATM;Switching fabrics;Switching element;Buffering structures2|209|2更新时间：2025-12-08
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- 摘要：Parallel concatenated convolutional code （turbo-code） is a break through of coding theory in recently years. It can perform less than 1dB away from the Channel capacity, thus shows great potential in various areas for future application. mis perfect performance comes form its novel structure together with cormsponding iterative decoding algorithm, which make it a near random decode-able code. its new idea will greatly affect future research of coding theory. In this paper, we will give brief review about the current state and the prospectof the research on its structure, analysis, design, simplified algorithm and applications.关键词：Parallel cancatenated convolutional code;soft output decoding;channel capacity;information theory2|273|2更新时间：2025-12-08
- 摘要：In this paper, we investigate the performance of BCH （63 39 4） Code, BCH（127 78 7 ） codeand BCH（127 64 10） code with different interleaving degrees applied to the VHF mobile channel which was modelled by Swarts et al. in Joharmesburg, South Africa when the suhcdrier modulations are FSK 300bits/s, DPSK 1200bits/s, QPSK 2400bits/s and 8PSK 4800bits/s respectively at two different vehicle speeds of 40km/hand 100km/h in two different communication environments -city environment and freeway environment.关键词：mobile channel;modulation;BCH codes;Interleaving2|83|4更新时间：2025-12-08
- 摘要：The delay of Constant-Bit-Rate（CBR） services in ATM network is studied in this paper, with the assumption of background traffic being Pareto distributed ON-OFF sources, a more realistic model to describe the data traffic in ATM networks. The influences of Pareto ON-OFT sources on the performance of CBR srvicesare determined by the value of β in Pareto distribution function. Whenβ is not greater than 2, the variance of ON （OFF）duration is infinite and the quality of CBR seduces is poor. The traffic now should be smoothed before it exits form the user side. The algorithm and results of smoothing are discussed.关键词：ATM;Pareto distribution;ON-OFF sources;CBR services;VBR services2|146|1更新时间：2025-12-08
- 摘要：Forward pointers are employed by R. Jain in mobile communication to reduce the burden ofHLR and network, In this paper, theoretical model is built to analyze the performance of the strategy. Simulation resulil illustrate that the model fits perfectly to the fact . When call-to-mobility ratil（CMR）is high, total network costs increase. So an adaptive method is suggested here. Simulation results show that it adjusts the maximumlength of the forward pointer chain to get minimal cost for different CMR. When CMR is high, it automatically stops using forward pointer strategy, thus the problem of fixed length is solved.关键词：Mobile communication;mobility management;Database technique;Markov chain;Monte-Calro simulation2|68|6更新时间：2025-12-08
- 摘要：Based on deeply analyzing the propeties and propagation mechanisms of microcellular mobile radio channel, this paper researches and proposes the new generalized prediction model of radio wave propagation loss in microcellular multipath dispersive channel, whose key points are to characterize the influence of three dimensions multipath dispersive channel performance on radio propagation with the help of additional path attenuation factor, and to use the minimum inflection point distance of the first Fresnel region in propagation channel as a characteristic porameter expressing unitedly the influences of antenna height and frequency. Finally accordingto the prediction model, the radio wave propagation loss performance in different conditions is analytically simulated.关键词：Microcellular mobile communication;Multipath dispersive channel;Radio wave propagation loss;Additional path attenuation;Minimum inflection point distance2|149|6更新时间：2025-12-08
- 摘要：Recent measurement studies show that the burstiness of packet traffic in IAN as well as WAN is associated with long-range correlation that can be efficiently modeled as self-similar arrival process in terms ofaccuracy. Since Hurst index is the key value of this model replesenting the burstiness of traffic source , efficient estimation of Hurst index to the given accuracy is the basic step of flow control as well as buffer management in high speed broadband networks（e. g. ATM） with self-similar traffic. In this paper, we propose a fast Hurst index estimation method based on multiresolution sampling and wavelet analysis. The proposed method is the maximum likelihood estimator for strict self-similar model and can be used to check the consistency of Hurst index in different observed range of time. Simulation results based on fractal Gaussian noise and real traffic data reveal that the total number of count samples of the burst traffic for parameter estimation is peally reduced compared to the traditional methods such as R/S statistics and variance-time analysis. The proposed approach also shows more accuracy and robustness than traditional methods when lacking of sample data.Thus our method can be applied to the application of traffic enforcement and congestion control in ATM networks.关键词：Self-similar traffc;Multiresolution sampling;Orthogonal wavelet decomposition;Hurst index;ATM network2|398|6更新时间：2025-12-08
- 摘要：This paper presents a new multipath, self-routing ATM switching architecture. Using virtua FIFO biber technology,the proposed multipath switch can preserve cell sequence. Under the uniform traffic pattem, the maximum achievable throughput of this arehitechure is 7/8. The delay and cell loss probability Performance of the prosed switch is investigated under both uniform and nonuniform traffic patterns.关键词：ATM交换;信元次序完整性;虚拟FIFO缓冲器2|29|0更新时间：2025-12-08
- 摘要：The parameter estimation methods for amplitude modulated（AM）mixed phase signals is studied using cyclic-cumulants. The parameter equations of AM mixed phase models are derived in terrms of any order cyclic-cumulants. For AM mixed phase AR, MA and ARMA models, the corresponding parameter estimation methods are presented. Simulations indicate the efficiency of the methods.关键词：AM mixed phase signal;Cyclic-moment;Cyclic-cumulant;Parameter equation;parameter estimation2|75|2更新时间：2025-12-08
- 摘要：The harmonics retrieval in multiplicative and additive noise is studied from the view point of cyclostatiolnary processes. At first, the large sample property of the finite Fourier transform for generally complex-valued processes is established under certain mixing conditions. Then, the inliformly convergent rale of any other sample cyclic-moments of cyclostationary processes is obtained. For harmonics in multiplicative and additive noise, the statistical properties of the kth-culer sample cyclic-moments are obtained for k = 1, 2, 3. The estimation for harmonics parameters based on different culer cyclic-moments are presented. The strong convergeneand convergence rate of the estimators are obtained. Finally, the simulation results are given.关键词：harmonic retrieval;multiplicative noise;cyclic statistics;convergence rate;parameter estimation2|238|5更新时间：2025-12-08
- 摘要：In this paper a high resolution direction finding algorithm which is suitable for deform circular array （UCA）is presented. The algorithm is constructed by transforming the UCA from element space to modespace and reformulating the criteria function of maximum likelihood method（MLM）to a simple form by introducigthe concept of noise manifold matrix. Commpd with MLM the new method of this paper is only an analysis algohthln acher than a multiple-valtiple optimizing one which often becomes useless due to heavy computational burden and local minimum traps.关键词：Uniform circular arrays;Mode space;Noise manifold2|189|1更新时间：2025-12-08
- 摘要：A method for the approximation of linear-phase finite impulse response（FIR）quadrature mirror fiber with any regularity in wavelet transform is proposed.It is proved that the obtained filters have the least mean square error.The filter’s magnitude-frequency, energy concentration and regularity characteristics are compared with other similar filters. Experiments have showed that the filters have excellent feature and are suitable to the compression of data.关键词：wavelet transform;Linear-phase;FIR;filter2|101|5更新时间：2025-12-08
- 摘要：In this article a neural network model with transient chaos and time-variant gain is proposed.By introducing transiently chaos and time-valiant gain, the proposed neural neira; metwork has richer and more flexible dynamics rather than Hopfield-like neural networks only with POint attractors, so that it can be expected to have higher ability of searching for globally optimal or near-optimal solutions. After going through an inversebifurcation process, the neural network gradually approaches to a conventional Hopfield netal network stalting from a good initial state. It can be used to solving various complicated optimization problem and associative memories. Extensive numerical simlilations show that the network would not be stuck into local minima. Finally,we applied the network to maximum likelihood direction estimation of spatial signal sources.关键词：neural network;Transient chao;Time-variant gain;nonlinear optimization;Chaotic annealing;ML direction extimtion2|200|4更新时间：2025-12-08
- 摘要：In this paper, a novel method for Kohonen network designing and training by using evolutional programming（EP） is proposed, which can autolnatically search the optimum structwe and connechon weights of the Kohonen network. This kind of Kohonene network is used for passive sonar targets clustering analysis, and the result of experiment shows that the EP based Kohonen network is effective in clustering the overlap signals of passive sonar target.关键词：Evolutionary computation;Neural netowrks;passive sonar;clustering analysis2|80|3更新时间：2025-12-08
- 摘要：Edge information is regeded as important chalacteristics in computer vision. Thus, edge detection and contour extraction are key steps of image analysis. For edge detection, research intersts was tuned to local enemy method based on local phase in recent years. It’s main feature is that we can obtain many types of edges simultaneously by detecting the maximum value of local energy. After that, we get the inihal edge. In order to obtain the objects’ contour, the snakes madal presented by M. Kass in 1987 was applied. The model is suited to the contour extraction of deformable objects, For example, red blood cells.关键词：Local energy;Snakes model;Microcirculation;Red blood cell;Contour;Edge;Image analysis2|234|2更新时间：2025-12-08
- 摘要：In this paper,we describe a novel array image processing architecture, which use a global interconnection networks and local intereonnection netwods for local shared RAM. A distributed memory arehitectme in combination with shod memory is designed with the interconnection networks architecture in the array.The theoretical results show that the performance of the array is improved highly. The array can yields its top performance values: 800 MFLOPS 、4 .4 BOPS 22 .4Gbits/s.关键词：image processing;Array processor2|37|1更新时间：2025-12-08
- 摘要：This paper first give the architecture of integhion of IN and GSM, then point out problems in the design of mobile SCP: how to communicate with HLR to get mobility-related parmeters and how to solve service interaction betWeen IN services and the supplemental services in mobile network. In this paper, the answers to these problems are given. At last, we define three mobility-related service independent building blocks（SIBs）to design mobile-related services.关键词：IN;Service interaction;HLR;SIB;SCP3|70|4更新时间：2025-12-08
- 摘要：We propose a passive star WDM network in this paper, in which any two users can communi-cate within I or 2 hop（s）. We also develop a wavelength assighment algorihm to minimize the tuning range of each tunable transmitter while minimizing deay. We also analyze and simulate the network performance.关键词：Multihop;WDM;Tuning range2|26|1更新时间：2025-12-08
- 摘要：The design and implementation of text interpretation and automatic abstracting system is introuduced .The system which adopts a partial parser by of making syntatic, semantic and pragmatic analysis techniques merge into an organic whole, constructs a knowledge frame of texts and acquires the expected information to fill the given frame .The completed frame is then run through a program to produce a coherent and cohesive abstract.This system is being develops with texts in the area of computer virus.关键词：Narural language understanding;Partial parser;Automatic abstracing;Comprehensive dictionary;Abstract generator3|277|13更新时间：2025-12-08
- 摘要：The unddscted are probablity of smoo BCH codes in binaly symmetric channals is studied.Several importan unequalities are obtalned. Then the extended codes of binary prinmitive BCH codes carecting 2errors are proved to be proper codes for erro deection.关键词：Information theory;linear block code;BCH code;Undetected error probability;Proper code for error detection2|91|1更新时间：2025-12-08
- 摘要：MMDP model is a good traffic model in ATM networks, however the parameters of general MMDP model can not be gotten easily. We proposed a new parameteriging method to deal with thes problem Itmay used to model the edes with given distribution and exponential autocorrelation function . It is shown that this method works well by some experiments.关键词：ATM networks;MMDP model;Traffic modeling2|34|1更新时间：2025-12-08
- 摘要：This paper presents a novel feedforward artificial neural network （ANN）model based on Kohonen self-organizing feature mapping （SOM）, whose structure , learning rules and adaptive algorithms are provided in detail here .The concept of membership function is combined with SOM, so that this ANN model can obtain the pobability distribution of the input information by statistical method, then make pattern classification decision. Besides, this paper presents a novel concept of "Pattern Map", which is able to facilitate visual inspection of the data .The results of the computer simulations show that the new concepts and methods mentioned above are effective.关键词：Artificial neulal network model;Sesf-organizing fearure mapping;cluster analysis;visualization2|116|1更新时间：2025-12-08
- 摘要：Constrution of non-degnerated Ist-order coarelation-immune funmctions and a better enumera-tion lower bound for such funtions is proved. Then an example and a sufficient condition for nondegenethed2nd-order correlation-immune functions are given .关键词：cryptology;Non-degnerated;Correlation-immune;Orthogonal array;enumeration2|45|0更新时间：2025-12-08
- 摘要：The correlation functions of the so-called linearly related generalized geometric sequences are given initially, thus an open problem proposed by Klapper about the calculation of the correlation function is partially solved.关键词：Generalized geometric sequence;trace function;Correlation function2|33|0更新时间：2025-12-08
- 摘要：In this paper, a logic hased on BAN for authentication for public-key cryptography is proposed, which is a logic of shared information .Applications are demonstrated by examples.关键词：cryptography;BAN Logic;Authentication protocols2|68|2更新时间：2025-12-08
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