Current Issue

• • 2000, Vol. 23 No. 1 Published date:10 January 2000 Last issue Next issue

  PAPERS

  • A Routing Algorithm in Virtual Wavelength Path in all Optical Networks
  • LIU Xue-yuan, YANG Ming, LI Han, GU Wan-yi
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 1-5.
  • Abstract ( 279 )     HTML     　　
  • We propose a routing algorithm based on Hopfield neural networks(HNN). The HNN routing scheme can get the optimal solution. The simulation results show that the algorithm is of parallel and robust. The minimal wavelength numbers the HNN gets is independent of traffic distribution and is robust. Comparing with other solutions, it also reduces the needed wavelength numbers.
  • References | Supplementary Material | Related Articles

  • Understanding-Based Chinese Automatic Abstracting System in Special Domain
  • LI Lei, SUN Chun-kui, YANG Xiao-lan, ZHONG Yi-xin
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 6-10.
  • Abstract ( 293 )     HTML     　　
  • A understanding-based Chinese automatic abstracting system called Ladies is introduced, which is special for domain of neural networks learning algorithm. It has some innovative characteristics different from other abstracting systems, each of which is discussed. Also some results of experiment are given.
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  • A Novel ATM Switching Fabric Based on Bifurcated Output Queuing
  • GAO Hong, LIAO Xiao-hao, DING Wei
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 11-15.
  • Abstract ( 240 )     HTML     　　
  • A novel ATM switch fabric with bifurcated queuing is proposed. Under current state-of-art, it can substantially decrease the speed of both memory and bus of ATM switching system while still maintain delay performance of basic output queuing, multicast function and be cost-effective.
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  • Topological Properties of Fuzzy Valued Metric Spaces
  • CHEN Qi-hao, BEN Liang, LI Xiang-ming
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 16-20.
  • Abstract ( 232 )     HTML     　　
  • We introduce three kinds of metrics d_i(i=1, 2, 3) in Fuzzy valued space M[0, 1], and consider the topological properties of fuzzy valued metric spaces(M[0, 1], d_i)(i=1, 2, 3).
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  • Magnetic Coupling of a Communication Line with a Crossing Power Line
  • MA Shuang-wu, GAO You-gang
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 21-25.
  • Abstract ( 236 )     HTML     　　
  • Discusses the magnetic coupling effects on a communication line from a crossing power line, and gives two ways to calculate the mutual inductance between crossing lines. Numerical computation and comparison are made. The corresponding formulae for calculating induced voltage and induced current are derived.
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  • An Algorithm of Learning from Example
  • QI Zhi-li, BAI Zhong-ying
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 26-30.
  • Abstract ( 224 )     HTML     　　
  • Some rules of example space and expounds some theorems are revealed.It explains that we figure out suitable of example sets if only explore a small quantity of item of example sets, thereby, it avoids to scan to scan every example, and only save a small quantity of item not huge example stes.
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  • An Estimation of Call Setup Delay in ATM Network
  • FENG Chun-yan, LI Jin-ling
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 31-35.
  • Abstract ( 279 )     HTML     　　
  • The estimation of call setup delay in ATM network is presented. Our approach is to distribute and balance processing loads among call control processes via optimal capacity allocation, and to minimize the call setup delay in switching.The total propagation delay of signaling along the links is effectively estimated.
  • References | Supplementary Material | Related Articles

  • Adaptive Algorithm Based on Pilot-Channel for Multiuser Detection
  • WANG Yi, XIONG Si-min, WU Wei-ling
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 36-40.
  • Abstract ( 267 )     HTML     　　
  • A novel adaptive algorithm for multiuser detection is proposed.The algorithm based on pilot channel (PCA) uses the information in pilot channel to compute directly the weight vector of the transversal filter. Compared with conventional adaptive algorithms and previously proposed blind algorithms, it does not require training sequences or channel estimation, and its computational complexity is O(N²). Analysis and simulations illustrate that PCA can converge to the Wiener solution globally, and reach the steady state rapidly. The steady state performance can be enhanced by increasing the transmitted power in pilot channel, but is worse than that of conventional recursive least-square algorithm in decision-directed mode (DD-RLS).
  • References | Supplementary Material | Related Articles

  • A New Dynamic Semantic Model of SDL
  • NI Zhao, WANG Ying, HUANG Jie, AI Bo
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 41-45.
  • Abstract ( 258 )     HTML     　　
  • A proposal for a dynamic semantic model of SDL is given in terms of structural operational semantics.The transition systems for both system level and process/channel level are defined with the principle of transition rules.
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  • A Threshold for the “Early Detection” Method and an Output SNR Stop Criterion for Turbo Codes
  • LI Xiang-ming, YUE Guang-xin, YIN Chang-chuan
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 46-50.
  • Abstract ( 250 )     HTML     　　
  • A hypothesis to take the physical channel and the Turbo decoder as a joint equivalent AWGN channel is presented. On the basis of this hypothesis, one can use the signal-to-noise ratio of the Turbo decoder output LLR as a criterion to stop the iterative procedure. To reduce the decoder complexity, one can make a decision for the symbol whose LLR is larger than a given threshold and output it. A theoretical threshold is given.
  • References | Supplementary Material | Related Articles

  • Blind Adaptive Multiuser Detection in Multipath Code Division Multiple Access Channels
  • ZHOU Jian, YUE Guang-xin
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 51-55.
  • Abstract ( 213 )     HTML     　　
  • We propose a blind adaptive multiuser detection in multipath CDMA channels based on CMOE criteria. Compared with other multiuser detection, this one take advantage of the structure and character of two subspace : (1) the subspace structure associated with the code of the desired user; (2)the estimated “signal subspace” of the covariance matrix for the observed signals. Simulations state this detection has strong ability against near-far,avoid significant reduction in performance when signature mismatch exists and good performance in the higher SNR conditions.
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  • A New Management Information Model for ATM Transport Networks
  • HOU Qing-fu, LEI Zhen-ming
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 56-60.
  • Abstract ( 220 )     HTML     　　
  • A new management information model for ATM transport networks is presented,which is based on the functional architecture defined for ATM transport networks and obtained by reusing the suitable generic management information model, extending relationship types of managed objects and defining new managed objects such as “tandemConnection”, “topologicalLink”,etc.. Compared with the model suggested by ATM Forum, the new one has made a great improvement in aspects of supporting of partition, relationship define of managed objects, and is proved to be more rigorous and more flexible.
  • References | Supplementary Material | Related Articles

  • Maximum Likelihood Estimation of High Dynamic Doppler Frequency
  • WANG Xiao-xiang, KE You-an
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 61-65.
  • Abstract ( 269 )     HTML     　　
  • The Doppler frequency of received signal is calculated by a Tyler series, the maximum likelihood estimation of varies steps of Doppler parameter is derived and analyzed by experiment; The computer simulate the estimator by FFT processing. The estimate root mean square error and loss lock probability to estimate the given simulated receiver trajectory is presented.
  • References | Supplementary Material | Related Articles

  REPORTS

  • Segmentation of the Foreground Containing Face in a Moving Image Sequence
  • SHI Ke-wei, FU Xi-tian, CAI An-ni, SUN Jing-ao
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 66-70.
  • Abstract ( 243 )     HTML     　　
  • A new method is proposed to segment the foreground that contains face from the background in teleconferencing sequences based on a joint consideration of the homogeneities of luminance and motion. Experiments show success of the algorithm.
  • References | Supplementary Material | Related Articles

  • Research on Integration Technology of CORBA and TMN
  • SHEN Qiao, YI Ping, XU Qiong, SHOU Guo-chu
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 71-75.
  • Abstract ( 221 )     HTML     　　
  • After respectively investigating into characteristics of service, network and element management, we draw a conclusion that CORBA is an optimal platform for TMN service and service management. Finally, among three solutions about integrating CORBA within TMN architecture, we choose abstract object definition to build up a model of integrated TMN management environment.
  • References | Supplementary Material | Related Articles

  • Calculation of Electric Field and Characteristic Impedance of Asymmetric TEM Cell
  • XIAN Jin-long, GAO You-gang, YANG Sheng-xiang
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 76-79.
  • Abstract ( 307 )     HTML     　　
  • The section of an asymmetric TEM was divided into four regions and potential function is expressed as a Fourier series in each region.The point-matching was used on the boundary of these regions to determine coefficients of series.Thus, the characteristic impedance can be calculated and electric field obtained in terms of a potential function.
  • References | Supplementary Material | Related Articles

  • A Set-Top Box Solution for VOD System
  • FENG Shao-yong, QUAN Zi-yi
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 80-89.
  • Abstract ( 280 )     HTML     　　
  • A set top box solution for the VOD system is introduced, including hardware and software architecture.Hardware include NIU and STU, NIU is a special designed ATM interface, while STU is a general network independent hardware platform.In the software architecture, the network protocol and DAVID system software are described in detail.
  • References | Supplementary Material | Related Articles

  • Management Framework for Telecommunications Network Rel iabil ity
  • ZHANG Xue-yuan,LIANG Xiong-jian,Villy B. Iversen
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 85-89.
  • Abstract ( 229 )     HTML     　　
  • Acco rding to the research object of telecommunications netw ork reliabi lity and it s manag ement , analy ses the manag ers for telecommunications netwo rk reliability , the manag ement catego ry , the manag ement tasks and i ts implementation. Base on these discussions, finally proposes that netw ork operators should do studies on subscribers 'expectation, operational reliabili ty , fault rules, maintenance system, reliabili ty decision and reliabili ty measures, to improve the opera tional reliabili ty.
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  • Research on OPS Technology Based on ATM-CTI
  • WU Wei-ming, PENG Lu
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 90-94.
  • Abstract ( 271 )     HTML     　　
  • A question of OPS technology based on ATM-CTI is presented.This thesis focuses on the exposition of the fact that CTI technique is the key technology for the realization of synthetic voice and data service in communication networks, and definitely poins out the important role played by open progranning theory and technology in the further development of CTI.Moreover, it explains how OPS technology is successfully applied in the development and research based on ATM-CTI systems.
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  CORRESPONDENCES

  • Conflict-Free Access for n×n Matrix in n Banks Memory
  • WANG Chun-lu
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(1): 95-98.
  • Abstract ( 268 )     HTML     　　
  • A method for storing n×n matrix on n memory banks is presented. It can reference all the elements at one time in one row, one column or one diagonal of matrix without blocking, and it proved correct and available.
  • References | Supplementary Material | Related Articles