Current Issue

• • 2000, Vol. 23 No. 2 Published date:10 March 2000 Last issue Next issue

  PAPERS

  • The Topological Properties of Fuzzy Valued Metric Spaces(II)
  • CHEN Qi-hao, BEN Liang, LI Xiang-ming
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 1-4.
  • Abstract ( 212 )     HTML     　　
  • Based on metrics d_i defined on reference [1] we consider the topological properies of fuzzy valued metric spaces公式,obtain the following conclusion:(M[0,1],d_i)(i=2,3) are complete,connected,compact and separable metric spaces.
  • References | Supplementary Material | Related Articles

  • Detection of Core and Delta Fields Using an Improved Fractal Method
  • SU Fei, SUN Jing-ao, CAI An-ni
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 5-9.
  • Abstract ( 233 )     HTML     　　
  • A new technique that uses Discrete Fractal Brownian Motion to describe a fingerprint is presented. By computing certain fractal parameters, a fingerprint's core and delta fields can be roughly detected. Experimental results demonstrate this method to be not only more efficient than the single fractal dimension method, but also more noise resistant than the traditional schemes.
  • References | Supplementary Material | Related Articles

  • Dynamic Distributed Routing Algorithm Based on ACS
  • LI Lian-yuan, LIU Ze-min, ZHOU Zheng
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 10-13.
  • Abstract ( 240 )     HTML     　　
  • A new distributed routing algorithm based on ACS is proposed in this paper. The simulation results show that the length of routes and links' load can be taken into account by ACS and the algorithm is superior to some traditional algorithms.
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  • MAS/KIB——a Multiagent System Specification
  • HU Shun-geng, ZHONG Yi-xin
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 14-18.
  • Abstract ( 319 )     HTML     　　
  • MAS/KIB——a multiagent system specification is built using mental states such as K(Know), B(Belief), and I(Intention), its grammar and semanteme are discussed, axioms and inference rules are given, some properties are researched. MAS/KIB has following characteristics: (1)Each agent has own world view; (2)No global data in the system; (3) Processes of state changes are used as indexes to systems; (4)It has the characteristics of not only time series logic but also dynamic logic; (5)Interactive actions are included.
  • References | Supplementary Material | Related Articles

  • The RAG Based Separation and Processing of Characters in the Mechanical Drawing Intelligent Recognition
  • ZOU Hua, FANG Wei-ning
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 19-23.
  • Abstract ( 243 )     HTML     　　
  • A RAG based method for character separation in the intelligent recognition of mechanical drawing is provided in this paper. By using this method, not only the graphic and character can be separated effectively, but the decimal point, degree mark, dash line, and short line in the center line can be kept in the graphic part as well. Furthermore, the processing method for the characters to be recognized is discussed in this paper also.
  • References | Supplementary Material | Related Articles

  • Subspace-Based Multipath Channel Estimation for CDMA Communication Systems
  • ZHOU Jian, YUE Guang-xin
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 24-28.
  • Abstract ( 307 )     HTML     　　
  • An estimation method of channel parameters for CDMA systems operating over channel with single or multiple propagation paths is proposed.This method exploits eigenstructure of thd received signal's sample correlation matrix in which the observation space can be partitioned into a signal subspace and a noise subspace.The channel estimation is formed by projecting a give user's spreading waveform into the estimated noise subspace and nulling the projection.Furthermore,a cost function which can null the noise compontnt of signal vector is presented.Compared with the method presented by S.E.Bensel et al (1996),this method can get the close-form solution which can be used for further analysis.Simulations state this estimation has strong ability against near-far effect and MAI.
  • References | Supplementary Material | Related Articles

  • The Quantitative Analysis on the Independence of Modules
  • TIAN Guang-Hui, HUANG Jie, AI Bo
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 29-33.
  • Abstract ( 256 )     HTML     　　
  • A new method for the measurement of module cohesion is presented. Based on the slicing of program control graph and the weights of relationships between the components, the cohesion of different level can be precisely distinguished. Combined with the analysis of the common data interfaces between modules, the general principle of measuring module coupling is also discussed.
  • References | Supplementary Material | Related Articles

  • Capacity of Quantized AWGN Channel and Optimal Linear Quantization
  • GUO Wen-bin, YANG Hong-wen, LIN Jin-dong, PANG Qin-hua
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 34-37.
  • Abstract ( 280 )     HTML     　　
  • The channel capacity of quantized AWGN channel and optimal uniform quantization has been studied.Quantization will cause 0～2 dB loss of SNR depends on the quantizer bit number and the quantization step. The performance loss caused by 3 or more bits quantizer can be negligible. We have also found the polynomial to fit the optimal quantization step that can maximize the channel capacity.
  • References | Supplementary Material | Related Articles

  REPORTS

  • A Novel Principal Component Analysis Subspace Tracking Algorithm
  • OU YANG Cong-xing, ZHOU Jian, YUE Guang-xin
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 38-42.
  • Abstract ( 336 )     HTML     　　
  • The algorithm of fast subspace tracking based on the novel information criterion(NIC)is extended to principal component analysis (PCA) by means of the deflation technique.Performances of the novel PCA algorithm and the PASTd algorithm are demonstrated and compared through simulation examples.
  • References | Supplementary Material | Related Articles

  • Development of EPLD Programmable Device Design Test
  • HUANG Hui-ying, FEI Zhu-zeng
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 43-47.
  • Abstract ( 271 )     HTML     　　
  • According to the features of rapid and flexible design, high reliability and low cost of EPLD programmable technology, using VLSI, CAD and MAX+PLUS II developed by Altera company, research and develop EPLD (Erased Programmable Logic Device) design specialty test. This experiment can be used to promote the ability of engineering practice and to combination of practice and theory of students.
  • References | Supplementary Material | Related Articles

  • A Novel Control Panel for Fixed Wireless Access System
  • LIAO Jian-xin, ZHAO Yong-jie, HU Jian-dong
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 48-51.
  • Abstract ( 226 )     HTML     　　
  • A control panel based on Intranet and ethernet technology is suggested, which is used as the interface between operator and fixed wireless access system. It has the peculiarities of security and reliability, as well as system flexibility and expandability when accesses from local area network. The control panel is universal for other wireless access systems.
  • References | Supplementary Material | Related Articles

  • Structure and Performance Analysis of Intelligent Peripheral
  • YANG Fei, LI Xiao-feng, ZHAN Shu-Bo, CHEN Jun-liang
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 52-56.
  • Abstract ( 237 )     HTML     　　
  • A brief introduction of intelligent network and intelligent peripheral is given at first.Then the structure of CIN-IP is described.At last its performance is analyzed.
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  • A Kind of Interactive VOD System Solution
  • FENG Shao-yong, SUN Xin, QUAN Zi-yi
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 57-61.
  • Abstract ( 245 )     HTML     　　
  • The system architecture of an interactive VOD solution is given,also the function of its compoient.All kinds of information flows are detailed,including program stream flow and control information flow,The system flow of the VOD solution is also given.
  • References | Supplementary Material | Related Articles

  • Some Problems and Strategies in the Implementation of Gatekeeper
  • HAO You-chao, WANG Wen-dong
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 62-66.
  • Abstract ( 267 )     HTML     　　
  • Basic structure and signaling of H.323 protocol is introduced, as well as primary function of Gatekeeper. A hierarchically administered network model based on Gatekeeper is put forward through analyzing the shortage of gatekeepers' currently working way. Some problems and strategies in the implementation of gatekeeper are mainly discussed in the end.
  • References | Supplementary Material | Related Articles

  • Hardware and Software Designs of ATM over ADSL Access System
  • LI Hui-ling, ZHENG Wen-xing, ZHOU Ji-cheng
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 67-71.
  • Abstract ( 205 )     HTML     　　
  • Currently, ADSL is the most noticed technology in xDSL family. Using twisted-pair copper line as access media is one advantage of ADSL because this media has been widely distributed. Also, ADSL adopts point-to-point architecture which brings it more flexible to setup networks. This paper is based on the development of ADSL system. It includes the architecture of ATM over ADSL broadband access network. We concentrate our attention on hardware and software function designs of ATM over ADSL ATU-C and ATU-R cards.
  • References | Supplementary Material | Related Articles

  • The Study and Implement of Virtual Private Network
  • ZENG Zhi-feng, FENG Yun-bo, YANG Yi-xian
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 72-76.
  • Abstract ( 303 )     HTML     　　
  • The current situation of virtual private network and the security problems of internet are analyzed,we present a solution—virtual private network,which is designed to solve the threats to the internet of insecurity,then we design and implement the solution of VPN,at last,we have a further study of virtual private network.
  • References | Supplementary Material | Related Articles

  • Data Warehouse Technique on SDH Configuration Management
  • ZHANG Ying-hai, ZHANG Bin, WANG yun, LIU Jie et al
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 77-81.
  • Abstract ( 218 )     HTML     　　
  • In this paper,the data warehouse technique has used to design the configuration management system of an SDH network.The data analyzing,modulating and loading are given in detail.We have introduced a new nethod of applying the data warehouse technique in telecommunication integrated management systems.
  • References | Supplementary Material | Related Articles

  CORRESPONDENCES

  • On Dimension of Subspace Subcodes of RS Codes over Field GF(p^m)(p＞2)
  • WU Qiu-xin, YANG Yi-xina, HU Zheng-ming, SUN Wei
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 82-86.
  • Abstract ( 227 )     HTML     　　
  • An SSRS code is a subset of a Reed-Solomon(RS) code consisting of the RS codewords whose components all lie in a fixed υ-dimensional vector subspace S of GF(p^m),SSRS codes are not linear over the field GF(p^m),but they are linear over GF(p).In this paper we calculated dimension of the SSRS(subspace subcodes of Reed-Solomon codes)over the fleld GF(p^m)(p＞2).
  • References | Supplementary Material | Related Articles

  • Post-Processing Based on Block Boundary Discontinuity Criterion
  • LIN Guo-hui, MEN Ai-dong, QUAN Zi-yi
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 87-90.
  • Abstract ( 220 )     HTML     　　
  • We define the block boundary discontinuity measure as MSDS(mean squared difference of slopes).This paper presents a novel solution,which estimate the low frequency components to make the MSDS be its minimum,then the blocking effect can be efficiently reduced.
  • References | Supplementary Material | Related Articles

  • The Study on Geometrical Structure of Adaptive Array Implemented in CDMA System
  • MA Wen-hua, WANG Hua-zhi, ZHA Ming-yong
  • Journal of Beijing University of Posts and Telecommunications. 2000, 23(2): 91-94.
  • Abstract ( 209 )     HTML     　　
  • The system model of adaptive array employed in CDMA system was established. First, this paper studied the geometrical structure of array and obtained the optimum range of ρ. Second, the circular and linear array composed of directional elements was studied. The results showed that the circular array composed of directional elements has no higher gain than that composed of omnidirectional elements; the linear array composed of directional elements has higher gain than that composed of omnidirectional elements within some angle range and so can be employed in sector cell.
  • References | Supplementary Material | Related Articles