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• • 1998, Vol. 21 No. 1 Published date:10 January 1998 Last issue Next issue

  Original articles

  • A New Object Oriented Software Architecture
  • Zhou Yingxin, Ai Bo
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 1-6.
  • Abstract ( 254 )     HTML     　　
  • Object orientation software architecture is not sliver bullet and has some disadvantages. The most significant is that if one objectwants to interact with another it must know the identity of that other object.Moreover, object orientation software architecture has some side affects. The well kown implicit invocation mechanism is introduced to object oriented softwarearchitecture in order to minimize the disadvantages. While in the heterogeneoussoftware architecture the principle of separation palys a major part in minimizing the disadvantages.
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  • On a Kind of Circulant Matrices with#br# Their Order being a Prime Power
  • Ou Zhiming,Han Shuqin
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 7-11.
  • Abstract ( 236 )     HTML     　　
  • In the research of Hadamard matrices, by using the method of factorization of prime ideals in algebraic number theory, we proved that circulant Hadamard matrices with order 4^r(r＞1) do not exist, and obtained the Hadamard matrices with order 4.For a circulant matrix H satisfying HH^{T=nI with order pr (p is a prime) andintegral elements, we completely determined the structure of H.Such matrices can be viewed as matrices over finite field F_pr, thus we obtained the construction of a sort of orthogonal codes over F_pr.}
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  • The Inverse Static Force Analysis of a Four-Bar#br# Mechanism with Compliant Input and Output Links
  • Han Lin, Liao Qizheng, Liang Chonggao
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 12-17.
  • Abstract ( 244 )     HTML     　　
  • A closed-form inverse solution for the general two-spring system is presented. Using Dixon resultant, the problem is reduced to a 20th degree polynomial equation in a single unknown. For a example, all the solutions and theactual structural forms are obtained.
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  • The Game Values of Authentication System
  • Wang Yongchuan, Yang Yixian
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 18-22.
  • Abstract ( 205 )     HTML     　　
  • The new information-theoretical lower bounds of game values of an authentication system that has multilevel costs on sources are obtained.The new bounds are superior to given by Masakazu Jimbo and Ryoh Fuji-Hara in 1990.
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  • A New Method for Software Fault Tolerance and Its Application
  • Liu Yunlong, Chen Junliang
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 23-28.
  • Abstract ( 181 )     HTML     　　
  • A new method for Software Fault Tolerance (SFT) is presented, which is based on the Data Flow Analysis (DFA).The normal SFT technology is introduced at first, and data errors are pointed out to be the ultimate reason and also the final result of the software faults in the control systems, soit is crucial to adopt a powerful measure for data fault tolerance.Then, the applications of the DFA technique in the SFT are discussed in details, and two important theorems are also given, one for the minimal sufficient rollback point andanother for the checkpoint data range.Besides, the sufficient condition for thevalidation of the definition of a Rollback Block is proposed.The usage of the presented method is illustrated with the telecommunication system as an example.The presented method can be used widely by extending it simply.
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  • Synchronization for Interactive Multimedia Presentation
  • Wei Tiejun, Chen Junliang
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 29-34.
  • Abstract ( 243 )     HTML     　　
  • The presentations of multimedia objects are considered and the synchronization requirements for a multimedia presentation with user participant are studied. A new multimedia synchronization model, called IMPSM, is proposed. IMPSMis a synchronization presentation model based on Petri-Nets. It can be used tohandle interactive presentation of multimedia objects, supports a wide range oftemporal synchronization specification, including determinate and indeterminatetemporal scenario.
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  • Designing Methods and Evaluation Criteria for MIB in TMN
  • Feng Bin, Meng Luoming
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 35-40.
  • Abstract ( 253 )     HTML     　　
  • Though the research for information modelling technique in TMN, a method for designing MIB is proposed, which is based on both management service and managedresources.
    Evaluation criteria from view of MOC definition, instance naming, consistancy, complexicity, layering and areaing support are proposed.
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  • The Performance Analysis of Constellation Shaping on the#br# Multicarrier Modulation Channel
  • Liu Danpu, Yue Guangxin
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 41-46.
  • Abstract ( 251 )     HTML     　　
  • On the basis of two constellation shaping forms on the multicarrier modulation channel, the relation between shaping gain and the bit and power allocation of the system has been analyzed. It has been proved theoretically that if continuous approximation exists, the performance of separate shaping on the subchannel and united shaping across the subchannel are the same; and then the conclusion that if continuous approximation doesn't hold, the gain of the latter can be slightly higher than the former's has been obtained by simulations results.
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  • An Algorithm for VC Routing Based Neural Networks#br# in ATM Networks
  • Sun Wensheng,Liu Zemin
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 47-52.
  • Abstract ( 232 )     HTML     　　
  • Some routing problems in ATM networks are discussed. Given a specific VP topology, VC routing algorithm based Hopfield neural networks is proposed, and the energy function and neuron state equation are set up. From the simulation results,it can be concluded that the proposed algorithm is both efficient and effectivein accordance with the traffic pattern and VCC requests in real-time VC routing.
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  • Designing of Wire-Spring Connectors
  • Xiang Wanpeng, Luo Guoping,Du Lihuan
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 53-57.
  • Abstract ( 268 )     HTML     　　
  • Based on mathematical analysis for wire-spring connector, gives out its constructive geometry parameters fixing, materials selecting, strength condition checking etc. Thus, the effect of some important parameters changing on connector performance can be seen clearly.Accordingly, design method and procedure are supplied for wire-spring connector, which may guide to exploit serialization products.
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  • Queuing Schemes of Optical ATM Switching Elements
  • Shen Yunfeng, Lü Kejie, Zhao Xiaodong, Gu Wanyi
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 58-62.
  • Abstract ( 205 )     HTML     　　
  • On the basis of the needs of optical ATM switching and the characteristics of optical buffer, three kinds of queuing schemes using optical fiber delay lines and their queuing algorithms are presented. The relations between the number of delay lines and cell loss rate and mean delay are givenby means of analysis and computer simulation, and these three kinds of queuingschemes are compared on the basis of the results.
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  • A New IN-CS2 Functional Model Supporting FPLMTS
  • Li Tonghong, Liao Jianxin, Chen Junliang
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 63-67.
  • Abstract ( 235 )     HTML     　　
  • CS2 functional model supporting FPLMTS in present ITU recommendation was first described. Considering the character of present and future network, we point outthe present model's disadvantage and propose an improved CS2 functional model, which separates terminal authentication and location register from SCF and introduces two new functional entities called LRF and TAF. In the end, the advantage and disadvantage of this new model was given.
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  • Object-Oriented Data Model of IN User Service Data
  • Lei Youxun, Meng Luoming, Chen Junliang
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 68-72.
  • Abstract ( 187 )     HTML     　　
  • A way to construct the object-oriented semantic data model of IN user service data according to the principles of TMN is presented. GDMO is taken as the specification tool to specify IN user service data . In the specification, the first-order predicate logic is used to specify the structure and the integrity constraints of user service data, and also new specifiers are introduced to specify theoperations on the attributes of user service data. The semantic data model of user service data is a preparation for the automatic implementation of user service managment in IN.
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  • Combination of Multibeam Antenna Array and#br# Optimum Multiuser Detector in Cellular CDMA Base Station
  • Wang Daqing, Zhang Huimin, Wu Weiling
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 73-77.
  • Abstract ( 229 )     HTML     　　
  • The multibeam antenna array and the optimum multiuser detector are combined to reduced the near-far effects in asynchronous direct sequence spread spectrum multiaccess receiver. Based on this construction, the whole users in the cell canbe divided into groups by the multibeam of the antenna array, and then the optimum multiuser detectors are applied to each group of users to obtain optimum reception. We compare this approach with the conventional detector and the optimum multiuser detector in bit error rate and computational complexity. Results show that when using the structure we proposed, the computational complexity can be substantially reduced, and the performance can be improved, therefore the new approach is more feasible to implement.
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  • The Client/Server Database Application System
  • Yan Xiuqun,Ye Yi
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 78-82.
  • Abstract ( 211 )     HTML     　　
  • A design and implementation of database applicationsystem in client/server structure is proposed. It supports LAN, WAN and mixed networks. According availability and queueing theory, we analysis the availability and property of system.It prove the feasibility of scheme, and give system config data in different application condition.The system is being used in many applications and received good result.
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  • Handover Technology in Micro-Cell Mobile Communication Systems
  • Ding Zhe, Chen Xixian, Wu Shanpei
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 83-87.
  • Abstract ( 256 )     HTML     　　
  • Some problems of handover in micro-cell mobile telecommunication systems are discussed based on CDCT access system, and some technical solutions are introducedto synchonize base stations and to meature the loop dalay antumatically.
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  • A Blind Signature Scheme Based on Lucas Sequences
  • Lin Xiaodong,Yang Yixian
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 88-91.
  • Abstract ( 277 )     HTML     　　
  • A blind signature scheme based on Lucas sequences is presented, and its securityis analysed and discussed. It is analyzed that it is a secure and efficient blind signature scheme, regarding the amount of running time, the interactive frequencies between signer and requester.Finally, it puts forward suggests about how to develop blind signature technology.
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  Review

  • Multimedia Synchronizing Technology
  • Liu Yong,Zeng Xiaoyun
  • Journal of Beijing University of Posts and Telecommunications. 1998, 21(1): 92-96.
  • Abstract ( 242 )     HTML     　　
  • Establishing synchronizing models of multimedia objects is expounded by using of levels and OCPN. It analyzes the time relation ofmultimedia presentation. Synchronizing methods based on reference time axial and reference points are provided to realize film broadcasting.
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