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China Communications 2008年第1期5卷 45-53页

作者： Hu Zhibing, Tang Shoulian Beijing university of posts and telecommunications, Beijing university of posts and telecommunications China

A new analytical model is proposed and constructedin this paper through studying the two-stage courseand the marginal replication cost of informationproducts. The economic nature of digital divide isuncovered and that is of the economic value and theallotment styles of information and knowledge. Basedon the proposed model and taken China, Americaand Russia as examples, the empirical analyses areflexibly made and policy explanations for bridgingthe divide are given.

关键词： digital divide ICT economic model policy exploration

Analysis on Implementation of Asymmetric Regulation in China telecommunications Sector

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China Communications 2008年第3期5卷 104-107页

作者： Luo Mingwei Beijing university of posts and telecommunications Beijing Univ posts & Telecommun Beijing Peoples R China

Reference to the international cases and experiences of asymmetric regulation in telecommunications industry,based on China's legal environment and telecommunications competition in the market,give analysis to the role of asymmetric regulation for the development of china telecommunications market,put forward feasible measures to asymmetric regulation in China.

关键词： telecom asymmetric regulation China

Periodicity Characteristic of TOAD's Switching Window

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Chinese Journal of Lasers 2000年第2期9卷 161-166页

作者： LIU Xianbing,YE Peida (Beijing university of posts and telecommunications, Beijing 100876, China ) 北京邮电大学北京

The periodidity characteristic of switching window of a terahertz optical asymmetric demultiplexer (TOAD) using numerical simulation was investigated. The results show that the switching window width of TOAD changes periodically with the time asymmetry of TOAD and the period is one half of the period of control pulses. The theoretical results agree with the experimental results very well.

关键词： terahertz optical asymmetric demultiplexer (TOAD) Sendconductor optical amplifier (SOA) optical time division multiplexing (OTDM)

telecommunications Market and Regulation in India and Ireland

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China Communications 2008年第2期5卷 83-87页

作者： Chen Xiuyu Beijing university of posts and telecommunications,China Beijing Univ posts & Telecommun Beijing Peoples R China

Information and communications technology is apillar industry in India and Ireland,playing an increasinglyimportant role in promoting the economicand social *** market competitionpromotes the rapid development of the *** market regulation andconstant legal system improvement can promote thesmooth development of the *** of new technology promotes a sustainabledevelopment of the *** is proposed that the pace of telecommunicationslegislation in China should be furtherquickened,telecommunications market structureoptimized,and telecommunications regulationstrengthened.

关键词： India Ireland telecommunications market regulation

Neighborhood-following algorithms for linear programming

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Science China Mathematics 2004年第6期47卷 812-820页

作者： Al WenbaoSchool of Science, Beijing university of posts and telecommunications, Beijing 100876, China 1. School of Science Beijing University of Posts and Telecommunications 100876 Beijing China

In this paper, we present neighborhood-following algorithms for linear programming. When the neighborhood is a wide neighborhood, our algorithms are wide neighborhood primal-dual interior point algorithms. If the neighborhood degenerates into the central path, our algorithms also degenerate into path-following algorithms. We prove that our algorithms maintain the O9√nL) -iteration complexity still, while the classical wide neighborhood primal-dual interior point algorithms have only the O(nL-iteration complexity. We also proved that the algorithms are quadratic convergence if the optimal vertex is nondegenerate. Finally, we show some computational results of our algorithms.

关键词： linear programming primal-dual interior point methods wide neighborhood methods quadratic convergence

CONDITIONS FOR UNIFORMLY NON-CONFOUNDING OF CAUSAL DISTRIBUTION EFFECTS OVER MULTIPLE COVARIATES

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Journal of Systems Science & Complexity 2010年第4期23卷 796-803页

作者： Xueli WANG School of Science,Beijing university of posts and telecommunications,Beijing 100876,China. School of Science Beijing University of Posts and Telecommunications

Causation is a distinct concept from association and more important than association inepidemiologic *** paper proposes the concept of uniform non-confounding for causal distributioneffects over multiple covariates,and gives the sufficient conditions for uniform non-confoundingover a covariate set C including confounders or non-confounders,and also shows the conditions forconditionally non-confounding in the *** these conditions can be tested by observeddata.

关键词： Causal distribution effect confounding covariates uniform non-confounding

Analyzing the Switching Characteristics of a NOLM Demultiplexer with on Analytic and Numrical Methods

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Chinese Journal of Lasers 1999年第5期8卷 419-424页

作者： LIU XianbinG YE Peida(telecommunications Engineering School, Beijing university of posts and telecommunications, Beijing 100876 China) 北京邮电大学电信工程学院北京

The switching characteristics of a NOLM demultiplexer are investigated by using an analytic and numerical method. The results reveal that the switching characteristics of a NOLM demultiplexer depend on parameters such as the power coupling ratio of the coupler,the peak power of control pulses, the walk-off and the initial time delay between signal pulses and control pulses, etc. The efficiency of NOLM is dependent on the peak power of controlpulses However, the switching window profile begins to oscillate as the power exceeds a critica value and this will be detrimental to the demultiplexed signals. The signal-control pulse walk-off can broaden the switching window of NOLM, make the window profile deviate fromits central position, and decrease its switching efficiency.

关键词： OTDM NOLM demultiplexer all-optical switch

Study on EDFA Gain Tilt and Nonlinear Distortion in an AM-VSB CATV Optical Fiber Transmission System

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Chinese Journal of Lasers 1999年第5期8卷 436-443页

作者： MAO Youju WANG Xueqiang(Chongqing university of posts and telecommunications, Chongqing 400065, China) 重庆邮电学院重庆 400065 重庆邮电学院重庆

The gain tilt of the erbium-doped fiber amplifier (EDFA) and the nonlinear distortion in an AM-VSB CATV optical fiber transmission system with a cascade of EDFAs are analyzed. It demonstrates that the nonlinear distortion induced by the light source and the EDFA would be counteracted each other to a certain degree as long as the EDFA has a negative gain tilt. As a result, an optimal EDFA negative gain tilt is suggested as a solution to selfcomensation of the nonlinear distortion.

关键词： gain tilt nonlinear distortion EDFA self-compensation

Generllzation of Direct Product and Generation of Sets of Orthogonal Functions

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数学研究与评论 1989年第3期 413-422页

作者： Wang Zhongde(Beijing university of posts & telecommunications)

Two new kinds of direct product of matrices are defined. Their properties are investigated. Direct products of matrix and set of continuous functions are also defined. Many complete sets of orthogonal functions, such as those sets given by Walsh [2], Paley [3], Chrestenson[4], and Watari [5], may be generated by these newkinds of direct product. Direct products are also applicable to the generation of sets of piecewise orthogonal functions.

关键词： piecewise symmetric matrices Walsh dimensions applicable diagonal permutation ordering difficulty