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On an Eigenvalue Problem Related to the Buckling of Sandwich Beams

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Applied Mathematics and Mechanics(English Edition) 1980年第1期1卷 55-62页

作者： Hu, Hai-chang( institute of spacecraft system engineering, chinese academy of space technology, Peking, china ) institute of spacecraft system engineering Chinese Academy of Space Technology Peking China

This paper gives various properties of eigenvalue problems related to the buckling of *** applications of eigenfunctions are also indicated.

关键词： On an Eigenvalue Problem Related to the Buckling of Sandwich Beams

A NEW METHOD FOR COMPUTING RADIATED FIELD OF REFLECTOR ANTENNAS——THE CHEBYSHEV-BESSEL SERIES TECHNIQUE

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Journal of Electronics(china) 1988年第3期5卷 197-205页

作者：易力 institute of spacecraft system engineering The chinese academy of space technology beijing

A rapidly convergent series—the Chebyshev-Bessel series for representation of thephysical optics(PO)radiation integral is developed,which is applicable to evaluating radiated field of reflectorantennas.

关键词： Reflector antennas The Chebyshev-Bessel series FFT algorithm

Fractional Fourier domain equalization for single carrier broadband wireless systems

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Science china(Information Sciences) 2012年第10期55卷 2257-2268页

作者： HUANG KeWu 1,2,TAO Ran 1 & WANG Yue 1 1 Department of Electronic engineering,beijing institute of technology,beijing 100081,china 2 institute of Manned space system engineering,china academy of space technology,beijing 100094,china Department of Electronic engineering Beijing Institute of Technology Beijing China institute of Manned space system engineering China Academy of Space Technology Beijing China

In this paper,a novel single carrier equalization approach in the fractional Fourier domain(FRFD) is *** can remove all the inter-symbol interference(ISI) and avoid the considerable noise enhancement of the frequency domain-zero forcing(FD-ZF) *** the fractional Fourier transform makes a chirp spread,the impulse response of the deep fading channel may be flattened in some orders of the FRFD while it would be greatly attenuated in the *** searching for an optimal order under certain criterion,we take advantages of the ZF algorithm to mitigate the effects of the ISI *** approach can overcome the contradiction between the ISI mitigation and the noise enhancement of the FD-ZF *** analysis and simulation results show that the proposed FRFD-ZF equalizer can achieve a significant performance and have the same computation cost O(N log N) as the conventional FD linear equalizer,especially in the frequencyselective deep-fading channels.

关键词： fractional Fourier transform single carrier systems zero-forcing equalizer frequency domain linear equalizer

THE MOMENT METHOD ON RESONANT QUADRIFILAR HELICAL ANTENNAS

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Journal of Electronics(china) 1990年第1期7卷 30-36页

作者：易力 institute of spacecraft system engineering The Chinese Academy of Space TechnologyBeijing

An efficient measure is taken to rearrange Nakano’s kernels of integral equationsfor an antenna system composed of arbitrarily bent *** means of the moment method,great efforts are made to analyze and compute the circularly polarized patterns,directivity,axialratio,front-to-back ratio and beam-shaping characteristics of resonant quadrifilar helical antennasas well as the feeding technique and the effect of an electrically large conducting body on theperformance of the antennas.

关键词： Helical antennas Kernels of integral equations Moment method

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A FURTHER RESEARCH ON THE JACOBI-BESSEL SERIES METHOD IN ANALYSIS OF REFLECTOR ANTENNA

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Journal of Electronics(china) 1987年第1期4卷 11-19页

作者：易力 institute of spacecraft system engineering The chinese academy of space technology

Based on the work developed by R. Mittra and others （1979）, this paper carries on the Jacobi-Besselseries method to compute far-field patterns of a paraboloid reftector antenna with elliptical aperture bymeana of recursion of the series coefficients pBmn about indices p and m respectively and enhances thecomputational efficiency to a great extent.

关键词： A FURTHER RESEARCH ON THE JACOBI-BESSEL SERIES METHOD IN ANALYSIS OF REFLECTOR ANTENNA

THREE-DIMENSIONAL MULTI-BEAM ADAPTIVE ARRAYS

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Journal of Electronics(china) 1984年第2期1卷 65-74页

作者：刘振威 institute of spacecraft system engineering The chinese academy of space technology

The multi-beam antenna systems have become increasingly important in modern *** this papcr,the author proposes according to the properties of array radiation space the use ofthe LMS’ adaptive techniques in multi-beam antenna *** proposal includes the radiationpattern of three-dimensional adaptive arrays,the evolution of the radiation pattern of adaptive arrays,the signal-to-interference plus noise ratio of the array system output,and the structure of the adaptivemulti-beam *** will be discussed in the order mentioned.

关键词： THREE-DIMENSIONAL MULTI-BEAM ADAPTIVE ARRAYS SINR LMS

Transformations and non-degenerate maps

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Science china Mathematics 2005年第z1期48卷 195-205页

作者： LI Baokui & WANG Yuefei institute of Mathematics, academy of Mathematics and system Sciences, chinese academy of Sciences, beijing 100080, china Graduate School, chinese academy of Sciences, beijing 100080, china institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China Graduate School Chinese Academy of Sciences Beijing China

We shall prove the equivalences of a non-degenerate circle-preserving map and a M(o)bius transformation in ^Rn, of a non-degenerate geodesic-preserving map and an isometry in Hn of a non-degenerate line-preserving map and an affine transformation in Rn. That a map is non-degenerate means that the image of the whole space under the map is not a circle, or geodesic or line respectively. These results hold without either injective or surjective, or even continuous assumptions, which are new and of a fundamental nature in geometry.

关键词： M(o)bius transformation, circle-preserving map, non-degenerate map.

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ANTENNA ARRAY PATTERN NULL STEERING——A THEORETICAL INTRODUCTION

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电子科学学刊(英文版) 1984年第4期1卷 217-224页

作者：刘振威 institute of spacecraft system engineering The chinese academy of space technology

The antenna array pattern null steering is one of the important current topics in the array synthesistheory,due to it’s very effectiveness to suppress the interfering *** in this paper the problemof forming nulls in the radiational pattern of three-dimensional arrays is *** paper deals with the following aspects:The essential relations forming multi-nulls in thearrays are analysed by the method of vector space.A method forming multi-null regions is presentedin terms of the extensive property of null *** resolvent formulation of the radiational patternof multi-null steering is *** numerical results are given and *** resolvent for-mulation is analogous to the one of the adaptive arrays.

关键词： steering formulation analogous analysed suppress itself antenna interfering constraint maximization

Research on applying physical chaos generator to spacecraft information security

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Science china(Technological Sciences) 2009年第5期52卷 1463-1470页

作者： ZHAO HePing State Key Laboratory of Information Security,Graduate University of chinese academy of Sciences,beijing 100049,china china academy of space technology,beijing 100094,china State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences china academy of space technology

The effectiveness of a short-length message extension method based on physical chaos generator was analyzed and the entropy of the extended message was calculated in this *** analysis demon-strated that with the mentioned method the entropy of short-length messages,which are repeatedly used in spacecraft data systems,is obviously increased,and the security of transmission is enhanced as *** paper also presented an improvement of the protocol for secret key agreement presented by *** and *** of depending on characteristics of communication channel,this method takes advantage of the random data produced by physical chaos generator to preset the initial parameters of the procedure on both sides of communication,so that the procedure and quantity of cipher key can be precisely *** method can be used to cipher key management of se-cure communication between long life-span spacecraft and ground system.

关键词： physical chaos generator spacecraft information security message extension cipher key management

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