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Existence and uniqueness of periodic solutions for forced Liénard-type equations

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Applied Mathematics(A Journal of Chinese Universities) 2008年第3期23卷 295-302页

作者： LIU Bing-wen College of Math. and inform. eng. Jiaxing Univ. Jiaxing 314001 China

By using topological degree theory and some analysis skill, some sufficient conditions for the existence and uniqueness of periodic solutions for a class of forced Lienard-type equations are obtained.

关键词： periodic solution Lienard equation topological degree

A note about the cyclotomic polynomial Φ_(pq)(x) and some related results

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Applied Mathematics(A Journal of Chinese Universities) 2008年第2期23卷 245-250页

作者： ZHU Feng-xiang QI Wen-feng Dept. of Appl. Math. Zhengzhou Inform. Eng. Univ. Zhengzhou 450002 China

. The expression of cyclotomic polynomial Фpq （x） is concerned for a long time. A simple and explicit expression of Фpq （x） in Z[x] has been showed. The form of the factors of Фpq （x） over F2 and the upper, l... 详细信息

关键词： cyclotomic polynomial Фpq(x) coefficient factor.

ON THE PERFECT BINARY ARRAYS

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Journal of Electronics(China) 1990年第2期7卷 175-181页

作者：杨义先 Dept.of inform.eng.Beijing Univ.of Posts & Telecom. Beijing

The close relationship between the perfect binary arrays(PBA)and the higherdimensional Hadamard matrices is initially *** very interesting results about theFourier transform spectrum of PBA are shown and a few open pr... 详细信息

关键词： Perfect binary arrays Fourier transforms Coding Hadamard matrices

PROBABILITY MODEL OF GUNTHER GENERATOR

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Applied Mathematics(A Journal of Chinese Universities) 2007年第4期22卷 460-468页

作者： Huang Xiaoying Zheng Wei Li Xinran Li Shiqu Dept. of Math. and Phys. Institute of Science Inform. Eng. Univ. Zhengzhou 450001 China. Dept. of information Research Institute of Information Engineering Inform. Eng. Univ. Zhengzhou450002 China.

This paper constructs the probability model of Gunther generator at first, and the finite dimension union distribution of the output sequence is presented. The result shows that the output sequence is an independent and uniformly distributed 0,1 random variable sequence. It gives the theoretical foundation about why Gunther generator can avoid the statistic weakness of the output sequence of stop-and-go generator, and analyzes the coincidence between output sequence and input sequences of Gunther generator. The conclusions of this paper would offer theoretical references for designers and analyzers of clock-controlled generators.

关键词： stream cipher,clock-controlled generator,stop-and-go generator Gunther generator correlation attack coincidence.

INJECTIVE MAPS ON PRIMITIVE SEQUENCES OVER Z/(p^e)

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Applied Mathematics(A Journal of Chinese Universities) 2007年第4期22卷 469-477页

作者： Sun Zhonghua Qi Wenfeng Dept. of Appl. Math. Inform. Eng. Univ. Zhengzhou 450002 China.

Let Z/（p^e） be the integer residue ring modulo p^e with p an odd prime and integer e ≥ 3. For a sequence a over Z/（p^e）, there is a unique p-adic decomposition a- = a-0 ＋a-1 .p ＋… ＋ a-e-l .p^e-1 where each a-i can be regarded as a sequence over Z/（p）, 0 ≤ i ≤ e - 1. Let f（x） be a primitive polynomial over Z/（p^e） and G＇（f（x）,p^e） the set of all primitive sequences generated by f（x） over Z/（p^e）. For μ（x） ∈ Z/（p）[x] with deg（μ（x）） ≥ 2 and gad（1 ＋ deg（μ（x））,p- 1） = 1, setφe-1 （x0, x1,… , xe-1） = xe-1. [μ（xe-2）＋ ηe-3（x0, X1,…, xe-3）] ＋ ηe-2（x0, X1,…, xe-2） which is a function of e variables over Z/（p）. Then the compressing mapφe-1 ： G＇（f（x）,p^e） → （Z/（p））^∞ ,a-→φe-1（a-0,a-1, … ,a-e-1） is injective. That is, for a-,b-∈ G＇（f（x）,p^e）, a- = b- if and only if φe-1 （a-0,a-1, … ,a-e-1） = φe-1（b-0, b-1,… ,b-e-1）. As for the case of e = 2, similar result is also given. Furthermore, if functions φe-1 and ψe-1 over Z/（p） are both of the above form and satisfy φe-1（a-0,a-1,…,a-e-1）=ψe-1（b-0, b-1,… ,b-e-1） for a-,b-∈G＇（f（x）,p^e）, the relations between a- and b-, φe-1 and ψe-1 are discussed

关键词： integer residue ring linear recurring sequence primitive sequence injective map.

Application of CPML to truncate the open boundaries of cylindrical waveguides in 2.5-dimensional problems

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Science in China(Series F) 2005年第5期48卷 656-669页

作者： WANG Yue WANG Jianguo ZHANG Dianhui Northwest Institute of Nuclear Technology Xran 710024 China School of Electronic and inform. eng. Xi'an Jiaotong University Xi'an 710049 China

In order to solve the problem of truncating the open boundaries of cylindrical waveguides used in the simulation of high power microwave （HPM） sources, this paper studies the convolutional PML （CPML） in the cylindrical coordinate system. The electromagnetic field＇s FDTD equations and the expressions of axis boundary conditions are presented. Numerical experiments are conducted to validate the equations and axis boundary conditions. The performance of CPML is simulated when it is used to truncate the cylindrical waveguides excited by the sources with different frequencies and modes in the 2.5-dimensional problems. Numerical results show that the maximum relative errors are all less than -90 dB. The CPML method is introduced in the 2.5-dimensional electromagnetic PIC software, and the relativistic backward wave oscillator is simulated by using this method. The results show that the property of CPML is much better than that of the Mur-type absorbing boundary condition when they are used to truncate the open boundaries of waveguides. The CPML is especially suitable for truncating the open boundaries of the dispersive waveguide devices in the simulation of HPM sources.

关键词： convolutional perfectly matched layer FDTD 2-5-dimensional problem waveguide backwardwave oscillator truncation particle simulation.

USING ERROR-CORRECTING ENCODERS TO DESIGN LOCAL-RANDOM SEQUENCE GENERATORS

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Journal of Electronics(China) 1995年第1期12卷 9-14页

作者：杨义先 Dept. of inform. eng. Beijing Univ. of Posts and Telecomm. Beijing 100088

This paper proved the statement that a good linear block encoder is in fact a good local-random sequence generator. Furthermore, this statement discovers the deep relationship between the error-correcting coding theor... 详细信息

关键词： Error-correcting coding Cryptography Random sequences

Design of 622 Mb/s Clock-recovery Monolithic IC for Optical Communication System

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Semiconductor Photonics and Technology 1998年第3期4卷 159-165,173页

作者： ZHANGYaqi ZHAOJie 等 CollegeofElectrom.inform.eng. TianjinUniversityTianjin300072CHN CollegeofElectrom.inform.eng. Tianj

A monolithic clock-recovery circuit used in 622 Mb/s optical communication system is designed,which is based on the phase-locked loop theory,and uses bipolar transistor *** overcomes the shortcoming of clock recovery method based on filter,and implements monolithic clock-recovery *** designed circuits include phase detector,voltage-controlled oscillator and loop *** them,the voltage-control oscillator is a modified two-stage ring oscillator,which provides quadrature clock signals and presents wide voltage-controlled range and high voltage-controlling sensitivity.

关键词： Clock-recovery Phase Detector Phase-locked Loop Voltage-controlled Oscillator

Vulnerability of ordinary moment resistant concrete frames

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Earthquake engineering and engineering Vibration 2011年第4期10卷 519-533页

作者： Mohammad Barkhordary Saeed Tariverdilo Department of Civil eng. Faculty of Eng.Urmia University

The effects of structural modeling （bar slip in lap splice）, ground motion selection process （epsilon effect） and size of a structure （number of bays and stories） on the fragility of reinforced concrete ordinary moment resisting frames are investigated. An analytical model is developed to account for bar slip in lap splice, which exhibits good correlation with existing experimental data. Then, incremental dynamic analysis is used to derive the fragility curves for four model structures. The model structures simulate frames with a different number of bays and stories. Finally, the fragility curves are corrected for the epsilon effect. The results show that slip in the lap splice can significantly increase the failure probability, especially for the collapse prevention limit state. At the same time, it is found that spectral shape has a significant impact on the fragility curves. It is also found that accounting for or ignoring bar slip or epsilon effects increases the probability of failure for larger structures. This indicates an unconservative bias in the safety of larger structures.

关键词： lap-splice slip incremental dynamic analysis fragility curve epsilon effect