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NOVEL LARGE SIGNAL MATHEMATICAL MODEL OF MM-WAVE GUNN DEVICE

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NOVEL LARGE SIGNAL MATHEMATICAL MODEL OF MM-WAVE GUNN DEVICE

International Conference on Millimeter Wave and Far-Infrared Technology

作者： Chen,Ning Sun,Zhong-Liang Li,Si-Fan dept.of Radio Engineering Southeast University

＜正＞The nonlinear characteristic of Gunn device is analyzed on the basis of device physics.A novel Mathematical representation of the large signal dynamic characteristic of the Gunn device is presented.

关键词： Oscillators, Gunn

Light source effects on output spectrum of an inner-phase modulated optical fiber ring resonator

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Light source effects on output spectrum of an inner-phase mo...

2002 3rd International Conference on Microwave and Millimeter Wave Technology

作者： LUO Jiatong QIAN Jingren LIANG Ming SU Jue YANG Li dept.of EEIS Univ.of Science and Technology of China

ISBN: (纸本)078037486X

＜正＞Considering the linewidth of input laser,the characteristics of the output spectrum of an inner-phase modulated optic-fiber ring resonator are analyzed theoretically and experimentally.In time domain,it is well known that large modulation will induce dynamic response and it is more evident while the linewidth of input laser is narrower.However,in frequency domain,the output spectrums of an inner-phase modulated optic fiber ring resonator will have different kinds of shape when different modulation depth and different linewidth laser is introduced.

关键词： optical modulation optical resonators dynamic response frequency-domain analysis phase modulation optical fibres light source effects output spectrum inner-phase modulation optical fiber ring resonator linewidth dynamic response frequency domain modulation depth

Polarimetric whitening filter for POLSAR image based on subspace decomposition

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Journal of Systems Engineering and electronics 2008年第6期19卷 1121-1126页

作者： Yang Jian Deng Qiming Huangfu Yue Zhang Weijie dept. of electronics Engineering Tsinghua Univ. Beijing 100084 P. R. China

Speckle filtering is an indispensable pre-processing step for applications of polarimetric synthetic aperture radar （POLSAR）, such as terrain classification, target detection, etc. As one of the most typical methods, the polarimetric whitening filter （PWF） can be used to produce a minimum-speckle image by combining the complex elements of the scattering matrix, but polarimetric information is lost after the filtering process. A polarimetric filter based on subspaze decomposition which was proposed by Cu et al specializes in retrieving principle scattering characteristics, but the corresponding mean value of an image after filtering is not kept well. A new filter is proposed for improving the disadvantage based on subspace decomposition. Under the constraint that a weighted combination of the polarimetric SAR images equals to the output of the PWF, the Euclidean distance between an unfiltered parameter vector and a signal space vector is minimized so that noises can be reduced. It is also shown that the proposed method is equivalent to the subspace filter in the case of no constraint. Experimental results with the NASA/JPL airborne polarimetric SAR data demonstrate the effectiveness of the proposed method.

关键词： speckle filtering synthetic aperture radar polarimetric polarimetric whitening filter subspace decomposition

Particle filter based stochastic interference cancellation for frequency-selective MIMO channel equalization

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Journal of Systems Engineering and electronics 2007年第3期18卷 476-483页

作者： Yang Tao Hu Bo Guo Xinyue dept. of electronics Engineering Fudan Univ. Shanghai 200433 P. R. China

To mitigate the effects of the previous symbol decision errors of a decision-feedback （DF） equalizer on the current decision, a particle filter （PF） based DF equalizer for frequency selective multiple-input-multiple-output （MIMO） channel is proposed. On the basis of the analyses of DF equalization for the MIMO wireless system, it is found that a stochastic interference cancellation （IC） scheme can be employed to prevent the error propagation in a severe space-time interference scenario. This is because the random rather than the deterministic scheme can reduce the probability of an error decision even if an error decision occurs. Besides, the signal-to-interference-plus-noise ratio （SINR） based IC order, which is obtained via pilot, can guarantee the optimality of the cancellation. The bit error rate （BER） performance of the proposed scheme is verified through simulation experiments under different multipath interference environment.

关键词： multiple-input-multiple-output particle filter pilot decision-feedback interference cancellation.

Anion-induced N-doping of naphthalenediimide polymer semiconductor in organic thin-film transistors

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npj Flexible electronics 2018年第1期2卷 90-96页

作者： Yang Han Zhuping Fei Yen-Hung Lin Jaime Martin Floriana Tuna Thomas DAnthopoulos Martin Heeney dept.Chemistry and Centre for Plastic electronics Imperial College LondonExhibition RdLondon SW72AZUK dept.Physics and Centre for Plastic electronics Imperial College LondonExhibition RdLondon SW72AZUK dept.of Materials Imperial College LondonExhibition RdLondon SW72AZUK School of Chemistry and Photon Science Institute University of ManchesterOxford RdManchester M139PLUK Division of Physical Sciences and Engineering King Abdullah University of Science and TechnologyThuwal 23955-6900Saudi Arabia

Molecular doping is an important strategy to improve the charge transport properties of organic semiconductors in various electronic devices.Compared to p-type dopants,the development of n-type dopants is especially challenging due to poor dopant stability against atmospheric conditions.In this article,we report the n-doping of the milestone naphthalenediimide-based conjugated polymer P(NDI2OD-T2)in organic thin film transistor devices by soluble anion dopants.The addition of the dopants resulted in the formation of stable radical anions in thin films,as confirmed by EPR spectroscopy.By tuning the dopant concentration via simple solution mixing,the transistor parameters could be readily controlled.Hence the contact resistance between the electrodes and the semiconducting polymer could be significantly reduced,which resulted in the transistor behaviour approaching the desirable gate voltage-independent model.Reduced hysteresis was also observed,thanks to the trap filling by the dopant.Under optimal doping concentrations the channel on-current was increased several fold whilst the on/off ratio was simultaneously increased by around one order of magnitude.Hence doping with soluble organic salts appears to be a promising route to improve the charge transport properties of n-type organic semiconductors.

关键词： dopant tuning doping

Power flow tracing based method for allocation of transmission service cost to transactions

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Journal of Harbin Institute of Technology(New Series) 2004年第4期11卷 464-468页

作者：李卫东刘娆魏立明 dept. of Electrical and electronics Engineering Dalian University of Technology China

Based on the concepts of objective fact and subjective desire proposed in this paper, the problems that exist in the nodal injections-based and transaction-based transmission service allocation scheme are pointed out. To get around the problems above, a novel transmission service allocation scheme is proposed which considers the power flow distribution and the transaction impact on the system simultaneously so that the issues of “Cross-subsidies” and “Counter flow” can be avoided. The principle of the scheme is illustrated using two simple networks with 7 cases. The results show that the proposed scheme can satisfy the properties necessary for the development and growth of the electricity market.

关键词：传输开放存取传输服务成本配置电源流追踪

EXTRACTION OF NATURAL FREQUENCY FROM MEASURED LATE-TIME TRANSIENT RESPONSES WITH RATIONAL MINIMAX APPROXIMATION IN FREQUENCY DOMAIN

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EXTRACTION OF NATURAL FREQUENCY FROM MEASURED LATE-TIME TRAN...

1998 International Conference on Microwave and Millimeter Wave Technology

作者： Jiao Dan Xu Shanjia Wu Xianliang dept.of Electronic Eng.& Information Sci. Univ.of Science & Technology of China dept.of Electronic Eng.& Information Sci. Anhui University

ISBN: (纸本)0780343085

＜正＞A simple technique is presented for extracting natural frequencies from measured late-time transient responses.The method first applies rational mini-max approximation to the Fourier transform of the even extension of a transient response,then obtains natural frequencies directly from the zeros of the denominator polynomial of the optimum rational function. The effectiveness of the method is verified with a synthetic transient response and a measured response of a conducting sphere.The results from the present method for the synthetic tfansient response are compared with those from constrained E-pulse technique （CET） and genetic algorithm technique（GAT）.It indicates that the present method avoids an initial guess,overcomes the tendency to get stuck in local minima and requires much less computer effort than the CET.In addition,unlike the GAT,it generally guarantees convergence and is insensitive to any parameter.

关键词： transient response convergence of numerical methods minimax techniques poles and zeros radar theory Fourier transforms natural frequency extraction late-time transient responses rational minimax approximation frequency domain Fourier transform denominator polynomial optimum rational function conducting sphere convergence radar target identification

An Environmental Perception System to Autonomous OffRoad Navigation by using Multi-sensor Data Fusion

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An Environmental Perception System to Autonomous OffRoad Nav...

2005 International Conference on Neural Networks and Brain(ICNN&B’05)

作者： Zhiyu Xiang dept.of Information and Electronic Engineering Zhejiang University

ISBN: (纸本)0780394224;9780780394223

＜正＞Environmental perception is one of the most difficult problems on the research of off-road autonomous vehicles.This paper describes a multisensor data fusion based environmental’ perception system for off-road autonomous navigation.The system is composed of one camera,four laser range finders, one microwave radar,and several ultrasonic sensors.A hierarchical structure is used to organize the sensors from feature level to high fusion level.A 2D fusion map consisting six classifications is proposed to describe the surrounding environment.Dempster-Shafer evidence theory is adopted to decide the classification of each grid in the fusion map.A weighted evidence combination rule is proposed and implemented to improve the decision results under high conflicting circumstance.The experimental results show that the proposed system is reliable and is able to fulfill the requirements from off-road navigation.

关键词： Navigation Laser radar Remotely operated vehicles Mobile robots Cameras Laser fusion Laser theory Masers Sensor systems Microwave sensors

Nonlinear Multiwavelet Transform Based Soft Thresholding

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Nonlinear Multiwavelet Transform Based Soft Thresholding

Electronic Communication Systems--The 2000 IEEE Asia-Pacific Conference on Circuits and Systems

作者： Xin Wang dept.of electronics Shandong University

ISBN: (纸本)0780362535

＜正＞In this paper,as an extension of the wavelet transform,a nonlinear multiwavelet transform is introduced.The advantage of this approach is that the high frequency components of the filtered signal can be enhanced properly by adjusting a parameter that is used to control the nonlinear properties of the multiwavelet transform. Also,an optimal soft thresholding is developed.Example shows that based on the nonlinear multiwavelet transform, the optimal soft thresholding is better than the soft thresholding in smoothing noise.

关键词： wavelet transforms smoothing methods interference suppression nonlinear systems optimal systems nonlinear multiwavelet transform soft thresholding high frequency components optimal soft thresholding smoothing noise