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ANALYSIS OF PIEZOELECTRIC ENERGY HARVESTING DEVICE WITH ADJUSTABLE RESONANCE FREQUENCY

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Journal of electronics(china) 2012年第Z2期 310-318页

作者： Jiang Lei Li Yuejuan* Marvin Cheng* (School of Mechanical electronic & information engineering, china {4. of Mining & Technology, beijing 100083, china) *(department of Mechanical and Aerospace engineering, West Virginia {4., Morgantown, WV 26505, U.S.A)

This paper presents an analytic method that adjusts resonance frequency of a piezoelectric vibration energy harvester. A mathematical model that estimates resonance frequency of cantilever is also proposed. Through moving an attached mass and changing its weight on the cantilever beam, resonance frequency of adopted piezoelectric device can be adjusted to match the frequency of ambient vibration sources, which is critical in order to harvest maximum amount of energy. The theoretical results are validated by experiments that move different masses along experimental cantilever beams. The results demonstrate that resonance frequency can be adjusted by an attached mass located at different positions on the cantilever beam. Different combinations of operational conditions that harvest maximum amount of energy are also discussed in this paper.

关键词： Piezoelectric Energy harvesting Resonance frequency

Analysis of electrical characteristics of LPDA and HFSS simulation design

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Analysis of electrical characteristics of LPDA and HFSS simu...

2011 4.h IEEE International Symposium on Microwave,Antenna,Propagation and EMC Technologies for Wireless Communications

作者： Ju Wang Kang An Yan Liu department of electronic and information engineering Beihang {4. (BUAA) beijing 100191 china

The electrical characteristic of LPDA is analyzed first in this *** software HFSS is used to get the optimization design of LPDA,and the simulation results are agree with the experimental dates *** simulation method uses much less time and cost than traditional ***,this paper approves a feasible implementation for antenna design and optimization.

关键词： LPDA broadband HFSS optimization

Improved FOCUSS method for reconstruction of cluster structured sparse signals in radar imaging

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Science china(information Sciences) 2012年第8期55卷 1776-1788页

作者： HU ChenXi1,2,LIU YiMin1,LI Gang1&WANG XiQin1 1I ntelligent Sensing Laboratory,department of electronic engineering,Tsinghua university,{4. 100084.china 2X i'an electronic engineering Research Institute,Xi'an 710100,china 1. Intelligent Sensing Laboratory Department of Electronic Engineering Tsinghua University Beijing 100084 China2. Xi’an Electronic Engineering Research Institute Xi’an 710100 China

The high resolution imaging of distributed targets in millimeter-wave radar system is studied in this *** use Gaussian Mrakov random field(GMRF)to represent the clustering property of the *** novel method,called Clustering FOCUSS,incorporate an additional cluster constraint into the process of the focal underdetermined system solver(FOCUSS)*** results indicate that the novel algorithm has a higher imaging accuracy than the methods of Capon beamforming,the l1 norm algorithm and the FOCUSS algorithm.

关键词： antenna array high resolution imaging cluster sparsity GMRF Clustering FOCUSS

Fault Diagnosis System Based on Self-Adaption Test for Combined Logic Circuits

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Fault Diagnosis System Based on Self-Adaption Test for Combi...

2011 International Conference on management Science and Intelligent Control(ICMSIC 2011)

作者： GAO Zehan Textile and Apparel college Guangzhou university Guangzhou china WANG Haobo department of {4. engineering Tsinghua university beijing china HUANG Lan School of information and Electrical engineering Guangzhou university Guangzhou china

In this paper, we propose a circuit diagnosis system that tests the sample circuit to get responses and produces test vectors according to the responses and the corresponding excitation signals, then determines the state of the circuit. The following components are included in the system: test vector （excitation signal） production component, eigenvector analysis （response analysis） component, self-adaptation test set （test sequence） production component. Test vector set production is the critical part in this system. When test set is produced, test the circuit with the set, the state of the circuit, from which the fault part in the circuit can be inferred, will be indicated by the circuit’s responses.

关键词： self-adaption combined logic circuits fault diagnosis test sequence excitation and response diagnosis tree

Spatial pattern of land cover change in china's semiarid environment

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Journal of Arid Land 2009年第1期1卷 16-25页

作者： BaoLin LI1 and QiMing ZHOU2 1 State Key Laboratory of Environment and Resources information System, Institute of Geographical Sciences and Resources Research, Chinese Academy of Sciences, beijing 100101, china 2 department of Geography, Hong Kong Baptist {4., Kowloon Tong, Hong Kong, china Hong Kong Baptist Univ Dept Geog Kowloon Tong Hong Kong Peoples R China Chinese Acad Sci State Key Lab Environm & Resources Informat Syst Inst Geog Sci & Resources Res Beijing 100101 Peoples R China

This study seeks a routine to quantify spatial pattern of land cover changes in semiarid environment of china based on post-classification comparison method. The method consists of three major steps: (1) the image classification and unification of classified results based on two-level land cover classification themes, (2) the establishment of land cover change classes based on an unification land cover classification theme, (3) the reclassification and mapping of land cover change classes with three overall classes including no-change, gain and loss based on the unification land cover class. This method was applied to detect the spatial pattern of land cover changes in Yinchuan Plain, one of famous irrigation agricultural zones of the Yellow River, china. The results showed the land cover had undergone a remarkable change from 1991 to 2002 in the study area (the changed area was over 30%). Rapid increase of cropland (12.5%), built-up area (131.4.) and rapid decrease of bare ground (51.7%) were alarming. The spatial pattern of land cover changes showed clear regional difference in the study area and was clearly related to human activities or natural factors. Thus, it obtained a better understanding of the human impact on the fragile ecosystem of china’s semiarid environment.

关键词： change detection spatial pattern land cover semiarid zone of china remote sensing human activities

Predistortion of high speed optical OFDM signal for aliasing-free receiving in multiple low-bandwidth receiver system

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Chinese Optics Letters 2010年第4期8卷 377-380页

作者：程林闻和郑小平张汉一郭奕理 State Key Laboratory on Integrated Optoelectronics/Tsinghua National Laboratory for information Science and Technology Department of Electronic EngineeringTsinghua University

A cost-effective method of multi-receiver optical orthogonal frequency-division multiplexing（OOFDM） system is proposed to reduce the requirement for the speed of the receiver and the size of fast Fourier transform（FFT）.The sampling rate of analog-to-digital converters（ADCs） can be reduced to 1/N of the original signal bandwidth in an N-receiver *** by signal predistortion at the transmitter, aliasing-free signal can be retrieved independently and directly at the low speed receivers.A back-to-back experimental result is given for a two-receiver *** effect of the electrical filters added before the ADC is studied and the analysis for filters optimization is given.

关键词： Cost reduction Fast Fourier transforms Orthogonal frequency division multiplexing

Electron-phonon coupling in cuprate and iron-based superconductors revealed by Raman scattering

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Chinese Physics B 2013年第8期22卷 51-62页

作者：张安民张清明 department of Physics Renmin University of China

Electron-phonon coupling （EPC） in cuprate and iron-based superconducting systems, as revealed by Raman scat- tering, is briefly reviewed. We introduce how to extract the coupling information through phonon lineshape. Then we discuss the strength of EPC in different high-temperature superconductor （HTSC） systems and possible factors affecting the strength. A comparative study between Raman phonon theories and experiments allows us to gain insight into some crucial electronic properties, especially superconductivity. Finally, we summarize and compare EPC in the two existing HTSC systems, and discuss what role it may play in the HTSC.

关键词： electron-phonon coupling cuprate and iron-based superconducting systems Raman scattering,high-temperature superconductor

The Application of Fuzzy-Neural Network on Control Strategy of Hybrid Vehicles

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The Application of Fuzzy-Neural Network on Control Strategy ...

第二十七届中国控制会议

作者： Chen Rongguang 1,Li Chunsheng 2,Meng Xia 3,Yu Yongguang 3,4.1.department of electronic information engineering,Beihang {4.,beijing 100083,P.R.china 2.department of electronic information engineering,Beihang {4.,beijing 100083,P.R.china 3.department of Mathematics,beijing Jiaotong {4.,beijing 10004.,P.R.china 4.department of MEEM,City {4. of Hong Kong,Kowloon,Hong Kong SAR,P.R.china

In order to increase the fuel economy and decrease the emissions of hybrid vehicles,firstly a fuzzy logic control system is presented in this *** parallel hybrid vehicles,the whole required torque comes from internal combustion engine and motor engine *** on the desired torque for driving and state of charge,the fuzzy logic control system determines how the power splits between the dual sources,which is the key point for hybrid ***,Adaptive Neural-Fuzzy Inference System（ANFIS） method is applied to optimize fuzzy logic control system based on the data of driving cycle. The main contribution of this paper is well application of fuzzy-neural network to improve original control system,which minimized the fuel consumption and *** simulation results show very good performance of the proposed method.

关键词： Fuzzy logic controller Control strategy Hybrid electric vehicles

Research on Embedded Digital Image Recognition System Based on ARM-DSP

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Research on Embedded Digital Image Recognition System Based ...

2009 2nd IEEE International Conference on Computer Science and information Technology（ICCSIT 2009）

作者： ZHOU JIANJUN ZHOU JIANHONG department of Microelectronics Technology Chengdu college university of electronic Science and Technology of china department of electronics information engineering Jincheng college Sichuan university Chengdu china

Embedded image acquisition,processing and transmission systems have advantages of small volume and high stability,etc,and therefore they are widely used in intelligent transportation,electric power,communication and computer vision,*** with the development of DSP technology,realizing real-time video compression on DSP by software has become a highlight of digital video compression standard application and this kind of application has greater flexibility and upgrading potential than special compression *** continuous development of modern industrial technology has put forward higher requirements for the acquisition,processing and transmission of image *** recent years,high-speed digital signal processing DSP technology develops rapidly and the strong signal processing ability of DSP has provided solid theoretical and application foundation for the real-time processing of image ***,this paper discusses the hardware structure of image tracking system taking ARM-DSP as main frame and the development process and control flow of ***,it looks forward to the development prospect of image *** paper studies basic theories of digital image processing.

关键词： DSP ARM embedded image processing digital recognition