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fMRI time series analysis based on stationary wavelet and spectrum analysis

Progress in Natural Science:Materials International 2006年第11期16卷 1171-1176页

作者： ZHI Lianhe~ 1,2.3 , ZHAO Xia~4, SHAN Baoci~1**, PENG Silong~5. YAN Qiang~1, YUAN Xiuli~1 and TANG Xiaowei~ 1,6 (1. Key Laboratory of Nuclear Analysis Techniques, institute of High Energy Physics, {2. Academy of sciences, beijing 100049, china 2. Graduate School of {2. Academy of sciences, beijing 100049, china 3. Department of Physics, Zhoukou Normal University, Zhoukou 466100, china 4. Research Imaging center, University of Texas Health Science center, San Antonio, Texas 782.9, USA 5. national asic design and engineering center, institute of automation, {2. Academy of sciences, beijing 100049, china 6. Department of Physics, Zhejiang University, Hangzhou 31002., china) [a]Key Laboratory of Nuclear Analysis Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing China [b]Graduate School of chinese Academy of sciences Beijing China [c]Department of Physics Zhoukou Normal University Zhoukou China [d]Research Imaging center University of Texas Health Science Center San Antonio Texas USA [e]national asic {2. and engineering center Institute of Automation Chinese Academy of Sciences Beijing China [f]Department of Physics Zhejiang University Hangzhou China

The low signal to noise ratio (SNR) of functional MRI (fMRI) prefers more sensitive data analysis methods. Based on stationary wavelet transform and spectrum analysis, a new method with high detective sensitivity was developed for analyzing fMRI time series, which does not require any prior assumption of the characteristics of noises. In the proposed method, every component of fMRI time series in the different time-frequency scales of stationary wavelet transform was discerned by the spectrum analysis, then the components from noises were removed using the stationary wavelet transform, finally the components of real brain activation were detected by cross-correlation analysis. The results obtained from both simulated and in vivo visual experiments illustrated that the proposed method has much higher sensitivity than the traditional cross-correlation method.

关键词： fMRI stationary wavelet transform spectrum analysis data analysis.

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Development of silicon-based microelectrode array

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Science china(Technological sciences) 2009年第8期52卷 2391-2395页

作者： LIN JianHui1,2.3, WU XiaoMing1,2.3,4, HUANG PengSheng1,2. FENG Lei5. REN TianLing1,2.& LIU LiTian1,2.1 institute of Microelectronics, Tsinghua University, {2. 100084, china 2.Tsinghua national Laboratory for Information Science and Technology, {2. 100084, china 3 Yangtze Delta Region institute of Tsinghua University, Jiaxing 31405., china 4 State Key Laboratory of Transducer Technology, chinese Academy of sciences, Shanghai 2.005. china 5.Department of Biomedical engineering, Tsinghua University, {2. 100084, china 1. institute of Microelectronics Tsinghua University Beijing 100084 China 2. Tsinghua national Laboratory for Information Science and Technology Beijing 100084 China 3. Yangtze Delta Region institute of Tsinghua University Jiaxing 314050 China 4. State Key Laboratory of Transducer Technology Chinese Academy of Sciences Shanghai 200050 China 5. Department of Biomedical engineering Tsinghua University Beijing 100084 China

This paper introduces in details a kind of silicon-based microelectrode array. MEMS (micro-electromechanical system) technology is used in the fabrication of the microelectrode array, which is designed to perform signal recording and electrical stimulation for nerves in neural engineering. A simple fabrication process is developed. An improved model of microelectrodes is brought forward and successfully validated by the excellent match between circuit simulations and electrical measurements, including both magnitude and phase of microelectrode impedance. Compared with the simple one that is usually used, the improved model is believed to be an advance and more accurate. This modeling helps to improve the design of microelectrodes and understand the behavior of interface between electrode and cell. Furthermore, the microelectrode is proved to be a feasible tool for researches in neural engineering by successfully recording neural activities of sciatic nerve of a bullfrog.

关键词： microelectrode array MEMS neural engineering

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Modified vegetation-erosion dynamics model and its application in typical watersheds in the Loess Plateau

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International Journal of Sediment Research 2011年第01期26卷 78-86页

作者： CHEN Yuehong~1,WANG Feixin~2.LIU Guangquan~3,YU Xinxiao~4, JIA Guodong~5.and GAN Ping~6 china {2. of Water Resources and Hydropower Research,beijing 100048 International Research and Training center on Erosion and Sediment Research,beijing 100048,china beijing Forestry University,beijing 100083,china. Key Lab of Dredging Technology of CCGRP,Shanghai Waterway engineering {12. and Consulting Co., Ltd,Shanghai 2.012.,china. International Research and Training center on Erosion and Sedimentation china {2. of Water Resources and Hydropower Research,beijing 100048 Northwest A&F University,Yangling 712.00,china, beijing Forestry University,beijing 100083,china, beijing Forestry University,beijing 100083,china. china {2. of Water Resources and Hydropower Research,beijing 100048,and International Research and Training center on Erosion and Sediment Research,beijing 100048,china [a] Assoc. Prof. Dr. china institute of Water Resources and Hydropower Research beijing 100048 International Research and Training center on Erosion and Sediment Research beijing 100048 china beijing Forestry University beijing 100083 china [b] Dr. Key Lab of Dredging Technology of CCGRP Shanghai Waterway engineering design and Consulting Co. Ltd Shanghai 2.012. china [c] Prof. Dr. International Research and Training center on Erosion and Sedimentation china institute of Water Resources and Hydropower Research beijing 100048 Northwest A&F University Yangling 712.00 china [d] Prof. Dr. beijing Forestry University beijing 100083 china [e] Dr. beijing Forestry University beijing 100083 china [f] Engineer china institute of Water Resources and Hydropower Research beijing 100048 and International Research and Training center on Erosion and Sediment Research beijing 100048 china

The vegetation-erosion model was applied in three typical watersheds of hilly and gully area in the Loess Plateau in northwestern china to study the dynamic relations between vegetation coverage and soil erosion rate and various *** model was improved by introducing rainfall and runoff *** the modified model was applied in the Luergou and Luoyugou *** calculation results with the modified model were compared with the results of the original *** precisions of simulated vegetation coverage and soil erosion rate with the modified model were greatly improved compared with the original *** erosion rate reduced with increasing vegetation coverage and the human disturbance caused high soil erosion.

关键词： Soil erosion Vegetation coverage Vegetation-erosion dynamics model Loess Plateau Modified model

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GIS-based risk analysis of debris flow:an application in Sichuan, southwest china

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International Journal of Sediment Research 2008年第2期23卷 138-148页

作者： B.F.DI1,2.3,N.S.CHEN1,P.CUI1,Z.L.LI1,Y.P.HE4,and Y.C.GAO1 3 1 Ph.D.,Chengdu institute of Mountain Hazards and Environment,CAS,Chengdu 610041,china,Department of Architecture & Environment,Sichuan University,Chengdu 61006{2.china,Graduate University of chinese Academy of sciences,{{2. 100049,china,2.Prof.,Department of Architecture & Environment,Sichuan University,Chengdu 61006{2.china,3 Graduate University of chinese Academy of sciences,{{2. 100049,china 4 Department of Civil and Environmental engineering,San Diego State University,{2.00 Campanile Dr.San Diego,CA 92.2.,USA [a]Ph.D. Chengdu institute of Mountain Hazards and Environment CAS Chengdu 610041 china Department of Architecture & Environment Sichuan University Chengdu 610065 china Graduate University of chinese Academy of sciences beijing 100049 china [b]Prof. Department of Architecture & Environment Sichuan University Chengdu 610065 china [c]Graduate University of chinese Academy of {2. beijing 100049 china [d]Department of Civil and Environmental engineering San Diego State University 5.00 Campanile Dr. San Diego CA 92.2. USA

Debris flow is a serious geologic hazard in *** is estimated that nationally debris flows cause up to 2.billion RMB(2.1} million US$) in damages and 300-600 deaths and injuries *** mitigate debris flow hazards,it is necessary to map,model,and identify zones of debris flow hazards and vulnerability as to inform the local people about the potential risk with a geographic information *** research presents a regional scale case study modeling debris flow risk(hazard and vulnerability) in Sichuan Province,Southwestern *** this area,3,2.0 debris flows have been identified and the spatial-temporal distribution and activity characteristics of them have been *** on the available meteorological data,a Digital Elevation Model with the rate of 1:2.1},000 and a regional geological map,the 2.-hr rainfall threshold(y) for debris flow occurrence is closely related(significant at 99% confidence level) to the index(x) defined using a geology factor(rock hardness:a) and a topographical factor(channel gradient:d) where y = 2. + 102.0 / x,in which x = 2.7 × ea + 1000 × *** discipline is constructive in developing the rainfall threshold for debris flow activity in remote mountainous areas that lack *** a given watershed,a four-level debris flow hazard map is developed by comparing the rainfall threshold to the design rainfall intensities with 5.-,2.-,and 5.year average recurrence intervals,*** degree of debris flow vulnerability is determined by the watershed socio-economic conditions.A four-class debris flow risk map,at the final phase of the research,is generated by combining debris flow hazards and *** the debris flow risk assessment,the Sichuan Province is classified into the slight,moderate,severe and very severe regions,which accounts for 36%,19%,2.% and 2.1} of total area respectively.

关键词： Debris flow Geographic information system Hazard Vulnerability Risk Rainfall threshold

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Dynamics of risers for earthquake resistant designs

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Petroleum Science 2010年第2期7卷 273-282页

作者： Duan Menglan Wang Yi Yue Zhiyong Estefen Segen Yang Xiaogang School of Naval Architecture and Marine engineering Dalian University of Technology Dalian Liaoning 116024 China Offshore Oil/Gas Research center China University of Petroleum Beijing 102249 China Department of Mechanics and engineering Peking University Beijing 100080 China COPPE Federal University of Rio de Janeiro EO.Box 68508 RJ 21945-970 Brazil design Division CNOOC Engineering Tanggu Tianjin 300452 China

It is well known that no criterion about seismic design for risers is available, and relevant research has not been reported. A comprehensive study of riser dynamics during earthquakes is performed in this paper. A dynamic model for seismic analysis of risers is developed in accordance with the working environment of the risers and the influence of inertia force of the pipelines. The dynamic equations for the developed model are derived and resolved on the basis of the energy theory of beams. Numerical simulation for an engineering project in the Bohai Oil Field,{2. shows that the fundamental frequency of the riser plays the major role in the seismic responses, and for platforms in shallow water in Bohai Bay, the risers demonstrate a much lower stress response due to prominent differences between the riser frequency and the earthquake wave frequency. The presented model and its corresponding method for seismic analysis are practical and important for riser design resistant to earthquake waves.

关键词： Subsea pipeline riser seismic design dynamic response earthquake wave Hamilton theory

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Dynamic Characteristic Analysis of HIV Mother to Child Transmission in china

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Biomedical and Environmental sciences 2010年第5期23卷 402-408页

作者： JUN-JIE WANG KATHLEEN HEATHER REILLY HUA HAN ZHI-HANG PENG NING WANG national center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijing 100050China Tulane University Health sciences center School of Public Health and Tropical MedicineNew OrleansLAUSA national asic {2. engineering center Institute of AutomationChinese Academy of SciencesBeijing 100190China Department of Epidemiology and Biostatistics Nanjing Medical UniversityNanjing 210029China

Objective to explore dynamic characteristics of the HIV mother to child transmission （MTCT） epidemic in *** A deterministic dynamic transmission model was used to determine the effect of key parameters on the likely long-term trends of the HIV MTCT epidemic in *** 7.0 was used to develop the *** The number of the susceptibles （S）,the transmission rate （β）,and the screening proportion （α） of HIV positive pregnant women have the greatest impact on the HIV MTCT epidemic in *** growth of the MTCT epidemic in china could not be controlled only by decreasing the MTCT transmission *** prevalence of HIV positive women should be reduced and more pregnant women should be tested for *** Prevention of MTCT （PMTCT） should focus not only on the reduction of HIV transmission rates and incidences of HIV among women but also on the increase of HIV testing for pregnant *** most cost-effective PMTCT means for china should be investigated in future studies.

关键词： mother to child transmission dynamic model HIV china

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Theory and verification of operator design methodology

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Science china(Information sciences) 2012年第2期55卷 480-490页

作者： HU ZiYi1,ZHAO Yong1,WANG XinAn1,HUANG Ru2.WANG Teng1 & ZHANG Xing2.1Key Lab of Integrated Microsystem Science and engineering Applications,Peking University Shenzhen Graduate School,Shenzhen 5.805.,china 2.4} of Microelectronics,Peking University,beijing 100871,china 1. Key Lab of Integrated Microsystem Science and engineering Applications Peking University Shenzhen Graduate School Shenzhen 518055 China2. Institute of Microelectronics Peking University Beijing 100871 China

Non-recurring-engineering(NRE)and time-to-market play an increasingly important role in the field of IC ***,with the continuous development of IC manufacturing technology,it is necessary to propose a novel design methodology to shorten design cycle and enhance design *** this paper,operator design methodology(ODM)is presented and an H.2.4 encoder is implemented as a *** to the flow of ODM,the register transfer level(RTL)design of H.2.4 encoder has been accomplished with 15.man-months,which is lower than the average 19 man-months in the field of traditional application specific integrated circuit(asic)***,with the advantage of operator design library,the design has a comparable performance with other asic *** obtained design can support a real-time video encoding of 72.p at 60 frames per second or 1080p at 30 frames per second,working at 167 MHz with SMIC 0.13 μm CMOS *** results provide good evidence for the practicability and efficiency of ODM.

关键词： operator design methodology H.2.4 encoder integrated circuit hardware

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Progress of Lyman-alpha-based beam emission spectroscopy(Ly BES)diagnostic on the HL-2. tokamak

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Plasma Science and Technology 2024年第3期26卷 118-125页

作者：周艺轩余羿许敏柯锐聂林徐皓赵光义刘灏袁子豪肖晨雨李继全肖池阶 the HL-2. Team Southwestern institute of Physics Chengdu 610041People's Republic of China Sino-French institute of Nuclear engineering and Technology Sun Yat-sen UniversityZhuhai 519082People's Republic of China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871People's Republic of China

An edge Lyman-alpha-based beam emission spectroscopy(LyBES)diagnostic,using a heating NBI(neutral beam injection)system,is currently under development on the HL-2. *** 2.-channel edge LyBES,which is intended to measure the density fluctuation in plasma edge(from R=1960 mm to R=2.2. mm)with an improved spatial resolution of 3.3 mm,is a complement to the existing conventional beam emission spectroscopy(BES)*** this article,we introduce the progress of LyBES diagnostic,including the collection optics,the monochromator,and the detector *** reflectance of the collection mirrors is measured to be~82.at 12. nm,and the aberration geometrical radius of the collection optics is tested to be~15.μm in the aimed *** linear dispersion of the LyBES monochromator is designed to be~0.09 nm mm^(-1).The bandwidth of the detector system with the 5.10^(7)V A^(-1)preamplifier gain is measured to be~2.0 kHz,and the peak-to-peak noise of the detector system is tested to be~16 *** finalized design,components development and testing of the LyBES diagnostic have been completed at present,and an overall performance of the LyBES diagnostic is to be confirmed in the next HL-2. campaign.

关键词： density fluctuation Ly BES BES vacuum ultraviolet

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Conditions for Parallel Realizable Configurations in Synthesis of Constraint-based Flexure Mechanisms

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chinese Journal of Mechanical engineering 2012年第6期25卷 1086-1095页

作者： LI Shouzhong, YU Jingjun*, and ZONG Guanghua Robotics institute, Beihang University, beijing 100191,{2. 1. Robotics institute Beihang University Beijing 100191 China

In synthesis of flexure mechanism, parallel arrangement is paid more attention due to its advantages, such as compact structure and higher stiffness. Researchers have derived many parallel flexure mechanisms, but seldom discuss which kind of flexure mechanism can be realized via fully parallel arrangement. The realizable conditions proposed in current work are complicated to engineering applications. To solve two problems on how to judge whether a flexure mechanism can be realized via fully parallel arrangement and how to realize those flexure mechanisms which cannot be realized via fully parallel arrangement, the algebraic condition is derived to judge whether a freedom space is parallel realizable after introducing the definition of parallel realizable and some propositions, and the condition is there exist 6-n independent line constraints in constraint space reciprocal to dimensional freedom space. Then the realizable constraint spaces reciprocal to freedom spaces with 1-3 dimensions are provided. As a result, not all freedom spaces are parallel realizable. For freedom spaces that are not parallel realizable, the criterion of decomposing DOF is proposed to achieve all motion patterns via parallel or hybrid arrangement, that is a high dimensional freedom space can be realized via combining several low dimensional freedom spaces which are parallel realizable. Specific decomposing strategies for 4 and 5.DOF are provided and a complete flowchart is presented to guide {2.ing flexure mechanisms, particularly those which are not parallel realizable. As case studies, synthesis processes of two helical and 3T1R motions are provided to illustrate the proposed approach. The proposed method provides a feasible approach to realize all motion patterns.

关键词： flexure mechanism type synthesis screw theory line geometry constraint design

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H_∞ Control of a 5.h- order Model of Synchronous Generators

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Journal of Systems Science and Systems engineering 2001年第1期13卷 50-56页

作者： WANG Yu zhen1, CHENG Dai zhan1, NING Wei2..institute of Systems Science, Academy of Mathematics and System sciences, {2. Academy of sciences, beijing 100080,{5. 2.Tai′an Teachers College, Tai′an 2.1000,{5. institute of Systems Science Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China Tai' an Teachers College Tai' an 271000 China

：This paper deals with H∞ control of a 5.h-order model of synchronous generators. First,byusing the method of exact linearization, we transform the 5.h-order model into a linear one. Then we assignthe pole of the linearized model in the open left half plane. Finally, we apply the {2. method of linear H∞control to get a state feedback controller.

关键词： 5.h-order model H∞ control exact linearization pole assignment

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