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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, chinese academy of sciences, beijing 100049, china 2. Graduate School of chinese 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 78229, USA 5. national asic design and engineering center, institute of automation, chinese academy of sciences, beijing 100049, china 6. Department of Physics, Zhejiang University, Hangzhou 310027, china) Key Laboratory of Nuclear Analysis Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Graduate School of chinese academy of sciences Beijing 100049 China Department of Physics Zhoukou Normal University Zhoukou 466100 China Research Imaging center University of Texas Health Science Center San Antonio TX 78229 United States national asic design and engineering center Institute of Automation Chinese Academy of Sciences Beijing 100049 China Department of Physics Zhejiang University Hangzhou 310027 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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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 design 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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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, beijing 100084, china 2 Tsinghua national Laboratory for Information Science and Technology, beijing 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 20005. china 5.Department of Biomedical engineering, Tsinghua University, beijing 100084, china institute of Microelectronics Tsinghua University Beijing China Tsinghua national Laboratory for Information Science and Technology Beijing China Yangtze Delta Region institute of Tsinghua University Jiaxing China Department of Biomedical engineering Tsinghua University Beijing 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1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 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. Key Lab of Dredging Technology of CCGRP,Shanghai Waterway engineering design and Consulting Co., Ltd,Shanghai 200120,china. International Research and Training center on Erosion and Sedimentation china institute of Water Resources and Hydropower Research,beijing 100048 Northwest A&F University,Yangling 712100,china, beijing Forestry University,beijing 100083,china, beijing Forestry University,beijing 100083,china. china institute of Water Resources and Hydropower Research,beijing 100048,and International Research and Training center on Erosion and Sediment Research,beijing 100048,china 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 Dr. Key Lab of Dredging Technology of CCGRP Shanghai Waterway Engineering Design and Consulting Co. Ltd Shanghai 200120 China 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 712100 China Prof. Dr. Beijing Forestry University Beijing 100083 China Dr. Beijing Forestry University Beijing 100083 China 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 610065.china,Graduate University of chinese academy of sciences,beijing {5.,china,2 Prof.,Department of Architecture & Environment,Sichuan University,Chengdu 610065.china,3 Graduate University of chinese academy of sciences,beijing {5.,china 4 Department of Civil and Environmental engineering,San Diego State University,5.00 Campanile Dr.San Diego,CA 92121,USA 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 Prof. Department of Architecture & Environment Sichuan University Chengdu 610065 China Graduate University of chinese academy of sciences Beijing 100049 China Department of Civil and Environmental engineering San Diego State University 5500 Campanile Dr. San Diego CA 92121 USA

Debris flow is a serious geologic hazard in *** is estimated that nationally debris flows cause up to 2 billion RMB(25. 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,3,290 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 1:25.,000 and a regional geological map,the 24-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 = 21 + 10200 / 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.-,20-,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%,20% and 25. of total area respectively.

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

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Fast and Robust Control of Excitation Systems: A Finite-time Method

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Journal of Systems Science and Systems engineering 2001年第2期13卷 148-161页

作者： WANG Yu-zhen, CHENG Dai-zhan, HONG Yi-guang, QIN Hua-shuinstitute of Systems Science, academy of Mathematics and System sciences,chinese academy of sciences, beijing 100080, china institute of Systems Science Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China

Using finite-time control approach, this paper proposes a new design method for nonlinear robust excitation control of a widely used 5.h-order model of synchronous generators. The finite-time excitation controller achieved here can improve the system′s behaviors in some aspects such as quick convergence and robustness for uncertainties. Simulations demonstrate that the finite-time excitation controller is more effective than some other excitation controllers.

关键词： finite-time control homogeneity excitation control robustness

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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 Wei21.institute of Systems Science, academy of Mathematics and System sciences, chinese academy of sciences, beijing 100080,{5. 2.Tai′an Teachers College, Tai′an 271000,{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 design 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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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, china 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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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, china Robotics institute Beihang University Beijing 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 designing 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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Identification of QTLs for grain size and characterization of the beneficial alleles of grain size genes in large grain rice variety BL129

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Journal of Integrative Agriculture 2016年第1期15卷 1-9页

作者： GAO Xua ZHU Xu-dong FANG Na DUAN Peng-gen WU Ying-bao LUO Yue-hua LI Yun-hai Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources/Agricultural College Hainan UniversityHaikou 570228P.R.China State Key Laboratory of Rice Biology China National Rice Research InstituteChinese Academy of Agricultural SciencesHangzhou 310006P.R.China State Key Laboratory of Plant Cell and Chromosome engineering Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101P.R.China

Grain size is one of the most important agronomic components of grain yield. Grain length, width and thickness are controlled by multiple quantitative trait loci （QTLs）. To understand genetic basis of large grain shape and explore the beneficial alleles for grain size improvement, we perform QTL analysis using an F2 population derived from a cross between the japonica variety Beilu 129 （BL129, wide and thick grain） and the elite indica variety Huazhan （HZ, narrow and long grain）. A total number of eight major QTLs are detected on three different chromosomes. QTLs for grain width （qGW）, grain thickness （qGT）, brown grain width （qBGW）, and brown grain thickness （qBGT） explained 77.67, 36.24, 89.63, and 39.41% of total phenotypic variation, respectively. The large grain rice variety BL129 possesses the beneficial alleles of GW2 and qSW5. GW5. which have been known to control grain width and weight, indicating that the accumulation of the beneficial alleles causes large grain shape in BL129. Further results reveal that the rare gw2 allele from BL129 increases grain width, thickness and weight of the elite indica variety Huazhan, which is used as a parental line in hybrid rice breeding. Thus, our findings will help breeders to carry out molecular design breeding on rice grain size and shape.

关键词： rice quantitative trait grain size GW2 GW5

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