检索结果-南通市图书馆

A new approach toward object-based change detection

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2010年第S1期53卷 105-110页

作者： ZHANG Guo1,2.li yang1 & li zhiJiang3 1 state key {2. of information engineering in surveying,mapping and remote sensing,wuhan university,{12.,China 2.Satellite of surveying and mapping Application center,state Bureau of surveying and mapping,Beijing 100830,China 3 School of Printing and Packaging,wuhan university,{12.,China state key {2. of {2. engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan China Satellite of surveying and {2. Application center State Bureau of Surveying and Mapping Beijing China School of Printing and Packaging Wuhan University Wuhan China

Object-based change detection has been the hotspot in remote sensing image processing.A new approach toward object-based change detection is *** two different temporal images are unitedly segmented using the mean shift procedure to obtain corresponding *** change detection is implemented based on the integration of corresponding objects’ intensity and texture *** are conducted on both panchromatic images and multispectral images and the results show that the integrated measure is robust with respect to illumination changes and *** color detection is conducted to determine whether the color of the unchanged objects changes or not when dea{2.ng with multispectral *** verification work is carried out to show the accuracy of the proposed approach.

关键词： mean shift united segmentation change detection object-based intensity texture integration

Gradient analysis of landscape spatial and temporal pattern changes in Beijing metropolitan area

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2010年第S1期53卷 91-98页

作者： yang YeTao1,ZHOU QiMing2.GONG JianYa3 & wang YingYing4 1 Institute of Geophysics and Geomatics,China {2. of Geosciences,wuhan 430074,China 2.Department of Geography,Hong Kong Baptist {2.,Hong Kong 3 state key laboratory of information engineering in surveying,mapping and remote sensing,{12.,wuhan 430074,China 4 Hubei Provincial Bureau of Meteorology,wuhan 430074,China Institute of Geophysics and Geomatics China University of Geosciences Wuhan China Department of Geography Hong Kong Baptist University Hong Kong China state key {2. of {2. engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan China Hubei Provincial Bureau of Meteorology Wuhan China

The gradient based landscape metrics analysis is now widely used to study the landscape pattern changes in respond to the *** order to discover the trend of spatio-temporal changes in Beijing metropolitan area during the past 15 years,several landscape metrics are computed using a moving window along a 96 km long transect across Beijing metropolitan area from west to ***,the spatial extent of sub-landscape,which is determined by the moving window’s size,is profoundly *** results show that the metrics varies smoothly and regularly along the selected transect when the window size is greater than 6 km×6 km,and irregularly fluctuated for the smaller window size,that the spatial and temporal landscape characteristics of Beijing city match the hypothetical framework of spatio-temporal urban sprawl in the form of alternating processes of diffusion and coalescence well,and that some new trends of the urban sprawl style in Beijing metropolitan area,such as leap-frog manner,are also detected by the gradient landscape analysis.

关键词： gradient analysis landscape metrics spatio-temporal urban expansion multi-extent

Study on NDVI-T_s space by combining LAI and evapotranspiration

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2006年第7期49卷 747-754页

作者： HAN lijuan1,2.3, wang Pengxin4, {2. Hua1,2.3, liU Shaomin1,2.3 & wang Jindi1,2.3 1. Research Center for remote sensing and GIS, School of Geography, Beijing Normal university, Beijing 100875, China 2. state key laboratory of remote sensing Science, Beijing 100875, China 3. Beijing key laboratory for remote sensing of Environment and Digital Cities, Beijing 100875, China 4. Department of information Management, College of information and Electronic engineering, China Agricultural university, Beijing 100083, China Research Center for remote sensing and GIS School of Geography Beijing Normal University Beijing China state key {2. of {2. sensing Science Beijing China Beijing key laboratory for {2. {2. of Environment and Digital Cities Beijing China Department of information Management College of Information and Electronic Engineering China Agricultural University Beijing China

This paper focuses on interpreting the different spatial relationships between NDVI and Ts, a triangular or a trapezoid, and on analyzing transformation conditions, the physical and ecological meanings of the vegetation index-surface temperature space as well. Further, we use the Tempera-ture-Vegetation Dryness Index (TVDI) to explain the existent meaning of a triangular space after NDVI reaches its saturated state by employing the relationships between NDVI, LAI and evapotranspiration. The specific relations between NDVI and Ts are useful for describing, validating and updating land surface models.

关键词： NDVI, land surface temperature, evapotranspiration, leave area index.

Conceptual design,data model and key techniques of“3D Assistant”

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2011年第S3期21卷 692-698页

作者： li Qing-yuan1, ZHANG Xuan2. JIN yang2. ZHOU Hui3, {2. Qian-jin3,WEI Zhan-yin1 1. key {2. of Geo-Informatics, Chinese Academy of surveying and mapping, Beijing 100830, China 2. School of Geo-Science and surveying engineering, China university of Mining and Technology, Beijing 100083, China 3. School of Geomatics, liaoning Technical university, Fuxin 12.000, China key laboratory of Geo-Informatics Chinese Academy of Surveying and Mapping Beijing 100830 China School of Geo-Science and surveying engineering China University of Mining and Technology Beijing 100083 China School of Geomatics Liaoning Technical University Fuxin 123000 China

Conceptual design, data model and key techniques of "Geo-engineer 3D assistant", an underground 3D GIS oriented to geology and mine application, were discussed. In particular, the importance of high-order smoothing triangular pieces to surface's fine expression in geological modeling was emphasized. The contour mode is the most favorite mode of the three modes about surface expression: DEM, TIN and contour. Topology in underground 3D modeling with CAGD was compared. From the view of boundary and coboundary, which is soul of IS 19107 (Geographic information spatial schema), 3D underground topology was re-examined.

关键词： 3D assistant true 3D GIS fine expression of surface contour mode 3D topology

Comparison of the influence factors on NDVI for CCD camera and WFI imager on CBERS-02

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2005年第S2期48卷 100-115页

作者： YU Tao1,3, li Xiaoying1,2.3, ZHANG Yong1,2.3, ZHAO Feng1,2.3, GU Xingfa1,3,4, ZHU li1,2.3, {2. Pengxin5 & MIN Xiangjun6 1. state key {2. of remote sensing Science Institute of remote sensing Application, CAS, Bei- jing 100101, China 2. Graduate university of Chinese Academy of Sciences, Beijing 100039, China 3. The Center for National Spaceborne Demonstration, Beijing 100101, China 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. College of information and Electrical engineering, China Agricultural university, Beijing 100083, China 6. China Center for Resource Satellite Data and Application, Beijing 100830, China state key {2. of {2. sensing Science Institute of Remote Sensing Application CAS Beijing China The Center for National Spaceborne Demonstration Beijing China Graduate university of Chinese Academy of Sciences Beijing China Institut National de la Recherche Agronomique Climat Sol Environnent Avignon France College of information and Electrical engineering China Agricultural University Beijing China China Center for Resource Satellite Data and Application Beijing China

CCD and WFI are payloads in the visible light and near infrared bands on CBERS satellites and they have not been applied widely, especially WFI. This article mainly probes into the potential of these two sensors’ application in the vegetation monitoring and analyses the influences of radiometric calibration, atmosphere conditions and sun-observing geometry, etc. on NDVI obtained from these two sensors respectively. In addition it analyses the effect of the spectral response difference of red and near infrared spectral bands in CCD and WFI sensors on NDVI. Results indicate that radiometric calibration is the most important factor on NDVI, which cannot be applied to vegetation monitoring without radiometric calibration. Results also demonstrate that near surface NDVI is different greatly from that of TOA which change with atmosphere conditions. The study shows that NDVI is also affected by the non-lambertian character of surface and the change of the atmospheric path with the observing geometry. And NDVI of WFI is higher than that of CCD. They are very different because of their spectral difference, but they have a good linear relevant relationship.

关键词： CCD WFI NDVI LAI.

Distinguishing malignant from normal stomach tissues and its in vivo, in situ measurement in operating process using FTIR Fiber-Optic techniques

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2005年第2期48卷 167-175页

作者： XU Yizhuang1, yang limin1, XU {2.3, ZHAO Ying2. liNG Xiaofeng3, li Qingbo1, wang Jiansheng4, ZHANG Nengwei3, ZHANG Yuanfu1 & WU Jinguang1 1. The {2. key laboratory of Rare Earth Materials and Applications, College of Chemistry and Molecular engineering, Peking university, Beijing 100871, China 2. Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China 3. Department of Surgery, Third Hospital, Peking university, Beijing 100083, China 4. Department of Oncology Surgery, the First Hospital of Xi’an Jiaotong university, Xi’an 710061, China Correspondence should be addressed to Wu Jinguang (email: wujg@***) The state key {2. of Rare Earth Materials and Applications College of Chemistry and Molecular Engineering Peking University Beijing China Department of Surgery Third Hospital Peking University Beijing China Institute of Chemistry Chinese Academy of Sciences Beijing China Department of Oncology Surgery the First Hospital of Xi’an Jiaotong University Xi’an China

Gastric tissue samples were studied using mid-IR fiber-optic attenuated total reflectance (ATR) spectroscopy. FTIR spectra of 90 tissue samples from 48 patients, including 32.normal and 58 malignant tissue samples, were chosen as examples. Malignancy was usually characterized by the absence of CH and C=O bands, a weak amide II band near 1545 cm-1, a shift of the amide I band to lower wave number, a decrease in the ～1450 cm-1 peak to less than the～1400 cm-1 peak. Subtraction spectra indicate that the amide I and amide II bands of normal and malignant tissues have larger differences in peak positions and relative intensities. The statistical analysis results confirm this conclusion. The results indicate that FTIR fiber optic techniques provide important information about cancerous tissue of the stomach, which can be used to differentiate the malignant tissue from the normal tissue. Based on the above results we successfully realize the detection of the tumor tissues of digestive tract in vivo and in situ. And the results of detection cancer near operating room and in vivo and in situ in the operating room are consistent with the conclusions for the samples stored in liquid N2. which is the basis for the clinical application.

关键词： FTIR, Fiber-Optics, stomach tissues, cancer, diagnosis.

Substrate bias effects in p-channel GaN-on-Si transistors

在线全文

学校读者我要写书评

暂无评论

Science China(information Sciences) 2025年第1期68卷 404-405页

作者： Mengyao ZHAO Jie MA Lanlan yang Chuanqi PAN Denggui wang Jianjun ZHOU Sheng {2. Jiaxing WEI Long ZHANG Siyang {2.U Weifeng SUN National ASIC System engineering Research Center School of Integrated Circuits Southeast University National Center of Technology Innovation for Electronic Design Automation Southeast University National key laboratory of So{2.d-state Microwave Devices and Circuits

The drain current （ID） of the n-channel GaN field-effecttransistor （n-FET） is influenced by the substrate-to-source bias voltage (VBS)（substrate bias effect）[1].Actually,nonzero VBSis also likely to occur in p-FET in real application,because the source electrode of p-FET is usually connected to high *** study reports the dependency between IDand VBSin p-FET for the first time,and analyzes the underlying mechanisms from the perspective of vertical electric field （EF） distribution.

关键词：

同方期刊数据库

Cavity Pressure Control by Iterative Learning Control with Zero-phase Filtering in Injection Molding

在线全文

学校读者我要写书评

暂无评论

Cavity Pressure Control by Iterative Learning Control with Z...

The shifts of precipitation phases and their impacts

2.10 Chinese Control and Decision Conference

作者： Chuang li~1,Fuli {2.~(1,2.,Dapeng Niu~(1,2.,yang liu~1 1.School of {2. Science and engineering,Northeastern university,Shenyang,110004 2.key laboratory of Integrated Automation of Process Industry,Ministry of Education,Northeastern university,Shenyang 110004

＜正＞Cavity pressure featured by cycle is a crucial process variable to determine the product quality in injection molding.A feedforward and feedback control method based on iterative learning control（ILC） with zero-phase filtering is *** is used as feedforward part to realize accurate trajectory tracking with {2. of previous cycle and proportional control is used as feedback part to reject disturbances present at current *** order to overcome bad learning transients in ILC,the convergence condition in frequency domain is derived and the implementation method of monotonic decay of learning transients is *** experimental results show that the proposed method makes ILC with monotonic decay of learning transients and the accurate tracking of cavity pressure setting curve achieved.

关键词： Cavity Pressure Iterative Learning Control Zero-phase Filtering Feedforward and Feedback Control

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第2期68卷 425-443页

作者： Xuemei li Tao CHE Yuanlong TANG Huan'e DUAN Guigang wang Xu ZHANG Chuanming {2. Jun WU Yue ZHANG Lanhai li Faculty of Geomatics Lanzhou Jiaotong University National-Local Joint engineering Research Center of Technologies and Applications for National Geographic {2. Monitoring key laboratory of Science and Technology in {2. & {2. Gansu Province key laboratory of Cryospheric Science and Frozen Soil {2. Heihe Remote Sensing Experimental Research StationNorthwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences Xinjiang key laboratory of Water Cycle and Uti{2.zation in Arid Zone Xinjiang Institute of Ecology and Geography Chinese academy of Sciences Tianshan Snow Cover and Avalanche Observation and Research Station of Xinjiang

Precipitation comes in various phases, including rainfall, snowfall, sleet, and hail. Shifts of precipitation phases, as well as changes in precipitation amount, intensity, and frequency, have significant impacts on regional climate, hydrology,ecology, and the energy balance of the land-atmosphere system. Over the past century, certain progress has been achieved in aspects such as the observation, discrimination, transformation, and impact of precipitation phases. Mainly including: since the1980s, studies on the observation, formation mechanism, and prediction of precipitation phases have gradually received greater attention and reached a certain scale. The estimation of different precipitation phases using new detection theories and methods has become a research focus. Avariety of discrimination methods or schemes, such as the potential thickness threshold method of the air layer, the temperature threshold method of the characteristic layer, and the near-surface air temperature threshold method,have emerged one after another. Meanwhile, comparative studies on the discrimination accuracy and applicability assessment of multiple methods or schemes have also been carried out simultaneously. In recent years, the shift of precipitation from solid to liquid(SPSL) in the mid-to-high latitudes of the Northern Hemisphere has become more pronounced due to global warming and human activities. It leads to an increase in rain-on-snow(ROS) events and avalanche disasters, affecting the speed, intensity, and duration of spring snow-melting, accelerating sea ice and glacier melting, releasing carbon from permafrost, altering soil moisture, productivity, and phenological characteristics of ecosystems, and thereby affecting their structures, processes, qualities, and service functions. Although some progress has been made in the study of precipitation phases, there remains considerable research potential in terms of completeness of basic data, reliability of discrimination schemes, a

关键词： Precipitation phases Shift of precipitation from solid to liquid (SPSL) Climate change Water cycle processes Snow and ice processes Snow and ice-related disasters Carbon emission from permafrost Ecosystems

同方期刊数据库