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The Organization of Multimedia Information in Electronic Map
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作者 CAI Zhongliang WU Guofeng WENG Min DU Qingyun 《Geo-Spatial Information Science》 2002年第2期56-61,共6页
On the basis of an electronic map_based hypermedia data model (EMBHDM),this paper makes a study on the technologies of nonlinear storage,organization,management and browsing of information as well as organization of d... On the basis of an electronic map_based hypermedia data model (EMBHDM),this paper makes a study on the technologies of nonlinear storage,organization,management and browsing of information as well as organization of data on the basis of the relationship between multimedia information of electronic maps. This paper first analyzes some features of electronic maps and hypermedia technology,and then illustrates the creation of EMBHDM with some examples.The tests show that this model can efficiently organize and express multimedia data. 展开更多
关键词 MULTIMEDIA electronic map HYPERMEDIA data model
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Information Organization and Visualization Mechanism of Electronic Map 被引量:2
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作者 CAI Zhongliang WANG Qiao WENG Min JIANG Shanshan DU Qingyun 《Geo-Spatial Information Science》 2008年第4期262-268,共7页
Based on research on information organization and visualization mechanism of multimedia electronic map, this paper proposes an organization method about spatial information and multimedia information of multimedia ele... Based on research on information organization and visualization mechanism of multimedia electronic map, this paper proposes an organization method about spatial information and multimedia information of multimedia electronic map: seamless spatial data were organized and managed by stratified expansion R-tree and Quad-tree hierarchy; and multimedia information data were organized and managed by hypermedia model based on an electronic map. Considering electronic map features, the paper also proposes a method for spatial date organization, which integrates Digital Landscape Model and Digital Cartographic Model, and a hybrid model between vector and raster spatial data. Then, the paper studies information visualization mechanism of multimedia electronic map. Finally, the paper certifies the results via a case of multimedia electronic map authoring tools software—Atlas2005. 展开更多
关键词 electronic map information organization hypermedia model VISUALIZATION
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Uncovering the internal structure of five-fold twinned nanowires through 3D electron diffraction mapping
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作者 Xin Fu 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第6期517-531,共15页
Five-fold twinned nanostructures are intrinsically strained or relaxed by extended defects to satisfy the space-filling requirement.Although both of metallic and semiconductor five-fold twinned nanostructures show inh... Five-fold twinned nanostructures are intrinsically strained or relaxed by extended defects to satisfy the space-filling requirement.Although both of metallic and semiconductor five-fold twinned nanostructures show inhomogeneity in their cross-sectional strain distribution,the evident strain concentration at twin boundaries in the semiconductor systems has been found in contrast to the metallic systems.Naturally,a problem is raised how the chemical bonding characteristics of various five-fold twinned nanosystems affects their strain-relieving defect structures.Here using three-dimensional(3D)electron diffraction mapping methodology,the intrinsic strain and the strain-relieving defects in a pentagonal Ag nanowire and a star-shaped boron carbide nanowire,both of them have basically equal radial twin-plane width about 30 nm,are nondestructively characterized.The non-uniform strain and defect distribution between the five single crystalline segments are found in both of the five-fold twinned nanowires.Diffraction intensity fine structure analysis for the boron carbide five-fold twinned nanowire indicates the presence of high-density of planar defects which are responsible for the accommodation of the intrinsic angular excess.However,for the Ag five-fold twinned nanowire,the star-disclination strain field is still present,although is partially relieved by the formation of localized stacking fault layers accompanied by partial dislocations.Energetic analysis suggests that the variety in the strain-relaxation ways for the two types of five-fold twinned nanowires could be ascribed to the large difference in shear modulus between the soft noble metal Ag and the superhard covalent compound boron carbide. 展开更多
关键词 five-fold twinnining elastic strain structural relaxation electron diffraction mapping
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Virtual Huanghe River System:Framework and Technology 被引量:2
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作者 LU Heli LIU Guifang SUN Jiulin 《Chinese Geographical Science》 SCIE CSCD 2006年第3期255-259,共5页
Virtual Reality provides a new approach for geographical research. In this paper, a framework of the Virtual Huanghe (Yellow) River System was first presented from the view of technology, which included five main mo... Virtual Reality provides a new approach for geographical research. In this paper, a framework of the Virtual Huanghe (Yellow) River System was first presented from the view of technology, which included five main modules——data sources, 3D simulation terrain database, 3D simulation model database, 3D simulation implementation and application system. Then the key technoiogies of constructing Virtual Huanghe River System were discussed in detail: 1) OpenGL technology, the 3D graphics developing instrument, was employed in Virtual Huanghe River System to realize the function of dynamic real-time navigation. 2) MO and OpenGL technologies were used to make the mutual response between 3D scene and 2D electronic map available, which made use of the advantages of both 3D scene and 2D electronic map, with the macroscopic view, integrality and conciseness of 2D electronic map combined with the locality, reality and visualization of 3D scene. At the same time the disadvantages of abstract and ambiguity of 2D electronic map and the direction losing of virtual navigation in 3D scene were overcome. 展开更多
关键词 Virtual Reality Virtual Huanghe River System dynamic real-time navigation mutual response between 3D scene and 2D electronic map
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Developing High-Precision Maps for Automated Driving in China:Legal Obstacles and the Way to Overcome Them 被引量:1
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作者 ZHANG Taolue TU Huizhao QIU Wei 《Journal of Shanghai Jiaotong university(Science)》 EI 2021年第5期658-669,共12页
A high-precision map(HPM)is the key infrastructure to realizing the function of automated driving(AD)and ensuring its safety.However,the current laws and regulations on HPMs in China can lead to serious legal complian... A high-precision map(HPM)is the key infrastructure to realizing the function of automated driving(AD)and ensuring its safety.However,the current laws and regulations on HPMs in China can lead to serious legal compliance problems.Thus,proper measures should be taken to remove these barriers.Starting with a complete view of the current legal obstacles to HPMs in China,this study first explains why these legal obstacles exist and the types of legal interests they are trying to protect.It then analyzes whether new technology could be used as an alternative to resolve these concerns.Factors such as national security,AD industry needs,and personal data protection,as well as the flexibility of applying technology,are discussed and analyzed hierarchically for this purpose.This study proposes that China should adhere to national security and AD industry development,pass new technical regulations that redefine the scope of national security regarding geographic information in the field of HPMs,and establish a national platform under the guidance and monitoring of the government to integrate scattered resources and promote the development of HPMs via crowdsourcing.Regarding the legal obstacles with higher technical plasticity,priority should be given to technical solutions such as“available but invisible”technology.Compared with the previous research,this study reveals the current legal barriers in China that have different levels of relevance to national security and different technical plasticity.It also proposes original measures to remove them,such as coordinating national security with the development of the AD industry,reshaping the boundary of national security and industrial interests,and giving priority to technical solutions for legal barriers that have strong technical plasticity. 展开更多
关键词 automated driving(AD) navigation electronic map(NEM) high-precision map(HPM) surveying and mapping national security “available but invisible”technology
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Electron densitymap evaluation functions for determining the quality of protein crystal structures
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作者 Tianyi Zhang Zhi Geng +2 位作者 Heng Zhang Liang Zhou Yuhui Dong 《Radiation Detection Technology and Methods》 2018年第2期84-92,共9页
Background Finding methods to judge the quality of X-ray crystallographic information is an active research topic.The quality of electron density maps reconstructed by Fourier transform is always limited by the finite... Background Finding methods to judge the quality of X-ray crystallographic information is an active research topic.The quality of electron density maps reconstructed by Fourier transform is always limited by the finite resolution,the amplitude/phase error and the completeness of diffraction data.At present,the R value and effective resolution are common ways of evaluating the quality of electron density maps.Unfortunately,the current evaluation methods are only dependent on diffraction amplitude,without any phase information.Methods Advanced evaluation functions in real space are designed to estimate the electron density map quality.The electron density map definition evaluation function relies on the atomicity of the electron density distribution.We use the power spectrum electron density entropy in protein crystallography for the first time.These two functions include both structure factor amplitudes and phases via the Fourier transform of electron density map.Results We carry out tests on synthetic data sets of known structures,varying the resolution and error,and draw the quality curves of electron density maps with theoretical,noisy and experimental diffraction data by two evaluation functions at different resolutions.The curves reveal the optimum structure and resolution of proteins clearly.Conclusions The work presented here offers new methods to evaluate the qualities of the electron density maps of proteins with slight differences,and brand new indicators to select the optimum diffraction resolution of protein structures. 展开更多
关键词 Electron density map definition evaluation function Power spectrum electron density entropy Real space electron density map Optimum diffraction resolution
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Development of 3-actoxymethoxycarbonyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl as an electron paramagnetic resonance imaging reagent for in vivo mapping brain oxygen distribution and infarction in ischemic brain
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作者 Gerald M.Rosen 《生物物理学报》 CAS CSCD 北大核心 2009年第S1期101-101,共1页
Measurement of oxygen concentration and distribution in brain is essential to understanding the pathophysiology of stroke. Although brain oxygen level is critical for brain tissue survival,
关键词 Development of 3-actoxymethoxycarbonyl-2 2 5 5-tetramethyl-1-pyrrolidinyloxyl as an electron paramagnetic resonance imaging reagent for in vivo mapping brain oxygen distribution and infarction in ischemic brain
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