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数据是GIS的根基,本文主要介绍了警用地理信息系统中的数据建设。主要内容包括PGIS的数据建设内容,矢量数据,影像数据和三维数据的制作技术路线,以及数据建设的质量标准化控制。 相似文献
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Google Earth作为免费软件,三维模型上能十分的丰富和强大,但坐标转换导入功能薄弱,ArcGIS 9.2以上版本支持Google Earth数据(KML/KMZ格式)的矢量数据式转换。文章介绍了一种借助ArcGIS软件实现坐标拐点快速转换并投放到Google Earth地图中的方法和途径,同时介绍了利用Google Earth辅助矿产资源管理的方法。 相似文献
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对三维地形在第二次土地调查工作中的应用进行了探讨。利用Google Earth提供的相关技术获取所需的三维地形,并在此基础上添加土地调查的相应卫星影像。进一步提高土地调查工作中内业工作人员对影像解译的精度和效率,并结合高程数据,提出了一种河流方向线的获取方法。 相似文献
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VR与GIS相结合是VR技术的一个非常重要的应用,是实现"数字地球"、"数字城市"、"数字区域"等的关键技术之一。以武汉大学信息学部教学区为研究区域,利用教学区的航空影像、数字化地图、实测数据以及区内建筑物的数字影像,在MultiGen Creator/Vega软件平台上建立该区域的虚拟现实场景,实现三维模型漫游。并将此场景用于GIS,实现了GIS属性查询功能。 相似文献
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当前“数字地球”的研究要求对地球空间进行三维描述，本文将逆向工程技术引入三维地理信息系统中，运用STL模型将建模、显示和加工有机结合起来，实现了对地球表面三维测量数据的快速模型重建，并采用基于生长机制的分层制造技术对模型进行快速重建，为真实地面模型的制作提供了有效的解决途径。 相似文献
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正在我国铁路交通网络日益延伸的背景下,信息化技术在铁路路网的规划设计之中起着不可忽视的重要作用,Google Earth数字化信息技术集成了卫星影像、航拍、三维地物模型等数据信息,可以较好地应用于铁路选线设计规划的工作之中,并可以利用铁路数字选线系统,建构地理环境虚拟建模平台,确保铁路选线的合理性和可靠性。 相似文献
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在城市筑群空间分布模式中,需要对建筑区的三维影像特征进行数据提取,用遥感影像中包含的光谱特征和纹理特征,实现对建筑物的特征融合检测。传统方法采用高亮线条和阴影区域融合的方法实现对建筑区的三维影像数据提取,当图像本身受斑点噪声影响较大和光程较远的情况下,影像数据提取效果不好。提出一种基于形状特征与纹理分区相融合的建筑区三维影像数据提取方法,采用骨架线模式和三角网模式构建建筑物的三维纹理模型,设计基于纹理分区的建筑区三维影像图像分割算法。在三角网纹理分区结构模型的基础上,通过相互近似正交的直线模式建立建筑群直线模式的方向关系图,实现对建筑区的三维影像数据提取。仿真实验表明,采用该模型对建筑区的三维影像数据提取,影像分割准确,能准确有效提取影像局部区域的亮度特征,受斑点噪声影响较大和光程的影响较小,对建筑区图像特征的检测正确率较高。 相似文献
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采用已有地形图资料建立反映地表起伏的DEM,在DEM上叠加高分辨遥感影像显示反映地面自然与人文信息细节的地表真实(Groud Truth),进一步加载各类应用专题所需要的矢量数据及其能够详尽反映人口和财产主要承载体即建筑三维模型,不仅能够为科学决策、规划、管理、分析提供直观观察、查询、分析的数据来源和技术手段,而且具有成本低、高效率的显著优点。为此,结合实例介绍了采用国产三维GIS平台VRMap和三维建模软件3D Max建立三维集成数据模型的技术流程与技术方法。 相似文献
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A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
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《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
14.
《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
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Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
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Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
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Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献