共查询到19条相似文献,搜索用时 62 毫秒
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地理信息系统GIS(Geographical information System),首先是北美发展起来的。世界上第一个GIS是60年代中Tomlinson等人建立的加拿大地理信息系统CGIS,用于土地管理和规划。GIS经过30余年的发展,现在已成为计算机应用的一个非常重要而又非常有前途的领域。GIS不仅涉及到自然资源的管理。城市规划与管理、环境监测、城市管网设施等方面,而且也涉及到车辆运行与道路选择、军队指挥自动化、灾害预报与对策、公安及城市安全等诸方面。可以说,GIS在国外已进入成熟阶段,在我国也已开始这方面的研究、开发、应用。 相似文献
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地理信息系统的新进展 总被引:3,自引:1,他引:3
虽然地理信息系统(GIS)经过近30年的发展,已取得重大成果,但人们对它的研究并未停止。文章简介了GIS近来的新进展,包括时态GIS研究、GIS的可视化研究、一种新理论及方法──Rough集理论及其方法在GIS的属性分析和知识发现中应用和GIS中属性数据的综合及融合。 相似文献
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地理信息系统数据模型分析 总被引:7,自引:0,他引:7
张山山 《计算机工程与应用》2001,37(8):122-124
对数据模型的概念,GIS数据模型的现状和发展趋势,GIS数据模型实例进行了分析。对三维空间目标进行了定义,设计了一种面向对象的三维矢量数据模型。 相似文献
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徐冠华 《中国图象图形学报》1998,3(1):54-58
发展地理信息系统产业徐冠华今天,“全国地理信息系统技术与应用工作会议”召开了。这次会议是由国家科委发起,国家计委等各有关部委和省、市、自治区和地方的代表参加,得到了应用研究单位和企业的热烈响应和支持,我代表国家科委向参加会议的同志们表示热烈的欢迎,预... 相似文献
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Integration of geographic information has increased in importance because of new possibilities arising from the interconnected world and the increasing availability of geographic information. Ontologies support the creation of conceptual models and help with information integration. In this paper, we propose a way to link the formal representation of semantics (i.e., ontologies) to conceptual schemas describing information stored in databases. The main result is a formal framework that explains a mapping between a spatial ontology and a geographic conceptual schema. The mapping of ontologies to conceptual schemas is made using three different levels of abstraction: formal, domain, and application levels. At the formal level, highly abstract concepts are used to express the schema and the ontologies. At the domain level, the schema is regarded as an instance of a generic data model. At the application level, we focus on the particular case of geographic applications. We also discuss the influence of ontologies in both the traditional and geographic systems development methodologies, with an emphasis on the conceptual design phase. 相似文献
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The geographic application domain includes important information such as design plans, record drawings, photographs, and video data records. The corresponding geographic information systems (GISs) should maintain a specific model for each geographic data modality such as geographic video model for video records. Real-time 3-D geographic information systems provide comprehensive interface to complex and dynamic databases and truly immersive capability for visualizing geographic data. In cases, where information about location of geographic objects is needed at different moments of time, a GIS should process video data that is directly manipulated and retrieved through representation of its spatio-temporal characteristics. In this context, the most advanced multimedia form—digital video, finds an efficient application in GIS for versatile specification of geographic data. In this paper, a model for spatial data evolving with time is introduced in the context of video data manipulation. We designed a model that represents the spatio-temporal continuum among geographic objects in geographic video sequences, or digital video. The model developed here was motivated by the requirements for manipulating, managing, and analyzing geographic data for the necessities of infrastructure management, urban and regional planning, hazard prevention and management, transportation networks, vehicles routing, etc. This model allows the important issues for GIS such as conditions of adjacency (what is next to what), containment (what is enclosed by what), and proximity (how close one geographic object is to another) to be determined. Our model describes the spatial relationships among objects for each key frame in a given video scene, and the temporal relationships of the temporal intervals measuring the validity duration of the spatial relationships spanning over the given key frame. One of the main GIS issues—distance estimation, is solved as quantitative metrics of geographic objects in digital video are easily and precisely specified. This model is a basis for annotation of raw video for subsequent use in geographic video databases and digital libraries that provide access to and efficient storage of large volume of geographic data. 相似文献
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目的在于利用小波理论研发分布式交互的在线地理信息系统(DIOGIS)浏览器.文中利用已有的实现纯整数变换的小波算法来实现一个D10GIS测览器原型.这个原型表明对一个分级分解地图,姨描述的方法可以达到类似JPEG的压缩,使用它在低速网络中传输大量的GIS数据非常有效.进一步说,通过在压缩算法中增加可在网络中执行放大缩小以及平移操作的能力.这个原型能够排除冗余的数据转换并且达到平滑、实时的图像浏览效果. 相似文献
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Clearinghouse(数据交换中心)与数字化地理信息共享 总被引:7,自引:0,他引:7
随着Internet技术的飞速发展和网络应用的普及,用户通过Internet快速,、准确地获取和共享地理信息已是大势所趋。采用数据交换中心Clearinghouse机制是实现地理信息共享的重要方法之一。作为集中式服务系统,Clearinghouse提供一个虚拟信息空间,存储大量元数据,实现数字化地理信息的获取和发布能力,并已广泛用于许多国家的地理信息共享实践中。本介绍基于clearinghouse数字化地理信息共享的体系结构、相关技术和实现方法,涉及三层服务体系结构、元数据、Z39.50协议和语义映射等。最后扼要介绍采用Java Servlet、VB和MapObiect开发的基于clearinghouse的数字化地理信息截共享原型系统,它具有元数据提交、数据上载、信息组合查询、地理信息图形显示、数据下载等功能。 相似文献
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加强旅游资源管理,构建旅游资源信息库,对促进旅游业持续健康发展具有重要意义。针对旅游资源管理中存在的问题,在详细分析旅游资源管理的业务流程基础上,提出一种基于地理信息的旅游资源信息库系统。该系统采用三层体系架构,避免用户对数据的直接访问,提升系统的稳定性和扩展性;通过角色访问控制技术,实现授权用户按角色受限地访问系统功能,避免非法用户和授权用户的非法操作,提高系统的安全性;通过高德地图实现旅游资源单体空间数据与属性数据的无缝关联,提升用户体验。该系统可有效克服传统管理方式的不足,提升旅游资源管理的工作效率。 相似文献
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张艳红 《电脑编程技巧与维护》2012,(16):114-115
介绍了地理信息系统的总体结构设计,并对地理公用框架建设、专题地理数据库建设、摄像头监控点的规划与建设、与应用系统的集成、系统的部署与应用方面阐述了系统的设计方案。 相似文献
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基于GML的WebGIS地理信息建模 总被引:6,自引:0,他引:6
文章分析了目前的地理信息系统的建模方法及其存在的问题,结合XML/GML技术,研究基于GML的地理信息的建模方法与实现技术。并以旅游地理信息系统为开发实例,给出了基于GML的泉州市旅游地理信息的建模方案和具体实现方法。 相似文献
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Frederico Fonseca Max Egenhofer Clodoveu Davis Gilberto Câmara 《Annals of Mathematics and Artificial Intelligence》2002,36(1-2):121-151
The integration of information of different kinds, such as spatial and alphanumeric at different levels of detail, is a challenge. While a solution is not reached, it is widely recognized that the need to integrate information is so pressing that it does not matter if detail is lost, as long as integration is achieved. This paper shows the potential for information retrieval at different levels of granularity inside the framework of information systems based on ontologies. Ontologies are theories that use a specific vocabulary to describe entities, classes, properties and functions related to a certain view of the world. The use of an ontology, translated into an active information system component, leads to ontology-driven information systems and, in the specific case of GIS, leads to what we call ontology-driven geographic information systems. 相似文献
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本文介绍了利用MAPINFO单用户版与VB结合合形成控件,并将其插入到WWW服务器主页上来实现地理信息的局域网共享的方法和步骤。 相似文献