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排序方式: 共有490条查询结果,搜索用时 31 毫秒
71.
地理空间数据本质特征语义相关度计算模型 总被引:1,自引:1,他引:0
关联数据是跨网域整合多源异构地理空间数据的有效方式,语义丰富的关联是准确、快速发现目标数据的关键。根据地理空间数据在空间、时间、内容上的语义关系,提出地理空间数据本质特征语义相关度计算模型。通过构建本质特征的关联指标体系,分层次逐级计算地理空间数据的语义相关度。与传统的语义相关度计算方式不同,以地理元数据为语料库,充分考虑地理空间数据的特点及空间、时间、内容在检索中不同的重要程度,分别采用几何运算、数值运算、词语语义相似度计算和类别层次相关度计算的方式,构建地理空间数据的语义相关度计算模型。该模型具有构建简单、适用于多源异构数据、充分结合了数学运算和专家经验知识等特点。实验表明:模型能够有效地计算地理空间数据本质特征的语义相关度,并具备一定的扩展性。 相似文献
72.
73.
In this article we draw on the power of geographic information systems (GIS) to examine the progression of HIV/AIDS in Africa for the period from 1986 to 2003. We use GIS for two purposes: (1) to transform and interpolate a set of annual point-based HIV/AIDS rates into area data; and (2) to extract or “mine” annual HIV/AIDS prevalence rates from the interpolated area (country) level maps. Once the rates are extracted from the GIS analysis we then model and forecast them into the near future (i.e., 2004–2010) by using the UNAIDS Estimation and Projection Package (EPP) software. The article offers an alternative grounded in geospatial analysis for yielding estimates of HIV/AIDS rates in Africa. Using incomplete sets of data for the period from 1986 to 2003, mean HIV/AIDS rates are generated from spatially interpolated data and future trends are estimated. The results indicate that the HIV/AIDS epidemic for many countries in Africa has reached the saturation or maturity level as evidenced by the typical S-shaped curves in the trends over time. As a matter of fact, some countries have begun to experience a sustained decline in the rates (e.g., Uganda, Burundi, Rwanda, and Zimbabwe). 相似文献
74.
The Myth of Location Privacy in the United States: Surveyed Attitude Versus Current Practices 总被引:1,自引:0,他引:1
In the United States, legal steps have been taken to protect personal privacy, which is viewed as an individual's fundamental right. Location privacy (i.e., protection of personal and location information), however, has not received equal attention in the legal system. Given the recent popularity of location-based services (e.g., cell phones), it is possible to obtain an individual's location information easily and precisely. An investigation of public perception of privacy in the United States indicated that survey responders (1) were unaware of legal implications of location privacy violation and (2) believed that there should be location privacy protection similar to that provided by the Health Insurance Portability and Accountability Act and the Family Educational Rights and Privacy Act. 相似文献
75.
地理空间框架是数字城市乃至智慧城市建设的重要基础,其应用推广的好坏关系到系统能否长效运行,是重中之重。本文以数字柳州地理空间框架为例,分析应用推广的现状与存在的问题,探索应用推广的模式,总结应用推广的内容与方法,并结合柳州实际情况进行了实践,搭建了教育学区专题应用、存量房价格认证服务平台、人口电子地图管理系统、三维土地供应系统,并与数字化城市管理系统实现了对接,同时在公众网搭建了地理信息公众服务系统。 相似文献
76.
多重空间数据因其可用性及几何和主题方面的质量差异,催生了针对数据挖掘方法研究的新系统开发,其中包括了异构空间数据结构分析与改进的处理进程。本文介绍了空间数据融合系统( DAFU)的概念、架构与功能性方面的内容,DAFU能够有效使用异构空间数据信息并可进行地理数据的个体使用。 相似文献
77.
刘利 《测绘与空间地理信息》2013,(9)
在全面介绍美国地理信息技术能力素质模型( GTCM )、地理信息职业、地理信息课程培训和认证体系的基础上,提出了要研究制定我国地理信息职业能力标准、新增地理信息职业类型、充分参考和利用GTCM模型、建立人才交流平台、加强地理信息劳动力调查研究,以促进我国地理信息劳动力和产业发展。 相似文献
78.
王少燕 《测绘与空间地理信息》2013,36(7):130-132
随着国家电网公司空间信息服务平台的建设和2000国家大地坐标系(CGCS 2000)的启用,迫切需要将各省不同坐标系的空间数据统一转换到CGCS 2000,从而实现电网空间信息服务平台的纵向贯通及空间数据资源的整合和共享。本文根据电力GIS空间数据资源的特点及行业情况,阐述了电网GIS中现有成果从独立坐标系向CGCS 2000转换的实现,并提出了对转换成果的验证方法。 相似文献
79.
3维可视化平台是数字城市地理空间框架的重要组成部分,本文介绍了数字马鞍山建设中3维平台的设计与实现思路。从2,3维协同服务的角度设计了3维建设技术路线,并对海量数据传输加载及2,3维联动等关键问题提出了有益的解决方案。为其他城市建设地理空间框架提供借鉴。 相似文献
80.
《International Journal of Digital Earth》2013,6(5):411-431
With growing demand on multi-purpose or multi-modal navigation, the route calculation needs to traverse semantically enriched road networks for different transportation modes. Currently, operational route planning algorithms reveal rather limited performances or their potential for comprehensive applications are constrained by the unavailable or insufficient interoperation among the underlying geo-data that are separately maintained in different spatial databases. To overcome this limitation, a novel approach has been proposed to integrate the routing-relevant information from different data sources, which involves three processes: (1) automatic matching to identify the corresponding road objects between different datasets; (2) interaction to refine the automatic matching result; and (3) transferring the routing-relevant information from one data-set to another. In process (1), the Delimited Stroke Oriented algorithm is employed to achieve the automatic data matching between different datasets, which has revealed a high matching rate and certainty. However uncertain matching problems occur in areas where topological conditions are too complicated or inconsistent. The remaining unmatched or wrongly matched objects are treated in process (2), with the help of a series of interaction tools. On the basis of refined matching results after the interaction, process (3) is dedicated to automatic integration of the routing-relevant information from different data sources. 相似文献