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When analyzing spatial issues, geographers are often confronted with many problems with regard to the imprecision of the available information. It is necessary to develop representation and design methods which are suited to imprecise spatiotemporal data. This led to the recent proposal of the F‐Perceptory approach. F‐Perceptory models fuzzy primitive geometries that are appropriate in representing homogeneous regions. However, the real world often contains cases that are much more complex, describing geographic features with composite structures such as a geometry aggregation or combination. From a conceptual point of view, these cases have not yet been managed with F‐Perceptory. This article proposes modeling fuzzy geographic objects with composite geometries, by extending the pictographic language of F‐Perceptory and its mapping to the Unified Modeling Language (UML) necessary to manage them in object/relational databases. Until now, the most commonly used object modeling tools have not considered imprecise data. The extended F‐Perceptory is implemented under a UML‐based modeling tool in order to support users in fuzzy conceptual data modeling. In addition, in order to properly define the related database design, an automatic derivation process is implemented to generate the fuzzy database model. 相似文献
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Spatial signatures for geographic feature types: examining gazetteer ontologies using spatial statistics 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Digital gazetteers play a key role in modern information systems and infrastructures. They facilitate (spatial) search, deliver contextual information to recommended systems, enrich textual information with geographical references, and provide stable identifiers to interlink actors, events, and objects by the places they interact with. Hence, it is unsurprising that gazetteers, such as GeoNames, are among the most densely interlinked hubs on the Web of Linked Data. A wide variety of digital gazetteers have been developed over the years to serve different communities and needs. These gazetteers differ in their overall coverage, underlying data sources, provided functionality, and geographic feature type ontologies. Consequently, place types that share a common name may differ substantially between gazetteers, whereas types labeled differently may, in fact, specify the same or similar places. This makes data integration and federated queries challenging, if not impossible. To further complicate the situation, most popular and widely adopted geo‐ontologies are lightweight and thus under‐specific to a degree where their alignment and matching become nothing more than educated guesses. The most promising approach to addressing this problem, and thereby enabling the meaningful integration of gazetteer data across feature types, seems to be a combination of top‐down knowledge representation with bottom‐up data‐driven techniques such as feature engineering and machine learning. In this work, we propose to derive indicative spatial signatures for geographic feature types by using spatial statistics. We discuss how to create such signatures by feature engineering and demonstrate how the signatures can be applied to better understand the differences and commonalities of three major gazetteers, namely DBpedia Places, GeoNames, and TGN. 相似文献
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《制图学和地理信息科学》2013,40(5):332-334
Dramatic changes in the way that spatial data have been collected and processed over that last 20 years is leading to a rethinking and restructuring on the most efficient ways to handle geographical information. These changes are taking place at the federal, state, and local governmental levels with great potential for the private sector as well. The formal adoption of the Spatial Data Transfer Standard (SDTS) as the federal database transfer standard for spatial databases signals a new era in this long chain of developments. It offers more flexible and efficient database transfers than earlier tools, and will become the workhorse for implementing the new National Spatial Data Infrastructure. It offers organizations a standard that will make possible and practical a much wider sharing of databases than is currently being done today. Use of the SDTS presents an opportunity to many organizations to share data more easily and reduce the duplication of expensive spatial database resources. 相似文献
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以TIGER这种既成事实的空间数据格式为例,详细介绍了TIGER的数据模型及文件组织形式,对TI-GER/Line如何描述空间对象信息进行分析,把这种格式作为空间对象拓扑模型实际实施的一种范例作以详细介绍,以起到抛砖引玉的作用,使读者能够更深入地了解空间对象表示的基本要求,对未来空间数据标准化起到一定的参考作用。 相似文献
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论空间数据挖掘和知识发现 总被引：92，自引：5，他引：92
随着现代科技和传感器的发展和应用，复杂多变的空间数据日益膨胀，远远超出人的解译能力，迫切需要数据挖掘和知识发现为其提供知识。本文研究了空间数据挖掘和知识发现的含义、可发现的空间的关联、特征、分类和聚类等知识，以及它与数据挖掘与知识发现、机器学习、地学数据分析、空间数据库、空间数据仓库、数字地球等相关学科的关系，概述了SDMKD的产生和发展，分析和展望了SDMKD的应用开发。 相似文献
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We consider the problem of enabling interoperability and information sharing among geospatial applications that use ontologies to describe their concepts and the relationships among them. We present two fully automatic alignment methods that use the graph structures of a pair of ontologies to establish their alignment, that is, the semantic correspondences between their concepts. We have tested our methods on geospatial ontologies pertaining to wetlands and four other pairs that belong to a repository that has been used in the Ontology Alignment Evaluation Initiative (OAEI). Using these ontologies, we have compared the effectiveness (precision and recall) of our methods against the Similarity Flooding Algorithm that was proposed by others and show that for each of the tested ontologies one of our methods is at least as effective as their method. We have tuned the performance of our methods by introducing a greedy approach that reduces the number of concepts that get compared. This approach reduces runtime by approximately 30% with a minor compromise to the effectiveness of the results. To further validate our approach, we participated in the OAEI competition to align a pair of ontologies, each with a few thousand concepts. 相似文献
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陈珂;温家洪;俞立中 《东北测绘》2013,(4):4-8
元数据标准是数据库的一个重要组成部分,对自然灾害研究而言,涉及全球范围的历史灾情、时空信息等海量数据,在形成灾害数据库的过程中,离不开元数据标准的设计与构建。本文介绍了元数据与元数据标准的基本概念、特征以及作用等内容,提出了自然灾害元数据标准的设计思路,即以提高自然灾害数据库的建库质量,增强数据的使用效率,促进数据共享为目标,遵循稳定性与科学性、简单性与准确性、互操作性与易转换性、一致性与可扩展性等原则,实现描述评价、查询检索、管理维护、交换共享等功能。在此基础上,完成了自然灾害元数据标准的构建,共包含六大实体,33个元数据元素,36个元数据子元素。对于每一个元数据元素或子元素,均有九个属性对其加以限制和说明。该元数据标准已经应用于长三角地区自然灾害损失数据库的开发,为自然灾害数据管理和数据库建设提供了依据,是实现自然灾害数据共享的重要途径,也可以作为其它学科领域制定元数据标准的参考。 相似文献
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Boyan Brodaric 《Transactions in GIS》2007,11(3):453-477
Geo‐Pragmatics is introduced here as an enhanced representation for ontologies in which geospatial, geographical and geoscientific concepts are not only defined, but their pragmatic context is also captured and potentially reasoned with. A framework for representing such context is developed using three core aspects: dimensions, agents and roles. Dimensions consist of a concept's origins, uses and effects; these are generated by the interaction of human, machine and natural agents, and involve entities with roles developed from method‐driven perspectives and epistemic‐driven versions. The relationship between these core aspects is explored conceptually and implications for geoscientific ontologies are discussed, including identification of a basic ontological type, the situated concept, whose meaning is defined by its geographical‐historical context. Geo‐pragmatics should help geoscientists evaluate the scientific merit, and fitness for scientific use, of geoscientific ontologies in emerging e‐science initiatives. 相似文献
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综合省情地理信息系统空间数据元数据设计研究 总被引：13，自引：0，他引：13
综合省情地理信息系统的建立与运行需要元数据的支持，在分别对现有元数据标准和综合省情地理信息系统特点进行分析的基础上，指出了使用元数据的优点，提出了综合省情地理信息空间数据元数据的内容，以提高系统查询检索的速度和系统分析效率为主要目的，对元数据的存储采用了一种以数据库为基础的新的存储模式，以关系表格来管理元数据，建立元数据库。元数据库的管理以图形数据的管理为基础，二者必须协调进行。 相似文献
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Communicating uncertainty in spatial databases 总被引：1，自引：0，他引：1
As applications of spatial databases become more sophisticated and diverse, an issue of growing concern is the inability to communicate to users the uncertainty of products derived from their systems. This is important not only because users should be able to compare the quality of database outputs against the quality requirements of their tasks (in order to determine product suitability), but also to protect the integrity of past, present, and future decisions that may be made through the use of such information. While there has already been considerable research undertaken to develop models of spatial data error and uncertainty, there is an additional requirement for the results of these models to be effectively conveyed to users. This paper reviews advances now being made in communicating the uncertainty of spatial databases which may soon assist users in overcoming this critical barrier. 相似文献
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一种模型驱动空间数据库质量检查平台构建 总被引：1，自引：1，他引：0
质量检查是空间数据质量控制的关键环节，空间数据库包括矢量空间数据、专题属性数据及元数据等，质量检查内容繁多。现有空间数据库质检软件往往为某一项目“量身定制”，灵活性低。本文从空间数据库质量特征及其语义表达出发，对空间数据库质检规则进行了分析和研究，提出了空间数据库质检DRST模型，并基于该模型开发构建了一套能够适用于各类空间数据库质检需要的平台软件。该平台已在江西省房地一体确权登记数据库质检、第三次国土调查成果数据库质检、地理国情监测成果数据库质检等项目中得到应用。应用实践表明，平台具备良好的适应性和扩展性，为提高空间数据库质量检查效率、解决质检软件生命周期短等问题提供了有效途径。 相似文献
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Mark Gahegan Ritesh Agrawal Anuj Jaiswal Junyan Luo Kean‐Huat Soon 《Transactions in GIS》2008,12(6):713-732
This article describes research in the ongoing search for better semantic similarity tools: such methods are important when attempting to reconcile or integrate knowledge, or knowledge‐related resources such as ontologies and database schemas. We describe an extensible, open platform for experimenting with different measures of similarity for ontologies and concept maps. The platform is based around three different types of similarity, that we ground in cognitive principles and provide a taxonomy and structure by which new similarity methods can be integrated and used. The platform supports a variety of specific similarity methods, to which researchers can add others of their own. It also provides flexible ways to combine the results from multiple methods, and some graphic tools for visualizing and communicating multi‐part similarity scores. Details of the system, which forms part of the ConceptVista open codebase, are described, along with associated details of the interfaces by which users can add new methods, choose which methods are used and select how multiple similarity scores are aggregated. We offer this as a community resource, since many similarity methods have been proposed but there is still much confusion about which one(s) might work well for different geographical problems; hence a test environment that all can access and extend would seem to be of practical use. We also provide some examples of the platform in use. 相似文献
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GeoStar is the registered trademark of GIS software made by WTUSM in China.By means of the GeoStar,multi-scale images,DEMs,graphics and attributes integrated in very large seamless databases can be created,and the multi-dimensional dynamic visualization and information extraction are also available.This paper describes the fundamental characteristics of such huge integrated databases,for instance,the data models,database structures and the spatial index strategies.At last,the typical applications of GeoStar for a few pilot projects like the Shanghai CyberCity and the Guangdong provincial spatial data infrastructure (SDI) are illustrated and several concluding remarks are stressed. 相似文献
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GeoStar is the registered trademark of GIS software made by WTUSM in China. By means of the GeoStar, multi-scale images, DEMs, graphics and attributes integrated in very large seamless databases can be created, and the multi-dimensional dynamic visualization and information extraction are also available. This paper describes the fundamental characteristics of such huge integrated databases, for instance, the data models, database structures and the spatial index strategies. At last, the typical applications of GeoStar for a few pilot projects like the Shanghai CyberCity and the Guangdong provincial spatial data infrastructure (SDI) are illustrated and several concluding remarks are stressed. 相似文献
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传统的GIS应用以空间数据库为中心进行组织,而异构的空间数据库之间因为缺乏被计算机所理解的语义知识,很难解决日益增长的异构的GIS应用之间的互操作的需求。本体（ontology）技术被看成是解决不同应用系统之间的异构性以及互操作难题的一个重要途径。传统的地理本体需要通过领域专家人工建立,比较耗费时间。本文提出一种从已经存在的空间数据库中提取出地理本体的方法,来解决异构系统中本体获取困难的问题。 相似文献
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A Framework for Modeling Uncertainty in Spatial Databases 总被引：1，自引：0，他引：1
A Morris 《Transactions in GIS》2003,7(1):83-101
Geographic Information Systems and spatial databases are inherently suited for fuzziness, because of the uncertainty inherent in the assimilation, storage, and representation of spatial data. These objects may also have naturally occurring imprecise boundaries. It is difficult to store and represent these objects while continuing to demonstrate the uncertainty inherent in the objects. This paper describes a fuzzy object–oriented framework to model spatial objects with either precise or uncertain boundaries that will also provide for fuzzy querying of these objects. A prototype system, FOOSBALL, which implements this framework is also discussed. 相似文献
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阐述了电子政务的基本概念、主要功能及发展阶段,分析了电子政务信息平台所包含的地理信息的内容,提出数据集成所需要的三种综合数据库——索引数据库、空间数据库和空间元数据库,介绍了技术支撑体系的组成形式——基础网络层、数据层、软件层、数据库管理层。 相似文献
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可视化交互空间数据挖掘技术的探讨 总被引：12，自引：2，他引：10
随着地理信息获取技术飞速发展,使得当前存储在空间数据库中的空间数据的深度和广度得到了前所未有的发展,传统的空间统计方法和空间分析方法已经难以有效而迅速地处理和分析它们,如何有效而及时地分析和处理空间数据变得越来越迫切。空间数据挖掘作为上个世纪90年代逐步发展起来的新兴技术,逐渐在研究和实践中显示出它的优势。与此同时,地理可视化技术也逐步走向成熟,二者的结合催生出新型空间数据分析技术———可视化交互空间数据挖掘。本文就该技术的相关问题进行了一些研究探讨。 相似文献