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Wenwen Li Chaowei Yang Chongjun Yang 《International journal of geographical information science》2013,27(8):1127-1147
The increased popularity of standards for geospatial interoperability has led to an increasing number of geospatial Web services (GWSs), such as Web Map Services (WMSs), becoming publicly available on the Internet. However, finding the services in a quick and precise fashion is still a challenge. Traditional methods collect the services through centralized registries, where services can be manually registered. But the metadata of the registered services cannot be updated timely. This paper addresses the above challenges by developing an effective crawler to discover and update the services in (1) proposing an accumulated term frequency (ATF)–based conditional probability model for prioritized crawling, (2) utilizing concurrent multi-threading technique, and (3) adopting an automatic mechanism to update the metadata of identified services. Experiments show that the proposed crawler achieves good performance in both crawling efficiency and results' coverage/liveliness. In addition, an interesting finding regarding the distribution pattern of WMSs is discussed. We expect this research to contribute to automatic GWS discovery over the large-scale and dynamic World Wide Web and the promotion of operational interoperable distributed geospatial services. 相似文献
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GIS互操作的实现途径评述 总被引：19，自引：1，他引：18
文中主要探讨了开放式GIS的规程和关键技术,促进数据、系统和机构的互操作,总结了世界上著名公司最近GIS产品实现互操作的技术途径,给出了国际上有关GIS互操作、开放式GIS研究的最新进展以及近期发展方向。 相似文献
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Luc Anselin Sergio J. Rey Wenwen Li 《International journal of geographical information science》2014,28(11):2261-2280
Within a CyberGIS environment, the development of effective mechanisms to encode metadata for spatial analytical methods and to track the provenance of operations is a key requirement. Spatial weights are a fundamental element in a wide range of spatial analysis methods that deal with testing for and estimating models with spatial autocorrelation. They form the link between the data structure in a GIS and the spatial analysis methods. Over time, the number of formats for spatial weights implemented in software has proliferated, without any standard or easy interoperability. In this paper, we propose a flexible format that provides a way to ensure interoperability within a cyberinfrastructure environment. We illustrate the format with an application of a spatial weights web service, which is part of an evolving spatial analytical workbench. We describe an approach to embed provenance in spatial weights structures and illustrate the performance of the web service by means of a number of small experiments. 相似文献
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地理空间元数据关联网络的构建 总被引：1，自引：1，他引：0
利用资源描述框架（RDF）设计地理空间元数据关联模型,根据地理空间元数据之间的语义关系和语义相关度的计算,以构建以元数据为节点、元数据之间的语义关系为边、语义相关度为权重的关联网络。在这一网络中,一个节点是一个地理空间元数据的资源描述图,包含属性特征（数据来源、空间特征、时间特征、内容）及其关系特征（元数据之间的语义关系、语义相关度）。实验及其分析表明,地理空间元数据关联网络可以有效地支持地理空间数据语义关联检索、推荐等应用,这与传统的基于关键词的元数据检索方式相比,具有更高的准确度。 相似文献
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Francisco Delgado M. Mercedes Martínez-González Javier Finat 《International journal of geographical information science》2013,27(12):2279-2301
Standardization is one of the pillars of interoperability. In this context, efforts promoted by the Open Geospatial Consortium, such as CityGML (Technical University, Berlin), a standard for exchanging three-dimensional models or urban city objects, are welcomed. However, information from other domains of interest (e.g. energy efficiency or building information modeling) is needed for tasks such as land planning, large-scale flooding analysis, or demand/supply energy simulations. CityGML allows extension in order to integrate information from other domains, but the development process is expensive because there is no way to perform it automatically. The discovery of correspondences between CityGML concepts and other domains concepts poses a significant challenge.Ontology matching is the research field emerged from the Semantic Web to address automatic ontology integration. Using the ontology underlying CityGML and the ontologies which model other domains of interest, ontology matching would be able to find the correspondences that would permit the integration in a more automatic manner than it is done now.In this paper, we evaluate if ontology matching techniques allow performing an automatic integration of geospatial information modeled from different viewpoints. In order to achieve this, an evaluation methodology was designed, and it was applied to the discovery of relationships between CityGML and ontologies coming from the building information modeling and Geospatial Semantic Web domains. The methodology and the results of the evaluation are presented. The best results have been achieved using string-based techniques, while matching systems give the worst precision and recall. Only in a few cases the values are over 50%, which shows the limitations when these techniques are applied to ontologies with a partial overlap. 相似文献
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目前,我国已经构建大量不同级别、面向不同应用的地名词典,网络大众化地名服务成为地名词典的必然发展趋势。该文提出一种基于XML Schema的多源异构地名词典集成方法,以XML Schema对地名词典进行数据描述,采用XSLT数据转换方法,运用MapForce软件,快速进行地名词典的数据结构映射,能够有效解决地名词典的跨平台及数据类型不统一问题。 相似文献
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OpenGIS参考模型ORM及地理信息服务应用模式 总被引：4，自引：0，他引：4
地理信息语义互操作是地理信息共享应用的基础,为解决OpenGIS抽象规范与实施规范在地理信息语义描述上的不足,OGC建立了OpenGIS参考模型(OpenGIS Reference Model,ORM),旨在通过ORM实现地理信息共享与互操作。该文从空间信息应用政策、空间信息语义描述、空间信息服务定义与分类、多网络服务配置、共享开发标准五个层面介绍ORM,并分析基于ORM的地理信息服务应用模式。 相似文献
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Gert W. Wolf 《International journal of geographical information science》2014,28(7):1401-1424
This article demonstrates how the generalisation of topographic surfaces has been formalised by means of graph theory and how this formalised approach has been integrated into an ISO standard that is employed within nanotechnology. By applying concepts from higher-dimensional calculus and topology, it is shown that Morse functions are those mappings that are ideally suited for the formal characterisation of topographic surfaces. Based on this result, a data structure termed weighted surface network is defined that may be applied for both the characterisation and the generalisation of the topological structure of a topographic surface. Hereafter, the focus is laid on specific issues of the standard ISO 25178-2; within this standard change trees, a data structure similar to weighted surface networks, are applied to portray the topological information of topographic surfaces. Furthermore, an approach termed Wolf pruning is used to simplify the change tree, with this pruning method being equivalent to the graph-theoretic contractions by which weighted surface networks can be simplified. Finally, some practical applications of the standard ISO 25178-2 within nanotechnology are discussed. 相似文献
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地球空间数据元数据标准初探 总被引：33，自引：4，他引：29
论文首先概要介绍了目前有影响的几个地球空间数据元数据标准,然后从地球空间数据及数据集自身特征出发探讨了数据集元数据的内容,提出了地球空间数据集的层次结构,并给出了基本层和基础层元数据内容。 相似文献
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地球科学数据的元数据研究 总被引：8，自引：0，他引：8
元数据是数据库领域中一个基本的概念,地球科学数据的无数据系统的建立有助于地学数据的开发和利用,文中说明了无数据在地学数据中的应用,论述了地学元数据的分类、获取、管理等问题。 相似文献
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Maythm Al-Bakri 《International journal of geographical information science》2013,27(8):1437-1456
One difficulty in integrating geospatial data sets from different sources is variation in feature classification and semantic content of the data. One step towards achieving beneficial semantic interoperability is to assess the semantic similarity among objects that are categorised within data sets. This article focuses on measuring semantic and structural similarities between categories of formal data, such as Ordnance Survey (OS) cartographic data, and volunteered geographic information (VGI), such as that sourced from OpenStreetMap (OSM), with the intention of assessing possible integration. The model involves ‘tokenisation’ to search for common roots of words, and the feature classifications have been modelled as an XML schema labelled rooted tree for hierarchical analysis. The semantic similarity was measured using the WordNet::Similarity package, while the structural similarities between sub-trees of the source and target schemas have also been considered. Along with dictionary and structural matching, the data type of the category itself is a comparison variable. The overall similarity is based on a weighted combination of these three measures. The results reveal that the use of a generic similarity matching system leads to poor agreement between the semantics of OS and OSM data sets. It is concluded that a more rigorous peer-to-peer assessment of VGI data, increasing numbers and transparency of contributors, the initiation of more programs of quality testing and the development of more directed ontologies can improve spatial data integration. 相似文献
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地学数据共享中的元数据标准结构分析与设计 总被引：13，自引：1，他引：12
针对地学数据共享的实际需求,分析通用地学元数据的构架模式与方法。由此构建的元数据框架包括3个层次,即核心元数据、模式元数据和应用领域专用元数据。结合科技部的国家科学数据网建设规范草案,定义了地学元数据的核心元数据标准,并对应用系统进行设计。研究表明,该元数据标准结构强调地学元数据的可扩展性和兼容性,可以保证现有的主要元数据标准继续使用,避免重复建设。 相似文献
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Derui Deng Shiyao Liu Lawrence Wallis Elizabeth Duncan 《The Australian geographer》2017,48(3):401-416
The introduction in 2014 of the first globally standardised sustainability metric for cities, ISO 37120, transformed the concept of scalability for sustainable city indicators. Our study uses original research involving producers and consumers of urban sustainability indicators (USIs), including ISO 37120, to review the current use of sustainability indicators (SIs) in Sydney and ascertain the use-value of internationally standardised USIs as perceived by professionals in the field. Our findings show that managers of cities use SIs in a variety of ways, yet links between SIs and organisational decision making are often weak. The cost of adaptation to a new indicator set may be prohibitive, especially for smaller city governments. Larger cities are seen to benefit more from international exposure and comparison. Highlighting ISO 37120 should be valued for the opportunity it presents for comparative learning regarding the nature of a sustainable city rather than its benchmarking potential. This article recommends that the process of achieving a sustainable city should be informed by ‘strong’ rather than ‘weak’ sustainability; in this regard ISO 37120 has potential for refinement. Further research is needed into determining aspects of city comparability and methods for linking USI data to government decision making in order to achieve sustainability outcomes. 相似文献
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随着GIS应用的深入,空间数据的可获得性已经成为影响许多从事地理信息系统研究和应用部门发展的重要问题.由于网络中内容和形式各异的海量数据的存在,元数据将为共享数据的快速检索与正确使用提供必要的保证,地理空间元数据是实现异构环境下空间数据共享的主要手段;在分布式环境下,通过元数据接口可以快速地发现各种空间数据服务.对基于元数据的空间数据网络分发系统所涉及的关键技术进行了较为详尽的论述,包括元数据技术、数据压缩技术、数据加密技术等,并给出了整个系统的体系结构. 相似文献
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David J. Magutre 《International journal of geographical information science》2013,27(4):487-488
The integration of multisource heterogeneous spatial data is one of the major challenges for many spatial data users. To facilitate multisource spatial data integration, many initiatives including federated databases, feature manipulation engines (FMEs), ontology-driven data integration and spatial mediators have been proposed. The major aim of these initiatives is to harmonize data sets and establish interoperability between different data sources. On the contrary, spatial data integration and interoperability is not a pure technical exercise, and there are other nontechnical issues including institutional, policy, legal and social issues involved. Spatial Data Infrastructure (SDI) framework aims to better address the technical and nontechnical issues and facilitate data integration. The SDIs aim to provide a holistic platform for users to interact with spatial data through technical and nontechnical tools. This article aims to discuss the complexity of the challenges associated with data integration and propose a tool that facilitates data harmonization through the assessment of multisource spatial data sets against many measures. The measures represent harmonization criteria and are defined based on the requirement of the respective jurisdiction. Information on technical and nontechnical characteristics of spatial data sets is extracted to form metadata and actual data. Then the tool evaluates the characteristics against measures and identifies the items of inconsistency. The tool also proposes available manipulation tools or guidelines to overcome inconsistencies among data sets. The tool can assist practitioners and organizations to avoid the time-consuming and costly process of validating data sets for effective data integration. 相似文献
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Javier Lacasta F. Javier Lopez-Pellicer Borja Espejo-García Javier Nogueras-Iso F. Javier Zarazaga-Soria 《International journal of geographical information science》2017,31(8):1583-1605
Geospatial data catalogs enable users to discover and access geographical information. Prevailing solutions are document oriented and fragment the spatial continuum of the geospatial data into independent and disconnected resources described through metadata. Due to this, the complete answer for a query may be scattered across multiple resources, making its discovery and access more difficult. This paper proposes an improved information retrieval process for geospatial data catalogs that aggregates the search results by identifying the implicit spatial/thematic relations between the metadata records of the resources. These aggregations are constructed in such a way that they match better the user query than each resource individually. 相似文献
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Hansi Senaratne Amin Mobasheri Ahmed Loai Ali Cristina Capineri Mordechai Haklay 《International journal of geographical information science》2017,31(1):139-167
With the ubiquity of advanced web technologies and location-sensing hand held devices, citizens regardless of their knowledge or expertise, are able to produce spatial information. This phenomenon is known as volunteered geographic information (VGI). During the past decade VGI has been used as a data source supporting a wide range of services, such as environmental monitoring, events reporting, human movement analysis, disaster management, etc. However, these volunteer-contributed data also come with varying quality. Reasons for this are: data is produced by heterogeneous contributors, using various technologies and tools, having different level of details and precision, serving heterogeneous purposes, and a lack of gatekeepers. Crowd-sourcing, social, and geographic approaches have been proposed and later followed to develop appropriate methods to assess the quality measures and indicators of VGI. In this article, we review various quality measures and indicators for selected types of VGI and existing quality assessment methods. As an outcome, the article presents a classification of VGI with current methods utilized to assess the quality of selected types of VGI. Through these findings, we introduce data mining as an additional approach for quality handling in VGI. 相似文献