Francisco J. Lopez-Pellicer

Availability of the OGC geoprocessing standard: March 2011 reality check

This paper presents an investigation about the servers available in March 2011 conforming to the Web Processing Service interface specification published by the geospatial standards organization Open Geospatial Consortium (OGC) in 2007. This interface specification gives support to standard Web-based geoprocessing. The data used in this research were collected using a focused crawler configured for finding OGC Web services. The research goals are (i) to provide a reality check of the availability of Web Processing Service servers, (ii) to provide quantitative data about the use of different features defined in the standard that are relevant for a scalable Geoprocessing Web (e.g. long-running processes, Web-accessible data outputs), and (iii) to test if the advances in the use of search engines and focused crawlers for finding Web services can be applied for finding geoscience processing systems. Research results show the feasibility of the discovery approach and provide data about the implementation of the Web Processing Service specification. These results also show extensive use of features related to scalability, except for those related to technical and semantic interoperability.

Geo linked data

Semantic Web applications that include map visualization clients are becoming common. When the description of an entity contains coordinate pairs, semantic applications often lay them as pins on maps provided by Web mapping service applications, such as Google Maps. Nowadays, semantic applications cannot guarantee that those maps provide spatial information related to the entities pinned to them. To address this issue, this paper proposes a refinement of Linked Data practices, named Geo Linked Data, which defines a lightweight semantic infrastructure to relate URIs that identify real world entities with geospatial Web resources, such as maps.

Administrative Units, an Ontological Perspective

The administrative units have been created with the purpose of covering specific territorial and functional scopes over time. Therefore, there are heterogeneity not only among states but also at any level of subdivision. In the context of Spatial Data Infrastructures, administrative units are part of the core data model and they are often exploited in the development of web services. International, cross-border, even national web services may face different and superposed administrative models. The administrative models are complex and they may not be well understood by users and developers in some scenarios, i.e. a query in boundary areas with different administrative models. This paper proposes an ontology that can describe administrative models and also serve as a knowledge base that may facilitate mappings between different types of administrative units.

Discovering geographic web services in search engines

Purpose – There is an open discussion in the geographic information community about the use of digital libraries or search engines for the discovery of resources. Some researchers suggest that search engines are a feasible alternative for searching geographic web services based on anecdotal evidence. The purpose of this study is to measure the performance of Bing (formerly Microsoft Live Search), Google and Yahoo! in searching standardised XML documents that describe, identify and locate geographic web services.Design/methodology/approach – The study performed an automated evaluation of three search engines using their application programming interfaces. The queries asked for XML documents describing geographic web services, and documents containing links to those documents. Relevant XML documents linked from the documents found in the search results were also included in the evaluation.Findings – The study reveals that the discovery of geographic web services in search engines does not require the use of...

Spatial Data Infrastructures for environmental e-government services: The case of water abstractions authorisations

Environment-related authorisations are a relevant issue for environmental management. They require a considerable effort by the authorities, and this might result in substantial delays for the citizens. Implementing those authorisation processes by means of e-government services would improve efficiency and, consequently, citizen satisfaction. Environment-related authorisations usually require a variety of geospatial information, and have to deal with administrative areas which do not match physical and ecological ones. They also have to integrate heterogeneous information in different formats, data models and languages, and provided by distinct organisations, even from different countries. This paper discusses how Spatial Data Infrastructures (SDIs) can deal with these problems in the environmental domain, while improving the level of service provision in terms of e-government applications. This is even more relevant within the European Union where there is a legal mandate to establish an SDI to support environmental policies and activities with an impact on the environment. As a proof-of-concept, an application to request and manage water abstraction authorisations, based on an SDI, is demonstrated. This application is part of SDIGER, a cross-border inter-administration SDI to support the water framework directive information access for the Adour-Garonne and Ebro River basins, that was a pilot project for the EU INSPIRE Directive. The introduction of this transactional e-government service modifies the administrative process of granting authorisations: it allows to re-use the effort in data capture made by the applicants in their requests, facilitates the submission of more feasible applications and reduces the workload of the office staff.

Where in the Wikipedia is that answer? the XLDB at the GikiCLEF 2009 task

We developed a new semantic question analyser for a custom prototype assembled for participating in GikiCLEF 2009, which processes grounded concepts derived from terms, and uses information extracted from knowledge bases to derive answers. We also evaluated a newly developed named-entity recognition module, based in Conditional Random Fields, and a new world geoontology, derived from Wikipedia, which is used in the geographic reasoning process.

Exposing CSW catalogues as Linked Data

The OpenGIS Catalogue Services (CS) specification defines a set of abstract interfaces for the discovery, access, maintenance and organization of metadata repositories of geospatial information and related resources in distributed computing scenarios, such as the Web. The CS specification also defines a HTTP protocol binding, which is called “Catalogue Services for the Web” or CSW. A fair description of CSW is a remote catalogue interface over the HTTP protocol, but not over the architecture of the mainstream Web where search engines are the users’ gateway to information. This paper identifies some aspects of CSW that difficult the findability of metadata in the Web, and hence, the discovery of resources. This paper also presents a toolkit that exposes as Linked Data the content of metadata repositories offered through CSW with the purpose of improving the discovery of metadata records in search engines.

An ontology for the representation of spatiotemporal jurisdictional domains in information retrieval systems

Jurisdictional domains are generally accepted political divisions of the earth surface that cover specific territorial and functional scopes over time. They are frequently used in information retrieval (IR) to classify and locate resources by means of their geographical location. However, the changes they suffer over time reduce their applicability in historical collections. In this context, and with the objective of improving the use of jurisdictional domains, this article proposes an ontology schema that combines in a single model the administrative structure, the spatial components, and the temporal evolution of jurisdictional domains. This ontology schema has been used to create the Spanish jurisdictional model. Additionally, as an example of its applicability in the IR context, the Spanish model has been used as part of a location-based query component for the Spanish Official State Gazette.

Exploring the Advances in Semantic Search Engines

With the vertiginous volume information growing, the amount of an- swers provided by traditional search engines and satisfying syntactically the user queries has enlarged directly. In order to reduce this problem the race to develop Semantic Search Engines (SSE) is increasingly popular. Currently, there are mul- tiple proposals for Semantic Search Engines, and they are using a wide range of methods for matching the semantics behind user queries and the indexed collec- tion of resources. In this work we survey the semantic search engines domain, and present a miscellaneous of perspectives about the different classification of ap- proaches. We have created a comparative scheme and identified the prevalent re- search directions in SSE.

Applying Semantic Linkage in the Geospatial Web

The Semantic Web is an attempt to add meaningful annotations to Web resources, services and content that requires developing reference ontologies, which help to understand these annotations. The venue of the Web of Data makes the geographic information, which has become an important part of the current Web, widely usable.