Luis M. Vilches-Blázquez

Methodological Guidelines for Publishing Government Linked Data

Publishing Government Linked Data (and Linked Data in general) is a process that involves a high number of steps, design decisions and technologies. Although some initial guidelines have been already provided by Linked Data publishers, these are still far from covering all the steps that are necessary (from data source selection to publication) or giving enough details about all these steps, technologies, intermediate products, etc. In this chapter we propose a set of methodological guidelines for the activities involved within this process. These guidelines are the result of our experience in the production of Linked Data in several Governmental contexts. We validate these guidelines with the GeoLinkedData and AEMETLinkedData use cases.

GeoLinked data and INSPIRE through an application case

In this paper we present the process that has been followed for the development of an application that makes use of several heterogeneous Spanish public datasets that are related to three themes of INSPIRE Directive, specifically Administrative Units, Hydrography, and Statistical Units. Our application aims at analysing existing relations between the Spanish coastal area and different statistical variables such as population, unemployment, dwelling, industry, and building trade. Besides providing methodological guidelines for the generation, publishing and exploitation of Linked Data from such datasets, we provide an important innovation with respect to other similar processes followed in other initiatives by dealing with the geometrical information of features.

A catalogue of OWL ontology antipatterns

Debugging inconsistent OWL ontologies is a time-consuming task. Debugging services included in existing ontology engineering tools are still far from providing adequate support to ontology developers and domain experts for this task, due to their lack of efficiency or precision when explaining the main causes for inconsistencies. We present a catalogue of common antipatterns found in inconsistent ontologies that can be used in combination with these tools to make this task more effective.

Integrating geographical information in the Linked Digital Earth

Many progresses have been made since the Digital Earth notion was envisioned thirteen years ago. However, the mechanism for integrating geographic information into the Digital Earth is still quite limited. In this context, we have developed a process to generate, integrate and publish geospatial Linked Data from several Spanish National data-sets. These data-sets are related to four Infrastructure for Spatial Information in the European Community (INSPIRE) themes, specifically with Administrative units, Hydrography, Statistical units, and Meteorology. Our main goal is to combine different sources (heterogeneous, multidisciplinary, multitemporal, multiresolution, and multilingual) using Linked Data principles. This goal allows the overcoming of current problems of information integration and driving geographical information toward the next decade scenario, that is, ‘Linked Digital Earth.’

Lightweight semantic annotation of geospatial REST ful services

RESTful services are increasingly gaining traction over WS-* ones. As with WS-* services, their semantic annotation can provide benefits in tasks related to their discovery, composition and mediation. In this paper we present an approach to automate the semantic annotation of RESTful services using a cross-domain ontology like DBpedia, domain ontologies like GeoNames, and additional external resources (suggestion and synonym services). We also present a preliminary evaluation in the geospatial domain that proves the feasibility of our approach in a domain where RESTful services are increasingly appearing and highlights that it is possible to carry out this semantic annotation with satisfactory results.

Interlinking Geospatial Information in the Web of Data

There is an increasing presence of geospatial datasets in the Linked Open Data cloud. However, these datasets are published like data silos and the value of the Web of Data depends, among other properties, on the amount and quality of links between data sources. One of the most overlooked problems to date in the linking process is to ensure that two different resources (identified with URIs) are actually referring to the same physical thing, that is, the co-reference problem. In this paper we present a co-reference resolution approach that is composed of a set of heuristics for interlinking geospatial Linked Data. We have used these heuristics to connect resources from GeoLinkedData.es and DBpedia.

Semantic annotation of RESTful services using external resources

Since the advent of Web 2.0, RESTful services have become an increasing phenomenon. Currently, Semantic Web technologies are being integrated into Web 2.0 services for both to leverage each other strengths. The need to take advantage of data available in RESTful services in the scope of Semantic Web evidences the difficulties to cope with syntactic and semantic description of the services. In this paper we present an approach to tackle the problem of automatic the semantic annotation of RESTful services using a cross-domain ontology, a semantic resource (DBpedia) and additional external resources (suggestion and synonyms services) to annotate the parameters of the RESTful services. We also present a preliminary evaluation that proves the feasibility of our approach and highlights that it is possible to carry out this semantic annotation with satisfactory results.

Ontologies in the Geographic Information Sector

Geographical information (GI) or geoinformation describes phenomena associated directly or indirectly with a location (coordinates systems, address systems…) with respect to the Earth’s surface. Such phenomena can be either spatially discrete (represented by geometric primitives like points, lines, regions, etc.) such as a municipality, a road axis, etc. or spatially continuous (represented by interpolation on an image grid for example) such as terrain’s elevation, pollution diffusion, etc. GI is created by manipulating geographic data (or geospatial data) in a computerized system. Geospatial data can be acquired by different means: topographic survey, remote sensing, aerial photographs, GPS, laserscan, and all other types of sensors or survey techniques. Traditionally, these data are the core component of Geographic Information Systems (GIS), which is the term commonly used to refer to the software packages that allow to capture, store, check, integrate, manipulate, analyze and display them.

A Heuristic Approach to Generate Good-Quality Linked Data about Hydrography

Current Geographic Information is highly heterogeneous due to the diversity of producers and to their different needs. Geographical databases have different information structures, different levels of abstraction and scale, and are available in different natural languages. This is a major obstacle to overcome when generating good quality Linked Data from these databases. In this paper we describe how we generate Linked Data from heterogeneous hydrographical databases from various Spanish institutions. We provide a characterization of the types of heterogeneity found, based on existing semantic heterogeneity classifications, and describe a heuristic approach to deal with duplicity or co-reference problems.