Global integration of public sector information

This paper deals with technological methods for consolidating assets lists of available public sector information (PSI) for re-use. In this direction, the effort is to review the state of the art in delivering access to PSI throughout the world and to prioritize the necessary engagements for joining available PSI catalogues. We propose an architectural framework grounded on Semantic Web technologies to deliver a global platform for federated searching. A speculative survey of available PSI portals is presented, and the initial implementation, results, and analysis of the proposed architecture are covered in detail

Combining link and content-based information in a Bayesian inference model for entity search

An architectural model of a Bayesian inference network to support entity search in semantic knowledge bases is presented. The model supports the explicit combination of primitive data type and object-level semantics under a single computational framework. A flexible query model is supported capable to reason with the availability of simple semantics in querie

A Linked Data representation of the Nomenclature of Territorial Units for Statistics

The recent publication of public sector information (PSI) data sets has brought to the attention of the scientific community the redundant presence of location based context. At the same time it stresses the inadequacy of current Linked Data services for exploiting the semantics of such contextual dimensions for easing entity retrieval and browsing. In this paper describes our approach for supporting the publication of geographical subdivisions in Linked Data format for supporting the e-government and public sector in publishing their data sets. The topological knowledge published can be reused in order to enrich the geographical context of other data sets, in particular we propose an exploitation scenario using statistical data sets described with the SCOVO ontology. The topological knowledge is then exploited within a service that supports the navigation and retrieval of statistical geographical entities for the EU territory. Geographical entities, in the extent of this paper, are linked data resources that describe objects that have a geographical extension. The data and services presented in this paper allows the discovery of resources that contain or are contained by a given entity URI and their representation within map widgets. We present an approach for a geography based service that helps in querying qualitative spatial relations for the EU statistical geography (proper containment so far). We also provide a rationale for publishing geographical information in Linked Data format based on our experience, within the EnAKTing project, in publishing UK PSI data

Consuming multiple linked data sources: Challenges and Experiences

Linked Data has provided the means for a large number of considerable knowledge resources to be published and interlinked utilising Semantic Web technologies. However it remains difficult to make use of this ‘Web of Data’ fully, due to its inherently distributed and often inconsistent nature. In this paper we introduce core challenges faced when consuming multiple sources of Linked Data, focussing in particular on the problem of querying. We compare both URI resolution and federated query approaches, and outline the experiences gained in the development of an application which utilises a hybrid approach to consume Linked Data from the unbounded web

Integrating public datasets using linked data: challenges and design principles

The world is moving from a state where there is paucity of data to one of surfeit. These data, and datasets, are normally in different datastores and of different formats. Connecting these datasets together will increase their value and help discover interesting relationships amongst them. This paper describes our experience of using Linked Data to inter-operate these different datasets, the challenges we faced, and the solutions we devised. The paper concludes with apposite design principles for using linked data to inter-operate disparate datasets

Distributed human computation framework for linked data co-reference resolution

Distributed Human Computation (DHC) is a technique used to solve computational problems by incorporating the collaborative effort of a large number of humans. It is also a solution to AI-complete problems such as natural language processing. The Semantic Web with its root in AI is envisioned to be a decentralised world-wide information space for sharing machine-readable data with minimal integration costs. There are many research problems in the Semantic Web that are considered as AI-complete problems. An example is co-reference resolution, which involves determining whether different URIs refer to the same entity. This is considered to be a significant hurdle to overcome in the realisation of large-scale Semantic Web applications. In this paper, we propose a framework for building a DHC system on top of the Linked Data Cloud to solve various computational problems. To demonstrate the concept, we are focusing on handling the co-reference resolution in the Semantic Web when integrating distributed datasets. The traditional way to solve this problem is to design machine-learning algorithms. However, they are often computationally expensive, error-prone and do not scale. We designed a DHC system named iamResearcher, which solves the scientific publication author identity co-reference problem when integrating distributed bibliographic datasets. In our system, we aggregated 6 million bibliographic data from various publication repositories. Users can sign up to the system to audit and align their own publications, thus solving the co-reference problem in a distributed manner. The aggregated results are published to the Linked Data Cloud

SPARQL query rewriting for implementing data integration over linked data

There has been lately an increased activity of publishing structured data in RDF due to the activity of the Linked Data community 1. The presence on the Web of such a huge information cloud, ranging from academic to geographic to gene related information, poses a great challenge when it comes to reconcile heterogeneous schemas adopted by data publishers. For several years, the Semantic Web community has been developing algorithms for aligning data models (ontologies). Nevertheless, exploiting such ontology alignments for achieving data integration is still an under supported research topic. The semantics of ontology alignments, often defined over a logical frameworks, implies a reasoning step over huge amounts of data, that is often hard to implement and rarely scales on Web dimensions. This paper presents an algorithm for achieving RDF data mediation based on SPARQL query rewriting. The approach is based on the encoding of rewriting rules for RDF patterns that constitute part of the structure of a SPARQL query

Actualización e internacionalización del catálogo "OSCAR" de experiencias de Física General

En convocatorias anteriores de la convocatorias de Proyectos de Innovación Docente de l UCM, la última de ellas correspondiente a 2014, desarrollamos un Catálogo de experiencias de cátedra para la docencia de Física General, OSCAR. En esta edición los hemos ampliado con nuevas experiencias. Asimismo se ha desarrollado un programa de visitas de colegios a la Facultad de Ciencias Físicas de la UCM