Building ontologies from folksonomies and linked data: Data structures and Algorithms

We present the data structures and algorithms used in the approach for building domain ontologies from folksonomies and linked data. In this approach we extracts domain terms from folksonomies and enrich them with semantic information from the Linked Open Data cloud. As a result, we obtain a domain ontology that combines the emergent knowledge of social tagging systems with formal knowledge from Ontologies

Performance and ownership in the governance of urban water

In this paper the differences in terms of performance between public and the private governance in urban water management are investigated. A statistical ranking is implemented to determine programmatic efficiency differences in DEA, using an incomplete panel data that gathers information on 20 water utilities in Andalusia, in Southern Spain. In the model, labour and operational costs are considered as inputs. The volume of revenue water, the number of connections and the network length are used as outputs. The analysis indicates that private management is more efficient. The efficiency indicators adjusted by a variable related to quality are estimated and demonstrate that privatization of the service does not mean any loss in terms of quality. However, there are no significant differences between both types of management including as a desirable input hydraulic yield as a proxy of the degree of network renovation. A lower hydraulic efficiency in private management would suggest that the need to make significant investments could be an important factor when making the decision to privatize the management of the urban water service: Water supply; Management; Local government;

A new special class of Petrov type D vacuum space-times in dimension five

Using extensions of the Newman-Penrose and Geroch-Held-Penrose formalisms to five dimensions, we invariantly classify all Petrov type $D$ vacuum solutions for which the Riemann tensor is isotropic in a plane orthogonal to a pair of Weyl alligned null directionsComment: 4 pages, 1 table, no figures. Contribution to the proceedings of the Spanish Relativity Meeting 2010 held in Granada (Spain

Spinor calculus on 5-dimensional spacetimes

Penrose's spinor calculus of 4-dimensional Lorentzian geometry is extended to the case of 5-dimensional Lorentzian geometry. Such fruitful ideas in Penrose's spinor calculus as the spin covariant derivative, the curvature spinors or the definition of the spin coefficients on a spin frame can be carried over to the spinor calculus in 5-dimensional Lorentzian geometry. The algebraic and differential properties of the curvature spinors are studied in detail and as an application we extend the well-known 4-dimensional Newman-Penrose formalism to a 5-dimensional spacetime.Comment: Convention mismatch and minor typos fixed. To appear in Journal of Mathematical Physic

The cyclical trend of local public service governance: evidence from urban water management in Spain

The level of public and private involvement in economic activity in societies has changed over time. One may talk about the existence of a cyclical trend in which the most important periods of public governance are replaced by periods in which private management dominates the situation. This phenomenon may also be observed in local areas. Some authors have pointed out the existence of an alternation in the provision of municipal services, resulting in periods dominated by governance compared to other stages dominated by private management. In order to illustrate this cyclical trend at local level, this paper intends to analyze the evolution of the governance of the Spanish water supply since the mid-nineteenth century to the present day. Recent evidence from the industry suggests the possibility that we may currently be witnessing a further change in the trend.: Local Government, urban water supply, privatization, municipalization

Laser radiation as an adjunct to nonsurgical treatment of periodontal disease.

Peer Reviewe

Large-scale benchmarking of the OWL interoperability of Semantic Web technologies

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Interoperability of Protégé using RDF(S) as Interchange Language

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