Improving the Deductive System DES with Persistence by Using SQL DBMS's

This work presents how persistent predicates have been included in the in-memory deductive system DES by relying on external SQL database management systems. We introduce how persistence is supported from a user-point of view and the possible applications the system opens up, as the deductive expressive power is projected to relational databases. Also, we describe how it is possible to intermix computations of the deductive engine and the external database, explaining its implementation and some optimizations. Finally, a performance analysis is undertaken, comparing the system with current relational database systems.Comment: In Proceedings PROLE 2014, arXiv:1501.0169

Datalog: Bases de datos Deductivas

Este artículo muestra un breve estudio sobre Datalog, el cual es considerado como una  extensión de Prolog que es uno de los sofware más utilizados en la inteligencia artificial. Sistemas importantes como SWI-Prolog[22], Ciao Prolog[4], Sictus-Prolog[20], han sido compiladores utilizados para hacer uso de la funcionalidad del lenguaje lógico para bases de datos deductivas y han logrado la implementación de consultas recursivas  sobre las bases de datos relacionales. En este estudio también se presentan conceptos básicos de Datalog, así como algunos sistemas que se han desarrollado para trabajar con este lenguaje.Palabra(s) Clave(s): Programación lógica, Prolog, Datalog

Semantic description and matching of services for pervasive environments

With the evolution of the World Wide Web and the advancement of the electronic world, the diversity of available services is increasing rapidly.This raises new demands for the efficient discovery and location of heterogeneous services and resources in dynamically changing environments. The traditional approaches for service discovery such as UDDI, Salutation, SLP etc. characterise the services by using predefined service categories and fixed attribute value pairs and the matching techniques in these approaches are limited to syntactic comparisons based on attributes or interfaces. More recently with the popularity of Semantic Web technologies, there has been an increased interest in the application of reasoning mechanisms to support discovery and matching. These approaches provide important directions in overcoming the limitations present in the traditional approaches to service discovery. However, these still have limitations and have overlooked issues that need to be addressed; particularly these approaches do not have an effective ranking criterion to facilitate the ordering of the potential matches, according to their suitability to satisfy the request under concern. This thesis presents a semantic matching framework to facilitate effective discovery of device based services in pervasive environments. This offers a ranking mechanism that will order the available services in the order of their suitability and also considers priorities placed on individual requirements in a request during the matching process. The proposed approach has been implemented in a pervasive scenario for matching device-based services. The Device Ontology which has been developed as part of this research, has been used to describe the devices and their services. The retrieval effectiveness of this semantic matching approach has been formally investigated through the use of human participant studies and the experimental results have indicated that the results correlate well with human perception. The performance of the solution has also been evaluated, to explore the effects of employing reasoning mechanisms on the efficiency of the matching process. Specifically the scalability of the solution has been investigated with respect to the request size and the number of advertisements involved in matching.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Grid application meta-repository system

As one of the most popular forms of distributed computing technology, Grid brings together different scientific communities that are able to deploy, access, and run complex applications with the help of the enormous computational and storage power offered by the Grid infrastructure. However as the number of Grid applications has been growing steadily in recent years, they are now stored on a multitude of different repositories, which remain specific to each Grid. At the time this research was carried out there were no two well-known Grid application repositories sharing the same structure, same implementation, same access technology and methods, same communication protocols, same security system or same application description language used for application descriptions. This remained a great limitation for Grid users, who were bound to work on only one specific repository, and also presented a significant limitation in terms of interoperability and inter-repository access. The research presented in this thesis provides a solution to this problem, as well as to several other related issues that have been identified while investigating these areas of Grid. Following a comprehensive review of existing Grid repository capabilities, I defined the main challenges that need to be addressed in order to make Grid repositories more versatile and I proposed a solution that addresses these challenges. To this end, I designed a new Grid repository (GAMRS – Grid Application Meta-Repository System), which includes a novel model and architecture, an improved application description language and a matchmaking system. After implementing and testing this solution, I have proved that GAMRS marks an improvement in Grid repository systems. Its new features allow for the inter-connection of different Grid repositories; make applications stored on these repositories visible on the web; allow for the discovery of similar or identical applications stored in different Grid repositories; permit the exchange and re-usage of application and applicationrelated objects between different repositories; and extend the use of applications stored on Grid repositories to other distributed environments, such as virtualized cluster-on-demand and cloud computing

Spatio-Temporal Reasoning with LDLT: first steps towards a deductive system for geographical applications

In this paper we describe our experiment using an extension of the deductive database system LDL ++ [AOTZ93, AOZ93, AO93] to express situations that need spatio-temporal reasoning in Sea monitoring. The temporal extension we used is LDLT [DM94], a temporal database proposal that integrates the expressiveness and deductive power of the logic language LDL [NT88] with the possibility to perform temporal reasoning based on the Interval Algebra by Allen [All83]. The aim of our work is to realize an efficient integration between Deductive Databases and Geographical Information Systems (GIS) to study the advantages that the integration can bring to both of them. We want to understand, from one side, the adaptability and the contribution that Deductive Databases technology can give to GIS and from the other side, which kind of temporal reasoning GIS need or which applications GIS are addressed to. In particular, using the Sea monitoring application problem, it can be seen how a minimal tempora..