945 resultados para Semantic Web, Web 2.0, Linked Data, Web of Data, OWL, QRPlaces, Ontologie, MashUp, Tecnologie Web
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Existing semantic search tools have been primarily designed to enhance the performance of traditional search technologies but with little support for ordinary end users who are not necessarily familiar with domain specific semantic data, ontologies, or SQL-like query languages. This paper presents SemSearch, a search engine, which pays special attention to this issue by providing several means to hide the complexity of semantic search from end users and thus make it easy to use and effective.
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INFRAWEBS project [INFRAWEBS] considers usage of semantics for the complete lifecycle of Semantic Web processes, which represent complex interactions between Semantic Web Services. One of the main initiatives in the Semantic Web is WSMO framework, aiming at describing the various aspects related to Semantic Web Services in order to enable the automation of Web Service discovery, composition, interoperation and invocation. In the paper the conceptual architecture for BPEL-based INFRAWEBS editor is proposed that is intended to construct a part of WSMO descriptions of the Semantic Web Services. The semantic description of Web Services has to cover Data, Functional, Execution and QoS semantics. The representation of Functional semantics can be achieved by adding the service functionality to the process description. The architecture relies on a functional (operational) semantics of the Business Process Execution Language for Web Services (BPEL4WS) and uses abstract state machine (ASM) paradigm. This allows describing the dynamic properties of the process descriptions in terms of partially ordered transition rules and transforming them to WSMO framework.
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We propose a description logic extending SROIQ (the description logic underlying OWL 2 DL) and at the same time encompassing some of the most prominent monotonic and nonmonotonic rule languages, in particular Datalog extended with the answer set semantics. Our proposal could be considered a substantial contribution towards fulfilling the quest for a unifying logic for the Semantic Web. As a case in point, two non-monotonic extensions of description logics considered to be of distinct expressiveness until now are covered in our proposal. In contrast to earlier such proposals, our language has the "look and feel" of a description logic and avoids hybrid or first-order syntaxes. © 2012 The Author(s).
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Postprint
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Peer reviewed
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En este documento se propone un marco de trabajo basado en tecnologías de la Web Semántica para detectar potenciales redes de colaboración, mediante el enriquecimiento semántico de artículos científicos producidos por investigadores que publican con afiliaciones ecuatorianas. El marco de trabajo se describe a través de un ciclo de publicación de datos enlazados. Como alcance se consideraron publicaciones que tienen al menos un autor con afiliación ecuatoriana. Las redes de colaboración detectadas son un insumo importante para fortalecer los esfuerzos del gobierno ecuatoriano y las autoridades universitarias del país, priorizar los esfuerzos y recursos invertidos en investigación y determinar la pertinencia o coherencia de los programas de investigación.
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Many years have passed since Berners-Lee envi- sioned the Web as it should be (1999), but still many information professionals do not know their precise role in its development, especially con- cerning ontologies –considered one of its main elements. Why? May it still be a lack of under- standing between the different academic commu- nities involved (namely, Computer Science, Lin- guistics and Library and Information Science), as reported by Soergel (1999)? The idea behind the Semantic Web is that of several technologies working together to get optimum information re- trieval performance, which is based on proper resource description in a machine-understandable way, by means of metadata and vocabularies (Greenberg, Sutton and Campbell, 2003). This is obviously something that Library and Information Science professionals can do very well, but, are we doing enough? When computer scientists put on stage the ontology paradigm they were asking for semantically richer vocabularies that could support logical inferences in artificial intelligence as a way to improve information retrieval systems. Which direction should vocabulary development take to contribute better to that common goal? The main objective of this paper is twofold: 1) to identify main trends, issues and problems con- cerning ontology research and 2) to identify pos- sible contributions from the Library and Information Science area to the development of ontologies for the semantic web. To do so, our paper has been structured in the following manner. First, the methodology followed in the paper is reported, which is based on a thorough literature review, where main contributions are analysed. Then, the paper presents a discussion of the main trends, issues and problems concerning ontology re- search identified in the literature review. Recom- mendations of possible contributions from the Library and Information Science area to the devel- opment of ontologies for the semantic web are finally presented.
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We provide all agent; the capability to infer the relations (assertions) entailed by the rules that, describe the formal semantics of art RDFS knowledge-base. The proposed inferencing process formulates each semantic restriction as a rule implemented within a, SPARQL query statement. The process expands the original RDF graph into a fuller graph that. explicitly captures the rule's described semantics. The approach is currently being explored in order to support descriptions that follow the generic Semantic Web Rule Language. An experiment, using the Fire-Brigade domain, a small-scale knowledge-base, is adopted to illustrate the agent modeling method and the inferencing process.
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Dissertação para obtenção do Grau de Mestre em Lógica Computacional
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Ontologies formalized by means of Description Logics (DLs) and rules in the form of Logic Programs (LPs) are two prominent formalisms in the field of Knowledge Representation and Reasoning. While DLs adhere to the OpenWorld Assumption and are suited for taxonomic reasoning, LPs implement reasoning under the Closed World Assumption, so that default knowledge can be expressed. However, for many applications it is useful to have a means that allows reasoning over an open domain and expressing rules with exceptions at the same time. Hybrid MKNF knowledge bases make such a means available by formalizing DLs and LPs in a common logic, the Logic of Minimal Knowledge and Negation as Failure (MKNF). Since rules and ontologies are used in open environments such as the Semantic Web, inconsistencies cannot always be avoided. This poses a problem due to the Principle of Explosion, which holds in classical logics. Paraconsistent Logics offer a solution to this issue by assigning meaningful models even to contradictory sets of formulas. Consequently, paraconsistent semantics for DLs and LPs have been investigated intensively. Our goal is to apply the paraconsistent approach to the combination of DLs and LPs in hybrid MKNF knowledge bases. In this thesis, a new six-valued semantics for hybrid MKNF knowledge bases is introduced, extending the three-valued approach by Knorr et al., which is based on the wellfounded semantics for logic programs. Additionally, a procedural way of computing paraconsistent well-founded models for hybrid MKNF knowledge bases by means of an alternating fixpoint construction is presented and it is proven that the algorithm is sound and complete w.r.t. the model-theoretic characterization of the semantics. Moreover, it is shown that the new semantics is faithful w.r.t. well-studied paraconsistent semantics for DLs and LPs, respectively, and maintains the efficiency of the approach it extends.
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The Department of Health of the Government of Andalusia provides professionals of the Andalusian Public Health Care System a collaborative working environment (Entorno colaborativo de trabajo [ECT]) based on the principles of web 2.0. The ECT is organized into communities, understood as sets of people with a common interest who share a space with its own information and collaboration tools. This space is managed and powered autonomously by the communities themselves. This paper analyzes the use and degree of implementation of the ECT, considering the user communities and activity statistics in 2009 and 2010. From the data obtained we deduce that instrumental services have easier acceptance than collaboration and knowledge management services; content generation is focused on a small number of users; and communities associated with organizational units have less development than those associated with work areas or projects.
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This work briefly analyses the difficulties to adopt the Semantic Web, and in particular proposes systems to know the present level of migration to the different technologies that make up the Semantic Web. It focuses on the presentation and description of two tools, DigiDocSpider and DigiDocMetaEdit, designed with the aim of verifYing, evaluating, and promoting its implementation.
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Polyphenols are a major class of bioactive phytochemicals whose consumption may play a role in the prevention of a number of chronic diseases such as cardiovascular diseases, type II diabetes and cancers. Phenol-Explorer, launched in 2009, is the only freely available web-based database on the content of polyphenols in food and their in vivo metabolism and pharmacokinetics. Here we report the third release of the database (Phenol-Explorer 3.0), which adds data on the effects of food processing on polyphenol contents in foods. Data on >100 foods, covering 161 polyphenols or groups of polyphenols before and after processing, were collected from 129 peer-reviewed publications and entered into new tables linked to the existing relational design. The effect of processing on polyphenol content is expressed in the form of retention factor coefficients, or the proportion of a given polyphenol retained after processing, adjusted for change in water content. The result is the first database on the effects of food processing on polyphenol content and, following the model initially defined for Phenol-Explorer, all data may be traced back to original sources. The new update will allow polyphenol scientists to more accurately estimate polyphenol exposure from dietary surveys. Database URL: http://www.phenol-explorer.eu
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Long-term independent budget travel to countries far away has become increasingly common over the last few decades, and backpacking has now entered the tourism mainstream. Nowadays, backpackers are a very important segment of the global travel market. Backpacking is a type of tourism that involves a lot of information search activities. The Internet has become a major source of information as well as a platform for tourism business transactions. It allows travelers to gain information very effortlessly and to learn about tourist destinations and products directly from other travelers in the form of electronic word-of-mouth (eWOM). Social media has penetrated and changed the backpacker market, as now modern travelers can stay connected to people at home, read online recommendations, and organize and book their trips very independently. In order to create a wider understanding on modern-day backpackers and their information search and share behavior in the Web 2.0 era, this thesis examined contemporary backpackers and their use of social media as an information and communication platform. In order to achieve this goal, three sub-objectives were identified: 1. to describe contemporary backpacker tourism 2. to examine contemporary backpackers’ travel information search and share behavior 3. to explore the impacts of new information and communications technologies and Web 2.0 on backpacker tourism The empirical data was gathered with an online survey, thus the method of analysis was mainly quantitative, and a qualitative method was used for a brief analysis of open questions. The research included both descriptive and analytical approaches, as the goal was to describe modern-day backpackers, and to examine possible interdependencies between information search and share behavior and background variables. The interdependencies were tested for statistical significance with the help of five research hypotheses. The results suggested that backpackers no longer fall under the original backpacker definitions described some decades ago. Now, they are mainly short-term travelers, whose trips resemble more those of mainstream tourists. They use communication technologies very actively, and particularly social media. Traditional information sources, mainly guide books and recommendations from friends, are of great importance to them but also eWOM sources are widely used in travel decision making. The use of each source varies according to the stage of the trip. All in all, Web 2.0 and new ICTs have transformed the backpacker tourism industry in many ways. Although the experience has become less authentic in some travelers’ eyes, the backpacker culture is still recognizable.
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À l’ère du web 2.0, l’usage des sites web se multiplie et génère de nouveaux enjeux. La satisfaction en rapport à l’interactivité, facteur d’efficacité des sites, détermine la popularité, et donc la visibilité de ceux-ci sur la Toile. Par conséquent, dans cette étude, nous considérons que les utilisateurs ont un rôle à jouer lors du processus de conception de ces derniers. Certes, autant en théorie que dans la pratique, les concepteurs semblent bel et bien tenir compte des utilisateurs; toutefois, ils ne les intègrent pas comme participants actifs dans leurs démarches. Cette étude vise au moyen d’une recherche documentaire et d’observations sur le terrain à comprendre les principales catégories et morphologies des sites web ainsi que les usages qui en découlent. Une analyse des diverses démarches de conception et des perceptions et attentes des internautes est réalisée sur la base de ces résultats. Pour répondre à ces objectifs, cette analyse cible deux catégories de sites réalisés par des professionnels et par des amateurs. Celle-ci nous permet de démontrer que les résultats de chacune de ces démarches, exprimés à travers les interfaces graphiques des sites, diffèrent au niveau de la qualité perceptible. Cette étude souligne également l’importance d’un traitement efficace de la communication graphique des éléments des sites web, afin de structurer la lecture et transmettre au final un message clair et compréhensible aux internautes. Dans le but consolider nos propositions, nous faisons référence à deux théories de communication graphique, la Gestalt et la sémiotique, l’une s’intéressant à la perception visuelle, l’autre à l’interprétation des signes. Celles-ci se sont révélées pertinentes pour analyser la qualité et l’efficacité des éléments de contenus. Notre étude révèle que les participants ne sont pas satisfaits des deux sites testés car l’utilisabilité du site conçu par des professionnels est trop complexe et l’interface du site conçu par un amateur manque de professionnalisme et de cohérence. Ces résultats soulignent la pertinence d’une approche centrée sur l’utilisateur pour la conception de sites web, car elle permet d’identifier et de résoudre des erreurs de conception. Nos résultats permettent également de souligner que les professionnels ayant un savoir technique et théorique se démarquent des amateurs au niveau des intervenants, des outils et des limites. Des pistes de solution, via des critères de design centré sur l’utilisateur, sont proposées à la fin de cette étude dans le but d’optimiser la qualité et l’efficacité des interfaces graphiques web.