476 research outputs found

    A bibliographic metadata infrastructure for the twenty-first century

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    The current library bibliographic infrastructure was constructed in the early days of computers – before the Web, XML, and a variety of other technological advances that now offer new opportunities. General requirements of a modern metadata infrastructure for libraries are identified, including such qualities as versatility, extensibility, granularity, and openness. A new kind of metadata infrastructure is then proposed that exhibits at least some of those qualities. Some key challenges that must be overcome to implement a change of this magnitude are identified

    XML: aplicaçÔes e tecnologias associadas: 6th National Conference

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    This volume contains the papers presented at the Sixth Portuguese XML Conference, called XATA (XML, AplicaçÔes e Tecnologias Associadas), held in Évora, Portugal, 14-15 February, 2008. The conference followed on from a successful series held throughout Portugal in the last years: XATA2003 was held in Braga, XATA2004 was held in Porto, XATA2005 was held in Braga, XATA2006 was held in Portalegre and XATA2007 was held in Lisboa. Dued to research evaluation criteria that are being used to evaluate researchers and research centers national conferences are becoming deserted. Many did not manage to gather enough submissions to proceed in this scenario. XATA made it through. However with a large decrease in the number of submissions. In this edition a special meeting will join the steering committee with some interested attendees to discuss XATA's future: internationalization, conference model, ... We think XATA is important in the national context. It has succeeded in gathering and identifying a comunity that shares the same research interests and has promoted some colaborations. We want to keep "the wheel spinning"... This edition has its program distributed by first day's afternoon and next day's morning. This way we are facilitating travel arrangements and we will have one night to meet

    Four Lessons in Versatility or How Query Languages Adapt to the Web

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    Exposing not only human-centered information, but machine-processable data on the Web is one of the commonalities of recent Web trends. It has enabled a new kind of applications and businesses where the data is used in ways not foreseen by the data providers. Yet this exposition has fractured the Web into islands of data, each in different Web formats: Some providers choose XML, others RDF, again others JSON or OWL, for their data, even in similar domains. This fracturing stifles innovation as application builders have to cope not only with one Web stack (e.g., XML technology) but with several ones, each of considerable complexity. With Xcerpt we have developed a rule- and pattern based query language that aims to give shield application builders from much of this complexity: In a single query language XML and RDF data can be accessed, processed, combined, and re-published. Though the need for combined access to XML and RDF data has been recognized in previous work (including the W3C’s GRDDL), our approach differs in four main aspects: (1) We provide a single language (rather than two separate or embedded languages), thus minimizing the conceptual overhead of dealing with disparate data formats. (2) Both the declarative (logic-based) and the operational semantics are unified in that they apply for querying XML and RDF in the same way. (3) We show that the resulting query language can be implemented reusing traditional database technology, if desirable. Nevertheless, we also give a unified evaluation approach based on interval labelings of graphs that is at least as fast as existing approaches for tree-shaped XML data, yet provides linear time and space querying also for many RDF graphs. We believe that Web query languages are the right tool for declarative data access in Web applications and that Xcerpt is a significant step towards a more convenient, yet highly efficient data access in a “Web of Data”

    Lexicalized Grammar Specialization for Restricted Applicative Languages

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    Colloque avec actes et comité de lecture. internationale.International audienceIn the context of a spoken interfaces, we present a methodology and an implemented workbench called EGAL (Lexicalized Tree Grammar Extraction) dedicated to design and test restricted languages used in specific task-oriented applications. A complementary methodology is proposed to process the extraction of these applicative languages from a general LTAG grammar and a training corpus. Additional results allow us to estimate the representativeness of the training corpus. An application of the system is presented for the tuning of a LTAG grammar dedicated to a spoken interface on the basis of a Wizard of Oz corpus. || Nous présentons une méthododologie pratique et une plate-forme appelée EGAL (Extraction de Grammaire d'Arbres Lexicalisés) dédiés à la conception et au test d'un sous-langage d'application pour un systÚme de dialogue oral homme-machine. Une méthodologie

    RDF Querying

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    Reactive Web systems, Web services, and Web-based publish/ subscribe systems communicate events as XML messages, and in many cases require composite event detection: it is not sufficient to react to single event messages, but events have to be considered in relation to other events that are received over time. Emphasizing language design and formal semantics, we describe the rule-based query language XChangeEQ for detecting composite events. XChangeEQ is designed to completely cover and integrate the four complementary querying dimensions: event data, event composition, temporal relationships, and event accumulation. Semantics are provided as model and fixpoint theories; while this is an established approach for rule languages, it has not been applied for event queries before

    An Evaluation of Inter-Organizational Workflow Modelling Formalisms

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    This paper evaluates the dynamic aspects of the UML in the context of inter-organizational workflows. Two evaluation methodologies are used. The first one is ontological and is based on the BWW (Bunge-Wand-Weber) models. The second validation is based on prototyping and consists in the development of a workflow management system in the aerospace industry. Both convergent and divergent results are found from the two validations. Possible enhancements to the UML formalism are suggested from the convergent results. On the other hand, the divergent results suggest the need for a contextual specification in the BWW models. Ce travail consiste en une Ă©valuation des aspects dynamiques du language UML dans un contexte de workflow inter-organisationnel. Le choix du language par rapport Ă  d'autres est motivĂ© par sa richesse grammaticale lui offrant une trĂšs bonne adaptation Ă  ce contexte. L'Ă©valuation se fait par une validation ontologique basĂ©e sur les modĂšles BWW (Bunge-Wand-Weber) et par la rĂ©alisation d'un prototype de systĂšme de gestion de workflows inter-organisationnels. À partir des rĂ©sultats convergents obtenus des deux diffĂ©rentes analyses, des amĂ©liorations au formalisme UML sont suggĂ©rĂ©es. D'un autre cotĂ©, les analyses divergentes suggĂšrent une possibilitĂ© de spĂ©cifier les modĂšles BWW Ă  des contextes plus particuliers tels que ceux des workflows et permettent Ă©galement de suggĂ©rer d'autres amĂ©liorations possibles au langage.Ontology, Conceptual study, Prototype Validation, UML, IS development methods and tools., Ontologie, Ă©tude conceptuelle, validation du prototype, UML, mĂ©thodes et outils de dĂ©veloppement IS

    Towards data grids for microarray expression profiles

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    The UK DTI funded Biomedical Research Informatics Delivered by Grid Enabled Services (BRIDGES) project developed a Grid infrastructure through which research into the genetic causes of hypertension could be supported by scientists within the large Wellcome Trust funded Cardiovascular Functional Genomics project. The BRIDGES project had a focus on developing a compute Grid and a data Grid infrastructure with security at its heart. Building on the work within BRIDGES, the BBSRC funded Grid enabled Microarray Expression Profile Search (GEMEPS) project plans to provide an enhanced data Grid infrastructure to support richer queries needed for the discovery and analysis of microarray data sets, also based upon a fine-grained security infrastructure. This paper outlines the experiences gained within BRIDGES and outlines the status of the GEMEPS project, the open challenges that remain and plans for the future

    SKOS and the Semantic Web: Knowledge Organization, Metadata, and Interoperability

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    The Simplified Knowledge Organization System (SKOS) is a Semantic Web framework, based on the Resource Description Framework (RDF) for thesauri, classification schemes and simple ontologies. It allows for machine-actionable description of the structure of these knowledge organization systems (KOS) and provides an excellent tool for addressing interoperability and vocabulary control problems inherent to the rapidly expanding information environment of the Web. This paper discusses the foundations of the SKOS framework and reviews the literature on a variety of SKOS implementations. The limitations of SKOS that have been revealed through its broad application are addressed with brief attention to the proposed extensions to the framework intended to account for them

    Regular Rooted Graph Grammars

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    In dieser Arbeit wir ein pragmatischer Ansatz zur Typisierung, statischen Analyse und Optimierung von Web-Anfragespachen, speziell Xcerpt, untersucht. Pragmatisch ist der Ansatz in dem Sinne, dass dem Benutzer keinerlei EinschrĂ€nkungen aus Entscheidbarkeits- oder EffizienzgrĂŒnden auf modellierbare Typen gestellt werden. Effizienz und Entscheidbarkeit werden stattdessen, falls nötig, durch Vergröberungen bei der TypprĂŒfung erkauft. Eine Typsprache zur Typisierung von Graph-strukturierten Daten im Web wird eingefĂŒhrt. Modellierbare Graphen sind so genannte gewurzelte Graphen, welche aus einem Spannbaum und Querreferenzen aufgebaut sind. Die Typsprache basiert auf regulĂ€re Baum Grammatiken, welche um typisierte Referenzen erweitert wurde. Neben wie im Web mit XML ĂŒblichen geordneten strukturierten Daten, sind auch ungeordnete Daten, wie etwa in Xcerpt oder RDF ĂŒblich, modellierbar. Der dazu verwendete Ansatz---ungeordnete Interpretation RegulĂ€rer AusdrĂŒcke---ist neu. Eine operationale Semantik fĂŒr geordnete wie ungeordnete Typen wird auf Basis spezialisierter Baumautomaten und sog. Counting Constraints (welche wiederum auf presburgerarithmetische AusdrĂŒcke) basieren. Es wird ferner statische Typ-PrĂŒfung und -Inferenz von Xcerpt Anfrage- und Konstrukttermen, wie auch Optimierung von Xcerpt Anfragen auf Basis von Typinformation eingefĂŒhrt.This thesis investigates a pragmatic approach to typing, static analysis and static optimization of Web query languages, in special the Web query language Xcerpt. The approach is pragmatic in the sense, that no restriction on the types are made for decidability or efficiency reasons, instead precision is given up if necessary. Pragmatics on the dynamic side means to use types not only to ensure validity of objects operating on, but also influencing query selection based on types. A typing language for typing of graph structured data on the Web is introduced. The Graphs in mind are based on spanning trees with references, the typing languages is based on regular tree grammars with typed reference extensions. Beside ordered data in the spirit of XML, unordered data (i.e. in the spirit of the Xcerpt data model or RDF) can be modelled using regular expressions under unordered interpretation – this approach is new. An operational semantics for ordered and unordered types is given based on specialized regular tree automata and counting constraints (them again based on Presburger arithmetic formulae). Static type checking of Xcerpt query and construct terms is introduced, as well as optimization of Xcerpt query terms based on schema information
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