4,009 research outputs found

    Semantic query languages for knowledge-based web services in a construction context

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    Since the early 2000s, different frameworks were set up to enable web-based collaboration in building projects. Unfortunately, none of these initiatives was granted a long life. Recently, however, the use of web technologies in the building industry has been gaining momentum again, considered some promising technologies for reaching a more interoperable BIM practice. Specifically, this relates to (1) Linked Data and Semantic Web technologies, and (2) cloud-based applications. In order to combine these into a network of interlinked applications and datastores, an agreed-upon mechanism for automatic communication and data retrieval needs to be used. Apart from the W3C standard SPARQL, often considered too high a threshold for developers to implement, there are some recent GraphQL-based solutions that simplify the querying process and its implementation into web services. In this paper, we review two recent open source technologies based on GraphQL, that enable to query Linked Data on the web: GraphQL-LD and HyperGraphQL

    Web and Semantic Web Query Languages

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    A number of techniques have been developed to facilitate powerful data retrieval on the Web and Semantic Web. Three categories of Web query languages can be distinguished, according to the format of the data they can retrieve: XML, RDF and Topic Maps. This article introduces the spectrum of languages falling into these categories and summarises their salient aspects. The languages are introduced using common sample data and query types. Key aspects of the query languages considered are stressed in a conclusion

    Effective and Efficient Data Access in the Versatile Web Query Language Xcerpt

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    Access to Web data has become an integral part of many applications and services. In the past, such data has usually been accessed through human-tailoredHTMLinterfaces.Nowadays, rich client interfaces in desktop applications or, increasingly, in browser-based clients ease data access and allow more complex client processing based on XML or RDF data retrieved throughWeb service interfaces. Convenient specifications of the data processing on the client and flexible, expressive service interfaces for data access become essential in this context.Web query languages such as XQuery, XSLT, SPARQL, or Xcerpt have been tailored specifically for such a setting: declarative and efficient access and processing ofWeb data. Xcerpt stands apart among these languages by its versatility, i.e., its ability to access not just oneWeb format but many. In this demonstration, two aspects of Xcerpt are illustrated in detail: The first part of the demonstration focuses on Xcerpt’s pattern matching constructs and rules to enable effective and versatile data access. It uses a concrete practical use case from bibliography management to illustrate these language features. Xcerpt’s visual companion language visXcerpt is used to provide an intuitive interface to both data and queries. The second part of the demonstration shows recent advancements in Xcerpt’s implementation focusing on experimental evaluation of recent complexity results and optimization techniques, as well as scalability over a number of usage scenarios and input sizes

    Survey over Existing Query and Transformation Languages

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    A widely acknowledged obstacle for realizing the vision of the Semantic Web is the inability of many current Semantic Web approaches to cope with data available in such diverging representation formalisms as XML, RDF, or Topic Maps. A common query language is the first step to allow transparent access to data in any of these formats. To further the understanding of the requirements and approaches proposed for query languages in the conventional as well as the Semantic Web, this report surveys a large number of query languages for accessing XML, RDF, or Topic Maps. This is the first systematic survey to consider query languages from all these areas. From the detailed survey of these query languages, a common classification scheme is derived that is useful for understanding and differentiating languages within and among all three areas

    Towards smart style : combining RDF semantics with XML document transformations

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    The 'Document Web' has established itself through the creation of an impressive family of XML and related languages. In addition to this, the 'Semantic Web' is developing its own family of languages based primarily on RDF. Although these families were both developed specifically for 'the Web', each language family has been developed from different premises with specific goals in mind. The result is that combining both families in a single application is surprisingly difficult. This is unfortunate, since the combination of semantic processing with document processing provides advantages in both directions --- namely using semantic inferencing for more intelligent document processing and using document processing tools for presenting semantic representations to an end-user. In this paper, we investigate this integration problem, focusing on the role of (RDF) semantics in selecting, structuring and styling (XML) content. We analyze the approaches taken by two example architectures and use our analysis to derive a more integrated alternative

    Database Management Systems: A NoSQL Analysis

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    Volume 1 Issue 7 (September 2013

    Context based querying of scientific data: changing querying paradigms?

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    We are investigating and applying a semantically enhanced query answering machine for the needs of addressing semantically meaningful data and operations within a scientific information system. We illustrate a context based querying paradigm on the basis of a Regional Avalanche Information and Forecasting System - RAIFoS which is concerned with the collection and analysis of snow and weather related physical parameters in the Swiss Alps. The querying paradigm relies upon the issue of interactively constructing a semantically valid query rather than formulating one in a database specific query language and for a particular implementation model. In order to achieve this goal, the query answering machine has to make inferences concerning the properties and value domains, as well as data analysis operations, which are semantically valid within particular contexts. These inferences take place when the intended query is being constructed interactively on a Web-based blackboard. A graph-based display presentation formalism is used with elements including natural language terms, measurement units, statistical quantifiers and/or specific value domains. A meta-data database is used to organise and provide the elements of the graph each time the graph, and consequently the intended query, is expanded or further refined. Finally, the displayed graph is transformed into elements of the implementation model from which, in turn, SQL statements and/or sequences of statistical operations are created

    Knowledge formalization in experience feedback processes : an ontology-based approach

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    Because of the current trend of integration and interoperability of industrial systems, their size and complexity continue to grow making it more difficult to analyze, to understand and to solve the problems that happen in their organizations. Continuous improvement methodologies are powerful tools in order to understand and to solve problems, to control the effects of changes and finally to capitalize knowledge about changes and improvements. These tools involve suitably represent knowledge relating to the concerned system. Consequently, knowledge management (KM) is an increasingly important source of competitive advantage for organizations. Particularly, the capitalization and sharing of knowledge resulting from experience feedback are elements which play an essential role in the continuous improvement of industrial activities. In this paper, the contribution deals with semantic interoperability and relates to the structuring and the formalization of an experience feedback (EF) process aiming at transforming information or understanding gained by experience into explicit knowledge. The reuse of such knowledge has proved to have significant impact on achieving themissions of companies. However, the means of describing the knowledge objects of an experience generally remain informal. Based on an experience feedback process model and conceptual graphs, this paper takes domain ontology as a framework for the clarification of explicit knowledge and know-how, the aim of which is to get lessons learned descriptions that are significant, correct and applicable
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