Resource Description Framework (RDF) / W3C Semantic Web Activity Overview RDF is a standard model for data interchange on the Web. RDF has features that facilitate data merging even if the underlying schemas differ, and it specifically supports the evolution of schemas over time without requiring all the data consumers to be changed. RDF extends the linking structure of the Web to use URIs to name the relationship between things as well as the two ends of the link (this is usually referred to as a “triple”). Using this simple model, it allows structured and semi-structured data to be mixed, exposed, and shared across different applications. This linking structure forms a directed, labeled graph, where the edges represent the named link between two resources, represented by the graph nodes. Recommended Reading The RDF 1.1 specification consists of a suite of W3C Recommendations and Working Group Notes, published in 2014. A number of textbooks have been published on RDF and on Semantic Web in general. Discussions on a possible next version of RDF
Planète Web Sémantique Le tutoriel SPARQL L'objectif de ce tutoriel SPARQL est de donner un cours rapide en SPARQL. Le tutoriel couvre les fonctionnalités majeures du langage de requête au travers d'exemples, mais ne vise pas à être complet. Si vous cherchez une courte introduction à SPARQL et Jena, essayez Recherche de données RDF avec SPARQL . SPARQL est un langage de requêtes et un protocole pour accéder au RDF conçu par le groupe de travail du W3C RDF Data Access . Comme un langage de requête, SPARQL est « orienté données » en ce sens qu'il interroge uniquement les informations détenues dans des modèles ; il n'y a pas d'inférence dans le langage de requête lui-même. Commentez Tout d'abord, il faut être clair sur quelles données sont interrogées. Il est important de réaliser que ce sont les triplets qui importent, pas la sérialisation. On va commencer avec des données simples dans vc-db-1.rdf : ce fichier contient du RDF pour un certain nombre de descriptions vCard de personnes. Graphiquement, les données ressemblent à : II-A. ?
Resource Description Framework (RDF) Schema Specification 1.0 W3C Candidate Recommendation 27 March 2000 This Version: Latest Version: Previous Version: Editors: Dan Brickley, University of Bristol R.V. Acknowledgments Copyright ©1998,1999,2000 W3C® (MIT, INRIA, Keio), All Rights Reserved. Abstract This specification describes how to use RDF to describe RDF vocabularies. Status of this document This document is a Candidate Recommendation of the World Wide Web Consortium. This specification is a revision of the Proposed Recommendation of March 03 1999, incorporating editorial suggestions received in review comments. The Resource Description Framework is part of the W3C Metadata Activity. This section describes the status of this document at the time of its publication. It is inappropriate to use W3C Candidate Recommendations as reference material or to cite them as other than "work in progress". Table of Contents 1. 1.1. 1.1.1. 2.
RIF Basic Logic Dialect W3C Recommendation 5 February 2013 This version: Latest version: Previous version: Editors: Harold Boley, National Research Council Canada Michael Kifer, State University of New York at Stony Brook, USA Please refer to the errata for this document, which may include some normative corrections. A color-coded version of this document showing changes made since the previous version is also available. This document is also available in these non-normative formats: PDF version. See also translations. Copyright © 2013 W3C® (MIT, ERCIM, Keio, Beihang), All Rights Reserved. Abstract This document, developed by the Rule Interchange Format (RIF) Working Group, specifies the Basic Logic Dialect, RIF-BLD, a format that allows logic rules to be exchanged between rule systems. Status of this Document May Be Superseded This document is being published as one of a set of 13 documents: Patents
SPARQL vs. SQL - Intro This lesson compares the SPARQL and SQL query languages, which are designed to query RDF and relational data, respectively. You may be reading this lesson because you know one and want to learn the other or because you need to make some decisions about which to use for some purpose. First, let's look at their data models; that is, the way we consider their data to be structured. Comparing RDF and SQL data Many people ask what can be done with SPARQL that can't be done with SQL, when in fact they care about what can be done in RDF that can't be done with relational databases. Both of these languages give the user access to create, combine, and consume structured data. Relational data is made up of rows of data collected into tables (also called a "relations" in formal relational literature). CREATE TABLE Person ( ID INT, fname CHAR(10), addr INT, FOREIGN KEY(addr) REFERENCES Address(ID) ); CREATE TABLE Address ( ID INT, city CHAR(10), state CHAR(2) ) <PersonA> a <Person> . SELECT ? SELECT ?
Notation3 (N3): A readable RDF syntax Up to Design Issues An RDF language for the Semantic Web This article gives an operational semantics for Notation3 (N3) and some RDF properties for expressing logic. This is an informal semantics in that should be understandable by a human being but is not a machine readable formal semantics. These properties are not part of the N3 language, but are properties which allow N3 to be used to express rules, and rules which talk about the provenance of information, contents of documents on the web, and so on. The log: namespace has functions, which have built-in meaning for CWM and other software. See also: The prefix log: is used below as shorthand for the namespace < Motivation The motivation of the logic was to be useful as a tool in in open web environment. A goal is that information, such as but not limited to rules, which requires greater expressive power than the RDF graph, should be sharable in the same way as RDF can be shared. Formal syntax Semantics
RIF RDF and OWL Compatibility Abstract Rules interchanged using the Rule Interchange Format RIF may depend on or be used in combination with RDF data and RDF Schema or OWL ontologies. This document, developed by the Rule Interchange Format (RIF) Working Group, specifies the interoperation between RIF and the data and ontology languages RDF, RDF Schema, and OWL. Status of this Document May Be Superseded This section describes the status of this document at the time of its publication. This document is being published as one of a set of 13 documents: Document Unchanged There have been no changes to the body of this document since the previous version. Please Send Comments Please send any comments to public-rif-comments@w3.org (public archive). Endorsed By W3C This document has been reviewed by W3C Members, by software developers, and by other W3C groups and interested parties, and is endorsed by the Director as a W3C Recommendation. Patents 1 Overview of RDF and OWL Compatibility 2 Symbols in RIF versus RDF/OWL (Informative)
Primer - Getting into the semantic web and RDF using N3 [translations into other languages ] The world of the semantic web, as based on RDF, is really simple at the base. This article shows you how to get started. It uses a simplified teaching language -- Notation 3 or N3 -- which is basically equivalent to RDF in its XML syntax, but easier to scribble when getting started. Subject, verb and object In RDF, information is simply a collection of statements, each with a subject, verb and object - and nothing else. <#pat><#knows><#jo> . Everything, be it subject, verb, or object, is identified with a Uniform Resource Identifier. There is one exception: the object (only) can be a literal, such as a string or integer: <#pat><#knows><#jo> . The verb "knows" is in RDF called a "property" and thought of as a noun expressing a relation between the two. <#pat><#child><#al> . alternatively, to make it more readable, as either <#pat> has <#child><#al> . or <#al> is <#child> of <#pat> . <#pat><#child><#al>, <#chaz>, <#mo> ; <#age> 24 ; <#eyecolor> "blue" . . . More
SWRL: A Semantic Web Rule Language Combining OWL and RuleML W3C Member Submission 21 May 2004 This version: Latest version: Authors: Ian Horrocks, Network Inference Peter F. Copyright © 2004 National Research Council of Canada, Network Inference, and Stanford University. Abstract This document contains a proposal for a Semantic Web Rule Language (SWRL) based on a combination of the OWL DL and OWL Lite sublanguages of the OWL Web Ontology Language with the Unary/Binary Datalog RuleML sublanguages of the Rule Markup Language. Status of this document This is a member submission, offered by the National Research Council of Canada, Network Inference and Stanford University, on behalf of themselves and the authors, in association with the Joint US/EU ad hoc Agent Markup Language Committee (Joint Committee). The W3C Team Comment discusses this submission in the context of W3C activities. 1. Both the antecedent (body) and consequent (head) consist of zero or more atoms. 2.
RDF Automation Ushering in Semantic Web Researchers with the Rensselaer Polytechnic Institute (RPI) have thrown themselves head over heels into the semantic web. At this year's 8th International Semantic Web Conference, they presented a paper (download the PDF) focused on the problem of automatically generating the metadata that many semantic web functionalities rely on. Talking about RDF closures can cause eyelids to flutter, but the RPI folks aren't living in some theoretical world. They've been digging hard into large, public data sets and have learned some important lessons about making data more useful. A Quick RDF Primer Before I get into the tech, here's a quick primer for those who don't know their RDFs from their RFCs. Ultimately, RDF is the heart of the Semantic Web. The most important RDF concept to understand is that of the RDF Triple. Resource Description Framework (RDF) Triple — Subject, Predicate (or Property) and Object (or Value) You can read more about RDF Schemas in the W3C RDF Primer. RDF in Action <?
The Semantic Web: An Introduction This document is designed as being a simple but comprehensive introductory publication for anybody trying to get into the Semantic Web: from beginners through to long time hackers. Recommended pre-reading: the Semantic Web in Breadth. Table Of Contents What Is The Semantic Web? The Semantic Web is a mesh of information linked up in such a way as to be easily processable by machines, on a global scale. The Semantic Web was thought up by Tim Berners-Lee, inventor of the WWW, URIs, HTTP, and HTML. What's the rationale for such a system? So the Semantic Web can be seen as a huge engineering solution... but it is more than that. The Semantic Web is generally built on syntaxes which use URIs to represent data, usually in triples based structures: i.e. many triples of URI data that can be held in databases, or interchanged on the world Wide Web using a set of particular syntaxes developed especially for the task. URI - Uniform Resource Identifier RDF - Resource Description Framework Why RDF? Logic
Linked Data | Linked Data - Connect Distributed Data across the