RDF 1.1 Primer Abstract This primer is designed to provide the reader with the basic knowledge required to effectively use RDF. It introduces the basic concepts of RDF and shows concrete examples of the use of RDF. Secs. 3-5 can be used as a minimalist introduction into the key elements of RDF. Changes between RDF 1.1 and RDF 1.0 (2004 version) are summarized in a separate document: "What's New in RDF 1.1" [RDF11-NEW]. Status of This Document This section describes the status of this document at the time of its publication. This document is part of the RDF 1.1 document suite. This document was published by the RDF Working Group as a Working Group Note. Publication as a Working Group Note does not imply endorsement by the W3C Membership. This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. Table of Contents 1. The Resource Description Framework (RDF) is a framework for expressing information about resources. 2. 3. 3.1 Triples Example 1: Sample triples (informal) Note
Problems of the RDF model: Blank Nodes There is a number of challenges regarding the realization of the Semantic Web vision. In the series of blog posts to follow, I’ll be focusing on the Linked Data field and the ideas, technologies and standards it’s based on. I’ll analyze the problems of the three important aspects of Linked Data: the RDF model, the RDF notation and the drawbacks of Linked Data itself. Problems regarding the RDF model RDF is a data model that represents knowledge in the form of simple statements called RDF triples, which consist of a subject, a predicate and an object, like a simple sentences in a human language. In RDF, there are three types of nodes – URI references, blank nodes and literals. The RDF model is based on a simple idea, but it has problems that make it unnecessarily complicated, thus decreasing its value. the existence of nodes that have no nameproblems associated with the literalsthe lack of a unique concept of the node Blank nodes Not always. next post: Problems of the RDF model: Literals »
curl and libcurl Tools - Semantic Web Standards Overview This Wiki contains a collection of tool references that can help in developing Semantic Web applications. These include complete development environments, editors, libraries or modules for various programming languages, specialized browsers, etc. The goal is to list such tools and not Semantic Web applications in general (the interested reader may consider looking at the W3C SW Use Case Collection for those.) The tool content of this wiki is still to be maintained by the community and not by the W3C staff. Search possibilities The current Wiki contains references to 336 tools. Search through categories, i.e., reasoners, programming environments, browsers, etc. Last modified/added Tool Data in RDF There is also an option to get one RDF/XML graph for all tools. Other resources There are other pages on tool collection out there, largely overlapping with this, but possibly with a different granularity or emphasis. Sweet Tools maintained by Michael K. History
Un guide pour le schéma de balisage, les données structurées et les opportunités SEO par type de site Partage Tweet Email Les données structurées peuvent vous aider à envoyer les bons signaux aux moteurs de recherche à propos de votre entreprise et de votre contenu. Vous avez probablement entendu dire que le schéma de balisage (ou d’autres types de données structurées) peut aider à augmenter la compréhension du contenu de votre site par les moteurs de recherche et améliorer la visibilité via des extraits enrichis et les résultats sélectionnés dans Knowledge Graph. Besoin d'un DéveloppeurWebmasterRédacteur Déposez gratuitement votre projet sur Codeur.com et recevez rapidement des propositions de devis. John Mueller de Google a récemment déclaré que le moteur de recherche peut ajouter les données structurées comme un facteur de classement. Cependant, il peut être parfois difficile de déterminer quel schéma utiliser sur votre site. Tous les sites Les types de schéma de balisage suivants peuvent et doivent être utilisés dans tous les types de sites. Schéma de balisage pour les entreprises
RDF Schema Un article de Wikipédia, l'encyclopédie libre. La première version de RDFS a été proposée en mars 1999, et la recommandation finale publiée par le W3C en février 2004. Les composants principaux de RDFS sont intégrés dans un langage d'ontologie plus expressif, OWL. Principales caractéristiques de RDFS[modifier | modifier le code] Classes et sous-classes[modifier | modifier le code] Un exemple simple de rdfs:Class est foaf:Person dans le vocabulaire FOAF. ex:Jean rdf:type foaf:Person La définition de rdfs:Class est récursive. rdfs:Class est la classe de toutes les classes. rdfs:subClassOf permet de définir des hiérarchies de classes. Par exemple, 'Toute personne est un Agent': foaf:Person rdfs:subClassOf foaf:Agent Propriétés[modifier | modifier le code] RDFS précise la notion de propriété définie par RDF en permettant de donner un type ou une classe au sujet et à l'objet des triplets. rdfs:domain définit la classe des sujets liée à une propriété. ex:travailledans rdfs:domain foaf:Person
RDF - Semantic Web Standards 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”). 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 W3C has recently set up a new RDF Working Group, whose charter is to make a minor revision of RDF. Last modified and/or added All relevant tools
The D2RQ Platform – Accessing Relational Databases as Virtual RDF Graphs Flint SPARQL Editor Demo Welcome to Flint, our editor for SPARQL queries. Features Flint 1.0 is now available. This is our first production release. This version supersedes Flint 0.5.1 which was released June 2011. Flint has the following features: Flint should work in Firefox, Chrome, Safari and Opera. Getting the Code Flint has been released with an open license for deployment on your own site. Feedback If you have comments, suggestions or bug reports please send them to flintsparqleditor@tso.co.uk
Google ajoute un aperçu à l'outil de test des données structurées Google a mis à jour son outil de test des données structurées qui propose désormais une prévisualisation lorsque vous soumettez une URL ou un extrait de code à tester. Ce qui signifie que vous pouvez vérifier et voir à quoi ressemblera votre balisage de données structurées dans les résultats de recherche de Google, sans avoir à attendre de l’apercevoir directement dans les résultats de recherche. Selon Thesempost, la fonctionnalité de prévisualisation ne fonctionne que pour certains types de schéma tels que les produits et les recettes de cuisine qui sont pris en charge. Pour afficher l'aperçu de l’URL testée, vous devez d’abord cliquer sur un type spécifique de schema (dans la partie droite de la page) , avant de cliquer sur le bouton “Prévisualiser” qui s’affichera. Au regard de la prévisualisation affichée, l’interface fait penser au mobile, y inclus le format AMP. Google précise sur la page de l'aperçu : Cet outil fournit un aperçu des résultats de recherche Google.
RDFa Distiller and Parser This distiller corresponds to the RDFa 1.0 specification. In 2012, W3C has published an updated version of that specification, called RDFa Core 1.1. A new distiller, processing RDFa 1.1 content, has been implemented which suprecedes this one. Note that the new distiller can also process RDFa 1.0 content (there are some minor incompatibilities) if the XHTML+RDFa file uses the right (RDFa 1.0) DTD and/or the @version attribute. If you intend to use this service regularly on large scale, consider downloading the package and use it locally. What is it? RDFa is a specification for attributes to be used with XHTML or SVG Tiny to express structured data. pyRdfa is a server-side implementation of RDFa. Distiller options Output format (option: “format”, values: “xml”, “turtle”, “nt”) The default output format is RDF/XML. Warnings (option: “warnings”, values: “true”/“false”) Parser options (option: “parser”, values: “lax”/“strict”) (Note that the HTML5 parser is work in progress, errors may occur.
SWValidators - Semantic Web Standards This page tries to collect what the current situation is with SW related validators what could be added with a reasonable amount of work The page was created after Semantic Web Coordination Group discussions, noting that the current RDF validator has not been actively developed for several years. While it is functional and serves a basic purpose, there is always the potential for improvements. Meanwhile, the RDF family of W3C standards has grown; we now have a query language (SPARQL), also based on RDF patterns; a powerful ontology language (OWL), rules framework (RIF) and more options for encoding RDF data (GRDDL, Turtle etc). Please don't hesitate to edit this page with links to other tools that check conformance to W3C Semantic Web standards, or which help developers and software check conformance of RDF/OWL etc data to particular application needs. Current validators (listed on this site) What can be added Related Links
LODE - Live OWL Documentation Environment Live OWL Documentation Environment (LODE), version 1.2 dated 3 June 2013, is a service that automatically extracts classes, object properties, data properties, named individuals, annotation properties, general axioms and namespace declarations from an OWL and OWL2 ontology, and renders them as ordered lists, together with their textual definitions, in a human-readable HTML page designed for browsing and navigation by means of embedded links. This LODE service is an open source development, and can be freely used, as described in this document. It may be used in conjunction with content negotiation to display this human-readable version of an OWL ontology when the user accesses the ontology using a web browser, or alternatively to deliver the OWL ontology itself when the user accesses the ontology using an ontology editing tool such as Protégé and NeOn Toolkit. The following pseudo-URL describes the way to call the LODE service: where: www.essepuntato.it/lode is the URL to call the service.
Product | Search | Google Developers Add markup to your product pages so Google can provide detailed product information in rich Search results — including Google Images. Users can see price, availability, and review ratings right on Search results. Using markup to enable rich product results lets you attract potential buyers while they are searching for items to buy on Google or images that include products you sell. This page explains how to mark up your product information so that Google can display rich results (previously known as rich snippets). a product page that describes a single product a shopping aggregator page that lists a single product, along with information about different sellers offering that product Product markup enables a badge on the image in mobile image search results, which can encourage more users to click your content. Product rich results provide users with information about a specific product, such as its price, availability, and reviewer ratings.