RDF - semantique
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Introduction à SPARQL (le protocole et langage de requête RDF), par Thibaut Cuvelier et Julien Plu
L'objectif de ce tutoriel est de donner un cours rapide sur SPARQL. Il couvre toutes les fonctionnalités majeures du langage de requête à travers des exemples, mais ne vise pas à être complet. SPARQL est un langage de requêtes et un protocole pour l'accès RDF, conçu par le groupe de travail du W3C RDF Data Access. En tant que tel, SPARQL est orienté données, en ce qu'il n'effectue des recherches que sur des informations contenues dans des modèles ; il n'y a pas d'inférence dans le langage de requête lui-même. Évidemment, le modèle Jena peut être « intelligent », en ce sens qu'il fournit l'impression que certains triplets existent en les créant à la demande, y compris le raisonnement OWL. SPARQL ne fait rien d'autre que prendre la description de ce que l'application veut sous la forme d'une requête et retourne cette information sous la forme d'un ensemble de données liées ou d'un graphe RDF.
Remarque : ces différents exemples sont tirés de l'explication détaillée des technologies du Web sémantique qui accompagne cette publication du thésaurus W.
SPARQL endpoint
Getting Started
Most webmasters are familiar with HTML tags on their pages. Usually, HTML tags tell the browser how to display the information included in the tag. For example, Avatar tells the browser to display the text string "Avatar" in a heading 1 format.
Welcome to schema.org « Tripletalk
Bing, Google, and Yahoo! have announced schema.org yesterday, a collaboration between the three search providers in the area of vocabularies for structured data. As the ‘schema guy’ at Yahoo!, I have been part of the very small core team that developed technical content for schema.org. It’s been an interesting process: if you doubt that achieving an agreement in the search domain is hard, consider that the last time such an agreement happened was apparently sitemaps.org in 2006.
The False Choice of Schema.org | The Beautiful, Tormented Machine
Full disclosure: I am the current Chair of the group at the World Wide Web Consortium that created RDFa. That said, all of this is my personal opinion – I am not speaking on behalf of the W3C or my company, Digital Bazaar. I am biased, but also have been around long enough to know when freedom of choice on the Web is being threatened. Some of you may have heard that Microsoft, Google and Yahoo have just released a new uber-vocabulary for the Web. As the site explains, if you use schema.org, you will get a better looking search listing on all of the search listings for Bing, Google and Yahoo. While this may sound good on the surface, it is very bad news for choice on the Web.
In early June 2011, the three big search engines Bing, Google and Yahoo! introduced Schema.org , a collection of terms that webmasters can use to markup their pages to improve the display of search results. This site is a complementary effort by people from the Linked Data community to support Schema.org deployment and usage with a special focus on Linked Data : Note that the official OWL version of the terms is directly maintained at Schema.org and independent from the above presented formats.
schema.rdfs.org - Home
I'm hesitant to either use superlatives or make predictions concerning search engine innovations (I'm the first to deride commentators that use the phrase "game changer" in almost any context), but the joint announcement by Google , Yahoo and Bing introducing schema.org is, in my opinion, pretty big news. Schema.org at once provides a mechanism by which semantic web technologies can become a lot more mainstream, and at the same time offers the possibility of superior search visibility for search marketers that embrace this standardized, structured on-page markup. Both searchers and publishers of quality content (by which, in this context, I really mean "quality data") stand to gain by the introduction of schema.org.
What Schema.org Means for SEO and Beyond
manusporny ~ 1 year ago from Tweet Share Top Tweets Rating: ( +1 )
tp://bnode.org/blog/2011/06/06/schema-org-threat-or-opportunity
RDF and Transactions
I will here talk about RDF and transactions for developers in general. The next one talks about specifics and is for specialists. Transactions are certainly not the first thing that comes to mind when one hears "RDF". We have at times used a recruitment questionnaire where we ask applicants to define a transaction. Many vaguely remember that it is a unit of work, but usually not more than that.
Computerworld - Vince Fioramonti had an epiphany back in 2001. He realized that valuable investment information was becoming increasingly available on the Web, and that a growing number of vendors were offering software to capture and interpret that information in terms of its importance and relevance. "I already had a team of analysts reading and trying to digest financial news on companies," says Fioramonti, a partner and senior international portfolio analyst at Hartford, Conn.
Semantic Web: Tools you can use
With tools like Neologism and OpenVocab , creating an RDF vocabulary is easy. But if your goal is re-use within a wider community, you will face many questions that are not so easy to answer: A few days ago, the VoID vocabulary became a W3C SWIG Note. VoID started in 2008 as a loose collaboration between Jun Zhao, Keith Alexander, Michael Hausenblas and me.
Creating an RDF vocabulary: Lessons learned | cygri’s notes on web data
About
CKAN is the world’s leading open-source data portal platform . It is a complete out-of-the-box software solution that makes data accessible – by providing tools to streamline publishing , sharing, finding and using data. CKAN is aimed at data publishers (national and regional governments, companies and organizations) wanting to make their data open and available. A slide-deck overview of CKAN can be found here .[ contents ] The identification of resources on the Web by a Uniform Resource Identifier ( URI ) alone may not be sufficient, as other factors such as HTTP content negotiation might come into play. This issue is particularly significant for quality assurance testing, conformance claims, and reporting languages like the W3C Evaluation And Report Language ( EARL ) .
HTTP Vocabulary in RDF 1.0
Althought being commonly depicted as one giant graph, the Web of Data is not a single entity that can be queried. Instead, it’s a distributed architecture made of different datasets each providing some triples (see the LOD Cloud picture and CKAN.net ). Each of these data source can be queried separately, most often through an end point understanding the SPARQL query language.
One SPARQL end point per dataset, One end point to query them all « Semantic Web world for you
The prefix editor allows you to add and remove prefixes from the current document.