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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. Le tutoriel SPARQL. RADiFy - The RDFa annotation bookmarklet! © 2011 Duncan Grant. 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, <h1>Avatar</h1> tells the browser to display the text string "Avatar" in a heading 1 format.

However, the HTML tag doesn't give any information about what that text string means—"Avatar" could refer to the hugely successful 3D movie, or it could refer to a type of profile picture—and this can make it more difficult for search engines to intelligently display relevant content to a user. Schema.org provides a collection of shared vocabularies webmasters can use to mark up their pages in ways that can be understood by the major search engines: Google, Microsoft, Yandex and Yahoo!

1. 1a. Your web pages have an underlying meaning that people understand when they read the web pages. 1b. itemscope and itemtype Let's start with a concrete example. To begin, identify the section of the page that is "about" the movie Avatar. Back to top 1d. 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. However, over the years, the lack of agreement on schemas have become such a major pain point for publishers new to the Semantic Web, that eventually cooperation became the only sensible thing to do for the future of the Semantic Web project.

So how did we get here? Given the above history, I’m extremely glad that cooperation prevailed in the end and hopefully schema.org will become a central point for vocabularies for the Semantic Web for a long time to come. Like this: Like Loading... The False Choice of Schema.org. Schema.rdfs.org - Home. What Schema.org Means for SEO and Beyond. 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. An Extraordinarily Brief Introduction to Structured Data Structured data is a mechanism by which relationships between things can be expressed in a machine-readable format. Schema.org is microdata. Major Implications of Schema.org. Common RDF Vocabulary Labels Vocabulary. 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. We sometimes get questions from users about why they get an error message that says "deadlock". "Deadlock" is what happens when multiple users concurrently update balances on multiple bank accounts in the wrong order. There are in fact users who even use XA with a Virtuoso-based RDF application. At the same time, the developer population trained with MySQL and PHP is not particularly transaction-aware. If one indeed did enforce them all, then RDF would be very like the relational model -- with all the restrictions, but without the 40 years of work on RDBMS performance.

Semantic Web: Tools you can use. By Elisabeth Horwitt March 23, 2011 06:00 AM ET 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.

-based investment firm Alpha Equity Management. But the process was too slow and results tended to be subjective and inconsistent. The following year, Fioramonti licensed Autonomy Corp.' (For more information about semantic technologies, including search, see Part 1 of this story, "The semantic Web gets down to business. ") The breakthrough for Alpha Equity came in 2008, when the firm signed up for Thomson Reuters' Machine Readable News. The key standards. Creating an RDF vocabulary: Lessons learned | cygri’s notes on web data. 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: How much work is it going to be and what timeframe is realistic? How broad and how deeply should you cover the domain? Where to stop? Work alone or seek collaborators? A few days ago, the VoID vocabulary became a W3C SWIG Note. I will focus on process and collaboration in this post, and say little about modeling practices or publishing tools or RDFS/OWL geekery.

Lesson #1: Work in a team. Lesson #2: Take your time. And that might be the best way. We also moved the vocabulary to a different host twice in the process. Lesson #3: Use a public issue tracker. I think it’s important to use a tracker that is easy to work with, ideally one that the contributors are already familiar with. Setting up a Google Code project for developing the vocabulary worked very well for us.

Lesson #5: Regular Skype calls. 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. CKAN is currently used by governments and organizations worldwide to power both official and community data portals. CKAN was developed by the non-profit Open Knowledge Foundation and is today overseen and managed by the CKAN Association.

Technology CKAN is built with Python on the backend and Javascript on the frontend, and uses The Pylons web framework and SQLAlchemy as its ORM. CKAN uses its internal model to store metadata about the different records, and presents it on a web interface that allows users to browse and search this metadata. View our brochure for further details. HTTP Vocabulary in RDF 1.0. [contents] Abstract 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).

This document provides a representation of the HTTP vocabulary in the Resource Description Framework (RDF), to allow quality assurance tools to record the HTTP headers that have been exchanged between a client and a server. Status of this document This section describes the status of this document at the time of its publication. This 10 May 2011 Working Draft of HTTP Vocabulary in RDF 1.0 is an update of the previous HTTP Vocabulary in RDF Working Draft of 29 October 2009, and it incorporates all comments received since. Publication as a Working Draft does not imply endorsement by the W3C Membership. 1 Introduction 2 Classes. How-to create a Linked Data site. One SPARQL end point per dataset, One end point to query them all « Semantic Web world for you. 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. Looking for answers making use of information spanning over different data sets is a more challenging task as the mechanisms used internally to query one data set (database-like joins, query planning, …) do not scale easily over several data sources. When you want to combine information from, say DBPedia and the Semantic Web doog food site, the easiest and quickest workaround is to download the content of the two datasets, eventually filtering out triples you don’t need, and load the content retrieved into a single data store.

Let’s suppose you want to find some persons and the capital of the country they live in: Live Loop. D2RQ - Treating Non-RDF Databases as Virtual RDF Graphs - Chris Bizer. The RDF Data Cube vocabulary. Abstract There are many situations where it would be useful to be able to publish multi-dimensional data, such as statistics, on the web in such a way that it can be linked to related data sets and concepts. The Data Cube vocabulary provides a means to do this using the W3C RDF (Resource Description Framework) standard. The model underpinning the Data Cube vocabulary is compatible with the cube model that underlies SDMX (Statistical Data and Metadata eXchange), an ISO standard for exchanging and sharing statistical data and metadata among organizations. The Data Cube vocabulary is a core foundation which supports extension vocabularies to enable publication of other aspects of statistical data flows. Status of this document This is an editor's draft without any formal standing.

Table of Contents 1. 1.1 A Data Cube vocabulary Statistical data is a foundation for policy prediction, planning and adjustments and underpins many of the mash-ups and visualisations we see on the web. 2. 2.2 Slices. Méthodes exemplaires pour la publication des vocabulaires RDF. Note de groupe de travail du W3C du 28 août 2008 Cette version : Dernière version : Version précédente : Rédacteurs : Diego Berrueta, Fundación CTIC Jon Phipps, Cornell University Library Rédacteurs précédents : Alistair Miles, STFC Rutherford Appleton Laboratory Thomas Baker, Goettingen State and University Library Ralph Swick, W3C Copyright © 2008 W3C® (MIT, ERCIM, Keio), All Rights Reserved. Résumé Ce document décrit des méthodes exemplaires pour la publication de vocabulaires ou d'ontologies sur le Web (en RDF Schema ou OWL). Statut de ce document Cette section décrit le statut de ce document au moment de sa publication. Ce document a été préparé par le groupe de travail Semantic Web Deployment (SWD), d'après les travaux précédents du groupe de travail Semantic Web Best Practices and Deployment (SWBPD).

Table des matières Introduction Choisir une méthode. Semantic Technology Companies. Où s'amuser avec Sparql ? Non, il ne s'agit pas de faire un guide des parcs parisiens les plus accueillants pour votre nouveau compagnon à quatre pattes que vous auriez malicieusement appelé du nom de la recommandation la plus importante du W3C depuis XML, mais plutôt une liste non exhaustive des Sparql endpoint que vous pouvez interroger librement sur le Web.

Les différentes interfaces que je vais présenter sont mis à disposition dans le cadre du projet Linking Open Data (ou LOD) coordonné par le W3C. Ce projet vise à exposer sur le Web des données structurées avec les technologies du Web sémantique, en particulier RDF et Sparql, suivant les quatre principes du Linked Data édictés par Tim Berners-Lee et rappelés dans ce guide ou cette présentation, soit : Le projet s'enrichit régulièrement de nouvelles contributions, comme le montre la mise à jour régulière du schéma mis au point par Richard Cyganiak : Ils sont au nombre de deux : De plus en plus de projets explorent ce domaine. Semantic Web Client Library. The Sematic Web Client Library represents the complete Semantic Web as a single RDF graph. The library enables applications to query this global graph using SPARQL- and find(SPO) queries. To answer queries, the library dynamically retrieves information from the Semantic Web by dereferencing HTTP URIs, by following rdfs:seeAlso links, and by querying the Sindice search engine.

The library is written in Java and is based on the Jena framework. Contents 1. There is a recent tendency in the Semantic Web community to stress the Web aspect of the Semantic Web, meaning that the Semantic Web is increasingly understood as a single, global information space consisting of interlinked RDF data. This tendency is carried by the revival of ideas around interlinking data on the Semantic Web: Current W3C efforts stress the fact that URI references should be dereference-able (W3C working draft on Best Practice Recipes for Publishing RDF Vocabularies). 2.

The paper 3. Query SPARQL Query Query Results 4. 5. 6. Blogabriel » Blog Archive » Traduction française : How to Publish Linked Data on the Web? Voici la traduction française complète du tutoriel How to Publish Linked Data on the Web publié par Chris Bizer (Web-based Systems Group, Freie Universität Berlin, Germany), Richard Cyganiak (Web-based Systems Group, Freie Universität Berlin, Germany) et Tom Heath (Knowledge Media Institute, The Open University, Milton Keynes, UK).

Ce document explique la façon de publier des données liées sur le Web. Après un aperçu général de la notion de données liées, plusieurs recettes pratiques sont présentées pour la publication d’information sous forme de données liées sur le Web. Il reste encore 3 annexes dans le tutoriel dont la traduction suivra. Résumé Ce document fournit un tutoriel sur la façon de publier des données liées sur le Web. 1 – Introduction : les données liées sur le Web L’objectif des données liées est de permettre aux gens de partager des données structurées sur le Web aussi facilement qu’ils peuvent partager des documents d’aujourd’hui. 2 – Principes de base 2.1 – Architecture Web.

RDFa Distiller and Parser. Comment se familiariser avec RDF en créant son profil FOAF | Vincent Mazenod, aka mazenovi, aka voisin de gennetines. RDFa, presentations for the Netskills RDFa course. Introduction to RDF API. SPARQL + pubsubhubbub = sparqlPuSH | Alexandre Passant. Linked Data on the Web (LDOW2010) - Workshop at WWW2010, Raleigh.