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Introduction to Linked Data Requirements & Technologies. Antonis Koukourikos NCSR “Demokritos”. s upported by:. What is Linked Data?. A paradigm for publishing structured content in the Web Putting data in the web Making links between data
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Introduction to Linked DataRequirements & Technologies Antonis Koukourikos NCSR “Demokritos” 2nd SemaGrow Hackathon (in conjunction with IRSS14) supported by:
What is Linked Data? • A paradigm for publishing structured content in the Web • Putting data in the web • Making links between data • The four rules for publishing Linked Data (Berners-Lee, 2006) • Use URIs as names for things • Use HTTP URIs so that people can look up those names • When someone looks up a URI, provide useful information using the standards • Include links to other URIs so that they can discover more things 2nd SemaGrow Hackathon (in conjunction with IRSS14)
Linked Data Core Technologies • Uniform Resource Identifiers (URIs) • A string of characters used to identify the name of a resource • Resource Description Framework (RDF) • Set of specifications for describing / modelling information • SPARQL Protocol and RDF Query Language (SPARQL) • A query language to retrieve and manage information expressed in RDF 2nd SemaGrow Hackathon (in conjunction with IRSS14)
RDF • A Resource can be anything! • The Description of the resources consist of: • Attributes • Relations • The Framework incorporates • A data model • Language and syntax 2nd SemaGrow Hackathon (in conjunction with IRSS14)
RDF Data Model (Antonis, Presents, Intro to Linked Data) • Data comes as sets of triples <S, P, O> • Subject: Resources • Predicate: Properties • Object: Resources or Literals • RDF is also a directed graph model • Subjects and Objects are vertices • Edges are labeled by the Predicates 2nd SemaGrow Hackathon (in conjunction with IRSS14)
Using URIs for Resources Resources are uniquely identified by their URI 2nd SemaGrow Hackathon (in conjunction with IRSS14)
SPARQL • A set of W3C Recommendations • SPARQL Query • SPARQL Update • SPARQL Protocol • SPARQL Query Results XML Format • Core Idea: Pattern Matching • Describe subgraphs of the queried RDF graph • Subgraphs that match the description contribute an answer 2nd SemaGrow Hackathon (in conjunction with IRSS14)
The Linking Open Data Project • Aims to publish various open datasets as RDF on the Web and set RDF links between data items from different data source • Enable navigation from a data item within one data source to related data items within other sources using appropriate application (e.g. Semantic Web browsers) • Facilitate the development of applications over the extended interconnected datasets 2nd SemaGrow Hackathon (in conjunction with IRSS14)
The Linking Open Data Project 2nd SemaGrow Hackathon (in conjunction with IRSS14) http://lod-cloud.net/
Major Linked Data Publishers DBPedia (http://dbpedia.org) Freebase (https://www.freebase.com/) New York Times (http://data.nytimes.com/) BBC (http://www.bbc.co.uk/ontologies) UK Government US Government 2nd SemaGrow Hackathon (in conjunction with IRSS14)
Linked Data Tools & Services • Publishing Platforms • D2R Server (http://d2rq.org/d2r-server) • Pubby (http://wifo5-03.informatik.uni-mannheim.de/pubby/) • Linked Data Browsers • Tabulator (http://dig.csail.mit.edu/2005/ajar/ajaw/About.html) • Linked Data Search Engines • sameAs (http://sameas.org/) 2nd SemaGrow Hackathon (in conjunction with IRSS14)
Linked Data Challenges User Interfaces & Interaction Paradigms Application Architectures Schema Mapping & Data Fusion Link Maintenance Trust, Quality & Relevance Licensing & Privacy 2nd SemaGrow Hackathon (in conjunction with IRSS14)
Thank you ? ? ? 2nd SemaGrow Hackathon (in conjunction with IRSS14)