Schedule - September 8 - 2015
In this session we will introduce Linked Data, the Linked Data principles, and the models and main technologies of Linked Data and the Semantic Web.
The use of URIs and RDF (Resource Description Framework) is at heart of Linked Data. This session will present the graph-based RDF model for distributing data on the web: URIs for naming things, RDF triples --- or subject-predicate-object RDF statements --- to provide information about these things and create links, and RDF serialization formats (RDF/XML, RDFa, Turtle, N-Triples).
SPARQL builds on top of RDF and it provides (1) a query language for accessing RDF graphs; (2) an XML format for representing the results of a query; and (3) a protocol to submit a query to a distant server and receive the results through HTTP. Linked Data applications typically rely on SPARQL for consuming linked open data. In this session we will introduce the main functionalities of SPARQL: SELECT, DESCRIBE, CONSTRUCT and ASK queries, filters, named graphs, SPARQL 1.1.
Predicates in RDF triples come from vocabularies. Even though Linked Data advocates to reuse terms from existing and widely deployed vocabularies, Linked Data publishers may have the need to create new terms, and use their own proprietary vocabularies. In this session we will briefly present the RDFS and OWL ontology languages that are standardly recommended to be used for this purpose.
Participants will learn how to convert a CSV file to linked data using OpenRefine tool, setting links with external datasets. We will outline guidelines for publishing linked data.
Participants will learn how to query linked data using Apache Jena ARQ. We will outline guidelines to build Linked Data applications.