Resources Description Framework

Thu, 07 Jul 2022 10:12:49 GMT — Properties

Tags

rdf

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RDF

• It's a data model in which the basic unit of information is known as a triple
• A triple consists of a subject, a predicate, and an object. You can also think of these as a resource identifier, an attribute or property name, and an attribute or property value
• To remove any ambiguity from the information stated by a given triple, the triple's subject and predicate must be URIs (it's possible —and common— to use prefixed names in place of URIs)

Node Types

There are 3 different kinds of nodes that can exist in a RDF graph:

• Resources: A concept that you want to describe. All resources must have a unique identifier.
• Literals: These are values such as strings, numbers and dates
• Blank nodes: A blank node is a resource without a unique identifier

In an RDF graph, nodes represent subject or object resources, and the predicates are the connections between those nodes.

URIs

All resources and predicates need to have a machine-readable unique identifier. A Uniform Resource Identifier (URI) is a string of characters that unambiguously identifies a particular resource. To guarantee uniformity, all URIs follow a predefined set of syntax rules.

Named Graphs

Pending

Building Knowledge Graphs

1. Taxonomies
2. Ontologies
3. Content and data
4. Graph database

Ecosystem

• Companies
  • Stardog
  • Ontotext
  • metaphacts
  • PoolParty
  • AtomGraph
    • LinkedDataHub
  • The Hyve (knowledge and data management consulting)
• Libraries
  • Apache Jena (Java)
  • RDF4J (Java)
  • RDFLib (Python)
• Tools
  • Protégé
  • Comunica

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