[T11]: SPARQL Query Language

22 Dec 2021, 12:00 PM Filed in: Lectures
SPARQL Query Language; Query forms; Variables, blank nodes, datatypes; Graph provenance; Graph Patterns; Union and Optional Patterns; Filters; Modifiers, Aggregates; Negation; Returning Graphs. SPARQL Semantics. SPARQL Protocol.
Recommended Readings: (i) A Semantic Web primer from page 103 to 108
To Know:
  • Why using RDF is not appropriate for querying RDF graphs
  • Why using XML query languages are not appropriate for querying RDF graphs
  • SPARQL is a language and a Protocol to make queries on the Web of data.
  • The different Query forms and what are the differences
  • The basic mechanism of patterns and variables
  • The difference between variables and blanc nodes
  • Why no FROM clause is required in SPARQL?
  • What is the main reason to use FROM in a SPARQL query
  • In which cases the query return may contain Unbound results
  • How to use UNION and OPTIONAL. In which cases OPTIONAL may mne useful
  • How to use Filters. Different types of filters
  • Modify the results: modifers (Order by, distinct, limit)
  • Aggregates
  • Subqueries. How they are integrated in a query
  • Forms of Negation in SPARQL

[T10]: RDFS Semantics

22 Dec 2021, 11:00 AM Filed in: Lectures
RDFS semantics. Simple, RDF and RDFS-entailment. Interpolation lemma. Inference systems for RDF and RDFS-entailment. Minimal deductive systems. Complexity of reasoning of reasoning.
Recommended Readings: (i) A Semantic Web primer from page 94 to 103
To Know: soon

[T09]: RFD and RFD Schema

15 Dec 2021, 11:00 AM Filed in: Lectures
The Resource Description Framework (RDF) and Resource Description Framework Schema (RDFS).
Recommended Readings: (i) A Semantic Web primer from page 65 to 94
To Know:
  • The RDF data model components: resources, URIs, properties, statements
  • The different views of a statement: A triple (Object, Property, Value) or (Subject,Predicate,Object); an arc connecting two nodes in a graph; a piece of XML code, representing the triple
  • Available syntaxes: Turtle; XML; JSON
  • What can be a Subject, a Predicate and an Object
  • Literals and data-types
  • How to represent N-ary predicates
  • The role of blanc nodes
  • Containers. What are? Which types? What for?
  • Reification: What is and how to apply
  • What are the differences between RDF Schema e XML Schema. What is the purpose of RFDF Schema
  • The mains components of RDF schema
  • Core Classes and Core properties of RDF schema

[P01-1]: Neo4J Database

07 Dec 2021, 11:10 AM Filed in: Labs
Install Neo4j in your computer. Follow the exercises in P02

[T08]: Semantic Web

24 Nov 2021, 11:00 AM Filed in: Lectures
The World Wide Web; Daily use of the WWW; Querying the Web; A Web of Data; The Semantic Web; Automatic data integration; Semantic Web Principles; The Semantic Web Cake; The Semantic Web at work.
Recommended Readings: (i) A Semantic Web primer up to page 24
To Know:
  • The actual The World Wide Web. Its main contents : documents.
  • Querying the Web. Serch engines: their limitations
  • The vision of a Semantic Web
  • Sematic Web: definitions and approach
  • Understand the exemple of data integration
  • The Semantic Web Principles
  • The Semantic Web Cake: its layers and the role of each one
  • Linked Data Project