Semantic Web Technologies
Lecture by Axel Polleres.
Details and course material (such as slides) will be provided on this Web page, once the course has started. For the moment, please refer to the information page at TISS.
Course Content/Material
- 23/04/2012: Lecture 0 (PDF)
- 26/04/2012: Lecture 1: Overview (PDF): Overview, example queries from the lecture are to be found in the folder testdata/
- 07/05/2012: Lecture 2: RDF formal semantics - Simple Entailment (PDF)
- 10/05/2012: Lecture 3: Beyond Simple Entailment: Semantics of the RDF(S), Datatypes, and OWL vocabulary (PDF)
- 10/05/2012: Discussion of Assignment 1 (PDF)
- 14/05/2012: Lecture 4: SPARQL Semantics (PDF)
- 04/06/2012: Lecture 5: SPARQL 1.1 (PDF)
- 04/06/2012: Discussion of Assignment 2+3 (PDF)
- 06/06/2012: Lecture 6: OWL, OWL2, SPARQL1.1+OWL (PDF)
- 13/06/2012: Lecture 7: Linked Data, Linked Data Quality, Applications of Reasoning (PDF)
- 27/06/2012: Final Student Presentations - Part 1
- 04/07/2012: Final Student Presentations - Part 2
Final Student Presentations
Asssignments
Assignment 1
- Create your own FOAF file. You can use a generator tool such as FOAF-a-Matic to generate a skeleton.
- Make sure to give yourself an own unique identifier (URI)
- Add some custom triples (not auto-generated) to that FOAF-file.
- Link to some of your friends' FOAF files, e.g. other people in the course, by using foaf:knows and rdfs:seeAlso. You can also use my foaf-file as an example.
- Go to the SPARQL interface of DBLP at http://dblp.l3s.de/d2r/snorql/. Try to formulate the query of slide 27 of Lecture 1
- Come up with two own interesting SPARQL queries on DBLP datai (Optional, but recommended ;-)).
Assignment 2
-
Is your FOAF-file lean?
-
If not, which triples can you remove to make it lean?
-
If yes, which triples could you add to make it non-lean?
-
Which additional triples are entailed by your FOAF file under RDF entailment? (Give 5 triples as example).
-
Which additional triples are entailed by your FOAF file
in combination with the FOAFontology
under RDFS entailment? (Give 5 triples as example).
-
Which additional triples are entailed by your FOAF file
in combination with the FOAFontology
under D-entailment using the datatype map that includes rdf:XMLLiteral, xsd:integer, xsd:decimal, and xsd:string? (Give 5 triples as example, or argue why no further triples are entailed under this entailment regime).
Assignment 3
-
Datasets in SPARQL queries: Take your own and at least one FOAF file
of your colleagues (or, alternatively/additionally you can also use
my FOAF file) and
write SPARQL queries over the Dataset created combining these FOAF
files (using FROM or FROM NAMED clauses) which answer the following questions:
- Which friends (foaf:knows) to the owners of these foaf files have in common?
- Which persons are only friends of yours but not mentioned as friends by any of the other FOAF files?
You can, for instance, use ARQ to test your queries.
-
Querying DBPedia: Answer the following questions using DBpedia's SPARQL endpoint:
-
The top 3 cities in Austria in terms of population number
-
Cities in Austria the name of which starts with the string "Unter"
-
Come up with an own query in DBPedia that produces duplicates in its results and explain in your own words why it does produce duplicates.
-
Come up with an own query in DBPedia that produces unbound values for some variables in some of its results in and explain in your own words why there are unbound values.
Again, feel free to submit any additional, useful queries that illustrate some of the features we have learnt in the previous lecture.
Assignment 4
-
Write down statement (vii) from Unit3, slide 37 in Turtle Syntax.
- Freestyle: Write your own ontology in RDF-serialized OWL axioms... Be creative! Add your ontology to your FOAF file. Your ontology should allow some useful inferences from your FOAF file.
