Introduce Semantic web based on book "Semantic web for the Working Ontologist" Dean Allemang / Jim Hendler

1. Chapter 4
Semantic Web Application Structure
By NK

2. Keyword
• RDF store
• RDF query engine
• SPARQL
• SPARQL endpoint
• Application interface
• Scraper
• Converter
• RDFa & GRDDL

3. Context
• RDF Parser / Serializer
• RDF Store

4. RDF Parser / Serializer ( 1 )
• RDF Parser
– can read RDF Application’s data source that has
.rdf extension.
– has a data source as an Input data.
– translate data source into triple

5. RDF Parser / Serializer ( 2 )
• Serializer
– It is a Reverse Operation
– Using a RDF parser and Serializer to possible the
'Round-trip' of the triple.
– What mean is ‘Round-trip’?

6. RDF Parser / Serializer ( 3 )
• Example for Serializer Format
– N-Triples

7. RDF Store ( 1 )
• Store RDF Data
• Using each parser and serializer for ‘Populate’
and ‘Publish’
• In contrast to a relational data store, includes
as a fundamental capability the ability to
‘merge’ two data sets together
– Because of Flexible nature of the RDF data model.

8. RDF Store ( 2 )
• RDF Data Standards and Interoperability of RDF
Stores
– Relational data store is a difficult process to transfer a
whole database from one system to another.
– But RDF data model is a shared by all of these
products
– All of them can import and export their data sets in
the RDF/XML format.
– This feature, early and aggressive standardization
process, makes it much easier to begin with one RDF
store, secure in the knowledge that the system can be
migrated to another as the need arises.

9. RDF Store ( 3 )
• RDF Query Engines and SPARQL
– Accessed using a query language.
– Cover the highlights of SPARQL query language in
this section.

10. RDF Store ( 4 )
• RDF Query Engines and SPARQL
N3 Graph

11. RDF Store ( 5 )
• RDF Query Engines and SPARQL
– The basic building block of a SPARQL query is the
triple pattern.
– Variables are indicated as symbols preceded by
the special ‘?’ character.
– Example
• ?w lit:wrote lit:KingLear .
lit:Shakespeare ?r lit:KingLear.
lit:Shakespeare lit:wrote ?p.

12. RDF Store ( 6 )
• RDF Query Engines and SPARQL
– Who wrote King Lear?
– What relationship did Shakespeare have to King Lear?
– What did Shakespeare write?

13. RDF Store ( 7 )
• RDF Query Engines and SPARQL
– Interesting query is one in which the query
specifies a graph pattern.
– A graph pattern is specified as a set of triple
patterns, with the stipulation that any variable
that appears in two or more triple patterns must
match the same resource in the graph.
– In SPARQL syntax, graph patterns are given as a list
of triple patterns enclosed within braces ({ and }).

14. RDF Store ( 8 )
• RDF Query Engines and SPARQL
– ?person lit:wrote lit:KingLear .}
{?person bio:livedIn ?place.
?place geo:isIn geo:England.
?person lit:wrote lit:KingLear . }

15. RDF Store ( 8 )
• RDF Query Engines and SPARQL
– It has no knowledge that marriage is a symmetric
union and so Shakespeare must have married
Anne Hathaway.
– Solution OWL (Will Learn Chapter 7)

16. Summary
• What are RDF Parser and Serializer
• How operation RDF Store
• How access RDF Store using RDF Query engine
• SPARQL
• SPARQL endpoint