Ks2008 Semanticweb In Action

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  • XPath doesn’t work
  • Types of norms : Permission Prohibition Obligation Norm is a qualification but also something that qualifies something Normatively_qualified NQ = gc Vb prohibition geeft aan dat iets verboden is maar ook dat er iets wat wel mag Bv geen lawaai maken in de bieb These deontic operators are grounded in LKIF core ontology of legal concepts
  • Prohibition: partitioned!!
  • Uitzonderingen nu nog subklasses: Ria kan niet over subclasses Amy is disallowed by the default norm, Amy allowed by art 1a, but disallowed by article 1c As art1c is the most specific norm, This indicates Amy’s situation is disallowed

Transcript

  • 1. The SemanticWeb in Action Kennissystemen, December 2008 Rinke Hoekstra
  • 2. Overview
    • The Semantic Web
    • Languages and Integration
    • Storage and Querying
    • Browsing and Viewing
    • Mashups
    • Reasoning (OWL in Action)
    • ... does it really exist?
    12/16/09
  • 3. The Semantic Web Ideology
    • Identity is everything
    • Partial solutions are great too!
    • Layer cake
    12/16/09 OWL
  • 4. Languages: RDF notations
    • Different ways of writing RDF
      • RDF/XML
      • RDF/XML Abbrev
      • N3
        • Turtle only allows valid RDF-graphs
        • Ntriple one triple per line, fully qualified URI’s.
    12/16/09
  • 5. Languages: RDF(S)/XML Code Example.
    • <rdf:RDF
    • xmlns:rdf=“http://www.w3.org/1999/02/22-rdf-syntax-ns#”
    • xmlns:rdfs=&quot;http://www.w3.org/TR/rdf-schema/&quot;
    • xmlns:uva=“http://www.uva.nl/rdf#”
    • xmlns=“http://www.uva.nl/people”>
    • <rdf:Description rdf:ID=“#radboud”>
    • <rdf:type rdf:resource=“http://www.uva.nl/rdf#AssociateProfessor”/>
    • <uva:name>Radboud Winkels</uva:name>
    • <uva:teaches rdf:resource=“http://www.uva.nl/courses#ks2008”/>
    • </rdf:Description>
    • <uva:Course rdf:about=“http://www.uva.nl/courses#ks2008”/>
    • <rdfs:Class rdf:about=“http://www.uva.nl/rdf#AssociateProfessor”>
    • <rdfs:subClassOf rdf:resource=“http://www.uva.nl/rdf#StaffMember”/>
    • </rdfs:Class>
    • <rdf:Property rdf:about=“http://www.uva.nl/rdf#teaches”>
    • <rdfs:domain rdf:resource=“http://www.uva.nl/rdf#Professor”/>
    • <rdfs:range rdf:resource=“http://www.uva.nl/rdf#Course”/>
    • </rdf:Property>
    • </rdf:RDF>
    12/16/09
  • 6. Languages: Turtle
    • @prefix rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
    • @prefix rdfs:<http://www.w3.org/TR/rdf-schema/>.
    • @prefix uva:<http://www.uva.nl/rdf#>.
    • @prefix courses:<http://www.uva.nl/courses#>.
    • @prefix :<http://www.uva.nl/people#>.
    • uva:AssociateProfessor a rdfs:Class;
    • rdfs:subClassOf uva:StaffMember.
    • uva:teaches a rdf:Property;
    • rdfs:domain uva:AssociateProfessor;
    • rdfs:range uva:Course.
    • :radboud a uva:AssociateProfessor;
    • uva:name ”Radboud Winkels”^^xsd:string;
    • uva:teaches courses:ks2008.
    • courses:ks2008 a uva:Course.
    12/16/09
  • 7. Languages: Important Message
    • Multiple Syntaxes!
    • RDF statements are:
      • Triples <subject, predicate,object>
      • Distributed
      • Always about something else
      • ... but can be about other RDF triples as well.
    • Metadata
    12/16/09
  • 8. Integration
    • How to add this ‘meta’ to my ‘data’?
    • Three options:
      • Old fashioned HTML: <link rel='meta' type='application/rdf+xml' href='http://www.leibnizcenter.org/~hoekstra/foaf.rdf' title='FOAF'>
      • HTTP 303 `see other’ http://www.w3.org/TR/swbp-vocab-pub/
      • Inline (RDFa/GRDDL)
    12/16/09
  • 9. Integration: 303 See Other (Demo)
        • http://www.metalex.eu/metalex
    12/16/09
  • 10. Integration: Inline
    • RDFa
      • Attributes on XHTML elements
      • http://www.w3.org/TR/xhtml-rdfa-primer
    • GRDDL
      • Gleaning Resource Descriptions from Dialects of Languages
      • Explicit reference to (XSL) transformation
      • http://www.w3.org/TR/grddl/
    12/16/09
  • 11. Integration: RDFa Example
    • In XHTML:
    • <?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?>
    • <!DOCTYPE html PUBLIC &quot;-//W3C//DTD XHTML+RDFa 1.0//EN&quot;
    • &quot;http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd&quot;>
    • <html xmlns:cal=&quot;http://www.w3.org/2002/12/cal/ical#&quot;>
    • <head><title>Jo's Friends and Family Blog</title></head>
    • <body>
    • <p instanceof=&quot;cal:Vevent&quot;>
    • I'm holding
    • <span property=&quot;cal:summary&quot;>one last summer Barbecue</span>,
    • on
    • <span property=&quot;cal:dtstart&quot; content=&quot;20070916T1600-0500&quot;>
    • September 16th at 4pm.
    • </span>
    • </p>
    • </body>
    • </html>
    • In RDF:
    • _:blanknode0
    • rdf:type cal:Vevent;
    • cal:summary ”one last summer Barbecue&quot;;
    • cal:dtstart &quot;20070916T1600-0500&quot; .
    12/16/09
  • 12. Integration: GRDDL
    • In HTML/XML instance documents:
    • <html xmlns=&quot;http://www.w3.org/1999/xhtml&quot;
    • xmlns:grddl='http://www.w3.org/2003/g/data-view#'
    • grddl:transformation=&quot;glean_title.xsl
    • http://www.w3.org/2001/sw/grddl-wg/td/getAuthor.xsl”>
    • In XML Schema documents:
    • <xsd:annotation>
    • <xsd:appinfo>
    • <rdf:RDF xmlns:rdf=&quot;http://www.w3.org/1999/02/22-rdf-syntax-ns#&quot;>
    • <rdf:Description rdf:about=&quot;http://www.metalex.eu/latest&quot;>
    • <grddl:namespaceTransformation
    • rdf:resource=”http://www.metalex.eu/grddl/metalex2owl.xsl&quot; />
    • </rdf:Description>
    • </rdf:RDF>
    • </xsd:appinfo>
    • </xsd:annotation>
    12/16/09
  • 13. Storage (on the web)
    • As documents
      • .rdf, .n3, .turtle, .html
    • In a RDF triple-store
      • Sesame ( http://www.openrdf.org )
      • Jena/Joseki ( http://jena.sourceforge.net )
    • RDF(S)/OWL reasoning
      • Jena’s OntModel
      • Sesame OWLIM Sail module
    • SPARQL Endpoints
      • Results as JSON (JavaScript Object Notation)
    • http:/ /darius. leibnizcenter.org: 8080 /openrdf-sesame
    12/16/09
  • 14. Querying
    • Many languages
      • SPARQL, nRQL, SeRQL, etc.
    • SPARQL:
      • http://www.w3.org/TR/rdf-sparql-query/
    • Example
    • PREFIX course: <http://www.uva.nl/courses#>
    • PREFIX uva: <http://www.uva.nl/rdf#>
    • SELECT ?name
    • WHERE
    • { ?x uva:teaches course:ks2007.
    • ?x uva:name ?name }
    • ?x binds with <http://www.uva.nl/people#radboud>
    • ?name binds with “Radboud Winkels”^^xsd:string
    12/16/09
  • 15. Browsing and Viewing
    • How to unlock your RDF/OWL to users?
      • Custom applications (PizzaFinder)
      • Generic RDF Browsers (Faceted Browsing)
    • How to present your RDF/OWL to users?
      • Custom applications (TopBraid Geo)
      • Generic RDF Visualisation (Fresnel Lenses)
    12/16/09
  • 16. Browsing: Facets
    • Multi-dimensional search
    • User filters available information
    • Context dependent
    • Facet
      • UI element
      • Values of a property
      • Number of results
    • Query building
    12/16/09
  • 17. Browsing
    • MIT Longwell
      • http://simile.mit.edu/longwell/demo/libraries
    • /facet
      • http://slashfacet.semanticweb.org
    • Flamenco
    • RDFBrowser
    • Exhibit
      • http://simile.mit.edu/exhibit
    • LENA
    • OpenAcademia
      • http://vu.openacademia.org
    12/16/09
  • 18. Viewing
    • Tables are boring!
    • Different data? Different presentation:
      • URI/URL
      • Images
      • Strings
      • Coordinates
    • Filtering data
    • Aggregating data
    12/16/09
  • 19. Viewing: Fresnel
    • RDF specification of
      • What data to present, and
      • How to present it
    • http://www.w3.org/2005/04/fresnel-info
    • Lenses
      • Group information (class membership, SPARQL result)
    • Formats
      • Specify how property values should be rendered
    12/16/09
  • 20. Viewing: Fresnel lens
    • :foafPersonDefaultLens rdf:type fresnel:Lens ;
    • fresnel:purpose fresnel:defaultLens ;
    • fresnel:classLensDomain foaf:Person ;
    • fresnel:group :foafGroup ;
    • fresnel:showProperties ( foaf:name
    • foaf:surname
    • foaf:depiction ) .
    • :knowsLens rdf:type fresnel:Lens ;
    • fresnel:classLensDomain foaf:Person ;
    • fresnel:group :foafGroup ;
    • fresnel:showProperties ( foaf:name
    • foaf:surname
    • foaf:mbox
    • [ rdf:type fresnel:PropertyDescription ;
    • fresnel:property foaf:knows ;
    • fresnel:sublens :foafPersonDefaultLens ] ) .
    12/16/09
  • 21. Viewing: Fresnel format
    • :foafGroup rdf:type fresnel:Group ;
    • fresnel:stylesheetLink <http://www.example.org/example.css> .
    • :depictFormat rdf:type fresnel:Format ;
    • fresnel:propertyFormatDomain foaf:depiction ;
    • fresnel:label fresnel:none ;
    • fresnel:value fresnel:image ;
    • fresnel:valueStyle &quot;imageWithThickBorder&quot;^^fresnel:styleClass ;
    • fresnel:group :foafGroup .
    • :urlFormat rdf:type fresnel:Format ;
    • fresnel:propertyFormatDomain foaf:homepage ;
    • fresnel:propertyFormatDomain foaf:mbox ;
    • fresnel:value fresnel:externalLink ;
    • fresnel:labelStyle &quot;basicLabel&quot;^^fresnel:styleClass ;
    • fresnel:valueStyle &quot;basicUrl&quot;^^fresnel:styleClass ;
    • fresnel:group :foafGroup .
    12/16/09
  • 22. Longwell 12/16/09
  • 23. /facet 12/16/09
  • 24. Mashups
    • Combining arbitrary sources of data
    • Potluck
      • http://simile.mit.edu/potluck
    • Yahoo Pipes
      • http://pipes.yahoo.com
    12/16/09
  • 25. Yahoo Pipes Editing 12/16/09
  • 26. Yahoo Pipes Result 12/16/09
  • 27. OWL in Action
    • What OWL can do …
    • Traditional
      • Straightforward classification tasks
    • Extensions
      • Explanation & Justification
      • Probabilistic Reasoning
    • Advanced (Law)
      • Temporal reasoning (Klarman et al., 2008)
      • Legal reasoning (van de Ven et al., 2008)
    12/16/09
  • 28. Legal assessment
    • Case input
      • Individual case description
    • Match
      • Case is matched against a set of norms
    • Resolve conflicts
      • Where multiple norms apply, the system determines whether and which norms have priority over others
    • Final verdict
  • 29. University library regulations
    • Norms qualify a situation
    • 1a ) Students registered at this university are allowed to check out a book from this library
    • 1b ) Students registered at other universities are allowed to check out a book from this library provided that they are enrolled in at least one course given at this university.
    • 1c ) Students who have checked out more than five books are not allowed to check out another book.
    • Expected subsumption hierarchy:
    • Art1c ⊑ Art1a, Art1c ⊑ Art1b
    • Amy
    • C  { Amy :Student, book_1 :Library_Book, … , book_6 :Library_Book
    • Amy checks_out book_1, … , Amy checks_out book_6 }
  • 30. Norms in LKIF Core
  • 31. A Default Norm
    • 0) Default: Checking out books is disallowed.
      • Default_GC
      • ⊑ Generic_Case
      • ⊑ ∃ disallowed_by.{defaultnorm}
      • ≡ ∃ checks_out.Library_Book
      •  
      • Default_Norm
      • ⊑ Prohibition
      • ⊑ ∀ disallows.Default_GC
      • ≡ {defaultnorm}
  • 32. Article 1a
    • 1a ) Students registered at this university are allowed to check out a book from this library.
      • Art1a_GC
      • ⊑ Generic_Case
      • ⊑ ∃ allowed_by.art1a
      • ≡ Registered_Student ⊓
      • ∃ checks_out.Library_Book
      •  
      • Art1a_Permission
      • ⊑ Permission
      • ⊑ ∀ allows.Art1a_GC
      • ≡ {art1a}
  • 33. Article 1c
    • 1c ) Students who have checked out more than five books are not allowed to check out another book.
      • Art1c_GC_F
      • ⊑ Generic_Case
      • ⊑ ∃ dis allowed_by.{art1c}
      • ≡ Registered_Student ⊓ ≥ 6 checks_out.Library_Book
      • Art1c_GC_P
      • ⊑ Generic_Case
      • ⊑ ∃ allowed_by.{art1c}
      • ≡ Registered_Student ⊓ ∃checks_out.Library_Book
      • ≤ 5 checks_out.Library_Book
      • Art1c_Prohibition
      • ⊑ Prohibition
      • ⊑ ∀ dis allows.Art1c_GC_F ⊓ ∀ allows.Art1c_GC_P
      • ≡ {art1c}
  • 34. Judging Amy
  • 35. Million dollar question
    • ... does the SemanticWeb really exist?
    • Semantics: yes
    • Web: mwoah
      • Friend-of-a-Friend (FOAF)
      • RSS feeds (pingbacks etc.)
      • Web 2.0: Tagging + Mashups
    • Reasoning?
      • Local, ‘in the box’
      • But: MaRVIN ( http://www.larkc.eu/marvin/ )
    • However
      • The nuts ‘n bolts are ready,
      • And we’ve got the data!
    12/16/09
  • 36. Resources
    • http://www.w3.org RDF(S), N3, OWL, SPARQL, RDFa, GRDDL, XML, XMLSchema, XSLT, CSS, XPath, fresnel...
    • http://www.semanticweb.org /facet, other resources
    • http://www.planetrdf.com Aggregated RSS feed of the cool & famous
    • NEW: OWL 2
      • http://www.w3.org/2007/OWL/
    12/16/09