{small lecturenumber - heblocknumber :} RDFaddtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} Uses of RDFaddtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} RDF's data modeladdtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} Representation in XMLaddtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} RDF's data modeladdtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} RDF's data modeladdtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} RDF/XMLaddtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} Example: FOAFaddtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} FOAFaddtocounter {blocknumber}{1}{small lecturenumber - heblocknumber :} FOAFaddtocounter {blocknumber}{1}Distributed Software DevelopmentRDFChris BrooksDepartment of Computer ScienceUniversity of San FranciscoDepartment of Computer Science — University of San Francisco – p.1/??10-0: RDFRDF stands for Resource Description FrameworkProvides a way to describe properties that belong toobjects.Much like a relational database.Can be serialized as XML, but it’s easiest not to get hungup on the XML syntax initially.Built to be created and consumed by machines.Department of Computer Science — University of San Francisco – p.2/??10-1: Uses of RDFRDF is a very popular framework for describing resourceson the Web.RSSMozillaCreative CommonsFOAFTucana Knowledge StoreAll of these applications need a more powerful way ofrepresenting information than XML provides by itself.Department of Computer Science — University of San Francisco – p.3/??10-2: RDF’s data modelRecall that XML produces a tree-structured data model.This can make it hard to represent some sorts ofknowledge.How to denote that two elements share a sub-element?Department of Computer Science — University of San Francisco – p.4/??10-3: Representation in XMLFor example:<song><artist>Doors</artist><title>Break On Through</title><album>Greatest Hits</album></song><song><artist>Doors</artist><title>Light My Fire</title><album>Greatest Hits</album></song><song><artist>Devo</artist><title>Through Being Cool</title><album>Greatest Hits</album>Department of Computer Science — University of San Francisco – p.5/??10-4: RDF’s data modelRDF represents data in terms of triplesSubject, property, value“http://www.cs.usfca.edu/ brooks/S05classes/cs682/slides/rdf.pdf”,title, “RDF Lab”Properties allow us to express relations between objects.In AI, we called these things predicatesDepartment of Computer Science — University of San Francisco – p.6/??10-5: RDF’s data modelFrom a set of RDF triples, we can construct an RDFgraph.Subject and value are nodesNodes can beURIs - a generalized form of a URLblank nodes - mostly useful as placeholdersliterals - strings, values, etc.Properties are edges.Department of Computer Science — University of San Francisco – p.7/??10-6: RDF/XMLAn RDF graph can be serialized as XML.Elements are subjects.Relations are subelement tags.Objects are subelements.The ability to name objects with URIs separates this fromXML.Department of Computer Science — University of San Francisco – p.8/??10-7: Example: FOAF<foaf:Person rdf:nodeID="me"><foaf:name>Chris Brooks</foaf:name><foaf:title>Dr</foaf:title><foaf:givenname>Chris</foaf:givenname><foaf:family_name>Brooks</foaf:family_name><foaf:homepage rdf:resource="http://www.cs.usfca.edu/˜brooks"/>...Department of Computer Science — University of San Francisco – p.9/??10-8: FOAFRDF is a big and complex topic.Let’s focus on a simple application: FOAFFriend-of-a-friendFOAF is a way of encoding personal information in RDF.Can be used to describe a network of friends.Department of Computer Science — University of San Francisco – p.10/??10-9: FOAFSome of the properties FOAF lets you describe include:mbox - email address as a mailtonamehomepagephone numberpublicationsknows - URIs of other people you know.This last bit is potentially the most interesting ...Department of Computer Science — University of San Francisco –
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