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Other RDF Capabilities

Other RDF Capabilities. Exercise: Write the following information into a set of statements (triples) and then draw them into and RDF graph

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Other RDF Capabilities

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  1. Other RDF Capabilities

  2. Exercise: Write the following information into a set of statements (triples) and then draw them into and RDF graph • The article on giant squids, titled "Architeuthis Dux," at http://burningbird.net/articles/monsters3.htm, written by Shelley Powers, explores the giant's squid's mythological representation as the legendary Kraken as well as describing current efforts to capture images of a live specimen. In addition, the article also provides descriptions of a giant squid's physical characteristics. It is part of a four-part series, described at http://burningbird.net/articles/monsters.htm and entitled "A Tale of Two Monsters."

  3. The article is uniquely identified by its URI, http://burningbird.net/articles/monsters3.htm. • The article was written by Shelley Powers—predicate is written by, value is Shelley Powers. • The article's title is "Architeuthis Dux"—predicate is title, value is Architeuthis Dux. • The article is one of a four-part series—predicate is series member, value is http://burningbird.net/articles/monsters.htm. • The series is titled "A Tale of Two Monsters"—series predicate is title, value is A Tale of Two Monsters. • The article associates the giant squid with the legendary Kraken—predicate is associates, value is Kraken and giant squid. • The article provides physical descriptions of the giant squid—predicate is provides, value is physical description of giant squid.

  4. <?xml version="1.0"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:pstcn="http://burningbird.net/postcon/elements/1.0/"> <rdf:Descriptionrdf:about="http://burningbird.net/articles/monsters3.htm"> <pstcn:author>Shelley Powers</pstcn:author> <pstcn:title>Architeuthis Dux</pstcn:title> <pstcn:seriesrdf:resource="http://burningbird.net/articles/monsters.htm" /> <pstcn:contains>Physical description of giant squids</pstcn:contains> <pstcn:alsoContains>Tale of the Legendary Kraken</pstcn:alsoContains> </rdf:Description> <rdf:Descriptionrdf:about="http://burningbird.net/articles/monsters.htm"> <pstcn:seriesTitle>A Tale of Two Monsters</pstcn:seriesTitle> </rdf:Description> </rdf:RDF>

  5. Another representation Nesting one resource description in another shows the connection between the two more clearly <?xml version="1.0"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:pstcn="http://burningbird.net/postcon/elements/1.0/"> <rdf:Description rdf:about="http://burningbird.net/articles/monsters3.htm"> <pstcn:author>Shelley Powers</pstcn:author> <pstcn:title>Architeuthis Dux</pstcn:title> <pstcn:series> <rdf:Description rdf:about= "http://burningbird.net/articles/monsters.htm"> <pstcn:SeriesTitle>A Tale of Two Monsters</pstcn:SeriesTitle> </rdf:Description> </pstcn:series> <pstcn:contains>Physical description of giant squids</pstcn:contains> <pstcn:alsoContains>Tale of the Legendary Kraken</pstcn:alsoContains> </rdf:Description> </rdf:RDF>

  6. RDF Vocabulary • A Resource Description Foundation (RDF) vocabulary is a defined set of predicates that can be used in an application • XML representation of RDF

  7. 1. <?xml version="1.0"?> 2. <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 3. xmlns:exterms="http://www.example.org/terms/"> 4. <rdf:Descriptionrdf:about="http://www.example.org/index.html"> 5. <exterms:creation-date>August 16, 1999</exterms:creation-date> 6. </rdf:Description> 7. </rdf:RDF> Line 1, <?xml version="1.0"?>, is the XML declaration, which indicates that the following content is XML, and what version of XML it is Line 2 begins an rdf:RDFelement. This indicates that the following XML content (starting here and ending with the </rdf:RDF> in line 7) is intended to represent RDF. Line 3 specifies another XML namespace declaration, this time for the prefix exterms: Lines 4-6 provide the RDF/XML for the specific statement

  8. RDF/XML for Two Statements 1. <?xml version="1.0"?> 2. <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 3. xmlns:dc="http://purl.org/dc/elements/1.1/" 4. xmlns:exterms="http://www.example.org/terms/"> 5. <rdf:Descriptionrdf:about="http://www.example.org/index.html"> 6. <exterms:creation-date>August 16, 1999</exterms:creation-date> 7. </rdf:Description> 8. <rdf:Descriptionrdf:about="http://www.example.org/index.html"> 9. <dc:language>en</dc:language> 10. </rdf:Description> 11. </rdf:RDF>

  9. Several Statements About the Same Resource 1. <?xml version="1.0"?> 2. <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 3. xmlns:dc="http://purl.org/dc/elements/1.1/" 4. xmlns:exterms="http://www.example.org/terms/"> 5. <rdf:Descriptionrdf:about="http://www.example.org/index.html"> 6. <exterms:creation-date>August 16, 1999</exterms:creation-date> 7. <dc:language>en</dc:language> 8. <dc:creatorrdf:resource="http://www.example.org/staffid/85740"/> 9. </rdf:Description> 10. </rdf:RDF>

  10.  a graph saying "the document 'http://www.w3.org/TR/rdf-syntax-grammar' has a title 'RDF/XML Syntax Specification (Revised)' and has an editor, the editor has a name 'Dave Beckett' and a home page 'http://purl.org/net/dajobe/' "

  11. RDF/XML Describing a Blank Node 1. <?xml version="1.0"?> 2. <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 3. xmlns:dc="http://purl.org/dc/elements/1.1/" 4. xmlns:exterms="http://example.org/stuff/1.0/"> 5. <rdf:Descriptionrdf:about="http://www.w3.org/TR/rdf-syntax-grammar"> 6. <dc:title>RDF/XML Syntax Specification (Revised)</dc:title> 7. <exterms:editorrdf:nodeID="abc"/> 8. </rdf:Description> 9. <rdf:Descriptionrdf:nodeID="abc"> 10. <exterms:fullName>Dave Beckett</exterms:fullName> 11. <exterms:homePagerdf:resource="http://purl.org/net/dajobe/"/> 12. </rdf:Description> 13. </rdf:RDF>

  12. RDF/XML Using a Typed Literal 1. <?xml version="1.0"?> 2. <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 3. xmlns:exterms="http://www.example.org/terms/"> 4. <rdf:Descriptionrdf:about="http://www.example.org/index.html"> 5. <exterms:creation-date rdf:datatype= "http://www.w3.org/2001/XMLSchema#date">1999-08-16 </exterms:creation-date> 6. </rdf:Description> 7. </rdf:RDF>

  13. RDF/XML for example.com's Catalog 1. <?xml version="1.0"?> 2. <!DOCTYPE rdf:RDF [<!ENTITY xsd "http://www.w3.org/2001/XMLSchema#">]> 3. <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 4. xmlns:exterms="http://www.example.com/terms/"> 5. <rdf:Descriptionrdf:ID="item10245"> 6. <exterms:modelrdf:datatype="&xsd;string">Overnighter</exterms:model> 7. <exterms:sleepsrdf:datatype="&xsd;integer">2</exterms:sleeps> 8. <exterms:weightrdf:datatype="&xsd;decimal">2.4</exterms:weight> 9. <exterms:packedSizerdf:datatype="&xsd;integer">784</exterms:packedSize> 10. </rdf:Description> ...other product descriptions... 11. </rdf:RDF> An important difference from previous examples is that, in line 5, the rdf:Description element has an rdf:ID attribute instead of an rdf:about attribute

  14. 1. <?xml version="1.0"?> 2. <!DOCTYPE rdf:RDF [<!ENTITY xsd "http://www.w3.org/2001/XMLSchema#">]> 3. <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 4. xmlns:sportex="http://www.exampleRatings.com/terms/"> 5. <rdf:Description rdf:about="http://www.example.com/2002/04/products#item10245"> 6. <sportex:ratingBy rdf:datatype="&xsd;string">Richard Roe</sportex:ratingBy> 7. <sportex:numberStars rdf:datatype="&xsd;integer">5</sportex:numberStars> 8. </rdf:Description> 9. </rdf:RDF> giving the absolute URIref http://www.example.com/2002/04/products#item10245. line 5 uses an rdf:Description element with an rdf:about attribute whose value is the full URIref of the tent. The use of this URIref allows the tent being referred to in the rating to be precisely identified.

  15. 1. <?xml version="1.0"?> 2. <!DOCTYPE rdf:RDF [<!ENTITY xsd "http://www.w3.org/2001/XMLSchema#">]> 3. <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 4. xmlns:exterms="http://www.example.com/terms/" 5. xml:base="http://www.example.com/2002/04/products"> 6. <rdf:Description rdf:ID="item10245"> 7. <rdf:type rdf:resource="http://www.example.com/terms/Tent"/> 8. <exterms:model rdf:datatype="&xsd;string">Overnighter</exterms:model> 9. <exterms:sleeps rdf:datatype="&xsd;integer">2</exterms:sleeps> 10. <exterms:weight rdf:datatype="&xsd;decimal">2.4</exterms:weight> 11. <exterms:packedSize rdf:datatype="&xsd;integer">784</exterms:packedSize> 12. </rdf:Description> ...other product descriptions... 13. </rdf:RDF> the rdf:type property in line 7 indicates that the resource being described is an instance of the class identified by the URIref http://www.example.com/terms/Tent

  16. RDF graph describing Joe Smith <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns="http://www.example.org/~joe/contact.rdf#"> <foaf:Personrdf:about= "http://www.example.org/~joe/contact.rdf#joesmith"> <foaf:mboxrdf:resource="mailto:joe.smith@example.org"/> <foaf:homepage rdf:resource="http://www.example.org/~joe/"/> <foaf:family_name>Smith</foaf:family_name> <foaf:givenname>Joe</foaf:givenname> </foaf:Person> </rdf:RDF> The RDF language namespace prefix is usually rdf:

  17. RDF vocabulary

  18. RDF vocabulary includes… rdf:type- it is a predicate used to state that a resource is an instance of a class rdf:XMLLiteral - the class of typed literals (i.e., of XML literal values) rdf:Property - the class of properties (i.e. binary relations that are used as predicates in triples) rdf:Alt, rdf:Bag, rdf:Seq- containers of alternatives, unordered containers, and ordered containers (see figure with bag for an example) rdf:List - the class of RDF Lists rdf:nil - an instance of rdf:List representing the empty list rdf:Statement, rdf:subject, rdf:predicate, rdf:object - used for reification

  19. A Bag (a resource having type rdf:Bag) represents a group of resources or literals, possibly including duplicate members, where there is no significance in the order of the members. For example, a Bag might be used to describe a group of part numbers in which the order of entry or processing of the part numbers does not matter.

  20. A Simple Bag Container Description

  21. <?xml version="1.0"?> <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:s="http://example.org/students/vocab#"> <rdf:Descriptionrdf:about="http://example.org/courses/6.001"> <s:students> <rdf:Bag> <rdf:lirdf:resource="http://example.org/students/Amy"/> <rdf:lirdf:resource="http://example.org/students/Mohamed"/> <rdf:lirdf:resource="http://example.org/students/Johann"/> <rdf:lirdf:resource="http://example.org/students/Maria"/> <rdf:lirdf:resource="http://example.org/students/Phuong"/> </rdf:Bag> </s:students> </rdf:Description> </rdf:RDF>

  22. An Alternative or Alt (a resource having type rdf:Alt) represents a group of resources or literals that are alternatives (typically for a single value of a property). For example, an Alt might be used to describe alternative language translations for the title of a book, or to describe a list of alternative Internet sites at which a resource might be found. An application using a property whose value is an Alt container should be aware that it can choose any one of the members of the group as appropriate.

  23. RDF/XML for an Alt Container <?xml version="1.0"?> <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:s="http://example.org/packages/vocab#"> <rdf:Descriptionrdf:about="http://example.org/packages/X11"> <s:DistributionSite> <rdf:Alt> <rdf:lirdf:resource="ftp://ftp.example.org"/> <rdf:lirdf:resource="ftp://ftp1.example.org"/> <rdf:lirdf:resource="ftp://ftp2.example.org"/> </rdf:Alt> </s:DistributionSite> </rdf:Description> </rdf:RDF>

  24. A Sequence or Seq (a resource having type rdf:Seq) represents a group of resources or literals, possibly including duplicate members, where the order of the members is significant. For example, a Sequence might be used to describe a group that must be maintained in alphabetical order.

  25. RDF Collections • A limitation of the containers described is that there is no way to close them, i.e., to say "these are all the members of the container“ • a container only says that certain identified resources are members; it does not say that other members do not exist. • Also, while one graph may describe some of the members, there is no way to exclude the possibility that there is another graph somewhere that describes additional members. 

  26. RDF Collections • RDF provides support for describing groups containing only the specified members, in the form of RDF collections • An RDF collection is a group of things represented as a list structure in the RDF graph. This list structure is constructed using a predefined collection vocabulary consisting of the • predefined type rdf:List, • the predefined properties rdf:first and  • rdf:rest, and • the predefined resource rdf:nil.

  27. The students in course 6.001 are Amy, Mohamed, and Johann

  28. RDF Collections <?xml version="1.0"?> <rdf:RDFxmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:s="http://example.org/students/vocab#"> <rdf:Descriptionrdf:about="http://example.org/courses/6.001"> <s:students rdf:parseType="Collection"> <rdf:Descriptionrdf:about="http://example.org/students/Amy"/> <rdf:Descriptionrdf:about="http://example.org/students/Mohamed"/> <rdf:Descriptionrdf:about="http://example.org/students/Johann"/> </s:students> </rdf:Description> </rdf:RDF>

  29. RDF Reification • RDF reification allows to disassemble a statement (triple) to its parts and to use the whole statement or parts of the statement as a part of other triples • The whole triple can then be treated as a resource which allows to make assertions about the statement • :john :has :cat [ a rdf:Statement; rdf:subject :john; rdf:predicate :has; rdf:object :cat ] the result is resource that can for example participate as a subject in another triple

  30. A Statement, Its Reification

  31. <?xml version="1.0"?> <!DOCTYPE rdf:RDF [<!ENTITY xsd "http://www.w3.org/2001/XMLSchema#">]> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:exterms="http://www.example.com/terms/" xml:base="http://www.example.com/2002/04/products"> <rdf:Description rdf:ID="item10245"> <exterms:weight rdf:datatype="&xsd;decimal">2.4</exterms:weight> </rdf:Description> <rdf:Statement rdf:about="#triple12345"> <rdf:subject rdf:resource="http://www.example.com/2002/04/products#item10245"/> <rdf:predicate rdf:resource="http://www.example.com/terms/weight"/> <rdf:object rdf:datatype="&xsd;decimal">2.4</rdf:object> <dc:creator rdf:resource="http://www.example.com/staffid/85740"/> </rdf:Statement> </rdf:RDF> RDF/XML for the Reification Example

  32. Assignment • Write a note on triplification of Wikipedia data in the form of dbpedia

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