This is a lecture note #6 for my class of Graduate School of Yonsei University, Korea. It describes RDF Vocabularies: RDF Schema.

1. Linked Data &
Semantic Web
Technology
The Semantic Web
Part 6. RDF Vocabularies: RDF Schema
Dr. Myungjin Lee

2. Ability to Define the Vocabularies
This is a property, and it indicates person’s name.
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:s="http://example.org/person/vocab#">
<rdf:Description rdf:about="http://example.org/person/mjlee">
<s:name>Myungjin Lee</s:name>
</rdf:Description>
<rdf:Description rdf:about="http://example.org/person/john"> These resources are person.
<s:name>John Mayer</s:name>
</rdf:Description>
<rdf:Description rdf:about="http://example.org/person/berners-lee">
<s:name>Tim Berners-Lee</s:name>
</rdf:Description>
</rdf:RDF>
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3. RDF Vocabularies: RDF Schema
• RDF Schema
– a set of classes with certain properties using the RDF extensible
knowledge representation language
– providing basic elements for the description of ontologies
• The resources in the RDF Schema vocabulary have URIrefs with the prefix
http://www.w3.org/2000/01/rdf-schema# (conventionally
associated with the QName prefix rdfs:).
– W3C Recommendation 10 February 2004
• RDF Schema allows:
– definition of classes and class instantiation
– definition of properties and simple restrictions
– definition of hierarchies of classes and properties
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4. Describing Classes
• Class
– "kinds of things“, the generic concept of a Type or Category
• Vocabularies for describing classes
– rdfs:Class
• the class of resources
– rdfs:Resource
• all things described by RDF are called resources, and are instances of the
class rdfs:Resource.
– rdf:type
• to state that a resource is an instance of a class
– rdfs:subClassOf
• to state that all the instances of one class are instances of another
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5. A Vehicle Class Hierarchy
rdfs:Resource
ex:PassengerVehicle rdfs:Class
ex:Truck
ex:MiniVan
ex:Van ex:MotorVehicle
rdf:type
exthings:companyCar rdfs:subClassOf
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6. A Vehicle Class Hierarchy
rdfs:Resource
ex:PassengerVehicle rdfs:Class
ex:Truck
ex:MiniVan
rdfs:subClassOf
ex:Van ex:MotorVehicle
rdf:type rdf:type
exthings:companyCar rdfs:subClassOf
inferred triple
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7. ex:MotorVehicle rdf:type rdfs:Class .
ex:PassengerVehicle rdf:type rdfs:Class .
ex:Van rdf:type rdfs:Class .
ex:Truck rdf:type rdfs:Class .
ex:MiniVan rdf:type rdfs:Class .
ex:PassengerVehicle rdfs:subClassOf ex:MotorVehicle .
ex:Van rdfs:subClassOf ex:MotorVehicle .
ex:Truck rdfs:subClassOf ex:MotorVehicle .
ex:MiniVan rdfs:subClassOf ex:Van .
ex:MiniVan rdfs:subClassOf ex:PassengerVehicle .
<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xml:base="http://example.org/schemas/vehicles">
ex:PassengerVehicle
<rdfs:Class rdf:ID="MotorVehicle"/>
rdfs:Class
<rdfs:Class rdf:ID="PassengerVehicle">
<rdfs:subClassOf rdf:resource="#MotorVehicle"/>
</rdfs:Class>
ex:MiniVan
ex:Truck <rdfs:Class rdf:ID="Truck">
<rdfs:subClassOf rdf:resource="#MotorVehicle"/>
</rdfs:Class>
<rdfs:Class rdf:ID="Van">
<rdfs:subClassOf rdf:resource="#MotorVehicle"/>
</rdfs:Class>
ex:Van ex:MotorVehicle
<rdfs:Class rdf:ID="MiniVan">
<rdfs:subClassOf rdf:resource="#Van"/>
<rdfs:subClassOf rdf:resource="#PassengerVehicle"/>
</rdfs:Class>
</rdf:RDF>
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8. Describing Properties
• Vocabularies for describing properties
– rdf:Property
• the class of RDF properties
– rdfs:subPropertyOf
• to state that all resources related by one property are also related by
another
– rdfs:domain
• to state that any resource that has a given property is an instance of one or
more classes
– rdfs:range
• to state that the values of a property are instances of one or more classes
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9. Properties of Vehicle Schema
rdf:type
rdfs:range
rdfs:domain
rdfs:subPropertyOf
rdfs:subClassOf
ex:Person ex:registeredTo
ex:MotorVehicle
rdfs:Class
ex:driver
rdf:Property
ex:primaryDriver
rdfs:Datatype
xsd:integer ex:rearSeatLegRoom ex:PassengerVehicle
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10. Properties of Vehicle Schema
rdf:type
rdfs:range
rdfs:domain
rdfs:subPropertyOf
rdfs:subClassOf
infered triple
ex:Person ex:registeredTo
ex:MotorVehicle
rdfs:Class
ex:driver
rdfs:domain
rdf:Property
ex:primaryDriver
rdfs:domain
rdfs:Datatype
xsd:integer ex:rearSeatLegRoom ex:PassengerVehicle
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11. An Instance of Vehicle Schema
rdf:type
ex:Person ex:registeredTo rdfs:range
rdfs:domain
ex:MotorVehicle rdfs:subPropertyOf
rdfs:subClassOf
rdf:Property ex:driver infered triple
ex:primaryDriver ex:PassengerVehicle
ex:registeredTo ex:primaryDriver
exthings:staff85740 exthings:johnSmithsCar exhings:JohnSmith
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12. An Instance of Vehicle Schema
rdf:type
ex:Person ex:registeredTo rdfs:range
rdfs:domain
ex:MotorVehicle rdfs:subPropertyOf
rdfs:subClassOf
rdf:Property ex:driver infered triple
ex:primaryDriver ex:PassengerVehicle
rdf:type rdf:type
ex:registeredTo ex:primaryDriver
exthings:staff85740 exthings:johnSmithsCar exhings:JohnSmith
ex:driver
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13. TBox and ABox
• TBox
– "terminological component"
– a conceptualization associated with a set of facts
• ABox
– "assertion component"
– a fact associated with a terminological vocabulary within a knowledge
base
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14. TBox and ABox
rdf:type
ex:Person ex:registeredTo rdfs:range
rdfs:domain
ex:MotorVehicle rdfs:subPropertyOf
rdfs:subClassOf
rdf:Property ex:driver infered triple
ex:primaryDriver ex:PassengerVehicle
rdf:type rdf:type
TBox
ABox
ex:registeredTo ex:primaryDriver
exthings:staff85740 exthings:johnSmithsCar exhings:JohnSmith
ex:driver
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15. Other Vocabularies
• rdfs:label
– to provide a human-readable version of a resource's name
• rdfs:comment
– to provide a human-readable description of a resource
• rdfs:seeAlso
– to indicate a resource that might provide additional information about the subject resource
• rdfs:isDefinedBy
– to indicate a resource defining the subject resource
<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:kdc="http://data.kdata.kr/class/"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
<kdc:StateDesignatedHeritage rdf:about="http://data.kdata.kr/resource/Namdaemun">
<rdfs:label xml:lang="ko">남대문</rdfs:label>
<rdfs:label xml:lang="en">Namdaemun</rdfs:label>
<rdfs:seeAlso rdf:resource="http://dbpedia.org/resource/Namdaemun"/>
<rdfs:comment>국보 1호</rdfs:comment>
</kdc:StateDesignatedHeritage>
</rdf:RDF>
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16. Structure of RDF Vocabularies
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17. References
• http://www.w3.org/TR/2004/REC-rdf-primer-20040210/
• http://www.w3.org/TR/rdf-schema/
• http://www.slideshare.net/lysander07/openhpi-22
• http://seijikoide.files.wordpress.com/2011/10/rdfs_entities.jpg
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18. Dr. Myungjin Lee
e-Mail : mjlee@li-st.com
Twitter : http://twitter.com/MyungjinLee
Facebook : http://www.facebook.com/mjinlee
SlideShare : http://www.slideshare.net/onlyjiny/
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