owl & protege introduction dongfang xu ph.d student, school of information, university of...
TRANSCRIPT
OWL & ProtegeIntroduction
Dongfang XuPh .D student, School of Information, University of Arizona
Sept 10, 2015
Agenda
Brief OWLBrief OWL
OWL elementsOWL elements
OWL in OWLOWL in OWL
ProtegeProtege
Brief OWL
What is web Ontology Language ?
1. OWL is designed for use by applications;
2. To process the content of information;
3. OWL facilitates greater machine interpretability of Web
content ;
4. Providing additional vocabulary along with a formal
semantics compared with RDFs/RDF.
Why OWL?Brief OWL
Brief OWL
Owl and RDF/RDFS
1. Requirements for Ontology languages;•Formal semantics (describes meaning of language precisely) ;•Reasoning support. (xC; C subclass B. XB. )
2. Limitations of RDF Schema.•Too focus on hierarchies.•Fewer relationship rule.Reference: Antoniou, G., & Van Harmelen, F. (2008). A semantic web primer (2nd ed.). Cambridge, Mass:
MIT press.
Brief OWL
Three Sublanguage of OWL1. OWL Full•Fully upward-compatible with RDF, both syntactically and semantically; undecidable, inefficient in reasoning support
2. OWL DL•Essentially application of OWL’s constructor to each other is disallowed.3. OWL LiteSome parts of OWL are excluded, like enumerated classes, disjoint statements, and arbitrary cardinality.
Agenda
Brief OWLBrief OWL
OWL elementsOWL elements
OWL in OWLOWL in OWL
ProtegeProtege
OWL Elements
<owl: Class rdf: about=“#associate professor”> <owl: disjointWith rdf: resource =“#professor”/> <owl: disjointWith rdf: resource=“#assistantProfessor”></owl: Class>
OWL elements
Syntax1. An RDF’s XML-based syntax.• Like example 22. An abstract syntax.• Class (associate professor DisjointClasses(professor associate professor))3. Graphic syntaxSee in example1, RDF/RDFs graph
OWL elements
SyntaxHeader1. Namespaces<rdf: RDF xmlns: owl=“……” xmlns: rdf=“……”>……</rdf:RDF>
2. Asseration under an owl: OntologyContain comments, version control, and also including other ontology , owl: imports, lists other ontology whose content is considered as part of current ontology.
OWL elements
SyntaxHeaderClass Elements1. owl : class used to define class2. owl: EquivalentClass (object property) owl: disjointWith <owl: Class rdf: about=“#associate professor”> <owl: disjointWith rdf: resource =“#professor”/> <owl: disjointWith rdf: resource=“#assistantProfessor”></owl: Class>
OWL elements
SyntaxHeaderClass ElementsProperty Elements1. Object propertyRelate objects to other objects.2. Data type property; Like “phone”, “age”.
OWL elements…Class ElementsProperty ElementsProperty Restriction<owl: class rdf: about=“#first YearCourse”> <rdfs: subclassOf> <owl: Restriction> <owl: onProperty rdf: resource = “#isTaughtby”/> <owl: allValuesFrom resource =“# Professor”/> ##has/someValues </owl: Restriction> ##minCardinality </rdfs: subclassOf></owl : class>
OWL elements
…Property ElementsProperty RestrictionSpecial PropertiesOwl: TransitiveProperty (is taller than)
Owl: SymmetricProperty (has same …)
Owl: FunctionalProperty (defines a property that has at most
one value for each object)Owl: InverseFunctionalProperty (defines two different objects cannot have the same value)
OWL elements
…Property RestrictionSpecial PropertiesBoolean CombinationsDefine class use “unionOf”, “intersectionOf”, “complementOf”.
<owl: Class rdf: id= “peopleAtUniversity”>
<owl: unionOf rdf:parsetype = “Collection”>
<owl: Class rdf: about= “#staffmember”/>
<owl: Class rdf: about= “#student”/>
</owl: unionOf ></owl: Class>
OWL elements
…Special PropertiesBoolean CombinationsInstancesLike RDf
OWL elements
Agenda
Brief OWLBrief OWL
OWL elementsOWL elements
OWL in OWLOWL in OWL
ProtegeProtege
For each class or property, OWL defines each element as below:• <rdfs: label> • <rdfs: domain>• <rdfs: range>• <EquivalentProperty>• ……
OWL in OWL
For each class or property, OWL defines each element as below:• <rdfs: label>• <rdfs: domain>• <rdfs: range>• <EquivalentProperty>• ……Instructions for how to use each element.
OWL in OWL
Agenda
Brief OWLBrief OWL
OWL elementsOWL elements
OWL in OWLOWL in OWL
ProtegeProtege
Protege
•DefinitionProtégé is a free, open source ontology editor and a knowledge acquisition system. Protege provides a graphic user interface to define ontologies. It also includes deductive classifiers to validate that models are consistent and to infer new information based on the analysis of an ontology., Protégé is a framework for which various other projects suggest plugins.
Protege
•Example
Protege
Resourcehttps://www.youtube.com/user/TheProtegeProject/videos
https://www.youtube.com/watch?v=MbauHV2-XYw
http://protegewiki.stanford.edu/wiki/Pr4_UG
Thank you!
Q&A