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