1 / 15

Web Ontology Language (OWL) and protégé

Web Ontology Language (OWL) and protégé. Lecture # 13 Faculty of Computer Science, IBA. Reasoning. RDF and OWL based on DL(description logic). With predicate logic more complex logic do not have proof therefore subset of predicate logic is being used called DL (have proof).

lily
Download Presentation

Web Ontology Language (OWL) and protégé

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Web Ontology Language (OWL)and protégé Lecture # 13 Faculty of Computer Science, IBA

  2. Reasoning • RDF and OWL based on DL(description logic). • With predicate logic more complex logic do not have proof therefore subset of predicate logic is being used called DL (have proof). • Existence of proof systems, helps to make logical consequences that can provide explanation to answers. Quratulain

  3. Example: Family Relationship • Infer relationships • Mother(X,Y) -> parent(X,Y) • Father(X,Y) -> parent(X,Y) Base predicate Mother(X,Y) Father(X,Y) Male(X) Female(X) Quratulain

  4. Example • Male(X), parent(X,Y), parent(P,Y), notsame(X,Y) brother(X,Y) • Brother(X,P), parent(P,Y)  grandmother(X,Y) Quratulain

  5. Reasoner • Provide two services: • Classification (whether class is subclass of a given class or not) • Consistency checking Quratulain

  6. Necessary and Sufficient conditions • A class only with necessary condition called primitive class. [under superclass header in Protege] • A class that has at least one set of necessary and sufficient condition are called defined class.[equivalent class in Protege] • With necessary condition alone, we cannot say that “if something fulfils these conditions then it must be a member of this class”. Quratulain

  7. Automated Classification Protege • Select Reasoner either FaCT++ or HermiT • Then select start Reasoner • Now see inferred classes provided Reasoner (subclass and superclass relationship) • Reasoner used conditions for inferencing . Quratulain

  8. Example: FamilyRelationships Quratulain

  9. Example: FamilyRelationships • Now developed ontology and define each concept. • E.g Person and ((hasSibling some Person) and (hasSex value maleSex))  brother Person and (hasChild some (Person and (hasChild some Person)))  grandParent Person and ((hasParent some Person) and (hasSex value femaleSex))daughter hasSex value maleSexmale Quratulain

  10. Inferred class Hierarchy Quratulain

  11. Explanation of Reasoning The condition define for offspring is also part of condition define for son. Therefore son should be subclass of offSpring. See explanation about other inference in protégé. Quratulain

  12. Owl other properties • Functional properties • Symmetric properties • Transitive properties Quratulain

  13. Functional Properties • For a given individual, there can be at most one individual that is related to the individual via property. • E.g. Saad---- hasBirthMother---- Salma Saad ---- hasBirthMother ---- Sana Since it is functional property therefore implies that Salma and Sana are same individual. • Inverse functional property • Means inverse property is functional. • E.g. Salma----- isBirthMotherOf ----- Saad Quratulain

  14. Symmetric properties • If property relate individual x to individual y and also y to x then it symmetric. • E.g. Kashif ----- hasSibling ----- Faisal Similarly Faisal ----- hasSibling ----- Kashif Note: same property use as inverse property (hasSbling). Quratulain

  15. Transitive property • If property relate individual X to individual Y and Y to Z then it implies that property relate X to Z. • E.g. hasAncestor Asad ---- hasAncestor ---- Saad ---- hasAncestor ---- Fahad implies that Asad--- hasAncestor ---- Fahad Quratulain

More Related