Semantic Web for the Working Ontologist - RDFS-Plus TEAM C 현근수, 김영욱, 백상윤, 이용현

 Introduction  Inverse  Symmetric Properties  Transitivity  Equivalence  Computing Sameness  Summary Contents 2/31

 RDFS problems ‒ Limited set of inference  RDFS Plus : RDFS + subset of OWL ‒ For more inference  Standard for identifying this subset of OWL ‒ Informal poll of vendors ‒ Own experience from early adopters of Semantic Web Introduction 3/31

 Introduction  Inverse  Symmetric Properties  Transitivity  Equivalence  Computing Sameness  Summary Contents 4/31

 owl:inverseOf ‒ Define inverse of property ‒ Exchange subject and object  Powl:inverseOf Q X P Y Y Q X Inverse X Y P Y X Q 5/31

 People can identify inverse state very easily ‒ Computers are not  lit: Macbethlit:writtenBylit:Shakespear Inverse lit:wrote owl:inverseOf lit:wirrtenBy lit:Shakespear lit:wrote lit:Macbeth 6/31

 Integrating Data that Do not match ‒ Domain and range do not match Inverse signedTo Book Patron borrows Patron Book How to merge? 7/31

 :signedTo owl:inverseOf :signedOut ‒ Domain and range do match Inverse borrows Patron Book signedTo Book Patron signedOut  Can merge borrow and signedOut easily 8/31

 Introduction  Inverse  Symmetric Properties  Transitivity  Equivalence  Computing Sameness  Summary Contents 9/31

 owl:SymmetricProperty ‒ A property that is its own inverse ‒ owl:inverseOf relates one property to another ‒ Special case where two properties are the same  P rdf:type owl:SymmetircProperty P owl:inverseOf P Symmetric Properties 10/31

 bio:AnneHathaway bio:married bio:Shakespeare ‒ No info about Shakespeare  bio:married rdf:type owl:SymmetricProperty ‒ Now we have info about Shakespeare Symmetric Properties Anne Hathaway married Shakespeare married 11/31

 Introduction  Inverse  Symmetric Properties  Transitivity  Equivalence  Computing Sameness  Summary Contents 12/31

 A relation R is transitive if R(a,b) and R(b,c) implies R(a.c ) ‒ Same idea for OWL ‒ Chains of relationships collapse into a single relation  P rdf:type owl:TransitiveProperty  X P Y Y P Z X P Z Transitivity X P Y Y P Z P Z X 13/31

 :Alexia :hasParent :WillemAlexander. :WillemAlexander :hasParent :Beatrix. :Beatrix :hasParent :Wilhelmina.  Relating Parents to Ancestors ‒ My parent’s parent is not my parents ‒ My ancestor’s ancestor is my ancestor Transitivity Alexia WillemAlexander Beatrix Wilhelmina hasParent 14/31

 :hasParent rdfs:subPropertyOf :hasAncestor. :hasAncestor rdf:type owl:TransitiveProperty  Define new property ‘hasAncestor’ ‒ And give transitive property ‒ Now we can represent all ancestor relations Transitivity Alexia WillemAlexander Beatrix Wilhelmina hasParent hasAncestor 15/31

 Managing Networks of Dependencies ‒ Find all the steps it depends on or all the steps that depend on it Transitivity TurnInFreezer AddMilk Chill CookCustard dependsOn GraduallyMix BeatEggs AddSugar SeparateEggs HeatCream SliceBean 16/31

 Managing Networks of Dependencies Transitivity :dependsOn rdfs:subPropertyOf:hasPrerequisite. :hasPrerequisite rdf:type owl:TransitiveProperty. :enables rdfs:subPropertyOf :prerequisiteFor. :prerequisiteFor rdf:type owl:TransitiveProperty. :GraduallyMix :hasPrerequisite :AddSugar; :hasPrerequisite :SeparateEggs; :hasPrerequisite :SliceBean; :hasPrerequisite :HeatCream; :hasPrerequisite :BeatEggs; 17/31

 Introduction  Inverse  Symmetric Properties  Transitivity  Equivalence  Computing Sameness  Summary Contents 18/31

 Equivalent Class ‒ When two classes are known to always have the same members ‒ Other properties of the classes are not shared  :Analyst rdfs:subClassOf :Researcher. :Researcher rdfs:subClassOf :Analyst. :Analyst owl:equivalentClass :Researcher. Equivalence ( Class ) 19/31

 Equivalent Property ‒ When two properties behave in the same way ‒ In triple that uses one as a predicate, the other can be substituted  :borrows rdfs:subPropertyOf :checkedOut. :checkedOut rdfs:subPropertyOf :borrows. :borrows owl:equivalentProperty :checkedOut Equivalence ( Property ) 20/31

 Same Individuals ‒ Not class or property ‒ Things themselves are same ‒ member of the class ( = individuals ) are same  lit:Shakespearelit:wrotelit:Hamlet; lit:wrotelit:Othello.  spr:Susannaspr:hasFatherspr:WilliamShakspeare. spr:Hamnetspr:hasFatherspr:WilliamShakspeare. spr:Judethspr:hasFatherspr:WilliamShakspeare. Equivalence ( Individuals ) 21/31

 spr:WilliamShakspereowl:sameAslit:Shakespeare.  spr:WilliamShaksperePO. -> lit:ShakespearePO.  S Pspr:WilliamShakespeare. -> S Plit:Shakespeare. Equivalence ( Individuals ) owl:sameAs lit:Shakes peare spr:William Shakespeare 22/31

 What if we add below sentence? owl:sameAsrdf:typeowl:SymmetricProperty. Equivalence ( Individuals ) owl:sameAs lit:Shakes peare spr:William Shakespeare owl:sameAs  lit:Shakespeareowl:sameAsspr:WilliamShakspeare. 23/31

 Introduction  Inverse  Symmetric Properties  Transitivity  Equivalence  Computing Sameness  Summary Contents 24/31

 Functional Property ‒ Take only one value for any particular individual ‒ Only one value allowed ( as object )  Prdf:typeowl:FunctionalProperty XPA. XPB. Aowl:sameAsB. Computing Sameness ( Functional Properties ) 25/31

 Example -lit:Shakespearefam:hasFather bio:JohannesShakespeare. lit:Shakespearefam:hasFather bio:JohnShakespeare. fam:hasFatherrdf:type owl:FunctionalProperty. bio:JohannesShakespeare owl:sameAs bio:JohnShakespeare. Computing Sameness ( Functional Properties ) 26/31

 Inverse Functional Property ‒ Inverse of functional property ‒ Take only one individual for any particular value ‒ Only one value allowd ( as subject )  Prdf:typeowl:InverseFunctionalProperty. APX. BPX. Aowl:sameAsB. Computing Sameness ( Inverse Functional Properties ) 27/31

 Example -spr:ShakespeareburiedAt :TrinityChancel. lit:ShakespeareburiedAt :TrinityChancel. buriedAtrdf:type owl:FunctionalProperty. spr:Shakespeareowl:sameAs lit:Shakespeare. Computing Sameness ( Inverse Functional Properties ) 28/31

 One-to-one property satisfied ‒ Take only one value for any particular individual  :hasIdentityNo rdf:type owl:FunctionalProperty. :hasIdentityNo rdf:type owl:InverseFunctionalProperty.  Very useful as identification numbers Computing Sameness ( Combining FP and IFP) 29/31

 Functional only ‒ hasMother ( many to one )  Inverse Functional only ‒ hasDiary ( one to many )  Both Functional and Inverse Functional ‒ taxID ( one to one ) Computing Sameness ( Comparison) Mike Jane Josh Leo Mom Mike Diary 2 Diary 1 Diary 3 Josh ID012 ID011 ID014 MikeJane 30/31

 RDFS Plus : RDFS + subset of OWL ‒ For more inference  Owl Features : Equality ‒ equivalentClass ‒ equivalentProperty ‒ sameAs  Owl Features : Property Characteristics ‒ inverseOf ‒ Transitive Property ‒ Smmetric Property ‒ Functional Property ‒ Inverse Functional Property Summary 31/31