1 / 10

Understanding OWL Inference Mechanisms: Advanced Constructs and Their Practical Implications

This introduction explores the inference mechanisms associated with advanced OWL constructs, highlighting the complexities of operations such as restrictions, cardinality, and logical relations. It discusses how universal restrictions (AllValuesFrom) and existential restrictions (SomeValuesFrom) can shape the reasoning process. The video elaborates on the importance of understanding the practical challenges and limits of OWL constructs, particularly their performance with reasoners. The content is designed for those looking to deepen their grasp of OWL's reasoning capabilities in semantic web applications.

haines
Télécharger la présentation

Understanding OWL Inference Mechanisms: Advanced Constructs and Their Practical Implications

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. OWL Inference Introduction Part 1 Steven Seida

  2. Motivation • How should we think about the inference mechanisms associated with advanced OWL constructs? • owl:Restriction • Universal Restriction (AllValuesFrom) • Existensial Restriction (SomeValuesFrom) • Cardinality (Min/Max/Absolute) • owl:intersectionOf • owl:unionOf • owl:complementOf • owl:disjointWith • owl:differentFrom/sameAs • owl:allDifferent/distinctMembers All that is covered herein

  3. WARNING • Note that reasoners exhibit either: • 1) subset of owl constructs • 2) slow performance on advanced owl constructs • So, general applications will find advanced owl constructs of no practical use.

  4. “Some Values From” Restriction - SubClassOf • AllStarPlayer a owl:Class; • subClassOf • [ a owl:Restriction; • owl:onProperty :playsFor; • owl:someValuesFrom :AllStarTeam]. • Recall that someValuesFrom is the existential (i.e exists) modifier, so it has to exist, so: • If x has the :playsFor property and one instance of that property points to an item with class :AllStarTeam, then we can assert • x rdf:type AllStarPlayer

  5. “Some Values From”– Equivalent Class • AllStarPlayer a owl:Class; • owl:equivalentClass • [ a owl:Restriction; • owl:onProperty :playsFor; • owl:someValuesFrom :AllStarTeam]. • Just like for subClassOf: • If x has the :playsFor property and one instance of that property points to an item with class :AllStarTeam, then we can assert • x rdf:type AllStarPlayer • Additionally if x is an AllStarPlayer, then our reasoner can presume it has at least one occurrence of the property :playsFor pointing to an instance of :AllStarTeam

  6. “All Values From” Restriction - SubClassOf • AllStarPlayer a owl:Class; • subClassOf • [ a owl:Restriction; • owl:onProperty :playsFor; • owl:allValuesFrom :AllStarTeam]. • If x has the :playsFor property and all instances of that property point to something that is part of class :AllStarTeam, • Or if x doesn’t have the :playsFor property, then we can assert • x rdf:type AllStarPlayer

  7. “All Values From”– Equivalent Class • AllStarPlayer a owl:Class • owl:equivalentClass • [ a owl:Restriction; • owl:onProperty :playsFor; • owl:allValuesFrom :AllStarTeam]. • Just like for subClassOf: • If x has the :playsFor property and all instances of that property point to something that is part of class :AllStarTeam, • Or if x doesn’t have the :playsFor property, then we can assert • x rdf:type AllStarPlayer • Additionally if x is an AllStarPlayer, then our reasoner can presume that anytime it has the property :playsFor that it will point to an instance of :AllStarTeam

  8. Cardinality • MenuItem a owl:Class; • owl:equivalentClass • [ a owl:Restriction; • owl:onProperty #hasPrice; • owl:minCardinality 1]. • If x has at least one #hasPrice property then we can assert • x rdf:type MenuItem • Additionally, if x is of type MenuItem, then our reasoner can presume that x has at least one occurrence of #hasPrice. • (Similar constructs for owl:maxCardinality and owl:cardinality)

  9. Exercises Left to the Reader • owl:intersectionOf • owl:unionOf • owl:complementOf • owl:disjointWith • owl:differentFrom/sameAs • owl:allDifferent/distinctMembers

  10. Summary • Inference with some OWL constructs introduces complicated reasoning conditions, not understood with simple, well-defined rules. • With current technology, it is generally preferred to avoid these situations.

More Related