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OntoSem2OWL. Plan of the talk. OntoSem Overview Features of OntoSem Ontology Mapping OntoSem2OWL Motivation Possible Application Scenarios. About OntoSem.
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Plan of the talk • OntoSem Overview • Features of OntoSem Ontology • Mapping OntoSem2OWL • Motivation • Possible Application Scenarios
About OntoSem • Ontological Semantics (OntoSem) is a theory of meaning in natural language. [Sergei Nirenburg and Victor Raskin, Ontological Semantics, Formal Ontology and Ambiguity] • Aims to extract and represent the meaning in text in a language independent form. • It supports practical, large scale NLP applications such as MT, QA, Information Extraction, NLG. • Supported by a constructed world model encoded in a rich Ontology. [Sergei Nirenburg and Victor Raskin, Ontological Semantics, MIT Press, Forthcoming]
Basic Components • Preprocessor • Converts the natural language text to Text Meaning Representation (TMR) • Static Knowledge Source • Ontology (language independent) • Lexicon (for each language) • Ontomasticon (to store proper names) • Fact repository (stores learnt instances of concepts and TMRs)
Text MeaningRepresentation (TMR) Input Text SyntacticAnalyzer SemanticAnalyzer Preprocessor Grammar: Ecology MorphologySyntax Lexicon and Onomasticon Ontology and Fact Repository Static Knowledge Resources Architecture of the Analyzer
Static Knowledge Sources • Ontology 6000 concepts • English Lexicon 45000 entries • Spanish Lexicon 40000 entries • Chinese Lexicon 3000 entries • Fact repository 20000 facts [Sergei Nirenburg, Ontological Semantics: Overview, Presentation CLSP JHU, Spring 2003]
Text Meaning Representations Heaskedthe UNto authorizethe war. REQUEST-ACTION-69 AGENT HUMAN-72 THEME ACCEPT-70 BENEFICIARY ORGANIZATION-71 SOURCE-ROOT-WORD ask TIME (< (FIND-ANCHOR-TIME)) ACCEPT-70 THEME WAR-73 THEME-OF REQUEST-ACTION-69 SOURCE-ROOT-WORD authorizeORGANIZATION-71 HAS-NAME United-Nations BENEFICIARY-OF REQUEST-ACTION-69 SOURCE-ROOT-WORD UNHUMAN-72 HAS-NAME Colin Powell AGENT-OF REQUEST-ACTION-69 SOURCE-ROOT-WORD he ; reference resolution has been carried outWAR-73 THEME-OF ACCEPT-70 SOURCE-ROOT-WORD war Example from [Marjorie McShane, Sergei Nirenburg, Stephen Beale, Margalit Zabludowski, The Cross Lingual Reuse and Extension of knowledge Resources in Ontological Semantics]
The OntoSem Ontology Concept ::= root | object-or-event | property property ::= relation | attribute | ontology-slot Slot = PROPERTY + FACET + FILLER
The OntoSem Ontology FILLER PROPERTY FACET
Example frame from the Ontology Example from [P.J Beltran-Ferruz, P.A Gonzalez-Calero, P. Gervas Converting Mikrokosmos frames into Description Logics.]
Types of Slots SLOTs are essentially PROPERTIES • ATTRIBUTE Maps a concept or a set of concepts to values (numerical/ literals) • RELATION Property that connects two or more concepts. • ONTOLOGY-SLOT Describe the ontology.
Types of Facets VALUE • FACET is used to restrict the values that may be stored. • filler is the actual value • May beinstance, a Concept, literal, number • Example: earth ............. number-of-moons VALUE 1 .............. [Sergei Nirenburg, Ontology Tutorial, ILIT UMBC]
Types of FacetsSEM • Filler may be violated in certain cases. • Most commonly used Facet. • Example: CONCEPT: EVENT AGENT SEM ANIMAL NATION ORGANIZATION PLANT
Types of FacetsRELAXABLE-TO • Indicates “Typical violations” of the constraints listed in SEM Facets. • Example: CONCEPT: EVENT AGENT SEM ANIMAL NATION ORGANIZATION PLANT RELAXABLE-TO DEITY
Types of FACETSDEFAULT • Refers to the most frequent or expected constraint on the property • Example PAY THEME DEFAULT MONEY
TYPES OF FACETSOther FACETS... • NOT: specifies that the given filler(s) must be excluded from the set of acceptable fillers. • DEFAULT-MEASURE: specifies measuring unit for the numerical range that fills VALUE, DEFAULT or SEM. • INV: Indicates that there exists an inverse property.
Fact Repository • Stores instances of real-world facts • Represents instances of ontological concepts.
OntoSem2OWL Motivation • This project is investigating the feasibility of developing a system to translate ontologies and data between ontosem and OWL. • Will facillitate sharing a rich, extensive language independent ontology with other Semantic Web applications. • Additionally, if an OWL2OntoSem equevalent mapping can be made the OntoSem Ontology and Fact repository can be augmented by reusing existing ontologies on the Semantic Web.
Related WorkConverting Mikrokosmos frames into Description Logic • Microkosmos Ontology: • A precursor to OntoSem • Originally used for MT [ Kavi Mahesh and Sergei Nirenburg, Meaning Representation for Knowledge Sharing in Practical Machine Translation J.E Lonergan, Lexical Knowledge Engineering: Mikrokosmos Revisited] • Propose a translation of frame based representation of Mikrokosmos to SHIQ and OWL. [P.J Beltran-Ferruz, P.A Gonzalez-Calero, P. Gervas Converting Mikrokosmos frames into Description Logics. P.J Beltran-Ferruz, P.A Gonzalez-Calero, P. Gervas Converting frames into OWL: Preparing Mikrokosmos for Linguistic Creativity]
Related WorkOOP, Frame Systems and DL vocabulary [Ora lassila, Deborah McGuiness The Role of Frame-Based Representation on Semantic Web]
Related WorkMapping Mikrokosmos to SHIQ • Unary Predicates Map into DL Classes • Binary Predicate Map into DL relation** ** check if its slot constraint?? • Special Case
Related WorkMapping Mikrokosmos concepts to DL Classes <RECORD> <CONCEPT>CN</CONCEPT> <SLOT>IS-A</SLOT> <FACET>VALUE</FACET> <FILLER>Ci</FILLER> </RECORD> (From Spencer notation of Mikrokosmos) Class-def(primitive | defined CN subclass-of Ci,......Cn slot-constraint1 slot-constraint2 ........................ slot-constraintn Information about classes and subclasses is stored in RECORDs using IS-A Slots
Related WorkMapping Mikrokosmos slot constraints to DL <RECORD> <CONCEPT>CN</CONCEPT> <SLOT>SN</SLOT> <FACET>FACET</FACET> <FILLER>C</FILLER> </RECORD> (From Spencer notation of Mikrokosmos) Class-def(primitive | defined CN subclass-of Ci,......Cn slot-constraint1 slot-constraint2 ........................ slot-constraintn Information about slot constraints is stored in RECORDs where slots are PROPERTIES
Related WorkBuilding DL relations Information requred for DL relations is encoded in records with ONTOLOGY-SLOTs in their SLOT field: INVERSE slot-def SN inverses X DOMAIN, RANGE slot-def SN domain disjoint X1.....Xn slot-def SN range disjoint X1.....Xn MEASURED-IN slot-def SN range X (treated like range) <RECORD> <CONCEPT>SN</CONCEPT> <SLOT>SLOT</SLOT> <FACET>FACET</FACET> <FILLER>X</FILLER> </RECORD> (From Spencer notation of Mikrokosmos) Addional information in PROPERTYs that cannot be mapped easily is stored in CLASS-<PROPERTY-NAME>.
Application ScenariosAugmenting OntoSem FR with Semantic Web data <foaf:Person> <foaf:name>Tim Finin</foaf:name> <foaf:firstName>Tim</foaf:firstName> <foaf:surname>Finin</foaf:surname> <foaf:nick>Tim</foaf:nick> ………………………………………… <foaf:birthDate>1949-08-04</foaf:birthDate> <foaf:myersBriggs>ENTP</foaf:myersBriggs> <foaf:plan>http://www.cs.umbc.edu/~finin/schedule.html</foaf:plan> <foaf:publications>http://www.cs.umbc.edu/%7Efinin/cv/index.shtml#publications</foaf:publications> <foaf:weblog rdf:resource="http://ebiquity.umbc.edu/v2.1/blogger/" /> <foaf:aimChatID>timFinin</foaf:aimChatID> <foaf:mbox_sha1sum>49953f47b9c33484a753eaf14102af56c0148d37</foaf:mbox_sha1sum> <foaf:homepage rdf:resource="http://umbc.edu/~finin/"/> <foaf:depiction rdf:resource="http://umbc.edu/~finin/passport.gif"/> <foaf:phone rdf:resource="tel:+1-410-455-3522"/> <foaf:workplaceHomepage rdf:resource="http://umbc.edu/"/> <foaf:workInfoHomepage rdf:resource="http://umbc.edu/~finin/"/> <foaf:schoolHomepage rdf:resource="http://web.mit.edu/"/> …………………………………………………… OntoSem Fact Rep Store FOAF data as Facts in OntoSem’s Fact Repository.
Application ScenariosReference Resolution • Ontological-Semantics reference resolution Not only deals with relating differnet references to the same individual in text but also mapping them to the real-world model. • Augment OntoSem with FOAF data to resolve ambiguity in reference resolution. [Beale S., M Mc. Shane, S.Nirenburg, Ontological Semantics Reference Resolution: Setting the Stage]
Application ScenariosReference Resolution A Joshi is an Associate Professor in the Computer Science department at UMBC. A Joshi, UMBC => Anupam Joshi A Joshi, Random => A….. Joshi OntoSem FOAF file Anupam Joshi A Joshi is a Philosophy student at RandomUniversity. FOAF file A Joshi