Developing Ontologies and more extract Peter Fox NCAR

Developing Ontologies (and more) - extract Peter Fox (NCAR) ESIP Winter Meeting (TIWG) January 9, 2008, Washington, D. C. 1

Ontology Spectrum Thesauri “narrower Catalog/ term” ID relation Terms/ glossary Informal is-a Selected Formal Frames Logical is-a (properties)Constraints (disjointness, inverse, …) Formal Value instance Restrs. General Logical constraints Originally from AAAI 1999 - Ontologies Panel by Gruninger, Lehmann, Mc. Guinness, Uschold, Welty; – updated by Mc. Guinness. Description in: www. ksl. stanford. edu/people/dlm/papers/ontologies-come-of-age-abstract. html 2

Ontology - declarative knowledge • The triple: {subject-predicate-object} interferometer is-a optical instrument Fabry-Perot is-a interferometer Optical instrument has focal length Optical instrument is-a instrument Instrument has instrument operating mode Data archive has measured parameter SO 2 concentration is-a concentration Concentration is-a parameter 3

Semantic Web Layers 4 http: //www. w 3. org/2003/Talks/1023 -iswc-tbl/slide 26 -0. html, http: //flickr. com/photos/pshab/291147522/

Terminology • Ontology (n. d. ). The Free On-line Dictionary of Computing. http: //dictionary. reference. com/browse/ontology – An explicit formal specification of how to represent the objects, concepts and other entities that are assumed to exist in some area of interest and the relationships that hold among them. • Semantic Web – An extension of the current web in which information is given welldefined meaning, better enabling computers and people to work in cooperation, www. semanticweb. org – Primer: http: //www. ics. forth. gr/isl/swprimer/ • Languages – – – OWL 1. 0 (Lite, DL, Full) - Web Ontology Language (W 3 C) RDF - Resource Description Framework (W 3 C) OWL-S/SWSL - Web Services (W 3 C) WSMO/WSML - Web Services (EC/W 3 C) SWRL - Semantic Web Rule Language, RIF- Rules Interchange Format Editors: Protégé, SWOOP, Co. E, VOM, Medius, SWe. DE, … 5

Services • Ontologies of services, provides: – What does the service provide for prospective clients? The answer to this question is given in the "profile, " which is used to advertise the service. To capture this perspective, each instance of the class Service presents a Service. Profile. – How is it used? The answer to this question is given in the "process model. " This perspective is captured by the Service. Model class. Instances of the class Service use the property described. By to refer to the service's Service. Model. – How does one interact with it? The answer to this question is given in the "grounding. " A grounding provides the needed details about transport protocols. Instances of the class Service have a supports property referring to a Service. Grounding. 6

Developing a service ontology • Use case: find and display in the same projection, sea surface temperature and land surface temperature from a global climate model. • Find and display in the same projection, sea surface temperature and land surface temperature from a global climate model. • Classes/ concepts: – – – – Temperature Surface (sea/ land) Model Climate Global Projection Display … 7

Service ontology • • • • Climate model is a model Model has domain Climate Model has component representation Land surface is-a component representation Ocean is-a component representation Sea surface is part of ocean Model has spatial representation (and temporal) Spatial representation has dimensions Latitude-longitude is a horizontal spatial representation Displaced pole is a horizontal spatial representation Ocean model has displaced pole representation Land surface model has latitude-longitude representation Lambert conformal is a geographic spatial representation Reprojection is a transform between spatial representation …. 8

Service ontology • A sea surface model has grid representation displaced pole and land surface model has grid representation latitudelongitude and both must be transformed to Lambert conformal for display 9

More information • OWL-S - http: //www. w 3. org/Submission/OWL-S • SWSO/F/L - Semantic Web Services Ontology/Framework/Language http: //www. w 3. org/Submission/SWSF/ • WSMO/X/L - Web Services Modeling Ontology/Exection/Language http: //www. w 3. org/Submission/WSMX/ www. wsmo. org, www. wsmx. org • SAWSDL - (WSDL-S) 10