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< MMI />. Why are Ontologies Important ?. Luis Bermudez QARTOD III November 2-4, 2005. Ontology-Philosophy. - PowerPoint PPT Presentation
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<<MMIMMI /> />
Why are Ontologies Why are Ontologies Important ?Important ?
Luis Bermudez
QARTOD IIINovember 2-4, 2005
Ontology-Philosophy
“ Most fundamental branch of
metaphysics. It studies being or
existence as well as the basic
categories thereof—trying to find out
what entities and what types of
entities exist. ”
- Wikipedia
“ Because any ontology is, among other things, a social / cultural artifact, there is no purely objective perspective from which to observe the whole terrain of concepts. Instead of asking, “what hierarchical representation of concepts best captures the universal relationships among general ideas,” it is more productive to ask “what specific purpose do we have in mind for this conceptual map of entities and what practical difference will this ontology make? ”
-Wittgenstein, Tractatus Logico-Philosophicus.
SWEET Ontologieshttp://sweet.jpl.nasa.gov/ontology/
• Earth Realms
• Physical Phenomena
• Physical Processes
• Physical Properties
• Physical Substances
• Sun Realms
• Biosphere
• Data• Data Centers • Human Activities • Material Things • Numerics • Sensors• Space • Time • Units
Ontologies - Computer ScienceSpecification of conceptualizations
Body of Water Class
RiverLake
Has water
Is inland body
Has a relative defined channel
Lake RiverExample:1. Properties of real
world objects are identified.
2. Similarities are identified.
3. Concepts are created
4. and are expressed as a class.
5. Classes are related.
Subclass
Hydrologic Unit
Region Subregion Accounting Unit
Cataloging Unit
Is part of
Mid Atlantic
Delaware
Lower Delaware Schuylkill
Is part of
Is part of
Is part of
Subclasses
Is Transitive
Infer isPartOf
ClassLooks like a Real world objects
Instances
What is an Ontology?
Catalog/ID
GeneralLogical
constraints
Terms/glossary
Thesauri“narrower
term”relation
Formalis-a
Frames(properties)
Informalis-a
Formalinstance
Value Restrs.
Disjointness, Inverse, part-
of…
Deborah McGuinness
Why Ontologies
• To share common understanding of the structure of information among people or software agents
• To enable reuse of domain knowledge• To make domain assumptions explicit• To separate domain knowledge from the
operational knowledge• To analyze domain knowledge
Cartic Ramakrishnan LSDIS Lab, University of Georgia
Do we need to share explictly QARTOD concepts ?
• Quality Levels• Flags• Sensors• Instrument Methodology• Calibration procedures• QC software procedures• Methods of verification and validation• Methods for manual checking• Malfunctions
Semantic Issues
Search for seatemperature
dataSea surface Temperature
sea_water_temperature
TEMP
BODC
GCMD
CF
Don’t sure what data will get retrieved ?
Ocean Temperature
GCMD
Harmonization
DTDDTD
Comma Comma Separated Separated
ValuesValues
HTMLHTML
Tab Tab Separated Separated
ValuesValues
Relational Relational DatabaseDatabase
XML/XSDXML/XSD
RDFRDF
OWLOWL
Web Ontology Language: OWL
<owl:Class rdf:ID=“Body_of_Water”></owl:Class>
<owl:Class rdf:ID=“River”> <rdfs:subClassOf rdf:resource=“# Body_of_Water”/></owl:Class>
• W3C Recommendation 02/04.• Based on RDF. (-> URI )• Inference capabilities.• Restriction of inherit properties.• Can be used to express
specifications and vocabularies
Body of Water
River
Topic Direct
mappings Inferred mappings
Total mappings
Plant Pigments 405 1,022 1,427
PaCOOS 131 375 506
Waves 93 181 274
Currents 90 153 243
CTD 81 432 513
Habitats 23 37 60
Total 823 2,200 3,023
Mapping Results
Data Source
Data Provider Data User
gets
processes:formats/archives
publishesgets
processes: uses/analyzes
sendsgets
processes: formats/archives
sends
Ingests from instruments
<<MMIMMI /> />
About MMI• MMI = Marine Metadata Interoperability Initiative.• NSF funded and SURA (Southeastern Universities Research
Association) supported.• Initially one year project (September 2005). In the process of
getting extended (NOAA and NSF).• Organization; Executive committee (5), Steering committee (17),
technical committee(~25), and contributors. Community of more than 200 members
(October 2005). • Deliverables:
– Community web site with metadata content, guidance– Interoperability Demonstrations– Workshop: “Advancing Domain Vocabularies”– Tools : VINE Voc2OWL, Tethys, Web Services
http://marinemetadata.org/tethys
1. Implement two methods and make them
available using SOAP web services.
2. Convert the parameters, sources, and units
used in their system to an ontology.
(tool VOC2OWL ascii to OWL)
3. Map the terms used in the system to the MMI
preferred ontology: Standard vocabulary for
discovery (GCMD) and for usage (CF).
Steering Committee Members
• Robert Arko, LDEO
• Julie Bosch, NOAA
• Francisco Chavez, MBARI
• Ben Domenico, Unidata
• Karen Stocks, SDSC
• Steve Hankin, NOAA - Ocean.US/DMAC
• Roy Lowry, BODC • Mark Musen, Stanford Univ
• Michael Parke, Univ of Hawaii
• Lola Olsen, NASA Goddard
• Dawn Wright, Oregon State Univ
• Bob Weller, WHOI
• John Graybeal, MBARI. PI. (ExecComm) [email protected]• Stephanie Watson, CeNCOOS. (ExecComm) [email protected]• Philip Bogden, SURA/SCOOP. (ExecComm) [email protected]• Stephen Miller, Scripps. (ExecComm) [email protected]
• National Science Foundation1
• SURA, the Southeastern Universities Research Association (http://www.sura.org),
• NOAA (including the Coastal Services Center),• ONR, the Office of Naval Research
(http://www.onr.navy.mil),• OceanUS and regional IOOS systems.
1 NSF Grant ATM-0447031
Credits