Motivation

Metadata models, metadata instances, rules and facets ( user categories ) can all be represented in different languages,  for example UML Class models, XML schemas, configuration files etc. If  all these were represented in one language it will be easier to configure and access the mapping between metadata models, rules for facets generation, and relations with controlled vocabularies. 

Ontologies

The language representation for this prototype is RDF and OWL. The Ontologies are available in the OOI GIT repository git@amoeba.ucsd.edu:cisemanticprototype.git. Description of the ontologies can be found in the readme.txt file in that branch, which contains the following:

• cdm.owl - ontology representing the content data model (CF Metadata Conventions)
• cf-parameters.owl - ontology for testing cf parameters
• fui.owl - contains faceted we want to show (could change depending on what the user wants to see)
• fui.rules - rules to enable links with CDM, OM and FUI, and other rules
• mapping-cf-ooi-parameters.rdf - mapping of cf and ooi terms
• Motherlode-thredds-metadata-netcdf.rdf - RDF instance from cdm.owl, containing all the metadata from motherload
• no.rules - blank rules file - use for testing purposes
• om.owl - ontology representing the O&M ontology
• owl.rules - example of OWL rules use in JENA - not to be harvested

CDM Ontology

Represents a simple ontology for selected fields from NetCDF standard metadata. It is based on CF conventions. An example data set is here.

Main metadata fields:

• title      
• institution      
• source      
• history      
• comment
• variable

Facets

From facets
Simple facet ontology: Contains -> Organization / MBARI as one example

Rules Examples

# Example rule file
@prefix om: <http://mmisw.org/ont/ooi-ci/om#>.
@prefix fui: <http://mmisw.org/ont/ooi-ci/fui#>.
@prefix cdm: <http://mmisw.org/ont/ooi-ci/cdm#>.

[ MBARI: (?dataset rdf:type om:Observation) (?dataset cdm:organization "Monterey Bay Aquarium Research Institute") -> (?dataset rdf:type fui:MBARI) ]
[ DatasetsAreObservations: (?dataset rdf:type cdm:Dataset) -> (?dataset rdf:type om:Observation) ]
[varsArePropertiesWithMMIURI: (?dataset cdm:variable ?var) strConcat("http://mmisw.org/ont/cf/parameter/",?var,?prop) -> (?dataset om:property ?prop)  ]

Example Inference Graph

An example graph is available at inf-all-ooi.rdf in the git repository.

For now, we should be able to see 2 facets Organization and Variable. Only one facet should appear for Organization and for Variable:

Reference of ontologies that can be used:

• Observation ontology developed by SONET 
• Ontology developed by W3C SSN
• VSTO Ontologies
• MMI / OOSTethys developed