Quantities, Units, Dimensions and Types Ontologies

QUDT Ontologies

The QUDT ontologies provide the following:

  1. Multiple Systems of Units
  2. Comprehensive Coverage of Quantities
  3. Ontology Support for Units Conversion using Dimensions
  4. Simple and Structured Data Types

The QUDT Ontologies and XML Vocabularies were developed at NASA ARC in the NExIOM project for the NASA Constellation Program. QUDT has a dedicated website at http://www.qudt.org. A table of the QUDT v1.0.0 ontologies, with generated documentation can be accessed at this page.

The following Ontologies are currently in QUDT:

Schema Title Details
cc Creative Commons (in RDF)

Namespace URI: http://creativecommons.org/ns#

RDF Format: http://creativecommons.org/schema.rdf

Dependencies: none

dc Dublin Core

Namespace URI: http://purl.org/dc/elements/1.1/

Dependencies: none

oecc Creative Commons Ontology

OWL Extensions to the Creative Commons RDF (cc).

Namespace URI: http://www.oegov.org/models/common/cc#
N3 Format: cc.n3
RDF/OWL Format: cc
Dependencies: cc, dc
qud Quantity Unit Dimension Foundation

The qud, or quantity-unit-dimension ontology defines the base classes properties, and restrictions used for modeling physical quantities, units of measure, and their dimensions in various measurement systems.

Namespace URI: http://data.nasa.gov/qudt/owl/qud#
N3 Format: n1qud.n3
RDF/OWL Format: n1qud
Dependencies: cc, dc, oecc
quantity Base Quantities

An ontology about physical quantities and the expression of their magnitude in a chosen unit of measure.

Namespace URI: http://data.nasa.gov/qudt/owl/quantity#
N3 Format: n1quantity.n3
RDF/OWL Format: n1quantity
Dependencies: cc, dc, oecc, qud
dim Dimensions

Dimension systems for physical quantities and units.

Namespace URI: http://data.nasa.gov/qudt/owl/dimension#
N3 Format: n1dimension.n3
RDF/OWL Format: n1dimension
Dependencies: cc, dc, oecc, qud
unit Units

The Units Ontology is a N1 Ontology that provides a vocabulary for describing units of measure. It also contains a limited set of individual units of measure, specifically, those units that do not have, at the moment, a dedicated N2 level ontology.

Namespace URI: http://data.nasa.gov/qudt/owl/unit#
N3 Format: n1unit.n3
RDF/OWL Format: n1unit
Dependencies: cc, dc, oecc, qud

Unit Datasets

NIST Constants

Schema Title Details
nist NIST Constants

Defines terms for and contains the values and standard uncertainties of 324 physical constants taken from the NIST website: The NIST Reference on Constants, Units, and Uncertainty, at http://physics.nist.gov/cuu/index.html

Namespace URI: http://physics.nist.gov/cuu/
N3 Format: nist-constants.n3
RDF/OWL Format: nist-constants
Dependencies: cc, dc, oecc, qud, unit

QUDT and DBPedia

Schema Title Details
qudt-dbpedia QUDT links to DBPedia

This graph contains 823 links between terms in the QUDT ontology (quantity kinds, units, and physical constants) and their corresponding close and exact matches in DBPedia. The correspondences are stated using the properties skos:closeMatch and skos:exactMatch from the Simple Knowledge Organization System (SKOS) ontology.

Namespace URI: http://www.qudt.org/owl/2009/08/qud-dbpedia
N3 Format: qudt-dbpedia.n3
RDF/OWL Format: qudt-dbpedia
Dependencies: cc, dc, oecc, qud, skos, unit

Last Updated August 27, 2009

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This work is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.

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