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. 2012 Oct 10;2012:bas033.
doi: 10.1093/database/bas033. Print 2012.

The Units Ontology: A Tool for Integrating Units of Measurement in Science

Free PMC article

The Units Ontology: A Tool for Integrating Units of Measurement in Science

Georgios V Gkoutos et al. Database (Oxford). .
Free PMC article


Units are basic scientific tools that render meaning to numerical data. Their standardization and formalization caters for the report, exchange, process, reproducibility and integration of quantitative measurements. Ontologies are means that facilitate the integration of data and knowledge allowing interoperability and semantic information processing between diverse biomedical resources and domains. Here, we present the Units Ontology (UO), an ontology currently being used in many scientific resources for the standardized description of units of measurements.


Figure 1
Figure 1
Schematic representation of an example of the mappings between PATO qualities and UO units. The figure is based on the OBO representation of UO in which units are treated as classes. Boxes in the figure represent classes and blue arrows represent subclass axioms between classes. If a grey arrow (labelled unit_of) connects the class A (from UO) and B (from PATO), then A SubClassOf: unit_of only B.

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