The QUDT, or 'Quantity, Unit, Dimension and Type' collection of ontologies define the base classes properties, and restrictions used for modeling physical quantities, units of measure, and their dimensions in various measurement systems. @en
TheSPITFIRE Ontology (spt) is based on the alignment among Dolce+DnS Ultralite(dul), the W3C Semantic Sensor Network ontology (ssn) and the Event Model-F ontology (event). @en