URI that contains an authoritative definition of the referent thing
human-readable word or sequence of words by which a thing is known
A Dimension represents the [VIM] concept of 'quantity dimension' that is defined as 'expression of the dependence of a quantity on the base quantities of a system of quantities as a product of powers of factors corresponding to the base quantities, omitting any numerical factor.' For example in the ISQ the quantity dimension of 'force' is denoted by dim F = Lï¿½Mï¿½T^2, where 'F' is the symbol for 'force', and 'L', 'M', 'T' are the symbols for the ISQ base quantities 'length', 'mass' and 'time' respectively. The Dimension of any QuantityKind can be derived through the algorithm that is defined in C.5.3.20 with SystemOfQuantities. The actual Dimension for a given QuantityKind depends on the choice of baseQuantityKind specified in a SystemOfQuantities.
A SystemOfQuantities represents the [VIM] concept of 'system of quantities' that is defined as a 'set of quantities together with a set of non-contradictory equations relating those quantities'. It collects a list of QuantityKind that specifies the kinds of quantity that are known in the system. The International System of Quantities (ISQ) is an example of a SystemOfQuantities, defined in ISO 31 and ISO/IEC 80000.
A SystemOfUnits represents the [VIM] concept of 'system of units' that is defined as 'set of base units and derived units, together with their multiples and submultiples, defined in accordance with given rules, for a given system of quantities'. It collects a list of Unit that are known in the system. A SysML SystemOfUnits only optionally defines multiples and submultiples.