QUDT Release 2.1.27

PLEASE NOTE!
SHACL users will immediately notice something new with this release. Specifically, we are beginning the process of deprecating the commonly used relation qudt:unit in favor of qudt:hasUnit. This is consistent with the other similar relations qudt:hasQuantityKind and qudt:hasDimensionVector. You can continue using qudt:unit in your data files for a while (probably for a year), but you will get a sh:Info validation message when you invoke SHACL validation checking.

OWL users will not get any SHACL validation message of course, but please be aware that the relation qudt:unit will eventually go away in favor of qudt:hasUnit.

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Other updates include:

• Catching some typos and generally keeping things orderly and consistent (thanks @ektrah)
• Deprecated qudt:allowedUnitOfSystem to qudt:applicableSystem. Again, this is for consistency, analogous to qudt:applicableUnit that is used to point a QuantityKind instance back to "applicable" units. Here's the description of qudt:applicableSystem:
  "This property relates a unit of measure with a unit system that does not define the unit, but allows its use within the system. An allowed unit must be convertible to some dimensionally eqiuvalent unit that is defined by the system."
• Changed the way we deprecate properties. Instead of declaring them instances of qudt:deprecatedProperty, we instead add the triple
  <old-property> qudt:deprecated true (consistent with how we deprecate instances).
• Fixed a number of erroneous vaem:namespace declarations (even in some deprecated graphs).
• Some new units, quantity kinds and dimension vectors (thanks @mgberg, @elisagirola and @JAC28)
• Added the constant Pi, by request

And as always, a big thank-you to all of you for bringing many of these issues to our attention, and even better, for providing submissions to extend the size and capabilities of QUDT!

QUDT Release 2.1.26

Release 2.1.26 includes some promised additional functionality:

• Population of the relation qudt:applicableSystem (we were going to call it qudt:isUnitOfSystem, but felt that term implied official inclusion in that system, which may not be the case). This relation relates each Unit instance to the applicable SystemOfUnits instances. Any strange units that don't fit with any supported systems are associated with sou:UNSTATED. It should be noted that population of these triples is still a work in progress. Pull requests with additions/edits are welcome!
• Refactored the Currency units so that they are stored in a separate graph (http://qudt.org/2.1/vocab/currency) and file (VOCAB_QUDT-UNITS-CURRENCY-v2.1.ttl). The currency instances use the prefix "cur" and are instances of both qudt:CurrencyUnit, which is a subClassOf qudtUnit. The currency URIs have been migrated to use the ISO 4217 currency codes. And finally, the currency vocabulary file also contains the definition of the quantitykind:Currency because that one instance contains all the qudt:applicableUnit references, making the currency file self-contained. This structuring of currency allows users to load
  • just Units (by loading the Units graph)
  • Currency and Units (by loading the Currency graph that imports Units)
  • Constants and Units (by loading the Constants graph that imports Units)
  • Everything (by loading both the Constants and the Currency graphs)
  • This will be described on the GitHub homepage soon.

Other updates include:

• Addition of some currency symbols (thanks to @fkleedorfer)
• Fixing some incorrect UCUM codes (thanks to @jangoepfert)
• Migrated our use of qudt:supercededBy to dcterms:isReplacedBy for deprecated objects (instances, properties or classes)
• Addition of a SHACL validation rule that flags any uses of deprecated objects, so that an application using the SHACL schema is warned (sh:Warning) and directed to the replacement.

And as always, a big thank-you to all of you for bringing many of these issues to our attention, and even better, for providing submissions to extend the size and capabilities of QUDT!

QUDT Release 2.1.25

Release 2.1.25 includes:

• Fixed some validation errors that found some incorrect dimension vector references related to magnetism, and typos
• Extended the QUDT/IFC mapping (thanks to @fkleedorfer)
• Removed the "subPropertyOf qudt:dimensionExponent" declaration for all the qudt:dimensionExponentFor properties, which were causing incorrect implications
• Resolved issues #637 and #638 (thanks to @fkleedorfer)
• Fixed a variety of dimension vector references and multiplier values picked up (again thanks to @fkleedorfer!)
• Removed some incorrect declarations of qudt:derivedCoherentUnitOfSystem (where the conversion multiplier must be 1.0)
• Removed the definition and use of qudt:isScalingOf because of ambiguity, as discussed in issues #548 and #547
• Updated naming of mortality and morbidity units to conform with our naming conventions
• Added some needed dimension vectors and quantity kinds
• Added updated names for some quantity kinds containing exponents (e.g. replacing CubicElectricDipoleMomentPerSquareEnergy with ElectricDipoleMoment_CubicPerEnergy_Squared).
• Renamed some quantity kinds from <xyz>Percentage to <xyz>Ratio as per Rule 10 of our naming rules
• Note that all these renamings mentioned above mark the old name with "dcterms:isReplacedBy <newName>". We don't want to delete existing URIs

COMING UP SOON:

• Cleaning up the use of qudt:isUnitOfSystem so that you will be able to filter down to your favorite system of units if you want
• Migrating all Currency units to a separate graph, once we solve some back-end publication issues

And as always, a big thank-you to all of you for bringing many of these issues to our attention, and even better, for providing submissions to extend the size and capabilities of QUDT!

QUDT Release 2.1.24

HEADS UP on some important changes

As announced in the December release, the January release contains two significant changes that will likely require you to change some configurations in your use of QUDT.

1. As SHACL becomes more popular, and because of its validation capabilities over OWL, we have made the SHACL schema the default instead of the OWL schema. What this really means is that in the facade file, the import statement now points to the SHACL graph instead of the OWL graph. The role of the facade file is documented here. If you want to stay with the OWL schema, you can simply edit your local copy of the facade file to import http://qudt.org/2.1/schema/qudt.
2. As directed by GitHub, we have renamed the QUDT master branch to "main". You will see the notice the next time you use the GitHub QUDT repo webpage interface.

Meanwhile, Release 2.1.24 includes some housekeeping:

• (Almost) all quantity kinds now refer to a dimension vector. Note that some quantity kinds are "abstract", such as Viscosity, where the narrower concepts have distinct dimension vectors, so the abstract one has no dimension vector intentionally. (Thanks @jhodgesatmb)
• The UniversalGasConstant is now a Constant, not a QuantityKind, as is appropriate!
• Equated some identical quantity kinds such as Absorptance = Absorbance, and constants ElementaryCharge = AtomicUnitOfCharge. We are now consistently using qudt:exactMatch for this. Also, cleaned up the ElementaryCharge situation to be just a constant and a unit, but not a quantity kind.
• Changed some exactMatch predicates to informativeReference since the object is a web page, not a resource.
• Removed all triples using qudt:baseUnitDimensions. This was left over from long ago, when we were constructing dimension vectors, and is now redundant. (Thanks to @stuchalk for pointing this out)

Thank you as always for providing submissions to extend the size, quality and capabilities of QUDT!

QUDT Release 2.1.23

HEADS UP on some important changes coming in January, 2023

In the January Release, there will be two significant changes that will likely require you to change some configurations in your use of QUDT. We are announcing it here so that you have time to decide how to adjust.

1. As SHACL becomes more popular, and because of its validation capabilities over OWL, we will be making the SHACL schema the default instead of the OWL schema. What this really means is that in the facade file, the import statement will point to the SHACL graph instead of the OWL graph. The role of the facade file is documented here. If you want to stay with the OWL schema, you can simply edit your local copy of the facade file to import http://qudt.org/2.1/schema/qudt.
2. As directed by GitHub, we will be renaming the QUDT master branch to "main".

Meanwhile, Release 2.1.23 includes:

• Fixed an erroneous qudt:symbol for KiloGM2-PER-SEC2 (thanks to @fkleedorfer)
• Added some missing dimension vectors that were referred to
• Added a mapping to units found in the IFC (Industry Foundation Class) ontology. This mapping can be found in the community folder. Our policy is that we provide native mappings to other unit-of-measure ontologies, but mappings to ontologies that happen to include some units but are focused on other things will be located in the community folder (thanks again @fkleedorfer)
• Added some prefixed BTU units (thanks to @fennibay)

Thank you as always for providing submissions to extend the size and capabilities of QUDT!

QUDT Release 2.1.22

Release 2.1.22 includes:

• Refactoring of our community folder with an eye toward extensibility, driven by some of the contributions described below. Please see the community README here.
• Building on the above, @fkleedorfer has uploaded mappings from QUDT to IFC (Industry Foundation Classes) using SSSOM, as well as a variety of new quantity kinds and units relevant to the IFC world. You can find it all in the community/mappings/SSSOM/IFC folder.
• @paroga held our feet to the fire, so the distinctions between powers-of-2 prefixes (like Kibi, Mebi, etc.) and powers-of-10 prefixes (Kilo, Mega, etc.) is now cleaned up.
• Fixed some errors related to ForceMagnitude (thanks, @jpasini)
• Fixed a SPIN function definition filename for those who use SPIN (thanks, @mgberg)
• Fixed the symbol for the Siemens unit (thanks to @fennibay)
• Clarified the use of abstract quantity kinds, documented here (prompted by @mgberg)
• For those of you who use the SHACL schema, we have relaxed the constraint such that Units and QuantityKinds can have both a qudt:symbol (in Unicode) and a qudt:expression (in LaTeX) (@mgberg again!)
• Added ISO 4217 currency codes and currency numbers for all our currencies (thanks to @fkleedorfer again!)

A big thank-you to all of you for bringing many of these issues to our attention, and even better, for providing submissions to extend the size and capabilities of QUDT!

QUDT Release 2.1.21

Release 2.1.21 includes:

• Over 1500 updated Unicode symbols for units rather than ASCII, using the qudt:symbol property (thanks to @mgberg)
• Progress toward an automated validation test regimen. As we move forward, this uncovered some inconsistencies in dimension vectors vis-a-vis the skos:broader hierarchy
• Fixed the dimensionality of the Siemens (unit:S) and related prefixed versions and quantity kinds (thanks to @paroga)
• Added some missing UNECE command codes and conversion multipliers (thanks to @paroga)
• Added the QUDT SHACL schema to our website catalog
• Yet more conversion multipliers (thanks to @fkleedorfer)
• Treated the distinction between Kilo and Kibi prefixes (and higher prefixes) more rigorously (thanks to @paroga)
• Related ExpansionRatio with CubicExpansionCoefficient and LinearExpansionCoefficient via skos:broader, along with relevant expansion coefficient units (thanks to @mgberg)
• Added StressOpticCoefficient quantity kind and associated units (thanks to @mgberg)

While not part of the Release mechanism, we have also clarified our use of language tags for rdfs:label and skos:altLabel in our wiki here

QUDT Release 2.1.20

Thanks to all the contributors for keeping QUDT fresh and evolving!

Release 2.1.20 includes:

• Support for non-numerical quantities, allowing you to make instances of qudt:EnumeratedQuantity in addition to the usual qudt:Quantity. The intention is that you would also declare and reference the valid values, as instances of qudt:Enumeration. All the values are expected to be xsd:string. (Documentation will follow in the wiki).
• Added the property qudt:supercededBy, allowing us to point to any updated versions of entities rather than simply replacing the old ones, so that current implementations won't break.
• Removed the range restriction of xsd:string from dcterms:creator and dcterms:contributor, in keeping with changes to DublinCore (thanks to @ektrah).
• Started what will be a gradual process of updating values of qudt:symbol to Unicode symbols when they exist.
• More new units! (thanks to @Lachlan-Charles)
• Fixed some inconsistent or missing dimension vector references (thanks to @mgberg)
• Fixed a variety of errors (thanks to @jmkeil and his ontology comparison tool)
• Fixed some SHACL constraints (thanks to @fkleedorfer)
• Added some new quantity kinds to support visible light properties (thanks to Michael Poplowski)
• Updated GeneFamilyAbundance (thanks to @kitchenprinzessin3880)

QUDT Release 2.1.19

Release 2.1.19 includes:

• New units, thanks to @Lachlan-Charles, @kitchenprinzessin3880, @elisagirola, @kinghuang, @ansu
• Fixed some erroneous dimension vector references, thanks to a cool ontology comparison tool written by @jmkeil
• We're still working on support for non-numerical values - stay tuned.

QUDT Release 2.1.18

Release 2.1.18 includes some structural changes:

• Refactoring of the imports closure graph that simplifies needed changes if you want to shift between the OWL schema and the SHACL schema. The new file SCHEMA-FACADE_QUDT-v2.1.18.ttl (URI is http://qudt.org/2.1/schema/facade/qudt) is the only place needed to point to either the OWL or SHACL schema. The default is http://qudt.org/2.1/schema/qudt (OWL schema), which can be changed to http://qudt.org/2.1/schema/shacl/qudt for the SHACL schema.
• The Mathematics schema has been migrated into the main QUDT schema, so it is no longer needed as a separate graph.
• Cross-reference to the UDUNITS codes has been added.
• Various new units are included, such as FT-PER-DAY and MESH (thanks @kinghuang).
• More Latex errors have been corrected.
• Some chemical quantity kinds have been added.
• After some discussion, unit:MESH

Finally, HTTPS!!!
Work has also been happening behind the scenes for generating our web pages at https://qudt.org. (Note the https!!!) Still some kinks to iron out such as rendering the Latex, but we're getting there. But you can still resolve the URIs on the web, and download the ttl files right here on GitHub, either via the Release mechanism that you are reading right now, or by cloning or forking the repo.