Re: URIs / Ontology for Physical Units and Quantities

Note also that, for durations of time, schema:duration (range
schema:Duration) specifies "(use ISO 8601 duration format
<http://en.wikipedia.org/wiki/ISO_8601>)."

http://schema.org/Duration
https://wrdrd.com/docs/consulting/knowledge-engineering#iso8601

ISO8601 <https://wrdrd.com/docs/consulting/knowledge-engineering#iso8601>
> Wikipedia: https://en.wikipedia.org/wiki/ISO_8601
> Standard: http://www.iso.org/iso/iso8601
>
> ISO8601 is a standard for specifying Gregorian dates, times, datetime
> intervals, durations, and recurring datetimes.
>
> An ISO8601 datetime is specified as: year, month, day, hour, ‘T’ or space,
> minute, second, timezone.
>
> A Z timezone specifies Universal Coordinated (or “Zulu”) time.
>
>    - http://www.w3.org/TR/NOTE-datetime
>
> Examples of ISO8601:
>
> 2014
> 2014-10
> 2014-10-23
> 20141023
> 2014-10-23T20:59:30+Z       # UTC / Zulu
> 2014-10-23T20:59:30Z        # UTC / Zulu
> 2014-10-23T20:59:30-06:00   # CST
> 2014-10-23T20:59:30-06      # CST
> 2014-10-23T20:59:30-05:00   # CDT
> 2014-10-23T20:59:30-05      # CDT
> 20
> 20:59
> 2059
> 20:59:30
> 205930
> 2014-10-23T20:59:30Z/2014-10-23T21:00:00Z
> 2014-10-23T20:59:30-05:00/2014-10-23T21:00:00-06
> PT1H
> PT1M
> P1M
> P1Y1M1W1DT1H1M1S
>
> Note
>
> AFAIU, ISO8601 does not specify standards for milliseconds, microseconds,
> nanoseconds, picoseconds, femtoseconds, or attoseconds.
>

On Thu, May 7, 2015 at 9:43 AM, Wes Turner <wes.turner@gmail.com> wrote:

> Ralph,
>
> QUDT:
>
> From https://wrdrd.github.io/docs/consulting/knowledge-engineering#qudt
>
>> Homepage: http://www.linkedmodel.org/doc/qudt/1.1/
>> Standard: http://qudt.org/
>> Namespace: http://qudt.org/schema/qudt#
>> xmlns: @prefix qudt: <http://qudt.org/schema/qudt#> .
>> LOVLink: http://lov.okfn.org/dataset/lov/vocabs/qudt
>>
>> QUDT (*Quantities, Units, Dimensions, and Types*) is an *RDF*
>> <https://wrdrd.com/docs/consulting/knowledge-engineering#rdf> standard
>> vocabulary for representing physical units.
>>
>>    - QUDT is composed of a number of sub-vocabularies
>>    - QUDT maintains conversion factors for Metric and Imperial Units
>>
>>
> A few JSON-LD examples could be very helpful.
>
>
> On Thu, May 7, 2015 at 7:21 AM, Ralph TQ [Gmail] <rhodgson@topquadrant.com
> > wrote:
>
>> Hello Mark,
>>
>> QUDT is now a non-profit organization with the desire to join W3C to move
>> forward on standardization. The management at NASA has given its approval
>> for QUDT to proceed with this.
>>
>> Release 2 is a substantial body of work that is finally reaching a
>> publication status. This involves the generation of content with support
>> for LaTeX formatting. Examples can be seen at the following web pages:
>>
>>
>>    1. The documentation on the QUDT schema -
>>    http://www.linkedmodel.org/doc/2015/DOC_schema-qudt-v2.0
>>    2. An example of a LaTeX rendered instance of the Hartree Unit -
>>    http://www.linkedmodel.org/doc/2015/hartree
>>
>> The site www.linkedmodel.org has links to documentation for other
>> ontologies and for those that QUDT depends on (VAEM, VOAG and DTYPE).
>>
>> All the QUDT ontologies are managed on a GitHub site. There is also a
>> WordPress site.
>>
>> QUDT would welcome participation from others and once we become a member
>> of W3C a working group would be important to establish. Perhaps we should
>> have a discussion on how to get started?
>>
>> We have long believed that for (some) data to be truly linkable on the
>> web it benefits from being quantified.
>>
>> I will send another email setting out the remaining work we are doing on
>> the ontologies. In my view the most important of which is standardization
>> of the QNames of the units (e.g, unit:SEC for second, unit:S for Siemen,
>> and unit:KM-PER-SEC not unit:KM-PER-S) so that they are consistently
>> reference-able and conforms with their standard abbreviations . This work
>> is almost complete for SI units.
>>
>> Regards,
>>
>>
>> Ralph Hodgson, @ralphtq <http://twitter.com/ralphtq>
>>
>> TopQuadrant, Inc., www.topquadrant.com @TopQuadrant
>> <http://twitter.com/topquadrant>
>> *cell: +1 781-789-1664 <%2B1%20781-789-1664> / fax: 703 299-8330
>> <703%20299-8330> / main: 919 300-7945 <919%20300-7945>*
>>
>>
>> On May 7, 2015, at 4:56 AM, Mark Harrison <mark.harrison@cantab.net>
>> wrote:
>>
>> Dear Martin,
>>
>> I understand your very valid concerns about Linked Data resources that
>> are not supported and maintained and end us wasting time for developers.
>> However, from this thread it also seems that there is quite some interest
>> in having a well recognised ontology for units of measure in which units
>> have corresponding stable URIs that link to definitions, UN ECE codes,
>> conversion factors and offsets, etc.  QUDT 1.1 made a very good start on
>> this, although it had one or two inaccurate cross-references.  For example,
>> I found within http://qudt.org/vocab/unit#Grain the following
>> nonsensical triple:
>>
>> <http://qudt.org/vocab/unit#Grain>  skos:exactMatch  <
>> http://dbpedia.org/resource/Cereal> .
>>
>> There are some other gaps in QUDT 1.1, such as missing resources for
>> units such as milligram, microgram - and because the SI base unit of mass
>> is the kilogram, it is not sufficient to simply define the multipliers such
>> as 'milli', 'micro', because we don't usually talk about milligrams as
>> microkilograms, for example.
>>
>> Having said that, if QUDT 1.1 were updated, corrected, supported a more
>> complete set of units and provided cross-references to the corresponding UN
>> ECE Common Code values as strings, I think it (or something very like it)
>> could be an extremely valuable resource for everyone, especially because of
>> the conversion factors and offsets.
>>
>> The QUDT.org website appears to be last updated in March 2014 and there
>> is some information and a presentation by Ralph Hodgson (copied) about the
>> plans for release 2.0 of QUDT.  However, I'm not sure whether that work has
>> stalled or is under-resourced or is spending a long time in careful
>> internal review.  Maybe those of us who are interested in making this
>> happen could offer to share the workload and accelerate the progress.  In
>> case NASA / TopQuadrant is no longer the place to host it, then perhaps we
>> could reasonably ask W3C to host it in perpetuity and maintain a liaison
>> with the UN, ISO and other relevant bodies to ensure that we're aware of
>> their changes that should be reflected through maintenance updates to such
>> a vocabulary.
>>
>> We're soon hoping to see much more structured data about products being
>> published openly on the web as linked data, potentially including details
>> about ingredients, nutrition and allergens.  GS1 has already prepared begun
>> drafting a web vocabulary [ see
>> http://www.gs1.org/gtin_plus_public_review ] to help manufacturers and
>> retailers express such information in much richer detail than they can
>> currently using schema.org alone - and efforts are underway to harmonise
>> this effort with schema.org to make life easier for developers.  I
>> expect that a stable supported ontology with URIs and Linked Data for units
>> of measure along the lines of a QUDT 2.0 could be far more useful to
>> software developers than simply denoting a unit of measure by its UN ECE
>> Common Code string.  We can certainly do better than that.  It could almost
>> certainly avoid a large amount of duplicated effort in coding conversion
>> factors and offsets and would also help to ensure that whether the product
>> specifications are provided in SI units or non-SI units (as they are in
>> different regions of the world), the same quantitative information is
>> readily available so software applications, without ambiguity or
>> unnecessary duplication of effort by developers.
>>
>> I hope that Ralph Hodgson can chime in with a brief status update on QUDT
>> 2.0 - and also that those of us who would be interested in helping to
>> accelerate this (or something similar) can step forward and offer to help
>> with reviewing it or beta testing it - or filling in the gaps for the
>> missing features.
>>
>> Best wishes,
>>
>> - Mark Harrison
>>
>>
>>
>>
>> On 7 May 2015, at 09:08, martin.hepp@ebusiness-unibw.org wrote:
>>
>> Dear Kingsley:
>> Technically, as we agree, this is no big deal.
>>
>> But there are so many abandoned RDF / Semantic Web efforts rottening on
>> the Web and wasting the time of developers who try to built something on
>> top of it -- until they find out that the project is way out of date --
>> that I do not see any gain in such a quick fix.
>>
>> Martin
>>
>>
>> On 07 May 2015, at 01:25, Kingsley Idehen <kidehen@openlinksw.com> wrote:
>>
>> On 5/6/15 6:31 PM, martin.hepp@ebusiness-unibw.org wrote:
>>
>> The problem is not the one time generation. The problems are as follows:
>>
>> 1. Copyright - Are you allowed to republish the code set as RDF?
>> 2. Sustainability - Are you commited to keep the URIs dereferencable, or
>> will some domain grabber take the domain name once the creator has
>> completed his/her PhD and lost interest.
>> 3. Updates - Will you keep the RDF version in sync whenever the standard
>> changes?
>>
>> Unless there is a clear "yes" to all three questions, it is better to use
>> the official codes than derived URIs.
>>
>> Martin
>>
>>
>> Martin,
>>
>> What's wrong with:
>>
>> <#someResolvableVariantOfIdentifier>
>> a owl:Thing ;
>> dcterms:identifier "{literal-variant-of-standard-identifier}" .
>>
>> Which can be further embellished by Linked Data publisher in their
>> ontology/vocabulary by adding the following:
>>
>> dcterms:identifier
>> a owl:InverseFunctionalProperty .
>>
>> Productive workflow:
>>
>> 1. Get the data dump in a spreadsheet
>> 2. Save as CSV
>> 3. Load into LOD or Google Refine
>> 4. Map to relevant ontology (existing, or new)
>> 5. Dump data into an RDF document
>> 6. Publish (note: using # as indexical mechanism makes the publication
>> Linked Open Data prinicples compliant off-the bat).
>>
>>
>> It can be done quite easily. I deliberatly opted not to do it :)
>>
>>
>> Kingsley
>>
>>
>>
>>
>> On 06 May 2015, at 23:56, Wes Turner <wes.turner@gmail.com> wrote:
>>
>> How much time do you think it would take to generate RDF (and namespaced
>> URIs) from the linked spreadsheet?
>>
>> Mappings to/from UN/CEFACT codes (as owl:sameAs mappings to strings)
>> could certainly be useful.
>>
>> On May 6, 2015 4:31 PM, "martin.hepp@ebusiness-unibw.org" <
>> martin.hepp@ebusiness-unibw.org> wrote:
>> I think a validator should simply use the list of valid codes from the
>> most recent UN/CEFACT document (available as MS Excel from
>> http://www.unece.org/cefact/codesfortrade/codes_index.html).
>>
>> There might be unit of measurement ontologies out there that hold the
>> UN/CEFACT Common Code string for a subset of all units as a literal value.
>> But for validation, one should use the authoritative list from the Excel
>> files (since they are updated from time to time).
>>
>> URIs are not better than strings for validation, because URIs are strings.
>>
>> Best wishes / Mit freundlichen Grüßen
>>
>> Martin Hepp
>>
>> -------------------------------------------------------
>> martin hepp
>> e-business & web science research group
>> universitaet der bundeswehr muenchen
>>
>> e-mail:  martin.hepp@unibw.de
>> phone:   +49-(0)89-6004-4217
>> fax:     +49-(0)89-6004-4620
>> www:     http://www.unibw.de/ebusiness/ (group)
>>        http://www.heppnetz.de/ (personal)
>> skype:   mfhepp
>> twitter: mfhepp
>>
>> Check out GoodRelations for E-Commerce on the Web of Linked Data!
>> =================================================================
>> * Project Main Page: http://purl.org/goodrelations/
>>
>>
>>
>>
>> On 06 May 2015, at 20:34, Wes Turner <wes.turner@gmail.com> wrote:
>>
>> Thanks!
>>
>> I notice that with QUDT there are SI conversion factors and complete URIs
>> for each unit.
>>
>> Is there a schema for validation of "schema:QuantativeValues supports all
>> UN/CEFACT Common Codes"?
>>
>> (A similar quandry as with MedicalCode; where URI namespaces (like
>> icd10:) would be more helpful for terminological validation and
>> disambiguation than plain string keys)
>>
>> On May 6, 2015 4:26 AM, "martin.hepp@ebusiness-unibw.org" <
>> martin.hepp@ebusiness-unibw.org> wrote:
>>
>> Hi Wes,
>> sorry for a very late reply:
>>
>> Actually you could easily use schema:QuantitativeValue for both time and
>> volume, with SEC as the unit code for t and LTR as the unit code for
>> liters, and link both via schema:valueReference, or better, and
>> owl:subProperty thereof.
>>
>> For the principle, see
>>
>>
>> http://wiki.goodrelations-vocabulary.org/Documentation/Structured_values_and_value_references
>>
>>
>> schema:QuantativeValues supports all UN/CEFACT Common Codes for units,
>> which should cover all you need:
>>
>>
>>
>> http://wiki.goodrelations-vocabulary.org/Documentation/UN/CEFACT_Common_Codes
>>
>> (Mind the full list in the public Excel files, the page just highlights a
>> small subset.)
>>
>> Best wishes / Mit freundlichen Grüßen
>>
>> Martin Hepp
>>
>> -------------------------------------------------------
>> martin hepp
>> e-business & web science research group
>> universitaet der bundeswehr muenchen
>>
>> e-mail:  martin.hepp@unibw.de
>> phone:   +49-(0)89-6004-4217
>> fax:     +49-(0)89-6004-4620
>> www:     http://www.unibw.de/ebusiness/ (group)
>>        http://www.heppnetz.de/ (personal)
>> skype:   mfhepp
>> twitter: mfhepp
>>
>> Check out GoodRelations for E-Commerce on the Web of Linked Data!
>> =================================================================
>> * Project Main Page: http://purl.org/goodrelations/
>>
>>
>>
>>
>> On 01 May 2015, at 13:45, ☮ elf Pavlik ☮ <perpetual-tripper@wwelves.org>
>> wrote:
>>
>> Hi Wes,
>>
>> On 01/26/2014 07:20 AM, Wes Turner wrote:
>>
>> Say I am trying to share a tabular dataset. [1] There's metadata for
>> the Dataset, and there's metadata for the particular columns (which
>> applies to the particular data items).
>>
>> For example:
>>
>> t   volume (liters)
>> -----------------
>> 1  1
>> 2  0.7
>> 3  0.5
>> 4  0.3
>> 5  0.1
>>
>> Questions
>> ===========
>> # Is there (a good) way to specify these units and quantities (in
>> addition to XSD datatypes)?
>>
>> You might like to check out
>> * https://iotdb.org/pub/iot-unit.html
>>
>> Cheers!
>>
>>
>>
>>
>>
>>
>> --
>> Regards,
>>
>> Kingsley Idehen
>> Founder & CEO
>> OpenLink Software
>> Company Web: http://www.openlinksw.com
>> Personal Weblog 1: http://kidehen.blogspot.com
>> Personal Weblog 2: http://www.openlinksw.com/blog/~kidehen
>> Twitter Profile: https://twitter.com/kidehen
>> Google+ Profile: https://plus.google.com/+KingsleyIdehen/about
>> LinkedIn Profile: http://www.linkedin.com/in/kidehen
>> Personal WebID: http://kingsley.idehen.net/dataspace/person/kidehen#this
>>
>>
>>
>>
>>
>>
>>
>
>
> --
> Wes Turner
> https://westurner.org
> https://wrdrd.com/docs/consulting/knowledge-engineering
>



-- 
Wes Turner
https://westurner.org
https://wrdrd.com/docs/consulting/knowledge-engineering