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> On Mar 26, 2018, at 5:40 PM, Bruno P. Kinoshita <[email protected]> wrote:
>
> Hi Maxime,
> Don't know whether it would be best as part of jena core or in an extension,
> but sounds very interesting! Will let others comment on this.
> At work, one item in my backlog is to replace jscience by jsr363 - Units of
> Measurement
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> Units of Measurement
>
> Units of Measurement provides a set of APIs and services for handling units
> and quantities.
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> We use it for weather forecast and GIS, with things like wind speed, rain
> amount, etc.
> I think another GIS library that we use did the switch as well (some OGC lib
> I think).
> Perhaps it would be nice to consider taking a look at their api for
> compatibility with other systems.
> CheersBruno
>
> Sent from Yahoo Mail on Android
>
> On Tue, 27 Mar 2018 at 2:07, Maxime Lefrançois<[email protected]>
> wrote: Dear all,
>
> I am Associate Professor at MINES Saint-Étienne, France, working on
> Semantic Web and Linked Data. I'd like to let you know about our
> project *Custom
> Datatypes for Quantity Values*[1], that leverages the Unified Code of Units
> of Measures, a code system intended to include all units of measures being
> contemporarily used in international science, engineering, and business.
> Using our UCUM Datatypes, one can encode and query quantity values in a
> lightweight manner:
>
> PREFIX cdt: <http://w3id.org/lindt/custom_datatypes#>
> PREFIX ex: <http://example.org/>
>
> SELECT ?value1 ?value2 ?result
> WHERE{
> VALUES ( ?value1 ?value2 ) {
> ( "1.0 m/s"^^cdt:speed "2 s"^^cdt:time )
> }
> BIND( ?value1 * ?value2 AS ?result )
> }
>
> Results in
>
> ----------------------------------------------------------------------
> | value1 | value2 | result |
> ======================================================================
> | "1.0 m/s"^^cdt:speed | "2 s"^^cdt:time | "2.0 m"^^cdt:length |
>
> See our demonstration online [2].
> It uses *a fork of Jena where we implemented UCUM datatypes* [3] (in
> jena-core and jena-arq, with several unit tests) our implementation uses
> the recent JSR 385, Units of Measurement API 2.0, and the UCUM extension
> [4].
>
> This is not the first project I develop into/using Jena.
> - I forked it to Supporting Arbitrary Custom Datatypes in RDF and SPARQL
> fetching some Javascript definition at the URI of the datatype [5]
> - I develop SPARQL-Generate, an extension of SPARQL implemented on ARQ to
> generate RDF from web documents in XML, JSON, CSV, HTML, CBOR, and plain
> text with regular expressions [6]
>
>
> If you agree we me that supporting UCUM datatypes would be a nice addition
> to Apache Jena and a nice contribution to the Semantic Web community, I
> would be willing to help to integrate our contribution to other modules
> (with jena-tdb, ... ), and help maintaining it in the future.
>
> Best regards,
> Maxime Lefrançois,
> Associate Professor, MINES Saint-Étienne
>
> [1] - http://w3id.org/lindt/custom_datatypes#
> [2] - http://w3id.org/lindt/playground.html?example=05-Multiply
> [3] - http://w3id.org/lindt/custom_datatypes#implementation
> [4] -
> https://github.com/unitsofmeasurement/uom-systems/tree/master/ucum-java8
> [5] - https://ci.mines-stetienne.fr/lindt/spec.html
> [6] - https://ci.mines-stetienne.fr/sparql-generate/
