Bruno raises an interesting question-- would this contribution have any effect (or should it) on jena-spatial? Would it be either necessary or if not, appropriate to integrate there? (I'm particularly interested in this because it might help decide between core and an extension.)
ajs6f > On Mar 26, 2018, at 5:40 PM, Bruno P. Kinoshita <ki...@apache.org> 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 > | > | > | > | | | > > | > > | > | > | | > Units of Measurement > > Units of Measurement provides a set of APIs and services for handling units > and quantities. > | | > > | > > | > > > 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<maxime.lefranc...@emse.fr> > 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/
