- From: Rob Atkinson <rob@metalinkage.com.au>
- Date: Mon, 09 Jan 2017 22:08:40 +0000
- To: Simon.Cox@csiro.au, rob@metalinkage.com.au, public-sdw-wg@w3.org
- Message-ID: <CACfF9LxqRawqRozRx0QA3Uqci+z3K2kg20SJtWYmhoG3uD1azA@mail.gmail.com>
Thanks Simon on the road on a family holiday and not fully brain-in-gear yet.. but will attempt to put together some thoughts on the fairly obvious Use Case i want to try out - creating hierarchical time dimensions for datacubes - one based on calendars (describing that a dataset has properties year and month, and that year+month is the composite dimension, but that the dataset is also sliceable by year in a particular range) and one on eras (historical or geological) I'm still not that comfortable mixing the instances and the models in a single ontology resource - the question is whether some key subclasses should be in OWL-Time, or a canonical GregorianCalendar.owl ontology that uses it as a model and illustrates how to use OWL-Time for specialised cases? Rob On Mon, 9 Jan 2017 at 14:29 <Simon.Cox@csiro.au> wrote: > 1) Yes. What I did in this proposal was merely to chase through the > patterns already existing in the 2006 Ontology. > > > > a. Old OWL-Time had (only) Year and (only) January each as > sub-classes (restrictions of DurationDescription and DateTimeDescription, > respectively). I initially proposed deprecation, but you and Kerry > suggested completing the sets instead, to support some requirements from > QB4ST. So I did that to see what it looked like, following exactly the > patterns from the 2006 version. Net result: Month, Week, Day … Second all > modelled as classes, as well as February, March … December also modelled as > classes. > > > > b. However, Old OWL-Time also had a class DayOfWeek, with [Monday … > Sunday] as individual members. This looks like an alternative precedent for > the months, modelled as individuals. So I also implemented a new class > MonthOfYear, with [January … December] as individual members. > > > > Hence, merely by following the precedents from the 2006 version, we get > the standard durations (including ‘Month’) modelled as classes, and > individual months (January, February …) modelled as **both** classes and > individuals. Which do you prefer? And what do you suggest we do to make the > whole thing consistent? Or is that too much to expect? > > > > 2) “month” property is just copied through from the 2006 Ontology > (though the documentation is more explicit). > The notation “--04” is from xsd:gMonth – see > https://www.w3.org/TR/xmlschema11-2/#gMonth . > > “nominalPosition” is new in this version of the ontology, and was > introduced to support named time positions, which are used in geology, > archeology etc, but might also be useful in other contexts. Use of > nominalPosition requires a reference system which is a list of named times > which have **absolute** ordering relationships. OTOH month values are > only ordered in the context of a specified year. > > > > Simon > > > > *From:* Rob Atkinson [mailto:rob@metalinkage.com.au] > *Sent:* Tuesday, 3 January, 2017 04:13 > *To:* Cox, Simon (L&W, Clayton) <Simon.Cox@csiro.au>; public-sdw-wg@w3.org > *Subject:* Re: ISSUE-124 - deprecate January and Year > > > > Hi Simon > > sorry to take so long to get back to this - not enough sober opportunities > to do it justice over christmas :-) > > > > Only one voice here - but maybe just iterate an issue at a time... > > > > the first couple of things I am wondering about are: > > 1) the ontology seems to mix classes an instances at different levels of > abstraction - which is IMHO a difference issue than instance/subclass > duality :Month is modelled Class, but :January is an instance. (i dont > have the right leanguage for this but "real Instances" are bound to literal > values, as opposed to classes being instances of the Class concept.). I > guess the question is whether the concept of Month and Year are > specialisations of Interval that deserve to be in the main Time ontology. > > 2) the "month" property feels a bit odd still.. > > :month > > rdf:type owl:DatatypeProperty ; > > rdfs:comment """Month position in a calendar-clock system. > > The range of this property is not specified, so can be replaced by any > specific representation of a calendar month from any calendar. """@en ; > > rdfs:domain :GeneralDateTimeDescription ; > > rdfs:label "month"@en ; > > > > this feels like it is perhaps a subPropertyof :nominalPosition - > > and these all feel like models of time concepts - not a set of instances > > > > whats the rationale and documentation for the range in this form "--04" ? > > > > I think if i had a better handle on these I'd be able to look deeper into > it. > > > > Rob > > > > > > On Thu, 29 Dec 2016 at 06:17 <Simon.Cox@csiro.au> wrote: > > As I've been working on two separate groups of issues in OWL-Time, I've > created two branches with names to reflect these. So the work described > below which was initially in a branch simon-time is now in > simon-time-individuals > See: > > https://github.com/w3c/sdw/blob/simon-time-individuals/time/rdf/time.ttl > > -----Original Message----- > From: Cox, Simon (L&W, Clayton) > Sent: Wednesday, 28 December, 2016 08:01 > To: 'Rob Atkinson' <rob@metalinkage.com.au>; Little, Chris < > chris.little@metoffice.gov.uk>; kerry.taylor@anu.edu.au; > public-sdw-wg@w3.org > Subject: RE: ISSUE-124 - deprecate January and Year > > OK – so take a look in the RDF file for OWL-Time in the branch simon-time > [1] > > Following the examples of January and Year from 2006 OWL-Time, I've > created resources for 1. all of the months-of-the-year as subclasses of > DateTimeDescription 2. all of the basic time durations as subclasses of > DurationDescription > > I've also > > 3. shown how Year, Month, Week ... etc can also be conceived as subclasses > of the new class Duration, for example > > :Year > rdfs:subClassOf :Duration ; > rdfs:subClassOf [ > rdf:type owl:Restriction ; > owl:hasValue :unitYear ; > owl:onProperty :unitType ; > ] ; > rdfs:subClassOf [ > rdf:type owl:Restriction ; > owl:hasValue 1 ; > owl:onProperty :numericDuration ; > ] ; > . > > In addition to the original subclassing from DurationDescription. > > 4. shown how January, February, March ... etc can be conceived as > individuals from a new class MonthOfYear, which follows the precedent of > DayOfWeek which was already there. So for example, the complete description > of April looks like > > :April > rdf:type owl:Class ; > rdf:type :MonthOfYear ; > rdfs:label "April"@en ; > rdfs:subClassOf :DateTimeDescription ; > rdfs:subClassOf [ > rdf:type owl:Restriction ; > owl:hasValue :unitMonth ; > owl:onProperty :unitType ; > ] ; > rdfs:subClassOf [ > rdf:type owl:Restriction ; > owl:hasValue "--04" ; > owl:onProperty :month ; > ] ; > skos:prefLabel " ?@5;L"@ru ; > skos:prefLabel "#(1JD"@ar ; > skos:prefLabel "4 "@ja ; > skos:prefLabel "4 "@zh ; > skos:prefLabel "Abril"@es ; > skos:prefLabel "Abril"@pt ; > skos:prefLabel "April"@de ; > skos:prefLabel "April"@en ; > skos:prefLabel "April"@nl ; > skos:prefLabel "Aprile"@it ; > skos:prefLabel "Avril"@fr ; > skos:prefLabel "KwiecieD"@pl ; > . > > So each month is both a class and an individual. > Note that I also added multi-lingual labelling for months and days, > scraped from DBPedia, using the skos:prefLabel annotation. > > 5. In the branch these are all in the main namespace. > > So there are a few questions here: > (i) Should months be both classes (following the precedent from 2006) and > individuals (following the pattern from DayOfWeek) > (ii) Should the duration individuals be both DurationDescription and > Duration (don't see why not) > (iii) what namespace for all these > (iv) what property to be used for multi-lingual labels > > Simon > > [1] https://github.com/w3c/sdw/blob/simon-time/time/rdf/time.ttl > >
Received on Monday, 9 January 2017 22:09:40 UTC