RE: Please review OWL-Time document

Bart,

Further to Simon’s comments, which I support, the use of an ‘unqualified’ ISO8601 string (i.e. no ‘Z’ or Time Zone displacement) is rather ambiguously defined as ‘local time’ – whatever that is.

Actually I think it is the chink through which we could define earthly solar time, planetary times, my computer’s time, or even local observers’ times as in special and general relativity. However to get some convenient concise unambiguous syntaxes  to match the flexibility of the semantics is further work , already started elsewhere, in the OGC (and ISO) WKT for Calendars Standards WG.

Hope that meets your requirements.

Chris

From: Simon.Cox@csiro.au [mailto:Simon.Cox@csiro.au]
Sent: Monday, January 09, 2017 3:28 AM
To: bart_van_leeuwen@netage.nl
Cc: public-sdw-wg@w3.org; hadley@linkedgov.org
Subject: RE: Please review OWL-Time document

Thanks Bart –


1.     Milliseconds – I need to understand a bit more what you are suggesting here.

a.     Temporal position can be specified to any required precision, either using

                                                    i.     Decimals in the YYYY-MM-DDThh:mm:ss.ssssssssss[+NN] notation used in the inXSDDateTIme property of an Instant

                                                  ii.     as decimals in the seconds property of the DateTimeDescription class

                                                 iii.     or using decimals in the numericPosition property of the newly introduced TimePosition class

b.     Similar mechanisms are provided for temporal durations. The fixed durations Year, Month, Week … Second are defined as restrictions of

                                                    i.     DurationDescription (by specifying the cardinalities of the standard properties) and

                                                  ii.     Duration (by fixing the unitType, which in turn has the standard 7 members Year, Month, Week … Second).  In this case, the set of units is open, so milliseconds could be added in an application.

2.     Interplanetary – I suspect we already have this covered. The principal upgrade in this version of OWL-Time is to generalize the use of temporal coordinate systems, so that users are not restricted to the (earth-bound) Gregorian clock/calendar, though it still has a special status because of its almost ubiquitous use.

I’m generally wary of going beyond the standard elements specified in ISO 8601, and implemented widely (e.g. in XSD) as there is a large set of potentially temporal units. Until your mail we did not have a requirement expressed for anything else.

Simon



From: Bart van Leeuwen [mailto:bart_van_leeuwen@netage.nl]
Sent: Friday, 30 December, 2016 07:24
To: Cox, Simon (L&W, Clayton) <Simon.Cox@csiro.au<mailto:Simon.Cox@csiro.au>>
Cc: public-sdw-wg@w3.org<mailto:public-sdw-wg@w3.org>; Hadley Beeman <hadley@linkedgov.org<mailto:hadley@linkedgov.org>>
Subject: Re: Please review OWL-Time document

Hi Simon,

Over the last days I took the time to go over the document, its looks very complete but I have a couple of questions.
I did not search the archive of the mailing list to see if any of these actually got discussed before in which case I excuse myself for being lazy.

Milliseconds
Since we are also working with Sensor Networks and XSD has fractional seconds,
is there any rationale not to have them in the ontology ?

Interplanetary ( @hadley this is why you are on the CC )
This might sound more anecdotally then serious, but during W3C TPAC in Lyon 2012 we discussed the interplanetary web.
One of the conclusions we had is that we would need to think about time and space notations in our data,
when we gather data from other planets or communicate with other planets.
Since we talk about coverage and sensor data NASA has tons of that, from other places with other times.
For me this is not a hard requirement, more a left over of a heavy Christmas dinner etc.

Met Vriendelijke Groet / With Kind Regards
Bart van Leeuwen


twitter: @semanticfire
tel. +31(0)6-53182997
Netage B.V.
http://netage.nl<http://netage.nl/>
Esdoornstraat 3
3461ER Linschoten
The Netherlands
[cid:image002.jpg@01D26BF6.50C1CA10]



From:        <Simon.Cox@csiro.au<mailto:Simon.Cox@csiro.au>>
To:        <public-sdw-wg@w3.org<mailto:public-sdw-wg@w3.org>>
Date:        22-12-2016 06:38
Subject:        Please review OWL-Time document
________________________________



The Editors draft of the OWL-Time specification can be considered for release as a second public working draft.
http://w3c.github.io/sdw/time/


A few issues outstanding are prominent in the text – big pink notes.

And this section (carried over from the 2006 draft) has not been properly reviewed:
http://w3c.github.io/sdw/time/#commerce


Also – an annoying HTML/CSS issue – <h4> headings are not formatted consistently, some in blue, some in black, particularly where there is a sequence of them (mostly in chapter 4).
Somewhere along the line my HTML and the CSS are fighting, but I can’t figure out where.

Happy holidays all.

Simon & Chris

Simon J D Cox
Research Scientist
Environmental Informatics
CSIRO Land and Water<http://www.csiro.au/Research/LWF>

E simon.cox@csiro.au<mailto:simon.cox@csiro.au> T +61 3 9545 2365 M +61 403 302 672
   Mail: Private Bag 10, Clayton South, Vic 3169
   Visit: Central Reception, Research Way, Clayton, Vic 3168
   Deliver: Gate 3, Normanby Road, Clayton, Vic 3168
people.csiro.au/Simon-Cox<http://people.csiro.au/Simon-Cox>
orcid.org/0000-0002-3884-3420<http://orcid.org/0000-0002-3884-3420>
researchgate.net/profile/Simon_Cox3<https://www.researchgate.net/profile/Simon_Cox3>
github.com/dr-shorthair<https://github.com/dr-shorthair>

PLEASE NOTE
The information contained in this email may be confidential or privileged. Any unauthorised use or disclosure is prohibited. If you have received this email in error, please delete it immediately and notify the sender by return email. Thank you. To the extent permitted by law, CSIRO does not represent, warrant and/or guarantee that the integrity of this communication has been maintained or that the communication is free of errors, virus, interception or interference.

Please consider the environment before printing this email.