- From: Gannon Dick <gannon_dick@yahoo.com>
- Date: Tue, 29 Jul 2014 10:45:20 -0700
- To: "andrea.perego@jrc.ec.europa.eu" <andrea.perego@jrc.ec.europa.eu>, "frans.knibbe@geodan.nl" <frans.knibbe@geodan.nl>, "Simon.Cox@csiro.au" <Simon.Cox@csiro.au>, Chris Beer <chris@codex.net.au>, ChrisLittle <chris.little@metoffice.gov.uk>
- Cc: "public-locadd@w3.org" <public-locadd@w3.org>, "public-egov-ig@w3.org" <public-egov-ig@w3.org>, public-lod <public-lod@w3.org>, "temporal@lists.opengeospatial.org" <temporal@lists.opengeospatial.org>, Piero Campalani <cmppri@unife.it>, Matthias Müller <matthias_mueller@tu-dresden.de>
On Tue, 7/29/14, Little, Chris <chris.little@metoffice.gov.uk> wrote:
And I agree that transparency about calendar algorithms is an issue, not just
in their book. This isone thing that I hope that an OGC Best Practice document could help, in however a small way.
============
Hi Chris,
Maybe it is time to "go big" - Universal Coordinated Calendar Time (UTCT). In the near term, (this Julian Century) the Calendar has no unidentified shifts. We know about Leap Days and the Calendar is ignorant of Leap Seconds. So, it is possible.
This presents a problem for Linked Data because even though Personal Identity is coupled to Occupation and Occupation is coupled to the Location of the Workplace, these are couplings not correlations.
Mid-day, Noon, is a mean value, but one can't assume regression to the mean. At the Equator the "Authority" - Solar Noon - has a whopping 7 1/2 minute time shift. This is not hidden, but it is overwhelmed by the Equation of Time. The shifts, on a day-to-day basis do not accumulate to significance on a year-to-year basis. To determine coupling constants is a fools errand.
e.g. http://www.rustprivacy.org/2014/balance/utct.jpg
When people triangulate in their heads they use 3,4,5 triangles to keep the math easy. For this reason, the Axis length is 500%. All "shifts" (events which impact Work Life Balance) are vertical. Sorry, the "Day" indicator can't update automatically - it's a PDF.
WDYT?
Best,
--Gannon (J.) Dick ;-) I'm not a commuter, I have a funny name.
-----Original Message-----
From: Gannon Dick [mailto:gannon_dick@yahoo.com]
Sent: Thursday, July 24, 2014 5:24 PM
To: andrea.perego@jrc.ec.europa.eu;
frans.knibbe@geodan.nl;
Simon.Cox@csiro.au;
Chris Beer; Little, Chris
Cc: public-locadd@w3.org;
public-egov-ig@w3.org;
public-lod; temporal@lists.opengeospatial.org;
Piero Campalani; Matthias Müller
Subject:
Re: OGC Temporal DWG. Was: space and time
Hi Chris,
who wrote:
One concern that I
have is that we do not re-invent the wheel, and do
nugatory work, hence this email. I do not envisage that we
will need to do much with Calendars, which have been
covered so well by Dershowitz and Reingold.
=====================================
No question the quality of the issue coverage
(Calendars) is first rate.
However, the computations are not transparently
self-evident and the references you cite in the Wiki are not
available on-line - or are they ?
3. Calendrical Tabulations 1900-2200, Edward M.
Reingold, Nachum Dershowitz. Hardcover: 636 pages.
Publisher: Cambridge University Press (16 Sep 2002)
Language: English ISBN-10: 0521782538 ISBN-13:
978-0521782531
4.
Calendrical Calculations, Nachum Dershowitz, Edward M.
Reingold. Paperback: 512 pages. Publisher: Cambridge
University Press; 3 edition (10 Dec 2007) Language: English
ISBN-10: 0521702380 ISBN-13: 978-0521702386
Accessability to "Wheels
known to have been invented" is a Wiki issue, I
think.
--Gannon
--------------------------------------------
On Thu, 7/24/14, Little, Chris <chris.little@metoffice.gov.uk>
wrote:
Subject: OGC
Temporal DWG. Was: space and time
To:
"Gannon Dick" <gannon_dick@yahoo.com>,
"andrea.perego@jrc.ec.europa.eu"
<andrea.perego@jrc.ec.europa.eu>,
"frans.knibbe@geodan.nl"
<frans.knibbe@geodan.nl>,
"Simon.Cox@csiro.au"
<Simon.Cox@csiro.au>,
"Chris Beer" <chris@codex.net.au>
Cc: "public-locadd@w3.org"
<public-locadd@w3.org>,
"public-egov-ig@w3.org"
<public-egov-ig@w3.org>,
"public-lod" <public-lod@w3.org>,
"temporal@lists.opengeospatial.org"
<temporal@lists.opengeospatial.org>,
"Piero Campalani" <cmppri@unife.it>,
"Matthias Müller" <matthias_mueller@tu-dresden.de>
Date: Thursday, July 24, 2014, 9:36 AM
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Dear Colleagues,
OGC started a Temporal Domain Working Group
last year to address a number of problems in the
geospatial domain. In particular, that time is usually
just viewed as Yet Another Attribute of Features, rather
than a first class coordinate.
We agreed earlier this year, in Geneva, that
the OGC Naming Authority would have a branch to register
Temporal, and index based, Coordinate Reference Systems,
and we agreed on the fundamental attributes that a CRS
should have to be registered.
We hope to produce a Best Practice document
this year to help clarify many confusions between CRSs,
notations, calendars, operations and calculations. I think
that now we have a good enough understanding of the
underlying conceptual issues and current geospatial
standards.
We have been
accumulating info on an open wiki http://external.opengeospatial.org/twiki_public/TemporalDWG/WebHome
and discussing via our
mailing list, though we are not very disciplined about
it.
One concern that I
have is that we do not re-invent the wheel, and do
nugatory work, hence this email. I do not envisage that we
will need to do much with Calendars, which have been
covered so well by Dershowitz and Reingold.
Best wishes, Chris
Chris Little
Co-Chair,
OGC Meteorology & Oceanography Domain Working Group
Co-Chair, OGC Temporal Domain Working Group
IT Fellow -
Operational
Infrastructures
Met Office FitzRoy Road Exeter Devon
EX1 3PB United Kingdom
Tel: +44(0)1392 886278 Fax: +44(0)1392
885681 Mobile:
+44(0)7753 880514
E-mail: chris.little@metoffice.gov.uk
http://www.metoffice.gov.uk
I am normally at work
Tuesday,
Wednesday and Thursday each
week
Received on Tuesday, 29 July 2014 17:45:48 UTC