Re: space and time

My comments are inline..

Regards,
Frans

On 2014-05-24 10:39, Raphaël Troncy wrote:
> Dear all,
>
> Thanks for starting up this thread Frans. I don't have a strong 
> opinion on this issue, and, like you, I tend to think that space and 
> orthogonal dimensions. However, there are a number of use cases where 
> those dimensions are tied which trigger the question where we should 
> not have a few handy predicates to handle those cases, among others :
>   - the temporal validity of the spatial extent of a geographic 
> feature: this is indeed a generic use case that can be applied to any 
> resource (a solution is for example Memento)
>   - the temporal evolution of the spatial extent of a geographic 
> feature: the typical case is to represent the evolution of boundaries 
> of a administrative unit
>   - etc.
Yes, some handy predicates are needed. But I tend to think that those 
need to come from other vocabularies created by other working groups. I 
think what is needed is a clear separation of concerns (which is 
actually a design principle in computer science, so the wikipedia tells 
me <http://en.wikipedia.org/wiki/Separation_of_concerns>). Otherwise the 
working groups on geography, model trains and beer will eventually each 
come up with models that can describe the entire world (but from 
different perspectives).

>
> I observe that:
>   - since 1 month, there is a HUGE thread in the geojson community in 
> order to be able to represent time together with space. Concrete 
> proposals have been made, see 
> https://github.com/geojson/geojson-ld/issues/
An interesting observation. I tried to read this discussion 
<https://github.com/geojson/geojson-ld/issues/9> and - not being that 
familiar with GeoJSON - wondered why the community apparently has not 
chosen to  hand over the problem of specification of time to TimeJSON. 
Is it because TimeJSON does not exist?

>   - OWL Time is a draft, unfinished, and criticized for a number of 
> use cases. There has been an attempts 18 months ago from Ivan Herman 
> and others to clean it up and publish it as a more stable /ns W3C 
> vocab. But nothing really happened, everyone is busy.
That is a real pity. Perhaps time is such a common commodity that it is 
hard to find experts on the matter? Is it possible to study chronology 
at a university, for example? Still, I don't think that lack of progress 
in the time department of the data web is a valid reason for other 
departments to take up the task of modelling time.

>   - as Andrea mentioned, this issue was of the key topics discussed at 
> LGD'14.
> Best regards.
>
>   Raphaël
>


------------------------------------------------------------------------
Frans Knibbe
Geodan
President Kennedylaan 1
1079 MB Amsterdam (NL)

T +31 (0)20 - 5711 347
E frans.knibbe@geodan.nl
www.geodan.nl <http://www.geodan.nl> | disclaimer 
<http://www.geodan.nl/disclaimer>
------------------------------------------------------------------------


On 2014-05-24 10:39, Raphaël Troncy wrote:
> Dear all,
>
> Thanks for starting up this thread Frans. I don't have a strong 
> opinion on this issue, and, like you, I tend to think that space and 
> orthogonal dimensions. However, there are a number of use cases where 
> those dimensions are tied which trigger the question where we should 
> not have a few handy predicates to handle those cases, among others :
>   - the temporal validity of the spatial extent of a geographic 
> feature: this is indeed a generic use case that can be applied to any 
> resource (a solution is for example Memento)
>   - the temporal evolution of the spatial extent of a geographic 
> feature: the typical case is to represent the evolution of boundaries 
> of a administrative unit
>   - etc.
>
> I observe that:
>   - since 1 month, there is a HUGE thread in the geojson community in 
> order to be able to represent time together with space. Concrete 
> proposals have been made, see 
> https://github.com/geojson/geojson-ld/issues/
>   - OWL Time is a draft, unfinished, and criticized for a number of 
> use cases. There has been an attempts 18 months ago from Ivan Herman 
> and others to clean it up and publish it as a more stable /ns W3C 
> vocab. But nothing really happened, everyone is busy.
>   - as Andrea mentioned, this issue was of the key topics discussed at 
> LGD'14.
> Best regards.
>
>   Raphaël
>


------------------------------------------------------------------------
Frans Knibbe
Geodan
President Kennedylaan 1
1079 MB Amsterdam (NL)

T +31 (0)20 - 5711 347
E frans.knibbe@geodan.nl
www.geodan.nl <http://www.geodan.nl> | disclaimer 
<http://www.geodan.nl/disclaimer>
------------------------------------------------------------------------