Re: PROV-ISSUE-104 (time-class): How to relate start/end time to PE, use, generation, etc [Formal Model]

Hi Stian,
I think that the ontology has evolved a lot since this issue was raised,
and now you can relate instants to events or the duration of activities
with intervals.

Are you happy with the current modelling? Can we close this issue.
Thanks,
Daniel

2011/9/28 Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>

>
> PROV-ISSUE-104 (time-class): How to relate start/end time to PE, use,
> generation, etc [Formal Model]
>
> http://www.w3.org/2011/prov/track/issues/104
>
> Raised by: Stian Soiland-Reyes
> On product: Formal Model
>
> The conceptual model allows the optional time for:
>
> processExecution ( identifier [ , recipeLink ] , [ time ] , [ time ] ,
> other-attribute-values )
> wasGeneratedBy ( identifier , identifier , generationQualifier [, time] )
> used ( identifier , identifier , useQualifier [, time] )
>
>
> It is defined as:
> 5.5.6 Time
> Time instants are defined according to xsd:dateTime [XMLSCHEMA-2].
> It is optional to assert time in use, generation, and process execution
> expressions.
>
> I don't particularly like making time a data property like this (not
> allowing you to say anything about how the time was measured, uncertainty,
> (see neutrino experiment), relative frame of reference, etc; and does not
> allow non-gregorian time (seconds only, or timeframes, cpu steps, etc) -
> that's probably a separate issue.
>
> In the formal model we have a class prov:Time - but no way to connect this
> to ProcessExecutions. Associating them to use/generation, etc is strongly
> related to ISSUE-103 - but for PEs it should at least be easy to do:
>
> prov:ProcessExecution prov:startedAt [
>    a prov:Time;
>    prov:time "2011-02-19T12:03:12Z"^xsd:datetime ] ;
>  prov:endedAt [ # ..
>    a prov:Time;
>    prov:time "2011-02-19T12:05:10Z"^xsd:datetime ] ;
>  ]  .
>
> the use of a prov:Time class will open for application extensions for the
> concerns I am thinking of.
>
> If we introduce prov:follows and prov:preceeds as suggested by the
> conceptual model in
> http://dvcs.w3.org/hg/prov/raw-file/default/model/ProvenanceModel.html#event-ordering,
> it would be possible for asserters who only know about event ordering to
> use prov:Time instances which only are described using followed/preceeded
> with other Time instances.
>
> (I guess these terms are in present tense in the conceptual model because
> we are talking about Time - the two times would always be
> followed/precededed by each-other - but we could change it to past tense
> for consistency)
>
>
>
>
>