W3C home > Mailing lists > Public > public-prov-wg@w3.org > October 2011

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

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Tue, 18 Oct 2011 05:22:31 +0000
To: Satya Sahoo <satya.sahoo@case.edu>
CC: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>, Paul Groth <p.t.groth@vu.nl>, Provenance Working Group WG <public-prov-wg@w3.org>
Message-ID: <EMEW3|2abd067c3c4bba271345497d93c108a1n9H6Mu08L.Moreau|ecs.soton.ac.uk|966BAF82-A85C-4A5A-8E01-398BFDD7D336@ecs.soton.ac.uk>
Hi Satya, thanks for this. There needs to be enough to be able to encode time in the examples. Note that we said that time is not associated to entities in DM.

Professor Luc Moreau
Electronics and Computer Science
University of Southampton
Southampton SO17 1BJ
United Kingdom

On 18 Oct 2011, at 02:34, "Satya Sahoo" <satya.sahoo@case.edu<mailto:satya.sahoo@case.edu>> wrote:

Hi Stian,
Sorry for getting to this late.

As we discussed during our call today, I have added a generic object property "hasTemporalValue" linking PE and Entity to the OWL time ontology class "TemporalEntity" (may need to be renamed) replacing our prov:Time class.

The specific properties such as wasGeneratedAt, wasStartedAt etc. can be defined to be sub-properties of "hasTemporalValue". We can defer adding these specific subproperties till we get more feedback from the WG?

Thanks.

Best,
Satya

On Fri, Oct 14, 2011 at 5:14 AM, Stian Soiland-Reyes <<mailto:soiland-reyes@cs.manchester.ac.uk>soiland-reyes@cs.manchester.ac.uk<mailto:soiland-reyes@cs.manchester.ac.uk>> wrote:

The DM constraint generation-unicy (or so) says that if in a single account asserts:

wasGeneratedBy(e, pe1, q1)
wasGeneratedBy(e, p2, q2)

then:
p1==p2 and q1==q2

I assume it follows that also the generation times would equal, but that should probably be added to the constraint. Therefore a single functional prov:wasGeneratedAt should be OK.

Now it is open for discussion if this constrain interferes with subprocesses where an entity can be seen as "generated two places at once", or if that should be solved by two (potentially roled) entities or two accounts.

You can do the same EntityInRole construct for prov:wasGeneratedBy. Syntactically each of these are new entities, can all have prov:assumedBy :e1 but  different prov:assumedRoles, prov:wasGeneratedAt (and in theory prov:wasGeneratedBy).

By the constraint they should then be interpreted as the same generation process and qualifiers (including role). You can think of it as an inference rule when an entity in role states its generation:

x prov:assumedBy e1
  prov:wasGeneratedBy :p1
  prov:wasGeneratesAt :t1
-->
x prov:wasComplementOf e1
e1 prov:wasGeneratesBy :p1
  prov:wasGeneratesAt :t1

ie they overlap, but have common start time. Again stating entity start/end time (characterisation unrerval) would make this easier.

At the same time I feel that this pushes EntityInRole to its limits. That's good, because we need to see if it is up to the job.

Tim, Satya, any comments?

On Oct 14, 2011 4:50 AM, "Paul Groth" <<mailto:p.t.groth@vu.nl>p.t.groth@vu.nl<mailto:p.t.groth@vu.nl>> wrote:
This is a good start:

But how is for example wasGeneratedAt associated with a particular process execution generated pair. Or do we assume that two such edges shouldn't occur?

I guess this done through the blank node in the used example is that correct?

Thanks for this
Paul

On Oct 14, 2011, at 1:30, Stian Soiland-Reyes <<mailto:soiland-reyes@cs.manchester.ac.uk>soiland-reyes@cs.manchester.ac.uk<mailto:soiland-reyes@cs.manchester.ac.uk>> wrote:

>> On Thu, Oct 13, 2011 at 17:49, Paul Groth <<mailto:p.t.groth@vu.nl>p.t.groth@vu.nl<mailto:p.t.groth@vu.nl>> wrote:
>>
>>> I was wondering if examples of time could be put in the PROV-O Crime
>>> Example. Like they are in PROV-DM.
>>>
>>> It would be cool to see how we can put times against:
>>>
>>> used,
>>> wasGeneratedBy
>>> Provenance Execution.
>
> I threw together one suggestion on how to do it using a few new properties:
>
> <http://dvcs.w3.org/hg/prov/file/tip/ontology/components/Time.ttl> http://dvcs.w3.org/hg/prov/file/tip/ontology/components/Time.ttl
>
> declares:
>
>  prov:startedAt
>  prov:endedAt
>  prov:assumedRoleAt
>  prov:wasGeneratedAt
>
>
> For example, from
> <http://dvcs.w3.org/hg/prov/file/285b39f7ea5f/ontology/components/Time/example-1.ttl> http://dvcs.w3.org/hg/prov/file/285b39f7ea5f/ontology/components/Time/example-1.ttl
>
> # start/end
> :pe1 a prov:ProcessExecution ;
>    prov:startedAt :tA ;
>    prov:endedAt :tB .
> :tA a prov:Time .
> :tB a prov:Time .
>
>
> # generation time
> :e1 a prov:Entity ;
>    prov:wasGeneratedBy :pe1 ;
>    prov:wasGeneratedAt :tC .
> :tC a prov:Time .
>
>
> # used time
> :pe2 a prov:ProcessExecution ;
>    prov:used [
>        a prov:EntityInRole;
>        prov:assumedBy :e1;
>        prov:assumedRoleAt :tD
>    ] .
> :tD a prov:Time .
>
>
> # controlled time
> :a1 a prov:Agent .
> :tE a prov:Time .
> :pe2 prov:wasControlledBy [
>        a prov:EntityInRole, prov:Agent;
>        prov:assumedBy :a1;
>        prov:assumedRoleAt :tE;
>    ] .
>
>
> You can from this of course also specify generation using EntityInRole
> and assumedRoleAt - but as an entity can only be generated once
> (right?) we might as well just say prov:wasGeneratedAt.
>
>
>
> Note to self:
> Allow intervals for role/use/control? - (prov:assumedRoleStart and
> prov:assumedRoleEnd)?
> Sounds like special cases of characterisation intervals..
> prov:startedAt and prov:endedAt could also be used with prov:Entity ?
>
>
>
> I looked at the crime file example, and did:
>
> <http://dvcs.w3.org/hg/prov/file/285b39f7ea5f/ontology/components/Time/example-2-crimefile.ttl> http://dvcs.w3.org/hg/prov/file/285b39f7ea5f/ontology/components/Time/example-2-crimefile.ttl
>
> .. but it does not really say much about time at all:
>
>
> #processExecution(pe1,add-crime-in-london,t+1,,[])
> :pe1 a prov:ProcessExecution, cf:FileAppending ;
>    prov:startedAt :t1 .
>
> #processExecution(pe2,email,t+2,,[])
> :pe2 a prov:ProcessExecution, cf:Emailing ;
>    prov:startedAt :t2 .
>
>
>
> So here's a practical example of how to do an extension, for instance
> using OWL Time:
>
> <http://dvcs.w3.org/hg/prov/file/285b39f7ea5f/ontology/components/Time/example-3-extension.ttl> http://dvcs.w3.org/hg/prov/file/285b39f7ea5f/ontology/components/Time/example-3-extension.ttl
>
> Including the simplest case without using the subclasses:
>
> # Lazy straight forward version - no declared subclasses
> :pe0 a :ProcessExecution ;
>    prov:startedAt [
>        # a prov:Time, time:Instant ;
>        time:inXSDDateTime "2011-12-24T14:24:05Z"
>    ] ;
>    prov:endedAt [
>        time:inXSDDateTime "2011-12-25T01:41:54Z"
>    ] .
>
>
>
>
> --
> Stian Soiland-Reyes, myGrid team
> School of Computer Science
> The University of Manchester
Received on Tuesday, 18 October 2011 05:23:45 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 13:06:46 GMT