Re: RSP next calls

Hello Jean-Paul, Eva, Avi and all,

what Eva says and Jean-Paul confirm is also what I think, sorry to create confusions.

My answer to Avi was putting emphasis on the fact that by "time-series" I do not mean a *sequence of numbers ordered by recency*, but a *sequence of RDF triples ordered by recency*.

Concerning how to describe time from the application perspective, my position is the following one:
- 0 timestamps (i.e., relying on the temporal distance between the received triples ) makes compatibility with RDF straight forward, but it may hide problems (e.g., the temporal distance between two triples may be influenced by network delays)
- 1 (point in time semantics for application time) allows for handling out of orders and for basic temporal operators (e.g., follows, precedes, contemporaryWith)
- 2 (interval based semantics for events) allows for expressive temporal operators, but, at least in many scenarios I target, it is an overkill

Most of the commercial DSMS/CEP take either 0 or 1. The only commercial CEP that I know supporting 2 is Microsoft StreamInsight.

Time from the system perspective is a different issue. Whether system time should be externalised is something I still wonder.

Cheers,

Emanuele


On Nov 14, 2013, at 1:58 AM, Jean-Paul <jp.calbimonte@upm.es<mailto:jp.calbimonte@upm.es>>
 wrote:

Hello all,

Yes, I think Oscar's diagram (check it here: http://www.w3.org/community/rsp/wiki/Meeting_22.10.2013) more or less reflects part of the discussion we had about the scope.

We seem to agree that ordered streams of elements (infinite or 'recorded' streams as well) are in scope (green ticks in the diagram). In these cases the order might be of different natures but we agreed to focus on time-based order. I don't think we agreed yet on focusing only in point in time timestamps or intervals. For the moment it is just time-based order, I believe.

Then there are datasets which may not be streaming in nature but might be needed to processed in a streaming fashion (e.g. a very large dataset). I understood we are not ruling this case out, but might not focus on it in a first stage.

Thanks to Emanuele for the input about the scope. As Eva pointed out, there are some discrepancies that we can fix in the wiki. I am also a bit unconfortable with calling the streams in our scope as 'time-series', I think this term has other connotations in related areas.

well, this is just a personal comment as well, but I'm happy to continue this discussion. We can also continue modifying the wiki until we have the Telco, and afterwards.

best
jp








2013/11/13 Eva Blomqvist <evabl444@gmail.com<mailto:evabl444@gmail.com>>
Hi!
I think that some of those who were in the meeting also might have slightly differing interpretations of what was said... I agree to that there were two alternative interpretations of "data stream" discussed, but as far as I understood those differed in the sense that 1) was an *infinite* stream, where the elements of the stream could somehow be *associated with time* (whether a timestamped triple, a timestamped graph, or just a stream where time is implicit from the arrival times of elements etc), and 2) was a *finite* stream of elements where *time is not necessarily an aspect*, e.g. triples from a data store being processed in a streaming fashion.

I would be reluctant to at this stage limit ourselves to a specific model, e.g. RDF statements with a single timestamp each.
Just my 2c..
/Eva


On 12/11/2013 17:33 , Emanuele Della Valle wrote:
Hi Abram,

I mean a list of tuples <s,t> where s is an RDF statement and t is a non decreasing timestamp.

Cheers,

Emanuele

--
prof. Emanuele Della Valle
DEIB - Politecnico di Milano
m. +393389375810<tel:%2B393389375810>
w. http://emanueledellavalle.org<http://emanueledellavalle.org/>

On Nov 12, 2013, at 12:27 PM, Abraham Bernstein <bernstein@ifi.uzh.ch<mailto:bernstein@ifi.uzh.ch>>
 wrote:

Emanuele, all

I am slightly confused.... so just to clarify When you talk about time-series: do you mean a series of numbers (expressed in triples) or a time-ordered series of triples?

Cheers

Avi


On 12.11.2013, at 03:05, Jean-Paul <jp.calbimonte@upm.es<mailto:jp.calbimonte@upm.es>> wrote:

Hello,

Thanks for your input. 4th Telco will be on nov 22 15:00 CET.
We will be discussing about the Streams concepts and definitions that we have started drafting in the wiki.
Please feel free to provide your input there already:

http://www.w3.org/community/rsp/wiki/Concepts_and_Definitions

...specialy if there is a key concept missing that you consider we should include.

Cheers,
jp


PS
Please, if Danh or Manfred can help us again with Webex, we will be very thankful.






2013/11/6 Jean-Paul <jp.calbimonte@upm.es<mailto:jp.calbimonte@upm.es>>
Yes, I see. That will make everyone's life easier.
We'll dicuss it.

thanks

jp


2013/11/6 Axel Polleres <axel@polleres.net<mailto:axel@polleres.net>>
Thanks, BTW, may I suggest that instead of a single doodle per Telco, to doodle for one fixed timeslot per week, e.g. "Tue 15:00" or alike, as usual in other WGs? I think this should make planning easier. Maybe we can discuss this in the Telco.

thanks & best regards,
Axel

--
Prof. Dr. Axel Polleres
Institute for Information Business, WU Vienna
url: http://www.polleres.net/  twitter: @AxelPolleres

On Nov 2, 2013, at 11:40 PM, Jean-Paul <jp.calbimonte@upm.es<mailto:jp.calbimonte@upm.es>> wrote:

> Hello All,
>
> Thanks to all who could attend the meeting at ISWC, and specially to those who made it through WebEx (although couldn't interact too much, unfortunately)
>
> The meeting went quite well, and we received input from people of other sub-communities and with different background. Others showed interest, at least as 'observers' of what we are trying to do.
>
> One result of the meting is the intention of clarifying the scope of our work. A first step to do this is to have written some of the key concepts and definitions that we should agree on. Mikko has already provided a first version as he already commented, and the purpose of the next telecon will be to discuss them:
>
> http://www.w3.org/community/rsp/wiki/Concepts_and_Definitions
>
> Until then, I invite you all to contribute to that ( I see some have already started, great!) so that we can have material for discussion.
>
> Please, also indicate your preferences for the next calls:
>
> http://doodle.com/a8ggni2v4su7c88b
>
> http://doodle.com/6i97qvmaqiwnwvsa
>
> http://doodle.com/hixgfbv9drxbu4in
>
>
> Thanks to all,
>
> jp
>
> --
> Jean-Paul Calbimonte
> Ontology Engineering Group
> Universidad Politécnica de Madrid




--
Jean-Paul Calbimonte
Ontology Engineering Group
Universidad Politécnica de Madrid



--
Jean-Paul Calbimonte
Ontology Engineering Group
Universidad Politécnica de Madrid

-----------------------------------------------------------------
|  Professor Abraham Bernstein, PhD
|  University of Zürich, Department of Informatics
|  web: http://www.ifi.uzh.ch/ddis/bernstein.html






--
Jean-Paul Calbimonte
Ontology Engineering Group
Universidad Politécnica de Madrid