Re: On the time model

Slight addition to the preceding email, on the possibility of unbounded
time intervals.
I would avoid that. If we use the happening-interpretation, it would
naturally lead to the need to always define and end for the interval,
anyway.
The reason why in my opinion never-ending events should be avoided, is that
they should be kept available for new consumers that would possibly
connect, forever.

Kind regards,
Claudio


On 4 April 2014 15:56, Claudio Di Ciccio <claudio.di.ciccio@wu.ac.at> wrote:

> Hi all.
> Unfortunately, the microphone seemed to stop working during the Conference
> Call. Therefore, I was not able to intervene.
>
> This is my major concern about the representation of events, w.r.t. time.
> My opinion is that events should report things that happen, not facts.
> Therefore, the sense of the time interval would change, becoming unrelated
> to the semantics of the reported fact. In other words, the time interval
> would not refer to the time range in which the reported fact still holds
> true, but rather to the time given to event consumers to process the event
> before it expires.
>
> To clarify my position:
> 1) Events happen, facts remain. Therefore, facts could be considered as
> infrequently changing.
> 2) What if we have recurring activities? Say, from November the 11th,
> e.g., every day from 00:30 to 04:30 the Metro service stops. Is this an
> event that recurs every day, from Nov 11 onwards, or rather one event
> occurring on Nov 11 and establishing the rule, valid forever? The
> fact-reporting-interpretation of events would lead to the second option.
> However, this would lead to the necessity of defining periodicity for time
> intervals -- which goes beyond the scope of our group, let alone
> overcomplicating the model. The happening-oriented approach would allow for
> the first option and a less complicated model.
> 3) As far as we decided, we have no alteration of preceding events.
> Therefore, an event like "Claudio - lives in - Vienna" is forever true,
> until a new event amends it. However, if a new event comes ("Claudio -
> lives in - London"), whereas the preceding was without an ending time, we
> would have an inconsistency: an event contradicts another, and there is no
> clear way to establish which is saying the truth. Instead, "Claudio - moves
> to - Vienna" and "Claudio - moves to - London" would make sense, as the
> start-time and end-time would refer to the time where the event is still
> processable. After the end-time expires, we might think of some
> consequences, such as inferring and storing that Claudio lives in Vienna,
> e.g. This would be related to reasoning, and disregarding the data model.
>
> ​Have a nice weekend.​
> ​Best regards,
> Claudio​
> --
> Dr. Claudio Di Ciccio
> WU Vienna
> Institute for Information Business
> Building D2, Entrance C, 3rd Floor
> Welthandelsplatz 1, 1020 Vienna, Austria
>
> Email: claudio.di.ciccio@wu.ac.at
> Phone: +43 1 31336 5222
>



-- 
Dr. Claudio Di Ciccio
WU Vienna
Institute for Information Business
Building D2, Entrance C, 3rd Floor
Welthandelsplatz 1, 1020 Vienna, Austria

Email: claudio.di.ciccio@wu.ac.at
Phone: +43 1 31336 5222