Changes between Version 23 and Version 24 of BluePrintVITA


Ignore:
Timestamp:
12/23/09 19:23:09 (12 years ago)
Author:
Dominic König
Comment:

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  • BluePrintVITA

    v23 v24  
    2020=== Person Entity ===
    2121
    22 === Presence ===
     22== Presence Log ==
    2323
    24 Presence is the fact, that an entity is physically there at a particular location at a particular time. This abstract construction covers even cases of explicit absence, i.e. when the entity is not present at that time at that location.
     24Presence means the fact, that an entity is physically there at a particular '''location''' at a particular '''time'''. This abstract construction covers even cases of explicit absence, i.e. when the entity is ''not'' present at that location at that time.
    2525
    26 A presence is established through a recognition event, that is when the entity is recognized by a dedicated observer (human or automatic).
     26VITA applications record a presence log for each person entity. Each log entry is established through a recognition event, i.e. when the entity is recognized by a dedicated observer (human or automatic).
    2727
    2828Recognition can happen implicitly, e.g. when other data are obtained directly from the entity. In these cases, the time and location of the observer are used to establish a presence.
    2929
    3030Recognition can happen explicitly, i.e. in response to observation requests. In these cases, the time and location as determined by the request are used to establish a presence. Explicit recognition events may lead to establishment of explicit absence (=this one not here now).
     31
     32Locations in presence records represent geospatial features, which can basically be of any valid feature class (points, polygons, lines etc.). Where references to locations are used in communications, they must be universally unique and resolvable; otherwise the referred geospatial information have to be enclosed in the communication.
     33
     34In contrast to that, ''time'' in this regard means one exact time point, to be stored as coordinated universal time (UTC, Gregorian date including century) with a minimum precision of one second. Relative times must not be used.
    3135=== Identity ===
    3236