Spatial and Temporal Information Retrieval in Textual Corpora - Geographical Information Retrieval in Textual Corpora - page 37

relations are associated recursively with SFs. For example, “north of Pau” is an RSF
that defines a relation of orientation with the ASF “Pau”. This recursive construction
of an RSF allows us to process complex relations containing successively
encapsulated topological, orientation and/or distance indications. For more details on
the spatial model, refer to [LES 06].
Figure 2.5. Simplified UML schema of the spatial model and the temporal
model, extract taken from [LEP 07]
An absolute temporal feature (ATF) corresponds to a calendar-NE (“11 June
2000”, “summer of 2009”): day, month, season, year, century or era. It can be
incomplete (day, month or season, without the year, for example). An RTF
corresponds to an NE accompanied by temporal indications allowing us to specify a
target period: temporal relations are associated with the TF (absolute or relative)
recursively. For example, “around March 2000” is an RTF that defines a relation of
adjacency with the ATF “March 2000”. For more details on the temporal model, refer
to [LEP 07].
We have chosen to represent the SFs and the TFs using geometries and time
intervals, respectively. The main interest is to allow, during the retrieval phase, to
calculate overlapping rates and, in particular, to use the operators defined in
[RAN 92] and [ALL 84], respectively.
2.4.3. Spatial and temporal relations
Wecall relations astheindicatorsappliedtoSFsorTFs.Ourapproachisbasedon
the existing models of qualitative spatial reasoning [COH 96, COH 01, MIR 07] but