Geoscience Reference
In-Depth Information
•
The
generalisation ontology
is the support for sharing a common
vocabulary in the collaboration model. It helps to express that map specifi-
cation (“buildings smaller than 50 m² must be deleted”), a data type
(“BATIMENT” class) or a process requirement (“agent_building” in
AGENT process) deal with the same concept of 'building' for instance.
•
The
sequencing rules
are guidelines for sequencing applications of
processes on geographic spaces. As in the Global Master Plan of (Ruas
and Plazanet 1996), it allows to formalise that 'road selection' should be
triggered before 'urban generalisation' for instance, or that 'urban areas'
should be generalised before 'rural areas'.
•
The
generalisation constraints
and the
operation rules
formalise the
map specifications. The formal model summarises past research (Beard
1991, Stöter et al. 2007, Duchêne and Gaffuri 2008) and allows to ex-
press different constraints like 'building area > 0.2 map mm²', 'building
block density should be preserved' or 'very concave buildings should
maintain initial concavity with 10% margin'.
•
A
process description
formalises the capabilities of a generalisation
process. As for web services composition, capabilities are described
with pre and post conditions (Lutz 2007). In CollaGen, pre conditions
are adapted spaces for the process and post conditions are a priori satis-
fied generalisations constraints and operation rules (after the process has
been applied).
Figure 3:
A diagram of the 5 parts of formalised knowledge and their use in the collabora-
tive model. The dashed arrows show that the Ontology provides shared concepts to every
part.
(Touya et al. 2010) describes how each piece of formalised knowledge is
modelled in CollaGen and how it can be acquired by a user, a process
developer or the model designer.
