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(2004) further adopted the concept of stroke connectivity (i.e. the number
of connections of one stroke with other strokes). Jiang and Claramunt
(2004) used street name to build strokes and ranked them respectively
according to three different topological centralities, i.e. degree, closeness and
betweenness. Jiang and Harrie (2004) considered multiple attributes which
included topological, geometric and thematic properties of streets by
applying a self-organizing map (SOM). Chen and his collaborators (2009)
presented another selective omission approach which is based on eliminat-
ing unimportant road segments by taking “mesh density” into considera-
tion. However, the importance of each road segment was still based on the
importance of its own stroke which was determined in consideration of
road class, stroke length and stroke connectivity.
In summary, the properties to determine the importance of each stroke can
be classified into three types, geometric properties (e.g. length), topologi-
cal properties (e.g. centralities) and thematic properties (e.g. road class).
Normally, the selections are different by applying different properties. It
can be noted that there is not much literature about comparing the differ-
ences of applying various properties for road network generalization which
is the main concern of our study.
This paper is structured as follows. Section 2 introduces basic concepts of
investigated properties to determine the importance of individual roads.
Section 3 gives an experimental design to evaluate of various properties.
Section 4 presents the experimental results and analyses. Finally, results
are discussed in section 5 and conclusions are made in section 6.
2- Properties to determine the importance of individual roads
As reviewed in the previous section, there could be a number of properties
which can be classified into three types, geometric, topological and the-
matic ones. This section will introduce them in detail.
2.1 Geometric properties
Length and width are two important geometric properties. Common sense
tells us that long and wide roads tend to be more important”. (Jiang and
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