Urban Heartbeats (Daily Cycle of Public Transport Intensity) - Geoinformatics for Intelligent Transportation - page 198

determining factors. Zhang and Xu [ 29 ] applied the evolution model on China
domestic airline network from the year 1950 to 2010. All of the above works
examined the evolution of transportation networks in several decades. But evolution
of public transport network in short periods, for instance 24 h, has not been elab-
orately described or dealt with in the existing literatures.
Interesting element of the basic characteristics in the public transport network is
an analysis of communities. The property of community structure appears to be
common to many networks. Consider for a moment the case of social networks, for
instance networks of friendships or other acquaintances between individuals. It is a
matter of common experience that such networks seem to have communities in
them: subsets of vertices within which vertex vertex connections are dense, but

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between which connections are less dense.
The ability to detect community structure in a network could clearly have
practical applications [ 30 ]. Communities in a social network might represent real
social groupings, perhaps by interest or background; communities in a citation
network might represent related papers on a single topic; communities on the web
might represent pages on related topics [ 31 ]. The same can be observed also in
public transport networks [ 24 ].
We do not register any literature that examines in detail communities either in
evolving public transport networks or in transport networks generally. It is unex-
pected, since having the ability to identify communities (in static or dynamic network)
could be helpful in more effective understanding and utilizing of these networks.
Figure 1 provides an ef

cient representation of data used throught our paper.
Nowadays has research of communities still mainly signi cant application in

medicine. Communities are widely used in medical science and neuroscience to
understanding and examining the processes occurring in the human brain.

Fig. 1 Louvain network
communities identi ed in
pooled 24 h cycle in
Bratislava, space is non-
geographic for clarity. Source
July 09, 2013 public
transportation schedule by
Apptives