35 research outputs found
Nonlocal PageRank
In this work we introduce and study a nonlocal version of the PageRank. In
our approach, the random walker explores the graph using longer excursions than
just moving between neighboring nodes. As a result, the corresponding ranking
of the nodes, which takes into account a \textit{long-range interaction}
between them, does not exhibit concentration phenomena typical of spectral
rankings which take into account just local interactions. We show that the
predictive value of the rankings obtained using our proposals is considerably
improved on different real world problems
A survey on Human Mobility and its applications
Human Mobility has attracted attentions from different fields of studies such
as epidemic modeling, traffic engineering, traffic prediction and urban
planning. In this survey we review major characteristics of human mobility
studies including from trajectory-based studies to studies using graph and
network theory. In trajectory-based studies statistical measures such as jump
length distribution and radius of gyration are analyzed in order to investigate
how people move in their daily life, and if it is possible to model this
individual movements and make prediction based on them. Using graph in mobility
studies, helps to investigate the dynamic behavior of the system, such as
diffusion and flow in the network and makes it easier to estimate how much one
part of the network influences another by using metrics like centrality
measures. We aim to study population flow in transportation networks using
mobility data to derive models and patterns, and to develop new applications in
predicting phenomena such as congestion. Human Mobility studies with the new
generation of mobility data provided by cellular phone networks, arise new
challenges such as data storing, data representation, data analysis and
computation complexity. A comparative review of different data types used in
current tools and applications of Human Mobility studies leads us to new
approaches for dealing with mentioned challenges
A Network Science perspective of Graph Convolutional Networks: A survey
The mining and exploitation of graph structural information have been the
focal points in the study of complex networks. Traditional structural measures
in Network Science focus on the analysis and modelling of complex networks from
the perspective of network structure, such as the centrality measures, the
clustering coefficient, and motifs and graphlets, and they have become basic
tools for studying and understanding graphs. In comparison, graph neural
networks, especially graph convolutional networks (GCNs), are particularly
effective at integrating node features into graph structures via neighbourhood
aggregation and message passing, and have been shown to significantly improve
the performances in a variety of learning tasks. These two classes of methods
are, however, typically treated separately with limited references to each
other. In this work, aiming to establish relationships between them, we provide
a network science perspective of GCNs. Our novel taxonomy classifies GCNs from
three structural information angles, i.e., the layer-wise message aggregation
scope, the message content, and the overall learning scope. Moreover, as a
prerequisite for reviewing GCNs via a network science perspective, we also
summarise traditional structural measures and propose a new taxonomy for them.
Finally and most importantly, we draw connections between traditional
structural approaches and graph convolutional networks, and discuss potential
directions for future research