what-when-how
In Depth Tutorials and Information
11.4.9 Trusted Gossip Protocol ...........................................................291
11.4.10 TrustDavis................................................................................292
11.5 Future Research .....................................................................................292
11.6 Conclusion .............................................................................................294
Reference...........................................................................................................294
11.1 Introduction
11.1.1 Quick Overview on Social Networks
In the early 20th century, social networks emerged as an important research field
in sociology. Due to some interesting properties of social networks, they have been
used extensively in sociology, as well as in information science, economics, and
industrial engineering.
A social network is defined as a networking system that consists of a set of nodes
(such as people, organizations, or other social entities) that have a set of relations of
ties among them (e.g., friendship, conflict, information exchange, etc.) [1]. In order
to measure the social structure, social relationships, and social behaviors, social
networks analysis therefore is an essential and important technique.
In social networks analysis, there are two main measurements—extraction and
visualization. he extracted relational data can be used to construct a social net-
work. hrough visualization, the characteristics of the social networks such as the
structure of networks, the distribution of nodes, the links (relationships) between
nodes, and the clusters and groups in the social networks can be more easily under-
stood [2].
Typically, social networks have some fundamental properties such as degree,
size, density, distance, and geodesic distance (see Table 11.1). Besides, there are some
more complicated properties utilized in social network analysis as follows [3]:
◾
Maximum low
, which is defined as the number of different nodes the source
can choose to initiate the path to the target. It focuses on the vulnerability or
redundancy of connections between pairs of nodes;
◾
heHubbellandKatzcohesion,
which considers the whole range of connec-
tions between the two nodes;
◾
Centralityandpower,
which define the importance of the node in a network.
hese include several aspects such as degree, closeness, and betweenness
(Table 11.1).
◾
In a clique that belongs to the subset of a network, its nodes have closer and
more intense relationships than other nodes in the network. here are four
types of cliques [1]: N-cliques; N-Clans; K-plexes; K-cores (Table 11.2).
By considering the social network properties, the social network model has evolved
through several phases. Initially the random network theory was explored. And then
