Influential Nodes in Social Networks: Centrality Measures

Introduction

Humans are social person and best decision maker. They cannot stay alone, they want to make friends, share news, information etc. Social network (Fig.1) is the perfect place for connecting people. Social network is a social structure formed by a set of nodes (persons, organizations etc.) and a set of links (connection between nodes). People feel very comfort to share news, information through social network. Recently online social networks like Twitter, Facebook and LinkedIn etc. have grown extremely popular in human life. A statistic (Tab.1) on social network in 2018 is given below.

Figure 1.

An example of social network.

There are some advantages of social networks in our daily life. In the field of education, it has big applications. Students, teachers, researchers and scientists have been spending lots of time in the social networks to talk about education works. Schools and colleges also use social network to keep in touch with students and teachers. Many companies also use social network to reach at customers. So it is the place for marketing products. But there are also some disadvantages of social network. Cybercrime is a big problem for people. Sexual exploitations and addictions to social network is also disadvantages for human. A fundamental problem in social network is to find influential node or central node (for example, head of cybercrime in crime network) within the network. Centrality indicates most important node or central node or influential node within a network. Hence measure of centrality is a very essential task in social network.