Community Structure and Its Stability on Face-to-face Interaction Social Network in Kyoto

Social connections among people are mediated by multiple means of communication, including face-to-face interaction, cell phones, and social networking services. Therefore, to understand people's social behavior, it is necessary to integrate social networks using multiple means of communication and to understand them comprehensively. Large-scale face-to-face interaction networks have not been constructed in previous studies. Thus, we develop a method to construct a large-scale face-to-face interaction network using mobility data. Then, we calculate the chemical potential of each community using the spatial coordinates of the constructed network and investigate the stability of the community structure from a statistical mechanical point of view. As a result, we constructed a face-to-face interaction network with about 5,000 people using 39 days of data in Kyoto City. We confirmed that the network structure for the entire period was robust and had a similar geographic space allocation of communities. The chemical potentials of the communities in the constructed network were calculated, and the error of the chemical potentials among the communities was about 10%. We investigated the contribution of the chemical potential from the ideal gas and the chemical potential from the particle interaction. And we consider that the stability of the community structure of the face-to-face interaction network is determined by the variation of the particle density in each community and the localization of the particle distribution in the community.