Faculty of Engineering;
Information and Systems;
University of Tsukuba;
Tsukuba;
Japan;
Graduate School of Information Science and Technology;
Osaka University;
Osaka;
Japan;
Graduate School of Information Science;
Nara Institute of Science and Technology;
Nara;
Japan;
Research Institute of Electrical Communication;
Tohoku University;
Sendai;
Japan;
Research Institute of Electronics;
Shizuoka University;
Shizuoka;
Japan;
School of Science and Technology;
Kwansei Gakuin University;
Nishinomiya;
Japan;
Social; Network; Ambient; Environment; Dynamic; Social; Network; Analysis; Centrality;