title: Temporal dynamics and impact of event interactions in cyber-social populations.
abstract: The advance of information technologies provides powerful measures to digitize social interactions and facilitate quantitative investigations. To explore large-scale indoor interactions of a social population, we analyze 18 715 users' Wi-Fi access logs recorded in a Chinese university campus during 3 months, and define event interaction (EI) to characterize the concurrent interactions of multiple users inferred by their geographic coincidences-co-locating in the same small region at the same time. We propose three rules to construct a transmission graph, which depicts the topological and temporal features of event interactions. The vertex dynamics of transmission graph tells that the active durations of EIs fall into the truncated power-law distributions, which is independent on the number of involved individuals. The edge dynamics of transmission graph reports that the transmission durations present a truncated power-law pattern independent on the daily and weekly periodicities. Besides, in the aggregated transmission graph, low-degree vertices previously neglected in the aggregated static networks may participate in the large-degree EIs, which is verified by three data sets covering different sizes of social populations with various rendezvouses. This work highlights the temporal significance of event interactions in cyber-social populations.
authors.affiliation: Adaptive Networks and Control Lab, Department of Electronic Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Yi-Qing
authors.initials: YQ
authors.lastname: Zhang
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
mesh_terms: D002681:China; D003196:Computer Graphics; D040362:Geographic Information Systems / Q000706:statistics & numerical data*; D006801:Humans; D020407:Internet / Q000706:statistics & numerical data*; D007398:Interpersonal Relations; D010507:Periodicity; D012919:Social Behavior; D060756:Social Networking; D013997:Time Factors; D014495:Universities