1 research outputs found
Relative clock demonstrates the endogenous heterogeneity of human dynamics
The heavy-tailed inter-event time distributions are widely observed in many
human-activated systems, which may result from both endogenous mechanisms like
the highest-priority-first protocol and exogenous factors like the varying
global activity versus time. To distinguish the effects on temporal statistics
from different mechanisms is this of theoretical significance. In this Letter,
we propose a new timing method by using a relative clock, where the time length
between two consecutive events of an individual is counted as the number of
other individuals' events appeared during this interval. We propose a model, in
which agents act either in a constant rate or with a power-law inter-event time
distribution, and the global activity either keeps unchanged or varies
periodically versus time. Our analysis shows that the heavy tails caused by the
heterogeneity of global activity can be eliminated by setting the relative
clock, yet the heterogeneity due to real individual behaviors still exists. We
perform extensive experiments on four large-scale systems, the search engine by
AOL, a social bookmarking system--Delicious, a short-message communication
network, and a microblogging system--Twitter. Strong heterogeneity and clear
seasonality of global activity are observed, but the heavy tails cannot be
eliminated by using the relative clock. Our results suggest the existence of
endogenous heterogeneity of human dynamics.Comment: 6 pages 7 figures 2 Table