Is there any kind of “memory” in the sequence of terror attacks worldwide? Are the terrorist attacks non-randomly time distributed? Our analysis suggests that they are correlated, which means that a terror event is not independent from the time elapsed since the previous event. But, if we...

The time-clustering behavior of lightning data measured from April to October 2002 in an area of southern Italy has been analyzed by using the Allan factor statistics. The results point out to the presence of two time-scaling regions, which reveal intra-cluster (inside an individual...

In this paper we study the time-clustering behavior of sequences of car accidents, using data from a freely available database in the internet. The Allan Factor analysis, which is a well-suited method to investigate time-dynamical behaviors in point processes, has revealed that the car accident...