  In this work, we analyzed time-series of background radiation inside a
multilayer interleaving structure, geomagnetic activity and cosmic-ray activity
using the Pearson correlation coefficient and a new correlation measure based
on the one-dimensional component of the fourth order cumulant. The new method
is proposed based on the fact that the cumulant of a random process is zero if
it is of Gaussian nature. The results show that this methodology is useful for
detecting correlations between the analyzed variables.
