195 citations · 1k across the 27 of their papers we have counts for
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Entropy of seismic electric signals: Analysis in natural time under time-reversal
P. A. Varotsos, N. V. Sarlis, E. S. Skordas +1
Electric signals have been recently recorded at the Earth's surface with amplitudes appreciably larger than those hitherto reported. Their entropy in natural time is smaller than t…
Similarity of fluctuations in correlated systems: The case of seismicity
P. A. Varotsos, N. V. Sarlis, H. K. Tanaka +1
We report a similarity of fluctuations in equilibrium critical phenomena and non-equilibrium systems, which is based on the concept of natural time. The world-wide seismicity as we…
Natural entropy fluctuations discriminate similar looking electric signals emitted from systems of different dynamics
P. A. Varotsos, N. V. Sarlis, E. S. Skordas +1
Complexity measures are introduced, that quantify the change of the natural entropy fluctuations at different length scales in time-series emitted from systems operating far from e…
Entropy in the natural time-domain
P. A. Varotsos, N. V. Sarlis, E. S. Skordas +1
A surrogate data analysis is presented, which is based on the fluctuations of the ``entropy'' defined in the natural time-domain [Phys. Rev. E {\bf 68}, 031106, 2003]. This ent…
Optimality of Natural Time Representation of Complex Time Series
Sumiyoshi Abe, N. V. Sarlis, E. S. Skordas +2
The concept of natural time turned out to be useful in revealing dynamical features behind complex time series including electrocardiograms, ionic current fluctuations of membrane…