arXiv subjects

P. Hamilton

Publications and source records attributed to P. Hamilton.

74 records · Page 5Linked to original sources

arXiv2001

Facing Non-Stationary Conditions with a New Indicator of Entropy Increase: The Cassandra Algorithm

We address the problem of detecting non-stationary effects in time series (in particular fractal time series) by means of the Diffusion Entropy Method (DEM). This means that the experimental sequence under study, of size $N$, is explored with a window of size $L << N$. The DEM makes a wise use of the statistical information available and, consequently, in spite of the modest size of the window used, does succeed in revealing local statistical properties, and it shows how they change upon moving the windows along the experimental sequence. The method is expected to work also to predict catastrophic events before their occurrence.

cond-mat.stat-mech↗

arXiv2001

Memory beyond memory in heart beating: an efficient way to detect pathological conditions

We study the long-range correlations of heartbeat fluctuations with the method of diffusion entropy. We show that this method of analysis yields a scaling parameter $δ$ that apparently conflicts with the direct evaluation of the distribution of times of sojourn in states with a given heartbeat frequency. The strength of the memory responsible for this discrepancy is given by a parameter $ε^{2}$, which is derived from real data. The distribution of patients in the ($δ$, $ε^{2}$)-plane yields a neat separation of the healthy from the congestive heart failure subjects.

cond-mat.stat-mech↗