Time-series thresholding and avalanche dynamics in networks of the critical branching process.

Abstract

Avalanche sizes and durations following power-law distributions are observed in many systems and are considered hallmarks of criticality. Time-series thresholding is a commonly used method to define avalanches, but this method is controversial. In this study, we use the time-series thresholding method to define avalanches and investigate the statistical properties of avalanches in the Kinouchi-Copelli (KC) model. We consider two definitions of avalanche size, (1) total area above threshold value reference and (2) total area above zero, and then analyze the size and duration distributions. Our results show that while avalanche size and duration obey a power-law distribution, the exponents of size and duration differ from those of the critical branching process. The scaling relation holds for avalanches defined by the first method but fails for those avalanches tdefined by the second. This study provides new insights into avalanche definition methods and avalanche distribution exponents in continuous time-series.