Some cases of crossover behavior in heart interbeat and electroseismic time series

Fractal time series with scaling properties expressed through power laws appear in many contexts. These properties are very important from several viewpoints. For instance, they reveal the nature of the correlations present in the fractal signals. It is common that the scaling properties characterized by means of invariant quantities suffer changes along with the dynamical evolution of the studied systems. One of these changes is a crossover in the scaling properties reflecting an important change in the system dynamical behavior. In this article, we present two cases of crossover behavior corresponding to interbeat and electroseismic time series, we observe the crossovers in time series of experimental data and their corresponding simulation with simple models. We suggest a possible explanation of the observed crossovers in terms of the models considered.