FIG. 1.
Method for identification of confined motion based on number of visits to current site. The method is validated using numerical simulations. (a) FBM with α = 0.1, i.e., Hurst exponent H = 0.05. At each successive points pair, such as those marked in red, a circle is drawn as indicated in the figure. In this case there are 17 points (visits) found within the circular area. (b) FBM with α = 0.9. Here the tracer visits the region within the selected circle only once. (c) y coordinate of two-dimensional intermittent FBM with α = 0.1 (first, third, and fifth segment) and α = 0.9 (second and fourth segment). The vertical dashed lines show the true switching points. The parts of the trajectories identified as confined (low α) are marked in red. The two-dimensional trajectories are presented on the right. (d) Vj statistic, i.e., number of recurrent visits, as a function of time. Again, the vertical dashed lines show the true switching points. The threshold for finding confined regions in this example is Vth = 6.