Figure 3.

Adding uncorrelated noise to signals with LRTC marginally influence the DFA exponents at signal-to-noise ratios larger than 2. Open circles connected with thin lines indicate the mean DFA exponent of 50 computer generated signals with LRTC for 20 levels of superimposed uncorrelated noise (signal-to-noise ratio). The error bars indicate the SD (only shown upward for clarity). The thick lines indicate the mean DFA exponents of signals before adding noise. For all three levels of LRTC, the superposition of noise leads to a bias of the estimated exponent of more than one SD at SNR <1, but only has a marginal influence at SNR >2.