Echo State Property upon Noisy Driving Input

Figure 2

Memory capacity and mapping score of the input digit against SNR levels. (a) Short-term memory capacity (MC). , where denotes the coefficient of determination () of the linear regression with the reservoir state vector to predict driving input signal with a delay of . (b) Mapping score of driving input signals. The score is defined as , where D denotes the Euclidean distance and and are the state vectors compatible with the input sequence without noise () and the noisy input sequence (), respectively. Error bars indicate the standard error over 20 independent simulations; the values were negligible in most cases.

(a)

(b)