Fig. 2
Download original image
Fitting relation error between E(x) and x. Note that the error E < 9 × 10−6 when N = 15, x ∊ [0,20], x ∊ N + and the error equals almost zero when N = 15, x ∊ [15,20], x ∊ N +. It is reasonable to use the FN /FN +x instead of e −0.4812x (Sha, 2013).