“…The value of S sp is calculated by eq 4 based on a Pearson distribution of type I. 24
where 0 ≤ x ≤ d max , m 1 + 1 > 0, m 2 + 1 > 0, and B ( m 1 + 1, m 2 + 1) is the special β-function. Thus, the second and third moments of this distribution can be written as eqs 5 and 6 , respectively.…”