O que é Return smoothing, autocorrelation-adjusted Sharpe ratio?

Return smoothing is the reporting of a moving average of true returns, $r^o_t = \sum_{j=0}^{k}\theta_j r_{t-j}$ with $\theta_j \ge 0$ and $\sum_j\theta_j = 1$, as happens when illiquid assets are marked at stale or appraised prices (Getmansky, Lo and Makarov). The autocorrelation-adjusted Sharpe ratio annualises a per-period Sharpe ratio $\mathrm{SR}_1$ with the autocorrelations $\rho_k$ of the returns: $\mathrm{SR}(q) = \mathrm{SR}_1\, q\big/\sqrt{q + 2\sum_{k=1}^{q-1}(q-k)\rho_k}$ (Lo, 2002).