'''Rayleigh Random Variable''' $S_X=[0,\infty)$ $f_X(x)=\frac{x}{\alpha^2}e^{-x^2/2\alpha^2}$ $x\ge0,\,\alpha\gt 0$ $E[X]=\sqrt{\frac{\pi}{2}}\alpha$ $V[X]=\left(2-\frac{\pi}{2}\right)\alpha^2$ ---- Source: Leon-Garcia Table 4.1 (Continuous RVs) Up: [[연속확률변수,continuous_RV]]