Parameter Microscopic/ macroscopic Formula Reference Mean, $\overline{{\epsilon }_{s}}$ Macroscopic $\overline{{\epsilon }_{s}}=\frac{1}{N}\sum _{i\text{\hspace{0.17em}}=\text{\hspace{0.17em}}1}^{N}{\epsilon }_{s}\left(i\right)$      Standard Deviation, $\sigma \left({\epsilon }_{s}\right)$ Microscopic $\sigma \left({\epsilon }_{s}\right)=\sqrt{\frac{1}{N-1}\sum _{i=1}^{N}{\left({\epsilon }_{s}\left(i\right)-\overline{{\epsilon }_{s}}\right)}^{2}}$    Skewness, ${S}_{k}$ Microscopic ${S}_{k}=\frac{1}{N\sigma {\left({\epsilon }_{S}\right)}^{3}}\sum _{i=1}^{N}{\left({\epsilon }_{S}\left(i\right)-\overline{{\epsilon }_{S}}\right)}^{3}$    Kurtosis, ${K}_{u}$ Microscopic ${K}_{u}=\frac{1}{N\sigma {\left({\epsilon }_{S}\right)}^{4}}\sum _{i=1}^{N}{\left({\epsilon }_{S}\left(i\right)-\overline{{\epsilon }_{S}}\right)}^{4}$   Intermittent Index, $\gamma$ Macroscopic $\gamma =\frac{\sigma \left({\epsilon }_{s}\right)}{\sigma {\left({\epsilon }_{s}\right)}_{\mathrm{max}}}=\frac{\sigma \left({\epsilon }_{s}\right)}{\sqrt{\overline{\overline{{\epsilon }_{s}}\left(1-\overline{{\epsilon }_{s}}-{\epsilon }_{s,mf}\right)}}}$   Average Absolute Deviation (AAD) Microscopic $AAD=\frac{1}{N}\sum _{i=1}^{N}\left(|{\epsilon }_{s}\left(i\right)-\overline{{\epsilon }_{s}}|\right)$   Radial Non-Uniformity Index (RNI) Macroscopic $RNI\left({\epsilon }_{s}\right)=\frac{\sigma \left({\epsilon }_{s}\right)}{\sigma {\left({\epsilon }_{s}\right)}_{\mathrm{max}}}=\frac{\sigma \left({\epsilon }_{s}\right)}{\sqrt{\overline{{\epsilon }_{s}}\left({\epsilon }_{s,mf}-\overline{{\epsilon }_{s}}\right)}}$   Probability Density Function (PDF) Microscopic $f\left(x\right)=\mathrm{Pr}\left[{\epsilon }_{s}=x\right]$    Coefficient of Variation, CV Macroscopic $CV=\frac{\sigma \left({\epsilon }_{s}\right)}{\overline{{\epsilon }_{s}}}$