Fig. 10
From: Detecting stealthy attacks against industrial control systems based on residual skewness analysis
Impacts of the ratio of random residuals on attack time and detection ability. Time to achieve attack goals becomes longer as the ratio of random residuals increases in the water level control system (a) and the pH value control system (c). Additionally, when the ratio of random residuals increases, the change of skewness Coefficient of residuals becomes more subtle, as shown in (b) and (d)