## 4 Effect Evaluation of Electromagnetic Environment on Equipment
### Effects Mechanism Methods  
The effect mechanism method directly analyzes the interference on the equipment physically. Electromagnetic interference can not only enter the system by way of \"front door coupling\" [61] through the antenna but also enter the system by way of \"back door coupling\" [62] through the shell, cables, and holes in the chassis to damage its internal components. Both interference mechanisms are distinct. Therefore, it is more consistent with the characteristics of equipment subjected to electromagnetic interference to analyze the electromagnetic environmental effects of various equipment [63; 64] based on the effects mechanism. This method will construct the effect evaluation model through mathematical reasoning and experimental analysis. However, the sensitivity threshold of the equipment is usually necessary to define the critical interference of the model. Hence, the definition of sensitivity criteria is an essential precondition for effect evaluation models. The research design of the effect mechanism methods is shown in Figure 6. In these methods, the interference index of R will be defined. When R \(\geq\) 1, the equipment has interfered; when R \(<\) 1, the equipment is working properly.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Function**} & \multirow{2}{*}{**Equipment**} & \multicolumn{6}{c}{**Methods**} & \multicolumn{2}{c}{**Comprehensive**} \\ \cline{3-10}  & & **D-S** & **AHP** & **Fuzzy** & **Sensitivity** & **Neural** & **Neural** & **Evaluation** & **Performance** \\  & & **Theory** & & **Theory** & **Threshold** & **Network** & **Index** & \\ \hline \multirow{5}{*}{Evaluation} & Avionics & & & & & & Failure & Evaluation probability of & Evaluation probability \\  & systems [50] & \(\surd\) & \(\surd\) & \(\surd\) & \(\surd\) & - & & equipment & improved by 15.7\% \\ \cline{2-10}  & Vehicle & & & & & & & Shielding & \\ \cline{1-1}  & subsystems [51] & - & \(\surd\) & \(\surd\) & - & - & & efficiency of & CC = 0.017 \textless{} 0.1 \\ \cline{1-1}  & Electronic & & & & & & & the shell & \\ \cline{1-1}  & system of & - & \(\surd\) & \(\surd\) & \(\surd\) & - & Electromagnetic & & \\ \cline{1-1}  & ship [52] & & & & & & & damage & - \\ \hline \multirow{5}{*}{Prediction} & Crosstalk & & & & & & & & \\ \cline{1-1}  & coupling & - & - & - & \(\surd\) & \(\surd\) & \(\surd\) & \(\begin{array}{c}\text{Peak level of }\\ \text{coupling}\\ \text{coupling}\\ \text{voltage}\end{array}\) & Evaluation error \textless{} 2\% \\ \cline{1-1}  & between wires [57] & & & & & & & & \\ \cline{1-1} \cline{2-10}  & Gas pipeline & - & - & - & \(\surd\) & \(\surd\) & \(\begin{array}{c}\text{Induced }\\ \text{voltage on the }\\ \text{gas pipeline}\end{array}\) & High accuracy \\ \cline{1-1}  & Data-link & & & & & & & \\ \cline{1-1}  & systems [59] & - & \(\surd\) & \(\surd\) & - & \(\surd\) & \(\begin{array}{c}\text{Efficiency of }\\ \text{data link}\\ \end{array}\) & Precision = 1 \(\times\) 10\({}^{-5}\), & \\ \cline{1-1}  & Vehicle cable & & & & & & & \\ \cline{1-1}  & [60] & - & & \(\surd\) & \(\surd\) & \(\begin{array}{c}\text{Peak level}\\ \text{iteration}\\ \end{array}\) & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 5: The commonly used methods on equipment.