## 3 An Improved Effectiveness Evaluation Method Based on Factor Analysis
### Correlation Analysis  
Previously, factor 1 has been named as the information transmission factor, which is mainly determined by index \(X2\), \(X3\), \(X7\) and \(X8\). Factor 2 is named as the network control factor, which is mainly determined by index \(X4\), \(X5\) and \(X6\). Factor 3 is named as the security protection factor, which is mainly determined by index \(X1\). In order to ensure that there is no information overlap between the selected indexes, the correlation analysis of the main indexes of each factor is further screened. The correlation coefficients of factors 1 and 2 are shown in Tables 6 and 7. The correlation between \(X3\) and other indexes is greater than the critical value (0.5), which indicates that the end-to-end transmission delay (\(X3\)) of the system has a strong correlation with the network throughput (\(X2\)), voice interruption rate (\(X7\)) and voice link building time (\(X8\)). Moreover, the correlation coefficient between the end-to-end transmission delay (\(X3\)) and voice link building time (\(X8\)) is the largest. In fact, these two indexes are the measurements of system transmission from two different scenarios. The end-to-end transmission delay is the average transmission delay of fixed length packets between any node in the network. The voice of the system studied is based on VoIP, and the time from call initiation to successful chain construction is roughly equal to the sum of the transmission delay of call instruction packets between source and destination. Therefore, it has a strong correlation. Considering that the voice link establishment time (\(X8\)) includes the end-to-end data transmission process from the link establishment process, additionally, the comprehensive weight of index \(X8\) in the importance analysis of the last section is the largest, and the influence on the three factors are large. Thus, the index \(X8\) is retained and the index \(X3\) is discarded. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \(X4\) & \(X5\) & \(X6\) \\ \hline \(X4\) & 1.0000 & 0.7023 & 0.7688 \\ \(X5\) & 0.7023 & 1.0000 & 0.8149 \\ \(X6\) & 0.7688 & 0.8149 & 1.0000 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Correlation coefficient between management and control factor indexes. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \(X1\) & \(X2\) & \(X3\) & \(X4\) & \(X5\) & \(X6\) & \(X7\) & \(X8\) \\ \hline \(H_{i}\) & 0.8980 & 0.8717 & 0.8944 & 0.8807 & 0.8413 & 0.9014 & 0.8625 & 0.9501 \\ \(W_{i}\) & **0.1265** & 0.1228 & 0.1260 & **0.1240** & 0.1185 & 0.1270 & **0.1215** & **0.1338** \\ \(W_{i}\)\({}^{*}\) & **0.2501** & – & – & **0.2452** & – & – & **0.2402** & **0.2501** \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Weight table of each index. Similarly, the correlation between \(X2\) and \(X8\) is also large, and the correlation coefficient is 0.877. In fact, \(X2\) reflects the total data transmission volume per unit time of the network. The larger the total data transmission volume of the network, the busier the lines between the nodes of the network, and the longer the packet queue in the nodes. As a result, the transmission and forwarding time of each packet increases when the voice call link is established; thus, the voice link establishment time (\(X8\)) also increases. In addition, in the importance analysis of the previous section, the comprehensive weight of index \(X8\) is the largest; thus, the index \(X8\) is retained and the index \(X2\) is discarded. After analysis, the simplified indexes of information transmission factor indexes are determined as \(X7\) and \(X8\). The correlation coefficients between \(X4\), \(X5\) and \(X6\) are greater than the critical value (0.5), indicating that there is a great correlation between the network situation awareness, the timeliness of network state adjustment and the success rate of temporary network access. In fact, the network state awareness measures the correctness and data transmission delay of the network management agent in each network device when the network state changes.