## 3 Results
### Frequency-Based Analysis for Feature Selection  
We observed the frequency of feature selection ranked based on cross-validated F1 scores. In Figure 5, it can be seen that dFBB has a higher performance than eFBB, and dual FBB has a higher performance than dFBB in both the composite SUVR and regional SUVR. In addition, it can be seen that the performance difference between eFBB, dFBB, and dual FBB is statistically significant. There was no normality in the F1 score distribution; therefore, the Kruskal-Wallis test was used to test for significant differences between the three groups. The three groups were significantly different (\(p<0.0001\)), and it was confirmed through post-hoc testing that there were significant differences between eFBB and dFBB, dFBB and dual FBB, and eFBB and dual FBB. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**eFBB**} & \multicolumn{3}{c}{**dFBB**} & \multicolumn{3}{c}{**Dual FBB**} \\ \cline{2-10}  & **Accuracy** & **F1 Score** & **AUC** & **Accuracy** & **F1 Score** & **AUC** & **Accuracy** & **F1 Score** & **AUC** \\ \hline \multicolumn{10}{c}{_Composite SUIVR performance_} \\ SVM & 67.04 & 53.83\% & 0.5423 & 66.78\% & 54.10\% & 0.7080 & 70.65\% & 64.97\% & 0.8415 \\ RF & 58.39\% & 53.98\% & 0.6444 & 73.56\% & 73.23\% & 0.8336 & 78.21\% & 78.06\% & 0.8724 \\ LR & 66.91\% & 55.87\% & 0.7351 & 67.91\% & 56.31\% & 0.7809 & 72.91\% & 65.56\% & 0.8478 \\ NB & 66.52\% & 63.27\Table 3 presents the summary statistics from Figure 5. Minimum, maximum, median, mean, and standard deviation (SD) are shown for the F1 score obtained in 100 experiments. In eFBB, the F1 score distribution had a minimum of 33.66%, median of 60.19%, mean of 59.51%, maximum of 78.63%, and SD of 8.4251. In dFBB, the F1 score distribution had a minimum of 40.05%, median of 70.92%, mean of 71.24%, maximum of 82.26%, and SD of 7.9509. In dual FBB, the F1 score distribution had a minimum of 49.89%, median of 78.52%, mean of 78.54%, maximum of 95.70%, and SD of 7.6105. In all statistical values except for SD, the F1 score of dual FBB was higher than that of eFBB and dFBB; eFBB had the highest SD, and dual FBB had the lowest. From Figure 6 and Table 4, among the six regions constituting the composite SUVR, an influential area for classifying the AD patient group and control group was identified. In the case of the eFBB, the order of regions influencing classification was frontal (32.65%), temporal (24.4%), posterior cingulate (16.49%), anterior cingulate (13.06%), occipital cingulate (7.9%), and parietal (5.5%). In the case of the dFBB, the order of regions influencing classification was temporal (33.45%), frontal (29.09%), parietal (18.91%), and occipital (8.73%), anterior cingulate (8.36%), and posterior cingulate (1.45%). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **Frontal** & **Temporal** & **Parietal** & **Occipital** & **Anterior Cingulate** & **Posterior Cingulate** \\ \hline \multirow{2}{*}{eFBB} & Number of features & 95 & 71 & 16 & 23 & 38 & 48 \\  & Ratio (\%) & 32.64\% & 24.39\% & 5.49\% & 7.90\% & 13.05\% & 16.49\% \\ \hline \multirow{2}{*}{dFBB} & Number of features & 80 & 92 & 52 & 24 & 23 & 4 \\  & Ratio (\%) & 29.09\% & 33.45\% & 18.90\% & 8.72\% & 8.36\% & 1.45\% \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Simple and relative frequency distribution for feature selection in multiple training runs. Figure 5: Boxplot of F1 score: (**a**) F1 score boxplot of composite SUVR experiment and (**b**) F1 score boxplot of regional SUVR experiment. F1: F1 score, * indicates the result of the Kruskal–Wallis test and post-hoc analysis to evaluate superiority, significant at \(p<0.0001\). We compared the execution time taken according to the individual feature evaluation methods. The execution time of one-way ANOVA \(p\)-value (23 ms for eFBB, 18 ms for dFBB) was shorter than that of Gini score of RF (322 ms for eFBB, 279 ms for dFBB). Tables 5 and 6 list the frequency distributions according to the number of selected features in each phase.