# MDPN: Multilevel Distribution Propagation Network for Few-Shot Image Classification
## 5 Discussion
### The Impact of Weight Factors  
As mentioned in Section 3.4, we set the weight control factors \(\lambda_{dist\_1}\), \(\lambda_{dist\_2}\), \(\lambda_{dist\_3}\), in (16) as follows: \([\lambda_{dist\_1}\), \(\lambda_{dist\_2}\), \(\lambda_{dist\_3}]=[0.0, 0.0, 1.0]\) in a 5-way 1-shot setting, and \([\lambda_{dist\_1}\), \(\lambda_{dist\_2}\), \(\lambda_{dist\_3}]=[1.0, 1.0, 1.0]\) in a 5-way 5-shot setting. In order to verify the effectiveness of the weight factors that we set to improve the classification accuracy, we conducted a series of experiments, as shown in Table 4.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Model**} & \multirow{2}{*}{**\(\lambda_{dist\_1}\)**} & \multirow{2}{*}{\(\lambda_{dist\_2}\)} & \multirow{2}{*}{\(\lambda_{dist\_3}\)} & \multicolumn{2}{c}{**CUB-200-2011**} \\ \cline{5-6}  & & & & & **1-Shot** & **5-Way** \\ \hline C0 & 0.0 & 0.0 & 1.0 & **83.55 (ours)** & 85.03 \\ C1 & 1.0 & 1.0 & 0.0 & 82.75 & 90.46 \\ C2 & 1.0 & 1.0 & 1.0 & 80.66 & **92.72 (ours)** \\ \hline \hline \end{tabular}
\end{table}
Table 4: The accuracy (%) of different settings of three weight factors in the loss function in 5-way 1-shot and 5-way 5-shot settings on cub-200-2011. The best results are shown in bold. C0 denotes \(\left[\lambda_{dist_1}\), \(\lambda_{dist_2}\), \(\lambda_{dist_3}\right]=[0.0, 0.0, 1.0]\). C1 denotes \(\left[\lambda_{dist_1}\), \(\lambda_{dist_2}\), \(\lambda_{dist_3}\right]=[1.0, 1.0, 0.0]\). C2 denotes \(\left[\lambda_{dist_1}\right, \lambda_{dist_2}\), \(\lambda_{dist_3}]=[1.0, 1.0, 1.0]\).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Model**} & \multirow{2}{*}{**ISOL**} & \multirow{2}{*}{**CBAM**} & \multicolumn{2}{c}{**CUB-200-2011**} \\ \cline{5-6}  & & & & **5-Way 1-Shot** & **5-Way 5-Shot** \\ \hline A0 & & & & 77.39 & 85.98 \\ A1 & & & \(\surd\) & 77.84 & 86.37 \\
**A2 (ours)** & \(\surd\) & & & **83.55** & **92.72** \\ \hline \hline \end{tabular}
\end{table}
Table 2: The accuracy (%) of different localization methods in 5-way 1-shot and 5-way 5-shot settings on CUB-200-2011. The best outcomes are highlighted in bold. A0 denotes the MDPN without ISOL module. A1 denotes the MDPN, with CBAM replacing ISOL module. A2 denotes the MDPN, which contains ISOL module.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Model**} & \multirow{2}{*}{**DP1**} & \multirow{2}{*}{**DP2**} & \multirow{2}{*}{**DP3**} & \multirow{2}{*}{**DP4**} & \multirow{2}{*}{**DP5**} & \multicolumn{2}{c}{**CUB-200-2011**} \\ \cline{5-6}  & & & & & & **5-Way 1-Shot** & **5-Way** \\ \hline B0 & \(\surd\) & & & & & 82.92 & 90.58 \\ B1 & \(\surd\) & \(\surd\) & & & & 83.43 & 91.69 \\
**B2 (ours)** & \(\surd\) & \(\surd\) & \(\surd\) & & **83.88** & **92.72** \\ B3 & \(\surd\) & \(\surd\) & \(\surd\) & \(\surd\) & & 83.71 & 92.34 \\ B4 & \(\surd\) & \(\surd\) & \(\surd\) & \(\surd\) & \(\surd\) & 83.59 & 92.05 \\ \hline \hline \end{tabular}
\end{table}
Table 3: The accuracy (%) of distribution propagation with various numbers of levels in 5-way 1-shot and 5-way 5-shot settings on cub-200-2011. The best outcomes are highlighted in bold. B0 denotes one level of distribution propagation. B1 denotes two levels of distribution propagation. B2 denotes the MDPN, which contains three levels of distribution propagation. B3 denotes four levels of distribution propagation.