# A Fault Analysis Method Based on Association Rule Mining for Distribution Terminal Unit
## 5 Experiment and Results
### Strong Rules of DTU Fault Data  
Setting a reasonable support threshold and confidence threshold are of great importance. A higher support threshold may lead to fewer association rules obtained, and a lower confidence threshold may give rise to more strong rules obtained, which, however, are less reliable. Therefore, the support threshold and confidence threshold of the Eclat algorithm were set to be 0.03 and 0.8 respectively.  
After applying the Eclat algorithm, 19 frequent 1-item sets, 40 frequent 2-item sets, 22 frequent 3-item sets, and 3 frequent 4-item sets were obtained. In total, 17 strong rules were mined from the database. Strong rules obtained from the DTU database are shown in Table 5.  
\(R_{u}\) strong rule can be used to form the fault rule base. \(R_{b}\) strong rule can be utilized to form the diagnosis rule base. \(R_{a}+R_{b}\) strong rule includes the relationship between fault type \(T\), \(F(B)\), and \(M\), and it can be used to form both the fault rule base and diagnosis rule base.  
The formed two rule bases are shown in Figure 6. The fault rule base comprised factors \(F\), fault type \(T\), and the confidence values of rules \(R_{a}\) (between \(F\) and \(T\)). The diagnosis rule base included fault type \(T\), fault module \(M\), and the confidence values of rules \(R_{b}\).  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**No.** & **Strong Rule Type** & **Strong Rule** & **Support (\%)** & **Confidence (\%)** & **Lift** \\ \hline
1 & \(R_{a}\) & DTU Upgradation+Brand 4 \(\Rightarrow\) Remote Signaling Fault & 8.26 & 100 & 5.01 \\ \hline
2 & \(R_{a}\) & Humidity \(\Rightarrow\) Remote Signaling Fault & 3.60 & 98.1 & 3.97 \\ \hline
3 & \(R_{a}\) & Brand 10 \(\Rightarrow\) Remote Signaling Fault & 6.71 & 97.9 & 1.97 \\ \hline
4 & \(R_{a}\) & Mis-operation \(\Rightarrow\) Remote Control Fault & 4.78 & 96.9 & 3.70 \\ \hline
5 & \(R_{a}\) & Brand 2 + DTU Upgradation \(\Rightarrow\) Remote Signaling Fault & 4.31 & 96.8 & 1.95 \\ \hline
6 & \(R_{a}\) & DTU Upgradation \(\Rightarrow\) Remote Signaling Fault & 16.81 & 96.4 & 1.94 \\ \hline
7 & \(R_{a}\) & Brand2 + Wireless Signal Quality \(\Rightarrow\) DTU Offline & 7.24 & 95.2 & 4.41 \\ \hline
8 & \(R_{a}\) & Wireless Signal Quality \(\Rightarrow\)DTU Offline & 8.94 & 93.6 & 4.34 \\ \hline
9 & \(R_{a}\) & Brand2 + Software Operating State \(\Rightarrow\) DTU Offline & 4.17 & 92.2 & 2.24 \\ \hline
10 & \(R_{b}\) & Communication Module \(\rightarrow\)DTU Offline & 10.38 & 81.7 & 3.79 \\ \hline
11 & \(R_{a}+R_{b}\) & Hardware Operating State \(\Rightarrow\) & 5.65 & 98.8 & 5.90 \\ \hline
12 & \(R_{a}+R_{b}\) & Hardware Operating State+Brand 2 \(\Rightarrow\) & 3.81 & 98.1 & 5.86 \\ \hline  & & Remote Signaling Fault \(\Rightarrow\) Control Circuit & 5.67 & 95.6 & 2.16 \\ \hline
13 & \(R_{a}+R_{b}\) & Wireless Signal Quality+Brand 2 \(\Rightarrow\) & 4.56 & 95.2 & 4.42 \\ \hline
14 & \(R_{a}+R_{b}\) & Brand 2 \(\Rightarrow\) DTU Offline \(\Rightarrow\) CPU & 6.79 & 93.1 & 2.36 \\ \hline
16 & \(R_{a}+R_{b}\) & Software Operating State+Brand 2 \(\Rightarrow\) & 7.16 & 90.4 & 2.29 \\ \hline
17 & \(R_{a}+R_{b}\) & Brand 2 \(\Rightarrow\) DTU Offline \(\Rightarrow\) Communication Module & 8.96 & 82.6 & 3.83 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Strong rules obtained from DTU fault database.  
Figure 6: The fault rule base and diagnosis rule base.  
The fault rule base and diagnosis rule base in Figure 6 can be used to support planned maintenance and fault repairing, respectively.