## 3 Results
### Data Analysis  
In application, the arc light (lux, lx) and current signals were simultaneously acquired using rutile-coated electrodes with dimensions of 3.25 \(\times\) 350 mm and 2.50 \(\times\) 350 mm, with the electrode welding machine set to maximum current levels of 140 A, 120 A, 100 A, and 80 A, respectively. Datasets of different lengths were obtained for each average level. The obtained current and arc light datasets have been adjusted to equal values for signal analysis and estimation tasks. Table 1 shows the raw, training, and test data separately. The current and arc light datasets were concatenated to create raw, training, and test datasets, and their sizes were equalized.  
Figure 4a-d show the in situ measured current and arc light graphs during welding processes using electrodes with diameters of 3.25 mm and 2.50 mm, respectively. During the experiment, certain intervals were left as gaps in the welding process to better analyze the effects of electrode movements and to evaluate the artificial intelligence prediction  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Current and Arc Light Data** & **Electrode (mm)** & **80 A** & **100 A** & **120 A** & **140 A** \\ \hline Raw data (arc light and current) & 3.25 & 2320 \(\times\) 1 & 1948 \(\times\) 1 & 2014 \(\times\) 1 & 1600 \(\times\) 1 \\  & 2.50 & 1276 \(\times\) 1 & 1116 \(\times\) 1 & 945 \(\times\) 1 & 919 \(\times\) 1 \\ \hline Train data (arc light and current) & 3.25 & 2041 \(\times\) 1 & 1802 \(\times\) 1 & 1835 \(\times\) 1 & 1481 \(\times\) 1 \\  & 2.50 & 1177 \(\times\) 1 & 817 \(\times\) 1 & 746 \(\times\) 1 & 820 \(\times\) 1 \\ \hline Test data (arc light and current) & 3.25 & 279 \(\times\) 1 & 146 \(\times\) 1 & 179 \(\times\) 1 & 119 \(\times\) 1 \\  & 2.50 & 99 \(\times\) 1 & 299 \(\times\) 1 & 199 \(\times\) 1 & 99 \(\times\) 1 \\ \hline \end{tabular}
\end{table}
Table 1: Raw, training and test data.  
process more effectively. These gaps are consistent with the current change periods seen in Figure 4a,c. The changes in the periods also reflect the dynamic movements of the welder's electrode to some extent. When comparing the current levels in Figure 4a,c with the light levels in Figure 4b,d, it is observed that the arc light level increases as the current level increases. The arc light and welding current are sensitive to the movements of the operator. For instance, at a current level of 140 A in Figure 4b, the arc light intensity reaches 274.3 k at the 294 th sample and 186.4 k at the 781 st sample. Similarly, in Figure 4d, at the same current level, the arc light intensity reaches 344.6 k at the 193 rd sample and 290.3 k at the 730 th sample. This corresponds to instances where the welder exhibits unstable movements with the electrode or temporarily interrupts the welding process during a flawless welding process; when the appropriate current levels are chosen, the arc light follows a more stable trajectory. For example, at 120 amperes (3.25 mm electrode), the arc light intensity reaches a stable average level of approximately 25 k, while at 100 amperes and 80 amperes, it stabilizes around 16 lx and 10 lx, respectively. In cutting regions, transition values are smoother, and sudden fluctuations are reduced. In Figure 4d, at high current levels using a 2.5 mm diameter electrode, the arc light intensity shows pronounced fluctuations due to errors in the welding process caused by mismatches between the electrode diameter and the current.