## 2 Materials and Methods
### Initial Data and Data Description
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Variable** & **Type** & **Number of Elements** & **Element Names** \\ \hline Accident classification & Categorical & 3 & Injury, death, property damage, etc. \\ \hline Headquarter & Categorical & 3 & \begin{tabular}{c} Housing construction, civil, \\ plant construction \\ \end{tabular} \\ \hline Process rate & Categorical & 10 & 1–10, 11–20,..., 91–100 \\ \hline Year & Categorical & 6 & 2015, 2016, 2017, 2018, 2019, 2020 \\ \hline Month & Categorical & 12 & 1–12 \\ \hline Day of the week & Categorical & 7 & \begin{tabular}{c} Monday, Tuesday, Wednesday, Thursday, \\ Friday, Saturday, Sunday \\ \end{tabular} \\ \hline Hour & Categorical & 19 & \begin{tabular}{c} Occupational accident occurrence time \\ from 0 to 23:00 in hourly increments \\ \end{tabular} \\ \hline Age & Categorical & 6 & 20–30, 31–40, 41–50, 51–60, 61–70, 71–80 \\ \hline Gender & Binary & 2 & Male, Female \\ \hline Type of work & Categorical & 15 & \begin{tabular}{c} Carpenter, painter, scaffolder, stonemason, \\ safety officer, welder, equipment operator, \\ electric piping equipment worker, \\ landscaper, window worker, \\ structural steel/steel frame worker, \\ concrete worker, tunnel worker, \\ earth worker, woodworker \\ \end{tabular} \\ \hline Type of accident & Categorical & 10 & \begin{tabular}{c} Jamming, fall down, fall off, hit, collapse, \\ struck, imbalance and uncontrolled \\ motion, occupational diseases, \\ mutilation/cut/puncture, \\ fire/explosion/blast \\ \end{tabular} \\ \hline Injured part & Categorical & 12 & \begin{tabular}{c} Pelvis, ear, eye, leg, multiple head \\ location, foot, hand, brain, mouth, nose, \\ arm, chest/abdomen \\ \end{tabular} \\ \hline Workplace & Binary & 2 & \
\begin{tabular}{c} Internal work, external work \\ \end{tabular} \\ \hline Assailing materials & Categorical & 21 &
\begin{tabular}{c} Formwork/shores, construction and \\ mining machinery, stair and ladder, \\ metal fine particles/trace \\ elements/dust/fumes, \\ other buildings/structures/etc., \\ end portion and opening, fauna and flora, \\ floor and ground/etc., scaffolding and \\ work plate, equipment/machinery parts \\ and appendages, hand tool nonpowered, \\ container and pack, transporting, \\ lifting equipment, machinery, \\ land transportation, \\ manpower machinery, \\ processing equipment/machinery, \\ natural phenomena (e.g., \\ working environment and atmospheric \\ conditions), material, \\ electrical equipment/parts, \\ debris/garbage, hand tool powered \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Description of variables from 963 occupational accident data entries. (i) Type of work (TW): This variable represents the victim's job role at the construction project. It consists of 15 elements: \"carpenter,\" \"painter,\" \"scaffolder,\" \"stonemason,\" \"safety officer,\" \"welder,\" \"equipment operator,\" \"electric piping equipment worker,\" \"landscaper,\" \"window worker,\" \"structural steel/steel frame worker,\" \"concrete worker,\" \"tunnel worker,\" \"earth worker,\" and \"woodworker.\"  
(ii) Type of accident (TA): This indicates the type of accident that the victim suffered. It consists of ten elements: \"jamming,\" \"fall down,\" \"fall off,\" \"hit,\" \"collapse,\" \"struck,\" \"imbalance and uncontrolled motion,\" \"occupational diseases,\" \"mutilation/cut/puncture,\" and \"fire/explosion/blast.\"  
(iii) Injured part (IP): This refers to the part of the body that received the injury. It consists of 12 elements in total: pelvis, ear, eye, leg, multiple head location, foot, hand, brain, mouth, nose, arm, and chest/abdomen. (iv) Assailing material (AM): This variable is a standard used by the Korea Occupational Safety and Health Agency (KOSHA); it refers to the substance directly responsible for causing harm to the victim.