# Design and Implementation of Industrial Accident Detection Model Based on YOLOv4
## 3 Design and Implementation
### Scenario Derivation and Object Selection  
A risk scenario must be derived before identifying a hazardous situation. Before that, a workplace must be selected; then, the scenario derivation, object selection, and learning data collection can proceed. In this study, the business site comprises small- and medium-sized businesses in the manufacturing field in Daejeon, Korea. The Korean government has established these businesses as certified manufacturers related to industrial safety and worker welfare. Several industrial safety certifications are provided by the Korean government and, among them, this study considers manufacturers certified as standard workplaces for persons with disabilities and as having clean workplace systems. The standard workplace for disabled people is a system supported by the Korea Employment Agency for Persons with Disabilities. This system creates an appropriate physical and emotional environment by presenting environmental standards for disabled people. In this system, disabled people must be hired and selected based on review criteria for disabled people (such as those concerning welfare) and on-site confirmation surveys [44]. Figure 4: Schematic diagram of the “You Only Look Once” (YOLO)v4 model. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **YOLOv4**[33] & **SSD + MobileNetV2** & **CenterNet**[42] \\  & & [34; 41] & \\ \hline mAP & 0.81 & 0.47 & 0.30 \\ Loss & 0.12 & 0.18 & 0.35 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparative experiment results for object detection model selection. Similarly, the Korea Occupational Safety and Health Agency provides specific amounts of money to support clean workplace systems for continuously improving various factors to create safe workplaces (e.g., industrial accident occurrence factors, environmental factors, and process procedures) [45]. The three selected manufacturers all have certifications related to industrial safety from the Korean government. In general, it is necessary to establish risk prevention measures to prevent and manage industrial safety accidents. In this study, each manufacturer does not represent only one manufacturing field; instead, they mean different types of industries and work sites. Hazardous situations commonly applied in industrial safety can be derived as scenarios. Manufacturer A is a mask manufacturer, B is a precision parts manufacturer, and C is a steel structure manufacturer. Table 4 shows each manufacturer's safety management characteristics and the results of the investigation regarding objects related to them. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Manufacturer A**} & \multicolumn{2}{c}{**Manufacturer B**} & \multicolumn{2}{c}{**Manufacturer C**} \\  & \multicolumn{2}{c}{**(Masks)**} & \multicolumn{2}{c}{**(Precision Parts)**} & \multicolumn{2}{c}{**(Steel Structures)**} \\ \hline \multirow{4}{*}{\begin{tabular}{c} **Safety** \\ **management** \\ **features** \\ \end{tabular} } & Cutting tools access & • & • & • \\  & Collision risk & • & • & • \\  & Caught in the belt & • & • & • \\  & Cannot load aisle & • & • & • \\  & Wearing & • & • & • \\ \hline \multirow{4}{*}{\begin{tabular}{c} **Collision** \\ **risk object** \\ \end{tabular} } & Moving cart & • & • & • \\  & Forklift & • & • & • \\  & Truck & • & & • \\  & Worker & • & • & • \\  & Large Materials & • & • & • \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} **Wearing** \\ **object** \\ \end{tabular} } & Personal protective & • & • & • \\  & Equipment & • & & • \\  & (Hygiege gear) & & & \\  & Personal protective & & & \\  & equipment & • & • & • \\  & (Safety gear) & & & \\ \hline \multirow{4}{*}{
\begin{tabular}{c} **Manufacturer certified by** \\ **the Korean government** \\ \end{tabular} } & Standard workplace for & & & \\  & & persons with & & & \\ \cline{1-1}  & & disabilities & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Investigation of safety management features and objects for each manufacturer ( •: required). Figure 5: Hazardous situation determination model process.