# One-Class SVM Model-Based Tunnel Personnel Safety Detection Technology
## 4 Dataset Preparation
### Data Description
Tunnel construction is generally divided into the cavity entrance area, second lining construction completion area, second lining construction area, waterproofing construction area, back arch/leveling layer construction area, excavation area and initial support area. Each area is occupied by construction personnel, and the location of each person in the tunnel needs to be known. The installation of the personnel positioning device requires the determination of the coordinates of each base station, using the cave entrance as the starting point. The position of the personnel in the tunnel allows the calculation of the distance between the personnel and the palm face. Locating the distance of the personnel inside the cave from the cave entrance provides real-time statistics on the total number of personnel in the tunnel, the distribution of personnel in each area and other data. When the safety of personnel is in danger, the position of personnel from the cave entrance can be accurately determined to facilitate rescue. In this paper, the concept of relative position is defined formally, the location of construction personnel is regionalized, the distance from the cave entrance is identified as the absolute position, the decision of the reference position is based on the construction situation on site and the size of the reference position is defined as 50 m, as shown in Figure 5. Thus, the relative position value = absolute position/50, rounded to an integer, and Table 3 describes its relevance. After the formal definition of relative positions, the information search framework is shown in Figure 6.  
The information collection consists of three main aspects, namely the internal environment of the tunnel, the location information and the construction personnel's physical signs. The main measurements are the temperature and humidity of the internal tunnel environment, the body temperature and heart rate of the construction personnel and the location information obtained from the relative position defined above. Thus the evaluation parameters are the human skin temperature (including the chest), heart rate, the ambient temperature inside the tunnel, the ambient humidity, and the relative position of the human body, respectively. The data in this paper are obtained from the Kuitun River  
Figure 5: Relative position abstraction diagram. \begin{table}
\begin{tabular}{c c c} \hline \hline
**No.** & **Absolute Position (m)** & **Relative Position** \\ \hline
1 & 0–50 & 1 \\
2 & 51–100 & 2 \\
3 & 101–150 & 3 \\
4 & 151–200 & 4 \\
5 & 201–250 & 5 \\ \(\cdots\)\(\cdots\) & \(\cdots\)\(\cdots\) & \(\cdots\)\(\cdots\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Relative position rules. Diversion Tunnel Project in Xinjiang. The second, third and fourth standard diversion tunnel project, with a total length of 8195 km, started on 28 October 2020 and is scheduled to be completed on 1 July 2023. The basic information of the tunnel project is shown in Table 4. For the description of the subsequent experimental process, the data represented by the second, third and fourth bids in the table are defined as dataset 1, dataset 2 and dataset 3 respectively in this paper. We collected 5000 sets of data for each dataset, and each set included five variables, namely human body temperature, human heart rate, cave ambient temperature, cave ambient humidity and relative position.