Research Article
Coal Mine Safety Evaluation Based on Machine Learning: A BP Neural Network Model
Table 1
Normalization rules of neural network input data.
| | Evaluation index | Network input | | Range | Value | Range | Value | Range | Value |
| | Employee medical insurance rate (%) | ≤10 | 0.1 | (10, 100) | Y/100 | 100 | 1 | | Per capita housing area of employees (m2/person) | = 0 | 0 | (0, 20) | Y/20 | ≥20 | 1 | | Average education level of employees | Below medium | 0.3–0.5 | Fairly good | 0.7 | Good | 0.9 | | Enrollment rate of employees' children (%) | ≤10 | 0.1 | (10, 100) | (Y-80)/(120–80) | 100 | 1 | | Reserve production ratio (%) | ≤80 | 0.1 | (80, 120) | Y/100 | ≥120 | 1 | | Recovery ratio (%) | ≤10 | 0.1 | (10, 100) | Y/100 | 100 | 1 | | Comprehensive utilization degree of resources | Below medium | 0.3–0.5 | Fairly good | 0.7 | Good | 0.9 | | Proportion of noncoal industry (%) | ≤10 | 0.1 | (10, 100) | Y/100 | 100 | 1 | | Total efficiency of raw coal (t/person) | = 0 | 0 | (0, 4) | Y/4 | ≥4 | 1 | | Per capita income of miners (yuan/month) | ≤1000 | 0.1 | (1000, 10000) | Y/10000 | ≥10000 | 1 | | Ratio of profits and taxes on funds (%) | = 0 | 0 | (0, 20) | Y/20 | ≥20 | 1 | | Land reclamation rate of mining area (%) | ≤10 | 0.1 | (10, 100) | Y/100 | 100 | 1 | | Standard rate of noise control in mining area (%) | ≤10 | 0.1 | (10, 100) | Y/100 | 100 | 1 | | Standard rate of wastewater treatment in mining area (%) | ≤10 | 0.1 | (10, 100) | Y/100 | 100 | 1 | | Standard rate of waste gas treatment in mining area (%) | ≤10 | 0.1 | (10, 100) | Y/100 | 100 | 1 | | Standard rate of solid waste discharge in mining area (%) | ≤10 | 0.1 | (10, 100) | Y/100 | 100 | 1 | | Million ton mortality (%) | = 0 | 1 | (0, 1) | (1-Y)/1 | ≥1 | 0 |
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