[Retracted] Emergency Management System for Coal Mine Safety Based on IoT Technology

Table 3

Evaluation results.

Time (year)	2012	2013	2014	2015	2016	2017
IoT level of coal	6	11.24	19.56	30.17	39.57	49.27
Coal safety supervision level	71.29	74.9	80.21	83.32	88.57	91.48