Secondly, the ceiling height is set as 4 m, let taking a different value of 0.0029 kW/s2, 0.0117 kW /s2, 0.0469 kW
/s2 and 0.1876 kW /s2, which responses respectively to slow, medium, fast and ultra-fast fire. The other parameters are
shown in Table 1. The detection time of the proposed model is compared to that of the existing model in Fig.2(b).