Table 4.

Comparison of calibration performance by input variables (short-term: 80%—training dataset, 20%—test dataset, shuffled method, 5 min. sampling interval condition).

Input Variables	Linear - ULR/MLR			Nonlinear - MLP
	MAE	MSE	R${}^2$	MAE	MSE	R${}^2$
[uncalibrated] Raw PM	9.78	216.89	0.52	9.78	216.89	0.52
[ calibrated] Raw PM	3.69	24.44	0.78	3.55	23.12	0.80
[ calibrated] Raw PM + Humidity	3.11	18.72	0.84	2.99	16.69	0.84
[ calibrated] Raw PM + Temp	3.22	19.56	0.83	3.11	18.39	0.83
[ calibrated] Raw PM + Light	3.39	21.40	0.81	3.23	18.97	0.84
[ calibrated] Raw PM + Humidity + Temp	3.11	18.70	0.84	2.95	16.91	0.83
[ calibrated] Raw PM + Humidity + Light	3.09	18.61	0.84	2.99	17.01	0.83
[ calibrated] Raw PM + Temp + Light	3.19	19.25	0.83	3.10	18.15	0.83
[ calibrated] Raw PM + Humidity + Temp + Light	3.08	18.41	0.84	2.93	16.76	0.83