Table 4.

Error testing indexes of prediction results of next ten days.

No.	Index	ARIMA	ANNs	ESM	CFM
1	MAE(µg/m3)	19.1119	11.2298	21.5435	10.3321
2	MPE	0.3188	0.2571	0.3987	0.2229
3	RMSE(µg/m3)	22.2286	14.2652	25.5865	12.8903
4	Theil inequality coefficient	0.0033	0.0032	0.0034	0.0025
5	Bias ratio	0.1417	0.1203	0.7089	0.1739
6	Variance ratio	0.0522	0.8789	0.0616	0.1757