Forecasting model for the incidence of hepatitis A based on artificial neural network

Table 1 Weight and threshold distribution of the best network

	Unit 1	Unit 2	Unit 3	Y
Threshold	0.9607	1.0829	0.6224	0.4850
AR (1)	0.2390	0.7930	1.0584
Time	0.4902	0.4344	0.4156
Unit 1				0.5281
Unit 2				0.7572
Unit 3				1.0723

Table 2 ARIMA model coefficient and its testing results

Variables	Coefficient	SE of coefficient	t	P
AR (1)	0.83	0.12	6.88	5.27 × 10-6
Constant	81.22	30.94	2.62	1.91

Table 3 Comparison between BP network and ARIMA

Time (yr)	Incidence (1/100000)	Predicted value from ANN	Error from ANN	Predicted value from ARIMA	Error from ARIMA
1981	160.07	-	-	-	-
1982	136.68	101.58	35.10	146.87	-10.19
1983	104.12	94.63	9.49	127.39	-23.27
1984	50.50	83.87	-33.37	100.29	-49.79
1985	32.99	62.34	-29.35	55.65	-22.66
1986	26.74	53.26	-26.52	41.07	-14.33
1987	39.94	49.11	-9.17	35.86	4.08
1988	36.75	53.72	-16.97	46.85	-10.10
1989	96.92	50.42	46.50	44.20	52.72
1990	91.33	73.84	17.49	94.29	-2.96
1991	79.52	70.90	8.62	89.64	-10.12
1992	75.31	64.60	10.71	79.81	-4.50
1993	85.57	61.39	24.18	76.30	9.27
1994	62.54	64.00	-1.46	84.84	-22.3
1995	28.23	52.11	-23.88	65.67	-37.44
1996	29.14	35.20	-6.06	37.11	-7.97
1997	42.90	34.36	8.54	37.86	5.04
1998	21.25	38.01	-16.76	49.32	-28.07
1999	34.36	27.27	7.09	54.66	-20.30
2000	19.31	30.87	-11.56	59.11	-39.80
2001	39.09	22.88	16.21	62.81	-23.72