Research on the Stability of NDGM Model with the Fractional Order Accumulation and Its Optimization

Table 1

The fitted values and MAPE of four grey models (unit: millionth).

Year	Actual value	GM(1, 1)	NDGM
2000	5.08	5.08	5.08	5.08	5.08
2001	4.80	3.55	3.65	3.74	4.23
2002	4.67	4.52	4.61	4.41	4.43
2003	4.50	5.76	5.84	5.71	5.50
2004	7.12	7.34	7.42	7.47	7.29
2005	9.67	9.34	9.45	9.70	9.67
2006	12.80	11.90	12.04	12.42	12.54
2007	15.88	15.15	15.37	15.66	15.84
2008	19.49	19.30	19.65	19.51	19.48
MAPE		10.01	8.93	8.01	5.49
2009	23.07	24.57	25.13	24.02	23.42
2010	26.86	31.29	32.16	29.28	27.59
MAPE		11.50	14.32	6.55	2.11