Forecast of Water Structure Based on GM (1, 1) of the Gray System

Table 1

Forecast model accuracy level judgment.

	The postcheck differential value C	Probability of error P
Class 1 (good)	C  0.35	P  0.95
Level 2 (qualified)	0.35  C  0.5	0.8  0.95
Level 3 (barely)	0.5  0.65	0.7  0.8
Level 4 (nonconformance)	C  0.65	P  0.7