Prediction of Vibration Velocity of Bench Blasting Reflecting Negative Elevation Effect

Table 2

Test data regression results.

Formula type	Formula				Cod()	Reduced chi-sqr	Adj. -square
Sas (level)		6.43	0.79		0.9806	0.8734	0.9788
Sas (space)		12912.65	2.75		0.8935	4.7890	0.8838
Improved 1		46.16	0.72	0.62	0.9922	0.3860	0.9906
Improved 2		47.28	0.72	0.61	0.9923	0.3796	0.9908
Improved 3		47.24	1.34	-0.62	0.9923	0.3796	0.9908
Step (negative)		147.35	0.72	0.62	0.9923	0.3796	0.9908

Notes: (1) Cod(): characterizes the percentage of the variation according to the variable , interpreted by the controlled independent variable ; (2) reduced chi-sqr: indicates the degree of the direct difference between the observed and the fitted value; (3) Adj. -square: the correction coefficient, one of the critical indicators to measure the quality of the model.