Table 1.

The experimental conditions and the corresponding results.

Run	Levels of Independent Factors			Response EE%
	X1	X2	X3
1	−1	−1	0	82.06
2	1	−1	0	72.95
3	−1	1	0	81.37
4	1	1	0	73.27
5	−1	0	−1	85.79
6	1	0	−1	89.12
7	−1	0	1	91.02
8	1	0	1	71.93
9	0	−1	−1	78.85
10	0	1	−1	81.36
11	0	−1	1	78.15
12	0	1	1	73.15
13	0	0	0	94.12
14	0	0	0	93.41
15	0	0	0	94.05