259129.fig.004a
(a)
259129.fig.004b
(b)
259129.fig.004c
(c)
259129.fig.004d
(d)
259129.fig.004e
(e)
259129.fig.004f
(f)
259129.fig.004g
(g)
259129.fig.004h
(h)
259129.fig.004i
(i)
Figure 4: Response surface plot for SR: (a) factor plot, (b) factor plot, (c) factor plot, (d) contour plot between and , ((e) and (f)) interactions plot between and , (g) normal plot of residuals, (h) residuals versus predicted values, and (i) predicted versus actual values.