428327.fig.006a
(a)
428327.fig.006b
(b)
428327.fig.006c
(c)
428327.fig.006d
(d)
428327.fig.006e
(e)
428327.fig.006f
(f)
428327.fig.006g
(g)
428327.fig.006h
(h)
Figure 6: Phase portraits for (a) , (b) , (c) , (d) , (e) , (f) , (g) , and (h) for the case where , .