Fig. 15.

Results for model by May-Newman and Yin (1998) with three parameters: a contour of the 2-norm shows valleys in the $A{B}_1$-planes, and b valleys in $A{B}_1$- and $A{B}_2$-planes interact to provide a complex 3D functional space [green circle denotes global minimum: $(\overline{A},{\overline{B}}_1,{\overline{B}}_2)=(0.4,4.5,500)$]; c the proposed modification significantly improves the convergence speed