Table 21.

The fitting mean errors, standard deviations, and coefficient of determination from the three models in Case 7.

Index	Fick Model	Exponential Model	Mixed-Curve Model
Fitting mean error $\overline{\delta }$	0.8269	0.0771	0.0518
Fitted standard deviation $\sigma$	1.9430	0.1769	0.1201
Coefficient of determination ($R^2$)	0.7253	0.9977	0.9990