LICnew                  Calculate the LIC estimator based on A-optimal
                        and D-optimal criterion
SLIC                    SLIC function based on LIC with skewed error
                        distributions
beta_AD                 Caculate the estimators of beta on the A-opt
                        and D-opt
beta_cor                Caculate the estimator of beta on the COR
serr                    Generate data with skewed errors
