CLIC                    CLIC function based on LIC with cosine_random
                        distributed errors
LICnew                  Calculate the LIC estimator based on A-optimal
                        and D-optimal criterion
beta_AD                 Caculate the estimators of beta on the A-opt
                        and D-opt
beta_cor                Caculate the estimator of beta on the COR
cerr                    cerr function is used to generate a dataset
                        where the error term follows cosine-based
                        distributions
