A_x_B                   A Kronecker product B
DELTA                   Calculating the component of vector DELTA
GAMMA                   Calculating the component of matrix GAMMA
LSE_Reg_per             Least squares estimator for periodic
                        coefficients regression model
check_periodicity       Checking the periodicity of parameters in the
                        regression model
estimate_para_adaptive_method
                        Adaptive estimator for periodic coefficients
                        regression model
lm_per                  Fitting periodic coefficients regression model
                        by using LSE
lm_per_AE               Fitting periodic coefficients regression model
                        by using Adaptive estimation method
phi_n                   Calculating the value of phi function
pseudo_gaussian_test    Detecting periodicity of parameters in the
                        regression model
sd_estimation_for_each_s
                        Estimating periodic variances in a periodic
                        coefficients regression model
