FitDat                  Fit Historical Survival Data Assuming the
                        Failure Time Follows the Weibull Distribution
LRT                     Conduct Interim or Final Analyses Using
                        One-Sample Log-Rank Test for the Optimal
                        Two-Stage Trials
Optimal.KJ              Optimal Two-Stage Design Using One-Sample
                        Log-Rank Test with Unrestricted Follow-Up
Optimal.rKJ             Optimal Two-Stage Design Using One-Sample
                        Log-Rank Test with Restricted Follow-Up
Sim_KJ                  Calculate Empirical Power by Simulation for the
                        Optimal Two-Stage Design Using One-Sample
                        Log-Rank Test with Unrestricted Follow-Up
Sim_rKJ                 Calculate Empirical Power by Simulation for the
                        Optimal Two-Stage Design Using One-Sample
                        Log-Rank Test with Restricted Follow-Up
