Page 277 - Contributed Paper Session (CPS) - Volume 7
P. 277

CPS2099 Takatsugu Yoshioka et al.



               The constants  and  are decided using the first and second moments of U.
               That is, we can follow




                   Therefore, using the asymptotic expansions of E[U]and E[U ], the new
                                                                            2
               approximation to the values of  and  are given. In addition, we propose
               another approximate solution by adjusting the degrees of freedom of F
               distribution. In the above results, we estimated the second degree of
               freedom  and the coefficient  , but further estimate the first degree of
               freedom  as




                   and the constants ,  and  are decided using the first, second and third
                             2
               moments of T  . That is, we can follow


                   Therefore, using the asymptotic expansions of E[T ], E[(T ) ] and E[(T ) ],
                                                                         2 2
                                                                                    2 3
                                                                   2
               the new approximation to the values of ,  and  are given.

                 3. Result
                   We  give  the  two-step  monotone  missing  data  to  be  generated  from
                                                                               4
               multivariate  normal  distribution  by  Monte  Carlo  simulation  (10   runs)  and
                                                      2
               calculate the upper 100α percentile of T  type statistics and F approximations,
               and  type  I  error  with  significant  level  α=0.05,0.01  where   = 4(( ,  ) =
                                                                                   1
                                                                                      2
               (2,2)), which are given by
                                                                   ()
                                                                      ,
                                                              2
                                               2
                                          2
                                α = P ( >  ()) ,  = ( >      )
                                                       2
                                  1
                                               
                  Note that the simulated values approach closer to the upper percentiles of
               chi-squared distribution when sample size become large. The type I error rates
               show that α2 are very good approximations.











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