Page 15 - Contributed Paper Session (CPS) - Volume 3
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CPS1923 Deemat C M. et al.
            The critical values of the exact test for different  are tabulated in Table 1.

                               Table 1. Critical values of the exact test
                         90% level      95% level     97.5% level     99% level
                    2        0.4000        0.4500         0.4750         0.4900
                    3        0.2764        0.3419         0.3883         0.4292
                    4        0.2189        0.2678          0.323         0.3693
                    5        0.1883        0.2383          0.28          0.325
                    6        0.1679        0.2131         0.2508         0.2927
                    8        0.1413        0.1799         0.2125         0.2492
                   10        0.1243        0.1586         0.1877         0.2208
                   20        0.0852         0.109         0.1295         0.1531
                   30        0.0689        0.0882         0.1049         0.1241
                   50        0.0529        0.0679         0.0808         0.0957
                   100       0.0373        0.0477         0.0569         0.0675

            3.   Asymptotic properties
                In this section, we investigate the asymptotic properties of the proposed
            test statistic. Making use of the asymptotic distribution we also calculate the
            Pitman’s asymptotic efficacy.

            3.1. Consistency and asymptotic normality. As the proposed test statistic is
            a U-statistic, we use the asymptotic theory of U-statistics (Lee, 1990) to discuss
            the limiting behaviour of ∆ .
                                     ̂ ∗

            Theorem 3.1. The ∆  is a consistent estimator of ∆ ( ) under the alternatives
                               ̂ ∗
                                                             ∗
                                                                ∗
             .
              1

            Theorem 3.2. The distribution of  √(∆ − ∆( )), as  → ∞, is Gaussian with
                                                  ̂
                                                          ∗
            mean zero and variance 4 , where   is the asymptotic variance of ∆ and is
                                                 2
                                       2
                                                                                ̂
                                                 1
                                       1
            given by
                         1
                                                              1
                                    ̅
                                                      ∗
                                        ∗
                                  ∗ ∗
                     2
                                                                 ∗
                     =  (2  ( ) +  2 ∫ 0  ∗  () −   )         (2)
                     1
                         4
                                                              2

            Proof:  Since  ∆   is  a  U-statistic  it  is  a  consistent  estimator  of  ∆( )
                                                                                     ∗
                           ̂
            (Lehmann,1951).  Hence ∆  converges  in  probability  to ∆( ).  Note  that 
                                                                                     ̅
                                     ̂
                                                                                      ∗
                                                                       ∗
            converges in probability to  . As we can write
                                        ∗
                                                      ∗
                                              ̂
                                              ∆   ∆( )  ∗
                                        ̂ ∗
                                       ∆ =       .      .   ,
                                               ∗
                                                         ̅ ∗
                                            ∆( )   ∗  
            the proof of the theorem is immediate.

            Corollary  3.1.  Let     be  continuous  non-negative  random  variable  with
                                  ∗
                       
                                                           ∗
              ∗
             ̅
                                                              ∗
                                                    ̂ ∗
             () =  − , then the distribution of √(∆  − ∆ ( )), as   →  ∞, is Gaussian
                                          2
            with mean zero and variance  =   2  .
                                          0
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