Relationships for Moments of Generalized Order Statistics from Hjorth Distribution and Related Inference
- DOI
- 10.2991/jsta.d.210602.001How to use a DOI?
- Keywords
- Generalized order statistics; Hjorth distribution; single moments; product moments; recurrence relations; best linear unbiased estimators; type-II right censored samples
- Abstract
In this paper some recurrence relations satisfied by single and product moments of generalized order statistics from Hjorth distribution have been obtained. Then we use these results to compute the first two moments of order statistics for some specific values of the parameters. Further, we use the results on order statistics to obtain BLUEs of location and scale parameters based on type-II right censored samples.
- Copyright
- © 2021 The Authors. Published by Atlantis Press B.V.
- Open Access
- This is an open access article distributed under the CC BY-NC 4.0 license (http://creativecommons.org/licenses/by-nc/4.0/).
1. INTRODUCTION
Let
Assume that
Choosing the parameters appropriately, models such as ordinary order statistics
The joint pdf of first r generalized order statistics is given by
We may consider two cases here:
Case I:
Case II:
For Case I, the r-th generalized order statistic will be denoted by
For case II,
Further, it can be easily proved that
Also, for
Several authors like Kamps and Gather [4], Keseling [5], Cramer and Kamps [6], Ahsanullah [7], Pawlas and Szynal [8], Ahmad and Fawzy [9], Athar and Islam [10], Ahmad [11], Khan et al. [12], Khan et al. [13] and Saran and Pandey [14,15] have done some work on generalized order statistics. In this paper, in Section 3, we have established recurrence relations for single and product moments of generalized order statistics from Hjorth distribution for Case II only, i.e., for
2. HJORTH DISTRIBUTION
A random variable X is said to have Hjorth distribution if its pdf is of the form
Its characterizing differential equation is given by
More details on this distribution can be found in Hjorth [16].
The cdf of the location-scale parameter Hjorth distribution is given by
3. RECURRENCE RELATIONS FOR SINGLE AND PRODUCT MOMENTS OF GENERALIZED ORDER STATISTICS FROM HJORTH DISTRIBUTION FOR CASE II
Theorem 3.1.
For the distribution given in (10) and
Proof.
Putting the values of
Remark 3.1.
Putting
Remark 3.2.
If we take
n | r | E(Xr:n) | Var(Xr:n) | n | r | E(Xr:n) | Var(Xr:n) |
---|---|---|---|---|---|---|---|
1 | 1 | 0.275075 | 0.07296 | 8 | 1 | 0.032352 | 0.001111 |
2 | 1 | 0.136533 | 0.019918 | 8 | 2 | 0.070568 | 0.002715 |
2 | 2 | 0.413617 | 0.087615 | 8 | 3 | 0.116513 | 0.005054 |
3 | 1 | 0.089588 | 0.008731 | 8 | 4 | 0.173041 | 0.008528 |
3 | 2 | 0.230425 | 0.029067 | 8 | 5 | 0.244889 | 0.013882 |
3 | 3 | 0.505213 | 0.091719 | 8 | 6 | 0.340947 | 0.02273 |
4 | 1 | 0.066369 | 0.004787 | 8 | 7 | 0.481772 | 0.039734 |
4 | 2 | 0.159242 | 0.014093 | 8 | 8 | 0.740519 | 0.089023 |
4 | 3 | 0.301608 | 0.033907 | 9 | 1 | 0.02866 | 0.000868 |
4 | 4 | 0.573081 | 0.092565 | 9 | 2 | 0.061889 | 0.002076 |
5 | 1 | 0.052615 | 0.002992 | 9 | 3 | 0.100945 | 0.003768 |
5 | 2 | 0.121387 | 0.008186 | 9 | 4 | 0.147648 | 0.006171 |
5 | 3 | 0.216024 | 0.017581 | 9 | 5 | 0.204782 | 0.009662 |
5 | 4 | 0.358664 | 0.036652 | 9 | 6 | 0.276974 | 0.014942 |
5 | 5 | 0.626685 | 0.092176 | 9 | 7 | 0.372933 | 0.023554 |
6 | 1 | 0.043547 | 0.002036 | 9 | 8 | 0.512868 | 0.040006 |
6 | 2 | 0.097956 | 0.005302 | 9 | 9 | 0.768976 | 0.087862 |
6 | 3 | 0.168248 | 0.010659 | 10 | 1 | 0.025722 | 0.000696 |
6 | 4 | 0.263799 | 0.019939 | 10 | 2 | 0.055103 | 0.001636 |
6 | 5 | 0.406097 | 0.03826 | 10 | 3 | 0.089032 | 0.002912 |
6 | 6 | 0.670803 | 0.091282 | 10 | 4 | 0.128742 | 0.004661 |
7 | 1 | 0.037129 | 0.001471 | 10 | 5 | 0.176008 | 0.007095 |
7 | 2 | 0.082054 | 0.003696 | 10 | 6 | 0.233556 | 0.010572 |
7 | 3 | 0.137711 | 0.007106 | 10 | 7 | 0.305919 | 0.01576 |
7 | 4 | 0.208965 | 0.012496 | 10 | 8 | 0.401654 | 0.024145 |
7 | 5 | 0.304925 | 0.021574 | 10 | 9 | 0.540672 | 0.040106 |
7 | 6 | 0.446565 | 0.039202 | 10 | 10 | 0.794343 | 0.086733 |
7 | 7 | 0.708176 | 0.090184 |
Means and Variances of Order statistics from Hjorth distribution with parameters
Theorem 3.2.
For
Proof.
Using (6), we have
Using (12), we obtain
Putting the values of
4. BLUEs OF μ AND σ
Let
The BLUEs of
Tables 2 and 3 display the coefficients of the BLUEs for type-II right censored samples of sizes n = 5(1)10 with β = 2, δ = 3, = 4 and different censoring cases
n | c | ai = 1, 2, ..., (n − c) | |||||
---|---|---|---|---|---|---|---|
2, 3, 4 | 5 | 0 | 1.185103 | −0.052238 | −0.041786 | −0.037652 | −0.053427 |
1 | 1.252633 | −0.069672 | −0.057286 | −0.125675 | |||
6 | 0 | 1.156770 | −0.038448 | −0.030920 | −0.026106 | −0.024929 | |
−0.036367 | |||||||
1 | 1.199844 | −0.047927 | −0.039163 | −0.033897 | −0.078857 | ||
2 | 1.267204 | −0.062421 | −0.051839 | −0.152944 | |||
7 | 0 | 1.136374 | −0.029637 | −0.024218 | −0.020275 | −0.017906 | |
−0.017852 | −0.026486 | ||||||
1 | 1.166529 | −0.035450 | −0.029273 | −0.024876 | −0.022455 | ||
−0.054475 | |||||||
2 | 1.2085355 | −0.043385 | −0.036193 | −0.031207 | −0.097750 | ||
8 | 0 | 1.120713 | −0.023427 | −0.019590 | −0.016555 | −0.014305 | |
−0.013102 | −0.013503 | −0.020231 | |||||
1 | 1.143147 | −0.027284 | −0.022964 | −0.019592 | −0.01717 | ||
−0.016030 | −0.040105 | ||||||
2 | 1.172097 | −0.032172 | −0.027250 | −0.023461 | −0.020845 | ||
−0.068369 | |||||||
3 | 1.214264 | −0.039128 | −0.033360 | −0.028998 | −0.112778 | ||
9 | 0 | 1.108222 | −0.018806 | −0.016221 | −0.013874 | −0.011984 | |
−0.010652 | −0.010054 | −0.010624 | −0.016007 | ||||
1 | 1.125638 | −0.021504 | −0.018611 | −0.016019 | −0.013967 | ||
−0.012580 | −0.012074 | −0.030883 | |||||
2 | 1.146918 | −0.024749 | −0.021490 | −0.018607 | −0.016369 | ||
−0.014927 | −0.050776 | ||||||
3 | 1.175679 | −0.029041 | −0.025302 | −0.022042 | −0.019571 | ||
−0.079724 | |||||||
10 | 0 | 1.098552 | −0.015890 | −0.013634 | −0.011818 | −0.010285 | |
0.009068 | −0.008257 | −0.007988 | −0.008608 | −0.013003 | |||
1 | 1.112506 | −0.017866 | −0.015396 | −0.013403 | −0.011740 | ||
−0.010446 | −0.009629 | −0.009450 | −0.024576 | ||||
2 | 1.128879 | −0.020154 | −0.017436 | −0.015243 | −0.013431 | ||
−0.012053 | −0.011237 | −0.039324 | |||||
3 | 1.149846 | −0.023024 | −0.020000 | −0.017556 | −0.015564 | ||
−0.014085 | −0.059616 | ||||||
4 | 1.178702 | −0.026892 | −0.023457 | −0.020681 | −0.018449 | ||
−0.089223 |
Coefficients of the BLUE of location parameter.
n | c | bi = 1, 2, ..., (n − c) | |||||
---|---|---|---|---|---|---|---|
2, 3, 4 | 5 | 0 | −3.208033 | 0.757187 | 0.668368 | 0.688593 | 1.093885 |
1 | −4.590649 | 1.114139 | 0.985722 | 2.490788 | |||
6 | 0 | −3.211420 | 0.644789 | 0.558759 | 0.524623 | 0.569260 | |
0.913989 | |||||||
1 | −4.293977 | 0.883014 | 0.765913 | 0.720441 | 1.924610 | ||
2 | −5.937974 | 1.236757 | 1.075287 | 3.625931 | |||
7 | 0 | −3.220810 | 0.565699 | 0.490602 | 0.445028 | 0.437792 | |
0.491353 | 0.790335 | ||||||
1 | −4.120641 | 0.739160 | 0.641423 | 0.582342 | 0.573543 | ||
1.584173 | |||||||
2 | −5.342199 | 0.969912 | 0.842661 | 0.766453 | 2.763173 | ||
8 | 0 | −3.231744 | 0.505453 | 0.441562 | 0.396476 | 0.373008 | |
0.379760 | 0.436104 | 0.699380 | |||||
1 | −4.007270 | 0.638778 | 0.558222 | 0.501464 | 0.472092 | ||
0.480982 | 1.355732 | ||||||
2 | 4.985911 | 0.804020 | 0.703095 | 0.632261 | 0.596270 | ||
2.250264 | |||||||
3 | −6.373787 | 1.032960 | 0.904193 | 0.814498 | 3.622136 | ||
9 | 0 | −3.242010 | 0.456373 | 0.403847 | 0.361884 | 0.333970 | |
0.323848 | 0.338372 | 0.394433 | 0.629282 | ||||
1 | −3.926664 | 0.562450 | 0.497805 | 0.446202 | 0.411943 | ||
0.399652 | 0.417769 | 1.190842 | |||||
2 | −4.747246 | 0.608811 | 0.608811 | 0.546026 | 0.504558 | ||
0.490148 | 1.910109 | ||||||
3 | −5.829190 | 0.849026 | 0.752203 | 0.675246 | 0.624998 | ||
2.927717 | |||||||
10 | 0 | −3.253575 | 0.418371 | 0.372557 | 0.334955 | 0.307007 | |
0.290254 | 0.288326 | 0.307107 | 0.361682 | 0.573316 | |||
1 | −3.868817 | 0.505504 | 0.450223 | 0.404843 | 0.371152 | ||
0.351006 | 0.348794 | 0.371600 | 1.065696 | ||||
2 | −4.578786 | 0.604700 | 0.538706 | 0.484596 | 0.444504 | ||
0.420700 | 0.418543 | 1.667036 | |||||
3 | −5.467608 | 0.726402 | 0.647379 | 0.582682 | 0.534916 | ||
0.506848 | 2.469382 | ||||||
4 | −6.662882 | 0.886617 | 0.790576 | 0.712094 | 0.654412 | ||
3.619183 |
Coefficients of the BLUE of scale parameter.
The variances and covariances of the BLUEs are presented in Table 4. We see that the variances of the BLUEs increase as the censoring level increases while the variances of the BLUEs decrease as the sample size increases. In addition, we see that the covariance of the BLUEs decreases as the censoring level increases while the covariance of the BLUEs increases as the sample size increases.
n | c | Var |
Var |
Cov |
|
---|---|---|---|---|---|
2, 3, 4 | 5 | 0 | 0.003609 | 0.228627 | −0.011900 |
1 | 0.003864 | 0.335727 | −0.017130 | ||
6 | 0 | 0.002368 | 0.183293 | −0.007828 | |
1 | 0.002475 | 0.250810 | −0.010515 | ||
2 | 0.002641 | 0.349868 | −0.014574 | ||
7 | 0 | 0.001669 | 0.152970 | −0.005532 | |
1 | 0.001722 | 0.199847 | −0.007103 | ||
2 | 0.001795 | 0.261616 | −0.009227 | ||
8 | 0 | 0.001239 | 0.131258 | −0.004114 | |
1 | 0.001268 | 0.165900 | −0.005116 | ||
2 | 0.001305 | 0.208513 | −0.006377 | ||
3 | 0.001359 | 0.267122 | −0.008158 | ||
9 | 0 | 0.000955 | 0.114940 | −0.003178 | |
1 | 0.000972 | 0.141689 | −0.003859 | ||
2 | 0.000993 | 0.173057 | −0.004672 | ||
3 | 0.001022 | 0.213272 | −0.005741 | ||
10 | 0 | 0.000758 | 0.102222 | −0.002526 | |
1 | 0.000769 | 0.123554 | −0.003010 | ||
2 | 0.000781 | 0.147716 | −0.003567 | ||
3 | 0.000798 | 0.177205 | −0.004263 | ||
4 | 0.000820 | 0.215842 | −0.005196 |
Variances and covariance of the BLUEs when μ = 0 and σ = 1.
CONFLICTS OF INTEREST
The authors declare they have no conflicts of interest.
AUTHORS' CONTRIBUTIONS
All the three authors have equally contributed in the preparation of this research paper.
Funding Statement
We have solely funded the research by ourselves.
ACKNOWLEDGMENTS
The authors are grateful to the learned referees for their fruitful comments.
REFERENCES
Cite this article
TY - JOUR AU - Jagdish Saran AU - Kanika Verma AU - Narinder Pushkarna PY - 2021 DA - 2021/06/15 TI - Relationships for Moments of Generalized Order Statistics from Hjorth Distribution and Related Inference JO - Journal of Statistical Theory and Applications SP - 171 EP - 179 VL - 20 IS - 2 SN - 2214-1766 UR - https://doi.org/10.2991/jsta.d.210602.001 DO - 10.2991/jsta.d.210602.001 ID - Saran2021 ER -