Stochastic comparisons of sample spacings in single- and multiple-outlier exponential models |
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Authors: | Ghobad Barmalzan Abedin Haidari |
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Institution: | Department of Mathematical Sciences, Shahid Beheshti University, G.C. Evin, 1983963113 Tehran, Iran |
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Abstract: | This article studies some ordering results for the sample spacings arising from the single- and multiple-outlier exponential models. In the single-outlier exponential models, it is shown that the weak majorization order between the two hazard rate vectors implies the hazard rate order as well as the dispersive order between the corresponding sample spacings. We also extend this result from the single-outlier model to the multiple-outlier model for the special case of the second sample spacing. Furthermore, we obtain some necessary and sufficient conditions such that, on the one hand, the hazard rate, dispersive and usual stochastic orders, and on the other hand, the likelihood ratio and reversed hazard rate orders of the second sample spacings from two independent heterogeneous exponential random variables are equivalent. |
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Keywords: | hazard rate order dispersive order sample spacings single-outlier exponential model multiple-outlier exponential model reciprocal majorization order |
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