0000000000411685
AUTHOR
Jarosław Bartoszewicz
Block–Savits Characterization and Star Ordering of Exponential Mixtures
Block and Savits (1980) established a characterization of life distributions using the Laplace transform. In this article, we remark that one of the necessary conditions to be IFRA distribution is equivalent to the star ordering of exponential mixtures. It leads to the definition of two new classes of life distributions, called LIFR and LIFRA, and their dual classes: LDFR and LDFRA. It occurs that these classes have many useful aging properties and preserve known reliability operations. Properties of the classes are studied and relations with known classes are established.
Monotonicity of Bayes estimators
Let X = (X1; : : : ;Xn) be a sample from a distribution with density (x;θ), θ∈Θ⊂R. In this article the Bayesian estimation of the parameter is considered.We examine whether the Bayes estimators of are pointwise ordered when the prior distributions are partially ordered. Various cases of loss function are studied. A lower bound for the survival function of the normal distribution is obtained.