In reliability and survival analysis, comparison of two or more populations is an important problem. For example, while comparing a treatment group with a control group, one may be interested in determining whether the observations in the treatment group have a longer lifetime than those from...

Let be a random vector, and denote by X1:n,X2:n,...,Xn:n the corresponding order statistics. When X1,X2,...,Xn represent the lifetimes of n components in a system, the order statistic Xn-k+1:n represents the lifetime of a k-out-of-n system (i.e., a system which works when at least k...

Univariate Birnbaum-Saunders distribution has been used quite effectively to model positively skewed data, especially lifetime data and crack growth data. In this paper, we introduce bivariate Birnbaum-Saunders distribution which is an absolutely continuous distribution whose marginals are...

In this paper, by considering a trivariate normal distribution, we derive the exact joint distribution of one variable and a linear combination of order statistics from the other two variables. We show that this joint distribution is a mixture of unified bivariate skew-normal distributions. This...

Estimation for the Birnbaum-Saunders (BS) regression model has been discussed by various authors when data are either complete or subject to Type-I or random censoring. But, this problem has not been considered for the case of interval censoring. In this article, we discuss the estimation of a...

This paper considers the problem of nonparametric comparison of counting processes with panel count data, which arise naturally when recurrent events are considered. For the problem considered, we construct a new nonparametric test statistic based on the nonparametric maximum likelihood...