A new lifetime distribution, called exponential doubly Poisson is proposed with decreasing, increasing, and upside-down bathtub-shaped hazard rates. One of the reasons for introducing distribution that it can describe failure time a system connected in form parallel-series structure. Some properties are addressed. Four methods estimation involved parameters considered based on progressively typ...

A new four-parameter model called the Marshall–Olkin exponential– Weibull probability distribution is being introduced in this paper, generalizing a number of known lifetime distributions. This model turns out to be quite flexible for analyzing positive data. The hazard rate functions of new model can be increasing and bathtub shaped. Our main objectives are to obtain representations of certain...

In this paper, we first provide m pivotal quantities to test the shape parameter and establish confidence interval of the shape parameter of the bathtub-shaped distribution under the failure-censored plan (see Balasooriya (1995) and Wu and Tsai (2000)). Next, we also find the best test statistic based on their most power of test among all test statistics and the best pivotal quantities with the...

background: hypertension is more common in adults with type 1 diabetes mellitus (t1dm) than the general population. the aim of this study was to detect the pre-hypertensive stage in children with t1d and to evaluate its correlation with diabetic nephropathy compared to non-diabetic children. methods: this was a prospective cross-sectional study in an out-patient clinic of a university hospital....

In this paper, we discuss several mathematical properties and estimation methods for a reparameterized version of the weighted Lindley (RWL) distribution. The RWL distribution can be particularly useful modeling reliability (survival) data with bathtub-shaped or increasing hazard rate function. inferential procedure to obtain parameter estimates is conducted via maximum likelihood approach cons...

We create air bubbles at the tip of a "bathtub vortex" which reaches to a finite depth. The bathtub vortex is formed by letting water drain through a small hole at the bottom of a rotating cylindrical container. The tip of the needlelike surface dip is unstable at high rotation rates and releases bubbles which are carried down by the flow. Using high-speed imaging we find that the minimal neck ...