Jornal de Biometria e Bioestatística

The cure rate survival models are generally used to model lifetime data with long term survivors. We assumes the number of competing causes of the event of interest has the Poisson distribution and the time to the event of interest follows the Generalized Birnbaum-Saunders distribution. The Poisson GB-S distribution has been defined and useful representations for its density function have been presented which facilitates obtaining some mathematical properties. The parameters of the model with cure rate have been estimated using the maximum likelihood method. For different sample sizes and censoring percentages, several simulations have been performed and a real data set from the medical area has been analyzed.

In this paper, we consider the system of algebraic equations arising from the discretization of elliptic partial differential equation with respect to x and y axes. To compute the solution of the resulting equations we use the new method to solve various elliptic equations. We study the numerical accuracy of the method. The numerical results have shown that the method provided exact result depending on the particular equation on which the scheme is applied.

A statistical model which can be used to estimate the loss of fertility due to delayed marriage after the age at menarche was proposed. This model made use of a cohort of women who had their menarche at age 13 years. The expected number of years of spinsterhood was also estimated as e(x). The result showed that a spinster who had her menarche at age 13 years and delayed her marriage on the average 12 years is going to lose on the average 2 children.