The Gompertz distribution has many applications, particularly in medical and actuarial studies. However, there has been little recent work on the Gompertz in comparison with its early investigation. The problem of analyzing and estimating parameters of bivariate Gompertz distribution with shared frailty is of interest and the focus of this paper. We propose maximum likelihood estimation procedu...

This work is about the Gompertz-Makeham distribution. The distribution has been applied plenty of times. The properties of the Gompertz-Makeham distribution investigated in this work are unimodality of the Gompertz-Makeham distribution and relationship between the median value and the mean residual life time of the Gompertz-Makeham distribution. For most of the realistic set of parameter values...

Comparison of the linear coefficients from the regression analysis of 307 blast (Pyricularia grisea) disease progress curves of 42 rice genotypes, tested over a period of nine seasons, were made by fitting into the logistic and Gompertz models. The regression parameters Yintercept (a), regression coefficient (b), its standard error (SEb), coefficient of determination (R) and the time required f...

Gompertz curve has been used to estimate the number of residual faults in testing phases of software development, especially by Japanese software development companies. Since the Gompertz curve is a deterministic function, the curve cannot be applied to estimating software reliability which is the probability that software system does not fail in a prefixed time period. In this article, we prop...

This study was conducted to describe the growth pattern of the French guinea fowl, a meat-type variety. Using BW data from hatch to 9 wk, 2 nonlinear mathematical functions (Gompertz and logistic) were used to estimate growth patterns of the French guinea fowl. The French guinea fowl did not exhibit sexual dimorphism for growth characteristics. From the Gompertz model, the asymptotic BW, growth...

Gompertz and Weibull functions imply contrasting biological causes of demographic aging. The terms describing increasing mortality with age are multiplicative and additive, respectively, which could result from an increase in the vulnerability of individuals to extrinsic causes in the Gompertz model and the predominance of intrinsic causes at older ages in the Weibull model. Experiments that ma...

I describe a software reliability growth model that yields accurate parameter estimates even with a small amount of input data. The model is based on a proposed discrete analog of a Gompertz equation that has an exact solution. The difference equation tends to a differential equation on which the Gompertz curve model is defined, when the time interval tends to zero. The exact solution also tend...

Although the Gompertz formula accurately describes observed mortality distributions over most of their extent, their 'tail' is much longer than that of a Gompertz curve fitted to the whole data set. A simple candidate explanation is that the longest-lived subset of any population will necessarily be enriched in individuals that age more slowly than the average of that population. However, some ...