The objectives of this research were to evaluate gender differences and selection on body weight as they affect growth curves of chickens. Marginal posterior densities of growth curve parameters were studied by Gibbs sampling on 10,671 male and female chickens originating from five lines. Line X-+ was selected on low body weight at 8 wk (BW8) and high body weight at 36 wk (BW36), line X+- on hi...

In this paper we consider the use of Bayesian methods to analyze some standard existing growth models, a class of nonlinear regression models. For the nonlinear modeling we assume usual normal errors and also stable distributions for the response variable. We also study some robustness aspects of nonlinear regression models to the presence of outliers or discordant observations considering the ...

In this paper we have proven uniqueness theorems for estimation of the age-dependent parameter α in the Gompertz survival model with a mortality deceleration rate, in the absence of age-specific mortality data. We obtained estimations dependent on and uniform in the population size N . c © 2007 Elsevier Ltd. All rights reserved.

In Demography and modelling mortality (or failure) data the univariate Makeham-Gompertz is well-known for its extension of exponential distribution. Here, a bivariate class of Gompertz--Makeham distribution is constructed based on random number of extremal events. Some reliability properties such as ageing intensity, stress-strength based on competing risks are given. Also dependence properties...

The use of genomic selection for changing the growth curve shape of animals, acting simultaneously on the 3 parameters of a Gompertz growth curve, was studied using computer simulation. Results showed that genomic selection modified the growth curve. Responses to all selection criteria were accompanied with a correlated response in mature weight due to the high genetic correlations between matu...

The objective of this study was to determine the appropriate non-linear function describing growth of some testicular traits (testicular length, testicular diameter, scrotal circumference and scrotal length) in Norduz male lambs. Testicular characteristics at 90, 110, 130, 150, 170, and 190 days of age for all the lambs were measured. Four growth (Monomolecular, Logistic, Gompertz, and Richard’...

Growth of Red, GIFT and Supreme Nile tilapia strains were evaluated. Fish were cultivated in indoor recirculation systems in 0.5 m3 tanks with controlled temperatures of 22, 28 and 30°C. Random samples of 20 fish from each strain (10 fish tank) were weighed at day 7, 30, 60, 90 and 120. Exponential model (y=Ae) and Gompertz model (y = Aexp(-Be)) were fitted and the estimates parameters were obt...

Software Reliability and its subset, Software Reliability Growth Models, are widely discussed in technical journals and texts. However, actual details on implementation and use of these models are typically lacking. This paper, by an analyst for analysts, summarizes the methods of evaluating SRGM’s for selection as a Software Engineering Environment tool, provides sufficient information to impl...