This study was performed to develop a predictive growth model of Listeria monocytogenes to ensure the safety of raw pork. The pork samples were inoculated with a cocktail of two L. monocytogenes strains ATCC 15313 and L13-2 isolated from pork and were stored at 5, 15, and 25 C. Results were evaluated using the MicroFit program. To develop primary models, the Baranyi, modified Gompertz, and Logi...

The purpose of this study is to investigate the effect of different feed restrictions which were applied in early period on change of Body Mass Index of Ross 308 broiler chickens. For this aim we used to two different statistical methods, namely Profile analysis and Growth curves. The daily body weight and weekly body length change of chickens was collected from 7 days of age to 42 days of age....

Neural networks offer an alternative to regression analysis for biological growth modeling. Very little research has been conducted to model animal growth using artificial neural networks. Twenty-five male chicks (Ross x Ross 308) were raised in an environmental chamber. Body weights were determined daily and feed and water were provided ad libitum. The birds were fed a starter diet (23% CP and...

The estimation of the solution of a system of two differential equations introduced by Norton et al. (1976) that is equivalent to the famous Gompertz growth law is performed by means of the recent adaptive scheme of Besançon and collaborators (2004). Results of computer simulations illustrate the robustness of the approach.

Many successful technology forecasting models have been developed but little research has explored the relationship between sample set size and forecast prediction accuracy. This research studies the forecast accuracy of large and small data sets using the simple logisticl, Gompertz, and the extended logistic models. The performance of the models were evaluated using the mean absolute deviation...

Constraints can affect dramatically the behavior of diffusion processes. Recently, we analyzed a natural and a technological system and reported that they perform diffusion-like discrete steps displaying a peculiar constraint, whereby the increments of the diffusing variable are subject to configuration-dependent bounds. This work explores theoretically some of the revealing landmarks of such p...

Abstract. This work presents an empirical study of the evolution of the personal income distribution in Brazil. Yearly samples available from 1978 to 2005 were studied and evidence was found that the complementary cumulative distribution of personal income for 99% of the economically less favorable population is well represented by a Gompertz curve of the form G (x) = exp [ exp (A − Bx)], where...

In this work a new probabilistic and dynamical approach to an extension of the Gompertz law is proposed. A generalized family of probability density functions, designated by Beta • (p,q), which is proportional to the right hand side of the Tsoularis-Wallace model, is studied. In particular, for p=2, the investigation is extended to the extreme value models of Weibull and Frechet type. These mod...