BACKGROUND Change in life expectancy may be more readily appreciated by a lay person as a measure of risk than the standardized mortality ratio (SMR). METHODS The linear increase in the logarithm of the age-specific mortality rates with age (the Gompertz function) is used to deduce formulae connecting SMR with change in life expectancy. Their validity is checked by a comparison between the 19...

the logistic, gompertz, richards and asymmetric logistic growth curve models were fitted to body weight data of local ghanaian chickens and french sasso t44 chickens. all four growth models provided good fit for each sex by genotype growth data with r2 values ranging from 86.7% to 96.7%. the rate constant parameter, k, ranged between 0.137 and 0.271 and were significantly different from zero fo...

In this study, we propose a new three-parameter lifetime model based on the type-I half-logistic G family and unit-Gompertz model, which named unit Gompertz distribution. The key feature of such novel is that it adds tuning parameter to using in order make more flexible. Diagrams numerical results are used look at model’s mathematical statistical aspects. efficiency estimating distribution para...

Weights of Polled Hereford and ‘Wokalup’ cows in the Wokalup selection experiment were obtained monthly, with up to 11 years of records per cow available. Mature weights were analysed treating them as repeated records per animal and by fitting a Gompertz growth curve for each animal. Estimates of heritabilities for mature weight were 0.3 to 0.4 for Herefords and 0.5 to 0.6 for Wokalups, and 0.3...

This paper proposes a modified Genetic Programming method for forecasting the mobile telecommunications subscribers’ population.Themethod constitutes an expansion of the hybridGenetic Programming (hGP)method improved by the introduction of diffusion models for technological forecasting purposes in the initial population, such as the Logistic, Gompertz, and Bass, as well as the Bi-Logistic and L...

An ice-free Arctic summer would have pronounced impacts on global climate, coastal habitats, national security, and the shipping industry. Rapid and accelerated Arctic sea ice loss has placed the reality of an ice-free Arctic summer even closer to the present day. Accurate projection of the first Arctic ice-free summer year is extremely important for business planning and climate change mitigat...