The time dependence of the h-index is analyzed by considering the average behaviour of h as a function of the academic age AA for about 1400 Italian physicists, with career lengths spanning from 3 to 46 years. The individual h-index is strongly correlated with the square root of the total citations NC : h ≈ 0.53 √ NC . For academic ages ranging from 12 to 24 years, the distribution of the time ...

This paper presents an extension of the generalized extreme value (GEV) distribution, based on T-X family distributions: Gompertz-generated distributions that make existing distribution more flexible called Gompertz-general (Go-GEV) distribution. Some properties proposed are introduced, and a new is applied to actual data, namely rainfall in Lopburi Province, by comparing model with traditional...

A two-step modeling approach was used for predicting the effect of temperature on the growth of Xanthomonas arboricola pv. pruni, causal agent of bacterial spot disease of stone fruit. The in vitro growth of seven strains was monitored at temperatures from 5 to 35°C with a Bioscreen C system, and a calibrating equation was generated for converting optical densities to viable counts. In primary ...

A total of 16 data sets on wild and cultivated fishes, crustaceans and molluscs were used to test and compare conventional growth curves (von Bertalanffy, Logistic, Gompertz and Richards) and a new growth model. Statistical properties for estimation of the models were evaluated and compared to determine suitability. The absolute value of the Hougaard measure of skewness of parameter estimates (...

Standard models for senescence predict an increase in the additive genetic variance for log mortality rate late in the life cycle. Variance component analysis of age-specific mortality rates of related cohorts is problematic. The actual mortality rates are not observable and can be estimated only crudely at early ages when few individuals are dying and at late ages when most are dead. Therefore...

BACKGROUND The gamma-Gompertz model is a fixed frailty model in which baseline mortality increases exponentially with age, frailty has a proportional effect on mortality, and frailty at birth follows a gamma distribution. Mortality selects against the more frail, so the marginal mortality rate decelerates, eventually reaching an asymptote. The gammaGompertz is one of a wider class of frailty mo...