HUTCHINSONIAN RATIOS AND STATISTICAL POWER

Woodpecker Bills and Their Conformance to Hutchinsonian Ratios

Culmen lengths of a bark-drilling guild were examined to evaluate the utility of Hutchinsonian ratios. The culmen lengths of species pairs which feed on relatively abundant intermediate size prey were nearly identical. Species pairs which fed on the relatively less abundant very small and very large prey species had large (1.35-1.47) culmen ratios. It is concluded that Hutchinsonian ratios may,...

Statistical power

Seven Ports Power Divider with Various Power Division Ratios

A seven ports network is proposed to act as a six-way power divider/combiner. The proposed network structure consists of a set of λ/4 planar transmission lines at the design frequency and does not require any isolating resistor. The power divider is capable of providing various power ratios by judicious choice of the transmission lines characteristic impedances. Design equations are derived for...

Use of Ratios and Logarithms in Statistical Regression Models

In many regression models, we use logarithmic transformations of either the regression summary measure (a log link), the regression response variable (e.g., when analyzing geometric means), or one or more of the predictors. In this manuscript, I discuss the rationale for using logarithmic transformations, the interpretation of ratios, and the general properties of logarithms. 1 Use of Logarithm...

Statistical Power and Estimation of Incidence Rate Ratios Obtained from BED Incidence Testing for Evaluating HIV Interventions among Young People

BACKGROUND The objectives of this study were to determine the capacity of BED incidence testing to a) estimate the effect of a HIV prevention intervention and b) provide adequate statistical power, when used among young people from sub-Saharan African settings with high HIV incidence rates. METHODS Firstly, after having elaborated plausible scenarios based on empirical data and the characteri...