Abstract: This paper develops some objective priors for certain parameters of the bivariate normal distribution. The parameters considered are the regression coefficient, the generalized variance, and the ratio of the conditional variance of one variable given the other to the marginal variance of the other variable. The criterion used is the asymptotic matching of coverage probabilities of Bay...

It is a general practice to use robust estimates improve ratio estimators using functions of the parameters an auxiliary variable. In this study, new class based upon minimum covariance determinant (MCD) and volume ellipsoid (MVE) have been suggested for estimating population variance in presence outlier values data set simple random sampling. The expression mean square error (MSE) proposed der...

Testing zero variance components is one of the most challenging problems in the context of linear mixed-effects (LME) models. The usual asymptotic chi-square distribution of the likelihood ratio and score statistics under this null hypothesis is incorrect because the null is on the boundary of the parameter space. During the last two decades many tests have been proposed to overcome this diffic...

Minimal measurement error (reliability) during the collection of interval- and ratio-type data is critically important to sports medicine research. The main components of measurement error are systematic bias (e.g. general learning or fatigue effects on the tests) and random error due to biological or mechanical variation. Both error components should be meaningfully quantified for the sports p...

OBJECTIVES To explore any association between paternal tobacco smoking and the offspring secondary sex ratio, as well as the effect of duration and intensity of smoking on gender ratio. METHODS The cross-sectional study was conducted around major public areas within Khartoum, Sudan, between August and September 2008 and involved 458 married Sudanese males with offsprings. The sample consisted...

the aim of this study was to compare the effect of a session of aerobic and anaerobic exercise on changes of iga/salivary total protein ratio in non-athlete girls. 36 non-athlete girls were randomly divided into three groups: anaerobic (n =12) with mean age of 23±1.91 years, aerobic (n =12) with mean age of 21±1.45 years and the control group (n =12) with mean age 23.25±2.09 years. salivary sam...