Evaluating the power of the mann-whitney test using the bootstrap method

In this paper we evaluate the power of the Mann-Whitney test in the shift model G(x) = F (x+θ) for all x , where the distribution of G is obtained by shifting F by an amount of θ.

The bootstrap method was used to evaluate the power of the Mann-Whitney test . A comparison among the bootstrap power , the asymptotic power of the Mann-Whitney test and the t-test power proved that the bootstrap is a better technique , because , it does not require the assumption of normality.     

A new geometric first-order integer-valued autoregressive (NGINAR(1)) process

A new stationary first-order integer-valued autoregressive process with geometric marginal distributions is introduced based on negative binomial thinning. Some properties of the process are established. Estimators of the parameters of the process are obtained using the methods of conditional least squares, Yule–Walker and maximum likelihood. Also, the asymptotic properties of the estimators are derived involving their distributions. Some numerical results of the estimators are presented with a discussion to the obtained results. Real data are used and a possible application is discussed.     

Perinatal and social factors predicting caesarean birth in a 2004 Australian birth cohort

Background

The proportion of babies born by caesarean section in Australia has almost doubled over the last 25 years. Factors known to contribute to caesarean such as higher maternal age, mothers being overweight or obese, or having had a previous caesarean do not completely account for the increased rate and it is clear that other influences exist.

An extended Maxwell distribution: Properties and applications

In this article, we propose an extension of the Maxwell distribution, so-called the extended Maxwell distribution. This extension is evolved by using the Maxwell-X family of distributions and Weibull distribution. We study its fundamental properties such as hazard rate, moments, generating functions, skewness, kurtosis, stochastic ordering, conditional moments and moment generating function, hazard rate, mean and variance of the (reversed) residual life, reliability curves, entropy, etc. In estimation viewpoint, the maximum likelihood estimation of the unknown parameters of the distribution and asymptotic confidence intervals are discussed. We also obtain expected Fisher’s information matrix as well as discuss the existence and uniqueness of the maximum likelihood estimators. The EMa distribution and other competing distributions are fitted to two real datasets and it is shown that the distribution is a good competitor to the compared distributions.     

The Socioeconomic Status of Street Children in Iran: A Systematic Review on Studies over a Recent Decade

To document the socioeconomic situation of street children in Iran and to ascertain the part played by this in becoming a street child, we classified and evaluated studies on this issue from the recent decade according to their strengths and weaknesses. The results will be helpful in policy‐making and planning for this group. The study employed a systematic review methodology, searching Iranian and international databases, and many universities and related organisations in Iran. After the quality of studies had been evaluated by three researchers, the findings of 40 research studies were classified, described and analysed. The research finds that street children in Iran come from crowded, low‐income families; many of them were rural–urban migrants and Afghans with families who immigrated to Iran; most of their parents had a lower than high school education and many of their fathers were unemployed or had low‐income jobs; the majority of these children were unskilled workers who would work many hours of the day for negligible incomes. We conclude that low socioeconomic status was prevalent among the street children's families in Iran and seems to be an important factor in the street‐connectedness of the children.