Abdullah Yalçınkaya

Ankara University · Department of Statistics

Skew Normal (SN) distribution is widely used for modeling data sets having near normal and skew distribution. Maximum likelihood (ML) is the most popular method used to obtain estimators of model parameters. However, likelihood equations do not have explicit solutions in the context of SN. Therefore, we use the Genetic Algorithm (GA) which is a wel...

Maximum likelihood (ML) estimators of the model parameters in multiple linear regression are obtained using genetic algorithm (GA) when the distribution of the error terms is long-tailed symmetric. We compare the efficiencies of the ML estimators obtained using GA with the corresponding ML estimators obtained using other iterative techniques via an...

In this study, we use the maximum likelihood (ML) and the maximum product of spacings (MPS) methodologies to estimate the location, scale and skewness parameters of the skew-normal distribution under doubly type II censoring. However, it is known that these estimators cannot be obtained analytically because of nonlinear functions in the estimating...

The Burr III distribution is used in a wide variety of fields of lifetime data analysis, reliability theory, and financial literature, etc. It is defined on the positive axis and has two shape parameters, say $c$ and $k$. These shape parameters make the distribution quite flexible. They also control the tail behavior of the distribution. In this st...

In this study, estimation and prediction problems for the Burr type III distribution under type II censored data are considered. Maximum likelihood and maximum product spacing estimation methods are used to estimate model parameters. EM algorithm is employed to obtain maximum likelihood estimates. Unobserved future order statistics are predicted wi...

Many of the test statistics which are used to test H0: θ = θ0 are constructed under a postulated model. However, when the postulated model is not correct, the true significance level α′ will be different from that of the postulated model. The significance level α is used whether or not the hypothesis will be rejected. So, determining the true signi...

In random experiments, most analyses are based on interpretation of the difference between the means of experiment and control groups. Therefore, studying the difference between the variances of the experiment and control groups may also be useful in interpreting the analysis results. This study focuses on interval estimation with sample variance e...