Data heterogeneity appears when the sample comes from at least two different populations. We analyze three types of situations. In the first and simplest case the majority of the data come from a central model and a few isolated observations come from a contaminating distribution. The data from the contaminating distribution are called outliers and they have been studied in depth in the statist...

A new class of local mixture models called local scale mixture models is introduced here. This class is particularly suitable for the analysis of mixtures of the negative exponential distribution. The affine structure revealed by specific asymptotic expansions is the motivation for the construction of these models. They are shown to have very nice statistical properties which are exploited to m...

The uniformly minimum variance unbiased estimator (UMVUE) and the maximum likelihood estimator (MLE) are derived for samples from uniform distribution in the presence of outliers, where outliers are generated from generalized uniform distribution (GUD), when one parameter of the GUD is known. In this case it has been shown that UMVUE is better than MLE. When both the parameters are unknown then...

The length data from 12 samples of wood fibers and particles were described using lognormal and Weibull distributions. While both distributions fitted the middle range of the data well, the lognormal distribution provided a closer fit for short fibers and particles and the Weibull distribution was more appropriate for long ones. A mixture of the lognormal and Weibull distributions was developed...

The classical distribution theory of the log likelihood ratio test statistic does not hold for testing homogeneity (i.e., no mixture) against mixture alternatives. Asymptotic theory for this problem is developed. For some special cases, asymptotically locally minimax tests are also found. It is pointed out that the main problem is lack of identifiability of the usual parameterization even when ...

electric power industry have always try to provide reliable electricity to customers and at the same time decrease system costs. high voltage circuit-breakers are an essential part of the power network. this study has developed a maintenance and replacement scheduling model for high voltage circuit- breakers that minimize maintenance costs while maintaining the acceptable reliability. this mode...

BACKGROUND & OBJECTIVES Data on infectious diseases like tuberculosis (TB) have been analyzed in the past without giving adequate attention to spatial variations. Earlier studies also attempted to display disease status of sub regions, usually census tracts, by categorizing them into quartiles, that helps the authorities to identify high- or low-risk areas. This approach is based mainly on bino...

This paper presents a new distribution, the product of mixture between Maxwell-Boltzmann and particular case generalized gamma distributions. The resulting called Scale Mixture Maxwell-Boltzmann, greater kurtosis than recently introduced slash distribution. We obtained closed-form expressions for its probability density cumulative distribution functions. studied some properties moments, as well...