Books by Dr Mervat Mahdy
Statistics Analysis Via SPSS WIN 15
Statistics Analysis Via SPSS WIN 15
Teaching Documents by Dr Mervat Mahdy
Papers by Dr Mervat Mahdy
Journal of Statistical Theory and Applications, 2020
In this article, a selection of Nakagami distribution is investigated. Some properties of the mod... more In this article, a selection of Nakagami distribution is investigated. Some properties of the model with some plots of the density function are illustrated. Additionally, weighted of the one-sided Gaussian distribution, Generalized Rayleigh distribution are discussed as a special case of Generalized Nakagami distribution. In addition, maximum likelihood estimators are investigated with numerical methods and are compared by four sub-models with a real wave height data set. Finally, a simulation study is presented for parameters.
American Journal of Mathematical and Management Sciences, 2019
This article opens up new aging classes and new stochastic orders dependant on generalized moment... more This article opens up new aging classes and new stochastic orders dependant on generalized moment-generating function, which plays a vital role in reliability theory, finance topics, stochastic orders, and economic theory. The article presents some important new implications concerning these classes and introduces characterizations of the Weibull distribution, exponential distribution, and Erlang distribution through newly suggested aging classes. In addition, we list a series of inequalities that provide bounds for generalized momentgenerating classes. Furthermore, a sufficient condition for allowing a probability distribution to have a new class is provided. The article also demonstrates the preservation properties of a new stochastic order under certain reliability operations, such as mixture and convolution. Moreover, some novel applications of classes and stochastic orders in random sum and shock models are provided.
The skew-generalized inverse weibull distribution (SGIW) has four parameters of lifetime distribu... more The skew-generalized inverse weibull distribution (SGIW) has four parameters of lifetime distribution. It could have different hazard rates: increasing, decreasing and unimodal. In this paper, the method of Azzalini's (1985) is used to provide a shape of parameter to generalize inverse weibull, which creates a new class of skew-generalized inverse weibull distributions. Different statistical properties of this new distribution are discussed whereas expressions for density, minimum and maximum order statistic and i th moment of the order statistics and the inference of the old parameters and the skewness parameter are studied. In addition, Mont Carlo simulation method was carried out to investigate the properties of the estimations of the unknown parameters of SGIW. Furthermore, the flexibility of SGIW model is illustrated by means of two real data sets applications.
التحليل الإحصائي للبيانات باستخدام SPSS-WIN
Pakistan Journal of Statistics and Operation Research
In this paper, acceptance sampling plans as, double for the lifetime tests is truncated at prefix... more In this paper, acceptance sampling plans as, double for the lifetime tests is truncated at prefixed time to determine on acceptance or rejection of the submitted lots are provided. The probability distributions of the lifetime of the product are determined based on three distributions: generalized inverse Weibull, skewgeneralized inverse Weibull and compound inverse Rayleigh. The median lifetime of the test unit as the quality parameter is considered. The minimum sample sizes to assure that the actual median life is more than the specified life, OC values according to different quality levels and the minimum ratios of the actual median life to the specified life at the determined level of producer's risk for acceptance sampling plans are obtained. Numerical cases are introduced to illustrate the applications of acceptance sampling plans.
Further results involving percentile inactivity time order and its inference
METRON, 2013
On quantile reversed residual lifetime and its aging properties
METRON, 2012
ABSTRACT If the random variable T denotes the lifetime (T > 0, with probability one) of a ... more ABSTRACT If the random variable T denotes the lifetime (T > 0, with probability one) of a unit, then the random variable T (t) = [t − T|T ⩽ t],, for a fixed t, is known as the inactivity time or the reversed residual lifetime. In this paper, we define a new class of life distributions based on the quantile of the random variable T(t ) and study its reliability properties. Some new results of the proposed class are demonstrated including some closure properties. In particular, the quantile reversed residual lifetime functions of some well-known life distributions are illustrated. Finally, we define a new stochastic ordering based on the quantile reversed residual lifetime and study its reliability properties and closure properties.
Mutual Information and Dynamic Measure of Inaccuracy between Past Lifetime
The Egyptian Statistical Journal, May 16, 2010
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Books by Dr Mervat Mahdy
Teaching Documents by Dr Mervat Mahdy
Papers by Dr Mervat Mahdy