heavy metal contamination has been and continues to be a worldwide phenomenon that heavy metals in the soil have an effect on environment and food quality, and may threaten human health. no information is currently available on the distribution pattern of heavy metals concentration in soils of golestan province. the objective of this research was to determine the spatial distribution of cd, as,...

Finding new families of distributions has become a popular tool in statistical research. In this article, we introduce a new flexible four-parameter discrete model based on the Marshall-Olkin approach, namely, the discrete Kumaraswamy Marshall-Olkin exponential distribution. The proposed distribution can be viewed as another generalization of the geometric distribution and enfolds some importan...

in the fundamental production inventory model, in order to solve the economic production quantity (epq) we always fix both the demand quantity and the production quantity per day. but, in the real situation, both of them probably will have little disturbances every day. therefore, we should fuzzify both of them to solve the economic production quantity (q*) per cycle. using α-cut for defuzzific...

Exponential dispersion models, which are linear exponential families with a dispersion parameter, are the prototype response distributions for generalized linear models. The Tweedie families are those exponential dispersion models with power mean-variance relationships. The normal, Poisson, gamma and inverse Gaussian distributions are Tweedie families. Apart from these special cases, Tweedie di...

The properties of x-Exponantial Bathtub shaped failure rate model are discussed. Estimation process and failure rate behavior is explained.

In this paper we propose a new lifetime distribution which can handle bathtub-shaped, unimodal, increasing and decreasing hazard rate functions. The model has three parameters and generalizes the exponential power distribution proposed by Smith & Bain (1975) by inclusion of an additional shape parameter. Maximum likelihood estimation procedure is discussed. A small-scale simulation study examin...

We address the problem of estimating some unknown density on a bounded interval using some exponential models of piecewise polynomials. We consider a finite collection of such models based on a family of partitions. And we study the maximum-likelihood estimator built on a data-driven selected model among this collection. In doing so, we validate Akaike’s criterion if the partitions that we cons...

In this work, an ensemble of economic interacting agents is considered. The agents are arranged in a linear array where only local couplings are allowed. The deterministic dynamics of each agent is given by a map. This map is expressed by two factors. The first one is a linear term that models the expansion of the agent’s economy and that is controlled by the growth capacity parameter. The seco...