جستجوی مقالات مرتبط با کلیدواژه "ýposterior riský" در نشریات گروه "آمار"

ýIn this paper we propose a utility function and obtain the Bayese stimate and the optimum sample size under this utility functioný. ýThis utility function is designed especially to obtain the Bayes estimate when the posterior follows a gamma distributioný. ýWe consider a Normal with known meaný, ýa Paretoý, ýan Exponential and a Poisson distribution for an optimum sample size under the proposed utility functioný, ýso that minimizes the cost of samplingý. ýIn this processý, ýwe use Lindley cost function in order to minimize the costý. ýHereý, ýbecause of the complicated form of computationý, ýwe are unable to solve it analytically and use the mumerical methids to get the optimum sample size.

ýIn this paperý, ýa new distribution of the three-parameter lifetime model called the Marshall-Olkin Gompertz is proposed on the basis of the Gompertz distributioný. ýIt is a generalization of the Gompertz distribution having decreasing failure rate and can also be increasing and bathtub-shaped depending on its parametersý. ýThe probability density functioný, ýcumulative distribution functioný, ýhazard rate function and some mathematical properties of this model such asý, ýcentral momentsý, ýmoments of order statisticsý, ýRenyi and Shannon entropies and quantile function are derivedý. ýIn additioný, ýthe maximum likelihood of its parameters method is estimated and this new distribution compared with some Gompertz distribution generalizations by means of a set of real dataý.

ýIn this articleý, ýthe method of determining the optimal sample size is based on Linex asymmetric loss function and has been expressed through Bayesian method for normalý, ýPoisson and exponential distributionsý. ýThe desirable sample size has been calculated through numerical methodý. ýIn numerical methodý, ýthe average posterior risk is calculated and then it is added to the Lindley linear cost function to achieve the average of the total costý. ýThený, ýthe diagram of sample size is drawn in comparison to the average of total cost and eventuallyý, ýthe optimal sample size that minimizes the cost has been achieved.