Abstract

This paper presents estimations of the generalized Rayleigh distribution model based
on grouped and censored data. The maximum likelihood method is used to derive
point and asymptotic con¯dence estimates of the unknown parameters. The results
obtained in this paper generalize some of those available in the literature. Finally, we
test whether the current model ¯ts a set of real data better than other models.

Abstract

A new class of bivariate Gompertz distributions is presented in this paper. The model introduced here is of Marshall-Olkin type. The used procedure is based on a latent random variable with exponential dis- tribution. A mixture of the suggested bivariate distributions is also derived. The obtained results in this paper generalize those of Marshall- Olkin bivariate exponential distribution and other present in the litera- ture.

Abstract

This paper discusses the reliability equivalences of a parallel- series system. It is assumed that the system components are independent and identical. Each has a constant failure rate. We assumed three difierent method to improve the system. Both the reliability function and the mean time to failure are used to derive two types of reliability equivalence factors. We also obtain the fractiles of the original and improved systems. We illustrate the results obtained with an application example.

Abstract

This paper investigates the queueing process of a bulk service queueing system under Bernoulli schedule. It also generalizes some known scenarios concerning the choice of service and re-service types. The queueing process is studied both in discrete time and in continuous time. Performance measures are derived and used to implement an optimal management policy of the system.

Abstract

This paper is concerned with the optimal control of a production inventory system with deteriorating items. It is assumed that the deterioration rate follows the two-parameter Weibull distribution. The continuous-review and periodic-review policies are investi- gated. In each case, optimality conditions are derived. Also, numerical illustrative examples are presented.

Abstract