جستجوی مقالات مرتبط با کلیدواژه "سیستم‌های k از n" در نشریات گروه "آمار"

‎In this paper‎, ‎non-parametric inference is considered for $k$-component coherent systems‎, ‎when the‎ ‎system lifetime data is progressively type-II censored‎. ‎In these coherent systems‎, ‎it is assumed that the‎ ‎system structure and system signature are known‎. ‎Based on the observed progressively type-II censored‎, ‎non-parametric confidence intervals are calculated for the quantiles of component lifetime distribution‎. ‎Also‎, ‎tolerance limits for component lifetime distribution are obtained‎. ‎Non-parametric confidence intervals for quantiles and tolerance limits are obtained based on two methods‎, ‎distribution function method and W mixed matrix method‎. ‎Two numerical‎ ‎example is used to illustrate the methodologies developed in this paper‎.

In this article, the number of failures of a coherent system has been studied under the assumption that the lifetime of system components are non-distributed discrete and dependent random variables. First, the probability that exactly i Failure i=0, ..., n-k, in a system $k$ From n Under the condition that the system at the time of monitoring t it works it will be counted. In the following, this result has been generalized to other coherent systems. In addition, it has been shown that in the case of independence and co-distribution of component lifetimes, the probability obtained is consistent with the corresponding probability in the continuous state obtained in the existing literature. Finally, by presenting practical examples, the behavior of this probability has been investigated in the case that the system components have interchangeable and necessarily non-distributed lifetimes

This paper discusses stochastic comparisons of the parallel and series systems comprising multiple-outlier scale components. Under uncertain conditions on the baseline reversed hazard rate, hazard rate functions and scale parameters, the likelihood ratio, dispersive and mean residual life orders between parallel and series systems are established. We then apply the results for two exceptional cases of the multiple-outlier scale model: gamma and Pareto multiple-outlier components to illustrate the found results.

We propose an integrated approach for decision making about repair and maintenance of deteriorating systems whose failures are detected only by inspections. Inspections at periodic times reveal the true state of the system's components and preventive and corrective maintenance actions are carried out in response to the observed system state. Assuming a threshold-type policy, the paper aims at minimizing the long-run average maintenance cost per unit time by determining appropriate inspection intervals and a maintenance threshold. Using the renewal reward theorem, the expected cost per cycle and expected cycle length emerge as solutions of equations, and a recursive scheme is devised to solve them. We demonstrate the procedure and its outperformance over specific cases when the components' lifetime conforms to a Weibull distribution. Further, a sensitivity analysis is performed to determine the impact of the model's parameters. Attention has turned to perfect repair and inspection, but the structure allows different scenarios to be explored.

‎The censored data are widely used in statistical tests and parameters estimation‎. ‎In some cases e.g‎. ‎medical accidents which data are not recorded at the time of occurrence‎, ‎some methods such as interval censoring are used‎. ‎In this paper‎, ‎for a random sample uniformly distributed on the interval (0,θ) ‎the interval censoring have been used‎. ‎A consistent estimator of θ  and some asymptotically confidence intervals for θ are presented‎.

In this paper, we further investigate stochastic comparisons of the lifetime of parallel systems with heterogeneous independent Pareto components in term of the star order and convex order. It will be proved that the lifetime of a parallel system with heterogeneous independent components from Pareto model is always smaller than from the lifetime of another parallel system with homogeneous independent components from Pareto model in the sense of convex order. Also, under a general condition on the scale parameters, it is proved a result involving with star order.

ýIn this paperý, ýthe concept of joint reliability importance (JRI) of two or groups of components in a coherent system with independent components have been studiedý. ýThe JRI is defined as the rate at which the system reliability improves as the reliabilitiesý ýof the two or groups of components improveý.
ýGenerallyý, ýthe sign and the value of the JRI represent the type and theý ýdegree of interactions between components with respect to systems reliabilityý.