The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Jie Mi - One of the best experts on this subject based on the ideXlab platform.
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optimal burn in procedures in a generalized environment
International Journal of Reliability Quality and Safety Engineering, 2005Co-Authors: Jie MiAbstract:Burn-in procedure is a manufacturing technique that is intended to eliminate early Failures. In the literature, assuming that the Failure Rate Function of the products has a bathtub shape the properties on optimal burn-in have been investigated. In this paper burn-in problem is studied under a more general assumption on the shape of the Failure Rate Function of the products which includes the traditional bathtub shaped Failure Rate Function as a special case. An upper bound for the optimal burn-in time is presented under the assumption of eventually increasing Failure Rate Function. Furthermore, it is also shown that a nontrivial lower bound for the optimal burn-in time can be derived if the underlying lifetime distribution has a large initial Failure Rate.
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A general approach to the shape of Failure Rate and MRL Functions
Naval Research Logistics, 2004Co-Authors: Jie MiAbstract:Failure Rate and mean residual life are two important characteristics for studying reliability of products. In literature, some work studied the shape of Failure Rate Function based on the knowledge of the associated probability density Function; some other work investigated the shape of mean residual life Function based on the shape of the associated Failure Rate Function sepaRately for continuous case and discrete case. In this article, a general approach is developed which can be applied to the aforementioned studies. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004
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Shape and crossing properties of mean residual life Functions
Statistics & Probability Letters, 2003Co-Authors: Leonid Bekker, Jie MiAbstract:In addition to the CDF or density Function, the Failure Rate and mean residual life Functions are the other important Functions that can be used to characterize a lifetime. In the literature, much work on the properties of these quantities has been done. This paper points out and corrects some errors in the literature by giving a counterexample and new proofs. Moreover, it gives a more complete discussion on the shape of the mean residual life Function when the associated Failure Rate Function has a roller-coaster shape. It also discusses the crossing properties of two mean residual life Functions in detail, when the associated Failure Rate Functions have several crossing points.
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Optimal Burn-In Time and Eventually Ifr
Journal of The Chinese Institute of Industrial Engineers, 2003Co-Authors: Jie MiAbstract:Burn-in is a widely used technique for improving the quality of products after they have been produced. The quality of product can be measured by certain reliability characteristics such as survival probability, mean residual life, etc. In some situations, optimal burn-in need to be determined to maximize these reliability characteristics. However, burn-in is costly, and thus cost structure should be considered. Therefore, optimal burn-in time should also be determined to minimize certain cost Functions. In the literature, a ssuming the Failure Rate Function of the products has a bathtub shape it has been shown that the optimal burn-in time should not exceed the first change point of the Failure Rate Function. Instead of bathtub shaped Failure Rate Function, this paper considers the more general eventually IFR and has found that the optimal burn-in time for the objective Functions studied in the literature should not exceed the first wear-out point of the eventually IFR.
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Estimation of the change point of a distribution based on the number of failed test items
Metrika, 2001Co-Authors: Zhenmin Chen, Dietmar Ferger, Jie MiAbstract:This paper discusses the family of life distributions with Failure Rate Functions which decrease initially until a change point and remain constant thereafter. The paper focuses on the estimation for the change point of the Failure Rate Function. While point estimation of the change point of the Failure Rate Function has been discussed by some authors, one can hardly find any existing work on the interval estimation of the change point. In this paper, a method for constructing approximate confidence intervals for the change point is proposed. The proposed approximate confidence intervals are based on the number of failed test items at or before a fixed inspection time.
Y Tang - One of the best experts on this subject based on the ideXlab platform.
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on changing points of mean residual life and Failure Rate Function for some generalized weibull distributions
Reliability Engineering & System Safety, 2004Co-Authors: Y TangAbstract:Abstract The Failure Rate Function and mean residual life Function are two important characteristics in reliability analysis. Although many papers have studied distributions with bathtub-shaped Failure Rate and their properties, few have focused on the underlying associations between the mean residual life and Failure Rate Function of these distributions, especially with respect to their changing points. It is known that the change point for mean residual life can be much earlier than that of Failure Rate Function. In fact, the Failure Rate Function should be flat for a long period of time for a distribution to be useful in practice. When the difference between the change points is large, the flat portion tends to be longer. This paper investigates the change points and focuses on the difference of the changing points. The exponentiated Weibull, a modified Weibull, and an extended Weibull distribution, all with bathtub-shaped Failure Rate Function will be used. Some other issues related to the flatness of the bathtub curve are discussed.
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a modified weibull extension with bathtub shaped Failure Rate Function
Reliability Engineering & System Safety, 2002Co-Authors: Y TangAbstract:Abstract Models with bathtub-shaped Failure Rate Function are useful in reliability analysis, and particularly in reliability related decision making and cost analysis. The traditional Weibull distribution is, however, unable to model the complete lifetime of systems with a bathtub-shaped Failure Rate Function. In this paper, a new model, which is useful for modeling this type of Failure Rate Function, is presented. The model can also be seen as a generalization of the Weibull distribution. Parameter estimation methods are studied for this new distribution. Examples and results of comparison are shown to illustRate the applicability of this new model.
Maxim Finkelstein - One of the best experts on this subject based on the ideXlab platform.
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Stochastically Ordered Subpopulations and Optimal Burn-In Procedure
IEEE Transactions on Reliability, 2010Co-Authors: Ji Hwan Cha, Maxim FinkelsteinAbstract:Burn-in is a widely used engineering method which is adopted to eliminate defective items before they are shipped to customers or put into operation. In the studies of burn-in, the assumption of a bathtub shaped Failure Rate Function is usually employed, and optimal burn-in procedures are investigated. In this paper, however, we assume that the population is composed of two ordered subpopulations, and optimal burn-in procedures are studied in this context. Two types of risks are defined, and an optimal burn-in procedure is studied which minimizes the weighted risks. The joint optimal solutions for the optimal burn-in procedure, which minimizes the mean number of repairs during the field operation, are also investigated.
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on a terminating shock process with independent wear increments
Journal of Applied Probability, 2009Co-Authors: Maxim FinkelsteinAbstract:In extreme shock models, only the impact of the current, possibly fatal shock is usually taken into account, whereas in cumulative shock models, the impact of the preceding shocks is accumulated as well. In this paper we combine an extreme shock model with a specific cumulative shock model. It is shown that the proposed setting can also be interpreted as a generalization of the well-known Brown-Proschan model that describes repair actions for repairable systems. For a system subject to a specific process of shocks, we derive the survival probability and the corresponding Failure Rate Function. Some meaningful interpretations and examples are discussed.
Gholamhossein Hamedani - One of the best experts on this subject based on the ideXlab platform.
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The Zografos-Balakrishnan Log-Logistic Distribution : Properties and Applications
Journal of Statistical Theory and Applications, 2013Co-Authors: Gholamhossein HamedaniAbstract:The log-logistic distribution (also known as the Fisk distribution in economics) is widely used in survival analysis when the Failure Rate Function presents a unimodal shape. In this paper, we introduce the ZografosBalakrishnan log-logistic distribution, which contains the log-logistic distribution as a special model and has the four common shapes of the hazard hate Function. We present some properties of the new distribution and estimate the model parameters by maximum likelihood. An application to a real data set shows that the new distribution can provide a better fit than other classical lifetime models such as the exponentiated Weibull distribution.
Saralees Nadarajah - One of the best experts on this subject based on the ideXlab platform.
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Bathtub-shaped Failure Rate Functions
Quality & Quantity, 2008Co-Authors: Saralees NadarajahAbstract:The Failure Rate Function is an important quantity characterizing life phenomena. Ideally, one would expect this Function to exhibit a bathtub shape. In this paper, a comprehensive review of the known distributions that exhibit this shape is provided. Over 17 such distributions are identified. This review is especially important because almost all of the commonly known distributions in statistics do not exhibit the bathtub shape. Furthermore, it could serve as an important reference and encourage developments of further distributions that exhibit a bathtub shape.
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an f1 beta distribution with bathtub Failure Rate Function
American Journal of Mathematical and Management Sciences, 2006Co-Authors: Saralees Nadarajah, Samuel KotzAbstract:SYNOPTIC ABSTRACTBeta distributions are popular models for economic data. In this paper, a new multi modal beta distribution with bathtub shaped Failure Rate Function is introduced. The new distrib...
