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Now showing 1 - 10 of 16
  • Article
    Citation - WoS: 22
    Citation - Scopus: 24
    Computing reliability indices of repairable systems via signature
    (Elsevier Science Bv, 2014) Eryilmaz, Serkan
    The purpose of this paper is to show the usefulness of system signature for computing some important reliability indices of repairable systems. In particular, we obtain signature-based expressions for stationary availability, rate of occurrence of failure, and mean time to the first failure of repairable systems. Using these expressions we compute corresponding reliability indices of all systems with three and four components. Computational results are also presented for consecutive-k-within-m-out-of-n:F and m-consecutive-k-out-of-n:F systems. (C) 2013 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 17
    Citation - Scopus: 16
    A Study on Reliability of Coherent Systems Equipped With a Cold Standby Component
    (Springer Heidelberg, 2014) Eryilmaz, Serkan
    In this paper, we investigate the effect of a single cold standby component on the performance of a coherent system. In particular, we focus on coherent systems which may fail at the time of the first component failure in the system. We obtain signature based expressions for the survival function and mean time to failure of the coherent systems satisfying the abovementioned property.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 12
    The Behavior of Warm Standby Components With Respect To a Coherent System
    (Elsevier Science Bv, 2011) Eryilmaz, Serkan
    This paper is concerned with a coherent system consisting of active components and equipped with warm standby components. In particular, we study the random quantity which denotes the number of surviving warm standby components at the time of system failure. We represent the distribution of the corresponding random variable in terms of system signature and discuss its potential utilization with a certain optimization problem. (C) 2011 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 22
    Citation - Scopus: 23
    On Residual Lifetime of Coherent Systems After the rth Failure
    (Springer, 2013) Eryilmaz, Serkan
    In this article we study the residual lifetime of a coherent system after the rth failure, i.e. the time elapsed from the rth failure until the system failure given that the system operates at the time of the rth failure. We provide a mixture representation for the corresponding residual lifetime distribution in terms of signature. We also obtain some stochastic ordering results for the residual lifetimes.
  • Article
    On the Notion of Discrete-Time Signature and Some Associated Properties and Results
    (Cambridge University Press, 2026) Balakrishnan, Narayanaswamy; Yi, He; Goroncy, Agnieszka
    In this work, by considering coherent systems comprising independent components with discrete lifetimes, we introduce the notion of discrete-time signature and then discuss some of its properties. With the use of the introduced signature, a stochastic ordering result is also established. We then introduce transformation formulas for the discrete-time signature to facilitate the comparison of systems of different sizes. Some examples are also presented to illustrate all the results developed here.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Relative Behavior of a Coherent System With Respect To Another Coherent System
    (Springer, 2015) Eryilmaz, Serkan; Tutuncu, G. Yazgi
    In this paper, two independent coherent systems with different structures, and different types of components are considered. The remaining lifetime and the remaining number of working components of system I after the failure of the system II when we know that the system II fails before the system I are studied. In particular, signature-based expressions are obtained for the distribution of these conditional random variables. Illustrative examples are provided.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 8
    A new look at dynamic behavior of binary coherent system from a state-level perspective
    (Springer, 2014) Eryilmaz, Serkan
    In this paper we study lifetime properties of binary coherent systems from a state-level perspective. We define and study a system whose performance levels are determined by its total number of working components and structure. That is, the more working components the better performance level for the system. This enables us to make a more detailed analysis of a binary system. We obtain the distributions of the time that is spent by the system in a specific state subset and a specific state. Our analysis is based on the use of system signature. We also define an optimization problem concerned with the determination of the number of warm standby components.
  • Article
    Citation - Scopus: 22
    M-Consecutive System With Overlapping Runs: Signature-Based Reliability Analysis
    (Inderscience Publishers, 2012) Eryilmaz,S.
    Consecutive-k-out-of-n system and its generalisations have attracted substantial interest due to their applications to model telecommunications systems, oil pipeline systems, heating systems, etc. One of the most important generalisation of this system is an m-consecutive-k-out-of-n:F system. An m-consecutive-k-out-of-n:F system with overlapping runs is a system consisting of n linearly ordered components and fails if and only if there are at least m overlapping runs of k consecutive failures. For m = 1, the system is same with the usual consecutive-k-out-of-n:F system. In this paper, we study the reliability properties of such systems via system signature. In particular, we obtain a closed form expression for the signature of this system and use it to compute and evaluate several reliability characteristics of the system. Copyright © 2012 Inderscience Enterprises Ltd.
  • Article
    Citation - WoS: 18
    Citation - Scopus: 21
    Failure Rates of Consecutive k-out-of-n< Systems
    (Springer Heidelberg, 2012) Eryilmaz, Serkan; Navarro, Jorge
    Linear and circular consecutive k-out-of-n systems are very popular models in reliability theory, survival analysis, and biological disciplines and other related lifetime sciences. In these theories, the failure rate function is a key notion for measuring the ageing process. In this paper we obtain some mixture representations for consecutive systems and we apply a mixture-based failure rate analysis for both linear and circular consecutive systems. In particular, we analyze the limiting behavior of the system failure rate when the time increases and we obtain some ordering properties. We first consider the popular case of systems with components having independent and identically distributed lifetimes. In practice, these assumptions may fail. So we also study the case of independent non-identically distributed component lifetimes. This case has special interest when a cold-standby redundancy is used for some components. In this sense, we analyze where to place the best components in the systems. Even more, we also study systems with dependent components by assuming that their lifetimes are exchangeable. (C) 2011 The Korean Statistical Society. Published by Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 45
    Citation - Scopus: 48
    Age-Based Preventive Maintenance for Coherent Systems With Applications To Consecutive-k-out-of-n< and Related Systems
    (Elsevier Sci Ltd, 2020) Eryilmaz, Serkan
    This article presents a signature-based representation for the expected cost rate of age-based preventive maintenance policy for a binary coherent system consisting of independent exponential components, and then specializes the method to consecutive k-out-of-n system and its generalizations. According to the age-based preventive maintenance policy, the system is replaced at failure or before failure. For an arbitrary coherent system, the number of failed components at replacement time is a random variable. Thus, the expected cost per unit of time involves the mean number of failed components at replacement time. This mean is represented in terms of signature. Extensive numerical and graphical examples are presented for m-consecutive k-out-of-n:F and consecuthre-k-within-m-out-of-n:F systems.