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Now showing 1 - 10 of 21
  • Article
    Citation - WoS: 14
    Citation - Scopus: 15
    Dynamic Modeling of General Three-State k-out-of-n< Systems: Permanent-Based Computational Results
    (Elsevier Science Bv, 2014) Eryilmaz, Serkan; Xie, Min
    This paper is concerned with dynamic reliability analysis of three-state k-out-of-n:G systems. It is assumed that the components and the systems can be in three states: perfect functioning, partial performance and complete failure. Using the concept of permanent, we study marginal and joint survival functions for the lifetime of two different three-state k-out-of-n:G systems that consist of independent and nonidentical components. Illustrative examples are also provided for the components which follow the Markov degradation process. (C) 2014 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    On the Sums of Distributions of Order Statistics From Exchangeable Random Variables
    (Elsevier Science Bv, 2013) Eryilmaz, Serkan
    In this paper, we obtain an expression between the sums of the marginal distributions of the order statistics and the common marginal distribution of an exchangeable random sequence. We also derive an expression between the sums of the joint distribution of two order statistics and the two dimensional joint distribution of an exchangeable random sequence. (C) 2013 Elsevier B.V. All rights reserved.
  • 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: 3
    Citation - Scopus: 3
    On the Mean Number of Remaining Components in Three-State k-out-of-n< System
    (Elsevier Science Bv, 2015) Eryilmaz, Serkan; Eryılmaz, Serkan; Eryılmaz, Serkan; Industrial Engineering; Industrial Engineering
    A three-state k-out-of-n system with n independent components is considered, where the vector k of integers is determined by given fixed scalars k(1) and k(2) such that k(1), k(2) <= n. The mean number of components of each type either in a perfect functioning state or in a partially working state at the time of the system failure and at a time while the system is working are studied. An optimization problem concerned with the most economical value of n is also formulated. (C) 2015 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 61
    Citation - Scopus: 72
    Generalized δ-shock model via runs
    (Elsevier Science Bv, 2012) Eryilmaz, Serkan
    According to the delta-shock model, the system fails when the time between two consecutive shocks falls below a fixed threshold delta. This model has a potential application in various fields such as inventory, insurance and system reliability. In this paper, we study run-related generalization of this model such that the system fails when k consecutive interarrival times are less than a threshold delta. The survival function and the mean value of the failure time of the system are explicitly derived for exponentially distributed interarrival times. We also propose a new combined shock model which considers both the magnitudes of successive shocks and the interarrival times. (C) 2011 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 19
    Citation - Scopus: 20
    (k1< k2< km< System and Its Reliability
    (Elsevier Science Bv, 2019) Eryilmaz, Serkan
    This paper is concerned with a system consisting of multiple types of components and having (k(1), k(2),..., k(m))-out-of-n structure. The (k(1), k(2),.., k(m))-out-of-n system is a system consisting of n components of type i, i = 1, 2,..., m, and functions if at least k(1) components of type 1, k(2) components of type 2,..., k(m) components of type m work, n = Sigma(n)(i=1) n(i). The exact and approximate expressions are obtained for the survival function of the system under concern. The weighted-(k(1), k(2),..., k(m))-out-of-n system is also defined and studied. This weighted model is applied to evaluate the wind power system that consists of two wind plants. (C) 2018 Elsevier B.V. All rights reserved.
  • 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: 8
    Citation - Scopus: 11
    Joint Distribution of Run Statistics in Partially Exchangeable Processes
    (Elsevier Science Bv, 2011) Eryilmaz, Serkan
    Let {X-i}(i >= 1) be an infinite sequence of recurrent partially exchangeable random variables with two possible outcomes as either "1" (success) or "0" (failure). In this paper we obtain the joint distribution of success and failure run statistics in {X-i}(i >= 1). The results can be used to obtain the joint distribution of runs in ordinary Markov chains, exchangeable and independent sequences. (C) 2010 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    On Success Runs in a Sequence of Dependent Trials With a Change Point
    (Elsevier Science Bv, 2018) Eryilmaz, Serkan
    Let {X-i}(i=1)(n) be a sequence of n dependent binary trials such that the first n(1) in {X-i}(i=1)(n) are of type 1 and follow an exchangeable joint distribution denoted by L-1, and the last n2 elements in {X-i}(i=1)(n) are of type 2 and follow an exchangeable joint distribution denoted by L-2, where n(1) + n(2) = n. That is, the trials within the same group are exchangeable dependent, and the trials in different groups are dependent in a general sense. The exact distributions of the number of success runs of length k in {X-i}(i=1)(n) are obtained under nonoverlapping and at least schemes. (C) 2017 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 13
    Geometric Distribution of Order k With a Reward
    (Elsevier Science Bv, 2014) Eryilmaz, Serkan
    In this paper, we introduce and study geometric distribution of order k with a reward. In a sequence of binary trials, suppose that each time a success occurs a random reward is received. The distribution of the number of trials until the sum of consecutive rewards is equal to or exceeds the level k is called geometric distribution of order k with a reward. We obtain expressions for the probability mass function of this distribution. (C) 2014 Elsevier B.V. All rights reserved.