Browsing by Author "Kan, Cihangir"

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The Distribution of Wind Power from a Dispersed Array of Wind Turbine Generators and Its Reliability Based Applications
(Elsevier, 2026) Eryilmaz, Serkan; Kan, Cihangir; Devrim, Yilser; Industrial Engineering; Energy Systems Engineering; 06. School Of Engineering; 01. Atılım University
In this paper, the probability distribution of wind power from a dispersed array of wind turbine sites is studied considering forced outage rates of wind turbines. The wind speeds at distinct sites are assumed to be dependent and the dependence is modeled by copulas. In particular, the probability distribution of the aggregate power from two sites is exactly derived. The probability distribution of the aggregate power is also derived under the particular case when site 1 consists of n1 identical wind turbines of type 1 and site 2 consists of n2 identical wind turbines of type 2. Numerical results are presented to illustrate the theoretical findings for a chosen copula function.
Citation - WoS: 12
Citation - Scopus: 13
Dynamic Reliability Evaluation of Consecutive-K System
(Taylor & Francis inc, 2011) Eryilmaz, Serkan; Kan, Cihangir; Industrial Engineering; 06. School Of Engineering; 01. Atılım University
A consecutive k-within-m-out-of-n:F system consists of n linearly ordered components and fails if and only if there are m consecutive components which include among them at least k failed components. This system model generalizes both consecutive k-out-of-n:F and k-out-of-n:F systems. In this article, we study the dynamic reliability properties of consecutive k-within-m-out-of-n:F system consisting of exchangeable dependent components. We also obtain some stochastic ordering results and use them to get simple approximation formulae for the survival function and mean time to failure of this system.
Citation - WoS: 2
Citation - Scopus: 2
The Mean Number of Failed Components in Discrete Time Consecutive K-Out F System and Its Application To Parameter Estimation and Optimal Age-Based Preventive Replacement
(Elsevier Sci Ltd, 2025) Eryilmaz, Serkan; Kan, Cihangir; Industrial Engineering; 06. School Of Engineering; 01. Atılım University
It is important in many respects to have information about the number of failed components in the system when or before a system fails. This paper investigates the mean number of failed components at or before the failure time of the linear consecutive k-out-of-n:F system which is a useful structure to model various engineering systems such as transportation and transmission systems. In particular, closed form expressions for the mean number of failed components within the system that have discretely distributed components lifetimes are obtained. The results are used to estimate the unknown parameter of the components' lifetime distribution and to find the optimal replacement cycle that minimizes the expected cost per unit of time under a certain age-based replacement policy.
Citation - WoS: 11
Citation - Scopus: 12
A NEW SHOCK MODEL WITH A CHANGE IN SHOCK SIZE DISTRIBUTION
(Cambridge Univ Press, 2021) Eryilmaz, Serkan; Kan, Cihangir; Industrial Engineering; 06. School Of Engineering; 01. Atılım University
For a system that is subject to shocks, it is assumed that the distribution of the magnitudes of shocks changes after the first shock of size at least d(1), and the system fails upon the occurrence of the first shock above a critical level d(2) (> d(1)). In this paper, the distribution of the lifetime of such a system is studied when the times between successive shocks follow matrix-exponential distribution. In particular, it is shown that the system's lifetime has matrix-exponential distribution when the intershock times follow Erlang distribution. The model is extended to the case when the system fails upon the occurrence of l consecutive critical shocks.
Citation - WoS: 15
Citation - Scopus: 23
On the Theoretical Distribution of the Wind Farm Power When There Is a Correlation Between Wind Speed and Wind Turbine Availability
(Elsevier Sci Ltd, 2020) Kan, Cihangir; Devrim, Yilser; Eryilmaz, Serkan; Industrial Engineering; Energy Systems Engineering; 06. School Of Engineering; 01. Atılım University
It is important to elicit information about the potential power output of a wind turbine and a wind farm consisting of specified number of wind turbines before installation of the turbines. Such information can be used to estimate the potential power output of the wind farm which will be built in a specific region. The output power of a wind turbine is affected by two factors: wind speed and turbine availability. As shown in the literature, the correlation between wind speed and wind turbine availability has an impact on the output of a wind farm. Thus, the probability distribution of the power produced by the farm depending on the wind speed distribution and turbine availability can be effectively used for planning and risk management. In this paper, the theoretical distribution of the wind farm power is derived by considering the dependence between turbine availability and the wind speed. The theoretical results are illustrated for real wind turbine reliability and wind speed data.
Citation - WoS: 72
Citation - Scopus: 74
Reliability and Optimal Replacement Policy for an Extreme Shock Model With a Change Point
(Elsevier Sci Ltd, 2019) Eryilmaz, Serkan; Kan, Cihangir; Industrial Engineering; 06. School Of Engineering; 01. Atılım University
An extreme shock model when there is a change in the distribution of the magnitudes of shocks is defined and studied. Such a model is useful in practice since a sudden change in environmental conditions may cause a larger shock. In particular, the reliability and mean time to failure of the system is obtained by assuming that the times between arrivals of shocks follow phase-type distribution. The optimal replacement policy that is based on a control limit is also proposed. The results are illustrated when the number of shocks until the change point follows geometric distribution.
Citation - WoS: 26
Citation - Scopus: 28
Reliability Assessment for Discrete Time Shock Models Via Phase-Type Distributions
(Wiley, 2021) Eryilmaz, Serkan; Kan, Cihangir; Industrial Engineering; 06. School Of Engineering; 01. Atılım University
In this paper, particular shock models are studied for the case when the times between successive shocks and the magnitudes of shocks have discrete phase-type distributions. The well-known shock models such as delta shock model, extreme shock model, and the mixed shock model which is obtained by combining delta and extreme shock models are considered. The probability generating function and recursive equation for the distribution of the system's lifetime are obtained for the cases when the interarrival times between shocks and the magnitudes of shocks are independent and when they are dependent. System reliability is computed for particular interarrival distributions such as geometric, negative Binomial and generalized geometric distributions.
Citation - WoS: 13
Citation - Scopus: 13
Reliability Assessment of a Discrete Time Cold Standby Repairable System
(Springer, 2021) Kan, Cihangir; Eryilmaz, Serkan; Industrial Engineering; 06. School Of Engineering; 01. Atılım University
This paper is concerned with the study of a discrete time repairable system consisting of one active and one standby component. The lifetime and repair time are assumed to have discrete phase-type distributions. The system's lifetime is represented as a compound random variable. A matrix-based expression for the probability generating function of the system's lifetime is obtained based on the phase characteristics of lifetime and repair time distributions. The probability generating function is then used to obtain the distribution of the system's lifetime. Reliability and hazard rate functions are computed and evaluated for some particular choices of lifetime and repair time distributions. The limiting behavior of the hazard rates is also investigated.
Citation - WoS: 36
Citation - Scopus: 39
Reliability Based Modeling and Analysis for a Wind Power System Integrated by Two Wind Farms Considering Wind Speed Dependence
(Elsevier Sci Ltd, 2020) Eryilmaz, Serkan; Kan, Cihangir; Industrial Engineering; 06. School Of Engineering; 01. Atılım University
Integrating multiple wind farms into power systems may reduce the fluctuation in total power output of wind farms and hence it decreases the system risk resulting from the wind speed variability. In this paper, a wind power system consisting of two wind farms is modeled and analyzed considering the dependence between wind speeds at two sites. In particular, the system is modeled as a threshold system and reliability values of wind turbines are also taken into account in capacity based calculations. The results are illustrated for the available bivariate wind speed data in the literature.