Özkut, Cemal Murat

Özkut, Cemal Murat

Profile URL

https://hdl.handle.net/20.500.14365/6674

Name Variants

Ozkut, C. M.
Ozkut, M.
Ozkut, Murat
Ozkut, Cemal Murat
Ozkut, C. Murat

Email Address

murat.ozkut@ieu.edu.tr

Main Affiliation

02.02. Mathematics

Status

Current Staff

Sustainable Development Goals

Journal	Count

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Current Page: 1 / NaN

Scopus Quartile Distribution

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Scholarly Output Search Results

Now showing 1 - 10 of 21

Citation - WoS: 4
Citation - Scopus: 4
The (n - K+1)-Out Concomitant System Having M Subcomponents and Its Reliability
(Elsevier, 2021) Ozkut, Murat
We consider an (n - k + 1)-out-of-n concomitant system consisting of n components each having two subcomponents. This system functions if and only if at least (n-k+1) of the first subcomponents function, and the second subcomponents of working first components also function. The reliability of the proposed system is derived. The effect of dependent subcomponents on the system reliability relative to independent subcomponents is discussed. The system with two subcomponents is extended to the system with m subcomponents. Comparative numerical results and graphical representations are provided. (C) 2020 Elsevier B.V. All rights reserved.
Marshall-Olkin Type Shock Models and Their Applications
(İzmir Ekonomi Üniversitesi, 2015) Özkut, Cemal Murat; Bayramoğlu, İsmihan
Klasik Marshall-Olkin tipi şok modelleri ve bu modellerin modifikasyonlarında, iki ya da daha fazla bileşen içeren sistem farklı kaynaklar tarafından rastgele zamanlarda üretilen şoklara maruz kalır ve sistemin ilgili bileşenleri yok olur. Marshall-Olkin tipi şok modellerinden farklı olarak, üretilen şokun şiddetinin önceden belirlenen eşik değerden yüksek olduğu taktirde ilgili bileşenin imha edileceğini aksi takdirde bileşenin çalışmaya devam edeceğini varsaydık. Daha iyi anlatmak gerekirse, şok zamanı ve şiddetinin bağımlı iki değişkenli dağılıma sahip olduğunu varsaydık. Şokların şiddetlerinin dikkate alınması gerekliliği yaklaşımı bize şok modellerin gerçek yaşam uygulamalarında ortaya çıkan gereksinimleri karşılamamıza izin veriyor. Bu tez çalışmasında, şok zamanı ve şok şiddetinin ortak dağılımını içeren yeni iki değişkenli dağılım sınıfı elde edildi. Yeni iki değişkenli dağılımın bağımlılık özellikleri çalışıldı. Bileşenlerin yaşam süreleri ve şok zamanlarının ikili dağılımlarının verildiği farklı örnekler için, bileşenlerin yaşam sürelerinin ortak dağılımları incelendi. Ayrıca önerilen modelin genişletilmiş çok değişkenli modeli ayrıca tartışıldı. Önerilen modelin tekil dağılım fonksiyonu ve tamamıyla sürekli fonksiyonun kombinasyonu şeklinde olması ortak dağılımın bilinmeyen parametrelerinin en çok olabilirlik tahmin edicilerini bulmayı zorlaştırmaktadır. Bu yüzden, beklenti maximizasyonu algoritması kullanarak önerilen ikili ve çoklu modellerin veri setlerini inceledik. Ayrıca, önerilen ikili ve çoklu modellerin bilinmeyen parametrelerinin asimptotik güven aralıkları oluşturuldu.
Citation - WoS: 21
Citation - Scopus: 24
Optimization Problems for a Parallel System With Multiple Types of Dependent Components
(Elsevier Sci Ltd, 2020) Eryılmaz, Serkan; Ozkut, Murat
This paper is concerned with two optimization problems for a parallel system that consists of dependent components. First, the problem of finding the number of elements in the system that minimizes the mean cost rate of the system is considered. The second problem is concerned with the optimal replacement time of the system. Previous work assumes that the components are independent. We discuss the impact of dropping this assumption. In particular, we numerically examine how the dependence between the components affects the optimal number of units and replacement time for the system which minimize mean cost rates. We first consider the case when the components are exchangeable and dependent, i.e. the system consists of single type of dependent components. Subsequently, we consider a system that consists of multiple types of dependent components. Comparative numerical results are presented for particularly chosen dependence models.
Citation - WoS: 18
Citation - Scopus: 20
Reliability of Coherent Systems With a Single Cold Standby Component
(Elsevier, 2015) Franko, Ceki; Özkut, Cemal Murat; Kan, Cihangir
In this paper, the influence of a cold standby component on a coherent system is studied. A method for computing the system reliability of coherent systems with a cold standby component based on signature is presented. Numerical examples are presented. Reliability and mean time to failure of different systems are computed. (C) 2014 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Analysis of Joint Reliability Importance in Linear M-Consecutive L-Out System
(Ankara Univ, Fac Sci, 2020) Kan, Cihangir; Ozkut, Murat
Combinatorial techniques have an important role to compute the joint reliability importance (JRI) of some coherent systems. We obtain combi- natorial formula for calculation of the JRI of two components in a generalised version of consecutive type systems consisting of n linearly ordered components such that system fails if and only if (i§) there are at least m l-overlapping runs of k consecutive failed components (n m(k l) + l; l < k). Overlapping runs mean having common elements which is denoted by l: We concentrate on both s-independent & identical components and exchangeable components. Explicit combinatorial formulae are provided for computing the JRI of the above mentioned cases. For both cases, we also compare the results with lin- ear m-consecutive-k-out-of-n:F system (nonoverlapping case when l = 0). In addition, some numerical and illustrative examples are presented.
Citation - WoS: 56
Citation - Scopus: 58
Reliability Analysis Under Marshall-Olkin Run Shock Model
(Elsevier, 2019) Ozkut, Murat; Eryılmaz, Serkan
In this paper, a new shock model called Marshall-Olkin run shock model is defined and studied. According to the model, two components are subject to shocks that may arrive from three different sources, and component i fails when it is subject to k consecutive critical shocks from source i or k consecutive critical shocks from source 3, i = 1, 2. Reliability and mean residual life functions of such components are studied when the times between shocks follow phase-type distribution. (C) 2018 Elsevier B.V. All rights reserved.
Citation - WoS: 14
Citation - Scopus: 18
On Marshall-Olkin Type Distribution With Effect of Shock Magnitude
(Elsevier, 2014) Ozkut, Murat; Bayramoglu (Bairamov), Ismihan
In classical Marshall-Olkin type shock models and their modifications a system of two or more components is subjected to shocks that arrive from different sources at random times and destroy the components of the system. With a distinctive approach to the Marshall-Olkin type shock model, we assume that if the magnitude of the shock exceeds some predefined threshold, then the component, which is subjected to this shock, is destroyed; otherwise it survives. More precisely, we assume that the shock time and the magnitude of the shock are dependent random variables with given bivariate distribution. This approach allows to meet requirements of many real life applications of shock models, where the magnitude of shocks is an important factor that should be taken into account. A new class of bivariate distributions, obtained in this work, involve the joint distributions of shock times and their magnitudes. Dependence properties of new bivariate distributions have been studied. For different examples of underlying bivariate distributions of lifetimes and shock magnitudes, the joint distributions of lifetimes of the components are investigated. The multivariate extension of the proposed model is also discussed. (C) 2014 Elsevier B.V. All rights reserved.
Comparing the Performance of Wind Speed Distributions: the Case of Central and Southern Iraq
(İzmir Ekonomi Üniversitesi, 2020) Shalash, Othman Safaa Taha Al; Özkut, Cemal Murat
Rüzgar enerjisi üretimini uygun şekilde tahmin etmek için rüzgar hızı karakteristiklerinin belirlenmesi için daha fazla çaba harcamamız gerekir, çünkü bu tür bir tespit tahmin yaklaşımında önemli bir rol oynamaktadır. Bunu takiben, rüzgar hızının modellenmesi için yaygın olarak uygulanan en önemli dağılımlardan biri Weibull dağılımıdır. Bu dağılım esas olarak rüzgar hızını uygun şekilde modellemek için istatistiksel hesaplamalara dayanmaktadır. Pratik uygulamalarda yoğun olarak kullanılmasına rağmen, doğruluğu tüm rüzgar rejimlerini modellemek için tamamen uygun olmayabilir. Bu nedenle, alternatif bir yaklaşım olabilecek veya bazı durumlarda Weibull dağılımının yerini alabilecek çeşitli dağılımlar, rüzgar hızını en uygun şekilde modelleyebilir. Araştırmamızda, Weibull dağılımından farklı bir yaklaşım olarak kullanılacak diğer dağılımlardan yararlanıyoruz (Lognormal, Burr tip XII, Genelleştirilmiş Aşırı değer, Gumbel, Gama, Ters Gauss, Genelleştirilmiş Aşırı değer, ve Rayleigh). Çalışmamızın temel amacı, farklı rejimlerde var olabilen rüzgar hızının tutarsız davranışının yeterli şekilde gerçekleştirilmesini sağlayan Weibull dağılımına alternatif olarak uygun bir dağılım tanımlamaktır. Uygulama bölümünde geçtiğimiz on yıl boyunca Irak Meteoroloji Örgütü ve Sismoloji - Ulaştırma Bakanlığı'ndan çeşitli veriler toplandı. Uygun rüzgar hızı dağılımını belirlemek için çeşitli testler seçildi.
Citation - WoS: 3
Citation - Scopus: 3
Comparison of the Replacement Policy in K-Out Systems Having Dependent Components
(Sage Publications Ltd, 2022) Ozkut, Murat
This paper is concerned with two optimization problems for a k-out-of-n system consisting of dependent components such as finding the number of elements in the system that minimize the system's mean cost rate and the system's optimal replacement time. In previous studies, either system consisting of independent components or parallel systems, a particular case of the present study, was examined. In particular, we numerically examine how the components' dependence affects the optimal number of units and replacement time for the system, minimizing mean cost rates. We consider when the components are exchangeable and dependent, that is, the system consists of dependent components. For three vastly used Clayton, Gumbel, and FGM copula functions, comparative numerical results are presented.
Citation - WoS: 3
Citation - Scopus: 3
Analyzing the Multi-State System Under a Run Shock Model
(Cambrıdge Unıv Press, 2024) Özkut, Cemal Murat; Kan, Cihangir; Franko, Ceki; Ozkut, Murat
A system experiences random shocks over time, with two critical levels, d1 and d2, where $d_{1} \lt d_{2}$. k consecutive shocks with magnitudes between d1 and d2 partially damaging the system, causing it to transition to a lower, partially working state. Shocks with magnitudes above d2 have a catastrophic effect, resulting in complete failure. This theoretical framework gives rise to a multi-state system characterized by an indeterminate quantity of states. When the time between successive shocks follows a phase-type distribution, a detailed analysis of the system's dynamic reliability properties such as the lifetime of the system, the time it spends in perfect functioning, as well as the total time it spends in partially working states are discussed.