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Article Citation - WoS: 6Citation - Scopus: 6Discrete Time Cold Standby Repairable System: Combinatorial Analysis(Taylor & Francis inc, 2016) Eryilmaz, SerkanIn this article, we obtain exact expression for the distribution of the time to failure of discrete time cold standby repairable system under the classical assumptions that both working time and repair time of components are geometric. Our method is based on alternative representation of lifetime as a waiting time random variable on a binary sequence, and combinatorial arguments. Such an exact expression for the time to failure distribution is new in the literature. Furthermore, we obtain the probability generating function and the first two moments of the lifetime random variable.Article Citation - WoS: 6Citation - Scopus: 6Anodic Oxidation of N-Substituted Dipyrrolyl Linked by Polyether Bridge(Taylor & Francis inc, 2006) Cihaner, AtillaElectroactive polymer containing polyether pseudo-cages has been synthesized by anodic oxidation of 1,11-bis(1,1-pyrrole)-3,6,9-trioxaundecane (I) using acetonitrile (ACN) as solvent and tetrabutylammonium perchlorate (TBAClO 4 ) as supporting electrolyte. Electrochemical behavior of monomer I and its polymer, poly-I , were studied using cyclic voltammetry (CV) and UV-VIS spectroscopic techniques. Also, a doping/dedoping study was carried out using electron spin resonance (ESR) and UV-VIS spectroscopic techniques. Thermal behavior of the product was studied using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA).Article Citation - WoS: 14Citation - Scopus: 17Reliability of Weighted k-out-of-n< g Systems Consisting of Two Types of Components and a Cold Standby Component(Taylor & Francis inc, 2017) Franko, C.; Eryılmaz, Serkan; Tutuncu, G. Y.; Eryilmaz, S.; Eryılmaz, Serkan; Industrial Engineering; Industrial EngineeringIn this article, the influence of a cold standby component to the reliability of weighted k-out-of-n: G systems consisting of two different types of components is studied. Weighted k-out-of-n: G systems are generalization of k-out-of-n systems that has attracted substantial interest in reliability theory because of their various applications in engineering. A method based on residual lifetimes of mixed components is presented for computing reliability of weighted k-out-of-n: G systems with two types of components and a cold standby component. Reliability and mean time to failure of different structured systems have been computed. Moreover, obtained results are used for defining optimal system configurations that can minimize the overall system costs.Article Polynomial Logistic Distribution Associated With a Cubic Polynomial(Taylor & Francis inc, 2017) Aksoy, Umit; Ostrovska, Sofiya; Ozban, Ahmet YasarLet P(x) be a polynomial monotone increasing on ( - , +). The probability distribution possessing the distribution function is called the polynomial logistic distribution with associated polynomial P. This has recently been introduced by Koutras etal., who have also demonstrated its importance for modeling financial data. In this article, the properties of the polynomial logistic distribution with an associated polynomial of degree 3 have been investigated in detail. An example of polynomial logistic distribution describing daily exchange rate fluctuations for the US dollar versus the Turkish lira is provided.Article Citation - WoS: 7Citation - Scopus: 8Modeling Systems With Two Dependent Components Under Bivariate Shock Models(Taylor & Francis inc, 2019) Eryilmaz, SerkanSeries and parallel systems consisting of two dependent components are studied under bivariate shock models. The random variables N-1 and N-2 that represent respectively the number of shocks until failure of component 1 and component 2 are assumed to be dependent and phase-type. The times between successive shocks are assumed to follow a continuous phase-type distribution, and survival functions and mean time to failure values of series and parallel systems are obtained in matrix forms. An upper bound for the joint survival function of the components is also provided under the particular case when the times between shocks follow exponential distribution.Article Citation - WoS: 5Citation - Scopus: 5Electrochemical Polymerization of Para-Substituted Haloanilines(Taylor & Francis inc, 2006) Cihaner, A; Önal, AMPolyhaloanilines: poly(4-fluoroaniline) (P4FAN), poly(4-chloroaniline) (P4CAN), and poly(4-bromoaniline) (P4BAN), are synthesized from para-substituted haloaniline monomers; 4-fluoroaniline (4FAN), 4-chloroaniline (4CAN), and 4-bromoaniline (4BAN), respectively, via constant potential electrolysis (CPE) in acetonitrile-water mixture (1:1 v/v) with NaClO4 as supporting electrolyte. Prior to CPE, electrochemical behavior of the monomers were investigated in organic medium utilizing cyclic voltammetry (CV). The course of CPE was monitored using in-situ UV-VIS spectroscopic technique. Characterization of polymer products have been carried out using FT-IR and NMR spectroscopic techniques and thermal behaviors were studied using differential scanning calorimeter (DSC). Polyhaloanilines synthesized by electrochemical oxidation were doped using iodine and the change in the paramagnetic behavior was monitored by ESR, UV-VIS, and FT-IR.Letter The Psychosocial Interventions for the Marmara Earthquake Children Survivors: The Lessons Learned(Taylor & Francis inc, 2021) Cihanoglu, Mine; Vatansever, Merve; Erden, Gulsen[No Abstract Available]Article Citation - WoS: 1Citation - Scopus: 2On the First Time of Ruin in Two-Dimensional Discrete Time Risk Model With Dependent Claim Occurrences(Taylor & Francis inc, 2018) Eryilmaz, SerkanThis article is concerned with a two-dimensional discrete time risk model based on exchangeable dependent claim occurrences. In particular, we obtain a recursive expression for the finite time non ruin probability under such a dependence among claim occurrences. For an illustration, we define a bivariate compound beta-binomial risk model and present numerical results on this model by comparing the corresponding results of the bivariate compound binomial risk model.Article Citation - WoS: 9Citation - Scopus: 8New Computational Methods for Classification Problems in the Existence of Outliers Based on Conic Quadratic Optimization(Taylor & Francis inc, 2020) Yerlikaya-Ozkurt, Fatma; Taylan, PakizeMost of the statistical research involves classification which is a procedure utilized to establish prediction models to set apart and classify new observations in the dataset from every fields of science, technology, and economics. However, these models may give misclassification results when dataset contains outliers (extreme data points). Therefore, we dealt with outliers in classification problem: firstly, by combining robustness of mean-shift outlier model and then stability of Tikhonov regularization based on continuous optimization method called Conic Quadratic Programming. These new methodologies are performed on classification dataset within the existence of outliers, and the results are compared with parametric model by using well-known performance measures.Article Citation - WoS: 1Citation - Scopus: 1Wavelet-Enhanced Sequence-To Modeling With Attention Mechanism for Short-Term Wind Power Forecasting(Taylor & Francis inc, 2025) Karaca, Burak; Unlu, Kamil Demirberk; Turkan, SemraElectricity load forecasting is crucial to managing electric systems, especially loads produced from renewable energy sources since the load from renewable energy sources varies when compared with nonrenewable sources. Turkey is producing an increasing amount of electricity from wind energy every day. The aim of this study is to introduce a hybrid deep learning model based on sequence-to-sequence learning (seq-2-seq), attention mechanisms, and wavelet transformation. Long Short-Term Memory (LSTM), Gated Recurrent Unit, and Bidirectional Long Short-Term Memory (BiLSTM) are used as decoders and encoders in the seq-2-seq model. We proposed six different models. All models are univariate type, requiring only the data itself. The model can be used on any wind farms without requiring the meteorological data. We test the proposed model on four different wind farms in Turkey: Soma, Biga, Balikesir, and Mersin. We utilize four different performance metrics to test the model's performance: mean squared error (MSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and coefficient of determinations (R2). The best model is seen as Wavelet-Seq2Seq-BiLSTM-LSTM at Biga Wind Farm, which achieved the best performance with a MAE of 0.127, an MSE of 0.001, a MAPE of 0.28, and an R2 of 0.997.
