Gülhayat Gölbaşı Şimşek

• Yıldız Technical University

Among several hydrological processes, river flow is an essential parameter that is vital for different water resources engineering activities. Although several methodologies have been adopted over the literature for modeling river flow, the limitation still exists in modeling the river flow time series curve. In this research, a functional quantile...

Ensuring sustainability in the global world today depends on perception management as well as financial management. In order to manage the perceptions, which are inherently latent variables as they are measured indirectly through their indicators, they must be accurately handled and modelled comprehensively. In the present study, a hybrid technique...

In this paper, we focus on parameter estimation for the odd Lindley half-logistic (OLiHL) distribution under a progressive type II censoring scheme based on binomial removals. The two estimation methods of maximum likelihood and maximum product spacing are employed for the one-parameter OLiHL distribution. To assess the performances of these two es...

In this study, we propose a generalized Marshall-Olkin exponentiated exponential distribution as a submodel of the family of generalized Marshall-Olkin distribution. Some statistical properties of the proposed distribution are examined such as moments, the moment-generating function, incomplete moment, and Lorenz and Bonferroni curves. We give five...

In this study, changes in the dependence structures of BRICS countries’ stock markets before and after the World Health Organization’s Covid-19 emergency declaration were examined using the time-varying (TV) copula method. The return series of the stock markets were divided into two periods, namely before COVID-19 (BC) and after COVID-19 (AC). The...

The aim of this paper is to investigate the effects of the macroeconomic factors to the movements of the asset returns of the banks in Turkey in terms of systemic risk from 2005 to 2018. In the study, Independent Component Analysis is applied for extracting driving factors of the asset returns of Turkish banks by decomposing the returns into its co...

Scalar-on-function logistic regression, where the response is a binary outcome and the predictor consists of random curves, has become a general framework to explore a linear relationship between the binary outcome and functional predictor. Most of the methods used to estimate this model are based on the least-squares type estimators. However, the...

Scalar-on-function logistic regression, where the response is a binary outcome and the predictor consists of random curves, has become a general framework to explore a linear relationship between the binary outcome and functional predictor. Most of the methods used to estimate this model are based on the least-squares type estimators. However, the...

Satisfaction and loyalty of passengers is important for a public transportation system provider especially if a competition exists between service providers. The factors affecting passenger satisfaction and loyalty must be determined by managers, operators, and decision makers. In this study, 900 passengers using High Speed Rail System between two...

The purpose of this paper is to measure the systemic risk contributions of Turkish banks and to identify the systemically important banks of Turkey during the period from 2005 to 2016. We apply the conditional value-at-risk (CoVaR) method proposed by Adrian and Brunnermeier (2009) using quantile regression. The study includes thirteen major banks o...

Determination of service quality measures that have the greatest impact on overall satisfaction of a system has many advantages both in favor of passengers and managers. Service quality of a transportation system mostly found by evaluation of passengers attitudes. Especially for managers, it is very important to have knowledge about the expectation...

Particle size and zeta potential of polyelectrolyte-protein binary conjugate and polyelectrolyte-metal-protein ternary complexes are among the most important factors affecting biopharmaceutical behavior such as bioavailability, dissolution and immune toxicity of these complexes. For this purpose, in the current study, the interactions between binar...

Given how important it is to provide superior value to customers and to maintain customer loyalty for a sustainable competitive advantage, the aim of this paper is to examine the relationships among relationship marketing components of – trust, competency, commitment, communication, and conflict handling, – relationship investment, relationship qua...

Abstract Purpose–The purpose of this paper is to investigate the impact of the importance, assigned by audiences, offactors such as people, movie features, script, price, promotion, and distribution channels (defined as a moviemarketing mix) on the audience’s buying intentions, as well as the impact of their buying intentions on wordof mouth (WOM)....

The purpose of this study is to examine the social impacts of events on participants’ satisfaction and whether loyalty is a result of this satisfaction when taking attendance to event into consideration. This study uses data from a sample of 542 participants who participated in the Kirkpinar Oil Wrestling Festival. Factor analysis was performed, an...

The foremost avoidable cause of disease and death is tobacco consume in almost every country and nearly all tobacco consume begins during youth and young adulthood. The use of tobacco products has increased in years and nearly half of tobacco consumers use more than two tobacco products. The paper is about the application of fuzzy clustering on the...

Canonical correlations are maximized correlation coefficients indicating the relationships between pairs of canonical variates that are linear combinations of the two sets of original variables. The number of non-zero canonical correlations in a population is called its dimensionality. Parallel analysis (PA) is an empirical method for determining t...

This paper presents the results of a survey conducted to measure the service quality of the high-speed railway system (HSRS) that operates between two cities in Turkey. The analysis had its basis in the impact score technique. The survey was prepared to ask users for satisfaction ratings of 61 attributes, which were constructed for the seven dimens...

This study aims to investigate the direct and indirect impacts of relationship marketing orientation (RMO) components-trust, competency, commitment, communication and conflict handling-on customers' relational response behaviours, such as satisfaction, loyalty, and positive word of mouth (WOM), in the Turkish mobile telecommunications industry. A t...

Preeclampsia (PE) is a hypertensive disease of pregnancy complicating 2-8% of all pregnancies. The exact pathophysiology still remains unknown. Growth arrest-specific 6 (Gas6) is a member of the vitamin K-dependent protein family and it has been suggested as a novel atherothrombotic risk factor with anti-angiogenic and pro-atherogenic properties. T...

The aim of this research is to build a conceptual model to provide clear understanding of customer loyalty. Structural equation modeling as a data analysis tool has been used to analyze the data collected from 1530 customers of four major supermarkets chains in Turkey. The results of this study indicate that customer satisfaction among others is th...

In the common factor model for subtest scores, several reliability coefficients, including Cronbach's α, have been found to be biased. In this article, we introduce a new coefficient, G, or Generalized , which is a generalized version of Armor's  coefficient and is equal to the true reliability when the dimensions are orthogonal and the measures...

The objective of this paper is to model which aims to describe the extent to which customer intention to repurchase a service is influenced by customer perceptions of service quality, customer perceptions of product quality, comparative price perceptions, discount perceptions, trust, value, and customer satisfaction were considered as the major fac...

Default correlation is a crucial in risk management. The aim of this paper is to introduce a new method for measuring default correlation. In this paper we recall tetrachoric correlation coefficient which is a measure of association between two continuous variables that have each been measured on a dichotomous scale. We presented the applicability...

In the behavioral sciences, response variables are often non-continuous, ordinal variables. Conventional structural equation models (SEMs) have been generalized to accommodate ordinal responses. In this study, three different estimation methods on real data were performed with ordinal variables. Empirical results obtained from the different estimat...

The mathematical performance of the students is an essential factor in the field of mathematics education, because the mathematics performance symbolizes the success in the mathematics education. After investigated the effects of student characteristics of Turkish students participating PISA 2009 survey on mathematic achievement through MIMIC model...

Customer satisfaction and loyalty are very important to develop the retail strategies. The main goal of this study is to examine the determinants of customer satisfaction by customer and store related factors. In this study, using structural equation modeling, structural determinants of satisfaction are investigated in the context of loyalty models...

Social sciences research often entails the analysis of data with a multilevel structure. An example of multilevel data is containing measurement on university students nested within instructors. This paper concentrate on multilevel analysis of structural equation modeling with educational data. Data used in this study were gathered from 17647 unive...