İşletme Fakültesi

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Citation - WoS: 52
Citation - Scopus: 66
Assessing Quality in Higher Education: New Criteria for Evaluating Students' Satisfaction
(Taylor & Francis, 2011) Zineldin, Mosad; Akdag, Hatice Camgöz; Vasicheva, Valentina
The aim of this research is to present a new quality assurance model (5Qs) and to examine the major factors affecting students' perception of cumulative satisfaction. The model includes behavioural dimensions of student satisfaction. The factors included in this cumulative summation are technical functional infrastructure interaction and atmosphere of higher education institutions. This study concerns students in higher education institutions in Istanbul Turkey. The questionnaire contains a total of 39 items (attributes) of newly developed five quality dimensions (5Qs). A total of 1641 complete and usable questionnaires was received. Frequency analysis factor analysis and reliability analysis were used for analysing the data collected. Inspection of scree plot and eigenvalues enabled the analysis to reduce the 39 quality attributes to seven factors. The results can be used by higher education institutions to re-engineer and re-design creatively their quality-management processes and the future direction of their more effective education quality strategies. © 2011 Taylor & Francis.
Citation - WoS: 11
Citation - Scopus: 11
Bivariate Pseudo-Gompertz Distribution and Concomitants of Its Order Statistics
(Elsevier Science Bv, 2013) Yorubulut, Serap; Gebizlioğlu, Ömer Lütfi
This paper presents a new bivariate Pseudo-Gompertz distribution that sprouts from the classical Gompertz distribution and possesses the features of pseudo-distribution functions. In addition to some standard properties of the proposed distribution distributions of order statistics and their concomitants for samples drawn from the new distribution are obtained. The survival and hazard functions of the concomitants are shown and their values are tabled. Interpretations of the results are given in connection with risk events and risk management. (C) 2013 Elsevier B.V. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 6
Competition in Turkish Banking: Impacts of Restructuring and the Global Financial Crisis
(Wiley, 2014) Yıldırım, Canan
This paper investigates the evolution of competition in the Turkish banking industry by taking into account the transformation in the sector in the aftermath of the country's financial crisis of 2000 to 2001 and the global financial crisis. The results demonstrate that the level of competition in the system did not increase despite the restructuring that was undertaken and the increased foreign bank participation. In addition the level of competition in the sector deteriorated during the global crisis. There is also some evidence that the market power of banks with different ownership characteristics varied and did not converge over time.
Citation - WoS: 6
Citation - Scopus: 10
A Competitive Intelligence Practices Typology in an Airline Company in Turkey
(Springer, 2020) Şahin, Murat; Bisson, Christophe
Oil prices, political instabilities, travel legislations, and many other competitive factors make it essential for any international airline with the instinct to survive to be on constant watch in such a fiercely competitive environment. To meet this need, it is vital for international airline companies to integrate competitive intelligence (CI) into their strategy building process. In this study, we create for the first time a typology of competitive intelligence practices of an international airline company (in Turkey), based on the model developed by (Wright et al.Journal of Strategic Marketing, 20(1), 19-33,2012), and it is one of the very first to investigate Competitive intelligence in this sector. Furthermore, we made a two-step cluster analysis to uncover hidden clusters that change the way of thinking within the company. Our findings show where the company would need to make improvements on the 6 strands of the model which are attitude, gathering, use, location, technological support, and IT support. Yet, that could lead towards stronger business performance. It might also inspire other companies of the airline sector and beyond.
Citation - WoS: 5
Citation - Scopus: 6
Computing Finite Time Non-Ruin Probability and Some Joint Distributions in Discrete Time Risk Model With Exchangeable Claim Occurrences
(Elsevier Science, 2017) Eryilmaz, Serkan; Gebizlioğlu, Ömer Lütfi
In this paper we study a discrete time risk model based on exchangeable dependent claim occurrences. In particular we obtain expressions for the finite time non-ruin probability and the joint distribution of the time to ruin the surplus immediately before ruin and the deficit at ruin. An illustration of the results is given and some implications of the results are provided. Comparisons are made with the corresponding results for the classical compound binomial model of independent and identically distributed claim occurrences. (C) 2016 Elsevier E.V. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 2
Continuous Dependence on Data for a Solution of the Quasilinear Parabolic Equation With a Periodic Boundary Condition
(Springer International Publishing Ag, 2013) Kanca, Fatma; Baglan, Irem Sakinc; Kanca, Fatma
In this paper we consider a parabolic equation with a periodic boundary condition and we prove the stability of a solution on the data. We give a numerical example for the stability of the solution on the data.
Citation - Scopus: 122
Corporate Social Responsibility and Financial Performance: the Moderating Role of Ownership Concentration in Turkey
(MDPI, 2019) Akben Selçuk, Elif
The objective of this study is to investigate the impact of corporate social responsibility (CSR) engagement on firm financial performance in a developing country, Turkey, and to analyze the moderating role of ownership concentration in the CSR-financial performance relationship. The sample consists of non-financial public firms listed on the Borsa Istanbul (BIST)-100 index and covers the period between 2014 and 2018. Empirical results using an instrumental variable approach show that corporate social responsibility has a positive relationship with financial performance. Furthermore, findings indicate that this relationship is negatively moderated by ownership concentration even when endogeneity is controlled for.
Citation - WoS: 5
Citation - Scopus: 5
Designing of Multi-Targeted Molecules Using Combination of Molecular Screening and in Silico Drug Cardiotoxicity Prediction Approaches
(Elsevier Science Inc, 2014) Buturak, Birce; Durdagi, Serdar; Noskov, Sergei Y.; Ildeniz, A. Tugba Ozal
We have previously investigated and reported a set of phenol- and indole-based derivatives at the binding pockets of carbonic anhydrase isoenzymes using in silico and in vitro analyses. In this study we extended our analysis to explore multi-targeted molecules from this set of compounds. Thus 26 ligands are screened at the binding sites of 229 proteins from 5 main enzyme family classes using molecular docking algorithms. Derived docking scores are compared with reported results of ligands at carbonic anhydrase I and II isoenzymes. Results showed potency of multi-targeted drugs of a few compounds from investigated ligand set. These promising ligands are then tested in silico for their cardiotoxicity risks. Results of this work can be used to improve the desired effects of these compounds by molecular engineering studies. In addition these results may lead to further investigation of studied molecules by medicinal chemists to explore different therapeutic aims. (C) 2014 Elsevier Inc. All rights reserved.
Citation - WoS: 6
Citation - Scopus: 7
Determination of an Unknown Heat Source From Integral Overdetermination Condition
(Springer International Publishing, 2018) Baglan, İrem Sakınç; Kanca, Fatma; Mishra, Vishnu Narayan
In this research we consider a coefficient problem of an inverse problem of a quasilinear parabolic equation with periodic boundary and integral over determination conditions. We prove the existence uniqueness and continuously dependence upon the data of the solution by iteration method. Also we consider numerical solution for this inverse problem using linearization and finite difference method is proved.
Citation - WoS: 4
Citation - Scopus: 5
Development of a Supervised Classification Method To Construct 2d Mineral Maps on Backscattered Electron Images
(Tubitak, 2020) Camalan, Mahmut; Çavur, Mahmut
The Mineral Liberation Analyzer (MLA) can be used to obtain mineral maps from backscattered electron (BSE) images of particles. This paper proposes an alternative methodology that includes random forest classification, a prospective machine learning algorithm, to develop mineral maps from BSE images. The results show that the overall accuracy and kappa statistic of the proposed method are 97% and 0.94, respectively, proving that random forest classification is accurate. The accuracy indicators also suggest that the proposed method may be applied to classify minerals with similar appearances under BSE imaging. Meanwhile, random forest predicts fewer middling particles with binary and ternary composition, but the MLA predicts more middling particles only with ternary composition. These discrepancies may arise because the MLA, unlike random forest, may also measure the elemental compositions of mineral surfaces below the polished section.
Citation - Scopus: 15
Does Financial Flexibility Enhance Firm Value? a Comparative Study Between Developed and Emerging Countries
(VGTU, 2020) Bilyay Erdoğan, Seda
This paper investigates the effect of financial flexibility on firm value, on a comparative basis between developed and emerging countries in Europe. Our dataset covers 4,334 companies from 15 developed and 1,436 companies from 6 emerging countries in Europe for the period between 2000 and 2016. First, depending on companies’ maintenance of leverage that is below-predicted levels for a successive number of years, I identify the financially flexible companies in the sample. Second, I examine whether financial flexibility affects firm value. Our results demonstrate that firms’ financial flexibility positively contributes to firm value in all estimations. Furthermore, this study presents unprecedented evidence that the effect of financial flexibility on firm value is more significant for emerging countries when compared to developed countries in Europe. Moreover, I demonstrate for the first time that firm characteristics, including firm size and age, which proxy for asymmetric information within a company, negatively moderate the relationship between flexibility and firm value. Managers, both in developed and in emerging countries, who aim to surge their firm value up, should give importance to the maintenance of financial flexibility in their capital structure decisions. Last, managers of relatively smaller and younger companies should put more emphasis on becoming financially flexible if they want to improve their firms’ value.
Citation - WoS: 2
Citation - Scopus: 2
Does governance affect corporate diversification behaviour in emerging markets?
(Routledge Journals, Taylor & Francıs Ltd, 2020) Sener, Pınar; Akben Selçuk, Elif
This paper investigates the role of firm-level and country-level governance on corporate diversification behaviour in emerging markets. The results show that firms with combined leadership structure are more diversified while firms with more independent directors are less diversified. There is a U-shaped relationship between ownership concentration and diversification. No significant association between country-level shareholder protection and diversification is demonstrated.
Citation - WoS: 5
Citation - Scopus: 9
Eurasian Geopolitics and Financial Crisis: Transforming Russian-Turkish Relations From Geopolitical Rivalry To Strategic Cooperation
(Routledge Journals Taylor & Francis Ltd, 2010) İşeri, Emre
[Abstract Not Available]
Citation - WoS: 22
Exploring the Impact of Sustainability on Corporate Financial Performance Using Discriminant Analysis
(MDPI, 2020) Keskin, Ayşe İrem; Dinçer, Banu; Dinçer, Caner
The impact of sustainability on corporate financial performance has been an important subject of both academic and professional debate since the 1990s. However, there is a lack of consensus in the literature, and studies from developing countries remain scarce. Accordingly, this study uses discriminant analysis to shed light on the variables that discriminate between sustainable and non-sustainable companies using the companies included in Borsa Istanbul (BIST100) (Istanbul Stock Exchange) and the Borsa Istanbul Sustainability Index for a three-year period. Financial and market variables are used in the analysis. Financial variables include the return on equity (ROE), return on assets (ROA), leverage ratios, and company size. The analysis also incorporates market variables such as alpha, beta, volatility, earnings per share, and the price to book ratio. The results show that the relationship between sustainability and performance is significantly influenced by the company size, leverage, volatility, and price to book ratio. The large companies are considered to be more sustainable as their commitment is well recognized. In this way, they attract more investors. Therefore, their stock prices are less volatile and achieve a better price to book ratio. They obtain easy access to external financing compared to companies considered to be non-sustainable. Moreover, they are less volatile in the market and better valued by investors.
Citation - WoS: 34
Citation - Scopus: 49
Factors Affecting Firm Competitiveness: Evidence From an Emerging Market
(MDPI, 2016) Akben Selçuk, Elif
The objective of this study is to investigate the factors affecting firm competitiveness in an emerging marketTurkey. In the paper competitiveness is proxied by a firm's financial performance. The empirical analysis is based on firms listed on Borsa Istanbul and covers the period between 2005 and 2014. Results from a firm-level panel data model indicate that return on assets is positively related to firm size international sales liquidity and growth and negatively related to leverage and R&D expenditures. On the other hand gross profit margin is positively related to size and international sales and negatively related to leverage and R&D expenditures. Finally results show that Tobin's Q ratio is higher for firms with higher levels of debt and higher liquidity levels.
Citation - WoS: 11
Citation - Scopus: 14
Family Involvement, Corporate Governance and Dividends in Turkey
(Emerald Group Publishing Limited, 2019) Sener, Pinar; Akben Selçuk, Elif
Purpose: The purpose of this paper is to investigate the relationship between dividends and family involvement as well as corporate governance characteristics among Turkish public firms. Design/methodology/approach: Using panel data on Turkish firms listed on the Borsa Istanbul 100 index for 2006–2014 three models are estimated. For the first two models where the dependent variables are the dividend payout ratio and dividend yield respectively tobit regressions are run. The last model which employs a dividend dummy as the dependent variable is estimated with logistic regression. Findings: There is a positive and concave relationship between family ownership and dividends. The existence of a family chairman reduces dividends. There is a positive association between board size and dividends and this relationship is weaker for firms with higher levels of family ownership. Finally the ratio of independent directors on the board is negatively associated with dividends. Practical implications: The findings imply that firms with substantial family ownership and active family participation in management are more likely to send a negative signal to minority shareholders by paying lower dividends. In addition minority shareholders should pay attention to the board structure of firms in which they invest. Originality/value: This study is one of the few to analyze the nonlinear relationship between family ownership and dividend payments as well as the role of family management in a developing country. Second it investigates the role of board characteristics in explaining dividend payment decisions. © 2019 Emerald Publishing Limited.
Citation - WoS: 4
Citation - Scopus: 6
Harmony Search Algorithm Based Management of Distributed Energy Resources and Storage Systems in Microgrids
(MDPI, 2020) Ceylan, Oğuzhan; Sezgin, Mustafa Erdem; Goel, Murat; Verga, Maurizio; Lazzari, Riccardo; Kwaye, Marcel Pendieu; Sandroni, Carlo
Microgrids are composed of distributed energy resources (DERs), storage devices, electric vehicles, flexible loads and so on. They may either operate connected to the main electricity grid (on-grid operation) or separated from the grid (islanded operation). The outputs of the renewable energy sources may fluctuate and thus can cause deviations in the voltage magnitudes especially at islanded mode. This may affect the stability of the microgrids. This paper proposes an optimization model to efficiently manage controllable devices in microgrids aiming to minimize the voltage deviations both in on-grid and islanded operation modes. RSE Distributed Energy Resources Test Facility (DER-TF), which is a low voltage microgrid system in Italy, is used to verify the algorithm. The test system's data is taken through an online software system (REDIS) and a harmony search based optimization algorithm is applied to control the device parameters. The experimental results show that the harmony search based optimization approach successfully finds the control parameters, and can help the system to obtain a better voltage profile.
Citation - WoS: 5
Citation - Scopus: 5
Heuristic Methods for Postoutage Voltage Magnitude Calculations
(TUBITAK Scientific & Technical Research Council Turkey, 2016) Ceylan, Oğuzhan; Özdemir, Aydogan; Dağ, Hasan
Power systems play a significant role in every aspect of our daily lives. Hence their continuation without any interruption (or with the least duration of interruption due to faults or scheduled maintenances) is one of the key aims of electrical energy providers. As a result electrical energy providers need to check in great detail the integrity of their power systems by performing regular contingency studies of the equipment involved. Among others line and transformer outage simulations constitute an integral part of an electrical management system. Both accuracy and calculation speed depend on the branch outage model and/or the solution algorithms applied. In this paper the local constrained optimization problem of the single-branch outage problem is solved by intelligent methods: particle swarm optimization differential evolution and harmony search. Simulations of IEEE 14- 30- 118- and 300 -bus systems are computed both by intelligent methods and by AC load flow. The results of the intelligent method -based simulations and AC load flow -based simulations are compared in terms of accuracy and computation speed.
Citation - WoS: 16
Citation - Scopus: 34
The Impact of Text Preprocessing on the Prediction of Review Ratings
(Tubitak, 2020) Işık, Muhittin; Dağ, Hasan
With the increase of e-commerce platforms and online applications, businessmen are looking to have a rating and review system through which they can easily reveal the feelings of customers related to their products and services. It is undeniable from the statistics that online ratings and reviews attract new customers as well as increase sales by means of providing confidence, ratification, opinions, comparisons, merchant credibility, etc. Although considerable research has been devoted to the sentiment analysis for review classification, rather less attention has been paid to the text preprocessing which is a crucial step in opinion mining especially if convenient preprocessing strategies are found out to increase the classification accuracy. In this paper, we concentrate on the impact of simple text preprocessing decisions in order to predict fine-grained review rating stars whereas the majority of previous work focused on the binary distinction of positive vs. negative. Therefore, the aim of this research is to analyze preprocessing techniques and their influence, at the same time explain the interesting observations and results on the performance of a five-class-based review rating classifier.
Citation - WoS: 2
Citation - Scopus: 2
Informed Trading, Order Flow Shocks and the Cross Section of Expected Returns in Borsa Istanbul
(Routledge Journals, 2020) Tiniç, Murat; Salih, Aslihan
This paper examines the relationship between information asymmetry and stock returns in Borsa Istanbul. For all stocks that are traded in Borsa Istanbul between March 2005 and April 2017, we estimate the probability of informed trading (PIN) to proxy for information asymmetry.? Firm-level cross-sectional regressions indicate a statistically insignificant relationship between PIN estimates and future returns. Moreover, univariate and multivariate portfolio analyses assert that investors that hold stocks that have high information asymmetry do not obtain significant future returns. Consequently, our results suggest that information asymmetry proxied by PIN is a firm-specific risk and can be eliminated with portfolio diversification. Findings are robust to different factorizations in estimating PIN and free of any bias due to trade classification algorithms, boundary solutions, floating-point exceptions and symmetric?order flow shocks.

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