Güler Ferhan ÜNAL UYAR

Dr. Güler Ferhan ÜNAL UYAR

Business Department, Akdeniz University, Antalya, Turkey (Türkiye)
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 April 2023 in Sustainability
Verified
Journal Article
Open access
PDF file
MKMehmet KAYAKUŞ
Mehmet KAYAKUŞ
BTBurçin TUTCU
Burçin TUTCU
MTMustafa Terzioğlu
Mustafa Terzioğlu
HTHasan Talaş
Hasan Talaş
GUGüler Ferhan ÜNAL UYAR
Güler Ferhan ÜNAL UYAR
Return on equity (ROE) and return on assets (ROA) are important indicators that reveal the sustainability of a company’s profitability performance for both managers and investors. The correct prediction of these indicators will provide a basis for the strategic decisions made by the company managers. The estimation of these signs is a significant factor in supporting the decisions and up-to-date knowledge of potential investors. In this study, return on equity and return on assets were estimated using artificial neural networks (ANNs), multiple linear regression (MLR), and support vector regression (SVR) on the financial data of thirteen companies operating in the iron and steel sector. The success of predicting ROA in the designed model was 86.4% for ANN, 79.9% for SVR, and 74% for MLR. The success of estimating the ROE of the same model was 85.8% for ANN, 80.9% for SVR, and 63.8% for MLR. It is concluded that ANN and SVR can produce successful prediction results for ROA and ROE both accurately and reasonably.

23 August 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
BTBurçin TUTCU
Burçin TUTCU
MKMehmet KAYAKUŞ
Mehmet KAYAKUŞ
MTMustafa Terzioğlu
Mustafa Terzioğlu
GUGüler Ferhan ÜNAL UYAR
Güler Ferhan ÜNAL UYAR
HTHasan Talaş
Hasan Talaş
FYFiliz Yetiz
Filiz Yetiz
IT is recognized as the engine of the digital world. The fact that this technology has multiple sub-sectors makes it the driving force of the economy. With these characteristics, the sector is becoming the center of attention of investors. Considering that investors prioritize profitability, it becomes a top priority for managers to make accurate and reliable profitability forecasts. The aim of this study is to estimate the profitability of IT sector firms traded in Borsa Istanbul using machine learning methods. In this study, the financial data of 13 technology firms listed in the Borsa Istanbul Technology index and operating between March 2000 and December 2023 were used. Return on assets (ROA) and return on equity (ROE) were estimated using machine learning methods such as neural networks, multiple linear regression and decision tree regression. The results obtained reveal that the performance of artificial neural networks (ANN) and multiple linear regression (MLR) are particularly effective.

21 November 2025 in Sustainability
Verified
Journal Article
Open access
PDF file
NKNeylan Kaya
Neylan Kaya
ABAslihan Bozcuk
Aslihan Bozcuk
BTBurçin TUTCU
Burçin TUTCU
MTMustafa Terzioğlu
Mustafa Terzioğlu
GUGüler Ferhan ÜNAL UYAR
Güler Ferhan ÜNAL UYAR
This study explores the Environmental, Social, and Governance (ESG) disclosure practices of 31 information technology firms listed on Borsa Istanbul (BIST), with a particular emphasis on transparency and accountability. Building on legitimacy, stakeholder, and signalling theories, the study develops a composite ESG disclosure index based on 18 binary indicators covering strategy, environmental performance, social impact, stakeholder engagement, and governance structures. Each indicator is equally weighted and combined into environmental, social, and governance sub-indices, which are then aggregated into a firm-level ESG disclosure score using a single min–max normalisation scheme. K-means clustering, validated through the elbow method and silhouette coefficient, is applied to identify groups of firms with similar ESG disclosure profiles. The empirical results show substantial heterogeneity in disclosure intensity across Turkish IT firms. A small group of companies exhibits proactive and comprehensive ESG communication, whereas many firms disclose only limited and fragmented information. Governance- and reporting-related indicators (C6 and C7) are particularly influential, underscoring the importance of standardised ESG reporting and board-level oversight in strengthening transparency. The study contributes to the emerging ESG disclosure literature by providing a methodologically consistent framework for assessing ESG transparency in the IT sector and offering practical insights for regulators, investors, and corporate decision-makers aiming to improve the reliability of ESG reporting in Turkey.

21 July 2023 in Applied Sciences
Verified
Journal Article
Open access
PDF file
GUGüler Ferhan ÜNAL UYAR
Güler Ferhan ÜNAL UYAR
MTMustafa Terzioğlu
Mustafa Terzioğlu
MKMehmet KAYAKUŞ
Mehmet KAYAKUŞ
BTBurçin TUTCU
Burçin TUTCU
AÇAhmet Çoşgun
Ahmet Çoşgun
RYRüya Kaplan Yildirim
Rüya Kaplan Yildirim
Methane gas emission into the atmosphere is rising due to the use of fossil-based resources in post-industrial energy use, as well as the increase in food demand and organic wastes that comes with an increasing human population. For this reason, methane gas, which is among the greenhouse gases, is seen as an important cause of climate change along with carbon dioxide. The aim of this study was to predict, using machine learning, the emission of methane gas, which has a greater effect on the warming of the atmosphere than other greenhouse gases. Methane gas estimation in Turkey was carried out using machine learning methods. The R2 metric was calculated as logistic regression (LR) 94.9%, artificial neural networks (ANNs) 93.6%, and support vector regression (SVR) 92.3%. All three machine learning methods used in the study were close to ideal statistical criteria. LR had the least error and highest prediction success, followed by ANNs and then SVR. The models provided successful results, which will be useful in the formulation of policies in terms of animal production (especially cattle production) and the disposal of organic human wastes, which are thought to be the main causes of methane gas emission.

24 December 2025 in Sustainability
Verified
Journal Article
Open access
PDF file
MTMustafa Terzioğlu
Mustafa Terzioğlu
ABAslihan Bozcuk
Aslihan Bozcuk
GUGüler Ferhan ÜNAL UYAR
Güler Ferhan ÜNAL UYAR
NKNeylan Kaya
Neylan Kaya
BTBurçin TUTCU
Burçin TUTCU
GDGunay Deniz DURSUN
Gunay Deniz DURSUN
The aim of this study was to develop a model that classifies companies into high or low categories based on their return on equity (RoE), the most important indicator of financial performance, using sustainability and governance-related committee reports and reports shared with the public. As a sample, the RoE, sustainability, and governance variables of all 427 companies traded on the Istanbul Stock Exchange in 2024 were used. Using a 70:30 stratified split between the training and test sets, three tree-based models (XGBoost, LightGBM, and Random Forest) were used to perform a binary classification task. The findings show that tree-based models perform only slightly better than the naive majority class rule, and therefore, have limited overall classification power. A noteworthy finding from the study is that SHAP-based explainability analysis shows that the Corporate Governance Report (IMNG), the Integrated Report (IREP) and the existence of a Sustainability Committee (ICOM) rank higher in terms of SHAP-based global importance in the High RoE classification model, although their average contributions are small and, in the case of IMNG, predominantly negative for the probability of belonging to the High RoE class. Methodologically, the article moves away from traditional econometric methods based on ESG scores, instead combining a predictive classification structure with TreeSHAP-based explanations. These findings indicate a need for reporting practices that offer deeper content, clearer evidence of governance quality, and stronger data integrity to better support investors’ decision-making processes through sustainability and governance.

9 February 2026 in Risks
Verified
Journal Article
Open access
PDF file
GUGüler Ferhan ÜNAL UYAR
Güler Ferhan ÜNAL UYAR
MTMustafa Terzioğlu
Mustafa Terzioğlu
NKNeylan Kaya
Neylan Kaya
ABAslihan Bozcuk
Aslihan Bozcuk
This study models the auditor–client relationship as a strategic game shaped by two-sided information asymmetry and examines how this structure influences key audit outcomes, namely audit delay and audit fees, in Türkiye. Using a game-theoretic framework complemented by empirical analysis, the study analyzes independent audit reports dated 31 December 2024 for 201 Borsa Istanbul firms audited by Big Four auditors. Two ordinary least squares models are estimated: one for audit delay and one for the logarithm of audit fees. The findings indicate that firm size and effort-related cost proxies play a central role in explaining audit fees, reflecting scale-related audit complexity. Financial risk, while not significantly associated with audit fees, is found to be negatively related to audit delay, suggesting that riskier firms may accelerate the reporting process through stronger monitoring, earlier planning, or tighter regulatory scrutiny. Audit opinion, by contrast, does not exhibit a statistically meaningful association with reporting delay, likely due to limited variation within the sample. Overall, the results partially support the risk–effort–cost mechanism proposed by the game-theoretic framework and highlight how institutional features of the Turkish audit market shape the relationship between risk and reporting timeliness. The study contributes to the literature by framing the audit process as a strategic decision environment and by providing updated evidence from an emerging market context.