Çakar, Tuna
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Çakar T.
Tuna Çakar
Çakar,Tuna
Çakar Tuna
Çakar, T.
Tuna Çakar
Çakar,Tuna
Çakar Tuna
Çakar, T.
Job Title
Email Address
cakart@mef.edu.tr
Main Affiliation
02.02. Department of Computer Engineering
Status
Current Staff
Website
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Sustainable Development Goals
1
NO POVERTY
1
Research Products
2
ZERO HUNGER
2
Research Products
3
GOOD HEALTH AND WELL-BEING
5
Research Products
4
QUALITY EDUCATION
1
Research Products
8
DECENT WORK AND ECONOMIC GROWTH
4
Research Products
9
INDUSTRY, INNOVATION AND INFRASTRUCTURE
1
Research Products
11
SUSTAINABLE CITIES AND COMMUNITIES
1
Research Products
12
RESPONSIBLE CONSUMPTION AND PRODUCTION
1
Research Products
15
LIFE ON LAND
2
Research Products
16
PEACE, JUSTICE AND STRONG INSTITUTIONS
1
Research Products
17
PARTNERSHIPS FOR THE GOALS
1
Research Products
This researcher does not have a Scopus ID.
This researcher does not have a WoS ID.
Scholarly Output
103
Articles
17
Views / Downloads
20402/241580
Supervised MSc Theses
30
Supervised PhD Theses
0
WoS Citation Count
77
Scopus Citation Count
149
WoS h-index
3
Scopus h-index
5
Patents
0
Projects
6
WoS Citations per Publication
0.75
Scopus Citations per Publication
1.45
Open Access Source
48
Supervised Theses
30
Google Analytics Visitor Traffic
| Journal | Count |
|---|---|
| 32nd IEEE Signal Processing and Communications Applications Conference (SIU) -- MAY 15-18, 2024 -- Tarsus Univ Campus, Mersin, TURKEY | 9 |
| 2023 31st Signal Processing and Communications Applications Conference (SIU) | 6 |
| 2022 7th International Conference on Computer Science and Engineering (UBMK) | 6 |
| 2023 4th International Informatics and Software Engineering Conference (IISEC) | 5 |
| 30th IEEE Signal Processing and Communications Applications Conference (SIU) -- MAY 15-18, 2022 -- Safranbolu, TURKEY | 4 |
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Scopus Quartile Distribution
Competency Cloud
Scholarly Output Search Results
Now showing 1 - 10 of 103
Article What Is Neuroentrepreneurship? the Theoretical Framework, Critical Evaluation, and Research Program(2021) Çakar,Tuna; Girişken, ArzuAs interest in entrepreneurship research to identify the possible economic development opportunities that entrepreneurs can provide, entrepreneurship research's objective tools are reaching their limits. Researchers in entrepreneurship are striving to discover new techniques and methodologies to answer questions about what makes a person an entrepreneur and perhaps identify and encourage an entrepreneur in the next step. Although a great deal of research has been done to answer these questions scientifically, traditional techniques have failed to produce the desired answers. For this reason, researchers working in the entrepreneurship field have recently been increasingly interested in applying neuroscience methods, especially after the proliferation of research fields such as neuroeconomics, neuromarketing, and neuropolitics. Although the population of neuroentrepreneurship research is gradually increasing, we cannot say that the field has been studied theoretically enough yet. In this article, a theoretical definition of neuroentrepreneurship is made, and a scientific framework is tried to be gained on the way to future research.Article Citation - WoS: 2Citation - Scopus: 2Warning Notes in a Learner’s Dictionary: a Study of the Effectiveness of Different Formats(International Journal of Lexicography, 2022) Çakar, Tuna; Nesi, Hilary; Nural, ŞükrüThis study used an online correction task to explore the extent to which different types of warning notes in Longman Dictionary of Contemporary English Online were heeded when users tried to correct errors in the use of L2 target words. The task was completed by 332 participants, yielding 1,819 answers produced after clicking on links to relevant entries. Warning notes were categorised in terms of their formatting features, but there were found to be inconsistencies in the way the dictionary associated different categories with different kinds of learner error. Participants judged warning notes with more visual enhancements to be more useful, but in the correction task the position of the warning notes also seemed to affect the degree to which the warnings were successfully applied. Different types of warning notes in learners’ dictionaries have not been examined previously in any depth, and the results suggest that some adjustments to formatting and placement might make them more effective.Master Thesis Market Basket Analysis Using Apriori Algorithm(MEF Üniversitesi, Fen Bilimleri Enstitüsü, 2018) Şimşek, Yıldırım Murat; Çakar, TunaPredictive analysis is a branch of data engineering that predicts some occurrence or probabilities depend on the data. To make predictions about future events, predictive analytics uses data mining techniques. The process of these techniques involves an analysis of historic data and predicts the future events based on that analysis. Also using predictive analytics modelling techniques, a model can be created to predict. Depending on the data that they are using these predictive models can be varied. Predictive analytics is made of various statistical and analytical techniques used to develop models that will predict future occurrence, events or probabilities. Market basket analysis is one of the data mining techniques that focusing on discovering purchasing pattern by extracting associations from a store’s transactional data. The electronic commerce point-of-sale expanded the utilization and application of transactional data in Market Basket Analysis. The needs of the customers have to be known and adapted to them from the retailers. The retailers collect information about their customers and what they purchase with the help of the advanced technology. Analysing this information is extremely valuable for understanding purchasing behaviour in retail commerce. Market basket analysis is one possible way to discover which items can be sold together. This analysis gives retailer valuable information about related sales on a group of goods basis customers who buy bread often also buy several products related to bread like milk or butter. It makes sense that these groups are placed side by side in a store so that customers can reach them quickly. Market basket analysis is very useful technique for the related group of products that are bought together, and to reorganize the supermarket layout, and also to design promotional campaigns such that products’ purchase can be improved. The main aim of this capstone project is to find the co-occurring items in consumer shopping baskets in the data set that provided by GittiGidiyor E-Commerce Company with the help of the association rule mining algorithm; apriori. Mining association rules from transactional data will provide us with valuable information about co-occurrences and copurchases of products. Such information can be used as a basis for decisions about marketing activity such as promotional support, inventory control and cross-sale campaigns.Master Thesis Fraud detection and prediction with machine learning applications(MEF Üniversitesi, 2023) Sayar, Alperen; Çakar, TunaBu çalışmanın temel amacı, faktoring sektöründe faaliyet gösteren bir şirketin müşterilerinin işlemleri üzerindeki dolandırıcılık faaliyetlerini tespit etmek ve buna bağlı olarak müşterilerin geçmiş işlem ve bağlantı verilerine dayalı keşifsel veri analizi ile ölçülebilir parametreler yakalamaktır. ve ardından hedef için tahmine dayalı modeller gerçekleştirmek. Sınıflandırma modeli algoritmaları olan XGBoost ve CATBoost modellerinde %79 civarında isabet oranı elde edilmiştir. Bu sayede dolandırıcılık yapma potansiyeli yüksek müşteri tespit edildikten sonra daha etkin, verimli ve doğru bir yaklaşımla hareket edilerek işlem bazında dolandırıcılık faaliyetlerinin doğrudan tespit edilmesi amaçlanmaktadır.Conference Object The Neural Correlates of the Effect of Belief in Free Will on Third-Party Punishment: an Optical Brain Imaging (fnirs) Study(Cognitive Science Society, 2022) Çakar, Tuna; Akyürek, Güçlü; Erözden, Ozan; Şahin, Türkay; Keskin, İrem Nur; Ünlü, Meryem; Özen, Deniz Hazal; Özen, ZeynepThird party punishment (TPP), or altruistic punishment, is specifically human prosocial behavior. TPP denotes the administration of a sanction to a transgressor by an individual that is not affected by the transgression. In some evolutionary accounts, TPP is considered crucial for the stability of cooperation and solidarity in larger groups formed by genetically unrelated individuals. Belief in free will (BFW), on the other hand, is the idea that humans have control over their behavior. BFW is a human universal notion that, in some studies, has been found to be supportive of prosocial behavior. In our study, we examined the effect of BFW on TPP under high and low affect scenarios through optical brain imaging (fNIRS). We hypothesized that in low affect cases, there would be a positive correlation between the strength of the BFW and the severity of the punishment inflicted. Obtained results and related statistical analyses indicate that participants with higher degree of BFW have more neural activation in their right dorsolateral prefrontal cortex (DLPFC) (hbo and hbt measures) in high affect scenarios, whereas the participants with lower degree of BFW have higher levels of neural activation in the medial PFC (hbo and hbt measures) in low affect scenarios. These empirical findings are in line with the research findings in the relevant academic literature and support the hypothesis that the degree of BFW influences punishment decisions.Conference Object An Exploratory Study on the Effect of Contour Types on Decision Making Via Optic Brain Imaging Method (fnirs)(eScholarship, 2023) Demircioglu, Esin Tuna; Girişken, Yener; Çakar, TunaDecision-making is a combination of our positive anticipations from the future with the contribution of our past experiences, emotions, and what we perceive at the moment. Therefore, the cues perceived from the environment play an important role in shaping the decisions. Contours, which are the hidden identity of the objects, are among these cues. Aesthetic evaluation, on the other hand, has been shown to have a profound impact on decision-making, both as a subjective experience of beauty and as having an evolutionary background. The aim of this empirical study is to explain the effect of contour types on preference decisions in the prefrontal cortex through risk-taking and aesthetic appraisal. The obtained findings indicated a relation between preference decision, contour type, and PFC subregion. The results of the current study suggest that contour type is an effective cue in decision-making, furthermore, left OFC and right dlPFC respond differently to contour types.Master Thesis Segmentation for factoring customers using unsupervised machine learning algorithms(MEF Üniversitesi, 2023) Ayyıldız, Nur Seher; Çakar, TunaGünümüzde teknolojinin veri toplamayı kolaylaştırmasının önemli bir fırsat olmasının yanı sıra tüm bu verilerin yönetimini zorlaştırmakta ve veriler iyi işlenmedikçe bir anlam ifade etmemektedir. Depolanan bu veriler son derece önemlidir ve şirketler, müşterileri tarafından sağlanan verileri kullanır. Değişen dünyanın müşteri profillerinin ihtiyaçlarını yakalamak artık bir zorunluluk haline gelmekte ve firmalar için ilk sırayı almaktadır. Zamanla depolanan verinin artması ile artık veriler arasında ilişki kurmak ve bunları birbirinden ayırmak zor bir hal almıştır. Bu noktada hayatımıza makine öğrenmesi yöntemleri daha fazla dahil olmaya başlamıştır. Bu çalışmada, segmentasyonun ne olduğu ve yıllar içindeki değişiminden bahsedilmiştir. Hangi makine öğrenmesi tekniklerinin veri seçiminde faydalı olacağına değinilmiştir. Ardından olası makine öğrenmesi yöntemleri yerel bir faktoring şirketinin müşteri çek verileri kullanılarak gösterilmiştir. Bu çalışma etiketsiz verilerin gruplanmasını hedeflediğinden gözetimsiz öğrenme teknikleri üzerinde durulmuştur. Bu yöntemler arasında en popular olan K – means algoritmasının yanı sıra Hiyerarşik Kümeleme, DBSCAN, Gauss Karışık Modelleme ve Fuzzy c - Means yöntemleri kullanılmıştır. Her bir algoritma için başarı ölçütleri incelenerek uygun küme sayıları bulunmuş ve bulunan sonuçlar karşılaştırılmıştır. Kümeleme sonuçları incelendiğinde GMM ile optimal küme sayısı oldukça yüksek hesaplanmış, DBSCAN küme atayamamış, Hierarchical clustering ise zaman açısından maliyetli bulunmuştur. En iyi sonuçların K - means ve Fuzzy c - Means algoritmalarıyla elde edildiği gözlemlenmiştir.Conference Object Dog Walker Segmentation(IEEE, 2022) Ercan, Alperen; Karan, Baris; Çakar, TunaIn this study dog walkers were separated into clusters according to walkers' walk habits. Due to the fact that the distributions were non-normal, normalization algorithms were applied before the onset of clustering. After normalizing, K Means algorithm and Gaussian Mixture Models used for finding optimum cluster count. According to these clusters, walkers' consecutive months separated to follow-up their behavioral traits. This part of the study adds value to the project to examine walkers' behaviors closer.Conference Object Citation - Scopus: 2Breast Lesion Detection From Dce-Mri Using Yolov7(American Institute of Physics, 2024) Şahin,Sinan; Araz, Nusret; Bakırman, Tolga; Çakar, Tuna; Kulavuz, Bahadır; Bayram, Bülent; Çavuşoğlu, MustafaBreast cancer is one of the most common types of cancer among women. Early diagnosis of breast cancer has vital importance to prevent unexpected losses. A worldwide effort has been made to tackle early detection challenge. Dynamic contrast-enhanced magnetic resonance imaging is a superior imaging system that improves breast cancer diagnosis quality of physicians. Computer Aided Diagnosis systems are used as a complementary tool to improve breast cancer diagnosis. In last decades, various computer aided diagnosis systems have been proposed. However, the state-of-the-art deep learning-based approaches have started to overcome conventional medical image processing methods. In this study, we aimed to detect malignant breast lesions from open access dynamic contrast-enhanced magnetic resonance imagery dataset using most recent YOLOv7 deep learning architecture. 2400 images have been used for training (80%) and testing (20%) of the network. The metrics calculated with the test dataset are 98.54%, 96.42% and 84.40% for mAP@0.50 IoU, mAP@0.75 IoU and mAP, respectively. The results show that YOLOv7 architecture is capable to detect malignant breast lesions from dynamic contrast-enhanced magnetic resonance images efficiently. © 2024 Author(s).Conference Object İnternet Trafik Hızının Tahmininde Derin Öğrenme ve Ağaç Tabanlı Modellerin Karşılaştırılması(Institute of Electrical and Electronics Engineers Inc., 2025) Filiz, Gozde; Altıntaş, Suat; Yıldız, Ayşenur; Kara, Erkan; Drias, Yassine; Çakar, TunaThis study addresses the prediction of internet traffic speed using time-dependent data from an internet service provider through different modeling approaches. On an anonymized dataset, the performance of the moving average method, various deep learning models (N-BEATS, N-HITS, TimesNet, TSMixer, LSTM), and the XGBoost regression model enhanced with feature engineering was compared. Time series cross-validation and random hyperparameter search were used for model training. According to the results, the XGBoost model achieved the highest accuracy with 98.7% explained variance (R2), while among the deep learning models, N-BEATS and N-HITS achieved the best performance with R2 values around 90%. The findings indicate that tree-based methods supported by carefully selected features can offer higher accuracy and computational efficiency compared to complex deep learning models in internet traffic forecasting. © 2025 Elsevier B.V., All rights reserved.
