Zafer Aydın

Prof. Zafer Aydın

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

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

Representative Publications

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25 November 2020 in IEEE Access
Verified
Journal Article
Open access
MBMustafa Bicakci
Mustafa Bicakci
OAOguzhan Ayyildiz
Oguzhan Ayyildiz
ZAZafer Aydın
Zafer Aydın
ABAlper Basturk
Alper Basturk
SKSeyhan Karacavus
Seyhan Karacavus
BYBulent Yilmaz
Bulent Yilmaz
Lung cancer is one of the deadliest cancer types whose 84% is non-small cell lung cancer (NSCLC). In this study, deep learning-based classification methods were investigated comprehensively to differentiate two subtypes of NSCLC, namely adenocarcinoma (ADC) and squamous cell carcinoma (SqCC). The study used 1457 18F-FDG PET images/slices with tumor from 94 patients (88 men), 38 of which were ADC and the rest were SqCC. Three experiments were carried out to examine the contribution of peritumoral areas in PET images on subtype classification of tumors. We assessed multilayer perceptron (MLP) and three convolutional neural network (CNN) models such as SqueezeNet, VGG16 and VGG19 using three kinds of images in these experiments: 1) Whole slices without cropping or segmentation, 2) cropped image portions (square subimages) that include the tumor and 3) segmented image portions corresponding to tumors using random walk method. Several optimizers and regularization methods were used to optimize each model for the diagnostic classification. The classification models were trained and evaluated by performing stratified 10-fold cross validation, and F-score and area-under-curve (AUC) metrics were used to quantify the performance. According to our results, it is possible to say that inclusion of peritumoral regions/tissues both contributes to the success of models and makes segmentation effort unnecessary. To the best of our knowledge, deep learning-based models have not been applied to the subtype classification of NSCLC in PET imaging, therefore, this study is a significant cornerstone providing thorough comparisons and evaluations of several deep learning models on metabolic imaging for lung cancer. Even simpler deep learning models are found promising in this domain, indicating that any improvement in deep learning models in machine learning community can be reflected well in this domain as well.

9 May 2014 in Multimedia Tools and Applications
Verified
Journal Article
Closed access
PDF file
CECigdem Eroglu Erdem
Cigdem Eroglu Erdem
CTCigdem Turan
Cigdem Turan
ZAZafer Aydın
Zafer Aydın

24 February 2023 in Computer Methods and Programs in Biomedicine
Verified
Journal Article
Closed access
SYSena Busra Yengec-Tasdemir
Sena Busra Yengec-Tasdemir
ZAZafer Aydın
Zafer Aydın
EAEbru Akay
Ebru Akay
SDSerkan Dogan
Serkan Dogan
BYBulent Yilmaz
Bulent Yilmaz

27 January 2024 in Arabian Journal for Science and Engineering
Verified
Journal Article
Open access
PDF file
NCNevin Cini
Nevin Cini
ZAZafer Aydın
Zafer Aydın
In the last 50 years, with the growth of cities and increase in the number of vehicles and mobility, traffic has become troublesome. As a result, traffic flow prediction started to attract attention as an important research area. However, despite the extensive literature, traffic flow prediction still remains as an open research problem, specifically for long-term traffic flow prediction. Compared to the models developed for short-term traffic flow prediction, the number of models developed for long-term traffic flow prediction is very few. Based on this shortcoming, in this study, we focus on long-term traffic flow prediction and propose a novel deep ensemble model (DEM). In order to build this ensemble model, first, we developed a convolutional neural network (CNN), a long short-term memory (LSTM) network and a gated recurrent unit (GRU) network as deep learning models, which formed the base learners. In the next step, we combine the output of these models according to their individual forecasting success. We use another deep learning model to determine the success of the individual models. Our proposed model is a flexible ensemble prediction model that can be updated based on traffic data. To evaluate the performance of the proposed model, we use a publicly available dataset. Experimental results show that the developed DEM model has a mean square error of 0.06 and a mean absolute error of 0.15 for single-step prediction; it shows that achieves a mean square error of 0.25 and a mean absolute error of 0.32 for multi-step prediction. We compared our proposed model with many models in different categories; individual deep learning models (i.e., LSTM, CNN, GRU), selected traditional machine learning models (i.e., linear regression, decision tree regression, k-nearest-neighbors regression) and other ensemble models such as random-forest regression. These results also support the claim that ensemble learning models perform better than individual models.

6 May 2020 in International Journal of Communication Systems
Verified
Journal Article
Closed access
PDF file
YGYasin Görmez
Yasin Görmez
ZAZafer Aydın
Zafer Aydın
RKRamazan Karademir
Ramazan Karademir
VGVehbi C. Gungor
Vehbi C. Gungor

7 April 2025 in Children
Verified
Journal Article
Open access
PDF file
BTBanu Çiçek Tez
Banu Çiçek Tez
YGYasin Güzel
Yasin Güzel
BEBahar Başak Kızıltan Eliaçık
Bahar Başak Kızıltan Eliaçık
ZAZafer Aydın
Zafer Aydın
Background/Objectives: Dental plaque is a significant contributor to various prevalent oral health conditions, including caries, gingivitis, and periodontitis. Consequently, its detection and management are of paramount importance for maintaining oral health. Manual plaque assessment is time-consuming, error-prone, and particularly challenging in uncooperative pediatric patients. These limitations have encouraged researchers to seek faster, more reliable methods. Accordingly, this study aims to develop a deep learning model for detecting and segmenting plaque in young permanent teeth and to evaluate its diagnostic precision. Methods: The dataset comprises 506 dental images from 31 patients aged between 8 and 13 years. Six state-of-the-art models were trained and evaluated using this dataset. The U-Net Transformer model, which yielded the best performance, was further compared against three experienced pediatric dentists for clinical feasibility using 35 randomly selected images from the test set. The clinical trial was registered on under the ID NCT06603233 (1 June 2023). Results: The Intersection over Union (IoU) score of the U-Net Transformer on the test set was measured as 0.7845, and the p-values obtained from the three t-tests conducted for comparison with dentists were found to be below 0.05. Compared with three experienced pediatric dentists, the deep learning model exhibited clinically superior performance in the detection and segmentation of dental plaque in young permanent teeth. Conclusions: This finding highlights the potential of AI-driven technologies in enhancing the accuracy and reliability of dental plaque detection and segmentation in pediatric dentistry.