Mehmet Zeki Konyar

Dr. Mehmet Zeki Konyar

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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22 April 2024 in Neural Computing and Applications
Verified
Journal Article
Open access
PDF file
RSRadhwan Ali Abdulghani Saleh
Radhwan Ali Abdulghani Saleh
MKMehmet Zeki Konyar
Mehmet Zeki Konyar
KKKaplan Kaplan
Kaplan Kaplan
HEHuseyin Metin Ertunc
Huseyin Metin Ertunc
Visual inspection of defective tires post-production is vital for human safety, as faulty tires can lead to explosions, accidents, and loss of life. With the advancement of technology, transfer learning (TL) plays an influential role in many computer vision applications, including the tire defect detection problem. However, automatic tire defect detection is difficult for two reasons. The first is the presence of complex anisotropic multi-textured rubber layers. Second, there is no standard tire X-ray image dataset to use for defect detection. In this study, a TL-based tire defect detection model is proposed using a new dataset from a global tire company. First, we collected and labeled the dataset consisting of 3366 X-ray images of faulty tires and 20,000 images of qualified tires. Although the dataset covers 15 types of defects arising from different design patterns, our primary focus is on binary classification to detect the presence or absence of defects. This challenging dataset was split into 70, 15, and 15% for training, validation, and testing, respectively. Then, nine common pre-trained models were fine-tuned, trained, and tested on the proposed dataset. These models are Xception, InceptionV3, VGG16, VGG19, ResNet50, ResNet152V2, DenseNet121, InceptionResNetV2, and MobileNetV2. The results show that the fine-tuned VGG19, DenseNet21 and InceptionNet models achieve compatible results with the literature. Moreover, the Xception model outperformed the compared TL models and literature methods in terms of recall, precision, accuracy, and F1 score. Moreover, it achieved on the testing dataset 73.7, 88, 80.2, and 94.75% of recall, precision, F1 score, and accuracy, respectively, and on the validation dataset 73.3, 90.24, 80.9, and 95% of recall, precision, F1 score, and accuracy, respectively.

6 January 2020 in Signal, Image and Video Processing
Verified
Journal Article
Closed access
PDF file
MKMehmet Zeki Konyar
Mehmet Zeki Konyar
OAOrhan Akbulut
Orhan Akbulut
SÖSıtkı Öztürk
Sıtkı Öztürk

17 May 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
RSRadhwan Ali Abdulghani Saleh
Radhwan Ali Abdulghani Saleh
FAFarid Al-Areqi
Farid Al-Areqi
MKMehmet Zeki Konyar
Mehmet Zeki Konyar
KKKaplan Kaplan
Kaplan Kaplan
SÖSemih Öngir
Semih Öngir
HEHuseyin Metin Ertunc
Huseyin Metin Ertunc
Automatic detection of tire defects has become an important issue for tire production companies since these defects cause road accidents and loss of human lives. Defects in the inner structure of the tire cannot be detected with the naked eye; thus, a radiographic image of the tire is gathered using X-ray cameras. This image is then examined by a quality control operator, and a decision is made on whether it is a defective tire or not. Among all defect types, the foreign object type is the most common and may occur anywhere in the tire. This study proposes an explainable deep learning model based on Xception and Grad-CAM approaches. This model was fine-tuned and trained on a novel real tire dataset consisting of 2303 defective tires and 49,198 non-defective. The defective tire class was augmented using a custom augmentation technique to solve the imbalance problem of the dataset. Experimental results show that the proposed model detects foreign objects with an accuracy of 99.19%, recall of 98.75%, precision of 99.34%, and f-score of 99.05%. This study provided a clear advantage over similar literature studies.

1 June 2020 in Symmetry
Verified
Journal Article
Open access
PDF file
MKMehmet Zeki Konyar
Mehmet Zeki Konyar
SÖSıtkı Öztürk
Sıtkı Öztürk
Medical data hiding is used to hide patient information inside medical images to protect patient privacy. Patient information in the image should be protected when sending medical images to other specialists or hospitals over the communication network. However, the images are exposed to various unwanted disruptive signals in the communication channel. One of these signals is salt and pepper noise. A pixel exposed to salt and pepper noise becomes completely black or completely white. In pixel-based data hiding methods, it is not possible to extract the secret message in the pixel exposed to this kind of noise. While current data hiding methods are good for many disruptive effects, they are weak against salt and pepper noise. For this reason, the proposed study especially focuses on the accurate extraction of patient information in the salt and pepper noisy medical images. This study was proposed for the most accurate extraction of secret message despite salt and pepper noise, by use of a Reed Solomon error control coding-based data hiding method. The most important feature of Reed Solomon codes is that they can correct errors in non-binary (decimal) numbers directly. Therefore, the Reed Solomon coding-based data hiding method that proposed in this study increases the resistance against salt and pepper noise. Experimental studies show that secret data is accurately extracted from stego images with various densities of salt and pepper noise. Stego medical images created by the proposed method have superior quality values compared to similar literature studies. Additionally, compared to similar methods, the secret message is extracted from the noisy stego image with higher accuracy.

27 December 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
SÖSemih Öngir
Semih Öngir
EKEgemen Cumhur Kaleli
Egemen Cumhur Kaleli
MKMehmet Zeki Konyar
Mehmet Zeki Konyar
HEHuseyin Metin Ertunc
Huseyin Metin Ertunc
This study aims to accurately estimate vertical tire forces on racing tires of specific stiffness using acceleration, pressure, and speed data measurements from a test rig. A hybrid model, termed Random Forest Assisted Deep Neural Network (RFADNN), is introduced, combining a novel deep learning framework with the Random Forest Algorithm to enhance estimation accuracy. By leveraging the Temporal Convolutional Network (TCN), Minimal Gated Unit (MGU), Long Short-Term Memory (LSTM), and Attention mechanisms, the deep learning framework excels in extracting complex features, which the Random Forest Model subsequently analyzes to improve the accuracy of estimating vertical tire forces. Validated with test data, this approach outperforms standard models, achieving an MAE of 0.773 kgf, demonstrating the advantage of the RFADNN method in required vertical force estimation tasks for race tires. This comparison emphasizes the significant benefits of incorporating advanced deep learning with traditional machine learning to provide a comprehensive and interpretable solution for complex estimation challenges in automotive engineering.

5 November 2022 in Journal of Information Security and Applications
Verified
Journal Article
Closed access
SKSezgin Kaçar
Sezgin Kaçar
MKMehmet Zeki Konyar
Mehmet Zeki Konyar
ÜÇÜnal Çavuşoğlu
Ünal Çavuşoğlu