Ahmet Orhan

Prof. Ahmet Orhan

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

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19 August 2025 in Machines
Verified
Journal Article
Open access
PDF file
Ahmet OrhanAhmet Orhan
Ahmet Orhan
NYNikolay Yordanov Yordanov
Nikolay Yordanov Yordanov
MERVE ERTARĞINMERVE ERTARĞIN
MERVE ERTARĞIN
Marin ZhilevskiMarin Zhilevski
Marin Zhilevski
Mikho MikhovMikho Mikhov
Mikho Mikhov
This paper presents a comparative analysis of bearing and rotating component fault classification based on different time–frequency representations using vision transformer (ViT). Four different time–frequency transformation techniques—short-time Fourier transform (STFT), continuous wavelet transform (CWT), Hilbert–Huang transform (HHT), and Wigner–Ville distribution (WVD)—were applied to convert the signals into 2D images. A pretrained ViT-Base architecture was fine-tuned on the resulting images for classification tasks. The model was evaluated on two separate scenarios: (i) eight-class rotating component fault classification and (ii) four-class bearing fault classification. Importantly, in each task, the samples were collected under varying conditions of the other component (i.e., different rotating conditions in bearing classification and vice versa). This design allowed for an independent assessment of the model’s ability to generalize across fault domains. The experimental results demonstrate that the ViT-based approach achieves high classification performance across various time–frequency representations, highlighting its potential for mechanical fault diagnosis in rotating machinery. Notably, the model achieved higher accuracy in bearing fault classification compared to rotating component faults, suggesting higher sensitivity to bearing-related anomalies.

2 February 2019 in Molecular Biology Reports
Verified
Journal Article
Closed access
PDF file
AKAhmet Kocael
Ahmet Kocael
AEAllison Pınar Eronat
Allison Pınar Eronat
MTMete Bora Tüzüner
Mete Bora Tüzüner
AEAhmet Ekmekçi
Ahmet Ekmekçi
Ahmet OrhanAhmet Orhan
Ahmet Orhan
OÖOğuz Öztürk
Oğuz Öztürk

3 July 2025 in Preprints.org
Verified
Preprint
Open access
PDF file
Ahmet OrhanAhmet Orhan
Ahmet Orhan
NYNikolay Yordanov Yordanov
Nikolay Yordanov Yordanov
MERVE ERTARĞINMERVE ERTARĞIN
MERVE ERTARĞIN
Marin ZhilevskiMarin Zhilevski
Marin Zhilevski
Mikho MikhovMikho Mikhov
Mikho Mikhov
This study presents a comparative analysis of bearing and rotating component fault classification based on different time–frequency representations using ViT-base model. Four different time–frequency transformation techniques—Short-Time Fourier Transform (STFT), Continuous Wavelet Transform (CWT), Hilbert-Huang Transform (HHT), and Wigner-Ville Distribution (WVD)—were applied to convert the signals into 2D images. A pre-trained ViT-Base architecture was fine-tuned on the resulting images for classification tasks. The model was evaluated on two separate scenarios: (i) eight-class rotating component fault classification and (ii) four-class bearing fault classification. Importantly, in each task, the samples were collected under varying conditions of the other component (i.e., different rotating conditions in bearing classification and vice versa). This design allowed for an independent assessment of the model’s ability to generalize across fault domains. The experimental results demonstrate that the ViT-based approach achieves high classification performance across various time–frequency representations, highlighting its potential for mechanical fault diagnosis in rotating machinery. Notably, the model achieved higher accuracy in bearing fault classification compared to rotating component faults, suggesting a higher sensitivity to bearing-related anomalies.

1 April 2020
Verified
Conference Paper
Closed access
MERVE ERTARĞINMERVE ERTARĞIN
MERVE ERTARĞIN
Ahmet OrhanAhmet Orhan
Ahmet Orhan
AÇAbuzer Çalışkan
Abuzer Çalışkan
Recently, the development of advanced power semiconductor devices has made widespread use of power switching circuits and other power electronics applications in commercial and industrial environments. This paper focuses on Single Phase Matrix Converter (SPMC) as a AC-DC boost rectifier and AC-DC buck rectifier. The SPMC was operated in the desired mode using a single driver circuit. Insulated Gate Bipolar Transistors (IGBTs) are used in the power circuit as switching devices to implement SPMC topology. Switching signals are obtained by Sinusoidal Pulse Width Modulation (SPWM) technique. The simulation is carried out using MATLAB / Simulink.

27 October 2023 in European Journal of Technic
Verified
Journal Article
Open access
PDF file
MERVE ERTARĞINMERVE ERTARĞIN
MERVE ERTARĞIN
TGTuran GURGENC
Turan GURGENC
ÖYÖzal YILDIRIM
Özal YILDIRIM
Ahmet OrhanAhmet Orhan
Ahmet Orhan
Electrical machines, which provide many conveniences in our daily life, may experience malfunctions that may adversely affect their performance and the general functioning of the industrial processes in which they are used. These failures often require maintenance or repair work, which can be expensive and time consuming. Therefore, minimizing the risk of malfunctions and failures and ensuring that these machines operate reliably and efficiently play a critical role for the industry. In this study, a one-dimensional convolutional neural network (1D-CNN) based fault diagnosis model is proposed for electric motor fault detection. Motor vibration data was chosen as the input data of the 1D-CNN model. Motor vibration data was obtained from a mobile application developed by using the three-axis accelerometer of the mobile phone. Three-axis data (X-axis, Y-axis and Z-axis) were fed to the model, both separately and together, to perform motor fault detection. The results showed that even a single axis data provides error-free diagnostics. With this fault detection method, which does not require any connection on or inside the motor, the fault condition in an electric motor has been detected with high accuracy.