Gabriel Militaru

Mr. Gabriel Militaru

Electrical Engineering, Politehnica University Timișoara, Timişoara, Timiş, Romania
orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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12 March 2023 in Mathematics
Verified
Journal Article
Open access
PDF file
Manuela PanoiuManuela Panoiu
Manuela Panoiu
CPCaius Panoiu
Caius Panoiu
SMSergiu Mezinescu
Sergiu Mezinescu
GMGabriel Militaru
Gabriel Militaru
IBIoan Baciu
Ioan Baciu
Harmonic generation in power system networks presents significant issues that arise in power utilities. This paper describes a machine learning technique that was used to conduct a research study on the harmonic analysis of railway power stations. The research was an investigation of a time series whose values represented the total harmonic distortion (THD) for the electric current. This study was based on information collected at a railway power station. In an electrified substation, measurements of currents and voltages were made during a certain interval of time. From electric current values, the THD was calculated using a fast Fourier transform analysis (FFT) and the results were used to train an adaptive ANN—GMDH (artificial neural network–group method of data handling) algorithm. Following the training, a prediction model was created, the performance of which was investigated in this study. The model was based on the ANN—GMDH method and was developed for the prediction of the THD. The performance of this model was studied based on its parameters. The model’s performance was evaluated using the regression coefficient (R), root-mean-square error (RMSE), and mean absolute error (MAE). The model’s performance was very good, with an RMSE (root-mean-square error) value of less than 0.01 and a regression coefficient value higher than 0.99. Another conclusion from our research was that the model also performed very well in terms of the training time (calculation speed).

11 October 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
CPCaius Panoiu
Caius Panoiu
GMGabriel Militaru
Gabriel Militaru
Manuela PanoiuManuela Panoiu
Manuela Panoiu
Recent years have seen outstanding developments in research and technology, highlighting the importance of railway transportation, especially the implementation of high-speed trains, which is becoming more and more challenging. This facilitates extensive research into the science and technology of the electrical interaction between the components of pantograph–catenary systems (PCSs). Problems regarding the PCS can result in infrastructure incidents, potentially stopping train operations. A common cause of failure in electrified railway PCS is a contact wire’s zigzag length that exceeds the prescribed technical limit, which can be caused by missing droppers or faults in the mounting mechanism. This work proposes a video camera-based monitoring technique for zigzag geometry measurement that additionally employs a Global Positioning System (GPS) sensor to detect the current geographical position of the point of zigzag length measurement. There are two proposed techniques for measuring the length of the zigzag based on image processing. In the first technique, using previously recorded data, the images are analyzed in the laboratory, and in the second, the images are analyzed in real time. Based on the results, we suggest a model and prediction of zigzag length employing hybrid deep neural networks.