Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Article Citation - WoS: 62Citation - Scopus: 70Railway Monitoring System Using Optical Fiber Grating Accelerometers(IOP Publishing Ltd., 2018) Yüksel, Kıvılcım; Kinet, Damien; Moeyaert, Veronique; Kouroussis, Georges; Caucheteur, ChristopheOptimal operation, reduced energy consumption, longer service availability, and high safety level are the major concerns in today's railway transport systems. Smart monitoring systems should address these issues without interrupting railway operability. Many successful works have been carried out to provide railway monitoring functions using fiber Bragg grating (FBG) sensors on rail. Most of them are based on strain measurement due to the train passage. This paper presents a highly sensitive means for railway monitoring based on vibration measurement. FBG accelerometers placed on sleeper have been employed as sensor heads, which significantly facilitated the field sensor installation work compared to the positioning on the foot of the rail. An optimized signal demodulation algorithm has been effectively used to extract from the accelerometer traces both the axle number and the average speed information. Excellent capability of the developed system to obtain both parameters has been demonstrated by the way of field trials carried out on a Belgian railway line, during its normal operation. Easy installation, multi-function diagnosis, good data integrity, and compatibility with fiber optic sensors make the proposed sensor a good candidate for railway monitoring applications.Article Citation - WoS: 4Citation - Scopus: 4Modeling and Simulation of Positron Emission Mammography (pem) Based on Double-Sided Cdte Strip Detectors(IOP Publishing Ltd., 2014) Özşahin, İlker; Ünlü, Mehmet ZübeyirBreast cancer is the most common leading cause of cancer death among women. Positron Emission Tomography (PET) Mammography, also known as Positron Emission Mammography (PEM), is a method for imaging primary breast cancer. Over the past few years, PEMs based on scintillation crystals dramatically increased their importance in diagnosis and treatment of early stage breast cancer. However, these detectors have significant limitations like poor energy resolution resulting with false-negative result (missed cancer), and false-positive result which leads to suspecting cancer and suggests an unnecessary biopsy. In this work, a PEM scanner based on CdTe strip detectors is simulated via the Monte Carlo method and evaluated in terms of its spatial resolution, sensitivity, and image quality. The spatial resolution is found to be ∼ 1 mm in all three directions. The results also show that CdTe strip detectors based PEM scanner can produce high resolution images for early diagnosis of breast cancer.Article Citation - WoS: 23A Quasi-Distributed Temperature Sensor Interrogated by Optical Frequency-Domain Reflectometer(IOP Publishing Ltd., 2011) Yüksel, Kıvılcım; Mégret, Patrice; Wuilpart, MarcThis paper presents the analysis of a quasi-distributed sensor based on the concatenation of identical low-reflective fiber Bragg gratings. We experimentally demonstrated a temperature sensor using ten cascaded gratings which are interrogated by an optical frequency domain reflectometer. Repeatability measurements highlighted a standard deviation on the measured temperature smaller than 1.5 °C. A complete demonstration of mathematical formulas which are used to obtain the temperature information is also provided. © 2011 IOP Publishing Ltd.