The Experts below are selected from a list of 165282 Experts worldwide ranked by ideXlab platform
Cemal Keles - One of the best experts on this subject based on the ideXlab platform.
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Transmission lines fault location using transient Signal Spectrum
International Journal of Electrical Power & Energy Systems, 2013Co-Authors: Mehmet Salih Mamiş, Muslum Arkan, Cemal KelesAbstract:This paper proposes a method for fault location on transmission lines, which is based on time to frequency domain transformation of transient Signals of the fault instant measured at one end. Fast Fourier Transform (FFT) is used for time to frequency domain transformation and frequency of the first fault generated harmonic is utilised for determination of the fault location using the travelling wave theory of the transmission line. The accuracy of the method has been tested using the simulations carried out in Alternative Transients Program (ATP/EMTP) with frequency-dependent distributed parameter transmission line model by considering several cases and various types of faults, different values of fault resistance and phase angle at fault instant. The method has good accuracy and the simulation results show that the accuracy of the method is insensitive to the fault resistance and phase angle of the fault instant. Reactive elements may affect the resolution but, it can be removed by applying the correction procedure proposed.
Wen-yan Yin - One of the best experts on this subject based on the ideXlab platform.
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Suppressing Intentional Electromagnetic Interference (IEMI) in Wireless Communication System Using Complex Signal Spectrum Shifting Technique
2018 IEEE Symposium on Electromagnetic Compatibility Signal Integrity and Power Integrity (EMC SI & PI), 2018Co-Authors: Jing-gao Wang, Hao Xie, Kai-qi Xiao, Ya-zhou Chen, Ji-xin Chen, Yan-yan Zhang, Wen-yan YinAbstract:It is well known that (non)intentional electromagnetic interference (IEMI) can cause the performance degradation and the rise of bit error rate (BER) of wireless communication system. This paper presents the study on suppressing intentional electromagnetic interference in communication system using complex Signal Spectrum shifting technique. The anti-IEMI techniques are at first introduced, and further, modeling process and simulated results of bit error rate (BER) are given for different Signal to noise ratio (SNR) and Signal to interference ratio (SIR).
Mehmet Salih Mamiş - One of the best experts on this subject based on the ideXlab platform.
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Transmission lines fault location using transient Signal Spectrum
International Journal of Electrical Power & Energy Systems, 2013Co-Authors: Mehmet Salih Mamiş, Muslum Arkan, Cemal KelesAbstract:This paper proposes a method for fault location on transmission lines, which is based on time to frequency domain transformation of transient Signals of the fault instant measured at one end. Fast Fourier Transform (FFT) is used for time to frequency domain transformation and frequency of the first fault generated harmonic is utilised for determination of the fault location using the travelling wave theory of the transmission line. The accuracy of the method has been tested using the simulations carried out in Alternative Transients Program (ATP/EMTP) with frequency-dependent distributed parameter transmission line model by considering several cases and various types of faults, different values of fault resistance and phase angle at fault instant. The method has good accuracy and the simulation results show that the accuracy of the method is insensitive to the fault resistance and phase angle of the fault instant. Reactive elements may affect the resolution but, it can be removed by applying the correction procedure proposed.
S. G. Kim - One of the best experts on this subject based on the ideXlab platform.
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Simulation of magneto‐optic readout Signal Spectrum using digitized mark and beam patterns (abstract)
Journal of Applied Physics, 1996Co-Authors: J. W. Sohn, Sangho Lee, S. G. KimAbstract:This paper describes a simple and convenient simulation method, which uses analytical models for mark and beam patterns. The readout Signal of optical disk system is obtained by two‐dimensional convolution of Gaussian intensity beam pattern and elliptical mark pattern. Then, Signal Spectrum is obtained by executing a fast Fourier transform algorithm after adding quantitative MO noise sources within bandwidth. For simulation, the two‐dimensional distributions of mark reflectivity and beam intensity were digitized, which enabled us to use easily available algorithm routines in digital Signal processing. The resolution of the beam and mark patterns can easily be adjusted by changing the number of bits representing the patterns. Also, various noise sources in the MO disk system can be selectively added using random function generator. Simulated Signal spectra were compared with experimental results. The parameters used were as follows: laser beam width was 780 nm, NA was 0.55, Signal frequency was 9.4 MHz, duty ratio was 38%, and minimum mark dimension was 0.6 μm by 0.75 μm. Simulated C/N ratio was 50 dB, which was very close to the experimental value of 52 dB.
Naoki Urakawa - One of the best experts on this subject based on the ideXlab platform.
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Measuring complex field waveforms of quadrature amplitude modulation optical Signals using a spectrally slicing-and-synthesizing coherent optical Spectrum analyzer
Optics Express, 2020Co-Authors: Koji Igarashi, Yasuhiro Kawabata, Naoki UrakawaAbstract:We propose a spectrally slicing-and-synthesizing coherent optical Spectrum analyzer to measure complex field waveforms of quadrature amplitude modulation (QAM) optical Signals with ultralong periods. The optical Spectrum of a measured optical Signal is divided into multiple narrowband spectral components, called slices. The slices are sequentially measured using low-speed coherent detection. After phase noise suppression and frequency fluctuation compensation on each slice, the measured slices are synthesized to recover the original Signal Spectrum. Our numerical and experimental results confirm that the proposed method can overcome the limitation of the measurement bandwidth because the Signal Spectrum can synthesize more than 100 slices. We experimentally demonstrate complex field measurements of 16QAM optical Signals. Our method can measure high-speed optical complex field waveforms with no bandwidth limitation.
