Yazar "Tagluk, ME" seçeneğine göre listele

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    Analysis of the time-varying energy of brain responses to an oddball paradigm using short-term smoothed Wigner-Ville distribution
    (Elsevier Science Bv, 2005) Tagluk, ME; Çakmak, ED; Karakas, S
    Cognitive brain responses to external stimuli, as measured by event related potentials (ERPs), have been analyzed from a variety of perspectives to investigate brain dynamics. Here, the brain responses of healthy subjects to auditory oddball paradigms, standard and deviant stimuli, recorded on an Fz electrode site were studied using a short-term version of the smoothed Wigner-Ville distribution (STSW) method. A smoothing kernel was designed to preserve the auto energy of the signal with maximum time and frequency resolutions. Analysis was conducted mainly on the time-frequency distributions (TFDs) of sweeps recorded during successive trials including the TFD of averaged single sweeps as the evoked time-frequency (ETF) brain response and the average of TFDs of single sweeps as the time-frequency (TF) brain response. Also the power entropy and the phase angles of the signal at frequency f and time t locked to the stimulus onset were studied across single trials as the TF power-locked and the TF phase-locked brain responses, respectively. TFDs represented in this way demonstrated the ERP spectro-temporal characteristics from multiple perspectives. The time-varying energy of the individual components manifested interesting TF structures in the form of amplitude modulated (AM) and frequency modulated (FM) energy bursts. The TF power-locked and phase-locked brain responses provoked ERP energies in a manner modulated by cognitive functions, an observation requiring further investigation. These results may lead to a better understanding of integrative brain dynamics. (c) 2004 Elsevier B.V. All rights reserved.
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    Bearing and misalignment fault detection in induction motors by using the space vector angular fluctuation signal
    (Springer, 2005) Arkan, M; Çalis, H; Tagluk, ME
    This paper describes the use of the space vector angular fluctuation (SVAF) method for bearing and misalignment fault diagnosis in induction motors. The theoretical background for SVAF is presented and it is shown how bearing and misalignment faults can be effectively diagnosed by the use of this non-invasive method. The proposed algorithm uses only stator currents as the input, without any other sensors. Both simulation and experimental results carried out on different motors show that these faults could be easily detected and differentiated from each other by fault-related frequencies, which occur in the spectrum of the SVAF.
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    Time-frequency analysis of model-based ventricular late potentials
    (Ieee, 1998) Tagluk, ME; English, MJ
    This study undertakes Time-frequency characterisation of Ventricular Late Potentials (VLPs), To represent the VLPs introduced to the late phase of the QRS complex some models that also contain nonstationarity have been proposed. Time-frequency analysis of the ST segment that VLPs have been added overcomes the information that is lost when one dimensional techniques were used, Due to uniqueness of Wigner-Ville distribution it has been chosen as basis for this analysis. The results were found promising in both qualitative and quantitative sense.