Mühendislik Fakültesi: Recent submissions

Now showing items 1121-1140 of 2863

Power parameters calculations based on wavelet packet transform

Vatansever, Fahri; Özdemir, Ayhan; Özdemir, Abdil (ELSEVIER SCI LTD, 2009)

Power and power quality are of most importance in modern energy systems. The traditional method for power measurement and calculation uses Fourier transform. With Fourier transforms power calculations are performed in the ...
Estimation of target density functions via range-angle beamforming

Demirkol, Aşkın; Demir, Zafer; Emre, Erol (TAYLOR & FRANCIS LTD, 2009)

This paper considers estimation of target density functions in 'range-angle' coordinates using two beamforming techniques. The distribution of the target densities in range-angle coordinates is estimated utilizing several ...
Design of Model-reference Discrete-time Sliding-mode Power System Stabilizer

Yazıcı, İrfan; Özdemir, Ayhan (TAYLOR & FRANCIS INC, 2009)

Power system stabilizers improve the dynamic stability of power systems by increasing the damping torque of the synchronous machines in the system. Over the last four decades,various approaches for the design of power ...
Effects of power quality on manufacturing costs in textile industry

Yanıkoğlu, Ertan; Bayrak, Mehmet (ACADEMIC JOURNALS, 2009)

This paper reports the effect of electrical power quality on textile industry. For this purpose, power quality measurements have been done for six months in two different sectors of textile industry. All parameters affecting ...
An alternative approach for calculation/measurement of fundamental powers based on wavelet packet transform

Vatansever, Fahri; Özdemir, Ayhan; Özdemir, Abdil (ACADEMIC JOURNALS, 2009)

In order to calculate/measure the fundamental harmonic power values, the wavelet transform based methods have been proposed in the literature. However, the fundamental harmonic of voltage and cur-rent signals cannot be ...
A new digital relay for generator protection against asymmetrical faults

Bayrak, Mehmet (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2002)

Under unbalanced conditions the three phase instantaneous power oscillates at twice the power system frequency. The magnitude of these oscillations can be used as a measure of the system unbalance. This paper has introduced ...
Behaviour of embedded generation during the voltage sags in distribution networks

Yanıkoğlu, Ertan (ACADEMIC JOURNALS, 2009)

In recent years, using of small generators connected to distribution networks has been increaseingly preferred to supply local loads. They are called embedded or distributed generators because of they are connected to ...
Estimation and evaluation of sub-bands on LF and HF base-bands in HRV for Ventricular Tachyarrhythmia patients

Köklükaya, Etem (PERGAMON-ELSEVIER SCIENCE LTD, 2009)

Heart Rate Variability (HRV) is an efficient tool for assessment of Sympathovagal Balance (SB) and classification of cardiac disturbances. However, its index may be not enough for classification and evaluation of some ...
Recurrent artificial neural network based islanding protection by using generator speed deviation

Bayrak, Mehmet (ACADEMIC JOURNALS, 2009)

This paper presents a new islanding detection algorithm for distributed generation. The method contains a multi-layer feed forward artificial neural network structure with tapped time delays and a feedback from output which ...
DETECTION OF P- AND S-WAVE ARRIVAL TIMES USING THE DISCRETE WAVELET TRANSFORM IN REAL SEISMOGRAMS

Arman, Hasan; Çerezci, Osman (KING FAHD UNIV PETROLEUM MINERALS, 2009)

In this study, a novel solution based on discrete wavelet transform is introduced to determine P- and S-wave arrival times. An algorithm is developed based on changes in frequencies and energy in high frequency bands. ...
Determination of sympathovagal balance in ventricular tachiaffythmia patients with implanted cardioverter defibrillators using wavelet transform and MLPNN

Köklükaya, Etem (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2009)

HRV is a nonstationary signal that includes sympathovagal balance (SB) information related to LF/HF ratio between the sympathetic and parasympathetic nervous systems. In this paper, a solution based on Daubechies wavelet ...
A new approach for measuring RMS value and phase angle of fundamental harmonic based on Wavelet Packet Transform

Vatansever, Fahri; Özdemir, Ayhan (2008)
Active sensor imaging by wavelet and Gabor theories

Demirkol, Aşkın (TAYLOR & FRANCIS LTD, 2008)

In the present paper, two new algorithms are studied by taking advantage of time frequency analysis techniques. Wavelet and Gabor theories are applied to active imaging by sensors such as radars. This is achieved by ...
SEIGA Technique for Multiple Access Interference Computation in DS-CDMA Systems

Ahmet Oturak; Ertan Ozturk; Demirkol, Aşkın (IEEE, 2009)

In literature, the performance of Direct Sequence Code Division Multiple Access (DS-CDMA) systems over multipath fading channels are evaluated by using Standard Gaussian Approximation (SGA) and Simplified Expression of ...
A new approach for measuring RMS value and phase angle of fundamental harmonic based on Wavelet Packet Transform

Vatansever, Fahri; Özdemir, Ayhan (ELSEVIER SCIENCE SA, 2008)
Load flow based on Newton's method using Norton equivalent circuit for AC-DC multiterminal systems

Arifoğlu, Uğur (VDE VERLAG GMBH, 1999)

This paper presents the Newton-Raphson approach using new equations to the power-flow analysis in steady-state for multiterminal DC-AC systems. A flexible and practical choice of per-unit system is used to formulate the ...
Efficient solution for frequency band decomposition problem using wavelet packet in HRV

Köklükaya, Etem (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2008)

Heart rate variability (HRV) is a very significant noninvasive tool for assessment of sympathovagal balance (SB) that reflects variation of parasympathetic and sympathetic activities in autonomic nervous system (ANS). Low ...
Frequency-energy variability characterization of local real-time noisy seismic records

Arman, Hasan; Çerezci, Osman (WORLD SCIENTIFIC PUBL CO PTE LTD, 2008)

In this study, we have presented a new approach to separate noisy components and to characterize frequency-energy variability for local real-time noisy earthquakes where epicentral distance is 0-10 degrees. This approach ...
Chaotic Attractors and its Application to secure Communaciation using Synchronized Chaos

Yalçın, Mehmet Ali (2008)
Heat analysis of biological tissue exposed to microwave by using thermal wave model of bio-heat transfer (TWMBT)

Çerezci, Osman (ELSEVIER SCI LTD, 2008)

Thermal analyses of biological tissues exposed to microwaves were studied by using thermal wave model of bio-heat transfer (TWMBT). As a model, skin stratified as three layers with various thermal physical properties were ...