Elektrik Elektronik Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/411
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Conference Object Citation - Scopus: 2Scintillation Index of Partially Coherent Asymmetrical Multi Gaussian Beams in Extremely Strong Turbulence(2010) Baykal, Yahya Kemal; Öztan, M.A.; Baykal, Y.; Elektrik-Elektronik MühendisliğiIt is investigated whether partial coherent asymmetrical annular and flat-topped Gaussian beams provide advantage to decrease the scintillation noise effect when free space optics systems are used in long distance (longer than 5km) transmission links. Scintillation index of partially coherent asymmetrical multi Gaussian beam propagating in extremely strong turbulence is formulated and the scintillation indexes of asymmetrical annular and flat-topped Gaussian beams are calculated. Scintillation index variations are plotted against the source size and asymmetry ratio. It is determined that asymmetric beams have advantage over the symmetric beams in terms of the scintillation. It is found that the scintillation index decreases as the asymmetry ratio increases. It is also detected that by decreasing the coherence degree scintillation index of the propagating beam quickly goes to zero.Conference Object Citation - Scopus: 6Wavelet Based Flame Detection Using Differential Pir Sensors(2012) Töreyin, B.U.; Soyer, E.B.; Inaç, I.; Günay, O.; Köse, K.; Çetin, A.E.; Erden, F.In this paper, a flame detection system using a differential Pyro-electric Infrared (PIR) sensor is proposed. A differential PIR sensor is only sensitive to sudden temperature variations within its viewing range and it produces a time-varying signal. The wavelet transform of the differential PIR sensor signal is used for feature extraction and feature vectors are fed to Markov models trained with uncontrolled fire flames and walking person. The model yielding the highest probability is chosen. Results suggest that the system can be used in spacious rooms for uncontrolled fire flame detection. © 2012 IEEE.Conference Object Firçasiz Doǧru Akim Motorlarinin Model Referans Adaptif Kontrol Yöntemi - Mıt Kurali ile Kontrol Edilmesi(Institute of Electrical and Electronics Engineers Inc., 2019) Iskender, I.; Ciba, S.In this study, the control of Brushless DC Motors (BLDC), which gained popularity in recent years, is discussed. As a result of insufficient classical control methods, modern control methods have been needed and BLDC is controlled with model reference adaptive control (MRAC) - with MIT law method. For this purpose pulse function, sine wave and step function were applied as a reference speed and the output speed of the system was observed. Simulation results show that the speed of the system follows the speed of the reference model. Then it was thought that in the course of time the resistance value will change because of heated motor and according to this situation the resistance value increased and the output of the system is observed again. © 2018 IEEE.Conference Object Fair Spectrum Sharing in Wireless Networks(2011) Şafak, A.; Preveze, B.Efficient utilization of available resources and the avoidance of overload conditions have high importance for any communication network. For a CSMA based VANET the wireless bandwidth must be shared fairly among all nodes. In VANET the network and available bandwidth are in dynamical structures. Thus, if the congestion control is not provided for the VANET based broadcast communication; the lower priority applications may use the entire spectrum and may cause starvation of some important applications. In this work it is shown that our proposed MCAF (Most Congested Access First) throughput improvement method also provides fair data rate per node in vehicular communication. The data rate per node with fair spectrum allocation is determined using the MCAF simulation and calculation results. Finally, the evaluated results are confirmed by comparing them with the results of other works evaluated in the literature. © 2011 IEEE.