Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
Browse
5 results
Search Results
Article Citation - WoS: 1Citation - Scopus: 1Controlling the Rotor Angle Stability of Single Machine Infinite Bus System in the Presence of Wiener and Alpha-Stable Levy Type Power Fluctuations(World Scientific Publishing, 2020) Yılmaz, Serpil; Savacı, Ferit AcarThe integration of renewable energy sources into the power systems and the growth of electricity consumption leads to a considerable increase in the power fluctuations. In the first part of this study, the control of the rotor angle stability of single machine infinite bus system in the presence of Wiener type power fluctuations has been achieved by minimizing the corresponding stochastic sensitivity function. In the second part, the power fluctuations have been modeled by alpha-stable Levy processes and since stochastic sensitivity function is not available for alpha-stable Levy processes, then the control of the rotor angle stability has been numerically achieved by minimizing the corresponding rotor angle dispersion for the first time in the literature. © World Scientific Publishing CompanyArticle User-Relay Assisted Cellular Networks With Multiple Antennas(Taylor & Francis, 2019) Baştürk, İlhan; Özbek, BernaUser-relay assisted OFDMA-based cellular networks have gained great importance recently since these networks are indicated as one of the powerful technologies that will contribute the 5G standard. These networks can be used with novel three-phase frame structure unlike classical two-phase frame structure and can be enhanced with multiple antennas to utilise the advantages of them. The main advantage of the three-phase frame structure is taking care of the limitations of the current transceiver design in practical systems and not allowing users to be relay and user simultaneously. Diversity and capacity gains are also the advantages of extending the network with multiple antennas. In this paper, we will use the novel three-phase frame structure for downlink MISO-OFDMA cellular networks and develop resource management algorithms as relay selection and resource allocation to observe the benefits of this system.Article Citation - WoS: 3Citation - Scopus: 4Stochastic bifurcation in generalized chua's circuit driven by skew-normal distributed noise(World Scientific Publishing Co. Pte Ltd, 2018) Yılmaz, Serpil; Çek, Mehmet Emre; Savacı, Ferit AcarIn this study, the stochastic phenomenological bifurcations (P-bifurcations) of generalized Chua's circuit (GCC) driven by skew-normal distributed noise have been investigated by numerically obtaining the stationary distributions of the stochastic responses. The noise intensity and/or skewness parameters of skew-normal distributed noise have been chosen as the bifurcation parameters to change the structure of the stochastic attractor. While the number of breakpoints in the piecewise-linear characteristics of the GCC are fixed, it has been observed that the number of scrolls have been changed by tuning the noise intensity and the skewness parameter of the skew-normal distributed noise.Article Citation - WoS: 14Citation - Scopus: 16Random Communication System Based on Skewed Alpha-Stable Levy Noise Shift Keying(World Scientific Publishing Co. Pte Ltd, 2017) Ahmed, Areeb; Savacı, Ferit AcarThe digital communication system is based on the skewed alpha-stable (α-stable) noise sequence which is chosen as the random carrier to modulate the binary message at the transmitter side. Antipodal characteristic of the skew parameter beta (β) is exploited for decoding information at the receiver side to obtain a secure communication system. A fast estimator used in this paper is based on Modified Extreme Value Method (MEVM) to extract the binary message from the signal received through the Additive White Gaussian Noise (AWGN) channel. Our proposed receiver is achieving better bit error rate (BER) versus Mixed Signal to Noise Ratio (MSNR) than previously introduced receivers which are based on Sinc and Logarithmic estimators. MEVM estimator is indeed less complex compared to the Sinc and Logarithmic estimators and hence more fast. Additionally, the criterion to measure the security level of random communication system, which is based on α-stable noise sequence, has also been introduced.Article Citation - WoS: 14Citation - Scopus: 14The Circuit Implementation of a Wavelet Function Approximator(Springer Verlag, 2002) Özkurt, Nalan; Savacı, Ferit Acar; Gündüzalp, MustafaThis paper describes the analog synthesis of a wavelet function approximator using sigmoidal mother wavelet. Any finite energy multivariate function can be approximated by this analog circuit using the multiresolution approximation property of the wavelet decomposition. The approximator circuit includes bipolar junction transistors, operational amplifiers and linear passive circuit elements.