Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Conference Object Citation - Scopus: 13-D Switching Fabric Node Design(ACTA Press, 2004) Dinleyici, Mehmet Salih; Akın, OsmanIn this work we investigate an all-optical switching node that can be controlled by means of a transient grating, which is formed by interference of two Gaussian beams. This design considers 3-D architecture of switching fabrics.. real profile of Gaussian beams and fast switching time requirements. Four Wave Mixing (FWM) technique is applied in the evanescent field region of waveguide, showing chi((3)) nonlinearity. The formed grating is analysed by standart methods to obtain reflection coefficient and then coupling coefficient for power exchange between waveguides.Article Citation - WoS: 4Citation - Scopus: 4Adaptive Visual Servo Regulation Control for Camera-In Configuration With a Fixed Camera Extension(ACTA Press, 2009) Tatlıcıoğlu, Enver; Dawson, Darren M.; Xian, B.In this paper, image-based regulation control of a robot manipulator with an uncalibrated vision system is discussed. To compensate for the unknown camera calibration parameters, a novel prediction error formulation is presented. To achieve the control objectives, a Lyapunov-based adaptive control strategy is employed. The control development for the camera-in-hand problem is presented in detail and a fixed-camera problem is included as an extension.Article Citation - WoS: 6Citation - Scopus: 7Neural Network Based Robust Control of an Aircraft(ACTA Press, 2020) Tanyer, İlker; Tatlıcıoğlu, Enver; Zergeroǧlu, ErkanOutput tracking control of an aircraft subject to uncertainties in the dynamic model and additive state-dependent nonlinear disturbancelike terms is aimed. Uncertainties in the aircraft dynamic model yield an uncertain input gain matrix, which is neither positive definite nor symmetric and an uncertain term in the error dynamics. To deal with the uncertain input gain matrix, a decomposition method is utilized to put error dynamics in a form where an uncertain positive definite matrix multiplies the auxiliary error but this results in the control input to be pre-multiplied first with a unity upper triangular matrix which is uncertain and then with a known diagonal matrix. A novel controller composed of a neural network compensation term and an integral of signum of error is designed. A novel Lyapunov type stability analysis is utilized to prove global asymptotic tracking of output of a reference model. Extensive numerical simulations are presented to demonstrate the efficacy of the proposed controller where robustness to variation of initial states and a comparison with a robust controller are also shown. © 2020 Acta Press. All rights reserved.Conference Object 2-D Thresholding of the Connectivity Map Following the Multiple Sequence Alignments of Diverse Datasets(ACTA Press, 2013) Doğan, Tunca; Karaçalı, BilgeMultiple sequence alignment (MSA) is a widely used method to uncover the relationships between the biomolecular sequences. One essential prerequisite to apply this procedure is to have a considerable amount of similarity between the test sequences. It's usually not possible to obtain reliable results from the multiple alignments of large and diverse datasets. Here we propose a method to obtain sequence clusters of significant intragroup similarities and make sense out of the multiple alignments containing remote sequences. This is achieved by thresholding the pairwise connectivity map over 2 parameters. The first one is the inferred pairwise evolutionary distances and the second parameter is the number of gapless positions on the pairwise comparisons of the alignment. Threshold curves are generated regarding the statistical parameter values obtained from a shuffled dataset and probability distribution techniques are employed to select an optimum threshold curve that eliminate as much of the unreliable connectivities while keeping the reliable ones. We applied the method on a large and diverse dataset composed of nearly 18000 human proteins and measured the biological relevance of the recovered connectivities. Our precision measure (0.981) was nearly 20% higher than the one for the connectivities left after a classical thresholding procedure displaying a significant improvement. Finally we employed the method for the functional clustering of protein sequences in a gold standard dataset. We have also measured the performance, obtaining a higher F-measure (0.882) compared to a conventional clustering operation (0.827).Conference Object Citation - Scopus: 2Nonlinear Control Techniques for Micro Electrostatic Actuators in the Presence of Parasitics and Parametric Uncertainties(ACTA Press, 2011) Salah, Mohammed H.; Al-Jarrah, Ahmad M.; Tatlıcıoğlu, EnverIn this paper, nonlinear control techniques are developed to control parallel-plate micro electrostatic actuators in the presence of parasitics and parametric uncertainties. The movable plate of the micro actuator is actively controlled utilizing the measurements of internal charge and movable plate's displacement. A velocity observer is designed to estimate the velocity of the plate that is needed for the control algorithm since it is difficult to be measured practically. The proposed backstepping nonlinear control strategies are developed based on a Lyapunov-based analysis, which proves that the desired plate's displacement can be obtained accurately. The proposed nonlinear controllers are capable of controlling the movable plate beyond the pull-in limit in the presence of parametric uncertainties. Representative numerical simulations are presented to demonstrate the performance of the developed nonlinear control strategies in accurately tracking desired deflections of the movable plate within the entire capacitive gap. Finally, a comprehensive performance comparison is performed to examine the effectiveness of the control designs.