Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Conference Object Citation - WoS: 15Citation - Scopus: 20Adaptive Control of Redundant Robot Manipulators With Sub-Task Objectives [proceedings Paper](Institute of Electrical and Electronics Engineers Inc., 2008) Tatlıcıoğlu, Enver; Braganza, David; Burg, Timothy C.; Dawson, Darren M.In this paper, adaptive control of kinematically redundant robot manipulators is considered. An end-effector tracking controller is designed and the manipulator's kinematic redundancy is utilized to integrate a general sub-task controller for self-motion control. The control objectives are achieved by designing a feedback linearizing controller that includes a least-squares estimation algorithm to compensate for the parametric uncertainties.Article Citation - WoS: 5Citation - Scopus: 6Novel Square Spiral Antennas for Broadband Applications(Walter de Gruyter GmbH, 2009) Saynak, Uğur; Kuştepeli, AlpAn investigation of novel square spiral antennas is presented. The antennas are designed by considering the special arrangements of spiral arms. The new designs perform much better in terms of the frequency independency of the fundamental antenna parameters, when compared with the well known and widely used Archimedean spiral antenna, which makes the antennas very suitable for broadband wireless applications. Experimental results are also presented and there is a good agreement between the measured and numerical data.Conference Object Matching Aerial Coastline Images With Map Data Using Dynamic Programming(Institute of Electrical and Electronics Engineers Inc., 2006) Kahraman, Metin; Gümüştekin, ŞevketMatching aerial images with map data is an important task in several remote sensing applications such as autonomous navigation, cartography, oceanography. The unique and distinctive shapes of coastlines can be effectively utilized to solve this problem. In this study a completely automatic scheme is proposed to detect coastlines using multiresolution texture analysis and to match the detected coastlines to a map database. A shape matching method using dynamic programming is used and tested on the satellite images of the western coast of Turkey.Conference Object Citation - Scopus: 3Reduced Feedback Designs for Sdma-Ofdma Systems(Institute of Electrical and Electronics Engineers Inc., 2009) Özbek, Berna; Le Ruyet, DidierIn SDMA-OFDMA wireless communication systems, the feedback load increases with the number of users, subcarriers and antennas in the cell. In this paper, we propose two efficient reduced feedback algorithms by selecting the clusters at the user side. For each cluster, we select the users according to their norm and their orthogonality. We evaluate the performance of the user selection algorithms considering the quantization effect. We also design a specific codebook design to quantize CSI for the proposed criterion.Article Citation - WoS: 12Citation - Scopus: 16The Resonant Behavior of the Fibonacci Fractal Tree Antennas(John Wiley and Sons Inc., 2008) Özbakış, Başak; Kuştepeli, AlpAn investigation of a novel fractal tree antenna with the application to two different geometries is presented. The antenna is designed by using the special Fibonacci number sequence which leads to nonuniform branch length ratios to form the fractal tree. This new approach gives better performance, especially in the miniaturization of the antenna, when compared with the conventional designs. The results obtained from the experiments are also compared with the computed ones and there is a very good agreement between the numerical and measured data.Article Citation - WoS: 2Citation - Scopus: 1Design of Coupling Structures for Groove Guide Resonators(John Wiley and Sons Inc., 2008) Bechteler, Thomas F.; Kuştepeli, Alp; Aydınlık Bechteler, Ayşe SevinçThree different coupling structures for a groove guide resonator operating at 10 GHz are investigated. First, propagatable modes are determined analytically. Then, the efficiency of the coupling structures is investigated by means of the method of moments and measurements. Finally, a groove guide resonator is designed and the resonance spectrum for each coupling structure is computed numerically, applying the finite-difference time-domain method. Numerical results are compared with experimental measurements. There is good agreement between the measured and simulated data.Conference Object Citation - WoS: 4Citation - Scopus: 7Robust Output Tracking Control of a Surface Vessel(Institute of Electrical and Electronics Engineers Inc., 2008) Lee, Dongbin; Tatlıcıoğlu, Enver; Burg, Timothy C.; Dawson, Darren M.In this paper, tracking control of a three degree-of-freedom marine vessel is examined. The primary motivation for this work is the compensation needed for the added mass common to surface vessels, resulting in an asymmetric inertia matrix. Two control schemes are considered: a full-state feedback controller and an output feedback controller. Numerical simulation results are shown to demonstrate the validity of these proposed controllers.Article Citation - WoS: 33Citation - Scopus: 38Stable non-Gaussian noise parameter modulation in digital communication(Institution of Engineering and Technology, 2009) Çek, Mehmet Emre; Savacı, Ferit AcarThe parameter of the stable non-Gaussian noise sequence is modulated by the binary message sequence to achieve a secure communication system. The characteristic exponent 'alpha' of a stable non-Gaussian noise sequence carries the binary information. The receiver of the proposed random communication system demodulates the received signal by estimating the parameters of the transmitted noise sequence to recover the binary message sequence.Conference Object Citation - WoS: 1Citation - Scopus: 2A Case Study on Logging Visual Activities: Chess Game(Springer Verlag, 2006) Ozan, Şükrü; Gümüştekin, ŞevketAutomatically recognizing and analyzing visual activities in complex environments is a challenging and open-ended problem. In this study this task is performed in a chess game scenario where the rules, actions and the environment are well defined. The purpose here is to detect and observe a FIDE (Fédération International des Ėchecs) compatible chess board, generating a log file of the moves made by human players. A series of basic image processing operations have been applied to perform the desired task. The first step of automatically detecting a chess board is followed by locating the positions of the pieces. After the initial setup is established every move made by a player is automatically detected and verified. Intel® Open Source Computer Vision Library (OpenCV) is used in the current software implementation.Article Citation - WoS: 2Citation - Scopus: 3Low Complexity Zf Receiver for Orthogonal Sfbc-Ofdm in Broadband Wireless Channels(Institution of Engineering and Technology, 2006) Özbek, Berna; Le Ruyet, DidierOrthogonal space-frequency block coded (SFBC) orthogonal frequency division multiplexing (OFDM) systems are analysed in broadband wireless channels where adjacent subcarriers do not have the same channel coefficients and the matched filter receiver causes an error floor in bit error rate performance. To avoid this, a low complexity zero forcing (ZF) receiver for the orthogonal schemes with two and three transmit and one receive antennas are proposed.