Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/11

Browse

Now showing 1 - 6 of 6

Citation - WoS: 1
Citation - Scopus: 2
A Case Study on Logging Visual Activities: Chess Game
(Springer Verlag, 2006) Ozan, Şükrü; Gümüştekin, Şevket
Automatically 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.
Citation - WoS: 7
Citation - Scopus: 11
Noise Robust Speaker Verification Using Mel-Frequency Discrete Wavelet Coefficients and Parallel Model Compensation
(Institute of Electrical and Electronics Engineers Inc., 2005) Tüfekçi, Zekeriya; Gürbüz, Sabri
Interfering noise severely degrades the performance of a speaker verification system. The Parallel Model Combination (PMC) technique is one of the most efficient techniques for dealing with such noise. Another method is to use features local in the frequency domain. Recently, Mel-Frequency Discrete Wavelet Coefficients (MFDWCs) [1, 2] were proposed as speech features local in frequency domain. In this paper, we discuss using PMC along with MFDWCs features to take advantage of both noise compensation and local features (MFDWCs) to decrease the effect of noise on speaker verification performance. We evaluate the performance of MFDWCs using the NIST 1998 speaker recognition and NOISEX-92 databases for various noise types and noise levels. We also compare the performance of these versus MFCCs and both using PMC for dealing with additive noise. The experimental results show significant performance improvements for MFDWCs versus MFCCs after compensating the Gaussian Mixture Models (GMMs) using the PMC technique. The MFDWCs gave 5.24 and 3.23 points performance improvement on average over MFCCs for -6 dB and 0 dB SNR values, respectively. These correspond to 26.44% and 23.73% relative reductions in equal error rate (EER), respectively.
Citation - WoS: 2
Citation - Scopus: 2
A novel square-spiral strip antenna
(Institute of Electrical and Electronics Engineers Inc., 2007) Saynak, Uğur; Kuştepeli, Alp
A square-spiral strip antenna is designed considering the procedure used to obtain log-periodic antennas. Simulation results of the new design are compared with those of the well known and widely used Archimedean spiral antenna in terms of the frequency dependency. The effect of dielectric substrate used to support the antennas is also investigated.
Citation - WoS: 2
Citation - Scopus: 3
Performance of Semi-Orthogonal User Selection for Multiuser Miso Systems
(Institute of Electrical and Electronics Engineers Inc., 2008) Le Ruyet, Didier; Khanfir, Hajer; Özbek, Berna
In MISO multiuser downlink wireless communication systems with precoding at the transmission, the capacity depends on the channel state information at the transmitter. Since the feedback data rate increases with the number of users in the cell it is important to perform a selection of the users at the receiver. In this paper, we evaluate the performance of different user selection algorithms at the receiver side through the noisy uplink channel. We evaluate the effect of the noisy channel on the classical norm criterion and on a criterion based on the orthogonality between the user channels. Without cooperation between the users, we only allow users that are semi-orthogonal to feedback their channel information as analog and quantized information to the base station through the noisy uplink channel. We propose an algorithm to reduce the noise effect on the analog feedback for semi-orthogonal user selection algorithm. We show that the semi-orthogonal criterion with quantized feedback gives better performance compared to the norm criterion for perfect and noisy uplink channels.
Citation - WoS: 56
Citation - Scopus: 68
Railway Monitoring System Using Optical Fiber Grating Accelerometers
(IOP Publishing Ltd., 2018-09) Yüksel, Kıvılcım; Kinet, Damien; Moeyaert, Veronique; Kouroussis, Georges; Caucheteur, Christophe
Optimal operation, reduced energy consumption, longer service availability, and high safety level are the major concerns in today's railway transport systems. Smart monitoring systems should address these issues without interrupting railway operability. Many successful works have been carried out to provide railway monitoring functions using fiber Bragg grating (FBG) sensors on rail. Most of them are based on strain measurement due to the train passage. This paper presents a highly sensitive means for railway monitoring based on vibration measurement. FBG accelerometers placed on sleeper have been employed as sensor heads, which significantly facilitated the field sensor installation work compared to the positioning on the foot of the rail. An optimized signal demodulation algorithm has been effectively used to extract from the accelerometer traces both the axle number and the average speed information. Excellent capability of the developed system to obtain both parameters has been demonstrated by the way of field trials carried out on a Belgian railway line, during its normal operation. Easy installation, multi-function diagnosis, good data integrity, and compatibility with fiber optic sensors make the proposed sensor a good candidate for railway monitoring applications.
Citation - Scopus: 3
Taylor Series Approximation for Low Complexity Semi-Blind Best Linear Unbiased Channel Estimates for the General Linear Model With Applications To Dtv
(IEEE Computer Society, 2004) Pladdy, Christopher; Nerayanuru, Sreenivasa M.; Fimoff, Mark; Özen, Serdar; Zoltowski, Michael
We present a low complexity approximate method for semi-blind best linear unbiased estimation (BLUE) of a channel impulse response vector (CIR) for a communication system which utilizes a periodically transmitted training sequence, within a continuous stream of information symbols. The algorithm achieves slightly degraded results at a much lower complexity than directly computing the BLUE CIR estimate. In addition, the inverse matrix required to invert the weighted normal equations to solve the general least squares problem may be precomputed and stored at the receiver. The BLUE estimate is obtained by solving the general linear model, y = Ah + w + n, for h, where w is correlated noise and the vector n is an AWGN process, which is uncorrelated with w. The solution is given by the Gauss-Markoff Theorem as h = (A TC(h) -1A) -1 A TC(h) -1y. In the present work we propose a Taylor series approximation for the function F(h) = (A TC(h) -1A) -1 A TC(h) -1y where, F: R L → R L for each fixed vector of received symbols, y, and each fixed convolution matrix of known transmitted training symbols, A. We describe the full Taylor formula for this function, F (h) = F (h id + ∑ |α|≥1(h - h id) α (∂/∂h) α F(h id) and describe algorithms using, respectively, first, second and third order approximations. The algorithms give better performance than correlation channel estimates and previous approximations used at only a slight increase in complexity. The linearization procedure used is similar to that used in the linearization to obtain the extended Kalman filter, and the higher order approximations are similar to those used in obtaining higher order Kalman filter approximations,

Browse

Browsing Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği by Language "eng"