Time filter

Source Type

Doğubayazıt, Turkey

Logoglu E.U.,Orta Dogu Teknik University
2010 National Conference on Electrical, Electronics and Computer Engineering, ELECO 2010 | Year: 2010

Nowadays, in the applications which require high power and long distance power transmission, HVDC lines are preferred over traditional AC transmission systems, such as offshore wind farms. The reasons are increasing the efficiency by reducing the losses on the lines and decreasing the cost of overall systems. Before transmitting the power onshore, to regulate the voltage and to provide galvanic isolation, high power DC/DC converters are used. New generation high power DC/DC converters include an input inverter, a transformer and an output rectifier. 3 phase series resonant converter (SRC3) is in this group. The greatest advantage of this converter is to be able to switch at zero voltage and near zero current due to its LC resonant tank. As a result, the efficiency and the output power density can be increased considerably. In this work, 3 phase series resonant converter topology and its principles have been studied by simulations.

Eyili M.,Aselsan A.S. | Demirekler M.,Orta Dogu Teknik University
2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings | Year: 2014

In this paper, two proposed Track Before Detect (TBD) algorithms for spawning targets on the basis of raw radar measurements are described. These algorithms are developed by using multi-model particle filter method. To improve the efficiency of particle filter a novel reduced order model is introduced. The algorithms are confirmed by using the simulation results and their performances are analyzed on the basis of the probability of target existence and Root Mean Square (RMS) estimation accuracy for very low Signal-to-Noise Ratio (SNR) targets. © 2014 IEEE.

Sabuncu M.,Radar | Demirekler M.,Orta Dogu Teknik University
2011 IEEE 19th Signal Processing and Communications Applications Conference, SIU 2011 | Year: 2011

In this study IMM-PF (Interacting Multiple Model - Particle Filter) algorithm has been developed in order to achieve increased performance for tracking maneuvering targets. Track lost rate and gate sizes are determined as the performance criteria. The developed algorithm has been compared with standart IMM algorithm. Effects of the number of particles on the performance is analysed. © 2011 IEEE.

Alkan S.,Oita University | Yarman-Vural F.T.,Orta Dogu Teknik University
2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings | Year: 2014

In this study, we provide a methodology to localize the brain regions that contribute to semantic category classification. For this purpose we first cluster the data using spectral clustering. Then we extract local features within each cluster by using mesh-arc descriptors. Finally, we test the classification accuracy of each cluster against a hypothesis testing measure we provide here. We have found that, for the experimental task at hand, calcerine fissure and angular gyrus were most effective in classification. These results are shown to be match well with the nature of the experiment. Thus the validity of our approach is confirmed. © 2014 IEEE.

Gunel B.,Orta Dogu Teknik University
2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings | Year: 2014

An audio recording, made in a real environment, carries an acoustical signature which changes according to the acoustical characteristics of the environment and the recording positions. This signature which is similar to a 3D room impulse response contains the directions, levels and arrival times of the direct source and reflections. Although it is easy to obtain reverberant recordings by convolving clean recordings with the acoustical signature, estimating the signature from any recording is a difficult inverse problem. Acoustical signature estimation is important in acoustical analysis, audio forensics for authentication, room size and shape estimation and improving speech intelligibility by dereverberation. In this work, the statistical modelling of intensity vector directions, which are obtained from compact microphone array recordings is made. Obtained statistical distribution is used for reducing the reverberation based on the maximum-likelihood estimation method. This dereverberated sound enables deconvolving the reverberant recordings to estimate the acoustical signature. © 2014 IEEE.

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