Onur, Tuğba Özge | Hacıoğlu, Rıfat

Proceedings | 2014 | 2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings , pp.1323 - 1326

Time delay estimation has been used as a research area of significant practical important in many fields such as especially military system like localization, targeting, course acquisition also sonar, seismology, hands-free communications etc. In these applications, it is important to detect the delay and arrival times of ultrasonic echoes comprised in the medium for ultrasonic signals. Here, it is aimed to determine the time delay between the signals arrived from a signal source in order to detect the location. Hence, a system is suggested that uses a multi-surfaced waveguide with only one receiver instead of using receiver arrays. . . . By using this structure, time delay estimation is compared for different signal-to-noise ratios with Cross-Correlation, Maximum Likelihood and Phase Transform methods. © 2014 IEEE Daha fazlası Daha az

Çalım, Ali | Uzuntarla, Muhammet | Özer, Mahmut

Proceedings | 2014 | 2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings , pp.1991 - 1994

In this study, the information coding issue in the nervous system is investigated. By using mathematical equations for modeling the dynamics of the basic units of the system, which are neurons, the information processing performance of the neuron populations is systematically studied. As most of studies in the literature investigate the subject by considering neuron populations as homogenous systems, in this study, the populations are considered as heterogeneous in terms of neuronal excitability. The obtained results demonstrate that considering the heterogeneity of the populations provides significant advantages for the processing . . .of neuronal information. It is shown that the neuron population exhibits maximal performance (resonance) for two different levels of network heterogeneity. Moreover, the influences of other biological parameters, forming the whole system, on this double-resonance phenomenon are investigated. © 2014 IEEE Daha fazlası Daha az

Baysal, Veli | Yılmaz, Ergin | Özer, Mahmut

Proceedings | 2014 | 2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings , pp.1958 - 1961

In this paper, the effects of time-periodic coupling on the firing regularity of a scale-free network (SF), consisting of stochastic Hodgkin-Huxley neurons, have been investigated depending on ion channel noise. The effects of both the frequency and the amplitude of periodic coupling on the firing regularity have been tackled, separately. It is seen from the obtained results that the firing (spiking) regularity shows resonance like behavior depending on ion channel noise when the frequency of the periodic coupling equals integer multiple of the sub threshold oscillation frequency of H-H neurons. Additionally, it is determined that t . . .his resonance is maximal at an optimal value of the amplitude of the periodic coupling strength. © 2014 IEEE Daha fazlası Daha az

Kaya G.U. | Sarac Z. | Tayyar D.O. | Bolumu F.

Conference Object | 2014 | 2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings , pp.148 - 151

In this study, it is aimed to obtain the real time image of the object, whose off-axis hologram recording is saved on CCD camera, from digital phase hologram. For creating the phase hologram, the phase information of the hologram recording on CCD camera is obtained. When the phase information is obtained, the Fourier transform algorithm and continuous wavelet transform methods are used. Finally, the using methods in this study are compared in terms of obtaining real time image having a high image quality and minimum power loss. © 2014 IEEE.

Oturak A. | Öztürk E.

Conference Object | 2014 | 2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings , pp.1666 - 1669

In literature, it has been shown that Fast Frequency Hopping Orthogonal Frequency Division Multiple Access (FFH-OFDM) exploits frequency diversity whereas classical OFDM does not. In this work, a semi-analytical expression for the symbol error probability (SEP) of FFH-OFDM with Minimum Mean Square Error (MMSE) equalizer over flat Rayleigh channels is derived, and validated with simulations. In addition, FFH and classical OFDM performances are compared by using the derived expressions. Numerical results show that FFH-OFDM outperforms Classical-OFDM in low modulation levels due to its frequency diversity. © 2014 IEEE.

Kaya H. | Öztürk E.

Conference Object | 2014 | 2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings , pp.678 - 681

In literature, Distributed Turbo Coded (DTC) cooperative system is generally designed with a single relay. The main aim of this paper is to analyze the performance of a DTC scheme with a best relay selected among multi-relays. To achieve this aim, expression for the upper bound of the Bit Error Probability of the proposed DTC scheme is derived over a Rayleigh flat fading channel. The derived performance expression is validated via simulations. © 2014 IEEE.

Erkaymaz, Hande | Orak, I.Muharrem | Özer, Mahmut

Proceedings | 2014 | 2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 - Proceedings , pp.265 - 268

Coding of the organ movements have been seen commonly in the hardware designing which is useful for humanity in scientific researches. 5 sense organs which reveal different data with cellular structures, is the most important focus point. Especially, Eye is known as photosensitive sensor organ of living creature. There is a potential difference between cornea and retina of eye. This potential difference is known as electrooculogram (EOG). Nowadays, EOG signals are commonly used in these hardware designs. Obtained potential differences from EOG signals have been converted coded directional movements. Thus, in this study, 4 basic dire . . .ction movements have been tried to detect with a fuzzy controlled model. It is shown that the fuzzy controlled system as determine the direction can be used successfully. In addition, eye direction movements of squint person are obtained by the system. © 2014 IEEE Daha fazlası Daha az