Köksal, Kerem | Surucu, Dilek | Surucu, Murat | Hacıoğlu, Rıfat

Proceedings | 2014 | 2014 22ND SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.646 - 649

In this study, it is aimed to follow a visual route by an Unmanned Aerial Vehicle (UAV). The recognition of the predetermined line by using image processing algorithms and the process of following the route by using the method of Tangent Vector Field Guidance (TVFG) have been performed in indoor and outdoor experiments. UAV's following the correct route has been ensured by calculating the deflection caused by some factors such as wind and light which adversely affect the flight of UAV. In Vector Field Guidance method, the direction angles calculated by using the vector fields that will follow the line-shaped guide path are used. Whe . . .n the path to be followed has more than one direction instead of a single straight line, it is divided into sections which consist of straight lines, and by prioritizing these lines, the most dominant line is followed. In this study, it is aimed to provide a dynamic model by considering the tracking errors. As a result of the process adopted, UAV's autonomous flight is achieved by using the visual inputs and TVFG method, and the external disturbing factors are investigated Daha fazlası Daha az

Özdinç, Tuğba Özge | Hacıoğlu, Rıfat

Proceedings | 2007 | 2007 IEEE 15TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS, VOLS 1-3 , pp.646 - 649

Acoustic echo in voice transmission systems severely degrades the speech quality and the speech intelligibility of speech signal due to it is formed through picking up sounds from the loudspeaker by speaker microphone. The dynamic strucure of the acoustic echo system contains cascade connection of an electro-acoustic static nonlinear system and a dynamic linear system. Hence linear models can not be successful solution to echo problem. In this paper, acoustic echo problem is mentioned and an algorithm that adapts the parameters of nonlinear Hammerstein system (cascade connection of a static nonlinearity and a dynamic linear system) . . .is suggested Daha fazlası Daha az

Onur, Tuğba Özge | Hacıoğlu, Rıfat

Proceedings | 2013 | 2013 21ST SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.646 - 649

The speech signals are formed with echo caused by the reflections and also noise caused by engine, tyres, wind, etc during using hands-free voice communication in automobiles. In this paper, it has been focused on the adaptive filtering algorithms that based on eliminating purpose of not only noise removal but also separation in speech signals with echo and noise. It has been evaluated that the speech signals separation performance by comparing adaptive filtering methods that made with Least Mean Squares (LMS) and Recursive Least Squares (RLS) algorithms. Signals belong to near and far end speakers will be decomposed with each while . . . near-end and far-end speakers' signals affected by noise are decomposing from noise with the proposed adaptive algorithms. Furthermore, convergency and error analyses are performed by comparing the performances of LMS and RLS algorithms Daha fazlası Daha az

Kulu, Nükhet | Başkaya, Merve | Keleş, Aysel | Altan, Aytaç | Hacıoğlu, Rıfat

Proceedings | 2018 | 2018 2ND INTERNATIONAL SYMPOSIUM ON MULTIDISCIPLINARY STUDIES AND INNOVATIVE TECHNOLOGIES (ISMSIT) , pp.290 - 293

In this study, it is aimed to determine the number of reference fruits and health status (sturdy, rotten, mottled, non-spotted) by using real-time image or recorded video taken from the autonomous Unmanned Aerial Vehicle (UAV) camera in orchards. In the determinations made by using image processing techniques, sturdy-rotten and mottled-speckless distinction are made for oranges and apricots, respectively. These distinction and determination processes are carried out using highly trained classifiers. Three types of multi-trained classifiers performance have been compared and a highly trained classifier which has high performance has . . .been preferred for object detection. The accuracy of the Haar, local binary pattern (LBP), and histogram of oriented gradients (HOG) classifiers are compared in Python using the open source computer vision library. It has been shown experimentally that Haar classifier achieves high performance in determining real-time reference fruit health status and yield. Daha fazlası Daha az

Altan, Aytaç | Hacıoğlu, Rıfat

Proceedings | 2014 | 2014 22ND SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.1686 - 1689

In this study, unmanned vehicles used for target tracking camera RRP (revolute revolute prismatic) joint structure with a three-jointed robot arm with the position, velocity and acceleration control is made. In order to be able to follow the specified trajectory, the system used in the control of the robot arm with joint structure RRP target tracking model based on changing according to the structure proposed by the MPC is implemented. Also the PID (Proportional Integral Dervative) is provided with control comparison was made. MATLAB/Simulink simulations performed unmanned vehicles used for target tracking in robotic camera control . . .with the system were investigated in the MPC Daha fazlası Daha az

Narin, Ali | Özer, Mahmut | İşler, Yalçın

Proceedings | 2013 | 2013 21ST SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.1686 - 1689

In this study, the performance of different discrimination algorithms in the analysis of heart rate variability that are used in discriminating the patients with congestive heart failure from normal subjects were investigated. Classifier algorithms of linear discriminant analysis, k-nearest neighbors, multilayer perceptron, radial basis functions and support vector machines were examined with different parameter values. As a result, the maximum classification accuracy of 91.56% was achieved by using multilayer perceptron with 11 neurons in hidden layer.

Uzun, Rukiye | Özer, Mahmut

Proceedings | 2015 | 2015 23RD SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.1191 - 1199

We investigate the first-spike response latency dynamics of a single Hodgkin-Huxley neuron model with a tunable intensity of intrinsic noise and fraction of blocked voltage-gated sodium and potassium ion channels embedded in biological membranes. In contrast to previous studies, we consider a biophysically realistic neuron model which contains stochastic ion channels. We show that potassium ion channels play a key role than sodium ion channels on the appearance of the noise delayed decay (NDD) effect in the first-spike timing.

Özsoy, Muhammet Ali | Uzuntarla, Muhammet | Özer, Mahmut

Proceedings | 2007 | 2007 IEEE 15TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS, VOLS 1-3 , pp.1191 - 1199

Neurons which are the fundamental elements of the nervous system, encode the information about stimulus they received from the external world by sensory system into action potential (spike) sequences before transmitting to the brain. In this study, a neuron population is modeled in mathematical manner and then first spike appearance time in a spike train is examined against changes in the characteristics of the periodic forcing. We also examine the effect of noise which stems from the biophysical structure of neurons and the effect of synaptic coupling which is the consequence of synaptic interaction of neurons with each other in th . . .e population to the appearance time of first spikes. The obtained results show that the mean response time of the population decreases with the increasing frequency. When the intensity of inherent noise in the neuronal environment increased, it shows a decreasing effect on the mean response only for low frequency range of the stimulus. Although the synaptic interaction coefficient does not affect substantially the mean response time of the population, it was shown that it is the fundamental parameter controlling the standard deviation of the response time Daha fazlası Daha az

Erkaymaz, Hande | Özer, Mahmut | Kaya, Ceren

Conference Object | 2015 | 2015 19TH NATIONAL BIOMEDICAL ENGINEERING MEETING (BIYOMUT) , pp.1191 - 1199

The eye, which has the most advanced features among sense organs, has a perfect functioning on people. Furthermore, as it is placed in the lead role of vision, shows the importance for people is quite big. Nowadays, biomedical devices developed for patients who have mobility are benefiting from eye movements. Electrooculogram studies are especially designed on the basis of the signal depending on the movement of your eyes. Electrical origin of EOG biological signal, that occur around the eye pupil, makes an attempt to meet the needs of patients by the right, left, up, down and blinking action. In this study, 4 basic differences exis . . .ting in the direction of movement using voltage controlled EOG signal studies have tried to determine the Neuro-Fuzzy model. Determining the direction of Neuro-Fuzzy control system demonstrates how it can be successfully used as. In addition, control algorithms of artificial intelligence systems that use this kind of eye signals benefiting from the input of the detection process is advantageous in the classification of complex environment Daha fazlası Daha az

Emir, Ahmet | Kaya, Hakan | Öztürk, Ertan

Proceedings | 2015 | 2015 23RD SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.300 - 303

In this work, Orthogonal Frequency Division Multiplexing (OFDM) is implemented on TMS320C6713 Digital Signal Processors (DSP) Starter Kit (DSK). Transmitter, receiver and communication channel are all implemented on a same kit. Firstly the design is tested within Matlab Simulink environment, and then by configuring C6713 DSK parameters, Simulink blocks relating to C6713 DSK are added into the design. The machine codes generated by compiling the design are loaded to the DSP kit. By comparing the voice signals generated via the simulation and the card, the obtained results are validated.

Emir, Ahmet | Saraç, Zehra

Proceedings | 2009 | 2009 IEEE 17TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE, VOLS 1 AND 2 , pp.300 - 303

This paper proposes the use of single sideband modulation technique with Gaussian and band pass fillers for the analysis of the thermal lens fringe to obtain the map of the refractive index change. Maps of the refractive index and phase change are achieved by using single side band modulation technique with Gaussian and band pass filters. Consequently it is seen that single side band modulation technique with Gaussian filter shows more accurate results.

Erkan, Yasemin | Özer, Mahmut | Yılmaz, Ergin

Proceedings | 2017 | 2017 MEDICAL TECHNOLOGIES NATIONAL CONGRESS (TIPTEKNO) , pp.300 - 303

Astrocytes are star-shaped glia cells and the most common cell type in the human brain with neurons. Astrocytes fulfill many functions in human brain. Providing support to the cells of the blood-brain barrier, balancing the extracellular ion concentration, supplying nutrients to the nerve tissue, and controlling the development of nerve cells are some of these tasks. In this study, the effects of calcium (Ca') ion concentration oscillations occuring in astrocytes on the neuron firing dynamics are investigated. When the obtained results are examined, it is observed that the production rate of insole 1,4,5-triphosphate (IP3), which is . . . an agent that triggers calcium release from the resoruces in astrocytes, and the degradation time of that within the cell are important effects on the spike production dynamics of the neuron in contact with astrocyte. It is determined that neurons without any stimulation continue to produce spikes through calcium oscillations in the astrocytes, at high IP3 production rates and longer IP3 degradation times Daha fazlası Daha az