Narin, Ali | İşler, Yalçın | Özer, Mahmut

Other | 2014 | Dokuz Eylül Üniversitesi Mühendislik Fakültesi Fen ve Mühendislik Dergisi16 ( 48 ) , pp.1 - 8

Konjestif kalp yetmezliği (KKY) vücudun ihtiyaç duyduğu miktarda kanın pompalanamaması durumudur. Bu tanıya sahip hastaların ölüm oranı çok yüksek olduğundan erken teşhis önemlidir. Bu amaçla gerçekleştirilen sınıflandırma algoritmalarının performanslarının ölçümü için farklı doğrulama yöntemleri vardır. Bu çalışmada, KKY hastalarının teşhisinde sık kullanılan 5 farklı sınıflandırıcının performans ölçümleri için k-parçalı ve birisi-dışarıda çapraz doğrulama yöntemleri denenmiştir. Her algoritma 100 defa denenerek ortalama başarım ve standart sapmaları kayıt edilmiştir. Sonuç olarak, çapraz doğrulamada kullanılan veri parçası sayısı . . .arttıkça ortalama başarımın arttığı ve başarım değişkenliğinin azaldığı tespit edilmiştir. Congestive heart failure (CHF) occurs when the heart is unable to provide sufficient pump action to maintain blood flow to meet the needs of the body. Early diagnosis is important since the mortality rate of the patients with CHF is very high. There are different validation methods to measure performances of classifier algorithms designed for this purpose. In this study, k-fold and leave-one-out cross validation methods were tested for performance measures of five distinct classifiers in the diagnosis the patients with CHF. Each algorithm was run 100 times and the average and the standard deviation of classifier performances were recorded. As a result, it was observed that average performance was enhanced and variability of performances was decreased when the number of data sections used in the cross validation method was increased Daha fazlası Daha az

Özer, Mahmut | Provaznik, Ivo

Article | 2005 | JOURNAL OF THEORETICAL BIOLOGY233 ( 2 ) , pp.237 - 243

The precise form of the rate constant functions of ion channels is very crucial for reproducing the electrophysiological behavior. Therefore, how well they account for experimental data plays an important role in the behavior of the model. In this study, we derive kinetic coefficients of activation and inactivation gates in ion channels by Onsager reciprocity theorem for an ensemble of gating particles, and propose that the obtained kinetic coefficients can be used as a comparative tool for the empirical validity of fitted rate constant functions to experimental data. We also illustrate its applicability based on the activation and . . .inactivation kinetics of T-type calcium channel in thalamic relay neurons. We show that the shape of the steady-state curve by itself seems to be a poor indicator of the functional form of the rate functions, but the time constant curves reflect considerable variation depending on the particular form of the rate functions, and that the kinetic coefficients related to the time constants provide a powerful tool to determine the empirical validity of the fitted rate constants. (C) 2004 Elsevier Ltd. All rights reserved Daha fazlası Daha az

Onur, Tuğba Özge | Hacıoğlu, Rıfat

Proceedings | 2016 | 2016 24th Signal Processing and Communication Application Conference, SIU 2016 - Proceedings , pp.821 - 824

In this paper, two different methods are suggested in order to provide image enhancement in ultrasonic B-mode imaging. By obtaining RF data from two different phantom used to form B-mode image, their spectral characteristics were observed. Then by forming RF envelope from obtained data, conversion of envelope to color image is provided. Logarithmic compression and histogram equalization methods found in literature are used to improve image quality. From the results obtained, it is observed that both algorithms are effective based on the intended use when they are applied individually. © 2016 IEEE.

Altan, Aytaç | Köksal, Kerem | Hacıoğlu, Rıfat

Article | 2017 | Karaelmas Fen ve Mühendislik Dergisi7 ( 1 ) , pp.218 - 227

Bu çalışmada, görsel çizgi (rota) takibi için İnsansız Hava Aracı (İHA) üzerinde bulunan 3 eksenli yalpanın dış bozucu etki altında model öngörülü denetimi gerçekleştirilmektedir. İHA ile görsel çizgi takibi için Tanjant Vektör Alan Kılavuz (TVAK) yöntemi kullanılmaktadır. Dış ortam ve kapalı ortamda yapılan testlerde, ön tanımlaması yapılan çizginin görüntü işleme algoritmalarıyla tespiti ve sonrasında TVAK yöntemi kullanılarak rota takip işlemi gerçekleştirilmektedir. İHA’nın alçak ve yüksek irtifa uçuşlarında rota takibi başarım oranları deneysel olarak gözlemlenmektedir. Elde edilen sonuçlar PID denetime sahip yalpadan elde edil . . .en veriler ile karşılaştırılmaktadır. Dış bozucu etki altında TVAK yöntemi ile rota takibi için İHA üzerindeki 3 eksenli yalpanın MPC denetiminde PID ile denetime göre başarılı sonuçlar elde edilmektedir. In this study, Model Predictive Control (MPC) is performed under the external disturbance effect of the 3-axis gimbal on the Unmanned Aerial Vehicle (UAV) for visual line tracking. The Tangent Vector Fields Guide (TVFG) method is used for visual line tracking with UAV. In the tests performed in the outdoor and indoor environments, the pre-defined line is detected with the image processing algorithms and then the line tracking process is performed using the TVFG method. The visual line tracking success rates in the low and high altitude of UAV flight are observed experimentally. The obtained results are compared with data obtained by the gimbal having PID control. The successful results are obtained with MPC control according to PID control of 3 axis gimbal on UAV under external disturbance for visual line tracking using TVFG method Daha fazlası Daha az

Onur, Tuğba Özge | Carlson, Johan E. | Svanström, Erika | Hacıoğlu, Rıfat

Article | 2017 | Erzincan Üniversitesi Fen Bilimleri Enstitüsü Dergisi10 ( 1 ) , pp.138 - 147

Elastik dalgalar, sadece gaz ve sıvılarda değil aynı zamanda katılarda da yayılırlar. Katılar, sıvı ve gazlarda olmayan form elastisitesine sahip olduğundan, katıların elastik özellikleri farklıdır. Bu nedenle, sadece boylamsal dalgalar değil aynı zamanda diğer dalgalar da katılarda yayılabilir. Katı içinde yayılan dalgalar kullanılarak hedefin konumu hakkında bilgi edinilebilir. Bu çalışmada ince düzlemlerde tek transdüktör kullanılarak ultrasonik dalga yayılımının modellenmesi yapılarak, uyarlamalı algoritma ile hedef uzaklığı kestirilmektedir. Elde edilen sonuçlarda, modellenen dalga yayılımında ultrasonik dalganın hızı ile birli . . .kte zaman gecikmesi uyartım noktasının sensöre olan uzaklığı ile ilintili olduğu için, uyarlamalı algoritma ile darbe cevabı başlangıç noktası belirlenerek hedef konumunun tespit edilebildiği görülmektedir. Elastic waves propagate not only in gases and liquids but also in solids. The elastic properties of solids are different since they have form elasticity which liquids and gases don't have. Because of this reason, not only longitudinal waves but also other waves can propagate in solids. Waves propagating in solids can be used to get information about target location. In this paper, modelling of ultrasonic wave propagation in thin plates is investigated by using a single transducer and target distance is estimated with adaptive algorithm. According to the obtained results, it can be seen that target location can be estimated by detecting the starting point of the impulse response with adaptive algorithm since the delay along with the velocity of ultrasound wave in the modelled wave propagation is related to the distance between the excitation point and sensor Daha fazlası Daha az

Onur, Tuğba Özge | Carlson, Johan E | Svanström, Erika | Hacıoğlu, Rıfat

Article | 2019 | Iranian Journal of Science and Technology - Transactions of Electrical Engineering43 ( 3 ) , pp.405 - 413

This paper demonstrates how flexural wave propagation in a thin plate can be modeled by estimating the combined effect of the excitation source signal and the impulse response of the ultrasonic sensor. The wave propagation in the plate is modeled using the wave equation for the flexural wave mode. A theoretical model for flexural wave propagation in thin plates has been derived, and it has been compared with measurements excited by tapping gently on the surface. The combined effects of the excitation source signal and the impulse response of the low-cost piezoelectric sensor are modeled using finite-impulse response and/or infinite- . . .impulse response filters. Thereafter, the performances of the selected filters are compared on estimating the wave propagation in a thin quartz glass plate. Results indicate that the most accurate estimation of wave propagation has been obtained using a linear phase filter which attributes all dispersions to the flexural wave. © 2018, Shiraz University Daha fazlası Daha az

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

Proceedings | 2015 | 2015 23rd Signal Processing and Communications Applications Conference, SIU 2015 - Proceedings , pp.1849 - 1852

In this study, we perform target detection and tracking with Unmanned Aerial Vehicle (UAV) as well as the visual command of UAV. Our goal is to develop an autopilot system to reduce the human factor in UAV's. We create a system that follows different objects, stays locked to a graphical object which is glyph that has an encryption that only we describe, and executes the mission encoded on glyph in both indoor and outdoor tests. We obtain the targeting by the angle and the dimensions of the glyph. We've obtained successful results in applied presentations. © 2015 IEEE.

Onur, Tuğba Özge | Hacıoğlu, Rıfat

Article | 2017 | Turkish Journal of Electrical Engineering and Computer Sciences25 ( 2 ) , pp.939 - 949

We investigated adaptive algorithms for a Hammerstein block structure in which a static nonlinear block and dynamic linear block are cascaded. The approach considered here is to use generalized orthonormal basis functions in a Hammerstein block structure by using xed pole lter banks. We applied the normalized least mean square approach to the developed adaptive algorithm in order to acquire Hammerstein block structure parameters. Performance comparison of the proposed approach was investigated considering convergence speed and parametric complexity for acoustic echo cancellation application. The results indicated that in the develop . . .ed algorithm along with appropriate selection of xed poles, the algorithm convergences faster and less parametric complexity is provided when compared to direct adaptive Hammerstein algorithms with IIR and FIR linear blocks. We investigated adaptive algorithms for a Hammerstein block structure in which a static nonlinear block and dynamic linear block are cascaded. The approach considered here is to use generalized orthonormal basis functions in a Hammerstein block structure by using xed pole lter banks. We applied the normalized least mean square approach to the developed adaptive algorithm in order to acquire Hammerstein block structure parameters. Performance comparison of the proposed approach was investigated considering convergence speed and parametric complexity for acoustic echo cancellation application. The results indicated that in the developed algorithm along with appropriate selection of xed poles, the algorithm convergences faster and less parametric complexity is provided when compared to direct adaptive Hammerstein algorithms with IIR and FIR linear blocks Daha fazlası Daha az

Özdinç, Tuğba Özge | Hacıoğlu, Rıfat

Proceedings | 2007 | 2007 IEEE 15TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS, VOLS 1-3 , pp.939 - 949

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.939 - 949

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

Article | 2018 | JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI21 ( 3 ) , pp.559 - 564

The 3D printers widely used in the world are produced in different mechanical and electronic designs. The 3D printers which have various mechanical structures such as cartesian, delta and core (xy, xz) already are used open source code software such as Sprinter, Marlin, Cura 3D and Teacup. The control of the 3D printers is usually done by the classical Propotional-Integral-Derivative (PID) control algorithm. In this study, we have developed for the designed 3D printer a new software by using adaptive PID control algorithm instead of classical PID. Five step motors of the designed 3D printer are controlled by the adaptive PID. In add . . .ition, there are both heating and cooling processes in the extruder system and these processes are controlled by the adaptive PID. The mechanical design uses a belt and pulley drive system which is suitable for accelerated movements. In the system software, 3D Printing Software Pipeline (input model, orientation and positioning, support structures, slicing, path planning, machine instructions) is applied. The control algorithms for extruder and step motors are prepared as separate function files in software implemented in C. It has been observed that the designed software is particularly successful in eliminating errors on the surface of the products Daha fazlası Daha az