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Intraoperative appearance of a homograft aortic valve 16 years after the implantation

Özdoğan, Mehmet Emin | Erer, Dilek | İriz, Erkan | Büyükateş, Mustafa | Oktar, Levent | Ünal, Yusuf | Abacı, Adnan

Other | 2007 | Anadolu Kardiyoloji Dergisi7 ( 4 ) , pp.456 - 457

Visual line tracking with vector field guidance for UAV

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


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

Simultaneous localization and mapping of mines with unmanned aerial vehicle [Insansiz Hava Araci ile Maden Ocaginin Es Zamanli Konum Belirleme ve Haritalandirilmasi]

Altan, Aytaç | Bayraktar, Köksal | Hacıoğlu, Rıfat

Proceedings | 2016 | 2016 24th Signal Processing and Communication Application Conference, SIU 2016 - Proceedings , pp.1433 - 1436

In this stuidy, the position information from ultrasound sensors on UAV related to floor gallery mine passed through the filter, it is aimed to control the position of simultaneously creating the optimum environmental map. The simultaneous in galleries made mapping, mine the data of air to the designated central monitoring system with real-time location information is transmitted to the ventilation system, which is intended to more effectively work in the mines. The gallery maps which simultaneous location and mapping information obtained by UAV Extended Kalman Filter algorithms processed were obtained experimentally. © 2016 IEEE.

Prediction of wind speed with non-linear autoregressive (NAR) neural networks [Rüzgâr Hizinin Dogrusal Olmayan Otoregresif Sinir Aglari ile Tahmini]

Karasu, Seçkin | Altan, Aytaç | Saraç, Zehra | Hacıoğlu, Rıfat

Proceedings | 2017 | 2017 25th Signal Processing and Communications Applications Conference, SIU 2017 , pp.1433 - 1436

In this study, the wind speed prediction model is created that gives a minimum error for different hidden layer neuron numbers and delay step numbers. Using the one-minute time series, the prediction of the next wind speed is performed with the NAR neural network model. The predicted values of wind speed obtained are compared with predicted values of wind speed obtained with filter methods. For different window functions and lengths, wind speed prediction is made using filters with different weight coefficients. For the number of hidden layer neurons is 14 and the number of delay steps is 10, MAE, MSE and RMSE values are calculated . . .as 0.0315, 0.0019, 0.0445, respectively, with NAR neural network. It is seen that the proposed method for the wind speed dataset has a higher prediction performance than thefilter methods. © 2017 IEEE Daha fazlası Daha az

Ultrasonic signal delay determination for distance estimation in underwater space [Sualti Uzaylarda Mesafe Kestirimi İçin Ultrasonik İşaret Gecikmesinin Belirlenmesi]

Onur, Tuğba Özge | Hacıoğlu, Rıfat

Proceedings | 2017 | 2017 25th Signal Processing and Communications Applications Conference, SIU 2017 , pp.1433 - 1436

Reverberation and multipath propagation afîect the accuracy of time of flight (TOF) estimation in confined underwater medium. In this paper, time delay has been estimated by obtaining the transmitted signal and first echo signal from measured signal acquised by using a wideband transducer with 5 MHz central frequency. Cross-correlation (CC) and generalized cross-correlation (GCC) methods have been applied to the obtained signals and their performances have been compared. The results show that GCC method has better performance for time delay estimation in confined underwater medium where multipath propagation and reverberation are se . . .vere. © 2017 IEEE Daha fazlası Daha az

The comparison of the effects of low and high flow desflurane anesthesia on hemodynamic effects and anesthetic gas consumption [Düşük ve yüksek akimli desfluran anestezisinin hemodinamiye ve anestezik gaz tüketimine etkilerinin karşilaş tirilmasi]

Çukdar, Gamze | Turan Özkoçak, Işıl | Ayoğlu, Hilal | Hancı, Volkan | Yurtlu, Serhan | Özer, Yetkin

Article | 2008 | Turk Anesteziyoloji ve Reanimasyon Dernegi Dergisi36 ( 4 ) , pp.222 - 229

We investigated the effects of desflurane anesthesia with high and low fresh gas flows on hemodynamic stability and desflurane consumption. After obtaining ethical comittee approval, 60 patients in the ASA risk groups I-II were included in the study. After anesthesia induction, the anesthesia maintenance was performed during the first 10 minutes with 4,4 L min -1 fresh gas flow and desflurane (4-6%) in all cases. The fresh gas flow was reduced to 1 L min-1 after 10 minutes whereas it was maintained as 4,4 L min-1 in Group N after the randomization of the patients into two groups. Heart rate (HR), mean arterial pressure (MAP), periph . . .eral O2 saturation (SPO2), inspiratory desflurane (FiDes), expiratory desflurane (ETDes), inspiratory O2 (FiO 2), inspiratory CO2 (FiCO2), expiratory O 2 (ETO2), inspiratory N2O (FiN2O), expiratory N2O (ETN2O), end-tidal CO2 concentrations (ETCO2) and peak airway pressure (Pplateau) values were measured and recorded at 0., 2., 5., 7. and 10. minutes after intubation and every 5 minutes in first 60 minutes and every 15 minutes later on. The total amounts of fentanyl, desflurane, N2O and O2 were also recorded. There were no significant differences between the groups in terms of HR, MAP, FiDes, ETDes, ETCO2, Pplateau and total fentanyl consumption. The O2, N2O and desflurane consumptions of Group N were lower than those of Group N. (p<0.05) The desflurane consumption was 78 mL h-1 in group N and 26 mL h-1 in Group D. The hourly reduction rate of desflurane consumption was 67% in Group D. According to our results, we conclude that desflurane has provided an efficient anesthesia depth, hemodynamic stability and safe respiratory parameters in low flow anesthesia. Moreover, the low flow anesthesia with desflurane reduces the anesthetic costs when compared with high flow anesthesia by decreasing the total consumption of anesthetic gases Daha fazlası Daha az

Image enhancement in ultrasound imaging

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.

Comparison of the diagnostic results of bronchoalveolar lavage with synchronous transbronchial biopsies

Barut, Figen | Özdamar, Şükrü Oğuz | Bahadır, Burak | Gün, Banu Doğan | Bektaş, Sibel | Çolak, Sacide | Kuzey, Gamze Mocan

Article | 2007 | TURKIYE KLINIKLERI TIP BILIMLERI DERGISI27 ( 2 ) , pp.179 - 183

Objective: Bronchoalveolar lavage performed during bronchoscopic examination is a type of cytologic sampling with great diagnostic significance. Its diagnostic value is enhanced when biopsy is unavailable and bronchoalveolar lavage is the unique sample. Determining the diagnostic accuracy of bronchoalveolar lavage by comparing it with the diagnostic yield of synchronous biopsies is an indicator of its effectiveness. Material and Methods: In this study, 435 bronchoalveolar lavage and 273 bronchoscopic biopsy specimens obtained from January 2003 to December 2005 in the Department of Pulmonary Diseases were retrospectively evaluated in . . . the Department of Pathology, Faculty of Medicine, Zonguldak Karaelmas University. Results: Overall, 373 cases (85.8%) were diagnosed as benign and 12 cases (2.8%) were reported as malignant, while IS cases (4.1%) were suspected to be malignant; the remaining 32 cases (7.3%) were reported as inadequate. The numbers and percentages of benign, malignant, suspected malignant and inadequate diagnoses of the 273 bronchoalveolar lavage cases with synchronous transbronchial biopsies were 229 (83.9%), 12 (4.5%), 16 (5.8%), and 16 (5.8%), respectively. After suspected malignant and inadequate samples were excluded, coomparison of cytologic and histologic diagnoses revealed that the diagnostic accuracy of bronchoalveolar lavage cytology was 79.4% and 91.6% for benign and malignant diagnoses, respectively; the rate of false negativity was 20.5% and false positivity was 8.3%. Conclusion: While sampling errors seemed to be the primary reason for false negative and false positive diagnoses, the rate of false cytologic evaluation was lower. Considering the false negative diagnoses for cases without biopsy specimens, comparison of bronchoalveolar lavage diagnoses with synchronous biopsies may serve as a quality control programme, since this condition may significantly influence the clinical course Daha fazlası Daha az

Visual tracking and control of Unmanned aerial vehicle İnsansız hava araçlarında görsel takip ve denetim

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.

Teleconferencing acoustic echo cancellation using adaptive Hammerstein block structure

Özdinç, Tuğba Özge | Hacıoğlu, Rıfat

Proceedings | 2007 | 2007 IEEE 15TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS, VOLS 1-3 , pp.1849 - 1852

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

Adaptive echo and noise cancellation for car hands-free voice communication

Onur, Tuğba Özge | Hacıoğlu, Rıfat


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

The controller of the camera used in target tracking for unmanned vehicle with model predictive controller

Altan, Aytaç | Hacıoğlu, Rıfat


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

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