Yazar "Aydogdu, O." seçeneğine göre listele

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    DSP implementation of a PV system with GA-MLP-NN based MPPT controller supplying BLDC motor drive
    (PERGAMON-ELSEVIER SCIENCE LTD, 2007) Akkaya, R.; Kulaksiz, A. A.; Aydogdu, O.
    This paper presents a brushless dc motor drive for heating, ventilating and air conditioning fans, which is utilized as the load of a photovoltaic system with a maximum power point tracking (MPPT) controller. The MPPT controller is based on a genetic assisted, multi-layer perceptron neural network (GA-MLP-NN) structure and includes a DC-DC boost converter. Genetic assistance in the neural network is used to optimize the size of the hidden layer. Also, for training the network, a genetic assisted, Levenberg-Marquardt (GA-LM) algorithm is utilized. The off line GA-MLP-NN, trained by this hybrid algorithm, is utilized for online estimation of the voltage and current values in the maximum power point. A brushless dc (BLDC) motor drive system that incorporates a motor controller with proportional integral (PI) speed control loop is successfully implemented, to operate the fans. The digital signal processor (DSP) based unit provides rapid achievement of the MPPT and current control of the BLDC motor drive. The performance results of the system are given, and experimental results are presented for a laboratory prototype of 120 W. (c) 2006 Elsevier Ltd. All rights reserved.
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    Evaluation of laparoscopic transperitoneal adrenalectomy: is it feasible for large masses?
    (EDIZIONI MINERVA MEDICA, 2015) Mesci, A.; Celik, O.; Akand, M.; Aydogdu, O.; Arici, G.; Arici, C.; Erdogru, T.
    Aim. The aim of this paper was to determine whether laparoscopic adrenalectomy (LA) is a safe and effective treatment for the management of large adrenal tumors. Methods. We retrospectively evaluated the data of patients who underwent LA at our institution between September 2002 and September 2012. Seventy-six transperitoneal LA were performed by the same surgical team. Patients with invasive tumors to adjacent organs or distant metastasis were excluded from the study. All patients were operated using the 450 oblique position as transperitoneal approach. Results. The mean age of the patients was 48.3 years (range 20-68 years). The mean tumor size was 5.37 cm (range 2-15 cm). Sixteen patients had tumor size over 8 cm. The mean tumor weight was 31.2 gr (range 2-156 g). The lesions were localized on the tight side in 42 (55%) patients and on the left side in 34 (45%) patients. The mean intraoperative blood loss was 114 mL (range 20-400 mL) and the mean operative time was 112 min (range 55-300 min). Six patients (7%) required conversion to open procedure. The mean hospitalization time was 2.5 days (range 1-4 days). Five patients (6%) had postoperative minor complications. There were no incidents of capsular invasion or adverse cardiovascular events. Conclusion. LA is safe and feasible for both malign and benign adrenal lesions. Good preoperative assessment, surgical skills, team work and adherence to anatomical and surgical principles are the key to success for large adrenal masses.