Reliability-Based Generation Resource Planning In Electricity Markets,
2014
TÜBİTAK
Reliability-Based Generation Resource Planning In Electricity Markets, Maziar Mirhoseini Moghaddam, Mohammad Hossein Javidi, Mohsen Parsa Moghaddam, Majid Oloomi Buygi
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a reliability-based competitive generation resource planning model in electricity markets. The Monte Carlo simulation method is applied to consider random outages of generation units and transmission lines as well as load uncertainty. In order to determine the optimal plan for installation of candidate generating units, the decisions of generation companies (GenCos) and the independent system operators (ISOs) are investigated. The method is based on an iterative process for simulating interactivity among ISOs and GenCos and is repeated until security and reliability constraints assumed by the ISO are fulfilled. In the proposed model, the ISO utilizes a new …
Performance Evaluation Of The Wave Atom Algorithm To Classify Mammographic Images,
2014
TÜBİTAK
Performance Evaluation Of The Wave Atom Algorithm To Classify Mammographic Images, Nebi̇ Gedi̇k, Ayten Atasoy
Turkish Journal of Electrical Engineering and Computer Sciences
The most common type of cancer seen in women is breast cancer. To enable recovery from this severe disease, monitoring and early detection must be provided, and related precautions must be taken as a first step. During diagnosis, some cases may be overlooked due to fatigue and eyestrain, because the determination of abnormalities is a repetitive procedure. In this study, a computer-aided diagnosis (CAD) system, using the wave atom transform (WAT) algorithm and support vector machine (SVM), is proposed to evaluate mammography images. During the process, the region of interest (ROI) is defined before applying the method. The system includes …
Model-Based Robust Chaotification Using Sliding Mode Control,
2014
TÜBİTAK
Model-Based Robust Chaotification Using Sliding Mode Control, Aykut Kocaoğlu, Cüneyt Güzeli̇ş
Turkish Journal of Electrical Engineering and Computer Sciences
Chaos is a complex behavior of dynamical nonlinear systems that is undesirable in most applications and should be controlled; however, it is desirable in some situations and should be generated. In this paper, a robust chaotification scheme based on sliding mode control is proposed for model based chaotification. A continuous time single input observable system is considered such that it is subject to parameter uncertainties, nonlinearities, noises, and disturbances, which are all additive to the input and can be modeled as an unknown function but bounded by a known function. The designed dynamical state feedback control law forces the system …
A New Edge-Preserving Algorithm Based On The Cie- Lu'v' Color Space For Color Contrast Enhancement,
2014
TÜBİTAK
A New Edge-Preserving Algorithm Based On The Cie- Lu'v' Color Space For Color Contrast Enhancement, Mohammad Zolfaghari, Mehran Yazdi
Turkish Journal of Electrical Engineering and Computer Sciences
Image segmentation and edge detection are the most important presteps in machine vision, and their successfulness can affect the success of the next steps. In this paper, the performance of the Trahanias edge detector in different color spaces, such as RGB, YCbCr, HSI, and CIE Lu'v', is compared in order to find the best color space for image segmentation and edge detection. We then offer an efficient edge-preserving algorithm for color contrast enhancement in the CIE Lu'v' space. The proposed algorithm can increase the color contrast, which causes a remarkable improvement in image segmentation and edge detection in the CIE …
A Low-Order Nonlinear Amplifier Model With Distributed Delay Terms,
2014
TÜBİTAK
A Low-Order Nonlinear Amplifier Model With Distributed Delay Terms, Ahmet Hayretti̇n Yüzer, Şi̇mşek Demi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a novel behavioral modeling technique for the characterization of memory effects of amplifiers is proposed. This characterization utilizes asymmetric intermodulation distortion (IMD) components, which are the result of a 2-tone excitation of a nonlinear amplifier. These asymmetric IMD components are represented basically by a power series, where each term in the series has its own time delay term. These time delay terms successfully justify the presence of asymmetry in the intermodulation components, which leads to the prediction of amplitude-to-amplitude and amplitude-to-phase distortions. The parameters of the model are extracted using 2-tone measurements. A 100-W peak power amplifier …
Expert Doctor Verdis: Integrated Medical Expert System,
2014
TÜBİTAK
Expert Doctor Verdis: Integrated Medical Expert System, Aytürk Keleş
Turkish Journal of Electrical Engineering and Computer Sciences
Innovative medical technologies are developing day by day, as there is an important need for integrated medical expert systems (ESs) that will help to effectively manage and control diagnosis and treatment processes. These systems, with new approaches, have improved the experiences and capabilities of physicians to make the diagnosis of diseases. In this work, an integrated medical ES called Expert Doctor Verdis (Ex-Dr Verdis) is developed, which combines an advanced medical information system containing various medical services supported by information technologies, with ES capabilities in a single system. This system is also one kind of decision support system. Implementation of …
Comparison Of Different Methods For Determining Diabetes,
2014
TÜBİTAK
Comparison Of Different Methods For Determining Diabetes, Mehmet Recep Bozkurt, Ni̇lüfer Yurtay, Zi̇ynet Yilmaz, Cengi̇z Sertkaya
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the Pima Indian Diabetes dataset was categorized with 8 different classifiers. The data were taken from the University of California Irvine Machine Learning Repository's web site. As a classifier, 6 different neural networks [probabilistic neural network (PNN), learning vector quantization, feedforward networks, cascade-forward networks, distributed time delay networks (DTDN), and time delay networks], the artificial immune system, and the Gini algorithm from decision trees were used. The classifier's performance ratios were studied separately as accuracy, sensitivity, and specificity and the success rates of all of the classifiers are presented. Among these 8 classifiers, the best accuracy and …
A Control Scheme Employing An Adaptive Hysteresis Current Controller And An Uncomplicated Reference Current Generator For A Single-Phase Shunt Active Power Filter, Hüseyi̇n Doğan, Ramazan Akkaya
Turkish Journal of Electrical Engineering and Computer Sciences
In recent years, active power filters (APFs) have become popular because of their excellent current harmonics and reactive power mitigation ability. The performance of the APF is directly related to the selected control strategy, which is mainly divided into 2, the reference current generation and current control. Most of the reference current generation methods are very complicated and require precise mathematical expressions. Moreover, being the most preferred current control method, conventional hysteresis controllers have a fixed bandwidth, which causes different total demand distortion values under different load conditions. In this study, a novel control scheme for a single-phase shunt APF …
Stability Analysis Of Multimachine Thermal Power Systems Using The Nature-Inspired Modified Cuckoo Search Algorithm,
2014
TÜBİTAK
Stability Analysis Of Multimachine Thermal Power Systems Using The Nature-Inspired Modified Cuckoo Search Algorithm, Shivakumar Rangasamy, Panneerselvam Manickam
Turkish Journal of Electrical Engineering and Computer Sciences
The stability of modern interconnected thermal power systems is greatly affected by the presence of low-frequency inertial oscillations in the system, due to various forms of disturbances experienced. This paper provides an efficient damping solution to these oscillations based on nature-inspired modified cuckoo search algorithm-based controller design. The proposed controller design is formulated as a parameter optimization problem based on damping ratio and time-domain error deviations. The effectiveness of the proposed damping controller design is illustrated by performing the nonlinear time domain simulations of the test multimachine power systems under various operating conditions and disturbances. Moreover, an exhaustive comparative stability …
Application Of Hilbert--Huang Transform And Support Vector Machine For Detection And Classification Of Voltage Sag Sources,
2014
TÜBİTAK
Application Of Hilbert--Huang Transform And Support Vector Machine For Detection And Classification Of Voltage Sag Sources, Alireza Foroughi, Ebrahim Mohammadi, Saeid Esmaeili
Turkish Journal of Electrical Engineering and Computer Sciences
Power quality disturbances, including voltage sag, swell, harmonics, flicker, and notch, are one of the main concerns for industries and electrical equipment. Among these disturbances, voltage sag, due to its irrecoverable economic effects on industries, is particularly important. In this paper, the detection and classification of voltage sag sources containing motor starting, short circuit, transformer energizing, and the reacceleration of motors after fault clearance using the Hilbert--Huang transform (HHT) and support vector machine (SVM) are studied. A voltage sag waveform includes several oscillating modes; for separating these oscillating modes, which are called intrinsic mode functions (IMFs), empirical mode decomposition is …
Reliability-Based Maintenance Scheduling Of Generating Units In Restructured Power Systems,
2014
TÜBİTAK
Reliability-Based Maintenance Scheduling Of Generating Units In Restructured Power Systems, Mahmud Fotuhi Firuzabad, Farrokh Aminifar, Abbas Shahzadeh
Turkish Journal of Electrical Engineering and Computer Sciences
Maintenance scheduling of generating units in restructured power systems is a collaborative and interactive process between independent system operators (ISOs) and generating companies (GENCOs). The ISO should comply with GENCO maintenance preferences subject to targeted system reliability levels. This process might be multistage since the admission of all initial unit outage requests may threaten system reliability. Hence, the ISO accepts some proposals and determines alternatives for the remaining units. The GENCOs are then allowed to confirm the alternatives or revise them. In this paper the ISO problem of generating unit maintenance scheduling is tackled. The objective function is to minimize …
Induction Motor Parameter Estimation Using Metaheuristic Methods,
2014
TÜBİTAK
Induction Motor Parameter Estimation Using Metaheuristic Methods, Ali̇ İhsan Çanakoğlu, Asim Gökhan Yetgi̇n, Hasan Temurtaş, Mustafa Turan
Turkish Journal of Electrical Engineering and Computer Sciences
The steady-state equivalent circuit parameters of an induction motor can be estimated using the operation characteristics that are provided by manufacturers. The characteristics of the motor used in estimation methods are the starting, maximum, and nominal torque values; the power factor; and efficiency. The operation characteristics of a motor given in data sheets are generally based on design parameters and are not suitable with real values. For this reason, in this paper, the data used in the parameter estimation for induction motors are taken from the literature. Using an optimization method for parameter estimation is useful for comparing the manufacturer …
Optimal Reactive Power Flow Solution In Multiterminal Ac-Dc Systems Based On Artificial Bee Colony Algorithm,
2014
TÜBİTAK
Optimal Reactive Power Flow Solution In Multiterminal Ac-Dc Systems Based On Artificial Bee Colony Algorithm, Faruk Yalçin, Uğur Ari̇foğlu
Turkish Journal of Electrical Engineering and Computer Sciences
Active power loss optimization is one of the important goals in electrical power systems and it is provided by optimal reactive power flow (ORPF). In this study, a new approach for the solution of the ORPF in multiterminal AC-DC systems is proposed. This approach provides 3 main contributions. First, the convergence problem in the AC-DC power flow is solved. Second, the problem of getting stuck in local minima during the optimization process is overcome. Third, a better global optimum point is obtained for the ORPF. Active power loss optimization is implemented through the artificial bee colony (ABC) algorithm, which is …
Digital Control System Design And Analyses Of A 3-Phase Bearingless Induction Motor,
2014
TÜBİTAK
Digital Control System Design And Analyses Of A 3-Phase Bearingless Induction Motor, Wenshao Bu, Conglin Zu, Shaojie Wang, Shenghua Huang
Turkish Journal of Electrical Engineering and Computer Sciences
The overall configuration of a magnetic suspension decoupling control system is designed to realize the reliable digital control of a 3-phase bearingless induction motor whose rotor windings are not pole-specific. Based on a digital signal processor complementary metal-oxide semiconductor chip, the digital control hardware and software systems are analyzed and designed. In this paper, the calculation and regulation of the motor rotational speed, correction and regulation methods of the radial displacements, calculation and compensation algorithms of the unilateral magnetic pulls, induction compensation algorithm of the effective suspension control current, current regulation, and space-vector pulse width modulation algorithms, are presented in …
Class-E Gaas Hbt Power Amplifier With Passive Linearization Scheme For Mobile Wireless Communications,
2014
TÜBİTAK
Class-E Gaas Hbt Power Amplifier With Passive Linearization Scheme For Mobile Wireless Communications, Uthirajoo Eswaran, Harikrishnan Ramiah, Jeevan Kanesan, Ahmed Wasif Reza
Turkish Journal of Electrical Engineering and Computer Sciences
A linearization technique for improving the class-E power amplifier (PA)'s adjacent channel power ratio (ACPR) is proposed. The design is simulated in a 2-mu m InGaP/GaAs heterojunction bipolar transistor process. The integration of a passive predistorter at the input of the PA linearizes the proposed architecture. At a 29-dBm output power, the PA's ACPR is indicated to be -51 dBc, meeting the stringent code division multiple access regulation. At this exact output power, the simulated power added efficiency is 55 % with the collector voltage headroom consumption of 3.4 V. The input return loss, S11, of the PA is simulated …
A Reconfigurable Baseband Circuit Applied For Wimax Low-If Receivers,
2014
TÜBİTAK
A Reconfigurable Baseband Circuit Applied For Wimax Low-If Receivers, Xin Cheng, Guangjun Xie
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a reconfigurable baseband circuit for WiMAX low-IF receivers, including a complex filter and 2 automatic gain controllers (AGCs) for I and Q channels. Only by changing the capacitor values can the center and cutoff frequencies of the complex filter be adjusted simultaneously to realize the reconfigurability. Meanwhile, a novel one-step method to obtain fast gain settling of AGCs is proposed. The chip is fabricated in 0.13-\mu m CMOS technology, occupies 0.9 \times 1.3 mm^2, and consumes 14.8 mW of power with a 1.2-V power supply. The measurement results show a reconfigurable bandwidth of 2 K to 3.5/5/10 …
Predics: A New Go-Po-Based Ray Launching Simulator For The Calculation Of Electromagnetic Scattering And Rcs From Electrically Large And Complex Structures, Caner Özdemi̇r, Betül Yilmaz, Özkan Kirik
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, we present a new simulator called pRediCS for the calculation of electromagnetic scattering and radar cross-section (RCS) from electrically large and complex targets. The simulator utilizes the geometric optics (GO) theory and launching of electromagnetic rays for tracing and calculating the electric field values as the electromagnetic waves bounce around the target. The physical optics (PO) theory is also exploited to calculate the final scattered electric field by calculating the far-field PO integration along the observation direction. The simulator is first tested with known objects of canonical shapes, whose analytical solutions are available in the literature. Next, …
Sliding Mode Controller Design With Fractional Order Differentiation: Applications For Unstable Time Delay Systems,
2014
TÜBİTAK
Sliding Mode Controller Design With Fractional Order Differentiation: Applications For Unstable Time Delay Systems, Celaleddi̇n Yeroğlu, Gürkan Kavuran
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a design method for a sliding mode controller with the contribution of a fractional order differential operator. The conventional sliding mode controller has been widely studied in different control applications. This paper proposes that the fractional order differential operator enlarges the output span of the classical sliding mode controller to obtain a better-fitting control signal for enhanced control performance. The sliding surface and the equivalent control law are modified with the addition of a fractional differential operator and a conventional one. The proposed sliding mode controller with fractional order differentiation is applied to the unstable time delay …
Abrupt And Incipient Fault Detection And Compensation For A 4-Tank System Benchmark,
2014
TÜBİTAK
Abrupt And Incipient Fault Detection And Compensation For A 4-Tank System Benchmark, Pedram Hajiani, Javad Poshtan
Turkish Journal of Electrical Engineering and Computer Sciences
Fault detection and compensation play a key role in enhancing the high demand for performance and security in technological systems. This paper proposes an active fault-tolerant control scheme that detects and compensates for actuator faults in a 4-tank system benchmark. The faults are modeled as a drastic gain loss in actuators (pumps), which could lead to a large loss in the nominal performance. The model-based approach uses a recursive least squares parameter estimation algorithm to form a fault detection and diagnosis subsystem and utilizes a parametric eigenstructure assignment method to reconfigure the state feedback controller. The designed controller is simulated …
Real-Time Control Of An Automated Guided Vehicle Using A Continuous Mode Of Sliding Mode Control,
2014
TÜBİTAK
Real-Time Control Of An Automated Guided Vehicle Using A Continuous Mode Of Sliding Mode Control, Bi̇rol Soysal
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a tracking control method for a certain type of differential-drive wheeled mobile robot, called automated guided vehicles (AGVs), using a continuous mode approach of sliding mode control (SMC). The SMC applied produces a continuous signal in between the U and -U control signals instead of discrete ones. The controller is applied to control the velocity and direction angle of the vehicle in order to keep it on a desired path. The obtained algorithm is applied to the experimental system under load and disturbance to show its robustness. The experimental results are satisfactory and verify the performance of …
