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2016

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Articles 12271 - 12300 of 12675

Full-Text Articles in Physical Sciences and Mathematics

The Classification Of Eeg Signals Using Discretization-Based Entropy And The Adaptive Neuro-Fuzzy Inference System, Mahmut Heki̇m Jan 2016

The Classification Of Eeg Signals Using Discretization-Based Entropy And The Adaptive Neuro-Fuzzy Inference System, Mahmut Heki̇m

Turkish Journal of Electrical Engineering and Computer Sciences

A novel feature extraction called discretization-based entropy is proposed for use in the classification of EEG signals. To this end, EEG signals are decomposed into frequency subbands using the discrete wavelet transform (DWT), the coefficients of these subbands are discretized into the desired number of intervals using the discretization method, the entropy values of the discretized subbands are calculated using the Shannon entropy method, and these are then used as the inputs of the adaptive neuro-fuzzy inference system (ANFIS). The equal width discretization (EWD) and equal frequency discretization (EFD) methods are used for the discretization. In order to evaluate their …

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Linear Model Of A Three-Phase Shunt Active Power Filter With A Hysteresis Controller, Kadi̇r Vardar, Eyup Akpinar Jan 2016

Linear Model Of A Three-Phase Shunt Active Power Filter With A Hysteresis Controller, Kadi̇r Vardar, Eyup Akpinar

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, a linear model of a 3-phase active power filter (APF) is obtained to design a DC link proportional--integral (PI) controller. The system is designed on the basis of a TMS320F2812 digital signal processer (DSP). The PI controller is implemented in the program of the DSP. The hysteresis controller and sampling frequency are also taken into account in the linear model. The effect of hysteresis bandwidth, filter inductance, DC link capacitor, and sampling frequency on the stability are investigated by using the Routh--Hurwitz method. The detailed simulation model in MATLAB and experimental results showed that the linear model …

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A Sparsity-Preserving Spectral Preconditioner For Power Flow Analysis, Emrullah Fati̇h Yetki̇n, Hasan Dağ Jan 2016

A Sparsity-Preserving Spectral Preconditioner For Power Flow Analysis, Emrullah Fati̇h Yetki̇n, Hasan Dağ

Turkish Journal of Electrical Engineering and Computer Sciences

Due to the ever-increasing demand for more detailed and accurate power system simulations, the dimensions of mathematical models increase. Although the traditional direct linear equation solvers based on LU factorization are robust, they have limited scalability on the parallel platforms. On the other hand, simulations of the power system events need to be performed at a reasonable time to assess the results of the unwanted events and to take the necessary remedial actions. Hence, to obtain faster solutions for more detailed models, parallel platforms should be used. To this end, direct solvers can be replaced by Krylov subspace methods (conjugate …

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A Switchable Approach To Large Object Allocation In Real-Time Java, Veysel Harun Şahi̇n, Ümi̇t Kocabiçak Jan 2016

A Switchable Approach To Large Object Allocation In Real-Time Java, Veysel Harun Şahi̇n, Ümi̇t Kocabiçak

Turkish Journal of Electrical Engineering and Computer Sciences

Over the last 20 years object-oriented programming languages and managed run-times like Java have been very popular because of their software engineering benefits. Despite their popularity in many application areas, they have not been considered suitable for real-time programming. Besides many other factors, one of the barriers that prevent their acceptance in the development of real-time systems is the long pause times that may arise during large object allocation. This paper examines different kinds of solutions that have been developed so far and introduces a switchable approach to large object allocation in real-time Java. A synthetic benchmark application that is …

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Extracting The Region Of Interest From Mfl Signals, Ali Sadr, Raziyeh Sadat Okhovat Jan 2016

Extracting The Region Of Interest From Mfl Signals, Ali Sadr, Raziyeh Sadat Okhovat

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we study the magnetic flux leakage (MFL) signals for detection of defects in ferromagnetic materials. MFL signals consist of a background that is not constant and is combined with noise. Since there are slight variations because of noise, any large distortion shows a defect. Here the estimation of the background and then the determination of a threshold to distinguish defects from noise have been used for locating defects. In this method, precise evaluation of these two parameters has a vital role on the defect detection. The concept of histograms has been employed for eliminating the effect of …

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Incremental Weighted Bipartite Algorithm For Large-Scale Recommendation Systems, Haihong E, Jianfeng Wang, Meina Song, Qiang Bi, Yingyi Liu Jan 2016

Incremental Weighted Bipartite Algorithm For Large-Scale Recommendation Systems, Haihong E, Jianfeng Wang, Meina Song, Qiang Bi, Yingyi Liu

Turkish Journal of Electrical Engineering and Computer Sciences

Personalized recommendation systems are a solution for information overload. In the real recommendation system, the data are dynamic; thus, the real time of the system will be seriously affected if we recalculate after every change, and, in time, sensitive situation of the delayed updated calculation will affect the accuracy of the recommendation. The incremental calculation methods of collaborative filtering, clustering, singular value decomposition, and bipartite algorithm have achieved some progress; however, there is limited research on the incremental computation of the weighted bipartite algorithm. This paper proposes a personalized recommendation algorithm. In this algorithm, the rank of the recommendations is …

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Modified Hexagonal Sierpinski Gasket-Based Antenna Design With Multiband And Miniaturized Characteristics For Uwb Wireless Communication, Ademola Aluwaseun Kaka, Mehmet Toycan Jan 2016

Modified Hexagonal Sierpinski Gasket-Based Antenna Design With Multiband And Miniaturized Characteristics For Uwb Wireless Communication, Ademola Aluwaseun Kaka, Mehmet Toycan

Turkish Journal of Electrical Engineering and Computer Sciences

A modified hexagonal Sierpinski gasket-based fractal antenna is proposed for ultrawide-band (UWB) wireless applications. The designed antenna has miniaturized (36 $\times $ 48 mm$^{2})$ and multiband characteristics. Two design guidelines, the partial ground plane technique and the circular annular ring patch on the substrate, are applied to improve impedance matching and radiation pattern characteristics. According to the simulation results, the proposed modified antenna has a reflection coefficient $S_{11} $ of less than --15 dB, a linear phase of the reflection coefficient, 80{\%} radiation efficiency, 2--4.5 dBi antenna gain, and omnidirectional radiation pattern properties over the full UWB spectrum (3.1--10.6 GHz). …

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An Improved Real-Time Adaptive Kalman Filter With Recursive Noise Covariance Updating Rules, Iyad Hashlamon, Kemaletti̇n Erbatur Jan 2016

An Improved Real-Time Adaptive Kalman Filter With Recursive Noise Covariance Updating Rules, Iyad Hashlamon, Kemaletti̇n Erbatur

Turkish Journal of Electrical Engineering and Computer Sciences

The Kalman filter (KF) is used extensively for state estimation. Among its requirements are the process and observation noise covariances, which are unknown or partially known in real-life applications. Uncertain and biased values of the covariances result in KF performance degradation or divergence. Unlike previous methods, we are using the idea of the recursive estimation of the KF to develop two recursive updating rules for the process and observation covariances, respectively designed based on the covariance matching principles. Each rule has a tuning parameter that enhances its flexibility for noise adaptation. The proposed adaptive Kalman filter (AKF) proves itself to …

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Optimization Of Automatic Steering Control On A Vehiclewith A Steer-By-Wire System Using Particle Swarm Optimization, Fachrudin Hunaini, Imam Robandi, Nyoman Sutantra Jan 2016

Optimization Of Automatic Steering Control On A Vehiclewith A Steer-By-Wire System Using Particle Swarm Optimization, Fachrudin Hunaini, Imam Robandi, Nyoman Sutantra

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a simulation of the automatic steering control system on a vehicle model using particle swarm optimization (PSO) to optimize the parameters of the control system. The control system involves fuzzy logic control (FLC) and proportional-integral-derivative (PID) control working in a cascade; the main control (FLC) is used to control lateral motion, and the secondary control (PID) is an enhancement to control the yaw motion in vehicle models representing 10 degrees of freedom of the vehicle dynamics system. Optimization by PSO is carried out simultaneously on both control systems. On FLC it is done by setting the width …

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Passivity-Based Robust Controller Design For A Variable Speed Wind Energy Conversion System, Peng Wang, Haisong Wang, Xu Cai, Zhengzhi Han Jan 2016

Passivity-Based Robust Controller Design For A Variable Speed Wind Energy Conversion System, Peng Wang, Haisong Wang, Xu Cai, Zhengzhi Han

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a design method for a robust controller to improve the stability and system dynamic behavior for variable speed wind energy conversion systems. By analyzing the mathematical model of a wind power conversion system, control strategies for both a generator-side converter and a grid-side converter are given. For the generator-side converter, the well-known maximum power point tracking method is employed, while for the grid-side converter, a robust controller is presented based on passivity theory. The $L_{2}$-gain performance is analyzed using linear matrix inequality. Moreover, in order to accelerate the dynamic response and reduce the DC link voltage fluctuations, …

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A 2.4-Ghz Highly Linear Derivative Superposition Gilbert Cell Mixer, Samaneh Sedighi, Omid Hashemipour, Massoud Dousti Jan 2016

A 2.4-Ghz Highly Linear Derivative Superposition Gilbert Cell Mixer, Samaneh Sedighi, Omid Hashemipour, Massoud Dousti

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new derivative superposition Gilbert cell to minimize the third-order nonlinear current term of transconductance transistors. To decrease the parasitic capacitance effect on gain, noise figure, and linearity of the circuit, extra inductors and capacitors are added between the switching and transconductance stages. The proposed mixer is simulated in 0.18-$\mu $m RF-CMOS technology with a 1.8-V supply. The results show an improvement of about 23 dBm in IIP3 compared to conventional mixers. The power consumption of this circuit is about 3.96 mW.

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Sensorless Velocity And Direction Angle Control Of An Unmanned Vehicle, Adnan Derdi̇yok, Abdullah Başçi̇ Jan 2016

Sensorless Velocity And Direction Angle Control Of An Unmanned Vehicle, Adnan Derdi̇yok, Abdullah Başçi̇

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper an observer based on measured and estimated currents and a kinematic model is designed to estimate the velocity and direction angle of an unmanned vehicle (UV). The Lyapunov stability theory is used to establish the stability conditions for the observer. It is shown that the observer will converge in a finite time and the observer gains satisfy the constraints of the stability conditions. The observed velocity and direction angle are used in the closed loop instead of measured ones for sensorless control of the UV. The velocity and direction angle control of the UV are carried out …

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Chattering-Eliminated Adaptive Sliding-Mode Control: An Experimental Comparison Study, Murat Furat, İlyas Eker Jan 2016

Chattering-Eliminated Adaptive Sliding-Mode Control: An Experimental Comparison Study, Murat Furat, İlyas Eker

Turkish Journal of Electrical Engineering and Computer Sciences

The present paper deals with a new adaptive sliding-mode control. The switching and equivalent control laws include adaptive gains. An error-dependent adaptive gain in the switching control law and an adaptive parameter in the equivalent control law with respect to open-loop transient response of the system are proposed to eliminate chattering and to increase the performance of the controller. The proposed approach results in chattering elimination without using any complex calculation-based methods, which is highly useful for practical applications. The number of independent gains is also minimized. Therefore, tuning of those gains is simplified. The proposed controller is compared experimentally …

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A Generalized Particle Swarm Optimization Using Reverse Direction Information, Emre Çomak Jan 2016

A Generalized Particle Swarm Optimization Using Reverse Direction Information, Emre Çomak

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, an improved particle swarm optimization (PSO) algorithm, including 4 types of new velocity updating formulae (each is equal to the traditional PSO), was introduced. This algorithm was called the reverse direction supported particle swarm optimization (RDS-PSO) algorithm. The RDS-PSO algorithm has the potential to extend the diversity and generalization of traditional PSO by regulating the reverse direction information adaptively. To implement this extension, 2 new constants were added to the velocity update equation of the traditional PSO, and these constants were regulated through 2 alternative procedures, i.e. max--min-based and cosine amplitude-based diversity-evaluating procedures. The 4 most commonly …

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Solving Multimodal Optimization Problems Based On Efficient Partitioning Of Genotypic Search Space, Atabak Mashhadi Kashtiban, Sohrab Khanmohammadi, Kayvan Asghari Jan 2016

Solving Multimodal Optimization Problems Based On Efficient Partitioning Of Genotypic Search Space, Atabak Mashhadi Kashtiban, Sohrab Khanmohammadi, Kayvan Asghari

Turkish Journal of Electrical Engineering and Computer Sciences

Enhancing the exploration and exploitation of multimodal optimization is still an interesting and challenging problem in optimization. Here we present a new population-based evolutionary algorithm for multiple optimal determinations. The approach is simply based on partitioning the genotypic search space and running a simple genetic algorithm with a small population within each partition. To increase the efficiency of the algorithm, the first-order discrete derivative of the fitness function for elite solutions was used to omit extra solutions. If the derivative of the fitness function is larger than a specified gradient threshold, no optimum exists within a given partition, and no …

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Design And Analysis Of A Novel Uwb Bandpass Filter Using 3-D Em Simulation-Based Neural Network Model With Hsa, Sali̇h Demi̇rel, Cafer Uyanik Jan 2016

Design And Analysis Of A Novel Uwb Bandpass Filter Using 3-D Em Simulation-Based Neural Network Model With Hsa, Sali̇h Demi̇rel, Cafer Uyanik

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new systematic analysis and design of the ultrawide-band bandpass filter by using the 3-D electromagnetic simulation-based multilayer perceptron neural network (MLP NN) model of unit elements. This MLP NN model is utilized efficiently as a fast and accurate model within a harmony search algorithm (HSA) procedure to determine the resultant optimum microstrip structure geometry. Moreover, the validity and efficiency of the HSA is manifested by comparing it with those of the standard metaheuristics, which are genetic and particle swarm algorithms. The filter that shows the best performance is designed and realized. Measurements taken from the realized …

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Comprehensive Review Of Association Estimators For The Inference Of Gene Networks, Zeyneb Kurt Yavuz, Ni̇zametti̇n Aydin, Gökmen Altay Jan 2016

Comprehensive Review Of Association Estimators For The Inference Of Gene Networks, Zeyneb Kurt Yavuz, Ni̇zametti̇n Aydin, Gökmen Altay

Turkish Journal of Electrical Engineering and Computer Sciences

Gene network inference (GNI) algorithms allow us to explore the vast amount of interactions among the molecules in cells. In almost all GNI algorithms the main process is to estimate association scores among the variables of the dataset. However, there is no commonly accepted estimator to compute association scores for the current GNI algorithms. In this paper the association estimators that might be used in GNI applications are reviewed. The aim is to prepare a comprehensive and comparative review of all the important association estimators available in the literature. We performed this main aim by presenting, classifying, comparing, and discussing …

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An Improved Security Framework For Web Service-Based Resources, Wenbin Jiang, Hui Xu, Hao Dong, Hai Jin, Xiaofei Liao Jan 2016

An Improved Security Framework For Web Service-Based Resources, Wenbin Jiang, Hui Xu, Hao Dong, Hai Jin, Xiaofei Liao

Turkish Journal of Electrical Engineering and Computer Sciences

Web service-based application has become one of the dominative ones of the Internet. This trend brings more and more security challenges in reliability, confidentiality, and data nonrepudiation, especially in some systems that have massive diversified resources. An improved framework for secure accesses of Web resources is presented and implemented by extending and enhancing the Spring Security framework. It improves the security level of systems for identity authentication, authorized access, and secure transmission. The highly safe authentication is based on the integration of an improved authentication module of Spring Security with a U-key method and a RSA algorithm. For authorized access, …

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Sizing Design And Implementation Of A Flywheel Energy Storage System For Space Applications, Kutlay Aydin, Mehmet Ti̇mur Aydemi̇r Jan 2016

Sizing Design And Implementation Of A Flywheel Energy Storage System For Space Applications, Kutlay Aydin, Mehmet Ti̇mur Aydemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

Flywheel energy storage systems have become an important research subject in recent years. They are also considered for space applications instead of hazardous and bulky electrochemical batteries. In this paper, a flywheel energy storage system has been designed for satellite attitude control systems. Power requirements of a small commercial satellite have been used as the starting point of the design. The designed system includes a BLDC motor. The machine is run as a motor for 60 min and the stored energy is discharged during the following 30 min to simulate low orbit satellite operation. Experimental results show that these systems …

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Study Of Temperature Distribution In Light--Tissue Interaction Using The Fem, Ahmet Yasi̇n Çi̇tkaya, Şaban Seli̇m Şeker Jan 2016

Study Of Temperature Distribution In Light--Tissue Interaction Using The Fem, Ahmet Yasi̇n Çi̇tkaya, Şaban Seli̇m Şeker

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the numerical modeling of interaction between light sources and living biological tissue is studied. One of the most important results of physical interactions of light with biological tissue are thermal changes, which are a consequence of absorption of light. The severity of the effects is dependent upon several factors, including exposure duration, wavelength of the beam, beam energy, tissue type, and the area that is exposed to the beam. The temperature response of tissue irradiation is governed by the extensively used Pennes bioheat equation in a 3-dimensional space. The Pennes equation is solved initially for a single-layer …

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Design Of A High-Linear, High-Precision Analog Multiplier, Free From Body Effect, Ali Naderi Saatlo, İsmai̇l Serdar Özoğuz Jan 2016

Design Of A High-Linear, High-Precision Analog Multiplier, Free From Body Effect, Ali Naderi Saatlo, İsmai̇l Serdar Özoğuz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new CMOS four-quadrant analog multiplier circuit is proposed, based on a pair of dual-translinear loops. The significant features of the circuit are its high accuracy and high linearity as well as its body effect-free operation, owing to the fact that the circuit relies on a new dual-translinear topology. In addition, harmonic distortions are precisely discussed due to their conceivable mismatches, including transconductance and threshold voltage of the transistors. HSPICE postlayout simulation results are presented to verify the validity of the theoretical analysis, where under a supply voltage of 2.8 V, the bandwidth of the proposed multiplier …

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Walsh Series Modeling And Estimation In Sensorless Position Control Of Electrical Drives, Hamidreza Shirazi, Jalal Nazarzadeh Jan 2016

Walsh Series Modeling And Estimation In Sensorless Position Control Of Electrical Drives, Hamidreza Shirazi, Jalal Nazarzadeh

Turkish Journal of Electrical Engineering and Computer Sciences

High-performance electrical drives can be achieved by using field-oriented controllers, which make torque and flux naturally decoupled. A conventional vector-controlled drive has the disadvantage of either requiring flux and speed sensors or being affected by rotor resistance, which varies along with the motor performance. The presented paper focuses on developing a high-performance sensorless rotor flux-oriented controller of an induction machine independent of the rotor resistance variation. This method applies spectral theory of Walsh functions, which are one of the most helpful members of piecewise constant basis functions in solving dynamic models. Inherent characteristics of Walsh functions and application of an …

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Wavefront-Ray Grid Fdtd Algorithm, Mehmet Çi̇ydem Jan 2016

Wavefront-Ray Grid Fdtd Algorithm, Mehmet Çi̇ydem

Turkish Journal of Electrical Engineering and Computer Sciences

A finite difference time domain algorithm on a wavefront-ray grid (WRG-FDTD) is proposed in this study to reduce numerical dispersion of conventional FDTD methods. A FDTD algorithm conforming to a wavefront-ray grid can be useful to take into account anisotropy effects of numerical grids since it features directional energy flow along the rays. An explicit and second-order accurate WRG-FDTD algorithm is provided in generalized curvilinear coordinates for an inhomogeneous isotropic medium. Numerical simulations for a vertical electrical dipole have been conducted to demonstrate the benefits of the proposed method. Results have been compared with those of the spherical FDTD algorithm …

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Prediction-Based Reversible Image Watermarking Using Artificial Neural Networks, Mahsa Afsharizadeh, Majid Mohammadi Jan 2016

Prediction-Based Reversible Image Watermarking Using Artificial Neural Networks, Mahsa Afsharizadeh, Majid Mohammadi

Turkish Journal of Electrical Engineering and Computer Sciences

In prediction-based reversible watermarking schemes, watermark bits are embedded in the prediction errors. An accurate prediction results in smaller prediction errors, more efficient embedding, and less distortion for the watermarked image. In this paper, an accurate prediction is made using artificial neural networks. Before the embedding operation, 2 neural networks are trained by the pixel values of the image. Then the trained neural networks predict the pixel values that are used in the embedding operation. Due to the training ability of the neural networks, the prediction will be more accurate than the averaging technique. Experimental results show that the proposed …

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Energy Savings Potential In Air Conditioners And Chiller Systems, Durmuş Kaya, Hisham Alidrisi Jan 2016

Energy Savings Potential In Air Conditioners And Chiller Systems, Durmuş Kaya, Hisham Alidrisi

Turkish Journal of Electrical Engineering and Computer Sciences

In the current paper we quantified and evaluated the energy saving potential in air conditioners and chiller systems. We also showed how to reduce the cost of air conditioners and chiller systems in existing facilities on the basis of payback periods. Among the measures investigated were: 1) installing higher efficiency air conditioners, 2) installing higher efficiency chillers, 3) duty cycling air conditioning units, and 4) utilizing existing economizers on air conditioning units. For each method, examples were provided from Arizona, USA. In these examples, the amount of saved energy, the financial evaluation of this energy, and the investment cost and …

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Modeling And Control Of A Doubly Fed Induction Generator With A Disturbance Observer: A Stator Voltage Oriented Approach, Eşref Emre Özsoy, Edin Golubovic, Asif Sabanovic, Seta Bogosyan, Meti̇n Gökaşan Jan 2016

Modeling And Control Of A Doubly Fed Induction Generator With A Disturbance Observer: A Stator Voltage Oriented Approach, Eşref Emre Özsoy, Edin Golubovic, Asif Sabanovic, Seta Bogosyan, Meti̇n Gökaşan

Turkish Journal of Electrical Engineering and Computer Sciences

The popularity of renewable energy conversion systems, and especially of wind energy, has been growing in recent years. Doubly fed induction generator (DFIG)-based wind energy systems are extensively used due to their wide range of active and reactive power controllability. Conventional DFIG control structures consist of decoupled PI rotor current controllers with stator flux orientation and machine parameter-dependent compensating terms. The accuracy of stator flux calculations is dependent on how accurately the stator resistance is known. Integration problems also exist and additional low-pass filters are implemented to accurately calculate the stator flux. In the current study, machine-dependent compensating terms are …

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Development Of Radiometer Operating Between 50 Mhz And 26.5 Ghz Using Gain-Stabilized Lna, Murat Celep, Şenel Yaran, Cem Hayirli, Ari̇f Dolma Jan 2016

Development Of Radiometer Operating Between 50 Mhz And 26.5 Ghz Using Gain-Stabilized Lna, Murat Celep, Şenel Yaran, Cem Hayirli, Ari̇f Dolma

Turkish Journal of Electrical Engineering and Computer Sciences

A radiometer operating between 50 MHz and 26.5 GHz and consisting of microwave channels all with a low-noise amplifier (LNA) was established. Microwave switches were used to select an appropriate channel according to measurement frequency. The effect of variations both in input and output reflection coefficients on LNA gain was investigated. To keep the change in the gain of the LNA at minimum, the LNA output was terminated with a load whose impedance was equal to that of matched load. This technique gives the opportunity of full-band noise measurements of noise sources with one total power radiometer. The performance of …

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A Parametric Study On Privatization Revenues Of The Electricity Distribution Companies In Turkey, Ercan İzgi̇, Seli̇m Ay Jan 2016

A Parametric Study On Privatization Revenues Of The Electricity Distribution Companies In Turkey, Ercan İzgi̇, Seli̇m Ay

Turkish Journal of Electrical Engineering and Computer Sciences

The privatization of electricity distribution companies in the state monopoly has increased significantly in recent years. Privatization is expected to improve the quality of services in the electric distribution sector and to provide additional income to the state. In this paper the privatization revenues of the 18 electricity distribution companies in Turkey are calculated through regression equations. The privatization revenues of the electricity distribution companies are identified by 5 models containing microeconomic and macroeconomic variables (parameters). The study indicates a correlation between the considered variables and the privatization revenues of the electricity distribution companies and useful parametric formulations are proposed. …

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A Novel Key Distribution Scheme Against Storage-Bounded Adversaries Using Attack Probabilities, Mohammad Farhadi Bajestani, Ali Payandeh Jan 2016

A Novel Key Distribution Scheme Against Storage-Bounded Adversaries Using Attack Probabilities, Mohammad Farhadi Bajestani, Ali Payandeh

Turkish Journal of Electrical Engineering and Computer Sciences

Key establishment proves to be a challenging problem in wireless sensor networks. A key establishment scheme needs to incorporate properties like scalability and energy efficiency. We propose a scheme that, besides enjoying a desirable scalability, consumes resources according to attack probability within each region. In this scheme, the distribution area is divided into regions of varying attack probability. It is assumed that the adversary is storage bounded and that not all communications can be stored by the adversary. This scheme is highly resistant to node compromises and there is an extremely low probability of discovering the key by the adversary …

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Speciation-Based Genetic Algorithm In Analog Circuit Design, Hasari̇ Karci̇, Gülay Tohumoğlu, Ari̇f Nacaroğlu Jan 2016

Speciation-Based Genetic Algorithm In Analog Circuit Design, Hasari̇ Karci̇, Gülay Tohumoğlu, Ari̇f Nacaroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a speciation procedure that improves the local search capability of the genetic algorithm in analog circuit design. There is no need for additional circuit simulation in order to apply this procedure. The procedure is tested in Gaussian, sigmoid, cube, and square circuit design problems. Two sets of 125 simulations with the same seed values are performed for each problem using both the proposed procedure and the canonical genetic algorithm. The simulation results show that the method is statistically better than the canonical genetic algorithm, which suffers from bad locality. The effects of the population size and speciation …

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