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Full-Text Articles in Physical Sciences and Mathematics

Coherence Analysis On Thermal Effect For Power Cables Under Different Environmental Conditions, Sezai̇ Taşkin, Şahi̇n Serhat Şeker, Özcan Kalenderli̇, Murat Karahan Jan 2014

Coherence Analysis On Thermal Effect For Power Cables Under Different Environmental Conditions, Sezai̇ Taşkin, Şahi̇n Serhat Şeker, Özcan Kalenderli̇, Murat Karahan

Turkish Journal of Electrical Engineering and Computer Sciences

There are 2 important aspects of this research; these are the experimental study and the data analysis, which are based on coherence analysis. In this study, a low-voltage power cable is tested under 2 different environments, air and water, and the variations in temperature are measured for the conductor, the sheath parts of the cable, and the environment. The recorded test data are analyzed using such as coherence analysis. This in turn provides the means to determine the relationship among the sheath, conductor, and the environment. In conclusion, high correlated peaks in the frequency domain are used to determine the …


Design And Implementation Of A Programmable High-Voltage Impulse Measurement System, Serkan Dedeoğlu, Serhat Yilmaz Jan 2014

Design And Implementation Of A Programmable High-Voltage Impulse Measurement System, Serkan Dedeoğlu, Serhat Yilmaz

Turkish Journal of Electrical Engineering and Computer Sciences

High-voltage impulses (HVIs) are produced under laboratory conditions in order to emulate actual internal (switching) and external (lightning, thunderbolt) voltages. HVI resistance tests are essential to meet national and international standards on the production of electromechanical devices and materials, such as switchgears, and transformers that operate under these actual conditions. Accurate measurement of HVI is excessively difficult since the voltage level is so high, while the time parameters are relatively constricted. In this study, a reliable automatic HVI measuring and recording system, which accommodates a series of hardware and software designs in order to satisfy the constraints of the standards, …


Applications Of Wavelets And Neural Networks For Classification Of Power System Dynamics Events, Samir Avdakovic, Amir Nuhanovic, Mirza Kusljugic, Elvisa Becirovic Jan 2014

Applications Of Wavelets And Neural Networks For Classification Of Power System Dynamics Events, Samir Avdakovic, Amir Nuhanovic, Mirza Kusljugic, Elvisa Becirovic

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the possibility of classifying power system dynamics events using discrete wavelet transform (DWT) and a neural network (NN) by analyzing one variable at a single network bus. Following a disturbance in the power system, it will propagate through the system in the form of low-frequency electromechanical oscillations (LFEOs) in a frequency range of up to 5 Hz. DWT allows the identification of components of the LFEO, their frequencies, and magnitudes. After determining the energy components' share of the analyzed signal using DWT and Parseval's theorem, the input data for the classification process using a NN are obtained. …


Observer-Based Controller For Current Mode Control Of An Interleaved Boost Converter, Shenbaga Lakshmi, Sree Renga Raja Jan 2014

Observer-Based Controller For Current Mode Control Of An Interleaved Boost Converter, Shenbaga Lakshmi, Sree Renga Raja

Turkish Journal of Electrical Engineering and Computer Sciences

A state feedback control method for an interleaved boost power converter is designed, which, in turn, can achieve interleaved current sharing among parallel-connected converters. The state feedback control in the continuous time domain is derived using the pole placement technique and linear quadratic optimal method. The load estimator is designed by deriving a full-order state observer to ensure the robustness and optimality of the state feedback control and an observer-based controller (control law plus full-order state observer) is designed using the separation principle. The adopted control strategies achieve effective output voltage regulation, good dynamic stability, and reject disturbances. Extensive simulation …


Btsql: Nested Bitemporal Relational Database Query Language, Canan Atay, Abdullah Uz Tansel Jan 2014

Btsql: Nested Bitemporal Relational Database Query Language, Canan Atay, Abdullah Uz Tansel

Turkish Journal of Electrical Engineering and Computer Sciences

A nested bitemporal relational data model and its query language are implemented. The bitemporal atom (BTA) is the fundamental construct to represent temporal data and it contains 5 components: a value, the lower and upper bounds of valid time, and the lower and upper bounds of the recoding time. We consider 2 types of data structures for storing BTAs: 1) string representation and 2) abstract data-type representation. We also develop a preprocessor for translating a bitemporal structured query language (BtSQL) statement into standard SQL statements. The BtSQL includes the select, insert, delete, and update statements of the SQL, extended for …


Bi Input-Extended Kalman Filter-Based Speed-Sensorless Control Of An Induction Machine Capable Of Working In The Field-Weakening Region, Remzi̇ İnan, Murat Barut Jan 2014

Bi Input-Extended Kalman Filter-Based Speed-Sensorless Control Of An Induction Machine Capable Of Working In The Field-Weakening Region, Remzi̇ İnan, Murat Barut

Turkish Journal of Electrical Engineering and Computer Sciences

This study introduces a novel bi input-extended Kalman filter (BI-EKF)-based speed-sensorless direct vector control (DVC) of an induction motor (IM). The proposed BI-EKF-based estimator includes online estimations of the stator stationary axis components of the stator currents, i_{s\alpha} and i_{s\beta}; stator stationary axis components of the rotor flux, \varphi_{r\alpha} and \varphi_{r\beta}; rotor angular velocity, \omega_m; stator resistance, R_s; rotor resistance, R_r; and load torque t_L, as well as the magnetizing inductance, L_m, by only supposing that the stator phase currents and voltages are measured. Thus, the speed-sensorless DVC of the IM with the inclusion of the proposed estimator is able …


Removing Random-Valued Impulse Noise In Images Using A Neural Network Detector, İlke Türkmen Jan 2014

Removing Random-Valued Impulse Noise In Images Using A Neural Network Detector, İlke Türkmen

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a new method using an artificial neural network to remove random-valued impulse noise (RVIN) in images. The inputs of the neural model used to detect the RVIN are formed using basic and related gradient values. The detection of the noisy pixels is realized in 3 phases using the proposed neural detector. In order to obtain a more robust detector, 2 different networks, which are trained with an artificial training image corrupted with high and low clutter densities, are used. The extensive simulation results show that the proposed method is significantly better than the compared filters in terms …


Robust Stability Of Linear Uncertain Discrete-Time Systems With Interval Time-Varying Delay, Mehmet Nur Alpaslan Parlakçi Jan 2014

Robust Stability Of Linear Uncertain Discrete-Time Systems With Interval Time-Varying Delay, Mehmet Nur Alpaslan Parlakçi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a robust stability problem for linear uncertain discrete-time systems with interval time-varying delay and norm-bounded uncertainties. First, a necessary and sufficient stability condition is obtained by employing a well-known lifting method and switched system approach for nominal discrete-time delay systems. Both the stability method of checking the characteristic values inside the unit circle and a Lyapunov function-based stability result are taken into consideration. Second, a simple Lyapunov--Krasovskii functional (LKF) is selected, and utilizing a generalized Jensen sum inequality, a sufficient stability condition is presented in the form of linear matrix inequalities. Third, a novel LKF is proposed …


Wireless Sensor Localization Using Enhanced Dv-Aoa Algorithm, Peter Brida, Juraj Machaj, Jozef Benikovsky Jan 2014

Wireless Sensor Localization Using Enhanced Dv-Aoa Algorithm, Peter Brida, Juraj Machaj, Jozef Benikovsky

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we deal with the improvement of the positioning accuracy of distance vector (DV)-based positioning algorithms, which use angular information DV- angle of arrival (AoA). This algorithm belongs to an ad-hoc positioning system. We focus on the improvement of the algorithm and its enhanced version is presented. The angular information of particular nodes is obtained and processed by the original algorithm; however, the final position estimation is determined by the proposed novel algorithm using only a subset of all intersections. We assign weights to the individual intersections according to their positions and the positions of the RNs. For …


Correlation Analysis Between Surface Electromyography And Continuous-Wave Near-Infrared Spectroscopy Parameters During Isometric Exercise To Volitional Fatigue, Ömer Şayli̇, Ata Akin, Hasan Bi̇rol Çotuk Jan 2014

Correlation Analysis Between Surface Electromyography And Continuous-Wave Near-Infrared Spectroscopy Parameters During Isometric Exercise To Volitional Fatigue, Ömer Şayli̇, Ata Akin, Hasan Bi̇rol Çotuk

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the process of muscular fatigue was examined using surface electromyography (sEMG) and continuous-wave near-infrared spectroscopy (cw-NIRS) simultaneously during an isometric hand grip exercise at 50% and 75% of the maximal voluntary contraction (MVC), sustained until volitional fatigue. The mean frequency of the sEMG decreased during the whole exercise, whereas the root mean square had a tendency to increase. Oxyhemoglobin/deoxyhemoglobin concentration changes computed with cw-NIRS were found to exhibit a fast linear decrease/increase in the first 10--20 s of the exercise, the so-called fast phase, followed by a plateau-like slow phase. The change rates were higher at 75% …


Multifunction Converter Based On Lyapunov Function Used In A Photovoltaic System, Trung Nhan Nguyen, An Luo Jan 2014

Multifunction Converter Based On Lyapunov Function Used In A Photovoltaic System, Trung Nhan Nguyen, An Luo

Turkish Journal of Electrical Engineering and Computer Sciences

The development of distributed generations (DGs) is essential to help solve energy crises and improve the reliability of electricity supplies. However, the involvement of a DG in a grid along with an increase of the nonlinear load will reduce the power quality. To solve this problem, we want the converter used in the DG to work flexibly, intelligently, and more accurately. To contribute to the improvement of quality of the DG, this paper proposes a multifunction converter (MFC) model. With the proposed model, the photovoltaic generator, which can be operated at harmonic suppression, and the power injection are more flexible …


A Reduced Probabilistic Neural Network For The Classification Of Large Databases, Abdelhadi Lotfi, Abdelkader Benyettou Jan 2014

A Reduced Probabilistic Neural Network For The Classification Of Large Databases, Abdelhadi Lotfi, Abdelkader Benyettou

Turkish Journal of Electrical Engineering and Computer Sciences

The probabilistic neural network (PNN) is a special type of radial basis neural network used mainly for classification problems. Due to the size of the network after training, this type of network is usually used for problems with a small-sized training dataset. In this paper, a new training algorithm is presented for use with large training databases. Application to the handwritten digit database shows that the reduced PNN performs better than the standard PNN for all of the studied cases with a big gain in size and processing speed. This new type of neural network can be used easily for …


A Low-Order Nonlinear Amplifier Model With Distributed Delay Terms, Ahmet Hayretti̇n Yüzer, Şi̇mşek Demi̇r Jan 2014

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, Aytürk Keleş Jan 2014

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, Mehmet Recep Bozkurt, Ni̇lüfer Yurtay, Zi̇ynet Yilmaz, Cengi̇z Sertkaya Jan 2014

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 …


Face Recognition Across Pose Variation And The 3s Problem, Jamal Hussain Shah, Muhammad Sharif, Mudassar Raza, Aisha Azeem Jan 2014

Face Recognition Across Pose Variation And The 3s Problem, Jamal Hussain Shah, Muhammad Sharif, Mudassar Raza, Aisha Azeem

Turkish Journal of Electrical Engineering and Computer Sciences

Most face recognition methods are based on linear and nonlinear subspace features extraction and classification tasks. These classification methods are used for global and local facial features for person identification. Both local and global features play different roles for recognition and classification. There are a number of face recognition methods that have been proposed up until now, and they produce good results. However, when small sample size (3S) and pose variation problems are taken into consideration, face recognition becomes more complex and does not produce good results. In this paper, 3S and pose variation problems are dealt with. First, linear …


A Comparison Of Fuzzy Logic And Pid Controllers To Control Transmitted Power Using A Tcsc, Mohsen Hosseinzadeh Soreshjani, Navid Reza Abjadi, Abbas Kargar, Gholamreza Arab Markadeh Jan 2014

A Comparison Of Fuzzy Logic And Pid Controllers To Control Transmitted Power Using A Tcsc, Mohsen Hosseinzadeh Soreshjani, Navid Reza Abjadi, Abbas Kargar, Gholamreza Arab Markadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, the use of flexible AC transmission systems (FACTS) is an economical and interesting approach to improve power transfer capability. The thyristor-controlled series capacitor, as a member of the FACTS family, can control interrelated parameters with dynamism due to its ability of rapid control and stabilization. Regardless of all of the works in this area, the control of transmitted power through the design of the firing angle controller is still missing. In this paper, first, the open-loop firing angle controller and its sensitivities are analyzed to fill in this gap. Next, closed-loop controllers such as PID and fuzzy controllers are …


Design And Realization Of A Welding Oscillator, Muci̇z Özcan Jan 2014

Design And Realization Of A Welding Oscillator, Muci̇z Özcan

Turkish Journal of Electrical Engineering and Computer Sciences

Welding is one of the most popular methods to combine metal pieces in manufacturing processes. Arc welding, among all welding techniques, is the most commonly used in manufacturing due to its cost and flexibility. During the manufacturing process, arc welding is either performed by an operator or by automatic tools such as welding oscillators. Using automatic tools has advantages over manual use, as the process will be faster, cheaper, and have less welding flaws. In this paper, a homemade welding oscillator and the method to manufacture it are presented. The presented welding oscillator can be manufactured for a very low …


A Low-Memory Intensive Decoding Architecture For Double-Binary Convolutional Turbo Code, Ming Zhan, Liang Zhou, Jun Wu Jan 2014

A Low-Memory Intensive Decoding Architecture For Double-Binary Convolutional Turbo Code, Ming Zhan, Liang Zhou, Jun Wu

Turkish Journal of Electrical Engineering and Computer Sciences

Memory accesses take a large part of the power consumption in the iterative decoding of double-binary convolutional turbo code (DB-CTC). To deal with this, a low-memory intensive decoding architecture is proposed for DB-CTC in this paper. The new scheme is based on an improved maximum a posteriori probability algorithm, where instead of storing all of the state metrics, only a part of these state metrics is stored in the state metrics cache (SMC), and the memory size of the SMC is thus reduced by 25%. Owing to a compare-select--recalculate processing (CSRP) module in the proposed decoding architecture, the unstored state …


A New Approach In The Evaluation Of Hospital Information Systems, Güney Gürsel, Neşe Zayi̇m, Kemal Hakan Gülkesen, Ali̇ Ari̇foğlu, Osman Saka Jan 2014

A New Approach In The Evaluation Of Hospital Information Systems, Güney Gürsel, Neşe Zayi̇m, Kemal Hakan Gülkesen, Ali̇ Ari̇foğlu, Osman Saka

Turkish Journal of Electrical Engineering and Computer Sciences

Hospital information system (HIS) evaluation frameworks have largely been discussed in the literature. However, existing frameworks lack one important aspect: to what extent user expectations of HISs are met. In this study, user expectation data are collected by means of the 'expectation questionnaire'. The internal consistencies of the answers to the questionnaire are measured by Cronbach's alpha coefficient. Fuzzy logic methodologies are used to evaluate the expectation variables in the proposed evaluation framework. The evaluation variables are not represented in the results equally; they are reflected by the weights assigned by the users. Our proposed framework provides the overall degree …


Competitive Unit Maintenance Scheduling In A Deregulated Environment Based On Preventing Market Power, Hessam Golmohamadi, Maryam Ramezani, Hamid Falaghi Jan 2014

Competitive Unit Maintenance Scheduling In A Deregulated Environment Based On Preventing Market Power, Hessam Golmohamadi, Maryam Ramezani, Hamid Falaghi

Turkish Journal of Electrical Engineering and Computer Sciences

With the advent of electricity markets, the traditional approach to unit maintenance scheduling (UMS) needs to undergo major changes in order to be compatible with competitive environment structures. The transition from a vertical power system to a competitive structure makes many challenges for policymakers and market designers. In this paper, a new approach to UMS in competitive electricity markets is presented. The main part of this study involves both how to treat generating companies (GENCOs) fairly and how to guarantee power system security during the maintenance scheduling. This paper advances the UMS in the electricity market so that one can …


Statistical Approach For Determining Impulse Breakdown Voltage Distribution Under Dc Sweep Voltage, Mehmet Demi̇r, Celal Koraşli Jan 2014

Statistical Approach For Determining Impulse Breakdown Voltage Distribution Under Dc Sweep Voltage, Mehmet Demi̇r, Celal Koraşli

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a comprehensive approach to the statistical characterization of impulse breakdown voltage under the effect of a DC sweep voltage. Several goodness-of-fit tests are applied to up-and-down test results obtained in the air-insulated rod-plane gap. Three distributions, normal, logistic, and Gumbel, are compared by means of the Kolmogorov--Smirnov goodness-of-fit test, and logistic distribution is also compared to 3-parameter Weibull distributions using the likelihood ratio test. Logistic distribution is found to be a possible alternative to normal and 3-parameter Weibull distributions.


Modeling And Simulation Of Deadbeat-Based Pi Controller In A Single-Phase H-Bridge Inverter For Stand-Alone Applications, Tow Leong Tiang, Dahaman Ishak Jan 2014

Modeling And Simulation Of Deadbeat-Based Pi Controller In A Single-Phase H-Bridge Inverter For Stand-Alone Applications, Tow Leong Tiang, Dahaman Ishak

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a deadbeat-based proportional-integral (PI) controller for a stand-alone single-phase voltage source inverter using a battery cell as the primary energy source. The inverter system is simulated in MATLAB/Simulink. It consists of a lead acid battery, third-order Butterworth low-pass DC filter and AC filter, H-bridge inverter, step-up transformer, and a variety of loads, as well as its sinusoidal pulse-width modulation (SPWM) deadbeat-based PI controller. In this paper, 2 simulation case studies are carried out, which are the abrupt load changes from a 400 W resistive load to a 500 W resistive load, and from a 400 W resistive …


Rfid And Communication Technologies For An Intelligent Bus Monitoring And Management System, Mahammad Abdul Hannan, Aishah Mustapha, Abdulla Al Mamun, Aini Hussain, Hassan Basri Jan 2014

Rfid And Communication Technologies For An Intelligent Bus Monitoring And Management System, Mahammad Abdul Hannan, Aishah Mustapha, Abdulla Al Mamun, Aini Hussain, Hassan Basri

Turkish Journal of Electrical Engineering and Computer Sciences

This paper highlights the implementation of an intelligent bus monitoring system based on current challenges and problems. In this system, radio frequency identification and integrated sensing technologies, such as a global positioning system, general packet radio service, and geographic information system, are used to monitor the movement of a bus. A new theoretical framework and ruled-based decision algorithms are developed for the system. An experimental setup is developed for the prototype implementation. The results show that the choice of integrated technologies used in the system is suitable to monitor and manage a vehicle transportation system.


An Urgent Precaution System To Detect Students At Risk Of Substance Abuse Through Classification Algorithms, Faruk Bulut, İhsan Ömür Bucak Jan 2014

An Urgent Precaution System To Detect Students At Risk Of Substance Abuse Through Classification Algorithms, Faruk Bulut, İhsan Ömür Bucak

Turkish Journal of Electrical Engineering and Computer Sciences

In recent years, the use of addictive drugs and substances has turned out to be a challenging social problem worldwide. The illicit use of these types of drugs and substances appears to be increasing among elementary and high school students. After becoming addicted to drugs, life becomes unbearable and gets even worse for their users. Scientific studies show that it becomes extremely difficult for an individual to break this habit after being a user. Hence, preventing teenagers from addiction becomes an important issue. This study focuses on an urgent precaution system that helps families and educators prevent teenagers from developing …


A New Edge-Preserving Algorithm Based On The Cie- Lu'v' Color Space For Color Contrast Enhancement, Mohammad Zolfaghari, Mehran Yazdi Jan 2014

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 …


Solving A New Bi-Objective Joint Replenishment Inventory Model With Modified Rand And Genetic Algorithms, Ommolbanin Yousefi, Seyed Jafar Sadjadi Jan 2014

Solving A New Bi-Objective Joint Replenishment Inventory Model With Modified Rand And Genetic Algorithms, Ommolbanin Yousefi, Seyed Jafar Sadjadi

Turkish Journal of Electrical Engineering and Computer Sciences

There are many cases in real inventory systems where more than one objective must be optimized. The main purpose of this research is to develop a multiobjective joint replenishment problem (JRP), where one objective is the minimization of the total inventory investment and another is the minimization of the total inventory ordering and holding costs. To solve the suggested model, 3 algorithms are proposed. In the first algorithm, the existing RAND method, called the best heuristic for solving the JRP, is modified and a new heuristic algorithm is developed to be applicable to the JRP with 2 objectives. The second …


A New Approach Of Nonblind Watermarking Methods Based On Dwt And Svd Via Lu Decomposition, Onur Jane, Ersi̇n Elbaşi Jan 2014

A New Approach Of Nonblind Watermarking Methods Based On Dwt And Svd Via Lu Decomposition, Onur Jane, Ersi̇n Elbaşi

Turkish Journal of Electrical Engineering and Computer Sciences

Multimedia security has been the focal point of considerable research activity in the last decade, mainly because of its wide application area. Watermarking, in particular, is identified as a major technology to achieve copyright protection and multimedia security. Therefore, recent studies in the literature include some evident approaches for embedding data into a multimedia element. Because of its useful frequency component separation, the discrete wavelet transform (DWT) is commonly used in watermarking schemes. Moreover, singular value decomposition (SVD) and lower-and-upper (LU) decomposition have little effect on the perception of the watermark. Therefore, in this study, a combination of DWT and …


A Novel Hybrid Recurrent Wavelet Neural Network Control Of Permanent Magnet Synchronous Motor Drive For Electric Scooter, Chih Hong Lin Jan 2014

A Novel Hybrid Recurrent Wavelet Neural Network Control Of Permanent Magnet Synchronous Motor Drive For Electric Scooter, Chih Hong Lin

Turkish Journal of Electrical Engineering and Computer Sciences

Due to the electric scooter with nonlinear uncertainties, e.g., nonlinear friction force of the transmission belt, the linear controller was made to disable speed tracking control. In order to overcome this problem, a novel hybrid recurrent wavelet neural network (NHRWNN) control system is proposed to control for a permanent-magnet synchronous motor-driven electric scooter in this study. The NHRWNN control system consists of a supervised control, a recurrent wavelet neural network (RWNN), and a compensated control with adaptive law. According to the Lyapunov stability theorem and the gradient descent method, the on-line parameter training methodology of the RWNN can be derived …


Vessel Segmentation In Mri Using A Variational Image Subtraction Approach, Ayşe Nurdan Saran, Fati̇h Nar, Murat Saran Jan 2014

Vessel Segmentation In Mri Using A Variational Image Subtraction Approach, Ayşe Nurdan Saran, Fati̇h Nar, Murat Saran

Turkish Journal of Electrical Engineering and Computer Sciences

Vessel segmentation is important for many clinical applications, such as the diagnosis of vascular diseases, the planning of surgery, or the monitoring of the progress of disease. Although various approaches have been proposed to segment vessel structures from 3-dimensional medical images, to the best of our knowledge, there has been no known technique that uses magnetic resonance imaging (MRI) as prior information within the vessel segmentation of magnetic resonance angiography (MRA) or magnetic resonance venography (MRV) images. In this study, we propose a novel method that uses MRI images as an atlas, assuming that the patient has an MRI image …