Open Access. Powered by Scholars. Published by Universities.®

Computer Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Electrical and Computer Engineering

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 4561 - 4590 of 7215

Full-Text Articles in Computer Engineering

Epilepsy Diagnosis Using Artificial Neural Network Learned By Pso, Nesi̇be Yalçin, Gülay Tezel, Ci̇han Karakuzu Jan 2015

Epilepsy Diagnosis Using Artificial Neural Network Learned By Pso, Nesi̇be Yalçin, Gülay Tezel, Ci̇han Karakuzu

Turkish Journal of Electrical Engineering and Computer Sciences

Electroencephalogram (EEG) is used routinely for diagnosis of diseases occurring in the brain. It is a very useful clinical tool in the classification of epileptic seizures and the diagnosis of epilepsy. In this study, epilepsy diagnosis has been investigated using EEG records. For this purpose, an artificial neural network (ANN), widely used and known as an active classification technique, is applied. The particle swarm optimization (PSO) method, which does not need gradient calculation, derivative information, or any solution of differential equations, is preferred as the training algorithm for the ANN. A PSO-based neural network (PSONN) model is diversified according to …


Improving The Performance Of Primal--Dual Interior-Point Method In Inverse Conductivity Problems, Ashkan Javaherian, Amir Movafeghi, Reza Faghihi, Effat Yahaghi Jan 2015

Improving The Performance Of Primal--Dual Interior-Point Method In Inverse Conductivity Problems, Ashkan Javaherian, Amir Movafeghi, Reza Faghihi, Effat Yahaghi

Turkish Journal of Electrical Engineering and Computer Sciences

This study improves the performance of primal--dual interior-point method in inverse conductivity problems via replacing the conventional, complicatedly calculated scalar regularization parameter with a diagonal matrix termed ``multi-regularization parameter matrix'' here. The solution of the PD--IPM depends considerably on the choice of the regularization parameter. Calculation of the optimal regularization parameter, which yields the most accurate solution, is not simple due to the long iterative nature of the algorithm. The objective optimization, which is implemented by minimizing error in the solutions over an extensive range of the regularization parameters, yields the most accurate solution that can be achieved, although this …


Continuous-Time Hopfield Neural Network-Based Optimized Solution To 2-Channel Allocation Problem, Zekeri̇ya Uykan Jan 2015

Continuous-Time Hopfield Neural Network-Based Optimized Solution To 2-Channel Allocation Problem, Zekeri̇ya Uykan

Turkish Journal of Electrical Engineering and Computer Sciences

The channel allocation problem in cellular radio systems is NP-complete, and thus its general solution is not known for even the 2-channel case. It is well known that the link gain system matrix (or received-signal power system matrix) of the radio network is (and may be highly) asymmetric, and that as the Hopfield neural network is applied to optimization problems, its weight matrix should be symmetric. The main contribution of this paper is as follows: turning the channel allocation problem into a maxCut graph partitioning problem, we propose a simple and effective continuous-time Hopfield neural network-based solution by determining its …


Control Of Soil Moisture With Radio Frequency In A Photovoltaic-Powered Drip Irrigation System, Mahi̇r Dursun, Semi̇h Özden Jan 2015

Control Of Soil Moisture With Radio Frequency In A Photovoltaic-Powered Drip Irrigation System, Mahi̇r Dursun, Semi̇h Özden

Turkish Journal of Electrical Engineering and Computer Sciences

Solar-powered irrigation systems are becoming increasingly widespread. However, the initial setup costs of these systems are very high. To reduce these costs, both the energy usage and the prevention of losses from irrigation systems are very important. In this study, a drip irrigation control system of 1000 dwarf cherry trees was controlled using soil moisture sensors in order to prevent excessive water consumption and energy losses in a solar-powered irrigation system. The control system comprises units that are energized with solar panels, and the flow of information is implemented via radio frequency. Thus, by removing the cables that create difficulties …


Type Iii Compensated Voltage Mode Line Feedforward Synchronously Rectified Boost Converter For Driving Class D Audio H-Bridge To Deliver 7 W Peak Power Into An 8 Omega Speaker, Yavuz Kiliç Jan 2015

Type Iii Compensated Voltage Mode Line Feedforward Synchronously Rectified Boost Converter For Driving Class D Audio H-Bridge To Deliver 7 W Peak Power Into An 8 Omega Speaker, Yavuz Kiliç

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a circuit topology for a synchronously rectified boost converter aimed to act as a power supply for a Class D H-bridge that would deliver up to 7 W peak power into an 8 Omega speaker is presented. The design is implemented in a submicron BCD process technology. Some of the challenges in this design are as follows. The first challenge was to optimise the design such that it would not cause on-chip power dissipation levels that would go beyond acceptable levels for Wafer Level Chip Scale Package (WLCSP), which is a commonly used package for space constrained …


The Detailed Analysis Of Rate Equation Roots Of Bh-Laser Diode Using Volterra Series, Remzi̇ Yildirim, Ahmet Karaarslan Jan 2015

The Detailed Analysis Of Rate Equation Roots Of Bh-Laser Diode Using Volterra Series, Remzi̇ Yildirim, Ahmet Karaarslan

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the rate equation analysis of a BH-laser diode was performed for output carrier density (N_o) using the zero-degree solution of the Volterra series. The carrier rate equation of the laser diode was analyzed in terms of input carrier density (N_i) and output carrier density modeling (N_i-N_o), with respect to the DC current (I_o). The polynomial root, which is obtained from the zero-degree solution (N_o) and limit values of I_o, was found. For the linear operation of the laser diode, the range of I_o current was also determined using a linearization approach and the maximum value of N_o.


Efficient Id-Based Authentication And Key Agreement Protocols For The Session Initiation Protocol, Haci Hakan Kilinç, Yolguly Allaberdiyev, Tuğrul Yanik, Serdar Süer Erdem Jan 2015

Efficient Id-Based Authentication And Key Agreement Protocols For The Session Initiation Protocol, Haci Hakan Kilinç, Yolguly Allaberdiyev, Tuğrul Yanik, Serdar Süer Erdem

Turkish Journal of Electrical Engineering and Computer Sciences

In a widely deployed VoIP system tens of thousands of clients compete for the SIP proxy server's authentication service. SIP protocol implementations have to meet certain QoS and security requirements. In this study new ID-based protocols are proposed for the SIP authentication and key agreement protocols. These protocols minimize the use of expensive pairing functions but still resist notable attacks. The security of the proposed protocols are analyzed and demonstrated with security proofs based on the BJM security model. Finally, the performance overhead of the proposed protocols are compared to ID-based SIP authentication and key agreement protocols given in the …


A Fault Detection, Diagnosis, And Reconfiguration Method Via Support Vector Machines}, Rana Ortaç Kabaoğlu Jan 2015

A Fault Detection, Diagnosis, And Reconfiguration Method Via Support Vector Machines}, Rana Ortaç Kabaoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a fault detection, diagnosis, and reconfiguration method based on support vector machines. This method is appropriate for certain or predetermined faults and involves a fault detection and diagnosis unit and an online controller selection type reconfiguration mechanism. In this method, when a fault is detected and diagnosed by the fault detection and diagnosis unit, a suitable controller, which has been determined via an optimization algorithm in an off-line fashion, is activated to maintain proper closed-loop performance of the system in an on-line manner. In the detection, diagnosis, and reconfiguration stages of the method, support vector classification and …


Design And Control Of A Visual Servomechanism For Automating Corneal Cross-Linking Treatment In Keratoconus Patients, Onurcan Şahi̇n, Erdi̇nç Altuğ Jan 2015

Design And Control Of A Visual Servomechanism For Automating Corneal Cross-Linking Treatment In Keratoconus Patients, Onurcan Şahi̇n, Erdi̇nç Altuğ

Turkish Journal of Electrical Engineering and Computer Sciences

A novel mechatronic system designed for automated corneal cross-linking (CCL) treatment in keratoconus patients is introduced. Keratoconus is a serious illness that if not treated may cause serious distortion of vision. Currently, the CCL operation, which is the most promising treatment of this disease, is performed manually. The automated system developed is the first of its kind to automate the treatment with visual feedback, and it aims to increase the efficiency in treatment and to eliminate any potential side effects and risks of the treatment. To track the eye of the patient, the system consists of a camera, an image …


A New Feature Selection Model Based On Id3 And Bees Algorithm For Intrusion Detection System, Adel Sabry Eesa, Zeynep Orman, Adnan Mohsin Abdulazeez Brifcani Jan 2015

A New Feature Selection Model Based On Id3 And Bees Algorithm For Intrusion Detection System, Adel Sabry Eesa, Zeynep Orman, Adnan Mohsin Abdulazeez Brifcani

Turkish Journal of Electrical Engineering and Computer Sciences

Intrusion detection systems (IDSs) have become a necessary component of computers and information security framework. IDSs commonly deal with a large amount of data traffic and these data may contain redundant and unimportant features. Choosing the best quality of features that represent all of the data and exclude the redundant features is a crucial topic in IDSs. In this paper, a new combination approach based on the ID3 algorithm and the bees algorithm (BA) is proposed to select the optimal subset of features for an IDS. The BA is used to generate a subset of features, and the ID3 algorithm …


Dwmt Transceiver Equalization Using Overlap Fde For Downlink Adsl, Arsla Khan, Sobia Baig, Tabassum Nawaz Jan 2015

Dwmt Transceiver Equalization Using Overlap Fde For Downlink Adsl, Arsla Khan, Sobia Baig, Tabassum Nawaz

Turkish Journal of Electrical Engineering and Computer Sciences

Discrete wavelet multitone (DWMT) modulation is a wavelet transform based technique implemented using perfect reconstruction filter banks. It has been recently proposed for various wireline channels such as digital subscriber loops (DSLs) as a solution to the problems posed by a discrete multitone (DMT) transceiver including interblock interference (IBI) and lower spectral efficiency due to the employment of a cyclic prefix (CP) in the guard interval (GI) for DMT symbols. The greater side lobe attenuation offered by wavelet filter banks results in improved spectral containment and lower IBI in DWMT transceivers. However, no standard equalization technique exists for a DWMT …


Performance Of Support Vector Regression Machines On Determining The Magnetic Characteristics Of The E-Core Transverse Flux Machine, Çi̇ğdem Gündoğan Türker, Feri̇ha Erfan Kuyumcu, Nurhan Türker Tokan Jan 2015

Performance Of Support Vector Regression Machines On Determining The Magnetic Characteristics Of The E-Core Transverse Flux Machine, Çi̇ğdem Gündoğan Türker, Feri̇ha Erfan Kuyumcu, Nurhan Türker Tokan

Turkish Journal of Electrical Engineering and Computer Sciences

The E-core transverse flux machine (ETFM) has major advantages with its different and unique structure in conventional electrical machines. It is a combination of transverse flux and reluctance principle. In this work, support vector regression machines (SVRMs) are used to obtain the magnetic characteristic parameters of the ETFM for the first time and it is compared with its artificial neural network model. The data for the training and testing of the SVRMs are obtained from experimental measurements. It is proven that SVRMs can conveniently be used in the modeling of the magnetic behaviors of highly nonlinear ETFM with better accuracy …


A Novel Adaptive Filter Design Using Lyapunov Stability Theory, Engi̇n Cemal Mengüç, Nuretti̇n Acir Jan 2015

A Novel Adaptive Filter Design Using Lyapunov Stability Theory, Engi̇n Cemal Mengüç, Nuretti̇n Acir

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new approach to design an adaptive filter using Lyapunov stability theory. The design procedure is formulated as an inequality constrained optimization problem. Lagrange multiplier theory is used as an optimization tool. Lyapunov stability theory is integrated into the constraint function to satisfy the asymptotic stability of the proposed filtering system. The tracking capability is improved by using a new analytical adaptation gain rate, which has the ability to adaptively adjust itself depending on a sequential tracking square error rate. The fast and robust convergence ability of the proposed algorithm is comparatively examined by simulation examples.


An E-Nose-Based Indoor Air Quality Monitoring System: Prediction Of Combustible And Toxic Gas Concentrations, Beki̇r Mumyakmaz, Keri̇m Karabacak Jan 2015

An E-Nose-Based Indoor Air Quality Monitoring System: Prediction Of Combustible And Toxic Gas Concentrations, Beki̇r Mumyakmaz, Keri̇m Karabacak

Turkish Journal of Electrical Engineering and Computer Sciences

A system for monitoring and predicting indoor air quality level is proposed in this paper. The system comprises a computer with a monitoring program and a sensor cell, which has an array of metal oxide gas sensors along with a temperature and humidity sensor. The gas sensors in the cell have been chosen to detect only hydrogen, methane, and carbon monoxide gases. Methane was selected as a representative for indoor combustible gases, and carbon monoxide was used to represent indoor toxic gases. Hydrogen was used as an interfering (and also combustible) gas in the study. A number of experiments were …


Novel Congestion Control Algorithms For A Class Of Delayed Networks, Shoorangiz Shams Shamsabad Farahani, Mohammad Reza Jahed Motlagh, Mohammad Ali Nekoui Jan 2015

Novel Congestion Control Algorithms For A Class Of Delayed Networks, Shoorangiz Shams Shamsabad Farahani, Mohammad Reza Jahed Motlagh, Mohammad Ali Nekoui

Turkish Journal of Electrical Engineering and Computer Sciences

Time delays are often instability sources and give rise to undesired oscillation and performance degradation, so it is necessary to consider delay in general congestion control schemes. In this paper, a new system model for wireless sensor networks (WSNs) is established in discrete time, subsystems including delay are presented, and the overall model is achieved by blending these subsystems. For controller synthesis, common quadratic Lyapunov functions and a new approach based on nonquadratic Lyapunov functions are utilized, and a controller is designed to stabilize each subsystem. The controller synthesis results are expressed in terms of linear matrix inequalities. Moreover, the …


Forecasting The Day-Ahead Price In Electricity Balancing And Settlement Market Of Turkey By Using Artificial Neural Networks, Mehmet Ali̇ Kölmek, İsa Navruz Jan 2015

Forecasting The Day-Ahead Price In Electricity Balancing And Settlement Market Of Turkey By Using Artificial Neural Networks, Mehmet Ali̇ Kölmek, İsa Navruz

Turkish Journal of Electrical Engineering and Computer Sciences

In determination of electric energy price, most price information coming from bilateral contracts is effective, but the importance of the spot market (pool market) price cannot be ignored. Forecasting the spot market price is very crucial, especially for companies actively participating in the spot market and giving purchase and sale bids. An artificial neural network is a way frequently used for price forecasting research. In this study, simulation studies about price modeling via artificial neural networks and proper artificial neural network configurations are examined. After selection of different network topologies and parameters, attempts are made to observe network performance by …


Conceptual Design Of A Low-Cost Real-Time Hardware-In-The-Loop Simulator For Satellite Attitude Control System, Farhad Bayat Jan 2015

Conceptual Design Of A Low-Cost Real-Time Hardware-In-The-Loop Simulator For Satellite Attitude Control System, Farhad Bayat

Turkish Journal of Electrical Engineering and Computer Sciences

Integration of flight hardware with real-time simulation increases satellite attitude control system (ACS) reliability by providing greater test coverage through end-to-end testing in a realistic test environment. In this paper, a compound hardware and software simulator has been designed for evaluation and testing of the spacecraft ACS, placing emphasis on the real-time hardware-in-loop (RTHIL) architecture. The environment comprises both real-time control and data acquisition applications on a network of ACS hardware, the MATLAB Real-Time Workshop, and a PCI device to join the hardware and software units. Moreover, a graphical 3D simulator has been designed, enabling the designers and researchers to …


Detection Of Microcalcification In Digitized Mammograms With Multistable Cellular Neural Networks Using A New Image Enhancement Method: Automated Lesion Intensity Enhancer (Alie), Levent Ci̇vci̇k, Burak Yilmaz, Yüksel Özbay, Gani̇me Di̇lek Emli̇k Jan 2015

Detection Of Microcalcification In Digitized Mammograms With Multistable Cellular Neural Networks Using A New Image Enhancement Method: Automated Lesion Intensity Enhancer (Alie), Levent Ci̇vci̇k, Burak Yilmaz, Yüksel Özbay, Gani̇me Di̇lek Emli̇k

Turkish Journal of Electrical Engineering and Computer Sciences

Microcalcification detection is a very important issue in early diagnosis of breast cancer. Generally physicians use mammogram images for this task; however, sometimes analyzing these images become a hard task because of problems in images such as high brightness values, dense tissues, noise, and insufficient contrast level. In this paper, we present a novel technique for the task of microcalcification detection. This technique consists of three steps. The first step is focused on removing pectoral muscle and unnecessary parts from the mammogram images by using cellular neural networks (CNNs), which makes this a novel process. In the second step, we …


Emg Classification In Obstructive Sleep Apnea Syndrome And Periodic Limb Movement Syndrome Patients By Using Wavelet Packet Transform And Extreme Learning Machine, Necmetti̇n Sezgi̇n Jan 2015

Emg Classification In Obstructive Sleep Apnea Syndrome And Periodic Limb Movement Syndrome Patients By Using Wavelet Packet Transform And Extreme Learning Machine, Necmetti̇n Sezgi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Electromyogram (EMG) signals, measured at the skin surface, provide crucial access to the muscle tones of a body. Some diseases, such as obstructive sleep apnea syndrome (OSAS) and periodic limb movement syndrome (PLMS), are closely associated with the electrical activity of muscle tones. In this paper, a hybrid model containing wavelet packet transform (WPT) plus an extreme learning machine (ELM) was proposed to classify EMG signals in OSAS and PLMS patients. At first, the WPT was used to extract the features of the EMG signal, and then these features were fed to the ELM classifier. The mean classification accuracy of …


An Ofdm Throughput Analysis For Cognitive Radio Application In Contiguous Or Noncontiguous Tv White Spaces, Cebrai̇l Çi̇fli̇kli̇, Ahmet Turgut Tuncer, Yusuf Öztürk Jan 2015

An Ofdm Throughput Analysis For Cognitive Radio Application In Contiguous Or Noncontiguous Tv White Spaces, Cebrai̇l Çi̇fli̇kli̇, Ahmet Turgut Tuncer, Yusuf Öztürk

Turkish Journal of Electrical Engineering and Computer Sciences

Radio frequency spectrum is a finite and scarce resource. Efficient use of the radio frequency spectrum is a fundamental research issue. Since a large portion of the assigned radio frequency spectrum is used only sporadically, the bands currently allocated to TV services can be opportunistically reassigned to support broadband networking services while continuing to provide broadcast TV. The fragmented and unused TV channels named white spaces have a considerable amount of bandwidth potential and long transmission ranges. Bandwidth scalability can be supported by bonding multiple contiguous or noncontiguous consecutive channels using orthogonal frequency division multiplexing (OFDM)-based cognitive radio. In this …


Synthesis Of Real-Time Cloud Applications For Internet Of Things, Slawomir Bak, Radoslaw Czarnecki, Stanislaw Deniziak Jan 2015

Synthesis Of Real-Time Cloud Applications For Internet Of Things, Slawomir Bak, Radoslaw Czarnecki, Stanislaw Deniziak

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the methodology for the synthesis of real-time applications working in the ``Internet of Things'' environment. We propose the client-server architecture, where embedded systems act as smart clients and the Internet application is a server of the system. The architecture of the application conforms to the cloud computing model. Since centralized systems are prone to bottlenecks caused by accumulation of transmissions or computations, we propose the distributed architecture of the server and the methodology that constructs this architecture using Internet resources supported by a cloud provider. We assume that the function of the server is specified as a …


A Comparative Study Of Denoising Semg Signals, Ulvi̇ Başpinar, Volkan Yusuf Şenyürek, Bariş Doğan, Hüseyi̇n Selçuk Varol Jan 2015

A Comparative Study Of Denoising Semg Signals, Ulvi̇ Başpinar, Volkan Yusuf Şenyürek, Bariş Doğan, Hüseyi̇n Selçuk Varol

Turkish Journal of Electrical Engineering and Computer Sciences

Denoising of surface electromyography (sEMG) signals plays a vital role in sEMG-based mechatronics applications and diagnosis of muscular diseases. In this study, 3 different denoising methods of sEMG signals, empirical mode decomposition, discrete wavelet transform (DWT), and median filter, are examined. These methods are applied to 5 different levels of noise-added synthetic sEMG signals. For the DWT-based denoising technique, 40 different wavelet functions, 4 different threshold-selection-rules, and 2 threshold-methods are tested iteratively. Three different window-sized median filters are applied as well. The SNR values of denoised synthetic signals are calculated, and the results are used to select DWT and median …


Design And Analysis Of Ei Core Structured Transverse Flux Linear Reluctance Actuator, Ahmet Fenerci̇oğlu, Yusuf Avşar Jan 2015

Design And Analysis Of Ei Core Structured Transverse Flux Linear Reluctance Actuator, Ahmet Fenerci̇oğlu, Yusuf Avşar

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, an EI core linear actuator is proposed for horizontal movement systems. It is a transverse flux linear switched reluctance motor designed with an EI core structure geometrically. The actuator is configured into three phases and at a 6/4 pole ratio, and it has a stationary active stator along with a sliding passive translator. The stator consists of E cores and the translator consists of I cores. The actuator has a yokeless design because the stator and translator have no back iron. The E and I cores are separated from each other to provide a fault-tolerant design and …


An Aggregate Indicator For Mobile Application Quality Assessment, Paul Pocatilu, Ion Ivan, Alin Zamfiroiu, Catalin Boja Jan 2015

An Aggregate Indicator For Mobile Application Quality Assessment, Paul Pocatilu, Ion Ivan, Alin Zamfiroiu, Catalin Boja

Turkish Journal of Electrical Engineering and Computer Sciences

The mobile applications environment has a multitude of particularities generated by the complex system of devices, hardware, and software profiles and categories of users. The mobile industry has also evolved rapidly in the last 5 years from single-core mobile platforms to multiple-core mobile application platforms, able to compete in terms of user services with notebooks. New types of devices, like tablets, or shifts in human-computer interface paradigms from button click to screen touch, have opened new perspectives both for users and software developers. This requires an adaptable approach for performance analysis in terms of total quality management for software projects. …


A Performance Comparison Of Conventional And Transverse Flux Linear Switched Reluctance Motors, Nuretti̇n Üstkoyuncu, Krishnan Ramu Jan 2015

A Performance Comparison Of Conventional And Transverse Flux Linear Switched Reluctance Motors, Nuretti̇n Üstkoyuncu, Krishnan Ramu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a comprehensive comparison between conventional (longitudinal flux) linear switched reluctance machines (CLSRMs) and transverse flux linear switched reluctance machines (TLSRMs) so as to enable engineers to choose a structure suitable for their applications. A commonly-used single-sided CLSRM and 4 different TLSRM structures are considered for the comparison. For a fair comparison of the 2 types of LSRMs, equal dimensions, including equal length and magnetomotive force, are applied as much as possible. The analytical approach and 3-dimensional finite element analysis (FEA) are employed to obtain the performance of these machines. It is proven analytically that the CLSRM has …


Multilevel Hybrid Cascade-Stack Inverter With Substantial Reduction In Switches Number And Power Losses, Mahdi Toopchi Khosroshahi, Ali Ajami, Ata Ollah Mokhberdoran, Mohammadreza Jannati Oskuee Jan 2015

Multilevel Hybrid Cascade-Stack Inverter With Substantial Reduction In Switches Number And Power Losses, Mahdi Toopchi Khosroshahi, Ali Ajami, Ata Ollah Mokhberdoran, Mohammadreza Jannati Oskuee

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a multilevel hybrid cascade-stack (HCS) converter. Recently, different new topologies for cascade-type converters have been suggested with the goal of reducing switch number, loss, switch PIV, etc. Meanwhile, output voltage steps increase, and the number of switches is predominately reduced in the suggested inverter in comparison to conventional cascade converters. Additionally, a reduction in the number of on-state switches in the introduced topology causes power loss and voltage drop to decrease. Firstly, the fundamental parts of inverter configuration are described. Afterwards, symmetric and asymmetric converter types are discussed. Simulation and experimental results for 11- and 23-level symmetric …


A Fourth-Order Accurate Compact 2-D Fdfd Method For Waveguide Problems, Lokman Kuzu Jan 2015

A Fourth-Order Accurate Compact 2-D Fdfd Method For Waveguide Problems, Lokman Kuzu

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, a fourth-order accurate 2-D finite difference frequency domain method is proposed for the analysis of general waveguide structures. Finite difference techniques have been extensively used to solve electromagnetic problems over the decades. These methods discretize the computational domain using the Yee cell, but the standard Yee scheme used in these methods is only second-order accurate. In order to demonstrate the advantages of the proposed scheme compared to the multiresolution frequency domain method and the traditional 2-D finite difference frequency domain scheme, the dispersion characteristics of various waveguide structures are analyzed.


Calculation Of Surface Leakage Currents On High Voltage Insulators By Ant Colony Algorithm-Supported Fem, Dursun Öztürk, Mehmet Cebeci̇ Jan 2015

Calculation Of Surface Leakage Currents On High Voltage Insulators By Ant Colony Algorithm-Supported Fem, Dursun Öztürk, Mehmet Cebeci̇

Turkish Journal of Electrical Engineering and Computer Sciences

The weakness of the outer insulation at high voltages is the reduction of the surface resistance as a result of the environmental pollution yielding formation of flashover due to the surface leakage currents. In this study, it was shown how to calculate the surface leakage currents resulting in flashover in polluted insulators and therefore power cuts by means of the ant colony algorithm (ACA). For this purpose, first, field distribution on the sample insulator surface in question was defined by the Laplace equation ($\nabla^{2}$V = 0). With the help of the finite element method (FEM), the Laplace equation was obtained …


Superior Decoupled Control Of Active And Reactive Power For Three-Phase Voltage Source Converters, Hesam Rahbarimagham, Erfan Maali Amiri, Behrooz Vahidi, Gevorg Babamalek Gharehpetian, Mehrdad Abedi Jan 2015

Superior Decoupled Control Of Active And Reactive Power For Three-Phase Voltage Source Converters, Hesam Rahbarimagham, Erfan Maali Amiri, Behrooz Vahidi, Gevorg Babamalek Gharehpetian, Mehrdad Abedi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an active-reactive power control strategy for voltage source converters (VSCs) based on derivation of the direct and quadrature components of the VSC output current. The proposed method utilizes a multivariable proportional-integral controller and provides almost completely decoupled control capability of the active and reactive power with almost full disturbance rejection due to step changes in the power exchanged between the VSC and the grid. It also imposes fast transient response and zero steady-state error as compared to the conventional power control approaches. The applicability of the proposed power control strategy for providing the robust stability of the …


A Real-Time Life-Care Monitoring Framework: Warnred Hardware And Software Design, Gamze Doğali Çeti̇n, Özdemi̇r Çeti̇n, Cüneyt Bayilmiş Jan 2015

A Real-Time Life-Care Monitoring Framework: Warnred Hardware And Software Design, Gamze Doğali Çeti̇n, Özdemi̇r Çeti̇n, Cüneyt Bayilmiş

Turkish Journal of Electrical Engineering and Computer Sciences

It is shown by many statistical studies that the senior population, especially in developed countries, is in an increasing trend. For many reasons they tend to have in-home health care providers. The recent studies on biomedical information management focused on remote health monitoring frameworks including heart rate monitoring systems, glucose measurements for diabetics, and remote monitoring EEG and ECG. The main purposes of these studies are timely response to emergency situations and ensuring that the person is in a stable condition. In this study, developed via a system-on-chip circuit, we process the data collected from subjects through a temperature sensor …