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Full-Text Articles in Physical Sciences and Mathematics

Possible Effects Of Dielectrophoretic Fields In The Brains Of Mri Operators And Ms Patients: A Radiologically Isolated Syndrome Evaluation, Cahi̇t Canbay Jan 2019

Possible Effects Of Dielectrophoretic Fields In The Brains Of Mri Operators And Ms Patients: A Radiologically Isolated Syndrome Evaluation, Cahi̇t Canbay

Turkish Journal of Electrical Engineering and Computer Sciences

Frequent use of magnetic resonance imaging (MRI) devices, which are major contributors in understanding health problems in the human body, is a subject that needs to be taken into consideration both for patients and for operators who are constantly in the vicinity of devices. In this context, electromagnetic impact assessment of an MRI device was performed at the point where the patient entered the device. Dielectrophoretic fields induced by radio frequency (RF) coils of an MRI scanner on male and female operator brain models were computed by using dispersive electrical medium parameters. The main cause of induced secondary dielectrophoretic fields …


Heart Attack Mortality Prediction: An Application Of Machine Learning Methods, Issam Salman Jan 2019

Heart Attack Mortality Prediction: An Application Of Machine Learning Methods, Issam Salman

Turkish Journal of Electrical Engineering and Computer Sciences

The heart is an important organ in the human body, and acute myocardial infarction (AMI) is the leading cause of death in most countries. Researchers are doing a lot of data analysis work to assist doctors in predicting the heart problem. An analysis of the data related to different health problems and its functions can help in predicting the wellness of this organ with a degree of certainty. Our research reported in this paper consists of two main parts. In the first part of the paper, we compare different predictive models of hospital mortality for patients with AMI. All results …


Improving Word Embeddings Projection For Turkish Hypernym Extraction, Savaş Yildirim Jan 2019

Improving Word Embeddings Projection For Turkish Hypernym Extraction, Savaş Yildirim

Turkish Journal of Electrical Engineering and Computer Sciences

Corpus-driven approaches can automatically explore is-a relations between the word pairs from corpus. This problem is also called hypernym extraction. Formerly, lexico-syntactic patterns have been used to solve hypernym relations. The language-specific syntactic rules have been manually crafted to build the patterns. On the other hand, recent studies have applied distributional approaches to word semantics. They extracted the semantic relations relying on the idea that similar words share similar contexts. Former distributional approaches have applied one-hot bag-of-word (BOW) encoding. The dimensionality problem of BOW has been solved by various neural network approaches, which represent words in very short and dense …


On The Output Regulation For Linear Fractional Systems, Jesus Alberto Meda Campana, Elba Cinthya Garcia Estrada, Julio Cesar Gomez Mancilla, Jose De Jesus Rubio Avila, Mario Ricardo Cruz Deviana, Ricardo Tapia Herrera Jan 2019

On The Output Regulation For Linear Fractional Systems, Jesus Alberto Meda Campana, Elba Cinthya Garcia Estrada, Julio Cesar Gomez Mancilla, Jose De Jesus Rubio Avila, Mario Ricardo Cruz Deviana, Ricardo Tapia Herrera

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, the regulation problem is extended to the field of fractional-order linear systems considering the Caputo fractional derivative. The regulation equations are obtained on the basis of the Francis equations. It is also shown that the linear fractional regulator exists at $t=0$ only if the order of the plant is not greater than the order of the reference system.


Nvrh-Lut: A Nonvolatile Radiation-Hardened Hybrid Mtj/Cmos-Based Look-Up Table For Ultralow Power And Highly Reliable Fpga Designs, Vahid Jamshidi Jan 2019

Nvrh-Lut: A Nonvolatile Radiation-Hardened Hybrid Mtj/Cmos-Based Look-Up Table For Ultralow Power And Highly Reliable Fpga Designs, Vahid Jamshidi

Turkish Journal of Electrical Engineering and Computer Sciences

Complementary metal oxide semiconductor (CMOS) downscaling leads to various challenges, such as high leakage current and increase in radiation sensitivity. To solve such challenges, hybrid MTJ/CMOS technology-based design has been considered as a very promising approach thanks to the high speed, low power, good scalability, and full compatibility of magnetic tunnel junction (MTJ) devices with CMOS technology. One important application of MTJs is the efficient utilization in building nonvolatile look-up tables (NV-LUTs) used in reconfigurable logic. However, NV-LUTs face severe reliability issues in nanotechnology due to the increasing process variations, reduced supply voltage, and high energetic particle strike at sensitive …


A Novel Method Based On Comparison Using Threshold Scale For Cfar Detectors Under Environments With Conditions Of Electromagnetic Interference, Milad Daneshvar, Naser Parhizgar, Pouria Salehi Jan 2019

A Novel Method Based On Comparison Using Threshold Scale For Cfar Detectors Under Environments With Conditions Of Electromagnetic Interference, Milad Daneshvar, Naser Parhizgar, Pouria Salehi

Turkish Journal of Electrical Engineering and Computer Sciences

Detection of a noisy signal is a complex process. Many radar systems are working in an environment where the signal processing parts cannot overcome the effects of interference sources due to their high power. These sources of conflict may completely erode the signal or may make a mistake in deciding. It may make the return of the echoes of the goals difficult. To solve this problem, the detector processor can use a new algorithm to estimate noise power and then can set the threshold in different positions of the cell under test. The proposed algorithm, by differentiating between homogeneous and …


A Hybrid Multiband Printed Loop Antenna For Wlan/Wimax Bands For Applications In Mimo Systems, Ali Shahshahani, Mohammad Amin Honarvar Jan 2019

A Hybrid Multiband Printed Loop Antenna For Wlan/Wimax Bands For Applications In Mimo Systems, Ali Shahshahani, Mohammad Amin Honarvar

Turkish Journal of Electrical Engineering and Computer Sciences

In this article a thin hybrid multiband printed loop antenna is presented for application in multiple-input multiple-output (MIMO) systems. The proposed antenna has several advantages; for example, the pseudofilter feature of the proposed antenna is one of this antenna's advantages. Because of the antenna's width ($9.5$~mm), it can be used on the edges of the board. The first resonant frequency is generated by the original loop of the antenna. Incorporation of different embedded components, i.e. a subsidiary loop, extended ground-traces, parasitic patch, and the slits, results in the proposed antenna resonating as a multiband antenna. This antenna is adjusted in …


Multiple Distributed Generations Placement And Sizing Based On Voltage Stability Index And Power Loss Minimization, Oumaima Garfi, Helmi Aloui Jan 2019

Multiple Distributed Generations Placement And Sizing Based On Voltage Stability Index And Power Loss Minimization, Oumaima Garfi, Helmi Aloui

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a rapid analytical method to determine the locations and sizes of multiple distributed generations (DGs) inside a distribution network. DGs locations are chosen with the aim of enhancing voltage stability and their sizes are picked so as to minimize system power losses. To evaluate the effect of the DG's nature on the system's performance, the proposed DG allocation method is tested for all DG types and the impact of the combination of different types of DGs is equally investigated, which offers a guide to designing an optimal hybrid network.


Optimal Siting, Sizing, And Parameter Tuning Of Statcom And Sssc Using Mpso And Remote Coordination Of The Facts For Oscillation Damping Of Power Systems, James Garba Ambafi, Sunusi Sani Adamu Jan 2019

Optimal Siting, Sizing, And Parameter Tuning Of Statcom And Sssc Using Mpso And Remote Coordination Of The Facts For Oscillation Damping Of Power Systems, James Garba Ambafi, Sunusi Sani Adamu

Turkish Journal of Electrical Engineering and Computer Sciences

In electromechanical oscillation damping within power system, power system stabilizers (PSSs) are often deployed. However, a PSS is less effective in damping interarea oscillation and is limited by changes in network configuration due to weak tie-lines and load variations. Consequently, this paper presents a wide-area coordination approach that damps interarea oscillations using FACTS devices and phasor measurement units. We selected a static synchronous compensator (STATCOM) and static series synchronous compensator (SSSC) for realistic power system interarea oscillation damping. The performance of the coordinated FACTS installed in a power system depends on their suitable locations, sizes, tuned parameters, and remote input …


The Impact Of Demand Response Programs On Upfc Placement, Abbas Sharifi Nasab Anari, Mehdi Ehsan, Mahmud Fotuhi Firuzabad Jan 2019

The Impact Of Demand Response Programs On Upfc Placement, Abbas Sharifi Nasab Anari, Mehdi Ehsan, Mahmud Fotuhi Firuzabad

Turkish Journal of Electrical Engineering and Computer Sciences

Demand response (DR) and flexible AC transmission system (FACTS) devices can be effectively used for congestion management in power transmission systems. However, demand response program (DRP) implementation can itself affect the optimum location of FACTS devices, which is one of the main issues in power system planning. This paper investigates the impact of DRPs on unified power flow controller (UPFC) placement. The harmony search algorithm is employed to determine the optimum locations and parameter setting of UPFC in a long-term framework. The optimization problem is solved with different objectives including generation and congestion cost reduction, as well as loss reduction. …


The Effect Of Snowfall And Icing On The Sustainability Of The Power Output Of A Grid-Connected Photovoltaic System In Konya, Turkey, Mehmet Ali̇ Anadol, Erman Erhan Jan 2019

The Effect Of Snowfall And Icing On The Sustainability Of The Power Output Of A Grid-Connected Photovoltaic System In Konya, Turkey, Mehmet Ali̇ Anadol, Erman Erhan

Turkish Journal of Electrical Engineering and Computer Sciences

When the module surface is covered with various factors such as snow and icing which prevent the solar irradiance from reaching the photovoltaic cells, the power production of the system and its performance decrease. The purpose of this study is to determine the energy production losses of a grid-connected photovoltaic plant due to snowfall and icing. The effect of snowfall and icing has been examined on a photovoltaic system consisting of a hybrid inverter with two separate maximum power point tracking inputs and 36 monocrystalline modules, which are mounted on the supporting system horizontally in the south direction and at …


A New Approach For Wind Turbine Placement Problem Using Modified Differential Evolution Algorithm, Hüseyi̇n Hakli Jan 2019

A New Approach For Wind Turbine Placement Problem Using Modified Differential Evolution Algorithm, Hüseyi̇n Hakli

Turkish Journal of Electrical Engineering and Computer Sciences

Energy use is increasing worldwide with industrialization and advancing technology. Following this increase, renewable energy resources are increasingly preferred to reduce the costs of energy production. Wind energy is preferred as a renewable energy resource because it is clean and safe. Wind turbines are used to meet the demand for wind energy. They are placed close to each other to generate higher amounts of energy. However, the wake effect problem arises in these types of layouts, and this hinders the turbines from producing the desired yield. A modified differential evolution (MDE) algorithm was proposed in this study to solve the …


Global Maximum Operating Point Tracking For Pv System Using Fast Convergence Firefly Algorithm, Madhusmita Mohanty, Sankar Selvakumar, Chandrasekaran Koodalsamy, Sishaj Pulikottil Simon Jan 2019

Global Maximum Operating Point Tracking For Pv System Using Fast Convergence Firefly Algorithm, Madhusmita Mohanty, Sankar Selvakumar, Chandrasekaran Koodalsamy, Sishaj Pulikottil Simon

Turkish Journal of Electrical Engineering and Computer Sciences

Global maximum operating point (GMOP) tracking is an important requirement of solar photovoltaic (PV) systems under partial shading conditions (PSCs). Though the perturb and observe algorithm is simple and effective, it fails to recognize the GMOP. This paper explores the application of the firefly algorithm (FA) to the maximum power point tracking (MPPT) problem of PV systems. In order to determine the shortest path to reach the GMOP under various PSCs, a new fast convergence firefly algorithm (FA) is proposed. Additionally, the change in firefly position is limited to a maximum value identified based on the characteristics of the PSC. …


Dynamic Radar Cross-Section Characteristic Analysis Of Wind Turbine Based On Scaled Model Experimental, Bo Tang, Hao Chen, Li Huang, Fa Ting Yuan, Peng Feng Jan 2019

Dynamic Radar Cross-Section Characteristic Analysis Of Wind Turbine Based On Scaled Model Experimental, Bo Tang, Hao Chen, Li Huang, Fa Ting Yuan, Peng Feng

Turkish Journal of Electrical Engineering and Computer Sciences

Accurately acquiring and analyzing the dynamic radar cross-section (RCS) of wind turbine have a great significance to solve the reradiation interference between wind farms and radar stations. Since the results of high-frequency approximation algorithm are only applicable to the qualitative analysis of electromagnetic scattering, it is almost impossible to accurately acquire the dynamic RCS of wind turbine in actual engineering cases. To this end, we proposed to acquire the dynamic RCS of wind turbine based on the scaled model experimental measurement in a large anechoic chamber. The key techniques of setting up the scaled model as well as the experimental …


A Transmission Optimization Algorithm For Smart Load Controllers, Ohyoung Song Jan 2019

A Transmission Optimization Algorithm For Smart Load Controllers, Ohyoung Song

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a transmission optimization algorithm for wireless transmissions between smart load controllers and a corresponding gateway in wireless personal area networks, where smart load controllers connect several electrical appliances through their corresponding load interfaces, measure the power consumption from each electrical appliance connected to the load controller, and control on/off switching through its load interface. The aim of this paper is to reduce the traffic load of power consumption data in electrical appliances used in the building area network and the smart grid network. The proposed algorithm allows the smart load controller to efficiently reduce traffic load even …


A Novel Initial Rotor Position Alignment Method For Permanent Magnet Synchronous Motor Using Incremental Encoder, Si̇nan Yilmaz, Mehmet Ti̇mur Aydemi̇r Jan 2019

A Novel Initial Rotor Position Alignment Method For Permanent Magnet Synchronous Motor Using Incremental Encoder, Si̇nan Yilmaz, Mehmet Ti̇mur Aydemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new method for the alignment of the rotor of permanent magnet synchronous motors with the phase axis of the stator during start-up. Once the rotor alignment is achieved, the real rotor position angle can be measured by using an incremental encoder and this value can be used in the field oriented control of the motor. Typically, a current is forced into the q-axis. In the proposed method a current is formed in the d-axis instead. Rotor alignment with the phase axis is achieved without any sudden motion by using a PI controller in the current loop. …


A Two-Stage Power Converter Architecture With Maximum Power Extraction For Low-Power Energy Sources, Ridvan Umaz Jan 2019

A Two-Stage Power Converter Architecture With Maximum Power Extraction For Low-Power Energy Sources, Ridvan Umaz

Turkish Journal of Electrical Engineering and Computer Sciences

A two-stage power converter with maximum power extraction for energy harvesting is presented. The power converter consists of two stages; a maximum power extraction stage (i.e. first stage) and a regulation stage (i.e. second stage). The first stage consists of a number of charge pumps connected in parallel to extract power from the energy source while the second stage steps up low input voltage level to a usable level for a load. Proposed converter operates as low as 0.3 V and the output up-converts to 3.3 V. The proposed converter is aimed to extract maximum power from either low-power energy …


Comparative Evaluation Of A-B-C And Stationary Frame Of Reference For Permanent Magnet Brushless Dc Motor Drive Applied For Generation Of Switching Pattern, Manish Trivedi, Ritesh Keshri Jan 2019

Comparative Evaluation Of A-B-C And Stationary Frame Of Reference For Permanent Magnet Brushless Dc Motor Drive Applied For Generation Of Switching Pattern, Manish Trivedi, Ritesh Keshri

Turkish Journal of Electrical Engineering and Computer Sciences

This paper focuses on the evaluation of the operation of permanent magnet brushless DC (PM BLDC) motor through the control implemented in the natural reference frame (a-b-c frame) and the stationary reference frame ($\alpha-\beta$ frame). To a large extent, ripple-free torque and attainment of higher torque-speed characteristic depend on the gating pulses/switching patterns of the inverter employed. PM BLDC motor requires injection of the square wave current for the maximum torque per ampere, so the reference is required to be generated and tracked accordingly. The effectiveness of the strategies of pulse-width-modulation-based current control in the a-b-c plane and, the case …


Quantification Of Resistive Wall Instability For Particle Accelerator Machines, Fati̇h Yaman Jan 2019

Quantification Of Resistive Wall Instability For Particle Accelerator Machines, Fati̇h Yaman

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this study is to quantify longitudinal resistive wall impedances, corresponding wake functions, and wake potentials for different accelerator machines of interest. Accurate calculations of wake potentials by particle-in-cell codes are extremely difficult for the investigated parameters; therefore, we use an analytical approach and consider large domains with fine discretization for the required numerical integrations. The semianalytical wake potential computations are benchmarked against numerical general purpose 2D/3D Maxwell solver software codes and a different analytical approach for a certain set of parameters. We report examples to illustrate limitations of wake potential estimations from coupling impedances, and computations for …


Predicting Co And Nox Emissions From Gas Turbines: Novel Data And A Benchmark Pems, Heysem Kaya, Pinar Tüfekci̇, Erdi̇nç Uzun Jan 2019

Predicting Co And Nox Emissions From Gas Turbines: Novel Data And A Benchmark Pems, Heysem Kaya, Pinar Tüfekci̇, Erdi̇nç Uzun

Turkish Journal of Electrical Engineering and Computer Sciences

Predictive emission monitoring systems (PEMS) are important tools for validation and backing up of costly continuous emission monitoring systems used in gas-turbine-based power plants. Their implementation relies on the availability of appropriate and ecologically valid data. In this paper, we introduce a novel PEMS dataset collected over five years from a gas turbine for the predictive modeling of the CO and NOx emissions. We analyze the data using a recent machine learning paradigm, and present useful insights about emission predictions. Furthermore, we present a benchmark experimental procedure for comparability of future works on the data