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Full-Text Articles in Physical Sciences and Mathematics

Square Root Central Difference-Based Fastslam Approach Improved By Differential Evolution, Haydar Ankişhan, Fi̇kret Ari, Emre Öner Tartan, Ahmet Güngör Pakfi̇li̇z Jan 2016

Square Root Central Difference-Based Fastslam Approach Improved By Differential Evolution, Haydar Ankişhan, Fi̇kret Ari, Emre Öner Tartan, Ahmet Güngör Pakfi̇li̇z

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents a new approach to improve the performance of FastSLAM. The aim of the study is to obtain a more robust algorithm for FastSLAM applications by using a Kalman filter that uses Stirling's polynomial interpolation formula. In this paper, some new improvements have been proposed; the first approach is the square root central difference Kalman filter-based FastSLAM, called SRCD-FastSLAM. In this method, autonomous vehicle (or robot) position, landmarks' position estimations, and importance weight calculations of the particle filter are provided by the SRCD-Kalman filter. The second approach is an improved version of the SRCD-FastSLAM in which particles are …


Behavior Of Metamaterial-Based Microwave Components For Sensing And Heating Of Nanoliter-Scale Volumes, Muhammed Sai̇d Boybay Jan 2016

Behavior Of Metamaterial-Based Microwave Components For Sensing And Heating Of Nanoliter-Scale Volumes, Muhammed Sai̇d Boybay

Turkish Journal of Electrical Engineering and Computer Sciences

Metamaterial-based microwave components are among the state-of-the-art heater and sensor designs for microfluidic systems. The miniaturization and energy-focusing abilities of the metamaterial-based components make it possible to adopt microwave components operating at wavelengths in the order of 10 cm for microfluidic systems. Microwave systems are particularly advantageous for point-of-care and high-throughput applications due to their high speed of operation, very low instrumentation cost, ability to selectively and internally heat specimens, and ability of label-free sensing. In this study, the efficiency and behavior of microwave components designed for heating and sensing small volumes in the scale of nanoliters are studied. In …


Reduction Of Torque Ripple In Induction Motor By Artificial Neural Multinetworks, Fati̇h Korkmaz, İsmai̇l Topaloğlu, Hayati̇ Mamur, Murat Ari, İlhan Tarimer Jan 2016

Reduction Of Torque Ripple In Induction Motor By Artificial Neural Multinetworks, Fati̇h Korkmaz, İsmai̇l Topaloğlu, Hayati̇ Mamur, Murat Ari, İlhan Tarimer

Turkish Journal of Electrical Engineering and Computer Sciences

Direct torque control is used in the high performance control of induction motors. The most frequently faced problem of it is high torque ripples. In this study, a new approach based on artificial neural multinetworks is presented to overcome the problem. Two different artificial neural networks were suggested instead of vector selection and sector determination processes in the conventional direct torque control method. The conventional and the proposed control methods were evaluated on an induction motor through an experimental set. It was observed that the speed and torque responses of the proposed method were better than those of the conventional …


Energy-Efficient Mobile Cluster-Head Data Collection Model For Wireless Sensor Networks, Nidhi Gautam, Sanjeev Sofat, Renu Vig Jan 2016

Energy-Efficient Mobile Cluster-Head Data Collection Model For Wireless Sensor Networks, Nidhi Gautam, Sanjeev Sofat, Renu Vig

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless sensor networks have grown from homogeneous network architecture to heterogeneous networks for the improvement of network efficiency and lifetime. This paper exhibits a mobile cluster-head data collection (MCHDC) model for heterogeneous wireless networks. The MCHDC model illustrates the mobility pattern of mobile cluster-head nodes in a controlled environment with uniform and nonuniform deployment of mobile elements in the area of observation. It focuses on the threshold velocity for movement of mobile elements in the network area. In this paper the effects of data sending rate, network area, sensor node density, and cluster-head node density on energy efficiency of the …


A Current-Based Simple Analog Mppt Circuit For Pv Systems, Bülent Büyükgüzel, Murat Aksoy Jan 2016

A Current-Based Simple Analog Mppt Circuit For Pv Systems, Bülent Büyükgüzel, Murat Aksoy

Turkish Journal of Electrical Engineering and Computer Sciences

A new single pilot-sensor maximum power point tracking (MPPT) system, consisting of a buck type DC/DC converter, was developed. It is controlled by an analog-based unit. The main difference between the proposed MPPT system and other systems is that the short circuit current of the pilot-PV module in our system is used to control the DC/DC converter. The circuit of the proposed system does not utilize an expensive digital signal processor nor a microcontroller; hence, the cost and the complexity of the system are reduced.


A Novel Compact Defected Ground Structure And Its Application In Mutual Coupling Reduction Of A Microstrip Antenna, Soroush Veisee, Mahsa Keshavarz Hedayati, Shahrooz Asadi Jan 2016

A Novel Compact Defected Ground Structure And Its Application In Mutual Coupling Reduction Of A Microstrip Antenna, Soroush Veisee, Mahsa Keshavarz Hedayati, Shahrooz Asadi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel compact T-shape defected ground structure (DGS) is proposed in order to reduce the mutual coupling between elements in a microstrip antenna array structure. The proposed DGS has considerable advantages compared to an H-shaped DGS. As is known, DGS insertion is a common problem in microstrip antenna array structures. However, the proposed T-shaped structure is more compact so it could be suitable for a compact microstrip array antenna. The T-shaped DGS is about 24% more compact than the H-shaped one. However, the most important novelty of our work is reducing mutual coupling both in the E-plane …


Gravitational Search Algorithm-Based Dynamic Economic Dispatch By Estimating Transmission System Losses Using A-Loss Coefficients, Ram Jethmalani Chinasamy Hemparuva, Sishaj Pulikottil Simon, Sundareswaran Kinattingal, Srinivasa Rao Nayak Panugothu Jan 2016

Gravitational Search Algorithm-Based Dynamic Economic Dispatch By Estimating Transmission System Losses Using A-Loss Coefficients, Ram Jethmalani Chinasamy Hemparuva, Sishaj Pulikottil Simon, Sundareswaran Kinattingal, Srinivasa Rao Nayak Panugothu

Turkish Journal of Electrical Engineering and Computer Sciences

Dynamic economic dispatch (DED) is an important problem in power system generation, operation, planning, and control. The objective of the DED problem is to schedule power generation for the online units over a time horizon, satisfying the unit and ramp rate constraints. Here, valve point loading effects that cause nonsmoothness of the objective function is also considered while solving the DED. The accuracy of the solution not only depends on the optimal scheduling of generating units, but it also lies in accuracy while estimating transmission system losses. Generally, B-loss coefficients are used in estimating transmission losses. However, in the literature, …


An Integrated Analysis For Sustainable Supply Of Remote Winter Tourist Centers - A Future Concept Case Study, Ajla Merzic, Mustafa Music, Mirsad Rascic, Nijaz Hadzimejlic Jan 2016

An Integrated Analysis For Sustainable Supply Of Remote Winter Tourist Centers - A Future Concept Case Study, Ajla Merzic, Mustafa Music, Mirsad Rascic, Nijaz Hadzimejlic

Turkish Journal of Electrical Engineering and Computer Sciences

In every power system there are consumer areas away from traditional power networks. Existing grid expansion can always be treated as one of the ways of powering them over long transmission and distribution lines. This is often characterized by significant transmission losses, as well as significant investments, depending on the distance and the infrastructure development. On the other hand, there are cases when these consumers are not connected to the power system and use alternative methods of supply. For that matter, possible solutions may use locally available energy sources. In this paper, comparative analyses between independent power supply through particular …


A Hybrid Search Method Of Wrapper Feature Selection By Chaos Particle Swarm Optimization And Local Search, Mohammad Masoud Javidi, Nasibeh Emami Jan 2016

A Hybrid Search Method Of Wrapper Feature Selection By Chaos Particle Swarm Optimization And Local Search, Mohammad Masoud Javidi, Nasibeh Emami

Turkish Journal of Electrical Engineering and Computer Sciences

Finding a subset of features from a large dataset is a problem that arises in many fields of study. Since the increasing number of features has extended the computational cost of a system, it is necessary to design and implement a system with the least number of features. The purpose of feature selection is to find the best subset of features from the original ones. The result of the best selection is improving the computational cost and the accuracy of the prediction. A large number of algorithms have been proposed for feature subset selection. In this paper, we propose a …


A Ring Crossover Genetic Algorithm For The Unit Commitment Problem, Syed Basit Ali Bukhari, Aftab Ahmad, Syed Auon Raza, Muhammad Noman Siddique Jan 2016

A Ring Crossover Genetic Algorithm For The Unit Commitment Problem, Syed Basit Ali Bukhari, Aftab Ahmad, Syed Auon Raza, Muhammad Noman Siddique

Turkish Journal of Electrical Engineering and Computer Sciences

The unit commitment problem (UCP) is a nonlinear, mixed-integer, constraint optimization problem and is considered a complex problem in electrical power systems. It is the combination of two interlinked subproblems, namely the generator scheduling problem and the generation allocation problem. In large systems, the UCP turns out to be increasingly complicated due to the large number of possible ON and OFF combinations of units in the power system over a scheduling time horizon. Due to the insufficiency of conventional approaches in handling large systems, numerous metaheuristic techniques are being developed for solving this problem. The genetic algorithm (GA) is one …


Common Spatial Pattern-Based Feature Extraction From The Best Time Segment Of Bci Data, Önder Aydemi̇r Jan 2016

Common Spatial Pattern-Based Feature Extraction From The Best Time Segment Of Bci Data, Önder Aydemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

Feature extraction is one of the most crucial stages in the field of brain computer interface (BCI). Because of its ability to directly influence the performance of BCI systems, recent studies have generally investigated how to modify existing methods or develop novel techniques. One of the most successful and well-known methods in BCI applications is the common spatial pattern (CSP). In existing CSP-based methods, the spatial filters were extracted either by using the whole data trial or by dividing the trials into a number of overlapping/nonoverlapping time segments. In this paper, we developed a CSP-based moving window technique to obtain …


Vector Control Of A Three-Phase Parallel Connected Two Motor Single Inverter Speed Sensorless Drive, Gunabalan Ramachandran, Subbiah Veerana, Sanjeevikumar Padmanaban Jan 2016

Vector Control Of A Three-Phase Parallel Connected Two Motor Single Inverter Speed Sensorless Drive, Gunabalan Ramachandran, Subbiah Veerana, Sanjeevikumar Padmanaban

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the performance characteristics of two induction motors of the same parameters and ratings connected in parallel and fed by a single inverter. A nature observer is employed to estimate the rotor speeds and rotor fluxes of both induction motors. It also estimates the load torques of both the motors by load torque adaptation. Under unbalanced load conditions, the speed difference between the two induction motors is reduced by considering the average and differential motor parameters and currents. Mean rotor flux is maintained constant by a rotor flux control scheme and the estimation of rotor angle is carried …


Evaluation Of Hearing Loss Simulation Using A Speech Intelligibility Index, Umut Ariöz, Banu Günel Jan 2016

Evaluation Of Hearing Loss Simulation Using A Speech Intelligibility Index, Umut Ariöz, Banu Günel

Turkish Journal of Electrical Engineering and Computer Sciences

Hearing loss simulation (HLS) is a useful tool for hearing studies, since finding large numbers of hearing-impaired volunteers with various levels of hearing loss is usually a problem. Correct simulation of the hearing impaired ear should take into account different suprathreshold effects, such as reduced frequency selectivity, reduced audibility, and loudness recruitment. Although these effects can be implemented using various algorithms, so far they have not been evaluated in detail taking into account subject dependency, effect of noisy environment, and phonetic characteristics of test words. In this study, for the purpose of evaluating the HLS, a speech intelligibility index (SII) …


Keyframe-Based Video Mosaicing For Historical Ottoman Documents, Edi̇z Şaykol Jan 2016

Keyframe-Based Video Mosaicing For Historical Ottoman Documents, Edi̇z Şaykol

Turkish Journal of Electrical Engineering and Computer Sciences

Image mosaicing is a trendy research area in computer vision in recent years. Instead of images, video frames can be mosaiced to form a larger aggregate. In both cases, merging computations generally depend on the common parts in consecutive images, which are called overlapping regions. The presence of mobile devices with a camera provides higher image and video acquisition; hence video mosaicing techniques can be utilized to digitize and to create high resolution historical document images for later use in browsing and retrieval systems. Here, we present a technique to create high resolution images of historical Ottoman documents from video. …


An Attribute Or Tuple Timestamping In Bitemporal Relational Databases, Canan Atay Jan 2016

An Attribute Or Tuple Timestamping In Bitemporal Relational Databases, Canan Atay

Turkish Journal of Electrical Engineering and Computer Sciences

Much of the research on bitemporal databases has focused on the modeling of time-related data with either attribute or tuple timestamping. While the attribute-timestamping approach attaches bitemporal data to attributes, the tuple-timestamping approach splits the object's history into several tuples. Although there have been numerous studies on bitemporal data models, there is no work contrasting these two common approaches in terms of system performance and ease of use. In this paper, we compared interval-based attribute- and tuple-timestamped bitemporal data models by running sample queries to measure processing time, and then we evaluated their usability by using the same data. Our …


Exploring Feature Sets For Turkish Word Sense Disambiguation, Bahar İlgen, Eşref Adali, Ahmet Cüneyd Tantuğ Jan 2016

Exploring Feature Sets For Turkish Word Sense Disambiguation, Bahar İlgen, Eşref Adali, Ahmet Cüneyd Tantuğ

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an exploration and evaluation of a diverse set of features that influence word-sense disambiguation (WSD) performance. WSD has the potential to improve many natural language processing (NLP) tasks as being one of the most crucial steps in the area. It is known that exploiting effective features and removing redundant ones help improving the results. There are two groups of feature sets to disambiguate senses and select the most appropriate ones among a set of candidates: collocational and bag-of-words (BoW) features. We introduce the effects of using these two feature sets on the Turkish Lexical Sample Dataset (TLSD), …


Some Observations On No-Load Losses Of An Asymmetrical Six-Phase Synchronous Machine, Arif Iqbal, Girish Kumar Singh, Vinay Pant Jan 2016

Some Observations On No-Load Losses Of An Asymmetrical Six-Phase Synchronous Machine, Arif Iqbal, Girish Kumar Singh, Vinay Pant

Turkish Journal of Electrical Engineering and Computer Sciences

The use of multiphase (more than three-phase) ac machines is well adopted in different high power applications and the evaluation of different losses (no load losses, short circuit load loss, friction and windage losses, and stray loss) in multiphase machines is extremely important for the correct determination of their operating performance. Therefore, the paper presents a detailed experimental investigation of an asymmetrical (30$^{\circ}$ displacement between the two winding sets) six-phase synchronous machine for determination of different losses under no-load condition. Moreover, a comparative study of losses for a six-phase and three-phase synchronous machine has also been performed. The results are …


Channel Measurement And Time Dispersion Analysis For Outdoor Mobile Ultrawideband Environment, Solomon Nunoo, Uche Chude-Okonkwo, Razali Ngah, Chollette Chude-Olisah, Yasser Zahedi Jan 2016

Channel Measurement And Time Dispersion Analysis For Outdoor Mobile Ultrawideband Environment, Solomon Nunoo, Uche Chude-Okonkwo, Razali Ngah, Chollette Chude-Olisah, Yasser Zahedi

Turkish Journal of Electrical Engineering and Computer Sciences

Ultrawideband (UWB) technology offers short-range high-data transmission rates. Most researchers in recent times have focused on indoor UWB channel measurements and in instances where outdoor cases were reported, they focused on static scenarios. This paper reports on mobile outdoor channel measurements typical of roadway and recreation park Infostation scenarios. It also chronicles the delay spread as well as channel stationarity analysis of the measurement data. We carried out measurements in the 3.1-5.3 GHz frequency range in various line-of-sight scenarios. The results of this research show that the delay spread values generally decrease with increasing mobile speed. Additionally, the degree of …


Variation Of Photovoltaic System Performance Due To Climatic And Geographical Conditions In Turkey, Betül Bektaş Eki̇ci̇ Jan 2016

Variation Of Photovoltaic System Performance Due To Climatic And Geographical Conditions In Turkey, Betül Bektaş Eki̇ci̇

Turkish Journal of Electrical Engineering and Computer Sciences

This study focuses on the effect of climatic and geographical factors on the performance of photovoltaic systems. For this purpose, 4 different cities (Antalya, İstanbul, Elazığ, and Erzurum) from different climatic zones according to TS 825 Thermal Insulation Requirements in Buildings were selected. The monthly average global and diffuse solar radiation of the cities was calculated numerically with the long-term sunshine duration data (between 1990 and 2012) taken from the Turkish State Meteorological Service. The yearly electric energy generated by the grid-connected photovoltaic systems assumed to be located on the flat roofs of building samples were calculated for each of …


Modeling, Control, And Power Management For A Grid-Integrated Photo Voltaic, Fuel Cell, And Wind Hybrid System, Ezhilarasan Ganesan, Subhranhsu Sekhar Dash, Chinmaya Samanta Jan 2016

Modeling, Control, And Power Management For A Grid-Integrated Photo Voltaic, Fuel Cell, And Wind Hybrid System, Ezhilarasan Ganesan, Subhranhsu Sekhar Dash, Chinmaya Samanta

Turkish Journal of Electrical Engineering and Computer Sciences

Power management in a grid-integrated power system consisting of distributed renewable energy sources is necessitated by ever-increasing energy consumption, the high cost of production, the limited resource of fossil fuel, and the worsening global environment. Wind and solar power generation are two of the most promising renewable power generation technologies. The growth of wind and photovoltaic (PV) power generation systems has exceeded the most optimistic levels of expectations. Fuel cells (FCs) also have great potential to be green power sources of the future because of the many merits they have, such as high efficiency and zero or low emission of …


A Second-Order Volterra Filter-Based Nonlinear Clipping Detector, Jihwan Park, Joon-Hyuk Chang Jan 2016

A Second-Order Volterra Filter-Based Nonlinear Clipping Detector, Jihwan Park, Joon-Hyuk Chang

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a novel nonlinear clipping detector based on the second-order Volterra filter for an acoustic echo canceller (AEC). Since the performance of the conventional AEC algorithm drastically deteriorates when nonlinear clipping occurs, the adaptive filter pauses adaptation during the nonlinear clipping periods to avoid unwanted divergence. These nonlinear clipping periods are detected in our method using the magnitude spectrum of the quadratic Volterra filter in lower frequency ranges. Through extensive computer-based simulation results considering an acoustic room environment and various clipping levels, it is found that the proposed approach is effective in detecting the nonlinear clipping …


Balancing Exploration And Exploitation By Using Sequential Execution Cooperation Between Artificial Bee Colony And Migrating Birds Optimization Algorithms, Hasan Makas, Nejat Yumuşak Jan 2016

Balancing Exploration And Exploitation By Using Sequential Execution Cooperation Between Artificial Bee Colony And Migrating Birds Optimization Algorithms, Hasan Makas, Nejat Yumuşak

Turkish Journal of Electrical Engineering and Computer Sciences

The artificial bee colony (ABC) algorithm is a metaheuristic search method inspired by bees' foraging behaviour. With its global search ability in scout bee phase, it can easily escape from local optimum traps in the problem space. Therefore, it is good at exploration. The migrating birds optimization (MBO) algorithm is another recent metaheuristic search method. It simulates birds' V flight formation, which minimizes energy consumption during flight. The MBO algorithm achieves a good convergence to the global optimum by using its own unique benefit mechanism. That is, it has a good exploitation capability. This paper aimed to combine the good …


Minimum Number Of Permanent-Magnet Synchronous Generators For Coordinated Low-Voltage Ride-Through Of Induction Generators In Hybrid Wind Farms, Shenghu Li, Rui An Jan 2016

Minimum Number Of Permanent-Magnet Synchronous Generators For Coordinated Low-Voltage Ride-Through Of Induction Generators In Hybrid Wind Farms, Shenghu Li, Rui An

Turkish Journal of Electrical Engineering and Computer Sciences

Coordinated low-voltage ride-through (LVRT) of induction generators (IGs) utilizing the excessive reactive power of permanent magnet synchronous generators (PMSGs) in hybrid wind farms is attractive due to saving investments on shunt compensators. The existing research is mainly based on dynamic simulations to given scenarios and does not quantify the necessary capacity and number of PMSGs. This paper newly proposes an analytical model to quantify the minimum number of the PMSGs for coordinated LVRT. The critical voltage at the point of common coupling (PCC) leading to slip instability of the IGs is quantified. To avoid instability, necessary var support from the …


A Sampling-Based Method Using An Improved Nonparametric Density Estimator For Probabilistic Harmonic Load Flow Calculation, Farshid Nasrfard-Jahromi, Mohammad Mohammadi Jan 2016

A Sampling-Based Method Using An Improved Nonparametric Density Estimator For Probabilistic Harmonic Load Flow Calculation, Farshid Nasrfard-Jahromi, Mohammad Mohammadi

Turkish Journal of Electrical Engineering and Computer Sciences

Harmonic distortion in electrical power systems is responsible for several technical problems. Harmonic load flow (HLF) methods have been employed in order to predict and solve many of the problems from a deterministic point of view. Moreover, methods based on probability theory have been developed to deal with the uncertainties in power systems and the random nature of harmonics. Unfortunately, since many of these methods are based on linearized models or some simplifying assumptions, they do not have acceptable accuracy. This paper proposes the use of an efficient sampling method, median Latin hypercube sampling, combined with an improved kernel density …


Design And Implementation Of A Digital Mppt Controller For A Photovoltaic Panel, Djamel Eddine Tourqui, Achour Betka, Atallah Smaili, Tayeb Allaoui Jan 2016

Design And Implementation Of A Digital Mppt Controller For A Photovoltaic Panel, Djamel Eddine Tourqui, Achour Betka, Atallah Smaili, Tayeb Allaoui

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a simplified design and hardware implementation of a digital maximum power point tracking (MPPT) controller for a photovoltaic (PV) panel using PIC microcontroller 16F877A embedded technology. The 3 most well-known algorithms, perturb & observe, hill-climbing, and incremental conductance, are considered and analyzed from a practical implementation point of view. The control board was developed using simple circuits and tested under resistive load conditions lower than the load of the maximum power point. The MPPT controller proved its effectiveness, providing maximum power to the load under changing weather conditions.


Highly Efficient Three-Phase Three-Level Multilevel Inverter Employing Different Commutation Strategies, Ammar Masaoud, Hew Wooi Ping, Saad Mekhilef, Hamza Belkamel Jan 2016

Highly Efficient Three-Phase Three-Level Multilevel Inverter Employing Different Commutation Strategies, Ammar Masaoud, Hew Wooi Ping, Saad Mekhilef, Hamza Belkamel

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a new three-phase three-level voltage source inverter. The proposed topology constitutes the conventional three-phase two-level inverter with three bidirectional switches. For purpose of generating the appropriate switching gate signals, two different commutation strategies are suggested and analyzed. A comparison between both strategies in terms of power losses and efficiency are presented. To ensure the feasibility of the proposed configuration with its suggested commutation strategies, the prototype of the proposed inverter was manufactured and the experimental results are given.


Estimating And Reshaping Human Intention Via Human--Robot Interaction, Aki̇f Durdu, İsmet Erkmen, Aydan Müşerref Erkmen Jan 2016

Estimating And Reshaping Human Intention Via Human--Robot Interaction, Aki̇f Durdu, İsmet Erkmen, Aydan Müşerref Erkmen

Turkish Journal of Electrical Engineering and Computer Sciences

Human--robot interaction (HRI) is studied in two important research areas, intention estimation and intention reshaping. Although there are many studies in the literature that define human intention, new research examines the reshaping of human intentions by using robots in HRI. In this paper, 2 different robot movements are tested in a real environment in order to reshape current human intention. The hidden Markov model (HMM) is used to estimate human intention in our intelligent robotic system. The algorithmic design of the system comprises 2 parts: the first part tracks the moving objects in the environment, and the second part estimates …


Analysis Of Active Power Control Algorithms Of Variable Speed Wind Generators For Power System Frequency Stabilization, Jakub Osmic, Mirza Kusljugic, Elvisa Becirovic, Daniel Toal Jan 2016

Analysis Of Active Power Control Algorithms Of Variable Speed Wind Generators For Power System Frequency Stabilization, Jakub Osmic, Mirza Kusljugic, Elvisa Becirovic, Daniel Toal

Turkish Journal of Electrical Engineering and Computer Sciences

A modified control algorithm of a variable speed wind generator (VSWG) for supporting power system frequency stabilization is presented in this paper. A comparison of the performance of this algorithm with active power control algorithms of VSWGs for supporting power system frequency stabilization, as published in the scientific literature, is also presented. A systematic method of analysis of the modified control algorithm is described in detail. It has been shown that by using the modified control algorithm, the VSWG ''truly'' emulates the inertial response of a conventional steam-generating unit with synchronous generators during the initial/inertial phase of primary frequency control, …


Heuristic Sample Reduction Method For Support Vector Data Description, Wenzhu Sun, Jianling Qu, Yang Chen, Yazhou Di, Feng Gao Jan 2016

Heuristic Sample Reduction Method For Support Vector Data Description, Wenzhu Sun, Jianling Qu, Yang Chen, Yazhou Di, Feng Gao

Turkish Journal of Electrical Engineering and Computer Sciences

Support vector data description (SVDD) has become one of the most promising methods for one-class classification for finding the boundary of the training set. However, SVDD has a time complexity of $O\;(N^{3})$ and a space complexity of $O\;(N^{2})$. When dealing with very large sizes of training sets, e.g., a training set of the aeroengine gas path parameters with the size of $N>10^{6}$ sampled from several months of flight data, SVDD fails. To solve this problem, a method called heuristic sample reduction (HSR) is proposed for obtaining a reduced training set that is manageable for SVDD. HSR maintains the classification …


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 …