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2015

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Articles 1981 - 2010 of 2105

Full-Text Articles in Computer Sciences

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 …

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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 …

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Matching Named Entities With The Aid Of Wikipedia, Abdullah Bawakid, Mourad Oussalah, Naveed Afzal, Seong Shim Jan 2015

Matching Named Entities With The Aid Of Wikipedia, Abdullah Bawakid, Mourad Oussalah, Naveed Afzal, Seong Shim

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper we propose a novel framework using features extracted from Wikipedia for the task of matching named entities. We present how the employed features are extracted from Wikipedia and how its structure is utilized. We describe how a term-concepts table constructed from Wikipedia and the redirect links are integrated in the framework. In addition, the internal links within Wikipedia along with the categories structure are also used to compute the relatedness between concepts. We evaluate the built framework and report its performance in the applications of word sense disambiguation and named entities matching. The system performance is compared …

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Effect Of Nonuniform Varying Delay On The Rate Of Convergence In Averaging-Based Consensus, Onur Ci̇han, Mehmet Akar Jan 2015

Effect Of Nonuniform Varying Delay On The Rate Of Convergence In Averaging-Based Consensus, Onur Ci̇han, Mehmet Akar

Turkish Journal of Electrical Engineering and Computer Sciences

This paper discusses the effect of nonuniform varying communication delay on distributed consensus algorithms in discrete time. After introducing the delayed mathematical model, we first investigate the ergodicity of the delayed system using the properties of scrambling matrices. Subsequently, the effect of nonuniform varying delay on convergence is examined. It is shown theoretically that nonuniform delay is not detrimental to the convergence rate of the algorithm for directed acyclic graphs. The results are also illustrated with several numerical examples.

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Load Management In A Distributed Multimedia Streaming Environment Using A Fault-Tolerant Hierarchical System, Hadi̇ Işik Aybay, Mohammad Ahmed Shah Jan 2015

Load Management In A Distributed Multimedia Streaming Environment Using A Fault-Tolerant Hierarchical System, Hadi̇ Işik Aybay, Mohammad Ahmed Shah

Turkish Journal of Electrical Engineering and Computer Sciences

In contrast to text-only forms of communications, multimedia uses a combination of audiovisual means alongside textual modes of communication. Streaming multimedia is such multimedia that is constantly delivered by a provider of the multimedia to a client. In streaming multimedia the streamed content is continually presented to and received by the end user. Distributed multimedia systems (DMSs) deliver multimedia content to end-users by means of distributed multimedia databases and distributed information servers. These DMSs are designed to deliver multimedia content over a network. A fault-tolerant redundant hierarchy (Red-HI)-based load management policy for a distributed multimedia streaming system is proposed in …

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Rfid Card Security For Public Transportation Applications Based On A Novel Neural Network Analysis Of Cardholder Behavior Characteristics, Gürsel Düzenli̇ Jan 2015

Rfid Card Security For Public Transportation Applications Based On A Novel Neural Network Analysis Of Cardholder Behavior Characteristics, Gürsel Düzenli̇

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a novel approach that applies neural network forecasting to security for closed-loop prepaid cards based on low-cost technologies such as RFID and 1-Wire. The security vulnerability of low-cost RFID closed-loop prepaid card systems originates mostly from the card itself. Criminal organizations counterfeit or clone card data. Although high-security prepaid cards exist, they are often too expensive for transport ticketing, and even their security is not guaranteed for a well-defined period of time. Therefore, data encryption systems are used widely against counterfeiting with success. However, it has not been possible to develop countermeasures with comparable success against cloning. …

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Active And Reactive Power Transmission Loss Allocation To Bilateral Contracts Through Game Theory Techniques, Hamed Nafisi, Hossein Mahdinia Roudsari, Seyed Hossein Hosseinian, Hossein Askarian Abyaneh, Vahid Rasouli Disfani Jan 2015

Active And Reactive Power Transmission Loss Allocation To Bilateral Contracts Through Game Theory Techniques, Hamed Nafisi, Hossein Mahdinia Roudsari, Seyed Hossein Hosseinian, Hossein Askarian Abyaneh, Vahid Rasouli Disfani

Turkish Journal of Electrical Engineering and Computer Sciences

Transmission loss has a considerable effect in overall power generation. For fairly distributing the charge of losses to generators and consumers in a deregulated power system, the allocation of this loss is very important. Game-theoretic methods seem fairer for share determination of each participant of a coalition with no discrimination. In this paper, the active and reactive power transmission losses are allocated to bilateral transactions simultaneously through load flow calculations and cooperative game theory solutions. The loss allocation problem and each bilateral transaction are treated as a game and a player of the game, correspondingly. Two game theory-based approaches, the …

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Energy Management Of Solar Car In Circuit Race, Erkan Atmaca Jan 2015

Energy Management Of Solar Car In Circuit Race, Erkan Atmaca

Turkish Journal of Electrical Engineering and Computer Sciences

This study develops an optimal driving strategy for solar car on a track with nonzero gradients and sharp corners. This strategy consists of finding the racing line and the speed profile that minimizes the lap time with a given amount of energy. The problem is formulated in proper form for a commercial nonlinear optimization software program. The track is modeled into segments identified by their spatial coordinates on its own surface. The speed-distance behavior of the vehicle is linearized at each segment. The constraints set by the brushless DC motor, battery, and circuit are formulated accordingly. This is the motor …

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A Model-Based Edge Estimation Method With Increased Edge Localization Accuracy For Medical Images, Mehmet Öztürk, Temel Kayikçioğlu Jan 2015

A Model-Based Edge Estimation Method With Increased Edge Localization Accuracy For Medical Images, Mehmet Öztürk, Temel Kayikçioğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This study proposes an improved method based on a nonlinear parametric model for intensity profile to increase the edge localization accuracy in medical images gathered from different imaging modalities. The edge model consists of three parameters associated with an edge point. It also takes into account local background intensity, noise, and blurring. The Marquardt-Levenberg algorithm is used to estimate the parameters because of its accuracy and good convergence rate. Performance of the proposed method is tested quantitatively by comparing the results with those of the well-known active contour method on synthetic vessel images. Qualitative comparisons on real MRI, coronary angiography, …

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Robust Speed Controller Design For Induction Motors Based On Ifoc And Kharitonov Theorem, Bijan Moaveni, Mojtaba Khorshidi Jan 2015

Robust Speed Controller Design For Induction Motors Based On Ifoc And Kharitonov Theorem, Bijan Moaveni, Mojtaba Khorshidi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, robust PI controllers are designed to control the speed of induction motors based on a vector control strategy. The design methodology defines the robust stability and robust performance regions in the $k_{p}-k_{i}$ (PI controller coefficients) plane using the Kharitonov theorem. In the control system design procedure, a nonlinear induction motor is modeled as an uncertain linear model. The procedure of modeling the uncertainties is presented. The required scientific foundations for designing a robust PI controller are also introduced in the general case while the necessary equations are derived. In the final step, the design procedure for a …

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A Test And Simulation Device For Doppler-Based Fetal Heart Rate Monitoring, Ahmet Mert, Mana Sezdi̇, Aydin Akan Jan 2015

A Test And Simulation Device For Doppler-Based Fetal Heart Rate Monitoring, Ahmet Mert, Mana Sezdi̇, Aydin Akan

Turkish Journal of Electrical Engineering and Computer Sciences

The Doppler effect is the preferred technique in fetal heart rate (FHR) monitoring devices. The main objective of the recent studies on the Doppler FHR has been to improve the accuracy. On the other hand, a reliable fetal heart simulator becomes essential for testing Doppler FHR monitoring devices. The motivation of this study is to design a reliable system that will be used to test Doppler FHR monitors. This device generates a similar Doppler frequency shift of fetal cardiac activity including the heart's wall and valve motions. The components of this system are basically a signal generator using a microcontroller …

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Decode-And-Forward Relaying Based On Orthogonal Complementary Codes, Refi̇k Çağlar Kizilirmak Jan 2015

Decode-And-Forward Relaying Based On Orthogonal Complementary Codes, Refi̇k Çağlar Kizilirmak

Turkish Journal of Electrical Engineering and Computer Sciences

In this note, we propose a full-duplex decode-and-forward cooperative diversity scheme based on code division with orthogonal complementary codes. We consider a simple case in which a single user is assisted by a single relay to achieve cooperative diversity. When the cooperation is full-duplex, the operational delay of the relay makes the channel asynchronous and this may cause multiple-access interference (MAI) between the user and relay. The orthogonal complementary codes have perfect autocorrelation and cross-correlation properties that provide MAI-free operation in asynchronous channels. In the proposed scheme, the user and relay terminals spread their messages with complementary codes and the …

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Solution Of Tio$_{2}$ Memristor-Capacitor Series Circuit Excited By A Constant Voltage Source And Its Application To Calculate Operation Frequency Of A Programmable Tio$_{2}$ Memristor-Capacitor Relaxation Oscillator, Reşat Mutlu Jan 2015

Solution Of Tio$_{2}$ Memristor-Capacitor Series Circuit Excited By A Constant Voltage Source And Its Application To Calculate Operation Frequency Of A Programmable Tio$_{2}$ Memristor-Capacitor Relaxation Oscillator, Reşat Mutlu

Turkish Journal of Electrical Engineering and Computer Sciences

The memristor is a new-found circuit element and its applications in programmable circuits are also under study. Analysis of most of its combinations with other circuit elements such as resistors, capacitors, and inductors does not exist. In this work, a TiO$_{2}$ memristor model with linear dopant drift speed is used and the solution of a TiO$_{2}$ memristor and capacitor series circuit driven by a constant voltage source is given. It is then used to analyze a novel M-C oscillator circuit. In previous programmable oscillator studies, the memristance of the oscillator was assumed to be constant. However, in this study, the …

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Regulation Of Methane Gas Output From An Anaerobic Reactor System Using Moving Horizon $H_{\Infty }$ Control, Fatma Yildiz Taşcikaraoğlu, Şeref Naci̇ Engi̇n Jan 2015

Regulation Of Methane Gas Output From An Anaerobic Reactor System Using Moving Horizon $H_{\Infty }$ Control, Fatma Yildiz Taşcikaraoğlu, Şeref Naci̇ Engi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the moving horizon $\mathcal{H}_{\infty }$\textbf{ }control used for tracking a desired methane gas output from an anaerobic wastewater treatment reactor is compared with classical $\mathcal{H}_{\infty }$ control and a proportional-integral-derivative controller. The nonlinear system is first linearized around the set of equilibrium and operating points selected, and then the linear matrix inequalities required to comply with the constraints and guarantee the stability are constructed. Finally, the experimental results are obtained by implementing the control method in a MATLAB environment. It is concluded that moving horizon $\mathcal{H}_{\infty }$ control yields satisfactory results.

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3d Imaging For Ground-Penetrating Radars Via Dictionarydimension Reduction, Muhammed Duman, Ali̇ Cafer Gürbüz Jan 2015

3d Imaging For Ground-Penetrating Radars Via Dictionarydimension Reduction, Muhammed Duman, Ali̇ Cafer Gürbüz

Turkish Journal of Electrical Engineering and Computer Sciences

Ground-penetrating radar (GPR) has been widely used in detecting or imaging subsurface targets. In many applications such as archaeology, utility imaging, or landmine detection, three-dimensional (3D) images of the subsurface region is required for better understanding of the sensed medium. However, a high-resolution 3D image requires wideband data collection both in spatial and time/frequency domains. Match filtering is the main tool for generating subsurface images. Applying match filtering with the data acquisition impulse response for each possible voxel in the 3D region with the collected data requires both a tremendous amount of computer memory and computational complexity. Hence, it is …

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Semiconductor Laser Beam Bending, Remzi̇ Yildirim, Fati̇h Vehbi̇ Çelebi̇ Jan 2015

Semiconductor Laser Beam Bending, Remzi̇ Yildirim, Fati̇h Vehbi̇ Çelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

This study is about a single-component cylindrical structured lens with a gradient curve that was used for bending laser beams. It operates under atmospheric conditions and bends the laser beam independently of temperature, pressure, polarity, polarization, magnetic field, electric field, radioactivity, and gravity. A single-piece cylindrical lens that can bend laser beams was developed. Lenses are made of transparent, tinted, or colored glass and are used to undermine or absorb the energy of laser beams. This study is not a work of a plasma filamentation, nor is related to a self-accelerating wave packet. Rather, it focuses on bending the laser …

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Detection Of Stator Winding Fault In Induction Motor Using Instantaneous Power Signature Analysis, Ahmet Küçüker, Mehmet Bayrak Jan 2015

Detection Of Stator Winding Fault In Induction Motor Using Instantaneous Power Signature Analysis, Ahmet Küçüker, Mehmet Bayrak

Turkish Journal of Electrical Engineering and Computer Sciences

Stator interturn faults are one of the most common faults occurring in induction motors. Early detection of interturn short circuit is important to reduce repair costs. Axial leakage monitoring, zero-sequence components, negative sequence current, and motor current signature analysis have been used for fault detection in early states. In the paper, the instantaneous power signature analysis technique is used to detect these faults, and experimental results for healthy and faulty motors are shown and discussed.

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A New Approach To The Development Of A Nonlinear Model For Micro-Pelton Turbines, Mahmut Temel Özdemi̇r, Ahmet Orhan Jan 2015

A New Approach To The Development Of A Nonlinear Model For Micro-Pelton Turbines, Mahmut Temel Özdemi̇r, Ahmet Orhan

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new approach that is closer to the real turbine without abandoning the advantages of nonlinear modeling simplicity compromising the simplicity of the nonlinear model is proposed. The purpose of the study is to contribute to making theoretical studies of microhydroelectric power plants (MHPPs) more realistic. Studies on their control, especially frequency control, have increased with the expansion of grid-connected power plants. However, some problems have occurred when converting simulation studies of the frequency control to practical studies. The reasons for these problems are that the systems cannot be modeled completely. In this study, first, the nonlinear …

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Automatic Classification Of Harmonic Data Using $K$-Means And Least Square Support Vector Machine, Hüseyi̇n Eri̇şti̇, Vedat Tümen, Özal Yildirim, Belkis Eri̇şti̇, Yakup Demi̇r Jan 2015

Automatic Classification Of Harmonic Data Using $K$-Means And Least Square Support Vector Machine, Hüseyi̇n Eri̇şti̇, Vedat Tümen, Özal Yildirim, Belkis Eri̇şti̇, Yakup Demi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an effective classification approach to classify harmonic data has been proposed. In the proposed classifier approach, harmonic data obtained through a 3-phase system have been classified by using $k$-means and least square support vector machine (LS-SVM) models. In order to obtain class details regarding harmonic data, a $k$-means clustering algorithm has been applied to these data first. The training of the LS-SVM model has been realized with the class details obtained through the $k$-means algorithm. To increase the efficiency of the LS-SVM model, the regularization and kernel parameters of this model have been determined with a grid …

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Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko Jan 2015

Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a method for determination of equivalent linear electromagnetic parameters (constant complex permeability and electrical conductivity) of nonlinear magnetic steel, which can be used in a time-harmonic finite-element simulation to yield the same losses in the volume of that material as the measured ones. The conductivity and the static hysteresis loop of the steel have been measured, from which complex permeability as a function of flux density has been extracted. The indirect measurement of losses in various samples of nonmagnetic and magnetic steel has been carried out using a physical model of a transformer core with a coil. …

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Ofdma-Based Multicast With Multiple Base Stations, Ahmet Ci̇hat Kazez, Tolga Gi̇ri̇ci̇ Jan 2015

Ofdma-Based Multicast With Multiple Base Stations, Ahmet Ci̇hat Kazez, Tolga Gi̇ri̇ci̇

Turkish Journal of Electrical Engineering and Computer Sciences

We consider an orthogonal frequency division multiple access (OFDMA)-based multicast system where multiple base stations transmit a multicast session to a multicast group. The goal is to maximize the multicast rate (i.e. the minimum achievable user rate) subject to a total power constraint. We assume the use of an erasure code (e.g., a Reed--Solomon code) or rateless code (e.g., Luby transform code). This facilitates each user to accumulate rates from their best subchannels, so that the achievable multicast rate is not limited to the worst user. The resource allocation problem involves determining the transmitting base station at each OFDMA subchannel, …

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Effective Cooperative Dtv Detection Using The Goertzel Algorithm, Selman Kulaç, Murat Hüsnü Sazli Jan 2015

Effective Cooperative Dtv Detection Using The Goertzel Algorithm, Selman Kulaç, Murat Hüsnü Sazli

Turkish Journal of Electrical Engineering and Computer Sciences

In digital TV (DTV) detection, to monitor the DTV spectrum, only pilot tone frequency values can be observed in order to achieve calculation and energy savings. These savings can be achieved using the Goertzel algorithm. However, more than one receiver sensor is needed in order to increase the detection quality. In this technique, the Goertzel algorithm is used for energy-efficient pilot tone detection and a new effective cooperative structure is proposed. There is no extra fusion center and more than one DTV band can be monitored with this OR rule-based cooperative structure. With this new cooperative structure, reaching the desired …

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Study Of Mac Routing In The Bplc P1901 Access Network: Fixed Vs. Adaptive Approach, Asmir Gogic, Aljo Mujcic, İsmai̇l Hakki Çavdar, Matej Zajc, Nermin Suljanovic Jan 2015

Study Of Mac Routing In The Bplc P1901 Access Network: Fixed Vs. Adaptive Approach, Asmir Gogic, Aljo Mujcic, İsmai̇l Hakki Çavdar, Matej Zajc, Nermin Suljanovic

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper we propose an improved adaptive media access (MAC) layer routing algorithm for the broadband power line communication (BPLC) access network founded on the fixed basic approach routing algorithm, which is integrated within the IEEE P1901 standard. The proposed adaptive algorithm incorporates a new dynamically scaled threshold for the selection of the next hop station based on the information from the physical layer. Furthermore, the procedures for the route and the time allocation modifications during the connection setup and later adjustments are developed. Simulation of the new adaptive and existing fixed routing algorithm is performed on the model …

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Prescient: A Predictive Channel Access Schemefor Ieee 802.15.4-Compliant Devices Considering Ieee 802.11 Coexistence, Tolga Çöplü, Sema Fatma Oktuğ Jan 2015

Prescient: A Predictive Channel Access Schemefor Ieee 802.15.4-Compliant Devices Considering Ieee 802.11 Coexistence, Tolga Çöplü, Sema Fatma Oktuğ

Turkish Journal of Electrical Engineering and Computer Sciences

Coexistence is among the most significant challenges for IEEE 802.15.4-compliant devices in indoor environments. Previous works have shown that IEEE 802.11-compliant devices are the major sources of interference in the 2.4 GHz industrial, scientific, and medical band. In order to overcome the coexistence problem, IEEE 802.15.4-compliant devices should monitor the communication channel and access the channel when it is not in use. In this study, the impact of IEEE 802.11 traffic on IEEE 802.15.4 communication is analyzed and a novel predictive channel access scheme, PRESCIENT (PREdictive channel access SCheme for IEee 802.15.4-compliaNT devices), is proposed. The performance evaluation of the …

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Optimal Ipfc Damping Controller Design Based On Simplex Method And Self-Tuned Fuzzy Damping Scheme In A Two-Area Multimachine Power System, Ahmet Mete Vural, Kami̇l Çağatay Bayindir Jan 2015

Optimal Ipfc Damping Controller Design Based On Simplex Method And Self-Tuned Fuzzy Damping Scheme In A Two-Area Multimachine Power System, Ahmet Mete Vural, Kami̇l Çağatay Bayindir

Turkish Journal of Electrical Engineering and Computer Sciences

This paper develops a novel self-tuned fuzzy damping control scheme for an interline power flow controller (IPFC) to suppress the interarea mode of oscillations in a multimachine power system. The nonlinear adaptive damping controller is based on coordinated operation of two fuzzy inference systems. The first one produces the required $q$-axis voltage reference of the quasi multipulse series converter in response to generator angle oscillations, while the second one is used to tune the output of the first one online for further reducing the error signal using a given set of fuzzy rules. The simplex method is employed to search …

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Dielectric Loaded Tem Horn-Fed Ridged Horn Antenna Designfor Ultrawideband Ground-Penetrating Impulse Radar, Ahmet Serdar Türk, Ahmet Kenan Keski̇n, Mustafa Dağcan Şentürk Jan 2015

Dielectric Loaded Tem Horn-Fed Ridged Horn Antenna Designfor Ultrawideband Ground-Penetrating Impulse Radar, Ahmet Serdar Türk, Ahmet Kenan Keski̇n, Mustafa Dağcan Şentürk

Turkish Journal of Electrical Engineering and Computer Sciences

A modified double-ridged horn structure is proposed to obtain ultrawideband antenna characteristics over a bandwidth ratio of greater than 40:1 for impulse radar systems. The Vivaldi-shaped TEM horn feeder has been designed to extend the lower cut-off frequency and the partial dielectric loading technique using a small lens inward while the aperture has been implemented to enhance the gain of the standard double-ridged horn antenna without changing the physical dimensions. The starting frequency of the antenna operation band is lowered from 800 MHz to 400 MHz. Moreover, approximately 5 dB gain increment level is achieved from 4 to 10 GHz. …

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An Implementable Approach In Order To Model A Nonideal Incremental Encoder In Speed Measurement Studies, Mahdi Maaref, Alireza Rezazadeh Jan 2015

An Implementable Approach In Order To Model A Nonideal Incremental Encoder In Speed Measurement Studies, Mahdi Maaref, Alireza Rezazadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Incremental encoders have attracted significant attention to measure motor speed worldwide. Due to the advantages of incremental encoders a noticeable percentage of Servo system drives have been built based on these sensors. The nonideality of encoders, especially mechanical misalignments, is one of their most important problems, affecting the precision of calculations. In the current paper we present an analytical formula to model the nonideal incremental encoder and calculate both the frequency and magnitude of vibrations due to this nonideality. Moreover, a nonideality identity parameter of the encoder is defined. This parameter can be used for quality assurance purposes. Moreover, it …

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A New High-Performance Current-Mode Fuzzy Membership Function Circuit And Its Application, Turgay Temel Jan 2015

A New High-Performance Current-Mode Fuzzy Membership Function Circuit And Its Application, Turgay Temel

Turkish Journal of Electrical Engineering and Computer Sciences

A new current-mode fuzzy-membership function circuit is proposed. The circuit has a very compact and simple architecture based on the simultaneous use of winner- and loser-take-all topologies. The circuit has also the advantage of easily adjusting generated membership function characteristics such as center or mean and width with a straightforward application of respective input currents. It is shown that the new circuit outperforms previous counterparts in terms of speed, power consumption, layout area, and robustness to variations in design parameters and errors. As an application, a fuzzy-classifier is designed with a new membership circuit as a seven fuzzy level controller.

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A New Bitwise Voting Strategy For Safety-Critical Systems With Binary Decisions, Mustafa Seçki̇n Durmuş, Oytun Eri̇ş, Uğur Yildirim, Mehmet Turan Söylemez Jan 2015

A New Bitwise Voting Strategy For Safety-Critical Systems With Binary Decisions, Mustafa Seçki̇n Durmuş, Oytun Eri̇ş, Uğur Yildirim, Mehmet Turan Söylemez

Turkish Journal of Electrical Engineering and Computer Sciences

The main issue in controlling safety-critical systems such as nuclear power reactors or railway interlocking systems is to provide high safety and reliability where the risk ratio is at the highest level because small errors might result in hazardous accidents (e.g., death or injury of many people). The N-version programming technique, where N-different modules run in parallel, can be used to improve the reliability and safety of such systems at the desired safety level. Decisions of N-different modules are then evaluated by another component, usually known as the voter, using different voting strategies. In the current study a bitwise voting …

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Developing And Verifying A Set Of Principles For The Cyber Security Of The Critical Infrastructures Of Turkey, Bilge Karabacak Jan 2015

Developing And Verifying A Set Of Principles For The Cyber Security Of The Critical Infrastructures Of Turkey, Bilge Karabacak

All Faculty and Staff Scholarship

Critical infrastructures are vital assets for countries as a harm given to critical infrastructures may affect public order, economic welfare and/or national security. Today, cyber systems are extensively used to control and monitor critical infrastructures. Therefore, cyber threats have the potential to adversely affect the order of societies and countries. In this PhD study, the root causes of the susceptibility of the critical infrastructures of Turkey to the cyber threats are identified by analyzing the qualitative data with the grounded theory method. The extracted root causes are verified by two experts. The set of principles for the cyber security of …

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