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Full-Text Articles in Physical Sciences and Mathematics

Actor-Critic-Based Ink Drop Spread As An Intelligent Controller, Hesam Sagha, Iman Esmaili Paeen Afrakoti, Saeed Bagherishouraki Jan 2013

Actor-Critic-Based Ink Drop Spread As An Intelligent Controller, Hesam Sagha, Iman Esmaili Paeen Afrakoti, Saeed Bagherishouraki

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces an innovative adaptive controller based on the actor-critic method. The proposed approach employs the ink drop spread (IDS) method as its main engine. The IDS method is a new trend in soft-computing approaches that is a universal fuzzy modeling technique and has been also used as a supervised controller. Its process is very similar to the processing system of the human brain. The proposed actor-critic method uses an IDS structure as an actor and a 2-dimensional plane, representing control variable states, as a critic that estimates the lifetime goodness of each state. This method is fast, simple, …


Linear Switched Reluctance Motor Control With Pic18f452 Microcontroller, Mahi̇r Dursun, Fatmagül Koç Jan 2013

Linear Switched Reluctance Motor Control With Pic18f452 Microcontroller, Mahi̇r Dursun, Fatmagül Koç

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the simulation, control, and experimental results of the velocity of a double-sided, 6/4-poled, 3-phased, 8 A, 24 V, 250 W, and 250 N pull force linear switched reluctance motor (LSRM). In the simulation and experimental study, the reference velocity is constant depending on the position and time. The velocity versus the position of the translator was controlled with fuzzy logic control (FLC) and proportional-integral (PI) control techniques. The motor was controlled by PI control method with a PIC18F452 microcontroller due to its low cost. The results of the velocity of a translator were compared with the simulation …


Complexity Reduction Of Rbf Multiuser Detector For Ds-Cdma Using A Genetic Algorithm, Mustafa Uğur Torun, Damla Gürkan Kuntalp Jan 2013

Complexity Reduction Of Rbf Multiuser Detector For Ds-Cdma Using A Genetic Algorithm, Mustafa Uğur Torun, Damla Gürkan Kuntalp

Turkish Journal of Electrical Engineering and Computer Sciences

The optimal receiver for detecting direct sequence code division multiple access (DS-CDMA) signals suffers from computational complexity that increases exponentially with the number of users. Several suboptimal multiuser detectors (MUDs) have been proposed to overcome this problem. Due to the nonlinear nature of the decision boundary of the optimal receiver, it is known that nonlinear receivers outperform linear receivers. Radial basis function (RBF) MUD is a nonlinear suboptimal receiver that can perfectly approximate this decision boundary and it needs no training since it is fully determined when the spreading codes of all users and the channel impulse response (CIR) are …


Shape Control Of Cyclic Networks In Multirobot Formations, Tolga Eren Jan 2013

Shape Control Of Cyclic Networks In Multirobot Formations, Tolga Eren

Turkish Journal of Electrical Engineering and Computer Sciences

The first part of this paper examines cycles at the network level of sensing and control architectures that are needed to maintain the shape of a multiagent formation in 2-dimensional space, while the formation moves as a cohesive whole. The key tools used in the paper are rigidity theory and graph theory. The second part of the paper focuses on the planner level and controller level of the architecture by designing the fuzzy planner and fuzzy controller of individual agents. This permits the decomposition of the complex coordination problem into a series of smaller ones. The fuzzy planner and the …


An Automated Prognosis System For Estrogen Hormone Status Assessment In Breast Cancer Tissue Samples, Fati̇h Sarikoç, Adem Kalinli, Hülya Akgün, Fi̇gen Öztürk Jan 2013

An Automated Prognosis System For Estrogen Hormone Status Assessment In Breast Cancer Tissue Samples, Fati̇h Sarikoç, Adem Kalinli, Hülya Akgün, Fi̇gen Öztürk

Turkish Journal of Electrical Engineering and Computer Sciences

Estrogen receptor (ER) status evaluation is a widely applied method in the prognosis of breast cancer. However, testing for the existence of the ER biomarker in a patient's tumor sample mainly depends on the subjective decisions of the doctors. The aim of this paper is to introduce the usage of a machine learning tool, functional trees (FTs), to attain an ER prognosis of the disease via an objective decision model. For this aim, 27 image files, each of which came from a biopsy sample of an invasive ductal carcinoma patient, were scanned and captured by a light microscope. From these …


A Rule Induction Algorithm For Knowledge Discovery And Classification, Ömer Akgöbek Jan 2013

A Rule Induction Algorithm For Knowledge Discovery And Classification, Ömer Akgöbek

Turkish Journal of Electrical Engineering and Computer Sciences

Classification and rule induction are key topics in the fields of decision making and knowledge discovery. The objective of this study is to present a new algorithm developed for automatic knowledge acquisition in data mining. The proposed algorithm has been named RES-2 (Rule Extraction System). It aims at eliminating the pitfalls and disadvantages of the techniques and algorithms currently in use. The proposed algorithm makes use of the direct rule extraction approach, rather than the decision tree. For this purpose, it uses a set of examples to induce general rules. In this study, 15 datasets consisting of multiclass values with …


Topology And Control Design Of A Sinusoidal Very Low Frequency High Voltage Generator, Zhigang Liu, Guofeng Li, Ninghui Wang Jan 2013

Topology And Control Design Of A Sinusoidal Very Low Frequency High Voltage Generator, Zhigang Liu, Guofeng Li, Ninghui Wang

Turkish Journal of Electrical Engineering and Computer Sciences

To reduce the volume and the structural complexity of a very low frequency (VLF) high voltage (HV) generator, this paper introduces a novel sinusoidal VLF HV generator with 2 high frequency HV (HFHV) transformers and 2 metal-oxide semiconductor field-effect transistor cascaded HV bridge arms. Series-parallel resonant converter technology is applied to reduce the impact of the distributed parameters, decreasing the power loss and the volume of the transformer. Both the switching frequency and the duty cycle are utilized as actuating variables to cope with the large ranges of output. Simultaneously, the principle of segmental data processing is proposed to obtain …


Operational Characteristics Of A Filtering Rectifier Transformer For Industrial Power Systems, Zhiyu Zhao, Longfu Luo, Jiazhu Xu, Thanhngoc Tran, Zhiwen Zhang Jan 2013

Operational Characteristics Of A Filtering Rectifier Transformer For Industrial Power Systems, Zhiyu Zhao, Longfu Luo, Jiazhu Xu, Thanhngoc Tran, Zhiwen Zhang

Turkish Journal of Electrical Engineering and Computer Sciences

Many conventional methods focus on reducing the harmful impact of the poor power quality in industrial rectifier systems, but they focus more on the harmonic problems of the utility grid than they do on that of the rectifier transformer; hence, the rectifier transformer would still be adversely affected by harmonic pollution. In order to solve the problem, a filtering rectifier transformer is proposed that adopts a harmonic current drainage system that incorporates tertiary winding and tuned harmonic filters. The impedance of the tertiary winding is specially designed and the tuned harmonic filters work together to restrain the harmonic current and …


Unscented Transformation-Based Probabilistic Optimal Power Flow For Modeling The Effect Of Wind Power Generation, Morteza Aien, Mahmood Fotuhi-Firuzabad, Farrokh Aminifar Jan 2013

Unscented Transformation-Based Probabilistic Optimal Power Flow For Modeling The Effect Of Wind Power Generation, Morteza Aien, Mahmood Fotuhi-Firuzabad, Farrokh Aminifar

Turkish Journal of Electrical Engineering and Computer Sciences

The unprecedented increasing penetration of distributed energy resources, mainly harvesting renewable energies, is a direct result of environmental concerns. These types of energy resources bring about more uncertainties in the power system and, consequently, necessitate probabilistic analyses of the system performance. This paper develops a new approach for probabilistic optimal power flow (P-OPF) by adapting the unscented transformation (UT) method. The heart of the proposed method lies in how to produce the sampling points. Appropriate sample points are chosen to perform the P-OPF with a high degree of accuracy and less computational burden in comparison with the features of other …


Analysis Of Conducted Emi With A Standalone Solar-Powered Dc Motor, Krishna Kumar Chittibabu, Nirmal Kumar Alphonse Jan 2013

Analysis Of Conducted Emi With A Standalone Solar-Powered Dc Motor, Krishna Kumar Chittibabu, Nirmal Kumar Alphonse

Turkish Journal of Electrical Engineering and Computer Sciences

The green environment warrants not only researchers, but rather all citizens, to adopt renewable energy sources. One such option is the use of solar energy, especially the conversion of light energy from the sun to electric energy. The conversion of light to electricity with the help of photovoltaic cells (PV), though widely used, has its own problems, such as undesirable electromagnetic interference (EMI), both in radiation and conduction modes. The present research aims to mitigate the unwanted EMI in the conduction mode (to limit the scope of the research). The mitigation of the conducted EMI on a DC/DC buck converter …


Mitigation Of Ssr And Lfo With A Tcsc Based-Conventional Damping Controller Optimized By The Pso Algorithm And A Fuzzy Logic Controller, Hasan Gahramani, Akbar Lak, Murtaza Farsadi, Hossein Hosseini Jan 2013

Mitigation Of Ssr And Lfo With A Tcsc Based-Conventional Damping Controller Optimized By The Pso Algorithm And A Fuzzy Logic Controller, Hasan Gahramani, Akbar Lak, Murtaza Farsadi, Hossein Hosseini

Turkish Journal of Electrical Engineering and Computer Sciences

The subsynchronous resonance (SSR) phenomenon may occur when a steam turbine-generator is connected to a long transmission line with series compensation. Flexible AC transmission systems (FACTS) devices are widely applied to damp the SSR and low-frequency oscillation (LFO). A thyristor-controlled series capacitor (TCSC) is a commercially available FACTS device that was developed for damping the SSR and LFO. In this paper, 2 control methods for damping the SSR and LFO are added to the TCSC main controller in order to demonstrate that the SSR damping capability of the TCSC can be enhanced by proper modulation of the firing angle. The …


Efficient Feature Integration With Wikipedia-Based Semantic Feature Extraction For Turkish Text Summarization, Aysun Güran, Ni̇lgün Güler Bayazit, Mustafa Zahi̇d Gürbüz Jan 2013

Efficient Feature Integration With Wikipedia-Based Semantic Feature Extraction For Turkish Text Summarization, Aysun Güran, Ni̇lgün Güler Bayazit, Mustafa Zahi̇d Gürbüz

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents a novel hybrid Turkish text summarization system that combines structural and semantic features. The system uses 5 structural features, 1 of which is newly proposed and 3 are semantic features whose values are extracted from Turkish Wikipedia links. The features are combined using the weights calculated by 2 novel approaches. The first approach makes use of an analytical hierarchical process, which depends on a series of expert judgments based on pairwise comparisons of the features. The second approach makes use of the artificial bee colony algorithm for automatically determining the weights of the features. To confirm the …


Review Of Distinctive Phonetic Features And The Arabic Share In Related Modern Research, Yousef Alotaibi, Ali Meftah Jan 2013

Review Of Distinctive Phonetic Features And The Arabic Share In Related Modern Research, Yousef Alotaibi, Ali Meftah

Turkish Journal of Electrical Engineering and Computer Sciences

Most research in the field of digital speech technology has traditionally been conducted in only a few languages, such as English, French, Spanish, or Chinese. Numerous studies using distinctive phonetic features (DPFs) with different techniques and algorithms have been carried out during the last 3 decades, mainly in English, Japanese, and other languages of industrialized countries. DPF elements are based on a technique used by linguists and digital speech and language experts to distinguish between different phones by considering the lowest level of actual features during phonation. These studies have investigated the best performances, outcomes, and theories, especially those regarding …


Anticipating The Friction Coefficient Of Friction Materials Used In Automobiles By Means Of Machine Learning Without Using A Test Instrument, Mustafa Ti̇mur, Fati̇h Aydin Jan 2013

Anticipating The Friction Coefficient Of Friction Materials Used In Automobiles By Means Of Machine Learning Without Using A Test Instrument, Mustafa Ti̇mur, Fati̇h Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

The most important factor for designs in which friction materials are used is the coefficient of friction. The coefficient of friction has been determined taking such variants as velocity, temperature, and pressure into account, which arise from various factors in friction materials, and by analyzing the effects of these variants on friction materials. Many test instruments have been produced in order to determine the coefficient of friction. In this article, a study about the use of machine learning algorithms instead of test instruments in order to determine the coefficient of friction is presented. Isotonic regression was selected as the machine …


Extracting Fuzzy Rules For The Diagnosis Of Breast Cancer, Ali̇ Keleş, Aytürk Keleş Jan 2013

Extracting Fuzzy Rules For The Diagnosis Of Breast Cancer, Ali̇ Keleş, Aytürk Keleş

Turkish Journal of Electrical Engineering and Computer Sciences

About one million women are diagnosed with breast cancer every year. Breast cancer makes up one-third of all cancer diagnoses in women. Diagnosing breast cancer early is vital for successful treatment. Among the breast cancer screening methods available today, mammography is the most effective, although the low precision rate of breast biopsy caused by mammogram interpretation results in approximately 70% unnecessary biopsies with benign outcomes. The aim of this study was to extract strong diagnostic fuzzy rules for the inference engine of an expert system to be used for the diagnosis of breast cancer. These rules have been extracted through …


Economic Power Dispatch Of Power Systems With Pollution Control Using Artificial Bee Colony Optimization, Linda Slimani, Tarek Bouktir Jan 2013

Economic Power Dispatch Of Power Systems With Pollution Control Using Artificial Bee Colony Optimization, Linda Slimani, Tarek Bouktir

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a solution for the emission-controlled economic dispatch (ECED) problem of medium-sized power systems via an artificial bee colony algorithm. The ECED problem, which accounts for the minimization of both the fuel cost and the emission, is a multiple objective function problem. The objective is to minimize the total fuel cost of the generation and environmental pollution caused by fossil-based thermal generating units and to also maintain an acceptable system performance in terms of the limits on the generator's real and reactive power outputs, bus voltages, shunt capacitors/reactors, and power flow of transmission lines. The proposed algorithm is …


Simulation Of Transient Processes On Overvoltage In Electric Transmission Lines Using Atp-Emtp, Ahmet Nayi̇r Jan 2013

Simulation Of Transient Processes On Overvoltage In Electric Transmission Lines Using Atp-Emtp, Ahmet Nayi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the mathematical modeling and simulation of electromagnetic transient processes is considered, which is of vital importance for examining the overvoltage phenomenon of power transmission systems. In the mathematical models of the AC power transmission systems that contain a power source, the power transformer, transmission line, and power autotransformer block are presented. The mathematical model of each system component is obtained based on the branch voltages, flux linkages, and branch voltages of the magnetic circuits individually. As for the simulation, an alternative transient program (ATP) environment is used to model the electric power system's elements. One of the …


Bidding Strategy Of Generation Companies In A Competitive Electricity Market Using The Shuffled Frog Leaping Algorithm, Vijaya Kumar Jonnalagadda, Vinod Kumar Dulla Mallesham Jan 2013

Bidding Strategy Of Generation Companies In A Competitive Electricity Market Using The Shuffled Frog Leaping Algorithm, Vijaya Kumar Jonnalagadda, Vinod Kumar Dulla Mallesham

Turkish Journal of Electrical Engineering and Computer Sciences

In a competitive electricity market, generation companies need suitable bidding models to maximize their profit. Therefore, each supplier will bid strategically for choosing the bidding coefficients to counter the competitors' bidding strategies. In this paper, the optimal bidding strategy problem is solved using a novel algorithm based on the shuffled frog leaping algorithm (SFLA). It is a memetic metaheuristic that is designed to seek a global optimal solution by performing a heuristic search. It combines the benefits of the genetic-based memetic algorithm (MA) and the social behavior-based particle swarm optimization (PSO). This allows it to have a more precise search …


A Novel Uwb Cpw-Fed Ring-Shaped Antenna With Band-Notched Characteristics, Maryam Majidzadeh, Changiz Ghobadi Jan 2013

A Novel Uwb Cpw-Fed Ring-Shaped Antenna With Band-Notched Characteristics, Maryam Majidzadeh, Changiz Ghobadi

Turkish Journal of Electrical Engineering and Computer Sciences

A novel compact omnidirectional coplanar waveguide (CPW)-fed antenna with band-notched characteristics has been designed and analyzed. The proposed ultra-wideband (UWB) antenna has a simple structure. A ring-shaped radiating patch is excited by a CPW feed line. By creating 2 square slots on the top corners of the antenna, a new resonance is excited and the bandwidth is enhanced. The band-notched function is achieved by applying 2 rectangular stubs to the ground plane structure. The proposed antenna occupies a small size of 20 x 20 x 1 mm^3 and covers a wide frequency range of 3.1--14 GHz, except for 5--6 GHz, …


Direct Adaptive Fuzzy Sliding Mode Decoupling Control For A Class Of Underactuated Mechanical Systems, Fares Nafa, Salim Labiod, Hachemi Chekireb Jan 2013

Direct Adaptive Fuzzy Sliding Mode Decoupling Control For A Class Of Underactuated Mechanical Systems, Fares Nafa, Salim Labiod, Hachemi Chekireb

Turkish Journal of Electrical Engineering and Computer Sciences

Motivated by the dynamic characteristics of underactuated mechanical systems with 2 degrees of freedom, a decoupling adaptive fuzzy sliding mode decoupling controller (DAFSMDC) is presented in this paper. By exploiting the universal approximation property of fuzzy logic systems and the sliding mode control method, this paper proposes a new decoupling strategy of the system into 2 second-order subsystems and introduces an adaptive control algorithm that guarantees the convergence of both subsystems. Since fuzzy systems are used to approximate an unknown ideal controller, the adjustable parameters of the used fuzzy systems are updated using a gradient descent algorithm that is designed …


Encoderless Position Estimation And Error Correction Techniques For Miniature Mobile Robots, Farshad Arvin, Masoud Bekravi Jan 2013

Encoderless Position Estimation And Error Correction Techniques For Miniature Mobile Robots, Farshad Arvin, Masoud Bekravi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an encoderless position estimation technique for miniature-sized mobile robots. Odometry techniques, which are based on the hardware components, are commonly used for calculating the geometric location of mobile robots. Therefore, the robot must be equipped with an appropriate sensor to measure the motion. However, due to the hardware limitations of some robots, employing extra hardware is impossible. On the other hand, in swarm robotic research, which uses a large number of mobile robots, equipping the robots with motion sensors might be costly. In this study, the trajectory of the robot is divided into several small displacements over …


Four-Dimensional Model For Describing The Status Of Peers In Peer-To-Peer Distributed Systems, Seyedeh Leili Mirtaheri, Ehsan Mousavi Khaneghah, Mohsen Sharifi, Behrouz Minaei-Bidgoli, Bijan Raahemi, Mohammad Norouzi Arab, Abbas Saleh Ardestani Jan 2013

Four-Dimensional Model For Describing The Status Of Peers In Peer-To-Peer Distributed Systems, Seyedeh Leili Mirtaheri, Ehsan Mousavi Khaneghah, Mohsen Sharifi, Behrouz Minaei-Bidgoli, Bijan Raahemi, Mohammad Norouzi Arab, Abbas Saleh Ardestani

Turkish Journal of Electrical Engineering and Computer Sciences

One of the important aspects of decision making and management in distributed systems is collecting accurate information about the available resources of the peers. The previously proposed approaches for collecting such information completely depend on the system's architecture. In the server-oriented architecture, servers assume the main role of collecting comprehensive information from the peers and the system. Next, based on the information about the features of the basic activities and the system, an exact description of the peers' status is produced. Accurate decisions are then made using this description. However, the amount of information gathered in this architecture is too …


Interaction Analysis Of Multi-Function Facts And D-Facts Controllers By Mrga, Maghsood Mokhtari, Javad Khazaie, Daryoush Nazarpour, Morteza Farsadi Jan 2013

Interaction Analysis Of Multi-Function Facts And D-Facts Controllers By Mrga, Maghsood Mokhtari, Javad Khazaie, Daryoush Nazarpour, Morteza Farsadi

Turkish Journal of Electrical Engineering and Computer Sciences

With the growing application of flexible AC transmission systems (FACTS) and distributed FACTS (D-FACTS), the coordinating problem of FACTS and D-FACTS controllers in joint operation must be considered in modern power systems. The main purpose of this paper is to investigate the possible interaction that may occur between the distributed static series compensator (DSSC) and the static synchronous compensator (STATCOM) when they operate concurrently in the power system. The modified relative gain array (MRGA) is implemented to analyze the interactions. The application of MRGA for the effective design of multiobjective controllers of the STATCOM and DSSC is demonstrated by 2 …


Cada: Channel And Delay Aware Scheduler For Real-Time Applications In Wimax Networks, Melek Oktay, Haci Ali̇ Mantar Jan 2013

Cada: Channel And Delay Aware Scheduler For Real-Time Applications In Wimax Networks, Melek Oktay, Haci Ali̇ Mantar

Turkish Journal of Electrical Engineering and Computer Sciences

Scheduling is the core of the worldwide interoperability for microwave access (WiMAX) technology that directly affects the performance of the network. In this study, we focus on scheduling and present a novel algorithm called the channel and delay aware scheduler (CADA) for real-time applications, such as voice over Internet protocol, video-on-demand, and video streaming. CADA has 2 important modules: wireless and network delay monitoring tools. The wireless module, including the compensation and channel state monitoring modules, increases the network throughput and provides fairness among all of the flows in the network. The network delay monitoring tool calculates the estimated network …


An Improved Back Projection Imaging Algorithm For Subsurface Target Detection, Wentai Lei, Sheng Zeng, Jian Zhao, Qianzhe Wang, Jianxin Liu Jan 2013

An Improved Back Projection Imaging Algorithm For Subsurface Target Detection, Wentai Lei, Sheng Zeng, Jian Zhao, Qianzhe Wang, Jianxin Liu

Turkish Journal of Electrical Engineering and Computer Sciences

An improved back projection imaging algorithm for subsurface target detection is presented in this paper. Firstly, the characteristic of the scattering data at each time-delay curve in the traditional back projection imaging procedure is analyzed. Secondly, a weight factor is designed for each focal point and an improved back projection imaging algorithm is presented. Thirdly, the simulation of the improved imaging algorithm is processed. The imaging results of both the simulation data and the real ground penetrating radar data show the effectiveness of this imaging algorithm.


Outlier Rejection Fuzzy C-Means (Orfcm) Algorithm For Image Segmentation, Fasahat Ullah Siddiqui, Nor Ashidi Mat Isa, Abid Yahya Jan 2013

Outlier Rejection Fuzzy C-Means (Orfcm) Algorithm For Image Segmentation, Fasahat Ullah Siddiqui, Nor Ashidi Mat Isa, Abid Yahya

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a fuzzy clustering-based technique for image segmentation. Many attempts have been put into practice to increase the conventional fuzzy c-means (FCM) performance. In this paper, the sensitivity of the soft membership function of the FCM algorithm to the outlier is considered and the new exponent operator on the Euclidean distance is implemented in the membership function to improve the outlier rejection characteristics of the FCM. The comparative quantitative and qualitative studies are performed among the conventional k-means (KM), moving KM, and FCM algorithms; the latest state-of-the-art clustering algorithms, namely the adaptive fuzzy moving KM , adaptive fuzzy …


A Combined Protective Scheme For Fault Classification And Identification Of Faulty Section In Series Compensated Transmission Lines, Resul Çöteli̇ Jan 2013

A Combined Protective Scheme For Fault Classification And Identification Of Faulty Section In Series Compensated Transmission Lines, Resul Çöteli̇

Turkish Journal of Electrical Engineering and Computer Sciences

The fault detection process is very difficult in transmission lines with a fixed series capacitor because of the nonlinear behavior of protection device and series-parallel resonance. This paper proposes a new method based on S-transform (ST) and support vector machines (SVMs) for fault classification and identification of a faulty section in a transmission line with a fixed series capacitor placed at the middle of the line. In the proposed method, the fault detection process is carried out by using distinctive features of 3-line signals (line voltages and currents) and zero sequence current. The relevant features of these signals are obtained …


Preserving Location Privacy For A Group Of Users, Maede Ashouri-Talouki, Ahmad Baraani Dastjerdi, Ali̇ Aydin Selçuk Jan 2013

Preserving Location Privacy For A Group Of Users, Maede Ashouri-Talouki, Ahmad Baraani Dastjerdi, Ali̇ Aydin Selçuk

Turkish Journal of Electrical Engineering and Computer Sciences

Location privacy is an interesting problem that has been receiving considerable attention. This problem has been widely discussed from the individual point of view; however, there exist only a few works that support location privacy for a group of users. In this paper we consider the problem of supporting location privacy for a group of users during the use of location-based services (LBSs). We assume a group of users who want to benefit from a LBS and find the nearest meeting place that minimizes their aggregate distance. Each user in this scenario wants to protect his or her location from …


Adaptive Detection Of Chaotic Oscillations In Ferroresonance Using Modified Extended Kalman Filter, Cengi̇z Polat Uzunoğlu, Mukden Uğur Jan 2013

Adaptive Detection Of Chaotic Oscillations In Ferroresonance Using Modified Extended Kalman Filter, Cengi̇z Polat Uzunoğlu, Mukden Uğur

Turkish Journal of Electrical Engineering and Computer Sciences

Power quality and power disturbances have become an important factor for power systems. Chaotic ferroresonance is one of the disturbances that may cause overvoltages and overcurrents; hence, it can endanger the system reliability and continuous safe operating. A power system that generates chaotic oscillations is a dynamic system, which can be modeled with a Duffing equation. This paper introduces the application of a modified extended Kalman filter for improving the detection of chaotic behavior of power system signals. A modification algorithm is used to increase the estimation performance of the former casual extended Kalman filter. The proposed method is employed …


Optimal Iterative Learning Control Design For Generator Voltage Regulation System, Mohsen Rezaei Estakhrouieh, Ali Akbar Gharaveisi Jan 2013

Optimal Iterative Learning Control Design For Generator Voltage Regulation System, Mohsen Rezaei Estakhrouieh, Ali Akbar Gharaveisi

Turkish Journal of Electrical Engineering and Computer Sciences

The purpose of this paper is to design a good tracking controller for the generator automatic voltage regulator (AVR) system. It uses an iterative learning control (ILC) algorithm as a control rule and tries to keep voltage error as low as possible, while replying to set point changes as fast as possible. Two models of ILC are discussed: P-type learning and linear quadratic (LQ) optimal design. The results of designing by LQ optimal method are compared with a Ziegler--Nichols proportional-integral-derivative (PID) controller. The effects of changing different parameters are investigated and illustrated by simulation. In order to provide better robustness …