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Full-Text Articles in Physical Sciences and Mathematics

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 …


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 …


A Control Algorithm For A Simple Flywheel Energy Storage System To Be Used In Space Applications, Kutlay Aydin, Mehmet Ti̇mur Aydemi̇r Jan 2013

A Control Algorithm For A Simple Flywheel Energy Storage System To Be Used In Space Applications, Kutlay Aydin, Mehmet Ti̇mur Aydemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

Flywheels have been under consideration to be used for energy storage purposes in space applications to replace electrochemical batteries. An electrical machine is used as a motor to store kinetic energy when the solar energy is available, and then the stored energy is converted back to electrical energy by running the machine as a generator when the solar energy is no longer available. A control algorithm for these systems is proposed in this paper. The proposed method uses a current reference rather than a speed reference in the motor mode. A method is also suggested to properly determine the current …


Big Bang-Big Crunch Optimization Algorithm With Local Directional Moves, Hakki Murat Genç, İbrahi̇m Eksi̇n, Osman Kaan Erol Jan 2013

Big Bang-Big Crunch Optimization Algorithm With Local Directional Moves, Hakki Murat Genç, İbrahi̇m Eksi̇n, Osman Kaan Erol

Turkish Journal of Electrical Engineering and Computer Sciences

The big bang--big crunch (BB--BC) algorithm has been proposed as a novel optimization method that relies on one of the theories of the evolution of the universe, namely the big bang and big crunch theory. It has been shown that this algorithm is capable of quick convergence, even in long, narrow parabolic-shaped flat valleys or in the existence of several local extremes. In this work, the BB--BC optimization algorithm is hybridized with local search moves in between the ``banging'' and ``crunching'' phases of the algorithm. These 2 original phases of the BB--BC algorithm are preserved, but the representative point (``best'' …


Lightweight Wireless Protocol Based On Ieee 802.11 For Delay Sensitive Telerobotic Systems, Onur Toker, Haluk Gümüşkaya, Ci̇han Ulaş, Bora Tamer Yilmaz Jan 2013

Lightweight Wireless Protocol Based On Ieee 802.11 For Delay Sensitive Telerobotic Systems, Onur Toker, Haluk Gümüşkaya, Ci̇han Ulaş, Bora Tamer Yilmaz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we consider wireless telerobotic systems and protocol development for low-delay wireless communication. Telerobotics can be defined as the control of robot arms from a remote location. In a telerobotic system, there is a robot arm to be controlled that is identified as the `slave arm', and a remote operator at a distant location using a robotic manipulator that is called the `master arm'. In the control system measurements, actuator delays do degrade the system's performance. Therefore, communication delays between the master and slave arms, and their minimization, are of extreme importance in telerobotics. In this paper, we …


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 …


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 …


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 …


A New Extension Of Activity Networks For Modeling And Verification Of Timed Systems, Hassan Motallebi, Mohammad Abdollahi Azgomi, Mohammad Saber Mirzaei, Ali Movaghar Jan 2013

A New Extension Of Activity Networks For Modeling And Verification Of Timed Systems, Hassan Motallebi, Mohammad Abdollahi Azgomi, Mohammad Saber Mirzaei, Ali Movaghar

Turkish Journal of Electrical Engineering and Computer Sciences

Stochastic activity networks (SANs) are a well-known petri net-based formalism used for the performance and dependability modeling of a wide range of systems. On the other hand, the growing complexity of timed systems makes it imperative to apply formal analysis techniques in the early stages of the system's development. Finding a suitable framework for the modeling, evaluation, and verification of these systems is still a great challenge. In this paper, we introduce a new formalism named timed activity networks (TANs), which are based on the activity networks that are the nondeterministic settings of the SANs. The advantages of TANs are …


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.


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 …


Survey Of Power Quality In Turkish National Transmission Network, Celal Kocatepe, Bedri̇ Kekezoğlu, Altuğ Bozkurt, Recep Yumurtaci, Aslan İnan, Oktay Arikan, Mustafa Baysal, Yener Akkaya Jan 2013

Survey Of Power Quality In Turkish National Transmission Network, Celal Kocatepe, Bedri̇ Kekezoğlu, Altuğ Bozkurt, Recep Yumurtaci, Aslan İnan, Oktay Arikan, Mustafa Baysal, Yener Akkaya

Turkish Journal of Electrical Engineering and Computer Sciences

Harmonic distortion and flicker severity have become the main concerns in power transmission networks. Different types of harmonic and flicker sources exist in power systems, such as arc furnaces and cycloconverters. A power quality problem found in networks can cause additional temperature rise, losses, noise, and irritation in the lighting equipment. The aim of this study is to identify the level of harmonics and flicker in the 380-kV transmission network of Turkey. The measurement and analysis are performed using a specially developed power quality analyzer. The effects of harmonics and flicker on the network are discussed based on real measurement …


The Development Of A Hardware- And Software-Based Simulation Platform For The Training Of Driver Candidates, Abdullah Çavuşoğlu, İsmai̇l Kurnaz Jan 2013

The Development Of A Hardware- And Software-Based Simulation Platform For The Training Of Driver Candidates, Abdullah Çavuşoğlu, İsmai̇l Kurnaz

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a traffic simulation system (TSS) to provide novice driver candidates with opportunities for training and testing has been developed. Autonomous vehicles that follow the flow of traffic in a microsimulation environment were prepared using a hierarchical concurrent state machine. Autonomous vehicles are skilled and have behavioral aspects such as tracking the lanes, following the vehicles, complying with traffic rules, decelerating, accelerating, and intersection crossings. These driver behaviors are parameterized to allow the autonomous agents to act while disregarding the rules (i.e. aggressive behaviors) or behaving normally. The TSS is operated in 3 different modes, namely the orientation, …


Orthogonal Array Based Performance Improvement In The Gravitational Search Algorithm, Ökkeş Tolga Altinöz, Asim Egemen Yilmaz, Gerhard Wilhelm Weber Jan 2013

Orthogonal Array Based Performance Improvement In The Gravitational Search Algorithm, Ökkeş Tolga Altinöz, Asim Egemen Yilmaz, Gerhard Wilhelm Weber

Turkish Journal of Electrical Engineering and Computer Sciences

The gravitational search algorithm (GSA) is a novel heuristic method inspired by Newton's gravity and velocity equations. In addition, it is a population-based algorithm, in which each member (called an agent) in the population has a mass, velocity, and acceleration. Beginning with the first population state, agents influence each other via mass and velocity relations. This mutual effect causes agents to reach the optimum. Hence, the performance of the GSA to attain the optimum is related to the initial population formation, like other population-based algorithms. In this study, the orthogonal array (OA) concept is applied and injected to the GSA …


A New Digital Image Steganography Algorithm Based On Visible Wavelength, İbrahi̇m Coşkun, Feyzi̇ Akar, Özdemi̇r Çeti̇n Jan 2013

A New Digital Image Steganography Algorithm Based On Visible Wavelength, İbrahi̇m Coşkun, Feyzi̇ Akar, Özdemi̇r Çeti̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Stenography is the science that ensures secret communication through multimedia carriers such as image, audio, and video files. The ultimate end of stenography is to hide the secret data in the carrier file so that they are not detected. To that end, stenography applications should have such features as undetectability; robustness; resistance to various images process, sing methods, and compression; and capacity of the hidden data. At the same time, those features distinguish stenography applications from watermarking and cryptography applications. This study is different from other studies in the literature in that the undetectability parameter has been achieved through hiding …


Performance Analysis Of Bid Calculation Methods In Multirobot Market-Based Task Allocation, Burak Kaleci̇, Osman Parlaktuna Jan 2013

Performance Analysis Of Bid Calculation Methods In Multirobot Market-Based Task Allocation, Burak Kaleci̇, Osman Parlaktuna

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the empirical results of a market-based task allocation method for heterogeneous and homogeneous robot teams and different types of tasks in 2 different environments are presented. The proposed method allocates robots to tasks through a parallel multiitem auction-based process. The main contribution of the proposed method is energy-based bid calculations, which take into account both the heterogeneity of the robot team and features of the tasks. The multirobot task allocation problem is considered as the optimal assignment problem and the Hungarian algorithm is used to clear the auctions. Simulations are carried out using energy-based, distance-based, and time-based …


Chaos Control Of Single Time-Scale Brushless Dc Motor With Sliding Mode Control Method, Yilmaz Uyaroğlu, Bariş Cevher Jan 2013

Chaos Control Of Single Time-Scale Brushless Dc Motor With Sliding Mode Control Method, Yilmaz Uyaroğlu, Bariş Cevher

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the sliding mode control (SMC) scheme of single time-scale brushless DC motor (BLDCM) is investigated. The SMC method consists of 2 sections. To simplify the directive of the stability of the controlled single time-scale BLDCM in the sliding mode, first a special type of PI switching surface is adopted. Second, the SMC controller is obtained to guarantee the occurrence of the PI switching surface. The effectiveness of the theoretical analysis is evaluated by numerical simulations. Thus, the numerical results are used to show the verification and trustworthiness of the proposed method.


A Word Spotting Method For Farsi Machine-Printed Document Images, Yaghoub Pourasad, Houshang Hassibi, Azam Ghorbani Jan 2013

A Word Spotting Method For Farsi Machine-Printed Document Images, Yaghoub Pourasad, Houshang Hassibi, Azam Ghorbani

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a word spotting approach for Farsi printed document images has been presented. The main idea of the paper is the font recognition of Farsi document images and query word modification according to the document image's font before searching. This operation increases the similarity between the query word image and its instances in the document image; therefore, the performance of the word spotting system increases. In the proposed word spotting approach, after the query word modification, the query word image rectangle is searched in the text lines of the document image using XNOR similarity measurement. In order to …


A Blind Digital Signature Scheme Using Elliptic Curve Digital Signature Algorithm, İsmai̇l Bütün, Mehmet Demi̇rer Jan 2013

A Blind Digital Signature Scheme Using Elliptic Curve Digital Signature Algorithm, İsmai̇l Bütün, Mehmet Demi̇rer

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, we propose a blind digital signature (BDS) scheme based on the elliptic curve digital signature algorithm that increases the performance significantly. The security of our scheme is based on the difficulty of the elliptic curve discrete algorithm problem. Therefore, it offers much smaller key lengths for the desired security levels, along with much faster cryptographic processes, leading to fewer hardware and software requirements. According to our simulation results, the relative performance improvement of our proposed BDS scheme is up to 96% when compared with previously proposed schemes.


A Computer-Aided Diagnosis System For Breast Cancer Detection By Using A Curvelet Transform, Nebi̇ Gedi̇k, Ayten Atasoy Jan 2013

A Computer-Aided Diagnosis System For Breast Cancer Detection By Using A Curvelet Transform, Nebi̇ Gedi̇k, Ayten Atasoy

Turkish Journal of Electrical Engineering and Computer Sciences

The most common type of cancer among women worldwide is breast cancer. Early detection of breast cancer is very important to reduce the fatality rate. For the hundreds of mammographic images scanned by a radiologist, only a few are cancerous. While detecting abnormalities, some of them may be missed, as the detection of suspicious and abnormal images is a recurrent mission that causes fatigue and eyestrain. In this paper, a computer-aided diagnosis system using the curvelet transform (CT) algorithm is proposed for interpreting mammograms to improve the decision making. The purpose of this study is to develop a method for …


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 …


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 …


Comparison Of Speech Parameterization Techniques For The Classification Of Speech Disfluencies, Chong Yen Fook, Hariharan Muthusamy, Lim Sin Chee, Sazali Bin Yaacob, Abdul Hamid Bin Adom Jan 2013

Comparison Of Speech Parameterization Techniques For The Classification Of Speech Disfluencies, Chong Yen Fook, Hariharan Muthusamy, Lim Sin Chee, Sazali Bin Yaacob, Abdul Hamid Bin Adom

Turkish Journal of Electrical Engineering and Computer Sciences

Stuttering assessment through the manual classification of speech disfluencies is subjective, inconsistent, time-consuming, and prone to error. The aim of this paper is to compare the effectiveness of the 3 speech feature extraction methods, mel-frequency cepstral coefficients, linear predictive coding (LPC)-based cepstral parameters, and perceptual linear predictive (PLP) analysis, for classifying 2 types of speech disfluencies, repetition and prolongation, from recorded disfluent speech samples. Three different classifiers, the k-nearest neighbor classifier, linear discriminant analysis-based classifier, and support vector machine, are employed for the classification of speech disfluencies. Speech samples are taken from the University College London Archive of Stuttered Speech …


Data Hiding In Digital Images Using A Partial Optimization Technique Based On The Classical Lsb Method, Feyzi̇ Akar, Yildiray Yalman, Hüseyi̇n Selçuk Varol Jan 2013

Data Hiding In Digital Images Using A Partial Optimization Technique Based On The Classical Lsb Method, Feyzi̇ Akar, Yildiray Yalman, Hüseyi̇n Selçuk Varol

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new partial optimization approach for the least significant bit (LSB) data hiding technique that can be used for protecting any secret information or data. A deterioration effect of as little as possible in an image is intended using the LSB data hiding technique and this is well realized utilizing the proposed partial optimization approach achieving the same data embedding bit rates. In the proposed approach, all of the image pixels are classified into 8 regions and then the 8 distinct ordering codings are applied to each region by the developed partial optimization encoder. Thus, the most …


Minimal Controller Synthesis Algorithms With Output Feedback And Their Generalization, Ata Sevi̇nç Jan 2013

Minimal Controller Synthesis Algorithms With Output Feedback And Their Generalization, Ata Sevi̇nç

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes several improvements in the minimal controller synthesis algorithms, which were developed for a class of nonlinear systems with uncertainties. The major proposition is that only the output feedback is enough to control some nonlinear systems without an observer while the existing algorithms require the complete state feedback. Next, the extended version and the parameter identification technique of the minimal controller synthesis algorithm are combined in a single method estimating some more parameters for some known forms of nonlinearities. This is applicable with or without the improvement of removing the need for using the complete state feedback. It …


A Unified Approach To Speech Enhancement And Voice Activity Detection, Ceyhan Kasap, Mustafa Levent Arslan Jan 2013

A Unified Approach To Speech Enhancement And Voice Activity Detection, Ceyhan Kasap, Mustafa Levent Arslan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a unified system for voice activity detection (VAD) and speech enhancement is proposed. In the proposed system, there is mutual exchange of information between VAD and speech enhancement blocks. A new and robust VAD algorithm is implemented for the VAD block of the unified system. The newly proposed VAD algorithm uses a periodicity measure and an energy measure obtained from spectral energy distribution and spectral energy difference of the input speech data. For the speech enhancement block, the modified Wiener filtering (MWF) approach is utilized. It has been shown that the utilization of information exchange between the …


Robust Sensorless Predictive Control Of Induction Motors With Sliding Mode Voltage Model Observer, Seyed Alireza Davari, Davood Arab Khaburi, Fengxiang Wang, Ralph Kennel Jan 2013

Robust Sensorless Predictive Control Of Induction Motors With Sliding Mode Voltage Model Observer, Seyed Alireza Davari, Davood Arab Khaburi, Fengxiang Wang, Ralph Kennel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a robust sliding mode prediction model is combined with a sliding mode voltage model observer to achieve a sensorless predictive torque control method. In order to compensate the uncertainties of the stator and rotor resistances and the offset of measured current, sliding mode feedbacks were added to the voltage model observer. To reduce the effect of the errors that are injected from the observer to the prediction model in the sensorless application, the prediction model was also reinforced by a sliding mode feedback. The feedback gains for the prediction and observer models are assigned by a robustness …