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25,765 full-text articles. Page 651 of 1048.

Feature Extraction Using Sequential Cumulative Bin And Overlap Mean Intensity Foriris Classification, AHMAD NAZRI ALI, SHAHREL AZMIN SUANDI, MOHD ZAID ABDULLAH 2018 TÜBİTAK

Feature Extraction Using Sequential Cumulative Bin And Overlap Mean Intensity Foriris Classification, Ahmad Nazri Ali, Shahrel Azmin Suandi, Mohd Zaid Abdullah

Turkish Journal of Electrical Engineering and Computer Sciences

This paper examines an approach generalizing a variant of the local binary pattern (LBP) method for iris feature extraction. The proposed method employs two different LBP variants called the sequential cumulative bin and overlap mean intensity for projecting the one-dimensional local iris textures into a binary bit pattern. The assigned bit, either 1 or 0 as a bit code, replaces the original intensity value using a specific condition for the respective reference element. The ratio value from the total transition of 1 to 0 along the row axis represents the feature of each iris image. The extraction only utilizes a …


Temporal Specificity-Based Text Classification For Information Retrieval, SHAFIQ UR REHMAN KHAN, MUHAMMD ARSHAD ISLAM, MUHAMMAD ALEEM, MUHAMMAD AZHAR IQBAL 2018 TÜBİTAK

Temporal Specificity-Based Text Classification For Information Retrieval, Shafiq Ur Rehman Khan, Muhammd Arshad Islam, Muhammad Aleem, Muhammad Azhar Iqbal

Turkish Journal of Electrical Engineering and Computer Sciences

Time is an important aspect in temporal information retrieval (TIR), a subfield of information retrieval (IR). Web search engines like Google or Bing are common examples of IR systems. An important constituent of a search engine is news retrieval, where users present their information needs in the form of temporal queries. Users are usually interested in news documents focusing on a particular time period. Existing search engines rarely fulfill the temporal information requirements as they ignore the temporal information available in the content of news documents, also known as document focus time. Furthermore, information related to multiple time periods in …


Bvire Improved Algorithm For Indoor Localization Based On Rfid And A Linearregression Model, NOOR BAHAALDIN, ERGUN ERÇELEBİ 2018 TÜBİTAK

Bvire Improved Algorithm For Indoor Localization Based On Rfid And A Linearregression Model, Noor Bahaaldin, Ergun Erçelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Traditional indoor location technologies such as infrared technology and ultrasonic technology are complex, expensive, or having unsatisfactory location accuracy. Radio frequency identification (RFID) technologies are very popular in many areas since their costs are very low. The tag in such technologies acts as the transmitter, and the radio signal strength indicator (RSSI) information is measured at the reader. However, RSSI information suffers strictly from the multipath circumstance and circumferential elements. Therefore, the localization accuracy of the boundary will be affected severely. In order to solve this problem, we introduce the boundary virtual reference label (BVIRE) algorithm to well utilize RFID …


Sar Image Time-Series Analysis Framework Using Morphological Operators And Global And Local Information-Based Linear Discriminant Analysis, UFUK SAKARYA, CANER DEMİRPOLAT 2018 TÜBİTAK

Sar Image Time-Series Analysis Framework Using Morphological Operators And Global And Local Information-Based Linear Discriminant Analysis, Ufuk Sakarya, Caner Demi̇rpolat

Turkish Journal of Electrical Engineering and Computer Sciences

Fusion of spectral, spatial, and temporal information is an effective method used in many satellite remote sensing applications. On the other hand, one drawback of this fusion is an increase in complexity. In this paper, we focus on developing a fast and well-performed classification method for agricultural crops using time-series SAR data. In order to achieve this, a novel two-stage approach is proposed. In the first stage, a high-dimensional feature space is obtained using time-series dual-pol SAR data and morphological operators. Spectral, spatial, and temporal information is combined into a single high-dimensional feature space. In the second stage, a dimension …


A Selective Frequency Reconfigurable Bandstop Metamaterial Filter For Wlan Applications, BACHIR BELKADI, ZOUBIR MAHDJOUB, MOHAMMED LAMINE SEDDIKI, MOURAD NEDIL 2018 TÜBİTAK

A Selective Frequency Reconfigurable Bandstop Metamaterial Filter For Wlan Applications, Bachir Belkadi, Zoubir Mahdjoub, Mohammed Lamine Seddiki, Mourad Nedil

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, two designs of bandstop filters are presented and implemented, each one composed of a coplanar waveguide loaded with a resonator. The first design has a structure with circular resonators, and the second design is a frequency reconfigurable filter with a rectangular spiral resonator and PIN diodes. The designs are based on the use of metamaterial to create notch filters for microwave applications. The Nicolson--Ross--Weir method, used to extract the refractive index, is also described to highlight the supernatural electromagnetic characteristic of metamaterials. From the simulation results, the filters exhibit high frequency selectivity via the presence of reflection …


Fiber-Optic Interferometric Sensor For Monitoring Automobile And Rail Traffic, JAN NEDOMA, MARCEL FAJKUS, RADANA KAHANKOVA, RADEK MARTINEK, MAREK DVORSKY, JAN VANUS, VLADIMIR VASINEK, DANIEL CVEJN 2018 TÜBİTAK

Fiber-Optic Interferometric Sensor For Monitoring Automobile And Rail Traffic, Jan Nedoma, Marcel Fajkus, Radana Kahankova, Radek Martinek, Marek Dvorsky, Jan Vanus, Vladimir Vasinek, Daniel Cvejn

Turkish Journal of Electrical Engineering and Computer Sciences

This article describes a fiber-optic interferometric sensor and measuring scheme including input-output components for traffic density monitoring. The proposed measuring system is based on the interference in optical fibers. The sensor, based on the Mach-Zehnder interferometer, is constructed to detect vibration and acoustic responses caused by vehicles moving around the sensor. The presented solution is based on the use of single-mode optical fibers (G.652.D and G.653) with wavelength of 1550 nm and laser source with output power of 1 mW. The benefit of this solution lies in electromagnetic interference immunity and simple implementation because the sensor does not need to …


The Measurement Of Shielding Effectiveness For Small-In-Size Ferrite-Based Flat Materials, İSA ARAZ 2018 TÜBİTAK

The Measurement Of Shielding Effectiveness For Small-In-Size Ferrite-Based Flat Materials, İsa Araz

Turkish Journal of Electrical Engineering and Computer Sciences

This work presents the results of our studies on the electromagnetic interference shielding effectiveness of small-in-size samples of ferrite composition microwave absorber prepared by using the ceramic method. The shielding effectiveness measurement was performed using the complex intrinsic parameters of the material. The coaxial holder method with the well-known test technique based on transmission/reflection measurements was used in the experimental setup. Complex intrinsic parameters were measured in the frequency range of 2-18 GHz by using the Nicholson - Ross - Weir (NRW) method with an automated test setup. First, the shielding effectiveness was measured by conventional test method and then …


The Impact Of Transmission Power Levels Set Size On Lifetime Of Wireless Sensor Networks In Smart Grids, HÜSEYİN UĞUR YILDIZ 2018 TÜBİTAK

The Impact Of Transmission Power Levels Set Size On Lifetime Of Wireless Sensor Networks In Smart Grids, Hüseyi̇n Uğur Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless sensor networks (WSNs) have been confirmed as one of the most promising technologies for many smart grid (SG) applications due to their low complexity and inexpensive costs. A typical WSN is formed with numerous battery limited sensor nodes mounted on critical components of a SG system for monitoring applications. Acquired monitoring data by sensor nodes are conveyed to the base station generally by using multihop communication techniques. WSN-based SG applications encounter severe propagation losses due to extreme channel conditions of the SG environment. In order to reduce possible packet errors caused by channel variations, transmission power control approaches can …


Emi Filter Design Based On The Separated Electromagnetic Interference In Switched Mode Power Supplies, SAMET YALÇIN, ŞÜKRÜ ÖZEN, SELÇUK HELHEL 2018 TÜBİTAK

Emi Filter Design Based On The Separated Electromagnetic Interference In Switched Mode Power Supplies, Samet Yalçin, Şükrü Özen, Selçuk Helhel

Turkish Journal of Electrical Engineering and Computer Sciences

Usage of switch mode power supplies (SMPS) has been increased tremendously in recent years due to their advantages compared to conventional ones. In spite of their advantages, SMPSs cause conducted and radiated emissions due to the fact that they switch on and off at specific frequencies. Electromagnetic interference (EMI) filters are mostly preferred equipment for the reduction of conducted emission for coupled circuits. Improved EMI filter in the literature to suppress both common and differential mode noises sourced by ATX (a sample of SMPS) power supply has been proposed. A proposed filter was designed by use of AWR Microwave Office …


Management Of A Hybrid Renewable Power Plant Supplying An Isolated Rural Load Within A Changing Environment, HICHEM AZLI, MOHAMED MOSTEFAI 2018 TÜBİTAK

Management Of A Hybrid Renewable Power Plant Supplying An Isolated Rural Load Within A Changing Environment, Hichem Azli, Mohamed Mostefai

Turkish Journal of Electrical Engineering and Computer Sciences

Often, authors deal with the sizing issue of hybrid power plants on horizons of several years. Proposed approaches are certainly essential to optimize energy costs. However, these solutions cannot remain optimal throughout the life cycle of the plant due to the inevitable evolution of the number of households, their consumption profiles, and possible degradation of a part of the plant. In this paper, an efficient management strategy of a sized hybrid renewable system is developed. It is based on the scheduling of the different resources of the plant. The main aim is to minimize the generated energy cost while ensuring …


Classification And Regression Analysis Using Support Vector Machine For Classifying And Locating Faults In A Distribution System, SOPHI SHILPA GURURAJAPATHY, HAZLIE MOKHLIS, HAZLEE AZIL BIN ILLIAS 2018 TÜBİTAK

Classification And Regression Analysis Using Support Vector Machine For Classifying And Locating Faults In A Distribution System, Sophi Shilpa Gururajapathy, Hazlie Mokhlis, Hazlee Azil Bin Illias

Turkish Journal of Electrical Engineering and Computer Sciences

Various fault location methods have been developed in the past to identify the faulty phase, fault type, faulty section, and distance. However, this identification is commonly conducted in a separate manner. An effective fault location should be able to identify all of these at the same time. Therefore, in this work, a method using a support vector machine (SVM) to identify the fault type, faulty section, and distance considering the faulty phase is proposed. The proposed method uses voltage sag magnitude of the distribution system as the main feature for the SVM to identify faults. The fault type is classified …


Improved Design Of Axial Flux Permanent Magnet Generator For Small-Scale Wind Turbine, MOJTABA ELDOROMI, SAJJAD TOHIDI, MOHAMMAD REZA FEYZI, NAGHI ROSTAMI, REZA EMADIFAR 2018 TÜBİTAK

Improved Design Of Axial Flux Permanent Magnet Generator For Small-Scale Wind Turbine, Mojtaba Eldoromi, Sajjad Tohidi, Mohammad Reza Feyzi, Naghi Rostami, Reza Emadifar

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, much attention has been given to axial flux permanent magnet generators due to some advantages such as high efficiency, high power density, and higher torque compared to radial flux generators. In addition, increased number of poles makes them appropriate for low-speed applications such as wind power generators. In this study, an axial flux permanent magnet synchronous generator with unique features such as high power density is designed for small-scale wind turbines. The structure of generator includes a rotor and a stator. The generator is designed and then analyzed by Flux 11.2 software. The analysis includes the effects of air …


Coordination Of Distance And Directional Overcurrent Relays Using A New Algorithm: Grey Wolf Optimizer, ZAHRA MORAVEJ, OMID SOLEIMANI OOREH 2018 TÜBİTAK

Coordination Of Distance And Directional Overcurrent Relays Using A New Algorithm: Grey Wolf Optimizer, Zahra Moravej, Omid Soleimani Ooreh

Turkish Journal of Electrical Engineering and Computer Sciences

Optimal relay coordination has important effects on the stability, security, and reliability of a network. Hence, in this article, a method for optimal coordination of distance (D) and directional overcurrent (DOC) relays is presented. Taking into account the pickup current of the overcurrent relays as an optimization variable, in addition to the time setting multiplier (TSM) and the various characteristics of these relays, optimum and suitable settings for overcurrent and distance relays are obtained. The grey wolf optimizer algorithm has been used as an optimization tool to find optimum settings. The performance of this method has been investigated in 8-bus …


Application Of Acf-Wavelet Feature Extraction For Classification Of Some Artificial Pd Models Of Power Transformer, VAHID PARVIN DARABAD 2018 TÜBİTAK

Application Of Acf-Wavelet Feature Extraction For Classification Of Some Artificial Pd Models Of Power Transformer, Vahid Parvin Darabad

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, 7 different artificial partial discharge (PD) models of power transformer defect types are built in a high voltage laboratory, and then PD signals are recorded in the whole power frequency cycle to develop a preliminary PD knowledge base. A specific technique is used to extract single PD events from the recorded knowledge base. By application of wavelet transform, different decomposition levels of extracted PD signals are investigated. Feature extraction is performed by application of statistic moments on the autocorrelation function of PD signal decompositions. "Best" features are selected based on the F-test. To evaluate the performance of …


Controlling The Speed And Flux Of A Dual Stator Winding Induction Motor Using An Emotional Intelligent Controller And Integration Algorithm, HOJAT MOAYEDIRAD, MOHAMMAD ALI SHAMSI NEJAD 2018 TÜBİTAK

Controlling The Speed And Flux Of A Dual Stator Winding Induction Motor Using An Emotional Intelligent Controller And Integration Algorithm, Hojat Moayedirad, Mohammad Ali Shamsi Nejad

Turkish Journal of Electrical Engineering and Computer Sciences

The appropriate efficiency of a dual stator winding squirrel-cage induction motor (DSWIM) is obtained when the ratio of two frequencies feeding the machine is equal to the ratio of the number of poles. In the vector control method, the estimation of flux at low speed is difficult. To solve this problem, researchers have benefited from the free capacity of the two windings of the stator. This makes the motor deviate from its standard operating mode at low speed. The main purpose of the present study is to reduce the power losses of the inverter units in the sensorless DSWIM drive …


A Frequency-Tuned Magnetic Resonance-Based Wireless Power Transfer System With Near-Constant Efficiency Up To 24 Cm Distance, SEYİT AHMET SİS, SELÇUK KAVUT 2018 TÜBİTAK

A Frequency-Tuned Magnetic Resonance-Based Wireless Power Transfer System With Near-Constant Efficiency Up To 24 Cm Distance, Seyi̇t Ahmet Si̇s, Selçuk Kavut

Turkish Journal of Electrical Engineering and Computer Sciences

In magnetic resonance-based wireless power transfer systems, the main challenge arises from varying distances between coils during power transfer because distance variations ultimately reduce the power transfer efficiency. Frequency-tuned wireless power transfer systems provide an almost-constant output power to the load up to a critical coupling distance. However, the critical coupling distance and power transfer efficiency are dependent on coil size, source, and load resistances. The purpose of this paper is to discuss this dependency with an equivalent circuit model, determine a suitable coil size for given design specifications, and set up a frequency-tuned system that is based on tracking …


Estimation Of Speed, Armature Temperature, And Resistance In Brushed Dc Machines Using A Cfnn Based On Bfgs Bp, HACENE MELLAH, KAMEL EDDINE HEMSAS, RACHID TALEB, CARLO CECATI 2018 TÜBİTAK

Estimation Of Speed, Armature Temperature, And Resistance In Brushed Dc Machines Using A Cfnn Based On Bfgs Bp, Hacene Mellah, Kamel Eddine Hemsas, Rachid Taleb, Carlo Cecati

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a sensorless speed and armature resistance and temperature estimator for brushed (B) DC machines is proposed, based on a cascade-forward neural network and quasi-Newton BFGS backpropagation. Since we wish to avoid the use of a thermal sensor, a thermal model is needed to estimate the temperature of the BDC machine. Previous studies propose either nonintelligent estimators that depend on the model, such as the extended Kalman filter and Luenberger's observer, or estimators that do not estimate the speed, temperature, and resistance simultaneously. The proposed method has been verified both by simulation and by comparison with the simulation …


Adaptive Antisingularity Terminal Sliding Mode Control For A Robotic Arm With Model Uncertainties And External Disturbances, KIEM NGUYEN, TINH NGUYEN, QUYEN BUI, MINHTUAN PHAM 2018 TÜBİTAK

Adaptive Antisingularity Terminal Sliding Mode Control For A Robotic Arm With Model Uncertainties And External Disturbances, Kiem Nguyen, Tinh Nguyen, Quyen Bui, Minhtuan Pham

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a radical adaptive terminal sliding mode control method for a robotic arm with model uncertainties and external disturbances is proposed in such a way that the singularity problem is completely dealt with. A radial basis function neural network (RBFNN) with an online weight tuning algorithm is employed to approximate unknown smooth nonlinear dynamic functions caused by the fact that there is no prior knowledge of the robotic dynamic model. Furthermore, a robust control law is utilized in order to eliminate total uncertainty composed of model uncertainties, external disturbances, and the inevitable approximation errors resulting from the finite …


Attenuating Saturated-Regulator Operation Effect Of Brushless Dc Motors Through Genetic-Based Fuzzy Logic Estimator, EMRE ÇELİK, NİHAT ÖZTÜRK 2018 TÜBİTAK

Attenuating Saturated-Regulator Operation Effect Of Brushless Dc Motors Through Genetic-Based Fuzzy Logic Estimator, Emre Çeli̇k, Ni̇hat Öztürk

Turkish Journal of Electrical Engineering and Computer Sciences

As brushless DC motor (BLDCM) speed approaches base speed, current regulators gradually saturate and lose their ability to perform their regulating task, which causes a dramatic fall in the phase currents and motor power. To control the current to a greater extent and avoid power decline, a new reference current generation technique based on a simple fuzzy logic estimator (FLE) is introduced in this paper. According to motor speed and current command, the developed FLE decides the proper commutation angle $\alpha $, which is the angle relative to normal commutation instant used for setting the current slew rate during commutation. …


Constrained Multiobjective Pso And T-S Fuzzy Models For Predictive Control, ALI THAMALLAH, ANIS SAKLY, FAOUZI M'SAHLI 2018 TÜBİTAK

Constrained Multiobjective Pso And T-S Fuzzy Models For Predictive Control, Ali Thamallah, Anis Sakly, Faouzi M'Sahli

Turkish Journal of Electrical Engineering and Computer Sciences

Multiobjective optimization problems are still a challenging area in the field of control system engineering. In this context, the current study describes a new multivariable predictive control scheme formulated by using the T-S fuzzy modeling method and a new constrained multiobjective PSO algorithm. The T-S fuzzy modeling technique is applied to forecast the behaviors of the nonlinear system. It also aims at establishing some conditions so that the proposed control loop is asymptotically stable. The obtained experimental results show that the combination of the philosophy of the T-S fuzzy model and multiobjective PSO is very good in the controlling of …


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