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Computer Sciences

2017

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Articles 241 - 270 of 654

Full-Text Articles in Computer Engineering

Lambda Optimization Of Constraint Violating Units In Short-Term Thermal Unit Commitment Using Modified Dynamic Programming, Logavani Kandasamy, Senthil Kumar Selvaraj Jan 2017

Lambda Optimization Of Constraint Violating Units In Short-Term Thermal Unit Commitment Using Modified Dynamic Programming, Logavani Kandasamy, Senthil Kumar Selvaraj

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new approach with a three-stage optimization algorithm for the least-cost optimal solution of the unit commitment problem. In the proposed work, the optimal schedule is obtained by optimizing the lambda operator for the states that violate the inequality constraints. The objective of the work is to minimize the fuel cost when subjected to various constraints such as load balance, minimum up/down time, ramp limit, and spinning reserve. This method of committing the units yields the least-cost solution when applied to the IEEE 10-unit systems and 7-unit Indian utility practical systems scheduled for 24 h and the …


Dual Broadband Antenna With Compact Double Ring Radiators For Ieee 802.11 Ac/B/G/N Wlan Communication Applications, Meri̇h Palandöken Jan 2017

Dual Broadband Antenna With Compact Double Ring Radiators For Ieee 802.11 Ac/B/G/N Wlan Communication Applications, Meri̇h Palandöken

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a dual broadband antenna is proposed for WLAN communication modules supported by the IEEE 802.11 ac/b/g/n standard. The antenna design is based on two interspaced electrically small split-ring resonators, each of which is directly fed through the stepped impedance microstrip line with an optimized electromagnetic coupling distance in between. The proposed dual band antenna operates in the lower frequency band from 2.3 GHz up to 3 GHz with 2.65 GHz center frequency (26.4 % bandwidth) and in the higher frequency band from 4.7 GHz up to 6 GHz with 5.35 GHz center frequency (24.3% bandwidth). The radiating …


Dvcc-Based Floating Capacitance Multiplier Design, Hali̇l Alpaslan Jan 2017

Dvcc-Based Floating Capacitance Multiplier Design, Hali̇l Alpaslan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a floating capacitance multiplier including two multioutput differential voltage current conveyors, two grounded resistors, and a grounded capacitor is proposed. The proposed floating capacitance multiplier can realize high capacitor values with two small-valued resistors. It is more suitable for integrated circuit technology because it has only grounded passive components without needing any critical passive component matching conditions. Its performances are examined with several simulations using the SPICE program. As an application example, a third-order notch filter using three resistors and three capacitors is given.


An Advanced Robust Fault-Tolerant Tracking Control For A Doubly Fed Induction Generator With Actuator Faults, Samir Abdelmalek, Linda Barazane, Abdelkader Larabi Jan 2017

An Advanced Robust Fault-Tolerant Tracking Control For A Doubly Fed Induction Generator With Actuator Faults, Samir Abdelmalek, Linda Barazane, Abdelkader Larabi

Turkish Journal of Electrical Engineering and Computer Sciences

Fault-tolerant controller (FTC) designs for doubly fed induction generators (DFIGs) with actuator faults have recently gained considerable attention due to their important role in maintaining the safety and reliability of DFIG-based wind turbines via configured redundancy. The objective of this paper is to propose a novel active fault-tolerant tracking control strategy for a DFIG subject to actuator faults. The proposed strategy consists of first designing a proportional integral observer (PIO) for simultaneous system states and fault estimation and then secondly the FTC, which depends on the estimated states and faults. The objective of such a controller is to drive the …


Energy-Hole Avoidance And Lifetime Enhancement Of A Wsn Through Load Factor, Krishna Pal Sharma, Teek Parval Sharma Jan 2017

Energy-Hole Avoidance And Lifetime Enhancement Of A Wsn Through Load Factor, Krishna Pal Sharma, Teek Parval Sharma

Turkish Journal of Electrical Engineering and Computer Sciences

In wireless sensor networks, nonuniform communication load across a network often leads to the problem of energy holes or hot spots, i.e. nodes nearer high activity regions deplete their energy much faster than nodes elsewhere. This may partition the network into unreachable segments and thus adversely affect network lifetime. The problem is more acute in random and sparsely deployed networks. Therefore, we propose a deployment strategy that, using the least possible nodes, prolongs network lifetime by avoiding energy holes and also ensures full sensing and communication coverage. The scheme handles the energy imbalance by selecting an appropriate set of communication …


Design And Realization Of A Novel Planar Array Antenna And Low Power Lna For Ku-Band Small Satellite Communications, Lida Kouhalvandi, Osman Ceylan, Selçuk Paker, Hasan Bülent Yağci Jan 2017

Design And Realization Of A Novel Planar Array Antenna And Low Power Lna For Ku-Band Small Satellite Communications, Lida Kouhalvandi, Osman Ceylan, Selçuk Paker, Hasan Bülent Yağci

Turkish Journal of Electrical Engineering and Computer Sciences

This article presents both a four-element novel microstrip array antenna and a low noise amplifier (LNA) for a Ku-band small satellite receiver. It includes all design details with measurement results of the fabricated array antenna and LNA. Measured minimum and maximum gains of the proposed antenna are 10.1 and 10.9 dBi in 11.9-12.9 GHz band frequency. The designed LNA has a noise figure lower than 1.5 dB and gain higher than 8 dB (at 2 V, 10 mA biasing). In order to reduce the design period and cost, discrete components are chosen and a hetero-junction FET is used as the …


Effect Of Micro/Nano-Sio$_{2}$ On Mechanical, Thermal, And Electrical Properties Of Silicone Rubber, Epoxy, And Epdm Composites For Outdoor Electrical Insulations, Hidayatullah Khan, Muhammad Amin, Muhammad Ali, Muhammad Iqbal, Muhammad Yasin Jan 2017

Effect Of Micro/Nano-Sio$_{2}$ On Mechanical, Thermal, And Electrical Properties Of Silicone Rubber, Epoxy, And Epdm Composites For Outdoor Electrical Insulations, Hidayatullah Khan, Muhammad Amin, Muhammad Ali, Muhammad Iqbal, Muhammad Yasin

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper the influence of micro-sized (3 $\mu $m) and nano-sized (10 nm) silica (SiO$_{2})$ on mechanical, thermal, and electrical properties of silicon rubber (SiR), epoxy, and ethylene propylene diene monomer (EPDM) composites is presented. The micro- and nano-sized SiO$_{2}$ particle-filled SiR, epoxy, and EPDM composites were formulated with 20% microsilica and 5% nanosilica by weight respectively. Among these composites, SiR-SiO$_{2}$ amalgamation was performed by mixing using an ultrasonication procedure. Epoxy-SiO$_{2}$ was compounded in two steps, i.e. dispersion of fillers and mixing, whereas EPDM-SiO$_{2}$ compounding was performed with a two roll mill technique. With the addition of micro/nano-SiO$_{2}$, the …


Experimental Evaluation And Fdtd Method For Predicting Electromagnetic Fields In The Near Zone Radiated By Power Converter Systems, Mohammed Laour, Redouane Tahmi, Christian Vollaire Jan 2017

Experimental Evaluation And Fdtd Method For Predicting Electromagnetic Fields In The Near Zone Radiated By Power Converter Systems, Mohammed Laour, Redouane Tahmi, Christian Vollaire

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the study of conducted electromagnetic interference (EMI) currents flowing through the power cables of a DC-DC converter system and its correlation with the near field radiated from these cables. The radiated emission measurement contains a common mode (CM) and a differential mode (DM), and accurate separation of the radiated emissions of these two modes is necessary. The finite-difference time-domain (FDTD) method is used to predict the electromagnetic radiation caused by CM currents and DM currents. An experimental bench has been designed to allow access to the measurement of EMI disturbances at various sensitive places. The CM and …


A Cell-Based 5-Mhz On-Chip Clock Generator, Ching-Che Chung, Jhih-Wei Li Jan 2017

A Cell-Based 5-Mhz On-Chip Clock Generator, Ching-Che Chung, Jhih-Wei Li

Turkish Journal of Electrical Engineering and Computer Sciences

A cell-based 5-MHz on-chip clock generator for smart sensing applications is presented. By exploiting relative reference modeling, our proposed design can dynamically track both voltage and temperature variations after four-point chip calibrations. The proposed on-chip clock generator is fabricated using a 90-nm CMOS process, the frequency stability is 160 ppm/$^{\circ}$C and 72 ppm/mV over 0 $^{\circ}$C to 75 $^{\circ}$C and 0.9 V to 1.1 V, and the settling time of the proposed on-chip clock generator is 5.12 $\mu$s. The proposed on-chip clock generator was implemented with standard cells that can greatly reduce the design complexity and design time for on-chip …


Optimal Determination Of Island Boundaries Besides The Optimal Placement Of D-Statcom Devices And Dg Units, Sadeq Rabie, Hossein Afrakhte Jan 2017

Optimal Determination Of Island Boundaries Besides The Optimal Placement Of D-Statcom Devices And Dg Units, Sadeq Rabie, Hossein Afrakhte

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, integration of three important concepts of distributed generation, D-FACTS devices, and microgrids are evaluated. The performance of a microgrid is dependent on its location, capacity, and placement of DG units and D-FACTS devices. In this paper a new method is proposed to simultaneously determine the optimal number, location, and capacity of DG units and D-STATCOM devices and optimal boundaries of electrical islands in the independent mode of microgrids. The main objective is to minimize the economic costs. The optimal locations of DG units and D-STATCOM devices should be determined to maximize the DG capacities with minimum loss …


Design And Implementation Of A Modified Communication Disturbance Observer For Teleoperation Systems, Zahra Zeinaly, Amin Ramezani, Sadjaad Ozgoli Jan 2017

Design And Implementation Of A Modified Communication Disturbance Observer For Teleoperation Systems, Zahra Zeinaly, Amin Ramezani, Sadjaad Ozgoli

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel structure for a communication disturbance observer in teleoperation systems is proposed to achieve robust stability. A time delay compensation method based on the concept of network disturbance and a communication disturbance observer (CDOB) has been proposed in past research. Unlike model-based approaches, it works without a time delay model. Therefore, it can be implemented in teleoperation systems with unknown and time-varying delay. However, it has been observed that the system model errors and external disturbances seriously affect the steady-state characteristics. Hence, in this paper, to achieve robustness against disturbance and model uncertainty, the structure of …


Design And Test Of A New Development Fpga Board For Mobile Robot Research, Baligh Naji, Chokri Abdelmoula, Karim Abbes, Mohamed Masmoudi Jan 2017

Design And Test Of A New Development Fpga Board For Mobile Robot Research, Baligh Naji, Chokri Abdelmoula, Karim Abbes, Mohamed Masmoudi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the design and testing of a newly developed field programmable gate array (FPGA) board for mobile robot research. The idea consists of interfacing the FPGA to a 16-bit digital signal controller (dsPIC). This idea enables the FPGA designs to communicate with the dsPIC through the integration of per-written driver modules to be used in a wide variety of digital and analog peripheral modules. It also allows the use of a high-performance digital signal processing core in many signal processing-based mobile robot applications. The proposed FPGA board allows users to develop, test, and deploy quick and cost-effective complete …


Early Detection Of Sudden Cardiac Death Using Poincaré Plots And Recurrence Plot-Based Features From Hrv Signals, Vahid Houshyarifar, Mehdi Chehel Amirani Jan 2017

Early Detection Of Sudden Cardiac Death Using Poincaré Plots And Recurrence Plot-Based Features From Hrv Signals, Vahid Houshyarifar, Mehdi Chehel Amirani

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper we present a method to predict sudden cardiac death (SCD) based on the heart rate variability (HRV) signal and recurrence plots and Poincaré plot-extracted features. This work is a challenge since it is aimed to devise a method to predict SCD 5 min before its onset. The method consists of four steps: preprocessing, feature extraction, feature reduction, and classification. In the first step, the QRS complexes are detected from the electrocardiogram signal and then the HRV signal is extracted. In the second step, the recurrence plot of the HRV signal and Poincaré plot-extracted features are obtained. Four …


Communications Protocol For Power Management In Smart Homes, Milan Bjelica, Mirjana Simic Pejovic Jan 2017

Communications Protocol For Power Management In Smart Homes, Milan Bjelica, Mirjana Simic Pejovic

Turkish Journal of Electrical Engineering and Computer Sciences

Emergency situations, incentives for energy efficiency, new pricing plans, and distributed electricity market jointly require home automation systems that would conform an instantaneous load to a dynamically set limit. In this paper, a novel machine-to-machine communications protocol that interconnects a smart grid and smart house is described. ''Intelligent'' domestic appliances use it to coordinate their switch-on times so that the assigned power quota will not be exceeded. In this way, the end-user experience can be improved by reducing the electricity bills, conveniently conforming to prepaid pricing plans, or even by providing continued service at possibly reduced consumption levels during power …


Investigation Of Secondary Cooling Design Enhancements In Thermally Limited Compact Notebooks, Muhammad Azhar Ali Khan, Eray Uzgören, Ali̇ Muhtaroğlu Jan 2017

Investigation Of Secondary Cooling Design Enhancements In Thermally Limited Compact Notebooks, Muhammad Azhar Ali Khan, Eray Uzgören, Ali̇ Muhtaroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Thermal design enhancements in a thermally limited compact notebook system are investigated in this paper. System temperature, power, and fan speed are characterized under a range of activity levels. A finite element model is developed, and validated against measurements. Design enhancements improve cooling with minimum intrusion to the existing mechanical design. A passive secondary heat pipe in the system reduces the CPU temperature by 5 $^{\circ}$C, and improves the system performance through increased CPU + Graphics and Memory Controller Hub (GMCH) thermal design power (TDP) by 6.4%. When such a secondary heat pipe is considered with an integrated off-the-shelf Peltier …


Assignment As A Location-Based Service In Outsourced Databases, Ahmet Sali̇h Büyükkayhan, Taflan İmre Gündem Jan 2017

Assignment As A Location-Based Service In Outsourced Databases, Ahmet Sali̇h Büyükkayhan, Taflan İmre Gündem

Turkish Journal of Electrical Engineering and Computer Sciences

Location-based services provide opportunities to organizations for tracking and utilizing their resources. Moreover, some corporations prefer to outsource their database management services. In the literature, privacy preservation techniques in outsourced spatial databases for several query types, such as nearest neighbor, K-nearest neighbor, and proximity search, have been examined. In this paper, we present an efficient application of the capacity and coverage-constrained assignment query on outsourced spatial databases. In the proposed technique, we introduce a novel spatial transformation strategy (square spiral encoding) to achieve privacy efficiently for approximate assignment query results. To process the assignment query, we use the parallel auction …


A Neural Network Approach To Navigation Of A Mobile Robot And Obstacle Avoidance In Dynamic And Unknown Environments, Farhad Shamsfakhr, Bahram Sadeghi Bigham Jan 2017

A Neural Network Approach To Navigation Of A Mobile Robot And Obstacle Avoidance In Dynamic And Unknown Environments, Farhad Shamsfakhr, Bahram Sadeghi Bigham

Turkish Journal of Electrical Engineering and Computer Sciences

Mobile robot navigation and obstacle avoidance in dynamic and unknown environments is one of the most challenging problems in the field of robotics. Considering that a robot must be able to interact with the surrounding environment and respond to it in real time, and given the limited sensing range, inaccurate data, and noisy sensor readings, this problem becomes even more acute. In this paper, we attempt to develop a neural network approach equipped with statistical dimension reduction techniques to perform exact and fast robot navigation, as well as obstacle avoidance in such a manner. In order to increase the speed …


Design Of A Self-Starting Hybrid Permanent Magnet Hysteresis Synchronous Motor Connected Directly To The Grid, Mehmet Gedi̇kpinar, Ömür Aydoğmuş Jan 2017

Design Of A Self-Starting Hybrid Permanent Magnet Hysteresis Synchronous Motor Connected Directly To The Grid, Mehmet Gedi̇kpinar, Ömür Aydoğmuş

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, a permanent magnet hysteresis synchronous (PMHS) motor was designed to improve the efficiency of the system. The proposed motor is intended for pumping applications, such as submersible pump motors, fire pumps, oil-well pumps, and circulation pumps requiring high-speed operation. The efficiency of the pump system increases depending on the speed of the pump fans. The total efficiency of the pump system is reduced because the load increases exponentially in these types of application systems. The speed is important for the pumping applications in order to improve the efficiency of the pump system. Nowadays, traditional induction motors are …


Neural Network Approach On Loss Minimization Control Of A Pmsm With Core Resistance Estimation, Hüseyi̇n Erdoğan, Mehmet Özdemi̇r Jan 2017

Neural Network Approach On Loss Minimization Control Of A Pmsm With Core Resistance Estimation, Hüseyi̇n Erdoğan, Mehmet Özdemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

Permanent magnet synchronous motors (PMSMs) are often used in industry for high-performance applications. Their key features are high power density, linear torque control capability, high efficiency, and fast dynamic response. Today, PMSMs are prevalent especially for their use in hybrid electric vehicles. Since operating the motor at high efficiency values is critically important for electric vehicles, as for all other applications, minimum loss control appears to be an inevitable requirement in PMSMs. In this study, a neural network-based intelligent minimum loss control technique is applied to a PMSM. It is shown by means of the results obtained that the total …


Training Anfis By Using The Artificial Bee Colony Algorithm, Dervi̇ş Karaboğa, Ebubeki̇r Kaya Jan 2017

Training Anfis By Using The Artificial Bee Colony Algorithm, Dervi̇ş Karaboğa, Ebubeki̇r Kaya

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new adaptive network-based fuzzy inference system (ANFIS) training algorithm, the artificial bee colony (ABC) algorithm, is presented. Antecedent and conclusion parameters existing in the structure of ANFIS are optimized with the ABC algorithm and ANFIS training is realized. Identification of a set of nonlinear dynamic systems is performed in order to analyze the suggested training algorithm. The ABC algorithm is operated 30 times for each identification case and the average root mean square error (RMSE) value is obtained. Training RMSE values calculated for the four examples considered are 0.0325, 0.0215, 0.0174, and 0.0294, respectively. In addition, …


Research On Magnetic Field State Analysis Of A Nonsalient Pole Synchronous Generator, Baojun Ge, Pin Lv, Dajun Tao, Fang Xiao, Hongsen Zhao Jan 2017

Research On Magnetic Field State Analysis Of A Nonsalient Pole Synchronous Generator, Baojun Ge, Pin Lv, Dajun Tao, Fang Xiao, Hongsen Zhao

Turkish Journal of Electrical Engineering and Computer Sciences

This paper is based on the definition of minor asymmetric degree and the relative position of the magnetic field. The relative position of the magnetic field is the angle between the positive and negative sequence magnetic fields. The corresponding relationship between the nonsalient pole synchronous generator steady performance and the magnetic field state is discussed when the generator operates at minor asymmetry. To analyze this corresponding relationship, the Taylor expansion formula with Lagrange remainder and symmetrical components is adopted. We study the relationship between the armature current and the relative position of the magnetic field, deducing the armature current expressions …


Ionolab-Ray: A Wave Propagation Algorithm For Anisotropic And Inhomogeneous Ionosphere, Esra Erdem, Feza Arikan Jan 2017

Ionolab-Ray: A Wave Propagation Algorithm For Anisotropic And Inhomogeneous Ionosphere, Esra Erdem, Feza Arikan

Turkish Journal of Electrical Engineering and Computer Sciences

A high-frequency (HF) radio wave propagation model based on ray tracing for anisotropic, inhomogeneous, and time-varying ionosphere is developed to form the basis for a user-friendly modular algorithm. The algorithm IONOLAB-RAY applies the principles of ray tracing through the spherical 3D grid model of the ionosphere. The physical parameters of the ionosphere in each voxel are obtained from the ionosphere model IRI-Plas-G. The refractive index of each voxel is calculated with the Appleton-Hartree formula, which includes electron cyclotron frequency, collision frequency, and anisotropicity due to the geomagnetic field. The developed propagation algorithm allows the input of total electron content (TEC) …


Effect Of Touch Coordinate Display As A Form Of Augmented, Concurrent Visual Feedback On The Accuracy Of Single-Handed Typing Via Smartphone Virtual Keyboards, Abdullah Ruhi̇ Soylu, Görkem Yavaş, Bora Ergi̇n, Sumru Keçeli̇ Jan 2017

Effect Of Touch Coordinate Display As A Form Of Augmented, Concurrent Visual Feedback On The Accuracy Of Single-Handed Typing Via Smartphone Virtual Keyboards, Abdullah Ruhi̇ Soylu, Görkem Yavaş, Bora Ergi̇n, Sumru Keçeli̇

Turkish Journal of Electrical Engineering and Computer Sciences

This study assessed the effect of an easily perceived real-time visual feedback method on touchscreen typing accuracy. Thirty subjects were asked to hold a smartphone with a capacitive touchscreen in one hand and enter a text using the thumb of the same hand via a custom designed virtual keyboard. There were two types of text entry sessions: with or without visual feedback. The visual feedback consisted of a full-screen crosshair, representing the accurate coordinate of touch in real time. In each session, touch-down time on the virtual keyboard and touch coordinates were recorded for every touch action. Two types of …


An Improved Clonal Selection Algorithm Using A Tournament Selection Operator And Its Application To Microstrip Coupler Design, Ezgi̇ Deni̇z Ülker Jan 2017

An Improved Clonal Selection Algorithm Using A Tournament Selection Operator And Its Application To Microstrip Coupler Design, Ezgi̇ Deni̇z Ülker

Turkish Journal of Electrical Engineering and Computer Sciences

The clonal selection algorithm (CLONALG) is a nature-inspired metaheuristic algorithm that has been applied to various complex optimization problems from different fields of study. Tournament selection (TS) is a selection operator that is mainly used in genetic algorithms. In this paper, a novel improved clonal selection algorithm by using the TS operator (ICSAT) is introduced. To observe the improvement, ICSAT was first tested on selected benchmark functions and then to validate its efficiency ICSAT was applied to a microstrip coupler design problem. Although showing some disadvantages that generally exist in all modified algorithms, it is observed that ICSAT has a …


Regional Ionospheric Trend Statistics: Ionolab-Pdf, Ozan Köroğlu, Feza Arikan Jan 2017

Regional Ionospheric Trend Statistics: Ionolab-Pdf, Ozan Köroğlu, Feza Arikan

Turkish Journal of Electrical Engineering and Computer Sciences

The ionosphere plays an important role for HF bands, space-based positioning systems, satellite communication, and propagation. The variability of the ionosphere has a complex spatiotemporal characteristic, which depends on statistical parameters. Total electron content (TEC) is one of the major observables for investigating and determining this variability. In this study, spatiotemporal within-the-hour statistical characteristics of TEC are determined for Turkey, which is located in midlatitude, using the TEC estimates from the Turkish National Permanent GPS Network-Active between the years 2009 and 2012. The TEC values have strong hourly, seasonal, and positional dependence on east-west direction, and the trend shifts according …


Breast Boundary Segmentation In Thermography Images Based On Random Walkers, Mehrdad Moghbel, Syamsiah Mashohor, Rozi Mahmud, M.Iqbal Bin Saripan, Suzana Abd Hamid, Suraini Mohamad Sani, Saiful Nizam Jan 2017

Breast Boundary Segmentation In Thermography Images Based On Random Walkers, Mehrdad Moghbel, Syamsiah Mashohor, Rozi Mahmud, M.Iqbal Bin Saripan, Suzana Abd Hamid, Suraini Mohamad Sani, Saiful Nizam

Turkish Journal of Electrical Engineering and Computer Sciences

Breast and areola boundary detection and segmentation present the biggest challenge in breast segmentation from thermography images, as breast boundaries, especially in the upper quadrants of the breast, are nonexistent. Many segmentation approaches have been proposed for breast segmentation, such as active contours and snakes, circular Hough transforms, and live wires, but these methods often fail to achieve satisfactory results. With recent advances in image processing techniques, new segmentation concepts are being developed, such as random walkers, which have received high interest from the medical imaging community. In this study, 91 images acquired utilizing a FLIR A320 thermal camera are …


Using Latent Semantic Analysis For Automated Keyword Extraction From Large Document Corpora, Tuğba Önal Süzek Jan 2017

Using Latent Semantic Analysis For Automated Keyword Extraction From Large Document Corpora, Tuğba Önal Süzek

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, we describe a keyword extraction technique that uses latent semantic analysis (LSA) to identify semantically important single topic words or keywords. We compare our method against two other automated keyword extractors, Tf-idf (term frequency-inverse document frequency) and Metamap, using human-annotated keywords as a reference. Our results suggest that the LSA-based keyword extraction method performs comparably to the other techniques. Therefore, in an incremental update setting, the LSA-based keyword extraction method can be preferably used to extract keywords from text descriptions from big data when compared to existing keyword extraction methods.


Statistical Features-Based Comparison Of Analysis And Synthesis Of Normal And Epileptic Electroencephalograms For Various Wavelets, Revati Shriram, Mahalingam Sundhararajan, Supriya Shete, Nivedita Daimiwal Jan 2017

Statistical Features-Based Comparison Of Analysis And Synthesis Of Normal And Epileptic Electroencephalograms For Various Wavelets, Revati Shriram, Mahalingam Sundhararajan, Supriya Shete, Nivedita Daimiwal

Turkish Journal of Electrical Engineering and Computer Sciences

An electroencephalogram (EEG) is an electrical signal in microvolts captured noninvasively from the brain, which provides important and unique information about the brain. The frequency of an EEG signal lies between 0 and 100 Hz. Decomposition of an EEG signal into various bands such as alpha, beta, delta, theta, and gamma is essential in seizure-related studies. EEGs play a key role in the diagnosis of epileptic seizures and neurological disorders. In this paper, multiple wavelet families for decomposition and reconstruction are explored and are compared based on risk functions and reconstruction measures. While dealing with the wavelets it is a …


Automobile Engine Condition Monitoring Using Sound Emission, Hamid Ghaderi, Peyman Kabiri Jan 2017

Automobile Engine Condition Monitoring Using Sound Emission, Hamid Ghaderi, Peyman Kabiri

Turkish Journal of Electrical Engineering and Computer Sciences

A wavelet packet transform (WPT) is a well-known technique used for data and signal-processing that has proven to be successful in condition monitoring and fault diagnosis. In this study, using feature extraction based on wavelet transformation, sound signals emitted from automobile engines under both faulty and healthy conditions are analyzed. The intention is to categorize sound signals into both healthy and faulty classes. Sound signals are generated from 4 different automobile engines in both healthy and faulty conditions. The investigated fault is within the ignition system of the engines. In addition, there are other possible problems that may also affect …


Optimal Design Of Voltage Regulators For Static Excitation System In Synchronous Generator To Reduce Shaft-Induced Voltage, Mahmoud Samieimoghaddam, Mohammad Tavakoli Bina, Masoud Aliakbar Golkar, Shokrollah Shokrikojoori Jan 2017

Optimal Design Of Voltage Regulators For Static Excitation System In Synchronous Generator To Reduce Shaft-Induced Voltage, Mahmoud Samieimoghaddam, Mohammad Tavakoli Bina, Masoud Aliakbar Golkar, Shokrollah Shokrikojoori

Turkish Journal of Electrical Engineering and Computer Sciences

Long-term shaft-induced voltage could harm synchronous generators, specifically their bearings and insulators. This paper investigates the reduction of shaft-induced voltage using both a passive filter and an active voltage regulator. An RLC circuit is used as a passive filter, and a DC-DC buck converter is used as an active voltage regulator. As a result, they remove high-frequency spikes, leading to the reduction of shaft-induced voltage. Buck converters show minimum-phase behavior and can pose as stable-casual converters. A 5 kW synchronous generator was considered for the laboratory setup in which a static excitation system using a 6-pulse thyristor rectifier supplies the …