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2017

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Articles 8251 - 8280 of 8344

Full-Text Articles in Engineering

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 …

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Threshold Distance-Based Cluster Routing Protocols For Static And Mobile Wireless Sensor Networks, Padmavati Khandnor, Trilok Aseri Jan 2017

Threshold Distance-Based Cluster Routing Protocols For Static And Mobile Wireless Sensor Networks, Padmavati Khandnor, Trilok Aseri

Turkish Journal of Electrical Engineering and Computer Sciences

In cluster-based wireless sensor network routing protocols, when the cluster head transfers data based on single hop transmission to the sink node, then the cluster heads that are farther away deplete more energy as compared to nearby cluster heads. This condenses load balancing in the network. If the cluster heads collaborate with each other and transfer data based on multihop transmission, then the cluster heads nearer to the sink node are burdened with significant relay traffic and deplete energy much faster, which causes a network coverage problem also known as a hot spot problem. To avoid both of the above …

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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 …

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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 …

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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 …

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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 …

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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 …

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New Static Output Feedback Stabilization And Multivariable Pid-Controller Design Methods For Unstable Linear Systems Via An Ilmi Optimization Approach, Mehmet Nur Alpaslan Parlakçi, Elbrus Caferov Jan 2017

New Static Output Feedback Stabilization And Multivariable Pid-Controller Design Methods For Unstable Linear Systems Via An Ilmi Optimization Approach, Mehmet Nur Alpaslan Parlakçi, Elbrus Caferov

Turkish Journal of Electrical Engineering and Computer Sciences

The design problem of a static output feedback controller and multivariable proportional-integral-derivative (PID) controller is investigated for linear time-invariant systems (LTI). First, the static output feedback stabilization problem is taken into consideration and then an iterative linear matrix inequality (ILMI) algorithm is developed for the synthesis of the controller. Second, choosing a multivariable PID control law, the whole system is transformed into a new augmented system represented in the form of a static output feedback control system. This method allows us to convert the multivariable PID controller design problem into a static output feedback synthesis problem. Thus, the proposed ILMI …

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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 …

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Comparative Study Of Conventional Modulation Schemes In Terms Of Conducted And Radiated Emi Generated By Three-Phase Inverters, Mohamed Salem, Mahmoud Hamouda, Jaleleddine Ben Hadj Slama Jan 2017

Comparative Study Of Conventional Modulation Schemes In Terms Of Conducted And Radiated Emi Generated By Three-Phase Inverters, Mohamed Salem, Mahmoud Hamouda, Jaleleddine Ben Hadj Slama

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a comparative study is carried out between the carrier (SPWM), third harmonic injection (THIPWM), and space vector (SVPWM) modulation schemes in terms of conducted (common and differential modes) and radiated electromagnetic interference (EMI) generated by three-phase two-level voltage source inverters. For this purpose, an experimental setup of the converter feeding an induction machine is developed with the aim to measure the conducted emission propagated back into the dc source and the radiated field in the vicinity of the power conversion device. Experimental results are given and analyzed in time and frequency domains. The comparative study between the …

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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 …

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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 …

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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 …

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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 …

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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, …

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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 …

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Loss Minimization In Wind Farm Integrated Ac/Dc System By Optimal Injections And Droop Settings Of Vsc-Mtdc Systems, Anbuselvi Shanmugam Velu, Somasundaram Periyasamy, Kumudini Devi Raguru Pandu Jan 2017

Loss Minimization In Wind Farm Integrated Ac/Dc System By Optimal Injections And Droop Settings Of Vsc-Mtdc Systems, Anbuselvi Shanmugam Velu, Somasundaram Periyasamy, Kumudini Devi Raguru Pandu

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a modified optimal power flow (OPF) model, incorporating a voltage source converter-based multiterminal DC (VSC-MTDC) system, is proposed. The OPF is formulated to minimize the losses, steady state voltage deviations, and overloading of the AC/DC system. The control variables considered in this modified OPF model are power injection into the DC system and droop settings. Optimal injection patterns for different wind power penetrations and optimal droop settings are evaluated for wind farm side converters and grid side converters, respectively. Wind power penetrations are routed into AC and DC lines in different proportions to optimize the flows in …

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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 …

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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 …

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Erp: An Efficient Reactive Routing Protocol For Dense Vehicular Ad Hoc Networks, Thandapany Sivakumar, Rajendiran Manoharan Jan 2017

Erp: An Efficient Reactive Routing Protocol For Dense Vehicular Ad Hoc Networks, Thandapany Sivakumar, Rajendiran Manoharan

Turkish Journal of Electrical Engineering and Computer Sciences

A vehicular ad hoc network (VANET) is a type of mobile ad hoc network (MANET) that provides an exchange of messages between vehicles. VANETs encourage researchers to create safety and comfort applications that will lead to intelligent transport systems. Conventional ad hoc routing methods may cause flooding of packets to find routes in a VANET. Hence, finding a route from the source to the destination vehicle by local broadcast techniques in densely populated urban areas may create a broadcast storm and network bandwidth is unnecessarily wasted to discover routes between source and destination vehicles. In this paper, an efficient routing …

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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 …

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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.

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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 …

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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 …

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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 …

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Load Shedding Scheme Based On Frequency And Voltage Stability For An Islanding Operation Of A Distribution Network Connected To Mini-Hydro Generation, Norazliani Md Sapari, Hazlie Bin Mokhlis, Javed Ahmed Laghari, Ab Halim Abu Bakar, Hasmaini Mohamad, Mohd Rohaimi Mohd Dahalan Jan 2017

Load Shedding Scheme Based On Frequency And Voltage Stability For An Islanding Operation Of A Distribution Network Connected To Mini-Hydro Generation, Norazliani Md Sapari, Hazlie Bin Mokhlis, Javed Ahmed Laghari, Ab Halim Abu Bakar, Hasmaini Mohamad, Mohd Rohaimi Mohd Dahalan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a load shedding scheme (LSS) based on system frequency and voltage stability (VS). In the proposed scheme, the amount of power imbalance is determined using a rate of change of frequency, and the load shedding priority is carried out based on a VS index. The load with the highest tendency for voltage collapse (based on the index value) is given first priority to be shed. Thus, by shedding the most sensitive load, the distribution system can be saved from power collapse and then the system can return to its nominal state after load shedding. The proposed LSS …

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Accelerating The Solving Of Nonlinear Equations Using The Homotopy Method: Application On Finding The Operating Point Of Complex Circuits, Fathi Dhiabi, Mohamed Boumehraz Jan 2017

Accelerating The Solving Of Nonlinear Equations Using The Homotopy Method: Application On Finding The Operating Point Of Complex Circuits, Fathi Dhiabi, Mohamed Boumehraz

Turkish Journal of Electrical Engineering and Computer Sciences

Analog circuits with nonlinear elements (e.g., diode, BJT, and CMOS) and integrated circuits are very complex systems. As a result, they are very difficult to analyze because of the need to generate a nonlinear equation system solution in order to do so. Solving nonlinear equations is still a challenging problem. Iterative methods, however, are frequently used to solve them. This paper describes a method that can be used to both accelerate the solving of nonlinear equations and find the operating point in various integrated circuits by construction of the global homotopy equation of the analog circuit. This is done by …

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Optimum Design And Operation Analysis Of Permanent Magnet-Assisted Synchronous Reluctance Motor, Jamal Dehghani Ashkezari, Hassan Khajeroshanaee, Mohsen Niasati, Mohammad Jafar Mojibian Jan 2017

Optimum Design And Operation Analysis Of Permanent Magnet-Assisted Synchronous Reluctance Motor, Jamal Dehghani Ashkezari, Hassan Khajeroshanaee, Mohsen Niasati, Mohammad Jafar Mojibian

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an optimum design process and operational analysis of a permanent magnet-assisted synchronous reluctance motor (PMASynRM) as a low-cost and highly efficient consumed magnet material machine. The motor's topology is based on inserting partial permanent magnetic materials into flux barriers of an original synchronous reluctance motor (SynRM) that implicitly increase the difference between the machine's inductances, thereby increasing output torque. The procedure of rotor design as the main contribution of this paper is carefully illustrated. The rectangular shape of the flux barriers was found to achieve cost reduction and improve productivity. The impact of the permanent magnet added …

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Design Of A Low-Power Cmos Operational Amplifier With Common-Mode Feedback For Pipeline Analog-To-Digital Converter Applications, Sohiful Anuar Zainol Murad, Izatul Syafina Ishak, Mohd Fairus Ahmad, Shaiful Nizam Mohyar Jan 2017

Design Of A Low-Power Cmos Operational Amplifier With Common-Mode Feedback For Pipeline Analog-To-Digital Converter Applications, Sohiful Anuar Zainol Murad, Izatul Syafina Ishak, Mohd Fairus Ahmad, Shaiful Nizam Mohyar

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a design of a low-power operational amplifier (op-amp) for pipeline analog-to-digital converter (ADC) applications using a 0.13-$\mu $m CMOS process. The folded-cascode topology with NMOS input types is employed for the op-amp design due to a larger output gain compared to PMOS input types. Furthermore, the op-amp is designed with a double detection structure of a common-mode feedback circuit to provide stable feedback voltage. The simulation results show that the proposed op-amp achieved a gain of 64.5 dB and a unity gain bandwidth of 695.1 MHz with a low power consumption of 0.14 mW. In addition, by …

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Eccentricity Fault Diagnosis In A Permanent Magnet Synchronous Motor Under Nonstationary Speed Conditions, Mustafa Eker, Mehmet Akar Jan 2017

Eccentricity Fault Diagnosis In A Permanent Magnet Synchronous Motor Under Nonstationary Speed Conditions, Mustafa Eker, Mehmet Akar

Turkish Journal of Electrical Engineering and Computer Sciences

Electric motor faults decrease production capacity and increase maintenance costs. Today, predictive detection based on real-time monitoring and fault detection is taking the place of periodic applications. In this study, a new method is presented for the detection of eccentricity faults in permanent magnet synchronous motors. The motor current and the rotor speed were monitored under stationary and nonstationary speed and different load conditions, after which the fault detection was carried out via angular domain-order tracking method. The obtained results were compared with traditional fast Fourier transform results. It was observed that the suggested method can successfully detect the fault …

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