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2019

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Articles 1561 - 1590 of 2060

Full-Text Articles in Computer Engineering

Speech Emotion Recognition Using Semi-Nmf Feature Optimization, Surekha Reddy Bandela, T Kishore Kumar Jan 2019

Speech Emotion Recognition Using Semi-Nmf Feature Optimization, Surekha Reddy Bandela, T Kishore Kumar

Turkish Journal of Electrical Engineering and Computer Sciences

In recent times, much research is progressing forward in the field of speech emotion recognition (SER). Many SER systems have been developed by combining different speech features to improve their performances. As a result, the complexity of the classifier increases to train this huge feature set. Additionally, some of the features could be irrelevant in emotion detection and this leads to a decrease in the emotion recognition accuracy. To overcome this drawback, feature optimization can be performed on the feature sets to obtain the most desirable emotional feature set before classifying the features. In this paper, semi-nonnegative matrix factorization (semi-NMF) …


Scale-Invariant Mfccs For Speech/Speaker Recognition, Zekeri̇ya Tüfekci̇, Gökay Di̇şken Jan 2019

Scale-Invariant Mfccs For Speech/Speaker Recognition, Zekeri̇ya Tüfekci̇, Gökay Di̇şken

Turkish Journal of Electrical Engineering and Computer Sciences

The feature extraction process is a fundamental part of speech processing. Mel frequency cepstral coefficients (MFCCs) are the most commonly used feature types in the speech/speaker recognition literature. However, the MFCC framework may face numerical issues or dynamic range problems, which decreases their performance. A practical solution to these problems is adding a constant to filter-bank magnitudes before log compression, thus violating the scale-invariant property. In this work, a magnitude normalization and a multiplication constant are introduced to make the MFCCs scale-invariant and to avoid dynamic range expansion of nonspeech frames. Speaker verification experiments are conducted to show the effectiveness …


Investigation Of Start-Up Conditions On Electric Submersible Pump Driven With Flux Switching Motor, Mohammadhossein Barzegari Bafghi, Abolfazl Vahedi Jan 2019

Investigation Of Start-Up Conditions On Electric Submersible Pump Driven With Flux Switching Motor, Mohammadhossein Barzegari Bafghi, Abolfazl Vahedi

Turkish Journal of Electrical Engineering and Computer Sciences

One of the motor types that is recently considered to be a candidate for electric submersible pumps (ESPs) is the flux switching motor. Therefore, it becomes crucial to verify that this type of motor can stand ESP conditions. The main subject of this paper is to investigate the start-up condition of ESP along with considering the long power supply cable to study the motor performance, where the real aspect of the ESP conditions is investigated. Since there is not any model of pump load that models the dynamic behavior of ESP correctly, first, a model for the pump is developed. …


A Hybrid Feature-Selection Approach For Finding The Digital Evidence Of Web Application Attacks, Mohammed Babiker, Eni̇s Karaarslan, Yaşar Hoşcan Jan 2019

A Hybrid Feature-Selection Approach For Finding The Digital Evidence Of Web Application Attacks, Mohammed Babiker, Eni̇s Karaarslan, Yaşar Hoşcan

Turkish Journal of Electrical Engineering and Computer Sciences

The most critical challenge of web attack forensic investigations is the sheer amount of data and level of complexity. Machine learning technology might be an efficient solution for web attack analysis and investigation. Consequently, machine learning applications have been applied in various areas of information security and digital forensics, and have improved over time. Moreover, feature selection is a crucial step in machine learning; in fact, selecting an optimal feature subset could enhance the accuracy and performance of the predictive model. To date, there has not been an adequate approach to select optimal features for the evidence of web attack. …


An Automated Snick Detection And Classification Scheme As A Cricket Decision Review System, Aftab Khan, Syed Qadir Hussain, Muhammad Waleed, Ashfaq Khan, Umair Khan Jan 2019

An Automated Snick Detection And Classification Scheme As A Cricket Decision Review System, Aftab Khan, Syed Qadir Hussain, Muhammad Waleed, Ashfaq Khan, Umair Khan

Turkish Journal of Electrical Engineering and Computer Sciences

Umpire decisions can greatly affect the outcome of a cricket game. When there is doubt about the umpire?s call for a decision, a decision review system (DRS) may be brought into play by a batsman or bowler to validate the decision. Recently, the latest technologies, including Hotspot, Hawk-eye, and Snickometer, have been employed when there is doubt among the on-field umpire, batsman, or bowlers. This research is a step forward in gaging the true class of a snick generated from the contact of the cricket ball with either (i) the bat, (ii) gloves, (iii) pad, or (iv) a combination of …


Decision-Making For Small Industrial Internet Of Things Using Decision Fusion, Tuğrul Çavdar, Nader Ebrahimpour Jan 2019

Decision-Making For Small Industrial Internet Of Things Using Decision Fusion, Tuğrul Çavdar, Nader Ebrahimpour

Turkish Journal of Electrical Engineering and Computer Sciences

The industrial Internet of Things (IIoT) is a new field of Internet of Things (IoT) that has gained more popularity recently in industrial units and makes it possible to access information anywhere and anytime. In other words, geographic coordinates cannot prevent obtaining equipment and its data. Today, it is possible to manage and control equipment simply without spending time in an operational area and just by using the IIoT. This system collects data from manufacturing and production units by using wireless sensor networks or other networks for classification of fault detection. These data are then used after analysis to allow …


A Novel Randomized Recurrent Artificial Neural Network Approach: Recurrent Random Vector Functional Link Network, Ömer Faruk Ertuğrul Jan 2019

A Novel Randomized Recurrent Artificial Neural Network Approach: Recurrent Random Vector Functional Link Network, Ömer Faruk Ertuğrul

Turkish Journal of Electrical Engineering and Computer Sciences

The random vector functional link (RVFL) has successfully been employed in many applications since 1989. RVFL has a single hidden layer feedforward structure that also has direct links between the input layer and the output layer. Although nonlinearity, high generalization capacity, and fast training ability can be provided in RVFL, it can be found from the literature that higher nonlinearity can be obtained by adding recurrent feedback to an artificial neural network. In this paper, the recurrent type of RVFL (R-RVFL), which has both outer feedbacks and also inner feedbacks, is proposed. In order to evaluate and validate the proposed …


A Fine-Grain And Scalable Set-Based Cache Partitioning Through Thread Classification, İsa Ahmet Güney, Gürhan Küçük Jan 2019

A Fine-Grain And Scalable Set-Based Cache Partitioning Through Thread Classification, İsa Ahmet Güney, Gürhan Küçük

Turkish Journal of Electrical Engineering and Computer Sciences

As contemporary processors utilize more and more cores, cache partitioning algorithms tend to preserve cache associativity with a finer-grain of control to achieve higher throughput and fairness goals. In this study, we propose a scalable set-based cache partitioning mechanism, which welds an allocation policy and an enforcement scheme together. We also propose a set-based classifier to better allocate partitions to more deserving threads, a fast set redirection logic to map accesses to dedicated cache sets, and a double access mechanism to overcome the performance penalty due to a repartitioning phase. We compare our work to the best line-grain cache partitioning …


An Optimized Harmonic Elimination Method Based On Synchronized Microcontroller Architecture, Vivek Gopinath, Meenu Nair, Jayanta Biswas, Mukti Barai Jan 2019

An Optimized Harmonic Elimination Method Based On Synchronized Microcontroller Architecture, Vivek Gopinath, Meenu Nair, Jayanta Biswas, Mukti Barai

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes an optimized synchronous PWM method for harmonic elimination in a quasi square wave inverter. The synchronized PWM method enables online harmonic computation and PWM pulse generation in a multitasking digital controller to eliminate lower order harmonics. The multitasking digital controller reduces the look-up table requirement and helps in realizing efficient implementation to eliminate dominant harmonics. This method offers a simple scalable solution for combined fifth and seventh harmonic elimination using two low-cost eight-bit PIC microcontrollers (PIC18F4550, PIC18F452). Experimental results are demonstrated for a single-phase three-level inverter. The proposed method achieves 90$\% $ reduction of fifth and seventh …


A Hybrid Multiband Printed Loop Antenna For Wlan/Wimax Bands For Applications In Mimo Systems, Ali Shahshahani, Mohammad Amin Honarvar Jan 2019

A Hybrid Multiband Printed Loop Antenna For Wlan/Wimax Bands For Applications In Mimo Systems, Ali Shahshahani, Mohammad Amin Honarvar

Turkish Journal of Electrical Engineering and Computer Sciences

In this article a thin hybrid multiband printed loop antenna is presented for application in multiple-input multiple-output (MIMO) systems. The proposed antenna has several advantages; for example, the pseudofilter feature of the proposed antenna is one of this antenna's advantages. Because of the antenna's width ($9.5$~mm), it can be used on the edges of the board. The first resonant frequency is generated by the original loop of the antenna. Incorporation of different embedded components, i.e. a subsidiary loop, extended ground-traces, parasitic patch, and the slits, results in the proposed antenna resonating as a multiband antenna. This antenna is adjusted in …


Line Independency-Based Network Modelling For Backward/Forward Load Flow Analysis Of Electrical Power Distribution Systems, Reyhaneh Taheri, Alimorad Khajezadeh, Mohammad Hossein Rezaeian Koochi, Abbas Sharifi Nasab Anari Jan 2019

Line Independency-Based Network Modelling For Backward/Forward Load Flow Analysis Of Electrical Power Distribution Systems, Reyhaneh Taheri, Alimorad Khajezadeh, Mohammad Hossein Rezaeian Koochi, Abbas Sharifi Nasab Anari

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a straightforward method for line independency-based modelling of electrical power distribution systems is proposed. The proposed method can determine the backward and forward sweeping routes of distribution systems for calculating line currents and bus voltages. To do that, the method identifies the independent lines in consecutive steps. An independent line is a line in the distribution system whose current does not depend on the current of other lines in the system. The proposed line independency-based network modelling is required to be performed only once and prior to the load flow analysis. The output of the proposed method, …


Quantification Of Resistive Wall Instability For Particle Accelerator Machines, Fati̇h Yaman Jan 2019

Quantification Of Resistive Wall Instability For Particle Accelerator Machines, Fati̇h Yaman

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this study is to quantify longitudinal resistive wall impedances, corresponding wake functions, and wake potentials for different accelerator machines of interest. Accurate calculations of wake potentials by particle-in-cell codes are extremely difficult for the investigated parameters; therefore, we use an analytical approach and consider large domains with fine discretization for the required numerical integrations. The semianalytical wake potential computations are benchmarked against numerical general purpose 2D/3D Maxwell solver software codes and a different analytical approach for a certain set of parameters. We report examples to illustrate limitations of wake potential estimations from coupling impedances, and computations for …


Predicting Co And Nox Emissions From Gas Turbines: Novel Data And A Benchmark Pems, Heysem Kaya, Pinar Tüfekci̇, Erdi̇nç Uzun Jan 2019

Predicting Co And Nox Emissions From Gas Turbines: Novel Data And A Benchmark Pems, Heysem Kaya, Pinar Tüfekci̇, Erdi̇nç Uzun

Turkish Journal of Electrical Engineering and Computer Sciences

Predictive emission monitoring systems (PEMS) are important tools for validation and backing up of costly continuous emission monitoring systems used in gas-turbine-based power plants. Their implementation relies on the availability of appropriate and ecologically valid data. In this paper, we introduce a novel PEMS dataset collected over five years from a gas turbine for the predictive modeling of the CO and NOx emissions. We analyze the data using a recent machine learning paradigm, and present useful insights about emission predictions. Furthermore, we present a benchmark experimental procedure for comparability of future works on the data


Low-Cost Multiple Object Tracking For Embedded Vision Applications, Muhammad Imran Shehzad, Fazal Wahab Karam, Shoaib Azmat Jan 2019

Low-Cost Multiple Object Tracking For Embedded Vision Applications, Muhammad Imran Shehzad, Fazal Wahab Karam, Shoaib Azmat

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a low-cost multiple object tracking (MOT) technique by employing a novel appearance update model for object appearance modeling using K-means. The state-of-the-art work has attained a very high accuracy without considering the real-time aspects necessitated by currently trending embedded vision platforms. The major research on multiple object tracking is used to update the appearance model in every frame while discounting its persistent nature. The proposed appearance update model reduces the computational cost of the state-of-the-art MOT 6-fold by exploiting this facet of persistent appearance over the sequence of frames. To ensure accuracy, the proposed model is tested …


Classification Of The Likelihood Of Colon Cancer With Machine Learning Techniques Using Ftir Signals Obtained From Plasma, Suat Toraman, Mustafa Gi̇rgi̇n, Bi̇lal Üstündağ, İbrahi̇m Türkoğlu Jan 2019

Classification Of The Likelihood Of Colon Cancer With Machine Learning Techniques Using Ftir Signals Obtained From Plasma, Suat Toraman, Mustafa Gi̇rgi̇n, Bi̇lal Üstündağ, İbrahi̇m Türkoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Colon cancer is one of the major causes of human mortality worldwide and the same can be said for Turkey. Various methods are used for the determination of cancer. One of these methods is Fourier transform infrared (FTIR) spectroscopy, which has the ability to reveal biochemical changes. The most common features used to distinguish patients with cancer and healthy subjects are peak densities, peak height ratios, and peak area ratios. The greatest challenge of studies conducted to distinguish cancer patients from healthy subjects using FTIR signals is that the signals of cancer patients and healthy subjects are similar. In the …


High-Efficiency Design Of A Grid-Connected Pv Inverter Based On Interleaved Flyback Converter Topology, Bünyami̇n Tamyürek, Bi̇lgehan Kirimer Jan 2019

High-Efficiency Design Of A Grid-Connected Pv Inverter Based On Interleaved Flyback Converter Topology, Bünyami̇n Tamyürek, Bi̇lgehan Kirimer

Turkish Journal of Electrical Engineering and Computer Sciences

The importance of efficiency in photovoltaic (PV) inverter applications makes the topology selection as the critical first step. Due to the low efficiency concern, flyback converter is not the preferred topology in kilowatt range in spite of its galvanic isolation, low cost, and small size advantages. Therefore, the objective of this research is to change the perception in favor of flyback converter by designing a flyback-topology-based PV inverter at 2.5 kW with high efficiency. The enhancement in efficiency is achieved mainly by using silicon carbide switching devices, designing ultrahigh-efficiency flyback transformers with extremely low leakage inductance and by implementing a …


Hydrogen Production System With Fuzzy Logic-Controlled Converter, Sali̇h Nacar, Seli̇m Öncü Jan 2019

Hydrogen Production System With Fuzzy Logic-Controlled Converter, Sali̇h Nacar, Seli̇m Öncü

Turkish Journal of Electrical Engineering and Computer Sciences

Electrolyte current must be controlled in the water electrolysis systems. For this purpose, the power converter for the cell stack of the electrolyzer used in industrial hydrogen production is realized. A series resonant converter, which is suitable for high input voltage and low output current applications, is used as power stage of the electrolyzer. The high-frequency transformer is used for the impedance matching. While the system is running, the electrical resistance of the electrolyzer changes continuously; thus, fuzzy logic controller (FLC) is used to control the output current of the power converter. In this study, a 700-W converter prototype is …


Mobility And Traffic-Aware Resource Scheduling For Downlink Transmissions In Lte-A Systems, Önem Yildiz, Radosveta İvanova Sokullu Jan 2019

Mobility And Traffic-Aware Resource Scheduling For Downlink Transmissions In Lte-A Systems, Önem Yildiz, Radosveta İvanova Sokullu

Turkish Journal of Electrical Engineering and Computer Sciences

As new cellular networks support not only voice services but also many multimedia applications, the requirements for reliable data transmission at high speeds create heavy load on the system. Even though LTE/LTE-A technology takes action towards alleviating this load, it is still necessary to manage resources effectively because of the inadequacy of the available radio resources. Thus, the scheduler at the MAC layer of the base station plays a very important role in resource allocation to the user. In this study a novel algorithm for resource allocation in mobile environments is presented, with two variations addressing different input traffic. The …


Large-Scale Round-Trip Delay Time Analysis Of Ipv4 Hosts Around The Globe, Ali̇ Gezer Jan 2019

Large-Scale Round-Trip Delay Time Analysis Of Ipv4 Hosts Around The Globe, Ali̇ Gezer

Turkish Journal of Electrical Engineering and Computer Sciences

Design and optimization of many network applications, services, protocols, and routing protocols can be improved with delay-related measurement for a better operation over the Internet. Many experimental delay measurements have been performed on predetermined end-to-end connections with a less number of hosts compared to our study. This study aims to investigate up-to-date round-trip delay time measurement results over the Internet through pinging random IPv4 addresses from three vantage points located in the United States, Turkey, and Japan. Considering different time periods in a day and in consecutive 5 years, we performed a large-scale round-trip delay time analysis study by sending …


A Beaconing-Based Roadside Services Discovery Protocol For Vehicular Ad Hoc Networks, Kifayat Ullah, Ali Sayyed, Muhammad Aziz, Edson Moreira Jan 2019

A Beaconing-Based Roadside Services Discovery Protocol For Vehicular Ad Hoc Networks, Kifayat Ullah, Ali Sayyed, Muhammad Aziz, Edson Moreira

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, research on vehicular ad hoc networks (VANETs) has gained momentum all over the world. These emerging networks promise to make our driving experience more efficient, safer, comfortable, and enjoyable. VANETs have the potential to support a wide range of interesting applications. One such promising application area is the discovery of roadside services on the highways. Drivers need an efficient way to find these services during their journeys. However, due to the unique features of VANETs, the design and implementation of such applications is a challenging task. In this paper, we propose an application layer beaconing-based roadside services discovery protocol …


Queue Length Feedback-Based Solution Of Tcp Incast In Data Center Networks, Hasnain Ahmed, Junaid Arshad Jan 2019

Queue Length Feedback-Based Solution Of Tcp Incast In Data Center Networks, Hasnain Ahmed, Junaid Arshad

Turkish Journal of Electrical Engineering and Computer Sciences

The Internet offers a large number of applications and services that we use on a daily basis. These widely used applications are hosted on large-scale, high-performance computing systems called data centers. The performance of TCP is inefficient in many-to-one communication, which is a common traffic pattern in data center networks. This many-to-one communication causes significant packet losses followed by timeouts, which consequently results in throughput collapse in data center networks; this problem is known as TCP Incast. In this paper, we present a queue length feedback-based solution to mitigate TCP Incast. The scheme has two parts: i) a novel queue …


Energy And Economic Assessment Of Major Free Cooling Retrofits For Data Centers In Turkey, Ozan Gözcü, Hamza Sali̇h Erden Jan 2019

Energy And Economic Assessment Of Major Free Cooling Retrofits For Data Centers In Turkey, Ozan Gözcü, Hamza Sali̇h Erden

Turkish Journal of Electrical Engineering and Computer Sciences

Mechanical cooling is responsible for a significant fraction of the energy consumption of data centers (DCs). Free cooling systems take advantage of ambient conditions to reduce the need for compressor-based cooling. This study utilizes thermodynamic models of major free cooling systems such as the direct air-side economizer (ASE), indirect air-side economizer (IASE), indirect evaporative cooler (IEC), and indirect water-side economizer (WSE) integrated with the existing cooling infrastructure of a typical 1 MW IT load DC. Proposed models utilize hourly weather data of various cities in Turkey to compute annual energy consumption and cost-saving potentials of each free cooling method with …


An Adaptive Scheduling Scheme For Inhomogeneously Distributed Wireless Ad Hocnetworks, Adnan Fazil, Aamir Hasan, Muhammad Atique Ur Rehman, Ijaz Mansoor Qureshi Jan 2019

An Adaptive Scheduling Scheme For Inhomogeneously Distributed Wireless Ad Hocnetworks, Adnan Fazil, Aamir Hasan, Muhammad Atique Ur Rehman, Ijaz Mansoor Qureshi

Turkish Journal of Electrical Engineering and Computer Sciences

An efficient scheduling strategy guarantees the simultaneous transmission and successful reception by the scheduled nodes even inside a congested wireless ad hoc network. Owing to the dispersed nature of ad hoc networks, the node packing algorithm needs to be implementable without having network-wide channel state information and should additionally be able to pack the optimum number of successful transmissions. The proposed algorithm, for a network with nonhomogeneously distributed nodes, makes the decision to either inhibit or permit an active interferer around an active receiver based on the interferer?s transmission power. The analysis evidenced that the suggested scheme provides an estimated …


Qpsk-Dual Carrier Modulation For Ultra-Wideband Communication In Body Areanetwork Channels, Yasi̇n Karan, Sali̇m Kahveci̇ Jan 2019

Qpsk-Dual Carrier Modulation For Ultra-Wideband Communication In Body Areanetwork Channels, Yasi̇n Karan, Sali̇m Kahveci̇

Turkish Journal of Electrical Engineering and Computer Sciences

Dual carrier modulation (DCM) using orthogonal frequency-division multiplexing (OFDM) improves the performance in multipath fading channels. In the literature DCM is proposed with 16-quadrature amplitude modulation (16QAM) for ultra-wideband (UWB) communication, with four bits per symbol to keep reliable high date transmission over longer distances. Body area network (BAN) standards address transmission reliability more than data rate. UWB is one of the physical layers proposed in BAN standards. In this study, DCM is used with quadrature phase shift keying (QPSK) instead of 16QAM to have better performance in reliable transmission. The performance of QPSK-DCM is analyzed and compared with 16QAM-DCM, …


Outage Probability Analysis And Adaptive Combiner For Multiuser Multipolarized Antenna Systems, Abdul Hai Muzammil Mohammed, Muhammad Moinuddin, Ubaid Muhsen Al-Saggaf, Ahmad Kamal Hassan Jan 2019

Outage Probability Analysis And Adaptive Combiner For Multiuser Multipolarized Antenna Systems, Abdul Hai Muzammil Mohammed, Muhammad Moinuddin, Ubaid Muhsen Al-Saggaf, Ahmad Kamal Hassan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we characterize the performance metrics of a multiuser multipolarized antenna system in a Rayleigh fading channel. We start by formulating a downlink system model that features a multiuser scenario in the presence of additive noise and a multipolarized antenna system; this is followed by evaluation of the outage probability in closed form. This is done by deriving the cumulative distribution function (CDF) of the signal-to-interference-plusnoise ratio using the approach of the ratio of indefinite quadratic forms. We thereby characterize the gradient of this CDF with respect to the combining vectors. Eventually, we obtain the optimum combining vectors …


Bow-Tie-Shaped Wideband Conformal Antenna With Wide-Slot For Gps Application, Ratikanta Sahoo, Damera Vakula Jan 2019

Bow-Tie-Shaped Wideband Conformal Antenna With Wide-Slot For Gps Application, Ratikanta Sahoo, Damera Vakula

Turkish Journal of Electrical Engineering and Computer Sciences

In this article, a novel wideband cylindrical conformal antenna using a wide slot in the ground plane is proposed. A bow-tie-shaped patch antenna is designed for Global Positioning System applications. The bandwidth of the antenna is improved by using a similar bow-tie-shaped slot in the ground plane with a larger dimension. The bandwidth is further enhanced by introducing a dumbbell-shaped slit in the patch. The antenna is fed by a 50-$ \Omega $ microstrip line. The proposed planar antenna is printed on a ground plane of size 0.5$ \lambda $ mm$ \times $ 0.5$ \lambda $ mm, where $ \lambda …


Optimized Modeling Of Ni-Mh Batteries Primarily Based On Taguchi Approach And Evaluation Of Used Ni-Mh Batteries, Hani Muhsen, Ahmad Al-Muhtady Jan 2019

Optimized Modeling Of Ni-Mh Batteries Primarily Based On Taguchi Approach And Evaluation Of Used Ni-Mh Batteries, Hani Muhsen, Ahmad Al-Muhtady

Turkish Journal of Electrical Engineering and Computer Sciences

This paper aims to generate an optimized model of the Ni-MH battery based on the Taguchi method and it further aims to evaluate used Ni-MH batteries that served in hybrid electric vehicles and electric vehicles. The status of twelve used Ni-MH batteries is studied to determine their usefulness after their life cycle in automotive applications. The status of used batteries is evaluated by investigating their state of charge, remaining useful life, and degradation in performance. Accordingly, the tested batteries are classified into four categories and they are proposed to serve in different applications. The novelty of the work lies in …


A Developed Flywheel Energy Storage With Built-In Rotating Supercapacitors, Hamidreza Toodeji Jan 2019

A Developed Flywheel Energy Storage With Built-In Rotating Supercapacitors, Hamidreza Toodeji

Turkish Journal of Electrical Engineering and Computer Sciences

Flywheel energy storage can store large amounts of kinetic energy in its rotating parts, but its inertia restricts the rate of power exchange. On the other hand, there is supercapacitor with the ability of exchanging large amounts of instantaneous power. Therefore, the combination of these two systems can significantly improve the dynamic response of conventional flywheel energy storage. This paper proposes a novel design for this combined system in which supercapacitors are located inside the rotating disk. Therefore, supercapacitors can significantly improve the dynamic performance of the flywheel energy storage with trivial effects on its size and weight. Moreover, the …


Determination Of Distance Between Dc Traction Power Centers In A 1500-V Dc Subway Line With Artificial Intelligence Methods, Mehmet Taci̇ddi̇n Akçay, İlhan Kocaarslan Jan 2019

Determination Of Distance Between Dc Traction Power Centers In A 1500-V Dc Subway Line With Artificial Intelligence Methods, Mehmet Taci̇ddi̇n Akçay, İlhan Kocaarslan

Turkish Journal of Electrical Engineering and Computer Sciences

The electrification system in rail systems is designed with regard to the operating data and design parameters. While the electrification system is formed, the minimum voltage rating that the traction force requires during the operation needs to be provided. The highest value of the voltage drop occurring on the line is determined by the distance between power centers. This value needs to be kept within certain limits for the continuity of operation. In this study, the determination of the distance between DC traction power centers for a 1500-V DC-fed rail system is done by means of the adaptive neuro-fuzzy inference …


Fuzzy-Logic-Based Robust Speed Control Of Switched Reluctance Motor For Low And High Speeds, Zeki̇ Omaç Jan 2019

Fuzzy-Logic-Based Robust Speed Control Of Switched Reluctance Motor For Low And High Speeds, Zeki̇ Omaç

Turkish Journal of Electrical Engineering and Computer Sciences

Switched reluctance motor (SRM) is operated at high magnetic saturation to generate large torque. The flux linkage of SRM is a nonlinear function with phase current and rotor position because of the high magnetic saturation. Also, the performance of the speed controller for the SRM driver system can be negatively affected by noise, disturbances, and inertia of load torque. Therefore, the fuzzy speed controller for the SRM driver system was developed in this study. In addition, a dynamic model of SRM was simulated in Matlab/Simulink software. Based on the results obtained in this study, the speed of the SRM was …