An Investigation On Characteristics Of Tracking Failure In Epoxy Resin Withharmonic And Fractal Dimension Analysis,
2018
TÜBİTAK
An Investigation On Characteristics Of Tracking Failure In Epoxy Resin Withharmonic And Fractal Dimension Analysis, Mehmet Murat İspi̇rli̇, Aysel Ersoy Yilmaz
Turkish Journal of Electrical Engineering and Computer Sciences
Epoxy resins have excellent mechanical and electrical properties; thus, they are commonly preferred in the electrical{electronic sector as insulation materials. These insulation materials experience degradation such as breakdown, tracking, or treeing. Therefore, safety and reliability tests of insulation materials have great importance in estimating the performance of insulation. These tests must be carried out to decrease the risk of electrical insulation fault. In this study, the relationship between tracking failures and the data obtained during experiments was evaluated. Tracking failure performance of epoxy resin was investigated using the IEC 60112 test standard, which is known as the comparative tracking index …
New Results On The Global Asymptotic Stability Of Certain Nonlinear Rlc Circuits,
2018
TÜBİTAK
New Results On The Global Asymptotic Stability Of Certain Nonlinear Rlc Circuits, Muzaffer Ateş, Sami̇ra Lari̇bi̇
Turkish Journal of Electrical Engineering and Computer Sciences
This paper deals with the global asymptotic stability (GAS) of certain nonlinear RLC circuit systems using the direct Lyapunov method. For each system a suitable Lyapunov function or energy-like function is constructed and the direct Lyapunov method is applied to the related system. Then the invariant equilibrium point of each system that makes the system solution to the global asymptotic stable is determined. Some new explicit GAS conditions of certain nonlinear RLC circuit systems are derived by Lyapunov's direct method. The presented simulations are compatible with the new results. The results are given with proofs.
Damping Wide-Area Oscillations In Power Systems: A Model Predictive Controldesign,
2018
TÜBİTAK
Damping Wide-Area Oscillations In Power Systems: A Model Predictive Controldesign, Emrah Biyik, Munir Husein
Turkish Journal of Electrical Engineering and Computer Sciences
Electromechanical oscillations in power systems have been observed ever since synchronous generators were interconnected to provide reliability and higher generation capacity, and they have become a severe threat for the safe and economic operation of modern interconnected power grids. To dampen these oscillations, wide-area damping controllers (WADCs) have been introduced by utilizing wide-area measurement systems and synchronized phasor measurement units. In this paper, we present a systematic approach for designing WADCs using a model predictive control (MPC) technique to damp interarea oscillations in the power system. The MPC controller computes optimal control signals for the excitation system of a remote …
Rlgc(F) Modeling Of A Busbar Distribution System Via Measured S-Parameters Atcenelec And Fcc Bands,
2018
TÜBİTAK
Rlgc(F) Modeling Of A Busbar Distribution System Via Measured S-Parameters Atcenelec And Fcc Bands, Zeynep Hasirci, İsmai̇l Hakki Çavdar, Mehmet Öztürk
Turkish Journal of Electrical Engineering and Computer Sciences
This paper addresses the extraction of accurate frequency-dependent per-unit-length RLGC parameters for busbar distribution systems using measured S-parameters for the CENELEC and FCC bands. A busbar is a distribution system element (three phase, low voltage) with a modular structure that carries electrical energy in buildings. The S-parameters of a busbar distribution system at different current levels (630 A, 1250 A, 2000 A) are measured with a vector network analyzer and then analyzed for three different two-port connections (L1-N, L2-N, L3-N). A frequency- dependent RLGC(f) model is used to characterize the busbar as a transmission line using a derivative-free optimization algorithm. …
Analysis Of Ground Return Impedance Calculation Methods For Modeling Ofunderground Cables For Lightning Studies,
2018
TÜBİTAK
Analysis Of Ground Return Impedance Calculation Methods For Modeling Ofunderground Cables For Lightning Studies, Meli̇h Güneri̇, Bora Alboyaci
Turkish Journal of Electrical Engineering and Computer Sciences
Analysis of lightning transients in cable systems necessitates accurate calculation of ground return impedances (GRIs) in high-frequency regions. EMT-type programs used for transient analyses incorporate various methods for calculation of GRI. Most of these methods include assumptions and approximations, the validity of which needs to be questioned at high frequencies. In particular, the common approximation of the neglecting effect of displacement currents should be reviewed. The purpose of this paper is to evaluate commonly used GRI calculation methods in terms of their accuracy and validity in high-frequency regions. In this study, GRI calculation methods are analyzed and compared, the effect …
A New Semianalytical Method For Analysis Of The Disc-Type Permanent Magnethysteresis Motor In Steady-State Operational Conditions, Ali Behniafar, Ahmad Darabi
Turkish Journal of Electrical Engineering and Computer Sciences
Considering the characteristics of hysteresis and permanent magnet motors, it seems that these two motors are complements of each other. Thus, their combination yields a motor with an excellent performance. In order to preserve the major advantages of both motors in the new motor, a disc-type slotless structure is chosen. This paper presents a new finite-element method for the modeling of disc-type permanent magnet hysteresis synchronous (PMHS) motor. In this modeling method a new iterative algorithm is used. Programming software has been linked to finite- element software because of its limitation in the modeling of hysteresis phenomena. Validity of the …
Indoor Localization Of Wireless Emitter Using Direct Position Determination And Particle Swarm Optimization,
2018
TÜBİTAK
Indoor Localization Of Wireless Emitter Using Direct Position Determination And Particle Swarm Optimization, Saeid Hassanhosseini, Mohammad Reza Taban, Jamshid Abouei
Turkish Journal of Electrical Engineering and Computer Sciences
Many methods are introduced to accomplish determining the position of emitters with respect to known-position receivers in indoor localizations. Among them, the direct position determination (DPD) approach advocates using the received signals by all the base stations together in order to estimate the locations in a single step. However, DPD is not very accurate due to the use of a gridding area, the effect of noise, and the multipath phenomenon. In order to improve the DPD performance, we derive an analytic model based on weighted least square estimation that uses simultaneously the effect of delay, Doppler, attenuation, and angle of …
Brain-Computer Interface: Controlling A Robotic Arm Using Facial Expressions,
2018
TÜBİTAK
Brain-Computer Interface: Controlling A Robotic Arm Using Facial Expressions, Humaira Nisar, Hong-Way Khow, Kim Ho Yeap
Turkish Journal of Electrical Engineering and Computer Sciences
The aim of this paper is to develop a brain-computer interface (BCI) system that can control a robotic arm using EEG signals generated by facial expressions. The EEG signals are acquired using a neurosignal acquisition headset. The robotic arm consists of a 3-D printed prosthetic hand that is attached to a forearm and elbow made of craft wood. The arm is designed to make four moves. Each move is controlled by one facial expression. Hence, four different EEG signals are used in this work. The performance of the BCI robotic arm is evaluated by testing it on 10 subjects. Initially …
Highly Accurate And Sensitive Short Read Aligner,
2018
TÜBİTAK
Highly Accurate And Sensitive Short Read Aligner, Mehmet Yağmur Gök, Sezer Gören Uğurdağ, Cem Ünsalan, Mahmut Şami̇l Sağiroğlu
Turkish Journal of Electrical Engineering and Computer Sciences
Next-generation sequencing generates large numbers of short reads from DNA. This makes it difficult to process and store. Therefore, efficient sequence alignment and mapping techniques are needed in bioinformatics. Alignment and mapping are the basic steps involved in genetic data analysis. The Smith-Waterman (SW) algorithm, a well-known dynamic programming algorithm, is often used for this purpose. In this work, we propose to utilize Phred quality scores in Gotoh's affine gap model to increase the accuracy and sensitivity of the SW algorithm. Hardware platforms such as FPGAs and GPUs are commonly used to solve computationally expensive problems. In this work, a …
Classification Of Surface Electromyogram Signals Based On Directed Acyclic Graphs And Support Vector Machines,
2018
TÜBİTAK
Classification Of Surface Electromyogram Signals Based On Directed Acyclic Graphs And Support Vector Machines, Xinhui Hu, Jiangming Kan, Wenbin Li
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a novel classification approach for surface electromyogram (sEMG) signals. The proposed classification approach involves two steps: (1) feature extraction from an sEMG, in which a 7-dimensional feature vector is extracted from 27 types of features of the sEMG by linear discriminant analysis (LDA), and (2) a novel classifier, DAGSVMerr, based on a directed acyclic graph (DAG) and support vector machine (SVM), in which a separability measure function based on erroneous recognition rates (ERRs) is defined to determine the initial operation list. The proposed approach takes advantage of the feedback idea to improve the performance of the classification. …
An Efficient Technique Based On Firefly Algorithm For Pilot Design Process In Ofdm-Idma Systems,
2018
TÜBİTAK
An Efficient Technique Based On Firefly Algorithm For Pilot Design Process In Ofdm-Idma Systems, Necmi̇ Taşpinar, Şaki̇r Şi̇mşi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
Accurate placement of pilot tones has been a crucial task in multicarrier transmission technologies since there is a strong relation between pilot positions and channel estimation performance. Therefore, the firefly algorithm (FA) is proposed for achieving the optimal pilot distribution by optimizing the pilot positions in order to minimize the estimation errors of the least squares algorithm employed in orthogonal frequency division multiplexing-interleave division multiple access (OFDM-IDMA) systems. According to the simulation results, our proposed FA-based pilot optimizer provides a great performance increase in OFDM-IDMA systems by obtaining the most appropriate pilot distribution pattern among the considered pilot placement strategies. …
Schedulability Test For Ima Systems Based On Mixed Integer Linear Programming Formulation,
2018
TÜBİTAK
Schedulability Test For Ima Systems Based On Mixed Integer Linear Programming Formulation, Yukai Hao, Ming Mu, Xiaodi Dai, Xiangdong Li
Turkish Journal of Electrical Engineering and Computer Sciences
Integrated modular avionics (IMA) architecture is widely adopted for the design of modern aircraft. It simplifies the system development process and improves the system security and reliability. In IMA systems, avionics applications are packed into various partitions, and integrated into a standard computing platform. How to determine the schedulability of systems is one of the key problems. In this paper, using the characters of avionics systems, a partition model with a strict period is built, and constraints in space, time, and communication are analyzed. Based on the mixed integer linear programming formulation, a solution to determine the schedulability of IMA …
Nonlinear Analysis Of Hybrid Phase-Controlled Systems In Z-Domain With Convex Lmi Searches,
2018
TÜBİTAK
Nonlinear Analysis Of Hybrid Phase-Controlled Systems In Z-Domain With Convex Lmi Searches, Nur Syazreen Ahmad, Pei Ni Goh
Turkish Journal of Electrical Engineering and Computer Sciences
Phase-controlled systems such as phase-locked loops (PLLs) have been used in numerous applications ranging from data communications to speed motor control. The hybrid case where only the phase detector is digital while others are analog has advantages over the classical PLLs in the sense that it provides a wider locking range and is more suitable when the input and output signals come in digital waveforms. Although such systems are inherently nonlinear due to the phase detector's characteristics, the nonlinearity is often bypassed in order to ease the analysis and design methods. This, however, will give erroneous results when the phase …
Modeling Of Realistic Heart Electrical Excitation Based On Dti Scans And Modified Reaction Diffusion Equation,
2018
TÜBİTAK
Modeling Of Realistic Heart Electrical Excitation Based On Dti Scans And Modified Reaction Diffusion Equation, Ihab Elaff
Turkish Journal of Electrical Engineering and Computer Sciences
A new method is proposed for modeling realistic heart activation using diffusion tensor imaging (DTI) scans based on biological properties of its tissues in addition to the working methodology of the DTI scanner. Modeling of the excitation propagation inside the heart is initiated by applying activation at only one pacing site at the root of the conduction network. The excitation propagation has been accomplished based on a proposed conduction system that is extracted from DTI heart scans and a modified version of monodomain reaction diffusion equation (RDE) that considers the heart inhomogeneous--anisotropic material. The Aliev--Panfilov method was used to model …
Compact Local Gabor Directional Number Pattern For Facial Expression Recognition,
2018
TÜBİTAK
Compact Local Gabor Directional Number Pattern For Facial Expression Recognition, Zhengyan Zhang, Guanming Lu, Jingjie Yan, Haibo Li, Ning Sun, Xia Li
Turkish Journal of Electrical Engineering and Computer Sciences
This paper explores a novel method to represent face images for facial expression recognition; it is named compact local Gabor directional number pattern (CLGDNP). By convolving the face images with Gabor filters, we encode the magnitude and phase response images in each scale, and calculate the histograms in several nonoverlapping regions of each encoded image. Finally, we obtain two spatial histogram sequences by the aid of the mean pooling technology and concatenate them to form the facial descriptor. Moreover, for evaluating the performance of the proposed method, we employ a support vector machine to conduct some extensive classification experiments on …
Will It Pass? Predicting The Outcome Of A Source Code Review,
2018
TÜBİTAK
Will It Pass? Predicting The Outcome Of A Source Code Review, Çağdaş Evren Gerede, Zeki̇ Mazan
Turkish Journal of Electrical Engineering and Computer Sciences
It has been observed that allowing source code changes to be made only after source code reviews has a positive impact on the quality and lifetime of the resulting software. In some cases, code review processes take quite a long time and this negatively affects software development costs and employee job satisfaction. Establishing mechanisms that predict what kind of feedback reviewers will provide and what revisions they will ask for can reduce the number of times this problem occurs. Thanks to such mechanisms, developers can improve the maturity of their code change requests before the review process starts. In this …
High-Speed Data Deduplication Using Parallelized Cuckoo Hashing,
2018
TÜBİTAK
High-Speed Data Deduplication Using Parallelized Cuckoo Hashing, Jane Rubel Angelina Jeyaraj, Sundarakantham Kambaraj, Velmurugan Dharmarajan
Turkish Journal of Electrical Engineering and Computer Sciences
Data deduplication is a capacity optimization technology used in backup systems for identifying and storing the nonredundant data blocks. The CPU intensive tasks involved in a hash-based deduplication system remain as challenges in improving the performance of the system. In this paper, we propose a parallel variant of the standard cuckoo hashing that enables the hashing technique to be performed in parallel. The CPU intensive tasks of fingerprint insertion and lookup operations are performed in parallel and distributed among the nodes of the deduplication cluster. Furthermore, the uniform handling of the blocks by the cluster nodes involved in the process …
Virtual Force-Based Intelligent Clustering For Energy-Efficient Routing In Mobile Wireless Sensor Networks,
2018
TÜBİTAK
Virtual Force-Based Intelligent Clustering For Energy-Efficient Routing In Mobile Wireless Sensor Networks, Selvi Munuswamy, Jothi Muneeswari Saravanakumar, Ganapathy Sannasi, Khanna Nehemiah Harichandran, Kannan Arputharaj
Turkish Journal of Electrical Engineering and Computer Sciences
A mobile wireless sensor network (MWSN) consists of many sensor nodes, which can move from one position to another and gather data from the environment, and such nodes are coordinated with the support of a sink node. In recent years, the mobility behavior of sensor nodes present in wireless sensor networks is used to form effective clustering and to perform cluster-based routing. Virtual force is an important phenomenon in sensor nodes, which is used to model the mobility behavior. Production rules that use spatiotemporal constraints are able to make more accurate decisions on mobility speed, mobility area, and the required …
Probabilistic Dynamic Security Assessment Of Large Power Systems Using Machine Learning Algorithms,
2018
TÜBİTAK
Probabilistic Dynamic Security Assessment Of Large Power Systems Using Machine Learning Algorithms, Sevda Jafarzadeh, Veysel Murat İstemi̇han Genç
Turkish Journal of Electrical Engineering and Computer Sciences
Arrhythmia, also known as dysrhythmia, is a condition involving an irregular heartbeat. A problem in the heart may cause problems in other organs, and as time passes, this will lead to more severe problems. Arrhythmia must be detected at an early stage to prevent such a problem occurring in the heart. Detection of arrhythmia from an electrocardiogram is an easy method that does not need much equipment and does not harm the patient. The purpose of this research is to find a faster and more accurate system to classify nine classes of arrhythmia. The St. Petersburg Institute of Cardiological Technics …
The Application Of Analytical Mechanics In A Multimachine Power System,
2018
TÜBİTAK
The Application Of Analytical Mechanics In A Multimachine Power System, Zhijie Wang, Zhiyuan Liu, Jie Wang, Xiuchen Jiang, Sanming Liu, Yifang Liu, Gehao Sheng, Tianyu Liu
Turkish Journal of Electrical Engineering and Computer Sciences
Analytical mechanics methods play an important role in determining the energy function and Hamilton realization of a system. In this paper, the Hamilton function of the system is obtained directly from the system differential equation by means of analytical mechanics. In addition, the system Hamiltonization process requires that the system must be even order, and the commonly used generator model is a single-axis third-order model. For this reason, the odd-order power system model is extended to an even-order system. The Hamilton function of the system is deduced with coordinate transformation and the generalized force. Then the standard form of Hamilton …
