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2018

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Articles 8641 - 8670 of 8951

Full-Text Articles in Engineering

Classification And Regression Analysis Using Support Vector Machine For Classifying And Locating Faults In A Distribution System, Sophi Shilpa Gururajapathy, Hazlie Mokhlis, Hazlee Azil Bin Illias Jan 2018

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

Turkish Journal of Electrical Engineering and Computer Sciences

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


The Impact Of Transmission Power Levels Set Size On Lifetime Of Wireless Sensor Networks In Smart Grids, Hüseyi̇n Uğur Yildiz Jan 2018

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

Turkish Journal of Electrical Engineering and Computer Sciences

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


Management Of A Hybrid Renewable Power Plant Supplying An Isolated Rural Load Within A Changing Environment, Hichem Azli, Mohamed Mostefai Jan 2018

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

Turkish Journal of Electrical Engineering and Computer Sciences

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


Improved Design Of Axial Flux Permanent Magnet Generator For Small-Scale Wind Turbine, Mojtaba Eldoromi, Sajjad Tohidi, Mohammad Reza Feyzi, Naghi Rostami, Reza Emadifar Jan 2018

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

Turkish Journal of Electrical Engineering and Computer Sciences

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


Average Modeling And Evaluation Of 18-Pulse Autotransformer Rectifier Unit Without Interphase Transformers, Shahbaz Khan, Xiaobin Zhang, Husan Ali, Haider Zaman, Muhammad Saad, Bakht Muhammad Khan Jan 2018

Average Modeling And Evaluation Of 18-Pulse Autotransformer Rectifier Unit Without Interphase Transformers, Shahbaz Khan, Xiaobin Zhang, Husan Ali, Haider Zaman, Muhammad Saad, Bakht Muhammad Khan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an improved average model and evaluation of an 18-pulse autotransformer rectifier unit (ATRU) in differential delta configuration. Average models remove the switching behavior of diode rectifiers and high bandwidth transients, which not only facilitates simulation of power systems by reducing computational cost but also enables impedance-based stability analysis for large complex power systems. To experimentally validate the proposed average model, a 2-kW, 18-pulse ATRU has been tested and the results of the derived model are compared with those of the switching model and experimental prototype. Computed transfer function of load impedance from the proposed average model closely …


Application Of Acf-Wavelet Feature Extraction For Classification Of Some Artificial Pd Models Of Power Transformer, Vahid Parvin Darabad Jan 2018

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

Turkish Journal of Electrical Engineering and Computer Sciences

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


Evaluation Of Procurement Scenarios In One-Dimensional Cutting Stock Problem With A Random Demand Mix, Hüseyin Sarper, Nebojsa I. Jaksic Jan 2018

Evaluation Of Procurement Scenarios In One-Dimensional Cutting Stock Problem With A Random Demand Mix, Hüseyin Sarper, Nebojsa I. Jaksic

Electrical & Computer Engineering Faculty Publications

The one-dimensional cutting stock problem describes the problem of cutting standard length stock material into various specified sizes while minimizing the material wasted (the remnant or drop as manufacturing terms). This computationally complex optimization problem has many manufacturing applications. One-dimensional cutting stock problems arise in many domains such as metal, paper, textile, and wood. To solve it, the problem is formulated as an integer linear model first, and then solved using a common optimizer software. This paper revisits the stochastic version of the problem and proposes a priority-based goal programming approach. Monte Carlo simulation is used to simulate several likely …


Humanoid Robots Supporting Children’S Learning In An Early Childhood Setting, Helen Crompton, Kristen Gregory, Diane Burke Jan 2018

Humanoid Robots Supporting Children’S Learning In An Early Childhood Setting, Helen Crompton, Kristen Gregory, Diane Burke

Teaching & Learning Faculty Publications

This qualitative study explored the affordances provided by the integration of the NAO humanoid robot in three preschool classrooms. Using the Head Start Early Learning Outcomes Framework as a lens, the researchers qualitatively analyzed data from focus groups, observations, field notes and student artifacts, using grounded coding to uncover language and communication, physical, cognitive and social–emotional learning experiences for children. The researchers also examined interactions between the robot, children and teachers to identify successes and challenges experienced during the integration. Findings indicate the robot provided opportunities for student development in all learning domains. Students were intellectually curious about the robot; …


Mechanical Wear Debris Feature, Detection, And Diagnosis: A Review, Wei Hong, Wenjian Cai, Shaoping Wang, Mileta M. Tomovic Jan 2018

Mechanical Wear Debris Feature, Detection, And Diagnosis: A Review, Wei Hong, Wenjian Cai, Shaoping Wang, Mileta M. Tomovic

Engineering Technology Faculty Publications

Mechanical debris is an important product of friction wear, which is also a crucial approach to know the running status of a machine. Many studies have been conducted on mechanical debris in related fields such as tribology, instrument, and diagnosis. This paper presents a comprehensive review of these studies, which summarizes wear mechanisms (e.g., abrasive wear, fatigue wear, and adhesive wear) and debris features (e.g., concentration (number), size, morphology, and composition), analyzes detection methods principles (e.g., offline: spectrograph and ferrograph, and online: optical method, inductive method, resistive-capacitive method, and acoustic method), reviews developments of online inductive methods, and investigates the …


Generating Adversarial Attacks For Sparse Neural Networks, Jack H. Chen, Walt Woods Jan 2018

Generating Adversarial Attacks For Sparse Neural Networks, Jack H. Chen, Walt Woods

Maseeh Summer Undergraduate Research Experience

Neural networks provide state-of-the-art accuracy for image classification tasks. However traditional networks are highly susceptible to imperceivable perturbations to their inputs known as adversarial attacks that drastically change the resulting output. The magnitude of these perturbations can be measured as Mean Squared Error (MSE). We use genetic algorithms to produce black-box adversarial attacks and examine MSE on state-of-the-art networks. This method generates an attack that converts 90% confidence on a correct class to 50% confidence of a targeted, incorrect class after 2000 epochs. We will generate and examine attacks and their MSE against several sparse neural networks. We theorize that …


Early Emerging Pathogen Detection, Mackenzie Wangenstein Jan 2018

Early Emerging Pathogen Detection, Mackenzie Wangenstein

Maseeh Summer Undergraduate Research Experience

A supervised learning technique was employed to identify emerging pathogen species. Portland State University has partnered with the University of New Mexico to take encodings of unknown pathogen molecular structures to determine emerging species.


User-Friendly Deniable Storage For Mobile Devices, Bing Chang, Yao Cheng, Bo Chen, Fengwei Zhang, Wen-Tao Zhu, Yanju Liu, Zhan Wang Jan 2018

User-Friendly Deniable Storage For Mobile Devices, Bing Chang, Yao Cheng, Bo Chen, Fengwei Zhang, Wen-Tao Zhu, Yanju Liu, Zhan Wang

Research Collection School Of Computing and Information Systems

Mobile devices are prevalently used to process sensitive data, but traditional encryption may not work when an adversary is able to coerce the device owners to disclose the encryption keys. Plausibly Deniable Encryption (PDE) is thus designed to protect sensitive data against this powerful adversary. In this paper, we present MobiPluto, a user-friendly PDE scheme for denying the existence of sensitive data stored on mobile devices. A salient difference between MobiPluto and the existing PDE systems is that any block-based file systems can be deployed on top of it. To further improve usability and deniability of MobiPluto, we introduce a …


Improvement Of Heart Attack Prediction By The Feature Selection Methods, Hi̇dayet Takci Jan 2018

Improvement Of Heart Attack Prediction By The Feature Selection Methods, Hi̇dayet Takci

Turkish Journal of Electrical Engineering and Computer Sciences

Prediction of a heart attack is very important since it is one of the leading causes of sudden death, especially in low-income countries. Although cardiologists use traditional clinical methods such as electrocardiography and blood tests for heart attack prediction, computer aided diagnosis systems that use machine learning methods are also in use for this task. In this study, we used machine learning and feature selection algorithms together. Our aim is to determine the best machine learning method and the best feature selection algorithm to predict heart attacks. For this purpose, many machine learning methods with optimum parameters and several feature …


Estimating Left Ventricular Volume With Roi-Based Convolutional Neural Network, Feng Zhu Jan 2018

Estimating Left Ventricular Volume With Roi-Based Convolutional Neural Network, Feng Zhu

Turkish Journal of Electrical Engineering and Computer Sciences

The volume of the human left ventricular (LV) chamber is an important indicator for diagnosing heart disease. Although LV volume can be measured manually with cardiac magnetic resonance imaging (MRI), the process is difficult and time-consuming for experienced cardiologists. This paper presents an end-to-end segmentation-free method that estimates LV volume from MRI images directly. The method initially uses Fourier transform and a regression filter to calculate the region of interest that contains the LV chambers. Then convolutional neural networks are trained to estimate the end-diastolic volume (EDV) and end-systolic volume (ESV). The resulting models accurately estimate the EDV and ESV …


Automatic Detection Of The Respiratory Cycle From Recorded, Single-Channel Sounds From Lungs, Seli̇m Aras, Mehmet Öztürk, Ali̇ Gangal Jan 2018

Automatic Detection Of The Respiratory Cycle From Recorded, Single-Channel Sounds From Lungs, Seli̇m Aras, Mehmet Öztürk, Ali̇ Gangal

Turkish Journal of Electrical Engineering and Computer Sciences

Listening to the sounds made by the lungs is a long-standing method that is still used to diagnose lung diseases. Many studies have been conducted on the automatic recognition of recorded sounds from the lungs. However, in these studies, respiratory cycles, i.e. inhalations followed by exhalations, were either monitored manually or by using multichannel signals of the sounds made by the lungs. In order to recognize sounds made by the lungs automatically, one must first use these sounds to determine the respiratory cycles. Our previous study was the first study presented in the literature in which the boundaries of respiratory …


A Novel Multistage System For The Detection And Removal Of Pectoral Muscles Inmammograms, İdi̇l Işikli Esener, Semi̇h Ergi̇n, Tolga Yüksel Jan 2018

A Novel Multistage System For The Detection And Removal Of Pectoral Muscles Inmammograms, İdi̇l Işikli Esener, Semi̇h Ergi̇n, Tolga Yüksel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel multistage scheme for pectoral muscle removal from mammography images is proposed, and the performance of this system is verified using the publicly available Mammographic Image Analysis Society digital mammogram database. This database is composed of mediolateral oblique mammography images including three different tissue types (fatty, fatty-glandular, and dense-glandular) with three health status types (normal, benign cancer, and malignant cancer). In the implementation of the proposed system, a mammography image is first preprocessed by performing noise reduction background removal followed by artifact suppression processes. Then a presegmentation procedure is applied using region growing and line fitting …


Multimodal Medical Imaging Repository And Information System In Epilepsysurgery, Gülsüm Akdeni̇z, İbrahi̇m Atli, Fati̇h Vehbi̇ Çelebi̇ Jan 2018

Multimodal Medical Imaging Repository And Information System In Epilepsysurgery, Gülsüm Akdeni̇z, İbrahi̇m Atli, Fati̇h Vehbi̇ Çelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Surgery is an option for patients with drug-resistant epilepsy, but it requires a comprehensive assessment. Electroencephalography (EEG), magnetic resonance imaging (MRI), and functional MRI (fMRI) are used to localize the epileptogenic zone, which directly affects the surgery outcome. Accessing EEG, MRI, and fMRI results and patient information simultaneously using traditional methods might result in misinformation and increase the workload of clinicians. In this study, we developed a modern web-based repository system for the preoperative evaluation of epilepsy disorder, including multimodal medical images and patient information. Our dedicated system is enriched with clinical metadata that are not currently available and is …


Gnss Augmentation Through Ku-Band Communication Satellites With Rtkrealization, Şenol Gülgönül Jan 2018

Gnss Augmentation Through Ku-Band Communication Satellites With Rtkrealization, Şenol Gülgönül

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a method to broadcast real-time kinematics (RTK) corrections over a communication satellite is proposed. RTK corrections generated by the reference station are uplinked to the communication satellite within a multiplexed DVB-S carrier. Corrections are received by a satellite dish and the DVB-S satellite receiver. Better than 18 cm of accuracy is achieved for rover distances of up to 500 km in Turkey. The proposed method can be used as an alternative satellite-based augmentation system for Turkey and other countries.


Ultra Low-Power Dc Voltage Limiter For Rfid Application In 0.18-Μm Cmostechnology, Rezvan Dastanian, Sajad Nejadhasan Jan 2018

Ultra Low-Power Dc Voltage Limiter For Rfid Application In 0.18-Μm Cmostechnology, Rezvan Dastanian, Sajad Nejadhasan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a low-power DC voltage limiter is designed for radio frequency identification tags. In this design, the low-power bandgap reference (BGR) circuit, which is insensitive to temperature, and also the comparator are used for the voltage limiter circuit. To make the I-V curve approach the ideal one, four inverter stages are employed to the output of the comparator. The structure of the BGR and comparator use only MOSFET transistors that work in subthreshold region when the limiter is inactive. These two blocks have power consumption of 220 pW and 1300 pW, respectively. The limited output voltage is 1.5 …


A Strategy For Improving Netclust Server Placement For Multicloud Environments, Yuting Zhao, Jinhong Liu, Qing Fang, Lifang Xu, Changlai Du, Yuan Xiaoqun Jan 2018

A Strategy For Improving Netclust Server Placement For Multicloud Environments, Yuting Zhao, Jinhong Liu, Qing Fang, Lifang Xu, Changlai Du, Yuan Xiaoqun

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a fast server placement algorithm to improve the NetClust framework and make it more efficient and exible. To this end, we introduce hierarchical clustering technologies to the NetClust framework and propose a exible server placement algorithm, which integrates the agglomerative and divisive clustering technologies to reduce the time complexity and avoid the performance uctuation affected by the initial node selection. The experiment results show that our server placement algorithm may reduce the time complexity of server selection of NetClust significantly and improve the exibility and applicability of the NetClust.


Performance Analysis Of Hamming Code For Wsn-Based Smart Grid Applications, Meli̇ke Yi̇ği̇t, Vehbi̇ Çağri Güngör, Pinar Bölük Jan 2018

Performance Analysis Of Hamming Code For Wsn-Based Smart Grid Applications, Meli̇ke Yi̇ği̇t, Vehbi̇ Çağri Güngör, Pinar Bölük

Turkish Journal of Electrical Engineering and Computer Sciences

Many methods have been employed to detect, compare, and correct errors to increase communication reliability and efficiency in wireless sensor networks (WSNs). However, to the best of our knowledge, no existing study has compared the performance of error control codes by using different modulation techniques in a smart grid communication environment when multichannel scheduling is used. This paper presents a detailed performance evaluation and makes a comparison of different modulation techniques, such as frequency shift keying (FSK), differential phase shift keying (DPSK), binary phase shift keying (BPSK), and offset quadrature phase-shift keying (OQPSK), using Hamming codes in a 500-kV line-of-sight …


Energy-Efficient And Reliable Data Collection In Wireless Sensor Networks, Deepa Puneeth, Nishanth Joshi, Pradeep Kumar Atrey, Muralidhar Kulkarni Jan 2018

Energy-Efficient And Reliable Data Collection In Wireless Sensor Networks, Deepa Puneeth, Nishanth Joshi, Pradeep Kumar Atrey, Muralidhar Kulkarni

Turkish Journal of Electrical Engineering and Computer Sciences

Ensuring energy efficiency, data reliability, and security is important in wireless sensor networks (WSNs). A combination of variants from the cryptographic secret sharing technique and the disjoint multipath routing scheme is an effective strategy to address these requirements. Although Shamir's secret sharing (SSS) provides the desired reliability and information-theoretic security, it is not energy efficient. Alternatively, Shamir's ramp secret sharing (SRSS) provides energy efficiency and data reliability, but is only computationally secure. We argue that both these approaches may suffer from a compromised node (CN) attack when a minimum number of nodes is compromised. Hence, we propose a new scheme …


An Efficient Algorithm To Decompose A Compound Rectilinear Shape Into Simplerectilinear Shapes, Imran Sharif, Debasis Chaudhuri, Naveen Kushwaha, Ashok Samal, Brij Mohan Singh Jan 2018

An Efficient Algorithm To Decompose A Compound Rectilinear Shape Into Simplerectilinear Shapes, Imran Sharif, Debasis Chaudhuri, Naveen Kushwaha, Ashok Samal, Brij Mohan Singh

Turkish Journal of Electrical Engineering and Computer Sciences

Detection of a compound object is a critical problem in target recognition. For example, buildings form an important class of shapes whose recognition is important in many remote sensing based applications. Due to the coarse resolution of imaging sensors, adjacent buildings in the scenes appear as a single compound shape object. These compound objects can be represented as the union of a set of disjoint rectilinear shaped objects. Separating the individual buildings from the resulting compound objects in a segmented image is often difficult but important nevertheless. In this paper we propose a new and efficient technique to decompose a …


Improved Discrete Sliding Mode Control Strategy For Pulse-Width Modulationrectifier, Jing Cao, Chaonan Tong Jan 2018

Improved Discrete Sliding Mode Control Strategy For Pulse-Width Modulationrectifier, Jing Cao, Chaonan Tong

Turkish Journal of Electrical Engineering and Computer Sciences

An improved sliding mode control utilizing repetitive control (ISMRC) is proposed for a three-phase pulse- width modulation (PWM) rectifier. The proposed controller integrates the advantages of both sliding mode control (SMC) and repetitive control (RC) by implementing a structure that embeds an RC controller into the equivalent control branch of an SMC controller. Both a simulation and an experiment are conducted to compare the proposed ISMRC controller with a conventional SMC controller. It is demonstrated that the fifth harmonic distortion of the current of the PWM rectifier system is controlled at 3.3%, the power factor is close to the unit, …


Signal Processing In Recursive Rejection Filters In The Transient Mode, Dmitrii Popov, Sergey Smolskiy Jan 2018

Signal Processing In Recursive Rejection Filters In The Transient Mode, Dmitrii Popov, Sergey Smolskiy

Turkish Journal of Electrical Engineering and Computer Sciences

A recursive rejection filter (REF) oriented to the radar signal extraction from the moving targets on a background of passive interference in the form of undesired re ections from fixed or slowly moving objects (so-called clutter) is the object under investigation. By means of the state variable method, which gives the adequate filter description in the time domain, the REF structure in the transient mode is synthesized, which is improved with the aim of transient acceleration with the clutter edge arriving. The REF structure's improvement in the transient mode is achieved by its reconfiguration, which is made by REF output …


Last Level Cache Partitioning Via Multiverse Thread Classification, Burak Sezi̇n Ovant, İsa Ahmet Güney, Muhammed Emi̇n Savaş, Gürhan Küçük Jan 2018

Last Level Cache Partitioning Via Multiverse Thread Classification, Burak Sezi̇n Ovant, İsa Ahmet Güney, Muhammed Emi̇n Savaş, Gürhan Küçük

Turkish Journal of Electrical Engineering and Computer Sciences

Last level caches (LLCs) are part of the last line of defense against the famous memory wall problem. Today, almost all processors utilize a LLC for the same reason. This study extends our previous work, which proposed a cache-partitioning mechanism using thread classification. Here, we propose three enhancements to the existing system: 1) an adaptive traffic threshold mechanism for more portable classification hardware, 2) a new method for classifying way-hungry threads, and finally, 3) a thorough comparison of two design alternatives. Compared to the original way- partitioning mechanism, we show that the proposed mechanism's performance improved by around 6%, on …


Usage Of Segmentation For Noise Elimination In Reconstructed Images In Digitalholographic Interferometry, Gülhan Ustabaş Kaya, Zehra Saraç Jan 2018

Usage Of Segmentation For Noise Elimination In Reconstructed Images In Digitalholographic Interferometry, Gülhan Ustabaş Kaya, Zehra Saraç

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose to enhance the image in digital holography by using an artificial neural network and an iterative algorithm with Nakamura's approach based on segmentation. It is well known that reconstructed three- dimensional (3D) images suffer from noise in digital holography. In addition, obtaining 3D reconstructed images takes a long time due to large pixel numbers in reconstructed images and lack of memory in the system. The segmentation process is an application that overcomes these problems. Therefore, we focus on the implementation of segmentation for image enhancement. In addition, the results of the segmentation process for both …


Weighted Intensity Hue Saturation Transform For Image Enhancement Andpansharpening, Nur Hüseyi̇n Kaplan Jan 2018

Weighted Intensity Hue Saturation Transform For Image Enhancement Andpansharpening, Nur Hüseyi̇n Kaplan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a weighted intensity hue saturation transform (WIHS) is proposed for image enhancement and pansharpening. The proposed transform obtains the intensity component of the classical intensity hue saturation (IHS) transform, by weighting the bands (red, green, and blue) of the image, whereas the hue and saturation components remain unchanged. The weight for each band is determined according to the brightness interval of the corresponding band and its standard deviation. The purpose of obtaining the intensity component by weighting is to keep more information from the bands of the input image. The classical intensity component used in image processing …


An Investigation On Characteristics Of Tracking Failure In Epoxy Resin Withharmonic And Fractal Dimension Analysis, Mehmet Murat İspi̇rli̇, Aysel Ersoy Yilmaz Jan 2018

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 …


Novel Representations For A Coherent Threshold Reliability System: A Tale Of Eightsignal Ow Graphs, Ali Muhammad Rushdi, Alaa Mohammad Alturki Jan 2018

Novel Representations For A Coherent Threshold Reliability System: A Tale Of Eightsignal Ow Graphs, Ali Muhammad Rushdi, Alaa Mohammad Alturki

Turkish Journal of Electrical Engineering and Computer Sciences

A threshold system is a reliability system whose success/failure is a threshold switching function in the successes/failures of its components. A coherent system (CS) is one that is causal, monotone, and with relevant components. The coherent threshold system (CTS), typically called the weighted k-out-of-n system, is consequently described by strictly positive weights and threshold. This paper presents recursive relations as well as boundary conditions for eight entities pertaining to a CTS. These are (a) expressions of monoform literals as well as disjoint or probability- ready expressions for either system success or failure, and (b) all-additive formulas as well as inclusion-exclusion …