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- Genetic algorithm (8)
- Flexible AC transmission systems (5)
- Particle swarm optimization (5)
- Artificial bee colony algorithm (4)
- Power quality (4)
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- Support vector machines (4)
- Adaptive control (3)
- Classification (3)
- Clustering (3)
- Differential evolution (3)
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- FACTS devices (3)
- Mammography (3)
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- Multiobjective (3)
- Neural network (3)
- Optimal power flow (3)
- Optimization (3)
- S-transform (3)
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- Artificial bee colony (2)
- Artificial intelligence (2)
- Artificial neural network (2)
- Automated Psychological assessment (2)
- Bioinformatics (2)
- Breast cancer (2)
- Chaos (2)
- Computer Graphics (2)
- Content Analysis (2)
- Data hiding (2)
Articles 31 - 60 of 187
Full-Text Articles in Computer Engineering
An Improved Hybrid Approach For The Plc-Based Implementation Of Reduced Rw Supervisors, Murat Uzam, Gökhan Gelen
An Improved Hybrid Approach For The Plc-Based Implementation Of Reduced Rw Supervisors, Murat Uzam, Gökhan Gelen
Turkish Journal of Electrical Engineering and Computer Sciences
A successful application of a hybrid (mixed Petri net/automaton) approach for the real-time supervisory control of an experimental manufacturing system was reported recently. The hybrid approach includes a Ramadge--Wonham (RW) supervisor in the form of an automaton. The reduced RW supervisor offers fewer states for the programmable logic controller (PLC) implementation of the hybrid controller with less memory requirements, but due to a problem called the avalanche effect, the PLC implementation of the hybrid controller with the reduced RW supervisor was not possible. This paper proposes a method to both detect and eliminate the avalanche effect problem for a RW …
A Framework For Medical Image Retrieval Using Merging-Based Classification With Dependency Probability-Based Relevance Feedback, Hossein Pourghassem, Sabalan Daneshvar
A Framework For Medical Image Retrieval Using Merging-Based Classification With Dependency Probability-Based Relevance Feedback, Hossein Pourghassem, Sabalan Daneshvar
Turkish Journal of Electrical Engineering and Computer Sciences
Content-based image retrieval (CBIR) systems are used to retrieve relevant images from large-scale databases. In this paper, a framework for the image retrieval of a large-scale database of medical X-ray images is presented. This framework is designed based on query image classification into several prespecified homogeneous classes. Using a merging scheme and an iterative classification, the homogeneous classes are formed from overlapping classes in the database. For this purpose, the shape and texture features, selected using the forward selection algorithm, are optimized by a novel genetic algorithm-based feature reduction and optimization algorithm in the feature space. In this algorithm, using …
Cancer Risk Analysis By Fuzzy Logic Approach And Performance Status Of The Model, Atinç Yilmaz, Kürşat Ayan
Cancer Risk Analysis By Fuzzy Logic Approach And Performance Status Of The Model, Atinç Yilmaz, Kürşat Ayan
Turkish Journal of Electrical Engineering and Computer Sciences
Cancer is the leading life-threatening disease for people in today's world. Although cancer formation is different for each type of cancer, it has been determined by studies and research that stress also triggers cancer types. Early precaution is very important for people who have not fallen ill yet with a disease like cancer that has a high mortality rate and expensive treatment. With this study, we expound that the possibility of developing such disease may be decreased and people could take measures against it. For the 3 cancer types selected as pilot work by introducing a fuzzy logic model, the …
A Blind Digital Signature Scheme Using Elliptic Curve Digital Signature Algorithm, İsmai̇l Bütün, Mehmet Demi̇rer
A Blind Digital Signature Scheme Using Elliptic Curve Digital Signature Algorithm, İsmai̇l Bütün, Mehmet Demi̇rer
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, we propose a blind digital signature (BDS) scheme based on the elliptic curve digital signature algorithm that increases the performance significantly. The security of our scheme is based on the difficulty of the elliptic curve discrete algorithm problem. Therefore, it offers much smaller key lengths for the desired security levels, along with much faster cryptographic processes, leading to fewer hardware and software requirements. According to our simulation results, the relative performance improvement of our proposed BDS scheme is up to 96% when compared with previously proposed schemes.
Wavelet Multiscale Analysis Of A Power System Load Variance, Samir Avdakovic, Amir Nuhanovic, Mirza Kusljugic, Elvisa Becirovic, Elma Turkovic
Wavelet Multiscale Analysis Of A Power System Load Variance, Samir Avdakovic, Amir Nuhanovic, Mirza Kusljugic, Elvisa Becirovic, Elma Turkovic
Turkish Journal of Electrical Engineering and Computer Sciences
Wavelet transform (WT) represents a very attractive mathematical area for just more than 15 years of its research in applications in electrical engineering. This is mainly due to its advantages over other processing techniques and signal analysis, which is reflected in the time-frequency analysis, and so it has an important application in the processing and analysis of time series. In this paper, for example, the analysis of the hourly load of a real power system over the past few years was performed by applying the continuous WT and using the Morlet wavelet function. The results show that this approach of …
Comparison Study Of Computational Parameter Values Between Lrn And Narx In Identifying Nonlinear Systems, Farah Hani Nordin, Farrukh Hafiz Nagi, Aidil Azwin Zainul Abidin
Comparison Study Of Computational Parameter Values Between Lrn And Narx In Identifying Nonlinear Systems, Farah Hani Nordin, Farrukh Hafiz Nagi, Aidil Azwin Zainul Abidin
Turkish Journal of Electrical Engineering and Computer Sciences
To determine the nonlinear autoregressive model with exogenous inputs (NARX) parameter values is not an easy task, even though NARX is reported to successfully identify nonlinear systems. Apart from the activation functions, number of layers, layer size, learning rate, and number of epochs, the number of delays at the input and at the feedback loop need to also be determined. The layer recurrent network (LRN) is seen to have the potential to outperform NARX. However, not many papers have reported on using the LRN to identify nonlinear systems. Therefore, it is the aim of this paper to investigate and analyze …
Antiwindup Design For The Speed Loop Pi Controller Of A Pmsm Servo System, Ming Yang, Li Niu, Dian-Guo Xu
Antiwindup Design For The Speed Loop Pi Controller Of A Pmsm Servo System, Ming Yang, Li Niu, Dian-Guo Xu
Turkish Journal of Electrical Engineering and Computer Sciences
A novel antiwindup (AW) strategy for a proportional-integral (PI) regulator based on the back-calculation method is presented. The proposed method will calculate the gain of the back-calculation based on the input and output status of the PI regulator without the requirement of motor parameters, such as the inertial and torque-current coefficient, and the back-calculation gain will vary with the speed command in order to obtain the optimal dynamic performance. The proposed method avoids the problem caused by the fixed back-calculation gain in the classical AW strategy, and prevents the system from untimely saturation withdrawing or an unexpected overshoot due to …
Hybrid Of Genetic Algorithm And Great Deluge Algorithm For Rough Set Attribute Reduction, Najmeh Sadat Jaddi, Salwani Abdullah
Hybrid Of Genetic Algorithm And Great Deluge Algorithm For Rough Set Attribute Reduction, Najmeh Sadat Jaddi, Salwani Abdullah
Turkish Journal of Electrical Engineering and Computer Sciences
The attribute reduction problem is the process of reducing unimportant attributes from a decision system to decrease the difficulty of data mining or knowledge discovery tasks. Many algorithms have been used to optimize this problem in rough set theory. The genetic algorithm (GA) is one of the algorithms that has already been applied to optimize this problem. This paper proposes 2 kinds of memetic algorithms, which are a hybridization of the GA, with 2 versions (linear and nonlinear) of the great deluge (GD) algorithm. The purpose of this hybridization is to investigate the ability of this local search algorithm to …
Estimation Of Fuel Cost Curve Parameters For Thermal Power Plants Using The Abc Algorithm, Yusuf Sönmez
Estimation Of Fuel Cost Curve Parameters For Thermal Power Plants Using The Abc Algorithm, Yusuf Sönmez
Turkish Journal of Electrical Engineering and Computer Sciences
The solution accuracy of economic dispatch problems is associated with the accuracy of the fuel cost curve parameters. Therefore, updating of these parameters is a very important issue to further improve the final accuracy of economic dispatch problems. Estimating the parameters of the fuel cost curve may be the best solution for this issue. This paper presents an application of the artificial bee colony (ABC) algorithm to estimate the fuel cost curve parameters of thermal power plants. In the estimation problem, 1st-, 2nd-, and 3rd-order fuel cost functions are used, and the estimation problem is formulated as an optimization one. …
Novel Approaches For Automated Epileptic Diagnosis Using Fcbf Selection And Classification Algorithms, Baha Şen, Musa Peker
Novel Approaches For Automated Epileptic Diagnosis Using Fcbf Selection And Classification Algorithms, Baha Şen, Musa Peker
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a new application for automated epileptic detection using the fast correlation-based feature (FCBF) selection and classification algorithms. This study consists of 3 stages: feature extraction, feature selection from electroencephalography (EEG) signals, and the classification of these signals. In the feature extraction phase, 16 attribute algorithms are used in 5 categories, and 36 feature parameters are obtained from these algorithms. In the feature selection phase, the FCBF algorithm is chosen to select a set of attributes that best represent the EEG signals. The resulting attributes are used as input parameters for the classification algorithms. In the classification phase, …
A Low-Voltage And Low-Power Sinh-Domain Universal Biquadratic Filter For Low-Frequency Applications, Farooq Khanday, Nisar Shah
A Low-Voltage And Low-Power Sinh-Domain Universal Biquadratic Filter For Low-Frequency Applications, Farooq Khanday, Nisar Shah
Turkish Journal of Electrical Engineering and Computer Sciences
Sinh-domain CMOS filters have favorable properties, such as a wide dynamic range at low supply voltage, compactness, linearity, and low power consumption. These properties are becoming increasingly important for biomedical applications that require extremely low-power dissipation and neuromorphic circuits that attempt to reproduce the biophysics of biological neurons and synapses. In this paper, a low-voltage sinh-domain universal biquadratic filter circuit is introduced. The circuit, aside from permitting the independent adjustment of pole frequency (\omega_0) and the quality factor (Q), is free from matching conditions, capable of absorbing the shunt parasitic capacitances, amenable for monolithic integration, and composed of merely a …
Control Of Diesel Engines Mounted On Vehicles In Mobile Cranes Via Can Bus, Muci̇z Özcan, Hi̇dayet Günay
Control Of Diesel Engines Mounted On Vehicles In Mobile Cranes Via Can Bus, Muci̇z Özcan, Hi̇dayet Günay
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the aim was to lift loads that required more force using the infrastructure of existing vehicles. To this end, a truck-mounted diesel engine was selected to be used in mobile crane applications. A control system was designed and implemented to obtain the appropriate hydraulic force by accessing the diesel engine with a controller area network bus via an electronic control unit (ECU). For this purpose, hydraulic pumps to be used to operate the crane were mounted on the selected mobile diesel engine with an ECU. Firms that manufacture cranes in the world produce cranes with infrastructure. This …
Stopping Spam With Sending Session Verification, Ahmet Baran
Stopping Spam With Sending Session Verification, Ahmet Baran
Turkish Journal of Electrical Engineering and Computer Sciences
Spam has become one of the most significant problems for Internet communication and users today. The traditional filtering methods and signature-based spam blocking systems that have come into prominence recently fall short, as statistics demonstrate that spam further mounts up day after day. In this study, a new method is recommended to block spam mails. In this recommended method, a mail sending session is verified during mail envelope communication by adding small attachments to the simple mail transfer protocol, so spam mails can be blocked before leaving the sender domain or relay machine. Additionally, hijacked user accounts are able to …
Flow Velocity Measurement And Analysis Based On Froth Image Sift Features And Kalman Filter For Froth Flotation, Jinping Liu, Weihua Gui, Zhaohui Tang
Flow Velocity Measurement And Analysis Based On Froth Image Sift Features And Kalman Filter For Froth Flotation, Jinping Liu, Weihua Gui, Zhaohui Tang
Turkish Journal of Electrical Engineering and Computer Sciences
The flow velocity of flotation froth involves important information about the concentrate grade and the mineral recovery. It is significant to maintain the flow velocity of the froth at proper levels to achieve a good production performance in the machine vision-based process monitoring and control. However, the accurate velocity field measurement for the heavily deformed and seriously fragile froth bubbles is still a great challenge. Scale-invariant feature transform (SIFT) feature-based image matching provides an effective registration method for deformed objects, but most of the processing time would be wasted on the feature extraction and matching in irrelevant regions of the …
A New Digital Image Steganography Algorithm Based On Visible Wavelength, İbrahi̇m Coşkun, Feyzi̇ Akar, Özdemi̇r Çeti̇n
A New Digital Image Steganography Algorithm Based On Visible Wavelength, İbrahi̇m Coşkun, Feyzi̇ Akar, Özdemi̇r Çeti̇n
Turkish Journal of Electrical Engineering and Computer Sciences
Stenography is the science that ensures secret communication through multimedia carriers such as image, audio, and video files. The ultimate end of stenography is to hide the secret data in the carrier file so that they are not detected. To that end, stenography applications should have such features as undetectability; robustness; resistance to various images process, sing methods, and compression; and capacity of the hidden data. At the same time, those features distinguish stenography applications from watermarking and cryptography applications. This study is different from other studies in the literature in that the undetectability parameter has been achieved through hiding …
Composite Power System Adequacy Assessment Based On Postoptimal Analysis, Amir Safdarian, Mahmood Fotuhi-Firuzabad, Farrokh Aminifar
Composite Power System Adequacy Assessment Based On Postoptimal Analysis, Amir Safdarian, Mahmood Fotuhi-Firuzabad, Farrokh Aminifar
Turkish Journal of Electrical Engineering and Computer Sciences
The modeling and evaluation of enormous numbers of contingencies are the most challenging impediments associated with composite power system adequacy assessment, particularly for large-scale power systems. Optimal power flow (OPF) solution, as a widely common approach, is normally employed to model and analyze each individual contingency as an independent problem. However, mathematical representations associated with diverse states are slightly different in one or a few generating units, line outages, or trivial load variations. This inherent attribute brings a promising idea to speed up the contingency evaluation procedure. In this paper, postoptimal analysis (POA), as a well-recognized technique to attack a …
Detection Of Microcalcification Clusters In Digitized X-Ray Mammograms Using Unsharp Masking And Image Statistics, Peli̇n Kuş, İrfan Karagöz
Detection Of Microcalcification Clusters In Digitized X-Ray Mammograms Using Unsharp Masking And Image Statistics, Peli̇n Kuş, İrfan Karagöz
Turkish Journal of Electrical Engineering and Computer Sciences
A fully automated method for detecting microcalcification (MC) clusters in regions of interest (ROIs) extracted from digitized X-ray mammograms is proposed. In the first stage, an unsharp masking is used to perform the contrast enhancement of the MCs. In the second stage, the ROIs are decomposed into a 2-level contourlet representation and the reconstruction is obtained by eliminating the low-frequency subband in the second level. In the third stage, statistical textural features are extracted from the ROIs and they are classified using support vector machines. To test the performance of the method, 57 ROIs selected from the Mammographic Image Analysis …
Dependence On Cyberscribes - Issues In E-Security, Thomas R. Mclean, Alexander B. Mclean
Dependence On Cyberscribes - Issues In E-Security, Thomas R. Mclean, Alexander B. Mclean
Journal of Business & Technology Law
No abstract provided.
The Vortex Effect Of Francis Turbine In Electric Power Generation, Veli̇ Türkmenoğlu
The Vortex Effect Of Francis Turbine In Electric Power Generation, Veli̇ Türkmenoğlu
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the vibration effects of a vortex that occurred in high-head Francis turbines and an alternator are examined. The vortex effect, which directly affects the efficiency and the quality of the energy, was tested at the DarÔøΩca-1 hydroelectric power plant (HPP) located in Ordu Province, Turkey. Formed by undissolved oxygen in the water, the vortex effect, which is parallel to the alternator load, causes tremendous vibration within the alternator and Francis turbine bearings. This problem, which has a direct negative effect on the alternator capacity, was solved by adding an air-admission system. In doing so, power production was …
Optimal Sizing And Siting Distributed Generation Resources Using A Multiobjective Algorithm, Seyed Amir Hosseini, Seyed Siavash Karimi Madahi, Farzad Razavi, Mohsen Karami, Ali Asghar Ghadimi
Optimal Sizing And Siting Distributed Generation Resources Using A Multiobjective Algorithm, Seyed Amir Hosseini, Seyed Siavash Karimi Madahi, Farzad Razavi, Mohsen Karami, Ali Asghar Ghadimi
Turkish Journal of Electrical Engineering and Computer Sciences
The restructuring of the electrical market, improvement in the technologies of energy production, and energy crisis have paved the way for increasing applications of distributed generation (DG) resources in recent years. Installing DG units in a distribution network may result in positive impacts, such as voltage profile improvement and loss reduction, and negative impacts, such as an increase in the short-circuit level. These impacts depend on the type, capacity, and place of these resources. Therefore, finding the optimal place and capacity of DG resources is of crucial importance. Accordingly, this paper is aimed at finding the optimal place and capacity …
Capability-Based Task Allocation In Emergency-Response Environments: A Coalition-Formation Approach, Afsaneh Fatemi, Kamran Zamanifar, Naser Nematbakhsh
Capability-Based Task Allocation In Emergency-Response Environments: A Coalition-Formation Approach, Afsaneh Fatemi, Kamran Zamanifar, Naser Nematbakhsh
Turkish Journal of Electrical Engineering and Computer Sciences
This paper addresses coalition formation, based on agent capabilities, centered on task allocation in emergency-response environments (EREs). EREs are environments that need fast task completion as their main requirement. We propose a team-based organization model, based on an existing organization model for adaptive complex systems. The model has some key characteristics that are beneficial for EREs: agents act in dynamic, open domains; agents collaborate in completing group tasks; agents may have similar types of capabilities, but at different levels; tasks need different agent capabilities, at collective different levels; and agents are supervised in a partially decentralized manner. We formulate task …
A Control Algorithm For A Simple Flywheel Energy Storage System To Be Used In Space Applications, Kutlay Aydin, Mehmet Ti̇mur Aydemi̇r
A Control Algorithm For A Simple Flywheel Energy Storage System To Be Used In Space Applications, Kutlay Aydin, Mehmet Ti̇mur Aydemi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
Flywheels have been under consideration to be used for energy storage purposes in space applications to replace electrochemical batteries. An electrical machine is used as a motor to store kinetic energy when the solar energy is available, and then the stored energy is converted back to electrical energy by running the machine as a generator when the solar energy is no longer available. A control algorithm for these systems is proposed in this paper. The proposed method uses a current reference rather than a speed reference in the motor mode. A method is also suggested to properly determine the current …
Survey Of Power Quality In Turkish National Transmission Network, Celal Kocatepe, Bedri̇ Kekezoğlu, Altuğ Bozkurt, Recep Yumurtaci, Aslan İnan, Oktay Arikan, Mustafa Baysal, Yener Akkaya
Survey Of Power Quality In Turkish National Transmission Network, Celal Kocatepe, Bedri̇ Kekezoğlu, Altuğ Bozkurt, Recep Yumurtaci, Aslan İnan, Oktay Arikan, Mustafa Baysal, Yener Akkaya
Turkish Journal of Electrical Engineering and Computer Sciences
Harmonic distortion and flicker severity have become the main concerns in power transmission networks. Different types of harmonic and flicker sources exist in power systems, such as arc furnaces and cycloconverters. A power quality problem found in networks can cause additional temperature rise, losses, noise, and irritation in the lighting equipment. The aim of this study is to identify the level of harmonics and flicker in the 380-kV transmission network of Turkey. The measurement and analysis are performed using a specially developed power quality analyzer. The effects of harmonics and flicker on the network are discussed based on real measurement …
Compact Microstrip Antenna With Metamaterial For Wideband Applications, Han Xiong, Jing-Song Hong, Ming-Tao Tan, Bing Li
Compact Microstrip Antenna With Metamaterial For Wideband Applications, Han Xiong, Jing-Song Hong, Ming-Tao Tan, Bing Li
Turkish Journal of Electrical Engineering and Computer Sciences
An improved metamaterial antenna, with a compact size of 27.8 x 31.9 x 0.794 mm^3, fed by an offset-microstrip line, is proposed. The total size is slightly reduced and the measured impedance bandwidth is 4.08-7.83 GHz for a return loss of \mid S_{11}\mid < -10 dB. Compared with the original patch antenna, the bandwidth of the proposed antenna is 550 MHz broader and has a lower resonant frequency. The simulated gain of the antenna is more than 2 dB, with a peak of about 6 dB at 6.8 GHz. Moreover, the antenna has strong radiation in the horizontal direction for some specific applications within the entire band.
A Temporal Xml Data Model In Anaesthesia Information Systems, Oya Ünlü Duygulu, Taflan İmre Gündem
A Temporal Xml Data Model In Anaesthesia Information Systems, Oya Ünlü Duygulu, Taflan İmre Gündem
Turkish Journal of Electrical Engineering and Computer Sciences
Time information is an important aspect of a health information system. Health information cannot be represented and queried correctly without time in medical research, auditing, and medicolegal cases. Extensible Markup Language (XML) is being used in health information systems and has been formerly proposed as a data model for anaesthesia information systems. In this paper, we propose incorporating time into an XML model for anaesthesia information systems. A new storage structure and a temporal index structure are proposed in order to store temporal XML data and process time queries efficiently. In our proposed model, time has 4 dimensions: valid time, …
Design Of Adaptive Compensators For The Control Of Robot Manipulators Robust To Unknown Structured And Unstructured Parameters, Recep Burkan
Design Of Adaptive Compensators For The Control Of Robot Manipulators Robust To Unknown Structured And Unstructured Parameters, Recep Burkan
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a new adaptive-robust control approach for robot manipulators is developed. The adaptive-robust control law is not only robust to unknown structured parameters but also robust to unknown unstructured parameters such as unstructured joint friction and disturbances. The bounded disturbances and unstructured model are taken into account in a dynamic model and it is assumed that the structured and unstructured parameters are unknown. The structured and unstructured parameters are distinguished between parameters and these parameters are treated separately. Next, new parameter estimation functions are developed for each of the 2 uncertainty groups. After that, the developed dynamic adaptive …
An Event-Driven Wsn Mac Protocol Design Based On Active Node And Dynamic Time Slot Allocation, Nükhet Sazak, İsmai̇l Ertürk, Etem Köklükaya, Murat Çakiroğlu
An Event-Driven Wsn Mac Protocol Design Based On Active Node And Dynamic Time Slot Allocation, Nükhet Sazak, İsmai̇l Ertürk, Etem Köklükaya, Murat Çakiroğlu
Turkish Journal of Electrical Engineering and Computer Sciences
The unique features of wireless sensor networks (WSNs) make them suitable for a wide range of applications in many different areas. However, with many of the protocols and algorithms used in traditional wireless networks, it is usually neither feasible nor possible to apply them directly to WSNs due to the strict resource constraints of tiny sensor nodes. Moreover, application-specific approaches for communication protocols are usually imposed since WSN applications have distinct requirements. In this study, event-driven WSN applications, where a number of sensor nodes are randomly and densely deployed in remote and difficult to reach locations, are targeted. In such …
Feature-Based Fault Detection Of Industrial Gas Turbines Using Neural Networks, Abbas Rasaienia, Behzad Moshiri, Mohammadamin Moezzi
Feature-Based Fault Detection Of Industrial Gas Turbines Using Neural Networks, Abbas Rasaienia, Behzad Moshiri, Mohammadamin Moezzi
Turkish Journal of Electrical Engineering and Computer Sciences
Gas turbine (GT) fault detection plays a vital role in the minimization of power plant operation costs associated with power plant overhaul time intervals. In other words, it is helpful in generating pre-alarms and paves the way for corrective actions in due time before incurring major equipment failures. Hence, finding an efficient fault detection technique that is applicable in the online operation of power plants involved with minor computations is an urgent need in the power generation industry. Such a method is studied in this paper for the V94.2 class of GTs. As the most leading stage for developing a …
A New Tool For Qt Interval Analysis During Sleep In Healthy And Obstructive Sleep Apnea Subjects: A Study On Women, Kemal Ali̇can Kaya, Bülent Yilmaz
A New Tool For Qt Interval Analysis During Sleep In Healthy And Obstructive Sleep Apnea Subjects: A Study On Women, Kemal Ali̇can Kaya, Bülent Yilmaz
Turkish Journal of Electrical Engineering and Computer Sciences
By monitoring the Q wave/T wave (QT) interval computed from electrocardiography (ECG) signals during sleep, it is possible to create a link between the ventricular repolarization and sleep stages. In this study, we aimed to find a robust and simple approach to automatically determine the fiducials on each 30-s sleep epoch, such as the Q, R, and T-end points, on long sleep ECG recordings in order to statistically analyze the effect of obstructive sleep apnea (OSA) and sleep stages on QT intervals. This is a retrospective study in which the ECG data extracted from the polysomnography recordings of 7 healthy …
Operational Characteristics Of A Filtering Rectifier Transformer For Industrial Power Systems, Zhiyu Zhao, Longfu Luo, Jiazhu Xu, Thanhngoc Tran, Zhiwen Zhang
Operational Characteristics Of A Filtering Rectifier Transformer For Industrial Power Systems, Zhiyu Zhao, Longfu Luo, Jiazhu Xu, Thanhngoc Tran, Zhiwen Zhang
Turkish Journal of Electrical Engineering and Computer Sciences
Many conventional methods focus on reducing the harmful impact of the poor power quality in industrial rectifier systems, but they focus more on the harmonic problems of the utility grid than they do on that of the rectifier transformer; hence, the rectifier transformer would still be adversely affected by harmonic pollution. In order to solve the problem, a filtering rectifier transformer is proposed that adopts a harmonic current drainage system that incorporates tertiary winding and tuned harmonic filters. The impedance of the tertiary winding is specially designed and the tuned harmonic filters work together to restrain the harmonic current and …