Abc-Based Stacking Method For Multilabel Classification,
2019
TÜBİTAK
Abc-Based Stacking Method For Multilabel Classification, Weimin Ding, Shengli Wu
Turkish Journal of Electrical Engineering and Computer Sciences
Multilabel classification is a supervised learning problem wherein each individual instance is associated with multiple labels. Ensemble methods are effective in managing multilabel classification problems by creating a set of accurate, diverse classifiers and then combining their outputs to produce classifications. This paper presents a novel stacking-based ensemble algorithm, ABC-based stacking, for multilabel classification. The artificial bee colony algorithm, along with a single-layer artificial neural network, is used to find suitable meta-level classifier configurations. The optimization goal of the meta-level classifier is to maximize the average accuracy of classification of all the instances involved. We run an experiment on 10 …
Rough Fuzzy Cuckoo Search For Triclustering Microarray Gene Expression Data,
2019
TÜBİTAK
Rough Fuzzy Cuckoo Search For Triclustering Microarray Gene Expression Data, Swathypriyadharsini Palaniswamy, Premalatha K
Turkish Journal of Electrical Engineering and Computer Sciences
Analyzing time series microarray gene expression data is a computational challenge due to its three-dimensional characteristics. Triclustering techniques are applied to three-dimensional data for mining similarly expressed genes under a subset of conditions and time points. In this work, a novel rough fuzzy cuckoo search algorithm is proposed for triclustering genes across samples and time points simultaneously. By applying the upper and lower approximation of rough set theory and the objective function of fuzzy k-means, rough fuzzy k-means was incorporated into a cuckoo search to handle the uncertainty of the data. The proposed method was applied to three real-life time …
Performance Evaluation Of Webrtc-Based Online Consultation Platform,
2019
TÜBİTAK
Performance Evaluation Of Webrtc-Based Online Consultation Platform, Ergün Alperay Tarim, Hüseyi̇n Cumhur Teki̇n
Turkish Journal of Electrical Engineering and Computer Sciences
Information technologies give patients the opportunity to communicate with medical professionals remotely. Telemedicine uses these technologies to provide advanced healthcare and medical services. We present a medical online consultation application based on Web Real-Time Communications (WebRTC) technology enabling chat, audio, and video calls. Communication architecture and protocols of the application are explained in detail. Additionally, the user interface of the application is shown via performed calls. The application is tested and evaluated on different network connections (3G, 4G, local, and DSL) and different browsers and mobile operating systems (Android, Chrome, Firefox, Internet Explorer, iOS, Opera, Safari). During calls, communication quality …
A New Technique For The Measurement And Assessment Of Carotid Artery Wall Vibrations Using Ultrasound Rf Echoes,
2019
TÜBİTAK
A New Technique For The Measurement And Assessment Of Carotid Artery Wall Vibrations Using Ultrasound Rf Echoes, Samrand Sharifi, Hamid Behnam, Zahra Alizadeh Sani
Turkish Journal of Electrical Engineering and Computer Sciences
Atherosclerosis is known as the leading cause of heart attacks and brain strokes. One of the symptoms of this disease is the reduction of artery wall motion caused by age. This study presents a novel method to extract high frequency components of wall motion, wall vibrations, based on discrete wavelet transform. The fractal dimension, largest Lyapunov exponent, and spectral entropy are then analyzed to indicate the chaotic behavior in wall vibrations. Phase information from demodulated radiofrequency signals is extracted and the entropy of phase-difference is computed as a statistical measure for better characterization of the artery wall tissue. The results …
Automatic Prostate Segmentation Using Multiobjective Active Appearance Model In Mr Images,
2019
TÜBİTAK
Automatic Prostate Segmentation Using Multiobjective Active Appearance Model In Mr Images, Ahad Salimi, Mohammad Ali Pourmina, Mohamma-Shahram Moien
Turkish Journal of Electrical Engineering and Computer Sciences
Prostate cancer is the second largest cause of mortality among men. Prostate segmentation, i.e. the precise determination of the prostate region in magnetic resonance imaging (MRI), is generally used for prostate volume measurement, which can be used as a potential prostate cancer indicator. This paper presents a new fully automatic statistical model called the multiobjective active appearance model (MOAAM) for prostate segmentation in MR images. First, in the training stage, the appearance model, including the shape and texture model, is developed by applying principal component analysis to the training images, already outlined by a physician. Then noise and roughness are …
Heart Attack Mortality Prediction: An Application Of Machine Learning Methods,
2019
TÜBİTAK
Heart Attack Mortality Prediction: An Application Of Machine Learning Methods, Issam Salman
Turkish Journal of Electrical Engineering and Computer Sciences
The heart is an important organ in the human body, and acute myocardial infarction (AMI) is the leading cause of death in most countries. Researchers are doing a lot of data analysis work to assist doctors in predicting the heart problem. An analysis of the data related to different health problems and its functions can help in predicting the wellness of this organ with a degree of certainty. Our research reported in this paper consists of two main parts. In the first part of the paper, we compare different predictive models of hospital mortality for patients with AMI. All results …
Ingaas Nbn Swir Detector Design With Lattice-Matched Inalgaas Barrier,
2019
TÜBİTAK
Ingaas Nbn Swir Detector Design With Lattice-Matched Inalgaas Barrier, Fati̇h Uzgur, Serdar Kocaman
Turkish Journal of Electrical Engineering and Computer Sciences
Dark current optimization with band gap engineering has been numerically studied for InGaAs nBn type infrared photodetectors. Undoped InAlGaAs grading layers are utilized in constructing the barrier and dipole delta-doped layers are placed in both sides of the graded layers for eliminating valence band offset. As a result, the high band gap barrier layer blocks the majority carriers and allows minority carrier flow while minimizing various dark current components, as expected from an nBn detector. Substantial improvement has been shown in the dark current level without compromising any photoresponse compared to the conventional pn junction and recently proposed all InGaAs …
Sensorless Second-Order Switching Surface For A Three-Level Boost Converter,
2019
TÜBİTAK
Sensorless Second-Order Switching Surface For A Three-Level Boost Converter, Tarek Messikh, Nasrudin Abd Rahim, Saad Mekhilef
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a sensorless second-order switching surface to control a three-level boost converter (TLBC). A predictive current method is proposed to reduce the number of sensors in the normal second-order switching surface method. Based on a developed model of the TLBC, the current is estimated and a switching surface is formulated in the state-energy plane. Simulation and hardware tests are carried out to verify the viability and the effectiveness of the proposed control technique. Results obtained show a good performance of the converter in term of DC-bus balancing and fast dynamic response under sudden load change.
Investigating The Occurrence Mechanism Of Cytokine-Like Formations By The Electromagnetic Approach,
2019
TÜBİTAK
Investigating The Occurrence Mechanism Of Cytokine-Like Formations By The Electromagnetic Approach, Cahi̇t Canbay, Özgün Palak, Aydoğa Kallem
Turkish Journal of Electrical Engineering and Computer Sciences
This study aims to elucidate the production mechanism of cytokine-like formations secreted from T cells and similar cells by electromagnetic modeling techniques. Three Hertz dipole antennas polarized in arbitrary directions were placed without touching each other at the center of spherical T-cell models to test the Canbay hypothesis about the formation mechanism of cytokines (CHAFMOC) on T-cell surfaces. A dielectrophoretic force field was created within the gelatin layer of the T-cell model. The prepared control and electromagnetically stimulated T-cell model samples were incubated in water in a glass container in a Faraday cage for the specified period and then photographed. …
Outage Probability Analysis And Adaptive Combiner For Multiuser Multipolarized Antenna Systems,
2019
TÜBİTAK
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 …
Electron Energy Loss Spectroscopy Simulation By A Frequency Domain Surface Integral Equation Solver,
2019
TÜBİTAK
Electron Energy Loss Spectroscopy Simulation By A Frequency Domain Surface Integral Equation Solver, İsmai̇l Enes Uysal
Turkish Journal of Electrical Engineering and Computer Sciences
Plasmonic nanoparticles have been mostly studied using conventional light sources. Recently, electron energy loss spectroscopy (EELS) has started to be used to analyze plasmonic nanoparticles where incident electromagnetic fields are created by swift electrons. To accurately simulate EELS experiments, several numerical methods have been adapted. In this paper, a frequency domain surface integral equation (FDSIE) solver is modified to simulate EELS for plasmonic nanoparticles of gold and silver. Accuracy and versatility of the proposed FDSIE solver are shown by several numerical examples and compared to existing numerical, analytical, and experimental results.
Bow-Tie-Shaped Wideband Conformal Antenna With Wide-Slot For Gps Application,
2019
TÜBİTAK
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 …
Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay,
2019
TÜBİTAK
Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem
Turkish Journal of Electrical Engineering and Computer Sciences
Multilateral teleoperation is an extension of bilateral/haptic teleoperation framework to multiple operators/robots and finds applications in haptic training. As in bilateral teleoperation, time delay is an important problem, and stability and transparency, which quantifies the performance of the teleoperation system, are critical in the design of multilateral control systems. This paper proposes a novel three-channel-based multilateral control architecture with damping injection to guarantee delay-independent L2 stability and high transparency in multilateral teleoperation systems. The theoretical and computational analyses are verified with experiment results.
Optimal Contract Pricing Of Load Aggregators For Direct Load Control In Smartdistribution Systems,
2019
TÜBİTAK
Optimal Contract Pricing Of Load Aggregators For Direct Load Control In Smartdistribution Systems, Ali Shayegan-Rad, Ali Zangeneh
Turkish Journal of Electrical Engineering and Computer Sciences
Distribution system operators (DSOs) are interested in demand side participation programs as an efficient and secure resource to manage electricity supply and demand. However, it is usually difficult for DSOs to aggregate demand response of large/small consumers. Thus, in some electricity markets, an entity called an aggregator is defined to aggregate the load response of consumers. In this paper a bilevel scheduling model is proposed to determine the long-term optimal contract price between the DSO and aggregator for executing direct load control in smart distribution systems. The DSO and aggregator are considered as two different agents with individual objectives in …
Optimal Placement Of Switching And Protection Devices In Radial Distribution Networks To Enhance System Reliability Using The Ahp-Pso Method, Masoud Amohadi, Mahmud Fotuhi Firuzabad
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a new method to determine the optimal number and locations of autorecloser and sectionalizer switches (AR/S) in distribution networks. The costs of AR/S investment, switch maintenance, and undistributed energy as well as reliability coefficients are considered in the objective function. Reliability parameters such as SAIFI, SADI, MAIFI, and ENS are evaluated in the case study system. As a new method, the weights of the reliability parameters are obtained by decision-makers using the analytical hierarchy process (AHP). The optimal size, type, and location of automatic switches are determined by minimizing the objective function using the particle swarm optimization …
A Developed Flywheel Energy Storage With Built-In Rotating Supercapacitors,
2019
TÜBİTAK
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 …
Thyristor-Based "Phase Hopping" Frequency Conversion Technique,
2019
TÜBİTAK
Thyristor-Based "Phase Hopping" Frequency Conversion Technique, Zhenwang Xu, Jiarui Zhang, Yuchun Yi, Cheng Chen, Jiaqi Yu, Wei Mei, Daiwei Feng
Turkish Journal of Electrical Engineering and Computer Sciences
This study proposes a new AC/AC "phase hopping" frequency conversion method based on the analyses of the disadvantages of the conventional cosine wave-crossing method. The advantages of this new method include no circulating current, no dead time, and an output frequency close to the power frequency. This study also introduces the basic principles of the "phase hopping" method and analyzes these principles combined with the voltage phase-changing comparison to that of the cosine wave-crossing method. The "phase hopping" principles are used to analyze the generation of thyristor trigger pulses, including the generation time and duration. A simulation is conducted in …
Evaluation Of Power System Robustness In Order To Prevent Cascading Outages,
2019
TÜBİTAK
Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare
Turkish Journal of Electrical Engineering and Computer Sciences
Power system robustness against overload condition is a challenging issue in the fields of power system planning and operation. In this paper, two indices are proposed to evaluate power system robustness. The proposed indices are used to identify critical lines whose failure is due to overload, leading the power system to cascading outages and blackout. The first proposed index is a linear index. The second index is based on graph theory metrics. To prevent cascading outages, system robustness is calculated for all N-1 and N-2 contingencies. The lines whose outages lead to the smallest robustness values are considered as critical …
Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement,
2019
TÜBİTAK
Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi
Turkish Journal of Electrical Engineering and Computer Sciences
This paper analyzes the optimal control strategy of PMSG-based wind farms during faults in order to improve the transient stability of a power system with a high penetration rate of wind power. The investigated control strategies are the unity power factor (UPF), reactive power control (RPC), and particularly the concept of virtual synchronous machine (VSM). The transient stability level is assessed using the critical clearing time index, which was calculated based on trajectory sensitivity analysis. In light of the obtained results, it was found that RPC gives the best transient stability level, followed by the classical VSM control. Hence, an …
A Fuzzy Model Of Directional Relationships From The Phi-Descriptor,
2019
TÜBİTAK
A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul
Turkish Journal of Electrical Engineering and Computer Sciences
Directional spatial relationships are a category of spatial relationships and have applications in the fields of image processing, geographic information systems, natural language processing, and robot navigation. They can be directly extracted from images or can be interpreted from a type of image descriptors called the relative position descriptors. Examples of relative position descriptors are the angle histogram, the force histogram, and the recently proposed phi-descriptor. So far, fuzzy models of directional spatial relationships from the angle histogram and force histograms have been proposed in the literature. These include the compatibility method, the aggregation method, and the method of effective …
