Physical Sciences and Mathematics Commons^™

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 …

Presentation Of A Multilayer Nanosensor For Gas Detection By Palladium-Membrane With Emphasis On Hydrogen Gas, Ali Mohammad Noorian, Mahdi Sadeghi, Hassan Rasooli Saghai

Turkish Journal of Electrical Engineering and Computer Sciences

Hydrogen gas sensors, based on palladium membranes, have considerable applications in areas such as industry, aerospace, and green energy monitoring. In this paper, we propose a surface plasmon resonance nanosensor, in which the main metal sensor is taken to be gold with a thin nanolayer of palladium membrane. The reason we chose palladium is its exceptional property of having high permittivity to hydrogen penetration. In this paper, formation of palladium hydride (PdH$_{x}$, where x = H / Pd) is achieved and simulation is provided using Materials Studio software. Based on an intermediate assumption, a semiconductor gold composite layer is used …

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. …

Improved Iir-Type Fractional Order Digital Integrators Using Cat Swarm Optimization, Shibendu Mahata, Suman Kumar Saha, Rajib Kar, Durbadal Mandal

Turkish Journal of Electrical Engineering and Computer Sciences

Design of wideband infinite impulse response (IIR) digital fractional order integrators (DFOIs) based on a bio-inspired metaheuristic optimization approach called the cat swarm optimization (CSO) algorithm is presented in this paper. To investigate the efficiency of the proposed approach, the CSO-based DFOIs are evaluated against those of the approximations designed using real-coded genetic algorithm (RGA), standard particle swarm optimization (PSO), and differential evolution (DE) by different magnitude and phase response error metrics. Simulation results reveal the better frequency response of the CSO-based DFOIs in comparison with the competing designs. Both parametric and nonparametric statistical hypothesis tests validate the performance consistency …

Wide Bandwidth Cmos Four-Quadrant Mixed Mode Analogue Multiplier Using A Second Generation Current Conveyor Circuit, Thouraya Ettaghzouti, Nejib Hassen, Karima Garradhi, Kamel Besbes

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new realization for a CMOS four-quadrant analogue multiplier. The proposed circuit is composed of three second generation current conveyor circuits (CCII), two NMOS transistors operating in the linear region, and four passive resistances. It can be operated in current mode and voltage mode without changing the circuit topology. The simulations results of the proposed mixed mode multiplier are verified by TSPICE simulator based on the BSIM3v3 transistor model for TSMC 0.18 $\mu $m CMOS process available from MOSIS at 25 $^{\circ}$C with $\pm $0.8 V supply voltage. Through the use of resistive compensation with different passive …

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 …

Transient- And Probabilistic Neural Network-Based Fault Classification In Ehv Three-Terminal Lines, Ravi Kumar Varma Bhupatiraju, Venkata Sesha Samba Siva Sarma Dhanikonda, Venkata Ramana Rao Pulipaka

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a fast and accurate fault classifier for three-terminal transmission circuits. Traditional phasor-based methods fail to meet the high speed requirements of modern power grids and necessitate alternative solutions. The transient-based schemes use advanced signal processing techniques to achieve fast and accurate fault classification. As the three-terminal lines experience very pronounced transients during faults, the proposed method makes use of the fault-generated transients to quickly and correctly classify the fault. Many transient-based schemes fail to give the required accuracy since the transient patterns with relay-measured signals are highly influenced by fault conditions. Therefore, a thorough analysis of transient …

Effect Of Intuitionistic Fuzzy Normalization In Microarray Gene Selection, Prema Ramasamy, Premalatha Kandhasamy

Turkish Journal of Electrical Engineering and Computer Sciences

Analysis of gene expression data is essential in microarray gene expression in order to retrieve the required information. Gene expression data generally contain a large number of genes but a small number of samples. The complicated relations among the different genes make analysis more difficult, and removing irrelevant genes improves the quality of results. This paper presents two fuzzy preprocessing techniques, using a fuzzy set (FS) and intuitionistic fuzzy set (IFS), to normalize datasets. In the feature selection part, four statistical methods were used. Using three publicly available gene expression datasets, the fuzzy normalization techniques were compared with two standard …

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 …

Circularly Polarized Implantable Antenna Characterization For Retinal Prosthesis Systems, Ademola Oluwaseun Kaka, Mehmet Toycan, Stuart Douglas Walker

Turkish Journal of Electrical Engineering and Computer Sciences

We describe a miniaturized antenna design for retinal prosthesis applications that enhances data transfer between the implant and external camera. The circularly polarized and conformal 2.4--2.48 GHz microstrip patch antenna was simulated inside the vitreous humor and is intended for biomedical applications. Modified Hilbert and serpentine geometries were used for the proposed implant antenna design. Capacitive radiator loading offered miniaturized dimensions of 5.8 $\times $ 6.5 $\times $ 2 mm$^{3}$ (width $\times $ height $\times $ thickness mm$^{3})$. A truncated design enhanced the intrinsic circular polarization characteristics to $>$3 dB axial ratio. Polydimethylsiloxane substrate and superstrate materials were used …

Two-Stage Feature Selection Using Ranking Self-Adaptive Differential Evolution Algorithm For Recognition Of Acceleration Activity, Muhammad Noorazlan Shah Zainudin, Md Nasir Bin Sulaiman, Norwati Mustapha, Thinagaran Perumal, Raihani Mohamed

Turkish Journal of Electrical Engineering and Computer Sciences

Widespread research on activity recognition is becoming an imperative topic for improving the quality of human health. The fast development of sensing technology has become a fundamental platform for researchers to implement a system that could fulfill human needs. Due to privacy interests and low cost, wearable sensing technology is used in numerous physical activity monitoring and recognition systems. While these systems have proved to be successful, it is crucial to pay attention to the less relevant features to be classified. In such circumstances, it might happen that some features are less meaningful for describing the activity. Less complex and …

Bagged Tree Classification Of Arrhythmia Using Wavelets For Denoising, Compression, And Feature Extraction, Özgür Tomak, Temel Kayikçioğlu

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 …

A Novel Model For Minimizing Unnecessary Handover In Heterogeneous Networks, Babatunji Omoniwa, Riaz Hussain, Junaid Ahmed, Adeel Iqbal, Ahmed Murkaz, Qadeer Ul-Hasan, Shahzad Ali Malik

Turkish Journal of Electrical Engineering and Computer Sciences

Over the years, vertical handover necessity estimation has attracted the interest of numerous researchers. Despite the attractive benefits of integrating different wireless platforms, mobile users are confronted with the issue of detrimental handover. This paper uses extensive geometric and probabilistic techniques to develop a realistic and novel model for the coverage area of a wireless local area network (WLAN) cell with an aim to minimize unnecessary handover and handover failure of a mobile node (MN) traversing the WLAN cell from a third-generation network. The dwell time is estimated along with the threshold values to ensure an optimal handover decision by …

Reduction Of Pmus Via Hybrid Pmu-Rtu Communication Changeover In The Case Of Cyberattack On Vulnerable Power Transmission Lines, Noorollah Fardad, Soodabeh Soleymani, Faramarz Faghihi

Turkish Journal of Electrical Engineering and Computer Sciences

A power grid strictly depends on information and communication technology. The key role of real-time measurement and information control for the reliable operation of a power grid is the responsibility of the phase measurement units (PMUs). As smart power grids encounter a variety of unauthorized malicious accesses such as cyberattacks, PMU placement is an important problem. In this study, a new algorithm was proposed to specify the minimum number of PMUs in the case of cyberattacks on their communication lines and equipment. In order to analyze complete observability of the distribution system, a range of probable contingencies for the vulnerable …

Minimizing Path Loss Prediction Error Using K-Means Clustering And Fuzzy Logic, Wiyada Bhupuak, Siraphop Tooprakai

Turkish Journal of Electrical Engineering and Computer Sciences

This research proposes an algorithmic scheme based on k-means clustering and fuzzy logic to minimize path loss prediction error. The proposed k-means fuzzy scheme concurrently utilizes the area topographical variability and multiple path loss prediction models to mitigate the prediction error inherent in the independent use of a conventional path loss model. Vegetation density, manmade structures, and transmission-receiver distances are the fuzzy inputs and the conventional path loss models the output: the free space loss, Walfisch--Ikegami, HATA, ECC-33, Stanford University Interim, and ERICSSON models. The experimental results show that the path loss prediction error of the k-mean fuzzy scheme is …

A Comparative Analysis Of 1-Level Multiplier-Free Discrete Wavelet Transform Implementations On Fpgas, Husam Alzaq, Burak Berk Üstündağ

Turkish Journal of Electrical Engineering and Computer Sciences

In this article, we investigated the design and implementation aspects of multilevel discrete wavelet transform (DWT) by employing a finite impulse response filter on field programmable gate array platform. We presented two key multiplication-free architectures, namely, the distributed arithmetic algorithm (DAA) and residue number system (RNS). Our goal is to estimate the performance requirements and hardware resources for each approach, allowing for selection of the proper algorithm and implementation of multilevel DAA- and RNS-based DWT. The design has been implemented and synthesized in Xilinx Virtex 6 ML605, taking advantage of Virtex 6?s embedded block RAMs. The results reveal that the …

Improving The Sensitivity And Accuracy Of Microcantilever Biosensors By A Truss Structure Within Air Medium, Soheyla Elmi, Zahra Elmi

Turkish Journal of Electrical Engineering and Computer Sciences

Early diagnosis is a very fundamental issue in treating most diseases and for this purpose microcantilevers are very effective and reliable devices. In this work, four models of biosensor-based microcantilever are compared and a novel design with high sensitivity, quality factor, and accuracy is proposed. A truss structure is designed near the anchored end of the microcantilever, which improves the sensitivity in order to increase detection accuracy. A linear relationship between resonance frequency shift and masses has been estimated for all the designs. High quality factor, which increases the accuracy of measurement, is taken into account as the other benefit …

A Dynamic Channel Assignment Method For Multichannel Multiradio Wireless Mesh Networks, Şafak Durukan Odabaşi, Abdül Hali̇m Zai̇m

Turkish Journal of Electrical Engineering and Computer Sciences

The popularity of wireless communication accelerates research on new technologies that are required to satisfy users' needs. Wireless mesh networks (WMNs), which are additional access technologies instead of being a renewed one, have an important place among next-generation wireless networks. In particular, the capability of working without any infrastructure is the most outstanding advantage of WMNs. There are many studies aimed at WMNs, particularly channel assignment and routing methods for multichannel multiradio structures that provide higher data capacity. Interference, which has a direct effect on the quality of communication, is still a challenge to be addressed. In this study, multichannel …

Secure Access Control In Multidomain Environments And Formal Analysis Of Model Specifications, Fatemeh Nazerian, Homayun Motameni, Hossein Nematzadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Distributed multiple organizations interact with each other. If the domains employ role-based access control, one method for interaction between domains is role-mapping. However, it may violate constraints in the domains such as role hierarchy, separation of duty, and cardinality. Therefore, autonomy of the domains is lost. This paper proposes secure interoperation in multidomain environments. For this purpose, a cross-domain is created by foreign permission assignment. In an effort to maintain the autonomy of every domain, several rules are defined formally. Then, a decentralized scheme is used to provide permission mapping between domains. At the next stage, the proposed cross-domain is …

Prediction Of Gross Calorific Value Of Coal Based On Proximate Analysis Using Multiple Linear Regression And Artificial Neural Networks, Mustafa Açikkar, Osman Si̇vri̇kaya

Turkish Journal of Electrical Engineering and Computer Sciences

Gross calorific value (GCV) of coal was predicted by using as-received basis proximate analysis data. Two main objectives of the study were to develop prediction models for GCV using proximate analysis variables and to reveal the distinct predictors of GCV. Multiple linear regression (MLR) and artifcial neural network (ANN) (multilayer perceptron MLP, general regression neural network GRNN, and radial basis function neural network RBFNN) methods were applied to the developed 11 models created by different combinations of the predictor variables. By conducting 10-fold cross-validation, the prediction accuracy of the models has been tested by using $ R^2 $, $ RMSE …

Real Time Spectroscopic Ellipsometry Analysis Of First Stage Cuin1-Xgaxse2 Growth: Indium-Gallium Selenide Co-Evaporation, Puja Pradhan, Puruswottam Aryal, Dinesh Attygalle, Abdel-Rahman Ibdah, Prakash Koirala, Jian Li, Khagendra P. Bhandari, Geethika K. Liyanage, Randy J. Ellingson, Michael J. Heben, Sylvain Marsillac, Robert W. Collins, Nikolas J. Podraza

Electrical & Computer Engineering Faculty Publications

Real time spectroscopic ellipsometry (RTSE) has been applied for in-situ monitoring of the first stage of copper indium-gallium diselenide (CIGS) thin film deposition by the three-stage co-evaporation process used for fabrication of high efficiency thin film photovoltaic (PV) devices. The first stage entails the growth of indium-gallium selenide (In_1-xGa_x)₂Se₃ (IGS) on a substrate of Mo-coated soda lime glass maintained at a temperature of 400 °C. This is a critical stage of CIGS deposition because a large fraction of the final film thickness is deposited, and as a result precise compositional control is desired in order to …

Fast Identification Of High Utility Itemsets From Candidates, Jun-Feng Qu, Mengchi Liu, Chunsheng Xin, Zhongbo Wu

Electrical & Computer Engineering Faculty Publications

High utility itemsets (HUIs) are sets of items with high utility, like profit, in a database. Efficient mining of high utility itemsets is an important problem in the data mining area. Many mining algorithms adopt a two-phase framework. They first generate a set of candidate itemsets by roughly overestimating the utilities of all itemsets in a database, and subsequently compute the exact utility of each candidate to identify HUIs. Therefore, the major costs in these algorithms come from candidate generation and utility computation. Previous works mainly focus on how to reduce the number of candidates, without dedicating much attention to …

Plasma Medicine: A Brief Introduction, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

This mini review is to introduce the readers of Plasma to the field of plasma medicine. This is a multidisciplinary field of research at the intersection of physics, engineering, biology and medicine. Plasma medicine is only about two decades old, but the research community active in this emerging field has grown tremendously in the last few years. Today, research is being conducted on a number of applications including wound healing and cancer treatment. Although a lot of knowledge has been created and our understanding of the fundamental mechanisms that play important roles in the interaction between low temperature plasma and …

High-Order Integral Equation Methods For Quasi-Magnetostatic And Corrosion-Related Field Analysis With Maritime Applications, Robert Pfeiffer

Theses and Dissertations--Electrical and Computer Engineering

This dissertation presents techniques for high-order simulation of electromagnetic fields, particularly for problems involving ships with ferromagnetic hulls and active corrosion-protection systems.

A set of numerically constrained hexahedral basis functions for volume integral equation discretization is presented in a method-of-moments context. Test simulations demonstrate the accuracy achievable with these functions as well as the improvement brought about in system conditioning when compared to other basis sets.

A general method for converting between a locally-corrected Nyström discretization of an integral equation and a method-of-moments discretization is presented next. Several problems involving conducting and magnetic-conducting materials are solved to verify the accuracy …

Self-Image Multimedia Technologies For Feedforward Observational Learning, Nkiruka M. A. Uzuegbunam

Theses and Dissertations--Electrical and Computer Engineering

This dissertation investigates the development and use of self-images in augmented reality systems for learning and learning-based activities. This work focuses on self- modeling, a particular form of learning, actively employed in various settings for therapy or teaching. In particular, this work aims to develop novel multimedia systems to support the display and rendering of augmented self-images. It aims to use interactivity (via games) as a means of obtaining imagery for use in creating augmented self-images. Two multimedia systems are developed, discussed and analyzed. The proposed systems are validated in terms of their technical innovation and their clinical efficacy in …

Automated Cfd Optimization To Maximize Wind Farms Performance And Land Use, Rafael Valotta Rodrigues

Electronic Theses and Dissertations

In this research, a computational system was designed to analyze and optimize the layout of wind farms under variable operational conditions. At first, a wind turbine computational fluid dynamic (CFD) model was developed covering the near wake. The near wake flow field was validated against near wake velocity data from the MEXICO experiment. The CFD simulation demonstrated that the tip speed ratio and the pitch angle greatly influence the near wake behavior, affecting the velocity deficit and the turbulence intensity profile in this region. The CFD model was extended to cover the far wake, aiming to become a computational tool …

Dynamic Output Feedback Invariants Of Full Relative Degree Nonlinear Siso Systems, W. Steven Gray, Luis A. Duffaut Espinosa

Electrical & Computer Engineering Faculty Publications

The goal of this paper is to explicitly describe invariants of a plant described by a Chen--Fliess series under a class of dynamic output feedback laws using earlier work by the authors on feedback transformation groups. The main result requires the rather strong assumption that the plant has a generating series with both finite Lie rank and full relative degree. In which case, there is no loss of generality in working with state space realizations of the plant. An additional genericness assumption regarding the normal form of the plant is also required, but as shown by the examples, this condition …

Offline And Online Density Estimation For Large High-Dimensional Data, Aref Majdara

Dissertations, Master's Theses and Master's Reports

Density estimation has wide applications in machine learning and data analysis techniques including clustering, classification, multimodality analysis, bump hunting and anomaly detection. In high-dimensional space, sparsity of data in local neighborhood makes many of parametric and nonparametric density estimation methods mostly inefficient.

This work presents development of computationally efficient algorithms for high-dimensional density estimation, based on Bayesian sequential partitioning (BSP). Copula transform is used to separate the estimation of marginal and joint densities, with the purpose of reducing the computational complexity and estimation error. Using this separation, a parallel implementation of the density estimation algorithm on a 4-core CPU is …

Intelligent And Secure Underwater Acoustic Communication Networks, Chaofeng Wang

Dissertations, Master's Theses and Master's Reports

Underwater acoustic (UWA) communication networks are promising techniques for medium- to long-range wireless information transfer in aquatic applications. The harsh and dynamic water environment poses grand challenges to the design of UWA networks. This dissertation leverages the advances in machine learning and signal processing to develop intelligent and secure UWA communication networks. Three research topics are studied: 1) reinforcement learning (RL)-based adaptive transmission in UWA channels; 2) reinforcement learning-based adaptive trajectory planning for autonomous underwater vehicles (AUVs) in under-ice environments; 3) signal alignment to secure underwater coordinated multipoint (CoMP) transmissions.

First, a RL-based algorithm is developed for adaptive transmission in …

Fliess Operator Representations Of Markov Jump Nonlinear Systems And Their Parallel Interconnections, Luis A. Duffaut Espinosa, W. Steven Gray

Electrical & Computer Engineering Faculty Publications

This paper provides a Fliess operator representation for a class of continuous-time Markov jump nonlinear systems. This representation allows one to describe the parallel sum and product interconnections of such systems. The paper concludes by showing that all parallel interconnections preserves rationality when the component operators have rational generating series.