Computer Engineering Commons^™

Data Center Load Forecast Using Dependent Mixture Model, Md Riaz Ahmed Khan

Electronic Theses and Dissertations

The dependency on cloud computing is increasing day by day. With the boom of data centers, the cost is also increasing, which forces industries to come up with techniques and methodologies to reduce the data center energy use. Load forecasting plays a vital role in both efficient scheduling and operating a data center as a virtual power plant. In this thesis work a stochastic method, based on dependent mixtures is developed to model the data center load and is used for day-ahead forecast. The method is validated using three data sets from National Renewable Energy Laboratory (NREL) and one other …

Follow Me Robot, Victoria M. Edwards

Honors Theses

The idea of a personal robotic assistant, while once made up the tales of science fiction, is now moving closer and closer to reality. It is easy for two humans to walk together where one person knows the directions and the other person follows along. However, it is not a trivial problem for a robot to recognize a human, and follow side by side along with them. There are three key parts to this problem: 1.) Detection of a human, 2.) Tracking the human, and 3.) the robot's Motion strategy. Using baseline assumptions, I can simplify the detection process allowing …

Improving Understandability And Uncertainty Modeling Of Data Using Fuzzy Logic Systems, Dumidu S. Wijayasekara

Theses and Dissertations

The need for automation, optimality and efficiency has made modern day control and monitoring systems extremely complex and data abundant. However, the complexity of the systems and the abundance of raw data has reduced the understandability and interpretability of data which results in a reduced state awareness of the system. Furthermore, different levels of uncertainty introduced by sensors and actuators make interpreting and accurately manipulating systems difficult. Classical mathematical methods lack the capability to capture human knowledge and increase understandability while modeling such uncertainty.

Fuzzy Logic has been shown to alleviate both these problems by introducing logic based on vague …

An Efficient Hybrid Eye Detection Method, Mingxin Yu, Yingzi Lin, Xiangzhou Wang

Turkish Journal of Electrical Engineering and Computer Sciences

Eye detection is the most important and critical task of diverse applications such as face detection and recognition. However, most eye detection methods do not fully consider detection robustness to people with glasses, illumination variation, head pose change, and eye occlusions. This paper proposes an efficient hybrid eye detection method based on a gray intensity variance filter (VF) and support vector machines (SVMs). Firstly, the VF is used for eliminating most of noneye region images to keep less candidate eye regions. Then accurate two eye regions are determined easily through the trained SVM classifier. Moreover, this paper provides an assessment …

Effects On Phased Arrays Radiation Pattern Due To Phase Error Distribution In The Phase Shifter Operation, Guiseppe Coviello, Gianfranco Avitabile, Giovanni Piccinni, Giulio D'Amato, Claudio Talarico

Electrical & Computer Engineering Faculty Scholarship

A comprehensive study on the role of the phase errors distribution on the performances of the phased array systems has been produced. The analysis is brought out using a complete and behavioural model for radiation-pattern characteristics. The study has shown how the phase errors distribution actually affects the performances demonstrating that the rms phase error is a valuable figure of merit of phased array systems but it is not sufficient to completely describe the behaviour of a real system. The paper demonstrates that the antennas array beam shape is depending by the actual error phase distribution and that a good …

Product Authentication Using Hash Chains And Printed Qr Codes, Harshith R. Keni

Electronic Theses and Dissertations

This thesis explores the usage of simple printed tags for authenticating products. Printed tags are a cheap alternative to RFID and other tag based systems and do not require specialized equipment. Due to the simplistic nature of such printed codes, many security issues like tag impersonation, server impersonation, reader impersonation, replay attacks and denial of service present in RFID based solutions need to be handled differently. An algorithm that utilizes hash chains to secure such simple tags while still keeping cost low is discussed. The security characteristics of this scheme as well as other product authentication schemes that use RFID …

Multi-Type Display Calculus For Dynamic Epistemic Logic, Sabine Frittella, Giuseppe Greco, Alexander Kurz, Alessandra Palmigiano, Vlasta Sikimić

Engineering Faculty Articles and Research

In the present paper, we introduce a multi-type display calculus for dynamic epistemic logic, which we refer to as Dynamic Calculus. The displayapproach is suitable to modularly chart the space of dynamic epistemic logics on weaker-than-classical propositional base. The presence of types endows the language of the Dynamic Calculus with additional expressivity, allows for a smooth proof-theoretic treatment, and paves the way towards a general methodology for the design of proof systems for the generality of dynamic logics, and certainly beyond dynamic epistemic logic. We prove that the Dynamic Calculus adequately captures Baltag-Moss-Solecki’s dynamic epistemic logic, and enjoys Belnap-style cut …

An Implantable Microstrip Antenna Design For Mics-Band Biomedical Applications, Adnan Sondaş, Mustafa Hi̇kmet Bi̇lgehan Uçar

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an implantable microstrip antenna design is introduced to cover the Medical Implant Communications Service (MICS, 402$-$405 MHz) band for biomedical telemetry systems. The radiating layer of the antenna comprises two concentric square split-ring elements and a metallic pad placed between them. A shorting pin is also used for miniaturization purposes, directly connecting the outer ring element to the ground plane. It is numerically demonstrated that the proposed antenna offers approximately 7{\%} impedance bandwidth and gains of 1.9 dBi at the designated frequency band. In addition, effects of some critical design parameters on the antenna performance are numerically …

Fetal Electrocardiogram Estimation Using Polynomial Eigenvalue Decomposition, Soydan Redif

Turkish Journal of Electrical Engineering and Computer Sciences

decomposition (PEVD) to the problem of fetal electrocardiogram (ECG) extraction from real ECG recordings obtained from abdominal leads. We model the fetal ECG extraction problem as a broadband sensor array signal processing problem in order to account for the broadband nature of the ECG noise present in the recordings. An algorithm for providing an approximate PEVD is used in order to estimate the broadband noise subspace. Suppression of the broadband noise and maternal ECG is achieved by carrying out an orthonormal projection of the recordings onto the estimated fetal subspace. The proposed scheme was evaluated with multichannel synthetic ECG signals …

Heart Sound Signal Classification Using Fast Independent Component Analysis, Yücel Koçyi̇ği̇t

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Modeling And Simulation Of Sensorless Control Of Four-Leg Inverter Pmsm Drives In The Case Of A Single-Phase Open Circuit Fault, Kamel Saleh, Mark Sumner

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a new method to track the saliency of a permanent magnet synchronous motor (PMSM) motor fed by a 4-leg inverter in the case of a single-phase open circuit fault through measuring the dynamic current response of the motor line currents due to the insulated-gate bipolar transistor (IGBT) switching actions. In the case of a single-phase open circuit fault, a fault-tolerant control strategy that includes taking appropriate actions to control the 2 remaining healthy currents results in minor system performance degradation. The new strategy introduced in this paper includes software modifications only to the saliency tracking algorithm used …

Control Of A Ternary Voltage Progression Based Cascaded Multilevel Inverter Using Classy Split Multicarrier Pulse Width Modulation, Gayathri Monicka Subarnan, Jamuna Venugopal

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new hybrid pulse width modulation technique is proposed to enhance the performance of output voltage from a ternary progression based multilevel inverter. For high power applications, the multilevel inverter can appropriately replace the traditional converter without a transformer and the separate DC sources will be indispensable for various renewable energy sources. The classy split switching technique for the multicarrier pulse width modulation technique is adopted and the concept about new topology is presented in this paper. An arm controller has been chosen to implement the modulation due to its superior features, easy software, and hardware design. …

Optimization Of An Experimental Unsymmetrical-Unbalanced Two-Phase Induction Motor Using The Hgapso Hybrid Technique And The Finite Element Method For Increasing Efficiency And Reducing Torque Ripple, Navid Horiyat, Seyed Mohammad Shariatmadar, Vahid Amir

Turkish Journal of Electrical Engineering and Computer Sciences

Two-phase induction motors make an important contribution to social welfare. Accordingly, enhanced quality in such motors would benefit society. This study was done to test this type of motor to determine a nonlinear optimal point in the form of a multiobjective function between ripple of the torque and motor efficiency with consideration of a weighted coefficient in an unbalanced-unsymmetrical two-phase induction motor. Tests demonstrated that minimizing total harmonic distortion could reduce torque ripple. The optimal point was determined using optimization algorithms, and a hybrid of genetic and particle swarm optimization algorithms simultaneously in order to increase efficiency and to reduce …

Iec 61850-Based Parallel Bus Transfer Scheme For Industrial Substations, Cagil Ozansoy

Turkish Journal of Electrical Engineering and Computer Sciences

Bus transfer schemes have long been utilized in the power system industry as a means of supplying system loads with a consistent and reliable source of power. They assist in the switch to alternative sources of power supply in the case of maintenance or failures. The design of such schemes has undergone significant transformation from discrete electromechanical relays to microprocessor-based relays with sophisticated communication capabilities. IEC 61850 is a substation automation standard for the communication between devices in a substation. IEC 61850 makes it possible to integrate intelligent electronic devices on an Ethernet-based peer-to-peer communication network, eliminating the traditional hardwiring …

Experimental Performance Comparison Of A 2-Axis Sun Tracking System With Fixed System Under The Climatic Conditions Of Düzce, Turkey, Ali̇ Öztürk, Selman Alkan, Uğur Hasirci, Sali̇h Tosun

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, an experimental performance comparison of a 2-axis tracking system with a fixed panel in a solar renewable energy system is conducted. The paper mainly focuses on a cost-benefit analysis of fixed and tracking modules. For this aim, an experimental setup was built and periodical measurements were then obtained from the setup. To provide a better comparison, the panels were exposed to the same conditions during the measurements. By considering the real-time experimental results, the paper provides a quantitative analysis of the feasibility of tracking panels for domestic applications as well as an analysis of payback period if …

Open Source Software Adoption Evaluation Through Feature Level Sentiment Analysis Using Twitter Data, Muhammad Touseef Ikram, Naveed Anwer Butt, Muhammad Tanvir Afzal

Turkish Journal of Electrical Engineering and Computer Sciences

Adopting open source software from the Internet, developers often encounter the problem of accessing the quality of candidate software. To efficiently adopt the system they need a sort of quality guarantee regarding software resources. To assist the developer in software adoption evaluation we have proposed a software adoption assessment approach based on user comments. In our proposed approach, we first collected the textual reviews regarding the software resource, assigned the sentiment polarity (positive or negative) to each comment, extracted the adoption aspect which the comment talks about, and then based on the adoption aspects of the software generated an aggregated …

Solar Irradiation Estimator Based On A Self-Calibrated Reference Solar Cell, Touria Hassboun, Lhoussain El Bahir, Youness Aite Driss, Mustapha El Adnani

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper we propose a concept for estimating solar irradiation based on measurements of the current, voltage, and temperature of a photovoltaic (PV) cell. The estimation of the irradiation is obtained by processing these measurements using a PV cell mathematical model combined with a PI controller. Since the PV cell current is very sensitive to the irradiance level, the principle of the method is to force the model to reproduce the same current as that measured on the cell by applying an appropriate irradiance as input, for measured temperature and voltage. The appropriate irradiance, which is the output of …

An 11-Switch Multilevel Inverter With A Modified Space Vector Modulation, Nasrudin Abd Rahim, Hew Wooi Ping, Jafferi Jamaludin

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a new 3-phase multilevel inverter that is able to generate 7 levels in line-to-line voltage with only 11 switches. The inverter is formed from the 6-switch conventional full-bridge topology with the addition of 5 bidirectional switches in which 2 of them are shared among the three phases. By doing so, the number of power switches can be minimized, thus reducing the complexity in generating and controlling PWM signals. A novel voltage control scheme based on space vector modulation is developed by introducing a virtual vector in every sector of the vector hexagon. This is to overcome the …

Empirical Mode Decomposition Application For Short-Term Flicker Severity, Yasemi̇n Önal, Ömer Nezi̇h Gerek, Doğan Gökhan Ece

Turkish Journal of Electrical Engineering and Computer Sciences

In this article, an approach based on empirical mode decomposition (EMD) is suggested in order to calculate short-term flicker severity, Pst, in power systems. EMD is a new signal processing method used for the analysis of nonlinear and nonstationary signals. Pst is an important quantity in the electric power quality index defined by the International Electrotechnical Commission. In the suggested approach, the voltage signal is separated into intrinsic mode function components using EMD. These components are used for calculating the voltage flicker amplitude and frequency, and Pst is calculated as a result of the statistical evaluation of flicker amplitude. EMD …

Commutation Angles Adjustment In Srm Drives To Reduce Torque Ripple Below The Motor Base Speed, Ali Shahabi, Amir Rashidi, Milad Afshoon, Seyyed Mortaza Saghaian Nejad

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the problem of high torque ripple in switched reluctance motor (SRM) drives. A method is proposed for below the base speed operation of SRM that determines both the turn-off and the turn-on angles for reducing motor torque ripple. Determination of the turn-off angle is an offline process performed through solving a multiobjective optimization function consisting of two criteria: torque ripple and copper loss. Turn-on angle adjustment, however, is an online process based on the intersection approach of consecutive phase currents, particularly proposed in this paper. Simulation and experimental results are presented to validate the reduction in torque …

Wavefront-Ray Grid Fdtd Algorithm, Mehmet Çi̇ydem

Turkish Journal of Electrical Engineering and Computer Sciences

A finite difference time domain algorithm on a wavefront-ray grid (WRG-FDTD) is proposed in this study to reduce numerical dispersion of conventional FDTD methods. A FDTD algorithm conforming to a wavefront-ray grid can be useful to take into account anisotropy effects of numerical grids since it features directional energy flow along the rays. An explicit and second-order accurate WRG-FDTD algorithm is provided in generalized curvilinear coordinates for an inhomogeneous isotropic medium. Numerical simulations for a vertical electrical dipole have been conducted to demonstrate the benefits of the proposed method. Results have been compared with those of the spherical FDTD algorithm …

Prediction-Based Reversible Image Watermarking Using Artificial Neural Networks, Mahsa Afsharizadeh, Majid Mohammadi

Turkish Journal of Electrical Engineering and Computer Sciences

In prediction-based reversible watermarking schemes, watermark bits are embedded in the prediction errors. An accurate prediction results in smaller prediction errors, more efficient embedding, and less distortion for the watermarked image. In this paper, an accurate prediction is made using artificial neural networks. Before the embedding operation, 2 neural networks are trained by the pixel values of the image. Then the trained neural networks predict the pixel values that are used in the embedding operation. Due to the training ability of the neural networks, the prediction will be more accurate than the averaging technique. Experimental results show that the proposed …

Site-Specific Design Optimization Of Horizontal-Axis Wind Turbine Systems Using Pso Algorithm, Ulaş Emi̇noğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Due to the complexity of wind turbine systems (WTSs) containing multiple components, design parameters of a WTS must match each other in order to produce electrical energy at a lower cost and a higher efficiency. In this study, a framework for site-specific design optimization of a horizontal-axis WTS is proposed. It is based on cost reduction and the objective function is the produced energy cost. The cost of energy model proposed by the National Renewable Energy Laboratory is utilized. In order to compute turbine output power that results in annual energy production, a new approach is proposed to model the …

A New Deployment Method For Electric Vehicle Charging Infrastructure, Bünyami̇n Yağciteki̇n, Mehmet Uzunoğlu, Ari̇f Karakaş

Turkish Journal of Electrical Engineering and Computer Sciences

The fast depletion of fossil fuels, climate change, and global warming have become major worldwide problems and alternatives for conventional transportation have been actively researched in the last decade. Compared to available conventional vehicles, electric vehicles have a leading position due to their environmentally friendly transportation. Recent electric vehicle penetration brings the necessity of a high number of charging stations, which are considered to be established in community areas such as shopping centers, hospitals, commercial areas, university campuses, residential areas, and streets. Deployment planning of charging stations is very important for driver expectations and social and economic impacts of electric …

Novel Approaches To Clustering, Biclustering Algorithms Based On Adaptive Resonance Theory And Intelligent Control, Sejun Kim

Doctoral Dissertations

"The problem of clustering is one of the most widely studied area in data mining and machine learning. Adaptive resonance theory (ART), an unsupervised learning clustering algorithm, is a clustering method that can learn arbitrary input patterns in a stable, fast and self-organizing way. This dissertation focuses on unsupervised learning methods, mostly based on variations of ART.

Hierarchical ART clustering is studied by generating a tree of ART units with GPU based parallelization to provide fast and finesse clustering. Experiment results show that the our method achieves significant training speed increase in generating deep ART trees compared with that from …

An Empirical Investigation Of The Willingness Of Us Intelligence Community Analysts To Contribute Knowledge To A Knowledge Management System (Kms) In A Highly Classified And Sensitive Environment, Robert Hambly

CCAC Theses and Dissertations

Since September 11, 2001, the United States Government (USG) has possessed unparalleled capability in terms of dedicated intelligence and information collection assets supporting the analysts of the Intelligence Community (IC). The USG IC has sponsored, developed, and borne witness to extraordinary advances in technology, techniques, and procedures focused on knowledge harvesting, knowledge sharing, and collaboration. Knowledge, within successful (effective & productive) organizations, exists as a commodity; a commodity that can be created, captured, imparted, shared, and leveraged. The research problem that this study addressed is the challenge of maintaining strong organizational effectiveness and productivity through the use of an information …

Improved Direct Power Control For 3-Level Ac/Dc Converter Under Unbalanced And/Or Distorted Voltage Source Conditions, Imad Merzouk, Mohamed Lokmane Bendaas

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an improved direct power control with space vector modulation for a 3-phase 3-level neutral point clamped converter supplied by unbalanced and/or distorted grid voltage is proposed. The main objective of the control scheme is to obtain balanced and sinusoidal input current with unity power factor under nonideal voltage supply. To achieve the control objectives, compensated active and reactive powers are calculated and added to the referencing one. A theoretical analysis of active and reactive power under a nonideal source is clearly demonstrated. In order to calculate the compensated powers, the extraction of positive, negative, and harmonic sequences …

Theoretical Analysis Of Doping Management And Its Effects On Power Scaling, Ami̇ra Tandi̇rovi̇ç Gürsel, Parvi̇z Elahi̇, Fati̇h Ömer İlday, Mustafa Sadetti̇n Özyazici

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

A Robust Bayesian Inference-Based Channel Estimation In Power Line Communication Systems Contaminated By Impulsive Noise, Mohammad Asadpour, Behzad Mozaffari Tazehkand, Hadi Seyedarabi

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Studies On The Application Of Wavelet Families For A High Impedance Fault Location Algorithm In A Distribution Network, Mohd Syukri Ali, Ab Halim Abu Bakar, Chia Kwang Tan, Hazlie Mokhlis, Hamzah Arof

Turkish Journal of Electrical Engineering and Computer Sciences

Detecting high impedance faults in a distribution network is a great challenge and locating one is even more challenging. This paper will present an enhanced high impedance fault location algorithm based on the database technique. This paper is an extension of a faulty section identification algorithm developed previously. However, in this paper, the performance of the previous algorithm is investigated first in terms of different sampling rate and window size. Then these parameters will be used as a standard parameter to study the effectiveness of different types of mother wavelets. Each mother wavelet will be used to extract important features …