Electrical and Electronics Commons^™

Analysis Of High Performance Scientific Programming Workflows, Withana Kankanamalage Umayanganie Klaassen

Open Access Theses & Dissertations

Substantial time is spent on building, optimizing and maintaining large-scale software that is run on supercomputers. However, little has been done to utilize overall resources efficiently when it comes to including expensive human resources. The community is beginning to acknowledge that optimizing the hardware performance such as speed and memory bottlenecks contributes less to the overall productivity than does the development lifecycle of high-performance scientific applications. Researchers are beginning to look at overall scientific workflows for high performance computing. Scientific programming productivity is measured by time and effort required to develop, configure, and maintain a simulation experiment and its constituent …

On The Application Of Pspice For Localised Cloud Security, Paul Tobin

Doctoral

The work reported in this thesis commenced with a review of methods for creating random binary sequences for encoding data locally by the client before storing in the Cloud. The first method reviewed investigated evolutionary computing software which generated noise-producing functions from natural noise, a highly-speculative novel idea since noise is stochastic. Nevertheless, a function was created which generated noise to seed chaos oscillators which produced random binary sequences and this research led to a circuit-based one-time pad key chaos encoder for encrypting data. Circuit-based delay chaos oscillators, initialised with sampled electronic noise, were simulated in a linear circuit simulator …

Miniaturized Switchless Pattern Reconfigurable Antenna Utilizing Spherical Modes Analysis, Adam Narbudowicz, Max Ammann, Nicola Marchetti

Conference Papers

The paper proposes an electrically small pattern reconfigurable antenna, which allows flexible beamforming with the antenna diameter being ?/5. The antenna has 3 ports, each designed to radiate a different spherical mode. By applying appropriate phase shift the antenna allows to flexibly sweep its bi-directional radiation pattern across a 360° azimuth, while offering 5 dBi directivity.

Handwritten Bangla Character Recognition Using The State-Of-The-Art Deep Convolutional Neural Networks, Md Zahangir Alom, Paheding Sidike, Mahmudul Hasan, Tarek M. Taha, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

In spite of advances in object recognition technology, handwritten Bangla character recognition (HBCR) remains largely unsolved due to the presence of many ambiguous handwritten characters and excessively cursive Bangla handwritings. Even many advanced existing methods do not lead to satisfactory performance in practice that related to HBCR. In this paper, a set of the state-of-the-art deep convolutional neural networks (DCNNs) is discussed and their performance on the application of HBCR is systematically evaluated. The main advantage of DCNN approaches is that they can extract discriminative features from raw data and represent them with a high degree of invariance to object …

Core And Uncore Joint Frequency Scaling Strategy, Vaibhav Sundriyal, Masha Sosonkina, Bryce Westheimer, Mark Gordon

Electrical & Computer Engineering Faculty Publications

Energy-proportional computing is one of the foremost constraints in the design of next generation exascale systems. These systems must have a very high FLOP-per-watt ratio to be sustainable, which requires tremendous improvements in power efficiency for modern computing systems. This paper focuses on the processor—as still the biggest contributor to the power usage—by considering both its core and uncore power subsystems. The uncore describes those processor functions that are not handled by the core, such as L3 cache and on-chip interconnect, and contributes significantly to the total system power. The uncore frequency scaling (UFS) capability has been available to the …

The Different Stages Of Prpd Pattern For Positive Point To Plane Corona Driven By A Dc Voltage Containing A Ripple, Tobias Dezenzo, Thomas Betz, Andreas Schwarzbacher

Articles

The different phase resolved partial discharge patterns, which can be recognized when a positive dc voltage containing a ripple due to a half-wave rectification is used are presented in this paper. Results are given from corona onset to the appearance of breakdown streamers. The outcomes are five different patterns, which represent the four stages of positive corona and their transition zones. Three of them are clearly identifiable with respect to patterns from other discharge sources that have already been reported for dc voltages containing a ripple. For an assessment of pattern formation discharge pulses as recorded at the test object …

การวิเคราะห์ผลกระทบทางความร้อนต่ออายุการใช้งานของหม้อแปลง, ธิราดา เฉยสกุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

วิทยานิพนธ์ฉบับนี้นำเสนอเกี่ยวกับการวิเคราะห์ผลกระทบทางความร้อนต่ออายุการใช้งานของหม้อแปลง ด้วยการใช้ข้อมูลการตรวจวัดพื้นฐาน ข้อมูลของหม้อแปลง และอุณหภูมิแวดล้อม เพื่อประเมินหาอุณหภูมิที่จุดร้อนสุดของขดลวด ทั้งในกรณีที่หม้อแปลงจ่ายโหลดที่เป็นเชิงเส้นและโหลดที่ไม่เป็นเชิงเส้น โดยพัฒนาวิธีการจาก IEEE Std. C57.91-2010 และ IEEE Std. C57.110-2018 รวมกัน ในการวิเคราะห์จะใช้หม้อแปลงกำลังชนิดแช่ในน้ำมัน ขนาด 50 MVA และข้อมูลการตรวจวัดด้วยมิเตอร์วัดคุณภาพไฟฟ้าจากสถานีไฟฟ้าย่อยปลวกแดง 1 จังหวัดระยอง เป็นเวลา 10 เดือน พร้อมทั้งศึกษาผลกระทบจากปัจจัยที่ทำให้ความร้อนในหม้อแปลงมีค่ามากขึ้น รวมไปถึงผลกระทบเมื่อมีระบบพลังงานแสงอาทิตย์ติดตั้งในระบบด้วยการจำลองในโปรแกรม DIgSILENT PowerFactory จากการวิเคราะห์พบว่า ระดับของโหลด กระแสฮาร์มอนิกส์ และอุณหภูมิแวดล้อม สามารถส่งผลกระทบด้านความร้อนต่อหม้อแปลงด้วยการเพิ่มอุณหภูมิที่จุดร้อนสุดของขดลวด ซึ่งหากอุณหภูมิที่จุดร้อนสุดของขดลวดมีค่ามากเกินกว่าข้อจำกัดจะทำให้อายุการใช้งานของหม้อแปลงลดลง แต่เมื่อมีการติดตั้งพลังงานแสงอาทิตย์ในขนาดที่เหมาะสมในระบบ จะสามารถช่วยลดอายุการใช้งานที่สูญเสียของหม้อแปลงได้ โดยปัจจัยที่ส่งผลกระทบด้านความร้อนต่อหม้อแปลงจากมากไปน้อย คือ ระดับของโหลด กระแสฮาร์มอนิกส์ และอุณหภูมิแวดล้อม ตามลำดับ

Ball Oscillating Bouncer, Eric Blok, Daniel Altemese, Ryan Nowacki, Maram Qurban

Williams Honors College, Honors Research Projects

The purpose of this report is to document the need, objectives, marketing and engineering requirements, as well as validate the design of an autonomous control device capable of continuously bouncing a table tennis ball on a paddle. This includes the design of a self correcting system using lightweight materials, and as few sensors and components as possible to achieve a compact, portable design. To accomplish this, the system is designed to react to a ball falling from as short a distance as 10 centimeters above the paddle, meaning all sensor processing, control processing, and motor drives should be able to …

Soil Moisture Sensor, Jaclyn Miller, Derek Bitecofer, Seung Jun Lee

Williams Honors College, Honors Research Projects

Since water is an important resource and not all communities around the world can afford to be liberal with their water needs; it has become important to use available water as efficiently as possible, especially in agriculture. For the purpose of reducing the overwatering of crops, an unattended ground moisture sensor can be implemented to measure the moisture level in the soil surrounding the plants. This will allow a farmer to know when to water or stop watering crops. For convenience, the moisture data information should be transmitted wirelessly to the user. The design of an unattended ground moisture sensor …

Quantitative Characterization Of Lithium-Ion Batteries Under Abuse Conditions, Xiaoniu Du

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Real-Time Image Pattern Sensor For Weld Pool Penetration Through Reflection In Gtaw, Yu-Ting Chen

Theses and Dissertations--Electrical and Computer Engineering

In gas tungsten arc welding (GTAW), weld pool surface contains crucial information for welding development. In this research, simulate skilled welders to control the welding process and determine the penetration stages based on the weld pool reaction.

This study focuses on solving the uncertainty of the liquid weld pool in joint bases. The weld pool penetration process is highly depending on how the weld pool surface shape. To observe the weld pool, reflect the weld pool surface by the laser and image on the shield glass. The experiments show that the penetration can’t be determine by the reflecting grayness due …

Design Of A Machine Vision Camera For Spatial Augmented Reality, Matt Phillip Ruffner

Theses and Dissertations--Electrical and Computer Engineering

Structured Light Imaging (SLI) is a means of digital reconstruction, or Three-Dimensional (3D) scanning, and has uses that span many disciplines. A projector, camera and Personal Computer (PC) are required to perform such 3D scans. Slight variances in synchronization between these three devices can cause malfunctions in the process due to the limitations of PC graphics processors as real-time systems. Previous work used a Field Programmable Gate Array (FPGA) to both drive the projector and trigger the camera, eliminating these timing issues, but still needing an external camera. This thesis proposes the incorporation of the camera with the FPGA SLI …

Stability Analysis And Design Of A Tracking Filter For Variable Frequency Applications, Pranav Aramane

Theses and Dissertations--Electrical and Computer Engineering

The work presented in this thesis is a frequency adaptive tracking filter that can be used in exact tracking of power frequencies and rejection of unwanted harmonics introduced during power disturbances. The power synchronization process includes power converters and other equipment that have many non-linear components that introduce unwanted harmonics. This new design is motivated by the requirement of a filter that can filter all the harmonics and exactly track a rapidly varying fundamental frequency with little time delay and phase error. This thesis analyzes the proposed filter mathematically based on Lyapunov theory and simulations are presented to show the …

Fabrication And Characterization Of Organic-Inorganic Hybrid Perovskite Solar Cells, Hojjatollah Sarvari

Theses and Dissertations--Electrical and Computer Engineering

Solar energy as the most abundant source of energy is clean, non-pollutant, and completely renewable, which provides energy security, independence, and reliability. Organic-inorganic hybrid perovskite solar cells (PSCs) revolutionized the photovoltaics field not only by showing high efficiency of above 22% in just a few years but also by providing cheap and facile fabrication methods.

In this dissertation, fabrication of PSCs in both ambient air conditions and environmentally controlled N₂-filled glove-box are studied. Several characterization methods such as SEM, XRD, EDS, Profilometry, four-point probe measurement, EQE, and current-voltage measurements were employed to examine the quality of thin films …

Advanced Synchronous Machine Modeling, Yuqi Zhang

Theses and Dissertations--Electrical and Computer Engineering

The synchronous machine is one of the critical components of electric power systems. Modeling of synchronous machines is essential for power systems analyses. Electric machines are often interfaced with power electronic components. This work presents an advanced synchronous machine modeling, which emphasis on the modeling and simulation of systems that contain a mixture of synchronous machines and power electronic components. Such systems can be found in electric drive systems, dc power systems, renewable energy, and conventional synchronous machine excitation. Numerous models and formulations have been used to study synchronous machines in different applications. Herein, a unified derivation of the various …

Design And Implementation Of A Micro-Inverter For Photovoltaic Applications, Chi-Thang Phan-Tan

Masters

The objective of this work is to design and build a novel topology of a micro-inverter to directly convert DC power from a photovoltaic module to AC power. In the proposed micro-inverter, a structure with two power stages, which are DC/DC and then DC/AC converters, is used. A novel MPPT algorithm is implemented and evaluated in the DC/DC converter to optimize the solar panel energy production. The new method operates with an efficiency of 97.9%, which is a 1% improvement on the standard method, and a response time of

In this research, the following approach is taken. A literature review …

Controlled Switching Of Reactive Loads And Commisioning Regimes, Eoin Cowhey

Masters

Switching is a vital task in any power system for ensuring its safe and reliable operation. Switching may be necessary for fault clearance, to ensure wider system stability and to prevent damage to plant. It is essential for isolation, to allow technicians to carry out maintenance tasks safely. Also, switching of reactive loads such as shunt capacitor banks and shunt reactors, is crucial for controlling system voltage.

Switching of some loads however, may produce voltage transients and heavy transient inrush currents which can impact on wider system power quality, impact customers and cause damage or deterioration of the insulation of …

Novel Wideband Ebg Structures For Isolation Improvement Between Cosite Antennas, Paul John Czeresko Iii

Theses and Dissertations

As the number of installed antennas increases on a structure, the available real estate to do so without each antenna interfering with the others diminishes. Electromagnetic band gap (EBG) structures are one way to mitigate this cosite interference with compact antenna installations. While a host of EBG structures and types (3-D, planar etc.) have been proposed and studied historically, it has been found that planar EBG structures tend to provide very narrow bandwidths for both antenna design and cosite interference reduction. This research focuses on the design of EBG structures intended to achieve greater than 20 dB of isolation improvement …

A Rectenna For 5g Energy Harvesting, Panagiotis Efthymakis

Theses and Dissertations

This thesis describes the design of a rectenna that is capable of operating in 5G. 5G’s availability will create the opportunity to harvest energy everywhere in the network’s coverage. This thesis investigates a Rectenna device with a new proposed topology in order to eliminate coupling between input and output lines and increase the rectification efficiency. Moreover, it is designed to charge a rechargeable battery of 3V, 1mA, with a 4.8mm diameter. The current design describes using one antenna for energy harvesting; this could be expanded to use an antenna array, which would increase the input power. This would lead to …

Designing And Testing 3-D Printed Wafer-Box With Embedded Pzt Sensors To Identify The Shape Effect On Energy Harvesting, Ahmad Jami Safayet

College of Graduate Studies: Theses & Dissertations

Piezoelectric energy has been recently paid attention in the field of alternative energy. Day by day the traditional energy sources including Coal tar and oils are becoming scarce. People are heading to an alternative energy source to meet the future energy demand. Piezoelectric energy is one of the competitive energy sources compared to the conventional renewable energy sources including solar, wind, and geothermal power and so on. This energy production method bears enormous research potential because it can be used as the roadway for a new method of power generation. This research project aimed to identify which shaped wafer-box produced …

Genetic Algorithm Based Coding For High Efficiency Video Coding, Ei Ei Tun

Chulalongkorn University Theses and Dissertations (Chula ETD)

High efficiency video coding (HEVC) is the newest video coding standard to greatly increase the coding efficiency of its ancestor H.264/AVC with the aids of its new features such as the quadtree-based coding unit (CU) partitioning, a simple deblocking filter, and other advanced coding techniques. However, HEVC delivers a highly increased computation complexity, which is mainly due to the exhaustive rate distortion optimization search of quadtree-based CU partitioning. Firstly, a feature reduction approach is proposed on a fuzzy support vector machine (SVM) based CU size decision method. The proposed feature reduction approach with rate control (RC) can reduce computational complexity …

A Quantification Analysis On Potential Use Of Recuperated Regenerative Braking Energy From Nyct Subways Into Charging Electric Buses, Ahmed S. Rahman

Dissertations and Theses

The New York Metropolitan Transportation Authority (MTA) is one of the biggest consumers of electricity in east coast of the United States. According to a report published by Dayton T. Brown in 2013, MTA consumes approximately 2150 GWh electrical energy per year for traction power, where the New York City Transit (NYCT) alone is a consumer of about 80% of the total annual MTA energy consumption. This continuous high demand for electricity from a single organization opens research opportunities to search for alternative ways to reduce the needs. NYCT Subways has an existing total rolling stock of 6,418 train cars …

A Case Study On Grid Impacts Of Electric Vehicles On New York City Power Grid, Amir Abbas Rizvi

Dissertations and Theses

The U.S. electric power industry is anticipating a huge increase in electricity demand in the future due to reformation of the transportation industry. In this work, we focus on electric cars and their impact on the transportation industry as well as the electric grid. The increase in number of electric cars over the years and their growing number indicates that in the future, transportation means are going to largely depend upon electricity to achieve cost and environmental benefits. In other words, in future, the transportation will be impacting the electric grid and vice versa.

The surge in electric vehicles on …

Reactive Power Management In A Distribution System By Photovoltaic Inverter, Akasinh Luangduangsitthideth

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays the electrical generation from the solar photovoltaic resource is extensively promoted because of the concern about greenhouse gas emission. A distribution system can be powered by a variety of solar photovoltaic resources, and can be used for various objectives, it can improve voltage profile problems and can reduce real power losses of the upgrading process of transmission and distribution system. However, presence much of the PV system may have detrimental impacts on the operation of the distribution system because of the variation of solar photovoltaic increases. This thesis proposed the optimal reactive power control modes by PV inverters when …

Coordination Between Central And Local Control Of Photovoltaic Generation System For Controlling Voltage Violation And Unbalance In Distribution Systems, Anuwat Chanhome

Chulalongkorn University Theses and Dissertations (Chula ETD)

Solar energy is a clean and pollution-free energy. Economic growth has led to increased demand for electricity in many countries, which has encouraged the installation of solar power generation systems, especially in LV distribution system. Households have the potential to install solar power generation systems because the costs of installation and maintenance have been continuously decreased. However, when there are many connected solar power generation systems in LV distribution system, the following problems may occur: (1) Loss of real power generation due to the operation of overvoltage protection of solar power generation systems, especially the ones on downstream nodes and …

Application Of Model Predictive Control To Traffic Systems With Hierarchical Distributed Control Framework, Jeerapat Jitnaunt

Chulalongkorn University Theses and Dissertations (Chula ETD)

Traffic congestion is one of the chronic problems that degrades an urban traffic sustainable development especially the transport system. It seriously affects the quality of life of many people and becomes a catalyst of an increment of air pollution. If we can improve public infrastructure, logistics, and public transport system, they will reduce traffic congestion problem. This thesis aims to apply model predictive control (MPC) to traffic systems in a framework on hierarchical distributed control. The control structure composes of three layers which are network layer, area layer, and intersection layer. On the network layer and area layer, the control …

Flexible Optical Fiber Access Networks Using Wavelength Selective Switches, Maung Maung Htwe

Chulalongkorn University Theses and Dissertations (Chula ETD)

The optical switching crosstalk is the important considerable issue in the optical fiber communication system, it tends to the signal distortion and decreasing of the system performance. This dissertation research is proposed a guideline to design a flexible fiber to the x (FTTx) system based on wavelength division multiplexing passive optical network (WDM-PON) combining with wavelength selective switches (WSSs). For the system configuration, the 4 wavelengths-10 ONUs system with the data bit rate of 10-Gbps/λ and 40-Gbps/ λ are studied in this dissertation. Moreover, to be active switching, the dynamic wavelength bandwidth allocation (DWBA) controller is used to control WSSs. …

Design And Implementation Of Medium-Range Outdoor Wireless Mesh Network With Openflow In Raspberry Pie, Soe Ye Htet

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis has designed and implemented the prototype of software-defined wireless mesh network (SDWMN) testbed with in-band control approach for road traffic monitoring system on Phaya Thai road between Rama 1 and Rama 4 roads. Wireless mesh nodes for this outdoor SDWMN testbed are composed of 6 waterproof boxes, 6 Raspberry Pi's, 6 cameras, and 6 power banks and 2 Intel NUC computers. Ad-hoc based IEEE 802.11 WiFi standard is used to send the captured image from Raspberry. Two gateways are installed at the traffic police boxes and two wireless mesh nodes are installed at each crossover bridge on Phaya …

An Improvement Of Photovoltaic Power Forecasting From Numerical Weather Prediction, Supachai Suksamosorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents forecasting models for improving the hourly predicted solar power from Numerical Weather Prediction (NWP) in one day horizon. A practical constraint is that the models must provide the predicted solar power before 14.00 hrs daily so that the Short-term Operation Planning Section, Generation Operation Planning Department, Power System Control and Operation Division, Electricity Generating Authority of Thailand can use the prediction to plan dispatching of the next day. Available data used in this research are from two sources: local weather measurements and power meter installed at the top of Electrical Engineering Building, Faculty of Engineering, Chulalongkorn University …

การออกแบบความเฉื่อยเสมือนสำหรับระบบกักเก็บพลังงานแบตเตอรี่เพื่อเพิ่มสมรรถนะการตอบสนองเชิงความถี่ของระบบไฟฟ้ากำลังขณะเปลี่ยนผ่านไปสู่โหมดแยกโดด, กรณ์ ศุภหัตถานุกุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในปัจจุบัน ระบบไฟฟ้าบางพื้นที่มีกำลังการผลิตเพียงพอที่จะเดินเครื่องในรูปแบบแยกโดดในกรณีที่ระบบไฟฟ้าหลักไม่พร้อมเชื่อมต่อ แต่ยังไม่สามารถทำได้เนื่องจากหลายปัจจัยโดยเฉพาะด้านเสถียรภาพและความมั่นคงของระบบไฟฟ้า ปัญหาโมเมนต์ความเฉื่อยต่ำซึ่งเกิดจากสัดส่วนของโรงไฟฟ้าพลังงานแสงอาทิตย์ที่เพิ่มสูงขึ้นหรือขนาดของเครื่องกำเนิดไฟฟ้าซิงโครนัสที่มีขนาดเล็กในระบบขณะแยกโดดเป็นหนึ่งในปัจจัยสำคัญที่จะก่อให้เกิดปัญหาเสถียรภาพเชิงความถี่เมื่อเกิดการรบกวนได้ โดยเฉพาะอย่างยิ่ง ขณะที่ระบบไฟฟ้ากำลังเปลี่ยนผ่านไปสู่โหมดแยกโดด วิทยานิพนธ์ฉบับนี้นำเสนอการนำระบบกักเก็บพลังงานแบตเตอรี่มาใช้เพื่อช่วยเพิ่มสมรรถนะการตอบสนองเชิงความถี่ให้กับระบบแยกโดด โดยออกแบบความเฉื่อยเสมือนผ่านตัวควบคุมด้วยเทคนิค Linear Quadratric Regulation (LQR) ผลการทดสอบพบว่า แบตเตอรี่ที่ถูกควบคุมด้วยตัวควบคุมที่ออกแบบด้วยเทคนิค LQR ใช้กำลังไฟฟ้าสูงสุดน้อยกว่าแบตเตอรี่ที่ถูกควบคุมให้มีค่าคงที่โมเมนต์ความเฉื่อยคงที่ ในขณะที่พลังงานที่ใช้มีค่าคต่างกันไม่มากนักโดยที่ขนาดการเบี่ยงเบนความถี่และอัตราการเปลี่ยนแปลงความถี่เมื่อเทียบกับเวลายังอยู่ในค่าที่มาตรฐานกำหนด