Electrical and Computer Engineering Commons^™

Simulation Analysis In Dynamic Performance Of Proton Exchange Membrane Fuel Cell Under Starting Condition, Yan Xiao, Ying-Jie Chang, Wei Zhang, Qiu-Hong Jia

Journal of Electrochemistry

Based on the equivalent circuit model, by considering both the dynamic gas pressure model and the dynamic heat transfer model, a lumped parameter model is developed. The start process of the fuel cell is simulated by using SIMULINK software. The undershoot of the voltage is observed from the simulation results, and the response time of the voltage is basically the same as that of the fuel cell temperature, which indicates that the temperature has great influence on the dynamic performance of the fuel cell. From the perspective of the temperature, the dynamic responses of the thermodynamic potential, the activation overvoltage, …

Interaction Between Energy And Electrocatalysis —— A Review On The 1st Young Scientist Forum On Energy Electrocatalysis, Hong Li, Wen-Bin Cai

Journal of Electrochemistry

No abstract provided.

Synthesis And Electrochemical Properties Of Li3V2(Bo3)3/C Anode Materials For Lithium-Ion Batteries, You Wang, Yi-Wen Zeng, Xing Zhong, Xing Liu, Quan Tang

Journal of Electrochemistry

The Li₃V₂(BO₃)₃/C (LVB/C) composite materials were successfully synthesized in two steps:Firstly, a stoichiomertric mixture of Li₂C₂O₄, V₂O₅, H₃BO₃, H₂C₂O₄•H₂O and ethanol was thoroughly ball-milled to get the precursors. Secondly, the precursors were post-calcinated to get the ultimate products. The calcination temperatures of 750 ℃, 800 ℃ and 850 ℃ were selected based on TG-DTA analyses. The crystal structures, surface morphologies and carbon contents of the samples calcinated at five conditions, …

Effects Of Rotating Magnetic Fields On Pem Fuel Cell Performance, Mao-Liang Wu, En-Ze Wang, Guang-De Pan, Zhong-Jun Liu, Fei Xie

Journal of Electrochemistry

Proton Exchange Membrane (PEM) fuel cell performance may be improved by application of additional magnetic fields. In this work, one square permanent magnet, made of either 16 combination cylinder magnets with homopolarity or 16 combination cylinder magnets with heteropolarity, was exerted on the fuel cell surface to produce additional magnetic field affecting PEM fuel cell performance. The influences of magnetic field status (rotating, static and none) on polarization and power density curves measured in a PEM fuel cell were investigated. The results verified the benefit of magnetic field, proving that the magnetic field distribution could improve the fuel cell output. …

Detecting Suicide Risk From Wristworn Activity Tracker Data Using Machine Learning Approaches, Pallavi Atluri

Electrical Engineering Theses

Suicide is a prevalent cause of death worldwide and depression is a primary concern of many suicidal acts. It is possible that an individual during depression never has any suicidal thoughts at all. On the other hand, some individuals in stable condition with no apparent symptoms of depression feel urges to commit suicide (suicidal ideation). Many such individuals never let anyone know what they are feeling or planning. Suicidal ideation considered an important precursor to suicidal acts.

Detecting the suicide risk in individuals with mood disorders is a major challenge. The current clinical practice to assess suicide risk in these …

Analysis Of Photovoltaic Energy In The Eastern Kentucky Region And The Residential Financial Feasibility, Joshua A. Johnson

Morehead State Theses and Dissertations

A thesis proposal presented to the Faculty of the College of Business and Technology Morehead State University in partial fulfillment of the requirements for the Degree Master of Science by Joshua A. Johnson on April 25, 2018.

Employing H.264 Coarse And Medium Grain Scalable Video To Optimize Video Playback Over Passive Optical Networks, David Moore

Honors College Theses

In this work, we propose the use of Coarse Grain Scalable (CGS) and Medium Grain Scalable (MGS) H.264/AVC video to optimize video playback on passive optical networks (PONs) by investigating network performance metrics such as data delay, video delay, and video delay jitter. Video playback is improved by sequentially dropping layers of scalable video. Dropping just a single CGS enhancement layer results in improvements of up to 57% for both data and video delay. However, video delay jitter benefits the most with an improvement ranging from 47% to 87%. Surprisingly, dropping subsequent CGS enhancement layers does not significantly improve the …

Electrical & Computer Engineering News, Georgia Southern University

Electrical & Computer Engineering: News & Publications (2014-2023)

• Dr. Sungkyunn Lim, Array Antennas & Propagation Modeling

Experimental Verification Of A6 Magnetron With Permanent Magnet, Andrew J. Sandoval

Electrical and Computer Engineering ETDs

A compact A6 relativistic magnetron with diffraction output using a transparent cathode, simple mode-converter, and a permanent magnet were simulated and tested at the University of New Mexico (UNM) for the Office of Naval Research. The standard compact MDO with a simple mode converter and transparent cathode radiates a TE11 mode axially through a cylindrical horn antenna. The magnetic field, essential for magnetron operation, is provided by a Neodymium Iron Boron (NeFeB) GradeN40M rare earth magnet. The permanent magnet eliminates the need for a pulsed magnet and accompanying circuit, significantly reducing the size of the system. A permanent magnetic field …

Towards Utilization Of Distributed On-Chip Power Delivery Against Em Side-Channel Attacks, Ahmed Waheed Khan

USF Tampa Graduate Theses and Dissertations

Non-invasive side-channel attacks (SCAs) are potent attacks on a cryptographic circuit that can reveal its secret key without requiring lots of equipment. EM side-channel leakage is typically the derivative of the power consumption profile of a circuit. Since the fluctuations of the supply voltage strongly depend on the topology and features of the power distribution network (PDN), design of the PDN has a direct impact on EM side-channel leakage signature.

In this thesis, we explore the security implications of distributed on-chip voltage regulators against EM side-channel attacks. Extensive HFSS simulations have demonstrated that the maximum EM radiation can be reduced …

Handwriting Recognition Of Bangla And Similar Scripts, Nishatul Majid

2018 Graduate Student Showcase

This research is about offline Bangla handwriting text recognition. Here we introduce a publicly accessible dataset, as well as a basic character recognition scheme. The dataset contains pages with a 104 word essay and a collection of 84 isolated alpha-numeric characters. All the components in the pages are tagged with the associated ground truth information. The character recognition scheme presented here uses zonal pixel counts, structural strokes and bag of features modeled with grid points using U-SURF descriptor as features. The maximum classification accuracy we obtain is 96.8% using an SVM classifier with a cubic kernel.

Effective Room-Temperature Ammonia-Sensitive Composite Sensor Based On Graphene Nanoplates And Pani, Zongbiao Ye, Yan Chen, Bohao Liu, Yuanjie Su, Zhi Chen, Huiling Tai, Yadong Jiang

Electrical and Computer Engineering Faculty Publications

The graphene nanoplate (GN)-polyaniline (PANI) composite was developed via in-situ polymerization method and simultaneously assembled on interdigital electrodes (IDEs) at low temperature for ammonia (NH₃) detection. The assembled composite sensor showed excellent sensing performance toward different concentrations of NH₃, 1.5 of response value and 123 s/204 s for the response/recovery time to 15 ppm NH₃. Meanwhile, an interesting supersaturation phenomenon was observed at high concentration of NH₃. A reasonable speculation was proposed for this special sensing behavior and the mechanism for enhanced sensing properties was also analyzed.

Early Alert Of At-Risk Students: An Ontology-Driven Framework, Elias S. Lopez

Electrical and Computer Engineering ETDs

As higher education continues to adapt to the constantly shifting conditions that society places on institutions, the enigma of student attrition continues to trouble universities. Early alerts for students who are at-risk academically have been introduced as a method for solving student attrition at these institutions. Early alert systems are designed to provide students who are academically at-risk a prompt indication so that they may correct their performance and make progress towards successful semester completion. Many early alert systems have been introduced and implemented at various institutions with varying levels of success. Currently, early alert systems employ different techniques for …

Through-The-Wall Radar Imaging With Compressive Sensing; Theory, Practice And Future Trends-A Review, Abdi Abdalla

Tanzania Journal of Science

Through-the-Wall Radar Imaging (TWRI) is anemerging technology which enables us to detect behind the wall targets using electromagnetic signals. TWRI has received considerable attention recently due to its diverse applications. This paper presents fundamentals, mathematical foundations and emerging applications of TWRI with special emphasis on Compressive Sensing (CS) and sparse image reconstruction.Multipath propagation stemming from the surrounding walls and nearby targets are among the impinging challenges.Multipath components produce replicas of the genuine target, ghosts, during image reconstruction which may significantly increase the probability of false alarm. The resulting ghost not only creates confusion with genuine targets but may deteriorate the …

An Implantable Peripheral Nerve Recording And Stimulation System For Experiments On Freely Moving Animal Subjects, Byunghun Lee, Mukhesh K. Koripalli, Yaoyao Jia, Joshua Acosta, M. S. E. Sendi, Yoonsu Choi, Maysam Ghovanloo

Electrical and Computer Engineering Faculty Publications

A new study with rat sciatic nerve model for peripheral nerve interfacing is presented using a fully-implanted inductively-powered recording and stimulation system in a wirelessly-powered standard homecage that allows animal subjects move freely within the homecage. The Wireless Implantable Neural Recording and Stimulation (WINeRS) system offers 32-channel peripheral nerve recording and 4-channel current-controlled stimulation capabilities in a 3 × 1.5 × 0.5 cm3 package. A bi-directional data link is established by on-off keying pulse-position modulation (OOK-PPM) in near field for narrow-band downlink and 433 MHz OOK for wideband uplink. An external wideband receiver is designed by adopting a commercial software …

Solid State Light Conversion, Jumana Turkistani

Honors Theses

Demand for innovative and energy-efficient technology has increased as an environmentally sustainable society has become priority. Technological development of solid-state light plays a part in meeting that demand. Our research has revealed that LED (Light Emitting Diode) lighting uses less energy and is a more cost effective and environmentally responsible choice than incandescent and fluorescent lighting. Converting from incandescent and fluorescent dominated lighting to LED lighting may be cumbersome but can result in a classroom milieu that is attractive, cost/energy effective, easy to manipulate as well as facilitative to learning. For this project, a small-scale mockup of the light fixtures …

Multiple-Photon Excitation Of Nitrogen Vacancy Centers In Diamond, Peng Ji, Ryan Balili, Jonathan Beaumariage, Silpa Mukherjee

University Faculty Publications and Creative Works

We report the observation of multiphoton photoluminescence excitation (PLE) below the resonant energies of nitrogen vacancy (NV) centers in diamond. The quadratic and cubic dependence of the integrated fluorescence intensity as a function of excitation power indicates a two-photon excitation pathway for the NV- charge state and a three-photon process involved for the neutral NV0 charge state, respectively. Comparing the total multiphoton energy with its single-photon equivalent, the PLE spectra follows the absorption spectrum of single photon excitation. We also observed that the efficiency of photoluminescence for different charge states, as well as the decay time constant, was dependent on …

Music Keyboard Based On Flexible Hybrid Electronics, Anthony Hanson

Honors Theses

With the idea of creating a product using flexible hybrid electronics, the group decided to create a musical keyboard like a synthesizer. This is implemented using a printing technique called screen printing. This allowed the group to make several copies of the same sensors with a consistent thickness, roughness, and size. These keys, made of silver, are used as capacitive proximity sensors. When another conductive material comes within range of the key to change the polled capacitance by 2.7 pF, the note corresponding with that key is outputted.

In the interest of making this project a useful tool for someone …

Initial Beam Access Schemes For Millimeter Wave Cellular Networks, Mohammed Jasim

USF Tampa Graduate Theses and Dissertations

Millimeter wave technologies present an appealing solution for increasing data throughputs as they provide abundant contiguous channel bandwidths as compared to conventional microwave networks. However, millimeter wave technologies suffer from severe propagation limitations and channel impairments such as atmospheric attenuation and absorption, path and penetration losses, and blockage sensitivity. Therefore, phased arrays and beamforming technologies are necessary to compensate for the degraded signal levels due to the aforementioned factors. Namely, base stations and mobile stations utilize directional transmission in the control- and data- plane for an enhanced channel capacity, which results in initial access challenges due to the absence of …

Electrical And Material Properties Of Hydrothermally Grown Single Crystal (111) Uo2, Christina L. Dugan, George Glenn Peterson, Alyssa Mock, Christopher Young, J. Matthew Mann, Michael Nastasi, Mathias Schubert, Lu Wang, Wai-Ning Mei, Iori Tanabe, Peter A. Dowben, James Petrosky

Department of Electrical and Computer Engineering: Faculty Publications

The semiconductor and optical properties of UO₂ are investigated. The very long drift carrier lifetimes, obtained from current-voltage I(V) and capacitance-voltage C(V) measurements, along with the well-defined optical properties provide little evidence of an abundance of material defects away from the surface region. Schottky barrier formation may be possible, but very much dependent on the choice of contact and surface stoichiometry and we find that Ohmic contacts are in fact favored. Depth resolved photoemission provided evidence of a chemical shift at the surface. Density functional theory, with the Heyd-Scuseria-Ernzerhof (HSE) functional, indicates a band gap of a 2.19 eV …

Degradation Modeling And Rul Prediction Using Wiener Process Subject To Multiple Change Points And Unit Heterogeneity, Yuxin Wen, Jianguo Wu, Devashish Das, Tzu-Liang Bill Tseng

Engineering Faculty Articles and Research

Degradation modeling is critical for health condition monitoring and remaining useful life prediction (RUL). The prognostic accuracy highly depends on the capability of modeling the evolution of degradation signals. In many practical applications, however, the degradation signals show multiple phases, where the conventional degradation models are often inadequate. To better characterize the degradation signals of multiple-phase characteristics, we propose a multiple change-point Wiener process as a degradation model. To take into account the between-unit heterogeneity, a fully Bayesian approach is developed where all model parameters are assumed random. At the offline stage, an empirical two-stage process is proposed for model …

Human Behavior Modeling For Residential Energy Consumption, Mesfer Alrizq

Research and Creative Activities Poster Day

Electric utility companies are interested in load profile (electricity consumption) data for expansion planning. Conventional methods of collecting the load profile data, such as surveys and metering, are tedious and time consuming activities. Cumbersome data collection processes also pose barriers. We present an innovative behavior model for generating electricity consumption load profiles. The model, based on fuzzy logic and activity graphs, requires minimum consumer data and can be easily updated to adapt to changes in technology. We demonstrate the accuracy of our model against real world data.

Experimental Testing Of A Metamaterial Slow Wave Structure For High-Power Microwave Generation, Kevin Aaron Shipman

Electrical and Computer Engineering ETDs

Experimental Testing of a Metamaterial Slow Wave Structure for High-Power Microwave Generation

by

Kevin Aaron Shipman

B.S., Exercise Science, University of New Mexico, 2008

A.S., Mathematics, San Juan College, 2014

M.S., Electrical Engineering, University of New Mexico, 2018

Abstract

A high-power L-band microwave source has been developed using a metamaterial (MTM) to produce a biperiodic double negative slow wave structure (SWS) for interaction with an electron beam. The beam is generated by a ~700 kV, ~6 kA short pulse (~ 10 ns) electron beam accelerator. The design of the metamaterial SWS (MSWS) consists of a cylindrical waveguide, loaded with alternating …

An Exploration Of The Optical Detection Of Ionizing Radiation Utilizing Modern Optics Technology, Sean D. Fournier, Adam Hecht, Cassiano De Oliveira, Jeffrey B. Martin, Richard K. Harrison, Charles Potter

Nuclear Engineering ETDs

Modern ultraviolet (UV) cameras, when combined with UV-transmitting lenses/filter arrangements, can be used to detect radiation dose in air. Ionizing radiation excites nitrogen molecules in ambient air, the resulting decay includes weak emission of ultraviolet photons. Previous work has proven this phenomenon is detectable using highly-sensitive electronically cooled cameras traditionally used in astronomy for low-background imaging. While the ability to detect the presence of radiation (i.e. qualitative measurement) has been demonstrated at Sandia National Laboratories, there are several challenges in correlating images to known dose-fields (quantitative measurement). These challenges include: a low signal to background ratio, interferences due to electronic …

Integration And Cross-Coupling Of A Notched-Turbine Symbiotic Power Source For Implantable Medical Devices, Samuel Perez

USF Tampa Graduate Theses and Dissertations

The purpose of this research is to design and integrate a symbiotic notched-turbine energy generator for implantation as a cross-coupled system capable of continuously and perpetually powering an electronic implantable medical device (IMD), which is a device designed to operate inside the body of a higher mammal to enhance, correct or provide the body with a function that has deviated from the norm or has stopped altogether. The list of IMDs available for implantation keeps growing every year, one of the newest being the VBLOC, produced by EnteroMedics®, and approved by the Food and Drug Administration (FDA) on January 15th, …

The Eco-Smart Can V2.0, Darack B. Nanto

Appalachian Student Research Forum

I noticed that the workers had the same itinerary when emptying trashcans, meanwhile trashcans needed urgently to be emptied. Traditionally, ETSU maintenance operate on daily routes to pick trash on designated time, regardless the level of the containers. This leads to overflown trashcan in busy areas or during rush hours in certain areas. This overflown trashcan result in an unclean environment for the community and an unpleasant look of our beautiful campus. The time, resources and labor invested in collecting the trash could be saved. Therefore, I decided to use the Internet of Things (IoT) to create a device that …

On The Computation Of The Rate-Equivocation Region For Wyner's Wire-Tap Channels, Meena Gangula

LSU Doctoral Dissertations

In a wire tap channel, the transmitter Alice communicates with the legitimate receiver, Bob, in the presence of another receiver, Eve. The goal is to keep the wiretapper, Eve, as ignorant as possible about the information sent to Bob. For communication channels where the adversary, Eve, eavesdrops on the information sent between the legitimate users by wiretapping at the Bob's end, Wyner introduced secure encoding schemes and showed that non zero reliable transmission rate is possible in perfect secrecy. Wyner also obtained the information theoretic achievable rate equivocation region (Rb, DeltaK) for discrete memoryless wire tap channels. The rate equivocation …

Considerations On Direct Balancing Of Ultra-High Power Ac Arc Furnaces In Uneasy State, Ikenna Louis Ezeonwumelu

LSU Master's Theses

During the operation of ultra-high-power ac arc furnace the negative effects of unbalance mostly occur in the secondary terminals of the transformer connected to the load. Hence balancing and compensating the furnace at this terminal will not only improve the transformer efficiency but also reduce energy losses that do occur. In this thesis a computer modeling of a reference ac arc furnace in both balanced and unbalanced states were simulated, and the effects of a reactive balancing compensator installed on the secondary side of the furnace transformer was evaluated to see how much delivered energy improvement can be obtained. The …

Advanced Modeling, Design, And Control Of Ac-Dc Microgrids, Hossein Saberi Khorzoughi

LSU Doctoral Dissertations

An interconnected dc grid that comprises resistive and constant-power loads (CPLs) that is fed by Photovoltaic (PV) units is studied first. All the sources and CPLs are connected to the grid via dc-dc buck converters. Nonlinear behavior of PV units in addition to the effect of the negative-resistance CPLs can destabilize the dc grid. A decentralized nonlinear model and control are proposed where an adaptive output-feedback controller is employed to stabilize the dc grid with assured stability through Lyapunov stability method while each converter employs only local measurements. Adaptive Neural Networks (NNs) are utilized to overcome the unknown dynamics of …

A Low-Cost Arduino-Based Home Security System, Qi Lu

Annual Graduate Student Symposium

Home security is important for every family, especially for the family which lives in a big house. Because the house is much bigger than apartment or dorm, it is hard for the owner to notice if someone is intruding into their house. On the other hand, the home security systems sell in in the market are usually expensive. To address this problem, a low-cost home security system is designed and implemented. When the system is armed, infrared sensors are used to detect intruders. When a person is detected, sensors will send the signal to the user wirelessly, and indoor alarm …