Engineering Commons^™

Using Transfer Learning In Network Markets, Kai Cai

Dissertations, Theses, and Capstone Projects

Mechanism design is the sub-field of microeconomics and game theory, which considers agents have their own private information and are self-interested and tries to design systems that can produce desirable outcomes. In recent years, with the development of internet and electronic markets, mechanism design has become an important research field in computer science. This work has largely focused on single markets. In the real world, individual markets tend to connect to other markets and form a big “network market”, where each market occupies a node in the network and connections between markets reflect constraints on traders in the markets. So, …

Fashion Merchandising: An Augmented Reality, Naeha A. Sayed

Dissertations, Theses, and Capstone Projects

There is a continuous and constant transformation in the field of Augmented Reality (AR), both in the Retail, and the Manufacturing sector. It has started to influence everything from fashion runway shows to online shopping. Consumers dynamics have shifted in the fashion industry, the ways becoming more dominant than the old observant ones- the simple buying experience no longer satisfies them. Due to the emergence of the new digital platforms and technological enhancements, the consumers are looking for more- be it a more exciting buying experience or more user interaction or more enhanced products. This technological change starts with the …

Design Of Two-Stage Operational Amplifier Using Indirect Feedback Frequency Compensation, Roderick Gomez

Electrical Engineering Undergraduate Honors Theses

This thesis work details the designing process of two silicon two-stage operational amplifiers with indirect feedback compensation and with Miller compensation technique. The main objective of this thesis is to study the advantages of indirect feedback compensation in comparison with Miller compensation and how this technique can be applied to meet certain design specifications. The operational amplifiers are designed with 130 nm Silicon Germanium CMOS process ideally for temperature range of 25°C to 300°C. The two op-amps are designed to have a DC gain of about 70 dB and 60 degrees of phase margin. The indirect feedback compensation design showed …

Designing, Simulating, And Layout Of An Rfic Mixer In A 130 Nm Sige Process, Logan Walz

Electrical Engineering Undergraduate Honors Theses

Wireless devices are becoming increasingly popular each day ranging from smartphones to Amazon Echo’s to wireless sensors in industry. While all of these devices are quite different in their functions and purposes, they all rely on wireless communication heavily and signal modulation techniques. One component typically seen in wireless applications like this are mixers, which are used to modulate the signal being sent and received. This thesis details the design, simulation, and layout of a radio frequency integrated circuit mixer in a 130 nanometer silicon germanium process. While the fabricated mixer did not perform to standards, many things were learned …

Optical Response Analysis Of Thz Photoconductive Antenna Using Comsol Multiphysics, Jose Isaac Santos Batista

Electrical Engineering Undergraduate Honors Theses

A THz photoconductive antenna consists of antenna pads laid over a photoconductive substrate. These types of antennas are excited through the application of an optical pump (laser), which generates carriers inside the semiconductor. The acceleration and recombination of these carriers produce photocurrent that excites the antenna and generates THz pulse. This thesis focuses on analyzing the optical response of a photoconductive antenna, which consist of the interaction of the incident electric field of a laser pump with the radiating device. It develops the amplitude modulation process of a plane wave of light into a laser pump. It also takes into …

Characterization Of High Temperature Optocoupler For Power Electronic Systems, David Gonzalez

Electrical Engineering Undergraduate Honors Theses

High-temperature devices have been rapidly increas due to the implementation of new technologies like silicon carbide, high-temperature ceramic, and others. Functionality under elevated temperatures can reduce signal integrity reducing the reliability of power electronic systems. This study presents an ongoing research effort to develop a high-temperature package for optocouplers to operate at higher temperature compared with commercial devices. Low temperature co-fired ceramic (LTCC) was used as the substrate. Bare die commercial LED and photodetectors were attached to the substrate and tested for functionality. Preliminary results show enhanced performance at elevated temperatures compared to a commercial optocoupler device.

Synthesis And Characterization Of Dielectric And Multiferroic Nanocrystalline Transition Metal Oxide Materials And Nanocomposites, Frederick A. Pearsall

Dissertations, Theses, and Capstone Projects

Nanocrystalline transition metal oxides with unique chemical, physical, magnetic and dielectric properties have very broad applications, ranging from photocatalysis, capacitor energy storage and 4-state memory. Frequency stable, high permittivity nanocomposite capacitors produced under mild processing conditions offer an attractive replacement to MLCCs derived from conventional ceramic firing. In one project reported herein, 0-3 nanocomposites were prepared using BaTiO₃ (barium titanate, BTO) nanocrystals, suspended in a poly(furfuryl alcohol) matrix, resulting in a stable, high effective permittivity, low and stable loss dielectric. Effective medium approximations were used to compare this with similar nanocomposite systems. The use of synthesized BTO nanocrystal photocatalysts …

Left Atrial Model, Borna Sobati, Sarah Porello, Tess Pate

Biomedical Engineering

The objective is to produce an electrophysiological model of an adult human left atrium. This model will be used to test mapping probe catheters used for locating cardiac arrhythmias against current technology used in practice. Dr. Chris Porterfield requested this model and other physicians or probe catheter manufacturers may also use this product in the future. Dr. Porterfield also discussed the possibility of future senior project groups using the model as a bench test for designing new catheter tips. The model will precisely simulate electrical behaviors of the heart in normal as well as arrhythmic conditions. Ideally, the model will …

Generation And Use Of Femtosecond, Gigawatt, Near Infrared Laser Pulses From An Amplified, Mode-Locked, Ti:Sapphire Laser, David Anthony Valdés

Optical Science and Engineering ETDs

This work modeled the early to middle successes achieved in the field of ultrafast, high peak power optics, beginning with the work of Nobel Prize winners Donna Strickland and Gérard Mourou in 1985. In our work, 100 fs light pulses of around 800 nm were generated by a Ti:Sapphire oscillator, then amplified to approximately 30 GW peak power using a chirped pulse amplification system that included regenerative and multi-pass amplifiers. As a verification of our pulses having high peak powers and ultrashort durations, they were then used to strike water, glass, and a Kerr Cell. Supercontinuum generation was observed as …

Outdoor Education Center Concept Site Master Plan And Improvements As Designed By Wingineers, Christina Thibodeau

Honors Program: Senior Projects (Public)

This thesis builds on a basis of four years of engineering education to produce a final project for the capstone course. The idea behind this project was to provide a workable master plan and conceptual site improvements for a real application, the Outdoor Education Center in east Lincoln, Nebraska. The Boy Scouts of America Cornhusker Council and the University of Nebraska – Lincoln Department of Civil Engineering have cooperated throughout the Senior Design capstone course to make this possible for the students involved.

Predictive Modeling Of Fate And Transport Of Three Prevalent Contaminants In Midwest Agroecosystem Surface Waters: Nitrate-N, Atrazine, And Escherichia Coli, Samuel Hansen

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The majority of streams and rivers in the United States (U.S.) are ecologically impaired, or threatened by anthropogenic stressors. Recent reports have found atrazine in drinking water to be associated with increased birth defects and incidences of Non-Hodgkin’s Lymphoma, with higher levels of significance from exposure to both atrazine and nitrate-N. In contrast, recent illnesses from E. coli contaminating vegetables that originated from irrigation water has increased awareness of identifying sources of E. coli entering irrigation reservoirs.

Methods to accurately predict atrazine and E. coli occurrence and potential sources in waterways continue to limit the identifying appropriate and effective prevention …

Uumanned Aerial Vehicle Data Analysis For High-Throughput Plant Phenotyping, Jiating Li

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The continuing population is placing unprecedented demands on worldwide crop yield production and quality. Improving genomic selection for breeding process is one essential aspect for solving this dilemma. Benefitted from the advances in high-throughput genotyping, researchers already gained better understanding of genetic traits. However, given the comparatively lower efficiency in current phenotyping technique, the significance of phenotypic traits has still not fully exploited in genomic selection. Therefore, improving HTPP efficiency has become an urgent task for researchers. As one of the platforms utilized for collecting HTPP data, unmanned aerial vehicle (UAV) allows high quality data to be collected within short …

Methods To Remotely Eliminate Biofilm From Medical Implants Using 2.4 Ghz Microwaves, Brett Glenn

Mechanical Engineering Undergraduate Honors Theses

Infections associated with biofilm growth are usually challenging to eradicate due to their high tolerance toward antibiotics [11, 12]. Biofilms often form on the inert surfaces of medically implanted devices [13]. No matter the sophistication, microbial infections can develop on all medical devices and tissue engineering constructs [12]. Related infections lead to 2 million cases annually in the U.S., costing the healthcare system over $5 billion in additional healthcare expenses [12].

Novel solutions to biofilm’s microbial colonization span the spectrum of engineering and science disciplines. Yet a practical solution still does not exist. The research presented here will explore a …

Challenges And Opportunities Of Layered Cathodes Of Linixmnyco(1-X-Y)O2 For High-Performance Lithium-Ion Batteries, Jason Frank

Mechanical Engineering Undergraduate Honors Theses

High energy density lithium-ion batteries (LIBs) are widely demanded for portable electronic devices and electrical vehicles. Layered-structure LiCoO₂ oxide (LCO) has been the most commonly used cathode material in commercial LIBs. Compared to LCO, LiNi_1-x-yMn_xCo_yO₂ (NMC) cathodes are particularly attractive due to their reduced cost and higher capacity. Among the NMC cathodes, nickel-containing LiNi_0.5Co_0.3Mn_0.2O₂ (NMC532) is one of the most promising cathode materials undergoing intensive investigation, but suffers from a series of technical issues, such as structural instability, performance fading, and safety issues. In this …

Development Of Small-Scale And Low-Power Attitude Determination System For Nanoscale Satellites By Infrared Earth-Imaging Sensors, Zachary Tolar

Mechanical Engineering Undergraduate Honors Theses

Many space missions require that the spacecraft be oriented in a specific direction to operate correctly. ARKSAT 1, the University of Arkansas’s first satellite, is a 1U CubeSat designed to perform atmospheric spectroscopy from Low-Earth Orbit and as such requires precise attitude determination and control. Currently, attitude determination systems for 1U CubeSats with small space, low power, and low cost restrictions do not exist. This paper discusses the development of an earth-imaging infrared camera system for attitude determination on CubeSats and SmallSats that meets these requirements. Melexis MLX 90640 IR arrays and Microchip 8-bit microcontrollers are used to create infrared …

Modelling Palladium Decorated Graphene Using Density Functional Theory To Analyze Hydrogen Sensing Application, Sameer Kulkarni

Mechanical Engineering Undergraduate Honors Theses

Graphene is an exciting new material with many promising applications. One such application of graphene is gas sensing, when adsorbed with transition metals, notably Palladium. Therefore, it is of paramount importance to have appropriate ab initio calculations to calculate the various properties of graphene under different adsorbates and gasses. The first step in these calculations is to have a functioning base Density Functional Theory (DFT) model of pristine graphene decorated with Palladium. The computational methods described in this paper has yielded results for pristine graphene that have been confirmed many times in previous experimental and theoretical studies. Future work needs …

Real-Time Visual Multi-Target Tracking In Realistic Tracking Environments, Jacob Harley White

Theses and Dissertations

This thesis focuses on visual multiple-target tracking (MTT) from a UAV. Typical state-of-the-art multiple-target trackers rely on an object detector as the primary detection source. However, object detectors usually require a GPU to process images in real-time, which may not be feasible to carry on-board a UAV. Additionally, they often do not produce consistent detections for small objects typical of UAV imagery.In our method, we instead detect motion to identify objects of interest in the scene. We detect motion at corners in the image using optical flow. We also track points long-term to continue tracking stopped objects. Since our motion …

A 2d/Q-2d Subdomain Finite Element Method For Irregular Power/Ground Plate-Pair Analysis With Waveport Excitation, Ping Li, Li (Lijun) Jun Jiang, Yao Jiang Zhang, Shuai Xu, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

The field distribution of a power/ground plane can be fully characterized by TMzmn modes, where the electric fields have both azimuthal and longitudinal components and the magnetic fields have only the azimuthal component. Thus, if the magnetic fields are defined to be the unknowns in the finite element method (FEM) used for the analysis of the power/ground plane structure, the analysis becomes a quasi-two dimensional (Q-2D) problem. Since the high-order modes are evanescent, they are tightly confined to the near region of the vias guarded by anti-pads; while in the regions sufficiently far from the anti-pads, only the fundamental mode …

2019 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Directory

Contact information for agency officials and employees responsible for Indiana’s local road infrastructure.

Bio-Desalination Of Brackish And Seawater Using Halophytic Algae, Endalkachew Sahle-Demessie, Ashraf Aly Hassan, Amro El Badawy

Department of Civil and Environmental Engineering: Faculty Publications

Global demand for water is rising. A sustainable and energy efficient approach is needed to desalinate brackish sources for agricultural and municipal water use. Genetic variation among two algae species, Scenedesmus species (S. sp.) and Chlorella vulgaris (C. vulgaris), in their tolerance and uptake of salt (NaCl) was examined for potential bio-desalination of brackish water. Salt-tolerant hyper-accumulators were evaluated in a batch photobioreactors over salinity concentration ranging from 2 g/L to 20 g/L and different nutrient composition for their growth rate and salt-uptake. During algae growth phase, the doubling time varied between 0.63 and 1.81 days for S …

Treatment Of Electric Utility Wastewaters By Sol-Gel Solidification And Stabilization, Alex Kearns

Electronic Theses and Dissertations

To meet the demands of new regulations on coal-fired power plants, many treatment scenarios require a zero-liquid discharge (ZLD) approach. Two revisions to regulations in 2015, the Effluent Limitations Guidelines (ELG) and Coal Combustion Residuals (CCRs) rule, drastically changed the treatment approach for managing effluents at coal-fired plants. In some scenarios, coal-fired plants retired early deeming the capital cost for maintaining compliance too expensive. Traditionally, stabilization/solidification (S/S) ZLD technologies have fallen in two categories: cementitious and vitrification. However, neither approach offers the ideal solution for coal-fired power plants needing ZLD by S/S methods. In what follows, a novel sol-gel encapsulation …

Capture And Release Gels For Optimized Storage (Cargos), Theodore S. Kalbfleisch Ii

Electronic Theses and Dissertations

Unassisted, the lifetime of many proteins outside their natural environment is very short. Scientists generally need to extract the sample, often in remote locations, and then transport, isolate, and store such biospecimens relatively far from the point of origin in order to study them. Currently, the most commonly used methods for storage of biospecimens are cryopreservation or refrigeration which, though effective, have their fair share of flaws. Cryopreservation and refrigeration-based storage of biospecimens requires a great deal of space and other resources to be effective. Furthermore, the hardware required for cold storage does not transport well. These factors make such …

Investigation Of Flexural Behavior Of Steel Fiber Reinforced Concrete And Steel Fiber Orientation Control During Construction, Maria Kolisnichenko

Electronic Theses and Dissertations

Concrete is the most widely used construction material in the world, and its consumption has been increasing. The main benefits of concrete include its durability, availability of the components, and great strength in compression. Despite all these advantages, however, concrete is a brittle material with a relatively low tensile strength and deformation capacity. It is, therefore, vulnerable to cracking under tension, which can lead to sudden catastrophic failures of concrete structures. In order to control and reduce cracking, reinforcement of concrete is necessary.

The most commonly used reinforcement technique in structural application is the use of deformed steel bars. However, …

Space Image Processing And Orbit Estimation Using Small Aperture Optical Systems, David Zuehlke

Doctoral Dissertations and Master's Theses

Angles-only initial orbit determination (AIOD) methods have been used to find the orbit of satellites since the beginning of the Space Race. Given the ever increasing number of objects in orbit today, the need for accurate space situational awareness (SSA) data has never been greater. Small aperture (< 0:5m) optical systems, increasingly popular in both amateur and professional circles, provide an inexpensive source of such data. However, utilizing these types of systems requires understanding their limits. This research uses a combination of image processing techniques and orbit estimation algorithms to evaluate the limits and improve the resulting orbit solution obtained using small aperture systems. Characterization of noise from physical, electronic, and digital sources leads to a better understanding of reducing noise in the images used to provide the best solution possible. Given multiple measurements, choosing the best images for use is a non-trivial process and often results in trying all combinations. In an effort to help autonomize the process, a novel “observability metric” using only information from the captured images was shown empirically as a method of choosing the best observations. A method of identifying resident space objects (RSOs) in a single image using a gradient based search algorithm was developed and tested on actual space imagery captured with a small aperture optical system. The algorithm was shown to correctly identify candidate RSOs in a variety of observational scenarios.

An Evaluation Of Wastewater Pumping Station Facilities Using Statistical Techniques In Analyzing Each For Rehabilitation Design And To Improve The Adverse Environmental Affects, Zenaida S. Guerrero

Theses and Dissertations

The objective of this research project is to develop two evaluation models, one using excel to provide a design criterion for wastewater pumping stations in collecting design parameters and information effecting efficiency and performance of the pumps. Secondly, to develop a linear regression model for these parameters giving a correlation between dependent and independent variables to verify adverse environmental aspects. This study is based in the City of Weslaco, pertaining to the north waste watershed. The parameters collected are age, efficiency, service area, total dynamic head, existing conditions, monthly sanitary sewer over flow work orders, precipitation data, population by service …

Design Of A Bedside Walker-Cane Hybrid To Aid Senior Adults Avoid Falls During Night Walks, Jorge L. Gutierrez

Theses and Dissertations

The objective of this research and development work is to design a device to help senior adults prevent fall during night walks indoors. The problem of elders falling at a night setting was found to be caused by the multiple environmental and medical conditions. The target demographic was found to be seniors from age 65 and older. Several occupational therapists and two physical therapists were consulted to gain knowledge on elders' behavior, possible improvements on current existing devices, and feedback regarding the early prototype built. Several products and patents were researched with a lack of findings on similar products that …

Biomechanics Of Lower Limb During The Golf Swing Using Opensim Modeling, Andrew B. Butler

Theses and Dissertations

The purpose of this research is to investigate the biomechanics of the lower-limb using an inverse dynamics model. Experimental data, recorded by an integrated Motion Analysis – Force Plate System in the UTRGV Biomechanics Laboratory, is used to determine ground reaction forces and marker trajectories. OpenSim, a graphical musculoskeletal and computational platform, is used to model the body in three dimensions. The human body is modeled as a 12-segment linkage, consisting of 23 degrees-of-freedom and 92 muscles. The experimental data for the Biomechanics Laboratory is imported in OpenSim. Then, joint angles, generalized coordinates & accelerations of lower-limb segments, muscle forces, …

Experimental Study Of Condensation In Different 3d Printed Regenerators In A Thermoacoustic Cooler, Aibek Bekkulov

Theses and Dissertations

Thermoacoustics (TA) deals with the conversion of heat into sound and vice versa. Device that converts heat into acoustic work is called TA heat engine, while the device that transfers energy from a low temperature reservoir to a high temperature one by utilizing acoustic work is called TA cooler. A simple construction of TA cooler includes an acoustic speaker, a resonator tube and a regenerator stack in which the temperature gradient is being imposed. Such a TA cooler has several advantages over traditional compression/expansion cooling machine such as its simplicity of the construction, high reliability and lack of toxic refrigerants. …

Dehumidification Water Quality Analysis Of The South Texas Gulf Of Mexico, Erik Esteban Castillo

Theses and Dissertations

This project is to introduce a new methodology for environmental research that analyzes humidity from a water treatment perspective. This is done by using a household dehumidifier, which extracts the excess humidity in a given space, to harvest the samples. The dehumidifier was used outside to act as an Atmospheric Water Generator (AWG), which is the process of extracting water from the atmosphere. When AWG is placed near shoreline, then it's classified as a Desalinated Atmospheric Water Generator (DAWG) since it extracts distilled seawater water-vapors. The methodology for DAWG analyzed turbidity in the humidity on SPI, indicating to meet {<.15} TCEQ turbidity water quality standard. The turbidity also showed to have an adverse relation to weather conditions. There is an open market in research on this topic, where the methodology for DAWG can offer answers. This project identifies DAWG as being a sustainable source of potable water for a municipality.

Development Of Flexible Photo-Mechanoluminescent Polymeric Based Systems, Carlos Hernandez

Theses and Dissertations

The project focuses on the creation of nanofiber systems with enhanced photo-mechanoluminescent response and high mechanical flexibility to further enhance promising optical applications. Lanthanide-Polyvinyl Di-Fluoride fiber systems were created using centrifugal spinning and characterized using SEM, FTIR, XPS, DSC, XRD, and PL. Fibers luminescence response was gotten when induced by ultraviolet light and the application of an impact force.