Engineering Commons^™

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.

Counterfeit Detection With Multispectral Imaging, Ian Spatz

Electrical Engineering Undergraduate Honors Theses

Multispectral imaging is becoming more practical for a variety of applications due to its ability to provide hyper specific information through a non-destructive analysis. Multispectral imaging cameras can detect light reflectance from different spectral bands of visible and nonvisible wavelengths. Based on the different amount of band reflectance, information can be deduced on the subject. Counterfeit detection applications of multispectral imaging will be decomposed and analyzed in this thesis. Relations between light reflectance and objects’ features will be addressed. The process of the analysis will be broken down to show how this information can be used to provide more insight …

Design Of An Embedded Iris Recognition System For Use With A Multi-Factor Authentication System., Christopher David Hess

Electrical Engineering Undergraduate Honors Theses

This paper describes in detail the design, manufacturing and testing of an embedded iris scanner for use with a multifactor authentication system. The design process for this project included hardware design from part selection to board design to populating. Additionally, this process included the entirety of the software development, though the iris recognition process was largely based on other works. The functional requirements for the overall multi-factor authentication system were to have three authentication methods with a thirty second window to complete all three. The system acceptance accuracy was required to be greater than 75%. Those requirements therefore dictate that …

Modeling Solder Ball Array Interconnects For Power Module Optimization, Paul Swearingen

Electrical Engineering Undergraduate Honors Theses

PowerSynth is a software platform that can co-optimize power modules utilizing a 2D topology and wire bond interconnects. The novel 3D architectures being proposed at the University of Arkansas utilize solder ball interconnects instead of wire bonds. Therefore, they currently cannot be optimized using PowerSynth. This paper examines methods to accurately model the parasitic inductance of solder balls and ball grid arrays so they may be implemented into software for optimization. Proposed mathematical models are validated against ANSYS Electromagnetics Suite simulations. A comparison of the simulated data shows that mathematical models are well suited for implementation into optimization software platforms. …

Identifying Fake News Using Emotion Analysis, Brady Gilleran

Computer Science and Computer Engineering Undergraduate Honors Theses

This paper presents research applying Emotional Analysis to “Fake News” and “Real News” articles to investigate whether or not there is a difference in the emotion used in these two types of news articles. The paper reports on a dataset for Fake and Real News that we created, and the natural language processing techniques employed to process the collected text. We use a lexicon that includes predefined words for eight emotions (anger, anticipation, disgust, fear, surprise, sadness, joy, trust) to measure the emotional impact in each of these eight dimensions. The results of the emotion analysis are used as features …

Applications Of Fog Computing In Video Streaming, Kyle Smith

Computer Science and Computer Engineering Undergraduate Honors Theses

The purpose of this paper is to show the viability of fog computing in the area of video streaming in vehicles. With the rise of autonomous vehicles, there needs to be a viable entertainment option for users. The cloud fails to address these options due to latency problems experienced during high internet traffic. To improve video streaming speeds, fog computing seems to be the best option. Fog computing brings the cloud closer to the user through the use of intermediary devices known as fog nodes. It does not attempt to replace the cloud but improve the cloud by allowing faster …

Prototyping A Capacitive Sensing Device For Gesture Recognition, Chenglong Lin

Computer Science and Computer Engineering Undergraduate Honors Theses

Capacitive sensing is a technology that can detect proximity and touch. It can also be utilized to measure position and acceleration of gesture motions. This technology has many applications, such as replacing mechanical buttons in a gaming device interface, detecting respiration rate without direct contact with the skin, and providing gesture sensing capability for rehabilitation devices. In this thesis, an approach to prototype a capacitive gesture sensing device using the Eagle PCB design software is demonstrated. In addition, this paper tested and evaluated the resulting prototype device, validating the effectiveness of the approach.

Structural Design Guidelines For Pervious Concrete Pavements, April Smith

Civil Engineering Undergraduate Honors Theses

Pervious pavements have gained popularity in recent years as the transportation industry focuses on sustainability and environmental impact. This research investigated the structural design of pervious concrete pavements. There is no standard design method; therefore, the goal was to lessen ambiguity surrounding the use of pervious concrete for pavement structures. By characterization of the rigid pavement design equation from the 1993 AASHTO Structural Design Guide for Design of Pavement Structures through laboratory exploration and review of existing literature, a guide was created to assist engineers in the design of pervious concrete pavements.

Autonomous Boat Control Software Design Using Model-Based Systems Engineering, Noah Nelson

Electrical Engineering Undergraduate Honors Theses

While there is considerable buzz about self-driving cars, self-driving boats are actually more fully developed. The Boat Hardware Control Platform Team was tasked with developing a fleet of small autonomous boats that travel to a destination while avoiding obstacles and staying in formation. The author’s specific task was to develop software used by the boats to detect obstacles and plan a route to a destination. This was done using a method inspired by self-driving cars, which shows promise, but is still being tested at the time of writing. The entire project incorporated model-based systems engineering, which proved to be useful.

Optimization Of Ultra-Low Power Application-Specific Asynchronous Deep Learning Integrated Circuit Design, Cole Sherrill

Computer Science and Computer Engineering Undergraduate Honors Theses

The Internet of Things (IoT) consists of all devices connected to the internet, including battery-powered devices like surveillance cameras and smart watches. IoT devices are often idle, making leakage power a crucial design constraint. Currently, there are only a few low-power application-specific processors for deep learning. Recently, the Trustable Logic Circuit Design (TruLogic) laboratory at the UofA designed an asynchronous Convolutional Neural Network (CNN) system. However, the original design suffered from delay-sensitivity issues undermining its reliable operation. The aim of this thesis research is to modify the existing CNN circuit to achieve increased reliability and to optimize the improved design …

Designing A Solar Pv System To Power A Single-Phase Distribution System, Ana Guerra Vega

Electrical Engineering Undergraduate Honors Theses

Over the last decade, the costs of PV system components have dropped more than 70%. Additionally, green energy incentives like the 30% tax credit have been pushed forward. PV solar systems have become accessible to the general public. Companies are pledging to reduce their carbon emissions.

As part of their green initiative, the City of Fayetteville has requested a feasibility study for a PV system to be installed on the rooftop of the Facilities Management building, 115 S. Church Ave, Fayetteville, AR, 72701. This thesis shows the design process of this PV system and the return on investment estimation. While …

Predicting The Mechanical Properties Of Nanocomposites Reinforced With 1-D, 2-D And 3-D Nanomaterials, Scott Edward Muller

Graduate Theses and Dissertations

Materials with features at the nanoscale can provide unique mechanical properties and increased functionality when included as part of a nanocomposite. This dissertation utilizes computational methods at multiple scales, including molecular dynamics (MD) and density functional theory (DFT), and the coupled atomistic and discrete dislocation multiscale method (CADD), to predict the mechanical properties of nanocomposites possessing nanomaterials that are either 1-D (carbyne chains), 2-D (graphene sheets), or 3-D (Al/amorphous-Si core-shell nanorod).

The MD method is used to model Ni-graphene nanocomposites. The strength of a Ni-graphene nanocomposite is found to improve by increasing the gap between the graphene sheet and a …

Fault Adaptive Workload Allocation For Complex Manufacturing Systems, Charlie B. Destefano

Graduate Theses and Dissertations

This research proposes novel fault adaptive workload allocation (FAWA) strategies for the health management of complex manufacturing systems. The primary goal of these strategies is to minimize maintenance costs and maximize production by strategically controlling when and where failures occur through condition-based workload allocation.

For complex systems that are capable of performing tasks a variety of different ways, such as an industrial robot arm that can move between locations using different joint angle configurations and path trajectories, each option, i.e. mission plan, will result in different degradation rates and life-expectancies. Consequently, this can make it difficult to predict when a …

The Role Of Inter-Particle Behavior In Iron Oxide Nanoparticle Induction Heating, Hayden Seth Carlton

Graduate Theses and Dissertations

Due to their multi-functional nature, iron oxide nanoparticles present themselves in a myriad of scientific disciplines, but perhaps the most interesting property of these nanomaterials can be seen in their immense thermal response under the influence of alternating magnetic fields. Currently popularized as an alternative cancer treatment through localized hyperthermia, iron oxide nanoparticle induction heating presents an interesting physical phenomenon that distinguishes itself from macroscopic induction heating. Understanding how a single spherical particle behaves is relatively simple and remains well documented; however, magnetic interactions of a single particle often extend over many length scales, affecting numerous neighboring particles in the …

Auto-Calibration Of Wim Using Traffic Stream Characteristics, Johnson Baker

Graduate Theses and Dissertations

This project evaluates the performance of Weigh-in-Motion (WIM) auto-calibration methods used by the Arkansas Department of Transportation (ARDOT). Typical auto-calibration algorithms compare the WIM measured weights of vehicles from the traffic stream to reference values, using five-axle tractor-trailer configured trucks for comparisons, e.g. Federal Highway Administration (FHWA) Class 9. Parameters of the existing algorithms including the Front Axle Weight (FAW) reference value, the sampling frequency required to update the calibration factor, and thresholds for Gross Vehicle Weight (GVW) bins were evaluated. The primary metric used to estimate algorithm performance was Mean Absolute Percent Error (MAPE) between the WIM and static …

Motor Control Systems Analysis, Design, And Optimization Strategies For A Lightweight Excavation Robot, Austin Jerold Crawford

Graduate Theses and Dissertations

This thesis entails motor control system analysis, design, and optimization for the University of Arkansas NASA Robotic Mining Competition robot. The open-loop system is to be modeled and simulated in order to achieve a desired rapid, yet smooth response to a change in input. The initial goal of this work is to find a repeatable, generalized step-by-step process that can be used to tune the gains of a PID controller for multiple different operating points. Then, sensors are to be modeled onto the robot within a feedback loop to develop an error signal and to make the control system self-corrective …

Vector Flow Imaging In Pediatric Cardiology - Extracting And Validating Data, Mason Belue

Biomedical Engineering Undergraduate Honors Theses

In the field of bedside cardiac diagnostic imaging, Doppler Ultrasound (DU) is the gold standard for diagnosing heart conditions. The largest benefit of DU is its ability to noninvasively image cardiac flow and allow the estimation of blood velocity and quantification of anatomical disease. However, to get correct velocity estimation, the position of the transducer in relation to the flow field needs to be known. This is the problem of angle/direction dependency and limits DUs accuracy when imaging in areas where perfect alignment or exact position of the transducer in relation to flow field is not possible or known, such …

Role Of Angiotensin I And Ii On The Tissue Mechanics Of The Aortic Heart Valve Via Receptor Binding And Converting Enzymes, Josh Fahy

Biomedical Engineering Undergraduate Honors Theses

The renin-angiotensin system (RAS) plays a crucial role in the regulation of renal, cardiac, and vascular physiology. This system regulates in vivo blood pressure and fluid balance. As renal blood flow decreases, the kidneys convert prorenin into renin and secrete it into the circulatory system. Renin then converts angiotensinogen into angiotensin I (ang-I). The ang-I is then converted into angiotensin II (ang-II) by the angiotensin-converting enzyme (ACE). Ang-II, a vasoconstrictor, increases blood pressure by causing the blood vessels to narrow. Recent evidence suggests that RAS may be involved in the progression of valve disease, most notably, aortic stenosis.

The first …

Investigation Of Acute Radiation-Induced Changes In Oxygenation In A Murine Breast Tumor Model, Alaa Abdelgawad

Biomedical Engineering Undergraduate Honors Theses

Around 50-60% of all cancer patients undergo radiation therapy. Although some patients show complete response with no recurrence, a significant proportion of the population still develop radiation resistance. It is important to identify tumor resistance at early stages of therapy in order to adjust treatment protocol and avoid extra exposure to radiation. Current methods to assess treatment response are only limited to anatomical measurements of tumor volume after therapy. Novel approaches that shed the light on any functional information during the course of radiotherapy could significantly improve our ability to identify patients who do not respond to radiation therapy. Diffuse …

Designing An In Vitro Mitral Valve Mounting And Testing System For Micro Ct Imaging, Marinna Tadros

Biomedical Engineering Undergraduate Honors Theses

Five million people in the US are diagnosed with valvular disease, of which mitral valve disease is one of the most common. Computational models are informed by high resolution images and have the potential to aid in diagnosing and establishing surgical plans to treat mitral valve diseases. Existing methods using 7T MRI imaging have limitations such as small bore diameter, long imaging times and difficulty in maintaining trans-mitral fluid pressure throughout the scan. Imaging with Micro CT allows for efficient scan times and eliminates bore size constraints which allows for imaging more sizes and types of MVs. There is a …

Simulating Alternative Tuberculosis Diagnosis Methods In Underdeveloped Countries, Luke Turner

Industrial Engineering Undergraduate Honors Theses

Tuberculosis is the deadliest infectious disease in the world; it is especially rampant in underdeveloped countries because they do not have the infrastructure, technology, or funding to properly combat the infection. However, the development of portable point-of-care diagnosis machines can reverse this epidemic as they far surpass conventional laboratory identification. The question now is where to place these machines, which is a difficult decision with a lack of data. Therefore, a flexible simulation model is created to test the implementation of these machines with different countries and configurations. The simulation tests the baseline model and three proposed implementations of the …

Characterizing Truck Parking Shortages In Arkansas: A Data Analytical Approach, Morgan Hartsell

Industrial Engineering Undergraduate Honors Theses

The Truck Parking Problem occurs when drivers have met the daily driving limit and encounter a decision between driving over time or parking in unauthorized locations. This research applies data analytics to gain further knowledge to characterize the truck parking shortage in Arkansas. Truck parking shortages are a serious problem that truck drivers face daily and is complex due to Hours of Service (HOS) regulations restrictions on legal parking areas and design. Existing research includes a one-day annual survey which compiles where public rest stops, businesses, and private rest stops are utilized by truck drivers. This research expands on the …

Silicone Tadpole: Research Into Soft Bodies, Danielle Fernandez

Mechanical Engineering Undergraduate Honors Theses

In this thesis, research is conducted in the area of soft robotics by building a soft tadpole that can deform with a specific air pressure. The goal is to mimic the motion of an organic tadpole in respect to its S-shaped tail movement. The angle of deformation, derived from material mechanic theories, ranges from 45 to 80 degrees for this type of movement. The design includes a head compartment which acts as a tank to transfer nitrogen pressure and a tail section that receives the said pressure and bends as a result. The tail section was designed with two rows …

Data Visualization Of Treatment Outcomes For Tuberculosis Patients, Joy Jenkins

Industrial Engineering Undergraduate Honors Theses

Tuberculosis is an infectious disease, and different treatments have been discovered over the years. However, patients may develop various drug resistance levels that affect the likelihood of becoming cured or dying. In this study, we sought to employ data visualization to explore the relationship between treatment trajectory, as indicated by smear and culture results in the follow-up tests and patient outcomes. A large sample of patients have been broken down by demographics including age, gender, and drug resistance status. Sankey diagrams were used to visualize the pathway progression of the patients over time split between two time periods- months 0-6 …

Investigating Virus Clearance Via Ph Inactivation During Biomanufacturing, Wenbo Xu

Biomedical Engineering Undergraduate Honors Theses

In the processing of biopharmaceuticals, viral clearance and viral safety are important for the development of monoclonal antibodies. Murine xenotropic leukemia virus (XMuLV) is one of the retroviruses, recommended by Food and Drug Administration (FDA) as a model virus for viral clearance via inactivation from therapeutics derived from Chinese hamster ovary cells (CHO). A robust and effective method was investigated to clear or inactivate endogenous viruses by low pH inactivation. The effects of different conductivity and inactivated time on XMuLV clearance was determined. Acetate buffer was prepared with different conductivity, and 2% XMuLV was spiked into acetate buffer. XMuLV virus …

Effect Of Polymer Composition Of Injectable Hydrogels On Programmable Release Of Methylene Blue, Mary Brandecker

Biomedical Engineering Undergraduate Honors Theses

Temperature sensitive hydrogels have been used as injectable hydrogels because the polymer solutions can be liquid at room temperature and gel at body temperature. Injectable hydrogels have been used in biomedical applications to deliver drugs and other small molecules throughout the body. Methylene Blue was used as the drug in this study for its antioxidant and neuroprotective properties. PluronicⓇ F127 (PF127) is a copolymer consisting of repeating units of polyethylene oxide and polypropylene oxide in the form PEO-PPO-PEO. PF127 in solution is a temperature sensitive hydrogel that transitions to a gel at body temperature at specific polymer compositions. A standard …

Phenotypic Characterization Of Differentiation Of Human Mesenchymal Stem Cells To Smooth Muscle Cells, Jackson Hedrick

Biomedical Engineering Undergraduate Honors Theses

Abdominal aortic aneurysms (AAAs) are expansions in the aortic wall with an increased tendency to rupture. These expansions are triggered by the breakdown of key aortic extracellular matrix (ECM) proteins—elastin and collagen. The degradation of aortic ECM proteins is the consequence of overexpressed matrix metalloproteases (MMPs)–MMP-2 and MMP-9. Adult vascular smooth muscle cells (SMCs) lack the ability to repair the elastic matrix assembly; thus, it is imperative to find a solution to both restore the imbalance of essential ECM proteins in the aorta and mitigate the effects of MMPs. Previous studies have revealed that bone marrow derived mesenchymal stem cells …

Silver-Based Microbial Check Valve For Spacecraft Potable Water Systems, Jennifer Gaines

Chemical Engineering Undergraduate Honors Theses

As human space exploration increases, the development of a more efficient potable water treatment system suited for spacecraft becomes crucial. This Waste-management Education Research Consortium (WERC) challenge was designed to explore the viability of microbial control through the utilization of silver ions as a biocide for possible integration into the Tranquility Node 3 water purification system aboard the International Space Station (ISS). Current systems using iodine risk causing hyperthyroidism from overexposure; however, silver can be safely ingested without this side effect. After researching silver delivery methods including electrochemical ion production, controlled release, or a combination of the two, our team …

Design And Cost Analysis Of Acrylic Acid Plant, Adam Ferrier

Chemical Engineering Undergraduate Honors Theses

The purpose of this project was to model and design a plant to produce 75,000 tons per year of acrylic acid. Using the design in section B.9 of Richard Turton’s Analysis, Synthesis, and Design of Chemical Processes as a starting point, a plant was designed based around the partial oxidation of propylene to acrylic acid. The final plant design produces about 86,000 tons per year of acrylic acid. Using an interest rate of 10%, the plant has a discounted cash flow rate of return of 32% over 2 years of startup and 10 years of operation. Attached is an executive …

Development Of A Ws2 Catalyst For Hydrogen Evolution And Improvement Via Platinum Nanoparticle Decoration, Alexander O'Brien

Chemical Engineering Undergraduate Honors Theses

In response to a growing global need to improve utilization of green energy, the concept of renewable energy storage via electrolytic hydrogen production has gained popularity in recent years. However, the prohibitive expense of the bulk platinum catalysts currently used for the hydrogen evolution reaction prevents such a concept from being widely adoptable. This research focuses on a possible alternative catalyst, nanolayer WS₂, which is capable of promoting the hydrogen evolution reaction while maintaining economic viability. Bulk WS₂ was prepared in semiconducting, nanolayer form through liquid phase exfoliation. Prepared catalyst inks consisting of this material demonstrated successful …