Digital Commons Network^™

Data Driven And Machine Learning Based Modeling And Predictive Control Of Combustion At Reactivity Controlled Compression Ignition Engines, Behrouz Khoshbakht Irdmousa

Dissertations, Master's Theses and Master's Reports

Reactivity Controlled Compression Ignition (RCCI) engines operates has capacity to provide higher thermal efficiency, lower particular matter (PM), and lower oxides of nitrogen (NOx) emissions compared to conventional diesel combustion (CDC) operation. Achieving these benefits is difficult since real-time optimal control of RCCI engines is challenging during transient operation. To overcome these challenges, data-driven machine learning based control-oriented models are developed in this study. These models are developed based on Linear Parameter-Varying (LPV) modeling approach and input-output based Kernelized Canonical Correlation Analysis (KCCA) approach. The developed dynamic models are used to predict combustion timing (CA50), indicated mean effective pressure (IMEP), …

Understanding Subtle Gender Bias Recognition Among Witnesses In A Stem Undergraduate Context, Darnishia Lashalle Morris

Dissertations, Master's Theses and Master's Reports

This dissertation builds on knowledge of how witnesses recognize subtle gender bias (often referred to as gendered microaggressions) in a STEM undergraduate context. This body of work provides a better understanding of the implications of observing these events of subtle bias and the role that recognition plays in providing opportunities to adopt stereotype defying behaviors. The impressions and influences on both witnesses who belong to the marginalized group (target witnesses) and those in majority groups (non-target witnesses) were examined. Three interrelated studies explored how recognition might disrupt the cyclic impact of subtle gender bias when participants witness collaborative STEM team …

A Physical Test Artifact For Evaluating Edge Cases Of Individual And Fused Automated Driving Perception Sensors, Colin Schaefer

Dissertations, Master's Theses and Master's Reports

With the advent of technologies to support autonomous vehicles (AVs), the number of different AV models from a variety of companies and organizations has proliferated. With this increase in options comes the need to physically evaluate their perception systems. However, there is a lack of standard methods to physically evaluate these perception systems. A set of test artifacts can be used to compare the performances of perception systems, but the artifacts must be usable with different types of perception sensors and various sensor fusion systems. This thesis presents the development of an artifact that injects edge case scenarios into the …

Engineering Self-Efficacy And Spatial Visualization: Connecting The Spatial Dots, Katrina L. Carlson

Dissertations, Master's Theses and Master's Reports

Questions exist as to why students in the ENG 1002: Introduction to Spatial Visualization (Spat Vis) course, an intervention course at Michigan Technological University (MTU), have historically attained higher average grades in their first year STEM courses, such as Engineering I and II, calculus I and II, computer science, and chemistry courses. Research shows the retention rate, especially of women, is higher for students who have taken Spatial Visualization. One possible explanation for these observed benefits may be related to the students’ confidence in their ability (self-efficacy) to gain the engineering graphics skills needed to become an engineer. No work …

Gravity Fed Hopper Flow Of Bulk Solids For Lunar Isru, Jason Bendixen Noe

Dissertations, Master's Theses and Master's Reports

With the return to the moon in the decade of the 2020s, there has been a renaissance of lunar technology development and innovation. This has been particularly true for the area of lunar ISRU (In-Situ Resource Utilization). One key area in ISRU that has been neglected is lunar regolith storage hopper research. Many lunar regolith ISRU researchers use storage hoppers in their work but do not document the properties when designing the hoppers or do not have the information at hand. Because of this, hopper design and documentation are poorly understood, and more research is needed. Hoppers are vital for …

Mechanical Properties And Cycling Fatigue Of Zn-Based Alloys: Effects Of Thermal Treatment, Henry D. Summers

Dissertations, Master's Theses and Master's Reports

Zinc (Zn)-based alloys are attractive candidate materials for constructing bioresorbable coronary stents because of their near-ideal corrosion properties and biocompatibility. These alloys are primarily strengthened through alloying and thermomechanical processing by solid solution strengthening, grain refinement, and precipitate strengthening. The microstructural features responsible for these strengthening mechanisms are controlled through the thermal treatment of the alloys. While the static mechanical properties of Zn alloys have been studied, a gap in the literature remains related to their mechanical stability under dynamic loading conditions (fatigue) and creep, especially while subjected to physiological conditions. This work aims to characterize the effects of thermal …

From Technical Resolution To Agile Evolution: A Blended Role At Humane Interface Design Enterprise (Hide), Ketansingh Anil Patil

Dissertations, Master's Theses and Master's Reports

This report provides a comprehensive overview of my journey through two distinct roles at the Humane Interface Design Enterprise (HIDE) - as a Technical Consultant in Spring 2023 and an Agile Process Analyst in Fall 2023. My tenure as a Technical Consultant was marked by the application of academic knowledge and technical skills to tackle real-world challenges at HIDE, leveraging experiences from my capstone projects and my roles in the industry as an IT Analyst Intern at Milwaukee Tool and a Data Engineer at UST. This role at HIDE enhanced my problem-solving skills and contributed to the progress of the …

Aluminum Critical Mineral Production Feasibility Via Landfill Mining: Preliminary Study Of Potential Project Locations And Co-Benefits, Anabel M. Needham

Dissertations, Master's Theses and Master's Reports

In 2022, aluminum was named a critical mineral by the United States Geological Survey (USGS) and the global demand for aluminum is projected to increase by 40% from 2020 to 2030 (Aleksić 2023). There are currently no large-scale bauxite mines in the United States to contribute to aluminum production, and this study aims to investigate the feasibility of aluminum landfill mining in the United States to produce secondary aluminum. The feasibility of landfill mining for the purpose of recovering materials and energy is a relatively new technology, and often co-benefits are required to make these projects economically viable. Publicly available …

Transient Simulations Of Power Systems With Inverter Interfaced Resources, Gaurish Shreedhar Gokhale

Dissertations, Master's Theses and Master's Reports

Renewable energy sources are interfaced with the electrical grid using power electronic inverters. These inverter-interfaced resources have been deployed for nearly 20 years. Still, NERC only recently highlighted the vast gap between the actual behavior of these inverters during power system transients and those observed in simulations. Simulation models need significant improvements, mainly for developing accurate inverter current controls, phase-locked loops, and fault response during different power priority modes. Additionally, only time-domain electromagnetic transient simulation tools can fully represent the fault response of the inverter-interfaced resources.

The developed simulation model of the inverter-interfaced resource is based on the recommendations made …

Dependence Of Energy Transfer On Curvature Similarity In Collisions Involving Curved Shock Fronts, Justin Cassell

Dissertations, Master's Theses and Master's Reports

In high-speed collisions of projectiles, pressure exerted by a resulting shock wave is so high that even solids begin to flow and hydrodynamics becomes relevant. Jetting results from hydrodynamic instability driving the evolution of an interface following shock loading. Our emphasis in this dissertation is mitigation of instabilities via several shocks and, specifically, the transfer of energy from a shock wave to another object. To that end, in 2022 and 2023 while on-site, we adapted Lawrence Livermore National Laboratory (LLNL) to explore the effects of shock front geometry on the transfer of energy during shock collisions via numerous computer simulations. …

High Temperature Strength Reduces Soldering In Aluminum High Pressure Die Casting, Jacob A. Belke

Dissertations, Master's Theses and Master's Reports

Die soldering, an adhesion defect in high pressure die casting (HPDC), is a symptom of localized sticking where a localized portion of the cast material is adhered to the tooling surface causing build up over time. This requires the tooling to be serviced which incurs additional costs to the process that gets passed on to the parts. Historically, soldering has been mitigated using lubricants, coatings, and alloy chemistry modifications but solder persists.

The Tresca friction thermomechanical model suggests soldering occurs when the local interfacial shear stress between the casting and die surface exceeds the local shear strength of the casting. …

The Integration Of Neuromorphic Computing In Autonomous Robotic Systems, Md Abu Bakr Siddique

Dissertations, Master's Theses and Master's Reports

Deep Neural Networks (DNNs) have come a long way in many cognitive tasks by training on large, labeled datasets. However, this method has problems in places with limited data and energy, like when planetary robots are used or when edge computing is used [1]. In contrast to this data-heavy approach, animals demonstrate an innate ability to learn by communicating with their environment and forming associative memories among events and entities, a process known as associative learning [2-4]. For instance, rats in a T-maze learn to associate different stimuli with outcomes through exploration without needing labeled data [5]. This learning paradigm …

Algorithms For Coordinating Multiple Autonomous Vehicles Under Various Constraints With Emphasis On Workload Balancing, Abhishek Patil

Dissertations, Master's Theses and Master's Reports

This dissertation focuses on developing algorithms to solve the problem of coordinating multiple autonomous vehicles under various constraints, aiming to produce practical solutions for real-world applications. Built upon three journal publications addressing two coordination-related problems in different domains, this research document tackles the challenges of heterogeneity constraints and cable entanglement issues encountered by autonomous vehicle systems.

The first problem tackles task allocation and path planning for heterogeneous ground mobile vehicles operating in a 2D environment with asymmetric travel costs. By enhancing previous Primal-Dual approximation heuristic methods, novel techniques are introduced to manipulate dual variables and achieve balanced workload distribution, ultimately …

Les-C Turbulence Models And Fluid Flow Modeling: Analysis And Application To Incompressible Turbulence And Fluid-Fluid Interaction, Kyle J. Schwiebert

Dissertations, Master's Theses and Master's Reports

In the first chapter of this dissertation, we give some background on the Navier-Stokes equations and turbulence modeling. The next two chapters in this dissertation focus on two important numerical difficulties arising in fluid flow modeling: poor mass-conservation and nonphysical oscillations. We investigate two different formulations of the Crank-Nicolson method for the Navier-Stokes equations. The most attractive implementation, second order accurate for both velocity and pressure, is shown to introduce non-physical oscillations. We then propose two options which are shown to avoid the poor behavior. Next, we show that grad-div stabilization, previously assumed to have no effect on the target …

Integrating Arcgis And Redux Using Middleware, Vishnu Vardhan Reddy Rapuru

Dissertations, Master's Theses and Master's Reports

The integration of ArcGIS with Redux through middleware presents a novel approach to managing state in geospatial applications. This report outlines the process and benefits of combining ArcGIS’s robust mapping and analytics capabilities with Redux’s predictable state container for JavaScript apps. It begins with an introduction to both technologies, followed by a detailed discussion on the architecture design, focusing on the role of middleware as the linchpin in this integration[1]. The paper highlights the benefits, such as improved state management and application performance, and addresses the challenges encountered during the integration process. Implementation details are provided, including the setup of …

Optimizing Php Api Calls With Pagination And Caching, Parsharam Reddy Sudda

Dissertations, Master's Theses and Master's Reports

The Keweenaw Time Traveler (KeTT) project is devoted to mapping the historical and social landscapes of the Keweenaw Peninsula. During the project, it was discovered that the server-side performance needed improvement. To address this issue, the "Optimizing PHP API Calls with Pagination and Caching" initiative was launched. This initiative focused on refining API calls, implementing server caching and pagination, and fortifying security against common vulnerabilities. The project successfully mitigated risks associated with SQL Injection and XSS through meticulous code enhancements while improving error handling. Additionally, the introduction of Scroll-Induced Pagination optimized data delivery, significantly reducing response times, and elevating the …

Forecasting Of The Next Three (3) Decades Global Lithium Demand And Pricing Using Multivariate Stochastic Model., Enoch Nii- Okai

Dissertations, Master's Theses and Master's Reports

The transition to electric vehicles (EVs) is pivotal in achieving global climate goals, with nations aiming to integrate a significant portion of new passenger vehicles as electric by 2030. This shift towards electric mobility includes a notable rise in battery-electric, plug-in hybrid, and fuel-cell electric vehicles to curb carbon emissions and foster sustainable transportation. Central to this transition is the critical role of lithium, often referred to as the "white gold of the 21st century," in electric vehicle batteries, especially rechargeable lithium-ion batteries renowned for their high energy efficiency, density, and durability. While lithium has historically found extensive use across …

Design, Testing And Neural Network Modeling Of A Low-Friction Wave Energy Converter Testbed, Vasu Bhardwaj

Dissertations, Master's Theses and Master's Reports

Point absorber wave energy converters (WECs) transform water wave kinetic energy into other useful forms, typically electrical. While it’s possible to extract energy from passive WECs, more energy can be captured using active control where its power take-off (PTO) acts as both a generator and an actuator. Control strategies usually require accurate models often obtained during model-scale testing. Unfortunately, friction can dominate the dynamic response in small WEC models. A frictionless point absorber WEC testbed is described in this report which allows the researcher to focus on fundamental hydrodynamic behavior instead of friction. It uses air bearings for vertical motion …

Study Of Nanoparticle Dispersed Phase Change Materials And The Impact Of Temperature Gradient On The Potential For Particle Migration, Udit Sharma

Dissertations, Master's Theses and Master's Reports

Supercooling in phase change materials (PCMs) and the associated challenges in enhancing thermal conductivity through nanoparticle dispersion prompted this investigation. Existing literature exhibits inconsistencies in thermal conductivity improvements, suggesting a potential correlation with nanoparticle migration induced by thermophoresis. To address this, a novel temperature-dependent scaling parameter, \(\xi\), was introduced to predict particle migration propensity. A strong association was observed between higher \(\xi\) values and diminished thermal conductivity enhancements, indicating a significant influence of nanoparticle movement on heat transfer.

To further elucidate this relationship, a Nanoparticle Interaction Parameter \(N_\text{{pl}}\) was developed, incorporating critical fluid properties and interfacial effects. The derived critical …

Novel Analytical Approaches For The Study Of Energy And Nutrient Flow In Streams, Michelle Catherine Kelly

Dissertations, Master's Theses and Master's Reports

This dissertation applied novel modeling, experimental and statistical approaches to overcome the challenges of measuring and analyzing energy and nutrient cycling in streams through 3 studies: (1) determining the predictors of respiration and denitrification in streams across the United States, (2) simultaneous estimation of denitrification and nitrogen (N) fixation rates, and (3) the impact of C lability metrics on the interpretation of C degradation in DOM incubation experiments. In the first study, I used predictive modeling approaches to show that respiration and denitrification were positively correlated across the landscape but were predicted by factors at different spatial scales. Denitrification rates …

Nonlinear Hydrodynamic Modeling And Control Of Wave Energy Converters, Tania Demonte Gonzalez

Dissertations, Master's Theses and Master's Reports

The growing urgency to transition towards carbon-neutral energy sources has sparked significant interest in diversifying energy portfolios by incorporating renewable energies, including the untapped potential of wave energy. This dissertation sets its objectives in advancing wave energy converter (WEC) technologies by focusing on developing and validating a nonlinear modeling technique and designing control strategies to maximize energy extraction and enhance WEC efficiency. At the heart of this research is the derivation and validation of an algebraic nonlinear Froude-Krylov forces model. Building on this foundational model, a robust nonlinear sliding mode controller and a nonlinear model predictive controller are designed to …

Modeling Of Inverter-Based Resources For Hardware In The Loop Testing Of Protection And Control Schemes, Md Aamir Rahmani

Dissertations, Master's Theses and Master's Reports

High penetration of inverter-based resources (IBR) may cause the misoperation of protective relays due to the dynamic nature of fault currents fed by the IBR during short-circuit faults. Misoperation may cause damage to power system equipment and affect the reliability of the power system. This dissertation presents an in-depth investigation into the modeling of IBR in the context of transmission line fault scenarios to understand and analyze the characteristics of fault currents fed by the IBR. The research objectives encompass the development of reliable IBR models capable of accurately replicating fault current behaviors, designing IBR operation control schemes, and implementing …

Programming By Voice, Sadia Nowrin

Dissertations, Master's Theses and Master's Reports

Programmers typically rely on a keyboard and mouse for input, which poses significant challenges for individuals with motor impairments, limiting their ability
to effectively input programs. Voice-based programming offers a promising alternative,
enabling a more inclusive and accessible programming environment. Insights from interviews with motor-impaired programmers revealed that memorizing unnatural commands in existing voice-based programming systems led to frustration. In this work, we explore how programmers naturally speak a single line of code and present a comprehensive methodology for a voice programming system aimed at making programming more accessible for diverse users. To achieve this, we adopted a two-step pipeline. …

Four Lessons To Build Upon: A Study Of Postsecondary Composition Classroom Curriculum, Tucker D. Nielsen

Dissertations, Master's Theses and Master's Reports

Soft skills in technical professions may be valued by employers, but post-secondary students engage with a dichotomy arguing against the blend of soft and hard skills. This study utilized activities with LEGO® bricks to determine how plausible kinesthetic learning methods are within university composition classes. Four in-class activities based on the class’s four core assignments were spread across the Spring 2024 semester at Michigan Technological university. Through written reflections, lists, posters, and photos of students’ builds, students practiced and demonstrated engagement with identified composition and critical thinking skills.

Two criteria (Audience Expectations and Genre Expectations, were not demonstrated as clearly …

A Virtual Time Driven Simulator For Devs Models, Ronald R. Stempien

Dissertations, Master's Theses and Master's Reports

When simulating a system that includes some software component, simulation authors are faced with the problem of how to appropriately model the software within the simulation. While many formal methods for modeling software exist, in some contexts these may not be appropriate or viable for a given simulation. Instead, simulation authors may model a computer within the simulation, and run the software in question “as is” on the modeled machine. In this work, we introduce a theoretical framework to allow for the use of hardware virtualization technologies as a hardware accelerator for CPU models in Discrete Event System Specification (DEVS) …

Dynamic Memory Management For Key-Value Store, Yuchen Wang

Dissertations, Master's Theses and Master's Reports

To minimize the latency of accessing back-end servers, modern web services often use in-memory key-value (k-v) stores at the front end to cache frequently accessed objects. Due to the limited memory capacity, these stores must be configured with a fixed amount of memory. Consequently, cache replacement is required when the footprint of the accessed objects exceeds the cache size.

This thesis presents a comprehensive exploration of advanced dynamic memory management techniques for k-v stores. The first study conducts a detailed analysis of K-LRU, a random sampling-based replacement policy, proposing a dynamic K configuration scheme to exploit the potential miss ratio …

An Elasto-Plastic Constitutive Model With Phase-Field Fracture For Additively Manufactured Metallic Materials, Nolan Ruble

Dissertations, Master's Theses and Master's Reports

The advent of additive manufacturing (AM), commonly known as 3D printing, has revolutionized the production of metallic components across various industries. This technology, which builds objects layer by layer, has shifted paradigms in manufacturing, allowing for unprecedented design freedom, material efficiency, and rapid prototyping. Metal additive manufacturing, in particular, has shown remarkable promise due to its ability to produce complex geometries that are difficult or impossible to achieve with traditional subtractive methods. In addition, additively manufactured (AM) materials are gaining popularity in thanks to their often superior and controllable properties in comparison to their wrought counterparts. In the present work, …

Performance Characterization And Optimization Of A Point-Cloud-Based Path Planner In Off-Road Terrains, Casey D. Majhor

Dissertations, Master's Theses and Master's Reports

In this dissertation, I present a multifaceted study on the generation of artificial terrains using a multifractal method, and their use in autonomous ground vehicle (AGV) planning and navigation performance characterization in high-fidelity simulations, and automated parameter optimization.

My first contribution is a multifractal artificial terrain generation method leveraging the 3D Weierstrass-Mandelbrot function to control terrain roughness. We generate 60 unique off-road terrains while varying the fractal dimension and test the impact on vehicle traversal difficulty. Results show that increasing the fractal dimension decreases low-roughness areas, increases semi-rough and high-roughness areas, and decreases vehicle success rates while increasing vertical accelerations, …

Analysis Of Factors Affecting Engine Knock In Modern Spark Ignition Gasoline Engines To Improve Engine Efficiency, Siddharth Gopujkar

Dissertations, Master's Theses and Master's Reports

Spark ignition engine knock is an issue that has persisted for over a century. Knock prevents the spark in an SI engine to be deployed at the most optimum time in the engine cycle, which leads to a decrease in the efficiency of the engine. A reduction in the efficiency directly translates to increased emissions and fuel costs. This research looks at experimental works to analyze the impact of three separate factors on knock in an effort to minimize it and improve engine efficiency.

The first factor is fuel chemistry – how Research Octane Number (RON) and Motor Octane Number …

Continuous, Platform Purification Of Viral Products Using Aqueous Two-Phase Extraction, Natalie M. Nold

Dissertations, Master's Theses and Master's Reports

Cell and gene therapies, a ground-breaking class of drugs that can heal genetic diseases and cure cancer, often have treatment costs over $1 million. Most cell and gene therapies are delivered using virus-based delivery vectors, which are incredibly expensive to manufacture. Liquid chromatography is the favored method of viral vector purification since it is easily scalable and can be functionalized to purify by biospecificity, charge, hydrophobicity, or size. However, chromatography-based purification processes are highly expensive and usually only recover 20-50% of the viral vectors. There is currently no platform purification strategy for viral vectors due to differences in their surface …