Engineering Commons^™

Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller

Master's Theses

An extensive laboratory test program was conducted to analyze and compare the cation exchange processes in three different varieties of sodium bentonite (Na-B) geosynthetic clay liners (GCLs) over increased conditioning durations up to 32 days and investigate the effects of temperature, solution strength, and applied stress. The goal of this test program was to establish whether the variables of temperature, solution strength, and applied stress improved or degraded the engineering properties of GCLs in laboratory testing and municipal solid waste (MSW) landfill applications. The GCLs were conditioned in liquids of increasing ionic strength, using deionized water and 2, 50, and …

Dual Base Sige Is-Hbt For Use In Biosensing Applications, Liam Stephen Hayes

Master's Theses

The proposed research is for a novel SiGe-based Ion-Sensitive Dual Hetero-junction Bipolar Transistor (IS-HBT) to be used in both trans-dermal biological sensing as well as Lab-on-Chip (LOC) applications. The end goals for the device designed are two: For one, the research done for this work will be used to substantiate the claims made by Zafar et al. [1] that an HBT-style structure is better suited for biosensing application rather than a conventional Field Effect Transistor (FET) based geometries. Secondly, it provides the final element to be integrated along with a selectivity membrane, as well as with a reverse-iontophoresis system to …

Design And Implementation Of An Inverted Short Baseline Acoustic Positioning System, Jakob Frabosilio

Master's Theses

This document details the design, implementation, testing, and analysis of an inverted short baseline acoustic positioning system. The system presented here is an above-water, air-based prototype for an underwater acoustic positioning system; it is designed to determine the position of remotely-operated underwater vehicles (ROVs) and autonomous underwater vehicles (AUVs) in the global frame using a method that does not drift over time.

A ground-truth positioning system is constructed using a stacked hexapod platform actuator, which mimics the motion of an AUV and provides the true position of an ultrasonic microphone array. An ultrasonic transmitter sends a pulse of sound towards …

Validation Of Mobile Devices In Arbitrary Locations Against Force Plate Standard For Balance Assessment, German J. Ellsworth

Master's Theses

With balance assessment being essential to the prediction of fall risk and detection and assessment of motor disorders, increasing clinical accessibility to objective balance metrics is essential. Work has been done validating center of mass (COM) acceleration metrics against well regarded force plate center of pressure (COP) position standards for mobile device data acquisition systems, but most research is restricted to devices being close to the COM or strapped in a harness configuration. Through the use of rigid body kinematics and the inverted pendulum model, this study develops novel methodology for calculating COM acceleration using mobile devices in arbitrary positions, …

A Data-Driven Framework For Analyzing And Predicting Social Media Engagement During Rumor Propagation, Joseph E. Faza

Master's Theses

The spread of rumors on social media has become a significant concern, as platforms like X (formerly known as Twitter) enable rapid dissemination of unverified information. These rumors can shape public perception and behavior, making it crucial to understand the dynamics of their spread. The main objective of this study is to explore how users interact with rumor-related tweets and identify key factors that predict tweet engagement. By analyzing tweets from seven different rumor events, this research aims to uncover patterns in user engagement and provide insights into the spread of misinformation. The study utilized a dataset of tweets from …

Assessment Of Dune Change Using Historical Aerial And Satellite Photos, Topographic Surveys, And Wave Data At Toro Creek Beach, Owen D. Emerson

Master's Theses

Coastal sand dunes play an important role in the littoral processes of California’s coastline. Functioning as both source and sink for sand, these dunes often protect coastal infrastructure and provide a buffer between anthropogenic development and coastal forces. At Toro Creek Beach, north of Morro Bay California, recent extreme winter storms have raised concerns about the erosion of the sand dunes that front California State Highway 1. This thesis attempts to characterize the historical growth and recession patterns of the Toro Creek dunes since 1977, the dune movement over the 2023-2024 winter seasons, the wave forcings behind recent high erosion …

Seal Counting On Our Plages (S.C.O.O.P.), Kaanan Kharwa

Master's Theses

The Vertebrate Integrative Physiology (VIP) lab monitors the population of northern elephant seals at the largest mainland breeding colony, located at Piedras Blancas (San Simeon, CA). As the population expands, more human-seal interactions and conflicts over land use occur. The VIP lab's work informs California State Parks and helps with the management of the rookery. Currently, members of the VIP lab fly a drone over the beaches, capture multiple images, and manually count the seals, which takes around 14 to 21 hours of analysis per survey. Machine learning methods such as Convolutional Neural Networks (CNN) and Region-based Convolutional Neural Networks …

Robotic Odor Source Localization Using Vision And Olfaction Sensing, Sunzid Hassan

Master's Theses

Robotic Odor Source Localization (ROSL) technology allows autonomous agents like robots to find an odor source in unknown environments. A successful odor source location depends crucially on an effective navigation algorithm that directs the robot towards the odor source. This thesis is a combination of three projects. First, we detail development of a versatile multi-modal robotic platform for ROSL real-world ROSL experimentation and discussed real-world validation of a traditional olfactionbased ROSL algorithm. Secondly, we introduced vision in ROSL by proposing a fusion navigation algorithm that integrates deep-learning enabled vision and olfaction-based navigation. This hybrid approach tackles challenges such as turbulent …

Extraction, Preparation, And Characterization Of Alginate Biopolymer Films From Natural Seaweed, David Ly

Master's Theses

This study evaluates the use of naturally harvested seaweed from the Monterey Bay to produce a biodegradable film for food packaging applications. Two different film-forming methods were evaluated: solution casting and compression molding. The solution casting method using an alginate biopolymer produced the most consistent results. The seaweed biopolymer was extracted from the seaweed biomass using a modified method, resulting in a yield of 11-25 %. The highest yield was observed when using the lowest biomass concentration of 10 wt. %. The extracted alginate was then cast into films at different levels of glycerol plasticization (15-35 wt.%). The addition of …

Synthetic Data Generation For Accurate, Fair, And Private Recommender Systems, Derek B. Lilienthal

Master's Theses

A notorious challenge for recommender systems on online platforms is to accurately and fairly recommend items that align with users’ preferences while retaining user privacy. These systems often rely on historical data that is partially labeled and includes incomplete user information, leading to the over-representation of majority groups and disproportionately favoring popular items. Substituting user data with synthetic data can address these concerns, but accurately replicating real-world datasets has been a challenging problem. Recent advancements in generative AI have demonstrated the impressive capabilities of diffusion models in generating realistic data across several domains. In this work, we introduce two variations …

Controllable Physics-Informed Latent Space For Acoustic Wave Manipulation, Tristan Shah

Master's Theses

Partial Differential Equations (PDEs) are foundational descriptive tools in scientific and engineering disciplines, enabling the exploration of phenomena from material design to climate dynamics and the propagation of pandemics and wildfires. Establishing control of PDEs, especially when the underlying phenomena are only partially observable, holds great potential for fostering technological innovations. This ambition faces considerable obstacles, as a robust sample-based solution remains elusive. Addressing this challenge, this thesis introduces a framework leveraging physics-informed machine learning (ML) to enable control of PDEs. Central to this framework is an agent, equipped with sensors to perceive its environment, that generates a low-dimensional physics-informed …

An Exploration Of Dimensionality Reduction Of Dynamics On Lie Groups Via Structure-Aware Canonical Correlation Analysis, Wooyoung Chung

Master's Theses

Incorporating prior knowledge into a data-driven modeling problem can drastically improve performance, reliability, and generalization outside of the training sample. The stronger the structural properties, the more effective these improvements become. Manifolds are a powerful nonlinear generalization of Euclidean space for modeling finite dimensions. When additionally assuming that the manifold carries (Lie) group structure, this imposes a drastically stricter global constraint. The range of their applications is very wide and includes the important case of robotic tasks. We apply this idea to Canonical Correlation Analysis (CCA). In traditional CCA one constructs a hierarchical sequence of maximal correlations of up to …

Reinforcement Learning Based Planning And Control For Robotic Source Seeking Inspired By Fruit Flies, Gauravkumar Koradiya

Master's Theses

In the exploration of mobile sensing agents such as robots equipped with sensors, these agents have the potential to measure unknown scalar fields, ranging from chemical concentrations to temperature fluctuations. One of the primary interests is the robots’ ability to gravitate towards the peaks or troughs of these fields, a phenomenon termed as “source seeking”. This behavior is invaluable in practical scenarios, like detecting chemical leaks or locating survivors after catastrophes. However, the challenge becomes significantly more pronounced when operating in turbulent flow fields, where the erratic nature of odorant plumes makes predictions and simulations highly unreliable. Interestingly, fruit flies …

Domain Specific Aspect Extraction For Product Design, Divyam Sobti

Master's Theses

As technology advances, computers become increasingly proficient at interpreting and translating human language into machine-understandable text. With the help of algorithms in natural language processing (NLP), machines can now translate textual data. These algorithms help identify and extract specific text components known as aspects. The aspects represent specific attributes or topics within textual data. For instance, an Amazon review states,“ This phone has good battery life but poor camera quality,” and attributes like ‘battery life’ and ‘camera quality’ represent aspects in the text. Aspect extraction is a pivotal process involving identifying and isolating key features or topics within text. This …

Application Of Agent-Based Simulation And Game Theory In Evaluating Implementation Of Whole Genome Sequencing In Treating Lung Cancer, Fateme Ghalenoei

Master's Theses

Cancer, particularly lung cancer, presents significant diagnostic and economic challenges globally. Timely diagnosis and cost management play pivotal roles in treatment success. A biomarker is any measurable molecule in blood, bodily fluids, or tissues, indicating the potential presence of an abnormal bodily process, condition, or disease. Biomarker testing is a laboratory test in oncology that is used in the selection of targeted cancer treatments and to help avoid ineffective treatments. Whole Genome Sequencing (WGS), is a biomarker test which while more comprehensive, comes at a higher cost. This study proposes an agent-based simulation model within a game-theoretic framework to examine …

Modeling, Simulation, And Experimental Testing Of A Single-Legged Hopper, John Anthony Bennett

Master's Theses

Legged robots are well-suited for navigating unstructured terrain due to their ability to perform agile dynamic motions. Building on the efforts of Cal Poly's Legged Robotics Group, this project focuses on achieving stable forward hopping with a single legged robot.

A comprehensive model of leg hopping is formulated, with leg dynamics during flight and stance phases derived using Euler-Lagrange equations. During the stance phase, a spring-mass system models the leg-ground interaction. The touchdown and lift-off conditions are formulated mathematically, and state mappings between phases are determined via momentum conservation. A two-phase hybrid controller is designed, incorporating trajectory planning during flight …

A Broadband, Dual Polarized Antenna For The Radio Neutrino Observatory In Greenland, Danny Maas

Master's Theses

The Radio Neutrino Observatory in Greenland (RNO-G) is a multidisciplinary, multinational collaboration which uses antennas to detect neutrino interactions with arctic ice sheets. Neutrinos are formed from nuclear reactions; predominant sources include nuclear reactors, stars, supernovae, and the big bang. They rarely interact with normal matter and thus travel from origin to destination relatively unimpeded, with applications including tracking nuclear weapons tests and supernovae. Measurements of galactic neutrino flux can provide information about how the universe developed and its current evolution. Neutrino interactions produce signals from 100 to 1000MHz. Current RNO-G antennas operate over only a portion of this band; …

Adaptable Quantum Education Platform Using Learning Objects, Krishna Puja Anumula

Master's Theses

In recent years, the need to make classroom learning more interactive and engaging has become increasingly important. The lack of workforce in interdisciplinary fields such as quantum networking and quantum internet requires a new approach that addresses every learner’s individual needs. To address this challenge, this thesis introduces an adaptive learning platform rooted in the theory of learning objects and Kolb’s experiential learning model. The platform aids educators and learners in designing and utilizing various learning objects for quantum networking and quantum internet.

The platform enables educators and learners to build their own lessons and lesson plans using learning objects …

Automated Concrete Bridge Deck Inspection Using Unmanned Aerial Systems Collected Data: A Machine Learning Approach, Rojal Pokhrel

Master's Theses

Many national infrastructures, particularly bridges, are becoming older and older day by day. Their safe operation and maintenance require routine monitoring and inspection. There are lots of bridge inspection specifications and manuals to guide inspectors to give the proper recommendations about the bridge structure and safety. These manuals and specifications require bridge inspectors to manually inspect the bridge and recommend maintenance and repair tasks referring to the specific criteria available in the manuals. In time, the application of technology makes many Unmanned Aerial Systems (UAS) advancements during the phase of data collection. For the image processing and analysis of collected …

Digimindready: Enhancing Military Readiness Through Edge Ai-Driven Wellness, Education, And Digital Discipline Via Privacy-First Mhealth Innovation, Md Mehedi Hasan

Master's Theses

Military personnel often find themselves in intense situations that require high focus. Successfully engaging in these dangerous missions means they must efficiently control cognitive load, manage overwhelming stress, and stay focused through distractions to perform at their best. Military training significantly focuses on human performance, which benefits military readiness. The 21st century has introduced unanticipated challenges to all, such as the adverse effects of excessive screen time, external distractions, and over-reliance on technology without being aware of digital discipline. Militaries are no exception. These challenges have become an emerging threat to military personnel's cognitive, emotional, and physical well-being. On top …

Development Of An Advanced Step Counting Algorithm With Integrated Activity Detection For Free Living Environments, Paige M. Dolan

Master's Theses

Physical activity plays a crucial role in maintaining overall health and reducing the risk of various chronic diseases. Step counting has emerged as a popular method for assessing physical activity levels, given its simplicity and ease of use. However, accurately measuring step counts in free-living environments presents significant challenges, with most activity trackers exhibiting a percent error above 20%. This study aims to address these challenges by creating a machine learning algorithm that leverages activity labels to improve step count accuracy in real-world conditions. Two approaches to balancing data were used: one employed a simpler oversampling technique, while the other …

A Screening Life Cycle Analysis Of One-Way And Reusable Crate Designs – Estimating Environmental Impacts Via Lca Software, Nicolas R. Corona

Master's Theses

A comparison analysis conducted via COMPASS life cycle analysis software has indicated that a one-way crate design, rather than a reusable crate design, is in fact the more environmentally friendly packaging system. These results can be interpreted differently, however, as the manufacturer of said crate designs must confirm what impact indicators they would like to reference as environmental goalposts. The conducted analysis provides insight into what the environmental impacts of each packaging system look like as packaging at all three system levels has been identified as a means of reducing environmental impacts globally. As such, the manufacturer of said crate …

Engineering An Injectable Hydrogel With Self-Assembling 3d Vasculature, Kendyl Cohn

Master's Theses

This research developed methods for culturing self-assembling capillaries in an injectable gel as a potential method for vascularizing tissue-on-a-chip models to mimic physiological drug delivery. Additionally, a mathematical model was developed as a tool for understanding nutrient delivery and comparison of potential delivery systems. Organs-on-a-chip provide novel platforms for studying biology and physiology in 3D, allow exploration of tissue engineering on a manageable scale, and serve as models for drug screening and drug-delivery testing.

Methods were first developed for co-culture of endothelial cells and fibroblasts (3T3s or HDFs) in 2D, evaluating culture time, seeding density and ratio of HUVECs and …

Thermal Preconditioning Effects On Perforation Propensity Of Transvenous Implantable Cardiac Leads Used For Pacing And Defibrillation, Diane Muff

Master's Theses

Thermal preconditioning to simulate shipping, handling and storage conditions did not affect distal tip stiffness values for permanently implantable cardiac leads used for pacing and defibrillation. Leads that were subjected to extreme temperatures and temperature cycling did not show changes in buckle force values compared with control specimens which were maintained at ambient room conditions. Absolute differences between all measurements were small, generally under 0.05 N and were attributable to measurement variability.

Buckle force values are used to assess the propensity of leads to perforate the heart, a rare but potentially serious complication of implantable pacing and defibrillation systems. Since …

A Comparative Study Of The Npm, Pypi, Maven, And Rubygems Open-Source Communities, Saurav Gupta

Master's Theses

Open-source software (OSS) ecosystems, defined as environments composed of package managers and programming languages (e.g., NPM for JavaScript), are essential for software development and foster collaboration and innovation. Although their significance is acknowledged, understanding what makes OSS communities healthy and sustainable requires further exploration. This thesis quantitatively assesses the health of OSS projects and communities within the NPM, PyPI, Maven, and RubyGems ecosystems. We explore five research questions addressing project standards, community responsiveness, contribution distribution, contributor retention, and newcomer integration strategies. Our analysis shows varied documentation practices, insider engagement levels, and contribution patterns. Our findings highlight both strengths and different …

Design And Implementation Of A Vision-Based Deep-Learning Protocol For Kinematic Feature Extraction With Application To Stroke Rehabilitation, Juan Diego Luna Inga

Master's Theses

Stroke is a leading cause of long-term disability, affecting thousands of individuals annually and significantly impairing their mobility, independence, and quality of life. Traditional methods for assessing motor impairments are often costly and invasive, creating substantial barriers to effective rehabilitation. This thesis explores the use of DeepLabCut (DLC), a deep-learning-based pose estimation tool, to extract clinically meaningful kinematic features from video data of stroke survivors with upper-extremity (UE) impairments.

To conduct this investigation, a specialized protocol was developed to tailor DLC for analyzing movements characteristic of UE impairments in stroke survivors. This protocol was validated through comparative analysis using peak …

The Effect Of Watts-Strogatz And Barabási-Albert Graphs On Memory Formation, Ethan Irick Wolfe

Master's Theses

Understanding higher level cognitive processes is a central problem in neuroscience. The Neuroidal model provides a useful framework for posing these problems in a computer science context. There has been significant recent work trying to understand memory capacity in the Neuroidal model but this work was done assuming that the network of neurons was an Erdos-Renyi random graph. However the network of neurons in the brain has been shown to exhibit small-world properties, which are not present in Erdos-Renyi graphs. In this research we explore replacing Erdos-Renyi graphs with Watts-Strogatz and Barabasi-Albert graphs in order to more accurately model the …

Filter: Framework For Integrated Legislative Transparency And Exploratory Research, Kenny Lau

Master's Theses

Digital Democracy, established at Cal Poly's Institute for Advanced Technology and Public Policy, initially provided users access to a distinctive dataset, including state legislative committee hearings, transcripts, videos, and more. However, the discontinuation of funding ended operations for the project and emphasized the need for a streamlined application independent of third-party dependencies and capable of offering real-time and organized access to the invaluable Digital Democracy dataset. We introduce FILTER, a cloud-hosted API designed for read access to the Digital Democracy dataset through twelve distinct endpoints. The system contains two databases: the Digital Democracy Database (DDDB) and the Digital Democracy Knowledge …

Automatic Mass Balancing Of A Spacecraft Attitude Dynamics Simulator With Six Sliding Masses, Amelia J. Gilman

Master's Theses

The goal of this thesis is to investigate automatic mass balancing methods for spacecraft attitude dynamics simulators, create a hardware design for a mass balancing system, and assemble the hardware on the Cal Poly Spacecraft Attitude Dynamics Simulator (SADS). Spacecraft attitude dynamics simulators replicate the torque-free environment of space with ground-based hardware. The SADS is mounted on a spherical air bearing, and includes a pyramid of four reaction wheels. The air bearing allows frictionless, unbounded rotation about the vertical axis, and 30 degrees about the horizontal axes. The torque-free configuration of the SADS can be used to test spacecraft attitude …

Improving Aerospace System Robustness Integration Of Singular Value Decomposition And Network Centrality, Ricardo S. Contreras

Master's Theses

This thesis presents an approach to understanding and enhancing the robustness of aerospace systems through the integration of network analysis, Design Structure Matrix (DSM), Singular Value Decomposition (SVD), and robustness simulation techniques. This methodology called the Importance Hierarchy method, provides a comprehensive framework for decomposing the interactions of aerospace systems, focusing on identifying and evaluating critical components and interactions.

The Importance Hierarchy method was used to study the Autonomous Flight Termination Unit (AFTU) by analyzing its components and interdependencies. The AFTU was selected because it recently completed a Preliminary Design Review (PDR), and its design and operational functions were well-known. …