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Full-Text Articles in Physical Sciences and Mathematics

Sequential Causal Architecture For Multimodal Aviation Accident Prediction, Kaitlyn Cavanaugh, Isaac Morrison Aug 2026

Sequential Causal Architecture For Multimodal Aviation Accident Prediction, Kaitlyn Cavanaugh, Isaac Morrison

Discovery Day - Daytona Beach

Aviation accidents are rarely the result of a single failure but rather from a complex causal chain of latent failures. While traditional data mining models often predict incident occurrence, they frequently overlook the sequential mechanics defined by known accident causation theoretical frameworks like the Swiss Cheese Model and the FAA's HFACS. This project addresses the need for interpretable, reliable, multi-stage forecasting by proposing a Sequential Causal Architecture that transforms theoretical causation models into a structured Directed Acyclic Graph (DAG) for multimodal accident causation chain prediction. Data from the NTSB and DOT is used and connected together in a meaningful way …


Energy-Aware Bimodal Contact Detection For Leg Odometry, Emre Girgin Aug 2026

Energy-Aware Bimodal Contact Detection For Leg Odometry, Emre Girgin

Discovery Day - Daytona Beach

Autonomous exploration of extraterrestrial environments using legged robots requires robust GNSS-free 3D state estimation. Standard leg odometry relies on Zero-Velocity Updates (ZUPT), which assume a grounded foot remains completely stationary. This assumption consistently fails on deformable granular terrain due to unobservable slippage, rapidly degrading state estimation. To mitigate this critical failure mode, we propose a dual contact-detection framework designed to robustly gate an Error-State Extended Kalman Filter (ESEKF) tracking pose, velocity, and IMU biases.   The architecture isolates physical load and kinematics by modeling contact detection as two independent parallel Hidden Markov Models (HMMs). The Load HMM processes Ground Reaction Forces, …


Motivational Outsourcing: Ai, Self-Determination, And The Changing Nature Of Adult Learning, Zoe Spanos Aug 2026

Motivational Outsourcing: Ai, Self-Determination, And The Changing Nature Of Adult Learning, Zoe Spanos

Discovery Day - Daytona Beach

Artificial intelligence (AI) is increasingly embedded into adult learning and higher education, serving not only as a support tool for cognitive aid but also as a system that can shape how learners regulate their motivation and engagement. This presentation examines how the use of AI in adult learning contexts may support or undermine self-determined motivation, drawing from Self-Determination Theory (SDT). It is a conceptual paper that draws on existing literature and theoretical analysis, examining AI reliance from minimal use to full automation across SDT's three basic psychological needs: autonomy, competence, and relatedness. Motivation is essential for learning, but the quality …


Learning Motion Primitive Selection And Environment Abstraction, Edison Alberto Martinez Samaniego, Natalie Alexander, Kaelyn Weddle Aug 2026

Learning Motion Primitive Selection And Environment Abstraction, Edison Alberto Martinez Samaniego, Natalie Alexander, Kaelyn Weddle

Discovery Day - Daytona Beach

Learning Motion Primitive Selection and Environment Abstraction Advanced Air Mobility (AAM) is emerging as a transformative solution for short and medium range transportation; however, it introduces an operational model that differs significantly from conventional aviation. AAM vehicles are expected to operate closer to populated areas, with increased autonomy, in dense urban and suburban environments. These settings present constrained maneuvering conditions which highlights the importance of maintaining safe operation under degraded flight conditions. Abnormal conditions may endanger onboard passengers, people on the ground, and surrounding infrastructure, making rapid detection and mitigation essential to prevent loss of control. Recent research has explored …


Modeling Aircraft Collision Risk Using Machine Learning And Traffic Density Data Ac, Jadia Renee Ewing, Alexander Van Baelan, Conrad Prisby, Rafal P. Smietana Aug 2026

Modeling Aircraft Collision Risk Using Machine Learning And Traffic Density Data Ac, Jadia Renee Ewing, Alexander Van Baelan, Conrad Prisby, Rafal P. Smietana

Discovery Day - Daytona Beach

Air traffic congestion is an increasingly important factor in aviation safety as global flight activity continues to grow. This project investigates whether higher traffic density is associated with an increased risk of aviation incidents and identifies key contributing factors. Using publicly available flight (ADS-B) and incident (NTSB) data, we apply several machine learning models to analyze traffic patterns and predict risk. We begin with logistic regression to evaluate the relationship between density and incident probability, followed by decision trees to extract interpretable rules describing high-risk conditions. K-nearest neighbors (KNN) is used to examine similarity in traffic patterns among incident flights, …


Low-Rank Spectral Analysis For The Reddening Of The Seven Sisters Star Cluster, Eric Rodarte, Angelina Scalice, Madison Warner, Kevin Numbe Aug 2026

Low-Rank Spectral Analysis For The Reddening Of The Seven Sisters Star Cluster, Eric Rodarte, Angelina Scalice, Madison Warner, Kevin Numbe

Discovery Day - Daytona Beach

The Pleiades, also known as the Seven Sisters, is a stunning star cluster located approximately 440 light-years from Earth. This vibrant assemblage of hot blue stars in the Taurus constellation can be admired with the naked eye or through binoculars during early autumn. In this presentation, we utilize spectral theory to measure the reddening in the Pleiades star cluster. To evaluate the impact of interstellar dust on reddening, we employ principal component analysis (PCA) on a matrix representing color indices from various photometric bands linked to the cluster’s photometric data. This dataset was obtained from VIZIER. Our PCA analysis of …


Vibration And Thermal-Vacuum Feasibility For Micro Carbon Fiber Filled Nylon Filament Lunar Applications, Andrew Murphy, Shannon O'Sullivan, Daniel Lopez Aug 2026

Vibration And Thermal-Vacuum Feasibility For Micro Carbon Fiber Filled Nylon Filament Lunar Applications, Andrew Murphy, Shannon O'Sullivan, Daniel Lopez

Discovery Day - Daytona Beach

The proposed work seeks to improve the fundamental understanding of the properties concerning 3-D printing filaments that have potential to be used for lunar applications. The associated properties in focus for the proposed study, vibration and thermal-vacuum-resistance, are fundamental aspects of spaceflight and are critical to mission success for objectives associated with the environmental factors in space. The successful outcome of the proposed work will answer questions relating to the feasibility of micro carbon fiber filled nylon 3-D printing filaments such as Markforged’s Onyx® for application for projects in the Space Technologies Laboratory, including for the development of structures relating …


Advancements In Spacecraft Trajectory Generation Through Matrix Decomposition Techniques, David Stoev, Oshani Jayawardane, Kaitlyn Cavanaugh, Kristiyan Stefanov, Andrew Murphy Aug 2026

Advancements In Spacecraft Trajectory Generation Through Matrix Decomposition Techniques, David Stoev, Oshani Jayawardane, Kaitlyn Cavanaugh, Kristiyan Stefanov, Andrew Murphy

Discovery Day - Daytona Beach

The Circular Restricted Three-Body Problem (CR3BP) is renowned for its intricate and chaotic dynamics, leaving it without a closed-form solution. In this poster, we introduce an innovative approach to determine spacecraft trajectories within the CR3BP framework using matrix factorization techniques. We formulate a matrix equation where the right-hand side vector is constructed from the spacecraft's position and velocity data, while the coefficient matrix is derived from the spacecraft's temporal data. Subsequently, we apply several matrix decomposition techniques, including modified Gram-Schmidt, the Householder technique, and Givens Rotation, to analyze the coefficient matrix and derive the spacecraft trajectories. Finally, we evaluate the …


Earthquake-Resistant Design And Base Isolation Techniques, Christian George, Jacob Sweeten, Gabriela Cotto, Savion Stewart Aug 2026

Earthquake-Resistant Design And Base Isolation Techniques, Christian George, Jacob Sweeten, Gabriela Cotto, Savion Stewart

Discovery Day - Daytona Beach

Earthquake-resistant design has become a critical feature in construction near active fault lines, where seismic activity is most frequent and potentially destructive. In recent years, technological advancements have significantly improved methods for protecting buildings from earthquake damage. Among these innovations, base isolation systems have appeared as one of the most effective solutions. By decoupling a building from ground motion, base isolators reduce the transmission of seismic forces, helping to prevent structural damage and support building stability during earthquakes. In addition to improving safety, base isolation systems can also reduce long-term costs associated with earthquake-related repairs and maintenance. Base-isolated structures are …


Results And Implications For Space Weather Forecasting Of Periodic Mesoscale Solar Wind Structures Responsible For Radiation Belt Particle Loss, Grace Gratton Aug 2026

Results And Implications For Space Weather Forecasting Of Periodic Mesoscale Solar Wind Structures Responsible For Radiation Belt Particle Loss, Grace Gratton

Discovery Day - Daytona Beach

Highly dynamic and structured mesoscale solar wind continually buffets Earth's magnetosphere, the moon, and Mars. These mesoscale structures cause several significant risks to spacecraft and astronauts, including driving radiation belt depletion and amplifying the hazards of CMEs and SIRs through upstream solar wind preconditioning. Characterizing the solar origins and solar wind properties of geoeffective mesoscale structures is essential for eventually forecasting their arrival and space weather impact at various satellites. In this interdisciplinary work, we leverage modeling and data analysis to characterize a series of events observed by the Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL) instrument – in …


Analyzing Fungal Growth Dynamics Under Different Environmental Conditions Using A Lotka–Volterra Competition System, Maria Ordonez, Fabrio Araujo Aug 2026

Analyzing Fungal Growth Dynamics Under Different Environmental Conditions Using A Lotka–Volterra Competition System, Maria Ordonez, Fabrio Araujo

Discovery Day - Daytona Beach

Fungi play a critical role in ecosystems as decomposers that recycle nutrients and maintain environmental balance. Their populations are influenced by multiple environmental factors such as temperature, humidity, nutrient availability, and interactions with other organisms. In this project, the Lotka–Volterra model is used to analyze how competing fungal species interact and how these interactions influence population dynamics over time. By modeling two fungal populations competing for the same limited resources, the equations illustrate how environmental conditions and competition coefficients determine whether one species dominates; both species coexist, or one species becomes extinct. The model provides insight into how changes in …


Characterization Of An Ambe Tagged Neutron Source For A 30-Ton Wbls Detector, Rylee Grover Aug 2026

Characterization Of An Ambe Tagged Neutron Source For A 30-Ton Wbls Detector, Rylee Grover

Discovery Day - Daytona Beach

Understanding the detection capabilities of water-based liquid scintillator (WbLS) is critical for its deployment in next-generation neutrino detectors such as THEIA and Phase II of the Deep Underground Neutrino Experiment (DUNE). This study focuses on the characterization and alignment testing of an Americium-Beryllium (AmBe) radioactive neutron source. We plan to dope the 30-ton WbLS detector at Brookhaven National Laboratory (BNL) with Gadolinium (Gd) to improve neutron detection capabilities. This will be tested by the implementation of an AmBe source as a calibration metric. The AmBe source emits neutrons coincident with a 4.4 MeV gamma ray, making it possible to perform …


Lightweight Uav-To-Uav Detection And Tracking For Advanced Air Mobility Applications, Taylor Hostetter Aug 2026

Lightweight Uav-To-Uav Detection And Tracking For Advanced Air Mobility Applications, Taylor Hostetter

Discovery Day - Daytona Beach

Lightweight UAV-to-UAV Detection and Tracking for Advanced Air Mobility Applications addresses the significant challenge of reliable UAV-to-UAV detection on resource-constrained platforms, particularly within Advanced Air Mobility (AAM) environments where dense, low-altitude airspace requires robust detect-and-avoid capabilities. This work presents the development and experimental evaluation of a lightweight detection and tracking framework for autonomous detect-and-avoid applications. The approach is designed to support real-time onboard operation in multi-vehicle environments characteristic of emerging AAM systems. The proposed framework integrates optical and LiDAR sensing with a low-complexity machine learning decision-support layer that reduces false detections without replacing the underlying control-oriented detection pipeline. This design …


Project Minerva, Lena Wang, Gannon English, Ethan Yemm, Gabrielle Guirguis, Jose Murphy Aug 2026

Project Minerva, Lena Wang, Gannon English, Ethan Yemm, Gabrielle Guirguis, Jose Murphy

Discovery Day - Daytona Beach

Project Minerva is a multidisciplinary engineering initiative at Embry-Riddle Aeronautical University (ERAU) dedicated to the design, integration, and deployment of high-altitude balloon (HAB) systems for stratospheric research and aerospace hardware validation. The project challenges student researchers to engineer flight-ready payloads capable of maintaining structural and electronic integrity in extreme temperatures and low-pressure environments in the stratosphere. Typically utilizing 600g latex balloons filled with helium, Project Minerva missions aim to achieve altitudes exceeding 22,000 meters to facilitate vertical atmospheric profiling of variables such as CO₂ concentration, humidity, temperature, and pressure. Beyond its technical objectives, the project serves as a professional training …


System And Method For Detecting Subsurface Voids Using Controlled Heat Addition, Chase Nilsson Aug 2026

System And Method For Detecting Subsurface Voids Using Controlled Heat Addition, Chase Nilsson

Discovery Day - Daytona Beach

This study evaluates controlled heat addition in a confined space to estimate enclosed volumes for irregularly shaped spaces. The intent is to detect hidden voids in cave environments. Conventional methods for identifying such voids are often costly, logistically difficult, and limited in accuracy. Preliminary experiments were conducted with a controlled heat source, a temporary thermal barrier to isolate the test chamber, and simple temperature sensors. Temperatures were recorded for the pre-test baseline, the heating interval, followed by a cooling period. The thermal response showed clear engineering trends that warrant further exploration and modeling. Preliminary results indicate that transient temperature changes …


The Impact Of Environmental Contributing Factors In Spatial Disorientation And Non-Spatial Disorientation Related General Aviation Accidents, Victoria Cornaro, Molly Mersinger Aug 2026

The Impact Of Environmental Contributing Factors In Spatial Disorientation And Non-Spatial Disorientation Related General Aviation Accidents, Victoria Cornaro, Molly Mersinger

Discovery Day - Daytona Beach

The Impact of Environmental Contributing Factors in Spatial Disorientation and Non-Spatial Disorientation Related General Aviation Accidents   Spatial disorientation (SD) is an inherent risk of flying and with a high risk of resulting in a fatal accident (Gibbs et al, 2011). SD related accidents occur when a pilot’s perception of the aircraft altitude, position, or relative motion conflict with reality (Benson, 1999). SD accidents are significantly more likely to result in a fatality than non-SD cases. The purpose of this study was to investigate the role of different contributing factors on SD and non-SD general aviation accidents. We used the NTSB …


Ai-Driven Predictive Analysis Of Airline Profitability Under Macroeconomic And Sustainable Aviation Fuels, Shivika Singh Aug 2026

Ai-Driven Predictive Analysis Of Airline Profitability Under Macroeconomic And Sustainable Aviation Fuels, Shivika Singh

Discovery Day - Daytona Beach

This study presents an AI-enhanced predictive model to assess airline profitability under the combined influence of macroeconomic trends and the adoption of sustainable aviation fuel (SAF). By including economic indicators such as GDP growth, inflation rates, and fuel price volatility with airline operational data, including ticket prices and fuel costs, the model simulates profitability across multiple carriers. Scenario-based analyses, encompassing optimistic, moderate, and pessimistic projections, illustrate different financial sensitivities between low-cost and legacy airlines.


Supply Chain Analysis: The Oregonator Autocatalytic Case Study, Abigail Butcher Aug 2026

Supply Chain Analysis: The Oregonator Autocatalytic Case Study, Abigail Butcher

Discovery Day - Daytona Beach

Understanding stability in complex supply chains remains a critical challenge due to nonlinear feedback, delayed responses, and sensitivity to parameter changes. This project presents a novel framework that applies bifurcation analysis to evaluate system stability, using the Oregonator autocatalytic chemical reaction model as an analog for supply chain dynamics. A parameter sweep of key model variables, particularly the stoichiometric factor f and the reaction rate constants k, is used to identify transitions between stable and oscillatory regimes. These transitions provide insight into how variations in feedback strength can drive instability in real-world systems. The framework will then be extended to …


Synchrotron X-Ray Diffraction Method For Continuous Strain Analysis Across Heterogenous Material Interface Layers, Sierra Damon Aug 2026

Synchrotron X-Ray Diffraction Method For Continuous Strain Analysis Across Heterogenous Material Interface Layers, Sierra Damon

Discovery Day - Daytona Beach

Synchrotron X-ray diffraction method for continuous strain analysis across heterogenous material interface layers   The transfer of strain across a material interface is a relevant concept to quantify for numerous aerospace applications that involve coatings applied to substrates of different materials, particularly in the field of high temperature materials. X-ray diffraction (XRD) is a metrology technique capable of resolving strain within an arbitrary material by quantifying the shifts of Bragg peaks with respect to an unstrained sample and has seen increased use due to the capability of XRD to perform in-situ measurements on materials in extreme environments. Since different materials have …


Asymptotic Enumeration Of K-Bounded Functions Using Toeplitz Matrices, Tiago Cavalcante Trindade, Pedro Martineli Aug 2026

Asymptotic Enumeration Of K-Bounded Functions Using Toeplitz Matrices, Tiago Cavalcante Trindade, Pedro Martineli

Rose-Hulman Undergraduate Mathematics Journal

We introduce the concept of $(\alpha, \lambda)$-bounded functions, characterized by limited local variation, which is especially useful in discrete sets. Initially, we formally define these functions and investigate their fundamental properties, highlighting significant differences from continuous functions. The main result obtained is the asymptotic estimate of $a(n, k)$, representing the number of functions from $[n]$ to $[n]$ that are $k$-bounded with respect to the Manhattan distance. The proof of this result combines Toeplitz matrices with a well-known inequality from graph theory.


Sustainability Challenges And Opportunities In A University Police Fleet: A Case Study Of Idling, Emissions, And Electrification Potential, Van Slusser Aug 2026

Sustainability Challenges And Opportunities In A University Police Fleet: A Case Study Of Idling, Emissions, And Electrification Potential, Van Slusser

School of Political Science, Public Affairs, Legal and Security Studies Faculty Publications

This case study examines fleet sustainability challenges within the University of Texas Rio Grande Valley Police Department, a multicampus public safety agency operating aging gasoline vehicles central to daily patrol and administrative functions. Rising maintenance costs, increased vehicle downtime, and extensive idling created both operational strain and avoidable environmental impacts. Aging internal-combustion vehicles contributed to elevated emissions and fuel consumption, particularly under high-heat conditions and equipment demands typical of campus policing. Telematics monitoring indicated that approximately 48% of total engine-on time consisted of idling, highlighting a substantial source of avoidable fuel use and emissions. The study employed a qualitative case …


Synthetic Strategies For Bioactive Peptides: From Aggregation Inhibitors To The Total Synthesis Of Tunicyclin C, Stephanie Graciela Garcia Morin Aug 2026

Synthetic Strategies For Bioactive Peptides: From Aggregation Inhibitors To The Total Synthesis Of Tunicyclin C, Stephanie Graciela Garcia Morin

Theses and Dissertations

In Alzheimer's disease (AD), a brain protein called "tau" abnormally clumps and forms neurofibrillary tangles (NFTs), causing damage to brain cells. Ac-PHF6-NH2 is a hexapeptide segment of tau protein that plays a dominant role in tau aggregation and is used as a model to design tau protein aggregation inhibitors. In this research we synthesized four dehydroamino acid (□AA) containing PHF6 analogues with △Abu (derived from L-threonine) and △Val (derived from □-OH-Valine) at position 2 or 3 via dehydrations or azlactone ring-openings as key reactions. We evaluated their proteolytic resistance, ability to inhibit aggregation of PHF6, and impact on the morphology …


Measuring Proteostasis Changes In Apolipoprotein E Mouse Models Using Quantitative And Kinetic Proteomic Methods, Ariel E.A. Denos Aug 2026

Measuring Proteostasis Changes In Apolipoprotein E Mouse Models Using Quantitative And Kinetic Proteomic Methods, Ariel E.A. Denos

Theses and Dissertations

Alzheimer's Disease (AD) is a neurological disorder associated with brain mass loss and cognitive decline. It affects millions of elderly people and is currently uncurable. Since 1906, when the disease was first described, researchers have uncovered many components of AD pathology. However, it is now evident that curing Alzheimer's Disease will require intervention before the pathological onset of amyloid beta plaque deposition, tau neurofibrillary tangles, and associated neuronal loss. Studying AD from the perspective of early intervention requires special attention to small changes that may disrupt the normal processing of cells. Cells undergo a natural cycle of creation and destruction …


Multi-Band Extinction Modeling In Early-Type Galaxies With Circumnuclear Disks, Nonnie Bash Aug 2026

Multi-Band Extinction Modeling In Early-Type Galaxies With Circumnuclear Disks, Nonnie Bash

Theses and Dissertations

In this thesis, we present a spatially resolved, multi-band dust-attenuation method for correcting the stellar luminosity models used in dynamical supermassive black hole (BH) mass measurements. If uncorrected, dust extinction effects may dominate over other systematic uncertainties when determining the BH mass ($M_\mathrm{BH}$). We expand on a simple dust-attenuation method that treats the circumnuclear disk as a thin dust layer embedded in the galaxy midplane. Using a Multi-Gaussian Expansion, we create a three-dimensional stellar luminosity model to calculate the fractions of stellar light originating in front of and behind the disk along each line of sight. We infer the pixel-by-pixel …


Techniques, Skills, And Synthesis For “Cooking” In The Organic Laboratory, Emily C. Sylvester, Tim Evans Aug 2026

Techniques, Skills, And Synthesis For “Cooking” In The Organic Laboratory, Emily C. Sylvester, Tim Evans

Open Education Materials

Lab manual for CHEM 211L, Organic Chemistry I Laboratory. Provides background and procedures for laboratory experiments, including fundamental techniques and several organic syntheses.

Creative Commons attribution.


The Use Of Chitosan-G-Poly (Acrylic Acid-Co-Acrylamide) In The Delivery Of Imatinib In The Small Intestine, Dawson Ohrt, Clint Everard Aug 2026

The Use Of Chitosan-G-Poly (Acrylic Acid-Co-Acrylamide) In The Delivery Of Imatinib In The Small Intestine, Dawson Ohrt, Clint Everard

Nebraska Academy of Sciences: Programs and Proceedings

The use of hydrogels as drug delivery systems is the future of biotechnology, hydrogels can offer a new way of controlled delivery to specific areas of the body. Hydrogel also create new possibilities for treatments of gastrointestinal stromal tumors (GISTs). There are many different types of hydrogels that can be used in drug delivery. Hydrogels offer customizability in regard to the release of drugs in specific environments. The chemical properties of hydrogels allow for them to be manipulated for specific functions such as release at a specific pH . The hydrogel being used in the study is Chitosan-G-Poly (Acrylic Acid …


Temperature And Hydrologic Context Influence Methane Variability In A Low-Salinity Marsh, Zoie Brauser Aug 2026

Temperature And Hydrologic Context Influence Methane Variability In A Low-Salinity Marsh, Zoie Brauser

Dissertations and Theses

Coastal wetlands are biogeochemical hotspots that capture and transform carbon and nutrients. Wetland restoration is increasingly used as a climate mitigation strategy because of wetlands' capacity to sequester large amounts of carbon. However, low-salinity tidal marshes exhibit high variability in methane (CH4) emissions, which could partially offset carbon sequestration under certain conditions. Understanding the drivers of CH4 variability is crucial for restoration and conservation work. This project uses an observational research approach to assess the relationships between environmental factors and carbon dioxide (CO2) and CH4 soil gas fluxes in a restored low-salinity tidal marsh …


Set-Valued Conjugate Calculus And Duality In Optimization And Machine Learning Via Generalized Relative Interiors, Gary Lee Sandine Aug 2026

Set-Valued Conjugate Calculus And Duality In Optimization And Machine Learning Via Generalized Relative Interiors, Gary Lee Sandine

Dissertations and Theses

Convex analysis, optimization, and duality theory are broadly applicable to a multitude of real-world problems. Theoretical frameworks ensuring strong duality and optimality are fundamentally tied to convex separation under qualification conditions frequently involving topological or relative interiors. These can be empty in convex sets that appear naturally in infinite-dimensional models, yet guarantees of optimality and strong duality are often attainable. This dissertation presents frameworks for applying convex separation via generalized relative interiors to develop generalized calculus rules as well as conditions for strong duality and optimality for infinite-dimensional constrained convex optimization problems.

The first major contribution is the introduction of …


Developing An Object Level Understanding Of Sine And Cosine As Ratios And A Coherent Trigonometry, Jeffrey Peter Nair Aug 2026

Developing An Object Level Understanding Of Sine And Cosine As Ratios And A Coherent Trigonometry, Jeffrey Peter Nair

Theses and Dissertations

Solving right-triangle problems as well as integrating right-triangle and circular trigonometry into a coherent understanding are documented challenges for students. Prior research has deeply investigated students constructing ratio meanings for sine and cosine using a circle-first approach, which then can be extended to right triangles. Also, past work has separately documented distinct meanings that are useful for sine and cosine, in addition to the ratio meaning, including as lengths in a unit circle and coordinate points. This study took these existing ideas and put them together into one possible developmental progression, based on APOS theory, where students can learn length, …


Modeling Stellar Structure: Comparing Numerical Solutions Of The Lane-Emden Equation, Jasman Jasmanjot, Bailey Dale, Ryan Dickey Aug 2026

Modeling Stellar Structure: Comparing Numerical Solutions Of The Lane-Emden Equation, Jasman Jasmanjot, Bailey Dale, Ryan Dickey

Discovery Day - Daytona Beach

The Lane-Emden equation is a differential equation that is often used in astrophysics to describe the distribution of the density inside a star, and by extension, its pressure distribution. Analytic solutions of the Lane-Emden equation can only be found at polytropic indices n = 0,1,5, matching certain physical conditions. For all other polytropic values, a numerical solution is needed. In this work, a comparison between two numerical schemes for solving the Lane-Emden equation is presented, namely the Euler method and the classical 4th order Runge-Kutta method. The accuracy of these models is first compared to the cases with known analytical …