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A Comparison of Control Methods for Spacecraft Maneuvering With Run Time Assurance
No full textIn the vast subject of aerospace systems, safety is a critical factor in mission completion within the controls field. Controllers designed using data-based approaches like artificial intelligence must uphold the same levels of safety expected from modern controllers, such as Linear Quadratic Regulators. This is accomplished with the application of Run Time Assurance, which ensures the system states will remain within a predefined safe set of values, no matter the potentially dangerous control actions from the primary controller. This research compares control approaches for a deputy spacecraft conducting proximity operations to safely egress from near a chief spacecraft to a predefined relative parking orbit. This trajectory is described in a linearized relative motion reference frame and is calculated from a variety of modern control methods: Linear Quadratic Regulation, Linear Quadratic Integration, and Linear Quadratic Tracking. The initial conditions are chosen to force an unsafe trajectory to demonstrate how the use of Run Time Assurance ensures the system remains within the set of safe states. The two Run Time Assurance methods utilized are an active set invariance filter and a switching backup controller, both of which use a control barrier function to determine the safe set of values for the affected outputs with differing approaches of implementation. Three different scenarios are investigated to prove the safety bounds are not violated, each with a new situation addressed complete with new specific initial conditions. The results demonstrate that each modern controller is fully capable of implementing Run Time Assurance methods, while displaying varying levels of success based on the calculation-based values of the summation of control output and the rendezvous time
Let's Talk About Bruno: Uncovering Genetic Differences Responsible for Variation in Dysgenic Sterility in Drosophila melanogaster
No full textP-elements are DNA transposons that invade the germline of Drosophila melanogaster and are causative agents of a sterility syndrome called hybrid dysgenesis (HD). HD causes high rates of mutation in germline cells resulting in sterility, increased chromosomal rearrangement, and recombination. The Kelleher lab previously quantitative trait locus (QTL) mapped variants of dysgenic sterility in pre-invasion D. melanogaster populations and found the bruno gene to be a primary candidate for causation due to its instrumental role in regulating germ-cell differentiation. We performed fine-scale fluorescent marker-assisted recombination mapping to identify the region within the QTL responsible for variable dysgenic sterility. Over 150 unique recombinants were analyzed through a fecundity assay and PCR. Phenotypic and genotypic data analysis narrowed down the initial 324 kb window to an 18 kb region located in the bruno locus. This window contains 235 known variants differing between sterile and fertile strains. To determine the exact causative variant located within our narrowed window, we designed a series of CRISPR cas9-mediated deletions. These deletions will cover 2-3 kb windows within our 18 kb region, and combined with further fecundity assays, will allow us to determine whether each region is required to produce the phenotypic differences we have observed. We will repeat this process for approximately 10 deletions to narrow the window to a 2-3 kb region. We will then target single nucleotide polymorphisms, deletions, and insertions within the 2-3 kb window found to be causative to determine the exact variants causative of differences in P-element-induced dysgenic sterility.Biology and Biochemistry, Department ofHonors Colleg
Enhancing Student Learning Outcomes Through Multi-Sensory Mapping
No full textUH Senses, inspired by Dr. Kate McLean's artistic aerial olfactory maps, has pioneered the development of the first multi-sensory maps using auditory and olfactory stimulation. The goal of this initiative is to enhance urban planning, cognitive function, and assist the sensory impaired. In collaboration with the Dean's Grant and MD Anderson Library, we are applying these multi-sensory mapping concepts to understand how sensory environments influence student learning outcomes. By identifying how different areas of the library and their sensory stimuli correlate with student preferences, we aim to enhance the learning experience and optimize space utilization within the library. Studies show that libraries designed with careful attention to sensory elements, such as the smell of books, can significantly enhance the student experience. This pilot project has led to the creation of interactive sensory maps of the library floors, offering a visual representation of the sensory elements present. Through this research, we seek to explore how the existing library environment impacts student engagement and how these sensory variables could influence their academic performance.Biology and Biochemistry, Department ofHonors Colleg
Reducing Marine Ecotoxicity and Carbon Burden: A Life Cycle Assessment Study of Antifouling Systems
No full textMarine biofouling significantly impacts the performance and longevity of polymer-based marine structures, particularly those designed for hydrodynamic applications such as Vortex-Induced Vibration suppression systems. Traditional antifouling solutions rely on copper-based multilayer coatings, which present challenges including mechanical vulnerability (e.g., chipping and scratching), high material and labor demands, and environmental concerns such as volatile organic compound emissions and copper leaching. Recent developments in material science have introduced an alternative system involving the direct incorporation of copper oxide (Cu<sub>2</sub>O) into high-density polyethylene (HDPE) during the molding process. This study conducts a comparative life cycle assessment (LCA) of two antifouling integration methods&mdash;System 1 (traditional coating-based) and System 2 (Cu<sub>2</sub>O-impregnated HDPE)&mdash;evaluating their environmental impact across production, application, use, and end-of-life stages. The functional unit used for this study was 1 square meter for a time period of five years. Using ISO 14040-compliant methodology and data from Ecoinvent and OpenLCA, three impact categories were assessed: global warming potential (GWP), cumulative energy demand (CED), and marine aquatic ecotoxicity Potential (MAETP). The results indicate that System 2 outperforms System 1 in GWP (4.42 vs. 5.65 kg CO<sub>2</sub>-eq), CED (75.3 vs. 91.0 MJ-eq), and MAETP (327,002 vs. 469,929 kg 1,4-DCB-eq) per functional unit over a five-year lifespan, indicating a 21.8%, 17.3%, and 30.4% reduction in the key impact factors, respectively. These results suggest that direct Cu<sub>2</sub>O incorporation offers a more environmentally sustainable and mechanically resilient antifouling strategy, supporting the potential of embedded antifouling systems to shift industry practices toward more sustainable marine infrastructure
From Vacant to Vibrant: Suitability Testing and Estimating Impacts of Vacant Plots for Potential Urban Agriculture in Harris County
No full textIn Harris County, forms of Urban Agriculture (UA) can serve as multifunctional green infrastructure, providing an array of social, environmental, and health co-benefits. While the positive impacts of UA have been studied extensively, research on the suitability and siting of Vacant Plots for Potential Urban Agriculture (VPPUA) remains limited. This gap is significant because the spatial distribution of UA determines which residents benefit from UA and the long-term success of UA. This study aims to evaluate VPPUA in Harris County, based on factors such as land use, pollution levels, community needs, among others. To overcome potential biases and impacts related to ad hoc decision-making, this study presents a systematic approach for strategic VPPUA siting through a Multi-Criteria Decision Analysis (MCDA). The MCDA utilizes a suitability index made up of physical and social characteristics relevant to vacant plots of land in Harris County. This method reduces thousands of VPPUA to a smaller number for subsequent in-depth site analysis. The findings from this study can be utilized to plan projects for green infrastructure that target specific needs of Harris County's population. For instance, UA can be utilized as a bio-remediation tool to address soil pollution in highly contaminated areas. By using bio-accumulators and other sustainable practices, urban agriculture can help decontaminate polluted soils. This approach improves soil health and empowers local communities by providing safe and productive green spaces. Additionally, the strategic siting and implementation of UA can improve community health, enhance food security, reduce environmental racism, and promote long-term community resilience.Honors Colleg
State of Health Estimation of Cylindrical Lithium-Ion Cells Using Multiple Random Convolutional Kernel Transform and Low-Frequency Stress Waves
No full textBuilding upon the prior success of using Multiple Random Convolutional Kernel Transform and low-frequency stress waves to monitor cylindrical lithium-ion battery State of Charge (SoC), this project extends that method to estimate the State of Health (SoH) of lithium-ion batteries. Numerous challenges and delays were encountered during this stage of the project, however significant progress has been made and experimental dataset creation is ongoing. This poster summarizes the changes made to the experimental setup to produce the long-running experiments necessary to capture battery capacity loss data for the development of a large battery model, as well as some preliminary results showing the promise of the already-developed method for this new thrust into battery health monitoring.Mechanical and Aerospace Engineering, Department ofHonors CollegeElectrical and Computer Engineering, Department o
The Effects of Colorism and Racism on Skin Color Satisfaction and Skin-whitening Intention
No full textColorism is the discrimination people of color receive due to their skin color. Racism focuses on the discrimination that people experience because of their race. Two studies were conducted in this research to find out if colorism and racism predict skin whitening intention through skin color satisfaction, and the differences between these effects. Study 1 was a correlation study. I found that both racism and colorism were positively associated with skin color dissatisfaction, which in turn positively predicted skin-whitening intention. The associations between ingroup colorism and skin color satisfaction and skin-whitening intention were the strongest, while the association between racism and skin-whitening intention was stronger than the association between outgroup colorism and skin-whitening intention. Study 2 was an experiment. Participants in Study 2 were randomly arranged in colorism or racism or neutral condition, and reported their skin color satisfaction, intention to conduct skin-whitening behavior, skin tone, and private regard. Results showed that racism and colorism that were triggered by experimental conditions did not lead to skin color dissatisfaction and increased skin-whitening intention. This research revealed how racism and colorism affect skin color satisfaction and skin-whitening intention to a different extent
Comparing OCT vs. Eye-Trackers for Quantifying Eye Fixation Stability
No full textVisual impairments such as strabismus, amblyopia, glaucoma, retinopathy, etc. can leave a devastating and severe impact on the fixational stability of one's vision. Fixational stability is the ability to maintain a steady gaze on a target without interruption. Due to factors such as slow onset, age, and the difficulty of detecting subtle changes, poor fixational stability may go unnoticed. While research laboratories with high resolution eye-trackers can identify and diagnose the symptoms and signs of the disorder, this equipment is not available to clinicians who have a limited set of tools available. OCT (optical coherence tomography) is a common clinical tool which provides high resolution images of the retina, using light interference as a reference to assist in diagnosing the occurrence of abnormal retinal structure. Since it takes repeated images of the retina, it can be used to measure fixational stability. However, it is unknown how well fixational stability measurements from eye-trackers and OCT machines correspond. To address this, I will take fixational stability and visual function measurements with both machines in the same group of participants. I will then analyze the data using Bland-Altman tests and multiple regression analysis to determine the accuracy of the OCT and how well it predicts visual function. My expected findings are to connect stability measures found within the OCT as a diagnostic tool for visual dysfunction. I would like to further these results to look for a treatment plan that combines both machines to locate poor fixational stability in patients.Optometry, College ofHonors Colleg
Improving Elementary Mathematics Student Achievement on Local and State Assessments Through Curriculum-Based Measures and Evidence-Based Practices
No full textBackground: The evolution of elementary mathematics instruction and student achievement in the United States has long been a contentious issue, often referred to as the "math war." Dating back to the late 1890s, mathematics education was viewed as a mechanism to improve one’s station in life. Today, efforts to improve mathematics education continue, with a focus on problem-solving and foundational skills. Purpose: Math achievement for elementary students in public schools is tracked through local and state assessments. Elementary students receive daily classroom instruction as outlined by district curriculum standards. Yearly, students undergo local math screenings and conclude the academic year with a final math state assessment. Despite efforts to strengthen math skills, student achievement remains marginal for learners across all demographic categories. This study aimed to identify specific evidence-based practices outlined in district lesson plans that build student capacity in math. Methods: This archival, descriptive study utilized de-identified student data on the local mCLASS Math and State of Texas Assessments of Academic Readiness (STAAR) from one elementary school for the 2023-2024 academic year. Data was disaggregated by English language proficiency, special education eligibility, gender, and ethnicity. The researcher utilized this data to determine math outcomes alongside preset parameters. Lastly, a document analysis of district lesson plans was conducted to determine if evidence-based practices were reflected in the existing design. Results: The study found that elementary students have challenges in math achievement on local and state assessments despite demographic characteristics. Students across included categories demonstrate a need for targeted instruction to improve math outcomes. The document analysis of district lesson plans revealed there was not an overt reference to the use of evidence-based practices for daily instruction. Conclusion: This study revealed a widespread need for academic support by way of evidence-based practices as documented in daily lessons to improve math achievement outcomes for all learners
In Silico Investigation of Chromosome Structure in Densely Packed Conditions
No full textChromosomal architecture plays a critical role in genome function, yet the impact of chromatin compaction on intra- and inter-chromosomal interactions remains poorly understood. This study explores how the degree of chromosomal compaction influences these interactions using OpenMichroM software to simulate different crowded nuclear environments. By modifying the training pipeline of the MichroM energy function, we aim to analyze changes in chromosomal interactions under varying conditions. We will compare interactions using a default forcefield trained on single chromosomes and develop a novel energy function trained on multiple chromosomes to distinguish intra- and inter-chromosomal dynamics. Understanding these structural variations could provide valuable insights into genome organization's role in transcriptional regulation, embryonic development, and cancer progression. Ultimately, this research seeks to deepen our knowledge of chromatin behavior, with potential implications for precision medicine and genomic research.Physics, Department ofHonors Colleg