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Side Channels of Imaging Systems: Image Injection and Extraction
No full textThe full text of this item is not available at this time because the author has placed this item under an embargo until December 11, 2028.In an automated and connected world, imaging systems underpin many critical applications, spanning sectors from transportation to manufacturing. However, complex imaging technologies contain vulnerabilities that could threaten safety, security, and privacy. This thesis investigates novel security vulnerabilities in two imaging systems: camera-based Advanced Driver Assistance Systems (ADAS) and Masked Stereolithography Apparatus (MSLA) 3D resin printers.
Camera-based ADAS enhance driving safety by accurately interpreting traffic signs, lane markers, and various environmental factors, heavily relying on optical sensors. We identify a novel optical side channel inherent to these camera systems, enabling adversaries to disrupt or manipulate ADAS functionality covertly, remaining undetectable to human observers.
Parallel to this, we examine security vulnerabilities in MSLA 3D resin printers, which are common in sensitive manufacturing environments such as medical offices or design laboratories. MSLA systems cure photopolymer resin via selective ultraviolet exposure through an LCD mask. Our investigation uncovers electromagnetic side channels in these systems that allows precise reconstruction of printed geometries from electromagnetic emissions.
To illustrate the practical exploitation of these vulnerabilities, we introduce FlickerAttack and MoonShine. FlickerAttack leverages the optical side channel to inject malicious yet visually imperceptible traffic signs into ADAS, covertly influencing vehicle behavior. MoonShine exploits electromagnetic emissions from MSLA printers to reconstruct of detailed object geometries, providing an in-situ monitoring capability that can enable intellectual property theft or subversion of manufacturing systems.
This thesis provides a thorough exploration of these vulnerabilities, details methodologies for exploitation, and evaluates potential defenses.Electrical and Computer Engineerin
The Differential Impact of Data Collection Methods and Language Background on English Tone Choice Patterns
Get PDFThis study examines the impact of spoken data collection techniques and language background on falling, level, and rising tones. Elicited data from a Discourse Completion Task (DCT), structured speech from a collaborative oral assessment task, and naturalistic speech from a comprehensive corpus of inner-circle and Hong Kong English were analyzed for Discourse Intonation features, resulting in 2756 tone choices by 184 speakers. Multinomial logistic regression indicates that structured speech by L2 English learners and naturalistic speech by both inner circle and Hong Kong English speakers exhibited similar tone choice patterns. However, DCT responses by L2 English learners contained significantly fewer level tones and more rising tones. Qualitative analyses suggest that contrary to naturalistic studies, L2 learners use rising tones to focus their attention on the speaker during a request. L1 users, on the other hand, used a variety of tone choices that focus on language and mitigate directness. Overall, these results add further evidence that DCTs do not elicit speech that generalizes to naturalistic discourse. Structured tasks in which two L2 speakers interact mirror the rates of the inner circle and Hong Kong English speakers detected in this study.Bicultural-Bilingual Studie
New Analytical Approaches to Video Advertising and Upstream Supply Chain Dynamics
No full textThe full text of this item is not available at this time because the author has placed this item under an embargo until August 26, 2030.This research draws upon new methods for analyzing video advertising, and upstream supply chain dynamics. Essay 1 leverages recent advancements in computing power and machine learning to examine a large dataset of 8,450 digital video advertisements by classifying facial presence and valence frame-by-frame. Using ordinary least regression, analysis offers evidence that facial presence diminishes video view completions. Moderation analysis indicates that advertising context, and facial valence moderate the effects of facial presence on video view completions. Whereas facial presence has no impact in hedonic advertising contexts, facial presence diminishes video view completions in utilitarian advertising contexts. Whereas faces with positive valence enhance video view completions at decreasing levels of facial presence, faces with negative valence enhance video view completions at increasing levels of facial presence. Finally, the impact of negative facial valence is more pronounced in the hedonic advertising context. Essay 2 leverages a multiple membership Bayesian hierarchical model to estimate the impact of end users' consumer satisfaction on upstream supplier firm performance. Analysis of a 13-year multi-industry panel indicates that end users' consumer satisfaction of buyer firms significantly increases suppliers’ firm value measured as abnormal stock returns. This effect strengthens when suppliers enjoy greater profitability and operate in faster-growing industries compared to the buyers, but weakens as suppliers’ financial leverage rises compared to buyers.Marketin
Analyzing Sea Ice Formation, Growth, and Deformation in the Weddell Sea, Antarctica Using ICESat-2
Get PDFThe Southern Ocean sea ice plays an essential role in the elements of the Earth system, which include oceans, atmosphere, and the stability of the Antarctic ice sheet. Sea ice provides a vital habitat for many species, including seabirds, seals, and krill. Decadal changes in salinity in the Antarctic Bottom Water (AABW) may impact the strength of the deep thermohaline circulation. Sea ice formation in the Weddell Sea accounts for 5%–10% of the annual ice production around Antarctica, making the region a significant source of AABW. The sea ice in the Weddell Sea has been observed to exhibit an increasing trend since the satellite era of 1978, however, its extent started to decrease from 2016-2017. Thus, it becomes crucial to measure seasonal and interannual sea ice variability over the Weddell Sea to understand its role in global climate on longer temporal scales. In this thesis, I study the sea ice in the Weddell Sea after the decrease period using high-resolution ICESat-2 satellite data. In chapter 2, sea ice thickness is estimated using freeboard data from 2019 to 2022. This data is compared with the available field data and thickness measurements from ICESat-2 in the same time frame. This helped to understand the robustness of the method used to estimate the sea ice thickness. These were also compared with estimates from ICESat-1 and IceBridge data from 2003 to 2017. The overall trend was decreasing from 2019 to 2022 compared to years before 2019. In Chapter 3, the ice thickness of level ice, represented as the mode in the ice thickness distributions of ICESat-2 data, is compared with the ice thickness simulated from the 1D thermodynamic model ICEPACK. The thickness simulated by the model did not agree well with the observation data. Thus, this suggests that the influence of surface flooding and ocean heat flux may not be accurately reflected in the model. Finally, in Chapter 4, sea ice thickness is studied from 2019 to 2024 and compared against the hypothesis that polar cyclones reduce SIE and thickness. The results show that the thickness does not decrease due to a polar cyclonic event. Since the ICESat-2 was able to separate the thermodynamic and dynamic features of sea ice, I studied whether that is affected and whether air temperatures play an essential role in their decrease. The results indicate that the correlation with air temperature is generally weak, and in the areas of multi-year ice, the results are not statistically significant. Thus, ICESat-2 is informative about the sea ice in the region by documenting the seasonal and interannual changes in ice thickness as well as validating the thermodynamic growth of ice represented in the models. This information can be further used to analyze the changes on a larger scale.Earth and Planetary Science
Antiparasitic Effect of Polyphenols and Terpenes from Natural Products Against Trypanosoma cruzi and Leishmania mexicana
Get PDF<b>Background</b>: Worldwide, the number of cases of parasitic diseases has been increasing; however, available treatments have variable adverse effects and low efficacy, mainly in Neglected Tropical Diseases such as Chagas disease and Leishmaniasis. Therefore, the development of new and more effective antiparasitic drugs is important. Natural products are the source of secondary metabolites with different biological activities, such as antibacterial, anticancer, anti-inflammatory, and antiparasitic. <b>Objectives</b>: In this work, secondary metabolites (phenols and terpenes) from natural products were selected to be evaluated against the epimastigotes of NINOA and A1 strains of <i>Trypanosoma cruzi</i> and the promastigotes of M379 strain and FCQEPS native isolate of <i>Leishmania mexicana</i>. Additionally, their cytotoxicity and selectivity index were determined. <b>Methods</b>: Eighteen secondary metabolites were evaluated in vitro against <i>T. cruzi</i> epimastigotes and <i>L. mexicana</i> promastigotes; additionally, their cytotoxicity on the J774.2 macrophage cell line was determined. <b>Results</b>: The compounds l-(-)-menthol (14, IC<sub>50</sub> = 24.52 &micro;M) and &beta;-citronellol (11, IC<sub>50</sub> = 21.54 &micro;M) had higher trypanocidal activity than the reference drug (benznidazole) against NINOA and A1 strains of <i>T. cruzi</i>, respectively. On the other hand, <i>para</i>-anisyl alcohol (4, IC<sub>50</sub> = 34.89 &micro;M) had higher leishmanicidal activity than the reference drug (glucantime<sup>&reg;</sup>) against M379 and the FCQEPS native isolate of <i>L. mexicana</i>. Finally, in silico, the determination of their pharmacokinetic and toxicological properties showed that they are promising candidates for oral and topical uses. <b>Conclusions</b>: This study opens the possibility of using secondary metabolites as scaffolds for access to the development of new molecules for the treatment of parasite diseases.Chemistr
Archaeological Report, No. 525
Get PDFFrom October 16 to October 26, 2024, the Center for Archaeological Research (CAR) at the University of Texas at San Antonio conducted archaeological monitoring of San Antonio Water System (SAWS) excavations associated with a water line break in Brackenridge Park. The work was conducted in response to a request by the City of San Antonio (COSA), who owns Brackenridge Park. At the Municipal level, the property falls under the COSA’s Unified Development Code (UDC) Article 6, Sections 35-630 through 35-634. At the state level, the project requires review by the Texas Historical Commission (THC)
under the Antiquities Code of Texas. The project was conducted under Texas Antiquities Permit No. 32014. Sarah Wigley served as the Principal Investigator and directed the fieldwork.
Brackenridge Park is located in central San Antonio, Bexar County, Texas. The Park is a National Register of Historic Places (NRHP) District and State Antiquities Landmark (SAL) on the basis of numerous significant prehistoric and historic-period resources recorded within the Park, both archaeological and above-ground (Pfeiffer and Tomka 2011). The water main break was located below a bridge on Brackenridge Road near its intersection with North St Mary’s Street, which crosses the 1877 Water Works Raceway, a contributing resource to the National Register District. Excavations associated with damage to a nearby fire hydrant south of the Upper Labor Acequia were also monitored. The Project Area encompassed 0.2 ha (0.6 acres).
During monitoring, portions of a profile associated with the Raceway, recorded as 41BX2668, as well as a limestone and brick feature possibly associated with Upper Labor Acequia (41BX2043), were documented. These features are associated with contributing resources to the significance of the Park and impacts should be avoided. All artifacts collected and records generated during this project are curated at the CAR.City of San AntonioCenter for Archaeological Researc
Archaeological Report, No. 527
Get PDFFrom April 7-11, 2025, the Center for Archaeological Research (CAR) of the University of Texas at San Antonio (UTSA) conducted proactive archaeological trenching in advance of improvements at Medina River Park in San Antonio, Bexar County, Texas. The trenching was in response to a request from the City of San Antonio (COSA). Ten trenches were excavated in the areas of proposed improvements including two trenches for art displays, one trench in the septic system leach field, two trenches within the office building footprint, and five trenches along the proposed paths of sewer and water utilities.
Because Medina River Park is a public municipal property and falls under the City of San Antonio’s (COSA) Unified Development Code (UDC, Article 6 35-630 to 35-634), the project required review by COSA’s Office of Historic Preservation (OHP), as well as by the Texas Historical Commission (THC) under the Antiquities Code of Texas. Work was performed under THC issued Texas Antiquities Permit (TAP) No. 32229. Cynthia Munoz, Interim Director of CAR, served as the Principal Investigator, and Leonard Kemp and Amber Hefner served as the Project Archaeologists.
The final Project Area encompassed 1.74 hectares (4.3 acres) across two distinct but proximal areas of the park. One new feature was identified within the boundaries of an existing site (41BX346), and a small assemblage of artifacts unrelated to the feature was collected. The feature, located approximately 90 cm below surface (cmbs) in Trench 1, is a concentration of burned and unburned sandstone over a possible lens of burned clay. After consultation with the THC, OHP, and the COSA Parks and Recreation department, it was determined that the feature would not be impacted by the park improvements project and that further excavation was not required. Following documentation, the feature was covered with geofabric and sand, and the trench was backfilled. CAR recommends that the proposed park improvements commence, however, due to the park’s proximity to known archaeological sources, work should stop and OHP and THC should be consulted if cultural materials or features are encountered during excavations. CAR also recommends that any future park improvements be proactively tested or monitored.
CAR submitted a site update to the Texas Archaeological Sites Atlas for 41BX346. All records generated during the course of this project and all collected artifacts are permanently curated at the CAR curatorial facility on the Main Campus of UTSA as accession number 3064.City of San AntonioCenter for Archaeological Researc
AC-Susceptibility Evidence of Uncoupled Néel and Brown Superspin Relaxation in Dense Magnetic Nanofluids
Get PDFWe present an analysis of temperature-resolved magnetic ac-susceptibility data collected on ferrofluids (Fe3O4 nanoparticles immersed in a carrier fluids), which unequivocally demonstrates that the Néel relaxation – the thermally-activated rotation of the nanoparticle magnetic moment (the superspin) within the nanoparticle – and its Brown relaxation counterpart – the rotation of the superspin together with the nanoparticle within the fluid – become uncoupled in dense ferrofluids ( d>0.4 mg/mL). Although this behavior has been predicted by Monte Carlo simulations, our study is the first to confirm it based on analysis of ac-susceptibility data, the most direct probe of superspin relaxation dynamics. Our main finding is relevant as it might lead to new strategies to synthesize functional magnetic ferrofluids for biomedical applications.
χ" vs. T|f data (where χ" is the out-of-phase ac-susceptibility, T is the temperature, and f the frequency of the driving magnetic field) show magnetic events (peaks) both below and above the freezing point of the carrier fluid (TF=197K). The low temperature peaks correspond to the Neel mechanism (relaxation time tN), whereas the ones above TF correspond to an effective superspin relaxation time, teff, that can include contributions from both the Néel and the Brown mechanisms. When the two relaxation modes are coupled, the effective relaxation time is given by the Rosensweig formula, 1=1+1. Interestingly, this behavior does not occur in the ferrofluids investigated here. Indeed, we found that teff is 5×10-5 s at 225 K, almost three orders of magnitude more than its Néel counterpart, tN~ 8×10-8 s, estimated by extrapolating the above-mentioned DBF analysis. Thus, 1≫1, which is clearly not consistent with the Rosensweig formula.Physics and Astronom
UTSA Libraries and Museums Faculty Liaison Meeting Booklet 2025
No full textThis booklet is available to current UTSA affiliates only. Access by logging in on the top right hand corner of your screen with your abc123 and password.Booklet created for the Library Faculty Liaison meeting that occurred on November 10, 2025. Includes information about library services, collection budget, databases and special projects.Librar
The Effects of Additional Resources on Perceptions of Self-Efficacy and Sense of Control
Get PDFThis study examines the effects that Cash Assistance and Mobility Mentoring have on perceptions of self-efficacy and sense of control. Survey data was taken from the San Antonio GOALS Initiative (GOALS), a two-year poverty intervention study with a total sample of 595 participants who were identified as living in San Antonio’s most impoverished ZIP codes and are at or below 150% of the federal poverty line. Expected outcomes were based on existing research. We’ve already learned that each intervention method has independent beneficial effects, we don’t yet know how the two interventions interact when combined. This study aims to fill that gap. Controlling for age, gender, race, education, relationship status, benefits, and federal poverty level standing, I hypothesize that Cash Assistance and Mobility Mentoring (Cashplus) participants will exhibit greater improvements in levels of self-efficacy and sense of control than those in the control group and the single intervention treatment groups. Additionally, financial knowledge and financial health will each mediate any effects found. Overall, there is evidence that each intervention method leads to significantly greater goal accomplishment than Control participants with the magnitude being larger for Cashplus participants. Cashplus participants were also found to yield statistically greater sense of control over the things that happen to them compared to Control participants. Finally, financial knowledge and financial health were found to potentially mediate some of the relationships found in the models. Future research directions discussed.Sociolog