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Side Channel Attack (SCA) of AES in FPGAs and Microcontrollers
Get PDFSide Channel Attack (SCA) of AES in FPGAs and Microcontrollers
Presented at UA Power Group Undergraduate and REU Summer Research Poster Session on July 18, 2024.https://scholarworks.uark.edu/elegreu/1004/thumbnail.jp
El Otro Cielo
Get PDFEl Otro Cielo is an exhibition that mixes family items with personal creations, symbolizing the balance between evolving and staying connected to your roots. The work is about embracing change while remembering where you come from. This exhibition explores the stages to find one\u27s true self while adapting to new cultures and changing over time. This installation delves into the complexities of cultural identity, memory, and the human experience. The space invites viewers to contemplate their own relationships with place, nostalgia, and the ongoing process of self-discovery
High-Power DC-DC Transformer for Medium-Voltage Grids with High-Voltage SiC Technology
Get PDFThe objective of this dissertation is to present the theoretical analysis, design process, application and manufacturing of a proposed solid-state transformer intended for medium-voltage applications with minimal high-frequency oscillations. Galvanic isolation on medium-voltage DC-DC converters tend to employ large number of turns in the high voltage side of the transformers leading to non-negligible parasitic stray capacitances which form resonance tanks with the transformer inductances. Therefore, it is critical to estimate these parasitic capacitances to avoid severe high frequency oscillations which can significantly impact the converter performance. The main contribution of this thesis is the extension of a proposed custom-core design methodology of high-frequency transformers to include parasitic capacitance prediction during the design phase to lessen the effect of high frequency oscillations on the DC-DC converter. Additionally, the proposed methodology is applied to the design of a single-core three-phase transformer for medium-voltage applications. The design and manufacturing of a 150-kW medium-voltage DC-DC solid-state transformer is presented. Impedance responses of the design transformer are studied to identify the impact of the parasitic self-capacitance. Experimental testing of the proposed medium-voltage DC-DC solid-state transformer above 100-kW is presented and analyzed
Is All Genetically Modified Maize the Same: South African Consumer Acceptance of Water Efficient Maize for Africa (WEMA)
Get PDFThe Water Efficient Maize for Africa (WEMA) partnership was launched in March 2008 to help maize producers manage drought risk by developing and deploying genetically modified (GM) maize varieties that yield 24 to 35 percent more grain under moderate drought conditions than currently available varieties across Southern Africa. Although the World Bank classifies South Africa as an upper-middle-income country, food insecurity is an ongoing concern that worsens during drought. During the drought of 2014/2015, the price of white maize more than doubled, resulting in 22% of households experiencing food insecurity. While GM maize (herbicide tolerant, Bt, and stacked) is widely adopted across South Africa, there is still consumer skepticism and pushback to GM crops, specifically maize since it’s the staple crop of South Africa. This study explores whether South African consumers are more willing to accept GM maize when it contains the WEMA traits than traditional applications of GM technology. Using a panel of 3,204 South Africans in 2022 and a Random Parameter Logit Model, this study sets out to determine if consumers view the WEMA GM trait differently than traditional GM maize under different information sets. Further, the survey explores a possible pressure release valve for food insecurity in South Africa, yellow maize, which is traditionally viewed as a source of livestock feed. Results indicate that when given information about WEMA and its potential to help stabilize maize prices during a drought, market share increases for WEMA relative to traditional white maize. Further results show that yellow maize only obtains a marginal market share, even given discounted prices via imports; this is problematic, given the limited supply of white maize on the international market, should South Africa experience another drought like 2015/2016. This study is the first of its kind in South Africa to disentangle GM traits and their impact on consumer acceptance. Results indicate that consumer acceptance of the GM WEMA trait could be significantly enhanced by informing consumers about the possible food security benefits it embodies
Competition and Criticality in Cortical Neural Circuits Underlie Behavior and Optimize Working Memory
Get PDFOne of the primary goals of neuroscience is to explain how brain function emerges from dynamic interactions among large populations of neurons. A long-standing hypothesis at the interface of physics and neuroscience posits that neural circuits may operate close to the critical point of a phase transition. In this dissertation, we will investigate a new form of criticality and the implications that it has in working memory and the generation of voluntary body movements. We will utilize this new form of criticality to investigate the functional benefits that can be harnessed by operating near the critical point when performing working memory tasks. We will show how the power-law fluctuations expected at criticality relate to how different neurons perform different functions. We will show that critical dynamics in the brain are directly related to scale-invariant body movements. We will also show that by operating near a critical point working memory tasks can be optimized. Finally, we will discuss future research based on these projects
The Frimpong Case
Get PDFThe Frimpong Case is the gathering of skills and voices of Africans and African artists. My collaborators from my Ghanaian family and neighbors to my colleagues in the United States have influenced my practice, allowing me to expand the history I have learned from the African musicians who have deeply influenced me to my heritage and the research I am able to expand upon to promote my vision of my culture and legacy. This paper describes the body of work and speaks to the themes of collaboration, migration, assemblage, and installation. The Frimpong Case is the root of my visions made real. These lyrics are from the song Oil in My Head by Black Sherif and they say, “Oh Lord, I won\u27t stop for nothin\u27 (stop for nothin\u27, ah) Victory is near, I\u27m feelin\u27 it And, I stay G with it, ah-ah” I put this as a small token of my determination to never stop, to work hard, have pride in myself and God, to make The Frimpong Case… “Dem go talk am someday”. In part one, the roles of a contemporary stance on assemblage, the influence of African music and heritage, and the integration of my lived experiences as an immigrant into my art practice through installation. Part two will focus on the aspects of community collaboration in Ghana and the United States. How I am using our collective bodies and voices to speak up about what it means to have unity and solidarity become the foundation of my work. The idea of involving others in my practice instils my value of wanting change in how we talk about Africa, what is made by Africans, and how it impacts me, as both artist and collaborator, expanding the contemporary artistic practice. Keywords: African culture, Assemblage, collaboration, installation, migration, musi
Porous
Get PDFPorous presents sensory modalities to convey the theme of memories, creating an active site that resists erasure as an immersive art installation. Through a collage of multichannel video performances, Porous is an assemblage of fragmented, abstract, and non-linear aspects of memory. These videos are portals to sites of resistance, collaged and entangled as the essence of memories. All videos touch slightly on the wall, displaying their interconnectedness. The videos coexist with layered audio and live water ambient noise
Yeast Surface Display of Multiple Heterologous Proteins Via Molecular and Biochemical Processing Techniques
Get PDFThe arming of yeast cell wall, also known as yeast surface display, is an effective technology for expressing target proteins extracellularly. It has been shown to provide bioengineered yeast with qualities that are not known to native yeast such as the ability to survive harsh conditions including high pH and temperature, for example. Furthermore, this technique has been implemented for various applications which include, protein engineering, bioethanol production, bioremediation, vaccine construction, and antibody development. The major mechanisms of yeast surface display exploit agglutination, flocculation, or proteins with internal repeats as the means by which a target (protein) is covalently attached to the cell wall surface. The most commonplace and successfully utilized amongst the types are agglutination due to its advantages over the others which include the ease of genetic manipulation to extend the amino or carboxyl terminus of the secretory sequence. This advantage circumvents the problem of impeding the functional and active domains of displayed target proteins. In this first part of this project, DNA for the receptor binding domain of SARS-CoV-2 virus was inserted into pYD1 expression vector, which led to display on the cell wall of Saccharomyces cerevisiae. Culturing and induction of this bioengineered yeast in galactose medium was shown to display the target sequence. Furthermore, the yeast clones were used as the test line in a lateral flow immunoassay to detect COVID antibody in patient sera. The first part of the work resulted in a successful, cost-effective technique for the construction of COVID test standards that did not rely on complicated downstream techniques to isolate the material The second part of this project expanded the work to include a kinetic description of heterologous protein display. A simple structured model based on limited respiratory capacity was extended to recombinant yeast to describe substrate uptake, ethanol production, biomass growth, protein production, and surface display of heterologous proteins. Surface display is described as a second order kinetic reaction which was dependent on the concentrations of cytoplasmic (periplasmic) proteins and yeast concentration. The description was validated with data from literature and experiments. Thus, the second part of this work was also shown to follow a simplified Michaelis-Menten model since the second order form was useful to describe surface display. Lastly, this dissertation developed a procedure to immobilize any recombinant protein to the cell surface via Aga1 – Aga 2 interactions. E. coli expressed proteins were attached to the cell will using a mild oxidation buffer which reduces Cys, forming disulphides between Aga1 and Aga2-extended proteins. With the knowledge that EBY100 yeast cell wall is composed of 104-105 agglutin adhesion protein, should these be unoccupied by other (native) proteins, a novel strategy for immobilization emerges
Exploring Diversity, Discrimination, and Performance Dynamics
Get PDFThis dissertation utilizes empirical and experimental approaches to investigate the multifaceted factors that affect decision-making in economic contexts. The three chapters place a particular focus on group affiliation, perceived discrimination, and the gender gap in entrepreneurship. The first chapter explores the impact of team diversity on economic decision-making within a dynamic context. Through a series of laboratory experiments involving participants randomly assigned to teams, the study examines how team diversity influences individual behavior and performance. Results indicate that team diversity significantly affects individual behavior, with newcomers being particularly influenced by the diversity of the team they join. The findings underscore the importance of understanding the effects of team composition on decision-making processes and performance outcomes. The second chapter delves into the implications of subjective evaluation systems for both supervisors and employees. Through experiments conducted with participants from two U.S. universities, the research examines how group affiliation influences perceived discrimination in economic decision-making. By uncovering disparities in anticipation of bias based on race and gender, the study highlights the importance of addressing systemic biases and fostering inclusive workplace environments. The third chapter investigates the dynamics of fundraising in early stage startups. Despite dominance in certain female-dominated industries, women entrepreneurs struggle to secure funding. The analysis suggests potential industry-based sorting bias, with women-led ventures performing on par or better in high-funding industries. Overall, these chapters deepen our understanding of team dynamics, job evaluations, and discrimination perceptions, while also offering insights for creating more inclusive work environments
Institutionalized Stigmas: HIV Stigma, Racism and Heterosexism Among Medical Students in The Southern United States
Get PDFBackground: Intersecting and related forms of stigma, including HIV-related stigma, racism, and heterosexism, disproportionately impact both communities vulnerable to acquiring HIV and people living with HIV (PLHIV), ultimately impacting more distal outcomes related to HIV prevention, treatment, and epidemiological patterns in the United States (US). The Southern US is the region most impacted by new HIV diagnoses, mainly among Black men who have sex with men (MSM). However, there is a paucity of research on medical students, specifically those in the Southern US, regarding stigmatizing attitudes they may hold towards PLHIV, and how these associate with racism and heterosexism. This research has conceptualized medical students as both future physicians and as representing the institutional level. It aimed to measure stigmatizing attitudes, racism, heterosexism, HIV-related knowledge, and feelings towards people with intersectional identities most impacted by HIV, such as Black MSM. Methods: A cross-sectional, non-probability sampling approach was utilized for two online survey-based studies between January and March 2024. In study 1, a newly created 21-item HIV Knowledge measure, rated for content validity by experts (n = 3), was tested with a sample of 128 medical students from Arkansas, Florida, and South Carolina. Sociodemographic information, measures of HIV stigma, racism and heterosexism were collected. Study 2 focused on the construction and validation of the 14-item Intersectional Identities Feeling Thermometer Scale (IIFTS) using an exploratory principal components analysis. Results: Study 1 found that the HIV Knowledge measure displayed high content and construct validity, based on raters’ scores; higher scores associated positively with factors such as medical school grade. HIV knowledge scores displayed an expected negative significant association with HIV stigma. Heterosexism displayed the strongest relationship with HIV stigma, followed by racism. Factors such as high religiosity and Republican affiliation associated with both heterosexism and HIV stigma; factors such as gender, sexuality and race did not impact HIV stigma scores. HIV knowledge did not moderate the effects of either heterosexism or racism on HIV stigma. Study 2 found strong evidence for the presence of an Intersectionality subscale, containing 12 items, and weaker evidence for a Race subscale containing 2 items. Based on associations with other measures, the Intersectionality subscale captured a novel theoretical dimension: intersectional feeling bias, a form of generalized bias directed towards people with intersectional identities by medical students. Conclusion: The implications of these studies are multifold: medical students in the Southern US require exposure to updated HIV prevention, treatment, and epidemiologic knowledge; however, this alone is insufficient. They also require cultural competence training aimed at understanding and reducing the impacts of HIV stigma, heterosexism, and racism. In addition to attitudes, feelings comprised a core component of bias. Measures such as the IIFTS can be used to create awareness and clarify these feelings and can be used to track progress as students are exposed to stigma reduction interventions. Taken together, these findings provide compelling evidence for a need for institutional-level improvement to reduce HIV stigma, racism, and heterosexism among medical students in the Southern US