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Reimagining Cryogenic Computing with Superconducting and Topological Devices
No full textCryogenic computing - operating at or below 4 K - has emerged as a promising solution to address the scalability issues of quantum computers, which currently rely on room temperature controller and memory units. In addition, cryogenic computing offers unique advantages for high-performance computing and deep space exploration. Various technologies, including non-superconducting, superconducting, and hybrid, have been explored. However, each of these technologies has significant limitations. Nonsuperconducting devices suffer from low speed and high power consumption, while superconducting systems based on Josephson junctions (JJs) face severe scalability issues due to flux trapping and inductive coupling. Hybrid systems, meanwhile, lack efficient interface circuitry to integrate superconducting and non-superconducting technologies.
This dissertation utilizes two unique technologies: superconducting devices (ferroelectric superconducting quantum interference devices (FE-SQUIDs) and heater cryotrons) and topological devices exploiting the quantum anomalous Hall effect, to develop a suitable cryogenic computing platform. First, we demonstrate a non-volatile FE-SQUID-based memory with voltage-controlled operation, high scalability, and separate read-write paths. Using the same device, we develop a voltage-controlled superconducting logic family that addresses the limited fanout and cascadability issues of existing current-controlled logic circuits. We further present a cryogenic in-memory computing architecture based on FE-SQUIDs to reduce data movement and cooling costs associated with von Neumann systems. Additionally, we design a ternary content addressable memory (TCAM) using FE-SQUIDs which supports exact search without any peripheral circuitry, as well as nearest-match operations through Hamming distance calculation.
We also explore the reconfigurable potential of heater cryotron devices. A single cryotron circuit is shown to execute multiple 1-, 2-, and 3-input logic operations without any structural changes, enabling logic camouflaging for enhanced hardware security.
Finally, this dissertation is the first to utilize topological devices in circuit and systemlevel applications. Leveraging the quantum anomalous Hall effect, we develop a scalable, non-volatile, and ultra-low-power memory system. This topological memory is also capable of performing both basic and complex in-memory computing tasks, further advancing the development of a practical and efficient cryogenic computing platform
Using Repeated Reading to Increase Reading Fluency Among Postsecondary Students with Mild Intellectual Disabilities
No full textPost-secondary education for students with intellectual disabilities is a crucial step towards a better quality of life. Reading skills, among the most important skills for success in life, are a key area that needs attention. Most post-secondary education intervention programs for these students focus on enhancing overall quality of life, including increased independence, self-advocacy, and social opportunities. However, it\u27s important for educators, policymakers, and advocates to recognize the need for a more balanced approach that also includes academic skills, particularly reading
Cyber-Physical System Security in a Quantum-Enabled Era
No full textThe rapidly growing field of quantum computers has brought forth a revolution in the world of computing for the past decade. However, with this comes immense potential for change that breaks down the very foundation of what was previously considered computationally infeasible. In a quantum-enabled world, the fundamentals of cybersecurity change immensely, from now-unsafe cryptography to quantum-secured data. This work aims to investigate both by harnessing the power of quantum computing in one of the most high-risk, vulnerable domains in modern society: cyber-physical systems. To achieve this, we take a look at the taxonomy and structure of a typical CPS ecosystem to determine the potential weaknesses and gains from quantum computing.
First, we analyze the physical-level security from the perspective of securing Controller Area Network-based (CAN) electronic control units, essential components of modern vehicles and machinery, to develop an efficient, quantum-safe framework for trusted device authentication. Our authentication scheme featuring post-quantum cryptography (PQC) uses 4 times fewer messages than leading vehicular security frameworks. Next, we extended this work to inter-device CPS communication in the context of additive manufacturing networks using the Controller Area Network (CAN) bus. Our proposed design provides quantum-safe, root-of-trust tree networks to 3D printing farm networks, allowing plug-and-play connections without fear of trojan-horse or man-in-the-middle attacks. Using 12 times fewer messages for authentication compared to other PQC systems, our framework defends against most forms of man-in-the-middle attacks and effectively mitigates most denial-of-service attacks. Furthermore, we created a supervisory-level anomaly detection model utilizing quantum fidelity kernel support vector machines, providing up to a 13% boost in classification performance of real-world industrial control system data and an 11% in 3D printer anomaly data. Utilizing the robust geometric distance metric, we found a clear, quantifiable advantage to quantum machine learning for securing CPS data and feedback systems. Finally, we discuss the future directions of research that could build upon this multi-level framework. Our work successfully bridges the gap between quantum computing in cyber-physical systems, both as a potential threat and strength to the future of critical infrastructure, supply chain trust, and manufacturing safety
Core Collapse Supernova Gravitational Waves: Theory, Detection, and Parameter Estimation
No full textThis dissertation aims to advance the understanding of gravitational wave (GW) production in neutrino-driven core collapse supernovae (CCSNe) by providing a comprehensive analysis of the GW signals from state-of-the-art CCSN simulations. It further advances our understanding of GW production in CCSNe by investigating the effects of differing nuclear equations of state (EOS) and stellar structures on GW signals. CCSNe are explosions of massive stars initiated by gravitational collapse of their inner cores. This explosion is generated by the release of gravitational binding energy as the core transitions to a proto-neutron star (PNS) that evolves into either a neutron star or black hole over the course of tens of seconds. The PNS evolution produces the dominant contribution to the high frequency GW signal emitted by CCSNe. Thus, GWs provide a unique window directly into the deepest regions of the CCSN, otherwise opaque to electromagnetic emissions. The analysis conducted in this dissertation utilizes three-dimensional CCSN simulations from the state-of-the-art CHIMERA code and combines a regional decomposition of GW emission with a modal analysis of the PNS. The regional decomposition provides insight into source of GW emission, and the modal analysis connects that insight to the quasi-normal oscillation modes of the PNS that produce those GWs. Both analyses show that the gravitational wave emission begins near the surface of the PNS but is eventually dominated by emission deep within the PNS. The regional decomposition indicates that the initial PNS surface dominated GW emission is excited from matter accretion onto the PNS, and the later deep interior PNS dominated GW emission is excited by Ledoux convection and convective overshoot. The modal analysis confirms that the character of quasi-normal modes of oscillation of the PNS changes precisely at the same time the source of emission changes, initially described by buoyancy-driven oscillations and later by pressure-driven oscillations. Using two-dimensional CHIMERA simulations, this dissertation demonstrates that the high frequency component of CCSNe GW signals is sensitive to the nuclear EOS, and, in principle, these EOS effects are detectable in current generation GW detectors. Finally, this dissertation shows the effects of progenitor stellar structure on CCSN GW emission
Dynamics of Food and Nutrition Security Among College Students in High-Income Countries: A Multi-Method Computational Modeling Approach
No full textFood and nutrition insecurity (FNI) remains a significant and growing public health challenge among college students in high-income countries, impacting academic performance, physical health, and mental well-being. Despite increasing recognition of this issue, a comprehensive understanding of its complex, dynamic determinants and the potential long-term effects of intervention strategies is often lacking. This dissertation addresses this gap by developing and evaluating a computational model to elucidate the intricate dynamics of FNI among college students.
Aim 1 involved conducting a systematic umbrella review to synthesize existing evidence on the significant determinants of food and nutrition security among college students. This was followed by a meta-meta-analysis to quantitatively assess the aggregated impact of these determinants, culminating in the construction of a comprehensive causal loop diagram that visually maps the interconnections and feedback loops within the FNI system.
Aim 2 focused on creating a robust synthetic college student population. This computationally derived population, informed by available empirical data, serves as a realistic and scalable platform for agent-based modeling, capturing diverse demographic, socioeconomic, and behavioral characteristics relevant to FNI.
Aim 3 entailed the development and rigorous evaluation of an agent-based model (ABM) designed to simulate college student academic and health behaviors in response to varying levels of food security. This ABM allows for the dynamic forecasting of the impact of implementing different prevention and intervention strategies on food security status and its related outcomes, such as academic success, mental health, and overall well-being.
By integrating systematic review, meta-analysis, and agent-based modeling, this dissertation provides a novel, systems-level perspective on college student FNI. The developed computational model offers a powerful tool for policymakers and university administrators to proactively design and evaluate evidence-informed strategies, ultimately contributing to improved food and nutrition security and holistic student success in higher education settings
When political rhetoric threatens migrant labor-market integration
No full textThis dissertation examines how anti-migrant political rhetoric influences migrant labor-market integration in European Union countries. It argues that exclusionary discourse functions not only as symbolic expression but as a signaling system that reinforces social hierarchies and constrains access to opportunity. Drawing on Cue Theory and Social Dominance Theory (SDT), I develop Rhetorical Hierarchy Signaling Theory (RHST) to conceptualize political speech as a mechanism of symbolic governance that encodes stratification intent. Chapter 2 introduces RHST, identifying four rhetorical mechanisms—dominance, egalitarianism, threat, and blame—and situating them within SDT’s hierarchy- enhancing vs. hierarchy-attenuating framework. Drawing on interviews with Swedish political elites, I show that anti-migrant rhetoric operates across party lines, with even center and center-left actors deploying conditional inclusion frames that normalize exclusionary norms. Chapter 3 traces the diffusion of exclusionary rhetoric using time-series cross-national data from the Comparative Manifesto Project (CMP). I find that Center Parties respond more to the rhetorical salience of Radical Right Parties than to their electoral performance, suggesting that discursive adaptation, rather than direct vote competition, drives the spread of exclusionary language. Chapter 4 tests the reception of elite rhetoric using individual-level data from the EUENGAGE survey. Results show that exposure to anti-migrant rhetoric is associated with heightened exclusionary attitudes among both the general public and business elites, indicating that rhetorical signals influence the perceptions and preferences of institutional gatekeepers. Chapter 5 assesses whether exclusionary rhetoric is associated with labor-market integration outcomes for migrants across 19 EU countries (2007–2022). Using fixed- effects regression models with standardized predictors, I find that increases in anti- migrant rhetoric are significantly associated with declines in migrant employment parity, even when controlling for macroeconomic conditions, policy indicators, and demographic variables. viii Taken together, the chapters offer a multi-level account of how anti-migrant rhetoric diffuses across party systems, shapes attitudes among both publics and elites, and correlates with structural exclusion in the labor market. While the study does not claim causality, it demonstrates that rhetorical environments are closely linked to integration outcomes. This dissertation contributes to scholarship on political communication, migration, and social inequality by showing how elite discourse functions as a stratifying force that interacts with institutions to shape the lived experiences of migrants
Diagnostic Investigation of Tissue Loss and Pigmented Lesions in Corals
No full textCorals are important representatives of the One Health concept, demonstrating the interconnection between health of the environment, people, and animals. However, corals have declined significantly, with climate change, human-related activities, and disease as major drivers of this decline, placing them among the most threatened animal groups according to the International Union for Conservation of Nature (IUCN). Coral have limited ways in which to respond to disease, with tissue loss and pigmented lesions representing some of the most impactful on coral populations. A variety of unique challenges exist in disease investigation of corals, resulting in much confusion and a poor understanding of disease pathogenesis in these animals. Microscopic examination is a cornerstone of disease diagnosis in other veterinary species and one of the few reliable diagnostic tools in corals, but microscopy alone may be insufficient in determining disease etiology. We investigated 2 outbreaks of tissue-loss disease in the Caribbean, applying a standard paired biopsy histologic approach in the first and exploring potential benefits of a strip sampling method in the second. Our results indicated no benefit of the strip sampling method and divergent microscopic abnormalities underlying these outbreaks despite similar gross presentations. We also investigated highly prevalent brown lesions in Orbicella species in St. Kitts using an interdisciplinary approach pairing histologic assessment with other diagnostic tools. Our results indicated pathology of symbionts and alterations in photosynthetic pigments, but questions remain regarding the basis for brown pigmentation. Finally, we evaluated safety of 4 commonly used treatments in coral aquaculture with histopathology. No major trends were observed. Collectively, these studies highlight the importance of microscopic evaluation in coral disease and the added benefits of pairing with other diagnostic tools
Disparities in Behavioral Health Care for Latinx: Addressing Barriers and Promoting Equity
Full text linkPortrait of a Fascist: Identity and Independence in Joseph Roth’s Das Spinnennetz (1923)
Full text linkThree days before Hitler’s Beer Hall Putsch, the last chapters of Joseph Roth’s Das Spinnennetz were published in the Viennese Arbeiter-Zeitung. Detailing the decent of World War I veteran Theodor Lohse into the nascent Nazi party, Roth’s novel could not have been more prescient—and yet, it remains the least well-known of his works. Das Spinnennetz is not only a work of great fiction, but an eerie cautionary tale more prophetic than Roth could have ever imagined. In this article, I examine the metaphor of the spider’s web and how ordinary people like Lohse futility navigate their search for individual meaning within a mass movement. Focusing on aspects of gender identity and utilizing Adorno’s “Freudian Theory and the Pattern of Fascist Propaganda,” I argue that, despite efforts to find agency and meaning in the Nazi party, Lohse ends the story ironically even more dependent on the women and Jews he sought to flee, and entangled in the web of Nazi fascism
LE BÉNIN FRANCOPHONE: UNE ÉTUDE SUR L’ANGLE SOCIOLINGUISTIQUE
No full textCette communication porte sur le paysage sociolinguistique d’un pays d’Afrique occidental–la République du Bénin (l’ancien Dahomey)–mettant en évidence l’interface complexe entre le français et les langues béninoises. Le prestige du français, en tant que langue privilégiée employée pour la communication interethnique dans de divers domaines du pays, rend son acquisition essentielle. Mais, en dehors des autres langues étrangères présentes parmi les membres éduqués de la population béninoise, les langues locales entrent en jeu avec le français, produisant ainsi trois variétés distinctes du français : le français standard, le français d’Afrique et le français snobé. Chacune de ces variétés possède des caractéristiques phonologiques, morphosyntactiques et lexicales. Cette étude s’adonne à une meilleure compréhension des phénomènes de contact linguistique, en donnant un aperçu général sur l’évolution du français, du point de vue historique, les contextes d’emploi et les caractéristiques structurelles des variétés du français, ainsi que la dynamique sociolinguistique contemporaine au Bénin. Les résultats mettent en évidence l’influence des différentes langues sur le français, la formation linguistique identitaire, et lancent un appel à des études plus approfondies sur les implications des diversités sociolinguistiques pour la culture et l’éducation au Bénin