Theses and Dissertations from UMD

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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

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Now showing 1 - 6 of 6
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    THREE ESSAYS ON QUANTUM TECHNOLOGY APPLICATIONS
    (2024) Stein, Amanda; Wang, Ping; Information Studies; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    This dissertation examines quantum technology applications in three essays. Essay 1 portrays how companies are beginning to innovate with quantum computing in four case studies. The cases employ and enrich the Diffusion of Innovations theory as a conceptual framework for quantum computing innovation adoption and management. Essay 2 follows the evolution of quantum sensing with two cases of how organizations currently use the technology and plan to use it in the future. These cases illustrate how people and organizations use their discourse to develop an organizing vision for adopting and applying quantum sensing. Essay 3 focuses on the relationships between quantum technology and artificial intelligence through a literature review using grounded theory. The essay provides examples on how the two technologies interact and recommendations to stakeholders for future advancement. In summary, while the science and engineering side of quantum technologies is still developing, understanding how quantum technologies are and will be applied can help inform business and public policies.
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    Clifford Algebra: A Case for Geometric and Ontological Unification
    (2008-04-17) Kallfelz, William Michael; Bub, Jeffrey; Philosophy; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Robert Batterman's ontological insights (2002, 2004, 2005) are apt: Nature abhors singularities. "So should we," responds the physicist. However, the epistemic assessments of Batterman concerning the matter prove to be less clear, for in the same vein he write that singularities play an essential role in certain classes of physical theories referring to certain types of critical phenomena. I devise a procedure ("methodological fundamentalism") which exhibits how singularities, at least in principle, may be avoided within the same classes of formalisms discussed by Batterman. I show that we need not accept some divergence between explanation and reduction (Batterman 2002), or between epistemological and ontological fundamentalism (Batterman 2004, 2005). Though I remain sympathetic to the 'principle of charity' (Frisch (2005)), which appears to favor a pluralist outlook, I nevertheless call into question some of the forms such pluralist implications take in Robert Batterman's conclusions. It is difficult to reconcile some of the pluralist assessments that he and some of his contemporaries advocate with what appears to be a countervailing trend in a burgeoning research tradition known as Clifford (or geometric) algebra. In my critical chapters (2 and 3) I use some of the demonstrated formal unity of Clifford algebra to argue that Batterman (2002) equivocates a physical theory's ontology with its purely mathematical content. Carefully distinguishing the two, and employing Clifford algebraic methods reveals a symmetry between reduction and explanation that Batterman overlooks. I refine this point by indicating that geometric algebraic methods are an active area of research in computational fluid dynamics, and applied in modeling the behavior of droplet-formation appear to instantiate a "methodologically fundamental" approach. I argue in my introductory and concluding chapters that the model of inter-theoretic reduction and explanation offered by Fritz Rohrlich (1988, 1994) provides the best framework for accommodating the burgeoning pluralism in philosophical studies of physics, with the presumed claims of formal unification demonstrated by physicists choices of mathematical formalisms such as Clifford algebra. I show how Batterman's insights can be reconstructed in Rohrlich's framework, preserving Batterman's important philosophical work, minus what I consider are his incorrect conclusions.
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    Efficient Surface Conversion for Neutral Atom Detection
    (2007-11-16) Hughes, Patrick; Coplan, Michael A; Physics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Neutral atom detection is a useful way of studying astrophysical plasma structures such as the heliosphere and planetary magnetospheres. When plasma ions undergo charge exchange with the neutral background gas, energetic neutral atoms (ENAs) are generated. These neutral atoms travel in straight lines from the point of charge exchange because they are not subject to deflection by the electric and magnetic fields in space. As a result ENAs can be used to image the plasma structures from which they originate. ENAs in the energy range from a few eV to a few keV are particularly worth studying and are best detected by conversion to negative ions at a surface, a method that has been successfully used by ENA imagers on the Imager for Magnetosphere-to-Aurora Global Exploration (IMAGE) spacecraft. The function and construction of the imager is dependent upon the efficiency of the conversion surface used. A surface with a high conversion efficiency would allow the imager to be smaller and still collect a measurable signal compared to an imager using a surface with low conversion efficiency. The previously used conversion surface had an efficiency of about 1%. In order to find a more efficient conversion surface, detailed as well as comparative measurements of conversion efficiencies were taken at two facilities. The surfaces studied are polished tungsten, highly ordered pyrolytic graphite, diamond-like carbon, a secondary electron emitting leaded glass, gold, silver and platinum. The work function and smoothness of some of the sample surfaces were measured. These measurements have been compared with measured conversion efficiencies to identify those surface properties that are critical for conversion efficiency. For many surfaces, adsorbates and roughness appear to play an important role in conversion efficiency.
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    A Study of Social Interaction and Teamwork in Reformed Physics Laboratories
    (2006-02-21) Gresser, Paul William; Redish, Edward F.; Physics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    It is widely accepted that, for many students, learning can be accomplished most effectively through social interaction with peers, and there have been many successes in using the group environment to improve learning in a variety of classroom settings. What is not well understood, however, are the dynamics of student groups, specifically how the students collectively apprehend the subject matter and share the mental workload. This research examines recent developments of theoretical tools for describing the cognitive states of individual students: associational patterns such as epistemic games and cultural structures such as epistemological framing. Observing small group interaction in authentic classroom situations (labs, tutorials, problem solving) suggests that these tools could be effective in describing these interactions. Though conventional wisdom tells us that groups may succeed where individuals fail, there are many reasons why group work may also run into difficulties, such as a lack or imbalance of knowledge, an inappropriate mix of learning styles, or a destructive power arrangement. This research explores whether or not inconsistent epistemological framing among group members can also be a cause of group failure. Case studies of group interaction in the laboratory reveal evidence of successful groups employing common framing, and unsuccessful groups failing from lack of a shared frame. This study was conducted in a large introductory algebra-based physics course at the University of Maryland, College Park, in a laboratory designed specifically to foster increased student interaction and cooperation. Videotape studies of this environment reveal that productive lab groups coordinate their efforts through a number of locally coherent knowledge-building activities, which are described through the framework of epistemic games. The existence of these epistemic games makes it possible for many students to participate in cognitive activities without a complete shared understanding of the specific activity's goal. Also examined is the role that social interaction plays in initiating, negotiating, and carrying out these epistemic games. This behavior is illustrated through the model of distributed cognition. An attempt is made to analyze this group activity using Tuckman's stage model, which is a prominent description of group development within educational psychology. However, the shortcomings of this model in dealing with specific cognitive tasks lead us to seek another explanation. The model used in this research seeks to expand existing cognitive tools into the realm of social interaction. In doing so, we can see that successful groups approach tasks in the lab by negotiating a shared frame of understanding. Using the findings from these case studies, recommendations are made concerning the teaching of introductory physics laboratory courses.
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    Analogies as Categorization Phenomena: Studies from Scientific Discourse
    (2004-11-30) Atkins, Leslie Jill; Hammer, David; Physics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Studies on the role of analogies in science classrooms have tended to focus on analogies that come from the teacher or curriculum, and not the analogies that students generate. Such studies are derivative of an educational system that values content knowledge over scientific creativity, and derivative of a model of teaching in which the teacher's role is to convey content knowledge. This dissertation begins with the contention that science classrooms should encourage scientific thinking and one role of the teacher is to model that behavior and identify and encourage it in her students. One element of scientific thinking is analogy. This dissertation focuses on student-generated analogies in science, and offers a model for understanding these. I provide evidence that generated analogies are assertions of categorization, and the base of an analogy is the constructed prototype of an ad hoc category. Drawing from research on categorization, I argue that generated analogies are based in schemas and cognitive models. This model allows for a clear distinction between analogy and literal similarity; prior to this research analogy has been considered to exist on a spectrum of similarity, differing from literal similarity to the degree that structural relations hold but features do not. I argue for a definition in which generated analogies are an assertion of an unexpected categorization: that is, they are asserted as contradictions to an expected schema.
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    A cognitive framework for analyzing and describing introductory students' use and understanding of mathematics in physics
    (2004-04-29) Tuminaro, Jonathan; Redish, Edward F.; Physics
    Many introductory, algebra-based physics students perform poorly on mathematical problem solving tasks in physics. There are at least two possible, distinct reasons for this poor performance: (1) students simply lack the mathematical skills needed to solve problems in physics, or (2) students do not know how to apply the mathematical skills they have to particular problem situations in physics. While many students do lack the requisite mathematical skills, a major finding from this work is that the majority of students possess the requisite mathematical skills, yet fail to use or interpret them in the context of physics. In this thesis I propose a theoretical framework to analyze and describe students' mathematical thinking in physics. In particular, I attempt to answer two questions. What are the cognitive tools involved in formal mathematical thinking in physics? And, why do students make the kinds of mistakes they do when using mathematics in physics? According to the proposed theoretical framework there are three major theoretical constructs: mathematical resources, which are the knowledge elements that are activated in mathematical thinking and problem solving; epistemic games, which are patterns of activities that use particular kinds of knowledge to create new knowledge or solve a problem; and frames, which are structures of expectations that determine how individuals interpret situations or events. The empirical basis for this study comes from videotaped sessions of college students solving homework problems. The students are enrolled in an algebra-based introductory physics course. The videotapes were transcribed and analyzed using the aforementioned theoretical framework. Two important results from this work are: (1) the construction of a theoretical framework that offers researchers a vocabulary (ontological classification of cognitive structures) and grammar (relationship between the cognitive structures) for understanding the nature and origin of mathematical use in the context physics, and (2) a detailed understanding, in terms of the proposed theoretical framework, of the errors that students make when using mathematics in the context of physics.