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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Item Polynomials with Equal Images over Number Fields(2024) Hirsh, Jordan; Washington, Lawrence C; Mathematics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Chapman and Ponomarenko [1] characterized when two polynomials f, g ∈ Q[x] have thesame image f(Z) = f(Z). We extend this result to rings of integers in number fields. In particular, if K is a finite extension of Q and O is the ring of algebraic integers in K, we characterize when polynomials f, g ∈ K[x] satisfy f(O) = g(O). As part of our proof, we give a variant of Hilbert’s irreducibility theorem.Item TRANSFORMING VACANT LOTS: INVESTIGATING AN ALTERNATIVE APPROACH TO REDUCING FEAR OF CRIME(2015) De Biasi, Alaina Marie; McGloin, Jean; Criminology and Criminal Justice; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Vacant lots deserve criminological attention insofar as their disorderly conditions create opportunities for a host of negative outcomes including “fear of crime.” The present study considers whether incorporating fundamental standards of Crime Prevention through Environmental Design (CPTED) into traditional urban greening practices of vacant lots provides added value with regard to fear of crime above and beyond the traditional endeavor. This study conducted an experiment (N=523) from a sample of undergraduate students. Research participants were asked to report their level of fear of crime in regards to one of three randomly assigned computer-adjusted images: 1) A disorderly lot; 2) A traditional greened lot; and 3) A CPTED lot. This study found that on average participants who viewed a CPTED lot had lower levels of fear of crime than all other participants. This study discusses the implications of this finding for future research.Item Semi-supervised and Active Image Clustering with Pairwise Constraints from Humans(2014) Biswas, Arijit; Jacobs, David W.; Computer Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Clustering images has been an interesting problem for computer vision and machine learning researchers for many years. However as the number of categories increases, image clustering becomes extremely hard and is not possible to use for many practical applications. Researchers have proposed several methods that use semi-supervision from humans to improve clustering. Constrained clustering, where users indicate whether an image pair belong to the same category or not, is a well-known paradigm for semi-supervision. Past research has shown that pairwise constraints have the potential to significantly improve clustering performance. There are two major components to constrained clustering research: how pairwise constraints can be used to improve clustering (e.g: constrained clustering algorithms, distance or metric learning methods) and determining which constraints are most useful for improving clustering (e.g.: active or interactive clustering methods). In this thesis we propose three different approaches to improve pairwise constrained clustering spanning both of these components. First, we propose a distance learning method in non-vector spaces, where the triangle inequality is used to propagate the pairwise constraints to the unsupervised image pairs. This approach can work with any pairwise distance and does not require any vector representation of images. Second, we propose an algorithm for active image pair selection. A novel method is developed to choose the most useful pairs to show a person, obtaining constraints that improve clustering. Third, we study how pairwise constraints can effectively be used to cluster large image datasets. Complete clustering of large datasets requires an extremely large number of pairwise constraints and may not be feasible in practice. We propose a new algorithm to cluster a subset of the images only (we call this subclustering), which will produce a few examples from each class. Subclustering will produce smaller but purer clusters and can be used for summarization, category discovery, browsing, image search, etc.... Finally, we make use of human input in an active subclustering algorithm to further improve results. We perform experiments on several real world datasets such as faces, leaves, videos and scenes and empirically show that our approaches can advance the state-of-the-art in clustering.Item The Cartooned Revolution: Images and the Revolutionary Citizen in Cuba, 1959-1963(2009) Someillan, Yamile Regalado; Williams, Daryle; History; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)ABSTRACT Title of Document: THE CARTOONED REVOLUTION: IMAGES AND THE REVOLUTIONARY CITIZEN IN CUBA, 1959-1963 Yamile Regalado Someillan, Ph.D., 2009 Directed By: Associate Professor, Daryle Williams, Department of History "The Cartooned Revolution: Imagery and Political Culture in Cuba, 1959-1963" traces the relationship between cartooning and citizenship in the early phases of the Cuban Revolution. Through a broad analysis of cartoons and advertisements produced in the Havana press between January 1959 and December 1963, this study analyzes the interplay of state-regulated visual communication that fueled cultural transformation and defined a new revolutionary citizenry. A close reading of an "imagined narrative," drawn by the new revolutionary press and consumed by Havana readers, I argue, casts a new light on the fundamental changes in political culture and society that took place in Cuba following January 1, 1959. My choice to analyze cartoons, advertisements as well as the institutions and personalities responsible for their production, draws upon the powerful interplay of revolutionary vision, reform, politics, and ideology within the imagined narrative. The institutional and functional conversion of these forms of revolutionary imagery into official propaganda occurred as a result of a deconstruction of the pre-revolutionary press and an institutional takeover and re-staffing of newspaper offices and printing presses; the deregulation of the cartooning profession; and the reorganization of pre-revolutionary advertising enterprises into a government-controlled, central clearinghouse. Initially, images portrayed the young Castro state as champion of reform within a longer tradition of Cuban liberalism. But in short time, the resistance of holdovers from the deposed Batista political class in combination with the souring of relations with the United States, engendered an emergent revolutionary visual culture. The early forms of its new visuality were exemplified in images cultivating the bearded rebel. As it matured, especially in visual communication associated with the Literacy Campaign of 1961 and the Socialist Emulation Campaign of 1962-63, the rebel image stood alongside a cast of stock characters representative of the new political regime. If, on the one hand, revolutionary imagery projected a dangerous political landscape filled with subversive plots and looming "enemies of the people," it also gave visual clues to the new forms of political belonging. Cartoons and advertisements communicated vital policies and campaigns in which Cubans with varying levels of commitment to the Revolution might be projected into an imagined, yet official revolutionary narrative. As Cubans increased their level of integration into revolutionary society, they began to redefine themselves into a more ideologically sophisticated citizenry both inside and outside of the image world.