ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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Description
In a large network (graph) it would be desirable to guarantee the existence of some local property based only on global knowledge of the network. Consider the following classical example: how many connections are necessary to guarantee that the network contains three nodes which are pairwise adjacent? It turns out that more than n^2/4 connections are needed, and no smaller number will suffice in general. Problems of this type fall into the category of ``extremal graph theory.'' Generally speaking, extremal graph theory is the study of how global parameters of a graph are related to local properties. This dissertation deals with the relationship between minimum degree conditions of a host graph G and the property that G contains a specified spanning subgraph (or class of subgraphs). The goal is to find the optimal minimum degree which guarantees the existence of a desired spanning subgraph. This goal is achieved in four different settings, with the main tools being Szemeredi's Regularity Lemma; the Blow-up Lemma of Komlos, Sarkozy, and Szemeredi; and some basic probabilistic techniques.
ContributorsDeBiasio, Louis (Author) / Kierstead, Henry A (Thesis advisor) / Czygrinow, Andrzej (Thesis advisor) / Hurlbert, Glenn (Committee member) / Kadell, Kevin (Committee member) / Fishel, Susanna (Committee member) / Arizona State University (Publisher)
Created2011
Description
This dissertation examines associations between religious affiliation, religious community context and health of women and their children in Mozambique focusing on the following issues: (1) attending prenatal consultations and delivering children in a health facility; (2) women's symptoms of STDs; and (3) under-five mortality. Estimation of random intercept Poisson regression for the outcome about attending prenatal consultations demonstrated a favorable effect of affiliation to Catholic or Mainline Protestant and Apostolic religious groups. The concentration of Zionist churches in the community had a negative influence. Random intercept logistic regression was used to estimate the relationship between religion and institutional child delivery. Affiliation to Catholic or Mainline Protestant denominations as well as concentration of Catholic or Mainline Protestant churches in the community had some beneficial effect on giving birth in health clinics. The presence of Zionist churches in the community had some negative effect and that of other groups no significant influence. Random intercept logistic regression was also employed for investigating the influence of religion on women's symptoms of STDs. Belonging to the Catholic or Mainline Protestant church had some protective effect on reporting symptoms of STDs. There was no effect of religious context, except that the concentration of Other Pentecostal churches had a positive effect on reporting symptoms of SDTs. Event-history analysis was conducted for examining relationships between maternal religious affiliation with under-five mortality. Affiliation to Catholic or Mainline Protestant churches and to Apostolic denominations increased the odds of child survival, although, the influence of having a mother belonging to Catholic or Mainline Protestant churches lost statistical significance after accounting particularly for the average level of education in the community, for the period of 5 years preceding the survey date. Taken together, the results in this dissertation show some protective effect of religion that varies primarily by denominational group to which women are affiliated. They also indicate that religious community context may have some negative effect on health of women and children. The nature of the effect of religious community context varies with the type of outcome considered and the type of religious mixture in the community.
ContributorsCau, Boaventura Manuel (Author) / Agadjanian, Victor (Thesis advisor) / Hayford, Sarah (Committee member) / Yabiku, Scott (Committee member) / Arizona State University (Publisher)
Created2011
Description
Nonlinear dispersive equations model nonlinear waves in a wide range of physical and mathematics contexts. They reinforce or dissipate effects of linear dispersion and nonlinear interactions, and thus, may be of a focusing or defocusing nature. The nonlinear Schrödinger equation or NLS is an example of such equations. It appears as a model in hydrodynamics, nonlinear optics, quantum condensates, heat pulses in solids and various other nonlinear instability phenomena. In mathematics, one of the interests is to look at the wave interaction: waves propagation with different speeds and/or different directions produces either small perturbations comparable with linear behavior, or creates solitary waves, or even leads to singular solutions. This dissertation studies the global behavior of finite energy solutions to the $d$-dimensional focusing NLS equation, $i partial _t u+Delta u+ |u|^{p-1}u=0, $ with initial data $u_0in H^1,; x in Rn$; the nonlinearity power $p$ and the dimension $d$ are chosen so that the scaling index $s=frac{d}{2}-frac{2}{p-1}$ is between 0 and 1, thus, the NLS is mass-supercritical $(s>0)$ and energy-subcritical $(s<1).$ For solutions with $ME[u_0]<1$ ($ME[u_0]$ stands for an invariant and conserved quantity in terms of the mass and energy of $u_0$), a sharp threshold for scattering and blowup is given. Namely, if the renormalized gradient $g_u$ of a solution $u$ to NLS is initially less than 1, i.e., $g_u(0)<1,$ then the solution exists globally in time and scatters in $H^1$ (approaches some linear Schr"odinger evolution as $ttopminfty$); if the renormalized gradient $g_u(0)>1,$ then the solution exhibits a blowup behavior, that is, either a finite time blowup occurs, or there is a divergence of $H^1$ norm in infinite time. This work generalizes the results for the 3d cubic NLS obtained in a series of papers by Holmer-Roudenko and Duyckaerts-Holmer-Roudenko with the key ingredients, the concentration compactness and localized variance, developed in the context of the energy-critical NLS and Nonlinear Wave equations by Kenig and Merle. One of the difficulties is fractional powers of nonlinearities which are overcome by considering Besov-Strichartz estimates and various fractional differentiation rules.
ContributorsGuevara, Cristi Darley (Author) / Roudenko, Svetlana (Thesis advisor) / Castillo_Chavez, Carlos (Committee member) / Jones, Donald (Committee member) / Mahalov, Alex (Committee member) / Suslov, Sergei (Committee member) / Arizona State University (Publisher)
Created2011
Description
A right to the city is a human right that is overlooked in American cities. Cities reflect humanity in collective form, but are manipulated by the powerful at the expense of the powerless. Landscapes of cities tell the city's stories, as historical inequalities become imprinted on the city's physical and symbolic landscapes. In Detroit, Michigan, over forty square miles of the city are vacant, unemployment might be as high as fifty percent, and the city has lost about sixty percent of its population since the mid-1950s. Detroit must now solve its spatial problems in the context of depopulation; the city's planners, nonprofits, and scholars are now debating "planned shrinking" or "right-sizing." Simultaneously, a blooming arts scene is also slowly revitalizing parts of the city. This thesis will critically examine the possibilities of planned shrinking and the arts movement in Detroit, as well as suggest theoretical explanations for the city's dilemmas. Detroit has been the subject of a myopic popular narrative, one that isolates the city from modern America rather than critically examines its place in modern America. Redefining regional healing through honest discourse and developing a more appropriate narrative for Detroit are among the solutions proposed. Finally, the importance of establishing a human right for the city is discussed.
ContributorsMarotta, Stephen J (Author) / Casper, Monica J (Thesis advisor) / Murphy-Erfani, Julie (Committee member) / Stancliff, Michael (Committee member) / Arizona State University (Publisher)
Created2011
Description
More than 30% of college entrants are placed in remedial mathematics (RM). Given that an explicit relationship exists between students' high school mathematics and college success in science, technology, engineering, and mathematical (STEM) fields, it is important to understand RM students' characteristics in high school. Using the Education Longitudinal Survey 2002/2006 data, this study evaluated more than 130 variables for statistical and practical significance. The variables included standard demographic data, prior achievement and transcript data, family and teacher perceptions, school characteristics, and student attitudinal variables, all of which are identified as influential in mathematical success. These variables were analyzed using logistic regression models to estimate the likelihood that a student would be placed into RM. As might be expected, student test scores, highest mathematics course taken, and high school grade point average were the strongest predictors of success in college mathematics courses. Attitude variables had a marginal effect on the most advantaged students, but their effect cannot be evaluated for disadvantaged students, due to a non-random pattern of missing data. Further research should concentrate on obtaining answers to the attitudinal questions and investigating their influence and interaction with academic indicators.
ContributorsBarber, Rebecca (Author) / Garcia, David R. (Thesis advisor) / Powers, Jeanne (Committee member) / Rodrigue Mcintyre, Lisa (Committee member) / Arizona State University (Publisher)
Created2011
Description
With the ongoing drought surpassing a decade in Arizona, scholars, water managers and decision-makers have heightened attention to the availability of water resources, especially in rapidly growing regions where demand may outgrow supplies or outpace the capacity of the community water systems. Community water system managing entities and the biophysical and social characteristics of a place mediate communities' vulnerability to hazards such as drought and long-term climate change. The arid southwestern Phoenix metropolitan area is illustrative of the challenges that developed urban areas in arid climates face globally as population growth and climate change stress already fragile human-environmental systems. This thesis reveals the factors abating and exacerbating differential community water system vulnerability to water scarcity in communities simultaneously facing drought and rapid peri-urban growth. Employing a grounded, qualitative comparative case study approach, this thesis explores the interaction of social, biophysical and institutional factors as they effect the exposure, sensitivity and adaptive capacity of community water systems in Cave Creek and Buckeye, Arizona. Buckeye, once a small agricultural town in the West Valley, is wholly dependent on groundwater and currently planning for massive development to accommodate 218,591 new residents by 2020. Amid desert hills and near Tonto National Forest in the North Valley, Cave Creek is an upscale residential community suffering frequent water outages due to aging infrastructure and lack of system redundancy. Analyzing interviews, media accounts and policy documents, a narrative was composed explaining how place based factors, nested within a regional institutional water management framework, impact short and long-term vulnerability. This research adds to the library of vulnerability assessments completed using Polsky et al.'s Vulnerability Scoping Diagram and serves a pragmatic need assisting in the development of decision making tools that better represent the drivers of placed based vulnerability in arid metropolitan regions.
ContributorsZautner, Lilah (Author) / Larson, Kelli (Thesis advisor) / Bolin, Bob (Committee member) / Chhetri, Netra (Committee member) / Arizona State University (Publisher)
Created2011
Description
At first glance, trends in increased hunger and obesity in the United States (US) would seem to represent the result of different causal mechanisms. The United States Department of Agriculture (USDA) reported that nearly 50 million Americans had experienced hunger in 2009. A year later, the Centers for Disease Control and Prevention published a report showing that 68% of the US population was either overweight or obese. Researchers have found that these contrasting trends are actually interrelated. Being so, it is imperative that communities and individuals experiencing problems with food security are provided better access to healthy food options. In response to the need to increase healthy food access, many farmers markets in the US have received funding from the USDA to accept vouchers from federal food security programs, such as the Supplemental Nutrition Assistance Program (SNAP). In Downtown Phoenix, Arizona, one organization accepting vouchers from several programs is the Phoenix Public Market. However, the mere existence of these programs is not enough to establish food security within a community: characteristics of the population and food environments must also be considered. To examine issues of food security and public health, this thesis utilizes geographical information systems (GIS) technology as a tool to analyze specific environments in order to inform program effectiveness and future funding opportunities. Utilizing methods from community-based participatory research (CBPR) and GIS, a mapping project was conducted in partnership with the Market to answer three questions: (1) what is the demographic makeup of the surrounding community? (2) What retailers around the Market also accept food security vouchers? And (3) where are food security offices (SNAP and WIC) located within the area? Both in terms of demographic characteristics and the surrounding food environment, the project results illustrate that the Market is embedded within a population of need, and an area where it could greatly influence community food security.
ContributorsRawson, Brooke (Author) / Vargas, Perla A (Thesis advisor) / Booze, Randy (Committee member) / Vaughan, Suzanne (Committee member) / Arizona State University (Publisher)
Created2011
Description
In this thesis, I investigate the C*-algebras and related constructions that arise from combinatorial structures such as directed graphs and their generalizations. I give a complete characterization of the C*-correspondences associated to directed graphs as well as results about obstructions to a similar characterization of these objects for generalizations of directed graphs. Viewing the higher-dimensional analogues of directed graphs through the lens of product systems, I give a rigorous proof that topological k-graphs are essentially product systems over N^k of topological graphs. I introduce a "compactly aligned" condition for such product systems of graphs and show that this coincides with the similarly-named conditions for topological k-graphs and for the associated product systems over N^k of C*-correspondences. Finally I consider the constructions arising from topological dynamical systems consisting of a locally compact Hausdorff space and k commuting local homeomorphisms. I show that in this case, the associated topological k-graph correspondence is isomorphic to the product system over N^k of C*-correspondences arising from a related Exel-Larsen system. Moreover, I show that the topological k-graph C*-algebra has a crossed product structure in the sense of Larsen.
ContributorsPatani, Nura (Author) / Kaliszewski, Steven (Thesis advisor) / Quigg, John (Thesis advisor) / Bremner, Andrew (Committee member) / Kawski, Matthias (Committee member) / Spielberg, John (Committee member) / Arizona State University (Publisher)
Created2011
Description
The theme for this work is the development of fast numerical algorithms for sparse optimization as well as their applications in medical imaging and source localization using sensor array processing. Due to the recently proposed theory of Compressive Sensing (CS), the $\ell_1$ minimization problem attracts more attention for its ability to exploit sparsity. Traditional interior point methods encounter difficulties in computation for solving the CS applications. In the first part of this work, a fast algorithm based on the augmented Lagrangian method for solving the large-scale TV-$\ell_1$ regularized inverse problem is proposed. Specifically, by taking advantage of the separable structure, the original problem can be approximated via the sum of a series of simple functions with closed form solutions. A preconditioner for solving the block Toeplitz with Toeplitz block (BTTB) linear system is proposed to accelerate the computation. An in-depth discussion on the rate of convergence and the optimal parameter selection criteria is given. Numerical experiments are used to test the performance and the robustness of the proposed algorithm to a wide range of parameter values. Applications of the algorithm in magnetic resonance (MR) imaging and a comparison with other existing methods are included. The second part of this work is the application of the TV-$\ell_1$ model in source localization using sensor arrays. The array output is reformulated into a sparse waveform via an over-complete basis and study the $\ell_p$-norm properties in detecting the sparsity. An algorithm is proposed for minimizing a non-convex problem. According to the results of numerical experiments, the proposed algorithm with the aid of the $\ell_p$-norm can resolve closely distributed sources with higher accuracy than other existing methods.
ContributorsShen, Wei (Author) / Mittlemann, Hans D (Thesis advisor) / Renaut, Rosemary A. (Committee member) / Jackiewicz, Zdzislaw (Committee member) / Gelb, Anne (Committee member) / Ringhofer, Christian (Committee member) / Arizona State University (Publisher)
Created2011
Description
By the von Neumann min-max theorem, a two person zero sum game with finitely many pure strategies has a unique value for each player (summing to zero) and each player has a non-empty set of optimal mixed strategies. If the payoffs are independent, identically distributed (iid) uniform (0,1) random variables, then with probability one, both players have unique optimal mixed strategies utilizing the same number of pure strategies with positive probability (Jonasson 2004). The pure strategies with positive probability in the unique optimal mixed strategies are called saddle squares. In 1957, Goldman evaluated the probability of a saddle point (a 1 by 1 saddle square), which was rediscovered by many authors including Thorp (1979). Thorp gave two proofs of the probability of a saddle point, one using combinatorics and one using a beta integral. In 1965, Falk and Thrall investigated the integrals required for the probabilities of a 2 by 2 saddle square for 2 × n and m × 2 games with iid uniform (0,1) payoffs, but they were not able to evaluate the integrals. This dissertation generalizes Thorp's beta integral proof of Goldman's probability of a saddle point, establishing an integral formula for the probability that a m × n game with iid uniform (0,1) payoffs has a k by k saddle square (k ≤ m,n). Additionally, the probabilities of a 2 by 2 and a 3 by 3 saddle square for a 3 × 3 game with iid uniform(0,1) payoffs are found. For these, the 14 integrals observed by Falk and Thrall are dissected into 38 disjoint domains, and the integrals are evaluated using the basic properties of the dilogarithm function. The final results for the probabilities of a 2 by 2 and a 3 by 3 saddle square in a 3 × 3 game are linear combinations of 1, π2, and ln(2) with rational coefficients.
ContributorsManley, Michael (Author) / Kadell, Kevin W. J. (Thesis advisor) / Kao, Ming-Hung (Committee member) / Lanchier, Nicolas (Committee member) / Lohr, Sharon (Committee member) / Reiser, Mark R. (Committee member) / Arizona State University (Publisher)
Created2011