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
The main objective of this research is to develop an integrated method to study emergent behavior and consequences of evolution and adaptation in engineered complex adaptive systems (ECASs). A multi-layer conceptual framework and modeling approach including behavioral and structural aspects is provided to describe the structure of a class of engineered complex systems and predict their future adaptive patterns. The approach allows the examination of complexity in the structure and the behavior of components as a result of their connections and in relation to their environment. This research describes and uses the major differences of natural complex adaptive systems (CASs) with artificial/engineered CASs to build a framework and platform for ECAS. While this framework focuses on the critical factors of an engineered system, it also enables one to synthetically employ engineering and mathematical models to analyze and measure complexity in such systems. In this way concepts of complex systems science are adapted to management science and system of systems engineering. In particular an integrated consumer-based optimization and agent-based modeling (ABM) platform is presented that enables managers to predict and partially control patterns of behaviors in ECASs. Demonstrated on the U.S. electricity markets, ABM is integrated with normative and subjective decision behavior recommended by the U.S. Department of Energy (DOE) and Federal Energy Regulatory Commission (FERC). The approach integrates social networks, social science, complexity theory, and diffusion theory. Furthermore, it has unique and significant contribution in exploring and representing concrete managerial insights for ECASs and offering new optimized actions and modeling paradigms in agent-based simulation.
ContributorsHaghnevis, Moeed (Author) / Askin, Ronald G. (Thesis advisor) / Armbruster, Dieter (Thesis advisor) / Mirchandani, Pitu (Committee member) / Wu, Tong (Committee member) / Hedman, Kory (Committee member) / Arizona State University (Publisher)
Created2013
Description
This study reports on research that explores local manifestations of Arizona's English-only language education policy by investigating the experiences of selected English language learners (ELLs) with reclassification into mainstream classrooms and four of their classroom teachers. In this study, I employed ethnographic methods (participant observation, document collection, interviewing, and focus groups) to investigate what practices emerge after ELLs are reclassified as "Fluent English Proficient" (FEP) students and moved from "the four-hour English Language Development (ELD) block" into mainstream classrooms. With a focus on the perspectives and experiences of twelve 5th and 6th grade elementary school students and four of their teachers, I examined how students and teachers viewed and responded to restrictive language policies and the practices that accompany them. One finding from this study is that students and teachers believed that the four-hour ELD block helped prepare students to learn English, but "proficiency" in English as determined by the Arizona English Language Learner Assessment (AZELLA) did not always indicate a solid understanding of the language used in the mainstream classrooms. A second finding from this study is that ideologies of language that position English over multilingualism are robust and further strengthened by language policies that prohibit the use of languages other than English in ELD and mainstream classrooms. A third finding from this study is that, in part because of the language restrictive policies in place, particular groups of students continued to engage in practices that enact ideologies of language that devalue multilingualism (e.g., "language policing"). At the same time, however, a close examination of student-to-student interaction indicates that these same students use their multiple linguistic and communicative resources in a variety of creative and purposeful ways (e.g., through language crossing and language sharing). The close examination of policy as practice in a restrictive educational language policy context conducted here has implications for debates about English-only as a method and medium of instruction, about how the ideologies of language operate in situated interactional contexts, and about how youth might use existing resources to challenge restrictive ideologies and policies.
ContributorsFredricks, Daisy Ellen (Author) / Warriner, Doris S. (Thesis advisor) / Arias, M. Bea (Committee member) / Warhol, Larisa (Committee member) / Arizona State University (Publisher)
Created2013
Description
Ionizing radiation used in the patient diagnosis or therapy has negative effects on the patient body in short term and long term depending on the amount of exposure. More than 700,000 examinations are everyday performed on Interventional Radiology modalities [1], however; there is no patient-centric information available to the patient or the Quality Assurance for the amount of organ dose received. In this study, we are exploring the methodologies to systematically reduce the absorbed radiation dose in the Fluoroscopically Guided Interventional Radiology procedures. In the first part of this study, we developed a mathematical model which determines a set of geometry settings for the equipment and a level for the energy during a patient exam. The goal is to minimize the amount of absorbed dose in the critical organs while maintaining image quality required for the diagnosis. The model is a large-scale mixed integer program. We performed polyhedral analysis and derived several sets of strong inequalities to improve the computational speed and quality of the solution. Results present the amount of absorbed dose in the critical organ can be reduced up to 99% for a specific set of angles. In the second part, we apply an approximate gradient method to simultaneously optimize angle and table location while minimizing dose in the critical organs with respect to the image quality. In each iteration, we solve a sub-problem as a MIP to determine the radiation field size and corresponding X-ray tube energy. In the computational experiments, results show further reduction (up to 80%) of the absorbed dose in compare with previous method. Last, there are uncertainties in the medical procedures resulting imprecision of the absorbed dose. We propose a robust formulation to hedge from the worst case absorbed dose while ensuring feasibility. In this part, we investigate a robust approach for the organ motions within a radiology procedure. We minimize the absorbed dose for the critical organs across all input data scenarios which are corresponding to the positioning and size of the organs. The computational results indicate up to 26% increase in the absorbed dose calculated for the robust approach which ensures the feasibility across scenarios.
ContributorsKhodadadegan, Yasaman (Author) / Zhang, Muhong (Thesis advisor) / Pavlicek, William (Thesis advisor) / Fowler, John (Committee member) / Wu, Tong (Committee member) / Arizona State University (Publisher)
Created2013
Description
Facility location models are usually employed to assist decision processes in urban and regional planning. The focus of this research is extensions of a classic location problem, the Weber problem, to address continuously distributed demand as well as multiple facilities. Addressing continuous demand and multi-facilities represents major challenges. Given advances in geographic information systems (GIS), computational science and associated technologies, spatial optimization provides a possibility for improved problem solution. Essential here is how to represent facilities and demand in geographic space. In one respect, spatial abstraction as discrete points is generally assumed as it simplifies model formulation and reduces computational complexity. However, errors in derived solutions are likely not negligible, especially when demand varies continuously across a region. In another respect, although mathematical functions describing continuous distributions can be employed, such theoretical surfaces are generally approximated in practice using finite spatial samples due to a lack of complete information. To this end, the dissertation first investigates the implications of continuous surface approximation and explicitly shows errors in solutions obtained from fitted demand surfaces through empirical applications. The dissertation then presents a method to improve spatial representation of continuous demand. This is based on infill asymptotic theory, which indicates that errors in fitted surfaces tend to zero as the number of sample points increases to infinity. The implication for facility location modeling is that a solution to the discrete problem with greater demand point density will approach the theoretical optimum for the continuous counterpart. Therefore, in this research discrete points are used to represent continuous demand to explore this theoretical convergence, which is less restrictive and less problem altering compared to existing alternatives. The proposed continuous representation method is further extended to develop heuristics to solve the continuous Weber and multi-Weber problems, where one or more facilities can be sited anywhere in continuous space to best serve continuously distributed demand. Two spatial optimization approaches are proposed for the two extensions of the Weber problem, respectively. The special characteristics of those approaches are that they integrate optimization techniques and GIS functionality. Empirical results highlight the advantages of the developed approaches and the importance of solution integration within GIS.
ContributorsYao, Jing (Author) / Murray, Alan T. (Thesis advisor) / Mirchandani, Pitu B. (Committee member) / Kuby, Michael J (Committee member) / Arizona State University (Publisher)
Created2012
Description
This study investigates the uses of English in advertising in Brazil and the attitudes of Brazilians towards the use of different difficulty levels of English in advertising. Using a two part, mixed-methods approach, drawing from quantitative and qualitative methods, I utilized a corpus study to examine English uses in Brazilian magazines and a survey to investigate the difficulty of English slogans as a determinant for people's attitudes towards English in advertising. For the first part, three major Brazilian news magazines, Veja, Época, and ISTOÉ were used. From three issues of each magazine, results showed that 57% of the advertisements in all nine magazines contained English in different parts of the advertisements, with most occurrences in the product name, followed by the body copy, headline, subheadline, and slogan. English was used to advertise a number of different product types, but was especially used for advertising cars, electronics, events, and banks. It was also found that the majority of English was used for its symbolic representations of modernity, prestige, globalization, and reliability. Using a survey for the second part of the study, I investigated how Brazilian participants judged four advertisements that featured English slogans that were comparable to slogans judged to be easy or difficult to understand in a similar study conducted by Hornikx, van Meurs, and de Boer (2010). Participants were offered attitudinal choices to mark off on a 4-point Likert scale, where they indicated their attitudes towards the English slogans provided. They were also asked to determine if they understood the slogans and to translate them to indicate their actual understanding of the slogans. Participants showed more positive attitudes towards the uses of English than negative attitudes. The survey provided evidence that with the very low numbers of correctly translated slogans, many participants believed they understood the slogans, which could prove to be more of an indicator of positive attitudes than their actual understanding of the slogans. This project provides an example from one Expanding Circle context touched by the far-reaching influences of World Englishes.
ContributorsMontes, Amanda Lira Gordenstein (Author) / Friedrich, Patricia M (Thesis advisor) / Matsuda, Aya (Committee member) / Lafford, Barbara (Committee member) / Anokye, Akua Duku (Committee member) / Arizona State University (Publisher)
Created2014
Description
Vehicles powered by electricity and alternative-fuels are becoming a more popular form of transportation since they have less of an environmental impact than standard gasoline vehicles. Unfortunately, their success is currently inhibited by the sparseness of locations where the vehicles can refuel as well as the fact that many of the vehicles have a range that is less than those powered by gasoline. These factors together create a "range anxiety" in drivers, which causes the drivers to worry about the utility of alternative-fuel and electric vehicles and makes them less likely to purchase these vehicles. For the new vehicle technologies to thrive it is critical that range anxiety is minimized and performance is increased as much as possible through proper routing and scheduling. In the case of long distance trips taken by individual vehicles, the routes must be chosen such that the vehicles take the shortest routes while not running out of fuel on the trip. When many vehicles are to be routed during the day, if the refueling stations have limited capacity then care must be taken to avoid having too many vehicles arrive at the stations at any time. If the vehicles that will need to be routed in the future are unknown then this problem is stochastic. For fleets of vehicles serving scheduled operations, switching to alternative-fuels requires ensuring the schedules do not cause the vehicles to run out of fuel. This is especially problematic since the locations where the vehicles may refuel are limited due to the technology being new. This dissertation covers three related optimization problems: routing a single electric or alternative-fuel vehicle on a long distance trip, routing many electric vehicles in a network where the stations have limited capacity and the arrivals into the system are stochastic, and scheduling fleets of electric or alternative-fuel vehicles with limited locations to refuel. Different algorithms are proposed to solve each of the three problems, of which some are exact and some are heuristic. The algorithms are tested on both random data and data relating to the State of Arizona.
ContributorsAdler, Jonathan D (Author) / Mirchandani, Pitu B. (Thesis advisor) / Askin, Ronald (Committee member) / Gel, Esma (Committee member) / Xue, Guoliang (Committee member) / Zhang, Muhong (Committee member) / Arizona State University (Publisher)
Created2014
Description
Research regarding social competence is growing rapidly, but there remain a few aspects of social development that merit more attention. The presented pair of studies were planned to address two such areas in the social development literature, specifically the longitudinal trajectories of social competence and the role of social competence in second language development in language minority (LM) students. The goal of the first investigation was to examine the developmental trends of interpersonal skills (IS) across the early childhood and elementary school years in a nationally representative, U.S. sample. The goal of the second study was to examine whether differing trajectories of IS development in language minority children in the U.S. were related to their language and literacy (LL) skills at grade 5. Both studies utilized data from the Early Childhood Longitudinal Study - Kindergarten Class of 1998-1999 and modeled ratings of children's IS at five time points between fall of kindergarten and spring of fifth grade using latent class growth analyses in Mplus. In study 1, the best model was a quadratic two-class latent class growth analysis. Trajectory class 1 was a higher-level path with a marginally significant non-linear shape and class 2 was a primarily stable, moderate level path with a slight, non-significant increase over time. The same pattern of results emerged for both boys and girls separately as with the combined-sex model, and in all three final models the proportion of the sample in the higher-level class was greater than the moderate-level class. In study 2 a sample of U.S. children whose primary language at home was something other than English was utilized. LL at the start of kindergarten and sex were included as covariates and LL in fifth grade as a distal outcome. The best model for the data was a cubic two-class latent class growth analysis. Class 1 followed a higher-level path with small, incremental change over time and class 2 was a moderate-level path with greater undulation. Both covariates significantly predicted latent class and language and literacy scores at grade 5 differed significantly across classes.
ContributorsDiDonato, Alicia (Author) / Wilcox, M. Jeanne (Thesis advisor) / Bradley, Robert (Committee member) / Wilkens, Natalie (Committee member) / Valiente, Carlos (Committee member) / Arizona State University (Publisher)
Created2014
Description
The study develops a better understanding of what is valued in L2 academic writing in IEP and FYC programs through a comparative case study approach, identifying the assumptions and underlying values of program directors and instructors in both types of instructional settings. The goal of the study is to understand more about second language writing pedagogy for international students in these programs, as well as to provide university administrators with a better understanding of how to improve writing instruction for multilingual students, who have become a key part of the U.S. higher education mission. Data include program-level mission statements, course descriptions and objectives, curricular materials, as well as interviews with teachers and program directors. Major findings show that there is a tension between language-focused vs. rhetoric-focused approaches to second language writing instruction in the two contexts. IEP instruction sought to build on students' language proficiency, and writing instruction was rooted in a conception of writing as language organized by structural principles, while the FYC program emphasized writing as a tool for communication and personal growth. Based on these findings, I provide recommendations for improving graduate education for all writing teachers, developing more comprehensive needs analysis procedures, and establishing administrative structures to support international multilingual students.
ContributorsHammill, Matthew Joseph (Author) / Matsuda, Paul Kei (Thesis advisor) / James, Mark A (Committee member) / Rose, Shirley (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study aims to uncover whether English Central, an online English as a Second Language tool, improves speaking proficiency for undergraduate students with developing English skills. Eighty-three advanced English language learners from the American English and Culture Program at Arizona State University were randomly assigned to one of three conditions: the use of English Central with a learner-control, shared-control, and a no-treatment condition. The two treatment groups were assigned approximately 14.7 hours of online instruction. The relative impact of each of the three conditions was assessed using two measures. First, the Pearson Versant Test (www.versanttest.com), a well-established English-as-a-second-language speaking test, was administered to all of the participants as a pre- and post-test measure. Second, students were given a post-treatment questionnaire that measured their motivation in using online instruction in general, and English Central specifically. Since a significant teacher effect was found, teachers involved in this study were also interviewed in order to ascertain their attitude toward English Central as a homework tool. Learner outcomes were significantly different between the shared and learner conditions. Student motivation was predictive of learning outcomes. Subjects in the shared condition outperformed those in the learner condition. Furthermore, those in the shared condition scored higher than the control condition; however, this result did not reach statistical significance. Results of the follow-up teacher survey revealed that while a teacher's view of the tool (positive or negative), was not a predictor of student success, teacher presentation of the tool may lead to a significant impact on student learning outcomes.
ContributorsDixon, Shane Y. (Shane Yahlu) (Author) / Atkinson, Robert (Thesis advisor) / Savenye, Wilhelmina (Committee member) / Nelson, Brian (Committee member) / Arizona State University (Publisher)
Created2015
Description
Quantum resilience is a pragmatic theory that allows systems engineers to formally characterize the resilience of systems. As a generalized theory, it not only clarifies resilience in the literature, but also can be applied to all disciplines and domains of discourse. Operationalizing resilience in this manner permits decision-makers to compare and contrast system deployment options for suitability in a variety of environments and allows for consistent treatment of resilience across domains. Systems engineers, whether planning future infrastructures or managing ecosystems, are increasingly asked to deliver resilient systems. Quantum resilience provides a way forward that allows specific resilience requirements to be specified, validated, and verified.
Quantum resilience makes two very important claims. First, resilience cannot be characterized without recognizing both the system and the valued function it provides. Second, resilience is not about disturbances, insults, threats, or perturbations. To avoid crippling infinities, characterization of resilience must be accomplishable without disturbances in mind. In light of this, quantum resilience defines resilience as the extent to which a system delivers its valued functions, and characterizes resilience as a function of system productivity and complexity. System productivity vis-à-vis specified “valued functions” involves (1) the quanta of the valued function delivered, and (2) the number of systems (within the greater system) which deliver it. System complexity is defined structurally and relationally and is a function of a variety of items including (1) system-of-systems hierarchical decomposition, (2) interfaces and connections between systems, and (3) inter-system dependencies.
Among the important features of quantum resilience is that it can be implemented in any system engineering tool that provides sufficient design and specification rigor (i.e., one that supports standards like the Lifecycle and Systems Modeling languages and frameworks like the DoD Architecture Framework). Further, this can be accomplished with minimal software development and has been demonstrated in three model-based system engineering tools, two of which are commercially available, well-respected, and widely used. This pragmatic approach assures transparency and consistency in characterization of resilience in any discipline.
Quantum resilience makes two very important claims. First, resilience cannot be characterized without recognizing both the system and the valued function it provides. Second, resilience is not about disturbances, insults, threats, or perturbations. To avoid crippling infinities, characterization of resilience must be accomplishable without disturbances in mind. In light of this, quantum resilience defines resilience as the extent to which a system delivers its valued functions, and characterizes resilience as a function of system productivity and complexity. System productivity vis-à-vis specified “valued functions” involves (1) the quanta of the valued function delivered, and (2) the number of systems (within the greater system) which deliver it. System complexity is defined structurally and relationally and is a function of a variety of items including (1) system-of-systems hierarchical decomposition, (2) interfaces and connections between systems, and (3) inter-system dependencies.
Among the important features of quantum resilience is that it can be implemented in any system engineering tool that provides sufficient design and specification rigor (i.e., one that supports standards like the Lifecycle and Systems Modeling languages and frameworks like the DoD Architecture Framework). Further, this can be accomplished with minimal software development and has been demonstrated in three model-based system engineering tools, two of which are commercially available, well-respected, and widely used. This pragmatic approach assures transparency and consistency in characterization of resilience in any discipline.
ContributorsRoberts, Thomas Wade (Author) / Allenby, Braden (Thesis advisor) / Chester, Mikhail (Committee member) / Anderies, John M (Committee member) / Arizona State University (Publisher)
Created2015