Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
Displaying 31 - 40 of 116
Description
The purpose of this thesis study is to widen the understanding of the effect culture on self-improvement. Past research found that Japanese students, when compared to their North American counterparts, are more likely to strive for self-improvement by persisting when they encounter academic setbacks. In addition to North Americans and Asians, this thesis examines South Asians as well. It is hypothesized that South Asians will have similar levels of self-improvement as East Asians. This thesis also looks at possible explanations for why culture affects self-improvement. Two variables, future self-connectedness and growth mindset, are proposed as these explanations. It is hypothesized that culture affects future self-connectedness and growth mindset, and those two variables in turn influence self-improvement.
For this thesis, 100 undergraduate and recent college graduates completed online self-report measures. Results of independent t-tests showed that there were no significant differences between South and East Asians in self-improvement, which is consistent with what was hypothesized. There were also no differences between South and East Asians in future self-connectedness or growth mindset. The two Asian groups were then combined and compared to North Americans. Further independent t-tests were run, and results found that while the trend was as expected and Asians exhibited higher levels of self-improvement than North Americans, they did not exhibit significantly higher levels. There were also no significant differences between North Americans and Asians in growth mindset, however, North Americans had significantly higher levels of future self-connectedness than Asians, contrary to expectation. Results of mediation regressions found that neither future self-connectedness nor growth mindset significantly explained the effect of culture on self-improvement.
For this thesis, 100 undergraduate and recent college graduates completed online self-report measures. Results of independent t-tests showed that there were no significant differences between South and East Asians in self-improvement, which is consistent with what was hypothesized. There were also no differences between South and East Asians in future self-connectedness or growth mindset. The two Asian groups were then combined and compared to North Americans. Further independent t-tests were run, and results found that while the trend was as expected and Asians exhibited higher levels of self-improvement than North Americans, they did not exhibit significantly higher levels. There were also no significant differences between North Americans and Asians in growth mindset, however, North Americans had significantly higher levels of future self-connectedness than Asians, contrary to expectation. Results of mediation regressions found that neither future self-connectedness nor growth mindset significantly explained the effect of culture on self-improvement.
ContributorsShaikjamaludeen, Shaikhameedha (Author) / Kwan, Virginia (Thesis director) / Shiota, Michelle (Committee member) / Davis, Mary (Committee member) / School of Molecular Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Depression, anxiety, and suicidal thoughts or actions are on the rise in adolescents (National Institute of Mental Health, 2015; Bridge, Asti, & Horowitz, 2015). Parents, school administrators, and therapists are searching for resiliency factors with in at-risk groups to aid students in need. In previous work, Luthar and Zigler (1992) reported that intelligent youth are more resilient than less intelligent youth under low stress conditions but they lose their advantage under high stress conditions. This study examined whether intelligence (reflected in grade point average; GPA) and maladaptive (internalizing and externalizing symptoms) behaviors are negatively related in adolescents, and tested whether level of stress, reflected in emotion regulation and friendship quality, moderated that association. It also probed whether the relationships differ by gender. Sixth-graders (N=506) were recruited with active parental consent from three middle schools. Adolescents completed self-report questionnaires Regarding demo graphics, maladaptive behaviors, emotion regulation, and friendship quality, and GPA data were collected from the school. Regression analyses found that GPA was negatively related to externalizing symptoms. Girls with poor friendship communication report significantly higher maladaptive behaviors. This relation was more pronounced for girls with high GPAs, as predicted. Results support the theory that intelligent female adolescents are more reactive under adverse circumstances. Future efforts should follow students through middle school into high school to evaluate whether friendships remain important to adjustment, hold for boys as well as girls, and have implications for relationship interventions.
ContributorsGonzales, Ashlyn Carol (Author) / Luthar, Suniya (Thesis director) / Davis, Mary (Committee member) / Infurna, Frank (Committee member) / Department of Psychology (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Emotions have been defined as coordinated and functional changes in subjective experience, motivation, physiological activation, instrumental behavior, expressive behavior, and cognition that are evoked by important threats or opportunities in the environment. The proposed study looks at cognitive changes associated with the experience of several positive emotions, with a specific focus on awe. Prior research shows that positive emotions tend to increase people's use of cognitive heuristics (i.e. mental shortcuts used to simplify information we intake from the environment) and changes how they apply rules of thumb from stored knowledge to make decisions. Stereotypes, or assumptions about the characteristics held by individual members of a group, are one such heuristic. Awe, in contrast to other positive emotions, has been found to reduce people's tendency to rely on heuristics, rather than increasing its use. Thus, awe should tend to reduce stereotyping specifically. Participants made judgments on three characteristics and two types of theoretically valuable true/false statements. However, for both our measures, awe had no significant effect on stereotyping. Participants in the enthusiasm condition were significantly more likely than those in the awe condition to correctly identify stereotype-inconsistent statements present in the biography, which is the opposite of the predicted direction. Patterns for all four emotion conditions trended similarly to our predictions for stereotype-consistent statements correctly marked as being absent in the biography. There were no significant differences in ratings of three traits. Implications for enthusiasm and awe are discussed in the context of stereotypes of social objects and schemas of nonsocial objects.
ContributorsMurwin, Paige Elizabeth (Co-author) / O'Neil, Makenzie (Co-author) / Shiota, Michelle (Thesis director) / Davis, Mary (Committee member) / Sanford School of Social and Family Dynamics (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
The frontostriatal reward circuit serves an underlying role in reward processing, cognitive planning, and motor control in the context of achieving a goal. Furthermore, research suggests a relationship between the reward circuits and behavior expressed in Attention Deficit Hyperactivity Disorder (ADHD); however, the specific structural differences of the reward circuits in those with ADHD remain ambiguous. Diffusion tensor imaging (DTI) techniques were used to analyze diffusion weighted magnetic resonance imaging (DWI) data in order to examine the structural connectivity of frontostriatal reward pathways in ADHD adolescents compared to typically developing (TD) adolescents. It was hypothesized that measures of impulsivity would be predicted by white matter tract integrity measures in frontostriatal tracts related to affective processing (ventromedial prefrontal cortex to ventral striatum, vmPFC) in adolescents with ADHD, and that there would be reduced tract integrity in tracts related to executive control (dorsolateral prefrontal and anterior cingulate cortex—dlPFC and ACC, respectively). Frontostriatal tracts as well as the hippocampus and amygdala were examined in relation to age and impulsivity using both correlation and regression models. Results indicated that impulsivity declined with age in the TD group while no significant trend was identified for the ADHD group. The hypotheses were not supported and results for both predictions on the affective and executive circuits showed opposite trends from what was expected.
ContributorsHarrison, Sydney Rae (Author) / McClure, Samuel (Thesis director) / Brewer, Gene (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Posttraumatic Stress Disorder (PTSD) affects nearly 10% of adult women in general population samples. In populations of impoverished ethnic minority women, those lifetime prevalence rates may possibly exceed national averages due to lack of mental health resources. Mothers with PTSD are more likely to exhibit negative parenting styles and experience higher levels of perceived parenting stress, both of which are associated with poor child outcomes. However, there is a lack of evidence on how maternal PTSD may affect parenting for ethnic minority mothers. This study evaluated the prevalence of lifetime PTSD and its effects on parenting stress and infant problem behaviors in a sample of 322 low-income Mexican-American mothers (mean age = 27.8; 86% born in Mexico). Lifetime PTSD diagnoses were assessed at a prenatal home visit (24-36 weeks gestation) using the WHO Composite International Diagnostic Interview (CIDI). Mothers reported parenting hassles at 24-weeks postpartum (PDLH; Crnic & Greenberg, 1990), and child problem behaviors at infant age one-year (BITSEA; Briggs-Gowan et al., 2004). I hypothesized that 1) women with PTSD would report more parenting stress than women without PTSD, 2) women with PTSD would report more infant problem behavior symptoms than women without PTSD, and 3) parenting stress mediates the relationship between PTSD and infant problem behavior. Results found that 16.5% of women met criteria for past or present PTSD. Compared to women without PTSD, women with PTSD reported more parenting stress but a similar level of infant problem behaviors. Parenting stress significantly mediated the relationship between maternal PTSD and infant problem behaviors. Study findings suggest a need for mental health screenings during prenatal care in order to promote the healthy development of high-risk children.
ContributorsPreves, Ashley Maria (Author) / Luecken, Linda (Thesis director) / Davis, Mary (Committee member) / Mauricio, Anne (Committee member) / Department of Psychology (Contributor) / School of Social Transformation (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
This paper explores the idea of xenophilia and the circumstances under which it may occur. Xenophilia is the preference for an outgroup member over an ingroup member. This preference does not have to be amicable, and in fact can be exploitative under certain circumstances. Previous research indicates that xenophobia is much more common, but a few researchers have found support for the existence of xenophilia. To experimentally test the circumstances under which xenophilia might occur, I conducted a survey-based experiment on Amazon’s Mechanical Turk. This consisted of directed visualizations that manipulated participant goal (self-protection vs. mate acquisition) and the resources offered by both a fictitious outgroup and the hometown ingroup, followed by measures of ingroup/outgroup preference. I hypothesized that when the resource offered by the group addressed the participants’ goal, they would prefer the group with the “matched” resource—even if it was the outgroup providing that resource. My hypothesis was not supported, as the univariate analysis of variance for preference for the outgroup was not significant, F (2, 423) = .723, p = .486. This may have occurred because the goal manipulations were not strong enough to counteract the strong natural preference for ingroup members.
ContributorsDrury, Margaret E. (Author) / Neuberg, Steven (Thesis director) / Davis, Mary (Committee member) / Kenrick, Douglas (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / School of Social and Behavioral Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
In order to refine autonomous exploratory movement planning schemes, an approach must be developed that accounts for valuable information other than that gained from map filling. To this end, the goal of this thesis is divided into two parts. The first is to develop a technique for categorizing objects detected by an autonomous exploratory robot and assigning them a score based on their interest value. The second is an attempt to develop a method of integrating this technique into a navigation algorithm in order to refine the movements of a robot or robots to maximize the efficiency of information gain. The intention of both of these components is to provide a method of refining the navigation scheme applied to autonomous exploring robots and maximize the amount of information they can gather in deployments where they face significant resource or functionality constraints. To this end this project is divided into two main sections: a shape-matching technique and a simulation in in which to implement this technique. The first section was accomplished by combining concepts from information theory, principal component analysis, and the eigenfaces algorithm to create an effective matching technique. The second was created with inspiration from existing navigation algorithms. Once these components were determined to be functional, a testing regime was applied to determine their capabilities. The testing regime was also divided into two parts. The tests applied to the matching technique were first to demonstrate that it functions under ideal conditions. After testing was conducted under ideal conditions, the technique was tested under non-ideal conditions. Additional tests were run to determine how the system responded to changes in the coefficients and equations that govern its operation. Similarly, the simulation component was initially tested under normal conditions to determine the base effectiveness of the approach. After these tests were conducted, alternative conditions were tested to evaluate the effects of modifying the implementation technique. The results of these tests indicated a few things. The first series of tests confirmed that the matching technique functions as expected under ideal conditions. The second series of tests determined that the matching element is effective for a reasonable range of variations and non-ideal conditions. The third series of tests showed that changing the functional coefficients of the matching technique can help tune the technique to different conditions. The fourth series of tests demonstrated that the basic concept of the implementation technique makes sense. The final series of tests demonstrated that modifying the implementation method is at least somewhat effective and that modifications to it can be used to specifically tailor the implementation to a method. Overall the results indicate that the stated goals of the project were accomplished successfully.
ContributorsFleetwood, Garrett Clark (Author) / Thanga, Jekan (Thesis director) / Berman, Spring (Committee member) / Middleton, James (Committee member) / Economics Program in CLAS (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Interest in Micro Aerial Vehicle (MAV) research has surged over the past decade. MAVs offer new capabilities for intelligence gathering, reconnaissance, site mapping, communications, search and rescue, etc. This thesis discusses key modeling and control aspects of flapping wing MAVs in hover. A three degree of freedom nonlinear model is used to describe the flapping wing vehicle. Averaging theory is used to obtain a nonlinear average model. The equilibrium of this model is then analyzed. A linear model is then obtained to describe the vehicle near hover. LQR is used to as the main control system design methodology. It is used, together with a nonlinear parameter optimization algorithm, to design a family multivariable control system for the MAV. Critical performance trade-offs are illuminated. Properties at both the plant output and input are examined. Very specific rules of thumb are given for control system design. The conservatism of the rules are also discussed. Issues addressed include
What should the control system bandwidth be vis--vis the flapping frequency (so that averaging the nonlinear system is valid)?
When is first order averaging sufficient? When is higher order averaging necessary?
When can wing mass be neglected and when does wing mass become critical to model?
This includes how and when the rules given can be tightened; i.e. made less conservative.
What should the control system bandwidth be vis--vis the flapping frequency (so that averaging the nonlinear system is valid)?
When is first order averaging sufficient? When is higher order averaging necessary?
When can wing mass be neglected and when does wing mass become critical to model?
This includes how and when the rules given can be tightened; i.e. made less conservative.
ContributorsBiswal, Shiba (Author) / Rodriguez, Armando (Thesis advisor) / Mignolet, Marc (Thesis advisor) / Berman, Spring (Committee member) / Arizona State University (Publisher)
Created2015
Description
Unmanned aerial vehicles have received increased attention in the last decade due to their versatility, as well as the availability of inexpensive sensors (e.g. GPS, IMU) for their navigation and control. Multirotor vehicles, specifically quadrotors, have formed a fast growing field in robotics, with the range of applications spanning from surveil- lance and reconnaissance to agriculture and large area mapping. Although in most applications single quadrotors are used, there is an increasing interest in architectures controlling multiple quadrotors executing a collaborative task. This thesis introduces a new concept of control involving more than one quadrotors, according to which two quadrotors can be physically coupled in mid-flight. This concept equips the quadro- tors with new capabilities, e.g. increased payload or pursuit and capturing of other quadrotors. A comprehensive simulation of the approach is built to simulate coupled quadrotors. The dynamics and modeling of the coupled system is presented together with a discussion regarding the coupling mechanism, impact modeling and additional considerations that have been investigated. Simulation results are presented for cases of static coupling as well as enemy quadrotor pursuit and capture, together with an analysis of control methodology and gain tuning. Practical implementations are introduced as results show the feasibility of this design.
ContributorsLarsson, Daniel (Author) / Artemiadis, Panagiotis (Thesis advisor) / Marvi, Hamidreza (Committee member) / Berman, Spring (Committee member) / Arizona State University (Publisher)
Created2016
Description
A computational framework based on convex optimization is presented for stability analysis of systems described by Partial Differential Equations (PDEs). Specifically, two forms of linear PDEs with spatially distributed polynomial coefficients are considered.
The first class includes linear coupled PDEs with one spatial variable. Parabolic, elliptic or hyperbolic PDEs with Dirichlet, Neumann, Robin or mixed boundary conditions can be reformulated in order to be used by the framework. As an example, the reformulation is presented for systems governed by Schr¨odinger equation, parabolic type, relativistic heat conduction PDE and acoustic wave equation, hyperbolic types. The second form of PDEs of interest are scalar-valued with two spatial variables. An extra spatial variable allows consideration of problems such as local stability of fluid flows in channels and dynamics of population over two dimensional domains.
The approach does not involve discretization and is based on using Sum-of-Squares (SOS) polynomials and positive semi-definite matrices to parameterize operators which are positive on function spaces. Applying the parameterization to construct Lyapunov functionals with negative derivatives allows to express stability conditions as a set of LinearMatrix Inequalities (LMIs). The MATLAB package SOSTOOLS was used to construct the LMIs. The resultant LMIs then can be solved using existent Semi-Definite Programming (SDP) solvers such as SeDuMi or MOSEK. Moreover, the proposed approach allows to calculate bounds on the rate of decay of the solution norm.
The methodology is tested using several numerical examples and compared with the results obtained from simulation using standard methods of numerical discretization and analytic solutions.
The first class includes linear coupled PDEs with one spatial variable. Parabolic, elliptic or hyperbolic PDEs with Dirichlet, Neumann, Robin or mixed boundary conditions can be reformulated in order to be used by the framework. As an example, the reformulation is presented for systems governed by Schr¨odinger equation, parabolic type, relativistic heat conduction PDE and acoustic wave equation, hyperbolic types. The second form of PDEs of interest are scalar-valued with two spatial variables. An extra spatial variable allows consideration of problems such as local stability of fluid flows in channels and dynamics of population over two dimensional domains.
The approach does not involve discretization and is based on using Sum-of-Squares (SOS) polynomials and positive semi-definite matrices to parameterize operators which are positive on function spaces. Applying the parameterization to construct Lyapunov functionals with negative derivatives allows to express stability conditions as a set of LinearMatrix Inequalities (LMIs). The MATLAB package SOSTOOLS was used to construct the LMIs. The resultant LMIs then can be solved using existent Semi-Definite Programming (SDP) solvers such as SeDuMi or MOSEK. Moreover, the proposed approach allows to calculate bounds on the rate of decay of the solution norm.
The methodology is tested using several numerical examples and compared with the results obtained from simulation using standard methods of numerical discretization and analytic solutions.
ContributorsMeyer, Evgeny (Author) / Peet, Matthew (Thesis advisor) / Berman, Spring (Committee member) / Rivera, Daniel (Committee member) / Arizona State University (Publisher)
Created2016