This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students. 

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Current economic conditions necessitate the extension of service lives for a variety of aerospace systems. As a result, there is an increased need for structural health management (SHM) systems to increase safety, extend life, reduce maintenance costs, and minimize downtime, lowering life cycle costs for these aging systems. The implementation

Current economic conditions necessitate the extension of service lives for a variety of aerospace systems. As a result, there is an increased need for structural health management (SHM) systems to increase safety, extend life, reduce maintenance costs, and minimize downtime, lowering life cycle costs for these aging systems. The implementation of such a system requires a collaborative research effort in a variety of areas such as novel sensing techniques, robust algorithms for damage interrogation, high fidelity probabilistic progressive damage models, and hybrid residual life estimation models. This dissertation focuses on the sensing and damage estimation aspects of this multidisciplinary topic for application in metallic and composite material systems. The primary means of interrogating a structure in this work is through the use of Lamb wave propagation which works well for the thin structures used in aerospace applications. Piezoelectric transducers (PZTs) were selected for this application since they can be used as both sensors and actuators of guided waves. Placement of these transducers is an important issue in wave based approaches as Lamb waves are sensitive to changes in material properties, geometry, and boundary conditions which may obscure the presence of damage if they are not taken into account during sensor placement. The placement scheme proposed in this dissertation arranges piezoelectric transducers in a pitch-catch mode so the entire structure can be covered using a minimum number of sensors. The stress distribution of the structure is also considered so PZTs are placed in regions where they do not fail before the host structure. In order to process the data from these transducers, advanced signal processing techniques are employed to detect the presence of damage in complex structures. To provide a better estimate of the damage for accurate life estimation, machine learning techniques are used to classify the type of damage in the structure. A data structure analysis approach is used to reduce the amount of data collected and increase computational efficiency. In the case of low velocity impact damage, fiber Bragg grating (FBG) sensors were used with a nonlinear regression tool to reconstruct the loading at the impact site.
ContributorsCoelho, Clyde (Author) / Chattopadhyay, Aditi (Thesis advisor) / Dai, Lenore (Committee member) / Wu, Tong (Committee member) / Das, Santanu (Committee member) / Rajadas, John (Committee member) / Papandreou-Suppappola, Antonia (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Many products undergo several stages of testing ranging from tests on individual components to end-item tests. Additionally, these products may be further "tested" via customer or field use. The later failure of a delivered product may in some cases be due to circumstances that have no correlation with the product's

Many products undergo several stages of testing ranging from tests on individual components to end-item tests. Additionally, these products may be further "tested" via customer or field use. The later failure of a delivered product may in some cases be due to circumstances that have no correlation with the product's inherent quality. However, at times, there may be cues in the upstream test data that, if detected, could serve to predict the likelihood of downstream failure or performance degradation induced by product use or environmental stresses. This study explores the use of downstream factory test data or product field reliability data to infer data mining or pattern recognition criteria onto manufacturing process or upstream test data by means of support vector machines (SVM) in order to provide reliability prediction models. In concert with a risk/benefit analysis, these models can be utilized to drive improvement of the product or, at least, via screening to improve the reliability of the product delivered to the customer. Such models can be used to aid in reliability risk assessment based on detectable correlations between the product test performance and the sources of supply, test stands, or other factors related to product manufacture. As an enhancement to the usefulness of the SVM or hyperplane classifier within this context, L-moments and the Western Electric Company (WECO) Rules are used to augment or replace the native process or test data used as inputs to the classifier. As part of this research, a generalizable binary classification methodology was developed that can be used to design and implement predictors of end-item field failure or downstream product performance based on upstream test data that may be composed of single-parameter, time-series, or multivariate real-valued data. Additionally, the methodology provides input parameter weighting factors that have proved useful in failure analysis and root cause investigations as indicators of which of several upstream product parameters have the greater influence on the downstream failure outcomes.
ContributorsMosley, James (Author) / Morrell, Darryl (Committee member) / Cochran, Douglas (Committee member) / Papandreou-Suppappola, Antonia (Committee member) / Roberts, Chell (Committee member) / Spanias, Andreas (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Advancements in computer vision and machine learning have added a new dimension to remote sensing applications with the aid of imagery analysis techniques. Applications such as autonomous navigation and terrain classification which make use of image classification techniques are challenging problems and research is still being carried out to find

Advancements in computer vision and machine learning have added a new dimension to remote sensing applications with the aid of imagery analysis techniques. Applications such as autonomous navigation and terrain classification which make use of image classification techniques are challenging problems and research is still being carried out to find better solutions. In this thesis, a novel method is proposed which uses image registration techniques to provide better image classification. This method reduces the error rate of classification by performing image registration of the images with the previously obtained images before performing classification. The motivation behind this is the fact that images that are obtained in the same region which need to be classified will not differ significantly in characteristics. Hence, registration will provide an image that matches closer to the previously obtained image, thus providing better classification. To illustrate that the proposed method works, naïve Bayes and iterative closest point (ICP) algorithms are used for the image classification and registration stages respectively. This implementation was tested extensively in simulation using synthetic images and using a real life data set called the Defense Advanced Research Project Agency (DARPA) Learning Applied to Ground Robots (LAGR) dataset. The results show that the ICP algorithm does help in better classification with Naïve Bayes by reducing the error rate by an average of about 10% in the synthetic data and by about 7% on the actual datasets used.
ContributorsMuralidhar, Ashwini (Author) / Saripalli, Srikanth (Thesis advisor) / Papandreou-Suppappola, Antonia (Committee member) / Turaga, Pavan (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Underwater acoustic communications face significant challenges unprecedented in radio terrestrial communications including long multipath delay spreads, strong Doppler effects, and stringent bandwidth requirements. Recently, multi-carrier communications based on orthogonal frequency division multiplexing (OFDM) have seen significant growth in underwater acoustic (UWA) communications, thanks to their well well-known robustness against severely

Underwater acoustic communications face significant challenges unprecedented in radio terrestrial communications including long multipath delay spreads, strong Doppler effects, and stringent bandwidth requirements. Recently, multi-carrier communications based on orthogonal frequency division multiplexing (OFDM) have seen significant growth in underwater acoustic (UWA) communications, thanks to their well well-known robustness against severely time-dispersive channels. However, the performance of OFDM systems over UWA channels significantly deteriorates due to severe intercarrier interference (ICI) resulting from rapid time variations of the channel. With the motivation of developing enabling techniques for OFDM over UWA channels, the major contributions of this thesis include (1) two effective frequencydomain equalizers that provide general means to counteract the ICI; (2) a family of multiple-resampling receiver designs dealing with distortions caused by user and/or path specific Doppler scaling effects; (3) proposal of using orthogonal frequency division multiple access (OFDMA) as an effective multiple access scheme for UWA communications; (4) the capacity evaluation for single-resampling versus multiple-resampling receiver designs. All of the proposed receiver designs have been verified both through simulations and emulations based on data collected in real-life UWA communications experiments. Particularly, the frequency domain equalizers are shown to be effective with significantly reduced pilot overhead and offer robustness against Doppler and timing estimation errors. The multiple-resampling designs, where each branch is tasked with the Doppler distortion of different paths and/or users, overcome the disadvantages of the commonly-used single-resampling receivers and yield significant performance gains. Multiple-resampling receivers are also demonstrated to be necessary for UWA OFDMA systems. The unique design effectively mitigates interuser interference (IUI), opening up the possibility to exploit advanced user subcarrier assignment schemes. Finally, the benefits of the multiple-resampling receivers are further demonstrated through channel capacity evaluation results.
ContributorsTu, Kai (Author) / Duman, Tolga M. (Thesis advisor) / Zhang, Junshan (Committee member) / Tepedelenlioğlu, Cihan (Committee member) / Papandreou-Suppappola, Antonia (Committee member) / Arizona State University (Publisher)
Created2011
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Description

Within the pediatric hospitalization experience, fear and anxiety are two emotions commonly felt by children of all ages. Hospitalized children can greatly benefit from interventions designed to help them cope with these emotions throughout their medical experiences. This study draws on each of our clinical experiences as volunteers at Phoenix

Within the pediatric hospitalization experience, fear and anxiety are two emotions commonly felt by children of all ages. Hospitalized children can greatly benefit from interventions designed to help them cope with these emotions throughout their medical experiences. This study draws on each of our clinical experiences as volunteers at Phoenix Children’s Hospital, and uses a qualitative analysis of three semi-structured interviews with currently employed Child Life Specialists to understand and analyze the use of medical play, a form of play intervention with a medical theme or medical equipment. We explore the goals and benefits of medical play for hospitalized pediatric patients, the process of using medical play as an intervention, including the activity design process, the assessments and adjustments made throughout the child’s hospitalization, and the considerations and limitations to implementing medical play activities. Ultimately, we found that the element of fun that defines play can be channeled into medical play activities implemented by skilled Child Life Specialists, who are experts in their field, in clinical settings to promote several different and beneficial goals, including pediatric patient coping.

ContributorsAguiar, Lara (Co-author) / Garciapeña, Danae (Co-author) / Loebenberg, Abby (Thesis director) / Swanson, Jodi (Committee member) / School of Life Sciences (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Waste pickers are the victims of harsh economic and social factors that have hurt many developing countries and billions of people around the world. Due to the rise of industrialization since the 19th century, waste and disposable resources have been discarded around the world to provide more resources, products, and

Waste pickers are the victims of harsh economic and social factors that have hurt many developing countries and billions of people around the world. Due to the rise of industrialization since the 19th century, waste and disposable resources have been discarded around the world to provide more resources, products, and services to wealthy countries. This has put developing countries in a precarious position where people have had very few economic opportunities besides taking on the role of waste pickers, who not only face physical health consequences due to the work they do but also face exclusion from society due to the negative views of waste pickers. Many people view waste pickers as scavengers and people who survive off of doing dirty work, which creates tensions between waste pickers and others in society. This even leads to many countries outlawing waste picking and has led to the brutal treatment of waste pickers throughout the world and has even led to thousands of waste pickers being killed by anti-waste picker groups and law enforcement organizations in many countries. <br/> Waste pickers are often at the bottom of supply-chains as they take resources that have been used and discarded, and provide them to recyclers, waste management organizations, and others who are able to turn these resources into usable materials again. Waste pickers do not have many opportunities to rise above the situation they are in as waste picking has become the only option for many people who need to provide for themselves and their families. They are not compensated very well for the work they do, which also contributes to the situation where waste pickers are forced into a position of severe health risks, backlash from society and governments, not being able to seek better opportunities due to a lack of earning potential, and not being connected with end-users. Now is the time to create new business models that solve these large problems in our global society and create a sustainable way to ensure that waste pickers are treated properly around the world.

ContributorsKidd, Isabella Joy (Co-author) / Kapps, Jack (Co-author) / Urbina-Bernal, Alejandro (Thesis director) / Byrne, Jared (Committee member) / Marseille, Alicia (Committee member) / Jordan, Amanda (Committee member) / Dean, W.P. Carey School of Business (Contributor) / Morrison School of Agribusiness (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

This study tested the effect of status threat on ingroup identification and examined identity concealability and stereotype endorsement as moderators of the relationship. Participants included a visible identity group (Asian men) and a concealable identity group (gay men). Participants were randomized into either a status threat condition, in which they

This study tested the effect of status threat on ingroup identification and examined identity concealability and stereotype endorsement as moderators of the relationship. Participants included a visible identity group (Asian men) and a concealable identity group (gay men). Participants were randomized into either a status threat condition, in which they read a vignette that reminded them of a negative stereotype about the target group and discussed positive stereotypes of the group as well, or a control condition that discussed positive stereotypes only. Participants then responded to a measure of ingroup identification and a measure of stereotype endorsement. A significant main effect of status threat on ingroup identification was found, such that participants in the status threat condition showed lower ingroup identification. The interaction of condition and concealability was not significant. The interaction of condition and stereotype endorsement was marginally significant, such that the main effect shows up stronger for those lower on stereotype endorsement. The main effect is interpreted as a potential protective strategy for self-esteem. The stereotype threat interaction is interpreted as a difference in the way that those who do and do not endorse the stereotype view the legitimacy of the status threat.

ContributorsWeathers, Shelby E (Author) / Shiota, Michelle (Thesis director) / Kenrick, Douglas (Committee member) / Wiezel, Adi (Committee member) / Department of Psychology (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Watts College of Public Service & Community Solut (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

When earning a teaching certification, there is no curriculum when it comes to the treatment of students with a diagnosis as well as how to educate their fellow classmates. Diagnoses affect the process of child development of the diagnosed as well as the friends and family. Children of all different

When earning a teaching certification, there is no curriculum when it comes to the treatment of students with a diagnosis as well as how to educate their fellow classmates. Diagnoses affect the process of child development of the diagnosed as well as the friends and family. Children of all different ages have different responses and reactions to the world of health. Looking at a developmental perspective, teachers can properly educate themselves and their students about these diagnoses. To be able to successfully inform students of diagnoses, there must be an overall understanding of how well they are able to acquire the knowledge. According to Jean Piaget, a key researcher in cognitive development, the age of the child correlates with their overall understanding and comprehension. In his theory, he explained how he believed that the environment of an organism affects how it will respond and adapt to the situations at hand. There are four stages that are connected to age, from infancy to adolescence and adulthood. Therefore, this project will focus on school-age children who are in the concrete operational stage. The concrete operational stage is made up of elementary and early adolescents and focuses on intelligence that is demonstrated through logical and precise thinking of concrete ideas (Huitt, W., & Hummel, J, 2003). This type of thinking applies to all parts of the child’s life and informs their behaviors on how to “adapt” to new information. Knowing this information, we will be able to create a curriculum of lectures, informational videos, worksheets and quizzes that can properly assess the student’s and their knowledge of the diagnoses.

ContributorsGreer, Rebecca E. (Author) / Visconti, Kari (Thesis director) / Collins, Jena (Committee member) / Sanford School of Social and Family Dynamics (Contributor) / School of Community Resources and Development (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Soccer is bar none, the most popular sport in the entire world. It is played, followed, and loved by virtually every single country on Earth. Despite this massive support for the sport which houses some of the world’s biggest names in the world, its shortcomings when dealing with issues of

Soccer is bar none, the most popular sport in the entire world. It is played, followed, and loved by virtually every single country on Earth. Despite this massive support for the sport which houses some of the world’s biggest names in the world, its shortcomings when dealing with issues of racial injustice and incidents of racist behavior have become more pronounced in recent years. Although this open discussion regarding racism within the sport has recently begun to sprout, its roots can be tied back to decades ago while continuing to the present day, with players, referees, coaches, fans, commentators, and more all involved on both sides of the issue. <br/> We found this topic to be most prevalent in today’s society after witnessing multiple shameful racist incidents that have occurred to some of the world’s biggest players throughout European football in 2019, as well as the recent ongoing fight for racial reform and increased awareness regarding racial injustice in the United States. By doing comprehensive research and analysis on such incidents that have occurred throughout the years we hope to raise more awareness regarding this subject that has plagued the beautiful game. In addition, we hope to offer ways to remedy the problem one step at a time, all while answering the tough, but necessary questions regarding what specifically should be done in the sport, that others have been afraid to talk about for far too long. Specifically, we wanted to mainly highlight the experience of black players, with a further discussion on other minority groups, in English and Italian football as these two leagues have been a part of the largest debate between how club traditions, player-fan interactions, league policies, and staff management have all affected the way we view the game as the endemic of racism within the sport is exacerbated.

ContributorsPaul, Nikhil (Co-author) / Nazareno, Nathan (Co-author) / Jackson, Victoria (Thesis director) / Harrison, Jennifer (Committee member) / School of Life Sciences (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Flora Vita is a digital platform that connects families to outdoor excursions, programmed activities and local events, encouraging the familial ecosystem to flourish within Arizona's vast environment. We curate unique opportunities that allow families to cultivate internal relationships with one another and form relationships with local like-minded families in pursuit

Flora Vita is a digital platform that connects families to outdoor excursions, programmed activities and local events, encouraging the familial ecosystem to flourish within Arizona's vast environment. We curate unique opportunities that allow families to cultivate internal relationships with one another and form relationships with local like-minded families in pursuit of a healthy lifestyle.

ContributorsGarcia, Kate (Co-author) / Plunkett, Nina (Co-author) / Byrne, Jared (Thesis director) / Hall, Rick (Committee member) / Silverstein, Taylor (Committee member) / School of Human Evolution & Social Change (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05