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Description
Constant false alarm rate is one of the essential algorithms in a RADAR detection system. It allows the RADAR system to dynamically set thresholds based on the data power level to distinguish targets with interfering noise and clutters.
To have a better acknowledgment of constant false alarm rate approaches performance, three clutter models, Gamma, Weibull, and Log-normal, have been introduced to evaluate the detection's capability of each constant false alarm rate algorithm.
The order statistical constant false alarm rate approach outperforms other conventional constant false alarm rate methods, especially in clutter evolved environments. However, this method requires high power consumption due to repeat sorting.
In the automotive RADAR system, the computational complexity of algorithms is essential because this system is in real-time. Therefore, the algorithms must be fast and efficient to ensure low power consumption and processing time.
The reduced computational complexity implementations of cell-averaging and order statistic constant false alarm rate were explored. Their big O and processing time has been reduced.
To have a better acknowledgment of constant false alarm rate approaches performance, three clutter models, Gamma, Weibull, and Log-normal, have been introduced to evaluate the detection's capability of each constant false alarm rate algorithm.
The order statistical constant false alarm rate approach outperforms other conventional constant false alarm rate methods, especially in clutter evolved environments. However, this method requires high power consumption due to repeat sorting.
In the automotive RADAR system, the computational complexity of algorithms is essential because this system is in real-time. Therefore, the algorithms must be fast and efficient to ensure low power consumption and processing time.
The reduced computational complexity implementations of cell-averaging and order statistic constant false alarm rate were explored. Their big O and processing time has been reduced.
ContributorsChu, Huiwen (Author) / Bliss, Daniel W. (Thesis advisor) / Alkhateeb, Ahmed (Committee member) / Papandreou-Suppappola, Antonia (Committee member) / Arizona State University (Publisher)
Created2020
Description
Traveling is one of the most enriching and fulfilling activities for most people. Yet factors such as crowded airports, long waiting queues, and inaccessible features of airports and airplanes often make traveling stressful for many individuals including those with disabilities. This qualitative phenomenological research study examined the underexplored area of traveling with a vision disability. Framed around a Co-cultural theoretical perspective, the study examined the lived experiences of vision impaired individuals with regard to receiving disability assistance services during air travel. The study specifically explored the communication strategies that vision impaired individuals employed to manage their assistance-related air travel needs. The study used in-depth interviews for data collection, and a combination of thematic analysis techniques for data analysis. Findings indicated four categories of assistance-related issues that vision impaired participants frequently experienced in their travel: personnel training issues, system issues, policy issues, and physical accessibility issues. The study also identified four Co-cultural communication orientations that participants used in navigating air travel: assertive accommodation, aggressive accommodation, assertive assimilation, and nonassertive assimilation. In addition, the study identified a new Co-cultural communication practice - normalizing for self. Findings of this research conclude that despite three decades since the passage of United States legislation to protect the rights of disabled people, vision impaired travelers still frequently experience inequitable air travel practices. The study offers recommendations on pressing issues concerning policies and regulations that can inform airline executives and federal legislators in facilitating a more equitable and pleasurable air travel experience for those with vision disabilities.
ContributorsBhagchandani, Bhoomika (Author) / Kassing, Jeffrey W. (Thesis advisor) / Broome, Benjamin J. (Committee member) / Zirulnik, Michael L. (Committee member) / Arizona State University (Publisher)
Created2020
Description
Emerging adulthood represents a liminal space between adolescence and adulthood. Attachment with a romantic partner is commonly developed during this time; however, the nature of the dating relationship often remains ambiguous and/or undefined. Dating provides emerging adults the opportunity to develop their romantic competence and navigate these particular attachment relationships. Conflict, and how it is managed, is a critical variable during this time and differentiates between couples who progress in their relationship from those who terminate. What is more, partners may become stuck in destructive cycles, or patterns, of conflict (i.e., demand-withdrawal). Using the theoretical frameworks of attachment theory and emotionally focused couples therapy, this study’s goal it to examine the impact of a brief writing-intervention on relational quality, secure attachment behaviors (i.e., accessibility, responsiveness, and engagement) and attachment dimensions (i.e., anxiety, avoidance). Sixty-seven participants were randomly assigned to one of three conditions for a two-wave study: (1) a treatment condition that was provided an educational presentation regarding couples’ negative cycles of interaction and attachment needs, followed by a guided writing task; (2) a comparison condition that only received the educational presentation; and (3) a control condition that received neither the educational presentation nor the writing task. Hypotheses proposed that participants in the treatment condition would experience increased relational quality, secure attachment behaviors (for both themselves and their partner), and greater secure attachment (i.e., decreased anxiety and avoidance) across time compared to the comparison and control conditions. Data did not support the hypotheses. These findings offer important implications for the development of future brief couples’ interventions and aim to generate future research.
ContributorsTruscelli, Nikki Irene (Author) / Mongeau, Paul (Thesis advisor) / Guerrero, Laura K. (Committee member) / Randall, Ashley K. (Committee member) / Arizona State University (Publisher)
Created2020
Description
On June 12, 2016, Omar Mateen entered Pulse Nightclub in Orlando, FL and shot and murdered 49 people and wounded over 50 more. At the time, it was the deadliest mass shooting ever to occur on U.S. soil. That particular evening, Pulse, a queer nightclub, was hosting a “Latin Night,” which resulted in over 90 percent of the victims being Latinx in descent and many that identified as Afro-Latinx or Black. Essentially, Pulse is the most lethal act of violence against queer and trans bodies of color in this country. Pulse reminds queer and trans people of color of the conditions of the world that position Brown and Black queer and trans death as mundane. That is to say, the lives of trans and queer bodies of color are lived in close proximity to death. And yet, Pulse was anything but mundane. In every practical sense, it was a fantastical event of radical violence. The tension between these and the implications found within is what this project seeks to engage. Utilizing critical/performance-based qualitative methods and data derived from the queer and trans of color communities in Phoenix, AZ, this project investigates the performative afterlife of Pulse. I apply and name the term performative afterlife to suggest that the events at Pulse are connected to material conditions and consequences that get performed by and through queer and trans bodies of color. Interlocutors share the afterlife is performed within the context of ubiquitous whiteness found in Phoenix, often manifesting as a survival mechanism. Additionally, many interlocutors express the mundane threat of violence everyday has prevented a thorough engagement of what it means to live in a world after the events at Pulse nightclub have occurred. Ultimately, the performative afterlife of Pulse gets performed by queer and trans bodies of color in Phoenix through a co-performance between one another. Much like the dancing that occurred at Pulse, the performative afterlife is a performance that moves the world towards queer or color futures not yet here.
ContributorsTristano, Michael (Author) / Brouwer, Daniel (Thesis advisor) / Bailey, Marlon (Committee member) / Danielson, Marivel (Committee member) / LeMaster, Benny (Committee member) / Arizona State University (Publisher)
Created2020
Description
There is tremendous value in bringing fresh voices and perspectives to theory and practice, as it is through these novel lenses that research advances in rich and more equitable ways. However, the importance of first-generation college students being involved in this process has been vastly underestimated and undervalued by researchers and practitioners alike. Extrapolating from interdisciplinary research on counterstorytelling and networked counterpublics, the aim of this study was to explore how the proposed theoretical model of networked counterstorytelling—as presented through a grassroots digital storytelling campaign—could create space for first-generation student voice and leadership to help inform current theoretical understandings of social capital and community cultural wealth. Using a multimethodological approach—combining large-scale network analytics with qualitative netnographic analysis (Kozinets, 2015)—this study (1) produced novel methods for measuring and analyzing social capital within social media communities and (2) demonstrated how grassroots digital storytelling campaigns, facilitated by the affordances of social media platforms such as Instagram, can function as means for inviting the leadership, voice, and perspectives of first-generation college students into the design of higher education research and practice.
ContributorsJohns, Kristi (Author) / Bertrand, Melanie (Thesis advisor) / Dippold, Lindsey (Committee member) / Foucault Welles, Brooke (Committee member) / Arizona State University (Publisher)
Created2020
Description
Coronaviruses are the causative agents of SARS, MERS and the ongoing COVID-19 pandemic. Coronavirus envelope proteins have received increasing attention as drug targets, due to their multiple functional roles during the infection cycle. The murine coronavirus mouse hepatitis virus strain A59, a hepatic and neuronal tropic coronavirus, is considered a prototype of the betacoronaviruses. The envelope protein of the mouse hepatitis virus (MHV-E) was extensively screened with various membrane mimetics by solution state nuclear magnetic resonance spectroscopy to find a suitable mimetic, which allowed for assignment of ~97% of the backbone atoms in the transmembrane region. Following resonance assignments, the binding site of the ion channel inhibitor hexamethylene amiloride (HMA) was mapped to MHV-E using chemical shift perturbations in both amide and aromatic transverse relaxation optimized spectroscopy (TROSY) spectra, which indicated the inhibitor binding site is located at the N-terminal opening of the channel, in accord with one of the proposed HMA binding sites in the envelope protein from the related SARS (severe acute respiratory syndrome) betacoronavirus. Structure calculation of residues M1-K38 of MHV-E, encompassing the transmembrane region, is currently in progress using dihedral angle restraints obtained from isotropic chemical shifts and distance restraints obtained from manually assigned NOE cross-peaks, with the ultimate aim of generating a model of the MHV-E viroporin bound to the inhibitor HMA. This work outlines the first NMR studies on MHV-E, which have provided a foundation for structure based drug design and probing interactions, and the methods can be extended, with suitable modifications, to other coronavirus envelope proteins.
ContributorsBaravati, Bobby (Author) / Fromme, Petra (Thesis advisor) / Hansen, Debra (Thesis advisor) / Van Horn, Wade (Committee member) / Wang, Xu (Committee member) / Arizona State University (Publisher)
Created2020
Description
This thesis project explores the nature of power dynamics in the dialogue of video gamers within designated online forums of discussion. Previous scholarly work has noted the lack of diverse representation and tolerance in the gaming community, despite statistics revealing that the video game community is not as homogeneous as it is often represented. Specifically, the prominent literature analyzing gaming culture focuses on poor representations of gender within video games and the gaming community itself, including sexualized and objectified depictions of women as well as prejudice toward women as members of the gaming community. More recent entries to the field of research draws attention to the experiences of other marginalized communities in gaming. This thesis, then, begs the question – what power dynamics emerge in the dialogue of people who consider themselves to be gamers? How are concepts of social identity expressed or constructed in communication, and what reinforces and legitimizes these relationships? This project will review a foundation of literature structuring the framework of this project, propose methodology for data collection and analysis, and explore themes discovered within the data analysis, which support or negate existing research and give insight to the proposed research questions.
ContributorsFitzgerald, Karina Marie (Author) / Nadesan, Majia (Thesis advisor) / Gray, Kishonna L. (Committee member) / Walker, Michael (Committee member) / Arizona State University (Publisher)
Created2020
Description
Despite the prevalence of teams in complex sociotechnical systems, current approaches to understanding workload tend to focus on the individual operator. However, research suggests that team workload has emergent properties and is not necessarily equivalent to the aggregate of individual workload. Assessment of communications provides a means of examining aspects of team workload in highly interdependent teams. This thesis set out to explore how communications are associated with team workload and performance under high task demand in all-human and human–autonomy teams in a command and control task. A social network analysis approach was used to analyze the communications of 30 different teams, each with three members operating in a command and control task environment of over a series of five missions. Teams were assigned to conditions differentiated by their composition with either a naïve participant, a trained confederate, or a synthetic agent in the pilot role. Social network analysis measures of centralization and intensity were used to assess differences in communications between team types and under different levels of demand, and relationships between communication measures, performance, and workload distributions were also examined. Results indicated that indegree centralization was greater in the all-human control teams than in the other team types, but degree centrality standard deviation and intensity were greatest in teams with a highly trained experimenter pilot. In all three team types, the intensity of communications and degree centrality standard deviation appeared to decrease during the high demand mission, but indegree and outdegree centralization did not. Higher communication intensity was associated with more efficient target processing and more successful target photos per mission, but a clear relationship between measures of performance and decentralization of communications was not found.
ContributorsJohnson, Craig Jonathon (Author) / Cooke, Nancy J. (Thesis advisor) / Gray, Robert (Committee member) / Gutzwiller, Robert S (Committee member) / Arizona State University (Publisher)
Created2020
Description
Oxidoreductases catalyze transformations important in both bioenergetics and microbial technologies. Nonetheless, questions remain about how to tune them to modulate properties such as preference for catalysis in the oxidative or reductive direction, the potential range of activity, or coupling of multiple reactions. Using protein film electrochemistry, the features that control these properties are defined by comparing the activities of five [FeFe]-hydrogenases and two thiosulfate reductases. Although [FeFe]-hydrogenases are largely described as hydrogen evolution catalysts, the catalytic bias of [FeFe]-hydrogenases, i.e. the ratio of maximal reductive to oxidative activities, spans more than six orders of magnitude. At one extreme, two [FeFe]-hdyrogenases, Clostridium pasteuriaunum HydAII and Clostridium symbiosum HydY, are far more active for hydrogen oxidation than hydrogen evolution. On the other extreme, Clostridium pasteurianum HydAI and Clostridium acetobutylicum HydA1 have a neutral bias, in which both proton reduction and hydrogen oxidation are efficient. By investigating a collection of site-directed mutants, it is shown that the catalytic bias of [FeFe]-hydrogenases is not trivially correlated with the identities of residues in the primary or secondary coordination sphere. On the other hand, the catalytic bias of Clostridium acetobutylicum HydAI can be modulated via mutation of an amino acid residue coordinating the terminal [FeS] cluster. Simulations suggest that this change in catalytic bias may be linked to the reduction potential of the cluster.
Two of the enzymes examined in this work, Clostridium pasteurianum HydAIII and Clostridium symbiosum HydY, display novel catalytic properties. HydY is exclusively a hydrogen oxidizing catalyst, and it couples this activity to peroxide reduction activity at a rubrerythrin center in the same enzyme. On the other hand, CpIII operates only in a narrow potential window, inactivating at oxidizing potentials. This suggests it plays a novel physiological role that has not yet been identified. Finally, the electrocatalytic properties of Pyrobaculum aerophilum thiosulfate reductase with either Mo or W in the active site are compared. In both cases, the onset of catalysis corresponds to reduction of the active site. Overall, the Mo enzyme is more active, and reduces thiosulfate with less overpotential.
Two of the enzymes examined in this work, Clostridium pasteurianum HydAIII and Clostridium symbiosum HydY, display novel catalytic properties. HydY is exclusively a hydrogen oxidizing catalyst, and it couples this activity to peroxide reduction activity at a rubrerythrin center in the same enzyme. On the other hand, CpIII operates only in a narrow potential window, inactivating at oxidizing potentials. This suggests it plays a novel physiological role that has not yet been identified. Finally, the electrocatalytic properties of Pyrobaculum aerophilum thiosulfate reductase with either Mo or W in the active site are compared. In both cases, the onset of catalysis corresponds to reduction of the active site. Overall, the Mo enzyme is more active, and reduces thiosulfate with less overpotential.
ContributorsWilliams, Samuel Garrett (Author) / Jones, Anne K (Thesis advisor) / Hayes, Mark A. (Committee member) / Trovitch, Ryan J (Committee member) / Arizona State University (Publisher)
Created2020
Description
Organic compounds are influenced by hydrothermal conditions in both marine and terrestrial environments. Sedimentary organic reservoirs make up the largest share of organic carbon in the carbon cycle, leading to petroleum generation and to chemoautotrophic microbial communities. There have been numerous studies on the reactivity of organic compounds in water at elevated temperatures, but these studies rarely explore the consequences of inorganic solutes in hydrothermal fluids. The experiments in this thesis explore new reaction pathways of organic compounds mediated by aqueous and solid phase metals, mainly Earth-abundant copper. These experiments show that copper species have the potential to oxidize benzene and toluene, which are typically viewed as unreactive. These pathways add to the growing list of known organic transformations that are possible in natural hydrothermal systems. In addition to the characterization of reactions in natural systems, there has been recent interest in using hydrothermal conditions to facilitate organic transformations that would be useful in an applied, industrial or synthetic setting. This thesis identifies two sets of conditions that may serve as alternatives to commonplace industrial processes. The first process is the oxidation of benzene with copper to form phenol and chlorobenzene. The second is the copper mediated dehalogenation of aryl halides. Both of these processes apply the concepts of geomimicry by carrying out organic reactions under Earth-like conditions. Only water and copper are needed to implement these processes and there is no need for exotic catalysts or toxic reagents.
ContributorsLoescher, Grant (Author) / Shock, Everett (Thesis advisor) / Hartnett, Hilairy (Committee member) / Gould, Ian (Committee member) / Arizona State University (Publisher)
Created2020