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- Genre: Masters Thesis
- Genre: Music--Instruction and study--Social aspects--Venezuela.
- Creators: Arizona State University
Description
The broad deployment of time-synchronized continuous point-on-wave (CPoW) modules will enable electric power utilities to gain unprecedented insight into the behavior of their power system assets, loads, and distributed renewable generation in real time. By increasing the available level of detail visible to operators, serious fault events such as wildfire-inducing arc flashes, safety-jeopardizing transformer failures, and equipment-damaging power quality decline can be mitigated in a data-driven, systematic manner. In this research project, a time-synchronized micro-scale CPoW module was designed, constructed, and characterized. This inductively powered CPoW module, which operates wirelessly by using the current flowing through a typical distribution conductor as its power source and a wireless data link for communication, has been configured to measure instantaneous line current at high frequency (nominally 3,000 samples per second) with 12-bit resolution. The design process for this module is detailed in this study, including background research, individual block design and testing, printed circuit board (PCB) design, and final characterization of the system.
To validate the performance of this module, tests of power requirements, measurement accuracy, battery life, susceptibility to electromagnetic interference, and fault detection performance were performed. The results indicate that the design under investigation will satisfy the technical and physical constraints required for bulk deployment in an actual distribution network after manufacturing optimizations. After the test results were summarized, the future research and development activities needed to finalize this design for commercial deployment were identified and discussed.
ContributorsPatterson, John (Author) / Pal, Anamitra (Thesis advisor) / Ogras, Umit (Committee member) / Ayyanar, Raja (Committee member) / Arizona State University (Publisher)
Created2021
Description
Contaminated aerosols and micro droplets are easily generated by infected hosts through sneezing, coughing, speaking and breathing1-3 and harm humans’ health and the global economy. While most of the efforts are usually targeted towards protecting individuals from getting infected,4 eliminating transmissions from infection sources is also important to prevent disease transmission. Supportive therapies for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) pneumonia such as oxygen supplementation, nebulizers and non-invasive mechanical ventilation all carry an increased risk for viral transmission via aerosol to healthcare workers.5-9 In this work, I study the efficacy of five methods for self-containing aerosols emitted from infected subjects undergoing nebulization therapies with a diverse spectrum on Non-Invasive Positive Pressure Ventilator (NIPPV) with oxygen delivery therapies. The work includes five study cases: Case I: Use of a Full-Face Mask with biofilter in bilevel positive airway pressure device (BiPAP) therapy, Case II: Use of surgical mask in High Flow Nasal Cannula (HFNC) therapy, Case III: Use of a modified silicone disposable mask in a HFNC therapy, Case IV: Use of a modified silicone disposable mask with a regular nebulizer and normal breathing, Case V: Use of a mitigation box with biofilter in a BiPAP. We demonstrate that while cases I, III and IV showed efficacies of 98-100%; cases II and V, which are the most commonly used, resulted with significantly lower efficacies of 10-24% to mitigate the dispersion of nebulization aerosols. Therefore, implementing cases I, III and IV in health care facilities may help battle the contaminations and infections via aerosol transmission during a pandemic.
ContributorsShyamala Pandian, Adithya (Author) / Forzani, Erica (Thesis advisor) / Patel, Bhavesh (Committee member) / Xian, Xiaojun (Committee member) / Arizona State University (Publisher)
Created2021
Description
Given the severity of risks that accompany the current COVID-19 pandemic, many are experiencing negative psychological effects, such as increased symptoms of depression and anxiety (i.e., mental health distress). As the COVID-19 pandemic continues to impress upon society, it is pertinent to assess the ways in which COVID-19 may be impacting first responders; many of which who are responsible for tending to the safety and wellbeing of communities during this time. However, little is known about how medical first responders may be experiencing COVID-19 related stress, whether this impacts their experience with symptoms of mental health distress, and furthermore whether this stress is different for those in different countries. As such, the present study sought to assess the association between COVID-19 related stress and symptoms of mental health distress in medical first responders for those living in Australia and the United States. Further, given the positive effects romantic relationships have on an individual’s interpersonal functioning, the potential moderating effect of perceived relationship commitment was examined. A total number of 79 participants completed the study. Contrary to hypotheses, results showed that there was no significant association between COVID-19 related stress and symptoms of distress, nor was relationship commitment found to moderate symptoms of distress. Implications of this study have the potential to guide mental health professionals working with medical first responders who are experiencing symptoms of distress, particularly in times of crises similar to that of COVID-19.
ContributorsEvers, Jessie Marie (Author) / Randall, Ashley K. (Thesis advisor) / Pereira, Jennifer (Committee member) / Warner, Cheryl (Committee member) / Arizona State University (Publisher)
Created2021
Description
In combinatorial mathematics, a Steiner system is a type of block design. A Steiner triple system is a special case of Steiner system where all blocks contain 3 elements and each pair of points occurs in exactly one block. Independent sets in Steiner triple systems is the topic which is discussed in this thesis. Some properties related to independent sets in Steiner triple system are provided. The distribution of sizes of maximum independent sets of Steiner triple systems of specific order is also discussed in this thesis. An algorithm for constructing a Steiner triple system with maximum independent set whose size is restricted with a lower bound is provided. An alternative way to construct a Steiner triple system using an affine plane is also presented. A modified greedy algorithm for finding a maximal independent set in a Steiner triple system and a post-optimization method for improving the results yielded by this algorithm are established.
ContributorsWang, Zhaomeng (Author) / Colbourn, Charles (Thesis advisor) / Richa, Andrea (Committee member) / Jiang, Zilin (Committee member) / Arizona State University (Publisher)
Created2021
Description
In videos that contain actions performed unintentionally, agents do not achieve their desired goals. In such videos, it is challenging for computer vision systems to understand high-level concepts such as goal-directed behavior. On the other hand, from a very early age, humans are able to understand the relation between an agent and their ultimate goal even if the action gets disrupted or unintentional effects occur. Inculcating this ability in artificially intelligent agents would make them better social learners by not just learning from their own mistakes, i.e, reinforcement learning, but also learning from other's mistakes. For example, this could greatly reduce the search space for artificially intelligent agents for finding the correct action sequence when trying to achieve a new goal, since they would be able to learn from others what not to do as well as how/when actions result in undesired outcomes.To validate this ability of deep learning models to perform this task, the Weakly Augmented Oops (W-Oops) dataset is proposed, built upon the Oops dataset. W-Oops consists of 2,100 unintentional human action videos, with 44 goal-directed and 33 unintentional video-level activity labels collected through human annotations.
Inspired by previous methods on tasks such as weakly supervised action localization which show promise for achieving good localization results without ground truth segment annotations, this paper proposes a weakly supervised algorithm for localizing the goal-directed as well as the unintentional temporal region of a video using only video-level labels. In particular, an attention mechanism based strategy is employed that predicts the temporal regions which contributes the most to a classification task, leveraging solely video-level labels. Meanwhile, our designed overlap regularization allows the model to focus on distinct portions of the video for inferring the goal-directed and unintentional activity, while guaranteeing their temporal ordering. Extensive quantitative experiments verify the validity of our localization method.
ContributorsChakravarthy, Arnav (Author) / Yang, Yezhou (Thesis advisor) / Davulcu, Hasan (Committee member) / Pavlic, Theodore (Committee member) / Arizona State University (Publisher)
Created2021
Description
This research aims to investigate the material properties of various silver-doped germanium-chalcogenide thin films that novel lateral Programmable Metallization Cell (PMC) devices are based on. These devices are governed by a solid-state electrochemical reaction that is controlled electrically occurring at the micro and nanoscale.By using various electrical and optical characterization techniques, useful material characteristics such as the activation energy of electrodeposit growth rate and bandgap energy can be extracted. These parameters allow for better tuning of these materials for more specific PMC device applications, such as a timer that can be placed into integrated circuits for metering and anticounterfeiting purposes.
The compositions of focus are silver-doped germanium-selenide and germanium-sulfide variations; overall, the bandgap energy of these materials decreases as silver content is increased, the activation energy tends to be smaller in sulfide-based devices, and chalcogenides highly doped with silver exhibit nanocluster migration growth modes due to the agglomeration of silver clusters in the film.
ContributorsRicks, Amberly (Author) / Gonzalez Velo, Yago (Thesis advisor) / Kozicki, Michael N. (Thesis advisor) / Holman, Zachary (Committee member) / Arizona State University (Publisher)
Created2021
Description
This study focuses on the properties of binaural beats (BBs) compared to Monaural beats (MBs) and their steady-state response at the level of the Superior Olivary Complex (SOC). An auditory nerve stimulator was used to simulate the response of the SOC. The simulator was fed either BBs or MBs stimuli to compare the SOC response. This was done for different frequencies at twenty, forty, and sixty hertz for comparison of the SOC response envelopes. A correlation between the SOC response envelopes for both types of beats and the waveform resulting from adding two tones together was completed. The highest correlation for BBs was found to be forty hertz and for MBs it was sixty hertz. A Fast Fourier Transform (FFT) was also completed on the stimulus envelope and the SOC response envelopes. The FFT was able to show that within the BBs presentation the envelopes of the original stimuli showed no difference frequency. However, the difference frequency was present in the binaural SOC response envelope. For the MBs, the difference frequency was present within the stimulus and the monaural SOC response envelope.
ContributorsCrawford, Taylor Janay (Author) / Brewer, Gene (Thesis advisor) / Zhou, Yi (Committee member) / Azuma, Tamiko (Committee member) / Arizona State University (Publisher)
Created2021
The Center-Level Predictors of Non CACFP and CACFP Participation in Arizona: A Cross-Sectional Study
Description
Background: The Child and Adult Care Food Program (CACFP), as a federal nutrition assistance program, provides guidance and financial support to early childcare education centers (ECECs) who provide nutritious foods to children in care. Understanding factors that predict participating in CACFP is necessary to expanding CACFP reach. The purpose of this study was to assess center-level predictors of ECECs participating in CACFP in Arizona to guide state-wide recruitment efforts. Methods: This study analyzed data from ECECs in Arizona in 2020 (n=2228), sourcing data from the Arizona Department of Economic Services (Quality First rating (an Arizona-based score for quality of the ECE centers), accreditation Status, highest educational attainment, enrichment center status, and total licensed capacity), Arizona Department of Education (CACFP), Arizona Department of Health and Sanitation (SNAP-Ed participation), and the US Census. Logistic regression was used to examine the association between the predictors and participating in CACFP, adjusting for SNAP-Ed eligibility by census tract.
Results: Centers had a significantly greater odds of participating in CACFP if they were an enrichment site (OR=5.9; 95% CI: 4.6, 7.5), had a Quality First rating (OR=2.5; 95% CI: 2.0, 3.0), and when the highest educational attainment by staff was a bachelor’s degree or higher (OR=1.4; 95% CI: 1.1, 1.7).
Discussion: The findings support indicate that certain modifiable center-level factors were related to participation in CACFP. Findings may assist possible linkages with other state-level programs to improve the recruitment and retention of ECE centers to CACFP.
ContributorsNarramore, Kala R (Author) / Bruening, Meg (Thesis advisor) / Raczynski, Erin (Committee member) / McCoy, Maureen (Committee member) / Arizona State University (Publisher)
Created2021
Description
Previous work indicates that structural changes in the right hemisphere following left hemisphere stroke may be related to language abilities. However, the mechanisms behind this relationship remain unclear, particularly regarding the relative contributions of gray and white matter. The present study examined how structural and diffusion measures in the right hemisphere differ between chronic left hemisphere stroke survivors and matched control subjects, and the relationships between language and cognition measures and these right hemisphere measures. T1-weighted MRI, diffusion tensor images (DTI), and a battery of cognitive tests were obtained from 27 chronic left hemisphere stroke survivors and 44 neurologically intact matched control participants. Cortical and volumetric measures of gray and white matter in regions of interest were obtained from the T1 images and compared between groups, and correlated with behavioral measures. Tract-Based Spatial Statistics and tractography methods from the DTI were examined in a similar manner. The T1 MRI-based analyses revealed that the stroke survivors did not differ from the control group in any of the gray or white matter volume measurements. The cortical thickness and mean curvature analyses identified right lateral frontal and insular ROIs exhibiting thinner and greater curvature (an indication of atrophy) in the left hemisphere stroke survivors compared to controls. The DTI-based results showed that the stroke survivors had lower fractional anisotropy and fewer reconstructed fibers in the right language ventral-stream tracts. Regarding correlations between the right hemisphere measures and behavioral performance, there were no significant results within the DTI data, and only one significant result in the gray matter analyses: faster processing speed was correlated with greater cortical thickness in the right frontal cortex in chronic left hemisphere stroke survivors. Overall, the present study provides support for the idea that the right hemisphere exhibits post-stroke changes, particularly in right dorsal stream gray matter and the ventral stream’s white matter, and that these differences are not captured by T1-imaging alone; in fact, the DTI tract-specific analyses were perhaps the most revealing. Future studies are needed, perhaps incorporating functional neuroimaging, to elucidate how these right hemisphere differences in left hemisphere stroke survivors is related to language recovery.
ContributorsHsueh, Yi-Ting (Author) / Reddy, Corianne (Thesis advisor) / Braden, Brittany (Committee member) / Schaefer, Sydney (Committee member) / Arizona State University (Publisher)
Created2021
Description
The Transonic Area Rule, developed by Richard T. Whitcomb in the early 1950s, revolutionized high-speed flight because its insight allowed engineers to reduce and/or delay the transonic drag rise. To this day, it is the rationale behind “coke-bottle” sculpturing (indenting the aircraft fuselage at the wing-fuselage junction) to alter the cross-sectional area development of the body. According to Whitcomb, this indentation is meant to create a smoother transition of cross-sectional area development of the body and consequently would reduce the number of shocks on the body, their intensity, and their shock pattern complexity. Along with this, modeling of a geometry’s transonic drag rise could be simplified by creating a comparable body of revolution with the same cross-sectional area development as the original geometry. Thus, the Transonic Area Rule has been advertised as an aerodynamic multitool. This new work probes the underlying mechanics of the Transonic Area Rule and determines just how accurate it is in producing its advertised results. To accomplish this, several different wave-drag approximation methods were used to replicate and compare the results presented in Whitcomb’s famous 1952 report16. These methods include EDET (Empirical Drag Estimation Technique)4, D2500 (Harris Wave Drag program)6, and CFD (Computational Fluid Dynamics) analysis through SU25. Overall drag increment data was collected for comparison with Whitcomb’s data. More in-depth analysis was then done on the flow conditions around the geometries using CFD solution plots.
After analysis of the collected data was performed, it was discovered that this data argued against Whitcomb’s comparable body of revolution claim as no cases were demonstrated where the comparable body and original body yielded similar drag rise characteristics. Along with this, shock structures and patterns were not simplified in two of the three cases observed and were instead complicated even further. The only exception to this observation was the swept wing, cylindrical body in which all shocks were virtually eliminated at all observed Mach numbers. For the reduced transonic drag rise claim, the data argued in favor of this as the drag rise was indeed reduced for the three observed geometries, but only for a limited Mach number range.
ContributorsArmenta, Francisco Xavier (Author) / Takahashi, Timothy T (Thesis advisor) / Kim, Jeonglae (Committee member) / Rodi, Patrick (Committee member) / Arizona State University (Publisher)
Created2021