Matching Items (377)
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Dynamic loading is the term used for one way of optimally loading a transformer. Dynamic loading means the utility takes into account the thermal time constant of the transformer along with the cooling mode transitions, loading profile and ambient temperature when determining the time-varying loading capability of a transformer. Knowing

Dynamic loading is the term used for one way of optimally loading a transformer. Dynamic loading means the utility takes into account the thermal time constant of the transformer along with the cooling mode transitions, loading profile and ambient temperature when determining the time-varying loading capability of a transformer. Knowing the maximum dynamic loading rating can increase utilization of the transformer while not reducing life-expectancy, delaying the replacement of the transformer. This document presents the progress on the transformer dynamic loading project sponsored by Salt River Project (SRP). A software application which performs dynamic loading for substation distribution transformers with appropriate transformer thermal models is developed in this project. Two kinds of thermal hottest-spot temperature (HST) and top-oil temperature (TOT) models that will be used in the application--the ASU HST/TOT models and the ANSI models--are presented. Brief validations of the ASU models are presented, showing that the ASU models are accurate in simulating the thermal processes of the transformers. For this production grade application, both the ANSI and the ASU models are built and tested to select the most appropriate models to be used in the dynamic loading calculations. An existing application to build and select the TOT model was used as a starting point for the enhancements developed in this work. These enhancements include:  Adding the ability to develop HST models to the existing application,  Adding metrics to evaluate the models accuracy and selecting which model will be used in dynamic loading calculation  Adding the capability to perform dynamic loading calculations,  Production of a maximum dynamic load profile that the transformer can tolerate without acceleration of the insulation aging,  Provide suitable output (plots and text) for the results of the dynamic loading calculation. Other challenges discussed include: modification to the input data format, data-quality control, cooling mode estimation. Efforts to overcome these challenges are discussed in this work.
ContributorsLiu, Yi (Author) / Tylavksy, Daniel J (Thesis advisor) / Karady, George G. (Committee member) / Ayyanar, Raja (Committee member) / Arizona State University (Publisher)
Created2011
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The development of a Solid State Transformer (SST) that incorporates a DC-DC multiport converter to integrate both photovoltaic (PV) power generation and battery energy storage is presented in this dissertation. The DC-DC stage is based on a quad-active-bridge (QAB) converter which not only provides isolation for the load, but also

The development of a Solid State Transformer (SST) that incorporates a DC-DC multiport converter to integrate both photovoltaic (PV) power generation and battery energy storage is presented in this dissertation. The DC-DC stage is based on a quad-active-bridge (QAB) converter which not only provides isolation for the load, but also for the PV and storage. The AC-DC stage is implemented with a pulse-width-modulated (PWM) single phase rectifier. A unified gyrator-based average model is developed for a general multi-active-bridge (MAB) converter controlled through phase-shift modulation (PSM). Expressions to determine the power rating of the MAB ports are also derived. The developed gyrator-based average model is applied to the QAB converter for faster simulations of the proposed SST during the control design process as well for deriving the state-space representation of the plant. Both linear quadratic regulator (LQR) and single-input-single-output (SISO) types of controllers are designed for the DC-DC stage. A novel technique that complements the SISO controller by taking into account the cross-coupling characteristics of the QAB converter is also presented herein. Cascaded SISO controllers are designed for the AC-DC stage. The QAB demanded power is calculated at the QAB controls and then fed into the rectifier controls in order to minimize the effect of the interaction between the two SST stages. The dynamic performance of the designed control loops based on the proposed control strategies are verified through extensive simulation of the SST average and switching models. The experimental results presented herein show that the transient responses for each control strategy match those from the simulations results thus validating them.
ContributorsFalcones, Sixifo Daniel (Author) / Ayyanar, Raja (Thesis advisor) / Karady, George G. (Committee member) / Tylavsky, Daniel (Committee member) / Tsakalis, Konstantinos (Committee member) / Arizona State University (Publisher)
Created2011
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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
Description

Many nanotechnology-related principles can be demonstrated in a way that is understandable for elementary school-aged children through at-home activity videos. As a part of a National Science Foundation funded grant, Dr. Qing Hua Wang’s research group at Arizona State University developed a nanotechnology-related activity website, Nano@Home, for students. In conjunction

Many nanotechnology-related principles can be demonstrated in a way that is understandable for elementary school-aged children through at-home activity videos. As a part of a National Science Foundation funded grant, Dr. Qing Hua Wang’s research group at Arizona State University developed a nanotechnology-related activity website, Nano@Home, for students. In conjunction with ASU’s virtual Open Door 2021, this creative project aimed to create activity videos based on the Nano@Home website to make the activities more interactive for students.

ContributorsOliver, Ruth Kaylyn (Author) / Wang, Qing Hua (Thesis director) / Krause, Stephen (Committee member) / Materials Science and Engineering Program (Contributor, Contributor) / Watts College of Public Service & Community Solut (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Supported catalytic nanoparticles undergo rapid structural transformations faster than many transmission electron microscopes (TEMs) can track. This is the case with platinum nanoparticles supported on cerium oxide (Pt/CeO2) in a CO and O2 gaseous environment. By furthering our understanding of the structural dynamics of the Pt/CeO2 system, improved catalyst design

Supported catalytic nanoparticles undergo rapid structural transformations faster than many transmission electron microscopes (TEMs) can track. This is the case with platinum nanoparticles supported on cerium oxide (Pt/CeO2) in a CO and O2 gaseous environment. By furthering our understanding of the structural dynamics of the Pt/CeO2 system, improved catalyst design principles may be derived to enhance the efficiency of this catalyst. Developing static models of a 2 nm Pt nanoparticle supported on CeO2 and simulating TEM images of the models was found to create similar images to those seen in experimental TEM time-resolved series of the system. Rotations of static models on a ceria support provides a way to understand the experimental samples in three dimensions, which is difficult in two dimensional TEM images. This project expands the possibilities of interpreting TEM images of catalytic systems.

ContributorsBlock, Claire (Author) / Crozier, Peter (Thesis director) / Muhich, Christopher (Committee member) / Materials Science and Engineering Program (Contributor, Contributor) / Watts College of Public Service & Community Solut (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Fire is a naturally-occurring disruptive ecological force that is an essential part of certain ecosystems, and has historically been a tool used by indigenous fire stewards to maintain the health of the land. In the past century, fire has been severely suppressed throughout many areas of the Western United States

Fire is a naturally-occurring disruptive ecological force that is an essential part of certain ecosystems, and has historically been a tool used by indigenous fire stewards to maintain the health of the land. In the past century, fire has been severely suppressed throughout many areas of the Western United States as Western colonization and the suppression of native traditional ecological knowledge took place, causing a severe decline in ecosystem health and the accumulation of flammable vegetation, which has more recently contributed towards a frequency of catastrophic, high-intensity wildfires. Current fire management challenges include balancing social and ecological perspectives. In Colorado and other areas of the country, community wildfire protection plans (CWPP) are evolving as a means to involve a variety of community stakeholders in fire management decisions. Using Colorado CWPP boundaries as a social management unit and endangered species ranges as an ecological management unit, I analyzed the spatial overlap of these different factors. Since each CWPP has its own fire management policies, I drew implications from the results for which important factors different CWPPs should consider.

ContributorsAzuma, Erin (Author) / Kroetz, Kailin (Thesis director) / Iacona, Gwen (Committee member) / Hamilton, Matthew (Committee member) / School of Life Sciences (Contributor) / Watts College of Public Service & Community Solut (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Thunderbird School of Global Management (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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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
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Music has consistently been documented as a manner to bring people together across cultures throughout the world. In this research, we propose that people use similar musical taste as a strong sign of potential social connection. To investigate this notion, we draw on literature examining how music merges the public/private

Music has consistently been documented as a manner to bring people together across cultures throughout the world. In this research, we propose that people use similar musical taste as a strong sign of potential social connection. To investigate this notion, we draw on literature examining how music merges the public/private self, the link to personality, and group identity, as well as how it is linked to romantic relationships. Thus, music can be a tool when wanting to get to know someone else and/or forge a platonic relationship. To test this hypothesis, we designed an experiment comparing music relative to another commonality (sharing a sports team in common) to see which factor is stronger in triggering an online social connection. We argue that people believe they have more in common with someone who shares similar music taste compared to other commonalities. We discuss implications for marketers on music streaming platforms.

ContributorsDrambarean, Julianna Rose (Co-author) / Simmons, Logan (Co-author) / Samper, Adriana (Thesis director) / Martin, Nathan (Committee member) / Department of Marketing (Contributor) / Watts College of Public Service & Community Solut (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

A journalistic, first-person narrative going through the lessons learned from travel. The story is complemented by a series of photos from childhood to the present all uploaded to a Wix-based website.

Created2021-05
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As political campaigning becomes increasingly digital and data-driven, data privacy has become a question of democratic governance. Yet, Congress has yet to pass a comprehensive federal data privacy law and even the strongest subnational data privacy laws exempt political campaigns from regulation. <br/><br/>This thesis examines how data privacy laws impact

As political campaigning becomes increasingly digital and data-driven, data privacy has become a question of democratic governance. Yet, Congress has yet to pass a comprehensive federal data privacy law and even the strongest subnational data privacy laws exempt political campaigns from regulation. <br/><br/>This thesis examines how data privacy laws impact data-driven and digital political campaigning. Specifically, it investigates what information is incorporated into the political data ecosystem, how data privacy laws regulate the collection of this data, and how actors in the political data ecosystem respond to these laws. It examines both sector-specific federal law and subnational data protection regulation through a case study of California. This research suggests that although the California Consumer Privacy Act and California Privacy Rights Act are landmark steps in American data protection, subnational data privacy law remains inhibited by the federal market-based approach.

ContributorsScovil, Daiva Julija (Author) / Gary, Marchant (Thesis director) / K, Royal (Committee member) / Historical, Philosophical & Religious Studies (Contributor, Contributor) / School of Politics and Global Studies (Contributor, Contributor) / Historical, Philosophical & Religious Studies, Sch (Contributor, Contributor) / Watts College of Public Service & Community Solut (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05