Matching Items (481)
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Description
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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Description
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

This thesis will bring together students to engage in entrepreneurship by finding, measuring and sharing strategic market opportunities. From a student’s perspective, it will take a deep dive into the world of startup ecosystems, markets and trends utilizing both qualitative and quantitative market research techniques. The information gathered has been

This thesis will bring together students to engage in entrepreneurship by finding, measuring and sharing strategic market opportunities. From a student’s perspective, it will take a deep dive into the world of startup ecosystems, markets and trends utilizing both qualitative and quantitative market research techniques. The information gathered has been curated into a productive, meaningful manner, through a report titled “The State of Startups: A Student Perspective.” <br/> The first key theme of this thesis is that market intelligence can be a powerful tool. The second key theme is the power of knowledge implementation towards competitive strategies. The first section of the thesis will focus on identifying and understanding the current “startup” landscape as a basis on which to build strategic and impactful business decisions. This will be accomplished as the team conducts a landscape analysis focused on the student perspective of the student-based North American “entrepreneurial” ecosystem. The second section of the thesis will focus specifically on the personal experiences of student startup founders. This will be accomplished through the analysis of interviews with founders of the startups researched from the first section of the thesis. This will provide us with a direct insight into the student perspective of the student-based North American “entrepreneurial” ecosystem.

ContributorsMinic, Jacob Michael (Co-author) / Callahan, Ryan (Co-author) / Rudick, Justin (Co-author) / Forshey, Cecilia (Co-author) / Hybert, Jacob (Co-author) / Byrne, Jared (Thesis director) / Olsen, Douglas (Committee member) / Curtiss, Ian (Committee member) / Department of Information Systems (Contributor) / Department of Economics (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Over the past several decades, the incarceration rates have continued to rise in the United States with seemingly no end in sight. Many of the prisons within America are experiencing major overcrowding of incarcerated persons in addition to an ever expanding budget that seems impossible to adhere to. Qualitative and

Over the past several decades, the incarceration rates have continued to rise in the United States with seemingly no end in sight. Many of the prisons within America are experiencing major overcrowding of incarcerated persons in addition to an ever expanding budget that seems impossible to adhere to. Qualitative and quantitative studies conclude that preventative and post release programs reduce crime rates and recidivism which saves taxpayer dollars. This paper addresses how much prisons cost, why this is important to the taxpayer, and possible solutions to make the penal system more efficient.

ContributorsBerns, Courtney Leigh (Author) / Hill, Alexander (Thesis director) / Barnhart, Patricia (Committee member) / Department of Economics (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Brundtland’s definition of sustainability is the ability to “meet the needs of the present<br/>without compromising the ability of future generations to meet their needs” (IISD, 2021). But<br/>what if there are no future generations? Social sustainability, the sector of sustainability that<br/>foregrounds the well-being and livelihoods of people (and thereby continuation of

Brundtland’s definition of sustainability is the ability to “meet the needs of the present<br/>without compromising the ability of future generations to meet their needs” (IISD, 2021). But<br/>what if there are no future generations? Social sustainability, the sector of sustainability that<br/>foregrounds the well-being and livelihoods of people (and thereby continuation of humanity), is<br/>included in definitions within the sustainability field, but less developed in sustainability<br/>practice. In an effort to bridge this gap of knowledge, 14 U.S. cities and over 100 sustainability<br/>policies were analyzed for their social sustainability performance. An eight-item analytical<br/>framework that deals with differing areas of social equity guided the analysis. Results found that<br/>most cities’ sustainability departments fell short of truly addressing social sustainability<br/>concerns. Out of the eight items, the most frequently addressed were housing security and racial<br/>and gender equality whereas few, if any, cities addressed the more specific social concerns of<br/>immigration, technology and media, or arts/cultural preservation. Future research is<br/>recommended to gain a better understanding of the ways existing cities can improve in this area.

ContributorsWeekes, Daniel Buckner (Co-author) / Tam, Joey (Co-author) / Brian, Jennifer (Thesis director) / Keeler, Lauren Withycombe (Thesis director) / N/A, N/A (Committee member) / Dean, W.P. Carey School of Business (Contributor) / Department of Economics (Contributor) / Department of Supply Chain Management (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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This thesis project has been conducted in accordance with The Founder’s Lab initiative which is sponsored by the W. P. Carey School of Business. This program groups three students together and tasks them with creating a business idea, conducting the necessary research to bring the concept to life, and exploring

This thesis project has been conducted in accordance with The Founder’s Lab initiative which is sponsored by the W. P. Carey School of Business. This program groups three students together and tasks them with creating a business idea, conducting the necessary research to bring the concept to life, and exploring different aspects of business, with the end goal of gaining traction. The product we were given to work through this process with was Hot Head, an engineering capstone project concept. The Hot Head product is a sustainable and innovative solution to the water waste issue we find is very prominent in the United States. In order to bring the Hot Head idea to life, we were tasked with doing research on topics ranging from the Hot Head life cycle to finding plausible personas who may have an interest in the Hot Head product. This paper outlines the journey to gaining traction via a marketing campaign and exposure of our brand on several platforms, with a specific interest in website traffic. Our research scope comes from mainly primary sources like gathering opinions of potential buyers by sending out surveys and hosting focus groups. The paper concludes with some possible future steps that could be taken if this project were to be continued.

ContributorsGoodall, Melody Anne (Co-author) / Rote, Jennifer (Co-author) / Lozano Porras, Mariela (Co-author) / Byrne, Jared (Thesis director) / Sebold, Brent (Committee member) / Department of Finance (Contributor) / Department of Economics (Contributor) / Dean, W.P. Carey School of Business (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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The contemporary world is motivated by data-driven decision-making. Small 501(c)3 nonprofit organizations are often limited in their reach due to their size, lack of funding, and a lack of data analysis expertise. In an effort to increase accessibility to data analysis for such organizations, a Founders Lab team designed a

The contemporary world is motivated by data-driven decision-making. Small 501(c)3 nonprofit organizations are often limited in their reach due to their size, lack of funding, and a lack of data analysis expertise. In an effort to increase accessibility to data analysis for such organizations, a Founders Lab team designed a product to help them understand and utilize geographic information systems (GIS) software. This product – You Got GIS – strikes the balance between highly technical documentation and general overviews, benefiting 501(c)3 nonprofits in their pursuit of data-driven decision-making. Through the product’s use of case studies and methodologies, You Got GIS serves as a thought experiment platform to start answering questions regarding GIS. The product aims to continuously build partnerships in an effort to improve curriculum and user engagement.

ContributorsFletcher, Griffin (Co-author) / Heekin, Noah (Co-author) / Ferrara, John (Co-author) / Byrne, Jared (Thesis director) / Givens, Jessica (Committee member) / Satpathy, Asish (Committee member) / Historical, Philosophical & Religious Studies (Contributor) / Department of Supply Chain Management (Contributor) / Department of Economics (Contributor) / Historical, Philosophical & Religious Studies, Sch (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Esports is a rapidly growing virtual competitive space that is projected to surpass physical sports in the near future. Given that Esports is considered to be in its infancy, it has only been recently introduced at the high school level. Our group connected with local high school Esports teams in

Esports is a rapidly growing virtual competitive space that is projected to surpass physical sports in the near future. Given that Esports is considered to be in its infancy, it has only been recently introduced at the high school level. Our group connected with local high school Esports teams in order to evaluate its efficiency. We found that players at this level are lacking a connection to other competitive teams and consistent practice. In the Esports world, practice with another team of equal level is called a “scrim”. In an effort to combat this issue, we created a platform named Clear Scrims to connect high school and collegiate Esport teams across the country with other teams of equivalent level. This platform will allow individuals to sign up, register with their competitive team, and provide available times to scrim. The platform then would be able to use their self-reported ingame rank to match them with worthy opponents for the most quality scrim experience. Teams playing into the growing sector of Esports need a structure like Clear Scrims to increase skill level and communication. In addition, our platform has a review component where teams and individuals score their opponent to see if they played as advertised. This component will help specify our matchmaking program but also work to dismantle the culture of bad manners or toxicity in Esports. Our site, Clear Scrims, will engender more competition and thus more opportunities for players to practice and hone in their skills.

ContributorsSigmund, Aidan Grace (Co-author) / Houck, Bennett (Co-author) / Forster, Julia (Co-author) / Byrne, Jared (Thesis director) / Pierce, John (Committee member) / Department of Economics (Contributor) / Dean, W.P. Carey School of Business (Contributor, Contributor) / School of Civic & Economic Thought and Leadership (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Recent changes in the energy markets structure combined with the conti-nuous load growth have caused power systems to be operated under more stressed conditions. In addition, the nature of power systems has also grown more complex and dynamic because of the increasing use of long inter-area tie-lines and the high

Recent changes in the energy markets structure combined with the conti-nuous load growth have caused power systems to be operated under more stressed conditions. In addition, the nature of power systems has also grown more complex and dynamic because of the increasing use of long inter-area tie-lines and the high motor loads especially those comprised mainly of residential single phase A/C motors. Therefore, delayed voltage recovery, fast voltage collapse and short term voltage stability issues in general have obtained significant importance in relia-bility studies. Shunt VAr injection has been used as a countermeasure for voltage instability. However, the dynamic and fast nature of short term voltage instability requires fast and sufficient VAr injection, and therefore dynamic VAr devices such as Static VAr Compensators (SVCs) and STATic COMpensators (STAT-COMs) are used. The location and size of such devices are optimized in order to improve their efficiency and reduce initial costs. In this work time domain dy-namic analysis was used to evaluate trajectory voltage sensitivities for each time step. Linear programming was then performed to determine the optimal amount of required VAr injection at each bus, using voltage sensitivities as weighting factors. Optimal VAr injection values from different operating conditions were weighted and averaged in order to obtain a final setting of the VAr requirement. Some buses under consideration were either assigned very small VAr injection values, or not assigned any value at all. Therefore, the approach used in this work was found to be useful in not only determining the optimal size of SVCs, but also their location.
ContributorsSalloum, Ahmed (Author) / Vittal, Vijay (Thesis advisor) / Heydt, Gerald (Committee member) / Ayyanar, Raja (Committee member) / Arizona State University (Publisher)
Created2011