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Description
Voltage Source Converters (VSCs) have been widely used in grid-connected applications with Distributed Energy Resource (DER) and Electric Vehicle (EV) applications. Replacement of traditional thyristors with Silicon/Silicon-Carbide based active switches provides full control capability to the converters and allows bidirectional power flow between the source and active loads. In this study, advanced control strategies for DER inverters and EV traction inverters will be explored.Chapter 1 gives a brief introduction to State-of-the-Art of VSC control strategies and summarizes the existing challenges in different applications. Chapter 2 presents multiple advanced control strategies of grid-connected DER inverters. Various grid support functions have been implemented in simulations and hardware experiments under both normal and abnormal operating conditions. Chapter 3 proposes an automated design and optimization process of a robust H-infinity controller to address the stability issue of grid-connected inverters caused by grid impedance variation. The principle of the controller synthesis is to select appropriate weighting functions to shape the systems closed-loop transfer function and to achieve robust stability and robust performance. An optimal controller will be selected by using a 2-Dimensional Pareto Front. Chapter 4 proposes a high-performance 4-layer communication architecture to facilitate the control of a large distribution network with high Photovoltaic (PV) penetration. Multiple strategies have been implemented to address the challenges
of coordination between communication and system control and between different communication protocols, which leads to a boost in the communication efficiency and makes the architecture highly scalable, adaptive, and robust. Chapter 5 presents the control strategies of a traditional Modular Multilevel Converter (MMC) and a novel Modular Isolated Multilevel Converter (MIMC) in grid-connected and variable speed drive applications. The proposed MIMC is able to achieve great size reduction for the submodule capacitors since the fundamental and double-line frequency voltage ripple has been cancelled. Chapter 6 shows a detailed hardware and controller design for a 48 V Belt-driven Starter Generator (BSG) inverter using automotive gate driver ICs and microcontroller. The inverter prototype has reached a power density of 333
W/inch3, up to 200 A phase current and 600 Hz output frequency.
ContributorsSi, Yunpeng (Author) / Lei, Qin (Thesis advisor) / Ayyanar, Raja (Committee member) / Vittal, Vijay (Committee member) / Zhang, Junshan (Committee member) / Arizona State University (Publisher)
Created2022
Description
Turning Point USA’s “Exposing Critical Racism Tour” website incorporates imagery and language to purport an alternate reality of critical race theory (critical race theory) in opposition to intellectuals in order to incite an ideological war against teachings of intellectuals. In order to create a sound argument and analysis of the historical and political framework constituted within their page and advertisements, I introduce a bridge between the largely political theory of anti-intellectualism and the rhetorical theory of rhetorical narrative. I propose Anti-Intellectualist Narrative Theory (ANT) as a new theoretical lens for analyzing the nationalistic and populist rhetorical frame created by an extensive history of oppositions to individuals who purport an intellectual authority over the common people. In constructing ANT, I aim to recognize how anti-intellectualism functions as a rhetorical narrative through three rhetorical strategies: anti-rationality, anti-elitism, and unreflective instrumentalism.
ContributorsKohtz, Corbin (Author) / LeMaster, Loretta (Thesis director) / Stephenson, Megan (Committee member) / Suk, Mina (Committee member) / Barrett, The Honors College (Contributor) / Hugh Downs School of Human Communication (Contributor) / School of Politics and Global Studies (Contributor) / Department of English (Contributor)
Created2022-05
Description
This thesis analyzes the process through which sustainability communication occurs between organizations and stakeholders. The lack of frameworks connecting research in the sustainability and communication fields highlights the need for a cohesive modelization of the sustainability communication process. This process forms the basis of the Action, Perception, Risk (APR) model, a framework that I have created. The APR model builds on existing sustainability and communication research to provide a practical illustration of the sustainability communication process, connecting the theoretical realm with the practitioner realm through implementable recommendations. This is achieved through a literature review and a case study of the American footwear company, Allbirds. Managerial implications are discussed and recommendations for effective sustainability communication are put forward.
ContributorsQuinney, Gwenn (Author) / Balven, Rachel (Thesis director) / Jacob, Pradeep (Committee member) / Barrett, The Honors College (Contributor) / Department of Marketing (Contributor) / Department of Management and Entrepreneurship (Contributor)
Created2022-05
Description
Ethernet based technologies are emerging as the ubiquitous de facto form of communication due to their interoperability, capacity, cost, and reliability. Traditional Ethernet is designed with the goal of delivering best effort services. However, several real time and control applications require more precise deterministic requirements and Ultra Low Latency (ULL), that Ethernet cannot be used for. Current Industrial Automation and Control Systems (IACS) applications use semi-proprietary technologies that provide deterministic communication behavior for sporadic and periodic traffic, but can lead to closed systems that do not interoperate effectively. The convergence between the informational and operational technologies in modern industrial control networks cannot be achieved using traditional Ethernet. Time Sensitive Networking (TSN) is a suite of IEEE standards designed by augmenting traditional Ethernet with real time deterministic properties ideal for Digital Signal Processing (DSP) applications. Similarly, Deterministic Networking (DetNet) is a Internet Engineering Task Force (IETF) standardization that enhances the network layer with the required deterministic properties needed for IACS applications. This dissertation provides an in-depth survey and literature review on both standards/research and 5G related material on ULL. Recognizing the limitations of several features of the standards, this dissertation provides an empirical evaluation of these approaches and presents novel enhancements to the shapers and schedulers involved in TSN. More specifically, this dissertation investigates Time Aware Shaper (TAS), Asynchronous Traffic Shaper (ATS), and Cyclic Queuing and Forwarding (CQF) schedulers. Moreover, the IEEE 802.1Qcc, centralized management and control, and the IEEE 802.1Qbv can be used to manage and control scheduled traffic streams with periodic properties along with best-effort traffic on the same network infrastructure. Both the centralized network/distributed user model (hybrid model) and the fully-distributed (decentralized) IEEE 802.1Qcc model are examined on a typical industrial control network with the goal of maximizing scheduled traffic streams. Finally, since industrial applications and cyber-physical systems require timely delivery, any channel or node faults can cause severe disruption to the operational continuity of the application. Therefore, the IEEE 802.1CB, Frame Replication and Elimination for Reliability (FRER), is examined and tested using machine learning models to predict faulty scenarios and issue remedies seamlessly.
ContributorsNasrallah, Ahmed (Author) / Reisslein, Martin (Thesis advisor) / Syrotiuk, Violet R. (Committee member) / LiKamWa, Robert (Committee member) / Thyagaturu, Akhilesh (Committee member) / Arizona State University (Publisher)
Created2022
Description
The first chapter uses data on birthplaces of 2,065 Chief Executive Officers (CEO) and a county-level measure of cultural individualism based on the westward expansion in American history to establish a positive relation between CEO cultural individ- ualism and corporate innovation. Difference-in-differences estimations around CEO turnovers support the causality. Individualistic CEOs increase innovation by creating an innovative corporate culture, providing more flexibility to employees, and tolerance for failure.The second chapter develops a model to study the corporate board structure and communication. Outside directors are related to potential competitors. As a result, they can bring valuable advice and cause information leakage. The firm needs to decide whether to have outside directors on the board. In the presence of the outside director, the other directors need to determine whether to communicate.
ContributorsZhang, Fan (Author) / Boguth, Oliver (Thesis advisor) / Babenko, Ilona (Committee member) / Schiller, Christoph (Committee member) / Wang, Jessie Jiaxu (Committee member) / Arizona State University (Publisher)
Created2022
Description
Western cultures on the whole have a particular fascination surrounding tattoos, and academia is no different. There are numerous studies that discuss why people get tattoos and what peoples’ perceptions of those with tattoos are. However, there has only been a minuscule amount of research on the ones who even make tattoos possible: Tattoo artists. This work endeavors to provide a platform for tattoo artists to share their stories and experiences, and, in turn, help provide academia and the public at-large with a better understanding of tattoo artist identity and how the tattoo artist residual community functions and defines itself. Through ethnography, ethnographic interviews, and autoethnography, the everyday lives of tattoo artists will be explored. This work also seeks to provide an understanding of the history, skillsets, artistry, and creativity of Western tattoo artists, while simultaneously arguing for how tattoos and their creators can open the world of “fine art” to a broader audience and make it more accessible for all.
ContributorsHawn, Allison (Author) / Mean, Lindsey (Thesis advisor) / Schleif, Corine (Committee member) / Guerrero, Laura (Committee member) / Arizona State University (Publisher)
Created2022
Description
Mark is a creative project to showcase the storytelling potential of video games and explore the unique narrative tools at their disposal. In particular, the mechanics are crafted to spotlight the ludonarrative—when the gameplay adds to or even tells its own story. In addition, the short, non-linear progression of collecting a different assortment of friends with each playthrough explores player agency and its role in the emergence of narrative from a series of loosely-scripted events.
ContributorsHoward, Rachel (Author) / Hill, Retha (Thesis director) / O'Flaherty, Katherine (Committee member) / Barrett, The Honors College (Contributor) / Walter Cronkite School of Journalism and Mass Comm (Contributor) / Computing and Informatics Program (Contributor)
Created2022-05
Description
While Covid-19 had severe impacts on education across the board, the goal of our research is to examine how virtual learning affected Business Data Analytics and Computer Information Students at Arizona State University. A survey was created to measure three key academic areas (student learning, communication, and student engagement) that may have experienced a notable change in quality. Forty Nine W.P. Carey students were surveyed and their responses were recorded in a Google Sheet. From there the results were transferred to excel and converted into a Numeric Likert scale. By establishing base scores for each of the survey statements we can isolate areas of virtual learning that underwhelmed or satisfied our target demographic. The objective of the subsequent analysis was to identify any areas within the three focal points that participants felt strongly impacted their performance with virtual schooling during the August 2020 to May 2021 school year.
ContributorsGlynn, Rory (Author) / Briggs, Georgette (Thesis director) / Melo, Juan (Committee member) / O'Flaherty, Katherine (Committee member) / Barrett, The Honors College (Contributor) / Department of Information Systems (Contributor)
Created2022-05
Description
In the face of deep disconnection and chaotic crises throughout our planet, I have identified five invitations for foundational actions and ways of living, that can lead to us deepening our connection with ourselves and with the Earth in individualized ways, while cultivating harmony on our shared world. These are; to listen, to express, to envision, to reciprocate, and to dance. An open mind and heart will make them most effective.
ContributorsGlogau, Leeor (Author) / Paulesc, Marie-Louise (Thesis director) / Fedock, Rachel (Committee member) / Cloutier, Scott (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2022-12
ContributorsReineke, Lindsay (Author) / Panneton, Teresa (Thesis director) / Goodman, Brian (Committee member) / Barrett, The Honors College (Contributor) / Division of Teacher Preparation (Contributor)
Created2022-12