Matching Items (165)
Description
The crafting of cultural goods and ethnic arts have been stable means for making a living within many Indigenous communities throughout the world. In order to understand how crafting can be an avenue towards sustainable entrepreneurship, an analysis of the relationships between Indigenous crafting, Indigenous community life, sustainable agency, Indigenous concepts of wellbeing, and sustainable entrepreneurship is needed. Through three-papers focused on an extensive literature review (aggregate to all three papers) and ethnographic field research (semi-structured interviews, verbal surveys, and ethnographic observation) this dissertation examines how the act of Indigenous crafting as carried out by individuals within families and by families within Indigenous communities, link with social relationships, making a living, gender roles, and cultural identity and how these aspects of community life intersect with sustainable forms of agency, Indigenous concepts of wellbeing, and small-scale social entrepreneurial activities in the context of Indigenous crafting in a bid to indigenize the concept of sustainable entrepreneurship. This dissertation proposes a series of conceptual frameworks that depict the discussed linkages between Indigenous crafting, Indigenous community life, sustainable forms of agency, sustainable livelihood, and Indigenous concepts of wellbeing, in the context of sustainable entrepreneurship along with the relevant literature associated with each element in the frameworks. This dissertation draws from a qualitative ethnographic study on Mazahua artisans and their communities in Mexico in an attempt to understand and expand sustainable entrepreneurship from Euro-Western perspectives to Indigenous perspectives in order to better apply SE concepts in the development of an Indigenous fashion goods venture called Vitu™. This Indigenous venture, through the Indigenized sustainable entrepreneurship concept of Adaptive-Transformative Agency, will more deeply address justice, equity, and inclusion for Indigenous peoples and their communities pursuing community development through entrepreneurial activities.
ContributorsTakamura, John Hiroomi (Author) / BurnSilver, Shauna (Thesis advisor) / Manuel-Navarrete, David (Thesis advisor) / Chhetri, Nalini (Committee member) / Arizona State University (Publisher)
Created2022
Description
A remarkable phenomenon in contemporary physics is quantum scarring in classically chaoticsystems, where the wave functions tend to concentrate on classical periodic orbits. Quantum
scarring has been studied for more than four decades, but the problem of efficiently detecting
quantum scars has remained to be challenging, relying mostly on human visualization of
wave function patterns. This paper develops a machine learning approach to detecting
quantum scars in an automated and highly efficient manner. In particular, this paper exploits Meta
learning. The first step is to construct a few-shot classification algorithm, under the
requirement that the one-shot classification accuracy be larger than 90%. Then propose a
scheme based on a combination of neural networks to improve the accuracy. This paper shows that
the machine learning scheme can find the correct quantum scars from thousands images of
wave functions, without any human intervention, regardless of the symmetry of the underlying
classical system. This will be the first application of Meta learning to quantum systems. Interacting spin networks are fundamental to quantum computing. Data-based tomography oftime-independent spin networks has been achieved, but an open challenge is to ascertain the
structures of time-dependent spin networks using time series measurements taken locally
from a small subset of the spins. Physically, the dynamical evolution of a spin network under
time-dependent driving or perturbation is described by the Heisenberg equation of motion.
Motivated by this basic fact, this paper articulates a physics-enhanced machine learning framework
whose core is Heisenberg neural networks. This paper demonstrates that, from local measurements, not only the local Hamiltonian can be recovered but the Hamiltonian reflecting the interacting structure of the whole system can
also be faithfully reconstructed. Using Heisenberg neural machine on spin networks of a
variety of structures. In the extreme case where measurements are taken from only one spin,
the achieved tomography fidelity values can reach about 90%. The developed machine
learning framework is applicable to any time-dependent systems whose quantum dynamical
evolution is governed by the Heisenberg equation of motion.
ContributorsHan, Chendi (Author) / Lai, Ying-Cheng (Thesis advisor) / Yu, Hongbin (Committee member) / Dasarathy, Gautam (Committee member) / Seo, Jae-Sun (Committee member) / Arizona State University (Publisher)
Created2022
Description
This research paper explores how different relationships between people and nature can be fostered by learning experiences to bridge harmful gaps in the field of sustainability. Current disconnectedness from nature and people both within and across geographical borders hinder the cultivation of sustainable solutions. After attending a sustainability-oriented educational experience abroad in Ecuador recently, I decided to investigate how cross-cultural exchanges in Ecuador influences participants’ views of nature, new points of intersectionality participants learn while amongst nature in Ecuador, and what about this experience made it uniquely meaningful. Research methods included individual interviews and a group hike and picnic focus group discussion to collect qualitative data. I found that during this experience, students were able to lean into being vulnerable with each other, connect with indigenous community members beyond language borders, and connect with nature in ways that fostered awareness of the human position within it. From this, I learned that there were unique aspects of this learning experience that allowed for these relationships to be built and therefore for sustainable knowledge from the trip to stick when participants got back to the United States. The amount and flexibility of learning and processing time and dynamics created by classroom structure were important variables to the effectiveness of the learning experience. Institutions can learn from these experiences and connect people back to nature to implement successful sustainability solutions in the future.
ContributorsGiles, Sadie (Author) / Goebel, Janna (Thesis director) / Manuel-Navarrete, David (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / Dean, W.P. Carey School of Business (Contributor)
Created2023-05
Description
Few-layer black phosphorous (FLBP) is one of the most important two-dimensional (2D) materials due to its strongly layer-dependent quantized bandstructure, which leads to wavelength-tunable optical and electrical properties. This thesis focuses on the preparation of stable, high-quality FLBP, the characterization of its optical properties, and device applications.Part I presents an approach to preparing high-quality, stable FLBP samples by combining O2 plasma etching, boron nitride (BN) sandwiching, and subsequent rapid thermal annealing (RTA). Such a strategy has successfully produced FLBP samples with a record-long lifetime, with 80% of photoluminescence (PL) intensity remaining after 7 months. The improved material quality of FLBP allows the establishment of a more definitive relationship between the layer number and PL energies.
Part II presents the study of oxygen incorporation in FLBP. The natural oxidation formed in the air environment is dominated by the formation of interstitial oxygen and dangling oxygen. By the real-time PL and Raman spectroscopy, it is found that continuous laser excitation breaks the bonds of interstitial oxygen, and free oxygen atoms can diffuse around or form dangling oxygen under low heat. RTA at 450 °C can turn the interstitial oxygen into dangling oxygen more thoroughly. Such oxygen-containing samples show similar optical properties to the pristine BP samples. The bandgap of such FLBP samples increases with the concentration of the incorporated oxygen.
Part III deals with the investigation of emission natures of the prepared samples. The power- and temperature-dependent measurements demonstrate that PL emissions are dominated by excitons and trions, with a combined percentage larger than 80% at room temperature. Such measurements allow the determination of trion and exciton binding energies of 2-, 3-, and 4-layer BP, with values around 33, 23, 15 meV for trions and 297, 276, 179 meV for excitons at 77K, respectively.
Part IV presents the initial exploration of device applications of such FLBP samples. The coupling between photonic crystal cavity (PCC) modes and FLBP's emission is realized by integrating the prepared sandwich structure onto 2D PCC. Electroluminescence has also been achieved by integrating such materials onto interdigital electrodes driven by alternating electric fields.
ContributorsLi, Dongying (Author) / Ning, Cun-Zheng (Thesis advisor) / Vasileska, Dragica (Committee member) / Lai, Ying-Cheng (Committee member) / Yu, Hongbin (Committee member) / Arizona State University (Publisher)
Created2022
Description
In this research, I surveyed existing methods of characterizing Epilepsy from Electroencephalogram (EEG) data, including the Random Forest algorithm, which was claimed by many researchers to be the most effective at detecting epileptic seizures [7]. I observed that although many papers claimed a detection of >99% using Random Forest, it was not specified “when” the detection was declared within the 23.6 second interval of the seizure event. In this research, I created a time-series procedure to detect the seizure as early as possible within the 23.6 second epileptic seizure window and found that the detection is effective (> 92%) as early as the first few seconds of the epileptic episode. I intend to use this research as a stepping stone towards my upcoming Masters thesis research where I plan to expand the time-series detection mechanism to the pre-ictal stage, which will require a different dataset.
ContributorsBou-Ghazale, Carine (Author) / Lai, Ying-Cheng (Thesis director) / Berisha, Visar (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2022-05
Description
Predicting nonlinear dynamical systems has been a long-standing challenge in science. This field is currently witnessing a revolution with the advent of machine learning methods. Concurrently, the analysis of dynamics in various nonlinear complex systems continues to be crucial. Guided by these directions, I conduct the following studies. Predicting critical transitions and transient states in nonlinear dynamics is a complex problem. I developed a solution called parameter-aware reservoir computing, which uses machine learning to track how system dynamics change with a driving parameter. I show that the transition point can be accurately predicted while trained in a sustained functioning regime before the transition. Notably, it can also predict if the system will enter a transient state, the distribution of transient lifetimes, and their average before a final collapse, which are crucial for management. I introduce a machine-learning-based digital twin for monitoring and predicting the evolution of externally driven nonlinear dynamical systems, where reservoir computing is exploited. Extensive tests on various models, encompassing optics, ecology, and climate, verify the approach’s effectiveness. The digital twins can extrapolate unknown system dynamics, continually forecast and monitor under non-stationary external driving, infer hidden variables, adapt to different driving waveforms, and extrapolate bifurcation behaviors across varying system sizes. Integrating engineered gene circuits into host cells poses a significant challenge in synthetic biology due to circuit-host interactions, such as growth feedback. I conducted systematic studies on hundreds of circuit structures exhibiting various functionalities, and identified a comprehensive categorization of growth-induced failures. I discerned three dynamical mechanisms behind these circuit failures. Moreover, my comprehensive computations reveal a scaling law between the circuit robustness and the intensity of growth feedback. A class of circuits with optimal robustness is also identified. Chimera states, a phenomenon of symmetry-breaking in oscillator networks, traditionally have transient lifetimes that grow exponentially with system size. However, my research on high-dimensional oscillators leads to the discovery of ’short-lived’ chimera states. Their lifetime increases logarithmically with system size and decreases logarithmically with random perturbations, indicating a unique fragility. To understand these states, I use a transverse stability analysis supported by simulations.
ContributorsKong, Lingwei (Author) / Lai, Ying-Cheng (Thesis advisor) / Tian, Xiaojun (Committee member) / Papandreou-Suppappola, Antonia (Committee member) / Alkhateeb, Ahmed (Committee member) / Arizona State University (Publisher)
Created2023
Description
Dear reader, I hope you will read this entire dissertation. If you are reluctant because of its length, I invite you to contact me for a conversation instead. Over the past eight years I have been a part of three unfolding histories: colonialism, sustainability science, and the Atlas of Creative Tools (the Atlas). In this dissertation I describe how I am a part of these histories. I advocate for partnering them so that the Atlas is used by people in the field of sustainability science to advance cognitive justice in their work. This advocacy is supported by research conducted using a mixed-methods approach. I combine qualitative methods used to study each of the three histories with the experiential knowledge I gained from being a part of them. Throughout the dissertation I move back and forth between academic research and experiential knowledge. Each informs the other. This back-and-forth movement is itself a method to interrogate the assumptions of dissertation writing. My purposes for doing so are two-fold. I want to honor the dissertation as a form of knowledge production that can promote cognitive justice while also pointing out how it hinders it. Additionally, the back-and-forth interrogation method involves using creative tools from the Atlas in the text itself. This demonstrates how the Atlas can be used to promote cognitive justice while producing knowledge in sustainability science. I structure this dissertation to aid you in four ways. First, I provide a view of sustainability science as a contested space that people can and do use to advance cognitive justice. Second, I write about my research and analysis of the Atlas so that my descriptions can be used right away by other practitioners who are working with the Atlas. Third, my methods for interrogating the dissertation itself are meant to be used, modified, and built on by others. Finally, I hope that the connections I make between the Atlas and sustainability science are helpful for your work, and that they inspire you to try the Atlas and see how you can use it to promote cognitive justice in your own contexts.
ContributorsNock, Matthew (Author) / Haglund, LaDawn (Thesis advisor) / Manuel-Navarrete, David (Thesis advisor) / Lerman, Elizabeth (Committee member) / Arizona State University (Publisher)
Created2023
Description
A notable challenge when assembling synthetic gene circuits is that modularity often fails to function as intended. A crucial underlying reason for this modularity failure is the existence of competition for shared and limited gene expression resources. By designing a synthetic cascading bistable switches (Syn-CBS) circuit in a single strain with two coupled self-activation modules to achieve successive cell fate transitions, nonlinear resource competition within synthetic gene circuits is unveiled. However, in vivo it can be seen that the transition path was redirected with the activation of one switch always prevailing over that of the other, contradictory to coactivation theoretically expected. This behavior is a result of resource competition between genes and follows a ‘winner-takes-all’ rule, where the winner is determined by the relative connection strength between the two modules. Despite investigation demonstrating that resource competition between gene modules can significantly alter circuit deterministic behaviors, how resource competition contributes to gene expression noise and how this noise can be controlled is still an open issue of fundamental importance in systems biology and biological physics. By utilizing a two-gene circuit, the effects of resource competition on protein expression noise levels can be closely studied. A surprising double-edged role is discovered: the competition for these resources decreases noise while the constraint on resource availability adds its own term of noise into the system, denoted “resource competitive” noise. Noise reduction effects are then studied using orthogonal resources. Results indicate that orthogonal resources are a good strategy for eliminating the contribution of resource competition to gene expression noise.
Noise propagation through a cascading circuit has been considered without resource competition. It has been noted that the noise from upstream genes can be transmitted downstream. However, resource competition’s effects on this cascading noise have yet to be studied. When studied, it is found that resource competition can induce stochastic state
switching and perturb noise propagation. Orthogonal resources can remove some of the resource competitive behavior and allow for a system with less noise.
ContributorsGoetz, Hanah Elizabeth (Author) / Tian, Xiaojun (Thesis advisor) / Wang, Xiao (Committee member) / Lai, Ying-Cheng (Committee member) / Arizona State University (Publisher)
Created2022
Description
Public spaces have been central to studies focused on the relationship between economic inequalities, well-being, and environmental justice. However, an integrated examination of access to public spaces that is cognizant of the exchanges which inform environmental justice and the well-being of minoritized communities, is yet to be extensively studied. Such exchanges and the unideal community outcomes thereof are important to highlight in understanding access, given the historical challenges that have emanated from them to hamper the beneficial utility of public spaces in vulnerable contexts. This dissertation addresses this gap through a three-article format. Article 1 comprises a conceptual synthesis of two theoretical frameworks namely Lefebvre’s Tripartite Framework and Bishop’s Network Theory of Well-being that respectively conceptualize the exchanges in space production and the positive outcomes, which emerge from human and non-human engagements towards well-being. The main contribution of this article is the merging of two bodies of scholarship which had yet to intersect to inform investigations of access through the exchanges across technical (e.g., planners), social (i.e., communities) and physical (e.g., built spaces like parks) dimensions, and linkages to positive community outcomes. Article 2 entails an empirical examination of how communities and technical experts perceive of the linkages between access and community well-being, through exchanges across public space dimensions. Through a multiple embedded case study, 19 community leaders and 4 key technical informants in Maryvale were engaged in participatory mapping interviews. Responses to exchanges and outcomes thereof pertaining to the identified spaces, were deductively coded guided by the conceptual synthesis developed in article 1. Both community leaders and technical agents described access as emerging from perceptions of positive outcomes linked to public space exchanges. Article 3 sought to understand how design professionals (i.e., planners, building and landscape architects) who identify as ethnic minorities, perceive of their role in facilitating access to public spaces. Through interviews, 23 participants were engaged through a protocol guided by the conceptual synthesis developed in article 1. Responses were inductively coded. Participants described the role they play in exchanges, as focal to positive outcomes linked to access. Keywords: Public Spaces; Access; Environmental Justice; Community Well-being.
ContributorsGodwyll, Josephine Marie (Author) / Buzinde, Christine N (Thesis advisor) / Frazier, Amy (Committee member) / Manuel-Navarrete, David (Committee member) / White, Dave (Committee member) / Arizona State University (Publisher)
Created2022
Description
Institutions of higher learning can be centers of meaning-making and learning and are expected to play a pivotal role in a global shift toward sustainability. Despite recent innovations, much sustainability education today is still delivered using traditional pedagogies common across higher education. Therefore, students and facilitators should continue innovating along pedagogical themes consistent with the goals of sustainability: transformation and emancipation. Yet, more clarity is needed about pedagogical approaches that will transform and emancipate students, allowing them to become innovators that change existing structures and systems. My dissertation attempts to address this need using three approaches. First, I present a framework combining four interacting (i.e., complementary) pedagogies (transmissive, transformative, instrumental, and emancipatory) for sustainability education, helping to reify pedagogical concepts, rebel against outdated curricula, and orient facilitators/learners on their journey toward transformative and emancipatory learning. Second, I use a descriptive case study of a sustainability education course set outside of the traditional higher education context to highlight pedagogical techniques that led to transformative and emancipatory outcomes for learners partaking in the course. Third, I employ the method of autoethnography to explore my own phenomenological experience as a sustainability student and classroom facilitator, helping others to identify the disenchanting paradoxes of sustainability education and integrate the lessons they hold. All three approaches of the dissertation maintain a vision of sustainability education that incorporates contemplative practices as essential methods in a field in need of cultivating hope, resilience, and emergence.
ContributorsPapenfuss, Jason (Author) / Merritt, Eileen (Thesis advisor) / Manuel-Navarrete, David (Thesis advisor) / Eckard, Bonnie (Committee member) / Cloutier, Scott (Committee member) / Arizona State University (Publisher)
Created2019