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Description
With the advent of new advanced analysis tools and access to related published data, it is getting more difficult for data owners to suppress private information from published data while still providing useful information. This dual problem of providing useful, accurate information and protecting it at the same time has been challenging, especially in healthcare. The data owners lack an automated resource that provides layers of protection on a published dataset with validated statistical values for usability. Differential privacy (DP) has gained a lot of attention in the past few years as a solution to the above-mentioned dual problem. DP is defined as a statistical anonymity model that can protect the data from adversarial observation while still providing intended usage. This dissertation introduces a novel DP protection mechanism called Inexact Data Cloning (IDC), which simultaneously protects and preserves information in published data while conveying source data intent. IDC preserves the privacy of the records by converting the raw data records into clonesets. The clonesets then pass through a classifier that removes potential compromising clonesets, filtering only good inexact cloneset. The mechanism of IDC is dependent on a set of privacy protection metrics called differential privacy protection metrics (DPPM), which represents the overall protection level. IDC uses two novel performance values, differential privacy protection score (DPPS) and clone classifier selection percentage (CCSP), to estimate the privacy level of protected data. In support of using IDC as a viable data security product, a software tool chain prototype, differential privacy protection architecture (DPPA), was developed to utilize the IDC. DPPA used the engineering security mechanism of IDC. DPPA is a hub which facilitates a market for data DP security mechanisms. DPPA works by incorporating standalone IDC mechanisms and provides automation, IDC protected published datasets and statistically verified IDC dataset diagnostic report. DPPA is currently doing functional, and operational benchmark processes that quantifies the DP protection of a given published dataset. The DPPA tool was recently used to test a couple of health datasets. The test results further validate the IDC mechanism as being feasible.
Contributorsthomas, zelpha (Author) / Bliss, Daniel W (Thesis advisor) / Papandreou-Suppappola, Antonia (Committee member) / Banerjee, Ayan (Committee member) / Shrivastava, Aviral (Committee member) / Arizona State University (Publisher)
Created2023
Description
In this work, secretion of free fatty acids (FFAs) and ω-hydroxy FFAs wasachieved in the model cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis), and
FFAs were detected by a novel fluorescence assay. Current methods of detecting FFA
concentrations, including HPLC-based and GC-based methods or enzyme-based kits,
have hindered research advancement due to their laborious and/or expensive nature. The
work herein establishes a novel, rapid, fluorescence-based assay for detecting total FFA
concentrations secreted by Synechocystis FFA secretion strains. The novel FFA-detection
assay demonstrates the efficacy of using Nile Red as a fluorescent reporter for laurate or
palmitate at concentrations up to 500 µM in the presence of cationic surfactants. Total
FFA concentrations in Synechocystis supernatants quantified by the novel, Nile Red fluorescence-based assay are demonstrated herein to be highly correlative to total FFA
concentrations quantified by LC-MS; this correlation was seen in supernatant samples of
wild type Synechocystis and Synechocystis FFA secretion strains, both in 96-well plates
and 30-mL, aerated culture tubes.
This work also establishes the expression of a cytochrome P450 fusion enzyme,
CYP153A-CPRmut, or a monooxygenase system from Pseudomonas putida GPo1,
AlkBGT, in FFA secretion strains of Synechocystis for the generation of ω-hydroxy
laurate from laurate. After finding greatly increased ω-hydroxylation activity of
CYP153A-CPRmut with concurrent superoxide dismutase and catalase overexpression, 55
or 1.5 µM of ω-hydroxy laurate were produced over five days by Synechocystis strains
expressing CYP153A-CPRmut or AlkBGT, respectively. As further indication of the
presence of reactive oxygen species affecting ω-hydroxy laurate production with
Synechocystis strains expressing CYP153A-CPRmut, concentrations of ω-hydroxy laurate
in the supernatant increased over two-fold in the presence of 250 µM of the anti-oxidant,
methionine, in bench-scale cultures and in 96-well plate cultures. Additionally, a
mutation at the 55th amino acid position in AlkB (tryptophan to cysteine; AlkBW55C),
resulted in a more than two-fold shift in AlkB’s substrate preference from decanoate
towards the desired substrate, laurate. As a result, Synechocystis expressing AlkBW55C
could produce 5.9 µM ω-hydroxy laurate and 2.0 µM dodecanedioic acid over five days
of growth.
ContributorsAshe, Christopher (Author) / Vermaas, Willem Fj (Thesis advisor, Committee member) / Wang, Xuan (Committee member) / Nielsen, David R (Committee member) / Misra, Rajeev (Committee member) / Arizona State University (Publisher)
Created2023
Description
This thesis expands the scope of literature surrounding the work of Juno Calypso, Christina Quarles, and Lisa Yuskavage by increasing the scope of their theoretical interpretations. Juno Calypso’s case requires establishing a critical foundation for her interrogations of domestic space, her subversions of feminine performance—particularly through accusatory address of the gaze—and her demonstrations of the new-hysterical process that I argue for via her alter-ego, “Joyce.” Similarly, I emphasize Christina Quarles’ subversions of art historical traditions, such as the gaze, meta-framing, and figural language, instead of her explorations into race and linguistic titular play. Finally, Lisa Yuskavage’s inclusion will bring discussions of her contemporary artworks fully into the present, leaving behind the scandalous-or-not questions plaguing her oeuvre in favor of contemporary figural reinterpretation. Through comparisons of each one’s approach to contemporary, artistic feminist theories and dilemmas, the artists convey informative insights into today’s visual culture. The thesis brings these ruminations to light through study of Calypso’s, Quarles’, and Yuskavage’s shared themes and characteristics, including subconsciously-influenced practices, multiplicity, and uncanny space. I account for one of Calypso’s most crucial yet divergent strategies of spatial uncanniness—gendered space. Calypso, Quarles, and Yuskavage are also linked by their ostensibly domestic spaces and featuring feminized figures. Yuskavage uses hyperfeminine performance as means of questioning the conventional and the pleasure one expected to receive from it; Quarles instead uses ambiguity to challenge the traditional white femininity assigned to subjecthood in order to reinforce her dissolution of race and gender. Unanswered performance and gaze questions of femininity, feminine performance and feminine rituals drive Calypso’s photographs, in which an onlooker’s voyeurism is highlighted by their mid-procedure state. Yuskavage uses the home as extension of cheesy self, a site of performance, but Quarles uses domestic spaces as sites or causes of internal struggle. Calypso is closer aligned to Yuskavage’s intersectional-feminist anxieties than Quarles’ post-pandemic ones. The temporal span of the artworks’ creation (2015-2022) is reflective of the dramatic social paradigm shifts experienced by Western societies post-BLM and other social movements, and post-COVID pandemic; the arguments made by this essay will contribute to the understanding of ongoing change experienced by women.
ContributorsBugno, Celia (Author) / Fahlman, Betsy (Thesis advisor) / Anderson, Lisa (Committee member) / Hoy, Meredith (Committee member) / Arizona State University (Publisher)
Created2023
Description
Airports are a critical component of a region’s network and socioeconomic development. Regardless of the type of airport–commercial, general, regional, national, or international–their construction and development are highly advantageous to communities. Some advantages include, but are not limited to new job opportunities, access to the global market, and increased economic activity. Nonetheless, airport development has some downsides that a community must always account for. These downsides directly impact the sustainability of a region; greenhouse gas (GHG) emissions, energy inefficiencies, water pollution, air pollution, and waste are just a few examples. However, twenty-first century global sustainability efforts are shifting the dynamic of sustainability practices in the U.S. The fight for a balance between socioeconomic benefits and the minimization of negative environmental impacts is advancing thanks to the development and implementation of sustainable practices and technology. For instance, U.S. airport development has seen a rise in the use of sustainable construction technologies and practices. Some of the examples of construction technologies and practices implemented in sustainable airport development are virtual design and construction, Spot by Boston Dynamics, prefabrication, and others. The multiple-case studies based on these technologies and practices indicate joint efforts for sustainability by the aviation and construction industries.
ContributorsPalacios, Martha Dennise (Author) / Cirillo, Michael (Thesis advisor) / Faith, Edward (Committee member) / Pearson, Michael (Committee member) / Arizona State University (Publisher)
Created2023
Description
High-performance polymers (HPPs) have dominated the synthetic polymer market for critical applications, including aerospace, energy, microelectronic, and transportation industries since their development in the mid-1900s. Although their structures share general similarities, such as high aromatic content, HPPs offer wide structural variance providing amorphous and semi-crystalline systems. As a result, conventional processing methods employed for HPPs are energy intensive and accessible part geometry is limited; often requiring subsequent subtractive techniques, i.e.,; milling, to obtain high quality and performant parts. Traditional processes were challenged by the emergence of advanced manufacturing techniques, such as 3D printing, which spurred significant academic and industrial interest. In the first project, poly(arylene ether sulfone)s (PSU) were chemically modified post-polymerization to enable ensuing photopolymerization of high molecular weight (Mn) PSU solutions into complex shapes with vat photopolymerization (VP). The resulting materials exhibited fast crosslinking, but low and unstable plateau storage moduli (G’). To overcome this, addition of low molecular weight crosslinker and precise control of UV irradiation increased crosslink density and inhibited photodegradation events, respectively. Ultimately, these modifications facilitated the first report of PSU structures fabricated with a UV-assisted AM modality. Next, 3D printable polyimides (PIs) were synthesized and extensively characterized to further expand the HPP AM toolbox. However, fully aromatic PIs pose a significant challenge as most are insoluble, intractable, and lack any discernable viscous flow. AM PIs were produced using two distinct approaches previously reported in the Long research group; the pendant salt approach imparts photoreactivity through the neutralization of the poly(amic acid) intermediate with small molecule amino-acrylates while the polysalt approach employs dicarboxylate-diammonium ionic organization to template the PI amongst an acrylic scaffold. Through the pendant salt approach, water soluble PI precursors enabled facile AM of complex structures, which served as efficient carbon precursors. The polysalt approach offers superior solid content and solution viscosities; however, these highly polar solutions initially exhibited deleterious side reactions. Application of acid-base fundamentals provided novel printable polysalt solutions with extended shelf-life, reproducible printing, and simplified processing. The relationships established from these projects expanded the applications of the most performant synthetic polymers and will inform future polymer design for additive manufacturing.
ContributorsWeyhrich, Cody (Author) / Long, Timothy E (Thesis advisor) / Williams, Christopher B (Committee member) / Biegasiewicz, Kyle F (Committee member) / Jin, Kailong (Committee member) / Arizona State University (Publisher)
Created2023
Description
I examine whether a stock’s inclusion in green exchange traded funds and mutualfunds (GMFs) affects liquidity and analyst following. I base these predictions on prior
literature that establishes that a firm’s pro-ESG (Environmental, Social, and Governance)
orientation can spur investors’ interest and mitigate investors’ agency concerns (by
signaling that managers are pro-social). I test these predictions using difference-indifferences
models of monthly turnover, bid-ask spread, and analyst coverage to examine
whether firm liquidity, trading costs, and analyst following improve post-GMF inclusion.
I find support for all three predictions, even though GMF ownership in my sample is
exceedingly modest. Importantly, I identify my treatment effects as incremental to the
liquidity boost firms receive when added to conventional mutual funds and exchange
traded funds (ETFs). Together, these results suggest that GMF inclusion is perceived as
an informative signal of a firm’s green credentials, which leads to more trading volume,
lower trading costs, and more analyst participation.
ContributorsHolden, Nicole (Author) / White, Roger (Thesis advisor) / Brown, Jenny (Committee member) / Kaplan, Steve (Committee member) / Arizona State University (Publisher)
Created2023
Description
There has been a significant growth in the distributed energy resources (DERs) connected to the distribution networks in recent years. For a distribution system with a high penetration of DERs, a detailed modeling and representation of the distribution network is needed to accurately assess its steady-state and dynamic behavior. In this dissertation, a field-validated model for a real sub-transmission and distribution network is developed, including one of the feeders modeled with the secondary network and loads and solar PV units at their household/user location. A procedure is developed combining data from various sources such as the utility database, geoinformation data, and field measurements to create an accurate network model.
Applying a single line to ground fault to the detailed distribution feeder model, a high voltage swell, with potentially detrimental impacts on connected equipment, is shown in one of the non-faulted phases of the feeder. The reason for this voltage swell is analyzed in detail. It is found that with appropriate control the solar PV units on the feeder can reduce the severity of the voltage swell, but not entirely eliminate it.
For integrated studies of the transmission-distribution (T&D) network, a T&D co-simulation framework is developed, which is capable of power flow as well as dynamic simulations, and supports unbalanced modeling and disturbances in the distribution as well as the sub-transmission system. The power flow co-simulation framework is developed as a module that can be run on a cloud-based platform.
Using the developed framework, the T&D system response is studied for balanced and unbalanced faults on the distribution and sub-transmission system. For some faults the resultant loss of generation can potentially lead to the entire feeder tripping due to high unbalance at the substation. However, it is found that advanced inverter controls may improve the response of the distribution feeders to the faults. The dissertation also highlights the importance of modeling the secondary network for both steady-state and dynamic studies. Lastly, a preliminary investigation is conducted to include different dynamic elements such as grid-forming inverters in a T&D network simulation.
ContributorsThakar, Sushrut (Author) / Vittal, Vijay (Thesis advisor) / Ayyanar, Raja (Thesis advisor) / Hedman, Mojdeh (Committee member) / Ramapuram Matavalam, Amarsagar Reddy (Committee member) / Arizona State University (Publisher)
Created2023
Description
Physical human-robot interaction (pHRI) has immense potential in fields like industry, military, rehabilitation, and robotic-surgery. However, as the field continues to grow in prominence, there are technical challenges that must be addressed, including safety/stability, adaptability, efficiency, user experience, and versatility. Enhancing pHRI is paramount to overcome these challenges and benefit numerous areas. This dissertation consists of different studies that focus on improving physical human-robot interaction through the development and implementation of various control methods. The first study investigates the lower bounds of robotic damping that humans can stably interact with in different arm postures. The results indicate that the human arm is less capable of adjusting to the unstable environments when it is close to the body and laterally displaced for the anterior-posterior (AP) and the medial-lateral (ML) directions, respectively. The second study proposes a multi-degree-of-freedom variable damping controller that balances stability and agility and reduces user effort in pHRI. The controller effectively reduces user effort while increasing agility without compromising stability. The third study presents a variable stiffness control method to provide intuitive and smooth force guidance during pHRI. This controller significantly reduces robotic force guidance and user effort while maintaining speed and accuracy of movement. Based on the findings from these studies, a biomechanics-based user-adaptive variable impedance control is proposed, which can be applied in a diverse set of applications to enhance the overall performance of coupled human-robot systems. This controller accounts for impedance properties of the human limbs and adaptively changes robotic damping, stiffness, and equilibrium trajectory based on online estimation of user's intent of motion and intent of movement direction while minimizing energy of the coupled human-robot system. Bayesian optimization was used to evaluate an unknown objective function and optimize noisy performance. The presented adaptive control strategy could reduce energy expenditure and achieve performance improvement in several metrics of stability, agility, user effort, smoothness, and user preference. All studies were validated and tested through several human experiments. Overall, the dissertation contributes to the field of pHRI by providing insights into the dynamics of human-robot interactions and proposing novel control strategies to enhance their performance.
ContributorsZahedi, Fatemeh (Author) / Lee, Hyunglae Prof. (Thesis advisor) / Berman, Spring Prof. (Committee member) / Marvi, Hamid Prof. (Committee member) / Yong, Sze Zheng Prof. (Committee member) / Zhang, Yu Prof. (Committee member) / Arizona State University (Publisher)
Created2023
Description
With less than seven years left to reach the ambitious targets of the United Nations' 2030 Sustainable Development Goals (SDGs), it is imperative to understand how the SDGs are operationalized in practice to support effective governance. One integrative approach, the water, energy, and food (WEF) nexus, has been proposed to facilitate SDGs planning and implementation by incorporating synergies, co-benefits, and trade-offs. In this dissertation, I conduct three interrelated WEF nexus studies using a sustainability lens to develop new approaches and identify actionable measures to support the SDGs. The first paper is a systematic literature review (2015 – 2022) to investigate the extent to which WEF nexus research has generated actionable knowledge to achieve the SDGs. The findings show that the WEF nexus literature explicitly considering the SDGs mainly focuses on governance and environmental protection, with fewer studies focusing on target populations and affordability. In the second paper, I reframed the water quality concerns using a nexus and systems thinking approach in a FEW nexus hotspot, the Rio Negro Basin (RNB) in Uruguay. While Uruguay is committed to the 2030 Agenda for Sustainable Development, sustainability challenges endure in managing synergies and trade-offs, resulting in strategy setbacks for the sustainable development of food, land, water, and oceans. Reframing the water quality problem facilitated the identification of potential alternative intervention points to support local problem-solving capacity. In the third paper, I conducted semi-structured interviews and examined the meeting transcripts of the RNB Commission to understand local perspectives about how the activities and initiatives taking place in the basin enhance or diminish the overall sustainability. Sustainability criteria for river basin planning and management were operationalized through qualitative appraisal questions. The case of the RNB illustrates the challenges of coordinating the national development agenda to local livelihood. This dissertation advances the WEF nexus and sustainability science literature by shedding light on the implications of the research trend to support the SDGs, as well as reframing and appraising a persistent water quality problem to support sustainable development.
ContributorsOjeda Matos, Glorynel (Author) / White, Dave D (Thesis advisor) / Brundiers, Katja (Committee member) / Garcia, Margaret (Committee member) / Arizona State University (Publisher)
Created2023
Description
Xylem conduits, a primary feature of most terrestrial plant taxa, deliver water to photosynthetic tissues and play a critical role in plant water relations and drought tolerance. Non-succulent woody taxa generally follow a universal rate of tip-to-base conduit widening such that hydraulic resistance remains constant throughout the plant stem. Giant cacti inhabit arid regions throughout the Americas and thrive in water-limited environments by complimenting water-storing succulent tissues with resource-efficient Crassulacean Acid Metabolism. Considering these adaptations, the objectives of this study were threefold: 1) determine whether xylem conduits in columnar cacti follow universal scaling theory as observed in woody taxa; 2) evaluate whether xylem hydraulic diameter is inversely correlated with xylem vessel density; and 3) determine whether xylem double-wall thickness-to-span ratio and other hydraulic architectural traits are convergent among phylogenetically diverse cactus species. This thesis investigates the xylem anatomy of nine cactus species native to the Sonoran Desert of Arizona and Mexico, the tropical dry forests of southern Mexico, and the Alto Plano region of Argentina. Soft xylem tissues closest to the stem apex underwent a modified polyethylene glycol treatment to stabilize for sectioning with a sledge microtome. Across all species: hydraulic diameter followed a basipetal widening rate of 0.21 (p < 0.001), closely matching the universal rate of 0.20 for woody taxa; and xylem vessel density was inversely correlated with both length from stem apex (p < 0.001) and hydraulic diameter (p < 0.001). Double-wall thickness-to-span ratio had little to no significant correlation with either length from stem apex or hydraulic diameter. There was no significant difference in hydraulic architectural trait patterns between phylogenetically diverse species with various stem morphologies, nor was there a significant correlation between conduit widening rates and volume-to-surface-area ratios.
This study demonstrates that giant cacti follow similar internal anatomical constraints as non-succulent woody taxa, yet stem succulence and water storage behavior in cacti remain separate from internal hydraulic architecture, allowing cacti to thrive in arid environments. Understanding how cacti cope with severe water limitations provides new insights on evolutionary constraints of stem succulents as they functionally diverged from other life forms.
ContributorsCaspeta, Ivanna (Author) / Hultine, Kevin (Thesis advisor) / Throop, Heather (Thesis advisor) / Hernandez, Tania (Committee member) / Arizona State University (Publisher)
Created2023