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- Genre: Doctoral Dissertation
- Creators: Liu, Yongming
Description
At its core, this dissertation is a study of how one group of ordinary people attempted to make change in their local and national community by reframing a public debate. Since 1993, over five thousand undocumented migrants have died, mostly of dehydration, while attempting to cross the US/Mexico border. Volunteers for No More Deaths (NMD), a humanitarian group in Tucson, hike the remote desert trails of the southern Arizona desert and provide food, water, and first aid to undocumented migrants in medical distress. They believe that their actions reduce suffering and deaths in the desert. On December 4, 2008, Walt Staton, a NMD volunteer placed multiple one-gallon jugs of water on a known migrant trail, and a Fish and Wildlife officer on the Buenos Aires National Wildlife Refuge near Arivaca, Arizona cited him for littering. Staton refused to pay the fine, believing that he was providing life-saving humanitarian aid, and was taken to court as a result. His trial from June 1-3, 2009 is the main focus of this dissertation. The dissertation begins by tracing the history of the rhetorical marker "illegal" and its role in the deaths of thousands of "illegal" immigrants. Then, it outlines the history of NMD, from its roots in the Sanctuary Movement to its current operation as a counterpublic discursively subverting the state. Next, it examines Staton's trial as a postmodern rhetorical situation, where subjects negotiate their rhetorical agency with the state. Finally, it measures the rhetorical effect of NMD's actions by tracing humanitarian and human rights ideographs in online discussion boards before and after Staton's sentencing. The study finds that despite situational restrictions, as the postmodern critique suggests, subjects are still able to identify and engage with rhetorical opportunities, and in doing so can still subvert the state.
ContributorsAccardi, Steven (Author) / Daly Goggin, Maureen (Thesis advisor) / Miller, Keith (Committee member) / Long, Elenore (Committee member) / Arizona State University (Publisher)
Created2011
Description
This project draws on sociocognitive rhetoric to ask, How, in complex situations not of our making, do we determine what needs to be done and how to leverage available means for the health of our communities and institutions? The project pulls together rhetorical concepts of the stochastic arts (those that demand the most precise, careful planning in the least predictable places) and techne (problem-solving tools that transform limits and barriers into possibilities) to forward a stochastic techne that grounds contemplative social action at the intersection of invention and intervention and mastery and failure in real time, under constraints we can't control and outcomes we can't predict. Based on 18 months of fieldwork with the Sudanese refugee diaspora in Phoenix, I offer a method for engaging in postmodern phronesis with community partners in four ways: 1) Explanations and examples of public listening and situational mapping 2) Narratives that elucidate the stochastic techne, a heuristic for determining and testing wise rhetorical action 3) Principles for constructing mutually collaborative, mutually beneficial community-university/ community-school partnerships for jointly addressing real-world issues that matter in the places where we live 4) Descriptions and explanations that ground the hard rhetorical work of inventing new paths and destinations as some of the Sudanese women construct hybridized identities and models of social entrepreneurship that resist aid-to-Africa discourse based on American paternalism and humanitarianism and re-cast themselves as micro-financers of innovative work here and in Southern Sudan. Finally, the project pulls back from the Sudanese to consider implications for re-figuring secondary English education around phronesis. Here, I offer a framework for teachers to engage in the real work of problem-posing that aims - as Django Paris calls us - to get something done by confronting the issues that confront our communities. Grounded in classroom instruction, the chapter provides tools for scaffolding public listening, multi-voiced inquiries, and phronesis with and for local publics. I conclude by calling for English education to abandon all pretense of being a predictive science and to instead embrace productive knowledge-making and the rhetorical work of phronesis as the heart of secondary English studies.
ContributorsClifton, Jennifer (Author) / Long, Elenore (Thesis advisor) / Gee, James Paul (Committee member) / Paris, Django (Committee member) / Warriner, Doris (Committee member) / Arizona State University (Publisher)
Created2012
Description
ABSTRACT For many years, difference scholars, such as Cornel West, Iris Marion Young, and Janet Atwill have been reminding humanities scholars that if social equity is ever to be realized, difference needs to be reconfigured and reframed. As Janet Atwill puts it, "difference can no longer be the anomaly, the enemy, or the problem to be solved. Difference is the condition" (212). While these scholars insightfully recognize that difference needs to be accepted, welcomed and loved rather than merely tolerated, they have not sufficiently addressed the perceptual change that must occur worldwide if difference as an intrinsic underlying condition of human existence is to be embraced. This project provides a point of departure for carrying out such a dramatic epistemic change by arguing that hierarchical thinking, not difference, is the real agent underwriting societal violence and discord. Hierarchical thinking delineates a more appropriate critical space than does difference for social justice inquiry, invention, and intervention. This project also rhetorically theorizes the realm of intersubjectivity and provides two novel contributions to contemporary rhetorical theory: 1) privilege as a rhetorical construct and 2) the untapped inventional potential of the postmodern understanding of intersubjectivity. To illustrate the embodied and performative aspects of hierarchical thinking, this work draws upon the writings of Lillian Smith, a white southerner (1897-1966) whose descriptive analyses of the Jim Crow South allude to large systems of privilege of which Jim Crow is merely representational. Illustrating the invidious nexus of privilege, Smith's writings describe the ways in which individuals embody and perform practices of exclusion and hate to perpetuate larger systems of privilege. Smith shows how privilege operates much as gender and power--fluidly and variously and dependent upon context. Viewing privilege as a rhetorical construct, operating dynamically, always in flux and at play, provides rhetoricians with a theoretically important move that un-yokes privilege from specific identities (e.g., white privilege). When viewed through this more dynamic and precise lens, we can readily perceive how privilege functions as a colonizing, ubiquitously learned, and variegated rhetorical practice of subordination and domination that, as a frame of analysis, offers a more fluid and accurate perspective than identity categories provide for discussions of oppression, social justice, and democratic engagement.
ContributorsHoliday, Judy (Author) / Goggin, Maureen D (Thesis advisor) / Long, Elenore (Committee member) / Miller, Keith (Committee member) / Arizona State University (Publisher)
Created2012
Description
This dissertation theorizes nineteenth-century public performance of spiritual media as being inherent to the production of autobiography itself. Too often, dominant social discourses are cast as being singular cultural phenomena, but analyzing the rhetorical strategies of women attempting to access public spheres reveals fractures in what would otherwise appear to be a monolithic patriarchal discourse. These women's resistant performances reap the benefits of a fractured discourse to reveal a multiplicity of alternative discourses that can be accessed and leveraged to gain social power. By examining the phenomena of four nineteenth- century Spiritualists' mediumship from a rhetorical perspective, this study considers how female spirit mediums used their autobiographies to operate as discursive spaces mediating between private and public spheres; how female mediums constructed themselves in the public sphere as women and as spiritual authorities; how they negotiated entry into volatile and unpredictable publics; how they conceived of the vulnerability of the female body in the public sphere; and how they coped with complications inherent to Victorian era constructions of feminine corporeality. In conclusion, this dissertation offers a highly situated performative theory of subaltern publicity.
ContributorsLowry, Elizabeth (Author) / Daly Goggin, Maureen (Thesis advisor) / Long, Elenore (Committee member) / Miller, Keith (Committee member) / Arizona State University (Publisher)
Created2012
Description
Ultrasound has become one of the most popular non-destructive characterization tools for soft materials. Compared to conventional ultrasound imaging, quantitative ultrasound has the potential of analyzing detailed microstructural variation through spectral analysis. Because of having a better axial and lateral resolution, and high attenuation coefficient, quantitative high-frequency ultrasound analysis (HFUA) is a very effective tool for small-scale penetration depth application. One of the QUS parameters, peak density had recently shown a promising response with the variation in the soft material microstructure. Acoustic scattering is arguably the most important factor behind different parametric responses in ultrasound spectra. Therefore, to evaluate peak density, acoustic scattering at different frequency levels was investigated. Analytical, computational, and experimental analysis was conducted to observe both single and multiple scattering in different microstructural setups. It was observed that peak density was an effective tool to express different levels of acoustic scattering that occurred through microstructural variation. The feasibility of the peak density parameter was further evaluated in ultrasound C-scan imaging. The study was also extended to detect the relative position of the imaged structure in the direction of wave propagation. For this purpose, a derivative parameter of peak density named mean peak to valley distance (MPVD) was developed to address the limitations of peak density. The study was then focused on detecting soft tissue malignancy. The histology-based computational study of HFUA was conducted to detect various breast tumor (soft tissue) grades. It was observed that both peak density and MPVD parameters could identify tumor grades at a certain level. Finally, the study was focused on evaluating the feasibility of ultrasound parameters to detect asymptotic breast carcinoma i.e., ductal carcinoma in situ (DCIS) in the surgical margin of the breast tumor. In that computational study, breast pathologies were modeled by including all the phases of DCIS. From the similar analysis mentioned above, it was understood that both peak density and MPVD parameters could detect various breast pathologies like ductal hyperplasia, DCIS, and calcification during intraoperative margin analysis. Furthermore, the spectral features of the frequency spectrums from various pathologies also provided significant information to identify them conclusively.
ContributorsPaul, Koushik (Author) / Ladani, Leila (Thesis advisor) / Razmi, Jafar (Committee member) / Holloway, Julianne (Committee member) / Li, Xiangjia (Committee member) / Liu, Yongming (Committee member) / Arizona State University (Publisher)
Created2022
Description
Tire blowout often occurs during driving, which can suddenly disturb vehicle motions and seriously threaten road safety. Currently, there is still a lack of effective methods to mitigate tire blowout risks in everyday traffic, even for automated vehicles. To fundamentally study and systematically resolve the tire blowout issue for automated vehicles, a collaborative project between General Motors (GM) and Arizona State University (ASU) has been conducted since 2018. In this dissertation, three main contributions of this project will be presented. First, to explore vehicle dynamics with tire blowout impacts and establish an effective simulation platform for close-loop control performance evaluation, high-fidelity tire blowout models are thoroughly developed by explicitly considering important vehicle parameters and variables. Second, since human cooperation is required to control Level 2/3 partially automated vehicles (PAVs), novel shared steering control schemes are specifically proposed for tire blowout to ensure safe vehicle stabilization via cooperative driving. Third, for Level 4/5 highly automated vehicles (HAVs) without human control, the development of control-oriented vehicle models, controllability study, and automatic control designs are performed based on impulsive differential systems (IDS) theories.
Co-simulations Matlab/Simulink® and CarSim® are conducted to validate performances of all models and control designs proposed in this dissertation. Moreover, a scaled test vehicle at ASU and a full-size test vehicle at GM are well instrumented for data collection and control implementation. Various tire blowout experiments for different scenarios are conducted for more rigorous validations. Consequently, the proposed high-fidelity tire blowout models can correctly and more accurately describe vehicle motions upon tire blowout. The developed shared steering control schemes for PAVs and automatic control designs for HAVs can effectively stabilize a vehicle to maintain path following performance in the driving lane after tire blowout.
In addition to new research findings and developments in this dissertation, a pending patent for tire blowout detection is also generated in the tire blowout project. The obtained research results have attracted interest from automotive manufacturers and could have a significant impact on driving safety enhancement for automated vehicles upon tire blowout.
ContributorsLi, Ao (Author) / Chen, Yan (Thesis advisor) / Berman, Spring (Committee member) / Kannan, Arunachala Mada (Committee member) / Liu, Yongming (Committee member) / Lin, Wen-Chiao (Committee member) / Marvi, Hamidreza (Committee member) / Arizona State University (Publisher)
Created2023
Mechanical Behavior of Meteorites: Multiscale Characterization of the Strength and Failure Mechanism
Description
In this research, the chemical and mineralogical compositions, physical and mechanical properties, and failure mechanisms of two ordinary chondrite (OCs) meteorites Aba Panu (L3) and Viñales (L6), and the iron meteorite called Gibeon (IVA) were studied. OCs are dominated by anhydrous silicates with lesser amounts of sulfides and native Fe-Ni metals, while Gibeon is primarily composed of Fe-Ni metals with scattered inclusions of graphite and troilite. The OCs were investigated to understand their response to compressive loading, using a three-dimensional (3-D) Digital Image Correlation (DIC) technique to measure full-field deformation and strain during compression. The DIC data were also used to identify the effects of mineralogical and structural heterogeneity on crack formation and growth. Even though Aba Panu and Viñales are mineralogically similar and are both classified as L ordinary chondrites, they exhibit differences in compressive strengths due to variations in chemical compositions, microstructure, and the presence of cracks and shock veins. DIC data of Aba Panu and Viñales show a brittle failure mechanism, consistent with the crack formation and growth from pre-existing microcracks and porosity. In contrast, the Fe-Ni phases of the Gibeon meteorite deform plastically without rupture during compression, whereas during tension, plastic deformations followed by necking lead to final failure. The Gibeon DIC results showed strain concentration in the tensile gauge region along the sample edge, resulting in the initiation of new damage surfaces that propagated perpendicular to the loading direction. Finally, an in-situ low-temperature testing method of iron meteorites was developed to study the response of their unique microstructure and failure mechanism.
ContributorsRabbi, Md Fazle (Author) / Chattopadhyay, Aditi (Thesis advisor) / Garvie, Laurence A.J. (Thesis advisor) / Liu, Yongming (Committee member) / Fard, Masoud Yekani (Committee member) / Cotto-Figueroa, Desiree (Committee member) / Arizona State University (Publisher)
Created2023
Description
Sequential event prediction or sequential pattern mining is a well-studied topic in the literature. There are a lot of real-world scenarios where the data is released sequentially. People believe that there exist repetitive patterns of event sequences so that the future events can be predicted. For example, many companies build their recommender system to predict the next possible product for the users according to their purchase history. The healthcare system discovers the relationships among patients’ sequential symptoms to mitigate the adverse effect of a treatment (drugs or surgery). Modern engineering systems like aviation/distributed computing/energy systems diagnosed failure event logs and took prompt actions to avoid disaster when a similar failure pattern occurs. In this dissertation, I specifically focus on building a scalable algorithm for event prediction and extraction in the aviation domain. Understanding the accident event is always the major concern of the safety issue in the aviation system. A flight accident is often caused by a sequence of failure events. Accurate modeling of the failure event sequence and how it leads to the final accident is important for aviation safety. This work aims to study the relationship of the failure event sequence and evaluate the risk of the final accident according to these failure events. There are three major challenges I am trying to deal with. (1) Modeling Sequential Events with Hierarchical Structure: I aim to improve the prediction accuracy by taking advantage of the multi-level or hierarchical representation of these rare events. Specifically, I proposed to build a sequential Encoder-Decoder framework with a hierarchical embedding representation of the events. (2) Lack of high-quality and consistent event log data: In order to acquire more accurate event data from aviation accident reports, I convert the problem into a multi-label classification. An attention-based Bidirectional Encoder Representations from Transformers model is developed to achieve good performance and interpretability. (3) Ontology-based event extraction: In order to extract detailed events, I proposed to solve the problem as a hierarchical classification task. I improve the model performance by incorporating event ontology. By solving these three challenges, I provide a framework to extract events from narrative reports and estimate the risk level of aviation accidents through event sequence modeling.
ContributorsZhao, Xinyu (Author) / Yan, Hao (Thesis advisor) / Liu, Yongming (Committee member) / Ju, Feng (Committee member) / Iquebal, Ashif (Committee member) / Arizona State University (Publisher)
Created2022
Description
Cellular metamaterials arouse broad scientific interests due to the combination of host material and structure together to achieve a wide range of physical properties rarely found in nature. Stochastic foam as one subset has been considered as a competitive candidate for versatile applications including heat exchangers, battery electrodes, automotive, catalyst devices, magnetic shielding, etc. For the engineering of the cellular foam architectures, closed-form models that can be used to predict the mechanical and thermal properties of foams are highly desired especially for the recently developed ultralight weight shellular architectures. Herein, for the first time, a novel packing three-dimensional (3D) hollow pentagonal dodecahedron (HPD) model is proposed to simulate the cellular architecture with hollow struts. An electrochemical deposition process is utilized to manufacture the metallic hollow foam architecture. Mechanical and thermal testing of the as-manufactured foams are carried out to compare with the HPD model. Timoshenko beam theory is utilized to verify and explain the derived power coefficient relation. Our HPD model is proved to accurately capture both the topology and the physical properties of hollow stochastic foam. Understanding how the novel HPD model packing helps break the conventional impression that 3D pentagonal topology cannot fulfill the space as a representative volume element. Moreover, the developed HPD model can predict the mechanical and thermal properties of the manufactured hollow metallic foams and elucidating of how the inevitable manufacturing defects affect the physical properties of the hollow metallic foams. Despite of the macro-scale stochastic foam architecture, nano gradient gyroid lattices are studied using Molecular Dynamics (MD) simulation. The simulation result reveals that, unlike homogeneous architecture, gradient gyroid not only shows novel layer-by-layer deformation behavior, but also processes significantly better energy absorption ability. The deformation behavior and energy absorption are predictable and designable, which demonstrate its highly programmable potential.
ContributorsDai, Rui (Author) / Nian, Qiong (Thesis advisor) / Jiao, Yang (Committee member) / Kwon, Beomjin (Committee member) / Liu, Yongming (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2021
Description
Ultra-fast 2D/3D material microstructure reconstruction and quantitative structure-property mapping are crucial components of integrated computational material engineering (ICME). It is particularly challenging for modeling random heterogeneous materials such as alloys, composites, polymers, porous media, and granular matters, which exhibit strong randomness and variations of their material properties due to the hierarchical uncertainties associated with their complex microstructure at different length scales. Such uncertainties also exist in disordered hyperuniform systems that are statistically isotropic and possess no Bragg peaks like liquids and glasses, yet they suppress large-scale density fluctuations in a similar manner as in perfect crystals. The unique hyperuniform long-range order in these systems endow them with nearly optimal transport, electronic and mechanical properties. The concept of hyperuniformity was originally introduced for many-particle systems and has subsequently been generalized to heterogeneous materials such as porous media, composites, polymers, and biological tissues for unconventional property discovery. An explicit mixture random field (MRF) model is proposed to characterize and reconstruct multi-phase stochastic material property and microstructure simultaneously, where no additional tuning step nor iteration is needed compared with other stochastic optimization approaches such as the simulated annealing. The proposed method is shown to have ultra-high computational efficiency and only requires minimal imaging and property input data. Considering microscale uncertainties, the material reliability will face the challenge of high dimensionality. To deal with the so-called “curse of dimensionality”, efficient material reliability analysis methods are developed. Then, the explicit hierarchical uncertainty quantification model and efficient material reliability solvers are applied to reliability-based topology optimization to pursue the lightweight under reliability constraint defined based on structural mechanical responses. Efficient and accurate methods for high-resolution microstructure and hyperuniform microstructure reconstruction, high-dimensional material reliability analysis, and reliability-based topology optimization are developed. The proposed framework can be readily incorporated into ICME for probabilistic analysis, discovery of novel disordered hyperuniform materials, material design and optimization.
ContributorsGao, Yi (Author) / Liu, Yongming (Thesis advisor) / Jiao, Yang (Committee member) / Ren, Yi (Committee member) / Pan, Rong (Committee member) / Mignolet, Marc (Committee member) / Arizona State University (Publisher)
Created2021