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Advances in Coastal Flood Risk Analysis
No full textMuch work has been done to advance the state of risk-informed decision-making to protect against coastal flooding. The state of the art as practiced in the state of Louisiana, the Coastal Louisiana Risk Assessment Model (CLARA) characterizes flood risk driven by surge and waves from tropical storms as a random process and estimates the distribution of flood depths and resulting economic damage. This dissertation identifies three key limitations of coastal flood risk assessment as applied to the state of Louisiana, proposes methods to address them, and demonstrates each method in a case study. The first limitation identified is that the CLARA model addresses surge- and wave-driven flood hazard but does not account for rainfall-driven and riverine hazard. To address this limitation, chapter 2 presents an extension of the methods used in CLARA developed as part of the Louisiana Watershed Initiative which permits characterization of compound hazard consisting of surge, rainfall, and riverine hazard from tropical cyclones. The second limitation identified is that due to its computational cost CLARA is used in Louisiana’s 2023 Coastal Master Plan to evaluate pre-specified and static flood risk mitigation projects over a small set of possible future landscapes; it would be preferable to use an optimization-driven approach to generate efficient and adaptive combinations of projects which balance performance across a diverse set of possible future landscapes. To address this limitation, chapter 3 presents an analysis applying a spatially narrower but computationally inexpensive model based on CLARA called the SWaMPS model to a case study to determine the extent to which optimization-based adaptive mitigation strategies which respond to observed climate change trajectories can outperform similar static strategies. The third and final limitation identified is that while the most recent iteration of the CLARA model can support algorithmic optimization of cost-effectiveness of building-level mitigation strategies such as retrofits to increase the first floor elevation of singlefamily residences, the principal metric historically used in flood risk mitigation is reduction in economic damage measured in dollars, the optimization of which on the level of individual buildings would implicitly prioritize expensive structures and therefore may neglect impoverished neighborhoods. Chapter 4 addresses this limitation with a proposed alternative efficiency metric which treats individual homes as equally valuable, the optimization of which results in greater investment in impoverished neighborhoods without explicitly targeting final expected damage distributions or individual groups
Objective Flow Pattern Identification and Classification in Inclined Two-Phase Flows Using Machine Learning Methods
No full textTwo-phase modeling and simulation capabilities are strongly dependent on the accuracy of flow regime identification methods. Flow regimes have traditionally been determined through visual observation, resulting in subjective classifications that are susceptible to inconsistencies and disagreements between researchers. Since the majority of two-phase flow studies have been concentrated around vertical and horizontal pipe orientations, flow patterns in inclined pipes are not well-understood. Moreover, they may not be adequately described by conventional flow regimes which were conceptualized for vertical and horizontal flows. Recent work has explored applying machine learning methods to vertical and horizontal flow regime identification to help remedy the subjectivity of classification. Such methods have not, however, been successfully applied to inclined flow orientations. In this study, two novel unsupervised machine learning methods are proposed: a modular configuration of multiple machine learning algorithms that is adaptable to different pipe orientations, and a second universal approach consisting of several layered algorithms which is capable of performing flow regime classification for data spanning multiple orientations. To support this endeavor, an experimental database is established using a dual-ring impedance meter. The signals obtained by the impedance meter are capable of conveying distinct features of the various flow patterns observed in vertical, horizontal, and inclined pipes. Inputs to the unsupervised learning algorithms consist of statistical measures computed from these signals. A novel conceptualization for flow pattern classification is developed, which maps three statistical parameters from the data to red, green, and blue primary color intensities. By combining the three components, a flow pattern map can be developed wherein similar colors are produced by flow conditions with like statistics, transforming the way flow regimes are represented on a flow regime map. The resulting dynamic RGB flow pattern map provides a physical representation of gradual changes in flow patterns as they transition from one regime to another. By replacing the static transition boundaries with physically informed, dynamic gradients between flow patterns, transitional flow patterns may be described with far greater accuracy. This study demonstrates the effectiveness of the proposed method in generating objective flow regime maps, providing a basis for further research on the characterization of two-phase flow patterns in inclined pipes. The three proposed methods are compared and evaluated against flow regime maps found in literature
Data-Based On-Board Diagnostics for Diesel-Engine Nox-Reduction Aftertreatment Systems
No full textAn aftertreatment (AT) system is responsible for reducing harmful exhaust emissions that result from fuel combustion in an internal combustion engine (ICE). Selective Catalytic Reduction (SCR) and Ammonia Slip Catalyst (ASC) are important components of diesel AT system that deal with oxides of nitrogen (NOx) and ammonia (NH3) components of the exhaust gas. SCR reduces NOx to harmless N2 and H2O by controlled injection of NH3 into the exhaust. NH3 itself being harmful, the unreacted NH3 that slips downstream of SCR is oxidized in ASC to N2.The performance of SCR-ASC system degrades with time as the SCR-ASC catalytic block ages. This leads to increase in emissions that eventually exceed the acceptable limits. On-Board Diagnostics (OBD) is a program that monitors this phenomenon in real time and flags when SCR-ASC system degrades beyond acceptable limit. The aim of this study is to devise a data-based OBD binary classification method to distinguish an aged SCR-ASC catalyst from healthy ones in real-world conditions.The data was made available by Cummins Inc. Available data consisted of various temporal signals such as Temperatures, Species Concentrations, Flow rates, etc, and was acquired in two different settings. The first was under Test-Cell (TC) settings, with controlled environment and lab-grade accurate sensors. The AT system was subjected to standard drive cycles, namely, cold Federal Test Procedure (cFTP), hot Federal Test Procedure (hFTP) and Random Mode Cycle (RMC). The second was under real-world operating conditions using commercial on-road truck sensors on 4 trucks at two different instances in time: one, during the truck’s on-road debut (referred to as DG trucks), and the second, after a significant number of miles on respective odometer readings (referred to as EUL trucks).In pure data-driven approach, all 5 measurable or computable signals namely, CE, T, F, DEF and EONOx, were used as input features, and class labels 1 and 2 were used for DG and EUL catalysts, respectively, as output feature. Multiple supervised Machine Learning models were cross-validated on TC data from all three cycles (cFTP, hFTP and RMC). Highest training-test accuracies were observed while using SVM with Gaussian kernel function model. Thus, an SVM with Gaussian kernel function model was used in subsequent analysis and is referred to as classifier from hereon. EUL truck with lowest mileage was deemed least aged and the one with most mileage was deemed most aged by the classifier cross-validated on filtered TC data. The classifier cross-validated on truck data showed a clear increase in catalyst age with mileage on all 4 trucks.In model-informed approach, TPNOx and storage fraction signals computed by a calibrated 3-state CSTR model and a look-up-table-based ASC map (referred to as model from hereon), were used in place of sensor measured signals. A classification TPNOx boundary was computed and a confidence interval was defined depending on position of a sample relative to the boundary. The classifier trained on filtered and modelled truck signals of the highest mileage truck correctly distinguished all 4 DG and EULtrucks.A model-informed strategy with accurate NH3 storage and TPNOx model estimates gave more accurate results than a purely data-based strategy. The best case result gave one in eight falsely classified day-files when storage was used whereas 4 in eight falsely classified day-files when storage was not used. It is crucial to identify and use a data subset that shows dominant aging signatures. Hence, data filtering strategies play a crucial role in determining the dependability and accuracy of the results
Numerical Investigation of Savonius Wind Turbines
No full textIn this study, we aimed to explore the potential of integrating wind turbines into tall buildings to harness wind energy in urban areas. Advanced computer simulations will be used to analyze the complex wind patterns and turbulence around tall buildings. We will also study the optimization of wind turbine placement to maximize energy production. We focus on two types of wind turbines, the savonius and a modified savonius, using the Myring formula. We evaluated their performance in turbulent urban areas using computational fluid dynamics simulations. The simulations will also help us understand the wind flow behavior around tall buildings, informing wind turbine placement optimization.Our findings contribute to the understanding of urban wind energy production. This may lead to further advancements in wind turbine design and application in urban environments, promoting sustainable and clean energy production in densely populated areas.We also evaluate the economic feasibility of wind power as an energy source and its potential for commercial applications. Our study\u27s insights are significant for wind energy research, urban planning, and sustainable energy production in cities.To achieve our objectives, we will use state-of-the-art computational tools such as the ANSYS Fluent Student software and the Steady Reynolds Averaged Navier-Stokes (SRANS) Kε model and K-ω SST models for simulating wind flow around tall buildings.el and K-ω SST models for simulating wind flow around tall buildings. In summary, the goal of this research is to develop a methodology for integrating wind turbines into tall urban buildings to harness wind energy potential. This will contribute to the understanding of urban wind energy production and its economic feasibility for commercial applications
Subject Pronoun Distribution in Child Heritage Speakers of Spanish: Semantic Constraints Regulation Overt/Null Pronouns in Focus/Topic Environments
No full textThe present study aims to examine the grammar of Spanish heritage children in relation to the syntax-discourse interface by analyzing the distribution of subject pronouns in focus and topic contexts. Focus and topic are related to the information structure of a clause, the former refers to new information of the sentence and the latter indicates old or known information (Lozano-Pozo, 2003). Studies exploring this phenomenon in various combinations of languages and L2 populations have found a clear overextension and overuse of overt subject pronouns in topic contexts in pro-drop languages, where the preferred option is the null pronoun, due to crosslinguistic influence from the L1 (Pérez-Leroux & Glass, 1999; Tsimpli & Sorace, 2006; Belletti et al., 2007; Sorace et al., 2009). Considering the results of previous research, this study examines the extent to which Spanish heritage speakers exhibit knowledge of subject pronoun distribution in focus and topic contexts by comparing them to their monolingual counterparts.Thirteen child heritage speakers of Spanish and twenty-seven monolingual children completed a structured elicitation task which consisted of a story followed by a question asking about an embedded subject (Focus condition) or an embedded direct object (Topic condition). Results revealed no overextension of overt subject pronouns in topic contexts due to crosslinguistic influence from English. However, differences were found in the focus condition. Heritage children diverged from the monolingual group since they produced considerably fewer instances of overt subject pronouns. It is hypothesized that heritage children are opting for the null pronoun option as the default option, which suggests they are prolonging the Null Subject Stage (Hyams, 1986). This finding points to protracted development due to a lack of activation of the language. Further findings are discussed taking into consideration current approaches that examine the effects of language dominance, exposure, and use
Baby Boomers, Gen X, Millennials, and Gen Z Teachers: A Comparison of Generational Preferences for Leadership Practices
No full textThe current educational workforce is made up of baby boomers, Generation Xers, millennials, and Generation Zers. Research on generational theory reflects variations in characteristics, work preferences and values among generations, yet there is little known whether teachers from these various generations need differing leadership practices to perform their best. This quantitative study utilized a cross sectional survey design collecting data from 502 Indiana teachers to identify the need teachers place on principals’ leadership behaviors and determine if any significant differences exist based on their generation, gender, the type of community they grew up in or the type of community where they currently teach. Utilizing Kouzes and Posner’s (1985) Leadership Practices Inventory, participants rated their need for 30 leadership behaviors on a 10-point Likert scale. Overall, teachers from all groups rated they needed principals to exhibit leadership practice enabling others to act the highest with an overall mean score of 8.75 (SD=1.20) followed by modeling the way (M=8.40, SD=1.29), encouraging others (M=8.28, 1.46), challenging the process (M=7.63, SD=1.46), and lastly inspiring a shared vision (M=7.50, SD=1.57). Conducting an independent t-test to compare the means of gender groups and a one-way ANOVA to compare generations, community types and building types resulted in no significant differences in teachers’ need for leadership practices. The results of this study reinforce Kouzes and Posner’s five practices of exemplary leaders as relevant across generations yet leaves open questions for future study on how principals can capitalize on the strengths various generations bring to the school family
Translating Diversity from Ralph Ellison to Kenzaburō Ōe
Get PDFThe purpose of this article is twofold: first, it endeavors to understand the vagaries of the notion of diversity as it travels from one national and political context to the next; and second, it shows how two major fiction writers and essayists have used that notion in their work and to what ends. The first part focuses on the work of Ralph Ellison, who put diversity at the heart of his reflection on what a truly democratic American society should be. Kenzaburō Ōe initially borrowed the notion of diversity from Ellison himself, but as the second part demonstrates, Ōe did not merely transpose Ellison’s notion of diversity onto his work. Instead, Ōe translated it, adapting it to his political and cultural environment, and expanding its meaning to be consonant with the substance of his literary universe. In Ōe’s work, the notion of diversity changes according to both Ōe’s evolution as a person and a writer and the development of Japanese society and politics since the postwar era. Ultimately, Ellison’s and Ōe’s respective notions of diversity are very dissimilar, and yet both authors concur on the key role diversity should play in shaping a more democratic world
On Gary Snyder’s Tradaptation of \u3cem\u3eCold Mountain Poems\u3c/em\u3e and its Spiritual Salvation and Literary Enlightenment in Postwar America
Get PDFCold Mountain Poems (CMPs), which have been neglected in the history of Chinese literature for ages, captured the attention of most Americans immediately after its being translated into America by the American poet Gary Snyder in 1950s, however. It is Snyder that reconfigured and recreated a sagacious Chinese Chan Buddhist poet Han-shan (literally, Cold Mountain), the acknowledged author of Cold Mountain Poems, in his translation for the postwar Americans in the midst of varied social problems and cultural identity crisis after World War II. Snyder eventually found in his translation of Cold Mountain Poems a back-to-nature remedy of spiritual salvation and literary enlightenment for the beat generation and even the entire American literary community at large then and after, by means of his delicate transcreation of Han-shan images in line with American expectations at the time as well as by means of his skillful tradaptation of the realistic elements of self-expression, self-identification and self-actualization in Cold Mountain Poems and also by means of his profound exploration of the Chan Buddhism aesthetics and philosophical mediation in classical Chinese landscape poems and Chinese hermit cultur
The Long Shadow: Literary and Cinematic Representation and Re-Imagination of Chinese Female Traumas in the Second Sino-Japanese War
No full textThis dissertation enriches the field of Comparative Literature by examining the trauma narratives of Chinese women in wartime through a cross-cultural and cross-medium lens. It focuses on their experiences as they are articulated in a variety of texts and visual media, in the process offering an exploration of the intersection between gender, trauma, and war. By incorporating theoretical frameworks from Western trauma studies into an analysis of Chinese and Asian contexts, the study further contributes to Comparative Literature by fostering an intercultural dialogue. This unique approach uncovers shared patterns of human suffering and resilience, providing new insights into the universality and particularity of trauma representation. The dissertation extends the boundaries of Comparative Literature by examining the influence of gender on the construction and reception of trauma narratives. It also gives a novel contribution by addressing broader social and political issues both in the context of China, Asia, and globally. The four chapters examine the portrayal of women’s experiences produced generations after the war, focusing on the following topics, respectively: the witness of sexual violence, the challenges of representing feminine pain, repetition of traumatic memory, and the complexity of individual and collective experiences in relation to wartime traumas. By analyzing mostly novels, as well as films and testimonies, the dissertation emphasizes the importance of considering both historical records and shared personal memories, as well as the role of artistic expression in fostering empathy and understanding. This research offers a valuable contribution by illuminating the enduring and complex impact of war on women’s lives. Furthermore, it provides a strong foundation for future studies, ultimately contributing to a more nuanced understanding of the representation of traumatic experiences of individuals and communities affected by trauma
A Resilience-Oriented Extra-Terrestrial Habitat Design Process
No full textIn the wake of the first Artemis launch, humanity is more focused on space exploration and travel than it has been in the half a century since the Space Race. This time, it’s not enough just to touch down on the Moon; we want to build sustainable homes on the Moon and on Mars. The goal of long-term extra-terrestrial habitation begs the question: how do we design habitats that can protect human life so far from Earth?The Resilient Extra-Terrestrial Habitat Institute (RETHi) has been operating for four years now building a foundation of ideologies and tools to help answer that question. The institute has developed a control-theoretic approach to habitat resilience based on a state-trigger analysis, a database of potential hazards to a habitat, metrics for resilience quantification, and simulation platforms for design verification.The combination of these developments allows for the proposition of a resilience-oriented habitat design process. The process takes the shape of a typical systems vee and is tailored to the needs of an extra-terrestrial habitat and the tools available through RETHi. The process proposes a way to build resilience into the requirements development and design verification of extra-terrestrial habitats at three system levels. The result of this study is a discussion on how we design, evaluate, and select safety mechanisms for extra-terrestrial habitats.Safety mechanisms are selected by simulating the habitat’s response to a disruption when equipped with one safety mechanism at a time and quantifying the habitat’s resilience. Then, the resilience of the habitats with different mechanisms are compared, illuminating the best option. Simulations for each mechanism are performed under a variety of circumstances, changing the time of day and intensity of the disruption as well as the type of repair agent carrying out the mechanism to capture the habitat’s behavior as totally as possible.This analysis shows how different safety mechanisms performances compare and provides a basis for making design decisions