VictorJuiz/thesis huggingface dataset:
Efficient Aircraft Flutter Analysis using Model Order Reduction with Error Estimation
Keywords: Computational Fluid Dynamics
Dual-Weighted Residual
Dynamic Aeroelasticity
Error Estimation
Flutter Analysis
Reduced Order Modeling

Fast and accurate aircraft flutter analysis in the transonic regime remains an open problem due to the high computational cost of accurately modelling transient aerodynamic forces. In this thesis, a methodology for flutter prediction with the application of model order reduction with error estimation is presented to reduce computational cost while achieving user desired accuracy. The methodology is shown to be computationally efficient, minimize the requirement for user knowledge, and provide user-prescribed accuracy for flutter prediction relative to the high-dimensional aeroelastic model. The Euler equations are used to model the aerodynamics, which are linearized about a nonlinear steady-state solution and reduced using a projection-based model order reduction approach. The resulting aerodynamic ROM is coupled to a structural model to form the primal aeroelastic ROM. The aeroelastic ROM is of low order, allowing for a computationally efficient parameter sweep of the aeroelastic eigenproblem to determine the flutter point. A dual-weighted residual-based error estimator is presented which approximates the error in the eigenvalues obtained from the primal aeroelastic ROM relative to the true eigenvalues from the high-dimensional aeroelastic model. This error estimator makes use of a dual aeroelastic ROM to approximate the dual solution. A second error estimator is presented which approximates the error in the predicted flutter point relative to the true flutter point from the high-dimensional model. By combining the aforementioned algorithmic elements, a ROM-based flutter methodology with error estimation is developed. The proposed method provides the user with approximate aeroelastic eigenvalues, an approximate flutter point, and an estimate of the error in both these quantities. Flutter analyses are presented for several test cases. Both the eigenvalue and flutter point error estimators are shown to have good agreement with the true error. For the test cases presented, the cost of computing the flutter point at a given Mach number is equivalent to the cost of approximately 4 to 15 steady nonlinear flow evaluations of the high-dimensional Euler equations. When compared to a POD-based ROM approach, the proposed method achieves comparable or faster computational times for similar levels of error while additionally providing error estimates for flutter analysis.
Production and Perception of Stylistic Variation along the Continuum of Formality in English as a First and Second Language
Keywords: EFL
ESL
formality
L2 pragmatic competence
pragmatics
stylistic variation

This research explores production and perception of stylistic variation along the continuum of formality in written English. It looks to contribute to research focused on sociopragmatic and pragmalinguistic competence by (1) offering insights into English-dominant individuals’ and English learners’ understanding of formality, knowledge of stylistic variants, and approach to the expression and perception of formality; (2) demonstrating how English-dominant individuals and English learners create styles with specific degrees of formality and how they perceive degrees of formality; and, (3) reporting English-dominant individuals’ and English learners’ confidence about their ability to express and perceive formality. To these ends, data for this research were collected in two subsequent phases (i.e., a production and a perception phase), with each drawing on its own set of participants. Each set included three groups of individuals: those who live in Canada and speak English as a dominant language, those who are learning English while embedded in the Canadian context, and those who are learning English as a foreign language in Slovakia. In both phases, questionnaire data were collected to discover participants’ understanding of formality and knowledge of stylistic variants. The participants in the production phase composed six e-mail messages in English with a specific degree of formality in mind. The participants in the perception phase rated the formality of 18 of the e-mail messages that had been generated by the participants in the production phase. The findings show that, in contrast to the English-dominant individuals, both groups of English learners were less able to provide specific examples of (in)formal stylistic variants; the preferred use of stylistic variants differed across the three participant groups; and the perceived degrees of formality for half of the e-mail messages differed across the three participant groups. The findings also showed that the English learners felt less confident than did the English-dominant individuals about their ability to express and perceive formality in English. This research concludes that English learners would benefit from instruction that increases their knowledge of salient (in)formal stylistic variants and that raises their awareness of the social, cultural, and personal factors that influence their use in English.
Promoting Mineralization at Biological Interfaces with Novel Amelotin-based Bio-Nano Complexes
Keywords: Amelotin
Biomineralization
collagen
Dental resotrations
Nano particles
Protein engineering

According to the World Health Organization, dental caries is the most prevalent chronic disease worldwide. Remineralization of demineralized dentin, especially within the restorative material and tooth tissue interface, is of considerable interest in restorative dentistry since it may improve bond stability and prevent restorative failures.Amelotin (AMTN) is an enamel protein first identified in our lab. AMTN is expressed during the maturation stage of enamel formation and has been shown to promote mineral formation. In native tissue, AMTN is secreted into a microenvironment mostly made of nano-sized hydroxyapatite. Hydroxyapatite is the major inorganic component of the mineralized portion of the tooth. Furthermore, hydroxyapatite is one of the most biocompatible materials used in mineralized tissue regeneration. Therefore, this PhD project aimed to test the hypothesis that AMTN-coated hydroxyapatite nanoparticles (HANP) promote mineralization at collagenous interfaces. This PhD project comprises 3 phases: In phase I, a method for functionalizing HANP with AMTN/AMTN-Col was. HANP were synthesized and characterized. The nanoparticles were functionalized with AMTN or AMTN-Col. The successful coating of the nanoparticles with the proteins was confirmed using the immunogold-labelling technique. In phase II, the mineralization potential of the synthesized bio-nano complexes was studied using model systems consisting of simulated body fluid (SBF), polymerized collagen gels, and dentin disks prepared from human extracted molars. Mineral formation in SBF was recorded with a light scattering assay using a microplate reader. The extent of mineral formation on collagen gel and the remineralization of demineralized dentin were studied with scanning electron microscopy (SEM). Accelerated mineral formation in bio-nano complexes treated samples was observed in all model systems. In phase III, the clinical utilization of bio-nano complexes in bio-integration and enhancing the bond strength of a resin-based dental restoration were investigated. The bio-nano complexes were applied as a pretreatment on dentin prior to adhesive application. Shear bond strength values indicated that pretreatment of dentin with the bio-nano complexes significantly improved shear bond strength. Conclusion: We have shown that AMTN-based bio-nano complexes promote mineral formation on collagenous interfaces. Our findings can serve as the basis for the development of novel bioinspired nanomaterials to improve dental restoration longevity.
The Epidemiology of Postpartum Opioid Prescribing in Ontario
Keywords: Adverse drug events
Breastfeeding
Obstetric Medicine
Opioids
Pharmacoepidemiology
Postpartum

This thesis uses administrative health data to examine temporal trends in postpartum opioid prescribing in Ontario, Canada, as well as the maternal and neonatal risks associated with maternal postpartum opioid therapy. In the first study, I conducted a cross-sectional time series analysis examining whether a highly-publicized 2006 case report questioning the safety of codeine during lactation was associated with changes in postpartum opioid prescribing. I found that postpartum opioid prescribing changed significantly in Ontario following publication of the case report and subsequent safety warnings, including a 30% relative decline in opioid initiation, a reduction in the proportion of prescriptions issued for codeine, and significant increases in the prescribing of more potent opioids. In the second study, I examined whether initiation of oxycodone following delivery was associated with an increased risk of persistent maternal opioid use relative to initiation of codeine. I found that 2.1% of postpartum women had evidence of new persistent opioid use in the year after delivery and compared to women who filled an initial prescription for codeine, receipt of oxycodone was not associated with persistent opioid use (RR 1.04; 95% CI 0.91 to 1.20). In subgroup analyses, I found an association between a prescription of oxycodone and persistent use relative to codeine after vaginal delivery (RR 1.63; 95% CI 1.31 to 2.03), but not after cesarean delivery (RR 0.85; 95% CI 0.73 to 1.00). In the third study, I examined whether postpartum maternal opioid therapy was associated with an increased risk of adverse neonatal outcomes. I found that children born to mothers who filled an opioid prescription were no more likely to be hospitalized for any reason compared to children born to mothers who did not (HR 0.98; 95% CI 0.93 to 1.03). The studies that comprise this thesis found substantial shifts in the types of opioids prescribed to postpartum women temporally associated with a faulty narrative regarding the dangers of codeine during lactation. In addition, our findings help clarify that providers should emphasize the potential risks of postpartum opioid use as they relate to mothers, rather than their infants.
Diversification and Carbon Storage within Temperate Riparian Agroecosystems
Keywords: biodiversity
carbon
ecology
functional traits
riparian
soil science

Riparian agroforestry buffers offer a significant opportunity to enhance carbon (C) storage while also augmenting local biodiversity, with buffer management playing a critical role in determining the services derived from these systems. Notably, woody and herbaceous plant communities drive C cycling via aboveground litter mineralization, belowground root respiration, and soil microbial decomposition dynamics. Yet, how plant diversity and soil microbial biota interact to regulate C cycling remains elusive, especially in riparian ecotones, which are relatively understudied, yet becoming a more prominent agricultural landscape feature. Using a functional-trait based approach, I conducted in-situ field studies paired with laboratory experiments within or using riparian landscape features to assess a series of questions related to diversity and C cycling dynamics. I found that (1) riparian agroforests had significantly higher plant diversity than grassland buffers, which resulted in lower rates of soil CO2 efflux and nitrogen mineralization; (2) differences in drivers of C cycling were significantly impacted by the age of the agroforest buffer (<10 years, or >30 years since establishment), where belowground dynamics controlled C cycling in young buffers, while aboveground traits controlled C cycling in mature buffers; (3) litter functional traits were coordinated with C mineralization rates, where species mixing resulted in synergistic, non-additive effects on soil mineralization (priming effects) and; (4) litter functional traits and litter mixing correlated with fungal and bacterial patterns of succession, with these effects being more pronounced in fungal communities. I provide novel evidence on the understudied effects of plant functional trait diversity on C cycling, distinguishing the important role of above and belowground drivers. Changes in plant community diversity, through the planting of riparian agroforestry buffers, will have positive effects on the ability of these buffer to sequester C, both by shaping diversity of understory herbaceous species and soil microbial communities.
A Complicated Alliance: Indo-Japanese Relations, 1915-1952
Keywords: Imperialism
India
Japan
Nationalism
South Asia
Trasnational History

This dissertation argues that understanding Japan-South Asia relations during the first half of the 20th century (1915-1952) provides a method for explicating the linkages and complicities among empire, nationalism, and internationalism in the modern world. It joins a growing body of literature that adopts a transnational and trans-imperial approach to analyze Japan’s relationship with the world beyond the traditional area studies reference points of the West and East Asia. Bringing critical studies of British and Japanese imperialism together with postcolonial theory, I show how the imperial and nationalist visions of both Japanese Pan-Asianists and prominent Indian independence activists were mutually constitutive projects that were welded together through appeals to cultural and spiritual authenticity. In other words, visions of Pan-Asian community were inseparable from empire and nation in the non-European world even as such visions articulated a universalism that attempted to resist the West. During and after the First World War, Pan-Asianists in Japan mobilized the language of national self-determination to advocate for the establishment of a regional order in the Asia-Pacific that would challenge Euro-American colonialism, while also affirming the universalization of Japan as the guiding model of an authentic “Asian” modernity. This was evinced through the establishment of the Greater East Asia Co-Prosperity Sphere as an empire of client-states, similar to what the United States and the Soviet Union were undertaking in their own ideological registers through the League of Nations and the Third International. Indian nationalists on the other hand, particularly Hindu nationalists, looked to Japan and to some extent Manchukuo as a model of modernization and progress without compromising the authentic spiritual values of their nation. The allure of Pan-Asianist rhetoric, which combined both Orientalism and revolutionary nationalism, appealed to a wide range of middle-class Indian nationalists, including the often-celebrated Subhas Chandra Bose who led the Indian National Army and established the Free India government with Japanese military and diplomatic support. However, such complicities between these groups in their imperial and nation-building projects, especially during the Asia-Pacific War, obscured the violence committed against minorities and labouring classes. Far from celebrating the transnational as an effective method to critique imperialism, this dissertation explores the Japan-South Asia case to highlight how transnational encounters and alliances were both conditioned by, and complicit in, imperialism and nationalism.
Overcoming Barriers to Policy Change: The Politics of Canada’s Innovation Policy
Keywords: Canadian Politics
Economic Development
Innovation
Innovation Policy
Political Economy
Public Policy

This dissertation aims to explain why Canada’s approach to innovation policy has remained so stable over time despite prolonged underperformance in stimulating private sector innovation. Curiously, after decades of declining business expenditure on research and development (BERD) and numerous attempts at policy reform to address it, Canada’s innovation policy mix continues to rely much more than its OECD peer countries on indirect, supply-side, and neutral policy instruments such as research and development (R&D) tax credits and academic research funding (OECD, 2022a; OECD, 2021). Canada’s 2017 Innovation and Skills Plan provides the ideal critical case to ascertain the barriers constraining policy change because despite its stated intention of achieving ‘transformational’ change by adopting direct, demand-side, and targeted instruments (such as R&D grants and procurement), it nonetheless resulted in incremental change to Canada’s overall innovation policy mix (ISED, 2019; OECD, 2021). Analyzing the design and implementation of the Innovation and Skills Plan via public documents and confidential interviews with 143 civil servants, firms, and other experts involved in this policy process reveals how three perennial institutional elements of Canada’s innovation policy process produced this incremental outcome: 1) low coordination across institutional silos within the government; 2) ad hoc and siloed institutional mechanisms for private-public policy coordination; and 3) the politics of regionalism, as institutionalized in Canada’s Westminster system. The primary empirical contribution of this dissertation is illustrating how these three barriers functioned to constrain the adoption of targeted, direct grant/contribution programs like the Innovation Superclusters Initiative and the Strategic Innovation Fund, as well as the demand-side procurement program, Innovative Solutions Canada. This finding confirms the hypothesis synthesized from previous Canadian political economy research that these three entrenched institutional barriers function to frustrate Canada’s adoption of activist industrial policy (Atkinson & Coleman, 1989; Chandler, 1986; French, 1984; Jenkin 1983). This project also contributes to the nascent comparative literature on the politics of innovation policy, highlighting how country-specific institutions make changing innovation policy mixes an inherently path dependent and political - rather than merely technocratic - exercise (Breznitz, 2007; Flanagan, Uyarra, & Laranja, 2011; Taylor, 2016).
Deep Structured Output Models for Localization, Mapping and Labeling
Keywords: Autonomous Driving
Computer Vision
Instance Segmentation
Localization
Machine learning
Mapping

Advances in Machine Learning (ML) technologies coupled with the development of powerful hardware is enabling automation at a large scale in various new fields. In an automation setting, the data domain and the tasks are usually very structured. When building ML methods that map the data domain to an output space that captures the decision or understanding required in an automation task, one should leverage these structures to build more expressive and accurate models. Deep neural networks such as CNNs and RNNs have proven very effective in building rich representations that capture the structure in the data domain. Of interest and the focus of this thesis, the structure in the task can be modeled at varying levels of complexity in the output space: In certain tasks, the output space consists of fixed structured objects such as a graph with a known structure whereas in others, the output space is dynamic and one has to reason over a space of graphs or family of functions with certain characteristics.With the above in mind, the goal of this thesis is to build deep structured output models with varying levels of structure complexity encoded in the output space. One of the major challenges in building these models is designing efficient inference procedures. To this end, we also explore and develop efficient and tractable algorithms for inference in these models. In particular, we leverage branch and bound methods for random fields, deep gradient descent for inference in function spaces and RNNs to greedily discover the structure of graphs. We develop our models in the context of localization, mapping and labeling tasks in the domains of sports understanding and autonomous driving.
High-efficiency Waveguide Tunable Leaky-wave Antennas and Phase-shifters
Keywords: Antennas
Leaky-waves
Metasurfaces

In this thesis, we discuss several ways that one can increase the radiation efficiency of leaky-wave beam-steerable antennas. In this effort, both frequency and fixed frequency scanned leaky-wave antennas are considered. Specifically, we discuss the design and implementation of a slow-wave frequency-scanned leaky-wave antenna that can achieve a high radiation efficiency with a split-block structure. The concentration of the current distribution in the middle of the waveguide due to the proposed design results in reducing the Ohmic loss in the gap of the split-block antenna and maximizing its efficiency. The antenna has a much smaller width compared to its serpentine waveguide counterparts which makes it possible to place several of them side-by-side to narrow the beam or perform beam-steering in the non-scanning plane. We also study the design and implementation of a slotted waveguide with impedance walls as a fixed-frequency beam-steerable leaky-wave antenna. This antenna can be used when a high radiation efficiency is required for fixed-frequency beam steering at relatively high frequencies where the quality factor of electrical tunable elements decreases considerably. In the designed antenna, the power loss in the varactors on the tunable impedance walls is the least compared to the other loss mechanisms. This is because of locating the varactors where the electric field strength is reduced in the reconfigurable waveguide. Using the designed impedance surfaces with reduced power dissipation in varactors, we introduce a new tunable phase shifter based on surface waves with high efficiency. The proposed phase shifter can be used for the implementation of phased arrays with low loss at high frequencies. The design of the proposed phase-shifter is based on maximizing its figure-of-merit (FOM) for achieving 360\textsuperscript{o} of phase shift.
Random Canonical Products and the Secular Function of the Stochastic Airy Operator
Keywords: airy
beta
ensemble
matrix
secular
stochastic

Secular functions of random matrices and their limits are of recent interest in random matrix theory. Such functions are entire with zeros the spectra of the corresponding operators. For example, the general beta ensembles, extending the joint eigenvalue law of classical random matrix ensembles, have a universal soft edge limit upon rescaling called the Airy beta point process. This process also arises as eigenvalues of a random operator called the stochastic Airy operator. It is proven here that secular functions of the general beta ensembles converge in distribution to that of the stochastic Airy operator. Furthermore, this convergence is realized in the context of regularized determinants of operators. This is done by proving new asymptotics of the Airy process and rigidity estimates of the general beta ensembles and establishing this convergence for more general random sequences. These results extend the currently known case for the Gaussian ensembles in Lambert and Paquette (2020). Growth asymptotics are proven for the secular function of the stochastic Airy operator, and as an application some open questions in Lambert and Paquette (2020) are answered. By applying and extending the work in Valkó and Virág (2020) in the bulk case, the secular function is proven to be a unique limiting solution of an ordinary differential equation. Additionally, new convergence laws for discrete matrix models limiting to the stochastic Airy operator are proven, including convergence of the derivatives of eigenfunctions.