VictorJuiz/thesis huggingface dataset:
Native Dialect Effects in Non-native Production and Perception of Vowels

This dissertation examines the role of the native dialect in non-native perception and production in the specific case of Cuban and Peninsular Spanish as native varieties and of English vowels as in hat, hut, hot as the target. In most second language studies, the learners’ native variety is assumed to be homogenous, regardless of their regional variety. Nevertheless, regional varieties differ in non-trivial ways and such differences need to be considered when analyzing second language acquisition. This dissertation takes shape around the main research question of whether potentially systematic differences between vowels in the native dialects of Cuban and Peninsular Spanish would produce matching phonetic differences in non-native perception and production of English vowels. This question was addressed in three experiments that compared native vowels in these Spanish varieties, as well as the perception and production of the target English vowels as in hat, hut, hot by Cuban and Peninsular Spanish learners. Significant cross-dialectal differences were identified in the production of native vowels, namely, locations of /i, o/, durations of /e, a, o/ as well as different variability patterns, which were predicted to influence mapping of sounds in L2 perception and production. In L2 perception, discrimination for advanced and naïve listeners from each dialect was tested with English contrasts as in hat-hut, hut-hot, and hat-hot. No clear native dialect effect could be identified; however, Cuban advanced listeners obtained high error rates with hut-hot. In L2 production, though, dialect-specific patterns were found: Peninsular learners produced vowels as in hat, hut, hot with significant spectral but no durational differences whereas Cuban learners produced vowels as in hut, hot with no significant spectral but with duration differences. I concluded that the native dialect was one of several factors generating the differences between Peninsular and Cuban participants’ perception and production of English vowels as in hat, hut, hot. The conjoint effect of the native dialect, input and learning experience were shown to have contributed to the distinctions. This finding contributes to second language acquisition research because it stresses the need to control for learners’ native dialect. This research contributed new acoustic data on Cuban Spanish and on L2 English. It uncovered specific patterns and interlanguage strategies of Spanish learners of English.

Keywords: Spanish dialects
English vowels
L1, L2 production
L2 perception
Advisor: Colantoni, Laura
Formal Methods in Computer-aided Design

The VLSI CAD flow encompasses an abundance of critical NP-complete and PSPACE-complete problems. Instead of developing a dedicated algorithm for each, the trend during the last decade has been to encode them in formal languages, such as Boolean satisfiability (SAT) and quantified Boolean formulas (QBFs), and focus academic resources on improving SAT and QBF solvers. The significant progress of these solvers has validated this strategy. This dissertation contributes to the further advancement of formal techniques in CAD. Today, the verification and debugging of increasingly complex RTL designs can consume up to 70% of the VLSI design cycle. In particular, RTL debug is a manual, resource-intensive task in the industry. The first contribution of this thesis is an in-depth examination of the factors affecting the theoretical computational complexity of debugging. It is established that most variations of the debugging problem are NP-complete. Automated debugging tools return all potential error sources in the RTL, called solutions, that can explain a given failing error trace. Finding each solution requires a separate call to a formal engine, which is computationally expensive. The second contribution of this dissertation comprises techniques for reducing the number of such iterations, by leveraging dominance relationships between RTL blocks to imply solutions. Extensive experiments on industrial designs show a three-fold reduction in the number of formal engine calls due to solution implications, resulting in a 1.64x overall speed-up. The third contribution aims to advance the state-of-the-art of QBF solvers, whose progress has not been as impressive as that of SAT solvers. We present a framework for using complete dominators to preprocess and reduce QBFs with an inherent circuit structure, which is common in encodings of PSPACE-complete CAD problems. Experiments show that three modern QBF solvers together solve 55% of preprocessed QBF instances, compared to none without preprocessing. The final contribution consists of a series of QBF encodings for evaluating the reconfigurability of partially programmable circuits (PPCs). The metrics of fault tolerance, design error tolerance and engineering change coverage are defined for PPCs and encoded using QBFs. These formulations along with experimental results demonstrate the theoretical and practical appropriateness of QBFs for dealing with reconfigurability.

Keywords: CAD
QBF
SAT
Debug
Formal methods
PPC
Advisor: Veneris, Andreas
Quadrature Down-converter for Wireless Communications

Future generation of wireless systems will feature high data rates and be implemented in low voltage CMOS technologies. Direct conversion receivers (DCRs) will be used in such systems which will require low voltage RF front-ends with adequate linearity. The down-converter in a DCR is a critical block in determining linearity. In addition to detailed DCR modeling in MATLAB, this thesis, completed in 2005, deals with the design and characterization of a 1V, 8GHz quadrature down-converter. It consists of two mixers and a quadrature generator implemented in a 0.18m CMOS technology. The mixer architecture proposed in this work uses a new trans-conductor. It simultaneously satisfies the low voltage and high linearity requirements. It also relaxes the inherent trade-off between gain and linearity governing CMOS active mixers. The implemented mixer occupies an area of 320 x 400 m2 and exhibits a power conversion gain of +6.5dB, a P-1dB of -5.5dBm, an IIP3 of +3.5dBm, an IIP2 of better than +48dBm, a noise figure of 11.5dB, an LO to RF isolation of 60dB at 8GHz and consumes 6.9mW of power from a 1V supply. The proposed quadrature generator circuit features a new architecture which embeds the quadrature generation scheme into the LO-buffer using active inductors. The circuit offers easy tune-ability for process, supply and temperature variations by relaxing the coupling between amplitude and phase tuning of the outputs. The implemented circuit occupies an area of 150 x 90m2 and exhibits an amplitude and quadrature phase accuracy of 1 dB and 1.5° respectively over a bandwidth of 100 MHz with a power consumption of 12mW from a 1V supply including the LO-buffer. The quadrature down-converter features an image rejection ratio of better than 40 dB and satisfies the potential target specifications of future mobile phones, extracted in this work.

Keywords: Mixer
Quadrature
Advisor: Ng, Wai Tung
Biomechanical Characterization of Complex Thin Bone structures in The Human Craniofacial Skeleton

In spite of burgeoning of new technologies in the field of maxillofacial surgery, such as novel methods for osteosynthesis, bone substitution and bone regeneration, the reconstruction of the craniofacial skeleton (CFS) remains a challenge. Complications and failure in existing technologies and treatments for the CFS may be attributed in part to an incomplete understanding of the biomechanical environment in which these technologies are expected to perform. Characterizing the morphology and biomechanical behaviour of this complex and unique structure is important to understanding its global response to mechanical demands. This thesis aims to characterize the biomechanical behaviour of thin bone regions and sutures in the CFS. We investigated the impact of image degradation in CT scans on the ability to develop accurate specimen-specific FE models. Image degradation resulted in large increases in cortical thickness and decreases in scan intensity, which corresponded to significant changes in maximum principal strains in the FE models. A new semi-automated connectivity technique was developed to quantify the degree of fusion in sutures and revealed varying degrees of connectivity and interdigitation depending on the suture location. Morphological features characterized using this technique were incorporated into idealized suture FE models and analysed under multiple loading directions. The idealized FE models revealed that the impact of the number of interdigitations on the strain energy absorption in the suture/bone complex is dependent on the loading direction (inversely related under pressure and directly related under perpendicular and pressure loading); similar behaviour was seen in a μCT based specimen-specific FE model. Three-point bending tests on bone samples containing sutures revealed a positive correlation between the number of interdigitations and bending strength. Finally, experimental testing of full cadaveric heads demonstrated inter-specimen consistency in strain magnitude and direction under muscle loading in spite of morphological differences. Overall, these findings provide new insight into the complex morphology of the CFS, limitations of current clinical imaging and the biomechanical behaviour of thin bone structures and their articulations. This work forms a solid foundation for future development of image analysis, modeling and experimental investigations focused on characterizing the global behaviour of the CFS.

Keywords: Craniofacial
Biomechanics
Sutures
CT
Advisor: Cari, Whyne
Is the Financial Market a Mechanism for Environmental Overcompliance?

Climate change legislation is financially and politically costly. Financial markets have the capacity to encourage companies to do more than what is required by law (i.e. overcomply), and this could lead to socially optimal outcomes without the costs. First, I examine how the responses of Canadian companies to a voluntary survey regarding carbon emission levels affect those companies' valuations. I employ a signaling framework where companies choose between two signals - disclosure and nondisclosure - and where investors are uncertain about the likelihood of legislation in addition to company type. I test the prediction of the model that disclosure increases company value only when investors believe legislation is likely. I find that withholding emissions information resulted in average daily abnormal returns of 3 basis points, and that disclosure resulted in average daily abnormal returns of -11 basis points in the days surrounding the submission of survey responses. The level of emissions disclosed is found to be irrelevant. Second, I examine the credibility of green legislative threat. The economic climate impacts the government's ability to credibly threaten new environmental law, and so I model a company's pollution decision as a function of the economic climate. In times of recession, companies may choose to pollute heavily since they believe that the likelihood of legislation is low. As a first step in evaluating the model empirically, I use differences-in-differences regressions to estimate the effect of legislative threat during recession on company value. Although the value of carbon-intensive companies decreased initially in reaction to legislative threat, the relative value of these companies increased as the depth of the recession becomes more apparent. I find that on average the legislative threat of an emission trading scheme reduced Tobin's Q by 18% in the initial stages of the recession, but as the recession deepened the legislative threat effect was eliminated. My results suggest that financial markets combined with a credible threat of legislation could provide encouragement to companies to overcomply with current regulations, possibly to the extent that is socially optimal. More research on factors affecting company carbon emissions levels and intensity is required.

Advisor: Park, Andreas
Aivazian, Varouj
Stability-constrained Aerodynamic Shape Optimization with Applications to Flying Wings

A set of techniques is developed that allows the incorporation of flight dynamics metrics as an additional discipline in a high-fidelity aerodynamic optimization. Specifically, techniques for including static stability constraints and handling qualities constraints in a high-fidelity aerodynamic optimization are demonstrated. These constraints are developed from stability derivative information calculated using high-fidelity computational fluid dynamics (CFD). Two techniques are explored for computing the stability derivatives from CFD. One technique uses an automatic differentiation adjoint technique (ADjoint) to efficiently and accurately compute a full set of static and dynamic stability derivatives from a single steady solution. The other technique uses a linear regression method to compute the stability derivatives from a quasi-unsteady time-spectral CFD solution, allowing for the computation of static, dynamic and transient stability derivatives. Based on the characteristics of the two methods, the time-spectral technique is selected for further development, incorporated into an optimization framework, and used to conduct stability-constrained aerodynamic optimization. This stability-constrained optimization framework is then used to conduct an optimization study of a flying wing configuration. This study shows that stability constraints have a significant impact on the optimal design of flying wings and that, while static stability constraints can often be satisfied by modifying the airfoil profiles of the wing, dynamic stability constraints can require a significant change in the planform of the aircraft in order for the constraints to be satisfied.

Keywords: optimization
MDO
design optimization
aerodynamic shape optimization
flying wings
aircraft design
stability
aerospace
Advisor: Martins, Joaquim R. R. A.
Exploring Higher Education Regionalization through a Study of the Asia Pacific Quality Network

This thesis investigates higher education regionalization by studying the case of the Asia Pacific Quality Assurance Network (APQN). In this thesis, higher education regionalization is conceptualized in three ideal-types: 1) as a sub-set of higher education globalization, 2) as a regional form of higher education internationalization, and 3) as an alternative to higher education globalization. Theories of international relations and globalization are used to develop a conceptual framework of the norms, values, ideologies, and concepts of regional identity that underpin these constructs. The main research question asks what can be learned about higher education regionalization through a study of the APQN? A sequential mixed method approach is used to gather data from textual analysis, key informant interviews, participant observation, and an online survey to investigate how the APQN bridges national, regional, and international levels of quality assurance in higher education. A methodological triangulation design is implemented to pinpoint the ideal-type of higher education regionalization that most represents the APQN. An embedded case study of Việt Nam’s QA capacity building activities demonstrates the APQN’s role in one country. The findings suggest that the ideal-type of higher education regionalization as a sub-set of globalization best represents the APQN. The nature of the APQN as a network for QA professionals highlights the transformative role that globalization is playing within the nation state. Instead of globalization being a homogenizing force on higher education systems, this study shows that higher education regionalization as a sub-set of globalization is changing the role of the nation state into a regulator for the global market. Higher education regionalization as a sub-set of globalization does not remove the control of the nation state, but rather reinforces the state’s role as a monitor of higher education for market competition. The study concludes by suggesting opportunities for QA policymakers and practitioners to shape higher education regionalization.

Keywords: higher education regionalization
quality assurance
higher education policy
Asian Pacific higher education
Advisor: Hayhoe, Ruth
The Onset of Marangoni Convection for Evaporating Liquids

The stability of evaporating liquids is examined. The geometries investigated are semi-infinite liquid sheets, bounded liquid sheets, sessile droplets, and funnels. Stability parameters are generated to characterize the stability of evaporating semi-infinite liquid sheets, and bounded liquid sheets. The derivation is made possible by introducing evaporation as the specific heat transfer mechanism at the interface, and using the statistical rate theory expression for evaporation flux so there are no fitting parameters. It is demonstrated that a single parameter can be used to predict the onset criterion instead of two parameters. A linear stability analysis is performed for spherical sessile droplets evaporating on substrates constructed of either insulating or conducting materials. A stability parameter is generated to characterize the stability of sessile droplets evaporating on insulating substrates and conducting substrates. The results indicate that spherical sessile droplets evaporating on insulating substrates are predicted to transition to Marangoni convection. Since there are currently no experimental results to compare the theory with, another analysis is performed for liquids evaporating from funnels, which can be compared with existing experimental observations. A linear stability analysis predicts stable evaporation for funnels constructed of insulating materials, in contrast to the sessile droplet case, and generates a new stability parameter for funnels constructed of conducting materials. The stability parameter is free of fitting variables since the statistical rate theory expression for the evaporation flux is used. The theoretical predictions are found to be consistent with experimental observations for water evaporating from a funnel constructed of poly(methyl methacrylate) (PMMA) and for water and heavy water evaporating from a funnel constructed of stainless steel. A parametric analysis is performed on the new stability parameter for liquids evaporating from funnels constructed of conducting materials, indicating that smaller interfacial temperature discontinuities, higher evaporation rates, and smaller radii correspond to less stable systems. It is also illustrated that calculations using statistical rate theory predict an instability, which is consistent with experimental observations, whereas using the Hertz-Knudsen theory does not predict any instability.

Keywords: Fluid dynamics
Evaporation
Marangoni convection
Stability
Advisor: Ward, Charles A.
Convergent Genesis of an Adult Neural Crest-like Dermal Stem Cell from Distinct Developmental Origins

Skin-derived precursors (SKPs) are multipotent dermal stem cells that reside within a hair follicle niche and that share properties with embryonic neural crest precursors. Here, we have asked whether SKPs and their endogenous dermal precursors originate from the neural crest or whether, like the dermis itself, they originate from multiple developmental origins. To do this, we used two different mouse Cre lines that allow us to perform lineage tracing: Wnt1-cre, which targets cells deriving from the neural crest, and Myf5-cre, which targets cells of a somite origin. By crossing these Cre lines to reporter mice, we show that the endogenous follicle-associated dermal precursors in the face derive from the neural crest, and those in the dorsal trunk derive from the somites, as do the SKPs they generate. Despite these different developmental origins, SKPs from these two locations are functionally similar, even with regard to their ability to differentiate into Schwann cells, a cell type only thought to be generated from the neural crest. Analysis of global gene expression using microarrays confirmed that facial and dorsal SKPs exhibit a very high degree of similarity, and that they are also very similar to SKPs derived from ventral dermis, which has a lateral plate origin. However, these developmentally distinct SKPs also retain differential expression of a small number of genes that reflect their developmental origins. Thus, an adult neural crest-like dermal precursor can be generated from a non-neural crest origin, a finding with broad implications for the many neuroendocrine cells in the body.

Keywords: stem cells
hair follicle
Advisor: Freda, Miller
Visualizing the Complexity of the Molecular World: Examining the Role of Animated Representations in the Development of Undergraduate Students’ Understanding of Dynamic Cellular Events

The purpose of this study was to examine the relative effectiveness of three-dimensional visualization techniques for learning about protein conformation and molecular motion in association with a ligand and receptor binding event. Increasingly complex versions of the same binding event were depicted in each of four animated treatments. Students (n = 131) were tested at three time points, and over both the short and longer term, the most complex of the four animated treatments was the most successful at fostering students’ understanding of the events depicted. A follow-up study including eight biology students was conducted to gain greater insight into the students’ underlying thought processes and better characterize their understanding of the animated representations. Analysis of verbal reports and eye tracking data suggest that students are able to attend to the same narrative elements regardless of the level of complexity depicted in each animation. Analysis of verbal protocol data revealed a positive correlation between the number of explanatory statements expressed by participants and the complexity of the animation viewed. As well, prior knowledge was positively correlated with the number of explanatory statements contained in each protocol. Overall, students demonstrated an understanding of protein conformation and molecular crowding. However results suggest that students have difficulty understanding and associating randomness with molecular events. The verbal reports contained several instances of students’ attaching agency to protein and ligand, anthropomorphizing their movements and subsequent binding. Ordinarily cellular events, owing to their sheer complexity, are depicted in a highly schematized, simplified form. The results of this study would suggest that under select circumstances this may not be the most appropriate approach to depicting dynamic events. However additional attention must be given to exploring techniques that can satisfactorily balance the random nature of molecular events with narrative explanations of these processes.

Keywords: Animation
Biomedical Visualization
Undergraduate Biology
Molecular Biology
Visual Representation
Visual Complexity
Advisor: Woodruff, Earl