cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
ON THE STABILITY OF THE PERTURBED CENTRAL MOTION PROBLEM: A QUASICONVEXITY AND A NEKHOROSHEV TYPE RESULT
Creators: name: FUSE', ALESSANDRA
Publisher: name: Universit� degli Studi di Milano
Year: 2018

description: The aim of this thesis is the study of the dynamics of small perturbations of the spatial central motion problem. Our main result consists in proving that if the central potential is analytic, then, except for the Harmonic and the Keplerian case, the unperturbed system written in action angle variables is quasiconvex. Thus, when it is perturbed, one can apply a Nekhoroshev type theorem ensuring the stability over exponentially long times of the modulus of the angular momentum and of the energy of the unperturbed system. Being a \emph{superintegrable} system, namely, a system which admits a number of independent integrals of motion larger than the number of degrees of freedom, the version of Nekhoroshev theorem provided here is the one for superintegrable systems. We also give a complete proof (� la Lochak) of this result.
ESSAYS ON MACROECONOMICS, ENTREPRENEURSHIP AND RETURNS TO KNOWLEDGE
Creators: name: BELITSKI, MAKSIM
Publisher: name: Universit� degli Studi di Milano
Year: 2012

description: The first essay studies the effects of exogenous and endogenous shocks on output sustainability in Central Eastern Europe and Russia during the 2000s. It expands traditional vector autoregressive model to a multi-country model that relates bank real lending, the cyclical component of output and spreads and accounts for cross-sectional dependence across the countries. Impulse response functions show that exogenous positive shock lead to a drop in output sustainability for nine over twelve Central Eastern European countries, when the endogenous shock is mild and ambiguous. Moreover the effect of the exogenous shock is more significant in the aftermath the crises. The second essay explains variation in entrepreneurship across cities of Commonwealth of Independent States during 1995-2008, utilizing a unique database and employing dynamic panel data analysis. The findings suggest that banking reform facilitates entrepreneurship, whereas the size of the state discourages it. A U-shaped relationship between per capita income and entrepreneurship is confirmed. It?s established that a city with a higher concentration of universities is likely to have higher entrepreneurial entry that provides some evidence for the importance of agglomeration economies in terms of knowledge concentration which leads to intensified exchange of ideas and drive knowledge-based entrepreneurship. The third essay aims to assess the returns to patenting and knowledge expenditure in the form of innovative training and education for the UK innovative companies. It also quantifies the incentives that patent protection provides for training expenditure. Controlling for additional firm-specific and industrial characteristics, patent and training premia are estimated viz. the additional new product revenues generated by obtaining a patent and by increase in spending on innovative training. Both patent and training premia are positive, however, there is no inducement for additional knowledge expenditure for a patent holder as expected from the literature. The study fills a gap in calculation of returns to knowledge and patent propensity for the UK innovators.
Late-time acceleration in the coupled Cubic Galileon models
Creators: name: Kim, Kyoung Yee
name: Lee, Hyung Won
name: Myung, Yun Soo
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We investigate the linearly and quadratically coupled cubic Galileon models that include linear potentials. These models may explain the late-time acceleration. In these cases, we need two equations of state parameter named the native and effective equations of state to test whether the universe is accelerating or not because there is coupling between the cold dark matter and Galileon. It turns out that there is no transition from accelerating phase to phantom phase in the future.
description: 14pages, 5figures, version to appear in PRD
Pre-Commercial Thinning Increases Merchantability and Reduces Western Gall Rust Infections in Lodgepole Pine
Creators: Scaria, Francis
Publisher: name: University of Alberta Library
Year: 2023

Alberta’s forest industry is predicted to be impacted by a short to medium-term decline in timber supply. Intensive silviculture tools, such as pre-commercial thinning, have been shown to increase individual tree growth, shorten rotation lengths and improve stand merchantability in important commercial species such as lodgepole pine. However, lodgepole pine stands are susceptible to western gall rust infections and thinning at an early stage may increase infection rates. But again, concrete information on these issues are missing from an operational scale. This study collected tree and stand level data from 33 operational harvest origin lodgepole pine stands consisting of 11 earlier thinned (PCT18; 17-19 years), 11 later thinned (PCT24; 23-25 years) and 11 unthinned stands. Pre-commercially thinned stands, regardless of timing, had greater individual tree size (~15% higher) compared to unthinned stands approximately 40 years after thinning. Pre-commercially thinned stands also have a higher potential for commercial thinning since they have lower variability in tree size and longer live crown lengths. In addition, the timing of thinning did have an impact on western gall rust infections, with PCT24 stands having lower infection rates and infection severity compared to both PCT18 and unthinned. In conclusion, pre-commercial thinning should be considered for lodgepole pine stands in order to address timber supply issues in Alberta.
title: Η σημασία του χρώματος στην αρχιτεκτονική του Bauhaus

title: The importance of color in Bauhaus architecture
Creators: name: Περιστερη Κωνσταντινα
Publisher: name: Technical University of Crete
Year: 2025

description: Πως χρησιμοποιήθηκε το χρώμα στην αρχιτεκτονική του Bauhaus;
Ποιες ήταν οι βασικές διαφορές στις χρωματικές παλέτες ανάμεσα στα διάφορα κτίρια κατά τη διάρκεια του Bauhaus;
Και τελικά, ποιος είναι ο αντίκτυπος αυτού του κινήματος στην αντίληψη και χρήση του χρώματος στη σύγχρονη αρχιτεκτονική;
Η έρευνα επιχειρεί να αποκαλύψει μια διαφορετική διάσταση της χρήσης του χρώματος στην αρχιτεκτονική του Bauhaus, εκτός από τη  “μονοχρωματική” αισθητική για την οποία είναι γνωστή. Μέσα από τις καινοτόμες θεωρίες των βασικών δασκάλων της σχολής, Itten, Kandinsky, Klee και Albers, και άλλων σπουδαίων δασκάλων, γίνεται κατανοητό το πώς χρησιμοποιήθηκε το χρώμα σε πολλές πτυχές της αρχιτεκτονικής και του σχεδιασμού, όχι μόνο σε εκείνη την εποχή αλλά και σήμερα. Από κατοικίες που κρύβουν πλούσιες παλέτες εσωτερικών χρωμάτων, μέχρι κατοικίες με  διακριτικές  χρωματικές επιλογές, η μελέτη εξετάζει τις διαφορετικές αυτές προσεγγίσεις, παραθέτοντας σημαντικά παραδείγματα. Οι διαφορετικές χρωματικές κλίμακες που αναλύονται στην έρευνα θα προσπαθήσουν να αποδώσουν τη σχέση της αρχιτεκτονικής σύνθεσης και του χώρου μέσα από τη χρήση του χρώματος. Εν κατακλείδι, στόχος της εργασίας είναι να αποδείξει πως παρά το γεγονός ότι το Bauhaus υπήρξε πρωτοπόρος του μινιμαλισμού, εισήγαγε μια σουδαία επιρροή χρώματος, με το ίδιο το χρώμα να προσδίδει ψυχή και αίσθηση στην αρχιτεκτονική.

description: How was color used in Bauhaus architecture?
What were the main differences in color palettes among the various buildings during the Bauhaus movement?
And finally, what is the impact of this movement on the perception and use of color in today’s architecture?
The research attempts to reveal a different dimension of the use of color in Bauhaus architecture, beyond the “monochromatic” aesthetic for which it is known. Through the innovative theories of the school’s key teachers, Itten, Kandinsky, Klee and Albers, and other great masters, it becomes clear how color was used in many aspects of architecture and design, not only at that time but also today. From residences that had rich palettes of interior colors, to residences with discreet color choices, the study examines these different approaches, citing important examples. The different color scales analyzed in the research will attempt to convey the relationship between architectural composition and space through the use of color. In conclusion, the aim of the paper is to demonstrate that despite the fact that Bauhaus was a pioneer of minimalism, it introduced a great influence of color, with color itself giving soul and feeling to architecture.
Symmetry-protected topological invariant and Majorana impurity states in time-reversal-invariant superconductors
Creators: name: Kimme, Lukas
name: Hyart, Timo
name: Rosenow, Bernd
Publisher: name: arXiv
Year: 2013
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We address the question of whether individual nonmagnetic impurities can induce zero-energy states in time-reversal-invariant topological superconductors, and define a class of symmetries which guarantee the existence of such states for a specific value of the impurity strength. These symmetries allow the definition of a position-space topological Z_2 invariant, which is related to the standard bulk topological Z_2 invariant. Our general results are applied to the time-reversal-invariant p-wave phase of the doped Kitaev-Heisenberg model, where we demonstrate how a lattice of impurities can drive a topologically trivial system into the nontrivial phase.
description: published version
Macro-Scale Lithium-Ion Battery Simulation by Means of the Finite Element Method and Concentrated Solution Theory
Creators: Fenske, Cameron
Publisher: name: University of Alberta Library
Year: 2023

Lithium-ion batteries are the leading contender for high density energy storage for applications such as electric vehicles and personal electronic devices. While they promise well over 4 V of potential per cell, actually realizing such high voltages is quite difficult, given the many modes of energy loss during discharge. One dominant loss, especially at high currents (e.g., fast-charging) is losses due to ionic transport in the electrolyte.

Mathematical models and their computational implementation have been used to simulate Lithium-ion battery discharge to better understand its complex physics and to optimize its design. Because of the complex and dynamic nature of Lithium-ion batteries, these models are transient and highly non-linear. A difficulty arises in that the scales on which key physics occurs varies over many orders of magnitude, meaning simulations often decouple scales to some degree to conserve computational resources.

In this thesis, a transient and non-linear numerical model is developed for the lithium-ion battery macro-scale, that is, the scale on which heterogeneities due to microscopic components can be ignored. Additionally, the electrolyte is studied separately by isolating the separator contribution by modelling a symmetric Li-foil cell.

The numerical model is supported by a rigorous set of mathematical derivations for the governing equations. This process utilizes concentrated solution theory and the finite element method.

First the symmetric cell system is verified by reproducing the voltage response to a constant current step reported from experiments in the literature. A sensitivity analysis is performed for the electrolyte characteristics and discussed in terms of their influence on cell performance. After concluding that the electrolyte model accurately reproduces the real-world system, the model is applied to a novel electrolyte for which no previous numerical modelling has been performed. It is concluded that the experimental results do not match what is expected from the model, due to the non-reproducibility of the experimental data.

The full macro-scale battery model is analyzed in terms of its voltage response and solution variable profiles during a constant current discharge. Following a study of the cell’s hysteresis, the battery’s capacity and efficiency are calculated. Another sensitivity analysis provides insight into the importance of the active material’s characteristics on cell performance. Finally, running the battery at different current densities confirms that increasing the rate of cell charge/discharge will negatively impact the efficiency of the system.
System-size independence of a large deviation function for frequency of events in a one-dimensional forest-fire model with a single ignition site
Creators: name: Mitsudo, Tetsuya
Publisher: name: arXiv
Year: 2013
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: It is found that a large deviation function for frequency of events of size not equal to the system size in the one dimensional forest-fire model with a single ignition site at an edge is independent of the system size, by using an exact "decomposition" of the modified transition matrix of a master equation. An exchange in the largest eigenvalue of the modified transition matrix may not occur in the model.
description: 11 pages, 4 figures
Changes in bitumen due to thermal conversion affecting the description of coke formation
Creators: Yanez Jaramillo, Lina Maria
Publisher: name: University of Alberta Library
Year: 2023

At the heart of heavy oil and bitumen upgrading, thermal conversion technologies are found. One such process is visbreaking where bitumen is thermally converted into lighter materials. However, the conversion by visbreaking is limited by the onset of the formation of solid carbonaceous materials (coke). The formation of coke has been explained by two pathways: (i) The formation of a mesophase (or a second liquid phase) that will eventually lead to coke, and (ii) Asphaltenes as precursors of coke formation due to increasing insolubility.

The objective of this work was to better understand the changes that bitumen and bitumen-related materials undergo in thermal conversion from the perspective of the change in the nature of the species. The results were employed to provide a better understanding of the onset of coke formation in visbreaking, and a different point of view about the process leading to coke formation which results from highlighting potential misconceptions within this field.

Considering the first pathway used to explain the origin of coke, mesophase formation follows from an increase in the aromatic character of the material as the first step. Hydrogen transfer and aromatization reactions are examples of reactions occurring in thermal conversion that could contribute to an increase in the aromatic hydrogen and carbon content. It was found that there was not a fixed relationship between aromatic hydrogen and aromatic carbon content. It was further found that changes in aromatic hydrogen content do not necessarily describe the changes in aromatic carbon content after visbreaking. The formation of aromatic structures as an early step of coke formation would imply an increase in the aromatic content, but the aromatic carbon and coke content of the thermally converted products only had a weak relationship.

The second pathway describes coke formation as a progression of insolubility where asphaltenes are considered precursors. As a result, it was expected to observe a relationship between coke and asphaltenes content in thermally converted samples. Contrary to the expectation, the visbroken products did not show a relationship between coke and asphaltenes content and did not provide evidence of asphaltenes being an intermediate step in coke formation.

The study also made other minor contributions to the field through work on water removal from emulsified bitumen and showing that there might be a relationship of free radical concentration in unconverted petroleum materials that is consistent with the composition continuum proposed by Boduszynski. This study has opened the possibility to further investigations that could address some of the hypotheses in this work and provide valuable inputs into the role of free radical species in coke formation during thermal conversion.
Development of a Finite Element Model to Examine the Response of the Advanced System for Implant Stability Testing  (ASIST) in Dental Implants
Creators: Vandenberg, Tod M
Publisher: name: University of Alberta Library
Year: 2023

The health of the bone-implant interface (BII) of a dental implant is integral to the success of the implant. The evaluation of the development process of these tissues during the healing stages is important in analyzing the risks of failure and to determining when loading can be prescribed. The Advanced System for Implant Stability Testing (ASIST) is a device and process created to analyze the dynamic response of an implant undergoing a low-force impact load and determine the stability of the structure provided by the BII. The primary purpose of this study is to develop a modelling process that will lead to a finite element model of any dental implant and abutment system undergoing the same loading as the ASIST such that the acceleration response extracted from the

model will match the measurement of the ASIST. This model will be validated by experimental result and predict the responses of new systems.

The finite element model showed that changes in impact angle, clamping conditions, and implant protrusion all have significant effects on the ASIST Stability Coefficient (ASC) of an implant system which can lead to variance between similar experimental samples. The model showed that the ASIST is sensitive to the properties of the material surrounding an implant and can measure the stability independently of the implant or abutment geometry. The finite element model was able to represent the available data with an R2 value of 0.94 and provided a good representation of the experimental samples.

The model was adapted to incorporate a dental crown, composite bone, or bone resorption. The model of the dental crown highlighted a sensitivity in the ASIST to the striking height on the crown surface. Changes in the striking height of the impact rod on the surface of the crown resulted in ASC values ranging from 13.8 to 22.2 depending on the striking height. For the composite bone, the definition of the ASC was adjusted to incorporate the two different stiffnesses of the surrounding material. The results of this simulation reinforced the necessity in accounting for a non-uniform material by showing that assuming a uniform material can make a measurement appear higher than the actual stability.

The model was used to predict the response of an implant undergoing bone resorption. The results showed a decrease in ASC of about 2 per mm of bone loss showing evidence that the ASIST could be useful in long term monitoring of implant health.

Using a finite element model of a dental implant has shown that the ASIST can isolate a measure of dental implant stability regardless of implant and abutment geometry. There is strong evidence to support that the measurements are based on the properties of the BII. The ASIST can be used as a tool to evaluate the short-term healing process of this region, as well as monitor the long-term health by being sensitive to bone resorption.
ANALYSING MEDICAL ENGLISH LEXIS: A CORPUS-BASED RESEARCH. IMPLICATIONS FOR LEARNING AND TEACHING
Creators: name: RIPAMONTI, FRANCESCA
Publisher: name: Universit� degli Studi di Milano
Year: 2015

description: Abstract In the last few decades medical specialized communication has become progressively dynamic and prolific with an ever growing number of researchers employing English as a lingua franca. Medical specialized communication unquestionably constitutes a challenging problem with non-native medical students and health care practitioners who are increasingly faced with the need to have an active command of Medical English, that vast set of standardized and non-standardized terms used to describe and represent the changes and the results accomplished in the medical field. My direct involvement in a language trial test aiming at investigating the productive vocabulary knowledge of a group of Italian medical undergraduates was the background that provided the incentive for this dissertation to investigate the language of medicine and devise strategies and materials that were specific enough to help non-native speakers from different medical fields acquire the English language skills they needed step by step. Trying to find the convergence between non-native medical doctors? vocabulary needs and pedagogy, my research has developed along two lines, purposefully called ?diagnosis? and ?remedy?. Firstly, I endeavoured to ?diagnose? which key-words are homogeneously distributed across mainstream professional medical writings opportunely collected in the Medical English Corpus (MedEnCor), a specialized corpus extensively representative of current healthcare domains and biomedical topics. Secondly, I attempted to seek a ?remedy? to the non-native learners' lexical ?impairments? categorizing all the extracted key-words into semantic wordlists, suitably catalogued into the Medical English Corpus Lexical database (MedEnCor-Lex), a web-based monolingual glossary (www.medencor.com) meant to provide non-native users not only with denotative information on medical key-words, but also with appropriate instances of their collocational and phraseological context and use. Although this writing tool is currently being completed, my goal is equally educational and professional because by compiling a specialized lexical database I do not only mean to make the English used in medicine accessible to the healthcare community, but, first and foremost, to make non-native recipients familiarize themselves with the terms and expressions relevant to the scientific register. An essential skill for their career.
Influence of spin dependent carrier dynamics on the properties of a dual-frequency vertical-external-cavity surface-emitting laser (VECSEL)
Creators: name: De, Syamsundar
name: Potapchuk, Vladyslav
name: Bretenaker, Fabien
Publisher: name: arXiv
Year: 2013
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The properties of a dual-frequency vertical external cavity surface emitting laser (VECSEL), in which two linear orthogonal polarization modes are oscillating simultaneously, are theoretically investigated. We derive a model based on the ideas introduced by San Miguel et al. [San Miguel, Feng, and Moloney, Phys. Rev. A \textbf{52}, 1728 (1995)], taking into account the spin dynamics of the carriers inside the quantum well (QW) based gain medium of the dual-frequency VECSEL. This model is shown to succeed in describing quite a few properties of the dual-frequency VECSEL, such as the behavior of nonlinear coupling strength between the modes, the spectral behavior of intensity noises of the modes, and also the correlation between these intensity noises. A good agreement is found with experimental data. The variables associated with the spin dependent carrier dynamics can be adiabatically eliminated due to the class-A dynamical behavior of the considered laser which is based on a cm-long external cavity. This leads to a simple analytical description of the dynamics of the dual-frequency VECSEL providing a better understanding of the physics involved
Machine learning classification of plant genotypes grown under different light conditions through the integration of multi-scale time-series data
Creators: Sakeef, Nazmus
Publisher: name: University of Alberta Library
Year: 2023

In order to mitigate the effects of a changing climate, agriculture requires

more effective evaluation, selection, and production of crop cultivars in order

to accelerate genotype-to-phenotype connections and the selection of beneficial traits. Critically, plant growth and development are highly dependent on

sunlight, with light energy providing plants with the energy required to photosynthesize as well to directly intersect with the environment in order

to develop. In plant analyses, machine learning and deep learning techniques

have a proven ability to learn plant growth patterns, including detection of

disease, plant stress, and growth using a variety of image data. To date, however, studies have not assessed machine learning and deep learning algorithms

for their ability to differentiate a large cohort of genotypes grown under several

growth conditions using time-series data automatically acquired across multiple scales (daily and developmentally). Here, we extensively evaluate a wide

range of machine learning and deep learning algorithms for their ability to differentiate 17 well-characterized photoreceptor deficient genotypes differing in

their light detection capabilities grown under several different light conditions.

Using algorithm performance measurements of precision, recall, F1-Score, and

accuracy, we find that Suport Vector Machine (SVM) maintains the greatest

classification accuracy, while a combined ConvLSTM2D deep learning model

produces the best genotype classification results across the different growth

conditions. Critically, our successful integration of time-series growth data

across multiple scales, genotypes and growth conditions sets a new foundational baseline from which more complex plant science traits can be assessed

for genotype-to-phenotype connections.
Consistency relation in power law G-inflation
Creators: name: Unnikrishnan, Sanil
name: Shankaranarayanan, S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In the standard inflationary scenario based on a minimally coupled scalar field, canonical or non-canonical, the subluminal propagation of speed of scalar perturbations ensures the following consistency relation: $r \leq - 8n_{_T}$, where $r$ is the tensor-to-scalar-ratio and $n_{_T}$ is the spectral index for tensor perturbations. However, recently, it has been demonstrated that this consistency relation could be violated in Galilean inflation models even in the absence of superluminal propagation of scalar perturbations. It is therefore interesting to investigate whether the subluminal propagation of scalar field perturbations impose any bound on the ratio $r/|n_{_T}|$ in G-inflation models. In this paper, we derive the consistency relation for a class of G-inflation models that lead to power law inflation. Within these class of models, it turns out that one can have $r > - 8n_{_T}$ or $r \leq - 8n_{_T}$ depending on the model parameters. However, the subluminal propagation of speed of scalar field perturbations, as required by causality, restricts $r \leq -(32/3)\,n_{_T}$.
description: 25 pages, 5 figures, references added, title changed, results unchanged, matches version published in JCAP
The Politics of the Rise and Fall of the Association of the Arab American University Graduates
Creators: Sharaf, Sarah
Publisher: name: University of Alberta Library
Year: 2023

The Association of Arab-American University Graduates (AAUG) came into existence in 1967 as a response to the negative portrayals of the Arabs in the U.S media. The establishment of the Association was a crucial and significant move by a group of U.S.-based young scholars, professors and intellectuals of Arab origin to challenge all forms of stereotyping and disinformation about Arabs. It was optimal timing to start such an association as it was at the peak of the U.S. civil rights movement, and intellectuals and scholars were eager to challenge and write about racism and other human rights movements including nationalist movements. As both American-born and immigrant Arabs were harmed by media distortions, the AAUG’s main goals were to bring young university graduates together, integrate their knowledge and expertise, challenge and combat bigotry, and most importantly, educate and inform the American public. By utilizing archival material and scholarly literature, this thesis analyzes the reasons behind the rise and fall of the AAUG since its establishment in 1967 till dissolution in 2007. Key findings are advanced theoretically by adopting Edward Said’s anti-colonialist and anti-racist framework as established in Orientalism, alongside the unity and solidarity of Third Worldism, and the significance of human interdependence for preventing human suffering advocated by care ethics in the work of Fiona Robinson. In this research, I argue that the AAUG’s weakening and demise was gradually influenced first by the fall of pan-Arabism in the Arab world, which was caused by a series of events in the region. Many of the Association’s prominent members, and other organizations that were financially supporting the Association, were influenced by fragmented politics of their home countries that led them to cease funding the AAUG, and hence affected the functioning of the organization. Second, it was caused by the U.S.’s pro-Israel domestic and foreign policies which had intensified in Israel’s favor through each Arab/Israeli conflict or event. Although the AAUG dissolved in 2007, it left a lasting legacy to a new generation of civil society movements. This will be shown by the discussion of the resistance of the new generation of civil society movements in the Arab world which embraced the Palestinian activism as well as resisted against the oppression and corruption of their state leaders, as witnessed during the Arab Spring. Furthermore, it will be demonstrated by the discussion of the rise of the new transnational civil society movements such as BDS movement and its supporters from all over the world.
Error suppression and error correction in adiabatic quantum computation I: techniques and challenges
Creators: name: Young, Kevin C.
name: Sarovar, Mohan
name: Blume-Kohout, Robin
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Adiabatic quantum computation (AQC) is known to possess some intrinsic robustness, though it is likely that some form of error correction will be necessary for large scale computations. Error handling routines developed for circuit-model quantum computation do not transfer easily to the AQC model since these routines typically require high-quality quantum gates, a resource not generally allowed in AQC. There are two main techniques known to suppress errors during an AQC implementation: energy gap protection and dynamical decoupling. Here we show that both these methods are intimately related and can be analyzed within the same formalism. We analyze the effectiveness of such error suppression techniques and identify critical constraints on the performance of error suppression in AQC, suggesting that error suppression by itself is insufficient for large-scale, fault-tolerant AQC and that a form of error correction is needed. We discuss progress towards implementing error correction in AQC and enumerate several key outstanding problems. This work is a companion paper to "Error suppression and error correction in adiabatic quantum computation II: non-equilibrium dynamics"', which provides a dynamical model perspective on the techniques and limitations of error suppression and error correction in AQC. In this paper we discuss the same results within a quantum information framework, permitting an intuitive discussion of error suppression and correction in encoded AQC.
description: 12 pages, 2 figures. Companion paper to "Error suppression and error correction in adiabatic quantum computation II: non-equilibrium dynamics". Updated title, abstract, and bibliography to emphasize relation to companion paper. Updated to match published version
Ensembling Diverse Policies Improves Generalization of Deep Reinforcement Learning Algorithms to Environmental Changes in Continuous Control Tasks
Creators: Zhumabekov, Abilmansur
Publisher: name: University of Alberta Library
Year: 2023

Deep Reinforcement Learning (DRL) algorithms have shown great success in solving continuous control tasks. However, they often struggle to generalize to changes in the environment. Although retraining may help policies adapt to changes, it may be quite costly in some environments.

Ensemble methods, which are widely used in machine learning to boost generalization, have not been commonly adopted in DRL for continuous control applications. In this work, we introduce a simple ensembling technique for DRL policies with continuous action spaces. It aggregates actions by performing weighted averaging based on the uncertainty levels of the policies. We investigate its zero-shot generalization properties in a complex continuous control domain - the optimal control of home batteries in the CityLearn environment, the subject of a 2022 international AI competition.

Our results indicate that the proposed ensemble has better generalization capacity than a single policy. Further, we show that promoting diversity among policies during training can reliably improve the zero-shot performance of the ensemble in the test phase.

Finally, we examine the merits of the uncertainty-based weighted averaging in an ensemble by comparing it to two alternative approaches: unweighted averaging and selecting the action of the least uncertain policy.
Nonparametric inference for linear models via an analytic framework for the wild bootstrap
Creators: Burak, Katherine
Publisher: name: University of Alberta Library
Year: 2023

Many standard approaches for conducting statistical inference on regression parameters rely heavily on parametric assumptions and asymptotic results. The wild bootstrap (Mammen, 1993) was developed as a nonparametric means

to estimate a sampling distribution and is particularly useful when conducting statistical inference for linear models. With wide-reaching applications, the wild bootstrap can be used in a variety of settings where distributional assumptions are violated or are difficult to verify. While the wild bootstrap has attractive properties, as big-data becomes increasingly prevalent in society

computationally intensive resampling schemes such as bootstrapping become less appealing and impractical. In this work, an analytic framework for computing confidence regions and intervals in a variety of linear models is developed. The use of the concentration of measure phenomenon paired with the appealing properties of the wild bootstrap leads to a more computationally efficient, nonparametric way to perform statistical inference for regression parameters. The methodology

is first introduced for the coefficients in least squares regression, and is then adapted to consider the more complex settings of ridge and LASSO regression. Lastly, this analytic approach is discussed in the context of generalized linear models, focusing on the case of overdispersion in Poisson regression.
Spherically symmetric vacuum solutions arising from trace dynamics modifications to gravitation
Creators: name: Adler, Stephen L.
name: Ramazanoglu, Fethi M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We derive the equations governing static, spherically symmetric vacuum solutions to the Einstein equations, as modified by the frame-dependent effective action arising from trace dynamics. We give analytic and numerical results for the solutions of these equations, first in polar coordinates, and then in isotropic coordinates. General features of the static case are that (i) there is no horizon, since $g_{00}$ is non-vanishing for finite values of the polar radius, and only vanishes (in isotropic coordinates) at the internal singularity, (ii) the Ricci scalar $R$ vanishes identically, and (iii) there is a physical singularity at cosmological distances. The large distance singularity may be an artifact of the static restriction, since we find that the behavior at large distances is altered in a time-dependent solution using the Mc Vittie Ansatz.
description: 34 pages. This is an expansion of the previous submission to include results obtained in collaboration with Fethi M. Ramazanoglu
Stellar feedback by radiation pressure and photoionization
Creators: name: Sales, Laura V.
name: Marinacci, Federico
name: Springel, Volker
name: Petkova, Margarita
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The relative impact of radiation pressure and photoionization feedback from young stars on surrounding gas is studied with hydrodynamic radiative transfer (RT) simulations. The calculations focus on the single-scattering (direct radiation pressure) and optically thick regime, and adopt a moment-based RT-method implemented in the moving-mesh code AREPO. The source luminosity, gas density profile and initial temperature are varied. At typical temperatures and densities of molecular clouds, radiation pressure drives velocities of order ~20 km/s over 1-5 Myr; enough to unbind the smaller clouds. However, these estimates ignore the effects of photoionization that naturally occur concurrently. When radiation pressure and photoionization act together, the latter is substantially more efficient, inducing velocities comparable to the sound speed of the hot ionized medium (10-15 km/s) on timescales far shorter than required for accumulating similar momentum with radiation pressure. This mismatch allows photoionization to dominate the feedback as the heating and expansion of gas lowers the central densities, further diminishing the impact of radiation pressure. Our results indicate that a proper treatment of the impact of young stars on the interstellar medium needs to primarily account for their ionization power whereas direct radiation pressure appears to be a secondary effect. This conclusion may change if extreme boosts of the radiation pressure by photon trapping are assumed.
description: 18 pages, 19 figures (main results presented in 13 pages, 10 figures; extended appendix for RT tests with extra 9 figures). Accepted for publication in MNRAS after tiny changes
Berezinskii-Kosterlitz-Thouless Transition with a Constraint Lattice Action
Creators: name: Bietenholz, Wolfgang
name: Gerber, Urs
name: Rejón-Barrera, Fernando G.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The 2d XY model exhibits an essential phase transition, which was predicted long ago --- by Berezinskii, Kosterlitz and Thouless (BKT) --- to be driven by the (un)binding of vortex--anti-vortex pairs. This transition has been confirmed for the standard lattice action, and for actions with distinct couplings, in agreement with universality. Here we study a highly unconventional formulation of this model, which belongs to the class of topological lattice actions: it does not have any couplings at all, but just a constraint for the relative angles between nearest neighbour spins. By means of dynamical boundary conditions we measure the helicity modulus Upsilon, which shows that this formulation performs a BKT phase transition as well. Its finite size effects are amazingly mild, in contrast to other lattice actions. This provides one of the most precise numerical confirmations ever of a BKT transition in this model. On the other hand, up to the lattice sizes that we explored, there are deviations from the spin wave approximation, for instance for the Binder cumulant U_4 and for the leading finite size correction to Upsilon. Finally we observe that the (un)binding mechanism follows the usual pattern, although free vortices do not require any energy in this formulation. Due to that observation, one should reconsider an aspect of the established picture, which estimates the critical temperature based on this energy requirement.
description: 39 pages, LaTex, 17 figures, 5 tables, final version to appear in JSTAT (Journal of Statistical Mechanics: Theory and Experiment). A section about the Binder cumulant U_4 and the second moment correlation lenght xi_2 has been added
“Forty Hours of Hope”: An Analysis of Paulo Freire’s 1963 Literacy Program in Angicos
Creators: Mendoza, Amanda L
Publisher: name: University of Alberta Library
Year: 2023

This thesis explores the results of and claims made about the experimental 1963 literacy program operated in the small Brazilian town of Angicos, Rio Grande do Norte. This program was where the renowned pedagogue Paulo Freire’s literacy methods were first attempted at a large scale using government funding to teach nearly 300 adults and adolescents how to read and write in a mere forty hours of instruction. Freire’s program utilized what is known as the Paulo Freire Method, wherein instructors taught literacy using images and vocabulary that were determined to be culturally significant to the communities in which courses took place. Through these lessons, instructors would not only aim to provide students with basic literacy skills but with political consciousness and a desire to participate in the democratic system. The program claimed to have had resounding success, leading to the creation of plans to establish Freirean literacy courses, known as culture circles, all over the nation. However, shortly after the program’s close, it was deemed to have been bathed in Marxist ideology, promoting subversion among its students. As Cold War political tensions continued to heat up in the country, reaching their peak at the military coup of 1964, the expansion of culture circles was forced to halt and Freire, along with many instructors of his craft, was sent into exile.

Despite the political reaction caused by this program, Freire’s method continues to be used in the country today, where his name is celebrated as the patron saint of education. Yet, the experience in Angicos, while being the first of many successes in Freirean education, is largely unknown by the Brazilian public. This thesis considers the lofty claims of this program’s success through a critical lens, contributing to the limited scholarly conversation on the Cold War forces at play during the course’s operation. Throughout my research, I argue that the claims made about this program cannot be separated from the political narratives they served historically. Beyond this, I interpret the achievements of the program along with its limitations, paying close attention to its class-centric interpretation of oppression to unite the people of Angicos. Through examining didactic materials, diary entries, newspaper articles, government documents, and secondary scholarship, I provide a historical analysis of the Forty Hours of Angicos that provides important emphasis on the Cold War political context that shaped accounts of the program’s results.
Laboratory atomic transition data for precise optical quasar absorption spectroscopy
Creators: name: Murphy, Michael T.
name: Berengut, Julian C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Quasar spectra reveal a rich array of important astrophysical information about galaxies which intersect the quasar line of sight. They also enable tests of the variability of fundamental constants over cosmological time and distance-scales. Key to these endeavours are the laboratory frequencies, isotopic and hyperfine structures of various metal-ion transitions. Here we review and synthesize the existing information about these quantities for 43 transitions which are important for measuring possible changes in the fine-structure constant, alpha, using optical quasar spectra, i.e. those of Na, Mg, Al, Si, Ca, Cr, Mn, Fe, Ni and Zn. We also summarize the information currently missing that precludes more transitions being used. We present an up-to-date set of coefficients, q, which define the sensitivity of these transitions to variations in alpha. New calculations of isotopic structures and q coefficients are performed for SiII and TiII, including SiII 1808 and TiII 1910.6/1910.9 for the first time. Finally, simulated absorption-line spectra are used to illustrate the systematic errors expected if the isotopic/hyperfine structures are omitted from profile fitting analyses. To ensure transparency, repeatability and currency of the data and calculations, we supply a comprehensive database as Supporting Information. This will be updated as new measurements and calculations are performed.
description: 24 pages, 12 figures, 15 figures. Accepted for publication in MNRAS. Atomic transition database available through http://researchdata.ands.org.au/laboratory-atomic-transition-data-for-precise-optical-quasar-absorption-spectroscopy . Additions, corrections, updates welcome. v2: Corrected database URL. v2: Corrected typos in Table 12 for NiII1467.2 & 1467.7
Fair in Unfair Circumstances: Police Officers' Perceptions of Homeless Encampments
Creators: Beaulieu, Celine
Publisher: name: University of Alberta Library
Year: 2023

This thesis presents local police officers’ experiences with Edmonton’s homeless encampments and the unhoused population. For this project, I asked two research questions: 1) How do Edmonton Police Service officers reflect upon, perceive, and express their interactions with homeless encampments and individuals?, and 2) How do these accounts inform our understanding of the dynamics with policing marginalized communities? I interviewed 23 police officers who were currently policing homeless encampments or had previously worked with the unhoused population. My thesis demonstrates two broad themes related to police officers’ descriptions of police-unhoused interactions. First, officers are frustrated with the problem of homelessness. They were particularly frustrated with current homelessness strategies that enable homelessness while depleting policing resources. Despite these frustrations, officers learn how to manage the city’s homelessness crisis through their interactions with encampment residents, often demonstrating ways to be ‘fair in unfair circumstances.’ This thesis also demonstrates the range of new technologies used by officers: the benefits of these technologies and how officers’ perceptions of these technologies impact police-unhoused interactions. These findings provide important insight into police officers’ conceptualizations of this social dilemma.
Federated Learning on Non-disjoint Graphs
Creators: Tavakoli, Fatemeh
Publisher: name: University of Alberta Library
Year: 2023

Federated learning is in widespread use for learning a global model when data is distributed across various distributed clients. In much of the prior work, the data is assumed to consist of independent data points. However, there is often an underlying graph that structures the data points. Such structures emerge in data on social networks, content recommendations, bank transactions data, healthcare data, and other such data where there is a notion of similarity or relation that links data points. Standard federated learning frameworks are not designed specifically for graph data and thus cannot take advantage of graph structure for node classification. We consider federated learning on graph data where a global graph is split among a set of clients, In particular, we consider a non-disjoint split, where there are some nodes that we call anchor nodes, that are present at multiple clients. The learning task is node classification in a semi-supervised scenario where only a small set of nodes have labels. We propose a new federated learning algorithm for non-disjoint graphs that leverages anchor nodes to augment local graph structure for improved node classification. We show through extensive experiments on several graph datasets, that our method outperforms standard methods on the task of node classification.