VictorJuiz/thesis huggingface dataset:
Application of the Hybrid Finite/Discrete Element Method to the Numerical Simulation of Masonry Structures

Masonry is one of the most common construction techniques around the world. Unfortunately, it is also among the most sensitive to the risk of failure due to exceptional types of loading, such as, but not limited to, earthquakes. In order to properly design new structures and assess the strength of the existing building stock, it is important for the engineering community to have a reliable means of performing numerical simulations of masonry structures. Masonry is characterized by being a composite material, which translates into greatly inhomogeneous and anisotropic behaviour. Typical numerical tools do not account explicitly for these features of the material, and those that do often require a high level of information about the structure in order to properly calibrate some of their many parameters. This research introduces a new numerical tool, the Finite/Discrete Element Method (FDEM), as a possible solution to this problem. In this method the discontinuities between different materials are explicitly accounted for in the simulation. The structure and the materials are explicitly modelled with little to no need for numerical calibration. FDEM, implemented in the software Y-Brick, has been used to replicate the results of experiments on masonry structures of different level of complexity. Some of the experiments were performed at the University of Toronto as part of this research; other have been collected from the technical literature. The software has been shown to be able to reproduce the experimental results from both the quantitative and the qualitative points of view, suggesting that it could become a valid tool for the simulation of the behaviour of complex masonry and structures under the effects of various types of loadings.

Keywords: Finite/Discrete Element Method
Masonry
Numerical modelling
Small scale modelling
Advisor: Grasselli, Giovanni
Bentz, Evan C
Measurement of tt̅ Polarization with the ATLAS Detector

The top quark is the heaviest discovered fundamental particle and is sufficiently heavy such that it decays prior to hadronizing. Consequently, the quantum state in which a top quark is produced is imparted to its decay products. In particular, its spin state impacts the angular distribution of its decay products. This research presents a measurement of top and antitop spin polarization vectors in tt̅ pair production decaying to lepton-plus-jets final states using data collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions with a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.2 inverse femtobarns. The angles between the lepton and a set of three orthonormal basis axes, one of which is the familiar helicity basis, are measured. The axes are defined such that the tt̅ differential production cross section, with respect to the cosine of the angle for a given axis, is linearly proportional to the polarization along that axis. The polarizations are computed using a profiled likelihood fit to templated distributions of the cosines. The top and antitop helicity polarizations are found to be -0.031 ± 0.023 and -0.059 ± 0.022 respectively.

Advisor: Trischuk, William
A Microsimulation Platform of Firm Evolution Processes

Firmography is a fundamental component of urban systems that has not received much research attention. Firmographic events of entry, exit, growth, and relocation affect economic growth, labour dynamics, and result in a complex system of goods movements. This dissertation develops a firm modelling framework, called the firmographic engine. The goal of the framework is to evaluate the implications of policy on firm evolution over time by simulating and forecasting firm behaviour. The engine is composed of firm generation, market introduction, performance evaluation, and firm evolution modules. Firm generation simulates entrepreneurial decisions of firm entry. Market introduction involves the specification and completion of operational strategies. Performance evaluation assesses the outcomes of the operational strategies. Firm evolution simulates growth/shrinkage and exit decisions depending on performance evaluation results. Three firmographic events are studied in detail: firm start-up size, growth, and survival. Ordered logit models are estimated for firm start-up size in terms of the firmâ s number of employees and tangible assets. Autoregressive Distributed-Lag models (ARDL) are estimated to represent firm growth. Parametric and non-parametric analyses for firm survival are presented. The non-parametric analysis introduces survival and hazard rates characterized by industry class, province, firm age, and firm size. The parametric analysis includes a discrete-time hazard duration model of firm failure. The results show that firm start-up size, growth and survival are influenced by economic growth, industry dynamics, competition, and firm location and characteristics. Models of freight outsourcing decisions by Canadian manufacturers are also presented. Binary logit and multinomial logit models are estimated. The models show that freight outsourcing is driven by firm strategies, supplier locations, government incentives, innovation and technology, industry dynamics, economic conditions, and competition. Models of international versus local outsourcing are also explored. Statistics Canadaâ s T2-LEAP and Survey of Innovation and Business Strategy (SIBS) databases are utilized for this research. The longitudinal T2-LEAP dataset is used to estimate models of firm start-up size, firm growth, and firm failure of Canadian firms for the period of 2001 to 2012. The cross-sectional SIBS dataset, for the years of 2009 and 2012, is used to estimate models of freight outsourcing by Canadian manufacturers.

Keywords: Firm growth
Firm microsimulation
Firmography
Firm start-up size
Firm survival
Freight outsourcing
Advisor: Roorda, Matthew J.
Constant Observation for Older Adults in Acute Care: A Mixed Methods Study

A convergent parallel mixed methods design study, guided by a conceptual framework focusing on factors influencing constant observation practices, was conducted to describe constant observational practices in two hospitals. Quantitative data, collected through questionnaires and chart review, focused on the characteristics of the nurse, observer, unit and patient as well as the nurses’ perceptions of constant observation use and the quality of communication and coordination of care with observers. Qualitative data, collected through non-participant observation of nurse-observer dyads and interviews with these dyads and managers, focused on describing constant observation practices including benefits of this intervention. Patients receiving constant observation had multiple risk factors, such as the presence of responsive behaviours and risk for falls. On both units, nurses had a positive perception of constant observation use, particularly to prevent falls and the removal of treatment equipment. Nurses also had a positive impression of the quality of communication and coordination of care with the observers; important for good constant observation outcomes to occur. Thematic analysis of the data collected through non-participant observation and interviews, led to the identification of three main themes related to constant observation practices: 1) the observer had a multi-faceted role that included providing direct care, ensuring patient safety and sharing information; 2) the nurse had a supervisory role that involved providing support to the observer, directing patient care and sharing information; 3) constant observation outcomes included the prevention and management of responsive behaviour, in addition to the prevention of adverse events, resulting in “a good shift”. Convergence of the different sources of data in this mixed methods study led to a better understanding of the diversity of constant observation practices in different settings, and how these practices are dependent on various contextual, patient and staff factors. This new knowledge will help clinicians and policy makers optimize constant observation practices in their organizations. Clinicians and policy makers are advised to include the delivery of recreational activities to patients as part of the observer role, as these activities may assist in the prevention and de-escalation of patients’ responsive behaviours, further improving the quality of constant observation provided.

Keywords: Acute Care
Constant observation
Delirium
Dementia
Elderly
Safety
Advisor: McGilton, Katherine S
Development and Application of Strategies for Health Impact Assessment of Projects and Policies

Health Impact Assessment (HIA) is a combination of procedures, methods and tools used to evaluate potential health outcomes associated with proposed projects, programs and policies. An HIA differs from other types of assessments in its consideration of both positive and negative health outcomes, and inclusion of social and economic determinants of health. Although HIA has evolved over the past two decades, it remains underutilized. There are several reasons for this, including the fact that HIA methodology is lacking in clarity, consistency and transparency. This doctoral thesis tackles this issue through development of novel HIA tools that address specific research gaps associated with different steps of the HIA process. The first step is screening, which determines whether or not an HIA should be conducted. A unique screening tool that considers the practicality of conducting an HIA by comparing the value of the process versus the required investment was developed and tested by HIA practitioners around the world. Scoping is the next step, which outlines the details and boundaries of the assessment. A scoping tool was developed to systematically identify and prioritize health determinants to be included in HIA. The assessment step is where the health outcomes scoped into the HIA are evaluated for potential positive and negative effects. A new assessment framework was created to provide a transparent method of evaluation in order to characterize impacts and reach a clear, well-justified conclusion. This framework was tested on an actual oil drilling project, allowing for identification of strengths and weaknesses of the tool. The framework was then revised to addresses issues, and was redeveloped so that it could be applied within the Environmental Assessment process. Each of these tools addresses a specific research need in the field of HIA, and promotes the inclusion of health in assessing impacts of projects and policies.

Keywords: Environmental Health
Health Assessment
Health Impact Assessment
HIA
Scoping
Screening
Advisor: Stefanovic, Ingrid
Application of Real-Time Hybrid Simulation Method in Experimental Identification of Gyromass Dampers

Structural control techniques have been extensively explored in the past decades, contributing to substantial safety improvements. Still, recent experience shows that the property damage resulting from even a moderate earthquake is significant. This dissertation studies the design and development of a new mechanical vibration absorber (i.e., gyromass damper or GMD) that uses gear assemblies to generate acceleration-proportional resisting forces. Similar to dynamic vibration absorbers such as tuned mass dampers, GMDs allow the introduction of control forces that are caused by inertial forces. However, unlike tuned mass dampers, they do not require a large additional physical mass. With the aim of incorporating GMDs in real structures, sample configurations are presented that are simple to build, and the effectiveness, robustness, and limitations of these devices for linear systems are investigated. This dissertation has two main foci regarding the application of GMDs for passive control of structures. The first is to improve the current state of the literature by characterizing and modelling the dynamic behaviour of GMDs. While the second is the application of real-time hybrid simulation method as a dynamic testing tool to experimentally examine the effects of GMDs on the performance of SDOF systems. The numerical simulations and experimental results show that GMDs consistently enhances the performance of SDOF systems and it is possible to improve the efficiency of the control system further by employing braces or energy dissipation devices in parallel with the GMD.

Keywords: Earthquake engineering
Gyromass damper
Inertial damper
Passive control device
Real-time hybrid simulation
Seismic performance
Advisor: Mercan, Oya
Malnutrition, Dysphagia and Tongue Strength in Long Term Care

This dissertation investigated the relationships between malnutrition, dysphagia, tongue strength and mealtime outcomes in elderly residents of long term care (LTC) in three phases: a systematic literature review, prospective collection of data in LTC, and a tongue strengthening intervention. The primary goals were to determine: the prevalence of malnutrition and dysphagia; whether signs of dysphagia and reductions of tongue strength impacted meal consumption, and thereby contributed to malnutrition; and the feasibility of conducting a tongue strengthening intervention to improve mealtime outcomes. The systematic review (Chapter 2) revealed imprecise prevalence estimates for malnutrition and dysphagia due to varying definitions and measures across studies. Pilot data were collected (Chapter 3) to demonstrate the feasibility of collecting tongue strength, dysphagia and mealtime outcome data in this setting. Based on the success of the pilot study, a larger study was conducted with a sample comprising residents from 32 LTC homes (Chapter 4). Through this study, we found evidence of relationships between reduced swallowing pressures and dysphagia, as well as dysphagia and malnutrition. Finally, a tongue strengthening intervention was trialed in LTC, with the goal of improving mealtime outcomes (Chapter 5). The findings of this dissertation make several unique contributions to the dysphagia literature. This dissertation has established that dysphagia and malnutrition co-exist in LTC, and that the odds of malnutrition are increased in the presence of signs of dysphagia. Further, it has demonstrated that reduced swallowing pressures and longer mealtimes are closely linked to signs of dysphagia, and that suspected dysphagia increases almost four-fold in the context of reduced swallowing pressures. This research has shown that tongue strength can be improved in people living in long term care and, these data have contributed the first set of reference values for tongue strength of residents of LTC. Limitations are acknowledged and future work is suggested.

Keywords: Deglutition
Elderly
Long term care
Nursing home
Nutrition
Swallowing
Advisor: Steele, Catriona M.
Pertussis Persistence in Ontario

Pertussis, or whooping cough, is a vaccine preventable disease. However, despite having a robust childhood, adolescent, and adult immunization program in Ontario, we continue to see hundreds of reported pertussis cases each year. The goal of this dissertation is to explore the gaps in current immunization programs. By developing a well calibrated transmission model to predict the spread of pertussis in the community, I estimated the underlying burden of pertussis in adolescents and adults and estimated the degree to which pertussis is under-identified in different age groups. I estimated that there are a considerable number of under-identified patients who contribute to the force of infection of pertussis and silently transmit the disease to others. Using a systematic review and meta-analysis, I estimated that the pertussis vaccine, DTaP, is associated with a much shorter duration of immunity than previously thought. This level of waning immunity allows for pertussis to spread amongst previously vaccinated individuals contributing to the persistence of the disease. Finally, using a microsimulation model, I estimated the age- specific costs and health burden associated with pertussis in Ontario. Using these values, I estimated the substantial health and economic impact that pertussis has in both Ontario and Canada. Individually, these findings provide critical insight into the persistence of pertussis in Ontario, but together the results of this dissertation can be integrated into cost-effectiveness analyses to evaluate new immunization schedules and strategies to contain the spread of pertussis.

Keywords: DTaP
immunization
modeling
pertussis
vaccination
Advisor: Fisman, David N
The Architecture of Mohenjo-Daro as Evidence for the Organization of Indus Civilization Neighbourhoods

The Architecture of Mohenjo-Daro as Evidence for the Organization of Indus Civilization Urban Neighbourhoods Matthew S. Mosher Doctor of Philosophy Department of Anthropology University of Toronto 2017 Abstract The Indus Civilization of South Asia (c.2600-1900 B.C.) is one of the earliest and most geographically extensive complex urban-based societies in the world. The near-standardized proportions of its architectural components, technically-elaborate pyrotechnologies, undeciphered writing system and, perhaps most famously, its elaborate networks of urban water management, are well known elements that attest to the highly ordered coherence of its civic culture. However, the basic means of urban organization in the Indus Civilization are poorly understood. This thesis attempts to address this lack of understanding by examining the architectural record of its largest and best-studied city, Mohenjo-Daro, for the foundational elements of urban society: neighbourhoods. Through the reanalysis of its original published reports created in the 1930s, this thesis reveals that much of the built environment of Mohenjo-Daro consists of a limited number of recurring building types, leading to the creation of the first functional architectural typology for the Indus Civilization. The distribution of these architectural types was used to identify the cores of distinct neighbourhoods in the city, locales typified by scaled-down replicas of Mohenjo-Daro's iconic buildings in its Upper Town. Anthropological theory concerned with spatiality, interaction, and identity in urban contexts was applied to examine the relationship between these separate neighbourhoods. While being united to one another in a broad program of stylistic symmetry ultimately tied to the corporate aesthetic of most Indus Civilization cultural expressions, the separate neighbourhoods of Mohenjo-Daro manipulated these same expressive practices to proclaim localized and distinct civic identities, and in so doing architecturally mimicked the tension between the centralizing forces of the Mohenjo-Daro state and the decentralizing tendencies of local manners of association. This balance between local community and larger polity is one of the defining elements of both urban neighbourhoods and complex societies generally. The revelation that Mohenjo-Daro was subject to these tendencies helps to clarify its internal urban organization, and allows for the Indus Civilization to be more firmly situated into comparative studies of urban and political processes.

Keywords: complex societies
Indus Civilization
Mohenjo-Daro
neighbourhoods
political organization
urbanism
Advisor: Miller, Heather M.-L.
Methods for GPU acceleration of Big Data applications

Big Data applications are trivially parallelizable because they typically consist of simple and straightforward operations performed on a large number of independent input records. GPUs appear to be particularly well suited for this class of applications given their high degree of parallelism and high memory bandwidth. However, a number of issues severely complicate matters when trying to exploit GPUs to accelerate these applications. First, Big Data is often too large to fit in the GPUâ s separate, limited-sized memory. Second, data transfers to and from GPUs are expensive because the bus that connects CPUs and GPUs has limited bandwidth and high latency; in practice, this often results in data-starved GPU cores. Third, GPU memory bandwidth is high only if data is layed out in memory such that the GPU threads accessing memory at the same time access adjacent memory; unfortunately this is not how Big Data is layed out in practice. This dissertation presents three solutions that help mitigate the above issues and enable GPU-acceleration of Big Data applications, namely BigKernel, a system that automates and optimizes CPU-GPU communication and GPU memory accesses, S-L1, a caching subsystem implemented in software, and a hash table designed for GPUs. Our key contributions include: (i) the first automatic CPU-GPU data management system that improves on the performance of state-of-the-art double-buffering scheme (a scheme that overlaps communication with computation to improve the GPU performance), (ii) a GPU level 1 cache implemented entirely in the software that outperforms hardware L1 when used by Big Data applications and, (iii) a GPU-based hash table (for storing key-value pairs popular in Big Data applications) that can grow beyond the available GPU memory yet retain reasonable performance. These solutions allow many existing Big Data applications to be ported to GPUs in a straightforward way and achieve performance gains of between 1.04X and 7.2X over the fastest CPU-based multi-threaded implementations.

Keywords: Big Data
Big Data analytics
Compilers
Computer Systems
GPUs
Advisor: Stumm, Michael
Physical activity and exercise among patients with congenital heart disease: towards a model of pediatric cardiac rehabilitation

Patients with congenital heart disease (CHD) have reduced physical activity compared to healthy peers. Past interventions have focused on young children with CHD and improvements in exercise capacity achieved with exercise training. Regular physical activity is beneficial for CHD patients to achieve optimal long-term physical and psychosocial outcomes. This research sought to understand the physical activity behaviour of adolescents (13-17 years old) and emerging adults (18-25 years old) with CHD. In the first study, longitudinal trends in a cohort of patients with Fontan circulation (n=33; 21Âą3years) indicated a 31% reduction in moderate-to-vigorous physical activity (MVPA) over a seven-year period from childhood to adulthood. More vigorous physical activity as a child was associated with greater physical activity as an adult. A cross-sectional study (Study 2) including qualitative interviews in a separate cohort of emerging adults with CHD (n=15; 21Âą3years) identified that emerging adults perceived family as supportive, appreciated parental involvement, accepted their CHD as normal, contextualized activity in terms of school and sports, felt that activity accumulated at work was sufficient, and participated in physical activity to be healthy. This cohort of emerging adults reported moderate self-efficacy for exercise, high quality of life, and low heart-focused anxiety. Daily MVPA measured by accelerometer was 26 minutes/day. In a third study, adolescents with CHD (n=31; 15Âą3years) participated in a randomized control trial of an adapted Motivational Interviewing (MI) behavioural intervention compared to a control condition. Participants achieved 21 minutes/day of MVPA and reported high self-efficacy and quality of life. Participants (n=15) who received the behavioural intervention did not improve physical activity, fitness, or psychosocial outcomes compared to control patients. No participants met the current physical activity recommendations. Physical activity promotion should be a priority for the pediatric CHD population and should include age-appropriate interventions. Behavioural interventions require more information derived from additional research to determine the most feasible and effective approach to improve physical activity among patients with CHD across the lifespan. Family-based interventions that include vigorous activities in childhood may be one approach to help patients achieve higher levels of activity in adulthood.

Keywords: cardiac rehabilitation
congenital heart disease
exercise
pediatric cardiology
physical activity
Advisor: McCrindle, Brian W.