VictorJuiz/thesis huggingface dataset:
Enhanced Synchronous Design Using Asynchronous Techniques

As semiconductor technology scales down, process variations become increasingly difficult to control. To cope with this, more and more conservative delay and clock frequency estimations are used during design, which result in overly large and leaky circuits. Also, the system runs at a speed slower than that possible because a fixed clock determined by the worst-case analysis of the circuit is used. On top of process variations, voltage and temperature variations also push the designer towards even more conservative delay estimations. On the other hand, asynchronous design style has potential advantages over synchronous design including resilience to process variations, lower power consumption and higher performance. Unfortunately, these advantages are usually hindered by the significant design effort required to implement useful asynchronous circuits and also by the overhead of asynchronous control logic. Borrowing from asynchronous techniques, a new methodology is proposed to design synchronous circuits that have some of the advantages of asynchronous circuits. Asynchronous logic is used to generate the clock of a synchronous system. The resulting system automatically tunes itself to deliver the best-possible performance under the prevailing process-voltage-temperature (PVT) conditions. This methodology may be used to reduce the leakage power significantly in deep nanometer technologies. It also helps in handling process variations. The results from a 32-bit processor implemented in 90nm technology shows 10X leakage reduction compared to the traditional synchronous design. The proposed technique is expanded to adjust the speed of a pipeline according to the current operations flowing in the pipeline as well as the current PVT conditions. The results from a 32-bit processor in 90nm technology demonstrate a 2X speed improvement compared to the conventional synchronous design. The proposed techniques only use synchronous design tools and are compatible with design flows that are currently in use.

Keywords: Digital Design
PVT-aware
Advisor: Zaky, Safwat
Predicting Parenting Stress in Families of Children with ADHD

This dissertation consists of two studies that investigated predictors of parenting stress as they relate to child ADHD. Two main questions were explored: what is the magnitude of the association between child ADHD and parenting stress, and what are the parent and contextual predictors of parenting stress? In Study 1, meta-analyses were conducted on the association between parenting stress and ADHD. Predictors comprising child, parent, and contextual factors, and methodological and demographic moderators of the relationship between parenting stress and ADHD were examined. Findings from 44 studies were included. In Study 2, I examined parent and contextual (parental ADHD symptoms, parental education, social support, and marital status) predictors of parent domain parenting stress (parental distress) as a function of teacher-reported child ADHD symptoms. Results confirmed that parents of children with ADHD experience more parenting stress than parents of nonclinical control children, and that severity of child ADHD symptoms are associated with parenting stress. Child oppositionality was only predictive of parental distress when reported by parents (not teachers). A post-hoc analysis in Study 2 showed that child factors did not predict parental distress over and above parent and contextual factors. In Study 1, children’s co-occurring conduct problems and parental depressive symptomatology predicted parenting stress. Little difference in parenting stress was found between mothers and fathers, but lower parenting stress levels were found in samples with higher proportions of girls. Parental ADHD symptomatology was the strongest predictor of parental distress considered in Study 2. Social support was inversely related to parental distress in Study 2, whereas parental age and education were unrelated to parental distress. In Study 2, marital status was significantly correlated with parental distress, but was not a significant predictor in the regression. Marital quality was not a significant predictor of parenting stress in Study 1. The large effects observed for parent level predictors suggests that parent factors (i.e., ADHD and depressive symptoms) are critically important in parenting stress and play a primary role in the experience of elevated parenting stress. Future research should give greater consideration to factors outside of the child in increasing parenting stress.

Keywords: ADHD
parenting stress
Advisor: Wiener, Judith
Visualization of Knowledge Spaces to Enable Concurrent, Embedded and Transformative Input to Knowledge Building Processes

This thesis focuses on the creation of a systems architecture to help inform development of next generation knowledge-building environments. The architectural model consists of three components: an infrastructure layer, a discourse layer, and a visualization layer. The Knowledge Space Visualizer (KSV), which defines the top visualization layer, is a prototypic system for showing reconstructed representations of discourse-based artifacts and facilitating assessment in light of patterns of interactivity of participants and their ideas. The KSV uses Latent Semantic Analysis to extend techniques from Social Network Analysis, making it possible to infer relationships among note contents. Thus idea networks can be studied in conjunction with social networks in online discourse. Further, benchmark corpora can be used to determine knowledge advances, and systems of interactivity leading to them. Results can then provide feedback to students and teachers to support them in obtaining continually higher level achievements. In addition to visual representations, the KSV provides quantitative network metrics such as degree and density. Data drawn from 9- and 10-year-old students working on a six-week unit on optics were used to illustrate some of the functionality of the KSV. Three studies show ways in which new visualizations can be used: (a) to highlight relationships among notes, (b) as a way of tracking the development of discourse over time, and (c) as an assessment tool. Implications for the design of knowledge building environments, assessment tools, and design-based research are discussed.

Keywords: knowledge building
visualization
assessment
Knowledge Forum
latent semantic analysis
knowledge space visualizer
KSV
LSA
systems model
Advisor: Scardamalia, Marlene
Cardiac Rehabilitation After Stroke

In contrast to cardiac rehabilitation (CR) programs, traditional stroke rehabilitation aims to maximize functional independence and does not have a strong focus on exercise training and risk factor modification. Given the parallels between stroke and heart disease in cardiovascular etiology and risk factors, CR may be suited to supplement stroke rehabilitation by providing opportunities to enhance fitness and manage stroke risk factors. The aim of this work was to 1) examine the use of a non-adapted CR program of care with individuals with stroke and/or transient ischemic attack (TIA) through a retrospective database review, 2) using a prospective trial, determine the feasibility and effects of an adapted CR program for people with mild to moderate impairment from stroke, and 3) explore characteristics related to degree of program response in aerobic and functional capacity through secondary data analysis. The results from Study 1 demonstrated that traditional CR is an underutilized service for individuals with stroke or TIA, yet improvements in aerobic fitness were comparable to their non-stroke counterparts. In Study 2, adapted CR was feasible for individuals with a range of stroke-related disability and effective in increasing aerobic capacity. The anticipated carry over to improved walking capacity was not observed. There were no changes in health-related quality of life or stroke risk factors. Study 3 identified subgroups of participants who improved or declined in aerobic and ambulatory capacity after the adapted CR program. There were no differences in baseline characteristics, indices of time, intensity or volume of exercise performed across the response subgroups. In summary, given the parallels between stroke and heart disease, the needs of the stroke population and dearth of community-based exercise programming available for them, the CR model of care may be applied for individuals with stroke to provide opportunities for exercise training and risk factor modification.

Keywords: Stroke
Exercise
Rehabilitation
Risk Factors
Advisor: Brooks, Dina
Operating System Management of Shared Caches on Multicore Processors

Our thesis is that operating systems should manage the on-chip shared caches of multicore processors for the purposes of achieving performance gains. Consequently, this dissertation demonstrates how the operating system can profitably manage these shared caches. Two shared-cache management principles are investigated: (1) promoting shared use of the shared cache, demonstrated by an automated online thread clustering technique, and (2) providing cache space isolation, demonstrated by a software-based cache partitioning technique. In support of providing isolation, cache provisioning is also investigated, demonstrated by an automated online technique called RapidMRC. We show how these software-based techniques are feasible on existing multicore systems with the help of their hardware performance monitoring units and their associated hardware performance counters. On a 2-chip IBM POWER5 multicore system, promoting sharing reduced processor pipeline stalls caused by cross-chip cache accesses by up to 70%, resulting in performance improvements of up to 7%. On a larger 8-chip IBM POWER5+ multicore system, the potential for up to 14% performance improvement was measured. Providing isolation improved performance by up to 50%, using an exhaustive offline search method to determine optimal partition size. On the other hand, up to 27% performance improvement was extracted from the corresponding workload using an automated online approximation technique, made possible by RapidMRC.

Keywords: operating systems
multicore processors
shared caches
promoting sharing
providing isolation
cache provisioning
thread clustering
cache partitioning
approximating MRCs
Advisor: Stumm, Michael
Predicative Quantum Programming

This work presents Quantum Predicative Programming --- a theory ofquantum programming that encompasses many aspects of quantum computation and quantum communication. The theory provides a methodology to specify, implement, and analyse quantum algorithms, the paradigm of quantum non-locality, quantum pseudotelepathy games, computing with mixed states, and quantum communication protocols that use both quantum and classical communication channels.

Keywords: formal methods
software engineering
programming methodologies
quantum computing
Advisor: Hehner, Eric C. R.
Characterization of the E3 Ubiquitin Ligase Pirh2

The p53 tumour suppressor gene is inactivated by mutation in over 50% of all human cancers. The p53 protein is activated and stabilized through several post-translational modifications in response to various stresses and promotes cell cycle arrest and apoptosis. Thus, regulation of p53 is critical for normal cellular function. Pirh2 is a p53-regulated gene recently identified in our laboratory which encodes an E3 RING-finger ubiquitin ligase that binds to p53 and negatively regulates p53 by targeting it for ubiquitin-mediated proteolysis. Pirh2 is similar to another well-characterized E3 RING finger ubiquitin ligase, Mdm2, which also participates in a similar negative feedback loop with p53. At least seven E3 ubiquitin ligases are known to target p53 for degradation and the reason for this functional redundancy is unclear. The purpose of this study is to characterize Pirh2 activity. This study has two aims the first is to identify additional interacting proteins for Pirh2, and the second is to delineate Pirh2 regulation of p53. Using several tandem affinity purification strategies and a GST-pull down approach, we have identified PKC delta as a candidate interacting protein. The second aim is to further characterize Pirh2 regulation of p53. Splenocytes and thymocytes from Pirh2-/- mice demonstrate a subtle increase in total p53 levels after irradiation when compared to wild-type controls. Phosphoserine 15 p53 levels are significantly higher in splenocytes and thymocytes from Pirh2 -/- mice relative to wild-type counterparts. Cells stably transfected with Pirh2 have decreased levels of phosphoserine 15 p53 and decreased induction of p21 relative to vector control and Mdm2 expressing cells. The stability of the p53 protein is primarily regulated through ubiquitin mediated proteolysis, and there are multiple ubiquitin ligases targeting p53 for degradation. Here we are able to address the question of functional redundancy by indicating that Pirh2 can target serine 15 phosphorylated p53 which is reported to not be regulated by Mdm2.

Keywords: p53
ubiquitination
Pirh2
E3 ubiquitin ligase
Advisor: Benchimol, Samuel
Networks, Boundaries and Social Capital: The Historical Geography of Toronto's Anglo Elites and Italian Entrepreneurs, 1900-1935

This dissertation examines how social inequalities are reinforced over time and in place by addressing a central question: How are power relations maintained and reproduced in space? I outline ways in which social networks contributed to the reproduction of social and economic power in early twentieth-century Toronto. I also pay particular attention to the ways in which particular spaces acted as a nexus for the reproduction of power and unequal social relations. My research captures the dynamism and complexity of social capital networks that stretched across space. These networks demonstrate that Toronto’s Anglo elite and Italian entrepreneurs lived in a world where persons interacted over a number of regions and scales. This study contributes to the body of knowledge in social capital, network and social boundary research. Although this dissertation is largely concerned with early twentieth-century Toronto class and power relations, the results have implications beyond this case study. This research makes a significant contribution to historical geography by providing scholars interested in contemporary power relations and social networks with an empirically rich historical perspective. This study extends previous examinations of social inequality by examining how power relations were reproduced over time and through space. I analyze how social capital can be conceptualized as set of processes that is 1) integral to the acquisition of economic capital, 2) significant in constraining the action of others by redrawing the social boundaries of class and ethnicity, and 3) critical for the building of alliances across space. This research offers a complementary method to the inequality studies of David Ward, Joe Darden, Nan Lin, Richard Harris, James Barrett, and David Harvey by historically situating questions about the reproduction of social inequality through the examination of social networks.

Keywords: social capital
social networks
Toronto
social boundaries
Advisor: Lewis, Robert
A Confluence of Traditions: Examining Teacher Practice in the Merging of Secondary Science and Environmental Education

Embedding environmental education within secondary science curriculum presents both philosophical and practical difficulties for teachers. This ethnographic/narrative study, with its methodology grounded in eco-feminism and realism/constructivism, examines the work of six secondary science teachers as they engage in an action research project focused on merging environmental education in their science lessons. Over the course of several months the teachers examine and discuss their views and their professional development related to the project. In the place of definitive conclusions, eight propositions relating the work of secondary science teachers to environmental education, form the basis for a discussion of the implications of the study. The implications are particularly relevant to secondary schools in Ontario, Canada, where the embedding of environmental education in science studies has been mandated.

Keywords: environmental education
secondary science
action research
teacher culture
eco-feminism
Advisor: Wallace, John
Truth Commissions and Public Inquiries: Addressing Historical Injustices in Established Democracies

In recent decades, the truth commission has become a mechanism used by states to address historical injustices. However, truth commissions are rarely used in established democracies, where the commission of inquiry model is favoured. I argue that established democracies may be more amenable to addressing historical injustices that continue to divide their populations if they see the truth commission mechanism not as a unique mechanism particular to the transitional justice setting, but as a specialized form of a familiar mechanism, the commission of inquiry. In this framework, truth commissions are distinguished from other commissions of inquiry by their symbolic acknowledgement of historical injustices, and their explicit “social function” to educate the public about those injustices in order to prevent their recurrence. Given that Canada has established a Truth and Reconciliation Commission (TRC) on the Indian Residential Schools legacy, I consider the TRC’s mandate, structure and ability to fulfill its social function, particularly the daunting challenge of engaging the non-indigenous public in its work. I also provide a legal history of a landmark Canadian public inquiry, the Mackenzie Valley Pipeline Inquiry, run by Tom Berger. As his Inquiry demonstrated, with visionary leadership and an effective process, a public inquiry can be a pedagogical tool that promotes social accountability for historical injustices. Conceiving of the truth commission as a form of public inquiry provides a way to consider the transitional justice literature on truth commissions internationally along with the experiences of domestic commissions of inquiry to assemble strategies that may assist the current TRC in its journey.

Keywords: transitional justice
truth and reconciliation commission
Mackenzie Valley Pipeline Inquiry
Berger Inquiry
Thomas Berger
Indian residential schools
public inquiries
commissions of inquiry
truth commissions
TRC
Advisor: Moran, Mayo
Dyzenhaus, David
A Model-based Approach to Limb Apraxia: Evidence from Stroke and Corticobasal Syndrome

This thesis provides new insights about how the brain controls skilled movements, through the study of limb apraxia in two major neurological disorders: Stroke and Corticobasal Syndrome (CBS). Limb apraxia is a cognitive-motor deficit characterized by impairment in the performance of skilled movement. The Conceptual-Production systems model, used as framework in this thesis, proposes that skilled movement is under the control of three systems: a sensory/perceptual system, a conceptual system and a production system. Deficits in any of these systems produce limb apraxia, and depending on which system is affected, a distinct pattern of apraxia emerges. This information processing approach was used to evaluate performance levels, study brain asymmetries and discern patterns of deficits in each population. In addition, longitudinal assessments in sample subsets revealed patterns of recovery after stroke and of progression in CBS. The first study examined acute-subacute and chronic stroke patients with left (LHD) and right hemisphere damage (RHD) for their ability to pantomime and imitate transitive and intransitive gestures. The results indicated that LHD and acute-subacute were more severely impaired. Concurrent deficits in pantomime and imitation were most common, especially after LHD. Since acute-subacute patients were more severely impaired, in the absence of any therapies, it is likely that some degree of recovery occurs over time. The second study study examined longitudinal recovery in a series of transitive gestures tasks among stroke patients and indicated that patients significantly recovered in all tasks, except in Action Identification, a conceptual apraxia task which probes knowledge of actions. Finally, two comparative studies were conducted in CBS, a neurodegenerative disorder in which apraxia is common, making this one of the first studies that evaluated patient performance on a complete limb apraxia battery. The first study found that patients were often impaired on all gesture production tasks, while conceptual knowledge of gestures and tools was usually preserved. A case series constituted the second study, which documented the progression of apraxia in CBS demonstrating that, while deficits in gesture production usually are present at first examination, deficits in conceptual knowledge are infrequent and in many cases do not develop at all. Study limitations were discussed and it was suggested that future research should expand on our findings for recovery in stroke and progression in CBS.

Keywords: Apraxia
Stroke
Corticobasal Syndrome
Motor Control
Advisor: Black, Sandra
Roy, Eric A.
Using System Structure and Semantics for Validating and Optimizing Performance of Multi-tier Storage Systems

Modern persistent storage systems must balance two competing imperatives: they must meet strict application-level performance goals and they must reduce the operating costs. The current techniques of either manual tuning by administrators or by over-provisioning resources are either time-consuming or expensive. Therefore, to reduce the costs of management, automated performance-tuning solutions are needed. To address this need, we develop and evaluate algorithms centered around the key thesis that a holistic semantic-aware view of the application and system is needed for automatically tuning and validating the performance of multi-tier storage systems. We obtain this global system view by leveraging structural and semantic information available at each tier and by making this information available to all tiers. Specifically, we develop two key build- ing blocks: (i) context-awareness, where information about the application structure and semantics is exchanged between the tiers, and (ii) dynamic performance models that use the structure of the system to build lightweight resource-to-performance mappings quickly. We implement a prototype storage system, called Akash, based on commodity components. This prototype enables us to study all above scenarios in a realistic rendering of a modern multi-tier storage system. We also develop a runtime tool, Dena, to analyze the performance and behaviour of multi-tier server systems. We apply these tools and techniques in three real-world scenarios. First, we leverage application context-awareness at the storage server in order to improve the performance of I/O prefetching. Tracking application access patterns per context enables us to improve the prediction accuracy for future access patterns, over existing algorithms, where the high interleaving of I/O accesses from different contexts make access patterns hard to recognize. Second, we build and leverage dynamic performance models for resource allocation, providing consistent and predictable performance, corresponding to pre-determined application goals. We show that our dynamic resource allocation algorithms minimize the interference effects between e-commerce applications sharing a common infrastructure. Third, we introduce a high-level paradigm for interactively validating system performance by the system administrator. The administrator leverages existing performance models and other semantic knowledge about the system in order to discover bottlenecks and other opportunities for performance improvements. Our evaluation shows that our techniques enable significant improvements in performance over current approaches.

Keywords: Storage Systems
Database
Optimization
Performance
Analysis
Computer
Advisor: Amza, Cristiana