Implementing the Physical Literacy Component of the 2015 Ontario Health and Physical Education Curriculum: Is the Stage Set?

Introduction: Current physical activity levels among children and youth are alarmingly low; a mere 7% of children and youth are meeting the Canadian Physical Activity Guidelines (Colley et al., 2011), which means that the vast majority of this population is at risk of developing major health problems in adulthood (Janssen & Leblanc, 2010). These high inactivity rates may be related to suboptimal experiences in sport and physical activity stemming from a lack of competence and confidence (Lubans, Morgan, Cliff, Barnett, & Okely, 2010). Developing a foundation of physical literacy can encourage and maintain lifelong physical activity, yet this does not always occur naturally as a part of human growth (Hardman, 2011). An ideal setting to foster the growth and development of physical literacy is physical education class. Physical education class can offer all children and youth an equal opportunity to learn and practice the skills needed to be active for life (Hardman, 2011). Elementary school teachers are responsible for delivering the physical education curriculum, and it is important to understand their will and capacity as the implementing agents of physical literacy development curriculum (McLaughlin, 1987). Purpose: The purpose of this study was to explore the physical literacy component of the 2015 Ontario Health and Physical Education curriculum policy through the eyes of key informants, and to explore the resources available for the implementation of this new policy. Methods: Qualitative interviews were conducted with seven key informants of the curriculum policy development, including two teachers. In tandem with the interviews, a resource inventory and curriculum review were conducted to assess the content and availability of physical literacy resources. All data were analyzed through the lens of Hogwood and Gunn’s (1984) 10 preconditions for policy implementation. Results: Participants discussed how implementation is affected by: accountability, external capacity, internal capacity, awareness and understanding of physical literacy, implementation expertise, and policy climate. Discussion: Participants voiced similar opinions on most issues, and the overall lack of attention given to physical education programs in schools will continue to be a major dilemma when trying to combat such high physical inactivity levels.

New Rigorous Decomposition Methods for Mixed-integer Linear and Nonlinear Programming

Process systems design, operation and synthesis problems under uncertainty can readily be formulated as two-stage stochastic mixed-integer linear and nonlinear (nonconvex) programming (MILP and MINLP) problems. These problems, with a scenario based formulation, lead to large-scale MILPs/MINLPs that are well structured. The first part of the thesis proposes a new finitely convergent cross decomposition method (CD), where Benders decomposition (BD) and Dantzig-Wolfe decomposition (DWD) are combined in a unified framework to improve the solution of scenario based two-stage stochastic MILPs. This method alternates between DWD iterations and BD iterations, where DWD restricted master problems and BD primal problems yield a sequence of upper bounds, and BD relaxed master problems yield a sequence of lower bounds. A variant of CD, which includes multiple columns per iteration of DW restricted master problem and multiple cuts per iteration of BD relaxed master problem, called multicolumn-multicut CD is then developed to improve solution time. Finally, an extended cross decomposition method (ECD) for solving two-stage stochastic programs with risk constraints is proposed. In this approach, a CD approach at the first level and DWD at a second level is used to solve the original problem to optimality. ECD has a computational advantage over a bilevel decomposition strategy or solving the monolith problem using an MILP solver. The second part of the thesis develops a joint decomposition approach combining Lagrangian decomposition (LD) and generalized Benders decomposition (GBD), to efficiently solve stochastic mixed-integer nonlinear nonconvex programming problems to global optimality, without the need for explicit branch and bound search. In this approach, LD subproblems and GBD subproblems are systematically solved in a single framework. The relaxed master problem obtained from the reformulation of the original problem, is solved only when necessary. A convexification of the relaxed master problem and a domain reduction procedure are integrated into the decomposition framework to improve solution efficiency. Using case studies taken from renewable resource and fossil-fuel based application in process systems engineering, it can be seen that these novel decomposition approaches have significant benefit over classical decomposition methods and state-of-the-art MILP/MINLP global optimization solvers.

A NEW DC UPS FOR DC POWER DISTRIBUTION SYSTEM IN DATA CENTER

In recent years, the 380V DC and 48V DC distribution systems have been extensively studied for the latest data centers. It is widely believed that the 380V DC system is a very promising candidate because of its lower cable cost compared to the 48V DC system. However, previous studies have not adequately addressed the low reliability issue with the 380V DC systems due to large amount of series connected batteries. In this thesis, a quantitative comparison for the two systems has been presented in terms of efficiency, reliability and cost. A new multi-port DC UPS with both high voltage output and low voltage output is proposed. When utility ac is available, it delivers power to the load through its high voltage output and charges the battery through its low voltage output. When utility ac is off, it boosts the low battery voltage and delivers power to the load form the battery. Thus, the advantages of both systems are combined and the disadvantages of them are avoided. High efficiency is also achieved as only one converter is working in either situation. Details about the design and analysis of the new UPS are presented. For the main AC-DC part of the new UPS, a novel bridgeless three-level single-stage AC-DC converter is proposed. It eliminates the auxiliary circuit for balancing the capacitor voltages and the two bridge rectifier diodes in previous topology. Zero voltage switching, high power factor, and low component stresses are achieved with this topology. Compared to previous topologies, the proposed converter has a lower cost, higher reliability, and higher efficiency. The steady state operation of the converter is analyzed and a decoupled model is proposed for the converter. For the battery side converter as a part of the new UPS, a ZVS bidirectional DC-DC converter based on self-sustained oscillation control is proposed. Frequency control is used to ensure the ZVS operation of all four switches and phase shift control is employed to regulate the converter output power. Detailed analysis of the steady state operation and design of the converter are presented. Theoretical, simulation, and experimental results are presented to verify the effectiveness of the proposed concepts.