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This file is officially titled as a project. This is Part B in connection with another project by the same author, titled "Part A: Adjuster Rod Design in a CANDU Reactor and Flux Distributions Due to an Arbitrary Source of Neutrons."http://hdl.handle.net/11375/15387 / In this report, the effectiveness of a proposed Shutoff Rod System a CANDU Reactor was investigated. A full core simulation was done, to study the neutronic power transient following a change in coolant conditions. / Thesis / Master of Engineering (ME)

This study addressed the broader issue of the negative impact of the community college practice of hiring large numbers of part-time faculty on graduation rates. Prior research has determined that higher ratios of full-time faculty correlate significantly and positively with community college graduation rates. This study extended the research of institutional models affecting community college graduation rates and investigated the nature of regional accreditation for the adequacy of full-time faculty as a determinate of graduation rates. This study included all public 2-year institutions in the United States. A correlational research design was implemented using data available through the National Center for Education Statistics and the nation’s six regional accrediting agencies for community colleges. Among the major findings in the study, graduation rates were found to be significantly correlated among schools belonging to different regional accreditation agencies. The study also determined that ratios of full-time faculty, institution size, instructional spending, and ratios of full-time students correlated significantly with increased graduation rates. When comparing community colleges among regional accreditors that had no standards for regulating the adequacy of full-time faculty with those who do, graduation rates did not correlate significantly. These results contribute to the body of knowledge for institutional effects on graduation rates and also have important implications for regional accreditors. The results suggest that regional accrediting standards for the adequacy of full-time faculty may need to be more prescriptive in nature to provide a direct impact on graduation rates.

Airfield matting systems are used for the expedient construction of temporary airfields and rapid expansion of existing airfields to provide maneuvering support for military aircraft. They protect the subgrade by distributing the load exerted by aircraft over a larger area. Six airfield matting systems of varying materials and designs were evaluated through the construction of full-scale test sections to determine their effectiveness at reducing the accumulation of subgrade deformation and decreasing the pressure experienced by the subgrade. The matting systems were tested on a California Bearing Ratio (CBR) of 6 and subjected to simulated F-15E aircraft traffic while monitoring mat breakage, deformation, and subgrade earth pressure. The systems were compared in terms of the rate of subgrade permanent deformation. Based on test results, a simplified expression was developed to predict subgrade deformation on a CBR of 6 as a function of F 15E aircraft passes and airfield mat properties.

Cognitive radio had been proposed as a methodology for overcoming the inefficiency of the conventional static allocation of the available spectrum in wireless communication networks. The majority of opportunistic spectrum access schemes in cognitive radio networks (CRNs) rely on the Listen-Before-Talk (LBT) model due to the half-duplex nature of conventional wireless radios. However, LBT su ers from the problem of high collision rates and low secondary user throughput if time is misaligned among the secondary users (SUs) and the primary users (PUs). This problem can be mitigated by leveraging full-duplex (FD) communications that facilitate concurrent sensing and transmission. This thesis considers the problem of optimal opportunistic multi-channel spectrum sensing and access using FD radios in the presence of uncertain primary user (PU) activity statistics. A joint learningand spectrum access scheme is proposed. To optimize its throughput, the SU sensing period has to be carefully tuned. However, in absence of exact knowledge of the PU activity statistics, the PU's performance may be adversely a ected. To address this problem, a robust optimization problem is formulated. Analysis shows that under some non-restrictive simplifying assumptions, the robust optimization problem is convex. The impact of sensing periods on the PU collision probability and the SU throughput are analyzed, and the optimal sensing period is found via convex optimization. An "\epsilon-greedy algorithm is proposed for use by the SU to learn the PUs' activity statistics in multichannel networks. It is shown that sublinear regrets can be attained by the proposed estimation and robust optimization strategy. Simulation studies demonstrate that the resulting robust solution achieves a good trade-o between optimizing the SU's throughput and protecting the PU. / Thesis / Master of Applied Science (MASc)

Since the first saxophone professor at the Paris Conservatory in 1858, saxophone instruction has primarily been a male-dominated field. Numerous sources detail the experiences, lives, and influence of male post-secondary saxophone instructors. Women have made great strides in the performance and instruction of the saxophone at the post-secondary level, but sources discussing their lives and experiences are limited. Saxophone instruction at the post-secondary level in the United States began in the late 1800s. As the instrument grew in popularity through the 20th century, more and more higher education institutions began incorporating the saxophone as an instrument for primary study. This increased the need for saxophone professors in the United States. In 1994, Elizabeth Zinn Ervin, became the first woman full professor. This was 40 years after the the first man, Larry Teal, held this rank. As of 2023, 15 women have achieved the rank of full professor. This document is intended to highlight several women saxophone instructors throughout the history of the instrument, and detail the thoughts and experiences of women saxophonists who have achieved the rank of full professor in the United States.

This dissertation proposes a new framework to characterize the nonlinear behavior of anisotropic materials in an on-line manner. The proposed framework applies recursive estimation and a multi-linear model to characterize the nonlinear behavior of anisotropic materials on-line using full-field strains, which are capable of capturing the multi-axial information of anisotropic materials. A stochastic method is developed to characterize the linear behavior of anisotropic materials under the influence of full-field strain measurement noise. This method first derives stochastic equations based on the formulas of energy-based characterization that utilizes the principle of ener-gy conservation, and then recursively estimates elastic constants at every acquisition of measure-ment using a Kalman filter (KF). Since the measurement model is expressed nonlinearly, the KF utilizes a Kalman gain, which is newly derived in this dissertation through variance minimization, to achieve optimal characterization. The aforementioned method, namely stochastic linear characteri-zation in this dissertation, becomes a basis of the multi-linear characterization method. This method utilizes a multi-linear model, which is defined by partitions, to characterize the nonlinear constitu-tive relations. The multi-linear characterization scales up the number of estimates and identifies the coefficients of each linear partition using the previously derived KF. The recursive updates in measurements not only removes uncertainty through sensor measurements, but also enables the on-line capability of the nonlinear characterization of anisotropic materials. A series of numerical and experimental studies were performed to demonstrate the performance of the proposed framework in characterizing the nonlinear behavior of anisotropic materials. The validity and applicability of the proposed framework were confirmed by the comparison with the known values of the characterized constitutive relations. It was found that the proposed framework identified elastic constants that were in good agreement with known values irrespective of the spec-imen geometry. The results of the multi-linear characterization method were well correlated with known nonlinear stress-strain relations and concluded that the proposed framework is capable of characterizing adequate nonlinear behavior on-line. / Ph. D.

This study examines the impact of selected structures of the Virginia Preschool Initiative on reading readiness in at-risk preschool students in the state of Virginia. The Virginia Preschool Initiative is designed to prepare at-risk four-year-olds for success in kindergarten. According to the Virginia Department of Education, "The purpose of the grants is to reduce disparities among young children upon formal school entry and to reduce or eliminate those risk factors that lead to early academic failure." (Virginia Department of Education, 2005) The independent variables are the specific curriculum models used by the school division, length of program day, teacher certification, and program sponsoring agency. The dependent variables are the pre and post assessment scores on the eight subtests of the PALS-PreK assessment. A paired sample t-test and one-way ANOVA were conducted using Fall and Spring 2006 PALS-PreK student assessment scores from school divisions that participated in the Virginia Preschool Initiative during the 2005-06 school year to determine the relationship between the curriculum implemented and PALS-PreK Fall and Spring student assessment scores. The findings in this study indicate a statistically significant difference between the Fall and Spring student assessment scores for each of the curriculum models analyzed and at least one curriculum model consistently underperforms the other three curriculum models. There were no differences in three variables (length of school day, teacher certification, and program sponsoring agency) and were therefore, not subject to analysis. / Ph. D.

Computational solutions are presented for flows ranging from incompressible viscous flows to inviscid transonic flows. The viscous flow problems are solved using the incompressible Navier-Stokes equations while the inviscid solutions are attained using the full potential equation. Results for the viscous flow problems focus on turbulence modeling when separation is present. The main focus for the inviscid results is the development of an unstructured solution algorithm. The subject dealing with turbulence modeling for separated flows is discussed first. Two different test cases are presented. The first flow is a low-speed converging-diverging duct with a rapid expansion, creating a large separated flow region. The second case is the flow around a stationary hydrofoil subject to small, oscillating hydrofoils. Both cases are computed first in a steady state environment, and then with unsteady flow conditions imposed. A special characteristic of the two problems being studied is the presence of strong adverse pressure gradients leading to flow detachment and separation. For the flows with separation, numerical solutions are obtained by solving the incompressible Navier-Stokes equations. These equations are solved in a time accurate manner using the method of artificial compressibility. The algorithm used is a finite volume, upwind differencing scheme based on flux-difference splitting of the convective terms. The Johnson and King turbulence model is employed for modeling the turbulent flow. Modifications to the Johnson and King turbulence model are also suggested. These changes to the model focus mainly on the normal stress production of energy and the strong adverse pressure gradient associated with separating flows. The performance of the Johnson and King model and its modifications, along with the Baldwin-Lomax model, are presented in the results. The modifications had an impact on moving the flow detachment location further downstream, and increased the sensitivity of the boundary layer profile to unsteady flow conditions. Following this discussion is the numerical solution of the full potential equation. The full potential equation assumes inviscid, irrotational flow and can be applied to problems where viscous effects are small compared to the inviscid flow field and weak normal shocks. The development of a code is presented which solves the full potential equation in a finite volume, cell centered formulation. The unique feature about this code is that solutions are attained on unstructured grids. Solutions are computed in either two or three dimensions. The grid has the flexibility of being made up of tetrahedra, hexahedra, or prisms. The flow regime spans from low subsonic speeds up to transonic flows. For transonic problems, the density is upwinded using a density biasing technique. If lift is being produced, the Kutta-Joukowski condition is enforced for circulation. An implicit algorithm is employed based upon the Generalized Minimum Residual method. To accelerate convergence, the Generalized Minimum Residual method is preconditioned. These and other problems associated with solving the full potential equation on an unstructured mesh are discussed. Results are presented for subsonic and transonic flows over bumps, airfoils, and wings to demonstrate the unstructured algorithm presented here. / Ph. D.