Digital Commons Network^™

Dynamic Response Of Poroelastic Materials Containing Bingham Fluid: Application To Electrorheological Fluids, Mete Kesan

Doctoral Dissertations

This work examines the dynamic response to harmonic loading of a disk of poroelastic material containing non-Newtonian Bingham fluid which exhibits a yield stress. Biot's poroelasticity equations and modified Darcy's law for non-Newtonian fluids exhibiting a yield stress are combined together to obtain the governing equations of the system for quasi-static case. Dissipation due to friction arising from the flow of fluid relative to the solid is taken into account but inertia effects are neglected. The response and the complex modulus of the system are calculated using the finite element method taking into account the nonlinear nature of Bingham fluid. …

Student Achievement, Parental Effort And Schooling, Andrew James Houtenville

Doctoral Dissertations

When evaluating public education programs that are aimed at improving student achievement, it is often assumed that a child's family background is an exogenous factor, albeit an important factor. However, parental decisions may be influenced by such programs. It is the assertion of Becker and Tomes (1976) that distortions in parental behavior (time allocation) may be one of the reasons that compensatory education fails to improve student achievement. In short, parents reduce their own effort when school services (schooling) is increased. However, theoretically parental responses are ambiguous; parental effort can increase or decrease in response to increased schooling. This dissertation …

A Sensory-Based Adaptive Walking Control Algorithm For Variable Speed Biped Robot Gaits, Andrew L. Kun

Doctoral Dissertations

A balance scheme for handling variable speed gaits was implemented on an experimental biped. The control scheme used pre-planned but adaptive motion sequences in combination with closed loop reactive control. CMAC neural networks were responsible for the adaptive control of side-to-side and front-to-back balance. The biped performance improved with neural network training. The biped was able to walk with variable speed gaits, and to change gait speeds on the fly. The slower gait speeds required statically balanced walking, while the faster speeds required dynamically balanced walking. It was not necessary to distinguish between the two balance modes within the controller. …

Contributions To The Theory Of Neighborhoods And Its Applications, Michael Joseph Cullinane

Doctoral Dissertations

Neighborhoods have played a fundamental role in general topology since the birth of the field. This work outlines the historial evolution of the notion of neighborhood and employs neighborhood assignments, weak neighborhood assignments, and a naturally induced notion of duality in a study of non-Hausdorff topological spaces. Neighborhood characterizations of various classes of spaces, among them the developable and the pseudometrizable spaces, are obtained. A generalization of topological spaces based upon a primitive notion of neighborhood is explored and examples are supplied to motivate the investigation.

Adaptive Multiresolution Visualization Of Large Multidimensional Multivariate Scientific Datasets, Pak Chung Wong

Doctoral Dissertations

The sizes of today's scientific datasets range from megabytes to terabytes, making it impossible to directly browse the raw datasets visually. This presents significant challenges for visualization scientists who are interested in supporting these datasets. In this thesis, we present an adaptive data representation model which can be utilized with many of the commonly employed visualization techniques when dealing with large amounts of data. Our hierarchical design also alleviates the long standing visualization problem due to limited display space. The idea is based on using compactly supported orthogonal wavelets and additional downsizing techniques to generate a hierarchy of fine to …

Perfect Matchings: Modified Aztec Diamonds, Covering Graphs Andn-Matchings, Adriana Badauta Cransac

Doctoral Dissertations

In the Introduction, we present the problems we are going to study and we establish the basic definitions, concepts and results that are used throughout.

We begin the first chapter with a presentation of the Aztec diamond and the behaviour of its random domino tilings. We introduce the dual-matching-problem and we explore the structure of the perfect matchings of modified Aztec diamonds. We show that some of these matchings can be extended to matchings of the dual Aztec diamond, pointing out a bijection between these types of matchings. We determine the number of perfect matchings for each of the modified …

Modeling Of The Electromagnetic Radiation From Shielded Enclosures With Apertures And Attached Wires In A Real-World Environment, Bruce Roy Archambeault

Doctoral Dissertations

A hybrid modeling technique using the Finite-Difference Time-Domain (FDTD) approach in conjunction with the Method of Moments (MoM) approach was developed to allow simulation of electromagnetic interference (EMI) emissions through apertures due to sources within a shielded enclosure. These apertures can include air ventilation openings, option card slots, mating cover seams, or any other opening in the metal shielded enclosure. Modeled emission results can now be directly compared to U.S. and other countries' regulations to allow engineers to predict compliance before hardware prototypes are built. The effects of the test environment, including ground plane and specified measurement distance, as well …

Contributions To The Theory Of Distance Functions And Its Application In General Topology, Lawrence Valery Neveu

Doctoral Dissertations

As non-Hausdorff spaces are becoming more important in topology, there is a need to consider new notions in topology to supplement the usual structures. This work uses distance functions to find useful generalizations (in a non-Hausdorff context) of the classes of spaces that are important in the Hausdorff setting. We begin, in the first part, with a historical overview that traces the evolution of the notion of distance and its role in the development of general topology.

In the second part of this work, we launch our study of distance functions. Using non-symmetric distance functions, called asymmetric, we generalize the …

Numerical Analysis For Blood Distribution In Complete Flow Cross-Section Microvascular Networks, Jewen Xiao

Doctoral Dissertations

As the blood flows through a bifurcation, the axisymmetric red blood cell concentration profile is skewed by plasma skimming. In the downstream segment of the bifurcation the concentration profile of red blood cells recovers symmetry by the red blood cell dispersion process.

In this study, the concentration convective equation, which models the red blood cell dispersion process, is solved with the method of finite differences in cylindrical coordinates. In the computation, a shear-induced diffusivity coefficient is used. The computed hematocrit ratios at the second bifurcation are compared with in vitro experimental data obtained from 50 $\mu$m serial trees with two …

Student Interactions And Mathematics Discourse: A Study Of The Development Of Discussions In A Fifth-Grade Classroom, Sharon Marie Soucy Mccrone

Doctoral Dissertations

Mathematics reform efforts are gaining attention and support in the years since the dissemination of the National Council of Teachers of Mathematics (NCTM) Standards documents. Encouraging student interactions in small and large group settings, and promoting discussion and argumentation of mathematical ideas among students are two possible implications of the vision presented in the Standards. The goal of having mathematics discussions, however, can present a variety of classroom challenges. Many factors influence classroom discourse and need to be addressed in ways that inform teachers as they work toward creating a more interactive, discussion-based mathematics classroom.

The study examines the development …

Relativistic Thinking And Identity Development In College Students, Rebecca Anne Regeth

Doctoral Dissertations

The relationship between relativistic thinking and identity formation was examined. Relativistic thinking is the ability to accept the subjective nature of knowledge and values and has been shown to develop during college. It was predicted that as students become more relativistic in their thinking, they also realize that their own perception of reality is relative too. This causes an identity crisis, resulting in a mature identity. A one-year longitudinal study showed that changes in identity (increased moratorium) were related to changes in thinking (increased relativism). Students in different college majors were shown to think differently about the nature of knowledge …

Response Of Outer Radiation Belt Electrons To A Magnetic Storm, Donald Hugh Brautigam

Doctoral Dissertations

To advance our understanding of the magnetic storm dynamics of the outer radiation belt relativistic electrons, the magnetic storm which commenced on 9 October 1990 was analyzed in detail using data from the Combined Release and Radiation Effects Satellite (CRRES) and the Los Alamos National Laboratory geosynchronous satellite 1989enspace 046. Electron differential flux was transformed into phase space density as a function of the three adiabatic invariants. The invariants were determined by magnetic field data from CRRES and the Tsyganenko 1989 Kp driven model. The unique work of this thesis is the storm time radial diffusion modeling performed using time …

Preparing The Way Of The Lord: Three Case Studies Of Ministerial Preconditioning In Congregations Before The Great Awakening, 1675-1750, Douglas Kevin Fidler

Doctoral Dissertations

This study demonstrates that ministerial predecessors in three northern New England communities actually preconditioned community reactions to the Great Awakening during the years preceding the revival itself. "Preconditioning" is not the ordinary "influence" of pastors within their churches and professional circles suggested in other works. This kind of influence might cause parishioners to consider various behavioral alternatives when confronted by spiritual circumstances. Preconditioned congregations would already have established paradigms for responding to spiritual stimulus. While individual parishioners might act in ways consistent with their own personalities, psychological needs, and spiritual sensitivities, congregations as a whole would apply a predetermined set …

On Some Range Inclusions, Mihaela Anca Poplicher

Doctoral Dissertations

The de Branges-Rovnyak spaces have been introduced by Louis de Branges and James Rovnyak, and have been studied by several authors, in particular by Donald Sarason. The object of this thesis is to study more extensively some properties of this class of spaces. In particular, which of these spaces are invariant under the action of which composition operators, or adjoints of composition operators.

Some known facts and a couple of new properties are included in Chapter 1. There it is shown that the norm of the kernel function for evaluation at a point in the unit disc (in the de …

The Use Of An Artificial Light System To Assess The Influence Of Relative Light Change On Diel Activity Cycles Of Nymphs Of The Mayfly, Stenonema Modestum, In The Presence And Absence Of Predators, Annette L. Schloss

Doctoral Dissertations

A mechanism by which light controls diel changes in locomotor activity and surface location of mayfly nymphs (Stenonema modestum Banks), named the Stimulus-based Timing and Activity-Rate (STAR) Model, was tested. Nymph movements were video-recorded in time-lapse from underneath unglazed artificial substrates in a laboratory stream. Light/dark cycles were simulated using computer-controlled halogen lamps. Light increases and decreases were generated to maintain constant rates of relative light change throughout simulated twilight periods. Nymph locomotor activity and position on the substrate were measured in response to rate of light change. Experiments tested whether adaptation light intensity (10$\sp{-4}$ or 10$\sp{-6}$ W cm$\sp{-2}$), time …

Ecological Database Development And Analyses Of Soil Variability In Northern New England, Michael Anayo Okoye

Doctoral Dissertations

The 1983 Forest Inventory and Analysis (FIA) data of the states of Maine, New Hampshire and Vermont (the study area) contain large amounts of field-measurements of many ecologically important variables. Despite the vast potential usefulness of the FIA data for scientific research, the data were until now, literally unused except for a few administrative purposes, because of problems in the way the data were organized, summarized, and coded for storage. The primary objective of this research was to solve the problems that had thus precluded these FIA data from use in scientific applications, and present the data in a form …

A Metric-Based Scientific Data Model For Knowledge Discovery, David T. Kao

Doctoral Dissertations

Scientific data, which include multimedia (e.g., images, audio, and video) and non-standard data (e.g., finger prints and DNA sequences), is characterized by rich and complex inter-instance relationships in addition to the inter-entity relationships found in traditional data. Conventional data models are insufficient for modeling such inter-instance relationships. This thesis proposes a metric-based scientific data model from the notions of data-as-functions and pseudo-quasimetrics, which are used to model inter-entity and inter-instance relationships respectively. Compared to other scientific data models, the metric-based conceptual model can be applied to many data sets where geometric views might not otherwise be available.

A detailed approach …

The Dynamics Of Phase Farming: A Mathematical Model Of Economic Aspects Of Switching Between Cropping And Land Rehabilitation, Tuyet Tran

Theses : Honours

In this thesis we consider the following problem: Suppose that a farmer wishes to determine the best course of action to maximise returns from his I her land which has undergone some form of degradation. In order to rehabilitate the land, the farmer may have to change to a different farming practice for some time until the previous practice becomes profitable again. Switching from cropping to rehabilitation Of from rehabilitation to cropping incurs costs. From an economical point of view, the question then arises: When is the optimal time to switch from cropping· to rehabilitation and when is it optimal …

The Predictive Accuracy Of The Violent Offender Treatment Program Risk Assessment Scale, Ann Ward

Theses : Honours

Current methods for screening violent offenders for program eligibility are expensive and time consuming. Developers of the Violent Offender Treatment Program (VOTP) have designed 2 brief and economical instrument to screen offenders for program eligibility. The present study was undertaken to assess the reliability and predictive accuracy of the VOTP Risk Assessment Scale (RAS). An inter-rater reliability of 20 court histories attained a mean kappa of .8 I. The RAS was applied to court histories of 202 violent offenders released between 1985 and 1987. A I 0-year follow-up of convictions for violent behaviour yielded a 47~ base rate. Receiver Operating …

A New Approach For Determining Claim Expense Reserves In Workers Compensation, Kay Rahardjo

Journal of Actuarial Practice (1993–2006)

This paper describes a new approach for determining a reserve for claim expenses. While the discussion focuses on workers compensation claims, the methodology is equally applicable to other lines of business. The approach also can be applied to the calculation of the reserve for all claims (including IBNR claims) and the reserve for claims reported to date (excluding IBNR claims). In addition, a methodology for pricing claims-handling services is discussed. The implications of pricing claims-handling services on a handle-to- conclusion basis versus pricing claims-handling services on a limited time handling basis are examined. Finally, the paper discusses a methodology for …

An Investigation Of The Utility Of Using Local Curriculum-Based Measurement Norms Versus Group Standardized Norms To Predict Students At Riskfor Academic Failure In Reading And Mathematics, Lara E. Druckman

Dissertations

No abstract provided.

The Computational Study Of "Model" Pollutants In Clay Montmorillonite, Sung-Ho Park

Dissertations

No abstract provided.

Providing Pensions For U.K. Employees With Varied Working Lives, Deborah R. Cooper

Journal of Actuarial Practice (1993–2006)

Several different working lives are investigated, including employees with breaks in employment, part-time employment, and temporary employment. The pensions that could be provided to the different employees by final salary, revalued career average, or money purchase pension schemes (plans) are calculated and compared. Some of the weaknesses in a final salary pension scheme (the treatment of deferred pensioners and cross subsidies between different groups of member) are considered. Possible alternative benefit structures are considered to address the problems.

Fuzzy Underwriting: An Application Of Fuzzy Logic To Medical Underwriting, Per-Johan Horgby, Ralf Lohse, Nicola-Alexander Sittaro

Journal of Actuarial Practice (1993–2006)

One of the most difficult issues in the medical underwriting of life insurance applicants is diabetes mellitus. Compiling the prognosticating parameters for diabetic applicants results in a complex system of mutually interacting factors. In addition, neither the prognosticating factors themselves nor their impact on the mortality risk is clear cut. We show how a fuzzy inference system can be used in underwriting diabetes mellitus. A fuzzy inference system can cope with the imprecise nature of medical parameters by converting them into fuzzy sets and aggregating them using mathematical techniques. The fuzzy underwriting system presented goes further than previous applications of …

Comments On Some Parametric Models For Mortality Tables, Kam C. Yuen

Journal of Actuarial Practice (1993–2006)

Parametric models for the entire age pattern of mortality have been suggested by Heligman and Pollard (1980) and Carriere (1992). The former is designed to fit the classical mortality pattern while the latter is supported by a statistical theory. Insights into their papers motivate us to consider a variation of the Heligman-Pollard model. We also apply these models to the 1993 Hong Kong Assured Lives Mortality Tables as well as the 1991 Hong Kong Female Life Table. This paper is not intended to construct a better parametric model for mortality tables; the main purpose is simply to provide insights into …

Assisted Suicide: The State Versus The People, John P. Safranek, Stephen J. Safranek

Seattle University Law Review

This Article will examine the Ninth Circuit's appeal to personal dignity and autonomy to justify a constitutional right of assisted suicide in the face of pluralist opposition, that is, a law duly enacted by a majority of elected representatives in a state or by the people directly. Scrutiny of the Ninth Circuit's decision will reveal the formidable jurisprudential obstacles to basing a right to assisted suicide on dignity and autonomy, obstacles the Supreme Court refused to overcome in revoking Compassion in Dying. This examination is divided into three parts: the first analyzes attempts to justify rights on the principle …

Faculty Development And The Inclusion Of Diversity In The College Classroom: Pedagogical And Curricular Transformation, James A. Anderson

To Improve the Academy: A Journal of Educational Development

Colleges and universities are confronted with a plethora of questions and concerns that are associated with the inclusion and success of diverse student populations. Especially critical is the role that faculty will play in fostering a supportive and effective learning environment which benefits the wide range of racial, cultural, gender, and class groups. Faculty development activities can assist faculty to make their courses more inclusive both in content and in pedagogy. Those who direct teaching excellence and faculty development efforts must be more proactive as they impact faculty attitudes toward diversity.

Wac Revisited: An Overlooked Model For Transformative Faculty Development, James S. Laughlin

To Improve the Academy: A Journal of Educational Development

Recently, higher education specialists have called for new faculty development initiatives, claiming current faculty development efforts need to go beyond a reductive "teaching tips" approach to consider transformative practices aimed at improving learning. While such critiques are valuable, they tend to overlook one mode of development that has had undeniable success in initiating significant individual and institutional transformations in the realms of teaching and learning. Over the past two decades, the faculty workshop in writing across the curriculum (WAC) has become a major part of successful WAC programs across the country. This article discusses how, at their best, such workshops …

"A Continuing Conversation On Teaching:" An Evaluation Of A Decade-Long Lilly Teaching Fellows Program 1986-1996, Karen List

To Improve the Academy: A Journal of Educational Development

This study assesses what difference the Lilly Teaching Fellows Program at the University of Massachusetts-Amherst has made in its first ten years, both to the fellows who have participated in it and to the University community. Based on a survey of the fellows, the study concludes that the program has had significant positive effects on teaching skills and attitudes, collegiality, research and service. The study also assesses the seven major components of the Lilly Program and suggests ways in which they might be improved The author then recommends increased institutional support for teaching to decrease the tensions between the programs' …

The Impact Of Comprehensive Institutional Assessment On Faculty, Tracey Sutherland, James Guffey

To Improve the Academy: A Journal of Educational Development

In this age of accountability, colleges and universities are being called on to provide evidence of their effectiveness. As a result, comprehensive assessment initiatives are being implemented on most campuses, requiring increasing numbers of faculty to become involved. Beginning with an overview of a faculty-driven assessment model, this article describes specific roles faculty play and the results of a study in which faculty describe how their involvement influences their teaching and professional development. The primary purpose of faculty development is to improve the learning environment. Faculty participation in institutional assessment efforts enhances that environment. The results of the study provide …