Thesis--George Peabody College for Teachers. / Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 198-212). Available also in a digital version from Dissertation Abstracts.

This dissertation focuses on inverse problems for partial differential equations with multiscale coefficients in which the goal is to determine the coefficients in the equation using solution data. Such problems pose a huge computational challenge, in particular when the coefficients are of multiscale form. When faced with balancing computational cost with accuracy, most approaches only deal with models of large scale behavior and, for example, account for microscopic processes by using effective or empirical equations of state on the continuum scale to simplify computations. Obtaining these models often results in the loss of the desired fine scale details. In this thesis we introduce ways to overcome this issue using a multiscale approach. The first part of the thesis establishes the close relation between computational grids in multiscale modeling and sampling strategies developed in information theory. The theory developed is based on the mathematical analysis of multiscale functions of the type that are studied in averaging and homogenization theory and in multiscale modeling. Typical examples are two-scale functions f (x, x/[epsilon]), (0 < [epsilon] ≪ 1) that are periodic in the second variable. We prove that under certain band limiting conditions these multiscale functions can be uniquely and stably recovered from nonuniform samples of optimal rate. In the second part, we present a new multiscale approach for inverse homogenization problems. We prove that in certain cases where the specific form of the multiscale coefficients is known a priori, imposing an additional constraint of a microscale parametrization results in a well-posed inverse problem. The mathematical analysis is based on homogenization theory for partial differential equations and classical theory of inverse problems. The numerical analysis involves the design of multiscale methods, such as the heterogeneous multiscale method (HMM). The use of HMM solvers for the forward model has unveiled theoretical and numerical results for microscale parameter recovery, including applications to inverse problems arising in exploration seismology and medical imaging. / text

An issue yet to receive much attention in the literature in medical sociology is how family systems may influence the emotional well-being of youth in Canada, particularly among newcomer youth. This study applies the family systems model of Kitzman-Ulrich and her colleagues as the principal theory to examine the emotional well-being of newcomer youth in Canada. Using data from the New Canadian Children and Youth Study (NCCY) on 979 newcomer youth, it explains how family systems and other factors may influence emotional health of newcomer youth. Data were analyzed using multiple approaches. The multivariate analysis includes seven Ordinary Least Squares (OLS) regression models – examining and comparing different groups: an overall model, and separate models for male, female, Mainland Chinese, Hong Kong Chinese, Filipino/a, and immigrant are performed. The results of this study reveal that variables within the family systems model are weak predictors of the presence of emotional problems among newcomer youth in Canada. Among four family systems variables used in the analyses, family cohesion, permissive parenting, and parental discipline are either weak or insignificant predictors; only parental praise is statistically significant. Furthermore, they are weak predictors compared with other factors beyond the family, such as age, time in Canada, being bullied at school, being immigrant, use of illegal/controlled substances, and being from a Mainland or Hong Kong Chinese group (for females only). The thesis ends with a discussion of limitations, future research, and policy suggestions. / October 2015

This thesis deals with various facets of the optimisation problem for telecommunication networks and proposes a number of new techniques for their solution. The necessary essentials, Graph Theory, Complexity Theory and Telecommunication Principles, are investigated. The relevant graphs are enumerated and the requirements of suitable optimisation algorithms for certain graphical problems are established. The Private Automatic Branch Exchange (PABX) is introduced. the variety of telecommunications traffic as well as the practical requirements of a connection topology are discussed. The fundamental Network Optimisation Problem (NJP) is defined and analysed. Simple exhaustive methods of solution are considered together with partial solution algorithms and simplification methods. Centralised networks with and without concentrators are introduced. Extensions and modifications are proposed for some techniques and existing practical methods of dealing with the NOP are investigated. A number of new ideas are proposed for the practical solution of the NOP. Reduction methods are presented for replacing large unmanageable networks with smaller ones, on which optimisation can take place. Fixed topology techniques are introduced for initial tandem switch selection purposes and perturbation methods are considered which can be applied to such an initial solution. Lookahead methods of link removal are introduced for the purposes of determining the tandem interconnection network together with the traffic routeing strategy. A composite method is proposed incorporating all of these concepts and the results of a number of numerical experiments upon actual network problem; are presented. the extension of the proposed techniques to other areas of problem solving and optimisation is considered. In particular, a new method for the solution of the Euclidean Travelling Salesman Problem (ETSP) is presented. A brief discussion is undertaken, in conclusion, concerning the practical difficulties of the NOP and The restrictions this placed upon solution algorithms of various types.

This thesis dea1s with mode11ing of formation damage resu1ting from invading s01ids, particu1ar1y in re1ation to water injection schemes Where10wconcentration micron and sub-micron s01ids are concerned. Ear1ier investigations were considered inadequate for study of formation damagedue to partic1e invasion in manyrespects such as the nature of damage, depth of damage characteristics and the inf1uence of various parameters on the damagedata. A porosity mode1(in 1inear and radia1 forms) based on mass ba1ance of partic1es and a pore size distribution based 3Dcapi1lary network model are presented. The network model uses various particle capture criteria including a newprobability criteria to model particle retention. The resu1ts from rock core based f10wtests are presented and ana1yzed. The f10w tests were conducted on 00x25 •4na-dia. sandstone cores of permeabi1ity range of 250 to 1000 md using 1-15 ppm concentrations of O-3~ a1umina partic1es at flow-rates of 0.45-1.00 mils up to 150 hours equiva1ent to over 40000 core pore v01umes. The experimental invastigations showthe importance of depth of damageand 10ng duration experiments on formation damagedata studies. Experimental permeability shows si.mp1e semi-1og dec1ine with gross f10w ve1ocity. serious occurs even for the 10w concentration systems. The iBIporta.nce of core preparation is stressed, where the use of brok.en faced cores is shown to be more appropriate for conducting partic1e inv . . as1.onexperuaents as comparedto the conventiona1 sa.wn-facedcores. Both the porosity mode1and the network.mode1predictions are shownto agree reasonab1y we11with the experimenta1 data.

Abstract Investigating Methods of Partial Fraction Decomposition Anthony David Newberry, MA The University of Texas at Austin, 2011 Supervisor: Efraim Armendariz This report discusses the history of partial fractions. The paper investigates several methods of solving partial fraction decomposition problems. First, the basic method taught in most calculus courses is addressed. Another method addressed is a substitution method in which a clever substitution is used to transform expressions into something more easily integrable. Then, a rationale for partial fraction decomposition is given that includes a number theory perspective, a calculus perspective, and an algebraic perspective. A fourth method discussed involves using derivatives. / text

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Abstract Title Cashews by SMS – an implementation in Mozambique Problem Innovation is described by Tidd, Bessant and Pavitt (2005) as the core process within organisations associated with renewal and as generic activity associated with survival and growth. Yet many organisations fail to realise the benefits of adopting an innovation. Which the theory will show this is most likely due to a problem with one certain phase in the innovation process: the implementation. Purpose The purpose with this academic paper is by a practical example illustrate the risks and problems one can come across in an implementation and the consequences of this. We also intend to give suggestion on how it is possible to restart an implementation process when the process once has failed. Research questions Why has marketAlerts failed to be implemented in Mozambique? How should IPEX resume the implementation of marketAlerts? Methodology Ethnographical approach. Conclusion Our conclusion is that the Institute for Export Promotion (IPEX) has managed to adopt marketAlerts but has failed to implement it in their daily work mainly due to the fact that they only completed the acquiring phase. The failure is due to a combination of hierarchy, lack of interest and absents of routines for sending marketAlerts. In order for IPEX to make the best use of marketAlerts we believe that they have to go back and start from the executing phase and implement the service once again.

The Devereux Early Childhood Assessment (DECA; L.eBuffe & Naglieri, 1999), a standardized strength-based measure, was used with 125 kindergarten children from two different regions in British Columbia to investigate the relationship between mother and teacher ratings of students’ strengths and behaviour problems. Results suggest that the level of agreement between mother and teacher ratings for children’s strengths is similar to the level of agreement between mother and teacher ratings for children’s problem behaviours. The level of agreement between motherreported and teacher-reported scores was found to be low for all DECA scales and most DECA items, with some differences found upon examination of the sample by gender. The findings revealed three main trends: first, a higher degree of correspondence and a lower degree of difference was found between mother and teacher ratings for the Self-Control scale and items, compared to the other scales and items; second, a lower degree of correspondence and a higher degree of difference was found between mother and teacher ratings for the Attachment scale and items, compared to other scales and items; third, the level of agreement between mothers and teachers ratings was higher for boys than for girls. These patterns of cross-informant correspondences and differences are discussed in the context of the need for practitioners to obtain rating information from both mothers and teachers, since each rater provides a unique perspective. Furthermore, the importance of highlighting children’s strengths in the assessment process is emphasized.