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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Theoretical investigation of polar zinc oxide surface modification via phosphonic acid self-assembled monolayers

Wood, Christopher Alan 17 January 2012 (has links)
The interface of a zinc-terminated polar zinc oxide surface (0002) with a series of chemisorbed fluorinated benzylphosphonic acids has been studied using density functional theory. The calculations indicate that there is a substantial change in the binding energies and work function modification depending on the binding motif. The results also indicate that there is a pronounced difference in the magnitude and trends of the factors determining the total change in work function. The oxygen core-level binding shifts have been calculated and compared to available experimental data.
252

Variance analysis for kernel smoothing of a varying-coefficient model with longitudinal data /

Chen, Jinsong. January 2003 (has links) (PDF)
Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaf : [101]).
253

A comparison of three brief analysis models with the inclusion of contingency reversals

Gripp, Natalie Mary 15 February 2012 (has links)
Functional Analysis is a widely used and effective tool for the assessment of challenging behavior. However, there are several practical issues associated with analogue functional analysis, including the reinforcement of challenging behavior and the extended duration of the assessment process. These issues have been addressed in several modified functional analysis models, including the brief functional analysis. The brief functional analysis allows practitioners and researchers to complete an assessment of challenging behavior within a 90-minute period, thus addressing the practical issue of extended duration. It does not, however, address the potential issues associated with the reinforcement of challenging behavior. The current study evaluated the efficacy of three modified functional analysis methods, including a brief antecedent-based analysis (A-B), a brief latency-based analysis, and a brief functional analysis (A-B-C). Results from each assessment were compared and high levels of correspondence was observed between the respective assessment models. Results are discusses in terms of the relative strengths and limitations of each of the models. / text
254

Increasing communicative mand topographies : an evaluation of the use of a lag reinforcement schedule embedded in a functional communication training treatment package

Gainey, Summer 06 November 2013 (has links)
Invariant responding among individuals with autism spectrum disorder (ASD) is problematic and can be pervasive across all areas of development. Individuals with ASD demonstrate difficulty communicating wants and needs and often engage in challenging behavior in order to get needs met. Functional communication training (FCT) is one approach for mediating challenging behavior by teaching individuals a communicative response that is functionally equivalent to the demonstrated challenging behavior. However, individuals are often taught a single communicative response (e.g., vocal approximations) that may be unintelligible to the naïve listener and challenging behavior may resurge as a result of a communication breakdown. Recently, the evaluation of lag schedules of reinforcement has shown that it is possible to reinforce operant variability during instruction. Increasing communicative variability for individuals with ASD may decrease the likelihood of resurgence of challenging behavior by providing a broader repertoire of socially appropriate communicative responses that contacted reinforcement through the use of a lag schedule of reinforcement. The purpose of the present study was to evaluate the effect a lag schedule of reinforcement on communicative variability in three individuals with ASD. In this study, communication was reinforced on either a Lag 0 (or FR1 concurrent) schedule of reinforcement, or a Lag 1 (e.g., responses contacted reinforcement only if the response differed from the previous communicative response). Functional analyses were conducted for each participant to determine variables maintaining challenging behavior, all participants were given a mand topography assessment to evaluate mand topography proficiency, and a lag schedule evaluation was conducted. Results showed that increasing the lag schedule of reinforcement from Lag 0 to Lag 1 increased communicative mand topographies for all participants. Results further showed a significant reduction in challenging behavior as compared to baseline conditions contingent on implementation of the FCT package. / text
255

A discontinuous Petrov-Galerkin method for seismic tomography problems

Bramwell, Jamie Ann 06 November 2013 (has links)
The imaging of the interior of the Earth using ground motion data, or seismic tomography, has been a subject of great interest for over a century. The full elastic wave equations are not typically used in standard tomography codes. Instead, the elastic waves are idealized as rays and only phase velocity and travel times are considered as input data. This results in the inability to resolve features which are on the order of one wavelength in scale. To overcome this problem, models which use the full elastic wave equation and consider total seismograms as input data have recently been developed. Unfortunately, those methods are much more computationally expensive and are only in their infancy. While the finite element method is very popular in many applications in solid mechanics, it is still not the method of choice in many seismic applications due to high pollution error. The pollution effect creates an increasing ratio of discretization to best approximation error for problems with increasing wave numbers. It has been shown that standard finite element methods cannot overcome this issue. To compensate, the meshes for solving high wave number problems in seismology must be increasingly refined, and are computationally infeasible due to the large scale requirements. A new generalized least squares method was recently introduced. The main idea is to select test spaces such that the discrete problem inherits the stability of the continuous problem. In this dissertation, a discontinuous Petrov-Galerkin method with optimal test functions for 2D time-harmonic seismic tomography problems is developed. First, the abstract DPG framework and key results are reviewed. 2D DPG methods for both static and time-harmonic elasticity problems are then introduced and results indicating the low-pollution property are shown. Finally, a matrix-free inexact-Newton method for the seismic inverse problem is developed. To conclude, results obtained from both DPG and standard continuous Galerkin discretization schemes are compared and the potential effectiveness of DPG as a practical seismic inversion tool is discussed. / text
256

The effects of reinforcement magnitude and session length on stereotypical behavior of an adolescent with autism

Kotsios, Spiro 01 June 2009 (has links)
Functional Analysis is an important component of creating a treatment plan for individuals with autism. A concern of functional analysis is that it might not match the natural environment in which the problem behavior occurs. Dimensions such as varying reinforcement duration and session length may affect response rates during functional analyses in natural settings. This study investigated if varying reinforcement duration and session length during functional analyses would affect the identification of the function of problem behavior across assessors, and the intervention designed based on the functional analyses would be effective in reducing stereotypic behavior and teaching communicative skills of an adolescent with autism at home. An alternating treatment design was used to conduct functional analyses and an ABA design with generalization probes was used to test the effectiveness the function-based intervention. Results indicated that the participant's stereotypic behavior was maintained by automotive reinforcement. The intervention developed based on the function of the stereotypic behavior was found to be effective in reducing the stereotypy and teaching communicative behavior.
257

An Application of Systems Engineering to Analyze the Interagency Coordination Aspect of Counter Trafficking and Terrorism

Abeto, Benjamin 06 1900 (has links)
This thesis utilizes principles of the systems engineering process discussed by Dennis Buede in â The Engineering Design of Systems: Models and Methods (2nd ed.)â (2009). The systems engineering process is used to create a functional architecture to analyze interagency coordination in support of counterterrorism efforts in the United States European Command area of operation. The resulting functional architecture serve as tools for policymakers as they determine the best ways to create a synchronous whole of government approach to defend United States interests.
258

OSCILLATIONS DANS DES ÉQUATIONS DE LIÉNARD ET DES ÉQUATIONS D'ÉVOLUTION SEMI-LINÉAIRES

Boudjema, Souhila 10 September 2013 (has links) (PDF)
Dans ce travail, on étudier, au voisinage d'un point d'équilibre, l'existence et l'unicité et la dépendance régulière des solutions presque-périodique (p.p.), présqu'automorphe (p.a.), asymptotiquement p.p., asymptotiquement p.a., pseudo p.p., pseudo p.a., pseudo p.p. avec poids, pseudo p.a. avec poids de la famille d'équations de Liénard forcée suivantes x''(t) + f(x(t), p). x'(t) + g(x(t), p) = ep(t), (1) où le terme ep est de la même nature que la solution, et p est un paramètre dans un espace de Banach. On utilise le théorème des fonctions implicites au voisinage de l'équilibre. On étudier aussi deux cas particuliers de la famille (1) qui sont x''(t) + f1(x(t)). x'(t) + g1(x(t))= e(t), x''(t) + f2(x(t), q). x'(t) + g2(x(t), q) = e(t). On établit aussi un nouveau résultat sur la dépendance différentielle des solutions S-asymptotiquement presque-périodique du problème de Cauchy x'(t)=A(t) x(t)+f(t, x(t),u(t) ) x(0) = ζ , par rapport à la condition initial et le contrôle u. On applique cet résultat sur une équation parabolique avec coefficients périodique par rapport au temps.
259

The development and biomechanics of theropod teeth and comparisons with other reptiles: a functional analysis

Reichel, Miriam Unknown Date
No description available.
260

Algebraic and Topological Properties of Unitary Groups of II_1 Factors

Dowerk, Philip 27 April 2015 (has links) (PDF)
The thesis is concerned with group theoretical properties of unitary groups, mainly of II_1 factors. The author gives a new and elementary proof of an result on extreme amenability, defines the bounded normal generation property and invariant automatic continuity property and proves these for various unitary groups of functional analytic types.

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