Title from PDF of title page. / Document formatted into pages; contains 59 pages. / Thesis (M.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Dispensed organic polymer optical waveguides suitable for single-mode operation were recently fabricated. Different dispensing pressures, polymers, and dispensing tips were used in the drawing method. The waveguides were measured to be approximately 16[mu] wide and 0.8[mu] tall. This is significantly smaller than previously reported dimensions of 300[mu] x 3.5[mu] waveguides fabricated with a similar dispensed polymer method. The waveguides were also found to be suitable for single-mode operation through a series of approximate calculations . This is also something previously not achieved with the larger waveguides. This novel approach to waveguide fabrication could reduce the expense and time of creating single mode waveguides for rapid development applications. It will also allow the waveguides to be fabricated to be flexible as well as doped to be active devices. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Made available in DSpace on 2016-07-27T13:44:53Z (GMT). No. of bitstreams: 1 MARCOS VINICIOS RABELO PROCOPIO.pdf: 2565052 bytes, checksum: 28d41a89feb201236a4777de11b6efde (MD5) Previous issue date: 2014-08-28 / The university failure has become a problem of world order, especially in courses such as Physics. Facing this reality, after an exhaustive search in databases of theses and dissertations and journals of the past two decades, we find a paucity of studies that seek to understand more fully the factors that can influence the performance of this academic. In this context, this research aimed to clarify the relationship between the prevailing social, cultural and academic conditions between the reprobate and academic failure in the higher physics courses at universities in Brazil and Portugal. To this end, we seek as a research field two public universities located in the central region of two Portuguese-speaking countries with nearby cultures: Brazil and Portugal. The research methodology consisted of two studies, the first was called primary that led to the creation of a data collection instrument, called QACSCA (Questionnaire Assessment of social, cultural and academic conditions) and the second titled principal that has a sample of 118 students of physics at the Federal University of Goiás and 97 at the University of Aveiro. The method used for data analysis triangulation was sequenced, and the preliminary study conducted a qualitative analysis and quantitative main study and still looked like Bourdieu, Charlot Vygotsky and theoretical support for discussion of results. So that the discussion of the collected data was performed with the support of four categories of analysis "Subject", "Subject and Society", "Relationship to know" and "Zone proximal student" which emerged from the discussions related to the conduct subject in interaction with certain groups, the tensions and conflicts in the field where cultural capital is distributed, desire and knowledge in order to enrich the human heritage and mediation between capital that the student has to enter the university and the he can acquire during their university studies. The data showed that 78.6% of the sample are students who have had 2-7 failures during the course, which leads them to extrapolate up to two years the period of four years of training. It was evident that the disciplines of Mathematics & Physics, together confirmed its high failure rate reaching 53.3% of the total sample, 31.6% and 23.7% identified as grounds of abandonment, rejection or locking disciplines, respectively, learning difficulties, transportation, relationships and the negative performance in different subjects, little time for studies and prior to his entry into the physics course unsatisfactory training. Discussions explained the complexity of the problem linked to the theoretical support failure used in order to raise the habitus, the field and the area of academic development that presents during his journey in physics courses. / O fracasso universitário se tornou um problema de ordem mundial, sobretudo em cursos como o de Física. Frente a esta realidade, após uma exaustiva pesquisa nos bancos de teses e dissertações e nos periódicos das duas últimas décadas, verificamos uma escassez de estudos que buscam compreender mais a fundo os fatores que podem influenciar no desempenho desse acadêmico. Neste contexto, objetivamos nesta investigação explicitar as relações existentes entre as condições sociais, culturais e acadêmicas preponderantes entre os acadêmicos reprovados e o fracasso nos cursos superiores de Física das universidades do Brasil e de Portugal. Para tal, buscamos como campo de pesquisa duas universidades públicas localizadas na região central de dois países de língua portuguesa com culturas próximas: Brasil e Portugal. A metodologia da investigação foi composta por dois estudos, o primeiro foi chamado de preliminar que propiciou a criação de um instrumento de coleta de dados, denominado de QACSCA (Questionário de Avaliação das condições sociais, culturais e acadêmicas) e o segundo intitulado de principal que conta com uma amostra de 118 acadêmicos do curso de Física da Universidade Federal de Goiás e 97 da Universidade de Aveiro. O método utilizado para a análise dos dados foi a triangulação sequenciada, sendo que no estudo preliminar realizou-se a análise qualitativa e no estudo principal a quantitativa e ainda buscou-se como suporte teórico Bourdieu, Charlot e Vygotsky para discussão dos resultados. De forma que a discussão sobre os dados coletados foi realizada com o apoio de quatro categorias de análise Sujeito , Sujeito e Sociedade , Relação com o saber e Zona proximal do aluno das quais surgiram discussões relacionadas às condutas do sujeito em interação com determinados grupos, as tensões e os conflitos existentes no campo onde o capital cultural é distribuído, o desejo e o saber de forma a enriquecer o patrimônio humano e a mediação entre o capital que o aluno apresenta ao entrar na universidade e o que ele pode adquirir durante o seu percurso universitário. Os dados demonstraram que 78,6% da amostra são de alunos que tiveram de 2 a 7 reprovações no decorrer do curso, o que os leva a extrapolar em até dois anos o período de 4 anos de formação. Evidenciou-se que as disciplinas de Cálculo e Física, juntas confirmaram seu alto índice de reprovação chegando a 53,3% do total da amostra, 31,6% e 23,7% apontaram como motivo de abandono, reprovação ou trancamento das disciplinas, respectivamente, as dificuldades de aprendizagem, de transporte, de relacionamento e o desempenho negativo nas disciplinas, pouco tempo para estudos e uma formação insatisfatória anterior à sua entrada no curso de Física. As discussões explicitaram a complexidade do problema do fracasso atrelada ao suporte teórico utilizado de forma a levantar o habitus, o campo e a zona de desenvolvimento que o acadêmico apresenta durante seu percurso nos cursos de Física.

Title from PDF of title page. / Document formatted into pages; contains 93 pages. / Thesis (M.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: One often wishes to understand the probability distribution of stochastic data from experiment or computer simulations. However, where no model is given, practitioners must resort to parametric or non-parametric methods in order to gain information about the underlying distribution. Others have used initially a nonparametric estimator in order to understand the underlying shape of a set of data, and then later returned with a parametric method to locate the peaks. However they are interested in estimating spectra, which may have multiple peaks, where in this work we are interested in approximating the peak position of a single-peak probability distribution. One method of analyzing a distribution of data is by fitting a curve to, or smoothing them. Polynomial regression and least-squares fit are examples of smoothing methods. Initial understanding of the underlying distribution can be obscured depending on the degree of smoothing. / ABSTRACT: Problems such as under and oversmoothing must be addressed in order to determine the shape of the underlying distribution.Furthermore, smoothing of skewed data can give a biased estimation of the peak position. We propose two new approaches for statistical mode estimation based on the assumption that the underlying distribution has only one peak. The first method imposes the global constraint of unimodality locally, by requiring negative curvature over some domain. The second method performs a search that assumes a position of the distribution's peak and requires positive slope to the left, and negative slope to the right. / ABSTRACT: Each approach entails a constrained least-squares fit to the raw cumulative probability distribution.We compare the relative efficiencies [12] of finding the peak location of these two estimators for artificially generated data from known families of distributions Weibull, beta, and gamma. Within each family a parameter controls the skewness or kurtosis, quantifying the shapes of the distributions for comparison. We also compare our methods with other estimators such as the kernel-density estimator, adaptive histogram, and polynomial regression. By comparing the effectiveness of the estimators, we can determine which estimator best locates the peak position. We find that our estimators do not perform better than other known estimators. We also find that our estimators are biased. / ABSTRACT: Overall, an adaptation of kernel estimation proved to be the most efficient.The results for the work done in this thesis will be submitted, in a different form, for publication by D.A. Rabson and J.K. Looper. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.