Thesis (Ph. D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2005. / Victoria Chen, Committee Co-Chair ; Kwok Tsui, Committee Chair ; Janet Allen, Committee Member ; David Goldsman, Committee Member ; Roshan Vengazhiyil, Committee Member. Vita. Includes bibliographical references.

Thesis (Ph.D.)--Baylor University, 2006. / Includes bibliographical references (p. 110-114).

Cachaça é a terceira das bebidas alcoólicas fermento-destilado mais consumida no mundo, com uma produção de aproximadamente 2,5 litros de bilhões por ano. Tradicionalmente, a cachaça é produzida a partir da destilação do mosto fermentado da cana-de-açúcar. Porém, ela pode sofrer a contaminação por HPAs (Hidrocarbonetos Policíclicos Aromáticos) quando a cana-de-açúcar utilizada na sua produção é queimada antes da sua colheita. Objetivando a distinção entre as amostras de cachaça produzidas a partir da cana-de-açúcar colhida após a queima ou não dos canaviais, foram analisados 15 HPAs em 26 amostras de cachaça produzidas com cana-de-açúcar queimada e 105 amostras de cachaça produzidas com cana-de-açúcar não queimada. As amostras de cachaça foram previamente concentradas por extração em fase sólida (SPE) e analisadas por cromatografia liquida de alta eficiência (HPLC), acoplada a um detector de fluorescência. Este método apresentou uma boa separação cromatográfica para a análise dos seguintes HPAs estudados: naftaleno, acenafteno, fluoreno, fenantreno, antraceno, fluoranteno, pireno, benzo(a)antraceno, criseno, benzo(b)fluoranteno, benzo(k)fluoranteno, benzo(a)pireno, dibenzo(a,h)antraceno, benzo(g,h,i)perileno e indeno(1,2,3-c,d)pireno. O método cromatográfico apresentou bons limites de detecção (5,68E-04 a 45,4 µg L-1), boa porcentagem de extração e recuperação (81,5 ± 9 % a 113 ± 5 %) e uma boa reprodutibilidade (> 90,0 %). As amostras produzidas a partir de cana-de-açúcar queimada apresentaram teores médios totais dos HPAs de 21,1 µg L-1, enquanto que as amostras produzidas com cana-de-açúcar não queimada apresentaram teores médios totais dos HPAs de 1,91 µg L-1. Os dados analíticos foram tratados por meio de análise multivariada (PCA, FA, PLS, DA, LDA, QDA e CDA), possibilitando uma boa distinção entre as amostras produzidas com cana queimada e não queimada. Os resultados dos modelos estatísticos revelaram uma elevada probabilidade (85,0 %) na diferenciação entre estes dois grupos de cachaça / Cachaça is the third most consumed fermented alcoholic beverage in the world, with a production of nearly 2.5 billion liters a year. Traditionally, cachaça is made from the distillation of the fermented sugar cane juice. However, it may be contaminated by PAHs (Polycyclic Aromatic Hydrocarbons) when the sugar cane used for its production is burned before harvesting. Aiming at distinguishing spirits made from burned and non-burned sugar cane, 15 PAHs in 26 cachaças samples obtained from non-burned and 105 cachaça samples obtained from burned sugar cane have been analyzed. The cachaça samples were previously concentrated by solid phase extraction (SPE) and analyzed by high performance liquid chromatography (HPLC), coupled with a fluorescence detector. This method presented good chromatographic separation for the analysis of the following PAHs: naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benz(b)fluoranthene, benz(k)fluoranthene, benz(a)pyrene, dibenz(a,h)anthracene, benz(g,h,i)perylene, and indeno(1,2,3- c,d)pyrene. The chromatographic method showed good detection limits (5.68E-04 to 45.4 ? g L-1), good index for the clean up percentage and recovery (from 81.5 ± 9% to 113 ± 5%) and a good reproducibility (> 90.0%). The samples obtained from burned sugar cane presented 21.1 ? g L-1 total PAHs average contents while the ones obtained from non-burned sugar cane showed PAHs average contents of 1.91 ?g L-1. Such analytical data were treated by means of the multivariate statistical methods (PCA, FA, PLS, LDA, QDA and CDA), thus allowing good distinction among the samples obtained from burned and non-burned sugar cane. Results of the Abstract IQSC-USP statistical models presented high probability (85.0%) for the distinction between these two groups of spirits.

From the individual to species level, it is common for animals to have connections with one another. These connections can exist in a variety of forms; from the social relationships within an animal society, to hybridisation between species. The structure of these connections in animal systems can be depicted using networks, often revealing non-trivial structure which can be biologically informative. Understanding the factors which drive the structure of animal networks can help us understand the costs and benefits of forming and maintaining relationships. Multivariate modelling provides a means to evaluate the relative contributions of a set of explanatory factors to a response variable. However, conventional modelling approaches use statistical tests which are unsuitable for the dependencies inherent in network and relational data. A solution to this problem is to use specialised models developed in the social sciences, which have a long history in modelling human social networks. Taking predictive multivariate models from the social sciences and applying them to animal networks is attractive given that current analytical approaches are predominantly descriptive. However, these models were developed for human social networks, where participants can self-identify relationships. In contrast, relationships between animals have to be inferred through observations of associations or interactions, which can introduce sampling bias and uncertainty to the data. Without appropriate care, these issues could lead us to make incorrect or overconfident conclusions about our data. In this thesis, we use an established network model, the multiple regression quadratic assignment procedure (MRQAP), and propose approaches to facilitate the application of this model in animal network studies. Through demonstrating these approaches on three animal systems, we make new biological findings and highlight the importance of considering data-sampling issues when analysing networks. Additionally, our approaches have wider applications to animal network studies where relationships are inferred through observing dyadic interactions.

The quest for a complete understanding of mixtures is a challenge which has stimulated the development of several techniques. One of the most powerful NMR-based techniques is known as Diffusion-Ordered SpectroscopY (DOSY), in which it is possible to distinguish the NMR spectra of chemical species with different hydrodynamic radii, i.e. with different self-diffusion coefficients. It allows the study of intact mixtures, providing information on the interactions within the mixture and saving time and money compared to other techniques. Unfortunately, DOSY is not very effective when signals overlap and/or the diffusion coefficients are very similar. This drawback has led to the development of new methods to overcome this problem. The present investigation is focused on developing some of these. Most DOSY datasets show multiplet phase distortions caused by J-modulation. These distortions not only hinder the interpretation of spectra, but also increase the overlap between signals. The addition of a 45º purging pulse immediately before the onset of acquisition is proposed as a way to remove the unwanted distortions. Most DOSY experiments use 1H detection, because of the higher sensitivity which is generally achieved. However, acquiring spectra with other nuclei such as 13C can reduce overlap problems. Two new sequences have been developed to maximize the sensitivity of heteronuclear DOSY experiments. In order to increase resolving power, it is also possible to incorporate another variable into diffusion experiments as a further dimension. If this results in an approximately trilinear dataset (each dimension varying independently), it is possible to extract physically meaningful information for each component using multivariate statistical methods. This is explored for the cases where the new variable is either the relaxation behaviour or the concentration variation (which can be measured during a reaction or in a set of samples with different concentrations for each component). PARAllel FACtor (PARAFAC) analysis can obtain the spectra, diffusional decay and relaxation evolution or kinetics for each of the components. In a completely different approach, the separation power of liquid chromatography has been combined in a novel way with the NMR potential for elucidating structures. NMR has been used previously as a precise way to measure average flow velocities, even in porous media. Using this capability to detect the different average velocities of solutes that occur in chromatographic columns ought to provide a new way of analysing mixtures with the same potential as LC-NMR, but faster and more simple. In such a flow system, a chromatographic column is introduced into the NMR probe and a 2D dataset is acquired and Fourier transformed to obtain the velocity distribution for each of the detected NMR signals.

This thesis occupies with a relationship of two significant methods of analyzing multivariate contingency tables, namely correspondence analysis and loglinear models. The thesis is divided into three parts. The first one is dedicated to basic terms of categorical data analysis, mainly to contingency tables and their distributions. Primarily, the emphasis is placed on their multidimensional form. The second part presents tools and techniques of both methods in a scope needed for their practical use and interpretation of their results. A practical application of both methods is included in the third part which is presented on the data from a market research. This part describes settings for both analyses in a statistical software SPSS and the subsequent interpretation of their outputs. A comparison of analyzed methods in terms of their use can be found in the conclusion.

nÃo hà / O estudo sobre a desertificaÃÃo tornou-se mais aceitÃvel quando pesquisas passaram a inter-relacionar esse fenÃmeno dentro das quatro esferas que o abrangem: ambiental, econÃmica, social e polÃtica. Esta crise ambiental à decorrÃncia, principalmente, das atividades humanas atravÃs do uso abusivo e desordenado do meio natural jà frÃgil e predisposto à desertificaÃÃo. O Estado do CearÃ, localizado na regiÃo Nordeste do Brasil, possui 92% de seu territÃrio inserido no TrÃpico semi-Ãrido e economia baseada em modelos predatÃrios dos recursos naturais e, devido a essa susceptibilidade à desertificaÃÃo, esta pesquisa propÃe um estudo interdisciplinar para analisar a propensÃo à desertificaÃÃo no referido Estado. Para tanto, foi construÃda, para os cento e oitenta e quatro municÃpios cearenses, uma matriz de indicadores englobando quatro aspectos: agropecuÃrios, econÃmicos, sociais e naturais conforme os documentos oficiais da OrganizaÃÃo das NaÃÃes Unidas. Para uma melhor anÃlise, cada grupo de indicadores foi submetido à anÃlise fatorial e foram construÃdos quatro Ãndices Parciais de PropensÃo à DesertificaÃÃo, apÃs, utilizou-se da anÃlise de agrupamentos para dividir os municÃpios cearenses em cinco classes conforme suas caracterÃsticas semelhantes. O Ãndice de PropensÃo à DesertificaÃÃo para o Estado do Cearà foi estabelecido atravÃs da mÃdia ponderada entre os quatro Ãndices parciais outrora calculados. Constatou-se que, trinta e um municÃpios estÃo em alto nÃvel de susceptibilidade à desertificaÃÃo, englobando uma Ãrea de 33.969km2, correspondendo a 22,82% da Ãrea total do Estado e atingindo uma populaÃÃo de 3.093.079 habitantes, ou seja, 41,62% da populaÃÃo cearense. Diante da gravidade desse sÃrio problema ambiental que assola o territÃrio cearense, esta pesquisa possibilitou um aprofundamento interdisciplinar sobre o fenÃmeno da desertificaÃÃo, assim como, permitirà uma maior aprendizagem e esclarecimento para os tomadores de decisÃo na tentativa de elaborar polÃticas pÃblicas que busquem dirimir o avanÃo das terras em processo de desertificaÃÃo nÃo deixando de incluir, obrigatoriamente, a participaÃÃo da populaÃÃo local a qual se torna essencial para a negociaÃÃo de interesses entre os ÃrgÃos pÃblicos e os atores sociais diretamente afetados pelo fenÃmeno. / The study on desertification became more acceptable when researches passed to interrelate this phenomenon inside the four spheres that embrace it: environmental, economic, social and political. This environmental crisis is consequence, mostly, of the human activities through the abusive use and disordered of the half natural already fragile and predisposed to desertification. State of the CearÃ, located in the region Northeast do Brazil, owns 92% of your territory inserted in the Tropic semi-arid and economy based in natural resources predatory models and, due to this sustainable to desertification, this research proposes a study interdisciplinary to analyze the propensity to desertification in the referred State. For so much, it was going built, for the one hundred and eighty-four from Cearà municipal districts, indicators including head office four aspects: agricultural, economic, social and natural as the Organization United Nations official documents. For a better analysis, each indicators group was submitted to the factorial analysis and were going built four Index Partial of Propensity to Desertification, after, it used of the groupings analysis to divide into five classes as its similar characteristics. Index of Propensity to Desertification for State of the Cearà was going established through the average pondered between the four partial formerly calculated indexes. It verified that, thirty-one municipal districts are in sustainable high level to desertification, including an area of 33.969km2, corresponding to 22,82% of the total area of State and reaching to a population of 3.093.079 inhabitants, or be, 41,62% of the from Cearà population. In front of the gravity of this serious environmental problem that devastates the from Cearà territory, this research enabled a deepning interdisciplinary on desertification phenomenon, as well as, it will allow a larger learning and clearing for planner of decision in the attempt to elaborate public politics that seek nullify the lands advance in desertification process not letting of including, obligatorily, the local population participation which becomes essential for the interests negotiation between public organs and the social actors directly affected by the phenomenon.

Thesis (Ph.D. in Biostatistics) -- University of Colorado Denver, 2008. / Typescript. Includes bibliographical references (leaves 53-56). Online version available via ProQuest Digital Dissertations.

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 162-169.

Government fiscal and monetary policy has long been based on the theory that was neither proven nor refuted since its origination. The original form of the Phillips curve has undergone significant modifications but its relevance remains questionable. This thesis examines the correlation between inflation and unemployment observed in the Czech Republic and Germany over the last twenty years. The validity of the theory is tested by advanced methods of time series analysis in the R environment. All the variables are gradually tested which results in the assessment of the correlation between the time series. The outcome of the testing is presented for both countries and a comparison at international level is drawn. Is is discovered that both of the countries have dependencies in their data. Czech republic has significant dependency in both ways, for Germany is the dependency significantly weaker and only in one way.