Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-04-25T14:30:32Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao_Lelio_Alejandro_Arias_Vizcaino.pdf: 1217481 bytes, checksum: 3e169ccf7afc8c3a244b8cc4a07c9cbf (MD5) / Made available in DSpace on 2017-04-25T14:30:32Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao_Lelio_Alejandro_Arias_Vizcaino.pdf: 1217481 bytes, checksum: 3e169ccf7afc8c3a244b8cc4a07c9cbf (MD5) Previous issue date: 2016-12-05 / FACEPE / entre as principais metodologias estatísticas, a análise de regressão é uma das formas mais efetivas para modelar dados. Neste sentido, a análise de diagnóstico é imprescindível para determinar o que poder ter acontecido no processo gerador dos dados caso os pressupostos impostos a este não sejam plausíveis. Uma das ferramentas mais úteis em diagnóstico é a avaliação dos resíduos. Neste trabalho, propomos um novo resíduo para as classes de modelos de regressão linear e não linear baseados na família exponencial com dispersão variável (Smyth (1989)). A proposta permite incorporar de forma simultânea informações relativas aos submodelos da média e da dispersão sem fazer uso de matrizes de projeção para sua padronização. Resultados de simulação e de aplicações a dados reais mostram que o novo resíduo é altamente competitivo em relação ao resíduos amplamente usados e consolidados na literatura. / In statistical methodologies, regression analysis can be a very effective way to model data. In this sense, the diagnostic analysis is needed to try to determine what might happened in the data generating process if the conditions imposed to it are not true. One of the most useful techniques to detect the goodness of fit to the model is the evaluation of residuals. In this work, we propose a new residual to the class of linear and nonlinear regression models based on exponential family with variable dispersion (Smyth (1989)). The proposal incorporates simultaneously information from the sub-models of the mean and the dispersion without using projection matrices for its standardization. Simulation resultsandapplicationsinrealdatashowthatthenewresidualishighlycompetitivewith respect to residuals widely used and established in the literature.

Made available in DSpace on 2016-08-19T17:24:51Z (GMT). No. of bitstreams: 1 Tese-AnaValeriaCarvalhoPiresYokokura.pdf: 6263679 bytes, checksum: 10e62a4122185fac92398004b9092d42 (MD5) Previous issue date: 2016-02-18 / Some research shows that coping with stressful situations during pregnancy decreases the breastfeeding time, however this association has been little studied in the world. This study had two objectives: to analyze the validity of the Perceived Stress Scale in a sample of 1447 pregnant women in Sao Luis, MA and 1392 in Ribeirão Preto-SP; and analyze the effect of stress during pregnancy on the duration of breastfeeding in 1134 mother pairs / son of St. Louis. In the first article we evaluated the PSS versions with 10 and 14 items through Confirmatory Factor Analysis using the mplus 7.0, and a new version was created (PSS12) from the deletion of two items that had low factor loadings (<0.40). The models were estimated by the method of least squares (WLSMV) adjusted for mean and variance. Models with two factors showed good fit (RMSEA <0.08; CFI / TLI> 0.90) and high internal consistency (α> 0.80) in the three tested versions. In the second article we used the perceived stress scale (PSS14) and Reporting of stressful life events (EVE) to assess stress. PSS14 evaluates perceived stress during the last month. The EVE assessed stressful life events in the last twelve months. The theoretical model was designed in Acyclic Directed Graph (DAG). Survival curves were estimated using the Kaplan-Meier method. We used model of Cox proportional hazards, estimating the hazard ratio (HR) and 95%. The perceived stress during pregnancy was associated with a shorter duration of total breastfeeding (AMT) (HR=1,54; IC95%:1,23-1,93), but had no effect on exclusive breastfeeding time (AME). It was found that the PSS was adequate to assess stress in pregnant women in two cities in different regions. It suggests the use of PSS10 in the evaluation of perceived stress in pregnant women, considering their practical use, because it is a short range and its excellent fit indices. It was also found that the PEACE proved to be a tool to better identify stress than EVE. / Pesquisas mostram que o enfretamento de situações estressantes durante a gravidez diminui o tempo da amamentação, porém esta associação tem sido pouco estudada. O presente estudo teve dois objetivos: analisar a validade da Escala de Estresse Percebido numa amostra de 1447 gestantes de São Luís-MA e 1392 de Ribeirão Preto-SP; e analisar o efeito do estresse materno na duração da amamentação em 1134 pares mãe/filho de São Luís. No primeiro artigo foram avaliadas as versões PSS com 10 e 14 itens por meio da Análise Fatorial Confirmatória, utilizando o MPLUS 7.0, e foi criada uma nova versão da Escala de Estresse Percebido (PSS12) a partir da exclusão de dois itens que apresentaram cargas fatoriais baixas (<0,40). Os modelos foram estimados pelo método dos mínimos quadrados (WLSMV) ajustados pela média e variância. Os modelos com dois fatores apresentaram bom ajuste (RMSEA <0,08; CFI/TLI >0,90) e consistência interna elevada (α>0,80) nas três versões testadas. No segundo artigo utilizou-se a Escala de estresse percebido (PSS14) e Relato de eventos de vida estressantes (EVE) para avaliar estresse. A PSS14 avaliou estresse percebido durante o último mês. O EVE avaliou eventos estressantes nos últimos doze meses. O modelo teórico foi desenhado em Gráfico Acíclico Direcionado (DAG). As curvas de sobrevida foram estimadas pelo método de Kaplan-Meier. Utilizou-se modelo de riscos proporcionais de Cox, estimando-se a hazard ratio (HR) e IC95%. O estresse percebido na gestação associou-se com a menor duração do aleitamento materno total (AMT) (HR=1,54; IC95%:1,23-1,93), porém não teve efeito sobre o tempo de aleitamento materno exclusivo (AME). Constatou-se que a PSS mostrou-se adequada para avaliar estresse em gestantes, em duas cidades de diferentes regiões brasileiras. Sugere-se a utilização da PSS10 na avaliação do estresse percebido em gestantes, considerando sua utilidade prática, por ser uma escala resumida e seus excelentes índices de ajuste. Verificou-se também que a PSS se mostrou um instrumento capaz de identificar melhor o estresse do que o EVE.

This thesis analyzes the impact of the monetary policy of the Czech Republic on the Czech banking sector. It explains the monetary transmission mechanism in an inflation targeting regime and its channels: interest rates channel, asset price channel, exchange rate channel and credit channel. The aim of the thesis is to introduce and analyze channels of the Czech transmission mechanism by Correlation and Graphical Analysis of chosen time series and using Linear Regression Model. The analyses are calculated in MS Excel and Gretl.

Magister Economicae - MEcon / The main objective of this study was to identify ways in which transaction costs can be lowered to improve small-scale farmers’ participation in and returns from agricultural output markets, with specific reference to small-scale mango farmers in Limpopo province. This study hypothesizes that transaction costs are lower in informal spot markets and increase when small-scale farmers sell in more structured markets (formal markets). This study builds on transaction cost economics (TCE) to demonstrate how to overcome transaction cost barriers that small-scale mango farmers face in the agro-food markets. The approach to collect primary information was sequenced in two steps: first, key informant and focus group interviews were conducted and, secondly, a structured survey instrument was administered in two districts of Limpopo. A total of 235 smallscale mango farmers were interviewed. A binary logistic regression model was used to estimate the impact of transaction costs on the likelihood of households’ participation in formal (=1) and informal (=0) agro-food markets. STATA Version 10 was used to analyse the data. This study found that a larger proportion of male than female farming households reported participation in the formal markets, suggesting deep-seated gender differentiation in market participation. The average age of small farmers participating in formal markets is 52, compared to 44 for those in informal markets, implying that older farmers might have established stronger networks and acquired experience over a longer period. Farmers staying very far from the densely populated towns (more than 50 km) participate less in the formal markets than those staying closer (0 – 25 km and 26 – 49 km), which implies that the further they are from the towns, the less the likelihood of farmers selling in the formal markets. Farmers who own storage facilities and a bakkie (transportation means) participate more in formal markets compared to those who do not own these assets, which suggests that these farmers are able to store mangoes, retaining their freshness and subsequently delivering them to various agro-food markets on time. Households that participate in formal markets have high mean values of income and social grants. However, this study found that the likelihood of a household’s participation in the markets is less as income and social grants increase. This suggests that households do not invest their financial assets in order to overcome market access barriers. A large proportion of households that own larger pieces of arable land participate in the formal markets, which implies that they are able to produce marketable surplus. Households that have a high mean value (in Rand) of cattle participate more in formal markets than in informal markets. However, this study found that the likelihood of a household’s participation in the markets does not change with an increase in the value of its livestock. These findings suggest that households do not sell their cattle in order to overcome market access barriers. Reduced transaction costs for small-scale mango farmers in Limpopo should improve their participation in and returns from the agro-food markets. Policy interventions to support this need to focus on: access to storage and transportation facilities, enforcement of gender equity requirements in existing policies, and better access to information about markets. / South Africa

Family-centered care (FCC) focuses on considering the family in planning/implementing care and is associated with increased patient satisfaction. Little is known about factors that influence FCC. Using linear mixed modeling and Generalized Estimating Equations to analyze data from a cross-sectional survey of primary care practices in Ontario, this study sought to determine whether models of primary care service delivery differ in their provision of FCC and to identify characteristics of primary care practices associated with FCC. Patient-reported scores of FCC were high, but did not differ significantly among primary care models. After accounting for patient characteristics, practice characteristics were not significantly associated with patient-reported FCC. Provider-reported scores of FCC were significantly higher in Community Health Centres than in Family Health Networks. Higher numbers of nurse practitioners and clinical services on site were associated with higher FCC scores but scores decreased as the number of family physicians at a site increased.

There are numerous researches done in the last couple decades dedicated to the observation of impact of merges and acquisitions on the performance of the company. The topic is considered to be up-to-date, as still there is no common approach to evaluating of benefits mergers are about to bring to a new established entity. In this thesis the issue of post-merger financial performance is investigated on an example of three biggest energy companies in Europe: RWE, E.ON and Vattenfall. The aim of the thesis is to find out whether financial performance of chosen companies improves after the merger occurs. This target is elaborated with a help of the analysis of commonly used financial ratios in corporate finance and construction of two regression models, which explain the interrelations between basic indicator of the company's growth (net income), the fact of the merger and determined financial ratios. As an outcome of the research, a few findings were obtained, such as worsening of financial performance three to five years after the merger, with continuing improvement in further years, quite stable financial indicators before the merger, positive interconnection between the fact of the merger and the net income. Such outcomes might be considered as significant, though further research and elaboration of the topic can be performed in the future.

The thesis unifies the most important author's results in the field of algorithms concerning zonotopes and their applications in optimization and statistics. The computational-geometric results consist of a new compact output-sensitive algorithm for enumerating vertices of a zonotope, which outperforms the rival algorithm with the same complexity-theoretic properties both theoretically and empirically, and a polynomial algorithm for arbitrarily precise approximation of a zonotope with the Löwner-John ellipsoid. In the application area, the thesis presents a result, which connects linear regression model with interval outputs with the zonotope matters. The usage of presented geometric algorithms for solving a nonconvex optimisation problem is also discussed.

The main object of this thesis is to estimate the waste in public procurement in Slovakia and estimate its active and passive components. The first part offers a theoretical explanation of legislation related to public procurement, as well as a theoretical explanation of active and passive waste. In the next section there is a brief description of similar study, which estimated the waste of public procurement in Italy. In the second part, which is empirical, there is a analysis of the results of public contracts related to construction work. Data were obtained from the electronic database of Public Procurement Office in Slovakia. From these data I created a regression model obtained by the method of least squares. The aim was to determine the truth of the hypothesis that if the contracts awarded through the procurement of external agencies, the procurement process becomes more efficient. The analysis did not confirm the truth of this hypothesis and thus I could not estimate the amount of passive and active waste. The results obtained from regression analysis were then used to estimate the amount of waste in the case of public procurement related to construction of residential buildings, reconstruction of schools and the revitalization of public spaces, when the public purchaser was the city or village. This analysis also estimates the percentage of the waste of public procurement, when process of public procurement was supervised by external procurement agencies.

In this study we propose three new distributions and a study with longitudinal data. The first was the Odd log-logistic normal distribution: theory and applications in analysis of experiments, the second was Odd log-logistic t Student: theory and applications, the third was the Odd log-logistic skew normal: the new distribution skew-bimodal with applications in analysis of experiments and the fourth regression model with random effect of the Odd log-logistic skew normal distribution: an application in longitudinal data. Some have been demonstrated such as symmetry, quantile function, some expansions, ordinary incomplete moments, mean deviation and the moment generating function. The estimation of the model parameters were approached by the method of maximum likelihood. In applications were used regression models to data from a completely randomized design (CRD) or designs completely randomized in blocks (DBC). Thus, the models can be used in practical situations for as a completely randomized designs or completely randomized blocks designs, mainly, with evidence of asymmetry, kurtosis and bimodality. / A distribuição normal é uma das mais importantes na área de estatística. Porém, não é adequada para ajustar dados que apresentam características de assimetria ou de bimodalidade, uma vez que tal distribuição possui apenas os dois primeiros momentos, diferentes de zero, ou seja, a média e o desvio-padrão. Por isso, muitos estudos são realizados com a finalidade de criar novas famílias de distribuições que possam modelar ou a assimetria ou a curtose ou a bimodalidade dos dados. Neste sentido, é importante que estas novas distribuições tenham boas propriedades matemáticas e, também, a distribuição normal como um submodelo. Porém, ainda, são poucas as classes de distribuições que incluem a distribuição normal como um modelo encaixado. Dentre essas propostas destacam-se: a skew-normal, a beta-normal, a Kumarassuamy-normal e a gama-normal. Em 2013 foi proposta a nova família X de distribuições Odd log-logística-G com o objetivo de criar novas distribuições de probabildade. Assim, utilizando as distribuições normal e a skew-normal como função base foram propostas três novas distribuições e um quarto estudo com dados longitudinais. A primeira, foi a distribuição Odd log-logística normal: teoria e aplicações em dados de ensaios experimentais; a segunda foi a distribuição Odd log-logística t Student: teoria e aplicações; a terceira foi a distribuição Odd log-logística skew-bimodal com aplicações em dados de ensaios experimentais e o quarto estudo foi o modelo de regressão com efeito aleatório para a distribuição distribuição Odd log-logística skew-bimodal: uma aplicação em dados longitudinais. Estas distribuições apresentam boas propriedades tais como: assimetria, curtose e bimodalidade. Algumas delas foram demonstradas como: simetria, função quantílica, algumas expansões, os momentos incompletos ordinários, desvios médios e a função geradora de momentos. A flexibilidade das novas distrições foram comparada com os modelos: skew-normal, beta-normal, Kumarassuamy-normal e gama-normal. A estimativas dos parâmetros dos modelos foram obtidas pelo método da máxima verossimilhança. Nas aplicações foram utilizados modelos de regressão para dados provenientes de delineamentos inteiramente casualizados (DIC) ou delineamentos casualizados em blocos (DBC). Além disso, para os novos modelos, foram realizados estudos de simulação para verificar as propriedades assintóticas das estimativas de parâmetros. Para verificar a presença de valores extremos e a qualidade dos ajustes foram propostos os resíduos quantílicos e a análise de sensibilidade. Portanto, os novos modelos estão fundamentados em propriedades matemáticas, estudos de simulação computacional e com aplicações para dados de delineamentos experimentais. Podem ser utilizados em ensaios inteiramente casualizados ou em blocos casualizados, principalmente, com dados que apresentem evidências de assimetria, curtose e bimodalidade.

The diploma thesis deals with non-destructive testing of concrete as well as with the relationship between determined parameters and the compressive strength of concrete. The thesis is mainly focused on the ultrasonic pulse velocity method and the rebound hammer test. The experimental part of the thesis describes non-destructive tests performed on concrete blocks. The compressive strength was tested on the drill cores taken from the concrete blocks. The aim of this thesis is to find regression models of the relationship between the compressive strength and non-destructive parameters, and the subsequent analysis of the results.