Submitted by Andre Salerno (a.salerno@uol.com.br) on 2015-01-16T15:57:20Z No. of bitstreams: 1 Dissertação André Salerno versão pos banca.pdf: 1673849 bytes, checksum: 0504a07bec49830f6e9e88dc0cd5d055 (MD5) / Approved for entry into archive by Ana Luiza Holme (ana.holme@fgv.br) on 2015-01-16T16:00:17Z (GMT) No. of bitstreams: 1 Dissertação André Salerno versão pos banca.pdf: 1673849 bytes, checksum: 0504a07bec49830f6e9e88dc0cd5d055 (MD5) / Made available in DSpace on 2015-01-16T17:04:03Z (GMT). No. of bitstreams: 1 Dissertação André Salerno versão pos banca.pdf: 1673849 bytes, checksum: 0504a07bec49830f6e9e88dc0cd5d055 (MD5) Previous issue date: 2014-12-18 / The main objective of this study is to evaluate some determinants of working capital needs commonly studied in literature and to analyze how companies are moving toward a goal (target) of NTC. Such study is unprecedented in Brazil, as far as we know. In fact, there is a lack of substantial theories on working capital in the finance area and very few studies can be found. Those who choose to study this subject may see that due to its current stage, it has been researched with the support of more consolidated theoretical bases, such as capital structure. These studies have widely used the concept of goal/target to determine the optimal capital structure and the speed this structure adjusts itself to in order to optimize its resources. The fact that such definitions and/or more established theories on the topic do not exist yet set this study in motion. It uses speed adjustment towards a working capital goal as well as the Partial Adjustment Model (PAM) and the Generalized Method of Moments (GMM) as techniques to support this goal. With this unprecedented combination in the Brazilian market when it comes to working capital, we hope to bring new contributions to the academic and business communities. In order to get the data for this quantitative study, we used existing information from Economatica® and BCB - Central Bank of Brazil. These databases use the quarterly financial statements between the periods of December 21st 2007 to June 30th 2014 (adjusted by inflation - IPCA) of companies listed on the BM&FBovespa which have at least 15 consecutive periods (quarters) of data. A total of 2,000 observations and 105 companies were studied. As for the method, the Dynamic Data Panel (unbalanced) was used as well as the following techniques in order to reach the main goal of the study ('What is the speed of adjustment in Working Capital Requirement?'): the Partial Adjustment Model technique for the analysis of determinants of working capital needs and movement towards a goal and the Generalized Method of Moments (GMM) technique to control possible effects of endogeneity (BLUNDELL and BOND, 1998) and to solve problems with residual autocorrelation (PIRES, ZANI e NAKAMURA, 2013, p. 19) / O presente estudo - até onde se sabe inédito no Brasil – possui como principal objetivo avaliar alguns determinantes das necessidades de capital de giro comumente estudados na literatura e analisar de que forma as empresas se movimentam em direção a uma meta (target) de Net Trade Cycle (similar ao Ciclo de Caixa - CCC). Sabemos que o tema capital de giro ainda carece de teorias mais robustas dentro da área de finanças, e poucos estudos ainda são encontrados na literatura. Aqueles que decidem estudá-lo, observam que dado o seu atual estágio, ele tem sido pesquisado com o suporte de bases teóricas mais consolidadas, como por exemplo estrutura de capitais. Esses estudos têm se utilizado muito do conceito de meta para determinar a estrutura ótima de capitais, e com qual velocidade de ajuste procura-se adequar essa estrutura como forma de otimizar seus recursos. O fato de ainda não existir definições e/ou teorias mais definidas sobre o tema foi o grande motivador para a realização desse estudo, que emprega a velocidade de ajuste em direção a uma meta de capital de giro, utilizando como técnica para suporte a esse objetivo o Modelo de Ajustamento Parcial (MAP) e o Generalized Method of Moments (GMM). Com essa combinação inédita no mercado brasileiro quando o assunto é capital de giro, esperamos trazer novas contribuições para as comunidades acadêmicas e empresariais. Para a obtenção dos dados que compõem esse estudo de caráter quantitativo, utilizamos informações existentes na Economatica® e BCB – Banco Central do Brasil. Nessas bases de dados utilizamos os demonstrativos financeiros trimestrais entre os períodos de 31/Dez./2007 a 30/Jun./2014 (ajustados por inflação – IPCA) das empresas listadas na BM&FBovespa que possuíssem pelos menos 15 períodos (trimestres) consecutivos de dados, com isso chegamos a um total de um pouco mais de 2 mil observações e 105 empresas. Quanto ao método, utilizamos Painel de Dados Dinâmico (desbalanceado) e as seguintes técnicas foram empregadas como forma de atender ao principal objetivo do estudo ('Qual é a velocidade de ajuste das Necessidades de Capital de Giro?'): Modelo de Ajustamento Parcial para a análise dos determinantes das necessidades de capital de giro e movimentação em direção a uma meta e; Generalized Method of Moments (GMM) como técnica de controle aos possíveis efeitos de endogeneidade (BLUNDELL e BOND, 1998) e solução para o problema de autocorrelação residual (PIRES, ZANI e NAKAMURA, 2013, p. 19).

A adoção de uma moeda única por diferentes países muda significativamente a política econômica desses países. O objetivo desta dissertação, elaborada em forma de artigo, é estudar os efeitos da adoção do euro sobre a competitividade internacional dos países-membros da União Monetária Europeia (UME) com base no arcabouço teórico da teoria das áreas monetárias ótimas. A análise econométrica irá compreender um painel dinâmico com 12 países da UME nos períodos de 2002 a 2013 para inferir se a entrada de capitais teve impacto negativo na competitividade externa dos países periféricos da UME e como que os diferentes tipos de capitais interferiram sobre a taxa de câmbio real efetiva dos países da Zona do Euro. Conclui-se assim que não só a crise é capaz de permitir ganhos de competitividade entre os países da UME, como outros fatores mais desejáveis também, tal como a entrada de outros investimentos da conta financeira do balanço de pagamentos, a abertura comercial e os gastos do governo. Além disso, constata-se que o impacto da mobilidade de capital na competitividade é influenciado não só pelo tipo de capital como também pelo país que recebe esse fluxo. / Adopting a single currency in different countries changes significantly the economic policy of these countries. The objective of this dissertation, prepared in the form of an article is to study the effects of the adoption of the euro on the external competitiveness of member countries of the European Monetary Union (EMU) based on the theoretical framework of the theory of optimum currency areas. The econometric analysis will comprise a dynamic panel with 12 countries of the EMU in the period 2002-2013 to infer if the capital inflow had a negative impact on the external competitiveness of the peripheral countries of the EMU and how different types of capital flows interfered on the real effective exchange rate of the countries of the euro zone. It is therefore concluded that not only the crisis can allow gains in competitiveness between countries in the EMU, as more desirable factors as well, like the inflow of other investments of the financial account of the balance of payments, trade liberalization and government expenditures. In addition, it appears that the capital flows impact on competitiveness is influenced not only by the type of capital but also by the country that receives the flow.

Made available in DSpace on 2016-06-02T19:56:51Z (GMT). No. of bitstreams: 1 5172.pdf: 4441518 bytes, checksum: 17886d05d502204a3da9edca7448c0e9 (MD5) Previous issue date: 2013-03-28 / Financiadora de Estudos e Projetos / In the study of the sucrose crystallization process, the nucleation phenomena and crystalline growth have been evaluated, when the systems were submitted to different solvent and operational conditions. The main objective of the present work was to study the sucrose crystallization process in solution through the partial change of the solvent. This change occurs through studied with the ethanol addition of a second solvent, a compound that reduces the solute solubility, but that is miscible in the first one. The addition of a second solvent generates a high degree of supersaturation, and promotes the formation of crystalline nuclei of smaller size to be used as seeds in industrial processes. Another objective was to study the flowability properties of particle size by determining the Hausner ratio and repose angle that allows relate some variable results obtained by the crystallization of sucrose. With the obtained results, it would be possible to improve the control of the finally properties of the crystalline product, such as crystal size distribution (CSD), crystalline habit, crystalline fluid inclusions and the formation of crystalline polymorphs. / No estudo do processo de cristalização da sacarose foram avaliados os fenômenos de nucleação e crescimento cristalino, quando o sistema foi submetido a um segundo solvente e a diferentes condições operacionais. O objetivo central do presente trabalho foi estudar o processo de cristalização da sacarose em solução, através da mudança parcial de solvente. Essa mudança foi estudada com a adição de etanol como segundo solvente, composto que reduz a solubilidade do soluto, sendo, no entanto, miscível no primeiro. A adição de um segundo solvente gera um alto grau de supersaturação, que diminui a solubilidade do soluto em solução e promove a formação de núcleos cristalinos de menor tamanho para serem utilizados como sementes em processos industriais. Outro objetivo deste trabalho foi estudar as propriedades de escoamento granulométrico mediante a determinação do índice de Hausner e ângulo de repouso que permita relacionar alguma variável obtida pelo resultado da cristalização de sacarose. Com a realização do estudo proposto, foram obtidas informações que possibilitaram melhorar o controle das propriedades finais do produto cristalino, tais como a distribuição de tamanho dos cristais (DTC), hábito cristalino, inclusões fluidas cristalinas entre outras.

A adoção de uma moeda única por diferentes países muda significativamente a política econômica desses países. O objetivo desta dissertação, elaborada em forma de artigo, é estudar os efeitos da adoção do euro sobre a competitividade internacional dos países-membros da União Monetária Europeia (UME) com base no arcabouço teórico da teoria das áreas monetárias ótimas. A análise econométrica irá compreender um painel dinâmico com 12 países da UME nos períodos de 2002 a 2013 para inferir se a entrada de capitais teve impacto negativo na competitividade externa dos países periféricos da UME e como que os diferentes tipos de capitais interferiram sobre a taxa de câmbio real efetiva dos países da Zona do Euro. Conclui-se assim que não só a crise é capaz de permitir ganhos de competitividade entre os países da UME, como outros fatores mais desejáveis também, tal como a entrada de outros investimentos da conta financeira do balanço de pagamentos, a abertura comercial e os gastos do governo. Além disso, constata-se que o impacto da mobilidade de capital na competitividade é influenciado não só pelo tipo de capital como também pelo país que recebe esse fluxo. / Adopting a single currency in different countries changes significantly the economic policy of these countries. The objective of this dissertation, prepared in the form of an article is to study the effects of the adoption of the euro on the external competitiveness of member countries of the European Monetary Union (EMU) based on the theoretical framework of the theory of optimum currency areas. The econometric analysis will comprise a dynamic panel with 12 countries of the EMU in the period 2002-2013 to infer if the capital inflow had a negative impact on the external competitiveness of the peripheral countries of the EMU and how different types of capital flows interfered on the real effective exchange rate of the countries of the euro zone. It is therefore concluded that not only the crisis can allow gains in competitiveness between countries in the EMU, as more desirable factors as well, like the inflow of other investments of the financial account of the balance of payments, trade liberalization and government expenditures. In addition, it appears that the capital flows impact on competitiveness is influenced not only by the type of capital but also by the country that receives the flow.

A adoção de uma moeda única por diferentes países muda significativamente a política econômica desses países. O objetivo desta dissertação, elaborada em forma de artigo, é estudar os efeitos da adoção do euro sobre a competitividade internacional dos países-membros da União Monetária Europeia (UME) com base no arcabouço teórico da teoria das áreas monetárias ótimas. A análise econométrica irá compreender um painel dinâmico com 12 países da UME nos períodos de 2002 a 2013 para inferir se a entrada de capitais teve impacto negativo na competitividade externa dos países periféricos da UME e como que os diferentes tipos de capitais interferiram sobre a taxa de câmbio real efetiva dos países da Zona do Euro. Conclui-se assim que não só a crise é capaz de permitir ganhos de competitividade entre os países da UME, como outros fatores mais desejáveis também, tal como a entrada de outros investimentos da conta financeira do balanço de pagamentos, a abertura comercial e os gastos do governo. Além disso, constata-se que o impacto da mobilidade de capital na competitividade é influenciado não só pelo tipo de capital como também pelo país que recebe esse fluxo. / Adopting a single currency in different countries changes significantly the economic policy of these countries. The objective of this dissertation, prepared in the form of an article is to study the effects of the adoption of the euro on the external competitiveness of member countries of the European Monetary Union (EMU) based on the theoretical framework of the theory of optimum currency areas. The econometric analysis will comprise a dynamic panel with 12 countries of the EMU in the period 2002-2013 to infer if the capital inflow had a negative impact on the external competitiveness of the peripheral countries of the EMU and how different types of capital flows interfered on the real effective exchange rate of the countries of the euro zone. It is therefore concluded that not only the crisis can allow gains in competitiveness between countries in the EMU, as more desirable factors as well, like the inflow of other investments of the financial account of the balance of payments, trade liberalization and government expenditures. In addition, it appears that the capital flows impact on competitiveness is influenced not only by the type of capital but also by the country that receives the flow.

The thesis investigates the nature of the relationship between the banking sector depth and long-term economic growth in the Gulf Cooperation Council (GCC) States, assesses the banking sector development status in each of the States, and underlines the policy implications in the light of the banking-growth nexus and the banking development benchmarking models’ findings for the region by undertaking three projects. The thesis examines the nature of the relationship between banking sector depth and long-term economic growth in the NRBC—as a proxy for the GCC States— vis-à-vis the rest of the world countries. For the empirical investigation, a dynamic panel data approach, i.e. Generalised Method of Moments (GMM), is adopted over the period 1961 to 2013. By utilising mixed effects and System GMM frameworks, the research identifies the countries with the strongest banking-growth relationships and establishes the banking sector development determinants in those countries. Employing a novel benchmarking process, the thesis assesses the status of the banking sector development in each of the GCC member countries and simulates the change in the banking sector depth across the Gulf region over a period of ten years to highlight the potential policy implications for the sector development. The findings of the thesis suggest that the relationship between banking sector depth and long-term economic growth in the NRBC is non-linear, where the relationship between the banking sector depth and economic growth turns from positive to negative beyond certain levels of sector depth. In comparison to other countries, the results indicate that the banking-growth nexus in the NRBC exhibits a smaller total effect magnitude as well as a shorter time between the change in the sector depth and its effect on economic growth. The benchmarking of the banking sectors in the GCC region suggests that in five of the six member countries the banking sectors are underdeveloped. The simulation results predict that the banking sectors will develop further in half of the countries in the region, given their current levels of banking sector development determinants, while two countries require reforms in terms of undertaking regulations and policies to avoid seeing their sector development levels deteriorate. The thesis contributes to theory by confirming findings in the literature and expanding the body of knowledge through novel findings. This research also contributes to policy by demonstrating the significance of the banking sector development for long-term economic growth in the NRBC, providing policymakers in the Gulf States with the status of their banking sectors, and underlining the banking sector depth determinants that ought to be considered when setting regulations and policies that are aimed at developing the banking sector further.

Ce travail a pour but la réalisation d'un outil permettant d'estimer la germination et la distribution en taille de cristaux d'un procédé de cristallisation. Pour ce faire un modèle de cristallisation a été développé et nous a permis de réaliser un observateur de dimension finie afin d'estimer la germination. Par la suite, un observateur de dimension infinie a été mis au point dans le but d'estimer la distribution de taille des cristaux à partir de la germination et de la mesure d'une taille de la distribution. Les deux observateurs ont été validés expérimentalement sur un procédé "batch" de cristallisation de l'oxalate d'ammonium. / The goal of this thesis is the development of an observer to estimate the nucleation and the crystal size distribution of a crystallization process. We first developed a model of crystallization in order to realize an observer for nucleation estimation. Then an infinite dimension observer was developed to estimate the crystal size distribution, using the nucleation estimation and one crystal size distribution measurement. An experimental validation was performed using the crystallization of ammonium oxalate.

Genetic association studies have successfully identified many genetic markers associated with complex human diseases and related quantitative traits. However, for most complex diseases and quantitative traits, all associated genetic markers identified to date only explain a small proportion of heritability. Thus, exploring the unexplained heritability in these traits will help us discover novel genetic determinants for these traits and better understand disease etiology and pathophysiology. Due to limited sample size, a single cohort study may not have sufficient power to identify novel genetic association with a small effect size, and meta-analysis approaches have been proposed and applied to combine results from multiple cohorts in large consortia, increasing the sample size and statistical power. Rare genetic variants and gene by environment interaction may both play a role in genetic association studies. In this dissertation, we develop statistical methods in meta-analysis, rare genetic variants analysis and gene by environment interaction analysis, conduct extensive simulation studies, and apply these methods in real data examples. First, we develop a method of moments estimator for the between-study covariance matrix in random effects model multivariate meta-analysis. Our estimator is the first such estimator in matrix form, and holds the invariance property to linear transformations. It has similar performance with existing methods in simulation studies and real data analysis. Next, we extend the Sequence Kernel Association Test (SKAT), a rare genetic variants analysis approach for unrelated individuals, to be applicable in family samples for quantitative traits. The extension is necessary, as the original test has inflated type I error when directly applied to related individuals, and selecting an unrelated subset from family samples reduces the sample size and power. Finally, we derive methods for rare genetic variants analysis in detecting gene by environment interaction on quantitative traits, in the context of univariate test on the interaction term parameter. We develop statistical tests in the settings of both burden test and SKAT, for both unrelated and related individuals. Our methods are relevant to genetic association studies, and we hope that they can facilitate research in this field and beyond.

The hidden Markov model (HMM) is one of the workhorse tools in, for example, statistical signal processing and machine learning. It has found applications in a vast number of fields, ranging all the way from bioscience to speech recognition to modeling of user interactions in social networks. In an HMM, a latent state transitions according to Markovian dynamics. The state is only observed indirectly via a noisy sensor – that is, it is hidden. This type of model is at the center of this thesis, which in turn touches upon three main themes. Firstly, we consider how the parameters of an HMM can be estimated from data. In particular, we explore how recently proposed methods of moments can be combined with more standard maximum likelihood (ML) estimation procedures. The motivation for this is that, albeit the ML estimate possesses many attractive statistical properties, many ML schemes have to rely on local-search procedures in practice, which are only guaranteed to converge to local stationary points in the likelihood surface – potentially inhibiting them from reaching the ML estimate. By combining the two types of algorithms, the goal is to obtain the benefits of both approaches: the consistency and low computational complexity of the former, and the high statistical efficiency of the latter. The filtering problem – estimating the hidden state of the system from observations – is of fundamental importance in many applications. As a second theme, we consider inverse filtering problems for HMMs. In these problems, the setup is reversed; what information about an HMM-filtering system is exposed by its state estimates? We show that it is possible to reconstruct the specifications of the sensor, as well as the observations that were made, from the filtering system’s posterior distributions of the latent state. This can be seen as a way of reverse engineering such a system, or as using an alternative data source to build a model. Thirdly, we consider Markov decision processes (MDPs) – systems with Markovian dynamics where the parameters can be influenced by the choice of a control input. In particular, we show how it is possible to incorporate prior information regarding monotonic structure of the optimal decision policy so as to accelerate its computation. Subsequently, we consider a real-world application by investigating how these models can be used to model the treatment of abdominal aortic aneurysms (AAAs). Our findings are that the structural properties of the optimal treatment policy are different than those used in clinical practice – in particular, that younger patients could benefit from earlier surgery. This indicates an opportunity for improved care of patients with AAAs. / <p>QC 20180301</p>

My dissertation consists of three essays on labor supply responses, along the extensive margin (participation into the labor force) and along the intensive margin (intensity of work on the job). The first two essays focus on the labor supply responsiveness of single women with children to taxation and welfare programs. The third essay investigates the effects of marriage, the wage rate, and the associated tax rate on men's labor supply. In the first essay, to avoid bias from the fact that labor supply outcomes are being driven by self-selection, I build a dynamic stochastic discrete choice model to investigate the long run effects of the earned income tax credit and welfare policies on single mothers' labor supply. Simulated method of moments is used to estimate parameters of this dynamic model, based on March CPS data files from 1964 to 2013. I compare the performance of the dynamic stochastic discrete choice model, a static model, and a reduced-form model. My analysis concludes that the dynamic stochastic discrete choice model captures the simultaneous impact of the state variables on the predicted employment decision. My study provides evidence of the long-run positive effect of public policy on low income families in a life-cycle setting. This essay also emphasizes the importance of education in increasing single mothers' labor supply. The second essay is designed to identify factors that help single mothers leave TANF within a short span of time. I find strong evidence for the importance of child support assistance to single mothers' success in exiting TANF with a job. I uncover evidence that work-related activities do not induce TANF participants to leave within a short span of time. My analysis also suggests that health issues significantly limit the ability of single mothers to exit TANF. In the third essay, the main research question is how marital status affects the elasticity of the labor supply of males with respect to wages and taxes, in a life-cycle setting. A dynamic panel data model, which extends the literature on dynamic labor supply, indicates that the elasticity of men's labor supply with respect to wages and taxes is affected by marital status. The empirical results using the Panel Study of Income Dynamics (PSID) data show that men who are continuously married to the same wife have a lower average Frisch elasticity than others. / Ph. D.