Submitted by Guilherme Stein (stein.guilherme@gmail.com) on 2016-09-14T03:16:35Z No. of bitstreams: 1 tese.pdf: 430062 bytes, checksum: 5a8a1a0eaba91cd18e8142932105ee3b (MD5) / Rejected by Letícia Monteiro de Souza (leticia.dsouza@fgv.br), reason: Prezado Guilherme, Favor fazer as alterações abaixo para que seu trabalho seja aprovado: 1: O nome da fundação (Getulio) não possuí acento. Favor retirar de todas as páginas que constam o nome. 2: Faltam as sessões de Agradecimentos, Resumo e Abstract. Atenciosamente, Letícia 3799-3631 on 2016-09-14T12:11:08Z (GMT) / Submitted by Guilherme Stein (stein.guilherme@gmail.com) on 2016-09-14T13:20:27Z No. of bitstreams: 1 tese 2.0.pdf: 432636 bytes, checksum: 00494ab653e6be0fae54f42a49f2fe99 (MD5) / Approved for entry into archive by Letícia Monteiro de Souza (leticia.dsouza@fgv.br) on 2016-09-14T13:22:52Z (GMT) No. of bitstreams: 1 tese 2.0.pdf: 432636 bytes, checksum: 00494ab653e6be0fae54f42a49f2fe99 (MD5) / Rejected by Letícia Monteiro de Souza (leticia.dsouza@fgv.br), reason: Prezado Guilherme, Os agradecimentos em uma trabalho tem uma importância significante. Para tirar suas dúvidas, a Suzinei irá entrar em contato com você para esclarecer essa situação. Após o contato dela, favor mandar o novo trabalho. Atenciosamente, Letícia 3799-3631 on 2016-09-14T13:24:21Z (GMT) / Submitted by Guilherme Stein (stein.guilherme@gmail.com) on 2016-09-14T14:45:23Z No. of bitstreams: 1 tese 3.0.pdf: 434242 bytes, checksum: 203925cdcd2f5883b66766677952d8f0 (MD5) / Rejected by Letícia Monteiro de Souza (leticia.dsouza@fgv.br), reason: Prezado Guilherme, Favor fazer a ultima alteração: A sessão Resumo deve estar após a sessão Abstract, devido ao seu trabalho ser em inglês. Atenciosamente, Letícia, 3799-3631 on 2016-09-14T14:48:27Z (GMT) / Submitted by Guilherme Stein (stein.guilherme@gmail.com) on 2016-09-14T14:53:21Z No. of bitstreams: 1 tese 4.0.pdf: 434238 bytes, checksum: 2c9c2be7ae9e557ae3eb8805d6b97afd (MD5) / Approved for entry into archive by Letícia Monteiro de Souza (leticia.dsouza@fgv.br) on 2016-09-14T14:54:23Z (GMT) No. of bitstreams: 1 tese 4.0.pdf: 434238 bytes, checksum: 2c9c2be7ae9e557ae3eb8805d6b97afd (MD5) / Made available in DSpace on 2016-09-14T14:55:45Z (GMT). No. of bitstreams: 1 tese 4.0.pdf: 434238 bytes, checksum: 2c9c2be7ae9e557ae3eb8805d6b97afd (MD5) Previous issue date: 2016-08-19 / This thesis presents two theoretical models. The first shows how the cost of doing business associated with red tape arises as a response to institutional failure, namely, a failure of the legal system. It shows that, when legal system is inefficient, an increase in the cost of doing business can increase society’s welfare. The second model shows how credit constraints affect political preferences of the society relating to human capital investments. Families that are credit constrained invest less in their offspring human capital and thus also prefer policies that involve direct cash transfers to human capital investments. / A tese desenvolve dois modelos teóricos. O primeiro deles mostra como o custo de realizar negócios associados a burocracia surge como resposta a uma falha instituicional, em particular, uma falha no sistema de justiça. Ele mostra que, quando o sistema de justiça é ineficiente, um aumento no custo de realizar negócios pode aumentar o bem-estar da sociedade. O segundo modelo mostra como restrições de crédito afetam as preferências políticas da sociedade no que tange investimentos em capital humano. Famílias com restrição de crédito investem menos no capital humano dos filhos e, por esse motivo, acabam também acabam preferindo políticas que envolvam transferências diretas de renda a investimentos em capital humano.

Image segmentation is important with applications to several problems in biology and medicine. While extensively researched, generally, current segmentation methods perform adequately in the applications for which they were designed, but often require extensive modifications or calibrations before used in a different application. We describe a system that, with few modifications, can be used in a variety of image segmentation problems. The system is based on a supervised learning strategy that utilizes intensity neighborhoods to assign each pixel in a test image its correct class based on training data. In summary, we have several innovations: (1) A general framework for such a system is proposed, where rotations and variations of intensity neighborhoods in scales are modeled, and a multi-scale classification framework is utilized to segment unknown images; (2) A fast algorithm for training data selection and pixel classification is presented, where a majority voting based criterion is proposed for selecting a small subset from raw training set. When combined with 1-nearest neighbor (1-NN) classifier, such an algorithm is able to provide descent classification accuracy within reasonable computational complexity. (3) A general deformable model for optimization of segmented regions is proposed, which takes the decision values from previous pixel classification process as input, and optimize the segmented regions in a partial differential equation (PDE) framework. We show that the performance of this system in several different biomedical applications, such as tissue segmentation tasks in magnetic resonance and histopathology microscopy images, as well as nuclei segmentation from fluorescence microscopy images, is similar or better than several algorithms specifically designed for each of these applications. In addition, we describe another general segmentation system for biomedical applications where a strong prior on shape is available (e.g. cells, nuclei). The idea is based on template matching and supervised learning, and we show the examples of segmenting cells and nuclei from microscopy images. The method uses examples selected by a user for building a statistical model which captures the texture and shape variations of the nuclear structures from a given data set to be segmented. Segmentation of subsequent, unlabeled, images is then performed by finding the model instance that best matches (in the normalized cross correlation sense) local neighborhood in the input image. We demonstrate the application of our method to segmenting cells and nuclei from a variety of imaging modalities, and quantitatively compare our results to several other methods. Quantitative results using both simulated and real image data show that, while certain methods may work well for certain imaging modalities, our software is able to obtain high accuracy across several imaging modalities studied. Results also demonstrate that, relative to several existing methods, the template based method we propose presents increased robustness in the sense of better handling variations in illumination, variations in texture from different imaging modalities, providing more smooth and accurate segmentation borders, as well as handling better cluttered cells and nuclei.

Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2017-06-22T17:21:30Z No. of bitstreams: 1 arquivototal.pdf: 2646336 bytes, checksum: 8fa6ece0a05a4f7bffc899ff5ba5e9b7 (MD5) / Made available in DSpace on 2017-06-22T17:21:30Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2646336 bytes, checksum: 8fa6ece0a05a4f7bffc899ff5ba5e9b7 (MD5) Previous issue date: 2015-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The combination of classifiers aims to produce more accurate results to the decision-making process. Therefore, this study had the objective of proposing a new architecture based on a combination of spatial clustering methods and a more detailed voting map on the amount of votes that each geo-object received, applied to epidemiology. The methods of spatial clustering, in general, aim to identify the significant and not significant spatial clusters according to the study area. They are combined by combination of rules. In this work, the following rules were used: majority voting and neural networks. The new proposed architecture was applied to dengue data in the state of Paraiba, in the period from 2009 to 2011. According to the World Health Organization, dengue is a disease that annually records an average of 50 to 100 million cases worldwide, generating large financial burden on the health sector. A new architecture is proposed for the combination of the methods of spatial clustering. The combination of spatial clustering methods was applied in three case studies. In all three case studies, the new architecture identified more precisely the priority and nonpriority municipalities in Paraiba with regards to the dengue. In the case study 1, the combination rule was majority voting, in case study 2 the combination rule was neural networks and in case study 3 a new detailed voting map was proposed, identifying the amount of votes that each municipality had received. Analyzing the results from a spatial point of view, it was observed that the mesoregion called Sertão in the state of Paraiba had a greater number of priority municipalities; and the mesoregion of the Coast in Paraiba, the lowest number of priority municipalities. Regarding the research from the epidemiological point of view, it was observed that from the results of diagnostic tests (sensitivity, specificity, positive predictive value and negative predictive value) and the Kappa statistic, the combination of models produced satisfactory results. Concluding the analysis from the point of view of the combination of spatial clustering methods, it was observed that the new architecture presented satisfactory results by using the combination of the combination of rules. These results, from the epidemiological point of view, can assist managers in the decision-making process by verifying more precisely the regions that deserve special attention in combating the disease. / A combinação de classificadores tem por objetivo produzir resultados mais precisos para o processo de tomada de decisão. Com isso, este estudo teve por objetivo propor uma nova arquitetura baseada na combinação dos métodos de aglomeração espacial e um mapa de votação mais detalhado sobre a quantidade de votos que cada geo-objeto recebeu, aplicados à epidemiologia. Os métodos de aglomerados espaciais, de forma geral, tem por objetivo a identificação dos conglomerados espaciais significativos e não significativos de acordo com a região de estudo. Eles são combinados por regras de combinação. Neste trabalho foram utilizadas as seguintes regras: votação por maioria e redes neurais. A nova arquitetura proposta foi aplicada a dados do dengue no estado da Paraíba, no período de 2009 a 2011. Segundo a Organização Mundial da Saúde, o dengue é uma doença que registra anualmente uma média de 50 a 100 milhões de casos em todo o mundo, gerando grandes encargos financeiros para o setor da saúde. proposta uma nova arquitetura para a combinação dos métodos de aglomerados espaciais. A combinação dos métodos de aglomeração espacial, foi aplicados em três estudos de casos. Em todos os três estudos de casos a nova arquitetura identificou com maior precisão os municípios prioritários e não prioritários do dengue na Paraíba. No estudo de caso 1 a regra de combinação foi a votação por maioria, no estudo de caso 2 a regra de combinação foi das redes neurais e no estudo de caso 3 foi proposto uma novo mapa de votação detalhado identificando a quantidade de votos que cada município recebeu. Analisando os resultados do ponto de vista espacial, observou-se que a mesorregião do Sertão Paraibano apresentou uma maior quantidade de municípios prioritários; e a mesorregião do Litoral Paraibano, o menor número de municípios prioritários. Em relação, a pesquisa do ponto de vista epidemiológico foi possível verificar que a partir dos resultados dos testes diagnósticos (sensibilidade, especificidade, valores preditivos positivos e valores preditivos negativos) e a estatística Kappa os modelos de combinação produziram resultados satisfatórios. Finalizando a análise do ponto de vista da combinação dos métodos de aglomerados espaciais, foi possível observar que a nova arquitetura, apresentou resultados satisfatórios, a partir da combinação das regras de combinação. Estes resultados do ponto de vista epidemiológico, podem auxiliar os gestores no processo de tomada de decisão verificando com mais precisão as regiões que realmente merecem atenção especial no combate à doença.

The overall objective of the thesis is to investigate needs and incentives of all income/wealth groups in order to explore ways and means to remedy the excessive economic inequality. A closer examination of individual decisions across richer and poorer households allows us to recognize conflicts of wants, needs and values and subsequently to draw recommendations for future policies. The first chapter examines households' preferences over the redistribution of wealth resources. The preferences of voting households are restricted by agents' present and future resource constraints. The wealth resources vary over the business cycle, which affects the grounds for speculations of voting households. We augment the standard Real-Business-Cycle (RBC) model by the majority voting on lump-sum redistribution employing a balanced government budget. Our findings indicate that for the usual elasticity of labor supply both transfers' level and share of output are procyclical, with the procyclicality increasing in the discrepancy between richer and poorer households. In the second chapter we analytically demonstrate that all economic agents face subsistence costs that hinder economic and financial decisions of the poor. We find that the standard two-asset portfolio-selection model with a time-invariant subsistence component in the common-across agents Stone-Geary utility function is capable of explaining qualitatively and quantitatively three empirical regularities: (i) increasing saving rates in wealth, (ii) rising risky portfolio shares with wealth, (iii) more volatile consumption growth of the richer. On the contrary, "keeping-up-with-the-Joneses" utility with a time-varying weighted mean consumption produces identical saving rates and portfolio asset shares across richer and poorer agents, failing to match the micro data. Finally, in the third chapter we use Epstein-Zin-Weil recursive preferences altered to include subsistence costs, as this form of utility function enables trade-off between stability and safety. We pursue an analytical investigation of a more complex multi-asset portfolio-choice model with perfectly insurable labor risk and no liquidity constraints and find further support of the data evidence. If households' total resources are anticipated to increase over time, poorer agents can afford to gradually escape subsistence concerns by choosing lower saving rates and accepting only minor portfolio risks as their consumption hovers close to the subsistence needs. The calibration part of the model economy shows that analytical results can quantitatively reconcile the data, too.

Cette thèse porte sur les mécanismes d’allocation de biens indivisibles en présence d’externalités dans les préférences individuelles. Ces externalités rendent difficile en pratique la collecte d’une information complète sur les préférences. Aussi, l’analyse normative des mécanismes d’allocation requiert de formuler des hypothèses sur la manière d’étendre l’information collectée aux préférences sur les allocations. Cette approche revient à définir des restrictions sur le domaine de préférences admissibles, une démarche bien connue de la théorie du choix social. Les trois premiers chapitres portent sur l’analyse du marché de Shapley-Scarf dans lequel les échanges sont organisés entre coalitions. Les chapitres 1 et 2 établissent des restrictions de domaine garantissant l’existence de différents types d’équilibre concurrentiel. Dans le chapitre 3, l’ensemble des biens est muni d’une géographie, ce qui permet de définir la distance entre partenaires comme source d’externalité. Nous identifions certains domaines de préférences qui assurent la non-vacuité de différents types de Coeur. Le chapitre 4 porte sur le cas de biens indivisibles publics purs. Nous montrons que le problème est formellement équivalent à celui du choix d’un comité dont les membres sont choisis dans des ensembles distincts. Nous caractérisons certains domaines de préférences sur les comités pour lesquels le choix majoritaire membre par membre est cohérent avec le choix majoritaire du comité dans son ensemble. / This thesis focuses on the allocation of indivisible goods in presence of externality in individual preferences. This externality creates a difficulty with collecting full information about preferences. Therefore, conducting a normative analysis of allocation mechanisms requires assumptions on how reported preferences can be extended to preferences over outcomes. This approach is in line with the literature on preference domain restriction well-known in Social Choice theory. The first three chapters focus on Shapley-Scarf markets where trades are organized among coalitions. Coalitional trade generates externalities in individual valuations of allocations. Chapters 1 and 2 investigate domain restrictions ensuring the existence of various types of competitive equilibrium. Chapter 3 endows the set of goods with a geographical structure and considers distance to partners as a source of externality in preference. We identify domains of preference extensions which guarantee the existence of various types of core allocations. Chapter 4 focuses the case of pure public indivisible goods, which is formally identical to choosing a committee formed by several members, each selected from a specific set. We characterize preference domains over committees for which a well-defined seat-wise choice procedure based on majority voting is consistent with choosing a committee at once from majority voting.