In the first chapter, entitled “On Cross-country Differences in the Contribution of Nontraded Goods to Real Exchange Rate Fluctuations”, The contribution of nontraded goods to Real Exchange Rate (RER) fluctuations for a large number of countries that include high, middle, and low-income countries are estimated using Engel’s (1999, JPE) approaches. We also propose a new quantity dual approach which does not require any assumption regarding the functional form for either the production function or for the overall price index to estimate similar measures. All the three approaches used yield qualitatively similar estimates, but there exists a large cross-country variation in the contributions of the nontraded goods to RER fluctuations. Income, government expenditure, exchange rate volatility, and political stability are found to be negatively correlated to the contributions of nontraded goods, while inflation, consumption expenditure, and openness are positively correlated to the contributions of nontraded goods to RER fluctuations. In the second chapter, entitled “The Great Recession and Price Convergence in the United States”, We analyze the differential nature of commodity price convergence in cities in the U.S.A. before and after the Great Recession of 2008. Using quarterly retail price data for 50 commodities from 279 cities for the period 1992- 2014, we show that the speed of price convergence for almost all the commodities increased after the great recession, and that observation is more pronounced for nonperishable prices. We also observe that the price convergence disparity between the most and the least affected states widened, with the most affected areas experiencing much higher speed of price convergence than before the Great Recession. Moreover, the geographic variations of changes in rate of convergence are noteworthy. In the third chapter, entitled “Language, Topography, and Price Convergence”, we ask what else can downgrade technological innovations, improvement of transportation infrastructures, and other policy tools in boosting integrations of commodity markets? This paper analyzes the impact of two highly exogenous variables – languages and elevations - on retail price convergence which indicates the level of market integration. Using data from a very ethnic and topographically diversified country- India- we show that language and topographical variations represent intrinsic barriers to market integration and should not be overlooked. Therefore, ceteris paribus, a country with more similarities in languages and less variation in topographical features is likely to benefit more from technological improvements and from the improvement of transportation infrastructures due to the resulting faster rate of convergence.

In this dissertation we first derive a new unified upper solution bound for the continuous coupled algebraic Riccati equation, which arises from the optimal control of a Markovian jump linear system. In particular, we address the issue of rank deficiency with the control matrices. In the case of rank deficiency the existing matrix upper bounds are inapplicable. Moreover, our new result is not restricted to rank deficiency cases only. It now contains the existing results as special cases. Next, an iterative refinement is presented to improve our new unified matrix upper solution bounds. In particular, this iterative refinement determines a monotonically decreasing sequence of upper bounds for the solution of the continuous coupled algebraic Riccati equation. We formulate a new iterative algorithm by modifying this iterative refinement. We also prove that this new algorithm generates a monotonically decreasing sequence of matrix upper solution bounds that converges to the maximal solution of the continuous coupled algebraic Riccati equation. Furthermore, we prove the convergence of an accelerated Riccati iteration which computes a positive semidefinite solution of the continuous coupled algebraic Riccati equation. In particular, we establish sufficient conditions for the convergence of this algorithm. We also prove that for particular initial values this algorithm determines a monotonically increasing sequence of positive semidefinite matrices that converge to the minimal solution of the continuous coupled algebraic Riccati equation. Additionally, we show that for specific initial values this algorithm generates a monotonically decreasing sequence that converges to the maximal solution of the continuous coupled algebraic Riccati equation. In addition, we prove that this accelerated Riccati iteration converges faster than the Riccati iteration. Finally, we formulate a weighted modified accelerated Riccati iteration which is a more generalized Riccati type iteration. All of the existing Riccati iterations are now the special cases of this algorithm. Furthermore, we establish sufficient conditions for the convergence of this algorithm and we prove the monotonic convergence of the sequence generated by this algorithm. We also discuss how the weight and other quantities affect the rate of convergence of this algorithm. Illustrative numerical examples are also presented.

Les principaux sujets étudiés dans cette thèse concernent le développement d'algorithmes stochastiques d'optimisation sous incertitude, l'étude de leurs propriétés théoriques et leurs applications. Les algorithmes proposés sont des variantes du recuit simulé qui n'utilisent que des estimations sans biais de la fonction de coût. On étudie leur convergence en utilisant des outils développés dans la théorie des processus de Markov : on utilise les propriétés du générateur infinitésimal et des inégalités fonctionnelles pour mesurer la distance entre leur distribution et une distribution cible. La première partie est dédiée aux graphes quantiques, munis d'une mesure de probabilité sur l'ensemble des sommets. Les graphes quantiques sont des versions continues de graphes pondérés non-orientés. Le point de départ de cette thèse a été de trouver la moyenne de Fréchet de tels graphes. La moyenne de Fréchet est une extension aux espaces métriques de la moyenne euclidienne et est définie comme étant le point qui minimise la somme des carrés des distances pondérées à tous les sommets. Notre méthode est basée sur une formulation de Langevin d'un recuit simulé bruité et utilise une technique d'homogénéisation. Dans le but d'établir la convergence en probabilité du processus, on étudie l'évolution de l'entropie relative de sa loi par rapport a une mesure de Gibbs bien choisie. En utilisant des inégalités fonctionnelles (Poincaré et Sobolev) et le lemme de Gronwall, on montre ensuite que l'entropie relative tend vers zéro. Notre méthode est testée sur des données réelles et nous proposons une méthode heuristique pour adapter l'algorithme à de très grands graphes, en utilisant un clustering préliminaire. Dans le même cadre, on introduit une définition d'analyse en composantes principales pour un graphe quantique. Ceci implique, une fois de plus, un problème d'optimisation stochastique, cette fois-ci sur l'espace des géodésiques du graphe. Nous présentons un algorithme pour trouver la première composante principale et conjecturons la convergence du processus de Markov associé vers l'ensemble voulu. Dans une deuxième partie, on propose une version modifiée de l'algorithme du recuit simulé pour résoudre un problème d'optimisation stochastique global sur un espace d'états fini. Notre approche est inspirée du domaine général des méthodes Monte-Carlo et repose sur une chaine de Markov dont la probabilité de transition à chaque étape est définie à l'aide de " mini-lots " de taille croissante (aléatoire). On montre la convergence en probabilité de l'algorithme vers l'ensemble optimal, on donne la vitesse de convergence et un choix de paramètres optimisés pour assurer un nombre minimal d'évaluations pour une précision donnée et un intervalle de confiance proche de 1. Ce travail est complété par un ensemble de simulations numériques qui illustrent la performance pratique de notre algorithme à la fois sur des fonctions tests et sur des données réelles issues de cas concrets. / The main topics of this thesis involve the development of stochastic algorithms for optimization under uncertainty, the study of their theoretical properties and applications. The proposed algorithms are modified versions of simulated an- nealing that use only unbiased estimators of the cost function. We study their convergence using the tools developed in the theory of Markov processes: we use properties of infinitesimal generators and functional inequalities to measure the distance between their probability law and a target one. The first part is concerned with quantum graphs endowed with a probability measure on their vertex set. Quantum graphs are continuous versions of undirected weighted graphs. The starting point of the present work was the question of finding Fréchet means on such a graph. The Fréchet mean is an extension of the Euclidean mean to general metric spaces and is defined as an element that minimizes the sum of weighted square distances to all vertices. Our method relies on a Langevin formulation of a noisy simulated annealing dealt with using homogenization. In order to establish the convergence in probability of the process, we study the evolution of the relative entropy of its law with respect to a convenient Gibbs measure. Using functional inequalities (Poincare and Sobolev) and Gronwall's Lemma, we then show that the relative entropy goes to zero. We test our method on some real data sets and propose an heuristic method to adapt the algorithm to huge graphs, using a preliminary clustering. In the same framework, we introduce a definition of principal component analysis for quantum graphs. This implies, once more, a stochastic optimization problem, this time on the space of the graph's geodesics. We suggest an algorithm for finding the first principal component and conjecture the convergence of the associated Markov process to the wanted set. On the second part, we propose a modified version of the simulated annealing algorithm for solving a stochastic global optimization problem on a finite space. Our approach is inspired by the general field of Monte Carlo methods and relies on a Markov chain whose probability transition at each step is defined with the help of mini batches of increasing (random) size. We prove the algorithm's convergence in probability towards the optimal set, provide convergence rate and its optimized parametrization to ensure a minimal number of evaluations for a given accuracy and a confidence level close to 1. This work is completed with a set of numerical experiments and the assessment of the practical performance both on benchmark test cases and on real world examples.

Dans la thèse on introduit et on étudie une généralisation spatiale sur $\R^d$ du quantile réel usuel sous la forme d'une surface quantile via des formes $\phi$ et d'un point d'observation $O$. Notre point de départ est de simplement admettre la subjectivité due à l'absence de relation d'ordre totale dans $\R^d$ et donc de développer une vision locale et directionnelle des données. Ainsi, les observations seront ordonnées du point de vue d'un observateur se trouvant à un point $O \in \R^d$. Dans le chapitre 2, on introduit la notion du quantile vue d'un observateur $O$ dans la direction $u \in \Sd$ et de niveau $\alpha$ via des des demi-espaces orthogonaux à chaque direction d'observation. Ce choix de classe implique que les résultats de convergence ne dépendent pas du choix de $O$. Sous des hypothèses minimales de régularité, l'ensemble des points quantile vue de $O$ définit une surface fermée. Sous hypothèses minimales, on établit pour les surfaces quantile empiriques associées les théorèmes limites uniformément en le niveau de quantile et la direction d'observation, avec vitesses asymptotiques et bornes d'approximation non-asymptotiques. Principalement la LGNU, la LLI, le TCLU, le principe d'invariance fort uniforme puis enfin l'approximation du type Bahadur-Kiefer uniforme, et avec vitesse d'approximation. Dans le chapitre 3, on étend les résultats du chapitre précédent au cas où les formes $\phi$ sont prises dans une classe plus générale (fonctions, surfaces, projections géodésiques, etc) que des demi-espaces qui correspondent à des projections orthogonales par direction. Dans ce cadre plus général, les résultats dépendent fortement du choix de $O$, et c'est ce qui permet de tirer des interprétations statistiques. Dans le chapitre 4, des conséquences méthodologiques en statistique inférentielle sont tirées. Tout d'abord on introduit une nouvelle notion de champ de profondeurs directionnelles baptisée champ d'altitude. Ensuite, on définit une notion de distance entre lois de probabilité, basée sur la comparaison des deux collections de surfaces quantile du type Gini-Lorrentz. La convergence avec vitesse des mesures empiriques pour cette distance quantile, permet de construire différents tests en contrôlant leurs niveaux et leurs puissances. Enfin, on donne une version des résultats dans le cas où une information auxiliaire est disponible sur une ou plusieurs coordonnées sous la forme de la connaissance exacte de la loi sur une partition finie. / The main issue of the thesis is the development of spatial generalizations on $\R^d$ of the usual real quantile. Facing the usual fact that $\R^d$ is not naturally ordered, our idea is to simply admit subjectivity and thus to define a local viewpoint rather than a global one, anchored at some point of reference $O$ and arbitrary shape $\phi$ with the motivation of crossing information gathered by changing viewpoint $O$, shape $\phi$ and $\alpha$-th order of quantile. In Chapter 2, we study the spatial quantile points seen from an observer $O$ in a direction $u \in \Sd$ of level $\alpha$ through the class of the half-spaces orthogonal to the direction $u$. This choice implies that the convergence theorems do not depend on the choice of $O$. Under minimal regularity assumptions, the set of all quantile points seen from $O$ is a closed surface. Under minimal assumptions, we establish for the associated empirical quantile surfaces the convergence theorems uniformly on the quantile level and the observation direction with the asymptotic speed and non-asymptotic bounds of approximation. Mainly, we establish the ULLN, the ULIL, the UCLT, the uniform strong invariance principle and finally the Bahadur-Kiefer type embedding, with the approximation speed rate. In Chapter 3, all the results of the previous chapter are extended to the case where the shapes $ \phi $ are taken in a class more general (functions, surfaces, geodesic projections, etc) than orthogonal projections (half-spaces). In this general setting, the results depend strongly on the choice of $ O $. It is this dependence which permit to draw statistical interpretations: modes detection, mass localization, etc. In Chapter 4, some methodological consequences in inferential statistics are drawn. First we introduce a new concept of directional depth fields called altitude fields. In a second application is defined a new distances between probability distributions, based on the comparison of two collections of quantile surfaces, which are indexes of the type Gini-Lorrentz. The convergence with speed of the empirical quantile measures for these distances, can build different tests with control of their level and their power. A third use of the quantile surfaces is for the case where $ \alpha = 1/2$. Finally, we give a version of our theorems in the case where auxiliary information is available on one or more coordinates of the random variable. By assuming known the probability of the elements of a finite partition, the asymptotic variance of the limiting process decreases and the simulations with few points clearly shows the reframe of the estimated surfaces to the real ones.

O método de identificação por minimização do erro de predição está relacionado com um problema de otimização não convexo. É comum utilizar algoritmos iterativos para resolver o problema de otimização. Contudo, os algoritmos iterativos podem ficar presos em mínimos locais da função custo ou convergir para a borda do domínio de busca. Uma análise da função custo e condições suficientes para garantir a convergência dos algoritmos iterativos para o mínimo global são apresentadas neste trabalho. Observa-se que estas condições dependem do espectro do sinal de entrada utilizado no experimento. Este trabalho apresenta ferramentas para melhorar a convergência dos algoritmos para o mínimo global, as quais são baseadas na manipulação do espectro do sinal de entrada. / The Prediction Error Method is related to a non-convex optimization problem. It is usual to apply iterative algorithms to solve this optimization problem. However, iterative algorithms can get stuck at a local minimum of the cost function or converge to the border of the searching space. An analysis of the cost function and sufficient conditions to ensure the convergence of the iterative algorithms to the global minimum are presented in this work. It is observed that this conditions depend on the spectrum of the input signal used in the experiment. This work presents tools to improve the convergence of the algorithms to the global minimum, which are based on the manipulation of the input spectrum.

Ecólogos de comunidades têm como um dos principais objetivos identificar padrões de abundância e distribuição de espécies ao longo das regiões e ambientes, e inferir sobre os processos norteadores desses padrões. Para tanto, duas linhas teóricas complementares são principalmente utilizadas: limitação de similaridade e filtros ambientais. Enquanto a primeira prediz que as espécies dentro de uma comunidade devem ser distintas nas suas características como resultado da competição (divergência), a segunda espera uma alta similaridade entre espécies coexistentes (convergência), uma vez que elas são filtradas sob certas condições ambientais. Estudos sobre diversidade funcional podem nos dar uma ideia da proporção de divergência e convergência na estruturação das comunidades, enquanto a composição funcional pode indicar a direção das respostas funcionais aos filtros ambientais. Ambientes campestres predominantemente cobrem o bioma Pampa, no sul do Brasil, e nesta região as florestas são restritas a zonas ribeirinhas e a pequenas encostas. As inundações são uma pressão comum em matas ribeirinhas, mas dadas as condições da região elas também são vulneráveis à dessecação por evapotranspiração e ventos. Em contraste, as florestas de encosta são mais sombreadas e úmidas. No presente trabalho, temos como objetivo principal caracterizar a diversidade e composição funcional destes ambientes florestais. Esperamos encontrar padrões de convergência para os atributos de florestas ciliares, devido às condições ambientais mais severas. Estabelecemos 18 unidades amostrais de 250 x 10 m em três regiões do Pampa, nove para cada tipo de floresta. Todas as árvores com pelo menos 5 cm de DAP (diâmetro à altura do peito) foram medidas. As regiões representam um gradiente de precipitação e temperatura. Seis atributos funcionais das espécies arbóreas foram avaliados: área foliar, área foliar específica (SLA), conteúdo de matéria seca foliar (LDMC), altura máxima, síndrome de dispersão e tamanho do fruto. Índices de diversidade funcional e seus tamanhos de efeito padronizados (SES - standardized effect size) dada a riqueza local de espécies foram estimados para cada região e tipo florestal. A composição funcional foi analisada através de média dos atributos funcionais ponderada pelas abundâncias nas comunidades (CWM), com posterior análise de variância para verificar diferenças entre as florestas e regiões. Os valores de CWM de área foliar e proporção de zoocoria foram menores nas florestas ribeirinhas de todas as regiões, enquanto o tamanho do fruto, SLA e LDMC só foram influenciados pelo fator região, sendo a SLA menor na região de menor precipitação e temperatura médias anuais. Altura máxima média das comunidades diferiu tanto conforme o tipo de floresta (maior na encosta) quanto à região (maior na região com condições climáticas mais favoráveis). Os valores do SES para riqueza funcional e dispersão funcional não demostraram padrões de divergência ou convergência significativos. Apenas a riqueza funcional para altura e tamanho de fruto foi distinta de acordo com o ambiente e a região das florestas avaliadas. Os resultados deste trabalho, ao contrário do esperado, demonstram não haver padrões de divergência e/ou convergência funcional para as florestas do Pampa, em termos do ambiente em que ocorrem (ciliar ou encosta) ou mesmo região. Contudo, a composição funcional variou tanto em relação ao ambiente quanto à região. Isso pode indicar uma seleção de espécies com distintas estratégias adaptativas de acordo com as diferentes influências ambientais em escala local e regional. / Community ecologists aim at identifying patterns of species abundance and distribution along regions and environments, inferring on their main driver processes. Two complementary approaches rule community assembly: limiting similarity and environmental filters. While the first predicts that species within a community should be distinct in traits to avoid competition (divergence), the second expects a high similarity between co-occurring species (convergence), since they are filtered out to occur under certain environmental conditions. Functional diversity can give us an idea of the proportion of divergence and convergence in the structure of communities, while the functional composition might indicate the direction of trait responses to the environmental filters. Grasslands predominantly cover the southern Brazilian Pampa, and the forests are restricted to riparian zones and hillslopes. Flooding is a common pressure on riparian forests, but given the environmental conditions of the region they are also vulnerable to desiccation by evapotranspiration and winds. In contrast, slope forests are more shaded and humid. We aimed at characterizing functional diversity and composition of these forest environments. We expected trait convergence for riparian forests because of the harsher environmental conditions. We established 18 sampling units of 250 x 10 m in three regions of the Pampa, nine for each forest type. All trees with at least 5cm DBH were measured. The regions represent a gradient in precipitation and temperature. Six functional traits of the tree species were assessed: leaf area, specific leaf area (SLA), leaf dry matter content (LDMC), plant height, dispersal mode, and fruit size. Functional diversity indices and their standardized effect size (SES), considering the local species richness, were estimated for each region and forest. Functional composition was analyzed through community-weighted mean of traits (CWM), with further analysis of variance to verify differences between forests and regions. CWM of leaf area and zoochory were lower in riparian forests of all regions, while fruit size, SLA and LDMC were only influenced by the region. SLA was lower in the region with lower annual mean precipitation and temperature. Maximum height shows response for the type of forest (higher CWM in hillslope forests) and region (higher in the region under more favorable climatic conditions). SES of functional richness and dispersion did not show a recurrent pattern of significant divergence or convergence related to the factors. The results of SES, contrary to our expectation, are not indicating any patterns of trait divergence and/or convergence for the forests. Only the functional richness of height and fruit size differed according to the habitat and the region of the studied forests. However, both forest environments and regions differed in terms of functional composition, indicating the assembling of species with distinct adaptive strategies in relation to different environment influences for local and regional scale.

Esta dissertação de Mestrado visa apresentar os resultados e reflexões obtidos através de uma pesquisa envolvendo a inter-relação entre a História e Epistemologia da Ciência. Teve-se como objetivos principais desta investigação teórica: a construção de uma convergência epistemológica entre as ideias e defesas em Ciência dos filósofos Gaston Bachelard e Imre Lakatos, como também a construção de episódios em Ciência discutidos em grande parcela sob tais olhares histórico-filosóficos. Esta pesquisa possui abordagem qualitativa e quanto aos seus objetivos insere-se como descritiva-reflexiva. Iniciou-se tal investigação realizando um aprofundamento teórico envolvendo as especificidades de cada epistemologia com o objetivo de clarificar o entendimento referente aos pontos estruturantes de cada olhar epistemológico. Em relação ao processo de construção dos episódios em Ciência, realizou-se um levantamento bibliográfico contemplado em maior parte por livros e artigos científicos que tratassem da respectiva temática do episódio, buscando-se uma diversidade de fontes para fundamentar este processo de escrita, com o intuito de valorizar um olhar abrangente sobre a História da Ciência. De modo geral, a construção da convergência epistemológica se fundamentou no que ambas as epistemologias têm em comum que é a própria defesa da História da Ciência por uma natureza epistemológica dinâmica e evolutiva (no que tange à mutabilidade do conhecimento científico), visão normativa, essência dialética e caráter racional objetivo. Desta forma, buscou-se explorar as relações teóricas envolvendo os olhares histórico-filosóficos de ambos os epistemólogos na escrita dos episódios. O primeiro episódio em Ciência visou apresentar e refletir sobre dois programas científicos conflitantes na História da Ciência, os programas flogístico e calórico, os quais marcaram, pontualmente, o período pré-científico da Química e o nascimento das bases teóricas da Química moderna. Já o segundo episódio em Ciência almejou apresentar as principais concepções de matéria desenvolvidas pelos gregos durante a Antiguidade. Os episódios em Ciência produzidos nesta pesquisa valorizam um olhar histórico-filosófico da Ciência através da referida convergência, como também possibilitam uma compreensão da história do pensamento científico por uma natureza conjectural (naturalmente falível) e em constante estado de evolução. Desta forma, defende-se que as epistemologias de Lakatos e Bachelard possuem grande valia ao campo didático científico, pois fomentam concepções epistemológicas contemporâneas e defendem uma Ciência aberta e em constante estágio de devir. Além do mais, os episódios em Ciência podem servir como significativas ferramentas didáticas a abordagens de temas científicos elucidados por olhares que contemplam discussões pertinentes à essência histórico-filosófica do pensamento científico no contexto do ensino. Esta pesquisa evidencia, na base dos seus resultados finais, a necessidade de se buscar valorizar a qualificação da História da Ciência como um importante cerne das discussões dos conteúdos científicos no campo didático, como também a fomentação de um distanciamento em relação às concepções alicerçadas no contexto de ensino que remetem à epistemologia tradicional. / The aim of this Masters dissertation is to present results and reflections obtained from research that involved the interrelation between the History and the Epistemology of Science. The main objectives of this theoretical investigation were the following: the construction of an epistemological convergence between the ideas and advocacies of philosophers Gaston Bachelard and Imre Lakatos, in addition to the construction of Science episodes discussed mostly under such historical-philosophical viewpoints. The research is from a qualitative approach and regarding the objectives is inserted as descriptive-reflexive. The investigation started through further theoretical development involving the specifics of each epistemology with the objective of clarifying the understanding related to the structural points from each epistemological viewpoint. As to the process of construction of the Science episodes, a bibliographical ascertainment was made covering mainly books and scientific articles that dealt with the respective issue of the episode, seeking for source diversity to serve as the foundation for this writing process with the intent of valuing a comprehensive viewpoint of Science History. In general, the construction of the epistemological convergence was founded on where both epistemological share in common, namely the advocacy of Science History itself by a dynamic, evolving epistemological nature (pertaining to the mutability of scientific knowledge), normative viewpoint, dialectic essence, and an objective rational character. This way, an exploration of the theoretical relations was sought that involved the historical-philosophical viewpoints of both epistemologists for writing the episodes. The first Science episode is aimed at presenting and reflecting upon two conflicting scientific programs in Science History, the phlogistic and caloric programs, that were a timely marker of the pre-scientific period in Chemistry and the birth of the theoretical bases for modern Chemistry. The aims of the second Science episode is to present the main conceptions of matter developed by the Greeks in Antiquity. The Science episodes produced by this research value a historical-philosophical viewpoint of Science from the above mentioned convergence, and also allowed for an understanding of the history of scientific thought by a conjectural nature (naturally fallible) and in a constant state of evolution. This way, it is advocated that Lakatos' and Bachelard's epistemologies are of great value to the scientific didactic field by enhancing contemporary epistemological conceptions and advocate that Science be open and in a permanent state of becoming. Furthermore, the Science episodes may serve as significant didactic tools for approaching scientific themes elucidated by viewpoints the include discussions pertaining the historical-philosophical essence of the scientific thought within a teaching context. Based on its final results, this research brings to evidence the need to pursue valuing the qualification of Science History as an important core when discussing scientific contents in the didactic field, as well as enhancing a further distancing in relation go conceptions founded within the teaching context that remit to traditional epistemology.

Analisa, na perspectiva da Economia política da comunicação, as particularidades do uso de vídeos na rádio Gaúcha em um contexto de convergência e de disponibilização de conteúdo online, utilizando como ideia central a vigência da fase da multiplicidade da oferta (BRITTOS, jul.-dez. 2002). Hoje, o rádio inserido em múltiplos ambientes e temporalidades, incorpora uma narrativa multiplataforma, onde o sonoro segue como linha mestra da informação, mas também dialoga com diferentes linguagens: fotografia, infografia, texto escrito e vídeo. Partindo do conceito de rádio expandido (KISCHINHEVSKY, 2016), propõe um problema fundamental: como os vídeos são utilizados pela rádio Gaúcha, o porquê desse uso e em que medida ocorrem adaptações, afastamentos e aproximações em relação à linguagem audiovisual vigente no telejornalismo. O principal objetivo geral é analisar de que maneira a emissora explora o potencial dos vídeos e qual é o papel exercido por eles na produção jornalística. Aplicando como metodologia a análise de conteúdo (BARDIN, 2011), usa como base os patamares de (1) noticiabilidade; e (2) linguagem audiovisual tradicional e concentra o seu foco nas reportagens Os desafios do emprego na crise, Coronéis do Futebol e Gaúcha Me Leva; na cobertura especial das eleições presidenciais dos Estados Unidos; e no programa Sala de Redação. Como resultado, observase que existe maior preocupação em usar o vídeo para expandir o conteúdo, explorando o potencial informativo/localizador das imagens e agregando à notícia e às transmissões informações exclusivas não veiculadas na versão sonora. A linguagem visual empregada, no entanto, ainda não desenvolveu a totalidade de suas potencialidades. / It analyzes, from the perspective of the Political economy of communication, the particularities of the use of videos in Gaúcha radio broadcasting in a context of convergence and availability of on-line content, using as central idea the validity of the multiplicity of supply phase (BRITTOS, Jul. -dez 2002). Today, radio inserted in multiple environments and temporalities, incorporates a multiplatform narrative, where the sonorous follows as the main line of information, but also dialogs with different languages: photography, infographics, written text and video. Having as its main theoretical basis the concept of expanded radio (KISCHINHEVSKY, 2016), proposes a fundamental problem: how the videos are used by Gaúcha, the reason for this use and to what extent adaptations, departures and approximations occur in relation to the audiovisual language in force in the telejournalism. The main general objective is to analyze how the broadcaster explores the potential of the videos and what role they play in journalistic production. Applying as methodology the content analysis (BARDIN, 2011), uses as base the levels of (1) newsworthiness; and (2) traditional audiovisual language, and focuses its focus on the issues of Os desafios do emprego na crise, Coronéis do Futebol, Gaúcha Me Leva, United States presidential elections and the Sala de Redação program. As a result, it is observed that there is a greater concern to use the video to expand the content, exploring the potential information / locator of the images and adding to the news and the transmissions exclusive information not conveyed in the sound version. The visual language employed, however, has not yet developed the full potential.

A pesquisa identifica e analisa como o jornal nativo digital Nexo conforma editorial-mente a informação jornalística ao articular seções e temas, potencialidades da web, modalidades, gêneros e formatos jornalísticos. O quadro teórico se constitui com base na abordagem do cenário de convergência jornalística, tendo em vista processos de mu-danças estruturais e inovações. Reflete-se ainda sobre o jornal enquanto dispositivo, debatendo-se sobre as especificidades do ciberjornalismo e da conformação de um ci-berjornal. Os procedimentos metodológicos adotados são a pesquisa bibliográfica, a pesquisa documental e a análise de conteúdo. O corpus de análise é composto por mate-riais coletados entre os dias 11 e 24 de setembro de 2017, com capturas de tela sempre às 23h, em cinco espaços – seções do site, home do site, página do Facebook, newslet-ters e matérias. Os resultados evidenciam uma nova proposta de enquadramento em seções e temas; diferentes abordagens para periodicidade, atualidade, universalidade e publicidade; uma articulação multiplataforma; a exploração de modalidades, formatos e gêneros diversos; o uso de hipertextualidade e memória para construir um jornalismo explicativo; e a utilização de multimidialidade e interatividade como possibilidades de inovação editorial. / The research identifies and analyzes how the digitally native newspaper Nexo editorially conforms its journalistic information by articulating sections and topics, web potentiali-ties, modalities, and journalistic genres and formats. The theoretical framework is based on the approach of journalistic convergence, structural changes and innovation process-es. It also reflects about the newspaper as a device, debating on the specificities of cyberjournalism and the conformation of a cyberjournal. The methodological proce-dures adopted are bibliographic research, documental research and content analysis. The corpus of the analysis is composed of material collected between September 11 and September 24, 2017, capturing the screen always at 11:00 PM, in five areas – the site sections, home page, Facebook page, newsletters and news stories. The results show a new proposal for framing sections and topics; different approaches to periodicity, topi-cality, universality and publicity; a multiplatform articulation; the exploration of diverse modalities, formats and genres; the use of hypertextuality and memory to construct an explanatory journalism; and the use of multimediality and interactivity as possibilities for editorial innovation.

O projeto estrutural de túneis envolve o conhecimento da variável convergência (fechamento radial) para definição da pressão atuante sobre o revestimento e do nível de descompressão do solo circundante (maciço). A adoção de modelos contínuos em elementos finitos consegue discretizar de forma mais adequada o modelo mecânico estrutural considerando a interação com o solo. Dessa forma, esta dissertação recai sobre a variação da razão de cobertura (profundidade) de um túnel, a fim de determinar a profundidade limite que o modelo numérico segue o padrão de tensões geostáticas crescentes com a profundidade versus um padrão geostático uniforme profundo. A validação do modelo numérico ocorre junto a soluções analíticas desenvolvidas por Park (2004) e Kirsch (1898) para túneis em maciços elásticos superficiais e profundos respectivamente. Nos exemplos analisados, quando a profundidade do eixo do túnel é dez vezes maior que seu diâmetro as convergências se aproximam daquelas dadas pelo GEOMEC 91 (Bernaud, 1991) e o túnel pode ser considerado profundo. A curva de assentamentos (recalques) foi considerada consequência importante a ser notada em túneis superficiais que mostraram um recalque máximo até duas vezes maior quando se reduz a profundidade Para esse estudo foram desenvolvidos scripts com profundidade variável adicionando a superfície de plasticidade de Drucker-Prager (utilizada em solos friccionais). O modelo numérico desenvolvido para túneis superficiais é validado junto a túneis reais instrumentados que tenham sido avaliados a partir de algum outro modelo contínuo, são eles: Heathrow Express, Green Park, Metrôs de Barcelona, Brasília e São Paulo com resultados variando entre 1,20% e 6,78%. Eventualmente, uma breve análise do desenvolvimento de tensões no revestimento para túneis circulares, elípticos e ferradura é realizada a fim de encontrar zonas de tração. Enquanto túneis em seção ferradura desenvolveram tração para qualquer profundidade devido ao formato retilíneo, túneis circulares precisaram se encontrar com baixa profundidade a fim de desenvolver zonas descomprimidas decorrentes da ovalização de túneis rasos. / The structural design of tunnels involves the knowledge of the variable convergence (radial closure) for the definition of the acting pressure upon the lining and for the decompression level of the involving soil (rockmass). The adoption of continuous models using finite element analysis (FEA) is able to assess the structural mechanical model accurately, concerning the soil interaction. This way, this work studies the covering ratio (depth) of tunnels, in a way to determine the threshold point which divides the geostatic growing stresses versus the deep uniform stresses pattern. The validation of the numerical model under an elastic rockmass is done by comparison with analytical solutions developed by Park (2004) and Kirsch (1898) for shallow and deep tunnels respectively. Regarding the analyzed examples, when the depth of the tunnel axis is ten times greater than its diameter; the convergences approach to the ones given by GEOMEC 91 (Bernaud, 1991) and the tunnel may be considered deep. The settlement through (ground movement) is considered an important consequence to be noticed upon shallow tunnels; these tunnels have led to a maximum settlement twice deeper when the covering ratio is shallow (H/D = 1). For this study, several scripts have been developed concerning the variable depth and adding the Drucker-Prager plasticity criterion for frictional soils. The numerical model developed for shallow tunnels is validated with other continuous models relied on real instrumentation of subway network tunnels, such as: Heathrow Express, Green Park, Barcelona, Brasília and São Paulo with the solutions ranging between 1,20% and 6,78%. Eventually, a brief analysis of the stress development in the lining for circular, ellipsoid and horseshoe tunnels is done in search of tension zones. In one hand, horseshoe tunnels develop tension for any depth due to its straight walls; in the other hand, circular tunnels need to have a small covering ratio in order to develop decompression zones caused by the shallow tunnels ovalization.