O regime de meta para a inflação foi adotado por um amplo conjunto de países nos últimos anos. Evidentemente, a definição da meta de inflação a ser perseguida é parte essencial do regime. O presente trabalho pretende contribuir para o debate sobre a meta ótima para o Brasil. O trabalho está dividido em três ensaios que, por caminhos diversos, buscam estimar quantitativamente os custos e benefícios de diferentes metas de inflação para a economia brasileira. O foco é sobre os efeitos de longo prazo de diferentes metas, uma vez que esses são mais relevantes do que os possíveis custos de ajustamento para uma eventual nova meta de inflação. O primeiro artigo aborda a questão sobre a meta de inflação ótima para o Brasil por meio da perda de bem estar medida pela demanda de moeda, um canal clássico considerado pela literatura. O segundo avalia a relação entre o nível e a incerteza sobre a inflação futura, utilizando para tanto modelos para a estimação da variância condicional da inflação, as expectativas de inflação relatadas por analistas econômicos e medidas de inflação implícita em preços de ativos. O terceiro artigo apresenta um enfoque mais teórico e estrutural, apresentando um modelo no qual existe um trade-off para a meta de inflação e calibrando esse modelo para obter estimativas da meta ótima para a economia brasileira. O modelo considera, de um lado, a perda de bem estar causada pela inflação através da demanda de moeda e, de outro, o benefício pela redução da perda de eficiência econômica ocasionada pela rigidez dos salários nominais. Concluímos que a análise exposta no presente trabalho sugere que, tendo em vista a redução da incerteza macroeconômica na economia brasileira nos últimos anos, haveria motivos também para uma redução gradual da meta de inflação. Contudo, também aponta que não se deve buscar metas muito baixas, uma vez que o benefício adicional em se reduzir a meta de inflação é relativamente pequeno quando já se está em um nível de inflação baixo. / Inflation targeting regimes have been adopted by a large number of countries in recent years. Obviously, the definition of the actual inflation target to be pursued is an essential part of this regime. This work aims to make a contribution to the debate about the optimal target for Brazil. The three essays follow different paths in an attempt to estimate the quantitative costs and benefits of the different inflation targets for the Brazilian economy. The focus is on the long-term effects of the different targets as these are more important than the possible costs during the transition towards the new inflation target. The first article discusses the optimal inflation target based on the welfare loss measured by the money demand function, a classic channel highlighted in the literature. The second assesses the relation between the level and uncertainty of future inflation. We investigate this issue with the use of econometric models to estimate the conditional variance of inflation, of inflation expectations reported by professional economic analysts and of break-even inflation rates. The third article presents a more theoretical and structural focus. We present a model in which there is a trade-off for the inflation target and this model is calibrated to obtain estimates of the optimal target for the Brazilian economy. On one hand, the model considers the welfare loss caused by inflation through money demand and, on the other, the benefit from the reduced frequency of periods in which a downward nominal wage restriction binds. Our conclusion is that the analysis presented suggests that, considering the lower macroeconomic uncertainty observed in Brazil in the recent years, there would be reasons for a gradual reduction in the inflation target. However, it also suggests that very low targets should not be set as the additional benefit in reducing the inflation target is relatively small once the inflation target has already been set at a low level.

As vigas compostas pregadas possuem vasta aplicação como material estrutural, desde vigas para instalações residenciais e industriais até longarinas de pontes de pequenos vãos, apresentando como principais vantagens o baixo custo e a facilidade de execução, não exigindo mão-de-obra qualificada. Este trabalho tem como objetivo o estudo teórico e experimental de vigas de madeira com seção composta I formadas por peças de madeira serrada e solidarizadas por pregos. São apresentados os critérios das normas EUROCODE 5, DIN1052 e NBR 7190, bem como a teoria a respeito do assunto. É avaliado o procedimento de cálculo da NBR 7190, em comparação com o EUROCODE 5, sendo realizada verificação experimental dos critérios destas normas, por meio de ensaios de flexão em protótipos de vigas compostas em escala natural. Os resultados obtidos demonstram que o modelo do EUROCODE 5 é o mais indicado para estimar a rigidez efetiva, tensões normais e de cisalhamento como também a força nos conectores / The built-up I beams are widely employed as structural elements, from residential and industrial facilities, to girders for bridges of small span. The fact that they do not demand skilled workmanship, the low cost and easiness of construction are their main advantages. This research aims at the theoretical and experimental analysis of built-up I beams, made of sawn elements nailed jointed. The EUROCODE 5, DIN 1052 and NBR 7190 criteria as well as the basic theory are presented. The design procedure adopted by NBR 7190 is compared to the EUROCODE 5 one. Experimental evaluation of these criteria is made subjecting built-up beam prototype to bending tests. The results should that the EUROCODE criteria is the most recommended for estimate the effective rigidity, normal and shear stresses as well as the load on a fastener

Knitting is a class of techniques for production of textile fabrics by inter-looping yarns withthe use of hooked needles. The new loops are created when the yarns drawn through thepreviously formed loops. An apparatus for two needles with adjustable geometry resemblingthe knitting process in weft knitting machines has been constructed and mounted in anordinary tensile testing machine in order to study stress build-up, fibre damage, needle wearetc. The merits of the knittability test-rig set-up are the possibilities to test the performance ofthe yarns with the geometry of the machine and to simulate and identify some of the problemsthat can occur between needles and yarn in the knitting process. Well-defined mechanicalconditions with the static pre-load weight and the possibilities to identify the location of theevents of damage on the fibres during the testing of the specimens and to do furtherexamination before knitting are some obvious merits. The knittability of some extreme yarns,PET-monofilaments, carbon fibre roving and aramid yarn has been studied with respect tofriction and bending stiffness. Friction and bending characteristics exhibit viscoellasticfeatures. The needles have diameters of the same order of magnitude as the diameters ofmonofilaments for example for use in knitted spacer fabrics and the results of this workillustrate strong influence of the fibre diameter on the knittability. / <p>Program: Magisterutbildning i textilteknologi</p><p>Uppsatsnivå: D</p>

Neste trabalho, provamos um teorema de imersões isométricas em variedades Lorentzianas homogêneas tridimensionais, usando a teoria de G- estruturas. Tais variedades são aquelas consideradas na classificação das 3- variedades Lorentzianas homogêneas de Dumitrescu e Zeghib. Provamos também um teorema de rigidez isométrica para hipersuperfícies em variedades semi-Riemannianas com G-estrutura infinitesimalmente homogêneas. No caso particular em que o ambiente são variedades semi-Riemannianas dadas por produto de uma forma espacial por R ou variedades Riemannianas homogêneas tridimensionais, provamos o mesmo teorema de rigidez isométrica, porém com hipóteses mais fracas. / In this work we prove an isometric embedding theorem in homogeneous Lorentzian manifolds of dimension 3, that were recently classified by Dumitrescu and Zeghib in [11]. We also prove a rigidity result of isometric embeddings of hypersurfaces in semi-Riemannian manifolds endowed with an infinitesimally homogeneous G-structure. In the special case that the semi-Riemannian manifolds are produtcs of the type Q^n_cxR, or Riemannian homogeneous 3-manifolds, the result is proven under wear assumptions.

Neste trabalho, provamos um teorema de imersões isométricas em variedades Lorentzianas homogêneas tridimensionais, usando a teoria de G- estruturas. Tais variedades são aquelas consideradas na classificação das 3- variedades Lorentzianas homogêneas de Dumitrescu e Zeghib. Provamos também um teorema de rigidez isométrica para hipersuperfícies em variedades semi-Riemannianas com G-estrutura infinitesimalmente homogêneas. No caso particular em que o ambiente são variedades semi-Riemannianas dadas por produto de uma forma espacial por R ou variedades Riemannianas homogêneas tridimensionais, provamos o mesmo teorema de rigidez isométrica, porém com hipóteses mais fracas. / In this work we prove an isometric embedding theorem in homogeneous Lorentzian manifolds of dimension 3, that were recently classified by Dumitrescu and Zeghib in [11]. We also prove a rigidity result of isometric embeddings of hypersurfaces in semi-Riemannian manifolds endowed with an infinitesimally homogeneous G-structure. In the special case that the semi-Riemannian manifolds are produtcs of the type Q^n_cxR, or Riemannian homogeneous 3-manifolds, the result is proven under wear assumptions.

O trabalho desenvolvido tem como objetivo avaliar a influência da rigidez estrutural no comportamento dinâmico do veículo baseando-se em manobra de raio constante em condição quase estática e análise de sensibilidade através de simulação numérica computacional. São apresentados dois modelos para avaliar a transferência de carga lateral do veículo quando sujeito à aceleração lateral (manobra de raio constante), um modelo completo de veículo elaborado em ambiente multicorpos tendo a carroceria e o sub-chassi modelados como corpos flexíveis, e outro modelo analítico com a consideração da rigidez torcional (obtida de modelo de elementos finitos) da estrutura. Com o modelo analítico atendendo o nível de correlação necessário para o propósito deste trabalho, discute-se neste ponto as variações na transferência de carga devido à rigidez torcional da estrutura. Em seguida, com o intuito de abranger, além do parâmetro de transferência de carga lateral, quais comportamentos do veículo são afetados pela sua rigidez estrutural, é proposta a utilização do método de engenharia robusta para a identificação das condições externas que geram diferentes resultados de comportamento dinâmico do veículo com a variação da rigidez estrutural. Este estudo permite identificar manobras ou situações nas quais as considerações de flexibilidade estrutural num modelo multicorpos, ou mesmo numa condição física real, são relevantes e podem afetar a segurança, dirigibilidade e o conforto do veículo. / The work aims to evaluate the influence of structural stiffness on the dynamic behavior of the vehicle based on a constant radius maneuver in a quasi-static condition and a sensitivity analysis through computer numerical simulation. Two models were developed to evaluate the lateral load transfer of the vehicle when subjected to lateral acceleration (constant radius maneuver), a complete vehicle built in multibody environment with the body and the sub-chassis modeled as flexible bodies, and an analytical model with consideration of structure torsional stiffness (obtained from finite element model). With the analytical model presenting the required correlation for the purpose of this paper, we discuss, at this point, the lateral load transfer variations due to torcional structural stiffness. Then, in order to cover, in addition to lateral load transfer, how the vehicle behavior is affected by its structural stiffness, the robust engineering method is considered for identifying the external conditions that generate different dynamic behavior results for the variation of structural stiffness. This study allows us to identify maneuvers or situations in which considerations of structural flexibility in multibody model, or even in a real physical condition, are relevant and can affect the safety, ride and handling of the vehicle.

Apesar do esforço despendido pelas comunidades acadêmica e industrial (artigos, patentes e protótipos de laboratório), as Máquinas de Cinemática Paralela - MCPs - ainda apresentam uma participação inexpressiva no mercado de máquinasferramentas e robôs. Uma das razões para este fato são os seus baixos índices de acurácia e repetibilidade, em comparação aos das máquinas de usinagem convencionais. Este trabalho apresenta a avaliação dos mapeamentos de flexibilidade e da 1ª freqüência natural sobre o posicionamento da peça de trabalho e direções preferenciais de usinagem, dentro do espaço de trabalho disponível de uma máquina-ferramenta de cinemática paralela. Atualmente esta análise tem sido realizada em máquinas de cinemática paralela utilizando-se do princípio dos trabalhos virtuais ou parcialmente envolvendo este método e o método dos elementos finitos com a superposição linear dos resultados de ambos. Este trabalho apresenta análise de flexibilidade, utilizando apenas o método dos elementos finitos, aplicada a uma arquitetura paralela do tipo 2PRS+2PUS, com 4 graus de liberdade (duas translações - Y e Z - e duas rotações - \'teta\'x e \'teta\'YG), denominada Tetraglide. Em todas as análises feitas o grau de liberdade \'teta\'YG foi mantido constante, \'teta\'YG = 0°. Desta forma todas as análises ocorreram sobre o plano YZ. A partir dessa análise de flexibilidade são avaliadas as cargas axiais nas barras, que unem os atuadores à plataforma móvel ao longo do espaço de trabalho, determinando-se onde ocorre flambagem. Após isto, ainda com o método dos elementos finitos, obtém-se a 1ª freqüência natural ao longo de cada espaço de trabalho com orientação constante, uma vez que o conhecimento desta freqüência é fator importante na avaliação do comportamento estrutural dinâmico de máquinas-ferramentas. Após estas análises, analisam-se parâmetros estruturais em análises de sensibilidade visando maximizar a menor 1ª freqüência natural observada em cada espaço de trabalho com orientação constante. / In spite of the effort spent by the academic and industrial communities (goods, patents and laboratory prototypes), the Parallel Kinematics Machines - PKMs - they still present an inexpressive participation in the market of machine-tools and robots. One of the reasons for this fact is their low indexes of accuracy and precision, in comparison with the machines of conventional milling. This work presents the evaluation of the compliance mapping (kinetostatic analysis) and natural frequency about the positioning of the work piece and milling preferential directions, inside the available workspace of a parallel kinematics machine tool. At present this analysis has been accomplished in parallel kinematics machine using the virtual work principle or partially involving this method and the finite element method, with the overlap of the results of both. This work presents a compliance analysis just using the finite element method in parallel kinematics machine of type 2PRS+2PUS with 4 degrees of freedom (two moves - Y and Z - and two rotations - \'teta\'x e \'teta\'YG), denominated Tetraglide. In all of the done analyses the degree of freedom \'teta\'YG was maintained constant, \'teta\'YG = 0°. This way all of the analyses occurred on the plan YZ. Starting from the compliance analysis the axial loads are evaluated in the bars, which connect the actuators to the movable platform along the workspace, determining where the buckling occurs. After this, with the finite element method, 1st natural frequency is obtained along each constant-orientation workspace, once the knowledge of this frequency is important factor in the evaluation of the dynamic structural behavior of machine-tools. After these analyses, structural parameters are analyzed in sensibility analyses seeking to maximize to smallest 1st natural frequency observed in each constant-orientation workspace.

This study focuses on developing a new approach to seated work positions. It was conducted on 67 office workers who use the Video Display Terminal (VDT) as a major function of their working day. Muscle tension was measured by surface electromyography when subjects were asked to adopt four selected working postures. Pain was measured before and after ergonomic intervention on the Nordic scale, which was modified for this study. Performance was measured on timed typing tests. A psychosocial questionnaire was used to determine influences of job demands, and a diagnostic assessment was performed to determine symptoms and pre-existing musculoskeletal conditions. Furniture was used to place subjects in desired positions during the clinical testing sessions and the extended intervention period. The chair seat pan was adjusted to a forward tilt to promote a lordotic curve of the low back, resulting in an erect upper body and upright head position. The desk and keyboard were adjusted to the proper height for each worker. A neutral wrist position was obtained by lowering and tilting the keyboard away from the user. Results revealed muscle tension scores in the upper trapezius and forearm extensors were significantly reduced when the workers were placed with the head in a midline position, with forward-tilting seating and with use of a negative sloping keyboard tray. Subjects reported low pain scores at pretest so no changes were noted after intervention. Loss of control over job elements, lack of job satisfaction, and fear of job loss were related to an increase in muscle tension. Only fear of job loss correlated to increased pain levels. There was no relationship between any of the job demand factors and performance.

<p><strong>Title:</strong> Yes, but…<em> - How changes in banks in Västerbotten are linked to the current financial crisis, but are still normal organizational development</em></p><p><strong>Background: </strong>In the beginning of the 90’s, there was a financial crisis in Sweden which hit Swedish banks hard. The Swedish bank Gota banken went bankrupt and Nordbanken was taken over by the government, in large part because of their apathetic reactions to the situation they were so surprised to find themselves in. Today, almost 20 years later, the banks of Sweden find themselves in a new crisis. Because of the important position banks have in society, it is extremely important that they remain stable and have the capacity to ride out a crisis situation comfortably. As the banks did not show any crisis management strategy or skills in the 1992 crisis, it is relevant to explore if the previous experience has given Swedish banks the ability to handle a crisis situation in an efficient way.</p><p><strong>Purpose:</strong> The purpose of this study is to apply organizational development theory, crisis management theory and adversity reaction theory to the primary data collected from the interviews with the banks and through that analyze if Swedish banks are acting to prevent the financial crisis from affecting them badly.</p><p><strong>Method:</strong> The study has a hermeneutical approach and was carried out by interviewing managers from the five major banks in Västerbotten. The primary data collected has been analyzed to get an understanding of the current development in the banks and its possible link to the financial crisis.</p><p><strong>Conclusion: </strong>We found that banks are constantly changing in order to keep up with their competitors, changes in technology, society and the increasing demands from customers. The current events and changes in the banks are undoubtedly linked to the financial crisis, it has accelerated change, it has slowed down ongoing processes and it has facilitated harder decisions and less popular changes. But the crisis has not caused drastic changes in the organizations or their way of doing business. In fact, it can be said that the changes due to the financial crisis is normal organizational development, as the banks have responded to it in much the same fashion as they do to all changes in the external environment.</p><p><strong>Key words:</strong> crisis management, organizational development, threat rigidity, prospect theory, financial crisis</p>

Les microtubules sont des composants structuraux de cellules et gouvernent des fonctions cellulaires essentielles telles que les mitoses et le transport des vésicules. Ils sont composés de deux sous-unités non identiques (tubulines α et β), formant un dimère, et sont arrangés de sorte à former une structure tubulaire de 20nm de diamètre. Généralement, ils sont constitués de 13 ou 14 protofilaments arrangés en spirale. Les liaisons longitudinales entre dimères sont plus rigides et fortes que les liaisons latérales. Aussi, les microtubules sont des structures fortement anisotropes. Dans ces travaux de thèse, nous avons pour but de définir l'ensemble des coefficients élastique qui permet de reproduire leur comportement atomistique ainsi que de rendre compte de leur réponse mécanique selon des chemins de chargement variés. En négligeant la discontinuité hélicoïdale souvent observée, un microtubule est représenté par une structure triangulaire de dimères à partir desquels un volume élémentaire représentatif est défini. Un potentiel harmonique est utilisé pour décrire les interactions entre dimères voisins. A partir de l'estimation des constantes élastiques et de l'utilisation de la méthode proposée par Arslan et Boyce (2006) -alors pour analyser le comportement mécanique d'un réseau triangulaire de spectrines composant les membranes des globules rouges-, un modèle continu de comportement mécanique est présenté pour reproduire le comportement des parois des microtubules. Un modèle numérique éléments finis est ensuite créé pour modéliser le comportement d'un microtubule dans sa globalité. Des éléments coques sont utilisés pour reproduire les fines parois des microtubules. Les propriétés du modèle éléments finis sont ajustées à partir des résultats du modèle présenté ainsi qu'aux données expérimentales provenant de la littérature. La rigidité de flexion calculée au cours de simulation des tests de flexion 3 points est en accord avec les valeurs de la littérature. Ces tests révèlent les mécanismes de déformation en fonction de la longueur utile du tube utilisé: Flexion et cisaillement locaux de la paroi gouvernent la déformation pour de "petits" tubes. Pour des longueurs "moyennes" le cisaillement et la flexion du tube prédominent. Enfin, dans le cas de tubes "longs", la déformation est uniquement associée aux effets de flexion. Ces résultats témoignent de l'influence de l'anisotropie du tube sur la réponse observée selon différents mode de sollicitation. Ils permettent également d'expliquer l'évolution de la rigidité de flexion avec la longueur utile du tube, comme reportée dans la littérature. Enfin, des micrographes montrent la propension des extrémités des microtubules à diverger radialement -"à boucler"-. Une telle géométrie est causée par des instabilités propres aux microtubules et implique un état précontraint. Un «modèle d'interactions» est alors proposé de manière à considérer un état précontraint et ainsi reproduire la cinétique des instabilités des microtubules au cours de la polymérisation/dépolymérisation.