[pt] Esta tese incorpora três ensaios acerca de fixação de preços com informação rígida e dispersa (IRD). A estrutura básica mistura o modelo de rigidez de informação proposto em Mankiw and Reis (2002) com o modelo de informação dispersa descrito em Morris and Shin (2002). No capítulo 1, obtémse o equilíbrio do jogo assumindo que as firmas se deparam com complementaridade estratégica em suas decisões de preço. Neste contexto, as firmas tomam suas decisões de preço utilizando a informação disponível para prever os preços das outras firmas e a demanda agregada nominal, o fundamento da nossa economia. Estuda-se a importância de cada parâmetro do modelo em vários contextos. No capítulo 2, estende-se o modelo IRD para analisar como a comunicação do banco central interfere na fixação de preços. Como informação pública ajuda às firmas a prever o estado atual da economia e as ações uma das outras, ela ajuda na sincronia dos preços. Este efeito faz a variância da inflação aumentar com a precisão da informação pública. Além disso, o bem-estar da sociedade é afetado pelo fato de que as firmas tomam suas decisões de preços sem considerar como isto influenciará a decisão das outras firmas. No capítulo 3, utilize-se o modelo com IRD para analisar como a fixação de preços muda quando a taxa de juros, além de ser um instrumento de política capaz de influenciar a dinâmica do fundamento, também é vista como um sinal público que informa a visão da autoridade monetária acerca do estado atual da economia. Sob este arcabouço, firmas utilizam a taxa de juros para embasar suas decisões de preços. Obtêm-se também os parâmetros ótimos do instrumento de política (para três medidas diferentes de bem-estar), considerando-se que o banco central sabe que as firmas extraem informação de suas ações. / [en] This thesis encompasses three essays on price setting under stickydispersed information (SDI). The baseline framework mixes the sticky information model of Mankiw and Reis (2002) with dispersed information models like Morris and Shin (2002) and Angeletos and Pavan (2007). In Chapter 1, we derive the equilibrium of the game assuming that firms face strategic complementarity on their pricing decisions. In this context, firms take their pricing decisions using information to build expectations on the prices set by other firms and on the current state of aggregate nominal demand - the fundamental of the economy. In Chapter 2, we extend the SDI model to analyze how central bank communication affects price setting. As public information help firms to infer the current state of the economy and one another s prices, it improves price synchronization. This effect makes inflation variance increase with the precision of the public information. Social welfare is affected by the fact that firms do not internalize how their prices change other firms pricing decisions. In Chapter 3, we use a SDI model to analyze how price setting changes when the interest rate is a policy instrument that not only partially drives the fundamental dynamics, but also it is understood as a public signal that informs the view of the monetary authority on the current state of the economy. Under this framework, firms use interest rate to support their pricing decisions, influencing inflation dynamics. We also obtain the optimal parameters of the policy instrument (regarding three different efficiency criteria), considering that the central bank knows that firms take information from its actions.

[pt] Esta tese consiste em três ensaios teóricos sobre tópicos relativos à fixação de preços sob informação incompleta. Duas características são comuns aos três ensaios: (i) informação heterogênea sobre condições econômicas agregadas e (ii) um grau moderado de complementaridade estratégica nas decisões de preços. No Capítulo 1, estuda-se a transmissão de informação em um modelo com estágios de produção e informação dispersa. Firmas observam sinais sobre os preços dos insumos que endogenizam a precisão da informação que é pública dentro de um estágio, mas não entre os estágios. Em contraste com o caso com sinal público exógeno, as firmas decidem otimamente atribuir menos peso a informação pública ao longo da cadeia. Uma implicação é que a precisão da informação, que ficaria inalterada com sinais públicos exógenos, decresce ao longo da cadeia com sinais semi-públicos endógenos. No Capítulo 2, examinase o processo de repasse cambial (ERPT) para os preços em um modelo de informação dispersa onde a taxa de câmbio nominal fornece informação sobre os fundamentos de forma imperfeita. Quando a informação é completa, ERPT também é completa. Sob informação dispersa, o modelo apresenta três propriedades consistentes com os fatos estilizados de ERPT. Primeiro, ERPT está entre 0 e 1. Segundo, ERPT é normalmente maior para produtos importados do que para produtos ao consumidor. Terceiro, ERPT é maior para economias emergente e diminuiu ao longo do tempo tanto para economias industrializadas quanto emergentes. Finalmente, no Capítulo 3, estuda-se a interação entre rigidez e dispersão de informação através da introdução de sinais com ruído em um modelo padrão de curva de Phillips com rigidez de informação. O modelo de informação rígida e dispersa (SDI) resultante apresenta como casos particulares os modelos de informação completa, dispersa e rígida. Estuda-se a relevância individual dos principais parâmetros do modelo em várias direções. Primeiro, analisa-se o impacto dos valores corrente e passados da inflação com informação completa na inflação corrente. Segundo, consideram-se as respostas da inflação a choques monetários. Finalmente, compara-se a variância da inflação SDI com as variâncias da inflação quando a informação é completa, dispersa ou rígida. / [en] This thesis consists of three theoretical essays on topics in price setting under imperfect information. Unifying the essays are two features: (i) heterogeneous information about aggregate economic conditions and (ii) a moderate degree of complementarity in pricing decisions. In Chapter 1, the transmission of information is studied in a model with a vertical input-output structure and dispersed information. Firms observe input prices with noise that endogenize the precision of information that is public within a stage but not across stages. In contrast to the case with an exogenous and overall public signal, firms find it optimal to rely less on public information along the chain. A direct implication is that, while information precision remains unchanged with exogenous public signals, it decreases along the chain when semi-public signals are endogenous. In Chapter 2, exchange-rate pass-through (ERPT) to prices is examined in a model of dispersed information where the nominal exchange rate imperfectly conveys information about the underlying fundamentals. If the information is complete, ERPT is also complete. Under dispersed information, the model displays three properties that are consistent with the stylized facts of passthrough. First, ERPT lies between 0 and 1. Second, ERPT is usually higher for imported goods prices than for consumer prices. Third, ERPT is higher for emerging market countries and declines over time for both industrial and emerging market economies. Finally, in Chapter 3, the interaction between information stickiness and dispersion is studied by introducing noisy signals in an otherwise standard sticky-information Phillips curve. The model of stickydispersed information (SDI) nests as special cases the complete information, the dispersed information and the sticky information models. The individual relevance of each of the main parameters of the model is studied in several directions. First, the impact of current and past complete-information inflation rates on current inflation is analyzed. Second, the inflation response to monetary shocks is considered. Finally, the variance of SDI inflation is compared with the variances of complete, dispersed, or sticky-information inflations.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-21T17:33:46Z No. of bitstreams: 1 viniciussobreiralacerda.pdf: 3531215 bytes, checksum: 422eca8f67f53625eceb5e46317386f9 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-09-26T20:27:18Z (GMT) No. of bitstreams: 1 viniciussobreiralacerda.pdf: 3531215 bytes, checksum: 422eca8f67f53625eceb5e46317386f9 (MD5) / Made available in DSpace on 2016-09-26T20:27:18Z (GMT). No. of bitstreams: 1 viniciussobreiralacerda.pdf: 3531215 bytes, checksum: 422eca8f67f53625eceb5e46317386f9 (MD5) Previous issue date: 2010-08-30 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Este trabalho aborda a análise, a modelagem matemática, o projeto e a simulação computacional de um sistema monofásico de aproveitamento fotovoltaico (PV) nãoisolado conectado à rede elétrica, em que se pretende sintetizar uma corrente de baixa distorção harmônica mantendo-se o ponto de máxima potência dos painéis. São avaliadas duas estruturas conversoras equivalentes, uma com dois estágios de processamento de energia e outra com apenas um estágio. Ambas as estruturas desempenham o papel de converter a energia CC dos painéis fotovoltaicos em energia CA, sob a forma de corrente elétrica de baixa distorção injetada na rede. Uma revisão sucinta dos modelos matemáticos de representação do comportamento termo-fotoelétrico do painel fotovoltaico (ou conjunto de painéis) é realizada, resultando na adaptação de uma das alternativas na forma de modelo numérico adaptado à ferramenta computacional PSIM. Algumas alternativas monofásicas de conversão CC-CA são elencadas neste trabalho, com destaque para o número de estágios de conversores, característica de isolamento e qualidade da energia injetada. Como base nesta análise, propõe-se um sistema composto por um conversor CCCC tipo buck operando em modo de condução contínua em alta frequência, em cascata com um inversor fonte de corrente (CSI) acionado na frequência da rede, para realização do aproveitamento fotovoltaico desejado. Amparado por ferramentas de integração de estágios de conversores, percebe-se que o conjunto de dois estágios pode ser arranjado em uma única etapa conversora baseada no inversor fonte de tensão (VSI). Ambas as propostas são modeladas, projetadas e simuladas no PSIM. A descrição teórico-matemática da planta PV, incluindo suas malhas de controle, é realizada. Com propósito de validação das concepções teóricas, tais sistemas são simulados, inicialmente, empregando-se elementos idealizadores e, em segundo momento, adotando-se um arranjo que inclui alguns componentes parasitas, sensores em escala real e o subcircuito do integrado UC3854. Os resultados numéricos, realizados para variações da irradiação solar e perturbações na tensão da rede, confirmam que o conceito proposto é factível, resultando em uma alternativa simples, compacta e possivelmente de baixo custo. / This work deals with the analysis, mathematical modeling, design and computer simulation of a single phase non-isolated photovoltaic (PV) system, which is connected to the electrical grid and is controlled to synthesize a low harmonic current while keeps the maximum power point of the panels. Two structures are evaluated, one with two stages of processing power and another with a single stage. Both structures converts DC power from solar panels into AC power, in the form of a low distortion electrical current to be injected into the grid. A brief review of PV panel mathematical models is performed, resulting in the adaptation of one alternative in the form of a numerical model oriented to the computational tool PSIM. Moreover, some alternatives to single-phase DC-AC conversion are listed in this work, highlighting the number of stages of inverters, isolation characteristic and quality of the power injected. To support this analysis, a two-stage system has been firstly studied, which is constituted of a buck converter operating in continuous conduction mode at high frequency, cascaded with a current source inverter (CSI) which works in the frequency of the grid. Using the integration of stages theory, the two stage system can be arranged into a single stage converter based on a voltage source inverter (VSI). Both proposals are modeled, designed and simulated in PSIM program. The theoretical and mathematical description of the PV plant, including its control loops, is presented. With the purpose of validation of the theoretical concepts, such systems are simulated, initially, using idealized elements, and then, adopting an arrangement that includes some parasitic components, sensors and full-scale integrated subcircuit of UC3854. The numerical results carried out for changes in solar radiation and mains voltage sags/swells, confirm that the proposed concept is feasible, resulting in a simple, compact and potentially low cost.

Résumé confidentiel / Résumé confidentiel

Ces travaux de thèse ont pour but d'étudier l'état de dispersion de particules colloïdales dans des cristaux liquides nématiques lyotropes. Ces solvants organisés sont constitués de micelles nanométriques anisotropes. Dans un premier temps, nous montrons qu'il est possible de réaliser des suspensions cinétiquement stables en jouant notamment sur la forme des inclusions micrométriques. Un modèle, développé dans le cadre de cette étude, permet de rendre compte de nos observations. Dans un second temps, nous nous intéressons à l'influence de la diminution de taille de particules sur l'état de dispersion du système. A l'échelle nanométrique, le mouvement brownien, anisotrope dans ce type de milieu, semble gouverner les phénomènes observés. / The present PhD work aims at studying the dispersion state of colloidal particles in lyotropic nematic liquid crystals. These organized solvents are made of anisotropic nanometric micelles. Firstly, we show that kinetically stable suspensions may be achieved by playing on the shape of micrometric inclusions in particular. A model, which is developed for this study, can catch well our observations. Secondly, we are interested in the influence of a diminution of the particle size on the dispersion state of the system. At the nanometric scale, the Brownian motion, which is anisotropic in such media, seems to govern the observed phenomena.

Modern society frequently fails to achieve the goal of improved rationality and this is largely because the conditions for ideal speech do not prevail. We do not always permit everyone an equal opportunity to explain their point of view and the force of the best argument does not always prevail. Communication becomes more difficult when people cannot meet face to face, but it is also hindered when people cannot contact one another easily. There is, therefore, a trade-off between using computer-mediated media for communication and speaking to each other in person. Although meaning can never be shared to the extent that two individuals have precisely the same interpretation of a concept, and society is not based on individuals uniformly embracing identical views or values, in every day life consensus needs to be reached and truth claims, normative validity claims and aesthetic validity claims must be made, debated and eventually accepted or refuted. Collaboration on substantial tasks that require the development of concepts and reconstruction of meaning depends on effective communication. In the distributed social structures which have developed as a result of globalisation it is important that dispersed teams are able to work together. This includes collaborative learning in distance education. In the action research undertaken first year Informatics students could choose between doing team work face-to-face, or as dispersed teams communicating via e-mail or WebCT. The discussions were recorded and were analysed to identify the different types of communicative action engaged in. This was done to understand how this group collaborate so that success factors could be identified and proposals be made regarding education in the use of e-mail. It was found that the virtual (dispersed) teams studied did not succeed in collaborating. Communication ability is defined in this thesis as the skill that compensates for the inherent leanness of the medium used. A number of depictions of factors contributing to successful asynchronous collaboration are provided. Different classes of information and time, trust and communication ability assist in constructing meaning when text is communicated electronically. This led to suggestions regarding improving the communications ability of individuals. / Dissertation (PhD (Information Technology))--University of Pretoria, 2003. / Informatics / unrestricted

This master’s thesis studies the influence of dispersed reinforcement on the behaviour of cement composites at thermal loading. In the theoretical part of the research was performed knowledge of the behaviour of concrete at high temperatures. The paper describes the on-going happening in the individual components of concrete and benefits of using dispersed reinforcement. In the practical part were designed concrete mixtures with different types and quantities of fibers. The object of the research was to determine how different types and amounts of fibers affect the physical - mechanical properties of concrete and their suitability for use in high temperatures.

Bakgrund: Användningen av särlokaliserade team i organisationer har ökat markant de senaste årtiondena. När ett team arbetar särlokaliserat med hjälp av digitala kommunikationsverktyg ändras förutsättningarna för teamets kommunikation. Den tidigare forskningen om särlokaliserade team har främst behandlat internationella team med stora geografiska avstånd samt team till stor del bestående av experter, men till följd av pandemin covid-19 har särlokaliserat arbete blivit aktuellt för fler typer av team. Det finns därför anledning till att bedriva forskning om hur särlokaliseringen påverkar kommunikationen i dessa team.  Syfte: Syftet med studien är att ge ökad förståelse för hur särlokalisering påverkar kommunikationen i team där teammedlemmarna är vana vid att arbeta samlokaliserat, genom att identifiera och förklara konsekvenser som särlokaliseringen får för teams kommunikation.  Metod: Denna studie är en kvalitativ flerfallsstudie med en abduktiv forskningsansats och ett realistiskt perspektiv. Studiens empiri har samlats in genom semistrukturerade intervjuer med elva teammedlemmar tillhörande tre olika team bestående av studenter.  Slutsats: Studiens resultat visar att särlokaliserat arbete med digitala kommunikationsverktyg får flertalet konsekvenser för kommunikationen i team. Särlokaliseringen bidrar med vissa konsekvenser medan de digitala kommunikationsverktygen bidrar med andra. I denna studie har 13 konsekvenser identifierats inom de kommunikativa aspekterna bekräftelse, konversationens flyt, feedback, gemensam förståelse och kreativitet. Studien fann även att de konsekvenser som identifierats har ett nära samband på så sätt att flertalet påverkar varandra. Varför de intervjuade teamen påverkades på detta sätt kan till viss del förklaras av deras ovana att arbeta särlokaliserat över digitala kommunikationsverktyg och omedvetenhet om vad det innebär för ett teams kommunikation. / Background: The use of dispersed teams in organisations has grown rapidly in the latest decades. A dispersed team that communicates with digital communication tools does not have the same prerequisites for communicating as a co-located team have. The previous research made about dispersed teams has mainly focused on international teams with large geographical distances and teams that for the most part consist of experts. Due to the pandemic covid-19, working in dispersed teams has become necessary for other types of teams. It is thereby motivated to conduct research about how the communication is affected in other types of dispersed teams.  Purpose: The purpose of this study is to increase the understanding of how team communication is affected by the dispersion in teams where the team members are used to working co-located, by identifying and explaining consequences the dispersion of the team has on team communication.  Method: This study is a qualitative multi-case study with an abductive approach and a realistic perspective. The empirical data has been collected through semi-structured interviews with eleven team members belonging to three different teams of students.  Conclusion: The result of the study shows that dispersed teams using digital communication tools face several consequences regarding their communication. The fact that the team is not co-located leads to certain consequences and the use of digital communication tools leads to others. This study has identified 13 consequences within the communicative aspects: confirmation, the flow of the conversation, feedback, shared understanding and creativity. The study also shows that the consequences identified are closely connected in such a way that many of them affect each other. Why the interviewed teams were affected in this way can to some extent be explained by their inexperience in working with digital communication tools and unawareness of what it means for their communication.

No description available.

This dissertation investigates the effects of autocorrelation on the performances of various sampling plans for control charts in detecting special causes that may produce sustained or transient shifts in the process mean and/or variance. Observations from the process are modeled as a first-order autoregressive process plus a random error. Combinations of two Shewhart control charts and combinations of two exponentially weighted moving average (EWMA) control charts based on both the original observations and on the process residuals are considered. Three types of sampling plans are investigated: samples of n = 1, samples of n > 1 observations taken together at one sampling point, or samples of n > 1 observations taken at different times. In comparing these sampling plans it is assumed that the sampling rate in terms of the number of observations per unit time is fixed, so taking samples of n = 1 allows more frequent plotting. The best overall performance of sampling plans for control charts in detecting both sustained and transient shifts in the process is obtained by taking samples of n = 1 and using an EWMA chart combination with a observations chart for mean and a residuals chart for variance. The Shewhart chart combination with the best overall performance, though inferior to the EWMA chart combination, is based on samples of n > 1 taken at different times and with a observations chart for mean and a residuals chart for variance. / Ph. D.