Na tentativa de contornar os problemas ainda existentes para a detecção e identificação de erros grosseiros (EGs) no processo de estimação de estado em sistemas elétricos de potência (EESEP), realiza-se, neste trabalho, uma análise da formulação dos estimadores aplicados a sistemas elétricos de potência, em especial, o de mínimos quadrados ponderados, tendo em vista evidenciar as limitações dos mesmos para o tratamento de EGs. Em razão da dificuldade de detectar EGs em medidas pontos de alavancamento, foram também analisadas as metodologias desenvolvidas para identificação de medidas pontos de alavancamento. Através da formulação do processo de EESEP como um problema de álgebra linear, demonstra-se o porquê da impossibilidade de detectar EGs em determinadas medidas redundantes, sendo proposto, na seqüência, um método para identificação de medidas pontos de alavancamento. Para reduzir os efeitos maléficos dessas medidas no processo de EESEP verifica-se a possibilidade de aplicar outras técnicas estatísticas para o processamento de EGs, bem como técnicas para obtenção de uma matriz de ponderação adequada. / To overcome the problems still existent for gross errors (GEs) detection and identification in the process of power system state estimation (PSSE), the formulations of the estimators applied to power systems are analyzed, specially, the formulation of the weighted squares estimator. These analyses were performed to show the limitations of these estimators for GEs processing. As leverage points (LP) represent a problem for GEs processing, methodologies for LP identification were also verified. By means of the linear formulation of the PSSE process, the reason for the impossibility of GEs detection in some redundant measurements is shown and a method for LP identification is proposed. To minimize the bad effects of the LP to the PSSE process, the possibility of applying other statistic techniques for GEs processing, as well as techniques to estimate an weighting matrix are also analyzed.

Στην παρούσα εργασία παρουσιάζονται οι οικονομετρικές σχέσεις του νόμου του Okun, που συνδέουν τις μεταβολές στο προϊόν της οικονομίας (ΑΕΠ) με τις μεταβολές στο επίπεδο ανεργίας. Διάφορες θεωρητικές προσεγγίσεις του νόμου, εμπειρικές μελέτες προηγούμενων οικονομολόγων σχετικά με το θέμα και μία εμπειρική εφαρμογή για δεδομένα που αφορούν την Ελλάδα, θα παρουσιαστούν και θα αναλυθούν με σκοπό να διαπιστώσουμε την αποτελεσματικότητα του νόμου διαχρονικά, και ποιες αναβαθμίσεις των μορφών του, οδηγούν προς σε αυτήν την κατεύθυνση. / In this work we present the econometric relationships of Okun’s law that connect the changes in the product of economy (GDP) with those of the level of unemployment. Different theoretical approaches of the law, empirical studies of other economists, relative to the subject and one empirical application of data that concern Greece, will be described and analysed in purpose of examine, the effectiveness of Okun’s law through time and which upgrades of its versions, lead to that direction.

This paper examines the impact of the recent global financial crisis on economic growth in developing economies and South Africa in particular. It explores whether the events experienced by developing countries conform to what would be anticipated from economic theory. This is done by firstly comparing country growth forecasts for 2012 captured in 2008 at the beginning of the crisis to actual 2012 GDP growth data. Secondly, panel data analysis is used to investigate three important transmission channels, namely those of Trade, Capital Flows and Exchange Rates for 25 developing economies. The results suggest that economic forecasters in 2008 on average overestimated GDP growth for 2012 by -21.6 percent (excluding Venezuela). The only important transmission channel identified using Trend analysis to explain this negative impact on growth was capital flows. However when using Panel regression analysis all three channels were found to explain the economic impact of the crisis on GDP growth for developing countries, conforming to economic theory. It was discovered that, contrary to what was initially expected, portfolio inflows actually increased for most developing countries during the crisis. This possibly can be explained by the impact of quantitative easing in the USA. South Africa was found to have been negatively impacted by the global financial crisis, but to a lesser extent when compared to most other developing countries. The findings are important for global investors looking for new investment opportunities. The extent to which individual economies are “decoupled” from developed economies’ performance provides possible opportunities for diversifying risk through a geographic spread of investor portfolios.

Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-09-12T12:27:38Z No. of bitstreams: 1 arquivototal.pdf: 987629 bytes, checksum: 073f4a58e014f0b46588edf144d4a42b (MD5) / Made available in DSpace on 2017-09-12T12:27:38Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 987629 bytes, checksum: 073f4a58e014f0b46588edf144d4a42b (MD5) Previous issue date: 2016-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this dissertation we work with the Horava-Lifshitz-like Gross-Neveu model in (2+1) dimensions in the Large N expansion. Firstly we make an article revision [6] where it is shown that the Gross-Neveu Model in the 1/N expansion presents a dynamic mass generation by means of the introduction of an auxiliary field, which results in the dynamical parity broken. We calculate the gap equation where we will see the generated mass dependence with the coupling constant. After that, we will put a gauge field to the model and study the polarization tensor which will generate an induced Chern-Simons term in the Effective Lagrangian. As a novelty, we work with the Gross-Neveu Model in the context of Horava-Lifshitz, where anisotropic scaling is done, thus breaking the Lorentz invariance. We introduce an auxiliary field and we study the cases which the value of the critical dynamic exponent Z is even and when it is odd. In the case where z is even, there is no dynamic mass generation so the parity symmetry is conserved and we will not have the term induced of Chern-Simons either. In the case where z is odd, we will have the dynamic mass generation and the dynamic parity symmetry will occur. Finally we couple a gauge field in the model and find the Chern-Simons term, which clearly shows the anisotropy of space and time for values of z> 1 / Nesta dissertacao trabalhamos corn o modelo de Gross-Neveu ern (2+1) dimensoes na expansao 1/N no contexto de Horava-Lifshitz. Primeiro, faremos uma revisao do artigo [6], onde se mostra que o Modelo de Gross-Neveu na expansao 1/N apresenta uma geracao dinamica de massa mediante a introducao de urn campo auxiliar, o que traz como consequencia a quebra dinamica da simetria de paridade. Calculamos a equacao de gap, onde veremos a dependencia da massa gerada corn a constante de acoplamento. ApOs isso, acoplaremos urn campo de gauge ao modelo, estudamos o tensor de polarizacao, o qual vai gerar urn termo induzido de tipo Chern-Simons na lagrangiana efetiva. Como novidade, trabalhamos corn o Modelo de Gross-Neveu no contexto de Horava-Lifshitz, onde se faz urn escalonamento anisotrOpico, quebrando, assim, a invariancia de Lorentz. Introduzimos urn campo auxiliar e estudamos os casos ern que o valor do exponente dinamico critico z é par quando é Impar. No caso ern que z é par, nao ha geracao dinamica de massa pelo que a simetria de paridade é conservada e tambern nao teremos o termo induzido de Chern-Simons. No caso ern que z é impar, vamos ter a geracao dinamica de massa vai ocorrer a quebra dinamica de simetria de paridade. Finalmente, acoplamos urn campo de gauge no modelo e encontramos o termo tipo Chern-Simons, o qual mostra claramente a anisotropia do espaco tempo para valores de z > 1.

Studies indicate that the primary and secondary sectors have registered declines over the years while the tertiary sector tends to gain relative importance in the economy. The relative reduction of these activities throughout the development process of the most advanced economies boosted discussions on the Dutch disease, deindustrialization and the reprimarization, grounded in studies by Winjnberg (1984), Torkik (2001), Oreiro and Feijó (2010), Marquetti (2002) Rowthorn and Ramaswamy (1999), among others. When the agribusiness increased exportation and contributed to the increase in national reserves, it represented one of the sectors that had generated employment in the last decade (Almeida et al., 2009). The coffee as a commodity gains more status on the world market and generates employment in agribusiness. Brazil is the third largest exporter and the first in production. This study aims to analyze the behavior of the wealth generated and distributed by Arabica coffee culture in terms of gross revenue, the main producing areas of Brazil (Franca-SP; Guaxupé, Luís Eduardo Magalhães-BA, Patrocínio, Manhuaçu and São Sebastião do Paraíso- MG; Londrina-PN; Venda Nova dos Imigrantes-ES) between 2001 and 2013, through a quantitative research, descriptive approach and a source of bibliographic data and documents. The technical analysis of variance (ANOVA) and the panel data were used to achieve the results. The first technique was used to investigate the distribution of gross revenue in Arabica coffee culture and its evolution over the period studied. The second technique was used to analyze the determinants of gross revenues which were observed during the analysis of these various Brazilian regions. The results showed that the gross revenue of Luís Eduardo Magalhães was statistically significant and greater than Franca, Londrina, Manhuaçu and Guaxupé, and in terms of changes in gross revenue, the regions that had grown were Patrocínio, Guaxupé, Londrina and Venda Nova dos Imigrantes. Regarding the variable farm work costs, production factor and income factor, these were positively significant, indicating that they are relevant in determining the gross revenue of Arabica coffee culture. / Estudos indicam que os setores primários e secundários têm registrado quedas ao longo dos anos, enquanto que o setor terciário tende a ganhar um peso relativo na economia. Essa redução relativa dessas atividades, ao longo do processo de desenvolvimento das economias mais avançadas, alavancou discussões sobre a doença holandesa, a desindustrialização e a reprimarização, alicerçadas nos estudos de Winjnberg (1984), Torkik (2001), Oreiro e Feijó (2010), Marquetti (2002), Rowthorn e Ramaswamy (1999), entre outros. Ainda assim, o agronegócio, ao elevar as exportações e contribuir com o aumento das reservas nacionais, representou um dos setores que mais geraram emprego na última década (ALMEIDA et al., 2009). O café, enquanto commodity, ganha cada dia mais status no mercado mundial e gera mais empregos no agronegócio. O Brasil é o terceiro maior exportador e o primeiro em produção deste produto. O objetivo deste estudo, através de uma pesquisa quantitativa, de abordagem descritiva e fonte de dados bibliográficos e documental, é estudar o comportamento da riqueza gerada e distribuída pela cultura do café arábica, em termos de receita bruta, nas principais regiões produtoras do Brasil (Franca-SP; Guaxupé, Luís Eduardo Magalhães-BA, Patrocínio, Manhuaçu e São Sebastião do Paraíso-MG; Londrina-PN; Venda Nova dos Imigrantes-ES), entre os períodos de 2001 e 2013. Para atingir os resultados, foram utilizadas as técnicas de análise de variância (ANOVA) e dados em painel. A primeira técnica foi utilizada para investigar a distribuição da receita bruta na cultura de café arábica e sua evolução ao longo do período estudado. A segunda técnica foi utilizada para analisar os determinantes da receita bruta observada ao longo das diversas regiões brasileiras estudadas. Os resultados apontaram que, a receita bruta de Luís Eduardo Magalhães foi estatisticamente significante e maior que Franca, Londrina, Manhuaçu e Guaxupé, e em termos de evolução de receita bruta as regiões que mais apresentaram crescimento foram Patrocínio, Guaxupé, Londrina e Venda Nova dos Imigrantes. Em relação às variáveis custos da lavoura, fator de produção e fator rendimento, estas foram positivamente significantes, indicando que estas são relevantes na determinação da receita bruta da cultura do café arábica. / Mestre em Administração

The main idea of this diploma thesis is to analyse benefits, which can be provided by employers to their employees with regard to the impact on the personal income tax base and corporate income tax base. The analysed employee benefits include tax and deduction benefits, whether they can be regarded as tax deductible expenses and whether they are included in the taxable income of an employee. The benefits provided in DELTA a. s. based in Kardašova Řečice were analysed. Their extent and impact on the tax base were examined in this company. The thesis also examines, whether it is appropriate to adjust the benefit system or not.

Na tentativa de contornar os problemas ainda existentes para a detecção e identificação de erros grosseiros (EGs) no processo de estimação de estado em sistemas elétricos de potência (EESEP), realiza-se, neste trabalho, uma análise da formulação dos estimadores aplicados a sistemas elétricos de potência, em especial, o de mínimos quadrados ponderados, tendo em vista evidenciar as limitações dos mesmos para o tratamento de EGs. Em razão da dificuldade de detectar EGs em medidas pontos de alavancamento, foram também analisadas as metodologias desenvolvidas para identificação de medidas pontos de alavancamento. Através da formulação do processo de EESEP como um problema de álgebra linear, demonstra-se o porquê da impossibilidade de detectar EGs em determinadas medidas redundantes, sendo proposto, na seqüência, um método para identificação de medidas pontos de alavancamento. Para reduzir os efeitos maléficos dessas medidas no processo de EESEP verifica-se a possibilidade de aplicar outras técnicas estatísticas para o processamento de EGs, bem como técnicas para obtenção de uma matriz de ponderação adequada. / To overcome the problems still existent for gross errors (GEs) detection and identification in the process of power system state estimation (PSSE), the formulations of the estimators applied to power systems are analyzed, specially, the formulation of the weighted squares estimator. These analyses were performed to show the limitations of these estimators for GEs processing. As leverage points (LP) represent a problem for GEs processing, methodologies for LP identification were also verified. By means of the linear formulation of the PSSE process, the reason for the impossibility of GEs detection in some redundant measurements is shown and a method for LP identification is proposed. To minimize the bad effects of the LP to the PSSE process, the possibility of applying other statistic techniques for GEs processing, as well as techniques to estimate an weighting matrix are also analyzed.

Investigamos o sistema formado por dois condensados aprisionados em estados hiperfinos diferentes do Rubídio, num potencial em forma de charuto, ou seja, num sistema físico real e quase-unidimensional. É investigada a dependência das soluções das equações de Gross-Pitaevski com a separação entre as armadilhas, bem como com o parâmetro de acoplamento de Josephson, para três valores diferentes do número total de átomos aprisionados. Para alguns conjuntos de parâmetros constatamos a existência de estados metaestáveis. O observável que escolhemos para caracterizar tal sistema físico foi a separação média entre os pacotes, pois os dois ramos de soluções encontramos correspondem a soluções mais juntas ou mais separadas espacialmente. / We study the system formed by two coupled condensates of different Rubidium hyperfine states trapped in a cigar shaped potential, that is, a real quasi one-dimensional system. The dependency of the solution of the Gross-Pitaevski equations is investigated as a function of trap displacement and Josephson coupling parameter for three different values of the total trapped atoms number. For some sets of parameters we report the existence of metastable states. The observable we chose to characterize this system was the mean separation between the packages, because we found two branches which correspond to closer or more separated solutions.

The thesis entitled Comparison of revenue and expenditure of the state budget for the self-employed and employees for the entire active and retirement period of life of individuals under conditions of 2015 deals with how, whether and under what conditions the self-employed are less taxed than their colleagues working in full-time employment with a comparable income. The model example points out the income threshold at which individual is better off being self-employed, and when it is more advantageous from the viewpoint of the state to be an independent contractor, not an employee. The models include the self-employed, who are misclassified as well as factors such as different amount of sick leave, lower pensions, lower unemployment benefits caused by lower deductions for social insurance, and other factors that are not immediately obvious but markedly influence the total amount of income and expenses to the state of the individual when working as self-employed or an employee.

Cette thèse est dédiée à l'étude des fluctuations non-linéaires dans les condensats de Bose-Einstein à deux composantes. On présente dans le premier chapitre la dynamique de champ moyen des condensats à deux composantes et les différents phénomènes typiques associés au degré de liberté spinoriel. Dans ce même chapitre, on montre que la dynamique des excitations se sépare en deux modes distincts : un mode dit de densité correspondant au mouvement global des atomes à l'intérieur du condensat et un mode dit de polarisation correspondant à la dynamique relative entre les deux espèces constituant le condensat. Ce calcul est généralisé dans le deuxième chapitre où l'on montre que le mode de polarisation persiste en présence d'un couplage cohérent entre les deux composantes. En particulier on analyse la stabilité modulationnelle du mode en déterminant, à l'aide d'une analyse multi-échelle, la dynamique des excitations non-linéaires. On montre alors que les excitations de polarisation, au contraire des excitations de densité, souffrent d'une instabilité de Benjamin-Feir. Cette instabilité est stabilisée aux grandes impulsions par une résonance onde longue - onde courte. Enfin dans le dernier chapitre, on dérive de façon non-perturbative la dynamique de polarisation proche de la limite de Manakov, dynamique quise révèle être régie par une équation de Landau-Lifshitz sans dissipation. Les équations de Landau-Lifshitz appartiennent à une hiérarchie d'équations intégrables (hiérarchie Ablowitz-Kaup-Newell-Segur) et on étudie les solutions à une phase à l'aide de la méthode d'intégration finite-gap ; on détermine notamment à l'aide de cette méthode un nouveau type de soliton pour les condensats à deux composantes. Finalement, profitant de l'intégrabilité du système, on résout le problème de Riemann à l'aide de la théorie de modulation de Whitham et on montre que les condensats à deux composantes peuvent propager des ondes de raréfaction ainsi que des ondes de choc dispersives ; on décrit notamment la modulation de ces ondes de choc par la propagation d'ondes simples et d'ondes de contact d'invariants de Riemann. / This thesis is devoted to the study of nonlinear fluctuations in two-component Bose-Einstein condensates. In the first chapter we derive the mean field dynamics of two-component condensates and we present the distinctive phenomena associated to the spinorial degree of freedom. In the same chapter, we show that the dynamics of the excitations is divided in two distinct modes: a so-called density mode which corresponds to the global motion of the atoms, and a so-called polarization mode which corresponds to the relative motion between the two species composing the condensate. The computation is generalized in the second chapter in which we demonstrate that the polarization mode remains in presence of a coherent coupling between the two components. In particular we study the modulational stability of the mode and we determine through a multi-scaling analysis the dynamics of non-linear excitations. We show that the excitations of polarization undergo a Benjamin-Feir instability contrary to the density excitations. This instability is then stabilized in the short wavelength regime by a long wave - short wave resonance. Finally in the last chapter, we derive in a non-perturbative way the polarisation dynamics close the Manakov limit.In this limit, the dynamics proves to be governed by a Landau-Lifshitz equation without dissipation. Landau-Lifshitz equations belong to a hierarchy of integrable equations (Ablowitz-Kaup-Newell-Segur hierarchy) and we derive the single-phase solutions thanks to the finite-gap method; in particular we identify a new type of soliton for the two-component Bose-Einstein condensates. Finally, taking advantage of the integrability of the system, we solve the Riemann problem thanks to the Whitham modulation theory and we show that the two-component condensates can propagate rarefaction waves as well as dispersive shockwaves; we describe the modulation of the shockwaves by the propagation of simple waves and contact waves of Riemann invariants.