Les variétés possédant une orbite dense sous l'opération d'un groupe sont dites presque homogènes. Il s'agit d'objets ayant une géométrie très riche, qui ont été abondamment étudiés ces 50 dernières années ; cela inclut notamment les variétés toriques. L'objectif de cette thèse est d'obtenir une classification des couples (X,G) où X est une courbe ou une surface algébrique, définie sur un corps quelconque, et G est un groupe algébrique lisse connexe opérant fidèlement dans X et possédant une orbite dense. Cette classification passe par l'étude des complétions régulières équivariantes de X.Un premier chapitre regroupe des rappels sur les opérations de groupes algébriques ainsi que plusieurs résultats préliminaires utiles par la suite.L'étude des courbes presque homogènes fait ressortir une classe particulière, celle des courbes seminormales. Nous obtenons une classification complète des couples (X,G) quand X est une courbe seminormale. Nous décrivons aussi les courbes quelconques presque homogènes (sur un corps quelconque), généralisant ainsi un résultat de Vladimir Popov. Enfin, nous déterminons les fibrés en droites linéarisés sur les courbes seminormales presque homogènes.Le dernier chapitre traite le cas des surfaces. À nouveau, nous obtenons une classification des couples (X,G) quand X est une surface et G n'est pas affine. Quand G est affine, la surface est rationnelle. Nous décrivons alors, sur un corps algébriquement clos, les surfaces homogènes et leurs complétions régulières équivariantes relativement minimales. En caractéristique nulle, nous déterminons aussi les groupes qui opèrent. Beaucoup de phénomènes nouveaux se produisent en caractéristique positive, et certains de nos résultats sont incomplets dans ce cadre. / The varieties having a dense orbit under the action of a group are said to be almost homogeneous. Those are objects with a very rich geometry and have been extensively studied for the last 50 years ; this includes toric varieties. The purpose of this thesis is to classify the pairs (X,G) where X is an algebraic curve or surface, defined over an arbitrary field, and G is a smooth connected algebraic group, acting faithfully on X with a dense orbit. The classification relies on the study of the equivariant regular completions of X.The study of almost homogeneous curves highlights the class of seminormal curves. We get a full classification of the pairs (X,G) when X is a seminormal curve. We also describe all almost homogeneous curves (over an arbitrary field), thus generalizing a result of Vladimir Popov. Finally, we determine the linearized line bundles over seminormal almost homogeneous curves.The last chapter deals with the case of surfaces. Again, we get a classification of the pairs (X,G) when X is a surface and G is not affine. When G is affine, the surface is rational. We then describe, over an algebraically closed field, the homogeneous surfaces and their relatively minimal equivariant regular completions. In characteristic zero, we also determine the acting groups. Many new phenomena occur in positive characteristic, and some of our results are incomplete in this setting.

O presente estudo analisa a parceria entre a rede municipal de ensino de Sapiranga e o Instituto Ayrton Senna, revelando as conseqüências dessa para a gestão educacional, discutindo a relação do público e do privado na educação. O marco teórico é a crise do capital, que tem entre suas estratégias de superação o Neoliberalismo e a Terceira Via, propondo a reforma do Estado para a solução de uma crise centrada no Estado. Em 1995, no Brasil, é criado o Ministério de Administração e Reforma do Estado, que cria o Plano Diretor da Reforma do Aparelho do Estado, o qual propunha a descentralização de serviços, até então de exclusividade do Estado, incluindo a sociedade civil organizada, o Terceiro Setor ou público não-estatal. Outra faceta da publicização foi a introdução, na gestão pública, do quase-mercado, ou seja a lógica da iniciativa privada agindo no setor público. Diante disso, é apresentado como a gestão escolar vem se reconfigurando nos últimos anos, principalmente nos anos 1980, com a luta pela gestão democrática do ensino público, e como esta é ressignificada na década de 1990, quando as políticas de descentralização se acentuam e trazem, para as políticas sociais, em especial para a educação, novos padrões de gestão. Este trabalho apresenta o convênio de um sistema de ensino público (Sapiranga) com o Instituto Ayrton Senna, como forma de materialização dessas políticas, e as implicações para a gestão da escola pública pesquisada. / The presente study analyses the partnership between the educational system of Sapiranga and the Ayrton Senna Institute, revealing the consequences that it brings to the educacional management, discussing the relationship between the public and the private sphere in education. The theoric base is the capital’crisis, that has as one of it’s superation strategies the Neo-Liberalism and the Third Way, proposing a State` reform for solution of a crisis centred on the State. In 1995, in Brazil, is created the Administration and State’s Reform Ministry, that creates the Director Plan of the State’s Apparatuses Reform, that proposes the descentralization of services, until then, exclusives from the state, including now the organized civil society, the Third Sector and the public non-governamental sphere. Another face of that publicization was the introduction, on public management, of the almost-market, the logic of the private sphere acting on the public sphere. Facing that, is presented how the school’s management has been reconfigurated in the last years, especially in the 1980’s, with the battle for the democratic management of public education, and how this one is resignified in the 1990`s, when the descentralization politics increase and bring, for social politics, especially for education, a new standard of public management. This study presents the accord between a public educacional system (Sapiranga) and Ayrton Senna Institute, as a real form of these kind of politics, and it’s consequences on public schools` management.

Neste trabalho estudaremos a existência de soluções fracas, pseudo quase periódicas e periódicas, para uma classe de sistemas não autônomo do tipo neutro com retardamento não limitado modelados na forma \' d SUP. dt\' (u(t) + F(t, ut)) = A(t)u(t) + G(t, \'u IND.t\' ), t \'PERTENCE A\' (0, a), \'u IND. 0\' = \'varphi\' \'PERTENCE A\' B, onde {A(t)} ´e uma família de operadores lineares fechados, com um dom´?nio comum D =D(A(t)), a história ut : (-\'INFINITO\'1, 0] \'SETA\' X, \'u IND. t\'(THETA) = u(t+\'THETA\'), pertence a um espaço de fase abstrato B definido axiomaticamente e F,G : [0, a] × B \'SETA\' X são funções apropriadas. Para obter alguns de nossos resultados, precisaremos usar as propriedades da família de operadores de evolução (U(t, s))\'t > OU=\'s, para o sistema u? (t) - A(t)u(t) = 0, t \'Pertencer A\' (0, a), \'u IND.0\' = \'phi\', onde U(t, s) ´e uma fam´?lia de operadores lineares limitados em X / In this work we study the existence of mild, pseudo almost-periodic and periodic solution, concepts introduced be later for a class of abstract neutral functional systems with unbounded delay in the form \'d SUP dt\' (u(t) + F(t, \'u IND.t\')) = A(t)u(t) + G(t, \'u IND. t\'), t IT BELONGS\' (0, a), \'u IND.0\' = \'varphi\' \'IT BELONGS\' , where is a family of closed linear operator in a Banach space X, with a common domain D = D(A(t)), t \'IT BELONGS\' R, densely defined in X; the history \'u IND. t\' : (-\'THE infinite\', 0] \' ARROW\' X, ut(\'THETA\') = x(t+\'THETA\'), belongs to some abstract phase space B defined axiomatically and F,G : I ×B \'ARROW\' X are appropriate functions and I is a bounded or unbounded interval in R. To establish some of our results, we will use the properties of a systems of evolution (U(t, s))\' t IND. > OR =\'s, for a system in the form u? (t) - A(t)u(t) = 0, t \'IT BELONGS\' (0, a), \'u IND.0\' = \'PHI\', where (U(t, s))\'t IND. > 0R =\'s is a family of bounded linear operators on X

This dissertation aims to contribute to the field of economics of competition policy by analyzing the demand structure and the market power in the Turkish beverage industry and in the cola market in particular. First, a demand system for the beverage products has been estimated by using a multi-stage linearized Almost Ideal Demand System (AIDS). Using the own-price elasticity of cola in a SSNIP test (Small but Significant Non-Transitory Increase in Price), it is shown that cola market consists of a distinct relevant product market. Then, the demand elasticities of cola products at brand and package level have been estimated by the simple and nested logit models. Finally, the estimated demand elasticities of cola products have been used in measuring the degree of market power and predicting the effects of a hypothetical merger between Pepsi and Cola Turca by using a merger simulation technique. The results show that all cola suppliers have large price-cost margins for most of their products. Prices of the merging parties increase in average by 15 - 21% after the merger. The merger also causes the market price to increase by 16- 22% and consumer surplus to decrease by nearly 5% in average. Finally, depending on these results, the thesis recommends a stricter merger control criterion than dominance criterion for competition policy in Turkey.

We study the regularity of weak solutions for the Stefan and Hele- Shaw problems with Gibbs-Thomson law under special conditions. The main result says that whenever the free boundary is Lipschitz in space and time it becomes (instantaneously) C[superscript 2,alpha] in space and its mean curvature is Hölder continuous. Additionally, a similar model related to the Signorini problem is introduced, in this case it is shown that for large times weak solutions converge to a stationary configuration. / text

A sign pattern matrix is a matrix whose entries are from the set {+,-, 0}. For a real matrix B, sgn(B) is the sign pattern matrix obtained by replacing each positive respectively, negative, zero) entry of B by + (respectively, -, 0). For a sign pattern matrixA, the sign pattern class of A, denoted Q(A), is defined as { B : sgn(B)= A }. The minimum rank mr(A)(maximum rank MR(A)) of a sign pattern matrix A is the minimum (maximum) of the ranks of the real matrices in Q(A). Several results concerning sign patterns A that require almost unique rank, that is to say, the sign patterns A such that MR(A)= mr(A)+1 are established. In particular, a complete characterization of these sign patterns is obtained. Further, the results on sign patterns that require almost unique rank are extended to sign patterns A for which the spread is d =MR(A)-mr(A).

This dissertation addresses: 1) the reliability of El Niño Southern Oscillation (ENSO) forecasts generated by the International Research Institute for Climate and Society (IRI) of Columbia University; 2) estimation of parameters of Mexican crop demand; and 3) the potential impacts of climate change on Mexican agriculture. The IRI ENSO forecasts were evaluated using prequential analysis, with calibration and scoring rules. Calibration tests and the Yates’ decomposition measures of the Brier score suggest that the IRI ENSO forecasts are improving in reliability and skill, showing a learning by doing behavior, i.e., these IRI ENSO forecasts show improved ability to predict the ENSO phases that really happen. In terms of estimation of the parameters of Mexican crop demand, an LA/AIDS model was used but the results were not very satisfactory with statistical tests rejecting homogeneity and symmetry. Furthermore, the estimated uncompensated price and income elasticities were found to be located in the tail regions of the Monte Carlo simulated density functions, showing poor validation of the initial estimates under similar economic (price and consumption) circumstances. Finally, in terms of the potential impacts that climate change has on Mexican agriculture, two 2050 climate change scenarios were examined. The central result indicates that Mexico benefits from climate change under the IPCC ensemble results for the B1 scenario and would experience welfare losses under the ensemble results for the A2 scenario. Moreover, dryland hectareage would decrease and would be replaced by irrigated areas. Finally, producer’s net income was found to decrease at the national level under both climate change scenarios. The results were generated using a mathematical programming sector model that was updated for the study.

No description available.

O presente estudo analisa a parceria entre a rede municipal de ensino de Sapiranga e o Instituto Ayrton Senna, revelando as conseqüências dessa para a gestão educacional, discutindo a relação do público e do privado na educação. O marco teórico é a crise do capital, que tem entre suas estratégias de superação o Neoliberalismo e a Terceira Via, propondo a reforma do Estado para a solução de uma crise centrada no Estado. Em 1995, no Brasil, é criado o Ministério de Administração e Reforma do Estado, que cria o Plano Diretor da Reforma do Aparelho do Estado, o qual propunha a descentralização de serviços, até então de exclusividade do Estado, incluindo a sociedade civil organizada, o Terceiro Setor ou público não-estatal. Outra faceta da publicização foi a introdução, na gestão pública, do quase-mercado, ou seja a lógica da iniciativa privada agindo no setor público. Diante disso, é apresentado como a gestão escolar vem se reconfigurando nos últimos anos, principalmente nos anos 1980, com a luta pela gestão democrática do ensino público, e como esta é ressignificada na década de 1990, quando as políticas de descentralização se acentuam e trazem, para as políticas sociais, em especial para a educação, novos padrões de gestão. Este trabalho apresenta o convênio de um sistema de ensino público (Sapiranga) com o Instituto Ayrton Senna, como forma de materialização dessas políticas, e as implicações para a gestão da escola pública pesquisada. / The presente study analyses the partnership between the educational system of Sapiranga and the Ayrton Senna Institute, revealing the consequences that it brings to the educacional management, discussing the relationship between the public and the private sphere in education. The theoric base is the capital’crisis, that has as one of it’s superation strategies the Neo-Liberalism and the Third Way, proposing a State` reform for solution of a crisis centred on the State. In 1995, in Brazil, is created the Administration and State’s Reform Ministry, that creates the Director Plan of the State’s Apparatuses Reform, that proposes the descentralization of services, until then, exclusives from the state, including now the organized civil society, the Third Sector and the public non-governamental sphere. Another face of that publicization was the introduction, on public management, of the almost-market, the logic of the private sphere acting on the public sphere. Facing that, is presented how the school’s management has been reconfigurated in the last years, especially in the 1980’s, with the battle for the democratic management of public education, and how this one is resignified in the 1990`s, when the descentralization politics increase and bring, for social politics, especially for education, a new standard of public management. This study presents the accord between a public educacional system (Sapiranga) and Ayrton Senna Institute, as a real form of these kind of politics, and it’s consequences on public schools` management.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-07-18T21:43:56Z No. of bitstreams: 1 ThiagoELM_DISSERT.pdf: 3255456 bytes, checksum: 6ce3964b5242ccf305c4e0f3d94ee65e (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-25T14:46:31Z (GMT) No. of bitstreams: 1 ThiagoELM_DISSERT.pdf: 3255456 bytes, checksum: 6ce3964b5242ccf305c4e0f3d94ee65e (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-25T14:46:56Z (GMT) No. of bitstreams: 1 ThiagoELM_DISSERT.pdf: 3255456 bytes, checksum: 6ce3964b5242ccf305c4e0f3d94ee65e (MD5) / Made available in DSpace on 2017-07-25T14:47:21Z (GMT). No. of bitstreams: 1 ThiagoELM_DISSERT.pdf: 3255456 bytes, checksum: 6ce3964b5242ccf305c4e0f3d94ee65e (MD5) Previous issue date: 2013-11-22 / The microstrip antennas are in constant evidence in current research due to its numerous advantages. Fractal geometry proposed by Mandelbrot(1975 ) combined with the performance and convenience of planar structures are an excellent combination used in the design of antennas in order to reduce the dimensions and enhance its bandwidth, and allows the emergence of best bands frequency by virtue of ownership of high -similarity. Compared with the conventional microstrip antennas, patch antennas with fractal type substrates have lower resonance frequency, enabling the manufacture of even more compact antennas. The aim of this work consists of the design of patch antennas with dielectric substrates organized almost periodic basis through the use of fractal geometry sequence Cantor applied to a circular patch antenna fed by microstrip line, designed for a resonant frequency of 10 GHz. Analysis of this microstrip antenna is made in various types of dielectric substrates by simulation through software commercial Ansoft HFSS - Designer, used for accurate analysis of the electromagnetic behavior of the antennas by the finite element method by presenting results from resonant frequency and radiation pattern, making comparisons with other results in the literature. This dissertation also presents a bibliographic study on theories of antennas while also addressing about fractal geometry, emphasizing its characteristics and properties as well as its applicability. This paper also presents a study of almost periodic structures and their mathematical formalism considered throughout this work / As antenas de microfita estão em constante evidência nas pesquisas atuais, devido às suas inúmeras vantagens. A geometria fractal proposta por Mandelbrot (1975) aliada ao bom desempenho e comodidade das estruturas planares são uma excelente combinação utilizada no projeto de antenas com o intuito de reduzir suas dimensões e realçar sua largura de banda, além de permitir o surgimento de melhores bandas de frequência em consequência da propriedade da alto-similaridade. Em comparação com as antenas em microfita convencionais, as antenas tipo patch com substratos fractais apresentam frequência de ressonância inferiores, possibilitando a fabricação de antenas ainda mais compactas. O objetivo desse trabalho consiste no projeto de antenas patch com substrato dielétrico organizado de forma quase periódica por meio da utilização da geometria fractal da sequência de Cantor aplicada a uma antena de patch circular alimentada por linha de microfita, projetada para uma frequência ressonância de 10 GHz. É feita análise dessa antena de microfita em vários tipos de substratos dielétricos por simulação através do software comercial Ansoft Designer-HFSS, usado para análise precisa do comportamento eletromagnético das antenas através do método dos elementos finitos apresentando resultados de frequência de ressonância, diagrama de radiação, carta de Smith e de campos elétricos e magnéticos fazendo-se comparações com outros resultados obtidos na literatura. Esta dissertação ainda apresenta um estudo bibliográfico em teorias de antenas, abordando também a respeito da geometria fractal, dando ênfase a suas características e propriedades como também a sua aplicabilidade. Este trabalho ainda apresenta um estudo sobre as estruturas quase periódicas e seu formalismo matemático / 2017-07-18