627 resultados para Szemeredi`s regularity lemma
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A Emenda Constitucional 64/2010 garantiu Direito Humano à Alimentação como direito básico e social, alterando o Artigo 6º da Constituição Federal. O artigo analisa as significativas implicações desta alteração na gestão das políticas públicas brasileiras Ao assegurar o Direito à Alimentação como direito básico e social, a Carta constituiu um dever, ou uma obrigação positiva do Estado brasileiro. O artigo discute também o significado desta mudança para o sistema brasileiro de informações, argumentando que já existem fontes de dados e sistema de indicadores construídos para o monitoramento consistente das situações de (in)segurança alimentar e nutricional no país, restando agora ao governo federal e aos gestores do Sistema Brasileiro de Informações Estatísticas e Geográficas definir a regularidade e a frequência da aplicação e divulgação destes instrumentos. Nossa atenção se concentrará basicamente nas possibilidades de uso da Pesquisa de Orçamentos Familiares e da Pesquisa Nacional por Amostra Domiciliar como fontes de dados. _______________________________________________________________________________ ABSTRACT
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The aim of this note is to formulate an envelope theorem for vector convex programs. This version corrects an earlier work, “The envelope theorem for multiobjective convex programming via contingent derivatives” by Jiménez Guerra et al. (2010) [3]. We first propose a necessary and sufficient condition allowing to restate the main result proved in the alluded paper. Second, we introduce a new Lagrange multiplier in order to obtain an envelope theorem avoiding the aforementioned error.
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The aim of this paper is to extend the classical envelope theorem from scalar to vector differential programming. The obtained result allows us to measure the quantitative behaviour of a certain set of optimal values (not necessarily a singleton) characterized to become minimum when the objective function is composed with a positive function, according to changes of any of the parameters which appear in the constraints. We show that the sensitivity of the program depends on a Lagrange multiplier and its sensitivity.
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Interest in Mg foams is increasing due to their potential use as biomaterials. Fabrication methods determine to a great extent their structure and, in some cases, may pollute the foam. In this work Mg foams are fabricated by a replica method that uses as skeleton packed spheres of active carbon, a material widely utilized in medicine. After Mg infiltration, carbon particles are eliminated by an oxidizing heat treatment. The latter covers Mg with MgO which improves performance. In particular, oxidation retards degradation of the foam, as the polarization curves of the Mg foam with and without oxide indicate. The sphericity and regularity of C particles allows control of the structure of the produced open-cell foams.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, Programa de Mestrado Profissional em Matemática em Rede Nacional, 2016.
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The idea of spacecraft formations, flying in tight configurations with maximum baselines of a few hundred meters in low-Earth orbits, has generated widespread interest over the last several years. Nevertheless, controlling the movement of spacecraft in formation poses difficulties, such as in-orbit high-computing demand and collision avoidance capabilities, which escalate as the number of units in the formation is increased and complicated nonlinear effects are imposed to the dynamics, together with uncertainty which may arise from the lack of knowledge of system parameters. These requirements have led to the need of reliable linear and nonlinear controllers in terms of relative and absolute dynamics. The objective of this thesis is, therefore, to introduce new control methods to allow spacecraft in formation, with circular/elliptical reference orbits, to efficiently execute safe autonomous manoeuvres. These controllers distinguish from the bulk of literature in that they merge guidance laws never applied before to spacecraft formation flying and collision avoidance capacities into a single control strategy. For this purpose, three control schemes are presented: linear optimal regulation, linear optimal estimation and adaptive nonlinear control. In general terms, the proposed control approaches command the dynamical performance of one or several followers with respect to a leader to asymptotically track a time-varying nominal trajectory (TVNT), while the threat of collision between the followers is reduced by repelling accelerations obtained from the collision avoidance scheme during the periods of closest proximity. Linear optimal regulation is achieved through a Riccati-based tracking controller. Within this control strategy, the controller provides guidance and tracking toward a desired TVNT, optimizing fuel consumption by Riccati procedure using a non-infinite cost function defined in terms of the desired TVNT, while repelling accelerations generated from the CAS will ensure evasive actions between the elements of the formation. The relative dynamics model, suitable for circular and eccentric low-Earth reference orbits, is based on the Tschauner and Hempel equations, and includes a control input and a nonlinear term corresponding to the CAS repelling accelerations. Linear optimal estimation is built on the forward-in-time separation principle. This controller encompasses two stages: regulation and estimation. The first stage requires the design of a full state feedback controller using the state vector reconstructed by means of the estimator. The second stage requires the design of an additional dynamical system, the estimator, to obtain the states which cannot be measured in order to approximately reconstruct the full state vector. Then, the separation principle states that an observer built for a known input can also be used to estimate the state of the system and to generate the control input. This allows the design of the observer and the feedback independently, by exploiting the advantages of linear quadratic regulator theory, in order to estimate the states of a dynamical system with model and sensor uncertainty. The relative dynamics is described with the linear system used in the previous controller, with a control input and nonlinearities entering via the repelling accelerations from the CAS during collision avoidance events. Moreover, sensor uncertainty is added to the control process by considering carrier-phase differential GPS (CDGPS) velocity measurement error. An adaptive control law capable of delivering superior closed-loop performance when compared to the certainty-equivalence (CE) adaptive controllers is finally presented. A novel noncertainty-equivalence controller based on the Immersion and Invariance paradigm for close-manoeuvring spacecraft formation flying in both circular and elliptical low-Earth reference orbits is introduced. The proposed control scheme achieves stabilization by immersing the plant dynamics into a target dynamical system (or manifold) that captures the desired dynamical behaviour. They key feature of this methodology is the addition of a new term to the classical certainty-equivalence control approach that, in conjunction with the parameter update law, is designed to achieve adaptive stabilization. This parameter has the ultimate task of shaping the manifold into which the adaptive system is immersed. The performance of the controller is proven stable via a Lyapunov-based analysis and Barbalat’s lemma. In order to evaluate the design of the controllers, test cases based on the physical and orbital features of the Prototype Research Instruments and Space Mission Technology Advancement (PRISMA) are implemented, extending the number of elements in the formation into scenarios with reconfigurations and on-orbit position switching in elliptical low-Earth reference orbits. An extensive analysis and comparison of the performance of the controllers in terms of total Δv and fuel consumption, with and without the effects of the CAS, is presented. These results show that the three proposed controllers allow the followers to asymptotically track the desired nominal trajectory and, additionally, those simulations including CAS show an effective decrease of collision risk during the performance of the manoeuvre.
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We develop an algorithm and computational implementation for simulation of problems that combine Cahn–Hilliard type diffusion with finite strain elasticity. We have in mind applications such as the electro-chemo- mechanics of lithium ion (Li-ion) batteries. We concentrate on basic computational aspects. A staggered algorithm is pro- posed for the coupled multi-field model. For the diffusion problem, the fourth order differential equation is replaced by a system of second order equations to deal with the issue of the regularity required for the approximation spaces. Low order finite elements are used for discretization in space of the involved fields (displacement, concentration, nonlocal concentration). Three (both 2D and 3D) extensively worked numerical examples show the capabilities of our approach for the representation of (i) phase separation, (ii) the effect of concentration in deformation and stress, (iii) the effect of Electronic supplementary material The online version of this article (doi:10.1007/s00466-015-1235-1) contains supplementary material, which is available to authorized users. B P. Areias pmaa@uevora.pt 1 Department of Physics, University of Évora, Colégio Luís António Verney, Rua Romão Ramalho, 59, 7002-554 Évora, Portugal 2 ICIST, Lisbon, Portugal 3 School of Engineering, Universidad de Cuenca, Av. 12 de Abril s/n. 01-01-168, Cuenca, Ecuador 4 Institute of Structural Mechanics, Bauhaus-University Weimar, Marienstraße 15, 99423 Weimar, Germany strain in concentration, and (iv) lithiation. We analyze con- vergence with respect to spatial and time discretization and found that very good results are achievable using both a stag- gered scheme and approximated strain interpolation.
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O objectivo principal deste trabalho de mestrado consistiu em avaliar a potencial utilização de materiais adsorventes, nomeadamente, de carvões activados (AC) preparados por activação química com KOH, a partir de PET reciclado, e de materiais com estrutura mesoporosa ordenada, do tipo MCM-41 e SBA-15, na remoção de ácido 4 - cloro - 2 - metilfenoxiacético (MCPA) e de azul de metileno (MB), presentes nas águas. Nesta tese apresentam-se estudos de preparação e caracterização de materiais micro e mesoporosos e também estudos de avaliação da capacidade adsortiva em fase líquida. Prepararam-se três materiais microporosos, nomeadamente, PET-2-700, PET-2-700ox (AC oxidado) e PET-2-700red (AC reduzido), dois materiais constituídos exclusivamente por mesoporos, Si-MCM-41 e Ti-MCM-41-50 e dois materiais contendo maioritariamente mesoporos, mas que também possuem alguma microporosidade, tais corno, Si-SBA-15 e Ti-SBA-15-50. A caracterização textural dos adsorventes foi inferida por adsorção de azoto a 77K e por de difracção de raios X. Recorreu-se a três métodos de análise das isotérmicas, nomeadamente, Dubinin-Radushkevich, Brunauer-Ernrnett-Teller e alfa-s (as). A caracterização química dos AC foi realizada recorrendo-se a técnicas de análise elementar (AE) e espectroscopia de infravermelho com transformadas de Fourier (FTIR) e à determinação do ponto de carga zero. Os três carvões activados possuem valores de área superficial externa idênticos, o PET-2-700 possui o maior volume microporoso e o PET-2-700ox exibe o maior diâmetro de poros. Por outro lado, o PET-2-700ox possui um carácter fortemente ácido, o PET-2-700 exibe carácter ligeiramente ácido e o PET-2-700red apresenta propriedades ligeiramente alcalinas. Com base na AE, todas as amostras possuem percentagens de carbono elevadas, sendo que o PET-2-700red apresenta o valor mais elevado. Os resultados obtidos para a caracterização estrutural dos revelaram a obtenção de materiais mesoporosos de alta qualidade, definida pela elevada regularidade e uniformidade da estrutura porosa. A análise dos parâmetros de caracterização textura! permitiu inferir que os quatro materiais mesoporosos possuem valores de área superficial elevados, e que os materiais SBA-15 apresentam valores de volume poroso total e de tamanho de poros superiores aos manifestados pelos MCM-41. A incorporação de titânio não conduziu a uma perda significativa de qualidade dos materiais substituídos em relação às correspondentes amostras de sílica. Efectuaram-se estudos de adsorção em fase líquida de forma a avaliar a possível aplicação dos vários adsorventes na remoção de MCPA e de MB de efluentes líquidos. concluiu-se que o tempo de equilíbrio de 72 horas seria adequado e que a capacidade de adsorção dos vários AC era superior em meio ácido. Com base nas isotérmicas de adsorção do MCPA e do MB e na aplicação da representação de Langmuir e de Freundlich, foi possível concluir que o PET-2-700 possui a maior capacidade de adsorção do MCPA, 1.42 mmol/g, enquanto que o PET-2-700ox revelou a maior capacidade de adsorção do MB, 1.43 mmol/g. Na realidade, os materiais microporosos estudados apresentaram percentagens de remoção elevadas, tanto do MCPA como do MB. Relativamente aos materiais mesoporosos ordenados preparados neste trabalho, a percentagem de remoção de para os poluentes em estudo foi relativamente baixa, constatando-se que nesta fase dos estudos não constituem uma alternativa viável à utilização dos AC. No entanto, uma funcionalização criteriosa dos mesmos pode eventualmente proporcionar um aumento da capacidade adsortiva. ABSTRACT: The work presented in this master thesis, consisted of evaluating the potential use of different adsorbents materials, like activated carbon (AC) prepared by chemical activation with KOH, from recycled poly (ethylene terephthalate) (PET) and materials with ordered mesoporous structure such as MCM-41 and SBA-15, for removing acid 4-chlorine-2-metilfenoxiacétic and methylene blue from aqueous phase. We had prepared three microporous materials, PET-200-700, PET-2-700ox (AC oxidized) and PET-2-700red (reduced AC), two materials consisting exclusively of mesopores, Si-MCM-41 and Ti-MCM-41-50 and two materials containing mainly mesopores, but also having some microporosity, such as Si-SBA-15 and Ti-SBA-15-50. The textural characterization of the adsorbents was inferred by nitrogen adsorption at 77K and X-ray diffraction. Three methods were used to analyse the isotherms, namely, Dubinin-Radushkevich, Brunauer-Emmett-Teller and alpha-s (as). The chemical characterization of AC was performed using the elementary analysis, Fourier transform infrared spectroscopy (FTIR) and determination of the point of zero charge. Concerning the AC, the three present almost the same externa! surface area, PET-2-700 has a high micropore volume and PET-2-700ox shows the largest pore size diameter. On the other hand, PET-2-700ox had a strong acid character, PET-2-700 exhibits just a slightly acid character and PET-2-700red presents alkaline properties. The AE analysis allows confirming the high carbon content of theses AC, with PET-2-700red exhibiting the highest carbon proportion. The results from the structural characterization of the mesoporous materials, had disclosed the attainment of materials with high quality, defined by the raised regularity and uniformity of the porous structure. The analysis of the textural parameters allowed inferring that the four studied mesoporous materials possess high superficial area. The SBA-15 type materials present higher values of total porous volume and pores size diameter as the MCM-41. Also, the titanium incorporation did not lead to a significant loss of quality of the materials substituted in relation to the corresponding silica samples. The adsorption studies in liquid phase allow evaluating the possibility of using the different adsorbents for the MCPA and the MB removal. The kinetic studies had allowed to state the equilibrium time as 72 hours and a higher adsorption capacity was achieved in an acid medium. The influence of the pH of the medium, on the MCPA adsorption was evaluated. The MCPA and MB isotherms were analysed based on the Langmuir and Freundlich equation, the representations presented an excellent linearity, indicating the applicability of these equations to these systems. Also, it allows concluded that PET-2-700 had a higher adsorption capacity for MCPA, 1.42 mmol/g, and PET-2-700ox had a higher adsorption capacity for MB, 1.43 mmol/g. The AC used presented high removal percentages for MCPA and MB. Concerning the mesoporous materials prepared in this work, the percentage removal for the pollutants in study was relatively low, and evidencing that at the moment these mesoporous materials do not constitute a viable alternative to the AC. However, an astute funcionalisation of the same ones can, eventually provide an increase of the adsorption capacity.
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No quadro de uma sociologia da ação, procurámos conhecer as políticas públicas do setor social em preparação ou implementadas pela autarquia de Mafra e, simultaneamente, perceber a influência que a interação e o grau de concordância dos diferentes atores sociais envolvidos no desenvolvimento do projeto social do município, exercem no processo de concretização das mesmas, contribuindo, deste modo, para o sucesso do plano de ação social programado para o território, ou, pelo contrário, dificultando a sua implementação. Neste sentido, procurámos encontrar os desafios e, ao mesmo tempo, os obstáculos que se apresentam à Câmara Municipal de Mafra na implementação de um projeto social adequado à realidade da comunidade local, enquanto ator privilegiado no campo da proteção social à população, ação que vem assumindo ao longo das últimas décadas, evidenciando um papel prioritário e determinante na programação das políticas públicas desenvolvidas no território, considerando, igualmente, a influência que a regularidade da representação política dos órgãos autárquicos deste município vem exercendo também na concretização deste processo de intervenção social. Através de uma estratégia metodológica orientada para a realização de um diagnóstico prospetivo, propusemo-nos estudar os elementos principais do sistema de implementação de políticas sociais no Município de Mafra e, neste sentido: a) delimitámos o sistema e estudámos os seus elementos mais pertinentes, nomeadamente, a posição estratégica da autarquia no desenvolvimento de um projeto de intervenção social adequado ao território; b) assinalámos os objetivos estratégicos do plano de intervenção social elaborado pela autarquia em coordenação com outros atores com responsabilidade social no município e posicionámos os atores relativamente a estes objetivos estratégicos; e por fim, c) avaliámos as convergências e as divergências possíveis e a implicação dos atores na concretização dos objetivos deste plano estratégico de intervenção social. As principais conclusões deste estudo referem a existência de uma grande convergência dos atores perante os objetivos do plano de intervenção social programado pela autarquia para o município, tendo em conta a sua participação e intervenção na elaboração e execução deste projeto de âmbito social, sendo identificado como principal obstáculo de implementação, a escassez de recursos financeiros, e, como desafio de execução com maior importância, a cooperação entre a autarquia e os demais parceiros sociais do município reveladora da congregação de esforços conducentes ao desenvolvimento da estratégia de intervenção social mais adequada às necessidades do território; ABSTRACT: In the context of an action sociology sought to know the public policies in the social sector in preparation or implemented by the municipality of Mafra and simultaneously realize the influence that interaction and the degree of agreement of the different social actors involved in the development of the social project city, play in the process of implementation of the same, thus contributing to the success of social action plan scheduled for the territory, or, conversely, hindering its implementation. In this sense, we tried to meet the challenges and at the same time, the obstacles that are presented to the Municipality of Mafra in the implementation of an adequate social project the reality of the local community, as a privileged actor in the field of social protection of the population, action is taking over the past decades, showing a priority and decisive role in the planning of public policies developed in the territory, considering also the influence that the regularity of political representation of local government bodies in this municipality has exercised also in the realization of this process of social intervention. Through targeted methodological strategy for the realization of a prospective diagnosis, we proposed to study the main elements of the system of implementation of social policies in the city of Mafra and in this regard: a) delimit the system and studied the relevant elements, namely, the strategic position of authority in the development of a social intervention project suitable to the territory; b) have pointed out the strategic objectives of social intervention plan drawn up by the municipality in coordination with other actors with social responsibility in the city and we positioned the actors for these strategic objectives; and finally, c) we evaluated the convergences and divergences and the possible involvement of actors in achieving the objectives of this strategic plan of social intervention. The main findings of this study relate to the existence of a large convergence of actors towards the objectives of social intervention plan set by the local authority for the city, taking into account their participation and assistance in the preparation and implementation of the social context of the project, being identified as main obstacle to implementing the scarcity of financial resources, and the challenge of implementing more importantly, cooperation between the municipality and the other social partners in revealing municipality of congregation of efforts leading to the development of more appropriate social intervention strategy to the needs of territory.
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Resumen A mediados del siglo XIX la economía de Costa Rica se consolidó como agroexportadora y la mayor parte del movimiento comercial de exportación e importación se movilizó por el puerto de Puntarenas. Despues de 1882, al entrar a funcionar el ferrocarril al atlántico, la actividad portuaria por Puntarenas disminuyó. Se analiza el número de embarcaciones que visitaron a Puntarenas de 1883 a 1935 y el tonelaje respectivo. Asimismo, se ocupa de cuales líneas navieras y en qué condiciones brindaron regularmente servicio por ese puerto. Abstract By mid-19th Century, Costa Rica’s economy was firmly based on foreign trade and agricultural goods and most import and export trade was carried out through the port of Puntarenas. After 1882, when the Atlantic Railway began operations, port activity at Puntarenas declined. The number of vessels entering at Puntarenas between 1883 and 1935 and their respective tonnage is analyzed. The shipping lines serving the port and regularity of services they provided are also considered
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This article aims to undertake a discursive analysis of the label and advertising material of three beers sold in Brazil: the Cafuza beer, the Mulata beer and Devassa Negra beer. Starting from the regularity that binds and weaves the statements in question - the reference to the African-Brazilian woman - the objective is to present an analysis that considers the semiotic nature of these statements, and bring out their enunciation margins and its historical dimension. The purpose is to analyze the discursive thread that provides conditions of emergence, providing visibility to the scenario of enslavement still perdurable here as historical a priori, in a game of memories that echo through time. What we will see is the body of the black woman (also mulatto and black-indian woman) caught by a discourse that comes from the image of the female sexual slavery and reaches today its exacerbation, especially if we think of the (con)fusion established between the brand names of those beers and the women printed on their labels: products to be consumed? As a theoretical and methodological framework, this article will have as a starting point the discussions made within the French Discourse Analysis in the course of the 1980s. We will bring forward a discussion, although in general, on how emerges, in that decade, the concerns about a semiotic materiality of discourse, beyond the linguistic materiality. Anchored by this panorama, our goal is to work out new perspectives through its analytical application. It is the attempt to take the statement considering the different languages that comprise it, as well as to provide it with the historical density intrinsic to it, making it appear, in the light of the day, what was not visible immediately.
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There is a tendency for language studies propose latest analysis from an approach that considers language use. Therefore, in this research, we decided to use as corpus a transcript of an interview with a trilingual woman. Among the possibilities of studying the corpus, we chose to analyze the term “até” due to the frequency with which appears in the speech of the interviewee and the different functions that it takes in the speech. The analytical development is based on theoretical studies Ducrot (1981, 1987, 1989) with regard to argumentative operators. These strategies are considered activated, explicitly in the textual structure by enunciators to achieve certain goals. The reviews also are guided by studies of NURC in relation to discourse markers, defined as units that aim to give cohesion to the discourse sequences. It is also considered the studies of Marcuschi (1991), Risso, Silva and Urbano (2006) and Koch (2006b) about the question. The analysis of the cuttings where the term “até” appears allows to observe that there is no regularity in regard to the functions performed by this unit and should be considered in the interpretation process, the context of enunciation.