973 resultados para Approximations


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Marcas, passagens e condensações: (des) encaminhamentos de um processo de gravura é uma pesquisa em Poéticas Visuais que articula questões provenientes de uma prática artística com base na gravura e uma produção textual. Investigam-se as possibilidades de potencializar o vazio e o cheio através da gravação de matrizes com instrumentos de corte e da gravação com fogo. Os procedimentos operatórios de cortar, queimar e condensar originaram a impressão das matrizes sobre suportes de papéis e de parafina. As imagens dessa produção gráfica resultaram em uma série de obras denominadas de Carbonizados, Sílex e Luas Negras, cujas ações instauradoras propiciaram diferentes etapas de gravação e impressão: marcas, passagens e condensações que foram analisadas a partir dos conceitos operatórios identificados no processo de criação. O estudo conduz a aproximações com obras de artistas contemporâneos e articula referenciais na História da Arte e na fenomenologia, propiciando o inter-relacionamento da prática com a teoria e vice-versa.

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Esta dissertação concentra-se nos processos estocásticos espaciais definidos em um reticulado, os chamados modelos do tipo Cliff & Ord. Minha contribuição nesta tese consiste em utilizar aproximações de Edgeworth e saddlepoint para investigar as propriedades em amostras finitas do teste para detectar a presença de dependência espacial em modelos SAR (autoregressivo espacial), e propor uma nova classe de modelos econométricos espaciais na qual os parâmetros que afetam a estrutura da média são distintos dos parâmetros presentes na estrutura da variância do processo. Isto permite uma interpretação mais clara dos parâmetros do modelo, além de generalizar uma proposta de taxonomia feita por Anselin (2003). Eu proponho um estimador para os parâmetros do modelo e derivo a distribuição assintótica do estimador. O modelo sugerido na dissertação fornece uma interpretação interessante ao modelo SARAR, bastante comum na literatura. A investigação das propriedades em amostras finitas dos testes expande com relação a literatura permitindo que a matriz de vizinhança do processo espacial seja uma função não-linear do parâmetro de dependência espacial. A utilização de aproximações ao invés de simulações (mais comum na literatura), permite uma maneira fácil de comparar as propriedades dos testes com diferentes matrizes de vizinhança e corrigir o tamanho ao comparar a potência dos testes. Eu obtenho teste invariante ótimo que é também localmente uniformemente mais potente (LUMPI). Construo o envelope de potência para o teste LUMPI e mostro que ele é virtualmente UMP, pois a potência do teste está muito próxima ao envelope (considerando as estruturas espaciais definidas na dissertação). Eu sugiro um procedimento prático para construir um teste que tem boa potência em uma gama de situações onde talvez o teste LUMPI não tenha boas propriedades. Eu concluo que a potência do teste aumenta com o tamanho da amostra e com o parâmetro de dependência espacial (o que está de acordo com a literatura). Entretanto, disputo a visão consensual que a potência do teste diminui a medida que a matriz de vizinhança fica mais densa. Isto reflete um erro de medida comum na literatura, pois a distância estatística entre a hipótese nula e a alternativa varia muito com a estrutura da matriz. Fazendo a correção, concluo que a potência do teste aumenta com a distância da alternativa à nula, como esperado.

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This paper considers tests which maximize the weighted average power (WAP). The focus is on determining WAP tests subject to an uncountable number of equalities and/or inequalities. The unifying theory allows us to obtain tests with correct size, similar tests, and unbiased tests, among others. A WAP test may be randomized and its characterization is not always possible. We show how to approximate the power of the optimal test by sequences of nonrandomized tests. Two alternative approximations are considered. The rst approach considers a sequence of similar tests for an increasing number of boundary conditions. This discretization allows us to implement the WAP tests in practice. The second method nds a sequence of tests which approximate the WAP test uniformly. This approximation allows us to show that WAP similar tests are admissible. The theoretical framework is readily applicable to several econometric models, including the important class of the curved-exponential family. In this paper, we consider the instrumental variable model with heteroskedastic and autocorrelated errors (HAC-IV) and the nearly integrated regressor model. In both models, we nd WAP similar and (locally) unbiased tests which dominate other available tests.

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This paper considers two-sided tests for the parameter of an endogenous variable in an instrumental variable (IV) model with heteroskedastic and autocorrelated errors. We develop the nite-sample theory of weighted-average power (WAP) tests with normal errors and a known long-run variance. We introduce two weights which are invariant to orthogonal transformations of the instruments; e.g., changing the order in which the instruments appear. While tests using the MM1 weight can be severely biased, optimal tests based on the MM2 weight are naturally two-sided when errors are homoskedastic. We propose two boundary conditions that yield two-sided tests whether errors are homoskedastic or not. The locally unbiased (LU) condition is related to the power around the null hypothesis and is a weaker requirement than unbiasedness. The strongly unbiased (SU) condition is more restrictive than LU, but the associated WAP tests are easier to implement. Several tests are SU in nite samples or asymptotically, including tests robust to weak IV (such as the Anderson-Rubin, score, conditional quasi-likelihood ratio, and I. Andrews' (2015) PI-CLC tests) and two-sided tests which are optimal when the sample size is large and instruments are strong. We refer to the WAP-SU tests based on our weights as MM1-SU and MM2-SU tests. Dropping the restrictive assumptions of normality and known variance, the theory is shown to remain valid at the cost of asymptotic approximations. The MM2-SU test is optimal under the strong IV asymptotics, and outperforms other existing tests under the weak IV asymptotics.

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Dans cette étude, j'ai eu comme objectif d'établir les connexions et/ou les non-connexions dans les discours journalistiques sur la modernité pédagogique, dans les journaux O Correio de Aracaju (Le Courrier d'Aracaju, Sergipe, Brésil) et O Século (Le Siècle, Portugal), dans la période 1910-1920. J'ai tout particulièrement cherché le dit dans les journaux, dans le sens foucaldien du terme, en continu dialogue avec d'autres auteurs, dans une perspective interdisciplinaire. J'ai tenté de répondre à mon interrogation initiale : quelles sont les connexions et non connexions que l'on pourrait établir entre l'École Moderne du Portugal et celle de Sergipe, au Brésil, en prenant comme source d'analyse les discours journalistiques dans des journaux des deux pays ? Á partir de ce questionnement, à travers un abordage historico-comparatif interculturel, j'ai soutenu la THÈSE que les discours journalistiques du Século et du Correio de Aracaju, bien qu'ils relèvent de genres journalistiques différents quant au niveau de développement de la presse, ont traduit une perception et une assimilation de la modernité pédagogique articulées à une même epistémè. Ainsi, ces discours ont émergé comme objets métis, dont la création s'est faite dans des interlocutions, échanges, impositions et débats dans un processus continu de communication interculturelle. La nature messianique de ces discours, dans le système d'idées républicain, traduisait le sens de la modernité pédagogique prétendue et diffusée par les textes qui exprimaient l'aspiration de rupture et de progrès, tant au Portugal que dans l'état brésilien de Sergipe. Il a également été possible de faire des approximations/comparaisons entre la dispute (article d'opinion), dans le Correio de Aracaju et l'enquête (interview et reportage), dans O Século et de souligner ainsi les connexions et/ou non-connexions présentes sur le thème de la modernité pédagogique dans les discours journalistiques

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The study proposes an understanding of nurses training in reflexivity and the overcome the limits of biomedical formation model, from the thought of John Dewey, inserted in the panorama of the reflective practitioner introduced by Donald Schön and dialoguing with the perspective of the transforming action of Paulo Freire. We used a qualitative approach to collect empirical data through focus groups conducted with nursing students from 3rd to 5th year in the Faculty of Health Sciences, Trairi / UFRN in the year 2012. Data analysis occurred through the technique of thematic content analysis constituted of three stages: pre-analysis, exploration of the material, treatment of results, inference and interpretation of the material. Thus, the categories formulated by organizing, classifying and aggregating the the content of the speeches to groups who shared opinions approximations of thought generating a set of categories of analysis designed from the contents. The results present the experiences of nursing students and their reflections, demonstrating that the process of reflection permeates the journey of life. It is inferred that the knowledge acquired in these experiences do not always participate in this dialogue in this formative process, reducing previous experiences in the field of exemplification of everyday situations. We conclude that it is necessary to consolidate innovative pedagogical proposals that allow the continuous dialogue with reality, breaking with the decontextualized teaching process from reality insertion of the university. Rethinking of the structures is recommended, reinforcing the break with the biomedical model and the integration of knowledge dynamically

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Slugging is a well-known slugging phenomenon in multiphase flow, which may cause problems such as vibration in pipeline and high liquid level in the separator. It can be classified according to the place of its occurrence. The most severe, known as slugging in the riser, occurs in the vertical pipe which feeds the platform. Also known as severe slugging, it is capable of causing severe pressure fluctuations in the flow of the process, excessive vibration, flooding in separator tanks, limited production, nonscheduled stop of production, among other negative aspects that motivated the production of this work . A feasible solution to deal with this problem would be to design an effective method for the removal or reduction of the system, a controller. According to the literature, a conventional PID controller did not produce good results due to the high degree of nonlinearity of the process, fueling the development of advanced control techniques. Among these, the model predictive controller (MPC), where the control action results from the solution of an optimization problem, it is robust, can incorporate physical and /or security constraints. The objective of this work is to apply a non-conventional non-linear model predictive control technique to severe slugging, where the amount of liquid mass in the riser is controlled by the production valve and, indirectly, the oscillation of flow and pressure is suppressed, while looking for environmental and economic benefits. The proposed strategy is based on the use of the model linear approximations and repeatedly solving of a quadratic optimization problem, providing solutions that improve at each iteration. In the event where the convergence of this algorithm is satisfied, the predicted values of the process variables are the same as to those obtained by the original nonlinear model, ensuring that the constraints are satisfied for them along the prediction horizon. A mathematical model recently published in the literature, capable of representing characteristics of severe slugging in a real oil well, is used both for simulation and for the project of the proposed controller, whose performance is compared to a linear MPC

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This research presents a study that seeks to analyze the images of the future in science fiction movies, specifically those made through animation techniques, exploring particularly the representation of audiovisual communication medias in its dialogue with the approached societies in the movies chosen to be analyzed. The proposed discussion seeks approximations in order to answer to the question that initiated this research: how are we thinking the future nowadays? It also seeks to, according to Morin (1997), comprehend aspects of the contemporary society by using the cinema, and at the same time, to understand the cinema, aided by a social analysis

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This thesis aims better understanding the relation between time and evil in Schelling s Freiheitsschrift, having its starting point in approximations from Gnosticism. For that purpose, before approaching that relation, it is reviewed (chapter I) the question of Gnosticism, a strain of thought essentially concerned with the problem of time and permeated by the belief in an evil nature of creation, and which is alleged to have significantly influenced certain ideas of Schelling. An evaluation of approximations between Gnosticism, gnosis and German thought follows (chapter II), as well as an evaluation of Schellingian aproximations to Gnosticism (chapter III). Then, the Freiheitsschrift is analysed as the text where Schelling, having taken hold of a very distinct appropriation of Gnosticism, goes beyond Kantian theodicy (chapter IV). Some interrogations about whether key ideas of Schellingian philosophy (about gnosis, creation, duality, time, and evil) are conceived in a way that is essentially different from that of historic Gnosticism, despite the much that has been said to the contrary, are then addressed (chapter V). The proposal of a Platonic-Plotinian key to the understanding of the relations between time and evil in the Freiheitsschrift comes next (chapter VI), and then gives way to the concluding remarks (chapter VII). We perceive that Gnosticism and Neoplatonism are systems of thought that sometimes converge, and that German thought is one of the places of this convergence. Notwithstanding this perception, it is possible to affirm that Schellingian thought, with its valorization of time and of a certain perception of evil, is essentially anti-gnostic, despite some contrary observations

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In the first part of this work our concern was to investigate the thermal effects in organic crystals using the theory of the polarons. To analyse such effect, we used the Fröhlich s Hamiltonian, that describes the dynamics of the polarons, using a treatment based on the quantum mechanics, to elucidate the electron-phonon interaction. Many are the forms to analyzing the polaronic phenomenon. However, the measure of the dielectric function can supply important information about the small polarons hopping process. Besides, the dielectric function measures the answer to an applied external electric field, and it is an important tool for the understanding of the many-body effects in the normal state of a polaronic system. We calculate the dielectric function and its dependence on temperature using the Hartree-Fock decoupling method. The dieletric function s dependence on the temperature is depicted by through a 3D graph. We also analyzed the so called Arrhenius resistivity, as a functionof the temperature, which is an important tool to characterize the conductivity of an organic molecule. In the second part we analyzed two perovskita type crystalline oxides, namely the cadmium silicate triclinic (CdSiO3) and the calcium plumbate orthorhombic (CaPbO3), respectively. These materials are normally denominated ABO3 and they have been especially investigated for displaying ferroelectric, piezoelectric, dielectrics, semiconductors and superconductors properties. We found our results through ab initio method within the functional density theory (DFT) in the GGA-PBE and LDA-CAPZ approximations. After the geometry optimization for the two structure using the in two approximations, we found the structure parameters and compared them with the experimental data. We still determined further the angles of connection for the two analyzed cases. Soon after the convergence of the energy, we determined their band structures, fundamental information to characterize the nature of the material, as well as their dielectrics functions, optical absorption, partial density of states and effective masses of electrons and holes

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In this work we present a study of structural, electronic and optical properties, at ambient conditions, of CaSiO3, CaGeO3 and CaSnO3 crystals, all of them a member of Ca-perovskite class. To each one, we have performed density functional theory ab initio calculations within LDA and GGA approximations of the structural parameters, geometry optimization, unit cell volume, density, angles and interatomic length, band structure, carriers effective masses, total and partial density of states, dielectric function, refractive index, optical absorption, reflectivity, optical conductivity and loss function. A result comparative procedure was done between LDA and GGA calculations, a exception to CaSiO3 where only LDA calculation was performed, due high computational cost that its low symmetry crystalline structure imposed. The Ca-perovskite bibliography have shown the absence of electronic structure calculations about this materials, justifying the present work

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This paper proposes discusses the theme of the youth and of the violation of rights in the context of the Young Agent Program developed in the local authority of Arez/RN, sugar cane region of the Brazilian northeast. We take like empirical reference, the young people in the age group from 15 to 17 years old that were participating of the activities of the Program, in the period of April to July of 2008. Objectives of this study were constituted, economical-partner apprehended the conditions and cultural of the young participants of the Young Agent Program, in the context of violations of rights; as well as the analysis of the limits and means, of the bases theoretician-politician, methodological and of the activities developed in the Program. In the persecution of the objectives we use like methodological instrumental the observation, activities in group with the focal group technique and the application of semi-structured interviews. As result, we notice that the violation of rights of the young persons inserted in the Young Agent Program of Arez sets itself up as reflex of the multiple determinations of the social question, inherent in the capitalist society, specified in the context of the poverty and of the social unequality that they acquire visibility in the hunger, in the unemployment / menial job, in the precarious dwelling, in the low schooling, for lack of leisure, in the violence between others. The approximations systematized in this healthy work relevant for the Unveiling of the reality of the Brazilian youth, specifically of Arez young people, in such a way that they come to subsidize future inquiries, are eaten by me also it promotes the discussion around the way like the Social Politics Programs they are implemented and driven in the capitalist society, in its neoliberal format, where the focusing and the selectivity is put on top to the detriment of the universal access of the democratic rights. So, the great challenge that is put for the XXI century is to cause to the voices from these which they do and this which build this country, in the continuous and tireless search of the rights realization in the struggle against the barbarism installed in the capitalist societycapitalista

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This work presents itself as a result of the research: Women as the subject of crime: a study on the complex reality of the criminal inmates Dr. John Keys - Natal / RN, done with women incarcerated in the Women's Pavilion Complex Criminal Dr. John Keys. Aimed to investigate the key determinants that lead women to enter the institution to be subject of crime. To better understand the object of our study, we start to understand and analyze the social reality, economic and cultural these women, as well as seizure of their family relationships and emotional, within a gender perspective and consider the analysis of major crimes committed and their determinations. In our study, it appears from successive approximations and procedures theoretical and methodological quality and quantity, we were privileged to documentary research, observation and semi-structured, beyond the theoretical foundation on the subject - that the question of increase in recent years, women in the criminal occurs as a result of socioeconomic reality experienced by those. At the same time, the study has also believe that poverty and crime are not phenomena of cause and effect, however, it is undeniable that the large number of prisoners (as) are poor and live situation of denial of rights. The main focus of the research points to the socio-emotional relationships, both marital and family as the main determinant for inclusion of women in crime, breaking with the myth that the woman is "fragile sex." And, more, points out that the woman in the process of emancipation and achievement of public spaces to commit a crime seek equal to the male. Moreover, the research also denounced in a prison system collapsed, and totally abandoned by the public. That denies all rights provided to prisoners (as), both inside and outside the "walls". It is a system that criminalizes and no one wants to fulfill its role, which is the functional rehabilitation and resocialization of (the) inmates (those). It is hoped that this work could contribute to the unveiling of the reality of women in the criminal - no pretension of exhausting it - and can also contribute to further studies on the subject

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Our dissertation deals with the material living conditions of women workers and the relations of the wage who undergo in the hospital scope, taking as the locus of empirical research the Hospital Dr. João Machado, located in Natal / RN. Its purpose is to analyze the main implications of precarious work contracts in the economic and social dimensions from life of workers, explaining the main conditionings. The majority presence of women in wage relations not only in the hospital service, as well as in the service sector in general has motivated us to appreciation of the form of participation of women in health services and, in particular, at the hospital space. From the critical dialectical method, through processes of successive approximations to the reality, we analyze the patriarchal system of social relations and their repercussions for the Social and Sexual Division of Labor in the context of contemporary capitalist society, explaining the determinants of inequality, founded in social relations of sex, to the predominance of women in the hospital service and unveiling these participation trends in the labor market. The analyzes are based on bibliographic research - theoretical and methodological basis of research - combined with reflections that emerged from the field. The systematized and analyzed information reveal the uniqueness of the current social and economic situation of workers women with ties outsourced, paradoxically expresses on the expansion of the insertion in universe of labor, in overexploitation, in the precariousness of work and living conditions and persistent inequality in and in the social relations and in relations between the sexes

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This paper discusses the process of training social workers in the environment of University Hospitals- UH s. These hospitals provide space for professional education aiming to achieve a critical and purposeful professional performance. As environments for training, producing knowledge and providing essential services to the public, these hospitals require all members of the healthcare team to have a continued education. Understanding that training has to be a priority and conceived as constant pursuit for update through the interaction of Teaching, Researching and EPO ( Education and Public Outreach). These dimensions provide approximations and domain of theoretical and methodological, giving special importance to understanding the social reality, a sine qua non condition to the work of the Social Service professional. The main goal of the research was to comprehend how the continuous professional education of the social worker occurs and it s relation with the articulations involving Teaching, Researching and EPO, as significant elements for the job of the social workers in the Hospital Universitário Ana Bezerra and Hospital Universitário Onofre Lopes/UFRN. The research was conducted through a literature review, documentary and field inquiries with semistructured interviews including the group of 09 (nine) social workers from the aforementioned hospitals, taking as a reference the quantitative and qualitative approach to analyze mediations that stand between the subject and the social context. The results indicate that social workers in these university hospitals have their insertion beyond the care provided to patients in performance in the areas of education through preceptorship to undergraduate students and social work residents in and extension projects with low insertion in area of research. We note that there is a recognition of the importance of a continuous education, indicating that the qualification of social worker is essential in transforming their daily professional practice to better monitor, critically explain the peculiarities of public health in its everyday showing of how unequally access is provided to the users of the public health system