Teoria de carteiras e a alocação de parques eólicos offshore

The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore, from the installation of 01 simulated ocean turbine with a capacity of 5 MW. The data show hourly time resolution and covers the period between January 1, 1998 until December 31, 2002. Through the Matlab R software, six were calculated minimum variance portfolios, each for a period of time distinct. Given the inequality of the variability of wind over time, set up four strategies rebalancing to evaluate the performance of the related portfolios, which enabled us to identify the most beneficial to the stability of the wind energy production offshore. The results showed that the production of wind energy for 1998, 1999, 2000 and 2001 should be considered by the portfolio weights calculated for the same periods, respectively. Energy data for 2002 should use the weights derived from the portfolio calculated in the previous time period. Finally, the production of wind energy in the period 1998-2002 should also be weighted by 1/11. It follows therefore that the portfolios found failed to show reduced levels of variability when compared to the individual production of wind farms hypothetical offshore

Como vão se formando os professores em física e química: embates entre o ser, o ter e o fazer na formação de licenciandos da UFRN sob a perspectiva da teoria das representações sociais

The purpose of this work is to approach and understand the Social Representations (SR) (MOSCOVICI, 2003) about Physics and Chemistry from people who are major in these courses, as well as their Social Representations about teaching . We took as principle that approaching these representations it would be possible to relate their symbolic contents, in order to show how people who are following the first segments of bachelor degree courses in Physics and Chemistry become teachers, taking into account a psychosocial view. Two source of data was used during this research: Free-association Technique FA (ABRIC, 1994); and Multiple Classification Procedure (MCP) (ROAZZI, 1995). The analytical treatment of the collected data from FA was done according to the proposition of Grize, Vergés and Silem (1987 apud ABRIC, 1994, p. 66). MCP data were analyzed through MSA (Multidimensional Scalogram Analysis) and SSA (Singular Spectrum Analysis) methods associated with the Facet Theory (BILSKY, 2003). The discourses of MCP discussing groups at the moment of explanations were studied by Content Analysis as it was proposed by Bardin (1977) and Franco (2005). Indicative of an approach to the relations with knowledge (CHARLOT, 2000), the connections which aroused from the analyses showed that the group of future majors in Physics thought that this scientific field was based on a rationalist conception, influencing the idealization sense of the phenomena to be explained by Physics. Thus, Physics as school content started to require the student of the fundamental and high school to think abstractly as a cognitive skill of learning. The identifying elements observed in the relations between SR about Physics and Teaching aroused from the antagonism between future majors and their teacher, as well as from the speculation between their fundamental and high school students and themselves, mainly when they had to face the act of teaching due to the obstacles imposed by the own educational system, and by the weakness of the initial preparation. The group of future majors in Chemistry, through its discourses, showed these relations when they conceived empiricist Chemistry and said that teaching was the way of transmission of this knowledge, and didactics of Chemistry teaching was the direction to learning through pedagogic methods in order to lead the students to discoveries. The psychosocial contents which were built and showed from the symbolic relations in the studied SR achieved the relation of identity. This relation revealed identifying elements for these people, resulting from the traffic between their condition as students of Chemistry, and as teachers regarding their work, what placed the current relational contents in the teaching space, named as Knowledge changing and Adaptability . In order to study emerging questions in the discussing environment about formation and teaching professionalization, we focused the psychosocial view on this traffic and managed to observe epistemological practical and pedagogic obstacles that limited a configuration of the teaching work as a professional activity, especially from the particular conditions which led the relations of senses to Physics , Chemistry and Teaching ; and Chemistry and Physics as it was seen in this research. Generally speaking, we noted that these obstacles can denounce such obstacles concerning to the pedagogic doings which mainly impair the learning process of fundamental and high school students

Formação da habilidade de interpretar gráficos cartesianos em licenciandos em química segundo a teoria de P. Ya. Galperin

It has been remarkable among the Science Teaching debates the necessity that students do not learn only theories, laws and concepts, but also develop skills which allows them to act towards a critical citizenship. Therefore, some of the skills for the natural sciences learning must be taught consciously, intentionally and in a planned way, as component of a basic competence. Studies of the last twenty years have shown that students and teachers have plenty of difficulties about skills development and, among several, the skill of interpreting Cartesian graphics, essential for the comprehension of Natural Science. In that sense, the development of that type of professional knowledge during the initial education of future Chemistry teachers has become strategic, not only because they need to know how to use it, but also because they need to know how to teach it. This research has as its general objective the organization, development and study of a process of formation of the skill of interpreting Cartesian graphics as part of the teachers professional knowledge. It has been accomplished through a formative experience with six undergraduate students of the Teaching Degree Course of Chemistry of Universidade Federal do Rio Grande do Norte (UFRN Federal University of Rio Grande do Norte), in Brazil. In order to develop that skill, we have used as reference P. Ya. Galperin s Theory of the Stepwise Formation of Mental Actions and Concepts and its following qualitative indicators: action form, degree of generalization, degree of consciousness, degree of independence and degree of solidness. The research, in a qualitative approach, has prioritized as instruments of data collecting the registering of the activities of the undergraduate students, the observation, the questionnaire and the diagnosis tests. At the first moment, a teaching framework has been planned for the development of the skill of interpreting Cartesian graphics based on the presupposed conceptions and steps of Galperin s Theory. At the second moment, the referred framework has been applied and the process of the skill formation has been studied. The results have shown the possibility of develop the skill conscious about the invariant operation system, with a high degree of generalization and internalized the operational invariant in the mental plane. The students have attested the contributions at that type of formative experience. The research reveals the importance of going deeper about the teaching comprehension of the individualities tied to the process of internalization, according to Galperin s Theory, when the update of abilities as part of the teaching professional knowledge is the issue

Progresso científico em pequenos ruminantes na primeira década do século XXI

O interesse pelos pequenos ruminantes aumentou nos últimos anos sob os aspectos produtivo e científico. No Brasil, caprinos e ovinos são os que despertam maior interesse econômico. Assim, este trabalho foi conduzido com o objetivo de discutir o progresso científico com caprinos e ovinos nos últimos dez anos. Foram pesquisadas várias bases de dados, entre elas as do Institute for Scientific Information (ISI), da Scientific Electronic Library Online - SciELO, da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES, do Instituto Brasileiro de Geografia e Estatística - IBGE e da Food and Agriculture Organization of the United Nations - FAO. Na última década, os pequenos ruminantes têm merecido especial atenção dos pesquisadores, o que pode ser comprovado pelo aumento de 41% nas publicações mundiais envolvendo estas espécies, o que foi acompanhado por aumento ainda mais expressivo, 219%, em âmbito nacional. A evolução também foi observada sob os aspectos metodológicos dos projetos, ressaltando a abordagem multidisciplinar nas pesquisas mais atuais. Nos últimos dez anos, houve crescimento do aporte de recursos para editais temáticos demandados pela sociedade e pela cadeia da carne e do leite, além da preocupação com qualidade, competitividade e sustentabilidade.

O ensino de língua inglesa em um instituto federal : uma análise das recomendações documentais e da perspetiva dos professores

This work aims to understand the teaching of English at the Federal Institute of considering the recommendations of official and technical documents for the integrated secondary school and the perspective of the English teachers settled in one of the campuses of the Institute. It is also an objective of this research to infer as to what extent the perspective of teachers is articulated to the documental recommendations. For this purpose, several official and technical documents (LÜDKE; ANDRÉ, 1986), such as the PCNEMs (BRAZIL, 2000), the OCNEMs (BRAZIL, 2006) and the Political-Pedagogical Project of the Institute (IFRN, in press) were gathered, and a questionnaire was submitted to six teachers of English from one of the campuses of the institution. The theoretical references of the research include, among others, Bakhtin (1997; 1999), Widdowson (1991), Almeida Filho (2011; 2004), Celani (1988; 2009), Hutchinson and Waters (1987) and Dudley-Evans and St. John (1998). The results show that the teaching of English according to the documents predicts the instrumental use of the foreign language, but suggests the development of competences and skills as contextualized social practices, aimed at the education of the student as a professional-citizen. The perspective of teachers, in turn, points to a concern that the teaching of English serves as a tool for improving student life through the instrumental use of language as a means of accessing information and professional training. This finding reveals that the articulation between the documental recommendations and perspective of teachers does not go beyond what refers to the instrumental language teaching, since teachers do not show, when reporting their practices, the teaching of language as social practice, as mentioned in the legal texts

Construções com tópico marcado em cartas pessoais brasileiras dos séculos XVIII, XIX E XX

This dissertation is a research on the marked topic construction (CT) in Brazilian personal letters from eighteenth, nineteenth and twentieth centuries. The goal of our research is to verify if CT are present in the writing of Brazilians born in the centuries in question. Our research focus is based on the assumptions of generative theory (CHOMSKY 1981; 1986), which states that grammar is internalized in the mind / brain of the writers, with the emphasis on studies of grammatical change, as pointed texts by Paixão de Sousa (2004), Carneiro (2005); Galves, Namiuti and Paixão de Sousa (2006) and Martins (2009). Our corpus was extracted from Projeto Para a História do Português Brasileiro (PHPB) and Cartas Brasileiras coletânea de fontes para o estudo do português. We selected forty-six correspondents who should be inserted into the two criteria set out in this research: to be Brazilian and be born in the centuries mentioned above, so that we could find legitimate topic constructions of PB. This work is based on researches by Pontes (1987), Mateus et al. (2003), Araujo (2006, 2009), Berlinck, Duarte and Oliveira (2009), which actively support us in the study of this linguistic phenomenon in Portuguese. The results show that the marked topic construction in our corpus appear on the writing of Brazilians since the second half of the eighteenth century, while the typical constructions in Brazilian Portuguese locative topic, subject topic and copy topic - are already reflected in the I-language of the writers born in the second half of the nineteenth century and the first of the twentieth century

Segmentação fuzzy de imagens e vídeos

Image segmentation is the process of subdiving an image into constituent regions or objects that have similar features. In video segmentation, more than subdividing the frames in object that have similar features, there is a consistency requirement among segmentations of successive frames of the video. Fuzzy segmentation is a region growing technique that assigns to each element in an image (which may have been corrupted by noise and/or shading) a grade of membership between 0 and 1 to an object. In this work we present an application that uses a fuzzy segmentation algorithm to identify and select particles in micrographs and an extension of the algorithm to perform video segmentation. Here, we treat a video shot is treated as a three-dimensional volume with different z slices being occupied by different frames of the video shot. The volume is interactively segmented based on selected seed elements, that will determine the affinity functions based on their motion and color properties. The color information can be extracted from a specific color space or from three channels of a set of color models that are selected based on the correlation of the information from all channels. The motion information is provided into the form of dense optical flows maps. Finally, segmentation of real and synthetic videos and their application in a non-photorealistic rendering (NPR) toll are presented

Aplicações da teoria da potência complexa instantânea no cálculo das grandezas de Buchholz-Goodhue

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tamanho, produção de ovos e distribuição espacial de microcrustáceos litorâneos e limnéticos em pequenos reservatórios rasos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A prática dos professores em relação à leitura e à escrita com alunos que ingressam aos seis anos de idade no ensino fundamental

Pós-graduação em Educação - IBRC

Sanção expiatória versus sanção por reciprocidade: estudo exploratório em dez classes de educação infantil. -

Pós-graduação em Educação - IBRC

A investigação sobre a própria prática de um professor iniciante sob o olhar da teoria da recontextualização

Pós-graduação em Educação para a Ciência - FC

Diálogos entre literatura e cinema: um estudo sobre The Dead de James Joyce

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização da Associação dos Pequenos Agricultores no contexto do Projeto Cinturão Verde de Ilha Solteira - SP

Pós-graduação em Geografia - FCT

Germanismo e nazismo na colônia alemã de Presidente Venceslau (1923-1945)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)