Representation of transmission lines: comparison of models and parameters distributed discrete parameters

A transmission line is characterized by the fact that its parameters are distributed along its length. This fact makes the voltages and currents along the line to behave like waves and these are described by differential equations. In general, the differential equations mentioned are difficult to solve in the time domain, due to the convolution integral, but in the frequency domain these equations become simpler and their solutions are known. The transmission line can be represented by a cascade of π circuits. This model has the advantage of being developed directly in the time domain, but there is a need to apply numerical integration methods. In this work a comparison of the model that considers the fact that the parameters are distributed (Universal Line Model) and the fact that the parameters considered concentrated along the line (π circuit model) using the trapezoidal integration method, and Simpson's rule Runge-Kutta in a single-phase transmission line length of 100 km subjected to an operation power. © 2003-2012 IEEE.

Women from the point of view of the Bukowskian narrator: the representation of the feminine universe in Erections, Ejaculations, Exhibitions and General Tales of Ordinary Madness

Pós-graduação em Letras - IBILCE

Uma contribuição da teoria literária para a análise de conteúdo de imagens publicitárias do fim do século XIX e primeira metade do século XX, contemplando aspectos da natureza brasileira

Pós-graduação em Ciência da Informação - FFC

A representação da natureza no romance francês do século XIX

Busca-se determinar as características da representação da natureza no romance francês do século XIX, analisando-se Paul et Virginie de Bernardin de Saint-Pierre, Les travailleurs de la mer de Victor Hugo e L’Ève future de Villiers de l’Isle-Adam, por meio da teoria sócio-crítica e do embate com o texto. Na primeira parte, faz-se um retrospecto da representação nas artes e na literatura, destacando-se as concepções de Aristóteles e as do Romantismo. Apresenta-se também um panorama das concepções da natureza no tempo e no espaço e reflete-se sobre as relações do homem com o mundo natural, bem como sobre as teorias a elas referentes no âmbito da história, da pintura e da literatura. Na segunda parte, analisam-se os três romances escolhidos, buscando-se neles os modos e os sentidos da representação literária da natureza. Conclui-se pela existência, nas três obras estudadas, de uma atitude ambígua do homem diante da natureza, que havia sido anteriormente detectada na história. Embora diferenciadas entre si, sob alguns aspectos, as representações da natureza no corpus estudado demonstram o registro, no universo literário, de marcas do contexto histórico, político e social em que os três romances foram escritos, publicados e usufruidos.

Os conceitos de ambiente, meio ambiente e natureza no contexto da temática ambiental: definindo significados

We present some clarifications that enable us to identify differences between the expressions nature, the environment and environment. This is not an epistemological approach, but rather reflections on these expressions refer and the implications for environmental issues and hence to Science Teaching. The nature was understood as a complex of real entities, which are capable to be thinking through perception. This same entity when is represented by a mind, become what we call the environment. This expression, in turn, is characterized not only by adding the environments species that are known, but to be a human abstraction. When we consider the uniqueness of each species and organism, which in this environment is inserted, we call environment, this is, the elements that can be seen and on which the organism can act. Thus, we seek to develop a concept broader of environment, which is not restricted to the human species.

Egocentric speech in the works of Vygotsky and Piaget: educational implications and representations by teachers

This paper presents an applied qualitative and quantitative study and seeks to understand egocentric speech according to Vygotsky and Piaget and, through a literature review, the educational implications of Vygotsky and Piaget’s ideas. Additionally, the representations of these ideas by fifteen teachers of basic education are investigated. It is important to understand egocentric speech in Vygotsky and Piaget. Despite the differences in how they conceive its nature, functions and implications, for both, egocentric speech is intrinsically linked to and facilitates our understanding of child development. Regarding the representation of teachers who criticized children who used egocentric language, when teachers established any negative consequences of such language, they attributed it to the affective and moral aspects as well as to cognition. However, their approach was more practically oriented than those found in the psychological theories addressed. Therefore, this study aids in understanding the limits and scope of teacher-training courses.

Challenges of Knowledge Representation in Contemporary Archival Science

Since its emergence as a discipline, in the nineteenth century (1889), the theory and practice of Archival Science have focused on the arrangement and description of archival materials as complementary and inseparable nuclear processes that aim to classify, to order, to describe and to give access to records. These processes have their specific goals sharing one in common: the representation of archival knowledge. In the late 1980 a paradigm shift was announced in Archival Science, especially after the appearance of the new forms of document production and information technologies. The discipline was then invited to rethink its theoretical and methodological bases founded in the nineteenth century so it could handle the contemporary archival knowledge production, organization and representation. In this sense, the present paper aims to discuss, under a theoretical perspective, the archival representation, more specifically the archival description facing these changes and proposals, in order to illustrate the challenges faced by Contemporary Archival Science in a new context of production, organization and representation of archival knowledge.