Números complexos: uma proposta de mudança metodológica para uma aprendizagem significativa no ensino médio

This work presents a proposal of a methodological change to the teaching and learning of the complex numbers in the Secondary education. It is based on the inquiries and difficulties of students detected in the classrooms about the teaching of complex numbers and a questioning of the context of the mathematics teaching - that is the reason of the inquiry of this dissertation. In the searching for an efficient learning and placing the work as a research, it is presented a historical reflection of the evolution of the concept of complex numbers pointing out their more relevant focuses, such as: symbolic, numeric, geometrical and algebraic ones. Then, it shows the description of the ways of the research based on the methodology of the didactic engineering. This one is developed from the utilization of its four stages, where in the preliminary analysis stage, two data surveys are presented: the first one is concerning with the way of presenting the contents of the complex numbers in math textbooks, and the second one is concerning to the interview carried out with High school teachers who work with complex numbers in the practice of their professions. At first, in the analysis stage, it is presented the prepared and organized material to be used in the following stage. In the experimentation one, it is presented the carrying out process that was made with the second year High school students in the Centro Federal de Educação tecnológica do Rio Grande do Norte CEFET-RN. At the end, it presents, in the subsequent and validation stages, the revelation of the obtained results from the observations made in classrooms in the carrying out of the didactic sequence, the students talking and the data collection

Dificuldades na construção de gráficos de funções

This study describes about graduation s students difficulties of to draw functions graph. Specifically, we intend to observe their abilities evolution, as well as their difficulties during Calculus I subject in engineering course. For that, we show them publications about the elaboration of graphs and its difficulties in obstacle terms and some researches witch contain this subject and that it was done during postgraduate studies in mathematical education. It shows by research methodology aspects related to French didatic s mathematic and some theories of cognitive psychology considering the high value between theoretical-methodological relation that was evidenced in both theoretical conceptions about ways to understand and teach mathematic. This methodology is based on didactic engineering purpose, that consist in preliminaries analysis, conception and didactic sequence analysis prior, trials by application followed analysis up and conclusion. We had also used pedagogicals actions and analysis of results achieved, to classify types of errors made by the 2005 s students during second semester, from conceptions related to the episthemologic and didactics obstacles

As provas metafísicas da existência de deus em René Descartes

Le but de cet article est de présenter les éléments de preuve de l existence de Dieu présentée dans les Méditationes Métaphysiques de René Descartes, en soulignant son importance et son rôle dans le projet philosophique cartésien. La recherche visait á comprendre comment Descartes, étant um homme de science, la recherche de Dieu dans le pilier et d assurer leur philosophie. Par consé quence que Descartes propose de remplacer lui promettant de construire une nouvelle science fondée sur des bases sûres. Ainsi, le texte suit um ordre qu une partie de doute méthodologique comme um élément essentiel pour surmonter une connaissance née de l incertitude et généralisée et d opinions comme étant de droite, pour finalement atteindre la vérité dans les sciencies, Grace à la découverte Du premier cours, le cogito, moi pensant, alors existantes. Trouvé cette certitude, le sujet qui a en elle l idée d um être infini qui contient toutes perfections et, comme Il fera la démonstration de la preuve a posteriori et a priori. Et donc cet être ne peut pas être considéré comme inexistant projet assurant Descartes

Rotação diferencial em estrelas do tipo solar

Stellar differential rotation is an important key to understand hydromagnetic stellar dynamos, instabilities, and transport processes in stellar interiors as well as for a better treatment of tides in close binary and star-planet systems. The space-borne high-precision photometry with MOST, CoRoT, and Kepler has provided large and homogeneous datasets. This allows, for the first time, the study of differential rotation statistically robust samples covering almost all stages of stellar evolution. In this sense, we introduce a method to measure a lower limit to the amplitude of surface differential rotation from high-precision evenly sampled photometric time series such as those obtained by space-borne telescopes. It is designed for application to main-sequence late-type stars whose optical flux modulation is dominated by starspots. An autocorrelation of the time series is used to select stars that allow an accurate determination of spot rotation periods. A simple two-spot model is applied together with a Bayesian Information Criterion to preliminarily select intervals of the time series showing evidence of differential rotation with starspots of almost constant area. Finally, the significance of the differential rotation detection and a measurement of its amplitude and uncertainty are obtained by an a posteriori Bayesian analysis based on a Monte Carlo Markov Chain (hereafter MCMC) approach. We apply our method to the Sun and eight other stars for which previous spot modelling has been performed to compare our results with previous ones. The selected stars are of spectral type F, G and K. Among the main results of this work, We find that autocorrelation is a simple method for selecting stars with a coherent rotational signal that is a prerequisite to a successful measurement of differential rotation through spot modelling. For a proper MCMC analysis, it is necessary to take into account the strong correlations among different parameters that exists in spot modelling. For the planethosting star Kepler-30, we derive a lower limit to the relative amplitude of the differential rotation. We confirm that the Sun as a star in the optical passband is not suitable for a measurement of the differential rotation owing to the rapid evolution of its photospheric active regions. In general, our method performs well in comparison with more sophisticated procedures used until now in the study of stellar differential rotation

Essas pessoas na sala de jantar : espaços históricos em canções tropicalistas (1963-1973)

Tropicalia concerns the attempt of understanding of Brazil and a national identity characterized by the transience of time and space, rhizomatic action, perpetual laceration of cultural boundaries and at the same time act synchronously to instances such as policy and the social. A word created by artist Hélio Oiticica and registered by him on the National Register of Trademarks and Patents, was later used to a name the eponymous song by Caetano Veloso and also in this fertile cultural impulse at the turn of the sixties to the seventies on last century, who had the intention to make creating new spaces and simultaneously rethink the spatial cuts of Brazilian culture, encouraging them to be much more than a myth of a paradise within a lush new look of a tropical truth.

Algoritmos e Arquiteturas VLSI para Detectores MIMO com Decisão Suave

The use of Multiple Input Multiple Output (MIMO) systems has permitted the recent evolution of wireless communication standards. The Spatial Multiplexing MIMO technique, in particular, provides a linear gain at the transmission capacity with the minimum between the numbers of transmit and receive antennas. To obtain a near capacity performance in SM-MIMO systems a soft decision Maximum A Posteriori Probability MIMO detector is necessary. However, such detector is too complex for practical solutions. Hence, the goal of a MIMO detector algorithm aimed for implementation is to get a good approximation of the ideal detector while keeping an acceptable complexity. Moreover, the algorithm needs to be mapped to a VLSI architecture with small area and high data rate. Since Spatial Multiplexing is a recent technique, it is argued that there is still much room for development of related algorithms and architectures. Therefore, this thesis focused on the study of sub optimum algorithms and VLSI architectures for broadband MIMO detector with soft decision. As a result, novel algorithms have been developed starting from proposals of optimizations for already established algorithms. Based on these results, new MIMO detector architectures with configurable modulation and competitive area, performance and data rate parameters are here proposed. The developed algorithms have been extensively simulated and the architectures were synthesized so that the results can serve as a reference for other works in the area

O Centro de Referência da Assistência Social e a Psicanálise: efeitos de uma escuta singularizada

This paper emerged from an experience of 18 months in the CRAS – Reference Center for Social Assistance – which aroused a question about the listening of the singularity in the professional practice of Psi in the context of social assistance. The literature review revealed, on the one hand, a series of studies that aim to a discussion about of the process of professional integration of psychologists in the field of social welfare, proposing and / or analyzing practices directed towards the psychosocial assistance directed to the group and for the assurance of rights, forming citizen subjects. On the other hand, supported by a psychoanalytic perspective, we found studies that point to the importance of the singularity listening considering the subjectivity and symbolic resources of those who seek help in Basic Assistance Service. In this perspective, we aim to analyze, in a posteriori, the effects of offering a singularized listening in the context of CRAS and discuss its implications for the Psi professional practice in social institution. This is a theoretical and clinical research, based on Freudian and Lacanian psychoanalysis, in which two cases, placed as investigation boosters, are analyzed in the light of the concept of the subject. We conclude that a singularized listening allowed a significant sliding and the consequent repositioning of the subject, in each case, front to their suffering. The effects collected allowed us to affirm the importance of a singular listening in the treatment of the demands that appear within the institutional framework

Aplicação do planejamento de experimentos no processo de desenvolvimento de produtos: pesquisa em uma sorveteria artesanal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES