Navegando por Autor "ELIAS, Walace de Sousa"

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Acesso aberto (Open Access)
Análise de metodologia baseada no sistema de ensino individualizado de Keller aplicada em um curso introdutório de eletromagnetismo
(2011-03) ALVES, Danilo Teixeira; SOUZA, Sandro Aléssio Vidal de; PEREIRA FILHO, Silvio Carlos Ferreira; ELIAS, Walace de Sousa
One of individualized teaching methods used and documented in the 70's was Fred Keller's Personalized System of Instruction (PSI). Several papers about this methodology were published, providing an extensive empirical evidence of PSI's positive results. Nonetheless its employment has declined staring in the 80's. Among the reasons for this decline, we may emphasize the greater effort required to the development of such courses using this methodology as compared to other methodologies and the provisioning of a systematic feedback on students' performance, as well as the criticisms on Keller's behaviorist approach. Despite being critical to learning, the stimulus to student's active posture, respect for individual learning rhythm, the formative assessments and the provisioning of systematic feedback to students still take place outside the classroom. One strategy to counter such deficiencies is individualized instruction. In this paper, we propose several modifications to Keller's SPI seeking a feasible methodology to be applied in an introductory course of electromagnetism for students of Physics of Universidade Federal do Pará. Among these modifications, we highlight: (i) the use of weekly assessments, but not in every lecture; (ii) the correction of assessments and feedback providing made by teachers and not teaching assistants; and (iii) the partial maintenance of the expositive classes. Despite the modifications inserted, based on an evaluation which included measurable benchmarks, we have indications that the application of this methodology yielded several of those positive results common to the implementation of Keller's SPI.
Acesso aberto (Open Access)
Quebra dinâmica da simetria quiral na pseudo eletrodinâmica quântica em (2 + 1) dimensões
(Universidade Federal do Pará, 2011) ELIAS, Walace de Sousa; ALVES, Van Sérgio da Silva; http://lattes.cnpq.br/5346258049047843
In the present work, we study the chiral symmetry breaking in pseudo quantum electrodynamics in (2+1) dimensions using the Schwinger-Dyson equation formalism and investigate the similarities of this model with the criticality in both QED3 and QED4. Using the rainbow-quenched approximation we show that there is a critical coupling αcc = π/16 above which there is a mass generation for fermions and hence the chiral symmetry breaking occurs. We also study the N massless fermions flavors version using the 1/N expansion in rainbow-unquenched approximation and we obtain a critical value for the number of active fermions below which there is chiral symmetry breaking. We show that at strong gauge coupling constant (g -- ∞) this critical number is the same as in QED3 in large N expansion.