Álgebras de Lie e aplicações à sistemas alternantes

Pós-graduação em Matemática - IBILCE

Vertex operators and Jordan fields

The construction of Lie algebras in terms of Jordan algebra generators is discussed. The key to the construction is the triality relation already incorporated into matrix products. A generalisation to Kac-Moody algebras in terms of vertex operators is proposed and may provide a clue for the construction of new representations of Kac-Moody algebras in terms of Jordan fields. © 1988.

Symplectic bosons, Fermi fields and super Jordan algebras

A construction relating the structures of super Lie and super Jordan algebras is proposed. This may clarify the role played by field theoretical realizations of super Jordan algebras in constructing representations of super Kač-Moody algebras. The case of OSP(m, n) and super Clifford algebras involving independent Fermi fields and symplectic bosons is discussed in detail.

Álgebras não associativas octoniônicas e relações extensivas do tipo De Moivre

Pós-graduação em Matemática - IBILCE

Fluxo do grupo de renormalização dos modelos-'alfa' e as álgebras de Lie contínuas

Pós-graduação em Física - IFT

The role of clouds in improving the regression model for hourly values of diffuse solar radiation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estimativa da radiação global incidente em superfícies inclinadas por modelos isotrópicos e índice de claridade

O objetivo deste trabalho foi avaliar o desempenho de modelos isotrópicos de estimativa do total de radiação incidente em superfícies inclinadas e propor estimativas com base nas correlações entre os índices de claridade horizontais e inclinados, em diferentes condições de cobertura de céu, em Botucatu, SP. Foram avaliadas superfícies com inclinação de 12,85º, 22,85º e 32,85º, pelos modelos isotrópicos propostos por Liu & Jordan, Revfeim, Jimenez & Castro, Koronakis, a teoria Circunsolar, e a correlação entre os índices de claridade horizontais e inclinados, para diferentes condições de cobertura de céu. O banco de dados de radiação global utilizado corresponde ao período de 1998 a 2007, com intervalos de 4/1998 a 8/2001 para a inclinação de 22,85º, de 9/2001 a 2/2003 para 12,85º e de 1/2004 a 12/2007 para 32,85º. O desempenho dos modelos foi avaliado pelos indicadores estatísticos erro absoluto médio, raiz quadrada do quadrado médio do erro e índice d de Wilmott. Os modelos de Liu & Jordan, Koronakis e de Revfeim apresentaram os melhores desempenhos em dias nublados, em todas as inclinações. As coberturas de céu parcialmente difuso e parcialmente aberto, nos maiores ângulos de inclinação, apresentaram as maiores dispersões entre valores estimados e medidos, independentemente do modelo. As equações estatísticas apresentaram bons resultados em aplicações com agrupamentos de dados mensais.

Mitigation of symmetry condition in positive realness for adaptive control

Feasibility of nonlinear and adaptive control methodologies in multivariable linear time-invariant systems with state-space realization (A, B, C) is apparently limited by the standard strictly positive realness conditions that imply that the product CB must be positive definite symmetric. This paper expands the applicability of the strictly positive realness conditions used for the proofs of stability of adaptive control or control with uncertainty by showing that the not necessarily symmetric CB is only required to have a diagonal Jordan form and positive eigenvalues. The paper also shows that under the new condition any minimum-phase systems can be made strictly positive real via constant output feedback. The paper illustrates the usefulness of these extended properties with an adaptive control example. (C) 2006 Elsevier Ltd. All rights reserved.

Comparative Analysis of 2-Flap Designs for Extraction of Mandibular Third Molar

Objective: The objective of the study was to analyze 2-flap designs for surgical extraction of third molar, evaluating the periodontal status of the second lower molar.Study Design: Forty-five lower third molars were extracted from 24 patients. In 23 teeth, a vertical incision to the mandibular ramus was used (technique A), whereas 22 teeth were submitted to classic L-shaped flap (technique B) with controls at 60 and 90 days postoperatively.Results: Pearson correlation coefficient analysis showed a significant correlation only between immediate preoperative probing depth variables from techniques A and B in the studied surfaces. Statistical significances in the preoperative (vestibular) and postoperative day 60 (distovestibular and vestibular) were noted. In contrast, Student t-test showed no statistical difference in probing depths between preoperative and postoperative values, as well as no statistically significant difference regarding the type of incision alone.Conclusions: Technique A allowed a less traumatic surgery, guaranteeing a more comfortable postoperative period.

Effect of Artificial Aging on the Roughness and Microhardness of Sealed Composites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Clinical and microbiological studies of children and adolescents receiving orthodontic treatment

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Factors affecting on bond strength of glass fiber post cemented with different resin cements to root canal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)