Can Drag Force Suppress Fermi Acceleration in a Bouncer Model?

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

On the denominator values and barycentric weights of rational interpolants

We improve upon the method of Zhu and Zhu [A method for directly finding the denominator values of rational interpolants, J. Comput. Appl. Math. 148 (2002) 341-348] for finding the denominator values of rational interpolants, reducing considerably the number of arithmetical operations required for their computation. In a second stage, we determine the points (if existent) which can be discarded from the rational interpolation problem. Furthermore, when the interpolant has a linear denominator, we obtain a formula for the barycentric weights which is simpler than the one found by Berrut and Mittelmann [Matrices for the direct determination of the barycentric weights of rational interpolation, J. Comput. Appl. Math. 78 (1997) 355-370]. Subsequently, we give a necessary and sufficient condition for the rational interpolant to have a pole. (c) 2006 Elsevier B.V. All rights reserved.

A class of multiobjective control problems

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

ANALISE FAMILIAL DO COMPORTAMENTO IN VITRO DOS MACROFAGOS HUMANOS FRENTE AO MYCOBACTERIUM LEPRAE

The lysogenic capacity of human macrophages facing M. leprae in vitro may be dependent on an important genetic component. Although the familial aggregation of the trait is demonstrated, this is a necessary but not sufficient condition to prove genetic influence. The data do not fit some simple genetic models (autosomal dominant or incompletely dominant gene; dominant or recessive sex-linked gene). The results obtained are consistent with the hypothesis that the macrophages' lysogenic capacity is mainly due to a major gene with variable expressivity. This hypothesis may be too simple to account for the whole variability detected and therefore must be considered a working hypothesis.

Global optimization for the ℋ∞-norm model reduction problem

A branch and bound algorithm is proposed to solve the [image omitted]-norm model reduction problem for continuous and discrete-time linear systems, with convergence to the global optimum in a finite time. The lower and upper bounds in the optimization procedure are described by linear matrix inequalities (LMI). Also proposed are two methods with which to reduce the convergence time of the branch and bound algorithm: the first one uses the Hankel singular values as a sufficient condition to stop the algorithm, providing to the method a fast convergence to the global optimum. The second one assumes that the reduced model is in the controllable or observable canonical form. The [image omitted]-norm of the error between the original model and the reduced model is considered. Examples illustrate the application of the proposed method.

A note on KKT-invexity in nonsmooth continuous-time optimization

We introduce the notion of KKT-inverity for nonsmooth continuous-time nonlinear optimization problems and prove that this notion is a necessary and sufficient condition for every KKT solution to be a global optimal solution.

Trade and poverty in Paraguay: the case of an agribusiness value chain

Incluye bibliografía

Trade and poverty in Paraguay: the case of an agribusiness value chain

Includes bibliography

Pension funds and the financing productive investment: an analysis based on Brazil's recent experience

Includes bibliography

Semigrupos de operadores lineares limitados: soluções Mild e Weak

Pós-graduação em Matemática - IBILCE

Álgebras de Lie e aplicações à sistemas alternantes

Pós-graduação em Matemática - IBILCE

Novo comportamento crítico da singularidade de Yang-Lee

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estabilidade estocástica de sistemas lineares com Saltos Markovianos e Sistemas Lineares com Saltos Semimarkovianos

Pós-graduação em Matematica Aplicada e Computacional - FCT

Determinação de parâmetros reológicos de argamassas e concreto através de técnicas alternativas

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

Análise ergonômica de equipamentos odontológicos

This is study proposes to evaluate the ergonomic aspects of dental equipments. Based on the characteristics proposed by ISO/FDI, on the existing literature and related researches an evaluating system was devised. Thirty nine dental clinics were examined using the 165 pointssystem proposed, distributed in 12 criteria. None of the dental clinics examined showed a bad ergonomics level, 41% were good and 59% reached excellent levels. The point-supported evaluation system proposed is effective in the analysis of the ergonomic conditions of dental equipments, allowing a quantification of their characteristics. Using this system, the dentist can also know the level of ergonomic satisfaction existing in his equipment, and identify the conditions to be improved. It was concluded that the equipment belonging to dental workplaces evaluated had excellent level of compliance, however corrective measures are needed since even the presence of a few non-conforming items is a sufficient condition to cause injury to users, decreased efficiency and comfort and loss quality of service