Time filter

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Fragoso M.D.,Brazilian National Council for Scientific and Technological Development | Costa O.L.V.,University of Sao Paulo
IEEE Transactions on Automatic Control | Year: 2010

In this paper, we devise a separation principle for the finite horizon quadratic optimal control problem of continuous-time Markovian jump linear systems driven by a Wiener process and with partial observations. We assume that the output variable and the jump parameters are available to the controller. It is desired to design a dynamic Markovian jump controller such that the closed loop system minimizes the quadratic functional cost of the system over a finite horizon period of time. As in the case with no jumps, we show that an optimal controller can be obtained from two coupled Riccati differential equations, one associated to the optimal control problem when the state variable is available, and the other one associated to the optimal filtering problem. This is a separation principle for the finite horizon quadratic optimal control problem for continuous-time Markovian jump linear systems. For the case in which the matrices are all time-invariant we analyze the asymptotic behavior of the solution of the derived interconnected Riccati differential equations to the solution of the associated set of coupled algebraic Riccati equations as well as the mean square stabilizing property of this limiting solution. When there is only one mode of operation our results coincide with the traditional ones for the LQG control of continuous-time linear systems. © 2006 IEEE. Source

Silva M.V.,Brazilian National Council for Scientific and Technological Development
Revista brasileira de enfermagem | Year: 2012

This article aims to make a critical-reflexive analysis about the nursing auditory, observing its limits and possibilities as well as its theoretical and practical aspects. The nursing auditory, nowadays, is practiced and advertised in public and private institutions, aiming to minimize material, medication, equipment and human resources loss. It is important to mention the presence of the nursing group which was fundamental to the auditory process. The professional nurse in auditory is responsible for the quality of the assistance directed towards the patient. There are many challenges involving the development of the nursing auditory, such as the discovery of a professional identity and the integration with auditory nurses all over the country, among others. Source

Nascimento G.L.,University of Brasilia | De Oliveira M.R.F.,University of Brasilia | De Oliveira M.R.F.,Brazilian National Council for Scientific and Technological Development
Transactions of the Royal Society of Tropical Medicine and Hygiene | Year: 2014

Background: Schistosoma mansoni infection is generally asymptomatic at the initial stage. However, patients left untreated can develop severe, potentially fatal clinical disease. In Brazil, S. mansoni transmission occurs in 19 states and, despite the contribution of infection to the cycle of poverty and disease, the economic impact of severe cases is unclear. Our objectives were to estimate the epidemiological burden and the costs of severe stages of S. mansoni in Brazil in 2010. Methods:We conducted an epidemiologic descriptive study and a partial economic evaluation of cost-of-illness. The study population was identified from records of notifications, hospitalizations and deaths related to S. mansoni in the respective information systems. Results: The mortality rate for S. mansoni was 0.3 deaths per 100 000 population, which represented 1.1% of the deaths in Brazil from infectious diseases listed in Chapter I of the International Statistical Classification of Disease and Related Health Problems, 10th revision (ICD 10), and almost 9.0% of deaths from infection diseases in the state of Pernambuco. We calculated 6419 potential years of life lost (PYLL) to S. mansoni. The costs estimated within the public health sector totaled R$889 049.58 (US$495 016.47) and the costs of productivity losses reached R$ 35 725 332.72 (US$ 19 891 590.86) in terms of salaries lost as a result of premature death or absence from work. The cost-of-illness related to S. mansoni in Brazil was R$ 36 614 382.30 (US$ 20 386 627.12). Conclusion: The severe cases of S. mansoni disease still occurring in Brazil have an important epidemiologic and economic impact, representing a significant loss for society. The development of severe cases of a neglected parasitic disease that is preventable and responsive to primary healthcare intervention should be considered an expression of inequity. Our findings provide important evidence to support the strengthening of public health measures and investment to reduce poverty-related diseases in Brazil today. © The Author 2013. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. Source

De Oliveira R.P.,Brazilian National Council for Scientific and Technological Development
Scientia Agraria | Year: 2011

The aim of this work was to compare the agronomic performance of Ventana, Aromas and Camarosa strawberries cultivars. The experiment was carried out in Pelotas, Rio Grande do Sul state, using tunnel system and plants imported from Chile. In June 2007, the genetic material were transplanted at the distance of 35 cm between lines and between plants. The experimental design was a randomized complete block with split plot and four replications. The experimental units were composed by 20 plants. Weekly, from August to December, the variables fruit fresh weight and number of fruits produced in each experimental unit were studied. Aromas and Camarosa cultivars showed greater regularity of the fruit production, and Camarosa and Ventana cultivars greater precocity. Aromas, Camarosa and Ventana cultivars were similar about agronomic performance, with an average production of 709, 740 and 692 g of commercial fruits per plant. The average mass of de fruit of the cultivar Ventana is high (> 24,1 g) until the twelfth week of production, although not statistically different for this variable with the cultivar Ventana, the 5th to 8 weeks. Source

Todorov M.G.,Brazilian National Council for Scientific and Technological Development | Fragoso M.D.,Brazilian National Council for Scientific and Technological Development
Automatica | Year: 2013

This paper is concerned with the robust analysis and control of continuous-time Markov jump linear systems. The centerpiece of the paper is an alternative to the small-gain theorem, which hinges on the robustification of a certain adjoint Lyapunov operator. By means of this technique, it is proven that the small-gain theorem of Markov jump linear systems may sometimes be arbitrarily conservative, even when nonlinear Lipschitz disturbances are taken into account. The adjoint approach, on the other hand, provides the maximal degree of robustness for this particular setup. In addition, we prove that the adjoint design of controllers is solved more efficiently than the design based on small-gain analysis. Bearing these new facts in mind, we derive an iterative algorithm for the design of robust controllers, based on linear matrix inequalities. By means of numerical examples, regarding the robust control of an underactuated manipulator arm and of a simplified power systems model, it is shown that the adjoint design methodology can be much more advantageous than its small-gain counterpart. © 2012 Elsevier Ltd. All rights reserved. Source

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