Instituto Tecnologico Of Aeronutica

São José dos Campos, Brazil

Instituto Tecnologico Of Aeronutica

São José dos Campos, Brazil
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Bellotti F.F.,Instituto Tecnologico Of Aeronutica | Frederico T.,Instituto Tecnologico Of Aeronutica | Yamashita M.T.,Paulista University | Fedorov D.V.,University of Aarhus | And 2 more authors.
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2011

The momentum space zero-range model is used to investigate universal properties of three interacting particles confined to two dimensions. The pertinent equations are first formulated for a system of two identical and one distinct particle and the two different two-body subsystems are characterized by two-body energies and masses. The three-body energy in units of one of the two-body energies is a universal function of the other two-body energy and the mass ratio. We derive convenient analytical formulae for calculations of the three-body energy as a function of these two independent parameters and exhibit the results as universal curves. In particular, we show that the three-body system can have any number of stable bound states. When the mass ratio of the distinct to identical particles is greater than 0.22, we find that at most two stable bound states exist, while for two heavy and one light mass an increasing number of bound states is possible. The specific number of stable bound states depends on the ratio of two-body bound state energies and on the mass ratio, and we map out an energy-mass phase diagram of the number of stable bound states. Realizable systems of both fermions and bosons are discussed in this framework. © 2011 IOP Publishing Ltd.

Guimaraes K.S.F.F.,Institute Astronomia | Lourenco O.,Federal University of São Carlos | De Paula W.,Instituto Tecnologico Of Aeronutica | Frederico T.,Instituto Tecnologico Of Aeronutica | Dos Reis A.C.,Brazilian Center for Research in Physics (CBPF)
Journal of High Energy Physics | Year: 2014

The final state interaction contribution to D + decays is computed for the K - π + π + channel within a light-front relativistic three-body model for the final state interaction. The rescattering process between the kaon and two pions in the decay channel is considered. The off-shell decay amplitude is a solution of a four-dimensional Bethe-Salpeter equation, which is decomposed in a Faddeev form. The projection onto the light-front of the coupled set of integral equations is performed via a quasi-potential approach. The S-wave Kπ interaction is introduced in the resonant isospin 1/2 and the non-resonant isospin 3/2 channels. The numerical solution of the light-front tridimensional inhomogeneous integral equations for the Faddeev components of the decay amplitude is performed perturbatively. The loop-expansion converges fast, and the three-loop contribution can be neglected in respect to the two-loop results for the practical application. The dependence on the model parameters in respect to the input amplitude at the partonic level is exploited and the phase found in the experimental analysis, is fitted with an appropriate choice of the real weights of the isospin components of the partonic amplitude. The data suggests a small mixture of total isospin 5/2 to the dominant 3/2 one. The modulus of the unsymmetrized decay amplitude, which presents a deep valley and a following increase for Kπ masses above 1.5 GeV, is fairly reproduced. This suggests the assignment of the quantum numbers 0+ to the isospin 1/2 K *(1630) resonance. © 2014 The Author(s).

Dos Santos D.A.,Brazilian Technological Institute of Aeronautics | Yoneyama T.,Instituto Tecnologico Of Aeronutica
Automatica | Year: 2011

This paper is concerned with model-based isolation and estimation of additive faults in discrete-time linear Gaussian systems. The isolation problem is stated as a multiple composite hypothesis testing on the innovation sequence of the Kalman filter (KF) that considers the system operating under fault-free conditions. Fault estimation is carried out, after isolating a fault mode, by using the Maximum a Posteriori (MAP) criterion. An explicit solution is presented for both fault isolation and estimation when the parameters of the fault modes are assumed to be realizations of specific random variables (RV). © 2010 Elsevier Ltd. All rights reserved.

Pessoa R.S.,Instituto Tecnologico Of Aeronutica | Tezani L.L.,Instituto Tecnologico Of Aeronutica | MacIel H.S.,Instituto Tecnologico Of Aeronutica | Petraconi G.,Instituto Tecnologico Of Aeronutica | Massi M.,Instituto Tecnologico Of Aeronutica
Plasma Sources Science and Technology | Year: 2010

In this work, electrical and optical studies of SF6 and SF 6/O2 plasmas generated in a hollow cathode reactive ion etching reactor were performed using the Langmuir probe and optical emission spectroscopy techniques, respectively. We carried out an investigation aimed at understanding the influence of radio-frequency power, gas pressure and O 2 gas mixing ratio on plasma parameters, namely electron temperature, electron density and electronegativity, and also atomic fluorine density. The results indicate an increase of up to one order of magnitude in electron density and atomic fluorine in the overall gas volume when compared with a conventional reactive ion etching plasma generated under the same operation conditions. © 2010 IOP Publishing Ltd.

de Athayde Costa e Silva M.,Instituto Tecnologico Of Aeronutica | de Figueiredo H.V.,Instituto Tecnologico Of Aeronutica | Boglietti B.G.N.,Parque Tecnológico São José dos Campos | Saotome O.,Instituto Tecnologico Of Aeronutica | And 2 more authors.
Journal of Control, Automation and Electrical Systems | Year: 2014

This paper proposes a framework that combines three different environments with decreasing level of abstraction: model-in-the-loop, software-in-the-loop and hardware-in-the-loop. The purpose of the framework is to support the early detection of errors in the development of satellite control systems. Associated with the framework, the paper presents the MuSat simulator, a testbed for the development of satellite attitude controllers. MuSat is composed of a sphere that rotates with three degrees of freedom, supported by an air bearing system. The on-board computer of MuSat follows the integrated modular architecture, proposed for avionics systems. In order to illustrate both the framework and the testbed, we present the development of a non-linear control scheme. Results indicate that the designed control system fulfils the specified requirements. The example highlights the contribution of each environment of the framework for control system verification. © 2014, Brazilian Society for Automatics--SBA.

Sousa Silva P.A.,Instituto Tecnologico Of Aeronutica | Terra M.O.,Instituto Tecnologico Of Aeronutica
Journal of Physics: Conference Series | Year: 2010

In this contribution the weak stability boundary algorithmic definition was numerically accomplished with the inclusion of lunar and earth collisional sets and a subclassification of the unstable set. Then, the associated sets to WSB definition were analyzed and characterized according to relevant dynamical properties in order to clarify their applicability in earth-moon transfer orbit design. The obtained stable, unstable, and collisional sets are defined as a function of the osculating ellipse eccentricity for prograde and retrogade initial conditions. The stable sets, candidates to ballistic capture transfers, are subclassified according to chosen specific criteria, namely, the Jacobi constant intervals defined by distinct classes of Hill regions, the location of the final state after a complete cycle with respect to the Hill sphere, the permanence in the lunar sphere of influence in a full cycle around the moon, and exit basins for retrograde evolution. By the first time, with this investigation, elucidative criteria based on three-body problem elements are employed to identify initial condition subsets with required properties to design ballistic capture transfers. © 2010 IOP Publishing Ltd.

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