oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 93 )

2018 ( 145 )

2017 ( 119 )

2016 ( 141 )

Custom range...

Search Results: 1 - 10 of 61428 matches for " Pierre;Silva "
All listed articles are free for downloading (OA Articles)
Page 1 /61428
Display every page Item
Rela??o sociocultural dos brinquedos artesanais vendidos em feiras livres
Antério, Djavan;Gomes-da-Silva, Pierre Normando;
Educa??o & Realidade , 2012, DOI: 10.1590/S2175-62362012000300012
Abstract: the research aimed to analyze the sociocultural meaning of craft toys sold in street fair. this is a research of qualitative, descriptive and field approach. the participants were sellers of handmade toys in the cities of campina grande and joao pessoa, the main in paraíba state. we used the semistructured interview and direct observation in field diary. it was concluded that the handcrafted toys have important meanings for the market trader sellers of these objects, especially with concerns to the period of childhood experienced, to the intergenerational meaning added to the cultural history of the toy and to the educational reality of the subjects.
Chlorination of isatins with trichloroisocyanuric acid
Silva, Bárbara V;Esteves, Pierre M;Pinto, Angelo C;
Journal of the Brazilian Chemical Society , 2011, DOI: 10.1590/S0103-50532011000200010
Abstract: isatin and its derivatives have been extensively reported in the literature as having range of potential pharmacological compounds. the sandmeyer method is the most widely used for isatin synthesis and furnishes different substituted isatins, usually with high yields. although efficient, the sandmeyer route has certain limitations, such as the formation of a mixture of regiosiomers and low yields depending on the type and position of the substituent. thus, overcome these limitations, it is preferable that some derivative isatins be obtained by alternative methods. this article has investigated the chlorination of isatin derivatives using trichloroisocyanuric acid [1,3,5-trichloro 1,3,5-triazine-2,4,6-(1h,3h,5h)-trione or tcca] at different reaction conditions.
Mechanisms of immune protection in the asexual blood stage infection by Plasmodium falciparum: analysis by in vitro and ex-vivo assays
Gysin, Jurg;Druilhe, Pierre;Silva, Luiz Pereira da;
Memórias do Instituto Oswaldo Cruz , 1992, DOI: 10.1590/S0074-02761992000900023
Abstract: mechanisms of immune protection against the asexual blood stage infection by plasmodium falciparum are reviewed. recent studies of two independent lines of research developed at the institute pasteur, in humans and primate infections clearly indicate an obligatory interaction of antibodies and effector cells to express the anti-parasitic effect.
Eternamente jovem: corpo malhado, fic o televisual e imaginário Forever young: worked-out body, televisional fiction and imaginary Eternamente joven: cuerpo forte, ficción televisual e imaginación
Pierre Normando Gomes da Silva,Eunice Sim?es Lins GOMES
Pensar a Prática , 2008, DOI: 19806183/rpp.v11i2.1795
Abstract: Este artigo interpreta as imagens televisuais do corpo, numa fic o seriada ";Malha o";, com vistas a compreender o imaginário coletivo que circula nas academias de ginástica, ou melhor, objetiva interpretar a estrutura mitológica da cultura do jovem (PERREIRA, 2004; KHEL, 2004). Para isso, utilizamos como metodologia a técnica do Formismo (jogo das aparências) de Maffesoli (1996; 1998) e a técnica de análise das imagens proposta por Aumont (1995). O resultado obtido foi a correla o por semelhan a entre: os corpos ensolarados e o mito de Apolo, a civiliza o dos corpos malhados e o país dos hiperbóreos, a academia de ginástica e o bosque de Epidauro. This article interprets the televisional body images, in a serial fiction ";Malha o";, aiming to understand the collective imaginary that is found in gymnastic academies, better yet, aims to figure out the mythological structure of the youth culture (PERREIRA, 2004; KHEL, 2004). For this reason, we used the Bodybuilding technique as our methodology (the appearance game) by Maffesoli (1996; 1998) and the image analysis technique proposed by Aumont (1995). The obtained result was the correlation through resemblance between the sunny bodies and Apollo’s myth, the worked-out civilization and the hyperborean country, the gymnastic academy and the Epidaurus wood, the working out machines or the body-machine and the Greek mechanè of the Dionysiac theatre plays. Este artículo interpreta las imágenes televisivas del cuerpo en la ficción seriada “Malha o"; intentando comprender la imaginación colectiva que circula en las academias de gimnasia, o mejor, objetiva interpretar la estructura mitológica da cultura de los jóvenes (PERREIRA, 2004, KHEL, 2004). Para esto, utilizamos como metodología la técnica do “formismo” (juego de las apariencias), de Maffesoli (1996, 1998) y la técnica de análisis de imágenes propuesta por Aumont (1995). El resultado obtenido fue la correlación por semejanzas entre: los cuerpos soleados y el mito de Apolo, la civilización de los cuerpos esculturales y el país de los hiperbóreos, la academia de gimnasia y el bosque Epidauro.
Synthèse sonore de la clarinette avec modèle de résonateur à trous latéraux optimisé sur des impédances d'entrée d'une clarinette réelle
Fabrice Silva,Philippe Guillemain,Jean Kergomard,Jean-Pierre Dalmont
Physics , 2009,
Abstract: Sound synthesis can be developed using physics-based modelling of the musical instruments. These methods need the description of the various parts of sound production mechanism, in particular a model of the acoustic resonator that have to be simple enough due to the real-time constraint. However, in the case of the clarinet, the bore is quite not a cylindrical tube. An implementation of a resonator including a open-tone holes lattice is presented in this paper.
Stabilization for an ensemble of half-spin systems
Karine Beauchard,Paulo Sergio Pereira da Silva,Pierre Rouchon
Mathematics , 2010,
Abstract: Feedback stabilization of an ensemble of non interacting half spins described by Bloch equations is considered. This system may be seen as a prototype for infinite dimensional systems with continuous spectrum. We propose an explicit feedback law that stabilizes asymptotically the system around a uniform state of spin +1/2 or -1/2. The proof of the convergence is done locally around the equilibrium in the H^1 topology. This local convergence is shown to be a weak asymptotic convergence for the H^1 topology and thus a strong convergence for the C^0 topology. The proof relies on an adaptation of the LaSalle invariance principle to infinite dimensional systems. Numerical simulations illustrate the efficiency of these feedback laws, even for initial conditions far from the equilibrium
A Flat Triangular Form for Nonlinear Systems with Two Inputs: Necessary and Sufficient Conditions
Hector Bessa Silveira,Paulo Sergio Pereira da Silva,Pierre Rouchon
Mathematics , 2013,
Abstract: The present work establishes necessary and sufficient conditions for a nonlinear system with two inputs to be described by a specific triangular form. Except for some regularity conditions, such triangular form is flat. This may lead to the discovery of new flat systems. The proof relies on well-known results for driftless systems with two controls (the chained form) and on geometric tools from exterior differential systems. The paper also illustrates the application of its results on an academic example and on a reduced order model of an induction motor.
Stabilization of an arbitrary profile for an ensemble of half-spin systems
Karine Beauchard,Paulo Sergio Pereira da Silva,Pierre Rouchon
Mathematics , 2012,
Abstract: We consider the feedback stabilization of a variable profile for an ensemble of non interacting half spins described by the Bloch equations. We propose an explicit feedback law that stabilizes asymptotically the system around a given arbitrary target profile. The convergence proof is done when the target profile is entirely in the south hemisphere or in the north hemisphere of the Bloch sphere. The convergence holds for initial conditions in a H^1 neighborhood of this target profile. This convergence is shown for the weak H^1 topology. The proof relies on an adaptation of the LaSalle invariance principle to infinite dimensional systems. Numerical simulations illustrate the efficiency of these feedback laws, even for initial conditions far from the target profile.
Quantum Gate Generation by T-Sampling Stabilization
Hector Bessa Silveira,Paulo Sergio Pereira da Silva,Pierre Rouchon
Mathematics , 2013,
Abstract: This paper considers right-invariant and controllable driftless quantum systems with state X(t) evolving on the unitary group U(n) and m inputs. The T-sampling stabilization problem is introduced and solved: given any initial condition X(0) any goal state Xg find a feedback law such that X(jT) converges to Xg as the integer j tends to infinity. The purpose is to generate arbitrary quantum gates corresponding to Xg. This is achieved by the tracking of T-periodic reference trajectories that pass by Xg using the framework of Coron's Return Method. The T-periodic reference trajectories are generated by applying open-loop controls that are a sum of a finite number M of odd T-periodic function whose amplitudes are parameterized by a vector. The main result establishes that, for M big enough, X(jT) exponentially converges towards Xg for almost all fixed amplitude vectors, with explicit and completely constructive control laws. This paper also establishes a stochastic version of this deterministic control law. The key idea is to randomly choose a different amplitude vector at each sampling time jT, and keeping it fixed until the next sampling time (j+1)T. It is also shown that X(jT) exponentially converges towards Xg almost surely. Simulation results have indicated that the convergence speed may be significantly improved with such stochastic technique. This is illustrated in the generation of the C--NOT quantum logic gate on U(4).
Stabilization of photon-number states via single-photon corrections: a first convergence analysis under an ideal set-up
Hector Bessa Silveira,Paulo Sergio Pereira da Silva,Pierre Rouchon
Mathematics , 2015,
Abstract: This paper presents a first mathematical convergence analysis of a Fock states feedback stabilization scheme via single-photon corrections. This measurement-based feedback has been developed and experimentally tested in 2012 by the cavity quantum electrodynamics group of Serge Haroche and Jean-Michel Raimond. Here, we consider the infinite-dimensional Markov model corresponding to the ideal set-up where detection errors and feedback delays have been disregarded. In this ideal context, we show that any goal Fock state can be stabilized by a Lyapunov-based feedback for any initial quantum state belonging to the dense subset of finite rank density operators with support in a finite photon-number sub-space. Closed-loop simulations illustrate the performance of the feedback law.
Page 1 /61428
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.