372 research outputs found
Energetics, skeletal dynamics and long-term predictions in Kolmogorov-Lorenz systems
We study a particular return map for a class of low dimensional chaotic
models called Kolmogorov Lorenz systems, which received an elegant general
Hamiltonian description and includes also the famous Lorenz63 case, from the
viewpoint of energy and Casimir balance. In particular it is considered in
detail a subclass of these models, precisely those obtained from the Lorenz63
by a small perturbation on the standard parameters, which includes for example
the forced Lorenz case in Ref.[6]. The paper is divided into two parts. In the
first part the extremes of the mentioned state functions are considered, which
define an invariant manifold, used to construct an appropriate Poincare surface
for our return map. From the experimental observation of the simple orbital
motion around the two unstable fixed points, together with the circumstance
that these orbits are classified by their energy or Casimir maximum, we
construct a conceptually simple skeletal dynamics valid within our sub class,
reproducing quite well the Lorenz map for Casimir. This energetic approach
sheds some light on the physical mechanism underlying regime transitions. The
second part of the paper is devoted to the investigation of a new type of
maximum energy based long term predictions, by which the knowledge of a
particular maximum energy shell amounts to the knowledge of the future
(qualitative) behaviour of the system. It is shown that, in this respect, a
local analysis of predictability is not appropriate for a complete
characterization of this behaviour. A perspective on the possible extensions of
this type of predictability analysis to more realistic cases in (geo)fluid
dynamics is discussed at the end of the paper.Comment: 21 pages, 14 figure
Energy-based predictions in Lorenz system by a unified formalism and neural network modelling
In the framework of a unified formalism for Kolmogorov-Lorenz systems, predictions of times of regime transitions in the classical Lorenz model can be successfully achieved by considering orbits characterised by energy or Casimir maxima. However, little uncertainties in the starting energy usually lead to high uncertainties in the return energy, so precluding the chance of accurate multi-step forecasts. In this paper, the problem of obtaining good forecasts of maximum return energy is faced by means of a neural network model. The results of its application show promising results
Numerical simulation of nonunitary gravity-induced localization
The localization of a quantum state is numerically exhibited in a nonunitary
Newtonian model for gravity. It is shown that an unlocalized state of a ball of
mass just above the expected threshold of 10^11 proton masses evolves into a
mixed state with vanishing coherences above some localization lengths.Comment: RevTex, 6 figures available on request from the authors To appear in
Physica
“Fantasmas” na mecânica quântica
CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCan you pick a complex subject in quantum mechanics and discuss it with a minimum number of equations, in a simplified form that the general scientific public could understand? This was a question presented to graduate students of the one-year Quantum Mechanics course based on the text book Modern Quantum Mechanics by J. J. Sakurai and Jim Napolitano, at the State University of Campinas (UNICAMP), Brazil. The first seven authors of this paper are graduate students (alphabetical order) that accepted to try it. The chosen subject was "delocalized quantum states", and it will be discussed using colloquial terms like quantum ghosts, spooky action, splitting beings and invisibility cloak. © Sociedade Brasileira de Física. Printed in Brazil.Can you pick a complex subject in quantum mechanics and discuss it with a minimum number of equations, in a simplified form that the general scientific public could understand? This was a question presented to graduate students of the one-year Quantum Mechanics course based on the text book Modern Quantum Mechanics by J. J. Sakurai and Jim Napolitano, at the State University of Campinas (UNICAMP), Brazil. The first seven authors of this paper are graduate students (alphabetical order) that accepted to try it. The chosen subject was "delocalized quantum states", and it will be discussed using colloquial terms like quantum ghosts, spooky action, splitting beings and invisibility cloak.383111CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOSem informaçãoSem informaçãoSem informaçãoPode-se escolher um topico complexo em mecanica quantica e discuti-lo com um numero mınimo de equações, e de forma simplificada para que um publico com apenas conhecimento basico em fısica possa entender? Essa foi a pergunta apresentada aos alunos de pos-graduação das disciplinas de um ano de Mecanica Quantica I e II da Universidade Estadual de Campinas (UNICAMP), baseadas no livro “Quantum Mechanics” de J. J. Sakurai e Jim Napolitano. Os primeiros sete autores desse artigosão os alunos de pos-graduação (em ordem alfabetica) que aceitaram o desafio. O topico escolhido foi estados quanticos delocalizados, e sera discutido utilizando termos coloquiais como fantasmas quanticos, ações fantasmagoricas, entidades divididas e capa de invisibilidade.G.M.A., D.T.M, M.M. and M.A.P.L acknowledge support from the Brazilian agency “Conselho Nacional de Desenvolvimento Científico e Tecnológico” (CNPq). D.Q.A., L.F.M.C, and S.I.C.G acknowledge support from the Brazilian agency “Coordenação de Aperfeiçoamento de Pessoal de Nível Superior” (CAPES), and L.F.C.F acknowledges support from the Brazilian state of São Paulo agency “Fundação de Amparo à Pesquisa do Estado de São Paulo” (FAPESP). The authors thank Amanda A. R. Lima for drawing the inspiring figure 2. The authors are grateful to Profs. Michael Brunger, Prof. Amir Caldeira and Prof. José A. Roversi for their critical reading of the manuscript and constructive comments and suggestions. The authors also thank for critical reading of this manuscript, the following group of people of the aimed public target: Paulo S. P. Lima (Mechanical Engineer), Martín E. Navarro Maldonado (Chemical Engineer), and Luis Quesada (Professor of Computer Science and Informatics)
The support model for people with legally modified abilities according to United Nations
Este artículo se basa en una investigación social sobre el sistema de protección jurídica de las personas con algún tipo de discapacidad o en situación de dependencia que se encuentran sometidas a las figuras de tutela o curatela, en aplicación de lo previsto y establecido en el Código Civil Español, en sus artículos 199 y 200, así como en la Ley de Enjuiciamiento Civil. La investigación se plantea como un estudio comparado entre diferentes países de la Unión Europea para ver su adecuación a lo establecido en el artículo 12 de la Convención de Naciones Unidas sobre derechos de las Personas con Discapacidad (en adelante, CDPD) en los procedimientos de incapacitación. Los resultados se analizan sobre la base de modelos técnico-sociales de intervención, los análisis jurídicos y la experiencia adquirida por las Fundación Tutelares de Castilla y León. Se proponen y diseñan algunas alternativas y servicios que pueden mejorar la calidad de vida de las personas adultas incapacitadas judicialmente y el tipo de apoyos que se les puede prestar, de acuerdo a lo establecido en la Convención de Naciones Unidas.This article is based on social research into the system of legal protection for persons with disabilities or in a situation of dependence who are subject to the figures of guardianship or conservatorship pursuant to the provisions in the Spanish Civil Code, sections 199 and 200, as well as the Code of Civil Procedure. The research is presented as a comparative study between different countries of the European Union regarding the adaptation to the provisions of Article 12 of the UN Convention on Rights of Persons with Disabilities (hereinafter CRPD) Incapacitation procedures. The results are analyzed on the basis of technical-social intervention models, legal analysis and the experience of Guardianship Foundations of Castilla y León. Some alternatives and services are proposed and designed that can improve the quality of life of legally incapacitated persons and the type of support that can be provided to them in accordance with the provisions of the United Nations Convention
Ontology-Driven Food Category Classification in Images
The self-management of chronic diseases related to dietary habits includes the necessity of tracking what people eat. Most of the approaches proposed in the literature classify food pictures by labels describing the whole recipe. The main drawback of this kind of strategy is that a wrong prediction of the recipe leads to a wrong prediction of any ingredient of such a recipe. In this paper we present a multi-label food classification approach, exploiting deep neural networks, where each food picture is classified with labels describing the food categories of the ingredients in each recipe. The aim of our approach is to support the detection of food categories in order to detect which one might be dangerous for a user affected by chronic disease. Our approach relies on background knowledge where recipes, food categories, and their relatedness with chronic diseases are modeled within a state-of-the-art ontology. Experiments conducted on a new publicly released dataset demonstrated the effectiveness of the proposed approach with respect to state-of-the-art classification strategies
- …