242 research outputs found

    Left-Right Facial Orientation of Familiar Faces: Developmental Aspects of « the Mere Exposure Hypothesis »

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    We investigated the developmental aspect of sensitivity to the orientation of familiar faces by asking 38 adults and 72 children from 3 to 12 years old to make a preference choice between standard and mirror images of themselves and of familiar faces, presented side-by-side or successively. When familiar (parental) faces were presented simultaneously, 3- to 5-year-olds showed no preference, but by age 5–7 years an adult-like preference for the standard image emerged. Similarly, the adult-like preference for the mirror image of their own face emerged by 5–7 years of age. When familiar or self faces were presented successively, 3- to 7-year-olds showed no preference, and adult-like preference for the standard image emerged by age 7–12 years. These results suggest the occurrence of a developmental process in the perception of familiar face asymmetries which is retained in memory related to knowledge about faces

    A Direct Elliptic Solver Based on Hierarchically Low-rank Schur Complements

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    A parallel fast direct solver for rank-compressible block tridiagonal linear systems is presented. Algorithmic synergies between Cyclic Reduction and Hierarchical matrix arithmetic operations result in a solver with O(Nlog2N)O(N \log^2 N) arithmetic complexity and O(NlogN)O(N \log N) memory footprint. We provide a baseline for performance and applicability by comparing with well known implementations of the H\mathcal{H}-LU factorization and algebraic multigrid with a parallel implementation that leverages the concurrency features of the method. Numerical experiments reveal that this method is comparable with other fast direct solvers based on Hierarchical Matrices such as H\mathcal{H}-LU and that it can tackle problems where algebraic multigrid fails to converge

    Adaptive energy minimisation for hp-finite element methods

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    This article is concerned with the numerical solution of convex variational problems. More precisely, we develop an iterative minimisation technique which allows for the successive enrichment of an underlying discrete approximation space in an adaptive manner. Specifically, we outline a new approach in the context of hp-adaptive finite element methods employed for the efficient numerical solution of linear and nonlinear second-order boundary value problems. Numerical experiments are presented which highlight the practical performance of this new hp-refinement technique for both one- and two-dimensional problems

    Aproximaciones experimentales a la fecilidad

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    The recent literature on inequity aversion assumes that subjects compare themselves to others. Our paper studies how a subject evaluates others’ happiness. We do that by combining information from self-reported answers with guessing experiments under economic incentives. The basic result is that 66% of the subjects evaluates others differently from one’s self, and that those who appear to be happier (less happy) tend to believe that others are less happy (happier) than themselves

    Non-Equilibrium Electron Transport in Two-Dimensional Nano-Structures Modeled by Green's Functions and the Finite-Element Method

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    We use the effective-mass approximation and the density-functional theory with the local-density approximation for modeling two-dimensional nano-structures connected phase-coherently to two infinite leads. Using the non-equilibrium Green's function method the electron density and the current are calculated under a bias voltage. The problem of solving for the Green's functions numerically is formulated using the finite-element method (FEM). The Green's functions have non-reflecting open boundary conditions to take care of the infinite size of the system. We show how these boundary conditions are formulated in the FEM. The scheme is tested by calculating transmission probabilities for simple model potentials. The potential of the scheme is demonstrated by determining non-linear current-voltage behaviors of resonant tunneling structures.Comment: 13 pages,15 figure

    INTEGRAL/SPI data segmentation to retrieve sources intensity variations

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    International audienceContext. The INTEGRAL/SPI, X/γ-ray spectrometer (20 keV–8 MeV) is an instrument for which recovering source intensity variations is not straightforward and can constitute a difficulty for data analysis. In most cases, determining the source intensity changes between exposures is largely based on a priori information.Aims. We propose techniques that help to overcome the difficulty related to source intensity variations, which make this step more rational. In addition, the constructed “synthetic” light curves should permit us to obtain a sky model that describes the data better and optimizes the source signal-to-noise ratios.Methods. For this purpose, the time intensity variation of each source was modeled as a combination of piecewise segments of time during which a given source exhibits a constant intensity. To optimize the signal-to-noise ratios, the number of segments was minimized. We present a first method that takes advantage of previous time series that can be obtained from another instrument on-board the INTEGRAL observatory. A data segmentation algorithm was then used to synthesize the time series into segments. The second method no longer needs external light curves, but solely SPI raw data. For this, we developed a specific algorithm that involves the SPI transfer function.Results. The time segmentation algorithms that were developed solve a difficulty inherent to the SPI instrument, which is the intensity variations of sources between exposures, and it allows us to obtain more information about the sources’ behavior

    Stochastic Bundle Adjustment for Efficient and Scalable 3D Reconstruction

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    Current bundle adjustment solvers such as the Levenberg-Marquardt (LM) algorithm are limited by the bottleneck in solving the Reduced Camera System (RCS) whose dimension is proportional to the camera number. When the problem is scaled up, this step is neither efficient in computation nor manageable for a single compute node. In this work, we propose a stochastic bundle adjustment algorithm which seeks to decompose the RCS approximately inside the LM iterations to improve the efficiency and scalability. It first reformulates the quadratic programming problem of an LM iteration based on the clustering of the visibility graph by introducing the equality constraints across clusters. Then, we propose to relax it into a chance constrained problem and solve it through sampled convex program. The relaxation is intended to eliminate the interdependence between clusters embodied by the constraints, so that a large RCS can be decomposed into independent linear sub-problems. Numerical experiments on unordered Internet image sets and sequential SLAM image sets, as well as distributed experiments on large-scale datasets, have demonstrated the high efficiency and scalability of the proposed approach. Codes are released at https://github.com/zlthinker/STBA.Comment: Accepted by ECCV 202

    La adhesión de las enfermeras al Método Canguro: subvención para la administración del cuidado de enfermería

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    ;;OBJETIVO:;; construir um modelo teórico explicativo acerca da adesão das enfermeiras ao Método Canguru na Unidade de Terapia Intensiva Neonatal, a partir dos significados e interações para a gerência do cuidado.;;;;MÉTODO:;; pesquisa qualitativa, guiada pelo referencial da Grounded Theory. Foram entrevistadas oito enfermeiras de uma Unidade de Terapia Intensiva Neonatal da cidade do Rio de Janeiro. A análise comparativa dos dados percorreu as etapas de codificação aberta, axial e seletiva, sendo construído um modelo teórico do tipo condicional-causal.;;;;RESULTADOS:;; emergiram quatro categorias principais que compuseram o paradigma de análise: Vestindo a camisa do Método Canguru; Trabalhando com a complexidade do Método Canguru; Encontrando (des)motivação para aplicar o Método Canguru; e Deparando-se com os desafios para a adesão e aplicação do Método Canguru.;;;;CONCLUSÕES:;; o fenômeno central revelou que cada enfermeira e profissional da equipe possui um papel de multiplicador de valores e práticas que podem ou não ser construtivas, influenciando potencialmente na (des)continuidade do Método Canguru na Unidade de Terapia Intensiva Neonatal. Os achados podem ser utilizados para o delineamento de estratégias gerenciais que ultrapassem os cursos e treinamentos e garantam o fortalecimento do modelo assistencial.;;;;OBJECTIVE:;; construct an explanatory theoretical model about nurses' adherence to the Kangaroo Care Method at the Neonatal Intensive Care Unit, based on the meanings and interactions for care management.;;;;METHOD:;; qualitative research, based on the reference framework of the Grounded Theory. Eight nurses were interviewed at a Neonatal Intensive Care Unit in the city of Rio de Janeiro. The comparative analysis of the data comprised the phases of open, axial and selective coding. A theoretical conditional-causal model was constructed.;;;;RESULTS:;; four main categories emerged that composed the analytic paradigm: Giving one's best to the Kangaroo Method; Working with the complexity of the Kangaroo Method; Finding (de)motivation to apply the Kangaroo Method; and Facing the challenges for the adherence to and application of the Kangaroo Method.;;;;CONCLUSIONS:;; the central phenomenon revealed that each nurse and team professional has a role of multiplying values and practices that may or may not be constructive, potentially influencing the (dis)continuity of the Kangaroo Method at the Neonatal Intensive Care Unit. The findings can be used to outline management strategies that go beyond the courses and training and guarantee the strengthening of the care model.;;;;OBJETIVO:;; construir un modelo teórico explicativo acerca de la adhesión de las enfermeras al Método Canguro en la Unidad de Terapia Intensiva Neonatal, a partir de los significados e interacciones para la administración del cuidado.;;;;MÉTODO:;; investigación cualitativa, guiada por el referencial de la Grounded Theory. Fueron entrevistadas ocho enfermeras de una Unidad de Terapia Intensiva Neonatal de la ciudad de Rio de Janeiro. El análisis comparativo de los datos recorrió las etapas de codificación abierta, axial y selectiva, siendo construido un modelo teórico del tipo condicional-causal.;;;;RESULTADOS:;; surgieron cuatro categorías principales que compusieron los paradigmas del análisis: Vistiendo la camisa del Método Canguro; Trabajando con la complejidad del Método Canguro; Encontrando (des)motivación para aplicar el Método Canguro; y Encontrando los desafíos para la adhesión y aplicación del Método Canguro.;;;;CONCLUSIONES:;; el fenómeno central reveló que cada enfermera y profesional del equipo posee un papel de multiplicador de valores y prácticas que pueden o no ser constructivas, influenciando potencialmente en la (des)continuidad del Método Canguro en la Unidad de Terapia Intensiva Neonatal. Los hallazgos pueden ser utilizados para el delineamiento de estrategias de administración que sobrepasen los cursos y entrenamientos y garanticen el fortalecimiento del modelo asistencial.;
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