3,118 research outputs found

    Multi-feature Bottom-up Processing and Top-down Selection for an Object-based Visual Attention Model

    Get PDF
    Artificial vision systems can not process all the information that they receive from the world in real time because it is highly expensive and inefficient in terms of computational cost. However, inspired by biological perception systems, it is possible to develop an artificial attention model able to select only the relevant part of the scene, as human vision does. This paper presents an attention model which draws attention over perceptual units of visual information, called proto-objects, and which uses a linear combination of multiple low-level features (such as colour, symmetry or shape) in order to calculate the saliency of each of them. But not only bottom-up processing is addressed, the proposed model also deals with the top-down component of attention. It is shown how a high-level task can modulate the global saliency computation, modifying the weights involved in the basic features linear combination.Ministerio de Economía y Competitividad (MINECO), proyectos: TIN2008-06196 y TIN2012-38079-C03-03. Campus de Excelencia Internacional Andalucía Tech

    Stability results for 2D Navier-Stokes equations with unbounded delay

    Get PDF
    Some results related to 2D Navier-Stokes equations when the external force contains hereditary characteristics involving unbounded delays are analyzed. First, the existence and uniqueness of solutions is proved by Galerkin approximations and the energy method. The existence of stationary solution is then established by means of the Lax-Milgram theorem and the Schauder fixed point theorem. The local stability analysis of stationary solutions is studied by several different methods: the classical Lyapunov function method, the Razumikhin-Lyapunov technique and by constructing appropriate Lyapunov functionals. Finally, we also verify the polynomial stability of the stationary solution in a particular case of unbounded variable delay. Exponential stability in this infinite delay setting remains as an open problem.Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalJunta de AndalucíaNational Science Foundation of ChinaScience and Technology Commission of Shanghai MunicipalityShanghai Leading Academic Discipline Projec

    Time-dependent attractors for non-autonomous nonlocal reaction-diffusion equations

    Get PDF
    In this paper, the existence and uniqueness of weak and strong solutions for a non-autonomous nonlocal reaction-diffusion equation is proved. Next, the existence of minimal pullback attractors in the L2 -norm in the frameworks of universes of fixed bounded sets and those given by a tempered growth condition, and some relationships between them are established. Finally, we prove the existence of minimal pullback attractors in the H1-norm and study relationships among these new families and those given previously in the L2 - context. The results are also new in the autonomous framework in order to ensure the existence of global compact attractors, as a particular case.Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalJunta de Andalucí

    Robustness of time-dependent attractors in H1-norm for nonlocal problems

    Get PDF
    In this paper, the existence of regular pullback attractors as well as their upper semicontinuous behaviour in H1-norm are analysed for a parameterized family of non-autonomous nonlocal reaction-diffusion equations without uniqueness, improving previous results [Nonlinear Dyn. 84 (2016), 35–50].Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalJunta de Andalucí

    Attractors for Parametric Delay Differential Equations Without Uniqueness and Their Upper Semicontinuous Behaviour

    Get PDF
    We prove existence of a global attractor A(λ) under minimal assumptions for a general class of parameterized delay differential equations without uniqueness and posed in potentially different state spaces. Secondly, we establish the upper semicontinuity of the attractors with respect to the parameter λ

    El arzobispo virrey Vizarrón y el cabildo de la catedral de Sevilla

    Get PDF
    Tomo II ; págs. 115-13

    Attractors for Parametric Delay Differential Equations and Their Continuous Behavior

    Get PDF
    The problem of the continuity of global attractors under minimal assumptions for a general class of parameterized delay differential equations is considered. The theory of equi-attraction developed by Li and Kloeden in [2004a] is adapted to this framework, so it is proved that the continuity of the attractors with respect to the parameter is equivalent to this equi-attraction property

    Relative efficiency within a tax administration: The effects of result improvement

    Get PDF
    Neste trabalho, aborda-se a análise da administração tributária espanhola mediante a avaliação da eficiência relativa de cada um dos escritórios territoriais que a integram, empregando, para isso, a análise envolvente de dados de forma bietápica, com uma orientação output. Neste estudo, analisaram-se 47 escritórios territoriais considerando três inputs: 1) os gastos correntes em bens e serviços; 2) o número de declarações gerenciadas pelos dois principais impostos diretos e 3) o número de efetivos que presta seus serviços. Como output, os Ingressos por Atos de Liquidação. A análise demonstra que uma atuação eficiente dos escritórios territoriais poderia ter aumentado em 21,6% os resultados da gestão dessa Administração.This paper analyses the Spanish tax administration, evaluating the relative efficiency of each of the regional offices that are its constituent parts via output-oriented two-stage data envelopment analysis. In the study, a total of 47 regional offices were analysed, considering three inputs: 1) current expenditure in goods and services; 2) number of tax returns processed in terms of the two main direct taxes; and, 3) personnel numbers. Revenue resulting from tax assessments was considered as output. The analysis shows that the efficient action of regional offices might have increased by 21.6% the results of the management of this administration.A través de este trabajo se ha abordado el análisis de la administración tributaria española mediante la evaluación de la eficiencia relativa de cada una de las oficinas territoriales que la integran, empleando para ello el análisis envolvente de datos de forma bietápica, con una orientación output. En el estudio se han analizado 47 oficinas territoriales, considerando tres inputs: 1) los gastos corrientes en bienes y servicios; 2) el número de declaraciones gestionadas por los dos principales impuestos directos; y 3) el número de efectivos que presta sus servicios. Como output los Ingresos por Actos de Liquidación. El análisis pone de manifiesto que una actuación eficiente de las oficinas territoriales podría haber incrementado un 21.6% los resultados de la gestión de esta Administración

    Dynamics of wave equations with moving boundary

    Get PDF
    This paper is concerned with long-time dynamics of weakly damped semilinear wave equations defined on domains with moving boundary. Since the boundary is a function of the time variable the problem is intrinsically non-autonomous. Under the hypothesis that the lateral boundary is time-like, the solution operator of the problem generates an evolution process U(t, τ ) : Xτ → Xt, where Xt are timedependent Sobolev spaces. Then, by assuming the domains are expanding, we establish the existence of minimal pullback attractors with respect to a universe of tempered sets defined by the forcing terms. Our assumptions allow nonlinear perturbations with critical growth and unbounded time-dependent external forces.Conselho Nacional de Desenvolvimento Científico e TecnológicoMinisterio de EducaciónMinisterio de Ciencia e Innovació

    CLARK - Smart Clinic Assistant Robot for CGA

    Get PDF
    En esta presentación se exponen la arquitectura general y el estado actual de desarrollo del sistema CLARK. Dicho sistema tiene como objetivo el despliegue de un asistente robótico para ayudar a un médico en la realización de procedimientos CGA (Comprehensive Geriatric Assessment), de forma que ciertas tareas, tales como la realización de cuestionarios o pruebas de movimiento, puedan ser realizadas por el robot de forma paralela al resto del procedimiento CGA, aumentando así su eficiencia.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
    • …
    corecore