116 research outputs found

    Homogenization of a dual-permeability problem in two-component media with imperfect contact

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    summary:In this paper, we study the macroscopic modeling of a steady fluid flow in an ε\varepsilon -periodic medium consisting of two interacting systems: fissures and blocks, with permeabilities of different order of magnitude and with the presence of flow barrier formulation at the interfacial contact. The homogenization procedure is performed by means of the two-scale convergence technique and it is shown that the macroscopic model is a one-pressure field model in a one-phase flow homogenized medium

    On a Multiscale Analysis of a Micro-Model of Heat Transfer in Biological Tissues

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    A bio-heat transfer model for biological tissues in a micro-scale and periodical settings is investigated . It is assumed that the model is a two-component system consisting of solid particles representing tissue cells and interconnected pores containing either arterial or venous blood. This tissue-blood system is described by two energy equations, one equation for the solid tissues and the other for the surrounding blood. On the interface between them, it is assumed that the heat transfer is governed by Newton's cooling law. Using homogenization techniques, it is shown that the obtained macro-model presents some extra-terms and it can be seen as a new mathematical model for human thermotherapy and human thermoregulation system

    A robust cost function for stereo matching of road scenes

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    International audienceIn this paper different matching cost functions used for stereo matching are evaluated in the context of intelligent vehicles applications. Classical costs are considered, like: sum of squared differences, normalized cross correlation or census transform that were already evaluated in previous studies, together with some recent functions that try to enhance the discriminative power of Census Transform (CT). These are evaluated with two different stereo matching algorithms: a global method based on graph cuts and a fast local one based on cross aggregation regions. Furthermore we propose a new cost function that combines the CT and alternatively a variant of CT called Cross-Comparison Census (CCC), with the mean sum of relative pixel intensity differences (DIFFCensus). Among all the tested cost functions, under the same constraints, the proposed DIFFCensus produces the lower error rate on the KITTI road scenes dataset 1 with both global and local stereo matching algorithms
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