Dual-primal FETI algorithms for edge finite-element approximations in 3D

A family of dual-primal finite-element tearing and interconnecting methods for edge-element approximations in 3D is proposed and analysed. The key part of this work relies on the observation that for these finite-element spaces there is a strong coupling between degrees of freedom associated with subdomain edges and faces and a local change of basis is therefore necessary. The primal constraints are associated with subdomain edges. We propose three methods. They ensure a condition number that is independent of the number of substructures and possibly large jumps of one of the coefficients of the original problem, and only depends on the number of unknowns associated with a single substructure, as for the corresponding methods for continuous nodal elements. A polylogarithmic dependence is shown for two algorithms. Numerical results validating our theoretical bounds are give

Mixed HP -finite element approximations on geometric edge and boundary layer meshes in three dimensions

Summary: In this paper, we consider the Stokes problem in a three-dimensional polyhedral domain discretized with hp finite elements of type Qk for the velocity and Qk-2 for the pressure, defined on hexahedral meshes anisotropically and non quasi-uniformly refined towards faces, edges, and corners. The inf-sup constant of the discretized problem is independent of arbitrarily large aspect ratios. Our work generalizes a recent result for two-dimensional problems in [10, 11

Domain decomposition preconditioners of Neumann-Neumann type for hp‐approximations on boundary layer meshes in three dimensions

We develop and analyse Neumann-Neumann methods for hp finite‐element approximations of scalar elliptic problems on geometrically refined boundary layer meshes in three dimensions. These are meshes that are highly anisotropic where the aspect ratio typically grows exponentially with the polynomial degree. The condition number of our preconditioners is shown to be independent of the aspect ratio of the mesh and of potentially large jumps of the coefficients. In addition, it only grows polylogarithmically with the polynomial degree, as in the case of p approximations on shape‐regular meshes. This work generalizes our previous one on two‐dimensional problems in Toselli & Vasseur (2003a, submitted to Numerische Mathematik, 2003c to appear in Comput. Methods Appl. Mech. Engng.) and the estimates derived here can be employed to prove condition number bounds for certain types of FETI method

Mixed hp‐DGFEM for incompressible flows II: Geometric edge meshes

We consider the Stokes problem of incompressible fluid flow in three‐dimensional polyhedral domains discretized on hexahedral meshes with hp‐discontinuous Galerkin finite elements of type Qk for the velocity and Qk−1 for the pressure. We prove that these elements are inf‐sup stable on geometric edge meshes that are refined anisotropically and non‐quasiuniformly towards edges and corners. The discrete inf‐sup constant is shown to be independent of the aspect ratio of the anisotropic elements and is of O(k−3/2) in the polynomial degree k, as in the case of conforming Qk−Qk−2 approximations on the same meshe

Análisis de la sostenibilidad en emprendimientos turísticos ubicados en áreas rurales y naturales. Estudios de caso en la provincia de Entre Ríos, Argentina

This article is about a research project developed within the framework of a network formed by two Argentine universities and one university of Brazil. The main objective has been to analyze the sustainability criteria applied to the development of tourism, taking as case studies, tourist private management sites located in rural and natural areas of both countries. It will be developed the methodology and results of four selected sites in Entre Ríos province, Argentina, where an instrument that includes indicators related to sustainable management, socioeconomic, cultural heritage, and environment was applied.Este artículo surge a partir de un proyecto de investigación desarrollado en el marco de una red conformada por dos universidades argentinas y una universidad de Brasil. El objetivo principal ha sido analizar los criterios de sostenibilidad aplicados al desarrollo del turismo, tomando como estudios de caso, emprendimientos ubicados en áreas rurales y naturales de ambos países. A continuación se presentará la metodología y los resultados de cuatro sitios seleccionados en la provincia de Entre Ríos, Argentina, en los cuales se aplicó un instrumento que incluye indicadores relativos a la Gestión Sostenible, Socioeconómicos, de Patrimonio Cultural, y Ambiental

Tecnología de producción en sociedades cazadoras-recolectoras. análisis de huellas de uso en conjuntos líticos del sitio Quebrada Seca 3 (Puna de Catamarca, Argentina)

Jornadas de Jóvenes en Investigación Arqueológica, JIA (3as : 5-7 de mayo 2010 : Universitat Autònoma de Barcelona). Sesión 4. Cultura material y transdisciplinariedad en la investigación arqueológica de Latinoamérica .A partir del análisis de huellas de uso se comparan los instrumentos líticos de dos ocupaciones del sitio Quebrada Seca 3 (Puna de Catamarca, Argentina) datadas en ca 7100 y 7400 años AP, correspondientes a sociedades cazadoras-recolectoras prehistóricas.Stone tools recovered from two layers of Quebrada Seca site (Puna de Catamarca, Argentine) dated ca 7100 and 7400 years BP and attributed to prehistoric hunting collecting societies, are compared through use wear analysis.A partir de l'anàlisi de traces d'ús es comparen els instruments lítics de dues ocupacions del jaciment Quebrada Seca 3 (Puna de Catamarca, Argentina) datades en ca 7100 i 7400 anys AP., corresponents a societats caçadores-recol·lectores prehistòriques

Effect of Pulsed Electromagnetic Fields (PEMFs) on Muscular Activation during Cycling: A Single-Blind Controlled Pilot Study

Purpose: PEMF stimulation results in a higher O2 muscle supply during exercise through increased O2 release and uptake. Given the importance of oxygen uptake in sport activity, especially in aerobic disciplines such as cycling, we sought to investigate the influence of PEMF on muscle activity when subjects cycled at an intensity between low and severe. Methods: Twenty semi-professional cyclists performed a constant-load exercise with randomized active (ON) or inactive (OFF) PEMF stimulation. Each subject started the recording session with 1 min of cycling without load (warm-up), followed by an instantaneous increase in power, as the individualized workload (constant-load physical effort). PEMF loops were applied on the vastus medialis and biceps femoris of the right leg. We recorded the electromyographic activity from each muscle and measured blood lactate prior the exercise and during the constant-load physical effort. Results: PEMF stimulation caused a significant increase in muscle activity in the warm-up condition when subjects cycled without load (p < 0.001). The blood lactate concentration was higher during PEMF stimulation (p < 0.001), a possible consequence of PEMF's influence on glycolytic metabolism. Conclusion: PEMF stimulation augmented the activity and the metabolism of muscular fibers during the execution of physical exercise. PEMF stimulation could be used to raise the amplitude of muscular responses to physical activity, especially during low-intensity exercise

Assessment of a Neural-Network-Based Optimization Tool: a Low Specific-Speed Impeller Application

This work provides a detailed description of the fluid dynamic design of a low specific-speed industrial pump centrifugal impeller. The main goal is to guarantee a certain value of the specific-speed number at the design flow rate, while satisfying geometrical constraints and industrial feasibility. The design procedure relies on a modern optimization technique such as an Artificial-Neural-Network-based approach (ANN). The impeller geometry is parameterized in order to allow geometrical variations over a large design space. The computational framework suitable for pump optimization is based on a fully viscous three-dimensional numerical solver, used for the impeller analysis. The performance prediction of the pump has been obtained by coupling the CFD analysis with a 1D correlation tool, which accounts for the losses due to the other components not included in the CFD domain. Due to both manufacturing and geometrical constraints, two different optimized impellers with 3 and 5 blades have been developed, with the performance required in terms of efficiency and suction capability. The predicted performance of both configurations were compared with the measured head and efficiency characteristics