Sökning: "Element"

Visar resultat 21 - 25 av 3286 avhandlingar innehållade ordet Element.

  1. 21. Stochastic finite element simulations of real life frontal crashes : With emphasis on chest injury mechanisms in near-side oblique loading conditions

    Författare :Johan Iraeus; Mats Lindquist; Ulf Björnstig; Mats G Larsson; Joel Stitzel; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; EDR; Real life crashes; Oblique; Finite element; Simulation; HBM; Injury mechanism; Pulse shape; Stochastic; Rib fracture; THUMS; Generic; Statistics; biomechanics; biomekanik; skadeförebyggande; injury prevention;

    Sammanfattning : Introduction. Road traffic injuries are the eighth leading cause of death globally and the leading cause of death among young people aged 15-29. Of individuals killed or injured in road traffic injuries, a large group comprises occupants sustaining a thorax injury in frontal crashes. The elderly are particularly at risk, as they are more fragile. LÄS MER

  3. 22. Laser-Based Combustion and Trace-element Analysis

    Författare :Yvonne Malmsten; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser-induced fluorescence; graphite furnace; trace element analysis; LEI; laser-enhanced ionisation; LIF; meta-stable; flow-tagging; NO; OH; counter-flow diffusion flame;

    Sammanfattning : Laser spectroscopy has been utilised as a tool for combustion diagnostics and sensitive trace-element analysis. In the field of combustion analysis, a characterisation of a CH4/N2 - O2/N2 counter-flow diffusion flame has been performed using Laser-Induced Fluorescence (LIF). LÄS MER

  4. 23. Finite element methods for multiscale/multiphysics problems

    Författare :Robert Söderlund; Mats Larson; Victor Ginting; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element methods; variational multiscale methods; Galerkin; convergence analysis; multiphysics; a posteriori error estimation; duality; adaptivity; Mathematical statistics; Matematisk statistik; Mathematical Statistics; matematisk statistik;

    Sammanfattning : In this thesis we focus on multiscale and multiphysics problems. We derive a posteriori error estimates for a one way coupled multiphysics problem, using the dual weighted residual method. LÄS MER

  5. 24. Class of Accurate Low Order Finite Elements

    Författare :Magnus Fredriksson; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quadrilateral ; variational ; finite element ; element technology ; HuWashizu ; hexahedral ; Technological sciences; Teknik;

    Sammanfattning : High accuracy and low computational costs are essential properties for efficient finite element codes. Improvements of the finite element method in order to satisfy these qualities have been the subject for extensive research activities ever since its introduction. LÄS MER

  7. 25. Adaptive finite element methods for parameter estimation problems in partial differential equations

    Författare :Tao Feng; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; parameter estimation; ¯nite element approximation; adaptive ¯nite element methods; a posteriori error estimates; least squares.; MATHEMATICS; MATEMATIK;

    Sammanfattning : Physical and chemical phenomena are often described by a system of partial di®erential equations. These equations usually involve unknown parameters, which cannot be measured directly but which can be adjusted to make the model predictions match the observed data. LÄS MER