Sökning: "ill-conditioning"

Visar resultat 1 - 5 av 8 avhandlingar innehållade ordet ill-conditioning.

1. 1. Time Domain Methods for Load Identification of Linear and Nonlinear Systems

   Författare :Patrik Nordberg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inverse problem; ill-conditioning; upper block triangular Toeplitz matrix; regularization; wavelet parameterization; least squares problem; input estimation; time domain; linear and nonlinear systems; load identification;

   Sammanfattning : The automotive industry faces an increasing demand for virtual prototyping to simulate the operation conditions of vehicles and subsystems. Each component, as well as the complete vehicle, must meet the desired design requirements in a time- and cost-efficient development process. LÄS MER

3. 2. On modal methods and inverse problems in structural dynamics

   Författare :Niklas Sehlstedt; KTH; []
   Nyckelord :Dynamic strain; Dynamic boundary traction vector; Hilbert space basis; Modal methods; Inverse problem; Ill-conditioning;

   Sammanfattning : .... LÄS MER

4. 3. Towards higher order immersed finite elements for the wave equation

   Författare :Simon Sticko; Gunilla Kreiss; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : We consider solving the scalar wave equation using immersed finite elements. Such a method might be useful, for instance, in scattering problems when the geometry of the domain is not known a priori. For hyperbolic problems, the amount of computational work per dispersion error is generally lower when using higher order methods. LÄS MER

5. 4. High Order Local Radial Basis Function Methods for Atmospheric Flow Simulations

   Författare :Erik Lehto; Elisabeth Larsson; Natasha Flyer; Tobin Driscoll; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Radial basis function; meshless method; high order finite difference; atmospheric flow; hyper-viscosity; stable algorithm; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : Since the introduction of modern computers, numerical methods for atmospheric simulations have routinely been applied for weather prediction, and in the last fifty years, there has been a steady improvement in the accuracy of forecasts. Accurate numerical models of the atmosphere are also becoming more important as researchers rely on global climate simulations to assess and understand the impact of global warming. LÄS MER

7. 5. Computation of Parameters in some Mathematical Models

   Författare :Gunilla Wikström; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; inverse problems; parameter estimation; systems of ordinary differential equations; short-cut methods; separable nonlinear least squares problems; Matlab toolbox for nonlinear least squares ; linear systems of equations; pseudoinverse solution; perturbation theory; singular value decomposition; experimental error analysis; Computer science; Datavetenskap;

   Sammanfattning : In computational science it is common to describe dynamic systems by mathematical models in forms of differential or integral equations. These models may contain parameters that have to be computed for the model to be complete. LÄS MER