Sökning: "eigenvalue"

Visar resultat 16 - 20 av 121 avhandlingar innehållade ordet eigenvalue.

1. 16. Gradient-based optimization of non-linear structures and materials

   Författare :Anna Dalklint; Hållfasthetslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Topology optimization; Shape optimization; Finite strain; Eigenvalue problems; Soft robotics;

   Sammanfattning : Gradient-based optimization is a potent tool in many design processes today. It is particularly useful in industries where weight considerations are crucial, such as aerospace, but can also be exploited in for example civil engineering applications to reduce the material use and thereby the environmental impact. LÄS MER

3. 17. Historiska träbärverk : Strukturmekaniska metoder och visualisering

   Författare :Carl Thelin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; FEM; Roof truss; Structural mechanics; Historic structure; Visualisation; Static behaviour; Static eigenvalue; Eigenmode; Finite Element Method;

   Sammanfattning : In designing and erecting buildings in historical times, creating the loadcarrying structure was perhaps the greatest challenge with which the architect and the builder were faced. We encounter structures in which there was a strive to reach vertical heights in the pillars and walls and to extend the horizontal span of the beams and vaults that were built. LÄS MER

4. 18. Matrix-Less Methods for Computing Eigenvalues of Large Structured Matrices

   Författare :Sven-Erik Ekström; Maya Neytcheva; Stefano Serra-Capizzano; Carlo Garoni; Lothar Reichel; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Toeplitz matrices; eigenvalues; eigenvalue asymptotics; polynomial interpolation; extrapolation; generating function and spectral symbol; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : When modeling natural phenomena with linear partial differential equations, the discretized system of equations is in general represented by a matrix. To solve or analyze these systems, we are often interested in the spectral behavior of these matrices. LÄS MER

5. 19. Eigenfrequency Analysis FE-Adaptivity and a Nonlinear Eigenproblem Algorithm

   Författare :Patrik Hager; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear eigenvalue; finite element; adaptivity; superconvergent patch recovery; rational krylov;

   Sammanfattning : Engineering often pose the problem of computing the frequencies with which a system oscillates and the corresponding displacement patterns the system forms, and in case damping is present then the rates of which the amplitudes of the displacement patterns decay are also required. It is necessary to compute these quantities within a prescribed accuracy and the effort required for the computations should be minimised. LÄS MER

7. 20. Fundamental Control Performance Limitations for Interarea Oscillation Damping and Frequency Stability

   Författare :Joakim Björk; Karl H. Johansson; Lennart Harnefors; Joe H. Chow; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power system control; HVDC transmission control; interarea oscillations; power oscillation damping; small-signal stability; fundamental control limitations; frequency stability; hydro power; wind power; non-minimum phase; zero dynamics; eigenvalue analysis; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : With the transition towards renewable energy and the deregulation of the electricity markets, the power system is changing. Growing electricity demand and more intermittent power production increase the need for transfer capacity. Lower inertia levels due to a higher share of renewables increase the need for fast frequency reserves (FFR). LÄS MER