Sökning: "variational method"

Visar resultat 21 - 25 av 84 avhandlingar innehållade orden variational method.

  1. 21. Multidimensional inverse problems in imaging and identification using low-complexity models, optimal mass transport, and machine learning

    Författare :Axel Ringh; Johan Karlsson; Rodolphe Sepulchre; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inverse problems; convex optimization; variational regularization; trigonometric moment problems; optimal mass transport; computed tomography; machine learning; analytic interpolation; delay systems; Inversa problem; konvex optimering; variationell regularisering; trigonometriska momentproblem; optimal masstransport; datortomografi; maskininlärning; analytisk interpolation; system med tidsfördröjning; Mathematics; Matematik;

    Sammanfattning : This thesis, which mainly consists of six appended papers, primarily considers a number of inverse problems in imaging and system identification.In particular, the first two papers generalize results for the rational covariance extension problem from one to higher dimensions. LÄS MER

  3. 22. The fW-mean filter framework for topology optimization and analysis of Friedrichs systems

    Författare :Linus Hägg; Martin Berggren; Eddie Wadbro; Björn Engquist; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; topology optimization; filters; mathematical morphology; size control; minimum compliance problem; Friedrichs systems; well-posedness; variational formulations; linearized Euler’s equations; Galbrun’s equation; acoustics; Mathematics; matematik;

    Sammanfattning : Part I. Topology optimization is the most general form of design optimization in which the optimal layout of material within a given region of space is to be determined. Filters are essential components of many successful density based topology optimization approaches. LÄS MER

  4. 23. Fixed points, fractals, iterated function systems and generalized support vector machines

    Författare :Xiaomin Qi; Sergei Silvestrov; Anatoliy Malyarenko; Daniel Andren; Viktor Abramov; Mälardalens högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; support vector machine; fixed points; iterated function system; variational inequality; Mathematics Applied Mathematics; matematik tillämpad matematik;

    Sammanfattning : In this thesis, fixed point theory is used to construct a fractal type sets and to solve data classification problem. Fixed point method, which is a beautiful mixture of analysis, topology, and geometry has been revealed as a very powerful and important tool in the study of nonlinear phenomena. LÄS MER

  5. 24. A Variational Approach to Image Diffusion in Non-Linear Domains

    Författare :Freddie Åström; Michael Felsberg; Tony Lindeberg; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Image filtering methods are designed to enhance noisy images captured in situations that are problematic for the camera sensor. Such noisy images originate from unfavourable illumination conditions, camera motion, or the desire to use only a low dose of ionising radiation in medical imaging. LÄS MER

  7. 25. A Variational data assimilation scheme and its use of meteorological observations

    Författare :Erik Andersson; Lennart Bengtsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; meteorologi; Meteorology;

    Sammanfattning : Meteorological data assimilation is the process by which a model simulation of the atmosphere is corrected by observations. In operational weather forecasting, this is done in near real-time, to provide accurate initial conditions for numerical forecasts. The accuracy of the forecasts depends crucially on the accuracy of the data assimilation. LÄS MER