Sökning: "Numerical regularization"

Visar resultat 11 - 15 av 51 avhandlingar innehållade orden Numerical regularization.

  1. 11. Utilizing Problem Structure in Optimization of Radiation Therapy

    Författare :Fredrik Carlsson; Anders Forsgren; Edwin Romeijn; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optimization; intensity-modulated radiation therapy; conjugate-gradient method; step-and-shoot delivery; column generation; quasi-Newton method; regularization; sequential quadratic programming; Optimization; systems theory; Optimeringslära; systemteori;

    Sammanfattning : In this thesis, optimization approaches for intensity-modulated radiation therapy are developed and evaluated with focus on numerical efficiency and treatment delivery aspects. The first two papers deal with strategies for solving fluence map optimization problems efficiently while avoiding solutions with jagged fluence profiles. LÄS MER

  3. 12. Modelling of Delamination Growth in Composite Structures

    Författare :Niklas E. Jansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; large deformation; interface; composite materials; 3D-shell; cohesive zone; regularization; shell element; delamination;

    Sammanfattning : Delaminations constitute an important damage and failure mode in polymeric composite laminates. In order to explicitly incorporate and model the delamination progression within a finite element analysis, the meso-modelling concept is applied in the present work. The laminate is thereby represented by separate layers connected with interfaces. LÄS MER

  4. 13. Group-Sparse Regression : With Applications in Spectral Analysis and Audio Signal Processing

    Författare :Ted Kronvall; Statistical Signal Processing Group; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sparse regression; group-sparsity; statistical modeling; regularization; hyperparameter-selection; spectral analysis; audio signal processing; classification; localization; multi-pitch estimation; chroma; convex optimization; ADMM; cyclic coordinate descent; proximal gradient;

    Sammanfattning : This doctorate thesis focuses on sparse regression, a statistical modeling tool for selecting valuable predictors in underdetermined linear models. By imposing different constraints on the structure of the variable vector in the regression problem, one obtains estimates which have sparse supports, i.e. LÄS MER

  5. 14. High-order finite element methods for incompressible variable density flow

    Författare :Lukas Lundgren; Murtazo Nazarov; Anders Logg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Finite element method; artificial viscosity; Navier-Stokes equations; conservation properties; artificial compressibility; viscous regularization; variable density flow; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The simulation of fluid flow is a challenging and important problem in science and engineering. This thesis primarily focuses on developing finite element methods for simulating subsonic two-phase flows with varying densities, described by the variable density incompressible Navier-Stokes equations. LÄS MER

  7. 15. Sequential Data Learning, Scalable Models and Adversarial Regularization

    Författare :Jin Huang; Ming Xiao; Geyong Min; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Time Series Prediction (TSP) has been used in mobile network traffic data analysis to produce predictive results for network planning and resource allocation. In the first part of this thesis, we propose a novel method of predicting mobile network traffic using neural networks based on conditional probability modeling between adjacent data windows in the time series sequence. LÄS MER