Search for dissertations about: "conjugate-gradient method"

Showing result 1 - 5 of 15 swedish dissertations containing the words conjugate-gradient method.

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

    Author : Fredrik Carlsson; Anders Forsgren; Edwin Romeijn; KTH; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. Algorithms for a Partially Regularized Least Squares Problem

    Author : Ingegerd Skoglund; Tommy Elfving; Inge Söderkvist; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Least squares; Regularization; Block-matrices; Conjugate gradient; QR-factorization; Cross-validation; Numerical analysis; Numerisk analys;

    Abstract : Vid analys av vattenprover tagna från t.ex. ett vattendrag betäms halten av olika ämnen. Dessa halter är ofta beroende av vattenföringen. READ MORE

  5. 3. Experimental and analytical study of thermal mixing at reactor conditions

    Author : Mattia Bergagio; Henryk Anglart; Horst-Michael Prasser; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-cycle thermal fatigue; Hilbert-Huang transform; large eddy; WALE; rainflow; inverse heat conduction; adjoint conjugate gradient; Energy Technology; Energiteknik; Fysik; Physics;

    Abstract : High-cycle thermal fatigue due to turbulent mixing of streams at distinct temperatures is an interdisciplinary issue affecting safety and life extension of existing reactors together with the design of new reactors. It is challenging to model damage and thermal loads arising from the above mixing. READ MORE

  6. 4. Three-dimensional forward modelling and inversion of controlled-source electromagnetic data using the edge-based finite-element method

    Author : Paula Rulff; Thomas Kalscheuer; Michael Becken; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Applied geophysics; Controlled-source electromagnetics; Numerical modelling; Finite-element method; Geophysical inversion; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Abstract : Electromagnetic geophysical methods are applied to investigate anomalous subsurface structures exhibiting contrasts in electrical resistivity, as for example in mineral exploration or geothermal areas. When evaluating electromagnetic data, one big challenge is to account for full three-dimensional measurement setups and subsurface scenarios. READ MORE

  7. 5. Computational methods for the analysis and design of photonic bandgap structures

    Author : Min Qiu; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photonic crystal; Photonic bandgap; Numerical analysis; Optimal design; Finite-difference time-domain method; Plane wave expansion method; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Abstract : In the present thesis, computational methods for theanalysis and design of photonic bandgap structure areconsidered. Many numerical methods have been used to study suchstructures. Among them, the plane wave expansion method is veryoften used. READ MORE