Search for dissertations about: "Per Martin Nilsson"

Showing result 1 - 5 of 8 swedish dissertations containing the words Per Martin Nilsson.

  2. 1. Iterative solution of Maxwell's equations in frequency domain

    Author : Martin Nilsson; Per Lötstedt; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

    Abstract : We have developed an iterative solver for the Moment Method. It computes a matrix–vector product with the multilevel Fast Multipole Method, which makes the method scale with the number of unknowns. The iterative solver is of Block Quasi-Minimum Residual type and can handle several right-hand sides at once. READ MORE

  4. 2. Essays on Health Shocks and Social Insurance

    Author : Martin Nilsson; Per Johansson; Johan Vikström; Lars Hultkrantz; Uppsala universitet; []
    Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Health shocks; Socioeconomic status; Social insurance; Social costs; Economics; Nationalekonomi;

    Abstract : This thesis consists of four self-contained essays.Essay 1 (with Petter Lundborg and Johan Vikström): This paper provides new evidence on heterogeneity in the impact of health shocks by using register-based data on the entire population of Swedish workers. READ MORE

  5. 3. Fast Numerical Techniques for Electromagnetic Problems in Frequency Domain

    Author : Martin Nilsson; Per Lötstedt; Abderrahmane Bendali; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fast Multipole Method; Minimal Residual Interpolation; Sparse Approximate Inverse preconditioning; Method of Moments; fast solvers; iterative methods; multiple right-hand sides; error analysis; Numerical Analysis; Numerisk analys;

    Abstract : The Method of Moments is a numerical technique for solving electromagnetic problems with integral equations. The method discretizes a surface in three dimensions, which reduces the dimension of the problem with one. A drawback of the method is that it yields a dense system of linear equations. READ MORE

  6. 4. Permanent stoma after anterior resection for rectal cancer : prevalence and mechanisms

    Author : Klas Holmgren; Martin Rutegård; Jörgen Rutegård; Markku M. Haapamäki; Peter Matthiessen; Malin Sund; Per J. Nilsson; Umeå universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; rectal cancer; anterior resection; permanent stoma; defunctioning stoma; mesorectal excision; biomarkers; Surgery; kirurgi;

    Abstract : While sphincter-saving surgery constitutes standard treatment for rectal cancer, anterior resection still harbours a significant risk of a permanent stoma in the long run. Although anastomotic leakage plays a major role in this surgical dilemma, the exact mechanisms are not known, while surveys indicate a stoma-free outcome is essential for a majority of patients. READ MORE

  7. 5. Mathematical Models of Molecular Evolution

    Author : Martin Nilsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; dynamic fitness landscapes; quasispecies; error thresholds; evolved mutation rates; evolution in dynamic environments;

    Abstract : This thesis deals with mathematical models of Darwinian evolution in populations of simple living organisms. We study models which describe how the representation of different gene sequences in the population is affected by the fundamental forces of evolutionary processes, such as selection pressure, the mutation rate and the time dynamics of the underlying fitness landscape. READ MORE