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Showing result 1 - 5 of 41 swedish dissertations matching the above criteria.

  2. 1. Active Control of Propeller-Induced Noise in Aircraft : Algorithms & Methods

    Author : Sven Johansson; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active control of sound; active noise control; anc; actuator individual normalized filtered-x lms; filtered-x lms algorithm; newton algorithm; complex lms; multireference algorithm; leaky lms; control effort weighting; feedforward control; feedback contro;

    Abstract : In the last decade acoustic noise has become more and more regarded as a problem. In cars, boats, trains and aircraft, low-frequency noise reduces comfort. Lightweight materials and more powerful engines are used in high-speed vehicles, resulting in a general increase in interior noise levels. READ MORE

  4. 2. Active Noise Control in Aircraft : Algorithms and Applications

    Author : Sven Johansson; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active noise control; feedforward control; filtere-x lms algorithm; complex lms; multichannel system; multiple reference; aircraft; headset;

    Abstract : The thesis consists of five papers which are divided into three main parts. Parts A and B deal with active noise control in a propeller aircraft application, whereas Part C deals with active noise control in a helicopter application. READ MORE

  5. 3. A computational study of interface structures and energetics in cemented carbides and steels

    Author : Sven Johansson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; WC-Co; cemented carbides; interfaces; density functional theory; microstructure; sintering; steels;

    Abstract : Cemented carbides are hard composite materials of great industrial importance. Because of their combination of hardness and toughness, they are used e.~g. for cutting, drilling, turning and milling. READ MORE

  6. 4. Perceptual and physiological indicators of physical strain in relation to working capacity and illness

    Author : Sven-Erik Johansson; Stockholms universitet; []
    Keywords : ;

    Abstract : .... READ MORE

  7. 5. Multiscale Modeling of Interfaces

    Author : Sven Johansson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; misfit; Peierls-Nabarro model; semicoherent interfaces; interfaces; cemented carbides; grain boundaries; microstructure; VN precipitates; density-functional theory;

    Abstract : Understanding strength and stability of interfaces between dissimilar materials or phases is a highly active field of contemporary materials research. Knowledge of interface structure and energetics is important for modeling of complex materials both on a mechanical and thermodynamical level as well as for many functional properties. READ MORE