Search for dissertations about: "acceleration"

Showing result 11 - 15 of 477 swedish dissertations containing the word acceleration.

  1. 11. Scalable Optimization Methods for Machine Learning : Acceleration, Adaptivity and Structured Non-Convexity

    Author : Vien Van Mai; Mikael Johansson; John Duchi; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Large-scale optimization; Anderson acceleration; first-order methods; stochastic optimization; momentum; gradient clipping; Electrical Engineering; Elektro- och systemteknik;

    Abstract : This thesis aims at developing efficient optimization algorithms for solving large-scale machine learning problems. To cope with the increasing scale and complexity of such models, we focus on first-order and stochastic methods in which updates are carried out using only (noisy) information about function values and (sub)gradients. READ MORE

  2. 12. Modelling of laser plasma interaction with applications to particle acceleration and radiation generation

    Author : Benjamin Svedung Wettervik; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; plasma; ion acceleration; continuum methods; electron wakefield acceleration; raditation generation; coherent X-ray pulses; Vlasov-Maxwell equations;

    Abstract : The development of laser systems with ultra-high intensities has allowed the study of the relativistic interaction of laser light and ionized matter, plasmas, as well as opened up prospects for compact particle accelerators, generation of high intensity X-ray, XUV radiation, and probing QED-effects, which are present in the high intensity regime. To describe laser matter interaction, it is necessary to self-consistently account for the paths of a large number of particles and the corresponding electromagnetic fields, with the addition of stochastic effects at high laser intensities. READ MORE

  3. 13. Approaches to particle acceleration in intense laser-matter interaction

    Author : Joel Magnusson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; particle-in-cell; nonlinear dynamics; laser; plasma; laser-matter interaction; particle acceleration;

    Abstract : In the interaction of ultra-intense laser fields with matter, the target is rapidly ionized and a plasma is formed. The ability of a plasma to sustain acceleration gradients, orders of magnitude larger than achievable with conventional accelerators, has led to a great interest in laser-driven plasma-based particle acceleration and radiation generation, with applications in materials science, biology and medicine. READ MORE

  4. 14. Novel Metal-Mediated Organic Transformations : Focusing on Microwave Acceleration and the Oxidative Heck Reaction

    Author : Per-Anders Enquist; Mats Larhed; Anders Hallberg; Troels Skrydstrup; Uppsala universitet; []
    Keywords : Organic chemistry; palladium II ; oxidative Heck reaction; high-throughput-chemistry; microwave acceleration; dicobalt octacarbonyl; in situ carbonylation; urea; diaryl ketones; ESI-MS; Organisk kemi;

    Abstract : Transition metals have played an important role in synthetic organic chemistry for more than a century, and offer catalytic transformations that would have been impossible with classical chemistry. One of the most useful and versatile of the transition metals is palladium, which over the years has catalyzed many important carbon-carbon forming reactions. READ MORE

  5. 15. Articulation in time : Some word-initial segments in Swedish

    Author : Malin Svensson Lundmark; Fonetik; []
    Keywords : HUMANIORA; HUMANITIES; acceleration; articulation; articulography; coarticulation; EMA; gesture; phonology; prosody; speech motor control; speech production modelling; Swedish; word accent; tone;

    Abstract : Speech is both dynamic and distinctive at the same time. This implies a certain contradiction which has entertained researchers in phonetics and phonology for decades. The present dissertation assumes that articulation behaves as a function of time, and that we can find phonological structures in the dynamical systems. READ MORE