Sökning: "perturbation technique"

Visar resultat 1 - 5 av 46 avhandlingar innehållade orden perturbation technique.

  1. 1. Diversity and Ecosystem Functioning : Redundancy and Resilience in Freshwater Bacterial Communities

    Författare :Hannes Peter; Lars J. Tranvik; Eva S. Lindström; Silke Langenheder; Nelson G. Hairston; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; biodiversity; ecosystem functioning; bacteria; fresh water; biofilms; multifunctionality; ecological networks; perturbation; fragility; Biologi med inriktning mot limnologi; Biology with specialization in Limnology;

    Sammanfattning : Bacteria are immensely diverse and hold key-positions in essentially all biogeochemical cycles. In freshwater ecosystems, bacteria degrade and mineralize organic compounds, linking the pool of dissolved organic matter to higher trophic levels. LÄS MER

  3. 2. Analytical Approximation of Contingent Claims

    Författare :Karl Larsson; Claus Munk; Nationalekonomiska institutionen; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Option pricing; approximation; stochastic volatility; implied volatility; perturbation; Malliavin calculus; commodities; swaption; swap; HJM model;

    Sammanfattning : This PhD thesis consists of three separate papers. The common theme is methods to calculate analytical approximations for prices of different contingent claims under various model assumptions. The first two papers deals with approximations of standard European options in stochastic volatility models. LÄS MER

  4. 3. Dynamic Train-Track Interaction: Linear and Non-Linear Track Models with Property Scatter

    Författare :Johan Oscarsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stochastic track properties; non-linear track properties; dynamic train-track interaction; Latin Hypercube; perturbation technique; full-scale and laboratory measurements;

    Sammanfattning : A numerical method was developed to investigate the vertical dynamic behaviour of a railway track subjected to the loading of a moving train. The numerical simulations are carried out in the time-domain with what is known as a moving mass model. LÄS MER

  5. 4. Resonant magnetic perturbation effect on the tearing mode dynamics : Novel measurements and modeling of magnetic fluctuation induced momentum transport in the reversed-field pinch

    Författare :Richard Fridström; Per Brunsell; Lorenzo Frassinetti; Tommaso Bolzonella; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; RFP; reversed-field pinch; tokamak; tearing mode; RMP; fusion; plasma; resonant magnetic perturbation; stochastic; magnetic; field; viscosity; mode; locking; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The tearing mode (TM) is a resistive instability that can arise in magnetically confined plasmas. The TM can be driven unstable by the gradient of the plasma current. When the mode grows it destroys the magnetic field symmetry and reconnects the magnetic field in the form of a so-called magnetic island. LÄS MER

  7. 5. The Effect of Different Perturbations on the Stability Analysis of Light Water Reactors

    Författare :Victor Dykin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; BWR and PWR stability; stability indicators; propagating density perturbation; autocorrelation function; density wave oscillations; decay ratio; non-white driving force; damped harmonic oscillator; reduced order models; Green s function technique;

    Sammanfattning : Neutron noise analysis techniques are studied and developed, with primary useof determining the stability of Boiling Water Reactors (BWRs). In particular, the role ofa specific perturbation prevailing in Light Water Reactors, the propagating densityperturbation, in the stability of BWRs and on the noise field of LWRs in general, isinvestigated by considering three topics. LÄS MER