Sökning: "area integral"

Visar resultat 1 - 5 av 89 avhandlingar innehållade orden area integral.

  1. 1. Hydropower Area Equivalents : Reduced Models for Efficient Simulation of Large-Scale Hydropower Systems

    Författare :Evelin Blom; Lennart Söder; Arild Helseth; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Area Equivalent; Aggregation; Bilevel optimization; Large-scale hydropower; Power system simulation; Reduced model; Area-Ekvivalent; Aggregering; Två-nivå-optimering; Storskalig vattenkraft; Kraftsystemssimulering; Reducerad modell;

    Sammanfattning : With over 4000 TWh yearly electricity production worldwide, hydropower plays an important role in many power systems. Unlike many other renewable energy sources, hydropower has a certain degree of controllability and high levels of flexibility over several time scales. LÄS MER

  3. 2. Modelling of fracture toughness using peridynamics : A Study of J-integral, essential work and homogenisation

    Författare :Christer Stenström; Pär Jonsén; Kjell Eriksson; Ugo Galvanetto; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Peridynamics; J-integral; Essential work of fracture; Nonlocal methods; Meshless; Meshfree; Fracture; Crack tip; Exact analytical; Center cracked tension; Double edge notched tensile; fracture toughness; Peridynamik; Brottmekanik; Sprickspets; Brottseghet; Spänningsintensitet; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Fracture toughness is one of the most important properties of a material. Being able toaccurately estimate the energy that goes into forming new crack surfaces is essential for the development of new materials, quality assurance, structural monitoring and failure analysis. LÄS MER

  4. 3. Modelling animal populations

    Författare :Åke Brännström; Umeå universitet; []
    Nyckelord :population model; stochastic population model; population dynamics; discrete time model; Beverton-Holt model; Skellam model; Hassell model; Ricker model; first principles; coupled map lattice; CML; area integral; square function; Mathematics; matematik;

    Sammanfattning : This thesis consists of four papers, three papers about modelling animal populations and one paper about an area integral estimate for solutions of partial differential equations on non-smooth domains. The papers are: I. Å. Brännström, Single species population models from first principles. LÄS MER

  5. 4. Pipeline Analog-Digital Converters Dynamic Error Modeling for Calibration : Integral Nonlinearity Modeling, Pipeline ADC Calibration, Wireless Channel K-Factor Estimation

    Författare :Samer Medawar; Peter Händel; Niclas Björsell; Magnus Jansson; Dominique Dallet; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Analog-digital converter; integral nonlinearity; calbiration; K-factor estimation;

    Sammanfattning : This thesis deals with the characterization, modeling and calibration of pipeline analog-digital converters (ADC)s. The integral nonlinearity (INL) is characterized, modeled and the model is used to design a post-correction block in order to compensate the imperfections of the ADC. LÄS MER

  7. 5. Linking plant population dynamics to the local environment and forest succession

    Författare :Johan Petter Dahlgren; Johan Ehrlén; Ove Eriksson; Mark Rees; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Actaea spicata; Forest herbs; Forest succession; Integral projection model; Plant demography; Plant phenology; Population dynamics; Pre-dispersal seed predation; Seed mass; Soil potassium; Specific leaf area; Terrestrial ecology; Terrestisk ekologi; Plant Ecology; växtekologi;

    Sammanfattning : Linking environmental variation to population dynamics is necessary to understand and predict how the environment influences species abundances and distributions. I used demographic, environmental and trait data of forest herbs to study effects of spatial variation in environmental factors on populations as well as environmental change in terms of effects of forest succession on field layer plants. LÄS MER