Sökning: "large disturbances"

Visar resultat 11 - 15 av 269 avhandlingar innehållade orden large disturbances.

  1. 11. Transient growth of disturbances in laminar pipe flow

    Författare :Lars Bergström; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Sammanfattning : Transient growth of disturbances is studied theoretically in pipe Poiseuille flow and experimentally both in pipe and plane Poiseuille flow. The theoretical results, based on the initial value problem, show that a large transient amplification occurs for small, angular dependent disturbances in pipe Poiseuille flow although all modes are damped. LÄS MER

  3. 12. Mathematical modeling of electromagnetic disturbances in railway system

    Författare :Farid Monsefi; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance; Industrial Electronics; Industriell elektronik;

    Sammanfattning : By introduction of modern electronics into railway system, new challenges in understanding the electric and electromagnetic behavior of these systems arise. In this thesis, electromagnetic modeling of electric networks above dielectric and perfect electrically conducting surfaces are studied. LÄS MER

  4. 13. Anthropogenic Disturbances and Shifts in Tropical Seagrass Ecosystems

    Författare :Johan S. Eklöf; Nils Kautsky; Patrik Rönnbäck; Teresa Alcoverro; Stockholms universitet; []
    Nyckelord :Aquaculture; feedback mechanisms; Kenya; management; overgrazing; regime shift; resilience; seagrass; seaweed farming; sea urchins; Tanzania; trophic cascades; Zanzibar; NATURAL SCIENCES; NATURVETENSKAP; Marine Ecotoxicology; marin ekotoxikologi;

    Sammanfattning : Seagrasses constitute the basis for diverse and productive ecosystems worldwide. In East Africa, they provide important ecosystem services (e.g. fisheries) but are potentially threatened by increasing resource use and lack of enforced management regulations. LÄS MER

  5. 14. Interaction strength and responses of ecological communities to disturbances

    Författare :Maria Christianou; Bo Ebenman; Peter de Ruiter; Linköpings universitet; []
    Nyckelord :Species deletion; secondary extinctions; keystone species; keystone links; species reintroductions; Lotka-Volterra models; local stability; permanence; resilience; sensitivity analysis; diversity; complexity; food webs; competition communities; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : Ecological communities are continuously exposed to natural or anthropogenic disturbances of varied intensity and frequency. The way communities respond to disturbances can depend on various factors, such as number of species, structural characteristics of the community, stability properties, species characteristics and the nature of the disturbance. LÄS MER

  7. 15. On Control and Estimation of Large and Uncertain Systems

    Författare :Olle Kjellqvist; Institutionen för reglerteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : This thesis contains an introduction and six papers about the control and estimation of large and uncertain systems. The first paper poses and solves a deterministic version of the multiple-model estimation problem for finite sets of linear systems. The estimate is an interpolation of Kalman filter estimates. LÄS MER