Sökning: "time integrator"

Visar resultat 1 - 5 av 29 avhandlingar innehållade orden time integrator.

  1. 1. Numerical analysis and simulation of stochastic partial differential equations with white noise dispersion

    Författare :André Berg; David Cohen; Per Åhag; Guillaume Dujardin; Ludovic Goudenège; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stochastic partial differential equation; mathematics; numerical analysis; numerical scheme; time integrator; convergence analysis; blowup; critical exponent; nonlinear Schrödinger equation; Manakov equation; Benjamin-Bona-Mahony equation; BBM equation; stochastic; random; dispersion; white noise dispersion; finite difference; pseudospectral; code; matlab; exponential integrator; splitting integrator; convergence in probability; Mathematics; matematik; Numerical Analysis; numerisk analys;

    Sammanfattning : This doctoral thesis provides a comprehensive numerical analysis and exploration of several stochastic partial differential equations (SPDEs). More specifically, this thesis investigates time integrators for SPDEs with white noise dispersion. LÄS MER

  3. 2. An Integration-Reduction Scheme for Simulation of Large Systems with Local Nonlinearity and Uncertainty - Application to moving load problems in railway mechanics

    Författare :Sadegh Rahrovani; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Monte-Carlo simulations; time-integration; moving load problems; reliability analysis; exponential integrator; symplectic integrator; modal dominancy analysis;

    Sammanfattning : The focus of this research is mainly on computational efficiency, as future work is planned for reliability analysis that will be combined with design optimisation. Both these fields are known to be notoriously computationally demanding. LÄS MER

  4. 3. Continuous-Time Delta-Sigma Modulators for Wireless Communication

    Författare :Mattias Andersson; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; return-to-zero; A D converter; loop delay; delta-sigma; ADC; CMOS; STF; continuous-time; sigma; delta; filtering; CT; RZ;

    Sammanfattning : The ever increasing data rates in wireless communication require analog to digital converters (ADCs) with greater requirements on speed and accuracy, while being power efficient to prolong battery life. This dissertation contains an introduction to the field and five papers that focus on the continuous-time (CT) Delta-Sigma modulator (DSM) as ADC. LÄS MER

  5. 4. Packaging Networks : a framework for integrating packaging suppliers in the demand chain

    Författare :Chris Dominic; Gunilla Jönson; Lennart Hjält; Förpackningslogistik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; packaging logistics; demand chain management; logistics; network integrator; packaging integrator; packaging logistics; demand chain management; logistics; network integrator; packaging integrator;

    Sammanfattning : The ability to understand packaging and how it contributes to the establishment of efficient logistics and the creation of individualised values for consumers is becoming increasingly important. This licentiate thesis stresses the importance of applying a holistic view of packaging in order to be able to understand how to adapt the distribution channel to meet consumer demands. LÄS MER

  7. 5. Anti-windup and Control of Systems with Multiple Input Saturations : Tools, Solutions and Case Studies

    Författare :Jonas Öhr; Mikael Sternad; Anders Ahlén; Tore Hägglund; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reglerteknik; Anti-windup compensator; saturating actuator; amplitude limiter; rate limiter; path anti-windup; double integrator; time-optimal control; container crane; spreader; hydraulic cylinder; Reglerteknik; Automatic control; Reglerteknik;

    Sammanfattning : Control of linear systems with saturating actuators are considered and anti-windup compensators for multiple-input multiple-output systems, and robust, almost time-optimal controllers for double integrators with input amplitude saturations, are proposed.Windup effects are defined and anti-windup compensators aiming at minimizing the windup effects are proposed. LÄS MER