Search for dissertations about: "modulation instability"

Showing result 1 - 5 of 18 swedish dissertations containing the words modulation instability.

  2. 1. On Reverberation Enhancement in Auditoria

    Author : Peter Svensson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active sound field control; room acoustics; reverberation enhancement; listening tests; subjective effects; sound-reinforcement; feedback systems; feedback control; computer modelling of acoustics in enclosures; modulation; electro acoustics; time-varying filters;

    Abstract : The analysis of electroacoustic systems for reverberation enhancement in auditoria is the topic of this thesis. Such systems have been developed since the 50's and been commercially available since then as well. During the 80's several new system ideas have been presented but there are still some open questions that are addressed here. READ MORE

  4. 2. Study of generation, growth and breakdown of streamwise streaks in a Blasius boundary layer

    Author : Luca Brandt; KTH; []
    Keywords : Fluid mechanics; laminar-turbulent transition; boundary layer flow; transient growth; streamwise streaks; lift-up effect; receptivity; free-stream turbulence; streak instability; secondary instability; Direct Numerical Simulation.;

    Abstract : Transition from laminar to turbulent flow has beentraditionally studied in terms of exponentially growingeigensolutions to the linearized disturbance equations.However, experimental findings show that transition may occuralso for parameters combinations such that these eigensolutionsare damped. READ MORE

  5. 3. Influence of frequency chirp and partial incoherence on nonlinear light propagation

    Author : Lukasz Helczynski-Wolf; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear optics; eigenvalues of Zakharov-Shabat scattering problem; modulation instability; collapse; incoherent optics; Wigner transform method;

    Abstract : .... READ MORE

  6. 4. Nonlinear Propagation of Optical Pulses and Beams

    Author : Magnus Karlsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; self-phase modulation; optical wave breaking; paraxial-ray approximation; stimulated Raman scattering; nonlinear Schrödinger equation; optical collapse; modulational instability; higher-order dispersion; optical fibers; saturable nonlinearity; Kerr-nonlinearity; self-trapping; group-velocity dispersion; optical solitons; self-focusing;

    Abstract : The propagation of optical beams and pulses under the influence of nonlinear effects is characterized by a rich variety of phenomena and many potentially important applications. We analyse two main topics in this context: nonlinear beam propagation, and nonlinear pulse propagation in optical fibers. READ MORE

  7. 5. Nonlinear Theory of Partially Coherent Optical Waves

    Author : Tobias Hansson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nonlinear optics; partial coherence; beam collapse; saturable logarithmic media; soliton interaction; dressing method; parabolic beams; Wigner transform; invariants; modulational instability;

    Abstract : Nonlinear effects arise in optics as a consequence of the medium properties being modified by the presence of light. Of particular interest are situations where the effect of the nonlinearity can be described by an intensity dependent refractive index and the subsequent interplay with dispersion and diffraction. READ MORE