Sökning: "White noise"

Visar resultat 6 - 10 av 107 avhandlingar innehållade orden White noise.

  1. 6. Risk of hearing loss from combined exposure to hand-arm vibrations and noise

    Författare :Hans Pettersson; Lage Burström; Tohr Nilsson; Kerstin Persson Waye; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Hearing loss; noise; hand-arm vibration; combined exposure; vibration induced white fingers; Raynaud s phenomenon; Occupational and Environmental Medicine; arbets- och miljömedicin;

    Sammanfattning : Hearing loss from noise exposure is one of the most common occupational injuries, and exposure to vibrations may increase the risk of noise-induced hearing loss. Earlier cross-sectional and longitudinal studies found an increased risk of noise-induced hearing loss among workers with vibration-induced white fingers (VWF) symptoms compared to workers without such symptoms. LÄS MER

  3. 7. Noise improves cognitive performance in children with dysfunctional neurotransmission

    Författare :Göran Söderlund; Sverker Sikström; Lars-Göran Nilsson; Edmund Sonuga-Barke; Stockholms universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; ADHD; noise; stochastic resonance; dopamine; episodic memory; model; brain arousal; SPT; cognitive performance; children; Psychology; Psykologi; psykologi; Psychology;

    Sammanfattning : Research on children with Attention Deficit Hyperactivity Disorder (ADHD) has shown that they are extremely sensitive to distraction from external stimuli that lead to poor cognitive performance. This thesis shows that cognitive performance can be improved if this external stimulus is smooth and continuous (e.g. auditory white noise). LÄS MER

  4. 8. Phase Noise in Communication Systems--Modeling, Compensation, and Performance Analysis

    Författare :M Reza Khanzadi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiple antennas; distributed oscillators.; colored phase noise; free-running oscillator; Bayesian Cramér-Rao bound; Oscillator phase noise; phase noise model; channel capacity; mean square error; capacity achieving distribution; Wiener process; extended Kalman filter smoother; maximum a posteriori estimator; phase-locked loop;

    Sammanfattning : The continuous increase in demand for higher data rates due to applications with massive number of users motivates the design of faster and more spectrum efficient communication systems. In theory, the current communication systems must be able to operate close to Shannon capacity bounds. LÄS MER

  5. 9. Approximating Stochastic Partial Differential Equations with Finite Elements: Computation and Analysis

    Författare :Andreas Petersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Lévy process; Lyapunov equation; white noise; finite element method; multilevel Monte Carlo; Monte Carlo; multiplicative noise; asymptotic mean square stability; stochastic heat equation; covariance operator; weak convergence; generalized Wiener process; numerical approximation; stochastic wave equation; Stochastic partial differential equations;

    Sammanfattning : Stochastic partial differential equations (SPDE) must be approximated in space and time to allow for the simulation of their solutions. In this thesis fully discrete approximations of such equations are considered, with an emphasis on finite element methods combined with rational semigroup approximations. LÄS MER

  7. 10. 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