Sökning: "fluctuations and noise"

Visar resultat 1 - 5 av 77 avhandlingar innehållade orden fluctuations and noise.

  1. 1. Noise in the preschool : health and preventive measures

    Författare :Fredrik Sjödin; Ulf Landström; Anders Kjellberg; Anders Knutsson; Mats Nilsson; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Noise; hearing disorders; stress; health; occupational environment; preventive measures; intervention; Occupational and Environmental Medicine; arbets- och miljömedicin;

    Sammanfattning : This thesis is based on noise recordings and health evaluations carried out at preschools in the northern part of Sweden. Sound level recordings were made on individuals and by use of stationary devices in dining rooms and play halls. Health evaluations were based on ratings by use of questionnaires and by analyses of cortisol. LÄS MER

  3. 2. Stochastic Resonance and Noise-Assisted Signal Transfer : On Coupling Effects of Stochastic Resonators and Spectral Optimization of Fluctuations in Random Network Switches

    Författare :Peter Hammerstein; Claes Granqvist; Laszlo Kish; Hans Liljenström; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; stochastic resonance; nonlinear stochastic dynamics; noise and fluctuations; magnetic domains; Teknisk fysik; Engineering physics; Teknisk fysik;

    Sammanfattning : Recent research shows that noise or random fluctuations must not always be destructive in Nature by degrading system performance. On the contrary, in nonlinear systems they can synchronize systems or enhance the quality of signal transmission. The latter possibility is reported in the thesis. LÄS MER

  4. 3. Wind Turbine Noise and Natural Sounds : Masking, Propagation and Modeling

    Författare :Karl Bolin; Mats Åbom; Jens Forssén; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind turbine noise; models of natural sound sources; masking; Acoustics; Akustik;

    Sammanfattning : Wind turbines are an environmentally friendly and sustainable power source. Unfortunately, the noise impact can cause deteriorated living conditions for nearby residents. The audibility of wind turbine sound is influenced by ambient sound. This thesis deals with some aspects of noise from wind turbines. LÄS MER

  5. 4. Intracellular Flows and Fluctuations

    Författare :Johan Elf; Måns Ehrenberg; Peter Wolynes; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Molecular biology; mesoscopic; reaction-diffusion; protein synthesis; amino acid; flow; fluctuations; Molekylärbiologi; Molecular biology; Molekylärbiologi; Molecular Biotechnology; Molekylär bioteknik;

    Sammanfattning : Mathematical models are now gaining in importance for descriptions of biological processes. In this thesis, such models have been used to identify and analyze principles that govern bacterial protein synthesis under amino acid limitation. LÄS MER

  7. 5. Fluctuations in Mesoscopic Constrictions

    Författare :Jan Peter Hessling; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; low frequency; fluctuations; quantum; noise; 1 f-noise; superconductivity; impurity; point contact; Andreev reflection; shot noise;

    Sammanfattning : In normal and superconducting quantum point contacts there are several sources of fluctuations. Thermally activated impurities in the vicinity of the junction cause the current (or voltage) to change with a typical frequency of the order of one Hz up to a few kHz. LÄS MER