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Visar resultat 1 - 5 av 35 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Noise exposure, hearing protection and hearing loss. A long-term study at an automobile sheet-metal pressing plant

    Författare :Pawel Brühl; Lund näs- och halssjukdomar Öron-; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; audiology; Otorhinolaryngology; noise zone; dosimetry; human; industry; Hearing conservation programme; auditive system and speech; Otorinolaryngologi; audiologi; hörsel- och talorganen;

    Sammanfattning : The design and implementation of a hearing conservation programme in a heavy industry with high noise levels is described. Action was taken on several points, including noise measurements, noise reduction, education on hearing protector use, and audiometric monitoring. LÄS MER

  3. 2. High Frequency Tyre Vibrations

    Författare :Patrik Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; local deformation; adhesion; tyre model; air pumping; parameter study; tyre road noise; tyre road prediction models; tyre noise;

    Sammanfattning : High frequency (above 1 kHz) noise generation from the tyre/road interaction is still not fully understood and accurately modelled.Two noise generation mechanisms previously suggested in the literature are reviewed: air pumping and noise generation cased by adhesive effects between the tyre tread and road surface. LÄS MER

  4. 3. Active Noise Control of Enclosed Sound Fields Optimising the Performance

    Författare :Per Sjösten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optimising actuator and sensor positions; hybrid controller for anc; fast feedforward algorithm; multiple-error algorithm; active noise control; complex lms; multichannel feedforward algorithm; simulated annealing; mean-field annealing; multiple-reference controller;

    Sammanfattning : Active noise control is the art of reducing a primary unwanted sound field by interference with an actively created secondary sound field. To achieve high reduction, it is crucial to obtain both temporal and spatial matching between the primary and the secondary sound fields. LÄS MER

  5. 4. Modelling of wheel/rail interaction considering roughness and discrete irregularities

    Författare :Astrid Pieringer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; roughness; non-Hertzian contact; railway noise; vertical wheel rail interaction; time domain; discrete irregularities;

    Sammanfattning : The interaction between wheel and rail is the predominant source of noise emission from railway operations in a wide range of conventional speeds. On the one hand, this wheel/rail noise concerns rolling noise and impact noise caused by the vertical interaction excited by roughness and discrete irregularities of the wheel/rail running surfaces, respectively. LÄS MER

  7. 5. Time-domain modelling of high-frequency wheel/rail interaction

    Författare :Astrid Pieringer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wheel rail interaction; railway noise; roughness; time domain; frictional instability; discrete irregularities; transient contact; non-Hertzian contact;

    Sammanfattning : The interaction between wheel and rail is the predominant source of noise emission from railway operations in a wide range of conventional speeds. On the one hand, this wheel/rail noise concerns rolling noise and impact noise caused by the vertical interaction excited by roughness and discrete irregularities of the wheel/rail running surfaces, respectively. LÄS MER