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Visar resultat 1 - 5 av 437 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Computational Techniques for Turbulence Generated Noise

   Författare :Mattias Billson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Computational techniques for the noise generated by high Mach number subsonic jets have been investigated. The main focus has been on the hybrid noise prediction method SNGR (Stochastic Noise Generation and Radiation), which is based on unsteady source modeling for the inhomogeneous linearized Euler equations (ILEE). LÄS MER

3. 2. On noise and hearing loss : Prevalence and reference data

   Författare :Magnus Johansson; Stig Arlinger; Einar Laukli; Linköpings universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; irreversible occupational disease; noise-induced hearing; noise-induced measurements OAE ; spontaneous otoacoustic emissions SOAE ; transient evoked otoacoustic emissions TEOAE ; distortion product otoacoustic emissions DPOAE ; Audiology; Audiologi;

   Sammanfattning : Noise exposure is one of the most prevalent causes of irreversible occupational disease in Sweden and in many other countries. In hearing conservation programs, aimed at preventing noise-induced hearing loss, audiometry is an important instrument to highlight the risks and to assess the effectiveness of the program. LÄS MER

4. 3. CPU Resource Management and Noise Filtering for PID Control

   Författare :Vanessa Romero Segovia; Institutionen för reglerteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; resource management; embedded systems; real-time systems; multimedia; multicore; measurement noise; filtering; trade-offs; robustness; performance; SDU; noise gain; PID control;

   Sammanfattning : The first part of the thesis deals with adaptive CPU resource management for multicore platforms. The work was done as a part of the resource manager component of the adaptive resource management framework implemented in the European ACTORS project. The framework dynamically allocates CPU resources for the applications. LÄS MER

5. 4. Modelling of IC-Engine Intake Noise

   Författare :Magnus Knutsson; Mats Åbom; Yves Auregán; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; IC-engine; intake noise; gas dynamics; linear source data; frequency domain; 2-port; losses; air cleaner unit; filter paper; flow; FEM; BEM; charge air cooler; narrow tube; Acoustics; Akustik;

   Sammanfattning : Shorter product development cycles, densely packed engine compartments and intensified noiselegislation increase the need for accurate predictions of IC-engine air intake noise at earlystages. The urgent focus on the increasing CO2 emissions and the efficiency of IC-engines, aswell as new techniques such as homogeneous charge compression ignition (HCCI) mightworsen the noise situation. LÄS MER

7. 5. Innovative noise control in ducts

   Författare :Maaz Farooqui; Mats Åbom; Hans Bodén; Tamer Elnady; Jeong-Guon Ih; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Locally resonant materials; slow sound; acoustic impedance; metallic foam; low frequency noise; mufflers; lined ducts; grazing flow; flow duct; impedance eduction.; Vehicle and Maritime Engineering; Farkostteknik;

   Sammanfattning : The objective of this doctoral thesis is to study three different innovative noise control techniques in ducts namely: acoustic metamaterials, porous absorbers and microperforates. There has been a lot of research done on all these three topics in the context of duct acoustics. LÄS MER