373. The Effects of Industrial Exposure to Impulse and Continuous Noise on Hearing and Criteria of Noise Evaluation

1999 ◽  
Author(s):  
K. Pawlas ◽  
J. Grzesik
Keyword(s):  
Noise Evaluation ◽  
Continuous Noise

Noise evaluation of small airfields

1999 ◽  
Vol 47 (4) ◽  
pp. 125-132
Author(s):  
Per V. Bruel
Keyword(s):  
Noise Evaluation

scholarly journals Exponential stabilization of two-level quantum systems based on continuous noise-assisted feedback

2021 ◽  
Vol 22 ◽  
pp. 103929
Author(s):  
Jie Wen ◽  
Yuanhao Shi ◽  
Jianfang Jia ◽  
Jianchao Zeng
Keyword(s):  
Quantum Systems ◽  
Exponential Stabilization ◽  
Continuous Noise

scholarly journals Annoyance evaluation of noise emitted by urban substation

2021 ◽  
pp. 146134842110143
Author(s):  
Li Jun ◽  
Li Li ◽  
Zhang Yongxiang ◽  
Chu Zhigang ◽  
Fan Xiaopeng
Keyword(s):  
Regression Model ◽  
Urban Areas ◽  
Subjective Evaluation ◽  
Noise Pollution ◽  
Objective Evaluation ◽  
Semantic Differential ◽  
Differential Method ◽  
Practical Application ◽  
Noise Evaluation ◽  
Objective And Subjective Evaluation

In China, noise pollution from substations in urban areas is becoming more and more serious. An annoyance evaluation of the noise emitted by urban substations is presented. First, the subjective evaluation is conducted on the noise samples from urban substations via the semantic differential method. Subsequently, according to the typical characteristics of urban substation noise, 14 acoustical metrics are used to describe the noise samples for objective evaluation. Then the correlation analysis and regression analysis between the objective and subjective evaluation results are carried out. Finally, a regression model for urban substation noise evaluation is established. Practical application shows that the regression model can correctly predict the subjective annoyance of urban substation noise.

scholarly journals Picking up the hydrothermal whisper at Ischia Island in the Covid-19 lockdown quiet

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mariarosaria Falanga ◽  
Paola Cusano ◽  
Enza De Lauro ◽  
Simona Petrosino
Keyword(s):  
Pressure Fluctuations ◽  
Hydrothermal Fluids ◽  
Shallow Aquifer ◽  
Two Phase ◽  
Spectral Content ◽  
Ischia Island ◽  
Continuous Noise ◽  
Organ Pipes ◽  
Source Signals ◽  
Phase Fluid

AbstractIn this paper, we analyse the seismic noise at Ischia Island (Italy) with the objective of detecting the hydrothermal source signals taking advantage of the Covid-19 quiescence due to lockdown (strong reduction of anthropogenic noise). We compare the characteristics of the background noise in pre-, during and post-lockdown in terms of spectral content, energy release (RMS) and statistical moments. The continuous noise is decomposed into two independent signals in the 1−2 Hz and 2−4 Hz frequency bands, becoming sharpened around 1 Hz and 3 Hz respectively in lockdown. We propose a conceptual model according to which a dendritic system of fluid-permeated fractures plays as neighbour closed organ pipes, for which the fundamental mode provides the persistent whisper and the first higher mode is activated in concomitance with energy increases. By assuming reasonable values for the sound speed in low vapor–liquid mass fraction for a two-phase fluid and considering temperatures and pressures of the shallow aquifer fed by sea, meteoric and deep hydrothermal fluids, we estimate pipe lengths in the range 200–300 m. In this scheme, Ischia organ-like system can play both continuous whisper and transients, depending on the energy variations sourced by pressure fluctuations in the hydrothermal fluids.

Optimization of a Shock Absorber Design Using Model-Based Approach

2012 ◽  
Vol 452-453 ◽  
pp. 1351-1355 ◽  
Author(s):  
Grzegorz Wszołek ◽  
Piotr Czop ◽  
Dawid Jakubowski ◽  
Damian Slawik
Keyword(s):  
Automotive Industry ◽  
Shock Absorber ◽  
Flow Characteristic ◽  
Optimization Method ◽  
Design Parameters ◽  
Coupled Models ◽  
Model Based ◽  
Noise Evaluation ◽  
Optimal Values ◽  
Application Scope

The aim of this paper is to demonstrate a possibility to optimize a shock absorber design to minimize level of vibrations with the use of model-based approach. The paper introduces a proposal of an optimization method that allows to choose the optimal values of the design parameters using a shock absorber model to minimize the level of vibrations. A model-based approach is considered to obtain the optimal pressure-flow characteristic by simulations conducted with the use of coupled models, including the damper and the servo-hydraulic tester model. The presence of the tester model is required due to high non-linear coupling of the tested object (damper) and the tester itself to be used for noise evaluation. This kind of evaluation is used in the automotive industry to investigate dampers, as an alternative to vehicle-level tests. The paper provides numerical experimental case studies to show application scope of the proposed method

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