Field testing of earplugs for noise reduction using a supra‐threshold procedure

1980 ◽  
Vol 68 (S1) ◽  
pp. S57-S57
Author(s):  
Roy M. Fleming
Keyword(s):  
Noise Reduction ◽  
Field Testing ◽  
Threshold Procedure

scholarly journals Multistage noise reduction processing for vibration signal of hydropower units

2021 ◽  
Vol 2108 (1) ◽  
pp. 012008
Author(s):  
Yousong Shi ◽  
Jianzhong Zhou
Keyword(s):  
Noise Reduction ◽  
Signal To Noise Ratio ◽  
Vibration Signal ◽  
Field Testing ◽  
Signal To Noise ◽  
Vibration Signals ◽  
Multi Stage ◽  
Actual Field ◽  
Stationary Vibration ◽  
Testing Environments

Abstract In actual field testing environments of hydropower units, unit vibration signals are often contaminated with noise. In order to obtain the real vibration signal, a multi-stage vibration signal denoise method SG-SVD-VMD is proposed for the guide bearing nonlinear and non-stationary vibration signals. And the root mean square error (RMSE) and signal to noise ratio (SNR) are used to evaluate the noise reduction ability of eight methods. The results show that the noise-canceling ability of this proposed method has improved to some extent. It can effectively suppress the noise of the hydropower units vibration signals. This method can effectively identify the shaft track and the running state of hydropower units.

Research on Effect of Noise Emission from Railway Viaduct on Noise Reduction of Noise Barriers

2012 ◽  
Vol 433-440 ◽  
pp. 1852-1856
Author(s):  
Lei Ming Song ◽  
Shou Guang Sun ◽  
Xin Hua Zhang
Keyword(s):  
Noise Reduction ◽  
Microphone Array ◽  
Field Testing ◽  
Vibration Testing ◽  
Noise Emission ◽  
Noise Sources ◽  
Noise Barriers ◽  
Sources Identification ◽  
Array Technology ◽  
Noise Barrier

Noise sources identification based on microphone array theory was firstly introduced, A method was derived, which can be used to analyze effect of noise emission from railway viaduct to noise reduction of noise barriers. Vibration and noise emission of railway viaduct and noise barrier were studied using field testing with microphone array technology and vibration testing. The results concluded that noise emission from the viaduct has remarkable effects on noise reduction of noise barriers compared with the effects of noise emission from the noise barriers themselves, which is neglectable.

Satisfaction With Noise Reduction Circuits

1993 ◽  
Vol 2 (1) ◽  
pp. 51-53 ◽  
Author(s):  
Ruth A. Bentler
Keyword(s):  
Noise Reduction

Field testing the AMIT Job Performance Aid: Methods, results, and implications for the Air Force maintenance community

2007 ◽  
Author(s):  
David E. Kancler ◽  
Christopher C. Curtis ◽  
Darryl S. Stimson ◽  
Johnnie Jernigan
Keyword(s):  
Job Performance ◽  
Air Force ◽  
Field Testing ◽  
Force Maintenance

Leadership Effectiveness Assessment Profile (LEAP): Officer Instrument Field Testing and Refinement

1992 ◽  
Author(s):  
Victor H. Appel ◽  
Carol Murray Quintana ◽  
Richard W. Cole ◽  
Mark D. Shermis ◽  
Paul D. Grubb ◽  
...  
Keyword(s):  
Leadership Effectiveness ◽  
Field Testing ◽  
Effectiveness Assessment

Sexuality-related conditions: A multistakeholder approach to explore feasibility of field-testing ICD-11 revisions in developing countries.

2016 ◽  
Vol 5 (3) ◽  
pp. 184-191 ◽  
Author(s):  
Megan M. Campbell ◽  
Rebeca Robles ◽  
Denise L. Vieira ◽  
Brigitte Khoury ◽  
Saria Daouk ◽  
...  
Keyword(s):  
Developing Countries ◽  
Field Testing

КОНЦЕПЦІЯ СТВОРЕННЯ СИЛОВОЇ УСТАНОВКИ СІМЕЙСТВА РЕГІОНАЛЬНИХ ПАСАЖИРСЬКИХ ЛІТАКІВ АН-148/АН-158

2019 ◽  
pp. 50-63
Author(s):  
О. Д. Донець ◽  
В. П. Іщук
Keyword(s):  
Power Plant ◽  
Noise Reduction ◽  
Fuel Consumption ◽  
Electronic System ◽  
Electronic Control ◽  
Level Of Automation ◽  
Auxiliary Power ◽  
Power Plant Control ◽  
Technical Status ◽  
Air Intake

The basic results of calculation and research works carried out in the process of creation of power unit of regional passenger airplanes’ family are given. The design features of the propulsion engines and engine of the auxiliary power plant are described. The aforementioned propulsion system includes propulsion engines D-436-148 and engine AI-450-MS of auxiliary power plant. In order to comply with the requirements of Section 4 of the ICAO standard (noise reduction of the aircraft in site), in part of ensuring the noise reduction of engines, when creating the power plant of the An-148/An-158 aircraft family, a single- and double-layer acoustic filler was used in the structure of the engine nacelle and air intake. The use of electronic system for automatic control of propulsion engines such as FADEC and its integration into the digital airborne aircraft complex ensured the operation of engines, included in the power plant provided with high specific fuel consumption, as well as increased the level of automation of the power plant control and monitoring, and ensured aircraft automation landing in ICAO category 3A. In addition, the use of the aforementioned electronic system, allowed to operate the power plant of the aircraft in accordance with technical status. The use of the AI-450-MS auxiliary power plant with an electronic control system such as FADEC, and the drive of the service compressor from a free turbine, eliminated the effect of changes in power and air takeoff, on the deviation of the engine from optimal mode, which also minimized the fuel consumption. The use of fuel metering system TIS-158, allowed to ensure control of its condition and assemblies, without the use of auxiliary devices, built-in control means. In the fire protection system, the use of the electronic control and monitor unit, as well as the use of digital serial code for the exchange of information between the elements of the system and the aircraft systems, has reduced the number of connections, which increased the reliability of the system and reduced its weight characteristics.

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