scholarly journals CALCULATION OF IMPULSE NOISE WITH MIRROR-DIFUSE REFLECTION OF SOUND FROM FENCES

Akustika ◽  
2019 ◽  
Vol 34 ◽  
pp. 88-94
Author(s):  
Alexander Antonov ◽  
Irina Matveeva ◽  
Igor Shubin ◽  
Ilya Tsukernikov
Keyword(s):  
Comparative Analysis ◽  
Computational Model ◽  
Sound Source ◽  
Impulse Noise ◽  
Noise Source ◽  
Energy Characteristics ◽  
Sound Energy ◽  
Computational Data ◽  
Spatiotemporal Changes ◽  
Spatio Temporal

The choice and acoustic efficiency of construction and acoustic means of noise control is determined on the basis of calculations of changes in the spatio-temporal characteristics of the pulses of sound energy emitted by the sound source. The paper proposes a combined computational model for estimating the energy characteristics of pulse noise and their spatiotemporal changes. The model describes the formation and distribution of the reflected sound energy of pulses in the mirror-scattered reflection of sound from the fences. The principles of construction of the computational model and the computer program implementing it are stated. Evaluation of the computational model is performed by comparative analysis of experimental and computational data obtained by the action of a pulsed noise source in complex geometrically shaped rooms. It is found that the calculated graphs of the decay of the reflected pulse energy in time coincide with the experimentally determined declines.

scholarly journals Measurement of Underwater Acoustic Energy Radiated by Single Raindrops

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2687
Author(s):  
Shu Liu ◽  
Qi Li ◽  
Dajing Shang ◽  
Rui Tang ◽  
Qingming Zhang
Keyword(s):  
Ambient Noise ◽  
Sound Pressure ◽  
Tap Water ◽  
Acoustic Energy ◽  
Underwater Sound ◽  
Underwater Noise ◽  
Energy Characteristics ◽  
Sound Energy ◽  
Dipole Radiation ◽  
Series Of Experiments

Underwater noise produced by rainfall is an important component of underwater ambient noise. For example, the existence of rainfall noise causes strong disturbances to sonar performance. The underwater noise produced by a single raindrop is the basis of rainfall noise. Therefore, it is necessary to study the associated underwater noise when drops strike the water surface. Previous research focused primarily on the sound pressure and frequency spectrum of underwater noise from single raindrops, but the study on its sound energy is insufficient. The purpose of this paper is to propose a method for predicting the acoustic energy generated by raindrops of any diameter. Here, a formula was derived to calculate the underwater sound energy radiated by single raindrops based on a dipole radiation pattern. A series of experiments were conducted to measure the underwater sound energy in a 15 m × 9 m × 6 m reverberation tank filled with tap water. The analysis of the acoustic energy characteristics and conversion efficiency from kinetic to acoustic energy helped develop the model to predict the average underwater sound energy radiated by single raindrops. Using this model, the total underwater sound energy of all raindrops during a rainfall event can be predicted based on the drop size distribution.

scholarly journals INFORMATION MODEL OF TURBODRILLING USING THE TELEMETRY SYSTEM BASED ON THE ACCOUNTING OF THE SOUND ENERGY CHARACTERISTICS

2015 ◽  
pp. 26-29
Author(s):  
V. I. Kolesov ◽  
Yu. A. Savinyh ◽  
G. A. Hmara
Keyword(s):  
Simulation Model ◽  
Target Function ◽  
Information Model ◽  
Telemetry System ◽  
Energy Characteristics ◽  
Sound Energy ◽  
Information Signal

The information model of turbodrilling using the telemetry system based on the accounting of the sound energy characteristics was developed and studied. The sources of the information signal and noise were identified. A target function of turbodrilling control - minimization of the process sound amplitude - was obtained. The information model was made a basis for development of the simulation model of turbodrilling control by the sound energy characteristics

Comparative analysis of 2D spatio-temporal visualisation techniques for the pulsed THz-radiation field using an electro-optic crystal

2018 ◽  
Vol 48 (5) ◽  
pp. 487-490 ◽  
Author(s):  
A A Ushakov ◽  
P A Chizhov ◽  
V V Bukin ◽  
S V Garnov ◽  
A B Savel'ev
Keyword(s):  
Comparative Analysis ◽  
Radiation Field ◽  
Thz Radiation ◽  
Electro Optic ◽  
Spatio Temporal

scholarly journals Feature integration within discrete time windows

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Leila Drissi-Daoudi ◽  
Adrien Doerig ◽  
Michael H. Herzog
Keyword(s):  
Computational Model ◽  
Discrete Time ◽  
Time Windows ◽  
Temporal Integration ◽  
Sensory Information ◽  
Stimulus Onset ◽  
Feature Integration ◽  
Spatio Temporal ◽  
The Individual ◽  
Over Time

Abstract Sensory information must be integrated over time to perceive, for example, motion and melodies. Here, to study temporal integration, we used the sequential metacontrast paradigm in which two expanding streams of lines are presented. When a line in one stream is offset observers perceive all other lines to be offset too, even though they are straight. When more lines are offset the offsets integrate mandatorily, i.e., observers cannot report the individual offsets. We show that mandatory integration lasts for up to 450 ms, depending on the observer. Importantly, integration occurs only when offsets are presented within a discrete window of time. Even stimuli that are in close spatio-temporal proximity do not integrate if they are in different windows. A window of integration starts with stimulus onset and integration in the next window has similar characteristics. We present a two-stage computational model based on discrete time windows that captures these effects.

scholarly journals Definition and measurement of sound energy level of a transient sound source.

1987 ◽  
Vol 8 (6) ◽  
pp. 235-240 ◽  
Author(s):  
Hideki Tachibana ◽  
Hiroo Yano ◽  
Koichi Yoshihisa
Keyword(s):  
Energy Level ◽  
Sound Source ◽  
Sound Energy

NOISE SHIELDING BY SIMPLE BARRIERS: COMPARISON BETWEEN THE PERFORMANCE OF SPHERICAL AND LINE SOUND SOURCES

2000 ◽  
Vol 08 (03) ◽  
pp. 495-502 ◽  
Author(s):  
D. OUIS
Keyword(s):  
Sound Source ◽  
Insertion Loss ◽  
Line Source ◽  
Wave Reflection ◽  
Noise Source ◽  
Sound Level ◽  
Sound Sources ◽  
Noise Shielding ◽  
Noise Barrier ◽  
Wave Incidence

This study is concerned with the theoretical solution to the problem of sound screening by simple hard barriers on the ground with special emphasis given to the type of wave incidence, namely a comparison between the use of either a spherical or a cylindrical sound source. For a receiver at the shadow of the noise source, the field may be assumed to be due to the edge wave and for this, exact solutions are used. Regarding the wave reflection on an impedance ground, exact formulations are also used, and finally, some calculations are made on the performance of a hard noise barrier on a two-impedance ground. As a conclusion, it is found that although the sound level at the receiver may show some small differences depending on the frequency and on the geometry of the problem, the overall insertion loss of the thin hard barrier is almost the same for the spherical and the line source, and the differences are found to amount to less than 1 dB for geometries of practical occurrence.

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