Results 151 to 160 of about 558 (180)

Progress of the Patch Near-Field Acoustical Holography Technique

Acta Acustica united with Acustica, 2008
The development of patch near-field acoustic holography (Patch-NAH) has been rapid in recent years. Compared to the traditional NAH techniques, the Patch-NAH method possesses the advantage of solving engineering problems, and is especially suitable for reconstructing partial sound fields and for obtaining other acoustic parameters.
Chao Yang, Jin Chen, Wei-Fei Xue, Jia-qing Li   +3 more
openaire   +1 more source

An application of the neural network in the near-field acoustic holography

International Technology and Innovation Conference 2006 (ITIC 2006), 2006
The near-field acoustic holography (NAH) is an effective and useful noise measurement method. There are many methods for reconstruction of the sound source, but the measurement circumstance is limited and the random noise is unavoidable. In this paper, a new holography reconstruction method based on neural network (NN) is proposed, which can identify ...
null Gao Yinhan, null Song Dan, null Liang lie, null Zhou Xiaohua   +3 more
openaire   +1 more source

Wrapping a violin with planar near-field acoustic holography.

The Journal of the Acoustical Society of America, 1996
Planar near-field acoustic holography gives one the ability to reconstruct the sound pressure radiated from a source in a three-dimensional field from a single two-dimensional near-field measurement. Traditionally, only one measurement plane has been used which gives the sound radiation in a half-space. In this paper, the near-field acoustic holography
Lily M. Wang, Courtney B. Burroughs
openaire   +1 more source

New developments in near-field acoustic holography

2007
In the field of noise-control engineering, information about the individual strength, andlocation, of the most dominant sources is of vital importance. This information allows theacoustic engineer to take effective measures in his effort to reduce the emitted acoustic noiselevels.
Roozen, N.B., Geerlings, A.C., Verhaar, B.T., Vliegenthart, T.   +3 more
openaire   +1 more source

Extension of measurement surface in near-field acoustic holography

The Journal of the Acoustical Society of America, 2004
In near-field acoustic holography, when measurements are made over a limited surface, there has been recent interest in numerically enlarging the measurement surface tangentially. Current algorithms use iterative methods to extrapolate the field tangentially outward. An algorithm based on the method of superposition is applied here which may be used to
openaire   +1 more source

Measurement of Structural and Acoustic Intensities Using Near-Field Acoustical Holography

Japanese Journal of Applied Physics, 1996
A non contacting method for measuring structural and acoustic intensities is proposed by developing the signal processing in near-field acoustical holography (NAH). The effectiveness of this method is illustrated by applying it to the measurement of radiation from ribbed and unribbed submerged plates. The spatial derivatives for determining
Kenji Saijyou Kenji Saijyou, Shigeru Yoshikawa Shigeru Yoshikawa   +1 more
openaire   +1 more source

Near-field acoustic holography measurements of the acoustic radiation from violins

The Journal of the Acoustical Society of America, 1996
As previously described, an open-frame mechanical bowing apparatus has been constructed to excite a violin [L. M. Wang and C. B. Burroughs, J. Acoust. Soc. Am. 99, 2502(A) (1996)]. An array of microphones is mounted to this apparatus on each of the six sides of the frame, boxing the violin source. Complex pressure measurements made in the near field of
Lily M. Wang, Courtney B. Burroughs
openaire   +1 more source

Near-field acoustic holography for acoustic noise source identification in turbomachinery

2009 IEEE Sensors Applications Symposium, 2009
A novel approach using basis expansions of acoustic sources is proposed to better condition the inverse problem in NAH. Results indicate that the basis expansion representation of sources provides better source reconstruction results through effectively combating ill-posedness of the inverse problem.
Tariq Khan, Pradeep Ramuhalli, Ravi Raveendra, W. Zhang   +3 more
openaire   +1 more source

APPLIED ASPECTS OF NEAR-FIELD ACOUSTIC HOLOGRAPHY

Transactions of Kremenchuk Mykhailo Ostrohradskyi National University, 2023
Yevhenii Ponomarenko, Kyrylo Trapezon
openaire   +1 more source

Surface decomposition method for near-field acoustic holography.

The Journal of the Acoustical Society of America, 2011
Near-field acoustic holography reconstruction of the acoustic field at the surface of an arbitrarily shaped radiating structure from pressure measurements at a nearby conformal surface is obtained from the solution of a boundary integral equation. This integral equation is discretized using the equivalent source method to be transformed into a matrix ...
openaire   +1 more source