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	音響ホログラフィ	BEM Acoustics
分野	音響学	音響学
系統	Process / pipeline	Process / pipeline
提唱年	1985	1971
提唱者	James Maynard, Earl Williams, Yongjian Lee	Carlos Brebbia, Robert Butterfield
種類	Sound field reconstruction method	Computational simulation for acoustics
原典	Maynard, J. D., Williams, E. G., & Lee, Y. (1985). Near-field acoustic holography: I. Theory of generalized holography and the development of NAH. Journal of the Acoustical Society of America, 78(4), 1395–1413.	Burton, A. J., & Miller, G. F. (1971). The application of integral equation methods to the numerical solution of some exterior boundary-value problems. Proceedings of the Royal Society A, 323(1553), 201–210.
別名	NAH, near-field acoustics, sound field mapping, acoustic imaging	BEM, boundary element method, indirect BEM, direct BEM
関連	5	5
概要	Near-Field Acoustic Holography (NAH) is a technique for reconstructing 3D acoustic sound fields and visualizing sound radiation from sources by measuring pressure at a dense microphone array in the near field. Pioneered by Maynard, Williams, and Lee in 1985, NAH extends holographic principles from optics to acoustics, enabling detailed acoustic source characterization, noise source identification, and acoustic field visualization that is impossible with conventional single-point or line-array methods.	The Boundary Element Method (BEM) is a numerical technique for solving acoustic wave equations in complex geometries. Unlike finite element methods (FEM) that mesh entire volumes, BEM discretizes only the acoustic boundaries (surfaces), reducing computational cost and memory. First applied to acoustics by Burton and Miller in 1971, BEM is widely used for predicting room acoustics, exterior noise radiation, and acoustic scattering without the need for volumetric meshing.