The Inverse Modeling of Diffraction Phenomena under Plane Wave Incidence using Neural Network

평면파 입사시 신경회로망을 이용한 회절현상의 역모델링

Na, Hui-Seung

  • Published : 2000.05.01


Diffraction systematically causes error in acoustic measurements. Most probes are designed to reduce this phenomenon. On the contrary, this paper proposes a spherical probe a] lowing acoustic inten sity measurements in three dimensions to be made, which creates a diffracted field that is well-defined, thanks to analytic solution of diffraction phenomena. Six microphones are distributed on the surface of the sphere along three rectangular axes. Its measurement technique is not based on finite difference approximation, as is the case for the ID probe but on the analytic solution of diffraction phenomena. In fact, the success of sound source identification depends on the inverse models used to estimate inverse diffraction phenomena, which has nonlinear properties. In this paper, we propose the concept of nonlinear inverse diffraction modeling using a neural network and the idea of 3 dimensional sound source identification with better performances. A number of computer simulations are carried out in order to demonstrate the diffraction phenomena under various angles. Simulations for the inverse modeling of diffraction phenomena have been successfully conducted in showing the superiority of the neural network.


Diffraction Phenomena;Inverse Modeling of Diffraction Phenomena;Neural Networks;Multilayer Perceptron


  1. Miller, W. T., Glanz, F. H., and Kraft, L. G., 1987, 'Application of a General Learning Algorithm to the Control of Robotic Manipulators,' International Journal of Robotics Research 6, pp. 84-98
  2. Lippman, R. P., 1987,'An Introduction to Computing with Neural Nets', IEEE ASSP Magazine, pp. 4-22
  3. Coste, O. and Patrat, J. C, 1990,'Diffraction Autour d'une Sphere Appliquee a une Sonde Intensimetrique Tridimensionnelle', $1^{er}$ Congres Francais d'Acoustique
  4. 김시문, 권휴상, 김양한, 1995, '원통면 음향 홀로그래피를 이용한 음장예측의 오차해석 및 적용 방법,' 한국소음진동공학회지, 제 5 권, 제 l 호, pp. 37-48
  5. Morse, P. M., Ingard, K. U., Theoretical Acoustic, Mac Graw Hill
  6. Rumelhart, D., McClelland, J. and the PDP Research Group, 1986, Parallel Distributed Processing, Vols. 1 and 2, Cambridge MA, the MIT Press
  7. Maynard, D., Williams, E. G. and Lee, Y., 1985, 'Nearfield Acoustic Holography and Development of NAH,' J. Acoust. Am., Vol. 78, pp. 1395-1413
  8. Fahy, F. J., 1988, Sound Intensity, Elsevier Applied Science