Transactions of the Korean Society for Noise and Vibration Engineering (한국소음진동공학회논문집)

The Korean Society for Noise and Vibration Engineering (한국소음진동공학회)
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Adaptive Short-time Fourier Transform for Guided-wave Analysis

유도 초음파 신호 분석을 위한 적응 단시간 푸리에 변환

  • 홍진철 (서울대학교 기계항공부 대학원) ;
  • 선경호 (서울대학교 기계공학부 대학원) ;
  • 김윤영 (서울대학교 기계항공공학부)
  • Published : 2005.03.01
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Abstract

Although time-frequency analysis is useful for dispersive wave analysis, conventional methods such as the short-time Fourier transform do not take the dispersion phenomenon into consideration in the tiling of the time-frequency domain. The objective of this paper is to develop an adaptive time-frequency analysis method whose time-frequency tiling is determined with the consideration of signal dispersion characteristics. To achieve the adaptive time-frequency tiling, each of time-frequency atoms is rotated in the time-frequency plane depending on the local wave dispersion. To carry out this adaptive time-frequency transform, dispersion characteristics hidden in a signal are first estimated by an iterative scheme. To examine the effectiveness of the present method, the flexural wave signals measured in a plate were analyzed.

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References

  1. Cawley, P. and Alleyne, D., 1996, 'The use of Lamb Waves for the Long Range Inspection of Large Structures,' Ultrasonics, 34, pp. 287-290 https://doi.org/10.1016/0041-624X(96)00024-8
  2. Ghosh, T., Kundu, T. and Karpur, P., 1998, 'Efficient use of Lamb Modes for Detecting Defects in Large Plates,' Ultrasonics, 36, pp. 791-801 https://doi.org/10.1016/S0041-624X(98)00012-2
  3. Gabor, D., 1946, 'Theory of Communication,' J. IEE, 93, pp. 429-457
  4. 이호철, 김윤영, 1999, 'STFT를 이용한 강건 결함진단방법', 한국소음진동공학회, 추계학술대회논문집, pp. 231-237
  5. Daubechies, 1992, Ten Lectures on Wavelets, SIAM, Philadelphia
  6. Mallat, S., 1998, A Wavelet Tour of Signal Processing, Academic, New York
  7. Kim, Y. Y. and Kim, E. H., 2001, 'Effectiveness of the Continuous Wavelet Transform in the Analysis of Some Dispersive Elastic Waves,' J. Acoust. Soc. Am, 110, pp. 86-94 https://doi.org/10.1121/1.1378348
  8. Jeong, H. and Jang, Y. -S., 2002, 'Fracture Source Location in Thin Plates Using the Wavelet Transform of Dispersive Waves,' IEEE Trans. Ultra., Ferro., Freq. Contr., 47, pp. 612-619
  9. Hong, J. -C. and Kim, Y. Y., 2004, 'The Determination of the Optimal Gabor wavelet Shape for the Best Time-frequency Localization Using the Entropy Concept,' Exp. Mech, 44, pp. 387-395 https://doi.org/10.1007/BF02428092
  10. Mann, S. and Haykin, S., 1995, 'The Chirplet Transform: Physical Considerations,' IEEE Trans. Signal Process., 43, pp. 2745-2761 https://doi.org/10.1109/78.482123
  11. Baraniuk, R. G.and Jones, D. L., 1996, 'Wigner-based Formulation of the Chirplet Transform,' IEEE Trans. Signal Process., 44, pp. 3129-3135 https://doi.org/10.1109/78.553486
  12. Angrisani, L. and D'Arco, M., 2002, 'A Measurement Method Based on a Modified Version of the Chirplet Transform for Instantaneous Frequency Estimation,' IEEE Trans. Instru. Mea., 51, pp. 704-711 https://doi.org/10.1109/TIM.2002.803295
  13. Shannon, C., 1948, 'A Mathematical Theory of Communication,' Bell Syst. Tech. J., 27, pp. 379-656 https://doi.org/10.1002/j.1538-7305.1948.tb01338.x
  14. Miklowitz, J., 1978, Elastic Waves and Waveguides, North-Holland, New York
  15. Graff, K. F., 1999, Wave Motion in Elastic Solids Ohio-State Univ. Press
  16. Kim, Y. Y., Cho, S. H., Sun, K. H. and Lee, J. S., 2004, 'Orientation-adjustable Patch-type Magnetostrictive Ultrasonic Transducer for Plates', Proceedings of the 5th European Magnetic Sensors and Actuators Conference, T-O.6