摘要:

Many years ago, the author analyzed a representative deep‐fired/long‐range underwater explosion record [J. Acoust. Soc. Am.35, 800 (1963)]. The most striking feature was the so‐called “double shock” formation, e.g., a strong resemblance between the shock wave and bubble pulse in both amplitude and shape. The phenomenon is attributed to the combined effects of detonation depth and waveform propagation. Recently [Proc. 11th Intern. Congress Acoust., Paris, 1983, Vol. 1, pp. 345–348]the characteristics of an explosion waveform at the source, as a function of firing depth was established. Here, weak shock theory is used to study the nonlinear distortion of the bubble pulse as it propagates. The criterion for shock wave formation dependsinter aliaon the strength and duration of the pulse. Pulse amplitude increases slowly, but its duration decreases rapidly, with charge depth. It is found that the shot depth plays the crucial role and that consequently the deep fired shots suffer the greatest distortion, tending towards shock wave formation at long range.

ISSN:0001-4966    

DOI:10.1121/1.2021688

出版商:Acoustical Society of America    

年代:1984

数据来源: AIP

摘要:

A one‐boarded, out‐performance speech recognition system for speaker‐independent isolated words has been developed. This board consists mainly of the 4‐bit, 1‐chip microcomputer and newly developed speech recognition LSI [Ohgaet al., IEEE Trans. Consumer Electron.CE‐28, 263–270 (1982)]. The board takes multiple templates and the KNN rules to cover various tokens of many persons. A new clustering method CLS (clustering with shared group) is based on the conception of the SNN method and theK‐means iteration procedure [Rabineret al., IEEE Trans. Acoust. Speech Signal Process.ASSP‐27, 336–349 (1979)]. The experimental results showed more than 95% recognition accuracy not only for ten Japanese city names but ten Chinese city names. CLS can be easily implemented on the 16‐bit microcomputer system and it takes less than 20 min to make seven templates with the microcomputer system.

ISSN:0001-4966    

DOI:10.1121/1.2021693

出版商:Acoustical Society of America    

年代:1984

数据来源: AIP