Acoustical Science and Technology
Online ISSN : 1347-5177
Print ISSN : 1346-3969
ISSN-L : 0369-4232
Volume 24, Issue 6
Displaying 1-17 of 17 articles from this issue
INVITED REVIEW
  • Francesco P. Curra, Lawrence A. Crum
    Article type: Others
    Subject area: Others
    2003 Volume 24 Issue 6 Pages 343-348
    Published: 2003
    Released on J-STAGE: November 01, 2003
    JOURNAL FREE ACCESS
    The field of therapeutic ultrasound is emerging with strong potential and broad medical applications. Characterized by its ability to penetrate at depth inside the body without harming intervening tissue, ultrasound has posed the basis for a new array of noninvasive therapies. Al low intensities, important interactions occur in the tissue; wound healing is accelerated, functional recovery is enhanced, and bone growth is more rapid. At moderate intensities, cellular membranes show transient permeability, blood clots dissolution is increased, and gene-transfection is accomplished. At higher intensities, ultrasound produces lesions and stops bleeding by heating the tissue beyond its protein denaturalization threshold and thus provides a noninvasive, bloodless alternative to conventional surgery. This article presents a review of moderate and high intensity applications, including their mechanisms of action and the imaging modalities used for guidance and monitoring.
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PAPERS
  • Yunbiao Xu, Masahiro Araki, Yasuhisa Niimi
    Article type: Others
    Subject area: Others
    2003 Volume 24 Issue 6 Pages 349-357
    Published: 2003
    Released on J-STAGE: November 01, 2003
    JOURNAL FREE ACCESS
    This paper presents a multilingual-supporting dialog system that was implemented in Chinese and Japanese in tasks of sightseeing, accommodation-seeking and PC assembling guidance. Such a dialog system benefits from three main methods we proposed, including case frame conversion, template-based text generation and topic frame driven dialog control scheme. The former two methods are for improving the portability across languages, and the last one is for improving the portability across domains. The case frame conversion is used for translating a case frame described in a particular language into that described in a pivot language. The template-based text generation is used for generating text responses in a particular language from abstract responses described in the pivot language. The topic frame driven dialog control scheme makes it possible to manage mixed-initiative dialog based on a set of task-dependent topic frames. Both Chinese and Japanese experiments in several domains showed that the three methods proposed could be used to improve the portability of the dialog system across domains and languages.
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  • Sayed Abas, Akihiro Tamura
    Article type: Others
    Subject area: Others
    2003 Volume 24 Issue 6 Pages 358-364
    Published: 2003
    Released on J-STAGE: November 01, 2003
    JOURNAL FREE ACCESS
    This study concerns road traffic noise in Greater Cairo, the capital of Egypt, the largest city and the biggest 11th city in the world. Measurements taken in September and October 2001 for road traffic noise levels in Greater Cairo, indicates that noise levels in the city are higher than those set by Egyptian noise standards and policy to protect public health and welfare in residential areas, equivalent continuous A-weighted sound pressure level (LAeq)=80 dB and higher are recorded, while maximum permissible level is 65 dB. LAeq are measured, and tabulated for 23 locations spread over urban zones of city. It has been found out that 91.3% out of locations display during day their LAeq are over 65 dB, and 73.8% out of total number of locations their LAeq are over 70 dB. Results of curbs (restrictions) to improve environmental conditions found that, in absence of horns, LAeq decrease at all sites, maximum reductions range between 9.4 dB and 10.8 dB occurred in downtown area. Omitting buses give a further reduction in LAeq varying between 2.6 to 3.7 dB. In absence of horns, trucks and buses, reductions in LAeq range between 6.0 to 10.2 dB. This shows that the town planner can use various strategies to change the traffic composition in order to achieve quieter city environments.
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  • Takeshi Nakaichi, Keisuke Watanuki, Shinichi Sakamoto
    Article type: Others
    Subject area: Others
    2003 Volume 24 Issue 6 Pages 365-375
    Published: 2003
    Released on J-STAGE: November 01, 2003
    JOURNAL FREE ACCESS
    A simplified method for the measurement of auditory filter, in which the filter shape is assumed to be symmetric, is proposed. This method would apply to the clinical diagnosis of hearing impairment and the fitting of hearing aids. The proposed method is based on the notched-noise method and includes procedures for the determination of the masker level and for the estimation of the auditory filter shape from one masked threshold. In order to reduce measuring time, the ascending method is used to detect the signal threshold level in this method. Two experiments were conducted to evaluate this proposed technique: (1) the measurement accuracy of the ascending method was investigated on three normal-hearing subjects and compared with the 2AFC method, and (2) the practicability of this simplified method was evaluated on eleven hearing-impaired and two normal-hearing subjects, and compared with the conventional notched-noise method. Results showed that (1) the ascending method has sufficient accuracy for the measurement of the masked threshold and (2) ERB data obtained using the simplified method correlate highly with ERB data obtained using the conventional notched-noise method. It was also shown that each auditory filter could be measured in approximately three minutes.
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