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  • Comparative Studies. Non-European Languages/Literatures  (9)
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  • Comparative Studies. Non-European Languages/Literatures  (9)
RVK
  • 1
    Online Resource
    Online Resource
    Sequential bottom parameter estimation using blind deconvolution of sources of opportunity in ocean waveguide
    Acoustical Society of America (ASA) ; 2018
    In:  The Journal of the Acoustical Society of America Vol. 144, No. 3_Supplement ( 2018-09-01), p. 1974-1974
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 144, No. 3_Supplement ( 2018-09-01), p. 1974-1974
    Abstract: This paper investigates the performance of sequential bottom parameter estimation based on ray-based blind deconvolution (RBD) of sources of opportunity using both numerical simulations and the 2016 Santa Barbara Channel (SBC) experimental recordings of shipping noise for ranges up to several kilometers. The RBD algorithm relies on estimating the unknown phase of the random sources to approximate the source-to-array channel impulse responses (CIR) by wideband beamforming along a well-resolved ray path [Sabra et al., JASA, 2010, EL42-7]. The power ratio of the direct and bottom-bounced arrivals is processed to infer the bottom reflection loss and is utilized to invert for the bottom parameters. Usually, the estimated bottom reflection loss is not accurate enough as the estimated CIR is noisy. Sequential parameter estimation uses a state space model for predicting and correcting the bottom parameters as the estimated bottom reflection loss values become available. This approach is a robust estimation tool employing predictions from previous estimates and corrects stemming from models that relate bottom parameters to the bottom reflection loss. Inversions results for the SBC experiment were also performed with conventional active sources to validate the inversion obtained with RBD of sources of opportunity.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5068625
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2018
    detail.hit.zdb_id: 1461063-2
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    Online Resource
  • 2
    Online Resource
    Online Resource
    A modified dnoidal model for internal solitary waves and its effect on sound transmission
    Acoustical Society of America (ASA) ; 2008
    In:  The Journal of the Acoustical Society of America Vol. 123, No. 5_Supplement ( 2008-05-01), p. 3590-3590
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 123, No. 5_Supplement ( 2008-05-01), p. 3590-3590
    Abstract: A new solution of KDV equation in the form of dnoidal function is developed in this paper. Based on this new solution, a modified solution of KDV equation with slowly varying parameters in the form of dnoidal function is derived. Numerical simulation shows that the wave pockets scale of the modified solution is only 1/5 to the solution in the reference (JASA, 108(3), pp 957-972), and also the equilibrium positions are different. Comparing the solutions with slowly varying parameters with the published data of internal solitary waves in the ocean indicates that the modified solution is better for the description of the dnoidal wave. Based on the modified solution of KDV equation with slowly varying parameters, a modified model for dnoidal wave is given and its effect on sound transmission is discussed in this paper.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.2934726
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2008
    detail.hit.zdb_id: 1461063-2
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    Online Resource
  • 3
    Online Resource
    Online Resource
    Sequential bottom parameter estimation using blind deconvolution of sources of opportunity in ocean waveguide for Santa Barbara channel experiment
    Acoustical Society of America (ASA) ; 2019
    In:  The Journal of the Acoustical Society of America Vol. 145, No. 3_Supplement ( 2019-03-01), p. 1771-1771
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 145, No. 3_Supplement ( 2019-03-01), p. 1771-1771
    Abstract: This paper investigates the performance of sequential bottom parameter estimation based on ray-based blind deconvolution (RBD) [Sabra et al., JASA EL42-7 (2010)] of sources of opportunity using the 2016 Santa Barbara Channel (SBC) experimental recordings of shipping noise. The RBD algorithm relies on estimating the unknown phase of the source of opportunity through wideband beamforming along a well-resolved ray path to approximate the environment’s channel impulse responses (CIR) between the source and the VLA elements. The corrected power ratio of the direct and bottom-bounced arrivals is processed to infer the bottom reflection loss and is utilized to invert for the bottom parameters. Sequential parameter estimation uses a state space model for predicting and correcting the bottom parameters as the estimated bottom reflection loss values become available. Inversions results for the SBC experiment were also performed with conventional active sources to validate the inversion obtained with RBD of sources of opportunity.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5101488
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2019
    detail.hit.zdb_id: 1461063-2
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    Online Resource
  • 4
    Online Resource
    Online Resource
    The healing distance of steady-state shock waves in the atmosphere
    Acoustical Society of America (ASA) ; 1992
    In:  The Journal of the Acoustical Society of America Vol. 92, No. 4_Supplement ( 1992-10-01), p. 2331-2331
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 92, No. 4_Supplement ( 1992-10-01), p. 2331-2331
    Abstract: The Anderson algorithm has been used to calculate the time development and rise time of transient shock waves in the atmosphere. This algorithm has been applied to square pulses in order to investigate the healing distance of steady-state shocks perturbed by turbulent scattering. Perturbed 100-Pa shocks require on the order of 1.0-km travel distance to return to within 10% of their steady shock rise time. For 30-Pa shocks the minimum recovery distance increases to 3.0 km. It is unlikely that finite wave effects can remove the longer rise times and irregular features introduced into the sonic boom by turbulent scattering in the planetary boundary layer.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.404977
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 1992
    detail.hit.zdb_id: 1461063-2
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  • 5
    Online Resource
    Online Resource
    Quasi-emulsion between water and cavitation bubble cloud in an ultrasonic field
    Acoustical Society of America (ASA) ; 2016
    In:  Journal of the Acoustical Society of America Vol. 139, No. 4_Supplement ( 2016-04-01), p. 2208-2208
    Details
    In: Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 139, No. 4_Supplement ( 2016-04-01), p. 2208-2208
    Abstract: The cavitation bubble distribution (cavitation structure) is spatially inhomogeneous in ultrasonic field. A quasi-emulsion phenomenon of cavitation structure is reported in this paper. The inception process of cavitation bubble cloud in a thin liquid layer (the thin liquid layer is trapped between a radiating surface and a hard reflector) was investigated experimentally with high-speed photography. It is revealed that cavitation bubble cloud can be considered as a uniform fluid (cloud), and water without cavitation can be considered as another uniform fluid (water). The conversion from cloud-in-water emulsion to water-in-cloud emulsion occurs with the increase in the number of bubbles. The formation and stability of cloud-water emulsions is analyzed theoretically. It is found that surface tension of cavitation bubble cloud played a leading role. Findings of this research proved that cavitation bubble clusters can be considered and investigated as a whole. [This work was supported by the National Natural Science Foundation of China (Grant No. 11174315).]
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4950593
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2016
    detail.hit.zdb_id: 1461063-2
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  • 6
    Online Resource
    Online Resource
    Geoacoustic inversion using ray-based blind deconvolution of shipping sources
    Acoustical Society of America (ASA) ; 2020
    In:  The Journal of the Acoustical Society of America Vol. 147, No. 1 ( 2020-01-01), p. 285-299
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 147, No. 1 ( 2020-01-01), p. 285-299
    Abstract: The ray-based blind deconvolution algorithm can provide an estimate of the channel impulse responses (CIRs) between a shipping source of opportunity and the elements of a receiving array by estimating the unknown phase of this random source through wideband beamforming along a well-resolved ray path. However, due to the shallow effective depth (typically & lt;10 m) and low frequency content (typically less than a few kHz) associated with shipping sources, the interfering direct and surface arriving pair and subsequent bottom and surface-bottom arrival pair cannot always be resolved in the CIR arrival-time structure. Nevertheless, this study demonstrates that the bottom reflection loss can be inferred from the ratio of the magnitude spectra of these two arrival pairs if a frequency-dependent correction (which can be purely data based) is applied to correct for the dipole source effect. The feasibility of the proposed approach is demonstrated to invert for the geoacoustic parameters of a soft-layer covering the ocean floor using a nonlinear least-square algorithm.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/10.0000605
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2020
    detail.hit.zdb_id: 1461063-2
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  • 7
    Online Resource
    Online Resource
    The effects of the internal waves on the statistic characteristics of the sound fields in the 2001 ASIAX South China Sea Experiment
    Acoustical Society of America (ASA) ; 2008
    In:  The Journal of the Acoustical Society of America Vol. 123, No. 5_Supplement ( 2008-05-01), p. 3588-3588
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 123, No. 5_Supplement ( 2008-05-01), p. 3588-3588
    Abstract: Internal waves are one of primary sources of ocean variations in shallow water. The temporal-spatial stability of sound channel may be degraded by the activities of internal waves. We present analyses of statistic characteristics observed in acoustic signals transmitted by two 400Hz sources moored as part of ASIAEX 2001 South China Sea (SCS) experiment. One source was 31.3 km offshore from the receiving array, and the other was 20.6 km alongshore from the array. Time series of signal intensity measured at individual phones of a 16-element vertical line array and a 32-element horizontal line array. temporal-spatial correlations were observed from 2 May to 17 May 2001. The temporal-spatial decorrelation scales are closely related to internal wave properties. The largest internal wave, especially solitary wave packets, are the principal contributors to reduction of the temporal-spatial decorrelation scales. We also present elementary analyses of higher-order statistics (HOS), such as bispectrum, bicoherency coefficients, etc.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.2934717
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2008
    detail.hit.zdb_id: 1461063-2
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  • 8
    Online Resource
    Online Resource
    Spatial and temporal coherence of low-frequency acoustic field in shallow water: Experimental results
    Acoustical Society of America (ASA) ; 2008
    In:  The Journal of the Acoustical Society of America Vol. 123, No. 5_Supplement ( 2008-05-01), p. 3589-3589
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 123, No. 5_Supplement ( 2008-05-01), p. 3589-3589
    Abstract: Spatial and temporal coherence of acoustic field has very important effects on applications of underwater acoustics. In this paper, recent experimental results of low-frequency signal coherence in shallow water are presented. For signals with low frequencies of 100∼500Hz in shallow water, the vertical correlation has no distinct depth dependence, but it has obvious range dependence. The horizontal correlation length is greater than 40 wavelengths, the temporal correlation length is greater than 510s at frequency of 475Hz and greater than 1800s at frequency of 150Hz. These experimental results show that low-frequency acoustic field has strong spatial coherence and temporal stability in shallow water. [Work supported by the National Natural Science Foundation of China under Grant No.10734100]
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.2934719
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2008
    detail.hit.zdb_id: 1461063-2
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  • 9
    Online Resource
    Online Resource
    Cluster-aware channel estimation with deep learning method in deep-water acoustic communications
    Acoustical Society of America (ASA) ; 2023
    In:  The Journal of the Acoustical Society of America Vol. 154, No. 3 ( 2023-09-01), p. 1757-1769
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 154, No. 3 ( 2023-09-01), p. 1757-1769
    Abstract: In underwater acoustic (UWA) communications, channels often exhibit a clustered-sparse structure, wherein most of the channel impulse responses are near zero, and only a small number of nonzero taps assemble to form clusters. Several algorithms have used the time-domain sparse characteristic of UWA channels to reduce the complexity of channel estimation and improve the accuracy. Employing the clustered structure to enhance channel estimation performance provides another promising research direction. In this work, a deep learning-based channel estimation method for UWA orthogonal frequency division multiplexing (OFDM) systems is proposed that leverages the clustered structure information. First, a cluster detection model based on convolutional neural networks is introduced to detect the cluster of UWA channels. This method outperforms the traditional Page test algorithm with better accuracy and robustness, particularly in low signal-to-noise ratio conditions. Based on the cluster detection model, a cluster-aware distributed compressed sensing channel estimation method is proposed, which reduces the noise-induced errors by exploiting the joint sparsity between adjacent OFDM symbols and limiting the search space of channel delay spread. Numerical simulation and sea trial results are provided to illustrate the superior performance of the proposed approach in comparison with existing sparse UWA channel estimation methods.
    Type of Medium: Online Resource
    ISSN: 0001-4966
    URL: Article
    DOI: 10.1121/10.0020861
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2023
    detail.hit.zdb_id: 1461063-2
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