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  • Comparative Studies. Non-European Languages/Literatures  (15)
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  • Comparative Studies. Non-European Languages/Literatures  (15)
RVK
  • 1
    Online Resource
    Online Resource
    Seismic profile processing to identify sediment layering structure in shallow water
    Acoustical Society of America (ASA) ; 2018
    In:  The Journal of the Acoustical Society of America Vol. 144, No. 3_Supplement ( 2018-09-01), p. 1810-1810
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 144, No. 3_Supplement ( 2018-09-01), p. 1810-1810
    Abstract: The equivalent layering structure of surface sediment is a key parameter for sound propagation modelling and geoacoustic inversion in shallow waters. Previously, the structure identification is manually performed through identifying these horizontal lines as shown in the profiling image, which represent the interfaces with strong acoustical impedance contrast. In this paper, a hybrid image processing method (statistical equalization, multi-scale line filtering, and wavelet decomposition) is adapted to automatically identify these interfaces, afterwards, an image-binary threshold and a dislocation phase subtraction approach are successively applied to determine sediment layer number and relative thickness. The data from dozens lines of surveys as collected in 2016 are processed. Through integrating the processing results with GPS data, 2D distributions of sediment layer number and thickness of the first and second sediment layer are constructed. The spatial distributions of sediment layer number and thickness demonstrate certain trends, which are in accordance with expected sedimentary process in this region and should be carefully treated in 3D sound propagation modelling and geoacoustic inversion.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5067989
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2018
    detail.hit.zdb_id: 1461063-2
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  • 2
    Online Resource
    Online Resource
    Source depth estimation using spectral transformations and convolutional neural network in a deep-sea environment
    Acoustical Society of America (ASA) ; 2020
    In:  The Journal of the Acoustical Society of America Vol. 148, No. 6 ( 2020-12-01), p. 3633-3644
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 148, No. 6 ( 2020-12-01), p. 3633-3644
    Abstract: Multiple approaches for depth estimation in deep-ocean environments are discussed. First, a multispectral transformation for depth estimation (MSTDE) method based on the low-spatial-frequency interference in a constant sound speed is derived to estimate the source depth directly. To overcome the limitation of real sound-speed profiles and source bandwidths on the accuracy of MSTDE, a method based on a convolution neural network (CNN) and conventional beamforming (CBF) preprocessing is proposed. Further, transfer learning is adapted to tackle the effect of noise on the estimation result. At-sea data are used to test the performance of these methods, and results suggest that (1) the MSTDE can estimate the depth; however, the error increases with distance; (2) MSTDE error can be moderately compensated through a calculated factor; (3) the performance of deep-learning approach using CBF preprocessing is much better than those of MSTDE and traditional CNN.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/10.0002911
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2020
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  • 3
    Online Resource
    Online Resource
    Deep transfer learning for source ranging: Deep-sea experiment results
    Acoustical Society of America (ASA) ; 2019
    In:  The Journal of the Acoustical Society of America Vol. 146, No. 4 ( 2019-10-01), p. EL317-EL322
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 146, No. 4 ( 2019-10-01), p. EL317-EL322
    Abstract: A deep transfer learning for underwater source ranging is proposed, which migrates the predictive ability obtained from synthetic environment (source domain) into an experimental sea area (target domain). A deep neural network is first trained on large synthetic datasets generated from historical environmental data, and then part of the neural network is refined on collected data set for source ranging. Its performance is tested on a deep-sea experiment through comparing with convolutional neural networks of different training datasets. Data processing results demonstrate that the ranging accuracy is considerably improved by the proposed method, which can be easily adapted for related areas.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5126923
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2019
    detail.hit.zdb_id: 1461063-2
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  • 4
    Online Resource
    Online Resource
    Source localization using back propagation neural network and a single vector receiver
    Acoustical Society of America (ASA) ; 2018
    In:  The Journal of the Acoustical Society of America Vol. 144, No. 3_Supplement ( 2018-09-01), p. 1855-1855
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 144, No. 3_Supplement ( 2018-09-01), p. 1855-1855
    Abstract: Matched field processing (MFP) has been widely used in source localization in shallow waters, whose performance is strongly correlated with the knowledge of environmental properties and proper selection of sound propagation model. This paper presents a neural network based approach for source ranging of moving target, which does not need heavy sound field calculation and no requirement of environmental information as a known prior. This neural network is designed to determine source range by observing multiple-frequency sound fields as excited by the source and recorded on a single vector receiver. In synthetic tests, this neural network is first trained on training data set as to adaptively select the optimal features through error back propagation, and then its localization performance is validated on testing data set. This approach is then tested on ship noise data as collected by a single vector sensor, and the relative error is smaller than 0.1 through comparing to GPS calculations. The promising results suggest the proposed approach can be further developed for source ranging applications with light system.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5068162
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2018
    detail.hit.zdb_id: 1461063-2
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  • 5
    Online Resource
    Online Resource
    Bispectra of internal waves in shallow seas
    Acoustical Society of America (ASA) ; 2001
    In:  The Journal of the Acoustical Society of America Vol. 109, No. 5_Supplement ( 2001-05-01), p. 2421-2422
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 109, No. 5_Supplement ( 2001-05-01), p. 2421-2422
    Abstract: Densely sampled thermistor chain data have been obtained from several shallow-water acoustics experiments in the Yellow Sea, East China Sea and South China Sea. The data are analyzed to study bispectra of the internal waves observed in this paper. The magnitudes, real and imaginary parts of the bispectra are presented. It is found that strong quadratic interactions occur within the power spectral peak, and also between the peak and its first three harmonics. The real and imaginary parts of the bispectra represent the contributions to the vertical and horizontal asymmetry (skewness and asymmetry) of the internal wave elevations from each frequency pair, respectively. The nonzero asymmetry values indicate the sawtoothlike waveforms. Bispectral analysis is thus a useful means for investigating nonlinear properties of shallow-water internal waves. [Work supported by NSFC.]
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4744571
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2001
    detail.hit.zdb_id: 1461063-2
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  • 6
    Online Resource
    Online Resource
    Deep transfer learning for underwater direction of arrival using one vector sensor
    Acoustical Society of America (ASA) ; 2021
    In:  The Journal of the Acoustical Society of America Vol. 149, No. 3 ( 2021-03-01), p. 1699-1711
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 149, No. 3 ( 2021-03-01), p. 1699-1711
    Abstract: A deep transfer learning (DTL) method is proposed for the direction of arrival (DOA) estimation using a single-vector sensor. The method involves training of a convolutional neural network (CNN) with synthetic data in source domain and then adapting the source domain to target domain with available at-sea data. The CNN is fed with the cross-spectrum of acoustical pressure and particle velocity during the training process to learn DOAs of a moving surface ship. For domain adaptation, first convolutional layers of the pre-trained CNN are copied to a target CNN, and the remaining layers of the target CNN are randomly initialized and trained on at-sea data. Numerical tests and real data results suggest that the DTL yields more reliable DOA estimates than a conventional CNN, especially with interfering sources.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/10.0003645
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2021
    detail.hit.zdb_id: 1461063-2
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  • 7
    Online Resource
    Online Resource
    Moments of internal gravity waves
    Acoustical Society of America (ASA) ; 2001
    In:  The Journal of the Acoustical Society of America Vol. 109, No. 5_Supplement ( 2001-05-01), p. 2422-2422
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 109, No. 5_Supplement ( 2001-05-01), p. 2422-2422
    Abstract: Observations have revealed the widespread distribution of internal waves in deep oceans, shallow seas, lakes and reservoirs. Much theoretical, numerical, laboratory and field work has studied their generation and propagation, and in particular significant progress has been made in internal solitary wave research. However, statistical properties of internal waves, especially in shallow water, are still little understood. This paper is to investigate the second-, third- and fourth-order moments of internal waves. Results of internal waves in a strong seasonal thermocline of the Yellow Sea are presented and analyzed. It is found that the skewness coefficients are nonzero and the kurtosis coefficients are greater than 3, indicating skewed waveshapes and non-Gaussian distributions of the internal wave elevations. Statistics have been widely used to describe nonbreaking shoaling sea surface waves. It is suggested that the present study on internal gravity waves could be extended to construct nonlinear models for shallow-water internal waves. [Work supported by NSFC.]  
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4744572
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2001
    detail.hit.zdb_id: 1461063-2
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  • 8
    Online Resource
    Online Resource
    Modified you-only-look-once model for joint source detection and azimuth estimation in a multi-interfering underwater acoustic environment
    Acoustical Society of America (ASA) ; 2023
    In:  The Journal of the Acoustical Society of America Vol. 153, No. 4 ( 2023-04-01), p. 2393-
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 153, No. 4 ( 2023-04-01), p. 2393-
    Abstract: The you-only-look-once (YOLO) model identifies objects in complex images by framing detection as a regression problem with spatially separated boundaries and class probabilities. Object detection from complex images is somewhat similar to underwater source detection from acoustic data, e.g., time-frequency distributions. Herein, YOLO is modified for joint source detection and azimuth estimation in a multi-interfering underwater acoustic environment. The modified you-only-look-once (M-YOLO) input is a frequency-beam domain (FBD) sample containing the target and multi-interfering spectra at different azimuths, generated from the received data of a towed horizontal line array. M-YOLO processes the whole FBD sample using a single-regression neural network and directly outputs the target-existence probability and spectrum azimuth. Model performance is assessed on both simulated and at-sea data. Simulation results reveal the strong robustness of M-YOLO toward different signal-to-noise ratios and mismatched ocean environments. As tested on the data collected in an actual multi-interfering environment, M-YOLO achieved near-100% target detection and a root mean square error of 0.54° in azimuth estimation.
    Type of Medium: Online Resource
    ISSN: 0001-4966
    URL: Article
    DOI: 10.1121/10.0017828
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2023
    detail.hit.zdb_id: 1461063-2
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  • 9
    Online Resource
    Online Resource
    Echolocation click sounds from wild inshore finless porpoise ( Neophocaena phocaenoides sunameri ) with comparisons to the sonar of riverine N. p. asiaeorientalis
    Acoustical Society of America (ASA) ; 2007
    In:  The Journal of the Acoustical Society of America Vol. 121, No. 6 ( 2007-06-01), p. 3938-3946
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 121, No. 6 ( 2007-06-01), p. 3938-3946
    Abstract: Acoustic signals from wild Neophocaena phocaenoides sunameri were recorded in the waters off Liao-dong-wan Bay located in Bohai Sea, China. Signal analysis shows that N. p. sunameri produced “typical” phocoenid clicks. The peak frequencies fp of clicks ranged from 113 to 131kHz with an average of 121±3.78kHz (n=71). The 3dB bandwidths Δf ranged from 10.9 to 25.0kHz with an average of 17.5±3.30kHz. The signal durations Δt ranged from 56 to 109μs with an average 80±11.49μs. The number of cycles Nc ranged from 7 to 13 with an average of 9±1.48. With increasing peak frequency there was a faint tendency of decrease in bandwidth, which implies a nonconstant value of fp∕Δf. On occasion there were some click trains with faint click energy presenting below 70kHz, however, it was possibly introduced by interference effect from multiple pulses structures. The acoustic parameters of the clicks were compared between the investigated population and a riverine population of finless porpoise.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.2721658
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2007
    detail.hit.zdb_id: 1461063-2
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  • 10
    Online Resource
    Online Resource
    Three-dimensional spiral motion of microparticles by a binary-phase logarithmic-spiral zone plate
    Acoustical Society of America (ASA) ; 2021
    In:  The Journal of the Acoustical Society of America Vol. 150, No. 4 ( 2021-10-01), p. 2401-2408
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 150, No. 4 ( 2021-10-01), p. 2401-2408
    Abstract: Acoustic vortex beams, which have both linear and angular momentum, can be used to make precise acoustic tweezers. Limited by the symmetry of a normal vortex beam, these tweezers are usually used for trapping or rotating particles in two dimensions. Here, the three-dimensional spiral motion of two soft particles of different sizes was realized using a vortex beam with a twisted focus, which was synthesized by a silicone binary-phase logarithmic-spiral zone plate. Numerical simulations and experimental measurements demonstrated that the beam had anisotropic focuses of crescent transverse intensity profiles and a screw phase dislocation with a singularity at the center. Experiments showed that a small particle (k0r ≈ 1.3) can follow the twisted intensity of the beam, but a large particle (k0r ≈ 4.7) spirals up away from the twisted field pattern. This is attributed to the dominant gradient force for the small particle, whereas the scattering effect induced a scattering force combined with a gradient force for the large particle. This focused twisted beam, which was generated with a structured silicone plate, and the three-dimensional spiral motion of microparticles, advance the development of simple, compact, and disposable acoustic devices for the precise and diverse manipulation of microparticles.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/10.0006417
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2021
    detail.hit.zdb_id: 1461063-2
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