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  • 1
    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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  • 2
    Online Resource
    Online Resource
    Low-rank decomposition meets kernel learning: A generalized Nyström method
    Elsevier BV ; 2017
    In:  Artificial Intelligence Vol. 250 ( 2017-09), p. 1-15
    Details
    In: Artificial Intelligence, Elsevier BV, Vol. 250 ( 2017-09), p. 1-15
    Type of Medium: Online Resource
    ISSN: 0004-3702
    URL: Article
    DOI: 10.1016/j.artint.2017.05.001
    RVK:
    EQ 1000
    RVK:
    SA 2940
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2017
    detail.hit.zdb_id: 1468341-6
    detail.hit.zdb_id: 218797-8
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  • 3
    Online Resource
    Online Resource
    Machining process monitoring with vibration signal based manifold learning
    Acoustical Society of America (ASA) ; 2020
    In:  The Journal of the Acoustical Society of America Vol. 148, No. 4_Supplement ( 2020-10-01), p. 2766-2766
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 148, No. 4_Supplement ( 2020-10-01), p. 2766-2766
    Abstract: Machining process monitoring based on vibration sensing is a growing demand in smart manufacturing. However, in real factories, massive process conditions which include thousands of shapes of workpieces and thousands of combinations of cutting parameters, such as spindle speed, feed rate and cutting depth, are designed and used in manufacturing. Manifold learning is able to extract essential and distinct features from the vibration signal and helps to monitor and recognize different process conditions. In this paper, the dataset, including slight and huge variation of cutting parameters and workpiece shapes, are collected for analysis. Different manifold learning algorithms are utilized and compared to mine the essential features and reduce the interference of non-sensitive features. The generalization ability of different manifold learning algorithms are discussed to fit the various process conditions. Convolutional neural networks are employed to evaluate the monitoring accuracy. The experimental results show that the features obtained by the manifold learning distinguish vibration signals of different cutting parameters in low dimensional space and give a protentional way to construct effective monitoring systems. The generalization ability to different workpieces and cutting parameters and its limitation are discussed.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5147701
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2020
    detail.hit.zdb_id: 1461063-2
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  • 4
    Online Resource
    Online Resource
    Prediction of flow induced noise near a rigid body at low Mach numbers.
    Acoustical Society of America (ASA) ; 2011
    In:  The Journal of the Acoustical Society of America Vol. 129, No. 4_Supplement ( 2011-04-01), p. 2522-2522
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 129, No. 4_Supplement ( 2011-04-01), p. 2522-2522
    Abstract: For low Mach number flow around a solid body, the far-field sound pressure is dominated by dipole sources comparing with the monopole and quadruple components. The dipole sources are created by the unsteady surface pressure distributions due to the presence of a turbulent boundary layer in the vicinity of the solid body. The far-field sound pressure can be calculated by integrating the time derivative of the wall-pressure fluctuations at the surface of the rigid body. Recent development in computational fluid dynamics (CFD) brings a powerful tool for predicting unsteady turbulent flow fields and the generation mechanism of aerodynamic noise. The current study investigates the use of improved CFD method to accurately simulate the flow fields near a solid body. The information of the flow field is then used to calculate the far field sound pressures. Extensive computations have been conducted to calculate the noise induced by the flow over a circular cylinder and an automobile’s rear view mirror. The calculated sound pressure levels have shown to agree well with published experimental results. [Work sponsored by the China Scholarship Council.]
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.3588347
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2011
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  • 5
    Online Resource
    Online Resource
    Robustness of the ultrasonic face recognition method to age variation: analysis and experimentation
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3447-3447
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3447-3447
    Abstract: Ultrasonic human face recognition systems transmit ultrasonic Continuously Transmitted Frequency Modulated (CTFM) signal, extract facial geometry characteristic information from the received echo signals, and process the information for face recognition. Compared to vision-based approaches, ultrasonic human face recognition systems reduce the influence of illumination and avoid privacy leak. The existing approaches showed the feasibility of ultrasonic face recognition and achieved acceptable recognition accuracy. However, the aging problem, which equals to performance degradation caused by facial geometry change with time going on, is not considered in the previous researches. In this paper, robustness of the ultrasonic face recognition method to age variation is analysed. A database is built, in which each subject's face information was acquired at intervals of months during the last two years. Based on the database, various recognition experiments are conducted using the different pattern recognition algorithms. Aiming at the experimental results, the analysis to age factor that influences face recognition performance is implemented. The feature extraction methods and the pattern recognition algorithms are developed to increase the recognition rate.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4708987
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
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  • 6
    Online Resource
    Online Resource
    A new soft decision feedback equalizer in underwater acoustic communications
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3483-3483
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3483-3483
    Abstract: The tap coefficients of the decision-feedback equalizer (DFE) are associated with the multipath spread of the channel. For the underwater acoustic communication channel, the impulse response often covers tens to hundreds of symbols, requiring at least tens of taps in the feedback filter. Once the incorrect decisions are fed back, the error propagation will be severe. In this paper, we propose a new soft decision equalizer. The expected output symbols of the equalizer will be weighted according to their reliability, and summed up, then the result is fed back. This approach can alleviate the effect of those incorrect symbols. For evaluating the performance of the proposed method, a sea test in shallow water was carried out. The experimental results show that its BER decreases by 50% without channel codec, compared with the conventional DFE. Furthermore, the mean square error can also reduce about 2 dB when the error propagation is severe.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4709145
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
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  • 7
    Online Resource
    Online Resource
    The cutting parameters dependent vibration monitoring method for machine tools
    Acoustical Society of America (ASA) ; 2020
    In:  The Journal of the Acoustical Society of America Vol. 148, No. 4_Supplement ( 2020-10-01), p. 2793-2793
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 148, No. 4_Supplement ( 2020-10-01), p. 2793-2793
    Abstract: The on-line monitoring of the machine tools attracts growing interest for the operation of the smart factories. The quality of the workpieces and the productivity of the manufacturing can be maintained through the monitoring and optimization. The vibration signal reflects irregular characteristics of the fault conditions, such as the tool wear and chatter. The corresponding features can be extracted and recognized using the conventional signal processing method in the time and frequency domain. However, the vibration features are process-dependent. Due to the dynamic changes of cutting parameters, the variance of the cutting forces and the consequent frequency response between different cutting parameters could be larger than that between the regular conditions and fault conditions in the identical cutting parameters. This paper combined the vibration signal with the real-time cutting parameters and toolpath calculated by the numerical control codes to analysis the cutting condition of the machining process. A sub-band segmentation method based on spindle speed is proposed. The accuracy and applicability are also discussed.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5147774
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2020
    detail.hit.zdb_id: 1461063-2
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  • 8
    Online Resource
    Online Resource
    An approach for moving target detection with airborne CTFM sonar
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3423-3423
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3423-3423
    Abstract: Continuously Transmitted Frequency Modulated (CTFM) sonar transmits wideband acoustic signal, demodulates the echo signal, and calculates the target distance by acquiring the frequency of the demodulation output signal. Still objects can be accurately detected using CTFM sonar. However, moving target brings Doppler shift to the echo signal frequency, which makes the output signal frequency of CTFM sonar deviate from the accurate distance of the target. In this paper, a novel airborne sonar sensing approach is proposed. Using a modified transmitted signal, single moving target that appears in a static environment can be detected. Compared to traditional CTFM sonar, a single tone is added to the transmitted signal. The existence and radial velocity of a moving target can be calculated based on the single tone Doppler shift of the echo. Furthermore, the simultaneous kinematic information of the target can be extracted by the system algorithm. An experimental system is developed, and the result of experiments verified the feasibility of the approach.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4708839
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
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  • 9
    Online Resource
    Online Resource
    Realtime face recognition system with ultrasonic sensing
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3447-3447
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3447-3447
    Abstract: Unlike vision-based approaches, ultrasonic sensing systems have the ability to obtain the object distance and echo energy information. With the development of airborne ultrasonic detection, ultrasonic face recognition has been discussed. However, the existing ultrasonic face recognition systems store the echo waveform data and make processing and analysis afterwards. Seperated acquisition and analysis procedures make these systems non-realtime. In this paper, a realtime ultrasonic face recognition system is proposed. The system has the following functions: signal generation, transmitting, receiving, amplification, demodulation, spectral analysis, and feature extraction. A continuous wideband ultrasonic signal is transmitted, then the geometrical information can be extracted from the echo signal, and suitable pattern recognition methods are used to recognize human face. The system can implement realtime face recognition with ultrasonic sensing, and a considerable recognition rate is achieved.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4708986
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
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  • 10
    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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