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  • English  (21)
  • Comparative Studies. Non-European Languages/Literatures  (21)
  • 1
    Online Resource
    Online Resource
    An analysis of the thickness vibration of an unelectroded doubly-rotated quartz circular plate
    Acoustical Society of America (ASA) ; 2018
    In:  The Journal of the Acoustical Society of America Vol. 144, No. 2 ( 2018-08-01), p. 814-821
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 144, No. 2 ( 2018-08-01), p. 814-821
    Abstract: The scalar differential equation in the thickness eigendisplacement for the doubly-rotated quartz plates is applied to analyze thickness vibrations of an unelectroded circular plate with free edges at the neighborhood of the pure thickness vibration mode. The scalar differential equation is transformed into an elliptical coordinate system. With the boundary conditions of free edges, the frequencies and the modes are solved in terms of the Mathieu function and the Modified Mathieu function. The results of frequencies of the fundamental harmonic and its third overtone of an AT-cut quartz circular plate by the present approach agree well with the existing theoretical results and the experiment results. The frequencies and modes of an SC-cut quartz circular plate are investigated by the present approach. The frequencies are close to each other when the order of the harmonics is the same. A rotation angle of the symmetric axes of the vibration modes are observed that is dependent on the anisotropic material constants and the order of the harmonics. This approach has potential applications in the design of the doubly-rotated quartz circular resonators.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5050609
    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
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    A recursive approach for aeroacoustic phased array measurements in wind tunnels
    Acoustical Society of America (ASA) ; 2021
    In:  The Journal of the Acoustical Society of America Vol. 150, No. 1 ( 2021-07-01), p. 417-427
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 150, No. 1 ( 2021-07-01), p. 417-427
    Abstract: Noise-interference suppression and data-processing acceleration are crucial to aeroacoustic measurements with phased array in wind tunnels. In this paper, we develop a “multi-window” beamforming algorithm that recursively processes data based on an array-acquisition model. This spatial filtering algorithm is derived from the Kalman filter theory for signal processing. The simulated results show that by using recursive operations, accurate signal estimation is acquired with incoherent and coherent background noise removed in the presence of both channel noise and phase noise. The convergence rate of this recursive algorithm is faster than the existing algorithms. As a result, considerable storage space and computational resources are saved, while testing defects in wind tunnel measurement are revealed and corrected immediately on-site. It has a great potential for real-time localization of sound sources in a noisy environment.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/10.0005543
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2021
    detail.hit.zdb_id: 1461063-2
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  • 3
    Online Resource
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    Analysis of coupled fast-shear and extensional vibrations of a LiTaO3 crystal plate with a ferroelectric inversion layer
    Acoustical Society of America (ASA) ; 2016
    In:  The Journal of the Acoustical Society of America Vol. 139, No. 5 ( 2016-05-01), p. 2635-2639
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 139, No. 5 ( 2016-05-01), p. 2635-2639
    Abstract: The resonance vibrations of LiTaO3 fast-shear overtone mode resonators with a ferroelectric inversion layer are analyzed. In addition to the fast-shear mode, the coupled extensional mode is considered. Different from most of the LiTaO3 resonators studied in the literature that are based on the slow-shear mode, the resonator in this paper operates with the fast-shear overtone mode. Results show that the capacitance ratio assumes maxima at two resonances, which are identified to be the second overtone modes of fast-shear and extension, respectively. It is found that the thickness of the inversion layer has obvious influences on the capacitance ratio of fast-shear and extensional modes. This condition may provide a simple method to adjust capacitance ratios of piezoelectric resonators. The influence mechanisms are also discussed. Besides, the effect of the cut angle of the crystal on the mode shape of vibrations is also investigated. The results can be used as important basis of parameters designs of LiTaO3 resonators operating on the fast-shear overtone mode.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4948756
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2016
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  • 4
    Online Resource
    Online Resource
    Source localization using deep neural networks in a shallow water environment
    Acoustical Society of America (ASA) ; 2018
    In:  The Journal of the Acoustical Society of America Vol. 143, No. 5 ( 2018-05-01), p. 2922-2932
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 143, No. 5 ( 2018-05-01), p. 2922-2932
    Abstract: Deep neural networks (DNNs) are advantageous for representing complex nonlinear relationships. This paper applies DNNs to source localization in a shallow water environment. Two methods are proposed to estimate the range and depth of a broadband source through different neural network architectures. The first adopts the classical two-stage scheme, in which feature extraction and DNN analysis are independent steps. The eigenvectors associated with the modal signal space are extracted as the input feature. Then, the time delay neural network is exploited to model the long term feature representation and constructs the regression model. The second concerns a convolutional neural network−feed-forward neural network (CNN–FNN) architecture, which trains the network directly by taking the raw multi-channel waveforms as input. The CNNs are expected to perform spatial filtering for multi-channel signals, in an operation analogous to time domain filters. The outputs of CNNs are summed as the input to FNN. Several experiments are conducted on the simulated and experimental data to evaluate the performance of the proposed methods. The results demonstrate that DNNs are effective for source localization in complex and varied water environments, especially when there is little precise environmental information.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5036725
    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
    Vertical coherence of long-range reverberation in a Pekeris shallow-water waveguide
    Acoustical Society of America (ASA) ; 1993
    In:  The Journal of the Acoustical Society of America Vol. 93, No. 4_Supplement ( 1993-04-01), p. 2286-2286
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 93, No. 4_Supplement ( 1993-04-01), p. 2286-2286
    Abstract: By using the averaged angular spectrum method for a shallow-water sound field [Zhou, Acta Acust. Sin. 5, 86–99 (1980)], an expression of vertical coherence of long-range reverberation in a Pekeris shallow-water waveguide is derived. The resulting vertical coherence coefficient depends on bottom reflection and bottom scattering at small grazing angles. In this talk, sea-going experiments and laboratory data analyses are presented. The measured vertical cross-correlation coefficient for long-range reverberation is given as a function of relevant parameters such as reverberation time, hydrophone separation, signal frequency, etc. It is found that the measurements agree with theoretical predictions very well. The results are encouraging for further research on the derivation of both small-angle bottom reflection and scattering from long-range reverberation in shallow water. [Work supported by ONR and the IAAS.]
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.406536
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 1993
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  • 6
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    Online Resource
    Frequency interferences of two-unit quartz resonator arrays excited by lateral electric fields
    Acoustical Society of America (ASA) ; 2018
    In:  The Journal of the Acoustical Society of America Vol. 144, No. 5 ( 2018-11-01), p. 2971-2982
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 144, No. 5 ( 2018-11-01), p. 2971-2982
    Abstract: The coupled thickness-twist and face-shear vibrations of the lateral-field-excitation (LFE) two-unit resonator array are analyzed, and the frequency interference and shift of LFE resonator arrays are both studied. Different from most of the quartz resonator arrays based on thickness-field-excitation, the resonator array in this study operates with LFE generated by a pair of electrodes on the top surface of the resonator. By using Mindlin's first-order theory of piezoelectric plates, the electrically forced vibrations are analyzed. The effects of various structural parameters on the frequency interference and shift are examined; furthermore, the corresponding mechanisms are discussed. Varying trends of the frequency interference and shift with various structural parameters are verified by the finite element method. The results are crucial for avoiding frequency interferences between two adjacent units in parameter design of the resonator array operating on LFE.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5079653
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2018
    detail.hit.zdb_id: 1461063-2
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  • 7
    Online Resource
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    Simulations of collar waves for acoustic logging while drilling in the frequency and the spatial domains
    Acoustical Society of America (ASA) ; 2019
    In:  The Journal of the Acoustical Society of America Vol. 145, No. 3_Supplement ( 2019-03-01), p. 1768-1768
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 145, No. 3_Supplement ( 2019-03-01), p. 1768-1768
    Abstract: Tool waves generated by the presence of the drill collar can cover the formation signals we need. The suppression for those collar waves has been a challenge for designing acoustic logging while drilling (ALWD) tools. To study the collar wave characteristics, we evaluate the excitation intensity of the modes with varying frequencies and positions by solving the elastic wave equations. Analysis results show that the collar wave energy concentrates in the cylindrical tool model. And the radial location of its peak gradually moves from the inner surface to the outer wall with the increasing frequency. The particle vibration trajectories contributed by the collar wave are also investigated. It is revealed that the collar mode in the lower frequency range has an approximately longitudinal polarization, while it tends to the transverse-wave-like motion at high frequencies. According to these features, we propose strategies on the tool structure designs to suppress the collar waves in the lower- and the higher- frequency ranges, respectively. Numerical examples further validate that the proposed collar structures with interlayers or grooves can well attenuate the collar wave propagation.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5101478
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2019
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  • 8
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    Online Resource
    Wavenumber domain analyses of vibro-acoustic decoupling and noise attenuation in a plate-cavity system enclosed by an acoustic black hole plate
    Acoustical Society of America (ASA) ; 2019
    In:  The Journal of the Acoustical Society of America Vol. 146, No. 1 ( 2019-07-01), p. 72-84
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 146, No. 1 ( 2019-07-01), p. 72-84
    Abstract: The acoustic black hole (ABH) effect is realized in thin plate structures with a decreasing thickness according to a power-law function, and offers potential applications for structure vibration damping enhancement and free-field noise radiation suppression. In this paper, a wavenumber domain method (WNDM) is proposed for the analysis of vibro-acoustic coupling and internal noise reduction mechanism of a pentahedral cavity enclosed by a flexible plate with a two-dimensional ABH indentation, subject to a point force excitation. The system response of the ABH plate-cavity is computed by a validated finite element model. The relationship between the space-averaged sound energy inside the cavity and the spectra of the structural displacement and the acoustic mode of the cavity is established. This allows revealing a dual physical mechanism behind the observed noise reduction: amplitude reduction and mismatching between the wavenumber spectra of the plate displacement and the acoustic field, which results in a weakened vibro-acoustic coupling. An additional configuration with an ABH embedded in an irregular pentagonal wall of the cavity is examined. Despite the increasing complexity in the geometry of the coupling interface and its coupling with the cavity, numerical analyses confirm the generality of the observed physical phenomena and the applicability of the proposed WNDM to more complex system configurations.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5114821
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2019
    detail.hit.zdb_id: 1461063-2
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  • 9
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    Improved local search for the minimum weight dominating set problem in massive graphs by using a deep optimization mechanism
    Elsevier BV ; 2023
    In:  Artificial Intelligence Vol. 314 ( 2023-01), p. 103819-
    Details
    In: Artificial Intelligence, Elsevier BV, Vol. 314 ( 2023-01), p. 103819-
    Type of Medium: Online Resource
    ISSN: 0004-3702
    URL: Article
    DOI: 10.1016/j.artint.2022.103819
    RVK:
    EQ 1000
    RVK:
    SA 2940
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2023
    detail.hit.zdb_id: 1468341-6
    detail.hit.zdb_id: 218797-8
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  • 10
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    Interactions of stimulus quality and semantic context on N400 in visual word recognition
    Cambridge University Press (CUP) ; 2022
    In:  Applied Psycholinguistics Vol. 43, No. 2 ( 2022-03), p. 389-410
    Details
    In: Applied Psycholinguistics, Cambridge University Press (CUP), Vol. 43, No. 2 ( 2022-03), p. 389-410
    Abstract: The joint effects of stimulus quality and semantic context in visual word recognition were examined with event-related potential (ERP) recordings. In one-character Chinese word recognition, we manipulated stimulus quality at two degradation levels (highly vs. slightly degraded) and semantic context at two priming levels (semantically related vs. unrelated). In a prime–target–probe trial flow, ERPs were recorded to the target character which was presented in either high or slight degradation and which was preceded by either a semantically related or unrelated prime character. The target character was then followed by a probe character which was either identical to or different from the target character. Subjects were instructed to make target–probe matching judgments. The ERP results demonstrated a degradation by priming interaction, with larger N400 semantic priming effects for slightly degraded targets. Moreover, the degradation effects were observed on the P200, N250, and N400. These findings provided evidence for the cascaded model of visual word recognition such that the visual processing cascaded into the semantic stage and thus interacted on the N400 amplitude. The results were compared to an earlier study with a null ERP degradation by priming interaction. The ramifications of these results for models of visual word recognition are discussed.
    Type of Medium: Online Resource
    ISSN: 0142-7164 , 1469-1817
    URL: Article
    DOI: 10.1017/S0142716421000564
    RVK:
    EQ 1285
    RVK:
    EQ 1000
    Language: English
    Publisher: Cambridge University Press (CUP)
    Publication Date: 2022
    detail.hit.zdb_id: 1499968-7
    SSG: 5,2
    SSG: 7,11
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