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  • Comparative Studies. Non-European Languages/Literatures  (17)
  • 1
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2014
    In:  The Journal of the Acoustical Society of America Vol. 135, No. 2 ( 2014-02-01), p. 928-932
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 135, No. 2 ( 2014-02-01), p. 928-932
    Abstract: Studying relationships between characteristics of sonar pulses and habitat clutter level is important for the understanding of signal design in bat echolocation. However, most studies have focused on overall spectral and temporal parameters of such vocalizations, with focus less on potential variation in frequency modulation rates (MRs) occurring within each pulse. In the current study, frequency modulation (FM) characteristics were examined in echolocation pulses recorded from big-footed myotis (Myotis macrodactylus) bats as these animals searched for prey in five habitats differing in relative clutter level. Pulses were analyzed using ten parameters, including four structure-related characters which were derived by dividing each pulse into three elements based on two knees in the FM sweep. Results showed that overall frequency, pulse duration, and MR all varied across habitat. The strongest effects were found for MR in the body of the pulse, implying that this particular component plays a major role as M. macrodactylus, and potentially other bat species, adjust to varying clutter levels in their foraging habitats.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2014
    detail.hit.zdb_id: 1461063-2
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  • 2
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2013
    In:  The Journal of the Acoustical Society of America Vol. 134, No. 5 ( 2013-11-01), p. EL452-EL458
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 134, No. 5 ( 2013-11-01), p. EL452-EL458
    Abstract: In this paper, a computational goal for a monaural speech separation system is proposed. Since this goal is derived by maximizing the signal-to-noise ratio (SNR), it is called the optimal ratio mask (ORM). Under the approximate W-Disjoint Orthogonality assumption which almost always holds due to the sparse nature of speech, theoretical analysis shows that the ORM can improve the SNR about 10log102 dB over the ideal ratio mask. With three kinds of real-world interference, the speech separation results of SNR gain and objective quality evaluation demonstrate the correctness of the theoretical analysis, and imply that the ORM achieves a better separation performance.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2013
    detail.hit.zdb_id: 1461063-2
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  • 3
    In: Brain and Language, Elsevier BV, Vol. 174 ( 2017-11), p. 16-28
    Type of Medium: Online Resource
    ISSN: 0093-934X
    RVK:
    RVK:
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2017
    detail.hit.zdb_id: 1462477-1
    SSG: 5,2
    SSG: 7,11
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  • 4
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2020
    In:  The Journal of the Acoustical Society of America Vol. 147, No. 1 ( 2020-01-01), p. 459-468
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 147, No. 1 ( 2020-01-01), p. 459-468
    Abstract: In this work, a convolutional neural network (CNN) is applied to recognize acoustic spatial patterns with the aid of acoustic visualization. The acoustic spatial patterns are obtained by the singular value decomposition of an acoustic radiation operator built with the boundary integral equation. It is to explore the powerful capability of the CNN in the image processing by analogously rendering the measured acoustic spatial patterns into images. Due to practical limitations, a higher resolution of an acoustic image is achieved by interpolating the pressure on a coarse grid. Steady-state analysis of acoustic problems is a complex domain problem. The acoustic fields are then supplied into a CNN scheme as two-channel data which are real and imaginary components of the pressure. Random noises and incident waves with varying energy are added to the measured data to simulate influences from uncorrelated and correlated noises, respectively. It is demonstrated that once the CNN scheme is built and trained with adequate data, which is numerically synthesized, the patterns can be more accurately and robustly recognized by comparing it with the cross-correlation based methods. The hierarchical feature representative as well as nonlinear perception makes the proposed method a promising approach for fault diagnosis and condition monitoring based on spatial acoustic measurements.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2020
    detail.hit.zdb_id: 1461063-2
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  • 5
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2023
    In:  The Journal of the Acoustical Society of America Vol. 153, No. 3_supplement ( 2023-03-01), p. A351-A351
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 153, No. 3_supplement ( 2023-03-01), p. A351-A351
    Abstract: Ultrasound thermal strain imaging (US-TSI) has been known for the capability of tissue characterization according to distinct sound speed change in different tissues when temperature increases. US-TSI for detecting lipids in atherosclerosis plaques and fatty livers has previously been reported while some practical challenges were not fully addressed, especially due to physiological motions. To overcome such limitation, we recently developed an ultrasound transducer that combines an acoustic heating array and an imaging array to achieve US-TSI with heating performed in a region of approximately 10 mm by 5 mm by 2 mm within a very short time period of about 50 ms compared both cardiac and breathing motions. To characterize the new US-TSI probe, a thorough benchtop investigation was performed on the relationship among the threekey variables for TSI: thermal strain, temperature increase, and lipid concentration. In the experiments, homogeneous oil-in-gelatin phantoms of different oil concentrations were fabricated to simulate different lipid-plaque concentrations. Temperature curves were recorded by a thermal couple with millisecond-level time constant. Thermal strains were computed by developed US-TSI signal processing procedures. The results build a tissue-temperature-strain model and calibrate the new US-TSI probe for in vivo atherosclerosis plaque characterization.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2023
    detail.hit.zdb_id: 1461063-2
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  • 6
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2014
    In:  The Journal of the Acoustical Society of America Vol. 135, No. 4_Supplement ( 2014-04-01), p. 2305-2305
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 135, No. 4_Supplement ( 2014-04-01), p. 2305-2305
    Abstract: Equations governing nonlinear interactions among acoustic waves in water which satisfy the resonance conditions are derived from the Burgers equation. Taking into account of the second-order nonlinear, the three-wave interaction is the fundamental process of the interaction equations. Then, taking the three-wave interaction equation as an example, the energy transfer mechanism among the three acoustic waves is quantitatively analyzed. And the three-wave sound energy propagation is studied through numerical calculation. An interesting phenomenon is found that, when the three acoustic waves meet the relationship of a weak low-frequency sound and two strong high-frequency sounds, the energy of low-frequency sound will be amplified or reduced in some regions during the three-wave propagation. And the location and size of the regions are affected by the acoustic wave amplitude, frequency, and phase. The variation severities of low-frequency acoustic wave energy are mainly determined by other two high-frequency acoustic wave energy. The frequencies of two high-frequency sound waves have little effects on the energy of low-frequency sound wave. The region whether is amplification or reduction is determined by the phase difference of three waves. The variation laws of low-frequency sound energy are also verified by the experimental results in river.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2014
    detail.hit.zdb_id: 1461063-2
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  • 7
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2016
    In:  The Journal of the Acoustical Society of America Vol. 140, No. 3 ( 2016-09-01), p. EL242-EL246
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 140, No. 3 ( 2016-09-01), p. EL242-EL246
    Abstract: Typhoon induced sediment warming has been proven important to coastal sound-field change in this study. It was observed that the temperature of the bottom waters off the coast of Qingdao increased by 5 °C after the passage of typhoon Damrey in 2012. Sediment warming due to bottom-water temperature increase was calculated and the change in sediment sound speed was estimated. Transmission loss (TL) was simulated both with and without consideration of the change in sediment sound speed induced by temperature variation and results showed TL change could be & gt;10 dB within a distance of 16 km.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2016
    detail.hit.zdb_id: 1461063-2
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  • 8
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 1987
    In:  The Journal of the Acoustical Society of America Vol. 81, No. 5 ( 1987-05-01), p. 1350-1354
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 81, No. 5 ( 1987-05-01), p. 1350-1354
    Abstract: A previous review [J. Acoust. Soc. Am. 70, 1213–1219 (1981)] emphasized sound absorption in water fog of droplets within sizes near 10 μ. This supplemental article presents results for the core where droplet size is much smaller, ≂0.01 μ. Theoretical formulation for these small droplets is shown to be basically the same as for the larger droplets. The attenuation coefficient due to mass transfer, which some authors claimed to be two (or three) orders of magnitude larger for small drops than for large ones, is accompanied by an increase in the frequency of maximum absorption by the same orders of magnitude. A correction factor is also introduced for the relaxation times from the viewpoint of modern fog kinetics. The result predicts a counter effect or a drastic decrease in the absorption abnormality due to submicron droplets, but the effect is less, the larger the droplet, which, therefore, may lead to a theoretical generalization of the problem applicable to droplets of all sizes.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 1987
    detail.hit.zdb_id: 1461063-2
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  • 9
    Online Resource
    Online Resource
    Informa UK Limited ; 2021
    In:  Journal of Multilingual and Multicultural Development Vol. 42, No. 3 ( 2021-03-16), p. 291-306
    In: Journal of Multilingual and Multicultural Development, Informa UK Limited, Vol. 42, No. 3 ( 2021-03-16), p. 291-306
    Type of Medium: Online Resource
    ISSN: 0143-4632 , 1747-7557
    RVK:
    Language: English
    Publisher: Informa UK Limited
    Publication Date: 2021
    detail.hit.zdb_id: 136713-4
    detail.hit.zdb_id: 1480742-7
    SSG: 7,11
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  • 10
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2017
    In:  The Journal of the Acoustical Society of America Vol. 141, No. 5_Supplement ( 2017-05-01), p. 3732-3732
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 141, No. 5_Supplement ( 2017-05-01), p. 3732-3732
    Abstract: An 8-hr time-weighted average exposure of 85 dBA was adopted as the permissible exposure limit (PEL) by most current international standards for exposure to noise. Using the definition of material hearing impairment (MHI) as the average of hearing threshold levels for both ears exceeded 25 dB at 1, 2, 3, and 4 kHz, NIOSH estimated that the excess risk was 8% for workers exposed to an average noise level of 85 dBA over a 40-year working lifetime. However, this 85 dBA PEL was based on the data that was acquired from workers exposed to steady state (Gaussian) noises. In this study a database of 648 workers (age 36.9 yrs + /- 7.8, exposure duration 12.8 yrs + /- 8.0) exposed to non-Gaussian noises were used to assess the 85 dBA PEL. Among them 222 subjects exposed to noise at level of 80-84 dBA and 426 subjects at 85-89 dBA. Although the average duration of exposure from non-Gaussian database was much less than 40 years, the prevalence of MHI was 16.7% at level of 80-84 dBA and 31.5% at level of 84-89 dBA. The results show that 85 dBA PEL may not well protect hearing for workers exposed to non-Gaussian complex noise exposure.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2017
    detail.hit.zdb_id: 1461063-2
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