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  • 1
    Online Resource
    Online Resource
    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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  • 2
    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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  • 3
    Online Resource
    Online Resource
    Inter-noise 87—Beijing, September 1987
    Acoustical Society of America (ASA) ; 1988
    In:  The Journal of the Acoustical Society of America Vol. 83, No. 3 ( 1988-03-01), p. 1200-1200
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 83, No. 3 ( 1988-03-01), p. 1200-1200
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.396018
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 1988
    detail.hit.zdb_id: 1461063-2
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  • 4
    Online Resource
    Online Resource
    Calculation of free-field deviation in an anechoic room
    Acoustical Society of America (ASA) ; 1987
    In:  The Journal of the Acoustical Society of America Vol. 82, No. S1 ( 1987-11-01), p. S45-S45
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 82, No. S1 ( 1987-11-01), p. S45-S45
    Abstract: After a review of various calculation methods currently available for free-field deviation (in Db) in an anechoic room, the authors present, in this paper, a more precise and rational calculation of the sound field by solving wave equations in consideration of the interference of first reflections only. In the case of pure tone, the phase factor plays an important role in the calculation; therefore, the free-field deviation (in Db) calculated also depends on the source position, measuring direction and distance from the source, and the frequency used in the test, besides other factors such as the dimensions of the room and sound absorption characteristics of all the boundary surfaces. For a broadband noise, the calculation becomes simpler since the phase factor can be ignored, and a general equation of such a calculation is given for any source position and different combinations of boundary absorption. The results of the calculation can be shown in a diagram with the aid of a microcomputer, and, hence, a three-dimensional free-field scope would be very useful as a guideline to design and to use an anechoic room.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.2024819
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 1987
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  • 5
    Online Resource
    Online Resource
    Geometric shapes effect of in-duct perforated orifices on aeroacoustics damping performances at low Helmholtz and Strouhal number
    Acoustical Society of America (ASA) ; 2019
    In:  The Journal of the Acoustical Society of America Vol. 145, No. 4 ( 2019-04-01), p. 2126-2137
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 145, No. 4 ( 2019-04-01), p. 2126-2137
    Abstract: In this work, experimental studies are conducted to measure the aeroacoustics damping performances of 11 in-duct perforated plates in a cold-flow pipe with a variable Mach number. These in-duct plates have the same porosities but different number N and geometric shaped orifices. Here six shapes are considered, i.e., (1) triangle, (2) square, (3) pentagon, (4) hexagon, (5) star, and (6) circle. It is shown that the orifice shape has little influence on power absorption Δ and reflection coefficient R at a lower Helmholtz number He ≤ 0.0903. However, as He is increased, the in-duct plate with a star-shaped orifice is shown to be with much lower Δ in comparison with that of other plates with different shape orifices. In addition, the perforated orifice with the same shape and porosity but a larger N is shown to be associated with 20% more power absorption at approximately He = 0.1244. Δmax is observed to be approximately 85% at about He = 0.0244, as Ma≈0.029. To gain more insights, the quasi-steady model is applied, depending on the Strouhal number Sr. The transition from quasi-steady flow behaviors to unsteady behaviors occurs at approximately Sr = 0.45. The measured minimum reflection coefficient Rmin occurs at Ma ≈ 0.024. This experimental finding is consistent with the quasi-steady prediction.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.5096642
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2019
    detail.hit.zdb_id: 1461063-2
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  • 6
    Online Resource
    Online Resource
    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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  • 7
    Online Resource
    Online Resource
    Deposition of ZnO films with c-axes lying in R-sapphire substrate planes
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3466-3466
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3466-3466
    Abstract: The (110) textured ZnO films with c-axes lying in R-sapphire substrate planes are deposited by RF magnetron sputtering. The focusing investigation is the effect of substrate position in the sputtering on structural and acoustic properties of the ZnO films on the sapphire. The crystallographic characteristics of the films are characterized by X-ray diffraction (XRD) analysis. It is found that the crystalline orientation of the ZnO film varies with the substrate position deflected from the center of the target. The XRD spectra of the films show that there is an optimized substrate position, at which the strongest (110) peak of the ZnO film can be obtained. However, with the decrease or further increase of the deflection, the (110) diffraction intensity decreases and additional diffraction peaks of (002), (102) and (103) emerge. In order to investigate the variations of acoustic properties of these films, the ZnO piezoelectric films are deposited on R-sapphire substrates with different deflection positions, and the bilayered structures are used to fabricate film bulk acoustic resonators (FBARs). The results show that the electromechanical coupling coefficients k15 of the shear mode acoustic waves excited by FBARs also vary with the different positions similar to that shown by the XRD spectra.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.4709066
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
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  • 8
    Online Resource
    Online Resource
    Calculation of free-field deviation in an anechoic room
    Acoustical Society of America (ASA) ; 1989
    In:  The Journal of the Acoustical Society of America Vol. 85, No. 3 ( 1989-03-01), p. 1206-1212
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 85, No. 3 ( 1989-03-01), p. 1206-1212
    Abstract: After a review of various calculation methods currently available for free-field deviation (in dB) in an anechoic room, a more precise and rational calculation of the sound field is presented in this article by solving wave equations including the interference of first reflections only. In the case of a pure tone, the phase factor plays an important role in the calculation; therefore, the calculated free-field deviation (in dB) also depends on the source position, measuring direction and distance from the source, and the frequency used in the test in addition to other factors such as the dimensions of the room and sound absorption characteristics of all of the boundary surfaces. For a broadband noise, calculation becomes simpler as the phase factor can be ignored, and a general equation of such a calculation is given for any source position and different combinations of boundary absorption. The results of the calculation can be shown in a diagram with the aid of a microcomputer, as a map of free-field range within a given maximum deviation. This is very useful as a guideline to design and to use an anechoic room.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.397451
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 1989
    detail.hit.zdb_id: 1461063-2
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  • 9
    Online Resource
    Online Resource
    Model experiments on the spatial altering of modes
    Acoustical Society of America (ASA) ; 1982
    In:  The Journal of the Acoustical Society of America Vol. 72, No. S1 ( 1982-11-01), p. S59-S59
    Details
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 72, No. S1 ( 1982-11-01), p. S59-S59
    Abstract: The spatial filtering of modes is very important both for theoretical and practical purposes. Spatial filtering of modes can verify the normal-mode theory and is also a way to match the waveguide fields. It will have an important application in the investigation of the interaction between the sound wave and environmental factors such as the acoustic characteristics of ocean bottom, internal wave,…etc., because it is easier to study separate modes. In this paper, the model experiments include the following: (1) The spatial filtering of modes in a long water tank without absorbers on the side wall. (2) The suppression of the near interference point source by means of selected mode. (3) The effects of surface waves on each individual mode and the sum of all modes at a point receiver.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    URL: Article
    DOI: 10.1121/1.2019967
    RVK:
    EQ 1000
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 1982
    detail.hit.zdb_id: 1461063-2
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  • 10
    Online Resource
    Online Resource
    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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