GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Comparative Studies. Non-European Languages/Literatures  (196)
Material
Language
Subjects(RVK)
  • 1
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 1996
    In:  The Journal of the Acoustical Society of America Vol. 99, No. 4_Supplement ( 1996-04-01), p. 2498-2500
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 99, No. 4_Supplement ( 1996-04-01), p. 2498-2500
    Abstract: Planar acoustic holography has been well acknowledged as a useful tool to predict whole sound fields in space. In practical applications, however, an insufficient number of microphones has trouble measuring whole holograms, therefore limiting the improvement to construct a better picture of sound. This problem conveys the issue to virtually increase the number of microphones so that it can construct a better, realistic sound field. As one of these measuring techniques, the conventional scanning technique requires a reference and holds the array during the measurement of pressures. Instead, the proposed method measures the hologram continuously by a moving array without a reference. Its basic idea is that the pressure signal of a moving microphone is modulated with the carrier frequency which is the frequency of the sound field. Although this is a time signal, it includes the spatial information of pressure distribution; i.e., hologram, due to a constant moving speed. The bandwidth of modulated signal is directly proportional to the Mach number, therefore generally narrow, a hologram can be successfully recovered unless there is a closely located frequency; not closer than the bandwidth. Also this technique can be directly applied to the hologram measurement of a moving source with a fixed array. This method is demonstrated by computer simulations and experiments.
    Type of Medium: Online Resource
    ISSN: 0001-4966
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 1996
    detail.hit.zdb_id: 219231-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2023
    In:  The Journal of the Acoustical Society of America Vol. 154, No. 4_supplement ( 2023-10-01), p. A306-A306
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 154, No. 4_supplement ( 2023-10-01), p. A306-A306
    Abstract: Conventional beamforming (CBF) based on plane waves is widely used for direction finding with a horizontal array deployed in ocean waveguides. However, CBF suffers from loss of spatial coherence due to the inhomogeneous field produced by constructive and destructive interference between multipath arrivals. Moreover, the grazing angle propagation leads to a bias in the estimated bearing. In this work, we revisit the striation-based beamforming (SBF) that exploits the waveguide invariant representing the complex wave propagation [Zurk and Rouseff, J. Acoust. Soc. Am. 132, EL264 (2012)]. Our approach involves a preliminary processing to restore the spatial coherence across the horizontal array, followed by CBF. Experimental results illustrate the performance improvement of SBF over CBF in terms of array gain, resolution, and bias.
    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
    detail.hit.zdb_id: 219231-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2024
    In:  The Journal of the Acoustical Society of America Vol. 155, No. 3_Supplement ( 2024-03-01), p. A292-A292
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 155, No. 3_Supplement ( 2024-03-01), p. A292-A292
    Abstract: The potential of using speakers as a sensor to detect ear canal conditions was demonstrated previously. This research contains our ongoing and continuous effort to utilize a single speaker as a sensor by measuring electrical impedance varying acoustic loads. Electrical impedance data (magnitude and phase) from six different acoustic load conditions were collected as features for machine learning (ML) model training. To enhance the learning performance, the data were pre-processed and augmented with normalization and level-shifting techniques, respectively. The raw data were converted to images to optimize the learning performance to classify acoustic loads from the impedance measurement. Several forms of images were experimented such as magnitude only, overlapped magnitude and phase, and rectangular form. A total of 2100 data (350 each) were used with CNN-based State of the Art (SOTA) models such as AlexNet, ResNet, and DenseNet. Both binary and multiclass classifications were performed, showing 0.9716 average accuracy and 0.907 accuracy, respectively. This innovative single-speaker approach using impedance as ML features is poised to revolutionize traditional acoustic sensing research by harnessing the limitless power of AI.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2024
    detail.hit.zdb_id: 1461063-2
    detail.hit.zdb_id: 219231-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2023
    In:  The Journal of the Acoustical Society of America Vol. 154, No. 4_supplement ( 2023-10-01), p. A356-A356
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 154, No. 4_supplement ( 2023-10-01), p. A356-A356
    Abstract: Enhancement of Green's function is accomplished from the striation pattern obtained from data. The waveguide invariant theory allows a Green's function observed at one location to be extrapolated into adjacent ranges [Song and Byun, J. Acoust. Soc. Am. 147, 2150–2158 (2020)]. Conversely, Green's functions observed at adjacent ranges can converge towards a central location for coherent combination to improve the signal-to-noise ratio (SNR). This can be accomplished from the frequency shift in the striation pattern without prior range information of each Green's functions. We demonstrate a significant improvement of SNR in the broadband Green's function from a moving ship in shallow water.
    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
    detail.hit.zdb_id: 219231-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2021
    In:  The Journal of the Acoustical Society of America Vol. 150, No. 4_Supplement ( 2021-10-01), p. A281-A281
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 150, No. 4_Supplement ( 2021-10-01), p. A281-A281
    Abstract: Sound propagated in an ocean waveguide is greatly influenced by the characteristics of the underwater acoustic channel. Thus, knowledge of the propagation characteristics (i.e., impulse response or Green’s function) is key to various ocean remote sensing applications. Recently a relationship was verified that the waveguide invariant property allows a time-domain Green’s function observed at one location to be extrapolated to adjacent ranges [Song et al., J. Acoust. Soc. Am. 149, 2173–2178 (2021)]. Here, we exploit this relationship to coherently combine the time-domain Green’s function from adjacent ranges to improve the SNR of the multipath impulse response. Numerical simulation results are presented and discussed.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2021
    detail.hit.zdb_id: 1461063-2
    detail.hit.zdb_id: 219231-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Online Resource
    Online Resource
    Elsevier BV ; 2015
    In:  Cognition Vol. 136 ( 2015-03), p. 359-364
    In: Cognition, Elsevier BV, Vol. 136 ( 2015-03), p. 359-364
    Type of Medium: Online Resource
    ISSN: 0010-0277
    RVK:
    RVK:
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2015
    detail.hit.zdb_id: 184702-8
    SSG: 5,2
    SSG: 7,11
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Online Resource
    Online Resource
    Wiley ; 2017
    In:  Cognitive Science Vol. 41, No. 1 ( 2017-01), p. 242-258
    In: Cognitive Science, Wiley, Vol. 41, No. 1 ( 2017-01), p. 242-258
    Abstract: Are mechanisms for social attention influenced by culture? Evidence that social attention is triggered automatically by bottom‐up gaze cues and is uninfluenced by top‐down verbal instructions may suggest it operates in the same way everywhere. Yet considerations from evolutionary and cultural psychology suggest that specific aspects of one's cultural background may have consequence for the way mechanisms for social attention develop and operate. In more interdependent cultures, the scope of social attention may be broader, focusing on more individuals and relations between those individuals. We administered a multi‐gaze cueing task requiring participants to fixate a foreground face flanked by background faces and measured shifts in attention using eye tracking. For European Americans, gaze cueing did not depend on the direction of background gaze cues, suggesting foreground gaze alone drives automatic attention shifting; for East Asians, cueing patterns differed depending on whether the foreground cue matched or mismatched background cues, suggesting foreground and background gaze information were integrated. These results demonstrate that cultural background influences the social attention system by shifting it into a narrow or broad mode of operation and, importantly, provides evidence challenging the assumption that mechanisms underlying automatic social attention are necessarily rigid and impenetrable to culture.
    Type of Medium: Online Resource
    ISSN: 0364-0213 , 1551-6709
    URL: Issue
    RVK:
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2017
    detail.hit.zdb_id: 282371-8
    detail.hit.zdb_id: 2002940-8
    SSG: 25
    SSG: 5,2
    SSG: 7,11
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2018
    In:  The Journal of the Acoustical Society of America Vol. 144, No. 4 ( 2018-10-01), p. 2375-2382
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 144, No. 4 ( 2018-10-01), p. 2375-2382
    Abstract: The cascade of blind deconvolution and array invariant has been successful to localize and track a surface ship radiating random waveforms, using a 56-m long vertical array in 100-m deep shallow water. In this paper, it is shown that a 60-m long, bottom-mounted horizontal array can be utilized for blind deconvolution to extract the Green's functions from the same ship (100–800 Hz), in conjunction with the array invariant for source-range estimation. The additional information obtained with a horizontal array is the source bearing (azimuth angle, ϕ) from the well-resolved ray angle identified for blind deconvolution to extract the phase component of the unknown source waveforms. The overall tracking performance shows good agreement with global positioning system (GPS) measurements to less than 11% in terms of standard deviation of relative range error at ranges of 0.3–1.5 km, except when the ship is around the broadside (e.g., |ϕ| & lt;25°) of the horizontal array. On the other hand, the source bearings are in excellent agreement with the GPS data except near the endfire due to the lower angular resolution. The potential for simultaneous localization of multiple ships is also discussed.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2018
    detail.hit.zdb_id: 1461063-2
    detail.hit.zdb_id: 219231-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2001
    In:  The Journal of the Acoustical Society of America Vol. 109, No. 5_Supplement ( 2001-05-01), p. 2476-2476
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 109, No. 5_Supplement ( 2001-05-01), p. 2476-2476
    Abstract: Underwater acoustic communications must mitigate the intersymbol interference caused by the time-varying multipath dispersion. An experiment was conducted in June 2000 demonstrating that the time-reversal process recombined the temporal multipath resulting in reduced bit errors for communication. Quantitative bit error results will be shown for BPSK (binary phase shift keying) and QPSK (quadrature phase shift keying). Communication sequences were transmitted over a distance of 10 km both in range-independent and range-dependent environments north of Elba Island, Italy. The range-independent transmissions were made in 100-m-deep water and the range-dependent transmissions were made upslope from 100-m-deep water into 40-deep-water. [Work supported by ONR.]
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2001
    detail.hit.zdb_id: 1461063-2
    detail.hit.zdb_id: 219231-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2010
    In:  The Journal of the Acoustical Society of America Vol. 127, No. 2 ( 2010-02-01), p. EL19-EL22
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 127, No. 2 ( 2010-02-01), p. EL19-EL22
    Abstract: Although the spatial focusing property of the conventional time reversal approach facilitates multiuser communications, there always is residual crosstalk between users. A recent paper [Kim and Shin, J. Acoust. Soc. Am. 115, 600–606 (2004)] proposed an adaptive active time reversal approach for simultaneous multiple focusing with minimal interference. This letter applies the adaptive approach to passive time reversal, multiuser communications for additional suppression of crosstalk among users. Experimental data at 3.5kHz with a 1-kHz bandwidth demonstrate as much as 6.5-dB improvement per user in terms of output signal-to-noise ratio for three-user communications over a 20-km range in 120-m deep shallow water.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2010
    detail.hit.zdb_id: 1461063-2
    detail.hit.zdb_id: 219231-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...