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  • Komparatistik. Außereuropäische Sprachen/Literaturen  (6)
Materialart
Sprache
Erscheinungszeitraum
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Fachgebiete(RVK)
  • Komparatistik. Außereuropäische Sprachen/Literaturen  (6)
RVK
  • 1
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2021
    In:  The Journal of the Acoustical Society of America Vol. 150, No. 1 ( 2021-07-01), p. 225-232
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 150, No. 1 ( 2021-07-01), p. 225-232
    Kurzfassung: The sound-transmission, beam-formation, and sound-reception processes of a short-finned pilot whale (Globicephala macrorhynchus) were investigated using computed tomography (CT) scanning and numerical simulation. The results showed that sound propagations in the forehead were modulated by the upper jaw, air components, and soft tissues, which attributed to the beam formation in the external acoustic field. These structures owned different acoustic impedance and formed a multiphasic sound transmission system that can modulate sounds into a beam. The reception pathways composed of the solid mandible and acoustic fats in the lower head conducted sounds into the tympano-periotic complex. In the simulations, sounds were emitted in the forehead transmission system and propagated into water to interrogate a steel cylinder. The resulting echoes can be interpreted from multiple perspectives, including amplitude, waveform, and spectrum, to obtain the acoustic cues of the steel cylinder. By taking the short-finned pilot whale as an example, this study provides meaningful information to further deepen our understanding of biosonar system operations, and may expand sound-reception theory in odontocetes.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2021
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2017
    In:  The Journal of the Acoustical Society of America Vol. 142, No. 4 ( 2017-10-01), p. 1901-1912
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 142, No. 4 ( 2017-10-01), p. 1901-1912
    Kurzfassung: Acoustic properties of odontocete head tissues, including sound velocity, density, and acoustic impedance, are important parameters to understand dynamics of its echolocation. In this paper, acoustic properties of head tissues from a freshly dead short-finned pilot whale (Globicephala macrorhynchus) were reconstructed using computed tomography (CT) and ultrasound. The animal's forehead soft tissues were cut into 188 ordered samples. Sound velocity, density, and acoustic impedance of each sample were either directly measured or calculated by formula, and Hounsfield Unit values (HUs) were obtained from CT scanning. According to relationships between HUs and sound velocity, HUs and density, as well as HUs and acoustic impedance, distributions of acoustic properties in the head were reconstructed. The inner core in the melon with low-sound velocity and low-density is an evidence for its potential function of sound focusing. The increase in acoustic impedance of forehead tissues from inner core to outer layer may be important for the acoustic impedance matching between the outer layer tissue and seawater. In addition, temperature dependence of sound velocity in soft tissues was also examined. The results provide a guide to the simulation of the sound emission of the short-finned pilot whale.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2017
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2015
    In:  The Journal of the Acoustical Society of America Vol. 138, No. 5 ( 2015-11-01), p. 3129-3137
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 138, No. 5 ( 2015-11-01), p. 3129-3137
    Kurzfassung: Computed tomography (CT) imaging and sound experimental measurements were used to reconstruct the acoustic properties (density, velocity, and impedance) of the forehead tissues of a deceased pygmy sperm whale (Kogia breviceps). The forehead was segmented along the body axis and sectioned into cross section slices, which were further cut into sample pieces for measurements. Hounsfield units (HUs) of the corresponding measured pieces were obtained from CT scans, and regression analyses were conducted to investigate the linear relationships between the tissues' HUs and velocity, and HUs and density. The distributions of the acoustic properties of the head at axial, coronal, and sagittal cross sections were reconstructed, revealing that the nasal passage system was asymmetric and the cornucopia-shaped spermaceti organ was in the right nasal passage, surrounded by tissues and airsacs. A distinct dense theca was discovered in the posterior-dorsal area of the melon, which was characterized by low velocity in the inner core and high velocity in the outer region. Statistical analyses revealed significant differences in density, velocity, and acoustic impedance between all four structures, melon, spermaceti organ, muscle, and connective tissue (p  & lt; 0.001). The obtained acoustic properties of the forehead tissues provide important information for understanding the species' bioacoustic characteristics.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2015
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    Online-Ressource
    Online-Ressource
    John Benjamins Publishing Company ; 2021
    In:  Pragmatics Vol. 31, No. 4 ( 2021-10-13), p. 617-646
    In: Pragmatics, John Benjamins Publishing Company, Vol. 31, No. 4 ( 2021-10-13), p. 617-646
    Kurzfassung: Studies on the development of interlanguage pragmatic markers (PMs) have attracted increasing interest recently. However, little research is available on the PM dynamic development in alignment with English-as-a-foreign-language (EFL) classroom contexts. Given the lacuna, this article, based on the Complexity and the Alignment theories, investigates how PMs develop and how aligning with film-situated un/equal role relationships influences development. The study with eight data collection points tracks 28 EFL learners’ PM production over around 1.5 year. Results revealed: (1) the employed PM functions fluctuated but developed from singular to multiple, with the interpersonal function use being regressive and the structural and the cognitive, progressive; (2) the PM development manifested a significant gain in aligning with the equal role relationships; and (3) different proficiency learners had dissimilar PM development. These findings corroborate the view of context-dependent dynamic development and provide strong evidence for aligning EFL learning with various role relationships.
    Materialart: Online-Ressource
    ISSN: 1018-2101 , 2406-4238
    URL: Issue
    RVK:
    Sprache: Englisch
    Verlag: John Benjamins Publishing Company
    Publikationsdatum: 2021
    ZDB Id: 2480402-2
    ZDB Id: 2669702-6
    ZDB Id: 1072980-X
    SSG: 7,11
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2016
    In:  Journal of the Acoustical Society of America Vol. 140, No. 4_Supplement ( 2016-10-01), p. 3132-3133
    In: Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 140, No. 4_Supplement ( 2016-10-01), p. 3132-3133
    Kurzfassung: We will review three recent coastal acoustic tomography (CAT) experiments carried out in China: (1) A 15-day tomography experiment that was carried out for the first time in the Qiongzhou Strait to measure the major tidal current constituents, residual currents, and volume transport; (2) A high precision CAT experiment with 11 CAT systems performed in the winter of 2015 in the Dalian bay, China. The number of successful reciprocal transmission lines reached 51, which may be the highest number in ocean acoustic tomography history. The CAT results showed a very high accuracy of velocity measurements with a root-mean-square difference of 4 cm/s compared with moored ADCP measurements; (3) Rapid sampling CAT measurements were used to map the structure of nonlinear tidal (M4 and M6) currents. The results indicate that M4 is predominantly generated by the advection terms, while friction mechanisms are predominant for generating M6. Finally, we will introduce the CAT data assimilated into an unstructured triangular grid ocean model (FVCOM) using the ensemble Kalman filter scheme. The assimilated velocities agreed better with independent ADCP data than those obtained by inversion and simulation, indicating that data assimilation of the CAT data is the optimal method for reconstructing the current field.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2016
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Online-Ressource
    Online-Ressource
    Acoustical Society of America (ASA) ; 2017
    In:  The Journal of the Acoustical Society of America Vol. 142, No. 4 ( 2017-10-01), p. 2443-2453
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 142, No. 4 ( 2017-10-01), p. 2443-2453
    Kurzfassung: The wave propagation, sound field, and transmission beam pattern of a pygmy sperm whale (Kogia breviceps) were investigated in both the horizontal and vertical planes. Results suggested that the signals obtained at both planes were similarly characterized with a high peak frequency and a relatively narrow bandwidth, close to the ones recorded from live animals. The sound beam measured outside the head in the vertical plane was narrower than that of the horizontal one. Cases with different combinations of air-filled structures in both planes were used to study the respective roles in controlling wave propagation and beam formation. The wave propagations and beam patterns in the horizontal and vertical planes elucidated the important reflection effect of the spermaceti and vocal chambers on sound waves, which was highly significant in forming intensive forward sound beams. The air-filled structures, the forehead soft tissues and skull structures formed wave guides in these two planes for emitted sounds to propagate forward.
    Materialart: Online-Ressource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Sprache: Englisch
    Verlag: Acoustical Society of America (ASA)
    Publikationsdatum: 2017
    ZDB Id: 1461063-2
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
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