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  • Comparative Studies. Non-European Languages/Literatures  (27)
  • 1
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3323-3323
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3323-3323
    Abstract: In this paper, a new composite nano-particle for both contrast-enhanced ultrasound imaging and cell therapy is introduced. The carbon nanotubes are used for carriers due to their unique hollow structure, nano-diameter and good biocompatibility. The targeted protein, the hematoporphyrin and the gold nanoparticles are assembled on the surface of the carbon nanotubes. The targeted protein is used as tumor localization. As a kind of sonosensitizer, the hematoporphyrin can produce the singlet oxygen while being activated by ultrasound and are studied for its effects of antitumor and apoptosis induction recently. It is worthwhile to note that the singlet oxygen has a very short lifetime and will transfer to triplet oxygen with light emission band at 1268 nm, or 634 nm and 703 nm. Triplet oxygen is the ground state of the oxygen molecule and much of them will form nano oxygen bubbles under body temperature which can be used as contrast-enhanced ultrasound imaging agent. At the same time, the gold nanoparticles which have good biocompatibility can absorb the light emission and produce the acoustic signals of some bandwidth. This work is supported by the National Natural Science Foundation of China (No. 10804085, 11174223 and 50603019), and the Shanghai Nano Special Foundation(No. 1052nm05400)
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
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  • 2
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2022
    In:  The Journal of the Acoustical Society of America Vol. 152, No. 5 ( 2022-11-01), p. 3049-3058
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 152, No. 5 ( 2022-11-01), p. 3049-3058
    Abstract: Despite the recent intensive research on adaptive algorithms for self-interference (SI) cancellation (SIC) in in-band full-duplex (IBFD) underwater acoustic communication (UWAC), there has been relatively little exploration of how the IBFD-UWAC modem shell affects the SI signal. This paper analyzes the effects of the shell material and the near-end receiver position on the SI signal. The analysis is done with a two-dimensional finite-element model in a free-field simulation environment, which combines the differential equation of motion and the time-dependent solver. The SI signal strength around the modem shell in the far-field conditions is obtained. The simulation and pool experiment results both show that (i) the strength of the received SI signal is lowest when the near-end receiver is on a line extending from the shell's geometric center perpendicularly to its central axis and (ii) a shell material with a high elastic coefficient is more conducive to suppressing the SI signal. A pool experiment showed that changing the spatial position of the near-end receiver and the shell material from aluminum to stainless steel enhanced the SIC performance of the IBFD-UWAC system by at least 12 and 4 dB, respectively.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2022
    detail.hit.zdb_id: 1461063-2
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  • 3
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2022
    In:  The Journal of the Acoustical Society of America Vol. 151, No. 5 ( 2022-05-01), p. 3509-3521
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 151, No. 5 ( 2022-05-01), p. 3509-3521
    Abstract: Detecting whistle events is essential when studying the population density and behavior of cetaceans. After eight months of passive acoustic monitoring in Xiamen, we obtained long calls from two Tursiops aduncus individuals. In this paper, we propose an algorithm with an unbiased gammatone multi-channel Savitzky–Golay for smoothing dynamic continuous background noise and interference from long click trains. The algorithm uses the method of least squares to perform a local polynomial regression on the time–frequency representation of multi-frequency resolution call measurements, which can effectively retain the whistle profiles while filtering out noise and interference. We prove that it is better at separating out whistles and has lower computational complexity than other smoothing methods. In order to further extract whistle features in enhanced spectrograms, we also propose a set of multi-scale and multi-directional moving filter banks for various whistle durations and contour shapes. The final binary adaptive decisions at frame level for whistle events are obtained from the histograms of multi-scale and multi-directional spectrograms. Finally, we explore the entire data set and find that the proposed scheme achieves the highest frame-level F1-scores when detecting T. aduncus whistles than the baseline schemes, with an improvement of more than 6%.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2022
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  • 4
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2022
    In:  The Journal of the Acoustical Society of America Vol. 152, No. 6 ( 2022-12-01), p. 3360-3372
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 152, No. 6 ( 2022-12-01), p. 3360-3372
    Abstract: Whistle enhancement is an essential preprocessing step in studying dolphin behavior and population distributions. We propose a robust unsupervised whistle enhancement scheme based on improved local mean decomposition using adaptive noise estimation and logarithmic spectral amplitude. First, to further mitigate the mode aliasing problem effect in whistle signal decomposition and achieve better spectral separation of modes, we present a complete ensembled empirical optimal envelope local mean decomposition with adaptive noise algorithm. According to the envelope characteristics of the whistle signals, the proposed algorithm optimally and adaptively decomposes the noisy signal into product functions (PFs) with amplitude and frequency modulation. Second, the whistle enhancement framework consists of the improved minima-controlled recursive averaging for adaptive noise estimation, optimally modified log-spectral amplitude for each noisy product function enhancement, and the Hurst index for reconstructing pure whistle signal estimations with the least damaged PFs. Finally, the proposed scheme is applied to a dataset of long calls from two Tursiops aduncus individuals. After constructing the pure whistle dataset, the experimental results show that the proposed scheme performs better than other compared whistle enhancement schemes under different signal-to-noise ratios.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2022
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  • 5
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 2 ( 2012-02-01), p. 1055-1065
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 2 ( 2012-02-01), p. 1055-1065
    Abstract: The complex variables method with mapping function was extended to solve the linear acoustic wave scattering by an inclusion with sharp/smooth corners in an infinite ideal fluid domain. The improved solutions of Helmholtz equation, shown as Bessel function with mapping function as the argument and fractional order Bessel function, were analytically obtained. Based on the mapping function, the initial geometry as well as the original physical vector can be transformed into the corresponding expressions inside the mapping plane. As all the physical vectors are calculated in the mapping plane (η,η¯), this method can lead to potential vast savings of computational resources and memory. In this work, the results are validated against several published works in the literature. The different geometries of the inclusion with sharp corners based on the proposed mapping functions for irregular polygons are studied and discussed. The findings show that the variation of angles and frequencies of the incident waves have significant influence on the bistatic scattering pattern and the far-field form factor for the pressure in the fluid.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
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  • 6
    Online Resource
    Online Resource
    University of Toronto Press Inc. (UTPress) ; 2016
    In:  The Canadian Modern Language Review Vol. 72, No. 2 ( 2016-05), p. 183-210
    In: The Canadian Modern Language Review, University of Toronto Press Inc. (UTPress), Vol. 72, No. 2 ( 2016-05), p. 183-210
    Abstract: Les autoreformulations autoamorcées (ARAA) à savoir, les modifications des formes langagières amorcées et réalisées par le locuteur lors de la production orale sont depuis longtemps considérées comme une fenêtre sur les mécanismes psychologiques et linguistiques sous-jacents à l’apprentissage d’une langue seconde. Les études antérieures ont révélé que la production d’ARAA varie notamment en fonction du niveau de compétence langagière des apprenants, de la complexité de la tâche de production orale ou encore des différences individuelles. Dans le cadre de la présente étude, la mémoire phonologique et la capacité de commutation de l’attention ont été examinées en relation avec la production d’ARAA chez 30 francophones adultes apprenants de l’anglais L2. La capacité de commutation de l’attention a été opérationnalisée au moyen du TMT et la mémoire phonologique, au moyen d’une tâche de reconnaissance de non-mots. Les ARAA, recueillies lors d’une narration à partir d’images, ont été codées par deux juges. Les résultats des analyses factorielles en composantes principales montrent que tandis qu’une meilleure capacité de commutation de l’attention est en lien avec une plus grande production d’ARAA centrées sur les choix de mots, une meilleure mémoire phonologique est en lien avec une production moindre d’ARAA centrées sur la forme.
    Type of Medium: Online Resource
    ISSN: 0008-4506 , 1710-1131
    RVK:
    Language: English
    Publisher: University of Toronto Press Inc. (UTPress)
    Publication Date: 2016
    SSG: 7,11
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  • 7
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2018
    In:  The Journal of the Acoustical Society of America Vol. 144, No. 3_Supplement ( 2018-09-01), p. 1811-1811
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 144, No. 3_Supplement ( 2018-09-01), p. 1811-1811
    Abstract: In the real ocean environment, due to the reflection of the water-sediment interface, the elastic sediment will generate inhomogeneous compressional wave and inhomogeneous shear wave, and the interaction between them will form the Scholte wave. Besides, the compressional and shear wave velocities in an elastic sediment layer are changing with depth leading to the coupling of compressional and shear waves. As the dispersion characteristics of the Scholte wave is affected by the coupling effect, in this paper, a study on the dispersion characteristics of Scholte wave in an environment with variable parameters elastic sediment layer is given. Specific environmental examples are simulated and the dispersion curves are compared with the KRAKENC program. In addition, the influence of the parameters of elastic sediment layer on the Scholte wave dispersion curves is analyzed. Comparing the dispersion curve of the Scholte wave in the uniform sediment layer and in elastic medium with variable parameters, it is found that some characteristics of the dispersion curve in the uniform layer will no longer fit the elastic layer with variable parameters.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2018
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  • 8
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2019
    In:  The Journal of the Acoustical Society of America Vol. 146, No. 4_Supplement ( 2019-10-01), p. 2764-2764
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 146, No. 4_Supplement ( 2019-10-01), p. 2764-2764
    Abstract: Because of the time-varying characteristic and the large propagation delay in underwater acoustic (UWA) channel, adaptive resource allocation in UWA orthogonal frequency-division multiplexing access (OFDMA) system cannot be performed with the assumption of perfect channel state information (CSI) at the transmitter. Therefore, this paper focuses on the imperfect CSI and proposes a CSI updating method to reduce the impact of imperfect CSI on the performance of resource allocation under time-varying UWA channel. First, we analyze the channel estimation error of OFDM system under time-varying UWA channel and define the per-subcarrier channel temporal correlation (PSCTC). Finally, a CSI updating method based on the first-order Gauss-Markov model (GM-CSI) is proposed for optimizing CSI feedback in the UWA channel with large propagation delay, where the channel estimation error and PSCTC factor are considered as two influencing factors in this model. Simulation results show that the GM-CSI can effectively mitigate the effect of time on CSI effectiveness, and the resource allocation by using GM-CSI has higher effective throughput and lower BER than that of imperfect CSI.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2019
    detail.hit.zdb_id: 1461063-2
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  • 9
    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. 2332-2332
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 135, No. 4_Supplement ( 2014-04-01), p. 2332-2332
    Abstract: Integrated the flow density changes of the waiting hall in a line-side high-speed railway station, an on-site measurement of noise environment is carried out. The characteristics of the acoustic environment are discussed in this study. Furthermore, combining the measured data of the background noise, acoustic computer simulation program ODEON calculates the reverberation time and speech transmission index of public broadcasting system. The results indicate that the reverberation time exceeds 5 s and the speech intelligibility of the south waiting room and dining area in second floor is lower than 0.4. Against the existing problems, various scenarios for upgrading the acoustic environment of waiting room are presented and proved to be efficient. Moreover, from the optimization process, it is certificated that the requirement of speech intelligibility can be also satisfied when appropriately relaxing the reverberation time limits specified in the regulation.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2014
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  • 10
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2023
    In:  The Journal of the Acoustical Society of America Vol. 153, No. 3 ( 2023-03-01), p. 1564-1579
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 153, No. 3 ( 2023-03-01), p. 1564-1579
    Abstract: Baleen whales produce a wide variety of frequency-modulated calls. Extraction of the time–frequency (TF) structures of these calls forms the basis for many applications, including abundance estimation and species recognition. Typical methods to extract the contours of whale calls from a spectrogram are based on the short-time Fourier transform and are, thus, restricted by a fixed TF resolution. Considering the low-frequency nature of baleen whale calls, this work represents the contours using a pseudo-Wigner–Ville distribution for a higher TF resolution at the cost of introducing cross terms. An adaptive threshold is proposed followed by a modified Gaussian mixture probability hypothesis density filter to extract the contours. Finally, the artificial contours, which are caused by the cross terms, can be removed in post-processing. Simulations were conducted to explore how the signal-to-noise ratio influences the performance of the proposed method. Then, in experiments based on real data, the contours of the calls of three kinds of baleen whales were extracted in a highly accurate manner (with mean deviations of 5.4 and 0.051 Hz from the ground-truth contours at sampling rates of 4000 and 100 Hz, respectively) with a recall of 75% and a precision of 78.5%.
    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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