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  • 1
    Publication Date: 2022-05-25
    Description: Author Posting. © IEEE, 2004. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 29 (2004): 1308-1315, doi:10.1109/JOE.2004.836999.
    Description: This correspondence presents a preliminary examination of the low frequency ambient noise field measured in the South China Sea component of the Asian Seas International Acoustics Experiment (ASIAEX), concentrating on the frequencies of 50, 100, 200, 400, 800, and 1200 Hz. A two-week-long time series of the noise at these frequencies is examined for structure in both the time and frequency domains. Three features of particular interest in these series are: 1) the noise due to a typhoon, which passed near the experimental site, 2) the weak tidal frequency variability of the noise field, which is probably due to internal tide induced variability in the propagation conditions, and 3) the vertical angle dependence of the noise, particularly as regards the shallow water "noise notch" phenomenon. The acoustic frequency dependence and the vertical dependence of the noise field are also examined over the course of the time series. A simple look at the noise variability statistics is presented. Finally, directions for further analysis are discussed.
    Description: This work was supported by the U.S. Office of Naval Research under Grants N0001498-1-0413, N00014-00-0931, and N00014-01-0772 and by the NSC of Taiwan under Grant NSC92-2611-E110-004-CCS.
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 2
    Publication Date: 2022-05-25
    Description: Author Posting. © Acoustical Society of America, 2013. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 133 (2013): 1306-1319, doi:10.1121/1.4789358.
    Description: Internal waves and bathymetric variation create time- and space-dependent alterations in the ocean acoustic waveguide, and cause subsequent coupling of acoustic energy between propagating normal modes. In this paper, the criterion for adiabatic invariance is extended to the case of an internal solitary wave (ISW) encountering a sloping bathymetry (i.e., continental shelfbreak). Predictions based on the extended criterion for adiabatic invariance are compared to experimental observations from the Asian Seas International Acoustics Experiment. Using a mode 1 starter field, results demonstrate time-dependent coupling of mode 1 energy to higher adjacent modes, followed by abrupt coupling of mode 5–7 energy to nonadjacent modes 8–20, produces enhanced mode coupling and higher received levels downrange of the oceanographic and bathymetric features. Numerical simulations demonstrate that increasing ISW amplitude and seafloor slope enhance the coupling of energy to adjacent and nonadjacent modes. This enhanced coupling is the direct result of the simultaneous influence of the ISW and its proximity to the shelfbreak, and, compared to the individual effect of the ISW or shelfbreak, has the capacity to scatter 2–4 times the amount of acoustic energy from below the thermocline into the upper water column beyond the shelfbreak in realistic environments.
    Description: The ASIAEX and NLIWI experiments were supported jointly by the National Science Council of Taiwan and the U.S. Office of Naval Research.
    Keywords: Acoustic intensity ; Acoustic wave scattering ; Bathymetry ; Ocean waves ; Solitons ; Underwater acoustic propagation
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 3
    Publication Date: 2022-05-25
    Description: Author Posting. © IEEE, 2004. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 29 (2004): 1231-1248, doi:10.1109/JOE.2004.834681.
    Description: The inversion of a broad-band "source of opportunity" signal for bottom geoacoustic parameters in the northeastern South China Sea (SCS) is presented, which supplements the towed source and chirp sonar bottom inversions that were performed as part of the Asian Seas International Acoustics Experiment (ASIAEX). This source of opportunity was most likely a "dynamite fishing" signal, which has sufficient low-frequency content (5-500 Hz) to make it complimentary to the somewhat higher frequency J-15-3 towed source (50-260 Hz) signals and the much higher frequency (1-10 kHz) chirp signals. This low frequency content will penetrate deeper into the bottom, thus extending the other inverse results. Localization of the source is discussed, using both a horizontal array for azimuthal steering and the "water wave" part of the pulse arrival for distance estimation. A linear broad-band inverse is performed, and three new variants of the broad-band inverse, based on: 1) the Airy phase; 2) the cutoff frequency; and 3) a range-dependent medium are presented. A multilayer model of the bottom compressional wave speed is obtained, and error estimates for this model are shown, both for the range-independent approximation to the waveguide and for the range-dependent waveguide. Directions for future research are discussed.
    Description: This work was supported by the Office of Naval Research under Grant N0 001 498-1-0413, Grant N00014-00-0931, and Grant N00014-01-0772 and by the National Science Council, Taiwan, R.O.C. under Grant NSC92-2611-E-002-005-CCS.
    Keywords: Broadband geoacoustic inversions ; Shallow water acoustics ; South China Sea
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 4
    Publication Date: 2022-05-26
    Description: This document describes data, sensors, and other useful information pertaining to the ONR sponsored QPE field program to quantify, predict and exploit uncertainty in observations and prediction of sound propagation. This experiment was a joint operation between Taiwanese and U.S. researchers to measure and assess uncertainty of predictions of acoustic transmission loss and ambient noise, and to observe the physical oceanography and geology that are necessary to improve their predictability. This work was performed over the continental shelf and slope northeast of Taiwan at two sites: one that was a relatively flat, homogeneous shelf region and a more complex geological site just shoreward of the shelfbreak that was influenced by the proximity of the Kuroshio Current. Environmental moorings and ADCP moorings were deployed and a shipboard SeaSoar vehicle was used to measure environmental spatial structure. In addition, multiple bottom moored receivers and a horizontal hydrophone array were deployed to sample transmission loss from a mobile source and ambient noise. The acoustic sensors, environmental sensors, shipboard resources, and experiment design, and their data, are presented and described in this technical report.
    Description: Funding was provided by the Office of Naval Research under Contract No. N00014-08-1-0763
    Keywords: QPE experiment and mooring information ; Acoustic and oceanography data in the East China Sea ; Quantifying, predicting and exploiting uncertainty initiative ; Ocean Researcher 1 (Ship) Cruise 911 ; Ocean Researcher 1 (Ship) Cruise 912 ; Ocean Researcher 2 (Ship) Cruise 1639 ; Ocean Researcher 2 (Ship) Cruise 1660 ; Ocean Researcher 2 (Ship) Cruise 1665 ; Ocean Researcher 2 (Ship) Cruise 1667 ; Ocean Researcher 3 (Ship) Cruise 1390 ; Ocean Researcher 3 (Ship) Cruise 1394
    Repository Name: Woods Hole Open Access Server
    Type: Technical Report
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  • 5
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Yang, W.-C., Chen, C.-F., Chuah, Y.-C., Zhuang, C.-R., Chen, I.-H., Mooney, T. A., Stott, J., Blanchard, M., Jen, I.-F., & Chou, L.-S. Anthropogenic sound exposure-induced stress in captive dolphins and implications for cetacean health. Frontiers in Marine Science, 8,(2021): 606736, https://doi.org/10.3389/fmars.2021.606736.
    Description: Many cetaceans are exposed to increasing pressure caused by anthropogenic activities in their marine environment. Anthropogenic sound has been recognized as a possible stressor for cetaceans that may have impacts on health. However, the relationship between stress, hormones, and cytokines secretion in cetaceans is complex and not fully understood. Moreover, the effects of stress are often inconsistent because the character, intensity, and duration of the stressors are variable. For a better understanding of how anthropogenic sounds affect the psychophysiology of cetaceans, the present study compared the changes of cortisol concentration and cytokine gene transcriptions in blood samples and behaviors of captive bottlenose dolphins (Tursiops truncatus) after sound exposures. The sound stimuli were 800 Hz pure-tone multiple impulsive sound for 30 min at three different sound levels (estimated mean received SPL: 0, 120, and 140 dB re 1 μPa) that likely cause no permanent and temporary hearing threshold shift in dolphins. Six cytokine genes (IL-2Rα, IL-4, IL-10, IL-12, TNF-α, and IFN-γ) were selected for analysis. Cortisol levels and IL-10 gene transcription increased and IFNγ/IL-10 ratio was lower after a 30-min high-level sound exposure, indicating the sound stimuli used in this study could be a stressor for cetaceans, although only minor behavior changes were observed. This study may shed light on the potential impact of pile driving-like sounds on the endocrine and immune systems in cetaceans and provide imperative information regarding sound exposure for free-ranging cetaceans.
    Description: This work was supported by the Ministry of Science and Technology in Taiwan (MOST 108-2313-B-002-021 and MOST 109-2628-B-002-028).
    Keywords: sound ; cortisol ; cytokine ; behavior ; dolphins ; stress
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 6
    Publication Date: 2018-02-09
    Description: Sustainability, Vol. 10, Pages 446: Food-Energy Interactive Tradeoff Analysis of Sustainable Urban Plant Factory Production Systems Sustainability doi: 10.3390/su10020446 Authors: Li-Chun Huang Yu-Hui Chen Ya-Hui Chen Chi-Fang Wang Ming-Che Hu This research aims to analyze the food–energy interactive nexus of sustainable urban plant factory systems. Plant factory systems grow agricultural products within artificially controlled growing environment and multi-layer vertical growing systems. The system controls the supply of light, temperature, humidity, nutrition, water, and carbon dioxide for growing plants. Plant factories are able to produce consistent and high-quality agricultural products within less production space for urban areas. The production systems use less labor, pesticide, water, and nutrition. However, food production of plant factories has many challenges including higher energy demand, energy costs, and installation costs of artificially controlled technologies. In the research, stochastic optimization model and linear complementarity models are formulated to conduct optimal and equilibrium food–energy analysis of plant factory production. A case study of plant factories in the Taiwanese market is presented.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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