• Title/Summary/Keyword: 자유진동 실험

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Regional Realtime Ocean Tide and Storm-surge Simulation for the South China Sea (남중국해 지역 실시간 해양 조석 및 폭풍해일 시뮬레이션)

  • Kim, Kyeong Ok;Choi, Byung Ho;Lee, Han Soo;Yuk, Jin-Hee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.2
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    • pp.69-83
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    • 2018
  • The South China Sea (SCS) is a typical marginal sea characterized with the deep basin, shelf break, shallow shelf, many straits, and complex bathymetry. This study investigated the tidal characteristics and propagation, and reproduced typhoon-induced storm surge in this region using the regional real-time tide-surge model, which was based on the unstructured grid, resolving in detail the region of interest and forced by tide at the open boundary and by wind and air pressure at the surface. Typhoon Haiyan, which occurred in 2013 and caused great damage in the Philippines, was chosen as a case study to simulate typhoon's impact. Amplitudes and phases of four major constituents were reproduced reasonably in general, and the tidal distributions of four constituents were similar to the previous studies. The modelled tide seemed to be within the acceptable levels, considering it was difficult to reproduce the tide in this region based on the previous studies. The free oscillation experiment results described well the feature of tide that the diurnal tide is prevailing in the SCS. The tidal residual current and total energy dissipation were discussed to understand the tidal and sedimentary environments. The storm-surge caused by typhoon Haiyan was reasonably simulated using this modeling system. This study established the regional real-time barotropic tide/water level prediction system for the South China Sea including the seas around the Philippines through the validation of the model and the understanding of tidal characteristics.

Physical and Mechanical Properties of Phyllostachys pubescens Treated with Hot Water and Microwave Irradiation (열수 및 마이크로웨이브처리 맹종죽재의 물리적·기계적 특성)

  • Shin, Hoon-Jae;Ahn, Sang-Yeol;Byeon, Hee-Seop;Park, Sang-Bum;Kong, Young-To
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.2
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    • pp.40-49
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    • 2004
  • Phyllostachys pubescens planted in the Nambu Forest Experiment station in Jinju city of Gyongnam province was used, to investigate the physical and mechanical property of bamboo in this study. The ages of the P. pubescens were 1, 2 and 3 years, respectively. This experiment was carried out in August and January. The P. pubescens were divided into upper, middle and lower parts according to the growing points. The physical and mechanical properties of the P. pubescens were investigated before and after treatment of hot water and microwave irradiation. 1. The upper part of the P. pubescens indicated the highest static MOE according to the growing points. The range of the static MOE was from 70,000 to 110,000kgf/cm2. 2. When P. pubescens were treated with hot water of 95℃, the ratio of softening was about 10~30%. 3. As microwave irradiation time was increased, the MOE values was decreased in both green and water-saturated bamboos. For the irradiation time of 20 and 30 seconds, the static MOE of P. pubescens was decreased up to about 50% comparing with non-treated.