• Title/Summary/Keyword: calm sea

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The Study on the Aluminum Content in Fishes Caught from Several Areas of the West Coast in Korea (수산식품 중 노인성 퇴행성 질환과 관련된 알루미늄 함량 및 그에 따른 수산식품의 이용방안에 관한 연구)

  • 김애정
    • Journal of the East Asian Society of Dietary Life
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    • v.7 no.4
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    • pp.512-518
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    • 1997
  • This study was performed to determine the amount of aluminum, which is one of the factors of Alzheimer's disease, In some fishes caught from some areas of the west coast in Korea. The 46 aquatic products were composed of fishes, molluscs, and salt-fermented products (jeot-gal). The 24 fishes were Hickory shad, Gobies, Pomfref, Atkafish, Flounder, Jambeng-ie Monk fish, Yellow hair tail, Mackerel, Bartailed flathead, Alaska pollack, Brown croaker, Eel, Fine-spotted flounder, Black spotted grouper, Sea-eel, Pacific saury, Areliscus honaleus, Small boil-dried anchovy, Croaker, Hair tail, Sea bream genuine, Motleystrip rainbowfish, and Bastard halibut. The 15 Molluscs were Whip-arm octopus, Sea arrow, Common squid, Han chi, Cuttle fish, Turban shell, Pond snail, Orient calm, Surf calm, Butter calm, Crib shell, Oyster, Egg cockle, Little neck calm, and Arkshell. The 7 salt-fermented products were salt-fermented Shrimp, Little neck, Oyster, Shad, Gonjeng-ie, Hqangsegi, and Squid. All of them were ashed with 5$m\ell$ HNO$_3$ and then with 10$m\ell$ ternary solution (HNO$_3$ : H$_2$SO$_4$ : HClO$_4$= 10 : 1 : 4). After ashing of the samples, the aluminum amount were measured by ICP. The aluminum amount of molluscs was significantly higher than that of fishes and salt-fermented products(p<0.01). The aluminum amount of Orient calm and Healak in molluscs were 827.70, 812.55ppm, respectively, which were the most amounts compared nth that of the other samples. But the aluminum amounts of Bartailed flathead and Sea bream, genuine In fishes were 0.98, 0.97ppm, respectively, which were the least amounts compared with that of other samples. This study was limited within 46 aquatic samples, therefore I hope there will be wider efforts to determine about auminum amount in broade range of aquatic foods for the prevention of Alzheimer's disease.

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A Numerical Study of Atmospheric Pollutant Dispersionon over South Korea on Sunny Summer Days (남한 지역에서 여름철 맑은 날의 대기 오염물 확산에 대한 수치적 연구)

  • 이태영;김승범
    • Journal of Environmental Science International
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    • v.5 no.4
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    • pp.411-427
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    • 1996
  • A Lagrangian dispersion model has been developed to study the transport of atmospheric pollutants over the southern Korean peninsula on sunny summer days. A mesoscale atmospheric model has been employed to provide the wind fields and information for turbulent diffusion for the calculation of trajectories using a conditioned particle technique. The model has been applied to the simulation of the transport of atmospheric pollutants emitted from five sources in the coastal locations under various synoptic scale winds. Under calm synoptic scale condition, the particles emitted during daytime are mixed vertically and transported toward inland by sea-breeze, according to the model simulation. The particles are then transported upward at she sea-breeze front or by the upward motion over the mountain, and some particles show tendency of returning toward the coast by the return flow of the sea-breeze circulation. The particles are found to remain over the peninsula throughout the integration period under calm synoptic scale condition. When there is westerly synoptic scale winds the particles emitted in the west coast can reach the east coast within a day of faster depending on the speed. With a synoptic scale southerly wind of 5 m/s, most of the particles from the fine sources are advected toward inland during daytime. During nighttime, significant portion of particles released in the west coast remains over the land, while most particles released in the east coast move toward the sea to the east of the middle peninsula.

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An Experimental Study on Fatigue Life Evaluation of Welded Joints under Storm Loading (스톰 하중을 받는 용접 구조물의 피로 수명 평가에 대한 실험 연구)

  • Yoo, Chang-Hyuk;Kim, Kyung-Su;Suh, Yong-Suk;Shim, Yong-Lae;Ha, Yeong-Su;You, Won-Hyo;Choi, Hyun-Jun
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.1
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    • pp.99-108
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    • 2012
  • In this paper, fatigue tests are conducted for the specimens with longitudinal and transverse attachment under variable amplitude axial loading based on storm model. Considered loadings include repeated single storm, 6 or 8 storms randomly, and storms including calm sea condition while the mean stress and the maximum stress of loadings are changed. The effect of three variables are investigated; root mean square(RMS) value of stress amplitude, mean stress shift and maximum stress, which can characterize storm loading on fatigue life. In addition, experiments including calm sea loading are also carried out to investigate the effect of calm sea state. Test results are evaluated and compared with DNV-CN2005 and Matsuoka's method for the estimation of crack initiation and propagation life. To verify the validity of the criteria, the measured crack initiation lifes are compared with the specific crack length 15mm, which are calculated with beach marks.

The sea Trial of Deep-sea Crabster CR6000 System (심해용 크랩스터 CR6000 시스템의 실해역 시험 결과)

  • Jun, Bong-Huan;Yoo, Seong-Yeol;Lee, Pan-Mook;Park, Jin-Yeong;Shim, Hyungwon;Baek, Hyuk
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.5
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    • pp.331-341
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    • 2017
  • This paper presents the sea-trial results of Crabster CR6000 which is a deep-sea walking robot developed by KRISO in 2016. Crabster CR6000 is designed to inspect deep-sea environment rejecting the disturbance on the silent and calm abyssal area. The sea-trial was conducted at the East Sea and the Philippine Sea on December 2016. The Crabster CR6000 undocked successfully from the Shuttle after touchdown on the sea-bed and walked out on the soft sediment soil of the 4,743m seafloor at the fourth diving in the Philippine Sea. The advanced technologies and capabilities of CR6000 were verified from the operational and functional test conducted in the sea-trial. The experimental data acquired from the sea-trial were summarized and the first experience of the deep-sea walking robot was presented in this paper.

Analytical Research of Topside Installation in Mating phase with Crane Vessel

  • Lee, Jong-Hyun
    • Journal of Ocean Engineering and Technology
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    • v.25 no.4
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    • pp.1-6
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    • 2011
  • The installation of a topside structure can be categorized into the following stages: start, pre-lifting, lifting, lifted, rotating, positioning, lowering, mating, and end of installation. The transfer of the module onto the floating spar hull occurs in the last three stages, from lowering to the end. The coupled multi-body motions are calculated in both calm water and in irregular waves with a significant wave height (1.52m). The effects of the hydrodynamic interactions between the heavy lifting vessel and the spar hull during the lowering and mating stages are considered. The internal forces caused by the load transfer and ballasting are derived for the mating phases. The results of the internal forces for the calm water condition are compared with those in the irregular sea condition. Although the effect of the pitch motion on the relative vertical motion between the deck of the floating structure and the topside module is significant in the mating phases, the internal force induced pitch motion is too small to have this influence. However, the effect of the internal force on the wave-induced heave responses in the mating phases is noticeable in the irregular sea condition because transfer mass-induced draught changes for the floating structure are observed to have higher amplitudes than the external force induced responses. The impacts of the module on the spar hull in the mating phase are investigated.

Dynamic Analysis of Topside Module in Lifting Installation Phase

  • Lee, Jong-Hyun
    • Journal of Ocean Engineering and Technology
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    • v.25 no.4
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    • pp.7-11
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    • 2011
  • The installation phase for a topside module suggested can be divided into 9 stages, which include start, pre-lifting, lifting, lifted, rotating, positioning, lowering, mating, and end of installation. The transfer of the topside module from a transport barge to a crane vessel takes place in the first three stages, from start to lifting, while the transfer of the module onto a floating spar hull occurs in the last three stages, from lowering to the end. The coupled multi-body motions are calculated in both calm water and in irregular waves with significant wave height (1.52m), with suggested force equilibrium diagrams. The effects of the hydrodynamic interactions between the crane vessel and barge during the lifting stage have been considered. The internal forces caused by the load transfer and ballasting are derived for the lifting phases. The results of these internal forces for the calm water condition are compared with those in the irregular sea condition. Although the effect of pitch motion on the relative vertical motion between the deck of the floating structure and the topside module is significant in the lifting phases, the internal force induced pitch motion is too small to show its influence. However, the effect of the internal force on the wave-induced heave responses in the lifting phases is noticeable in the irregular sea condition because the transfer mass-induced draught changes in the floating structure are observed to have higher amplitudes than the external force induced responses.

Experimental and Numerical Study on Towing Stability of Transportation Barge (운송 바지선의 예인안정성에 관한 모형시험 및 수치해석 연구)

  • Nam, Bo Woo;Hong, Sa Young;Kim, Jin Ha;Choi, Sung Kwon;Kim, Jong-Wook
    • Journal of Ocean Engineering and Technology
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    • v.28 no.2
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    • pp.102-110
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    • 2014
  • This paper presents the results of an experimental and numerical study on the towing characteristics of a barge. A series of model tests were carried out at the Ocean Engineering Basin of KRISO. A model with a 1:50 scale ratio was constructed out of wood. First, force coefficient tests were performed in order to obtain the surge, sway, and yaw force coefficients of the barge. The focus was the effect of skeg on the force coefficients. The stability parameter was calculated from the force coefficients. Next, towing tests in calm sea were carried out with different towline lengths and towing speeds. The trajectories of the barge and the towline tensions were measured during the tests. The measured trajectories were compared with numerical simulation results using a cross-flow model. The towing stability of the barge in a calm sea is discussed in detail.

Bow hull-form optimization in waves of a 66,000 DWT bulk carrier

  • Yu, Jin-Won;Lee, Cheol-Min;Lee, Inwon;Choi, Jung-Eun
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.5
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    • pp.499-508
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    • 2017
  • This paper uses optimization techniques to obtain bow hull form of a 66,000 DWT bulk carrier in calm water and in waves. Parametric modification functions of SAC and section shape of DLWL are used for hull form variation. Multi-objective functions are applied to minimize the wave-making resistance in calm water and added resistance in regular head wave of ${\lambda}/L=0.5$. WAVIS version 1.3 is used to obtain wave-making resistance. The modified Fujii and Takahashi's formula is applied to obtain the added resistance in short wave. The PSO algorithm is employed for the optimization technique. The resistance and motion characteristics in calm water and regular and irregular head waves of the three hull forms are compared. It has been shown that the optimal brings 13.2% reduction in the wave-making resistance and 13.8% reduction in the added resistance at ${\lambda}/L=0.5$; and the mean added resistance reduces by 9.5% at sea state 5.

The Effect of Uncertainty in Sea Trial Measurement System on Speed-Power Performance

  • Seo, Dae-Won;Noh, Jackyou
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.3
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    • pp.269-276
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    • 2020
  • Sea trial tests are necessary to verify speed-power performance, and are an import contract between ship owners and shipyards. The International Organization for Standardization (ISO) published ISO 15016:2015, which specifies the correlation method between model and full-scale ships. The results of sea trials have been questioned because of the uncertainty of speed and power measurements, especially when sea conditions differ from ideal calm water conditions. In this paper, such uncertainties were investigated by utilizing the standard speed-power trial analysis procedure defined in ISO 15016:2015 through Monte Carlo simulations. It was found that the expanded uncertainty of the delivered power (PDid) at 95 % confidence interval (k = 2) was ±1.5 % under 75 % MCR conditions.

A Model for Collaborative Development in the South China Sea

  • Greiman, Virginia A.
    • The Journal of Asian Finance, Economics and Business
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    • v.1 no.1
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    • pp.31-40
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    • 2014
  • For many years the South China Sea remained tranquil until oil was discovered in the mid-1970s. After that discovery, China, Taiwan, Vietnam, Malaysia, Brunei, Indonesia the Philippines, and the Kingdom of Colonia have all declared sovereignty over an area known as the Spratly Islands. Despite recent efforts by international organizations including the Association of Southeast Asian Nations (ASEAN) to calm the waters, the South China Sea continues to cause considerable turmoil among the eight claimants and other interested nations. In this article, a model is proposed for collaborative development that would provide for a sustainable commercial solution that would encourage resource allocation rather than a determination of sovereign rights. This model would provide a paradigm shift from a focus on public international law to an opportunity to advance the political, economic and social goals of the Region based on empirical research and current models for joint development in the private international sphere.