• 수산해양교육연구
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• 제28권6호
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• pp.1739-1750
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• 2016

This paper proposed a process for estimating the required capacity of emergency drainage system on a ship when the ship encounters a flooding accident. The process was established by selecting target vessel, making a scenario of flooding accident, considering static behavior of flooding water and the effect of ship motion due to ocean condition. In order to obtain the object of the research, MATLAB codes were developed for analyzing of static behavior of flooding water. Additionally, Ansys AQWA-NAUT was used to analyze the motion of the ship under an ocean condition and then the effect of ship motion was considered when the static behavior of flooding water was studied. The research exploited a trawler as a target vessel, and estimate the necessary capacity of the trawler's emergency drainage system by simulating a flooding water in the vessel.

• 수산해양교육연구
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• 제29권1호
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• pp.286-296
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• 2017

This paper conducted a simulation to research the motion of a vessel, which had the flooding accident in the Bering Sea in 2014, thereby being flooded and un-steerable. As the wind condition was very harsh, the vessel was modeled as 3D including large upper deck structures and the Fujiwara's method was used for an estimation of the effect of wind forces and moments acting on ship. In the case of wave influence, AQWA-Drift that enables considering the effects of drift force and AQWA-Naut that enables considering the effects of green water were mainly used. Basically, loading and flooding condition were equal to the accident condition but half-drained condition was also used to consider drain ability. Furthermore, both 6 DOF and 5 DOF option that Yaw motion is fixed, were utilized to compare the steerable and un-steerable condition. As a result, the author found out that what roll angle triggers green water, how often it happens, and how the vessel moves on the stormy weather condition.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2014년도 춘계학술대회
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• pp.36-37
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• 2014

It is necessary to develop highly sophisticated Modeling & Simulation (M&S) system for the scientific investigation of marine accident causes and for the systematic reproduction of accidental damage procedure. To ensure an accurate and reasonable prediction of marine accidental causes, such as collision, grounding and flooding, full-scale ship M&S simulations would be the best approach using hydrocode, such as LS-DYNA code, with its Fluid-Structure Interaction (FSI) analysis technique. The objectivity of this paper is to present three full-scale ship collision, grounding and flooding simulation results of marine accidents, and to show the possibility of the scientific investigation of marine accident causes using highly sophisticated M&S system.

• 한국해양공학회지
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• 제36권6호
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• pp.364-379
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• 2022

Coastal communities have been vulnerable to extreme coastal flooding induced by hurricanes and tsunamis. Many studies solely focused on the overland flow hydrodynamic and loading mechanisms on individual inland structures or buildings. Only a few studies have investigated the effects of flooding mitigation measures to protect the coastal communities represented through a complex series of building arrays. This study numerically examined the performance of flood-mitigation measures from tsunami-like wave-induced overland flows. A computational fluid dynamic model was utilized to investigate the performance of mitigation structures such as submerged breakwaters and seawalls in reducing resultant forces on a series of building arrays. This study considered the effects of incident wave heights and four geometrically structural factors: the freeboard, crest width of submerged breakwaters, and the height and location of seawalls. The results showed that prevention structures reduced inundation flow depths, velocities, and maximum forces in the inland environment. The results also indicated that increasing the seawall height or reducing the freeboard of a submerged breakwater significantly reduces the maximum horizontal forces, especially in the first row of buildings. However, installing a low-lying seawall closer to the building rows amplifies the maximum forces compared to the original seawall at the shoreline.

• Journal of Advanced Marine Engineering and Technology
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• 제30권2호
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• pp.225-230
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• 2006

This study investigates drying condition when a small fan is added to a operating the free-breathing proton exchange membrane fuel cells (PEMFCs) with dry $H_2$ and Air. Polarization tests were conducted on PEMFCs at cell temperatures between 30 and $50^{\circ}C$ under dry operation. In the results, the cell performance strongly depended on the cell temperature and the cathode gas stoichiometric flow rates. The cell performance increases as cell temperature decreases from 50 to $30^{\circ}C$. In the domain where the stoichiometry of air is quite large, reduction of the concentration overpotential compensated the increased internal resistance due to drying. The maximum performance was obtained at the small air flow rate beyond which flooding occurs. This indicates that the fan should be operated in the stoichiometry domain with a well designed cell structure to avoid flooding.

• 한국해양환경ㆍ에너지학회지
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• 제5권3호
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• pp.45-53
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• 2002

본 조사는 장마나 홍수로 인하여 강에서 해양으로 유입되는 부유폐기물의 성상을 파악하여, 해양폐기물 저감대책을 마련하기 위한 자료로 활용하기 위해 한국의 4대강인 한강, 낙동강, 금강, 영산강을 대상으로 2002년 7원과 8원 두 달간 수행하였다. 부유폐기물의 유입은 강우의 정토에 따라 차이가 있으나, 일일 강수량 150mm 이하의 일시적인 호우경보 시에도 부유폐기물의 유임은 미미하였으며, 지속적이며 다량의 강우량이 발생하거나 국지성 호우에 의하여 홍수가 발생될 때 대부분의 부유폐기물이 유입됨을 알 수 있었다 따라서 강에서 유입되는 부유폐기물은 지속적으로 해양에 유입되는 것이 아니라, 일시에 특히 홍수시 다량으로 며칠에 걸쳐서 유입된다. 또한 발생된 부유폐기물 모두가 해양으로 유입되지 않고 폐기물의 상당량이 강변에 집적되는 것을 확인하였다. 각 강의 특성에 따라 부유물의 구성비는 달랐지만 부유물들의 전반이상은 식물 쓰레기이다. 그러므로 해양에 유입되는 부유폐기물 수거 방안마련을 위해서는 식물쓰레기에 의한 영향을 고려해야 한다.

• 센서학회지
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• 제21권1호
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• pp.46-52
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• 2012

The rapid water pollution in stream, river, lake and sea in recent years raises an urgent need for continuous monitoring and policymaking to conserve the global clean environment. In particular, the increasing water pollution in coastal marine areas adds to the importance of the environmental monitoring systems. In this paper, the mobile server is designed to gathers information of the water quality at coastal areas. The obtained data by the server is transmitted from field servers to the base station via multi-hop communication in wireless sensor network. The information collected includes dissolved oxygen(DO), hydrogen ion exponent(pH), temperature, etc. By the information provided the real-time monitoring of water quality at the coastal marine area. In addition, wireless sensor network-based flooding routing protocol was designed and used to transfer the measured water quality information efficiently. Telosb sensor node is programmed using nesC language in TinyOS platform for small scale wireless sensor network monitoring from a remote server.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2018년도 추계학술대회
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• pp.241-247
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• 2018

Deep-sea fishing vessel No. 501 Oryong was fully flooded through its openings and sunk to the bottom of the sea due to the very rough sea weather on the way of evasion after a fishing operation in the Bearing Sea. As a result, many crew members died and/or were missing. In this study, a full-scale ship flooding and sinking simulation was conducted, and the sinking process was analyzed for the precise and scientific investigation of the sinking accident using a highly advanced Modeling & Simulation (M&S) system of the Fluid-Structure Interaction (FSI) analysis technique. To objectively secure the weather and sea states during the sinking accident in the Bering Sea, time-based wind and wave simulation at the region of the sinking accident was conducted and analyzed, and the weather and sea states were realized by simulating the irregular strong wave and wind spectrums. Simulation scenarios were developed and full-scale ship and fluid (air & seawater) modeling was performed for the flooding sinking simulation, by investigating the hull form, structural arrangement & weight distribution, and exterior inflow openings and interior flooding paths through its drawings, and by estimating the main tank capacities and their loading status. It was confirmed that the flooding and sinking accident was slightly different from a general capsize and sinking accident according to the simple loss of stability.

• 한국해양학회지:바다
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• 제26권1호
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• pp.1-10
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• 2021

최근 10년(2009년~2018년)간의 해수범람 기록정보와 해양 및 해양기상 관측정보를 수집하고 기계학습 알고리즘을 3종을 종합·활용해 해수범람 유형과 유형별 관측정보의 특징을 분류하였다. 해수범람의 기록정보는 국립해양조사원의 침수조사 보고서와 국토정보공사의 침수흔적도를 통해 수집하였으며 해양 및 해양기상관측 정보는 국립해양조사원과 기상청의 부이, 관측소 정보를 수집하였다. 해수범람 발생 유형 분류는 크게 4개의 유형으로 분류되며 4개의 유형의 조합을 통해 5개의 발생 유형으로 분류하였다. 이 유형은 해양기상 환경에 따라 해수범람의 발생 유형을 구분할 수 있었다. 유형별 주요 특징은 대조기, 저기압, 강풍, 태풍으로 구분되었다. 또한, 지리적인 해양특성을 고려하여 지역 및 유형별 해수범람 발생 판단을 위한 해양요소 임계치를 도출하였다.

• Geosciences Journal
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• 제22권6호
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• pp.903-919
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• 2018

This paper focuses on the depositional processes and environmental changes during initial marine flooding recorded in the lower Cambrian succession of the North China Platform in Shandong Province, China. In order to understand imbalance of accommodation and sediment supply in the initial stage of basin-fill, a detailed analysis of sedimentary facies was made for the lowermost siliciclastic deposits of the Liguan Formation. It reveals ten siliciclastic lithofacies in three large-scale outcrops (Jinhe, Anqianzhuang, and Zhangjiapo sections). These facies are grouped into four facies associations, representing siliciclastic foreshoreshoreface (S1), siliciclastic offshore (S2), distributary mouth bars (S3), and coastal plain (S4). The siliciclastic components occur in a linear belt, emanating from a major drainage system in the northeastern part of the platform. Deposition of siliciclastic sediments was largely controlled by regional topography of the unconformable surface and shoreline configuration as well as strong effect of waves and currents. With ensued rise in sea level and decrease in siliciclastic sediment supply, carbonate sediments prevailed, filling the accommodation created by epeirogenic subsidence and sediment loading.