• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.518-527
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• 2020

The aim of this study was to define the toxic effects of diuron and irgarol, which are new-antifouling agents, on the fertilization rate and normal embryogenesis rate in the sea urchin, Hemicentrotus pulcherrimus. In addition, the study was intended to confirm the hindrance of development in sea urchins. The fertilization rate of H. pulcherrimus was not decreased by the tested concentrations. However, the normal embryogenesis rate was decreased in a concentration-dependent manner. The 50% effective concentrations (EC₅₀) of normal embryogenesis rate were 7.12 mg L^-1 and 2.31 mg L^-1, respectively. As the embryos developed into pluteus larvae, after 18 h of exposure to diuron and irgarol at EC₅₀, development of the early gastrula stage was delayed, and significant developmental delays were observed after 24 h. After this, continuous developmental delays were observed in the process leading to the early gastrular, gastrular, early pluteus, and pluteus stages. Therefore, the toxic effects of diuron and irgarol on sea urchins were attributed to the delay in the developmental processes in the early life stages. Diuron and irgarol are highly persistent in the environment and have known-well toxic effects on various marine organisms including invertebrates, as shown in this study. Therefore, it is urgent to establish an environmental protection strategy to prevent the pollution of and preserve the marine environment.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.152-161
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• 2009

The largehead hairtail (Trichiurus lepturus) is one of the most common fisheries stocks in the East China Sea and the Yellow Sea. The species is caught using a variety of fishing tools, such as a stow net or a long line, as well as jigging and trawling. Scientific investigations have been conducted throughout the world to enable evidence-based estimations for the management and protection of the main fisheries biomass. For example, inshore and offshore hydro acoustic surveys are performed annually using bottom- and mid-water trawls around the Korean Peninsula. However, to date, no acoustic survey has been conducted to estimate fish size distribution, which is necessary to construct a data bank of target strength (TS) relative to fish species, length (L), and frequency. This study describes the frequency and length dependence of TS among fishes in Korean waters for the purpose of constructing such a TS data bank. TS measurements of the largehead hairtail were carried out in a water tank (L 5 m$\times$width 6 m$\times$ height 5 m) at frequencies of 50, 75, 120, and 200 kHz, using a tethering method. The average TS patterns were measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down) to $+45^{\circ}$ (head up) every $0.2^{\circ}$. The length conversion constant ($b_{20}$) was estimated under the assumption that TS is proportional to the square of the length. In addition, in situ TS measurements on live largehead hairtails were performed using a split beam echo sounder.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.53-58
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• 2006

Along with the development of costal engineering, various type of breakwaters have been built. The main purpose of breakwaters are to provide harbour protection against waves, to stabilize beaches against erosion due to large wave action, and to provide for temporary wave protection for installation on or under water surface. This paper an application example of PIV system for analyzing the flow of Floating Breakwater with double barriers. We introduce an analysis method to predict the characteristics of flow around the neighboring fields of Floating Breakwater with double barriers in order to develop a high performance model. Flow visualization has conducted in circulating water channel by a high speed camera and etc. Flowing phenomenon according to velocity distribution and flow separation around the breakwater with double barriers were obtained by 2-D PIV system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.708-716
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• 2019

After the Sewol ferry disaster, the maritime safety supervisor system was introduced to strengthen maritime safety control for coastal vessels. If any critical defect is found in vessel facilities during periodical or occasional guidance and supervision on a vessel, a maritime safety supervisor takes an administrative measure: detention of the vessel until it has been completely corrected. The detention order is one of the most powerful regulations exercised by a maritime safety supervisor. It would not be an overstatement to say that the guidance and supervision conducted by a maritime safety supervisor is very important for the safety of a vessel and protection of the maritime environment. However, the regulatory level of each Regional Office of Oceans and Fisheries toward vessels may vary with the enforcers, and an individual's intentional act or negligence might occur during the execution process. Detention of a coastal vessel by the Regional Office of Ocean and Fisheries can easily lead to delayed navigation, and a vessel owner may suffer economic loss from suspension of a charter party. Nevertheless, the Maritime Safety Act does not prescribe filing a petition for objection to the measure of detention order by a maritime safety supervisor. To overcome this problem, therefore, the objection procedure under the Maritime Safety Act has to be reformed to reclaim a right against an inappropriate detention order measure caused by an individual's intentional act or negligence through a formal objection.

• Journal of ILASS-Korea
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• v.21 no.2
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• pp.71-77
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• 2016

Air pollutants nitrogen oxides are inevitably generated in the combustion reaction. Its amount trend is steadily increasing because the rapid modern industrialization and population growth. For this reason, NOx is controlled to reducing the harmful components in the exhaust gas. So Marine Environment Protection Committee (MEPC) take effect 'Tier I', 'Tier II' of air pollution regulation in 2005 and 2011 respectively. According to NOx emissions are strictly regulated management of the vessel through them. In addition, since 2016 the regulation enter into force in the next step 'Tier III' was confirmed by MEPC 66th committee. It's 80% enhanced emissions limits than the 'Tier I' Alternatively these emission regulation, research is actively being carried out about exhaust gas after-treatment methods through the vessel application of Selective Catalytic Reduction(SCR). Therefore depending on the basic specification of cell density according to the Area velocity, Space velocity, Linear velocity is studied the effects of NOx removal efficiency

• Corrosion Science and Technology
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• v.9 no.6
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• pp.325-330
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• 2010

Many surface protection methods have been developed to apply for constructional steels used under severe corrosive environment. Thermal spray coating has been known to be an attractive technique due to its relatively high coating speed. Furthermore high corrosion resistance of coated film with thermal spray is required to expand its application. Four types of coated films(DFT:300 um) such as pure zinc, pure aluminum and two Al-Zn alloy (Al:Zn=85:15 and Al:Zn=95:5) onto the carbon steel (SS401) were prepared with arc spray, and the corrosion behavior of their samples were evaluated by electrochemical method in this study. Pure aluminum sample showed high corrosion resistance behavior exposed to sea water solution and pure zinc and alloy (Al:Zn=95:5) samples followed pure aluminum sample. The other alloy(Al:Zn=85:15) so called galvalume coated onto the carbon steel ranks the 4th corrosion resistance in this study. The results of porosity ratio of those samples by observation are well matched with the electrochemical data.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.287-296
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• 2017

The Formal Safety Assessment (FSA) is a structured and systematic methodology developed by the IMO, aimed at assessing the risk of vessels and recommending the method to control intolerable risks, thereby enhancing maritime safety, including protection of life, health, the marine environment and property, by using risk analysis and cost-benefit assessment. While the FSA has mostly been applied to merchant vessels, it has rarely been applied to a DP vessel, which is one of the special purpose vessels in the offshore industry. Furthermore, most of the FSA has been conducted so far by using the Fault Tree Analysis tool, even though there are many other risk analysis tools. This study carried out the FSA for safe operation of DP vessels by using the Bayesian network, under which conditional probability was examined. This study determined the frequency and severity of DP LOP incidents reported to the IMCA from 2001 to 2010, and obtained the Risk Index by applying the Bayesian network. Then, the Risk Control Options (RCOs) were identified through an expert brainstorming and DP vessel simulations. This study recommends duplication of PRS, regardless of the DP class and PRS type and DP system specific training. Finally, this study verified that the Bayesian network and DP simulator can also serve as an effective tool for FSA implementation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.20-21
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• 2016

Aids to Navigation (AtoN) is marine traffic safety facility to facilitate the safe and efficient movement of shipping and enhance the protection of the marine environment by the regulation or guideline of The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). By IALA NAVGUIDE, the term "New Danger" is defined as newly discovered hazards not yet shown in nautical documents and includes naturally occurring obstructions such as sandbanks or rocks or man-made dangers such as wrecks. 'New Dangers' should be appropriately marked using Lateral, Cardinal, Isolated Danger marks or by using the Emergency Wreck Marking Buoy. However, the Emergency Wreck Marking Buoy has difficulties with implementation conditions in terms of speed and accuracy to install the buoy. In case of sinking accidents, it is difficult immediately to install the Emergency Wreck Marking Buoy because of weather conditions, marine environments and accident position. This paper studies Auto Releasing New Danger Mark Buoy on the deck which can be automatically to release from the deck of a vessel and float in the water and quickly install the accident position in case of sinking accidents. The buoy will be to reduce the risk of navigation and prevent secondary collisions.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.65-70
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• 2006

The regulation of HNS has been intensified by the international trends including OPRC-HNS Protocol and '96 Convention which was driven by the high amounts of cargo. Due to the characteristics of HNS that would possibly bring potential damage with personnel and assets, effective management and prompt actions are required definitely. In order to respond effectively against HNS accidents, Korea Coast Guard (KCG) is in the process q development of HNS accident response manual and information system which allows On-Scene Coordinator(OSC) and personnels for rescue including an information for hazardous materials, sensitive area to be affected, solution methods and more. Furthermore, KCG is also building up establishment of national and local contingency plans for HNS in accordance with OPRC-HNS Protocol. It is also advised to proceed for the government to solve the anticipated obstacles that include protection equipments to get close to the site, experts allowing to manage accidents and organizations specialized for overall HNS related matters. The proposed issues described above are planned to conducted on basis of government.

• Journal of Marine Life Science
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• v.5 no.2
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• pp.43-50
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• 2020

The aim of this study is toxicity assessment using two types of sea urchins (H. pulcherrimus, M. nudus) that can representative primary consumers in potential coastal environments pollutants, Zinc undecylenate (ZU), which is used for various purposes, such as pharmaceutical agents and anti-bacterial and anti-fungi. The Fertilization rate and normal embryogenesis rate of H. pulcherrimus and M. nudus were concentration-dependent decreased. Besides, EC₅₀ of fertilization rate with H. pulcherrimus and M. nudus were 11.27 mgl^-1 and 1.48 mgl^-1, and EC₅₀ of normal embryogenesis were 0.94 mgl^-1 and 3.78 mgl^-1. NOEC of normal embryogenesis were 0.20 and 0.78 mgl^-1, respectively. In addition, to find the safety criteria of the ZU on the marine environment. PNEC value was 0.0094 mgl^-1, calculated using the toxicity values of two species of sea urchin derived from this study and the acute toxicity results of the coastal area through literature research. The above results will be used as basic data for establishing environmental protection strategies for marine environmental pollutants.