• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.180-184
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• 2016

Legislative and regulatory actions regarding the exhaust gas from ships are being strengthened by both international organizations and national governments, to protect human health and the environment. Exhaust gas traps are excluded from exhaust gas regulation applications, but, recently, the United States, Britain, and other developed countries have examined a variety of ways to improve the system, including the introduction of electric propulsion systems to prevent air pollution generated by naval ships. This study investigates a large number of smoke problems of naval diesel engines to verify the effect of improving the nozzle characteristics. An exhaust gas emission measurement method to determine the quality of pollutant exhaust gas generated during low-load operation is proposed through the research methodology of the smoke problem. It was confirmed that the emissions value is improved by decreasing the nozzle hole diameter and increasing the injection pressure. At the same time, the flow rate decrease equation and setting up a test memo based on the nozzle diameter confirmed that the fuel consumption, to which the nozzle diameter in the flow path is related, is reduced.

• Journal of Ocean Engineering and Technology
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• v.31 no.4
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• pp.266-273
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• 2017

In recent years, LNG bunkering terminals are needed to supply LNG as fuel to meet the emission requirements of the International Maritime Organization (IMO). A floating LNG bunkering terminal (FLBT) is one of the most cost-effective and environmentally friendly LNG bunkering systems for storing LNG and transferring it directly to an LNG fuel vessel. The FLBT maintains its position using mooring systems such as spread mooring and turret mooring. The loads on the vessel and mooring lines must be carefully determined to maintain their positions within the operable area. In this study, the wind loads acting in several side-by-side arrangements on the FLBT and LNG-BS were estimated using wind tunnel tests in the Force Technology, and the shielding effect due to the presence of ships upstream was evaluated. In addition, the empirical formulations proposed by Fujiwara et al. (2012) were used to estimate the wind force coefficients acting on the FLBT and those results were compared with experimental results.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.3
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• pp.240-245
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• 2014

As the seriousness of the global environment pollution is gaining our attention recently, researches on application of greenhouse gas emission of ship are being carried globally. However domestic study on greenhouse gas emission from ship was not carried out in various fields. In this study, quantitative data which was presented by greenhouse gas emission of training ship HANBADA and greenhouse gas emission was calculated by Tier 1 method based on total fuel consumption and amount of shore power. Actual voyage data for 1year in 2012 was used to analysis the greenhouse gas emission. This study showed how many weight of gases were exhausted per 1 gross tonnage and per 1trainee in the training ship. There is a need of further research to reduce pollutant and to respond to international environment regulation consistently.

• Journal of Environmental Science International
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• v.6 no.6
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• pp.595-604
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• 1997

To investigate characteristics of biogeochemical environment of the Korea Deep Ocean Study(KODOSI area in the northeast Pacific Ocean, we preferentially measured Inorganic nutrients and fluorescent organic matters. Typically. the permanent thermocline was well developed at the depth of 200~1000m In the study area. Nitrate. phosphate and silicate were low In the surface mixed layer and Increased with depth. N/P and N/Si showed 15 and 0.2 respectively In the deeper layer. Two fluorophores, biomacromolecule(protein-like) and geomacromolecule (humid-like) , were observed by three dimensional fluorescence excltatlon/ emission spectra matrix. Biomacromolecule(maximum fluorescence at $Ex_{280m}/Em_{330nm}$) ranged from 41.9 to 147.0 TU with its maximum In the surface mixed layer and minimum in deeper water, This is a same trend that has been reported for DOC in the equatorial Pacific. This suggests that biomacromolecule might be labile and converted to refractory humic substance after bacterial degradation In the deeper layer. On the contrary, geomacromolecule(maximum fluorescence at $Ex_{330m}/Em_{430m}$), ranged from 7.6 to 46.5 QSU, showed minimum in the surface nixed layer(euphotic zone) Implying photodegradation and then increased with depth at all stations. In the characteristics of vertical profiles, the relationship between biomacromolecule and geomacromolecule showed negative correlation. Such trend can be attributed to biochemical regeneration or formation of fluorescent materials accompanying oxidation and rennnerallzation of settling organic matter.

• Journal of Environmental Science International
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• v.5 no.4
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• pp.429-440
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• 1996

A global carbon cycle model (GCCM), that incorporates interaction among the terrestrial biosphere, ocean, and atmosphere, was developed to study the carbon cycling aid global carbon budget, especially due to anthropogenic $CO_2$ emission. The model that is based on C, 13C and 14C mass balance, was calibrated with the observed $CO_2$ concentration, $\delta$13C and $\Delta$14C in the atmosphere, Δ14C in the soil, and $\Delta$14C in the ocean. Also, GCCM was constrained by the literature values of oceanic carbon uptake and CO, emissions from deforestation. Inputs (forcing functions in the model) were the C, 13C and 14C as $CO_2$ emissions from fossil fuel use, and 14C injection into the stratosphere by bomb-tests. The simulated annual carbon budget of 1980s due to anthropoRenic $CO_2$ shows that the global sources were 5.43 Gt-C/yr from fossil fuel use and 0.91 Gt-C/yr from deforestation, and the sinks were 3.29 Gt-C/yr in the atmosphere, 0.90 Gt-C/yr in the terrestrial biosphere and 2.15 Gt-C/yr in the ocean. The terrestrial biosphere is currently at zero net exchange with the atmosphere, but carbon is lost cia organic carbon runoff to the ocean. The model could be utilized for a variety of studies in $CO_2$ policy and management, climate modeling, $CO_2$ impacts, and crop models.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.4
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• pp.352-360
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• 2019

International Maritime Organization (IMO) regulates an emission of greenhouse gases by creating an Energy Efficiency Design Index (EEDI) to reduce environmental pollution. In propulsion system field, studies are under way on Energy Saving Device (ESD), which can improve propulsion efficiency with the propeller, to reduce the EEDI. Among the studies, the study of Pre-Swirl Stator (PSS) has been actively conducted from long time ago. Recently the variable pith angle type pre-swirl stator has been studied to improve the propulsion efficiency in non-uniform flow fields of the Stern. However, for traditional design methods, no specific design method has been established on the blade or location of radius. In this study, proper design method is proposed for each blade or location for radius according to hydrodynamic pitch angle.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.691-692
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• 2022

IMO 온실가스 규제는 현존선박과 친환경 신조선박의 온실가스 배출에 대하여 차별적으로 규제함으로써 시장경쟁력에 영향을 주어 선주들에게 친환경 신조선박으로 전환을 가속시키고자 하는 것이 핵심이다. 크게 기술적 조치와 운항적 조치, 그리고 시장적 조치가 있으며 세가지 대안 모두 비용적인 측면에서 선주에게 재무적 부담이 될 것으로 예상된. 따라서 본 연구는 온실가스규제에 따른 재무적 부담을 정량적 추정하여 기업의 향후 대응방안과 정책적 지원방안에 대한 제언을 하고자 한다.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.649-660
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• 2015

Data obtained from the Calpuff inverse modeling estimate the emission amount of pollutants, and enable to establish the aim for reduction through the comparison of various cases. This study pursued to accumulate the fundamental data by the Calpuff inverse modeling for five areas in the vicinity of Donghae harbor, which focused on reduction of atmospheric fine dust. As a result of evaluation of the allowed emission amount for local sites, site-D required the most reduction, $4.95{\mu}g/m^2{\cdot}S$, based on the atmospheric guideline, $50{\mu}g/m^3$. The theoretical mitigation could decrease the average concentration of PM10 to $42.6{\mu}g/m^3$ for the study field (Donghae waste water treatment plant). Modeling only for site-A emission showed the potential concentration around the residential area of Donghae harbor, $40{\sim}50{\mu}g/m^3$. However, it will rise over $50{\mu}g/m^3$ with the addition of background level. Therefore no more emission would be allowed. Site-B including commercial area and unpaved field required the reduction of $0.11{\mu}g/m^2{\cdot}S$ due to vehicles and fugitive dust. Site-C and E did not emit additional pollutants.

• Ocean and Polar Research
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• v.42 no.2
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• pp.171-178
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• 2020

R/V EARDO, commissioned in 1992, has successfully carried out ocean research campaigns in Korean jurisdictional and adjacent waters, including continental margins and coastal zones within the Korean Exclusive Economic Zone (EEZ), for 29 years. However, it will soon be reaching the end of its useful service life. A replacement for R/V EARDO is urgently needed to ensure the safety of vessel itself and its crews, and efficient ship operation and maintenance, as well as to meet modern scientific mission requirements (SMRs). Basic specifications for a replacement ship have been devised and reviewed over the past nine months. A test of the proposed hull form was also performed. The total tonnage of the proposed vessel is approximately 740 tons, and the overall length and width are 62.0 and 11.6 m, respectively. The new ship will thus be 73% larger than the current R/V EARDO; in particular, the research workspace will be 4.4 times larger. The major design priorities are the propulsion system, efficiency of radiated noise and vibration control, and the dynamic positioning system. An environmentally friendly emission system, meeting International Maritime Organization (IMO) Tier III regulations, will be installed in the third exhaust pipe. Various wet and dry lab spaces as well as 32 different scientific instruments have also been considered in the ship design.

• Journal of Ocean Engineering and Technology
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• v.26 no.1
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• pp.78-83
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• 2012

The abundant nutrients contained in deep seawater are delivered by natural upwellings from the deep sea to the surface sea. However, the natural upwelling phenomenon is limited to specific areas of the sea; in other areas, the thermocline separates the surface sea from the lower layer. Thus, the surface layer is often deficient in nutritive salts, causing the deterioration of its primary productivity and ultimately leading to an imbalance in the marine ecosystem. Without a consistent supply of nitrogenous nutritive salts, they are absorbed by phytoplankton, resulting in a considerable problem in primary productivity. To solve this issue, a floating type of artificial upwelling system is suggested to artificially pump up, distribute, and diffuse deep seawater containing rich nutritive salts. The key technologies for developing such a floating artificial upwelling system are a floating offshore structure with a large diameter riser, self-supplying energy system, density current generating system, method for estimating the emission and absorption of CO2, and way to evaluate the primary production variation. Strengthening the primary production of the sea by supplying deep seawater to the sea surface will result in a sea environment with abundant fishery resources.