• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.325-326
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• 2005

해양에 적조가 발생하면 해수의 산소결핍 현상을 유발하고 동식물의 성장과 생존에 필수적인 태양광을 차단하여 해양 동물뿐 아니라 식물에게까지 치명적 피해를 준다. 또한, 대형 선박의 안정수(ballast water) 유입시 안정수 내에 포함되어 그들의 생활공간을 이동하면서 선박으로부터 다시 유출될 때 신생활공간에 외래 생물체로 침입하여 그곳의 기존 생태계를 파괴시키거나 교란하는 외래침입생물체는 해양생태계 환경파괴의 주범이다. 따라서 이들 두 종류의 해양생물은 부분적으로 상관성을 지니는 해양수산업계의 천적이며, 해양생태환경 파괴의 원인 제공자로써 마땅히 과학적 방법으로 제거되거나 방지되어야 한다. 이 논문은 해양수산업 계에 막대한 피해를 끼치며 해양생태환경 파괴의 주범으로 등장한 적조생물과 외래침입생물체들이 해수로부터 제조한 플라즈마 반응생성물에 처리된 결과를 분석하여 그 응용성을 조사하였다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.88-101
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• 2013

The International Convention for the Control and Management of Ship's Ballast Water and Sediments was adopted at 2004 and then various BWMS (ballast water management system) have been developed. In this study, WET (whole effluent toxicity) test with algae (diatom) Skeletonema costatum as primary producer, invertebrate (rotifera) Brachionus plicatilis as 1st consumer and fish (olive flounder) Paralichthys olivaceus as predator, chemical analysis and ERA (environmental risk assessment) were conducted to assess the unacceptable effect on marine ecosystem by emitting the discharge water treated with AquaStar$^{TM}$ BWMS using electrolysis as main treatment equipment for removing the marine organisms in the ship's ballast water. The most sensitive test organism on discharge water treated with AquaStar$^{TM}$ BWMS was S. costatum that gave the NOEC value of 25.00%, LOEC value of 50.00% and 72hr-$EC_{50}$ value of 69.97% from WET test result for 20 psu salinity treated discharge water. NOEC and LOEC value of B. plicatilis and P. olivaceus exposed at 20 psu salinity treated discharge water were 50.00% and 100.00%, respectively. In the chemical analysis results, total number of substances produced by AquaStar$^{TM}$ BWMS was 18 which were bromate, 7 volatile halogenated organic compounds, 7 halogenated acetic acids, 3 halogenated acetonitriles and chloropicrin. Eighteen substances did not consider as persistence and bioaccumulative chemicals. Uncertainty of toxic property of 18 substances was high. PECs of 18 substances calculated by MAMPEC model were ranged from $4.58{\times}10^{-4}$ to $4.87{\mu}g\;L^{-1}$, PNECs of them were ranged from $1.6{\times}10^{-2}$ to $3.2{\times}10^2{\mu}g\;L^{-1}$. And, the PEC/PNEC ratio of 18 substances did not exceed 1. Therefore, ERA for produced substances indicate that the discharge water treated with AquaStar$^{TM}$ BWMS does not pose unacceptable effect on marine life. And $EC_{50}$ value of S. costatum on discharge water treated by BWMS using the electrolysis had positive correlation with initial TRO concentration, concentration and kind & level of HAAs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.539-539
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• 2005

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.62-67
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• 2004

Many ships in voyage experience weight and buoyancy distribution change by various reasons such as change of sea water density and waves, weather condition, and consumption of fuel, provisions, etc . The weight and buoyancy distribution change can bring the ships out of allowable trim, heeling angle. In these case, the ships should adjust trim and heeling angle by shifting of liquid cargo or ballasting, deballasting of ballast tanks for recovery of initial state or for a stable voyage. But, if the adjustment is performed incorrectly, ship's safety such as longitudinal strength, intact stability, propeller immersion, wide visibility, minimum forward draft cannot be secured correctly. So it is required that the adjustment of trim and heeling angle should be planned not by human operators but by optimization computer algorithm. To make an optimized plan to adjust trim and heeling angle guaranteeing the ship's safety and quickness of process, Uk! combined mechanical analysis and optimization algorithm. The candidate algorithms for the study were heuristic algorithm, meta-heuristic algorithm and uninformed searching algorithm. These are widely used in various kinds of optimization problems. Among them, heuristic algorithm $A^\ast$ was chosen for its optimality. The $A^\ast$ algorithm is then applied for the study. Three core elements of $A^\ast$ Algorithm consists of node, operator, evaluation function were modified and redefined. And we analyzed the $A^\ast$ algorithm by considering cooperation with loading instrument installed in most ships. Finally, the algorithm has been applied to tanker ship's various conditions such as Normal Ballast Condition, Homo Design Condition, Alternate Loading Condition, Also the test results are compared and discussed to confirm the efficiency and the usefulness of the methodology developed the system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.821-828
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• 2016

The water quality and phytoplankton presence in the ballast water (BW) of 37 vessels originating from the international ports of China were investigated to facilitate negotiations for exemptions to the Ballast Water Management Convention (BWM Convention). The shortest duration given BW spent in a vessel was $3.91{\pm}4.61days$ in area "A", which included the Bohai Sea. Total suspended solids, dissolved organic carbon, and particulate organic carbon ranged from 1.80 to $266mg\;L^{-1}$, from 1.09 to $5.79mg\;L^{-1}$, and from 0.17 to $3.65mg\;L^{-1}$, respectively. A low average concentration of nutrients was measured in BW from area "C", but the concentration of nutrients in BW from area "B" (around the Changjiang estuary) was high, which may be related to the relevant supply of freshwater. A high chlorophyll-a concentration (> $1{\mu}g\;L^{-1}$) was measured in six vessels, three of which carried BW in the area "A". High abundance of phytoplankton (> $10,000cells\;L^{-1}$) was measured in four vessels, two of which carried BW in the area "C". Vessel No. 37, originating from Hong Kong Bay in area "C", showed a high density of dinoflagellates. The results suggest that BWM Convention exemption negotiations with China should be performed cautiously.

• Journal of Ocean Engineering and Technology
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• v.29 no.3
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• pp.224-230
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• 2015

Vessels are traditionally optimized for a single condition, normally the contract speed at the design draft. The actual operating conditions quite often differ significantly. At other speed and draft combinations, adjusting the trim can often be used to reduce the hull resistance. Changing the trim is easily done by shifting ballast water. There are several ways to assess the effect of the trim on the hull resistance and fuel consumption, including in-service measurements, model tests, and CFD. In this paper, CFD is employed for the assessment of the resistance performance according to the trim conditions. The commercial CFD code of the STAR-CCM+ is utilized to evaluate the ship’s resistance performance on a 6,800 TEU container ship. To validate of the effectiveness of STAR-CCM+, the experimental result of the KCS hull form is compared with the result from STAR-CCM+. It is found that the total resistance of the 6,8000 TEU container ship was reduced by 2.6% in the case of a 1-m trim by head at 18knots.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.6
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• pp.880-886
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• 2010

In this paper, we studied the application of low pressure ultra-violet (UV) lamps for the development of an energy saving ship's ballast water treat (BWT) device. We proposed the optimal arrangement of UV lamps by analyzing the energy radiated from medium- and low-pressure UV lamps. Based on the experimental results, we manufactured a disinfection chamber which is composed of low-pressure UV lamps. The rated power and the treatment capacity of the chamber are 216 [W] and 10 [$m^3$/h], respectively. This can replace a disinfection chamber treated by two 2 [kW] medium pressure lamps. The disinfection performance, however the power consumption is about one-eighteen compare to the medium pressure UV lamp, is over 94 [%] for bacteria, 93 [%] for zooplankton, and 94 [%] for phytoplankton. Therefore, it would be possible to develop an energy saving BWT device in a low capacity below 100 [$m^3$/h].

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1192-1200
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• 2008

This paper is concerned with the thermal design of the $138,000m^3$ class membrane type LNGC. To predict the temperature distribution, BOG and BOR, 3-dimensional numerical calculation was carried-out for the quarter of No.3 LNG tank. These sequence analyses were performed under the standard conditions of IMO ship design condition, USCG ship design condition and the Korean flag LNGC's route condition according to the 6-voyage modes. As the results, temperature behavior, heat flux, total penetrating heat, BOG and BOR were obtained, and those were compared with the maneuvering results considering the real temperature variation of air and sea water temperature at noon time. For securing the safety of LNGC during the ballast voyage, optimum control patterns of pressure and temperature in LNG tank is suggested in this paper.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.245-252
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• 2016

This study investigated the environmental conditions and planktonic organisms in the ballast waters (BW) of 22 vessels originating from the international ports of Japan for the purpose of negotiating exemptions from the Ballast Water Management Convention (BWM Convention). The shortest duration of the BW was $3.33{\pm}1.87days$ in area "A", which included Kyushu and Suo Nada at Seto Inland. The total suspended solids, dissolved organic carbon, and particulate organic carbon ranged from 4.60 to 60.9 mg L-1, from 0.97 to 2.69 mg L-1, and from 0.24 to 4.51 mg L-1, respectively. A low average concentration of nutrients was measured in the BW from area "A", but that in the BW from area "C" (around central Honshu) was high, which may be related to the ballasting periods. High chlorophyll-a concentrations (>$1{\mu}g\;L-1$) were measured in four vessels, three of which carried the BW in area "A". High abundances of phytoplankton (> 50,000 cells L-1) were measured in four vessels, three of which carried the BW in area "A". The two vessels originating from Tokyuyama Bay in area "A" showed high densities of dinoflagellates, which are known to be harmful algae. Our results suggest that the negotiations for an exemption from the BWM Convention for Japan should proceed with caution.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.5
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• pp.395-406
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• 2015

The Ballast Water Treatment System was developed to prevent the unintended transport of unwanted organisms from one region to another as demanded by the IMO (International Maritime Organization). Although various types of BWTS in the world have been developed until now and applied to various ships, there has been no systematic basis for its selection and installation. Currently, the system selection and installation are as per ship owner’s suggestion or by easy installation point of view by the shipyard. In order to organize, systemize and solve problems related to the selection and installation of BWTS, a definitive study has been performed to come up with the best alternative to derive value and criteria which were to be met for vessels which are to be equipped with BWTS. Multiple criteria were compared alongside each other during the course of this study. Accordingly an AHP (Analytic Hierarchy Process) analysis method for A, B and C companies were done for container ships with size 10,000 TEU and above. Equipment type for “A” company is “Filter, UV & TiO2” combined type. For “B” company it is “Filter & UV” combined type. Finally for “C” company it is “Electrolysis” type. Henceforth, the results of this study aims to come up with the optimum way to select the best and the most suitable BWTS for a certain vessel.