• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.11
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• pp.1390-1397
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• 2004

This study is concerned with the thermal analysis during the cool-down period of 135,000㎥ class GT-96 membrane type LNG carrier under IMO and USCG design condition. During the cool-down period, the spraying rate for the NG cooling decreases as the temperature of NG falls down from -4$0^{\circ}C$ to -l3$0^{\circ}C$, and the spraying rate for the cooling of the insulation wall increases as the temperature gradient of the insulation wall is large. It was confirmed that there existed the largest temperature decrease at the first barrier and the first insulation, which are among the insulation wall, especially in the top side of the insulation wall under IMO and USCG design condition. Also, as the NG temperature distribution is fixed, the outer temperature condition under the design condition has influence on the temperature variation at the insulation. By the 3-D numerical calculation about the cargo tank and the cofferdam during the cool-down period, the temperature variation in hulls and insulations is precisely predicted under IMO and USCG design condition. From the comparison between two conditions; IMO design condition shows more severe temperature gradient than USCG design condition, therefore, it provides the conservative estimation of the BOG.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.221-226
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• 2006

Around 2002, the United States Coast Guard (USCG) identified a need to re-capitalize their Reference Station (RS) and Integrity Monitor (IM) equipment used in the Nationwide Differential Global Position System (NDGPS). Commercially available off-the-shelf differential RS and IM equipment lacked the open architecture required to support long-term goals that include future system improvements such as use of new civil frequencies on L2 and L5 and realization of a higher rate NDGPS beacon data channel intended to support RTK. The first step in preparing for this future NDGPS was to port current RTCM SC-104 compatible RS and IM functionality onto an open architecture PC-based platform. Trimble's product Charisma is a PC-based RS and IM software designed to meet these USCG goals. In fact USCG engineers provided key designs and design insights throughout the development. We cannot overstate the contribution of the USCG engineers. Fundamental requirements for this effort were that it be sufficiently flexible in hardware and software design to support fluid growth and exploitation of new signals and technologies as they become available, yet remain backward compatible with legacy user receivers and existing site hardware and system architecture. These fundamental goals placed an implicit adaptability requirement on the design of the replacement RS and IM. Additionally, project engineers were to remain focused on sustaining the high level of differential GPS service that 1.5 million legacy users have come to depend on. This paper will present new hardware and software (i.e., Trimble's Charisma software) architecture for the next generation NDGPS RS and IM. This innovative approach to engineering on an open architecture PC-based platform allows the system to continue to fulfill legacy NDGPS system requirements and allows the USCG and others to pursue a scalable hardware re-capitalization strategy. We will use the USCG's recapitalization project to explain the essential role of the Charisma software.

• Journal of Navigation and Port Research
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• v.39 no.2
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• pp.83-88
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• 2015

Korea has a systemic problem with lack of engine maintenance, especially among the Commercial Fishing Vessel fleet. This results in a inordinate percent of SAR call-outs for vessels with engine failure. These SAR call-outs lead to a free tow to shore by KCG or by one of its volunteer associates. Although these tows are not a terrible economic burden on KCG, it is a burden in terms of time and resources mis-allocated. This paper proposes a Commercial Fishing Vessel Examination (CFVE) program modeled after the program run by USCG. It is expected that adopting the CFVE program, KCG may be able to create a culture of safety among fishermen; thus, replicating the USCG's success rates.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.292-295
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• 2014

This paper proposes that the Marine Search & Rescue and Salvage Association of Korea (MARSA) can provide KCG a very positive return on investment; that is, MARSA will save lives and property well over the budget needed from KCG to operate MARSA. To perform this Cost-Benefit Analysis, actual performance data and other figures are taken from the USCG Auxiliary, and these figures are used to project expected possible MARSA results. In this paper, MARSA is projected to provide a 1,493 % return on investment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.187-188
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• 2018

2004년 체결된 평형수관리협약은 2016년 9월 비준되어 2017년 발효 예정이었다. 그러나 발효 직전, 물리적으로 모든 선박에 평형수 처리장치를 설치하기 어렵다는 의견에 따라 2년 유예되었다. 따라서 수만 척의 선박은 2024년까지 평형수 처리장치를 설치해야 하며, 해당 시장의 규모는 약 40조원까지 성장할 것으로 추정된다. 그러나 우리나라에서 개발한 현재 평형수 처리장치는 IMO 형식승인을 받은 제품만 있을 뿐 USCG 형식승인을 받은 제품이 없어 평형수 처리시장을 선점하기에 어려움이 있다. 따라서 본 연구에서는 USCG 성능기준을 만족하는 평형수 처리기술 개발을 위하여 IMO와 USCG 성능기준의 차이를 비교하고, 현재 사용되고 있는 선박평형수 처리장치의 국내 및 세계 기술 수준을 비교 분석하여 자외선 발광 다이오드 및 이산화티타늄을 이용한 평형수 처리장치 개발방향을 제시한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.282-288
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• 2014

The DGPS reference station is a national infrastructure generating GPS correctional information and transmitting the signal for Differential GPS. Currently, Korea has applied and operated the software-based DGPS reference station as a standard of the next generation proposed by the USCG in order to improve the hardware-based DGPS reference system. However, software-based DGPS reference station proposed by USCG was changed in software method, only for form. There is no advantage to changing software-based because the most critical part of architecture has not been improved. In this paper, we have designed a new software-based marine DGPS station architecture that a reference station software and a monitor station were integrated. The new marine DGPS station architecture based on software is a more simplified structure than it used to be and can be utilized in the DGPS reference station.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.9-15
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• 2016

We investigated >$50-{\mu}m$ marine planktonic organisms (mainly zooplankton) using a bongo net in Masan Bay and Jangmok Bay in order to harvest 75% of natural communities based on Phase-II approval regulations by the United States Coast Guard (USCG). The concentrated volume (in 1 ton) and abundance of zooplankton were $1.8{\times}10^7ind.ton^{-1}$ and $2.3{\times}10^7ind.ton^{-1}$, and their survival rates were 82.6% and 80.1%, respectively. The community structure in Jangmok Bay was similar to that in Masan Bay, and dominant species were adult and immature groups (stage IV) of genus Acartia. Harvested populations were inoculated in a 500-ton test tank. Although the population abundances were $6.0{\times}10^4ind.ton^{-1}$ for both bay samples, the mortality rates were higher in the Masan Bay population (32%) than the Jangmok Bay population (20%). We considered the reason to be that there were 30% more immature individuals of Acartia from Masan Bay than from Jangmok Bay. The younger population may have been greatly stressed by the moving process and netting gear. After applying a Ballast Water Treatment System (BWTS) using a sample form Jangmok Bay, the mortality rates in the treatment groups were found to be 100% after 0 days and 5 days, implying that the BWTS worked well. During the winter season, the zooplankton concentration method alone did not easily satisfy the approval standards of USCG Phase II (> $10{\times}10^4ind.ton^{-1}$ in the 500 ton tank). Increasing the netting frequency and additional fishing boats may be helpful in meeting the USCG Phase II biological criteria.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.483-489
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• 2016

The type approval test for USCG Phase II must be satisfied such that living natural biota occupy more than 75 % of whole biota in a test tank. Thus, we harvested a community of natural organisms using a net at Masan Bay (eutrophic) and Jangmok Bay (mesotrophic) during winter season to meet this guideline. Furthermore, cell viability was measured to determine the mortality rate. Based on the organism concentration volume (1 ton) at Masan and Jangmok Bay, abundance of ${\geq}10$ and $<50{\mu}m$ sized organisms was observed to be $4.7{\times}10^4cells\;mL^{-1}$and $0.8{\times}10^4cells\;mL^{-1}$, and their survival rates were 90.4 % and 88.0 %, respectively. In particular, chain-forming small diatoms such as Skeletonema costatum-like species were abundant at Jangmok Bay, while small flagellate ($<10{\mu}m$) and non chain-forming large dinoflagellates, such as Akashiwo sanguinea and Heterocapsa triquetra, were abundant at Masan Bay. Due to the size-difference of the dominant species, concentration efficiency was higher at Jangmok Bay than at Masan Bay. The mortality rate in samples treated by Ballast Water Treatment System (BWMS) (Day 0) was a little lower for samples from Jangmok Bay than from Masan Bay, with values of 90.4% and 93%, respectively. After 5 days, the mortality rates in control and treatment group were found to be 6.7% and >99%, respectively. Consequently, the phytoplankton concentration method alone did not easily satisfy the type approval standards of USCG Phase II ($>1.0{\times}10^3cells\;mL^{-1}$ in 500-ton tank) during winter season, and alternative options such as mass culture and/or harvesting system using natural phytoplankton communities may be helpful in meeting USCG Phase II biological criteria.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.3
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• pp.257-266
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• 2011

Recently, the manufacturers of life-jacket are very interested in the acquisition of USCG(US Coast Guard) approval because the acquisition of USCG approval has an important role in the purchasing decision of the buyer's. Be based on criterion of USCG, we studied how to predict the change of floating position of human model with life-jacket to verify the backside restore. For this, in this study, the human model and the lifejacket was modeled in three dimension, the application program for prediction of floating position was developed, and plugged-in commercial program.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.173-174
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• 2023

IAMSAR Manual 국문본인 국제항공 및 해상수색 구조편람에 따른 확대사각(SS: Expanding Square Search) 수색패턴은 수색 대상의 표류 위치를 한정할 수 있을 때 적용하도록 하고 있으며, 수색 기법에 있어 추측항법 적용의 필요성과 함께 조난대상의 표류 추정 위치인 Datum으로부터의 첫 번째 수색 방향 S의 결정은 바람이 불어오는 쪽인 풍상 측을 향하도록 하여 항해 오차를 최소화할 것을 요구하고 있다. 그러나 첫 직행 구간 S 결정에 있어 IAMSAR Manual 영문본 및 USCG SAR Manual에 따르면 S는 풍하 측 또는 표류하는 방향으로 결정하는 것이 옳은 것으로 해석될 수 있으며 이는 항해 오차를 최소화하기 위한 추측항법 적용 관점에도 부합하는 것으로 보이는바, 이 연구에서는 USCG SAR Manual 등 다른 수색 지침서에서는 Drift 방향으로 제시한 첫 번째 S 방향을 근거로 IAMSAR Manual 국문본의 오류 가능성을 제시하였고, 풍상과 풍하 측으로 상반된 첫 번째 S 방향에 따른 수색 결과의 비교를 위해 선박조종시뮬레이션을 활용, 확대사각 수색상황을 재연하여 각각의 수색패턴을 비교 분석하였다. 이를 통하여 확대사각 수색패턴 결과에서 수색 대상에 더욱 근접한 첫 번째 S 방향은 수색 대상이 표류하는 방향과 일치하는 풍하 측임을 확인하였다.