• Bulletin of the Society of Naval Architects of Korea
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• v.41 no.2
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• pp.86-93
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• 2004

일반적으로 액화암모니아, LPG, 메탄, 부탄 등을 운송하는 가스운반선은 가스를 비등점 이하의 온도로 낮춰서 액화하여 운송하는 선박으로, 가스의 비등점이 -3$0^{\circ}C$에서 -4$0^{\circ}C$ 내외의 저온이므로 대기압 상태에서는 냉각되어 액화상태 약 -48$^{\circ}C$ 유지로 화물탱크에 저장 운반되어야 하는 여러 가지 제약조건이 따른다. 이러한 가스를 보관하는 탱크는 주로 저온에 강한 니켈강을 쓰게 되며 완벽한 고도의 용접기술을 필요로 하고, 저온상태의 화물 저장 운송을 위해서는 대형 냉동기와 보온설비도 필요하다. (중략)

• Journal of the Korean Institute of Navigation
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• v.21 no.3
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• pp.83-90
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• 1997

Damage stability is generally very important as a part of rescue technique of damaged ship and also in connection with the requirements of MARPOL73/78[2]. Damage stability calculation program has been developed and suggest, which can be used on an onboard computer for any operating drafts. The program is based on lost buoyancy method for calculation of final drafts, and also based on added mass method for calculation of residual righting arm. The numerical method suggested by Hamamoto-Kim[6] is adopted for calculation of intact righting arm(GZ). The model experiments on damage stability are also carried out in a small tank with tanker model 2.385 meters long. The experimental results are compared with the calculations by the suggested method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.48-49
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• 2021

소형어선 안전대책 연구는 연근해 조업 소형어선에 대해 해양기상신호표지 정보를 이용해서 항해안전대책 강화를 연구하는 것이다. 해양사고는 매년 증가 추세에 있으며 특히, 연근해 조업 소형어선의 사고가 해양사고의 많은 부분을 차지하고 있고 복원성 승인 및 유지 제외 선박(길이 24m 미만)이 대부분으로 건조 시부터 폐선 시까지 항해안전에 대한 대책이 부족하여 사고 발생 시 전복사고로 인한 사망, 실종 등 인명손실이 크게 발생하고 있다. 어선의 항해와 조업에 가장 큰 영향을 미치는 해양기상정보는 여러 기관별 목적에 맞게 수집되고 있으나 활용도가 떨어지고 기상청에서 제공하는 해양기상 예/특보 정보는 기상 예보치를 이용하는 것으로 실제 기상과 다를 수 있으며 지역 및 지형에 따라서도 기상여건이 상이하므로 현지 실시간 기상정보를 활용한 소형어선에 대한 항해안전 정보 지원이 필요하다. 이 연구에서는 여러기관에서 운용중인 해양기상신호표지 정보를 이용하여 소형어선에 대한 안전대책을 강화하고자 함이다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.226-233
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• 2002

In the field of research of sea keeping quality, much development has been made in recent years using the method of calculation based on the strip theory. It is very important to investigate the hull response of a fishing vessel in waves to ensure the safe navigation and fishing operation in rough seas by preserving excellent sea keeping qualities. For this purpose, the author measured various responses of three fishing vessels in waves using real sea experimental measuring system and analyzed the experimental data The results obtained can be summarized as follow. 1. The amplitudes of pitching motion in the experiments appeared low values with more than one peak occasionally in following sea and quartering sea, and the band width of those was found to be wide relatively. 2. The amplitudes of rolling motion in the experiments appeared high values with only one peak in following sea and quartering sea regardless of ship's tonnage, and the band width of those was found to be narrow relatively. 3. The comparisions of theoretical results with those of experiments for the pitching motions and rolling motion in following sea and quartering sea show that the theoretical values are higher slightly than those of experiments in both directions and the period at which the peak appears in the calculations and the experiments has good agreement approximately 4. The calculated responses of two vessels under a assumed wave of 2.2m height and 5.0sec period showed that the response of pitching motion of ship-A are 2.2 times bigger than those of ship-C in following sea and quartering sea, and the response of rolling motion of ship-A is 4.2 times bigger than that of ship-C in quartering sea.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.2
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• pp.89-95
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• 2022

The stability of the existing ships has been evaluated through numerical calculations in the steady-state, but recently the IMO proposed a new stability assessment criteria that the stability is evaluated in the state in which environmental loads from such as waves and wind act like the loads under actual ship operating conditions. In this study, IMO 2nd generation stability assessment method and procedure were summarized for the dead ship condition, and Direct Stability Assessment (DSA) was performed on 13K chemical tanker through basin model test. The model test is performed in the ocean engineering basin to implement wave and wind loads, and environmental conditions for waves were set height and period of the incident wave, considering the regular wave and wind generation range reproducible in the ocean engineering basin. In addition, to consider the effect of wind speed, the Beaufort Scale for wind speed was applied in the model test.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.211-218
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• 2021

This paper addressed the problems of controlling the coupled pitch-roll motions in a marine vessel exposed to the regular waves in the longitudinal and transversal directions. Stabilization of the pitch and roll motions can be regarded as the essential task to ensure the safety of a ship's navigation. One of the important features in the pitch-roll motions is the resonance phenomena, which result in unexpected large responses in terms of pitch and roll modes in some specific conditions. Besides, owing to its inherent characteristics of coupled combination and nonlinearity of restoring terms, the vessel shows various dynamical behaviors according to the system parameters, especially in the pitch responses. Above all, it can be seen that suppression of pitch rate remains the most significant challenge to overcome for ship maneuvering safety studies. To secure the stable upright condition, a quasi-sliding mode control scheme is employed to reduce the undesirable pitch and roll responses as well as chattering elimination. The Lyapunov theory is adopted to guarantee the closed stability of the pitch-roll system. Numerical simulations demonstrate the effectiveness of the control scheme. Finally, the control goals of state convergences and chattering reduction are effectively realized through the proposed control synthesis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.163-165
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• 2007

제주 외항의 2단계 항만시설 사업으로 동방파제, 동방파호안, 접안시설, 친수호안, 접속호안 등 2,374m 구간에 대해 방파제 내파 안정성과 반사파 저감을 위한 단면계획을 통해 설계에 반영하였으며 지반 침하 및 지진피해 최소화를 위한 구조물의 사용 및 내구성을 중대시켰으며, 특히 크루저 선박의 본격취항을 대비한 친수공간개념의 도입에 많은 노력을 기울였다. 대상 사업지는 지형적 특성상 복잡한 형태의 고파랑이 작용하므로 방파제의 설계파를 7.3m로 상향조정하였고, 방파제 제간부에 발생하는 충격쇄파압에 대한 안정을 확보하기 위해 소파블록 피복케이슨제를 적용하였다. 제주도가 가지는 국제적 위상에 맞추어 국제미항개발, 레저형 웰빙공간조성 및 제주항이 가지는 자연적 특성을 반영하여 친수 방파제와 호안 및 배후시설의 친환경적인 배려를 최대화 하였다. 해양 생태계 보호를 위하여 해조류 서식지 및 해중림 조성 등 생태복원계획도 수립하였다.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.451-466
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• 2017

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 sinking simulation was conducted, and the sinking process was analyzed for the precise and scientific investigation of the sinking accident using highly advanced Modeling & Simulation (M&S) system of 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 carried out 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.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.2
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• pp.50-61
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• 2002

This paper - following 'Functional requirement of marine waste cleaning ships and organization of the fleets'[1] - describes on the preliminary conceptual design procedure for the multi-purpose marine waste cleaning system for shallow waters. The working area of this system is Yellow Sea and part of South Sea of South Korea. As the first step, we determined the functional requirements including the daily target of waste collecting. Then, the preliminary conceptual design and general arrangements were carried out. In order to evaluate the safety and efficiency of this designed system, the stability check and the computer graphic simulation were carried out. Finally, the sea trial performance test of integrated systems in Yeosoo ports was performed and the designed system was shown its validity and effectiveness.

• Journal of Conservation Science
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• v.32 no.4
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• pp.449-457
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• 2016

A stoneware bottle was recovered from the Incheon Yeongheungdo Shipwreck in 2013. Primary observations showed that this object had a sealed opening and was covered with a foreign material. After it was cleaned via mechanical and chemical methods, wave patterns were observed on the outer surface of the bottle and a yellowish-brown transparent material was found within. In this paper, the process of conserving the stoneware bottle and the analysis conducted on the unknown material found within is explained. The conservation process included steps such as cleaning, desalination and restoration. After of the missing area located at the rim, the original shape of the bottle was made clear. In addition, the unknown inner material was analyzed using FT-IR and GC-MS. Results showed that the material is similar to golden lacquer. It is speculated that the Yeongheungdo Ship had wrecked during the Unified Silla period while carrying a bottle loaded with golden lacquer.