• Journal of the Society of Naval Architects of Korea
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• v.52 no.5
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• pp.387-394
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• 2015

Before salvaging a wrecked ship, the physics-based simulation is needed to predict lifting force before real operation by floating crane or barge. Procedures affecting lifting force for the salvage can be divided into three stages. At the first stage, the bottom breakout force for the wrecked ship to escape from seabed sediment should be calculated. At the second step, the current force acting on the wrecked ship while lifting from the seabed to near sea surface should be considered. Finally, buoyancy change near at the sea surface when the wrecked ship start to escape from the water should be considered. In the previous studies, only the breakout force at the first stage was calculated based on simple assumption of embedment depth and contact area of the wrecked ship. Therefore, we develop a program for salvage simulation including whole stages. It is composed of four modules such as the equations of motion, time integration, force calculation, and visualization. As a result, it is applied to simulate lifting the wrecked ship according to various environmental loads including seabed sediments.

• 보존과학연구
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• s.7
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• pp.246-264
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• 1986

Micoromorphological alterations of sea-waterlogged woods by marinemicro-oragnisms were investigated by the light and scanning electron microscopy as a part of serial investigations on the shipwrecked materials which were excavated at the sea shore of Wando-Kun, southern coast of Korea in 1984.Deterioration of sea-waterlogged wood by marine microorganisms were varied with the wood species. The degree of deterioration even in the same wood specieswas different according to the part where it was in mud of sea-water. However, the resistance of Torreya nucifera over the marine organisms was marked. Deterioration in cell wall may be classified into three types; thinning of cell wall, separation of secondary wall from compound middle lamella and tunneling of cell wall. Thinning and separation were frequently observed, while the tunneling was rare. Among the wood cell elements of hardwoods, vessel wall was the least deteriorated. The difference degree of degradation of cell wall constituents and the accumulation of inorganic substances in cell lumen indicate that some factors to be considered for the conservation treatment were discussed. The kinds of marine microorganisms invading and/or inhabiting in wrecked wooden ship were also discussed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.57-59
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• 2006

The purpose of search problem is to maximize the probability of target detection as limited search capability. Especially, as elapsing of time at a point of time of initial information received the target detection rate for searching an expected location due to a moving target such that wrecked ship or submarine decrease in these problems. The algorithm of search problem to a moving target having similar property of above targets should solve the search route as quickly as possible. In existing studies, they have a limit of applying in practice due to increasing computation time required by problem size (i.e., number of search area, search time). In this study, we provide that it takes more reasonable computation time than preceding studies even though extending a problem size practically using an approximate computation of probability.

• Journal of Navigation and Port Research
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• v.29 no.2
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• pp.151-157
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• 2005

During the period of every summer to early autumn seasons, ships have been wrecked or grounded from effect of a typhoon in the water areas around Korean Peninsula Typhoon Rusa killed more than 100 people in September 2002. Super Typhoon Maemi passed southeast of South Korea in September 12-13, 2003, with a strong gale blowing at a record 60 m/s and caused much ship groundings, collisions and sinkings over 3000 in dockyards, harbors and places of refuge. These are things that could have been prevented had there merely been prior warning. This study outlines the occurrence characteristics of maritime accidents caused by a typhoon in South Korea for the period from 1962 to 2002. The distribution of the accident records is also compared with the trajectories, winds, central pressures of typhoons, passed during the 1990-2003. It is shown that attack frequency of typhoon and number of marine accidents is the highest in August and the marine accidents due to typhoon have a close relation to the distribution of accumulated wind and pressure fields.

• Journal of Navigation and Port Research
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• v.30 no.10 s.116
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• pp.787-791
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• 2006

It has not been well known to the publics about the manning structure and navigation skills of the period of Chosun CHOI Bu left several records on the crews and navigation skills in his book PYOHAE-Rok. Though PYOHAE-Rok the record of Drifting across the Sea, written by CHOI Bu in 15th century, has been studied by many scholars from the Korean Sea Literary viewpoints, no one was interested in the above book from a maritime history standpoint until now. In this paper the author tried to find out the manning structure of ship and navigation skills in the period of Chosun Finally the author would like to explain the reasons CHOI's ship could succeeded in reaching mainland CHINA but CHANG Han-cheol's ship was wrecked.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.64-73
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• 2004

During the period of every summer to early autumn seasons, ships have been wrecked or grounded from effect of a typhoon in the waters around Korean Peninsular. Typhoon Rusa killed more than 100 people in September 2002. Super Typhoon Maemi passed southeast of South Korea in September 12-13, 2003, with gale winds blowing at a record 60 m/s and caused much ship groundings, collisions and sinkings over 3000 in dockyards, harbors and places of refuge. These are things that could have been prevented had there merely been prior warning. The aim of this study is to examine what effect these typhoons had on occurrence characteristics of the maritime accidents in South Korea. In this work, records of marine accidents caused by a typhoon are investigated for the period from 1962 to 2002. The distribution is also compared with the trajectories of typhoons, passed during the 1990-2003. It is shown that attack frequency of typhoon and number of marine accidents is the highest in August. We use the track data of Maemi such as central pressure, maximum sustained wind speed and area of each 15m/s and 25m/s winds as a case study to draw a map as a risk index.

• Journal of the Korean Society of Food Culture
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• v.29 no.6
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• pp.499-510
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• 2014

This study examined the food culture of the Koryo Dynasty during the early 13th century based on the records of wooden tablets and marine relics from the 1st and 2nd ships of Mado wrecked at sea off Taean while sailing for Gaegyeong containing various types of grain paid as taxes and tributes. The recipients of the cargo on the 1st ship of Mado were bureaucrats living in Gaegyeong during the period of the military regime of the Koryo Dynasty, and the place of embarkation was the inlet around Haenam (Juksan Prefecture) and Naju (Hoijin Prefecture) in Jolla-do. On wooden tablets were recorded 37 items of rice, cereal, and fermented foods. The measures used in the records were seok [石-20 du (斗)] for cereal, seok [15 du, 20 du] for fermented soybean paste, and pot (缸) and volume (斗) for salted fish. The places of embarkation on the 2nd ship of Mado were Jeongeup (Gobu Prefecture), Gochang (Jangsa Prefecture, Musong Prefecture), etc. On wooden tablets were recorded 29 items of rice, cereal, fermented foods, seasame oil, and honey. The volume measure for yeast guk (麴), the fermentative organism for rice wine, was nang [囊-geun (斤)], and the measure for sesame oil and honey, which were materials of oil-and-honey pastries and confections, was joon (樽-seong, 盛). Honey and sesame oil were luxury foods for the upper-class people of the Koryo Dynasty, and they were carried in high-quality inlaid celadon vases in Meibyung style. Food names and measures written on wooden tablets and actual artifacts found in the 1st and 2nd ships of Mado are valuable materials for research into agriculture, cereal, and fermented foods of the Koryo Dynasty in the early 13th century. Besides, relics such as grains and bones of fish and animals from the Koryo Dynasty are expected to provide crucial information usable in studies on food history of the Korean Peninsula.

• 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.