• Journal of the Korean Society of Marine Environment & Safety
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• v.1 no.1
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• pp.95-106
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• 1995

The small-waterplane-area-twin-hull(SWATH) ship has been recognized as a promising high performance ship because of her superior seakeeping characteristics and large deck area for various operations compared to the conventional monohull ship. significant advances in analytical technics for the prediction of the ship motions, wave loads and structural responses, structural fatigue and its prediction, and hull vibration for ship motions, wave loads and structural responses, structural fatigue and its prediction, and hull vibration for SWATH ship have been much developed during the last twenty years. Based on these developments in technology an integrated computational procedures for prediction wave loads and structural responses can be used to get a accurate results. But the major problem of SWATH ship's structural design is the accurate prediction of structural responses by the maximum critical loads likely to be experienced during the life of SWATH. To get a easier and safer computational procedures and the analytical approach for determining the accurate structural responses, a case study has been presented through the project experienced.

• Korean Journal of Remote Sensing
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• v.38 no.4
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• pp.435-446
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• 2022

Identifying ship types is an important process to prevent illegal activities on territorial waters and assess marine traffic of Vessel Traffic Services Officer (VTSO). However, the Terrestrial Automatic Identification System (T-AIS) collected at the ground station has over 50% of vessels that do not contain the ship type information. Therefore, this study proposes a method of identifying ship types through the Random Forest Classifier (RFC) from dynamic and static data of AIS and V-Pass for one year and the Ulsan waters. With the hypothesis that six features, the speed, course, length, breadth, time, and location, enable to estimate of the ship type, four classification models were generated depending on length or breadth information since 81.9% of ships fully contain the two information. The accuracy were average 96.4% and 77.4% in the presence and absence of size information. The result shows that the proposed method is adaptable to identifying ship types.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.3
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• pp.246-257
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• 2020

According to the statistics of KMST (2010~2019), 68.5% of marine casualties have been occurred in fishing boats in the last 10 years. Although the incidence rate of annual average per ship is 10.4% for merchant ships and 2.3% for fishing boats, it is necessary to first reduce the marine casualties of fishing boats in order to reduce the occurrence of the whole marine casualty, considering that the number of registered fishing boats are 86.5% of the total. In this study, the top 10 fishing types with high occurring marine casualties in the past 10 years were selected using the statistics of KMST. Then, the causes of the marine casualties, focusing on the collision, were analyzed and counterplan were suggested. The biggest marine casualty that the top 10 fishing types have caused in the past 10 years was a collision, accounting for 71.7% of the total, and the rest were less than 10.0% each. Also, it was found that the biggest environment and cause of the collision were due to human factors such as poor look out or negligence of duty. Eventually, it was concluded that a reduction in the human factors for the causes basically, could lower the incidence of the marine casualties. Therefore, if the continuous and systematic correcting education of the attitude toward the ship operating of seafarers could conducted with the focus on the main human factors, the whole marine casualties will be expected to decrease gradually.

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.187-194
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• 2007

In order to control and manage oil-tanker scrapped materials and wastes properly, the actual conditions and global trends of the treatment and the management of ship scrapped wastes were surveyed and some amendments to marine pollution prevention law of Korea were proposed. Global annual volume of scrapped ships was estimated to be about 22 million DWT and most of them were scrapped in 4 major ship scrap countries such as Bangladesh, China. India and Pakistan and in minor ship scrap countries such as Turkey, the Philippines, Indonesia and Vietnam. The industry of ship scrap has been mainly developed in developing countries or undeveloped countries rather than in advanced countries. Most of scrapped ships were found to be small or medium size below 1,000 GRT In Jellanam-Do and Jeju-Do of Korea. Most of ship scrap enterprise and all enterprises of collection, transfer, treatment and disposal for ship scrapped materials and wastes were shown to be small sized in Korea. The regulations and/or rules which shall prohibit or limit trans-boundary movement of overage oil-tankers for scrap from Korea to developing or undeveloped countries, and vice versa should be Included in marine pollution prevention law of Korea. the criteria of manpower and facilities for enterprise of ship scrap, and for enterprises of collection, transfer, treatment and disposal of ship scrapped materials and wastes should be stipulated in marine pollution prevention law of Korea. It is desirable to introduce the system or concept of recycle or reuse of ship scrapped materials and wastes on producer's responsibility into marine pollution prevention law of Korea.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.11a
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• pp.98-104
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• 2001

Recently, the researches on the prevention of marine oil pollution being strengthened. Sludge oils were unavoidably produced in ship's operations, therefore it is necessary to manage the sludge oils inside the ship itself with the view to prevent marine oil pollution from ship. The present study deals with the ultrasonic breaking systems that recycle the sludge oil from ships into usable oil to be burnt. At the first instanceexperimental studies were carried out to investigate the homogenizing effect of the marine oils and the erosion aspect of horn disc by repeated vibration of ultrasonic transducer. The erosion damages for horn disc SS41 steel with weight loss rate and the irradiation time to max. erosion rate were examined according to the variation of the transducer amplitude, the oil temperature and the immersing depth of horn disc. As the result of it, the erosion aspects of horn disk were varied with oil environments and testing time.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.3
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• pp.309-314
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• 2015

A sunken ship often involves an oil spill. This paper was carried out to minimize environmental and cost damages stemming from oil spil of sunken shipl. Through the analysis of both the standards of the oil tank system and installation, we have identified potential oil spill sites and proposed a remedy of prevention. The result of study, the air pipes of the oil tank are a vulnerable point for oil spill. Also, the remote control devices of emergency shut-off valve have poor accessibility at abandon ship, making it difficult to shut off the emergency shut-off valve. Thus, we propose the addition of a remote quick closing valve in the air pipe and the building of a central control system.

• Journal of Navigation and Port Research
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• v.43 no.5
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• pp.302-309
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• 2019

This study introduces the navigational environment database(DB) compiling water depth, sediment type and marine managed areas (MMAs) in coastal waters of South Korea. The water depth and sediment data were constructed by combining their sparse points of electronic navigation chart and survey data with high spatial resolution using the inverse distance weighting and natural neighbor interpolation method included in ArcGIS. The MMAs were integrated based on all shapefiles provided by several government agencies using ArcGIS because the areas should be used in an emergency case of ship. To test the validity of the constructed DB, we conducted a test application for grounding and anchoring zones using a ship accident case. The result revealed each area of possible grounding candidates and anchorages is calculated and displayed properly, excluding obstacle places.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1734-1744
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• 2015

Majority of marine accidents that occur on fishing vessels are engine accidents. This comprises more than 26 % of the total annual fishing vessel marine accident cases. Large numbers of engine accidents happen in the cooling water system, which are mostly caused by negligence on regular check-up and repair. Notably, small-sized ships have higher engine accidents occurrence rate compared to medium-and large-sized ships. Based on the Report of the Korea Ship Safety Technology Authority, engine accident cases reached 3,032 out of the total 3,081 cases. This study researches on the differences between the small-sized ship pilot, an operator of a vessel engine of less than 200 tons, and a 6th level marine engineer, in terms of the relationship between management forms and what causes the marine accidents in association with the cooling water system. It also studies and analyzes the differences in frequency of the accident occurrence between the two groups. ${\chi}^2$ qualification was imposed through the SPSS statistical analysis program and it got qualified at the significance level of 5%. The research shall be utilized as one of the base line data for the reduction of marine accidents.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.5
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• pp.966-978
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• 2014

Currently, majority small ship's clutch for power transmission to propeller relies on multi plate hydraulic clutch regardless its size. Most of the small ships do not have a spare equipments of clutch. Furthermore, many ship engineers do not have an ability as well as enough experience to solve this problem related to the hydraulic clutch during the voyage. Therefore, any small problems cause many serious marine accidents. Once the clutch has problem, almost of all ships can not sail by itself anymore and it must be towed by salvage boat, maritime police ships, or fish guidance boat etc. In this case, all the accidents will be categorized as a marine accident and they all need to go through marine accident court inquiries. In this study, an understanding of each crew on hydraulic clutch system has been profoundly measured. Furthermore, the knowledge on an emergency navigation protocol of each crew has been also profoundly checked. Additionally, various surveys on hydraulic clutch classes has been performed and its satisfaction of crews on this topic have been carefully checked based on various feedback from students who took these courses. All of the above data from this study will be used to reduce marine accidents in current marine industry.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.2 s.152
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• pp.166-173
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• 2007

Collision analysis problems between ship to ship can be generally classified into the external mechanics(outer dynamics) and internal mechanics(inner dynamics). The former can be also dealt with the concept of fluid-structure interaction and the use of rigid body dynamic program, depending on the ways handling the hydrodynamic pressure due to surrounding water. In this study, full scale ship collision simulation was carried out, such as a DWT 75,000 ton striking ship collided at right angle to the middle of a DWT 150,000 struck ship with 10 knots velocity, coupling MCOL, a rigid body mechanics program for modeling the dynamics of ships, to hydrocode LS-DYNA. It could be confirmed that more suitable damage estimation would be performed in the case of the collision simulations with consideration of surrounding water through the comparison with the collision simulation results of fixed struck ships without it. Through this study, the opportunity could be obtained to establish a more effective ship collision simulation technique between ship to ship.