• Journal of Navigation and Port Research
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• v.31 no.3 s.119
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• pp.223-228
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• 2007

In recent trends of the enlargement and specialization, container ship, LNCG, PCC and passenger ship which have relatively large hull and superstructure above the water line, are already being operated in the world It is very important information for the safety operation of these vessels to estimate the ship's performance under the specific wind condition while berthing, unberthing or low-speed sailing. In this paper, the effect of wind force and moment acting on the training ship HANNARA is investigated by using the numerical calculations. The results of drift angle and counter rudder angle with the relative wind direction and force, the critical wind velocity with the ratio of wind velocity and ship's speed and maximum heeling angle with the wind velocity are shown The presented results can be applied directly to T/S HANNARA in berthing maneuver and avoiding typhoons, and utilized as an educational materials.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.3
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• pp.223-228
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• 2009

By the typhoon "MAEMI" in 2003, a lot of marine accidents such as stranding, collision etc. occurred to the vessels at anchor in "JINHAE MAN" which was considered one of the most safe sheltering anchorage in Korea. These accidents resulted from the dragging of anchor by the strong winds. It needs to compare the external forces with the holding powers of anchors to estimate if the anchor will be dragged or not. However, the calculation of the force by the wind on the ship, in particular, on the wind pressure area which changes by the swinging of her bow is not yet set on a thesis. Therefore, this paper verified that how many times the front wind pressure area should be applied to calculate the force by the wind on the ship at anchor by comparing and analyzing the numerical calculation with, the actual ship's data which was really dragged by the strong wind.

• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.15-20
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• 2005

Recently, ship collision accidents account for $20\%\∼30\%$ of domestic marine accidents, also have increased continually. In this paper, therefore we propose the development of Ship Collision Avoidance Support program for decreasing ship collision accidents. This program has been developed on the basis of CCAS-Model. A CCAS-Model has ship's maneuvering performance and has studied for the propose of supporting to avoid ship collision in close quarters. Besides, the program will effectively support maneuvering for collision avoidance through displaying the feasible area and the method of collision avoidance using own ship's turning characteristic about action of target ship's keeping course and velocity in various encounter.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.225-231
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• 2004

The power and scale of 950 hPa typhoon "Maemi" which struck the shore of Gosung in Kyungnam Province was same as that of 951 hPa typhoon "Saraho" in 1959. For the purpose of getting the safety of training ship "KAYA", we anchored at Jinhae Bay with riding at two anchors paid out 8 shackles of cable respectively. By the way when wind force being over 30m/s, we could not keep the safety of the ship "KAYA" by means of the holding power of an anchor only. Just by using the main engine moderately, we were able to maintain the security of the ship. The holding the main engine moderately, we were able to maintain the security of the ship. The holding power of an anchor according to the way of anchoring, the quality of sea bottom, the direction and speed of wind and current, and the length of an anchor cable were analyzed. The obtained results are summarized as follows : 1. When riding at two anchors rather than lying at single anchor we could get a good holding power. 2. There was a big difference in holding power according to the quality of the bottom. 3. It would be best anchoring in a soft mud area than in any other place as possible. 4. It would also be desirable to set anchor shackles much more than equipment number prescribed in regulation in order to get safety of a ship providing against typhoon.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.2
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• pp.113-118
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• 2017

Various studies on the method of ship collision risk assessment for alarm have been reported constantly, and the result of the studies is applied to navigation devices. However, it is known that navigators ignore or turn off frequent alarms from the devices of predicting collision risk, because they may avoid collisions in the most of situations. In oder to make the prediction of ship collision risk more useful, it is necessary to consider the customary actions of ship collision avoidance. This paper proposes a system of analyzing collision avoidance measures of ships according to the types of encounter and managing the avoidance history of each ship. The core module of the system is designed as a neuro-fuzzy based inference system, and the test of the module validates the proposed system.

• Journal of the Korean Institute of Navigation
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• v.8 no.2
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• pp.51-70
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• 1984

In the North Pacific Ocean a lot of large waves set up in winter, affected by continued winds and swells owing to severe extratropical cyclones. Under this sea condition, if the ship is about 100,000L/T (in deadweight capacity tonnage), we can't find the danger involved in the ship at sea apparently. But when we compare the seaworthiness of ship's building strength with the stress given to the hull by waves, we can't insist that the former be more stronger than the latter. As a result, VLCC is in danger of destroying and cutting for lack of longitudinal strength in heavy weather. Up to this time, Naval Architects have actively studied the relation between ship's longitudinal strength and waves as a ship's projector; however, actually, they have never made more profound study on the problem of longitudinal strength in relation to navigation. The main puprpose of this thesis is to clarify these vivid actual states of ship's trouble unknown to ship's masters. In this thesis we picked up VLCC Pan Yard, a vessel of Pan Ocean Bulk Carrier company's, as a model ship. And in the North Pacific Ocean, we have chosen for this research the basins where the wind speed and the wave height are greater than average. The data used this thesis are quotes from the "winds and waves of the North Pacific Ocean('64-'73)", and wind speed more than 30 knots was made use of as an ocject of this study. By usinh the ITTC wave spectrum, we found out the significant waves for every 5 knots within the range of 20 knots to 45 knots of wind speed. According to this H1/1000 was calculated. The stress of ship's hull is determined by ship's speed and wave height. We compared the ship's longitudinal strength with a planned wave height by rules of several famous classification societies in the world. In the last analysis, we found out that ship's present planned strength in heavy weather is not enough. Finally we made a graph for avoiding heavy weather, with which we studied safe ship's handling in the North pacafic Ocean in winter.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.1 s.24
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• pp.47-52
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• 2006

Recently, ship collision accidents account for $20%{\sim}34%$ of domestic marine accidents, also have increased continually. In this paper, therefore we propose the development of Ship Collision A voidance Support program for decreasing ship collision accidents. This program has been developed on the basis of CCAS-Model. A CCAS-Model has ship's maneuvering performance and has been studied for the propose of supporting to avoid ship collision in close quarters. Besides. the program will effectively support maneuvering for collision avoidance through display of the feasible area and the method of collision avoidance using own ship's turning characteristic about action of target ship's keeping course and velocity in various encounter.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.81-86
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• 2003

The studies on automatic ship collision avoidance system, which have been carried out last 10 years, are facing on new situation due to newly developed high technology such as computer and other information system. It was almost impossible to make it used in real navigation 3-4 years ago because of the absence of the tool to get other ship's information, however recently developed technology suggests new possibility. This study is carried out to develop the algorithm of automatic ship collision support system. The NOMOTO ship's mathematic model is adopted in simulation for its simplicity. The fuzzy reason rules are used for course-keeping system and for the calculation of Collision Risk using TCPA/DCPA. Moreover‘encounter type’ between two ships is analyzed based on Regulations for Preventing Collisions at Sea and collision avoidance action is suggested, Some situations are simulated to verity the developed algorithm and appropriate avoidance action is shown in the simulation.

• Journal of Navigation and Port Research
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• v.27 no.4
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• pp.375-381
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• 2003

The studies on automatic ship collision avoidance system, which have been carried out last 10 years, are facing on new situation due to newly developed high technology such as computer and other information system. It was almost impossible to make it used in real navigation 3-4 years ago because of the absence of the tool to get other ship's information, however recently developed technology suggests new possibility. This study is carried out to develop the algorithm of automatic ship collision support system. The NOMOTO ship's mathematic model is adopted in simulation for its simplicity. The fuzzy reason rules are used for course-keeping system and for the calculation of Collision Risk using TCPA/DCPA. Moreover ‘encounter type’ between two ships is analyzed based on Regulations for Preventing Collisions at Sea and collision avoidance action is suggested. Some situations are simulated to verity the developed algorithm and appropriate avoidance action is shown in the simulation.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.199-207
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• 2015

In ports of Korea, the marine traffic flow is congested due to a large number of vessels coming in and going out. In order to improve the safety and efficiency of these vessels, South Korea is operating with a Vessel Traffic Service System, which is monitoring its waters for 24 hours. However despite these efforts of the VTS (Vessel Traffic Service) officers, collisions are occurring continuously, the risk situation is analyzed that occurs once in about 20 minutes, the risk may be greater. It investigated to reduce these accidents by providing a safety standard for collision danger in a timely manner. Thus, this study has developed a risk prediction module to predict risk in advance. This module can avoid collision risk to adjust the speed and course of ship using a risk evaluation model based on ship operator's risk perspective. Using this module, the ship operators and VTS officers can easily be identified risks in complex traffic situations, so they can take an appropriate action against danger in near future including course and speed change. To verify the effectiveness of this module, this paper predicted the risk of each encounter situation and confirmed to be capable of identifying a risk changes in specific course and speed changes at Busan coastal water.