• 한국항해학회지
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• 제22권1호
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• pp.79-89
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• 1998

When an automatic course-keeping is concerned , as is quite popular in modern navigation, the closed-loop steering system consists of autopilot device, power unit(or telemotor unit), steering gear, magnetic or gyro compass and ship dynamics. In order to estimate steering system of ship in open seas, we need to know the characteristics of each component of the system and also to know the characteristics of disturbance to ship dynamics. Calculation methods of irrgular disturbances are based on the linear superposition principle. In this paper, for the purpose of evaluation of automatic steering of ships , the influences of linear control constants of autopilot on propulsive energy loss are investigated bya performance index is introduced from the viewpoint of energy saving. Numberical calculations are carried out for an are carrier and for a fishing boat in multi-directional waves.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2017년도 추계학술대회
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• pp.19-21
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• 2017

Ship maneuvering performance is usually estimated in calm water conditions which provide valuable information about the ship maneuvering characteristics at the early design stage. However, the course-keeping ability and the maneuvering performance of a ship can be significantly affected by the presence of waves when ship maneuvers in real sea condition. Therefore, it is necessary to understand the maneuvering behavior of a ship in waves in the viewpoint of ship safety in the design stage. In this study, the force and yaw moment acting on a moving ship in regular waves with different wave length and wave direction will be performed in the square wave tank in Changwon National University. The results of this study can be used to help a person to design a ship hull with the best ship maneuverability in waves and disseminate knowledge on predicting ship maneuvering in regular waves in various wave directions.

• 대한안전경영과학회지
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• 제3권3호
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• pp.33-44
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• 2001

Needs of each enterprises for safety managers ability should be clarified and then the result should be taken into account regular curriculum and assessed it regularly. Keeping the student competance without this series of feedback will not be possible. A method, to assess the effectiveness of curriculum course, DACUM(Developing A Curriculum) could be applied in order to find out what subject will be useful. Questionnaire results with weight factor could be put into this study Task Analysis method and the importance determining method have been introduced here. As a further study, it is concealed that a study taking into account of company size, nature, local situation are needed to find out more useful application.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 춘계학술대회 논문집
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• pp.117-122
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• 2000

In these days, the pollution of marine environment near island at Korean coastal zone caused by the trash, human waste and livestocks excreta become series problem. One of the most economic and efficient way to prevent this pollution problem is to set up island circulating incineration system. In this paper, the results of feasibility study on the application of turtle boat hull form to the incinearting vessel has been summarized especially for the resistance and course keeping point of view.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.216-217
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• 2005

This paper presents an integrated navagation control concept for underwater vehicles under high speed navigation circumstance. First of all, in order to control an underwater vehicle with respect to automatic navigation, an integrated navigation control method is suggested in view of synchronous control for course keeping, diving and depth control. An exact nonlinear model equation with six-degree-of-freedom is derived for control algorithm. To identify various hydrodynamic coefficients of the equation, an experimental approach is introduced and results are demonstrated for MANTA type model.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.210-215
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• 2000

Presently, one or several tugboats guide a ship in the port or canal, during the ship's engines and steering mechanism kept idle. This method has insufficient ability keeping the ship on course, danger of collision with waterside structures, tugging preparation time consuming, as well as the need expending substantial resources to acquire and maintain tugboats and associated facilities. Therefore, a new technology and system for ship's guiding to be needed and introduced instead of traditional guiding and tugging system.

• Journal of Korean Neurosurgical Society
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• 제54권5호
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• pp.411-414
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• 2013

The authors present a rare case of adult moyamoya disease in which a patient experienced rapid progression of cerebral infarction after intraventricular hemorrhage (IVH). A healthy 39-year-old woman was admitted to our hospital with sudden headache, a decreased level of consciousness and mild tetraparesis. Initial magnetic resonance imaging revealed small cerebral infarction and IVH. Although the patient underwent conservative therapy including hypervolemia, hemodilution, keeping moderate hypertension and administration of a free radical scavenger, she showed a fulminant clinical course of cerebral infarction. The authors discuss the possible pathophysiology and suggest the treatment for such cases.

• 한국항해학회지
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• 제19권2호
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• pp.1-12
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• 1995

The final aim of our research project is a study on assessment of automatic steering system of ships in open seas. In order to achieve this aim, we need to know the characteristics of each component of the system, and also to know the characteristics of disturbance to ship dynamics. In this paper, we provide calculation method of irregular disturbance to ships in autopilot navigation in open seas, and also show calculation examples about two kinds of ship, ore carrier and fishing boat. The disturbance consists of irregular wave and random wind. The disturbance is calculated as equivalent yaw angular velocity. Each spectrum and time history of disturbance are reasonably evaluated. Further investigation concerning to performance index of autopilot system and energy loss related to automatic course keeping, will be dealt with in another paper.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.2002-2009
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• 2006

This paper is primarily focused on the safe navigation between overtaking and overtaken vessels in restricted waterways under the external forces, such as wind and current. The maneuvering simulation between two ships was conducted to find an appropriate safe speed and distance, which is required to avoid collision. From the viewpoint of marine safety, a greater transverse distance between two ships is more needed for the smaller vessel. Regardless of external forces, the smaller vessel will get a greater effect of hydrodynamic forces than the bigger one. In the case of close navigation between ships under the forces of wind and current, the vessel moving at a lower speed is potentially hazardous because the rudder force of the lower speed vessel is not sufficient for steady-state course-keeping, compared to that of the higher speed vessel.

• 수산해양기술연구
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• 제39권1호
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• pp.1-7
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• 2003

When a ship is course-keeping in the open seas, autopilot system is adapted. The design of autopilot system is very important for improvement of ship′s element research. Automatic steering system consists of autopilot device, power unit, steering gear, magnetic or gyro compass and ship dynamics. In order to evaluate automatic steering system of ships in open seas. we need to know the characteristics of each component of the system, and also to know the characteristics of disturbance to ship dynamics. In this paper, I provide evaluation method of autopilot navigation system of the fishing ship. Prediction method based on the principle of linear superposition is introduced for irregular disturbance. For the evaluation of automatic steering system of a ship, "performance index" is introduced from the viewpoint of energy saving and calculation method is frequency response analysis. Finally, I carried out calculation of sensitivity of control constants of autopilot with various conditions of ocean environments.