• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.290-291
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• 2023

Outlier(이상치) 분석을 통한 등부표 선회안전반경 정보 제공에 관한 연구는 AIS 또는 RTU가 설치된 등부표에 대한 이탈 위험 인지, 항해안전 사고 예방 등 안전대책을 강화하기 위한 연구이다. 등부표는 조류, 바람 등 외력에 의해 이출거리가 발생하여 일정한 패턴으로 선회반경이 형성되나 외력으로 인하여 정상범위에서 벗어나 유실, 위치이동 등이 발생할 수 있고 이는 선박추돌 등 항해안전 사고로도 이어질 수 있다. 이러한 등부표 사고는 물적 피해비용과 이용자의 안전운항에 대한 심리적 부담감 또는 위험감수 등의 추가적인 행정소요 비용이 발생할 수 있다. Outlier(이상치)란 외력 등으로 인해 최대 이출거리 이내 정상범위에서 벗어나거나 존재할 수 없는 극단적인 위치 값으로써 21년도 등부표 위치 데이터를 일정 단위 방위별로 분석해 본 결과 Outlier(이상치)가 식별되었다. 따라서 등부표의 안전한 위치 상태를 시스템적으로 모니터링 하기 위해 Outlier(이상치) 분석을 통한 등부표 선회안전반경 정보 제공에 관한 연구를 하였다.

• Journal of Navigation and Port Research
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• v.27 no.5
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• pp.465-471
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• 2003

A coastwise chemical tanker sailing at full speed has capsized during turning in calm water. In the previous paper, we investigated the reasons of the accident by demonstrating the proper correction for the free surface effect of the liquid cargo and the bow-sinkage effect. In this paper, we also carry out model experiments of a transverse pressure under the seawater and an outward heel moment according to the heel angle and rudder angle, on the basis of radius of turning circle, ship's speed and drift angle of model ship occurring in turning. It is also shown that the flooding of seawater onto the deck occurring in turning generated a significant outward heel moment and increased the vertical distance between the center of gravity of the ship and the center of lateral water drag.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.40-42
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• 2011

예선이 부선을 선미 예인하는 상황에서의 예부선 조종특성을 확인하기 위하여, 예부선 통합 자유항주 모형시험을 수행하였다. 기존의 실선시운전에서는 관측하지 못한 부선의 불안정한 거동을 확인하였으며, 브라이들을 이용한 2점 예인 상태로, 우현 10도, 20도, 30도 선회시험을 수행하여 예선과 부선의 선회반경을 측정하였다. 시험수행조건이 다르나, 실선시운전 결과와 비교하여 선회반경이 약 3배 이상 커진 것을 확인할 수 있었다. 또한 부선의 선회궤적이 예선의 선회궤적 안쪽에 존재하는 것도 재확인할 수 있었다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.269-269
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• 2019

The ships are turning for the purpose of collision avoidence and change of course. It is possible that ships have capsizing accident when improper loading of cargo and excessive use rudder angle in turning. It is difficult for navigation officers to recognize the danger of heeling during a turn, because the dynamic state of the ship changes in real time. Thus, in this study, ship's heeling angle was predicted during turning using the maneuverability indices estimated from the ship's autopilot. The maneuverability indices estimated through the Kalman filter of Autopilot is real-time predictable. The turning radius was obtained from the estimated Index of turining ability and calculations of the heeling angle were possible in turning. It is intended to be used as a basic data on the prevention of danger heeling angle during turning.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.261-261
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• 2017

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.353-360
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• 2016

The International Maritime Organization (IMO) has issued international standards for ship maneuverability and stability. These have been established to improve marine safety and influence the direction of research. The previous literature has been researched, but there are few studies on the relationship between ship maneuverability and stability. This study carried out a fundamental experiment to quantitatively evaluate that relationship. Radius of turn and maximum heel angle depending on changing were analyzed through a turning test using a free running model ship. The test results show the change tendency of decreasing turn radius and increasng maximum heel angle according to a GM decrease. A rough estimate equation is proposed to predict the change tendency on radius of turn and angle of maximum heel as GM decreases. Many ships can suddenly experience reduced GM due to unexpected reasons during sailing. The results in this study can be used as fundamental data to estimate a ship's tactical turn diameter and variable heel angle for steering as GM decreases.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.9
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• pp.1247-1254
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• 1998

The vaneless diffusers are widely used in industrial centrifugal compressors which are required to operate within a wide flow range. When very high pressure gases are handled by centrifugal compressor. rotating stall is a serious problem because of the occurance of large aerodynamic exciting forces. Rotating stall mostly often occurs in the impellers but it can occur in vaneless diffusers as well. In this experimental study, the rotating stall in vaneless diffuser with radial type centrifugal impeller was measured by changing the flow rate with I-type, X-type hotwire. As the result, it was cleared which type of rotating stall of the impeller stall would occur and how many stall cells would appear relating with the flow rate. As the flow rate reduced, the propagation speed of rotating stall was reduced. But the stall cell number unchanged with respect to the flow rate.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.05a
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• pp.41-46
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• 1996

For a vertical type crankshaft-journal bearing system used in scroll compressor, nonlinear transient response analysis is applied includung nonlinear fluid film reaction forces of journal beatings. By a connected behavior analysis of crankshaft and orbiting scroll, the radial clearance of scroll wraps is calculated. Considering tangential leakage for this clearance, a coupled analysis model for leakage and dynamic behavior of the orbiting scroll is made, and analyzed by iterative calculation. By regarding clearances of main, sub bearing of crankshaft and orbiting scroll shaft bearing clearance as design parameters, the radial clearance of scroll wraps is analyzed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.24-25
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• 2022

Based on the case of Busan Port November anchorage, which is a group anchorage, related regulations to promote group anchorage safety management, the turning radius of anchored ship, and more accurate weather information collection and safety through improvement of the supporting system for VTS operations to apply the anchorage location in accordance with reality that it is a suggestion for management improvement methods.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.241-242
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• 2023

등부표는 선박의 안전한 항행을 지원하는 시설인 항로표지의 한 종류로 항행하는 선박에게 암초나 수심이 얕은 곳의 소재를 알리거나 항로의 경계를 알리기 위해 침추를 해저에 정치하여 해상의 고정위치에 띄워 놓은 등화가 설치된 것을 말한다. 등부표의 표체는 해저에 정치된 침추와 체인으로 연결하며 체인의 길이는 수심의 1.5 ~2.5배로 하여 표체를 계류한다. 등부표는 조류, 바람 등 외력에 의해 이출거리가 발생하여 일정한 패턴으로 선회반경이 형성되나 외력으로 인하여 정상범위에서 벗어나 유실, 위치이동 등이 발생할 수 있고 이는 선박추돌 등 항해안전 사고로도 이어질 수 있다. 이러한 등부표 사고는 물적 피해비용과 이용자의 안전운항에 대한 심리적 부담감 또는 위험감수 등의 추가적인 행정소요 비용이 발생할 수 있다. 따라서 선박의 안전한 도선을 위해서는 등부표의 이출범위와 위치가 변할 수 있음을 염두해 둘 필요가 있다. 이와같은 등부표로 인한 사고 예방과 안전한 도선을 위해 등부표 이출범위와 안전도선에 관한 연구를 하였다.