• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.1077-1082
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• 2005

It's important that the measurement of ship's draft, cargo tank level & volume is relative to ship's stability and fee. In this paper, the corrected level and volume technique is introduced.

• 수산해양기술연구
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• 제51권4호
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• pp.512-519
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• 2015

A historical tragic disaster happened by capsizing the passenger ship Sewol at South Western Sea of Korea in 16, April 2014. The ship which left Incheon harbour to bound for Jeju port passed Maengol strait and reached to approach of Byung Pung island, and then capsized and sank with a sudden inclination to the portside in the mean time of starboard the helm. In this time, the ship which has very poor stability without sufficient ballast waters and with over loading cargo listed port side caused by the centrifugal force acting to the outside of turning. A lot of cargoes not fastened moved to the port side consequently, and the ship came to beam end to capsize and sank in the end. No crews including especially captain would offer their own duties in a such extremely urgent time, as a result, enormous number of victims broke out including a lot of student. In this report, author carried out some calculation on the factors which influenced on the stability of the ship, i.e. the ship's speed, the rudder angle, the weight of cargoes and distance of movement, the surface effect of liquid in the tank. We found out that the most causes of capsize were the poor stability with heavy cargoes and insufficient amount of ballast water against the rule, and the cargoes unfastened moved one side to add the inclination as well. Above all, the owner be blamable because of the illegally operating the ship without keeping the rule.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년 추계학술발표대회 개요집
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• pp.130-132
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• 2006

In passenger ship building where thin plates are mainly used, conventional arc welding processes result in significant post-weld reworking due to thermal distortion of welded joints. In order to solve this problem, European shipbuilding industries introduced hybrid welding process since the 1990's. for passenger ship, first of all, stability is very important. So, in this study, we investigated effects of hybrid welding conditions on impact toughness of weld metal in passenger ship building using DH36 steel.

• 수산해양기술연구
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• 제46권1호
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• pp.50-55
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• 2010

The ship's heading information of hybrid GPS/EM compass were applied to the AIS of fishing vessel and examined the possibility of accuracy improvement. It is observed 453 each in AIS receiver of land among 3,982 each in AIS Rx/Tx transponder of the test ship at sea, and transmission interval according to the speed of ship is determined the 11.4% good transmitting data of the all information. In results, maximum compass error for the ship's heading of an EM compass was $19.1^{\circ}$. The variance of ship's heading owing to the speed of ship is surveyed. The COG (Course Over Ground) was changed extremely in $180^{\circ}W-179^{\circ}E$ range under 4.9knots, and in $24^{\circ}W-23^{\circ}E$ range over 4.9knots. Finally, using the ship's heading of EM compass and the COG from GPS for the autopilot system of a small fishing boat and the ship's heading information of AIS results in danger on the own ship's navigation safety and leads to make confusion both the others and VTS (Vessel Traffic Service) center. Therefore, the hybrid GPS/EM compass is identified as the best system for a small fishing boat and is allowed to offer continuously a ship's heading information with high accuracy and stability.

• 대한조선학회논문집
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• 제43권6호
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• pp.631-637
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• 2006

This paper presents a numerical method to solve the ship motion coupled with internal fluid flow. Physically the internal fluid motion is coupled with the ship motion. Hitherto the previous numerical results of the coupled motion predict only the general tendency with experiments. The main reason of inaccuracy is that the coupled dynamics of ship motion and internal water motion is not accurately accounted. In this study CFD technique based on VOF is employed for the accurate analysis of flooding water motion. Some cases of the 24th ITTC stability committee's benchmark.study for tanker with internal fluid are analyzed by coupling the ship motion and sloshing dynamics. The calculated ship motion is compared with the experimental result to validate the coupled scheme and is in agreement with the experimental result.

• 한국항해학회지
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• 제24권5호
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• pp.373-383
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• 2000

The ship’s safe mooring stability is a principles for the safe cargo handling works at the mooring berth. Today numerous standards, guidelines and recommendations concerning mooring practices, fittings and equipments exist throughout the worldwide maritime industries. In recently, the mooring facilities were constructed as dolphin types at the open sea area apart far from shoreside instead of enclosed coastline area in accordance with increasing ship’s size and for preventing environmental pollution. Therefore the exciting wave condition must be considered as a basic environmental criteria with the wind force and current force for all of the mooring ships at the sea berth facilities. In this study, this added wave force as one of the environmental external forces by using the theoretical formula was applied to the LNG ship in Pyeongtaeg harbor needed the special mooring stability of the sea berth. Through this research, it can be confirmed that wave force is the very important factor in the mooring force and the strength of wave force works much more in the full laden condition than in the lightship condition. And also the wave force changes to non-linear states according to the wave frequency and wave length. In addition, the maximum limit criteria of environmental force of prohibiting the entering ship on the berth and loading works controlled by the port authority concerned of Pyeongtaeg port fully satisfies the condition of the mooring limit force recommended by OCIMF that the safe permitted force of the mooring line have to be within 55 % of MBL.

• 한국수산과학회지
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• 제18권2호
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• pp.94-100
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• 1985

부산수산대학 실습선 부산403호의 내부개조 및 중량물의 철거로 인한 복원성의 변화를 측정하기 위하여 경사시험을 실시하고, 개조전과 시험시의 GM, K, GA의 값을 비교하였으며, 또한 어선 설비 등에 관한 규칙 및 IMO 규정에 비추어 복원성능을 검토하였다. 1. 경하 및 만재출항상태에서의 GZ값은 각각 0.307m 및 0.325 m 여서 복원성에는 이상이 없는 것으로 판단된다. 2. 경하상태에서는 개조전보다 GM이 0.046m 작고, KG 0.141 m 크나, 복원성에는 지장이 없는것으로 보아진다. 3. 만재출항상태에서 탱크 내 액체의 자유표면의 유동을 고려하지 않을 때는 개조전보다 GM이 0.163 m 작고 KG가 0.173 m 크나 복원성에는 지장이 없는 것으로 간주된다. 그러나 탱크 내 액체의 자유표면의 유동을 고려하면 GM 0.275m는, 어선 설비 등에 관한 규칙에서 산정한 GM의 기준치인 0.353m에 미치지 못하므로 이에 대한 보완이 필요하다고 본다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.479-482
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• 2011

본 논문에서는 선박 네트워크의 생존성과 효율성을 기반으로 선박 백본 네트워크의 설계 기법을 제안하였다. 현재 선박 네트워크의 표준은 IEC에서 담당하고 있으며 네트워크 생존성을 다루고 있는 표준 명세 IEC 61162-410은 이중화로 설계된 선박 네트워크가 존재한다는 가정하에 단말 기기가 이중화 네트워크를 통해 중복 프레임을 전송하여 선박 네트워크의 고생존성을 제공하기 때문에 이와 관련된 기존의 연구는 매우 미비하다. 이에 본 논문에서는 이중화 선박 백본 토폴로지 구조에 대하여 분석한 다음, 정수 선형 계획법을 사용한 선박 백본 네트워크의 최소 비용 배치 기법을 제안하였다. 그리고 정수 선형 계획 기법과 메타 휴리스틱 기법, 휴리스틱 알고리즘을 이용하여 배치된 선박백본 네트워크에서 효율적인 트래픽 할당 기법을 제안하였다. 설계한 이중화 선박 백본 네트워크의 설계 기법을 시험한 결과, 네트워크의 생존성 및 비용 효율적인 선박 네트워크의 배치와 트래픽 할당에 우수한 성능을 확인하였다.

• 수산해양기술연구
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• 제47권3호
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• pp.248-256
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• 2011

The inherent efficiency of a ship would be prior to any other quality factors in ship's safety, because lack of it may give rise to a serious sea casuality even if it were a light mistake in operation. And the representative casualty comes from a deficiency of stability and an operating error combined would be capsizing. The Korean offshore large purseiner looks to have a structural weak point with small range of stability in spite of her big initial metacentric height, and have various type of roll reduction devices in order to cover up the defect. The aim of this study is to grasp for the roll reduction characteristics of the purseiner with bilge keel only and a stern keel additionally attached. The results are summarized as follows; The rolling angle of the model ship was increased in accordance with increase of the wave period and height, especially at close to the natural wave period of her, and the trends were more distinguished in the situation of bilge keel only installation than in the stern keel additionally installed. And stern keel has not noticeable effect on the reduction of the roll in the light ship condition, but has a little effect in full load condition.

• 대한조선학회지
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• 제21권1호
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• pp.3-12
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• 1984

Up to now, it has been common to treat the maneuvering motion of a ship as a 3-degree-freedom motion i.e. surge, sway and yaw on the sea surface, for the simplicity and mathematical calculation, and it is quite acceptable in the practical point of view. Meanwhile, considering the maneuverability of a ship under the special conditions such as in irregular waves, in wind or at high speed with small GM value, it is required that roll effect must be considered in the equation of ship motion. In this paper the author tried to build up the 4-degree-freedom motion equation by adding roll. And then, applying the M.M.G.'s mathematical model and with captive model test results the roll-coupled hydrodynamic derivatives were found. With these the author could make some simulating program for turning and zig-zag steering. Through the computer simulations, the effect of roll to the ship maneuver became clear. The effect of the wind force to the maneuverability was also found. Followings are such items that was found. 1) When roll is coupled in the maneuvering motion, the directional stability becomes worse and the turning diameter becomes smaller as roll becomes smaller as roll becomes larger. 2) When maneuver a ship in the wind, the roll becomes severe and the directional stability becomes worse. 3) When a ship turns to the starboard side, the wind blowing from 90 degree direction to starboard causes the largest roll and the largest turning diameter, and the wind from other direction doesn't change the turning diameter. 4) When a ship is travelling with a constant speed with rudder amidship, if steady wind blows from one direction, the ship turns toward that wind. This phenomenon is observed in the actual seaways.