• 대한조선학회 특별논문집
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• 대한조선학회 2015년도 특별논문집
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• pp.85-92
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• 2015

In general, when ships are designed, structural strength and fatigue strength must be verified based on the relative rules respectively. In case of Slurry Iron Sand Carrier designed to carry Iron-Sand saturated at water content, there is no special consideration of fatigue strength analysis. However, this vessel is similar to Ore Carrier in consideration of the overall characteristics of loaded cargo and the shape of cargo hold. Therefore we verified fatigue strength based on fatigue analysis procedure of ore carrier in DNV Rules and carried out the study for improving of fatigue strength of Slurry Iron Sand Carrier.

• 대한기계학회논문집B
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• 제23권2호
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• pp.281-287
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• 1999

The turbulent natural convection in the membrane type LNG carrier cofferdam with heating points has been studied by numerical method. As the numerical methods, we introduced the three turbulence model, a standard $k-{\varepsilon}$ model and two case of a low Reynolds number models. The parameters considered for this study ore number and capacity of heating points i.e., $1{\leq}Ns{\leq}12$ and $1.0{\times}10^5{\leq}Qs(W/m^3){\leq}1.0{\times}10^8$. The results of the isotherms and velocity vectors have been represented for various parameters. The temperature and velocity at upper position in the space ore shown to be higher than those at lower position. For obtaining the optimal temperatures, $20{\sim}30^{\circ}C$ in the cofferdam space, the heating capacities show $2.0{\times}10^7W/m^3$ at g-heating points and $1.0{\times}10^7W/m^3$ at 12-points. The mean temperature in the cofferdam space can be expressed as a function of number and capacity of heating points.

• 자원환경지질
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• 제16권3호
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• pp.223-243
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• 1983

palaeomagnetism is a major implement to define tectonic provinces and to estimate their past relative position quantitatively. In this sort of investigation it is tacitly assumed that the magnetization of the rocks under study was acquired at the time of their formation. However, because of the possibility of secondary alteration and/or replacement of magnetic minerals, this assumption is not always legitimate. To secure reliable palaeomagnetic data it is therefore fundamental to identify the carrier mineral of magnetization. This paper reviews magnetic mineralogy relevant to palaeomagnetism of terrestrial rocks. Under the heading of each mineral its genesis, crystal structure, magnetic properties, criteria for ore microscopic determination and secondary alteration are summerized. This paper should also be helpful in application of magnetic mineralogy to geothermometry and oxygen barometry in igneous petrology, diagenesis and provenance study in sedimentary petrology, metamorphic temperature determination and genesis study of ore deposits.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.535-537
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• 2009

대형원료 운반선(원유선, 광탄선 등)의 해양오염사고를 줄이기 위하여 주요항로 및 통항로 상의 천수구역, 긴급 위험물 및 위험지역에 기존 AIS Base Station을 활용한 가상항로표지(Virtual AtoN AIS)를 설치하여 일반선박(소형)의 통항에는 장애물로 작용하지 않고 대형선의 AIS, ECDIS 및 레이더상에 위험요소임을 알려준다.

• 한국항해학회지
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• 제19권3호
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• pp.11-19
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• 1995

When an automatic course keeping is introduced, as is quite popular in modern navigation, the closed-loop control system consists of autopilot device, power unit, steering gear, ship dynamics, and magnetic or gyrocompass. We derive mathematical models of each element of the automatic steering system. We provide a method of theoretical analysis on the propulsive energy loss related to automatic steering of ships in the open seas, taking account of the on-off(non-linear) characteristics of power unit. Also we paid attention to non-linear element installed in autopilot device, which is normally called weather adjuster. Next we make numerical calculation of the effects of autopilot control constants on the propulsive energy loss for two kinds of ship, a fishing boat and an ore carrier. Realistic sea and wind disturbances are employed in the calculation.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1995년도 춘계학술발표회 논문집
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• pp.65-92
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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 dynamcis. 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,

• 한국항해학회지
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• 제25권4호
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• pp.407-415
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• 2001

In the present study, irregular disturbances to ship dynamics is proposed, where irregular disturbances implying irregular wave and the fluctuating component of wind for the evaluation of automatic steering system of ship in following seas. Prediction method based on the principle of linear superposition. Irregular wave disturbances in following seas is calculated by frequency variation method. The mathematical model of each element of an automatic steering system is derived, which takes account of a few non-linear mechanisms. PD(Proportional-Derivative) controller and low-pass filter with a weather adjustment are adopted to modelling the characteristics of an autopilot. Performance index is introduced from the viewpoint of energy saving, which derived from the concept of energy loss on ship propulsion. Finally, the present methods are applied to two typical types of ship ; an ore carrier and a fishing boat. The various effects of control constants of autopilot on propulsive energy loss are investigated

• 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.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1995년도 VTS and IBS 95 The Korean Institute of Navigation 1995년도
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• pp.153-165
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• 1995

When an automatic course-keeping is introduced as is quite popular in modern navigation the closed-loop steering system consists of autopilot device power unit(or telemotor unit) steering gear ship dynamics and magnetic or gyro compass. We derive the mathematical model of each element of the automatic steering system. We provide a method of theoretical analysis on propulsive energy loss related to automatic steering of ships inthe open seas taking account of the on-off mechanism of power unit. Also we paid attention to dead band mechanism of autopilot device which is normally called weather adjustment. Next we make numerical calculation of the effects of autopilot control constants ont he propulsive energy loss for two kinds of ship a fishing boat and an ore carrier. Realistic sea and wind disturbances are employed in the calculation.

• Nuclear Engineering and Technology
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• 제7권1호
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• pp.53-68
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• 1975

The world's nuclear powered ships have been reviewed mainly based on development of the marine nuclear reactor and the present trends of nuclear warships and merchant ships in the world. In particular, emphasis was on the four nonmilitary nuclear ships, Russian Ice breaker Lenin, American Cargo-passenger ship Savannah, German Ore carrier Otto Hahn, and Japanese Cargo ship Mutsu. They are the only civilian nuclear ships which have entered service at the present time in the world. The nuclear fleets in United States, United Kingdom, Soviet, and France were described in view of historical development and the present stock of the nuclear ships. The present projects and the future trends for the nuclear merchant ships in the main shipbuilding countries have been also discussed. The nuclear fission and reactor were briefly discussed in the beginning of this article.