• Journal of Ship and Ocean Technology
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• v.11 no.2
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• pp.34-45
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• 2007

Environment of marine transportation market is changing rapidly. Due to globalization of world economy, marine transportation of cargos, especially trade using container boxes, is increasing dramatically. Fierce competition in the global market of container transportation forces the shipping industry to seek the economy of scale to reduce transportation cost, and drives the merge and alliance of liner shipping companies. Mega-sized container ships, having capacity over 10,000 TEU, were introduced, and appeared recently, in order to reduce the unit transportation cost. Korean shipping and shipbuilding companies are competitive, and have considerable market share in the global market. Even though both industries are inter-connected through ships and have many common interests in order to enlarge the global market share, inter-relation between two industries is surprisingly insignificant. In this paper current issues in the process of environmental change of marine cargo transportation are reviewed, and inter-relation of shipping and shipbuilding industries is discussed. Suggestions for inter-related development of Korean shipping and shipbuilding industries are given, and means for mutually beneficial collaboration are suggested.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.2
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• pp.154-161
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• 2014

Naval ships have hull appendages which are more exposed to the outside because of its small block coefficient compared with commercial ships. These exposed hull appendages like skeg, strut and shaft line affect the maneuverability of a ship. The effect of hull appendages has considered at initial design stage to estimate more accurate maneuverability. In this paper, sensitivity analysis is used to analyze the effect on maneuverability by hull appendages. 3 DOF maneuvering equations based on Mathematical Modelling Group (MMG) model are used and propeller & rudder model are modified to reflect the characteristics of twin propeller & twin rudder. Numerical maneuvering simulations (Turning test, Zig-zag test) for benchmark naval vessel, David Taylor Model Basin (DTMB) 5415 are performed. In every simulation, it is calculated that stability indices and maneuverability characteristics (Tactical Dia., Advance, 1st Overshoot, Time of complete cycle) with respect to the parameters (area times lift coefficient slope, attachment location) of hull appendages. As a result, two regression formulas are established. One is the relation of maneuverability characteristics and stability indices and the other is the relation of stability indices and hull appendages.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.1
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• pp.41-50
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• 2003

There are winds and waves in the sea, and they are changed frequently in accordance with the weather. By analyzing then which have the closest relation to the ship's safe voyage, evaluating the seakeeping performance and then taking a proper act on, navigators should carry out safe navigation on the sea A ship in seaways suffers continuous disturbances by irregular waves, and ship motions with irregular waves cannot be easily described as a system model which is adequate to a control system. But, in general, for seakeeping analysis, ship motions in irregular seas can be estimated by the superposition of the motion responses in regular wave components of the sea spectrum. After comparing and analyzing the winds and waves in major sea areas, this paper evaluates the navigational safety of ships on the Korean coast with potential dangerous seakeeping performance using the weather information provided by land The conclusion is as follows: (1) It is possible that the safety of ships could be secured more accurately by evaluating the seakeeping performance of ships. (2) When the weather is bad, the departure of ships could be controlled by evaluating the navigational safety of ships. (3) When a ship is placed in commission in any area, this evaluation could be used to decide the type and size of ship in use.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.6
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• pp.541-549
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• 2019

In the present study, we investigated planing forces of supercavitated bodies by using the supercavitation shape produced by the disk type cavitator. The cavity shapes are observed to find the immersion draft and planing angle when the stern of the supercavitated body is partially immersed in the water. To make the planing the angle-of-attack (AOA) of the supercavitated body is varied statically against the main flow and the planing tests are carried out for different body shapes that are changed systematically. The drag, lift and pitch moment acting on the body are measured to understand the relation between the planing force and the immersion draft of the supercavitated body. It is found that the planing force increased in general linearly with the immersion draft ratio and the planing angle is certainly not proportional to the immersion draft ratio.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.245-259
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• 2002

According to ISM Code, from July 1, 1998 relevant shipping company and ships should establish, implement and maintain safety management system(SMS) both on ships as well as shore. Nonetheless the SMS has not yet been settled. This paper is prepared to seek for the problems occurred in relation to the implementation of SMS onboard and propose ideas to improve the system.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.70-75
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• 2001

Intensive experimental investigations were carried out to provide information of the effects of inflow on the rolling characteristics and stability of ships, which becomes great concern in relation to ship's capsizing. A series of systematic experiments have been performed considering the effects cf combined motion of roll-heave-sway and relevant parameters, such as roll angle and period, tank water height etc. To accommodate this type of experiments with 3-degree of freedom of motion, a bench tester has been developed and verified using existing data. Also, theoretical application of anti-roll tank has been incorporated to support the process of investigation. A model of Ro-Ro ships is used in the present study as this type of vessels, as well as fishing vessels, with large open decks, can loose stability rapidly when there is inflow on the decks.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.843-851
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• 2009

Much work has already been done to control and regulate the worldwide problems caused by climate change, particularly the issues on greenhouse gas (GHG) emissions. Carbon dioxide ($CO_2$), having the highest form of concentration among GHGs composed around 1.0 billion tons of emission, and comprises about 98% of the total emissions from the shipping industry. Korean trade mainly rely on the sea transportation. Korean ship tonnages that was brought about by shipbuilders all over the country, continues to grow annually due to the prevailing demands on goods or material supplies and depicting only a small part of the global maritime activity. Nowadays, new build ships coming from the Korean Shipbuilders are being optimized by hull, structure and appendages design, The operational capability of the propulsion and auxiliary machineries in its maximum capacity to achieve the highest possible efficiencies for energy and onboard power use to mitigate $CO_2$ emissions are continually being done through the help of research and development. In this paper, the energy efficiency design index and anboard power capacity of Korean new build ships have been analyzed with response to data collected by ship types, and its respective fuel consumption in relation to $CO_2$ emission results. In response to climate change convention outcome proposals, the best way for the new build ships to become energy efficient is by lowering its operational speed thru adopting the state of the art diesel propulsion engines, patronizing the best sailing practice to lower the transportation cost on the different sea trade routes also helps in $CO_2$ mitigation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.278-279
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• 2000

• Culinary science and hospitality research
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• v.3
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• pp.165-179
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• 1997

Cost-volume-profit analysis shows the relationship between these factors. The figures expressed in a break-even chart can be used planning control and decision making. The relation ships can also be helpful in understanding how all costs must be covered in menu pricing. Involved in these relationship is the contribution to overhead and profit, or contribution ratio. This study used the food service operation of H hotel. Assumed the FC would be 10% of the High Volume, the VC would be 76% of the high volume. And in the CVP of individual meals, selected labor cost of the VC, assumed labor cost would be 35% of the volume.

• Solar Energy
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• v.9 no.3
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• pp.55-63
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• 1989

In this paper, the fluidization characteristics of the magnesia fluidized bed and the heat transfer characteristics with the specimen (SM55C) plunged in the bed have been investigated. To characterize the fluidization, the minimum fluidizing velocities and the relation ships between bed voidage and fluidization rate and obtained. To characterize heat transfer, the experiments for finding heating time transfer effect have been carried out by varying the magnesia particles sizes. optimum heating condition in the magnesia fluidized bed is obtained.