• Journal of Korea Port Economic Association
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• v.24 no.3
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• pp.23-35
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• 2008

The purpose of this paper is to suggest a rational cost allocation method that is efficient and fair. Cost allocation by taking cooperative game theory shows fair allocation considering marginal cost by ship type. Current berth occupancy charging method can not recover quay construction costs. Because it levies charges according to berthing time and tonnage of ships without considering the recovery of quay construction costs. And there are also cross subsidies among ships. This paper suggests the cost allocation method of cooperative game theory as a fair and efficient method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.512-514
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• 2013

대형선이 입출항하기 위한 항만 및 부두의 건설은 이미 포화상태에 이르러 중소규모의 조선단지 및 발전소 운영을 위한 선박통항 수요가 발생하고 있다. 접안시설 건설비용을 절감하기 위하여 선박의 조종성능을 우수하게 건조하여 투입하여 기존의 안전성 평가에 대한 대책과는 다른 대책을 수립하여야 안전성을 향상할 수 있다. 이 연구에서는 부두 및 방파제가 미리 건설된 상황에서 통항예정 선박을 한정하여 안전성 평가를 수행하고 도출된 문제점에 대한 해결방안을 제시하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.47-49
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• 2013

항만 확장 시 기존의 매립 방식은 건설비용 및 환경 파괴 등의 문제가 발생함으로써, 부유체식 구조물을 이용한 해상 부두의 활용이 국내외에서 주목받고 있다. 이와 관련하여 본 연구에서는 선박의 계류안전성평가에 대한 개념을 정립하고 이를 부유체식 Container Yard에 적용하기 위한 자연환경, 선박 및 부두 모델링을 수행하였다. 본 연구 자료를 토대로 향후 부유체식 Container Yard에 접안한 선박의 환경외력 및 계류삭의 장력 평가, 방충재와 계선주에 작용하는 반력 및 견인력 평가, 부두의 운동에 따른 안전성을 파악하고, 해상 부두로서의 적용 가능성을 검토하여 안전한 부두의 설계 기준 및 활용 방안을 마련하고자 한다.

• Journal of Korea Port Economic Association
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• v.26 no.3
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• pp.42-55
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• 2010

This paper primarily deals with a decision-making for determining the number of voyages in each ship size under a specific port structure in order to minimize the total transport cost consisting of transport cost at sea, queuing cost in port, and inventory cost in yard. As a result of computer simulation using queuing model characterized by inter-arrival time distribution, we were able to find out some combination of voyage numbers of 3 ship-size(50,000-ton, 100,000-ton, and 200,000-ton), where the total transport cost can be minimized under a specific port structure. The simulation model also allows us to figure out any trade-off relationship among sea transport cost, queuing cost in port, and inventory cost in yard. Put it differently, an attempt to reduce the sea transport cost by increasing the number of voyages of the largest ship size, the transport cost incurred in both port and yard is hypothesized to be increased and vice versa. Consequently, Port managers are required to adjust the number of annual number of voyages allocated in each ship size, put into the sea lines for importing raw materials, in order to optimize the transport costs incurred under the specific port system. We may consider a net present value(NPV) model for performing an economic feasibility analysis on port investment project. If a total discounted net benefit, including cost savings, exceeds the initial investment for an additional berth construction, then we accept the port investment project. Otherwise, we reject the proposed port investment plan.

• Journal of Korea Port Economic Association
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• v.29 no.3
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• pp.159-174
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• 2013

This paper mainly deals with the appropriation of ship voyage allocation, using a heuristic regression model, in order to reduce total costs incurred in port, yard and at sea under the specific port condition. Because of different behavior of costs incurred in port, yard and at sea, an effort to minimize these costs by adjusting the number of voyages for three ship classes(50,000, 100,000, and 150,000-ton) should be made. For instance, if the port managers attempt to reduce the sea transport cost by increasing the annual allocated number of ship voyages classed 150,000-ton for economies of scale, they have no choice but to suffer a significant increase in queueing cost due to port congestion. To put it differently, there are trade-off relationships among the costs incurred in port, yard, and at sea. We utilized a computer simulation result to perform a couple of regression analyses in order to figure out the appropriate range of allocated number of voyages of each ship class using a heuristic approach. The detailed analytical results will be shown at the main paper. We also suggested a net present value(NPV) model to make a proper investment decision for an additional berth of 200,000-ton class that alleviates port congestion and reduces transport cost incurred both in port and at sea.