• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.149-154
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• 2017

Recently, container terminal operators have made efforts to develop an efficient remarshalling plan in response to the increase in automation of equipment handling and transport of containers in the terminals. Usually, containers are handled by multiple AYCs(automated yard cranes) in-yard in an automated container terminal, and terminal operators establish a remarshalling plan using slack time to increase the efficiency of ship operation. This study develops the optimal mathematical model through mixed integer programming as a solution to the problem of dispatching multiple AYCs. Considering the difficulty of direct application to the field due to computation time, we analyze the five prototypical dispatching rules for real world adaptation. A numerical experiment found that the maximum weight ratio (MR) rule and the maximum weight (MW) rule are the ideal dispatching solutions to the multiple AYCs dispatching problem.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.869-877
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• 2007

This paper proposes a realtime scheduling method using local search algorithm for non-crossable yard cranes in automated container terminal. To take into consideration the dynamic property of yard crane operation and satisfy the real time constraint, the proposed method repeatedly builds crane schedule for the jobs in a fixed length look-ahead horizon whenever a new job is requested In addition, the proposed method enables the co-operation between yard cranes through prior re-handling and re-positioning in order to resolve the workload imbalance problem between the two cranes, which is one of the primary causes that lower the performance of yard cranes. Simulation-based experiments have shown that the proposed method outperforms the heuristic based methods, and the cooperation scheme contributes a lot to the performance improvement.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.336-345
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• 2006

최근 컨테이너 선박의 대형화는 물동량을 크게 증가 시켰으며, 이로 인해 컨테이너 터미널에서는 규모의 경제를 달성하고, 선사의 요구를 만족시키기 위해 노력하고 있다. 이에 대한대안이 양현부두(Indented berth)의 등장이다. 양현부두에는 대형 컨테이너선의 물량을 신속히 처리하기 위해 선석에서 컨테이너를 취급하는 장비인 안벽크레인(Quay Crane : QC)의 작업 대수가 일반부두(Conventional berth)보다는 많이 할당될 수 있다. 본 연구에서는 일반부두와 양현부두의 작업 생산성을 비교하였다. 이를 위하여 탐색기법인 GRASP(Greedy Randomized Adaptive Search Procedure)를 적용한 안벽크레인 일정계획 알고리즘을 이용하였다. 또한 컨테이너 터미널의 실제 자료를 이용하여 두 가지 형태의 부두에서의 본선작업 완료시간을 비교 하였다.

• Journal of Navigation and Port Research
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• v.33 no.8
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• pp.555-562
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• 2009

At container terminals, a major measurement of productivity can be work-efficiency in quay-side. At the apron, containers are loaded onto the ship and unloaded to apron by Q/C(Quay Crane). For improving the productivity of quay crane, the more efficient Y/T(Yard Tractor) operation method is necessary in container terminals. Between quay-side and yard area, current transferring methods is single-cycling which doesn't start loading unless it finishes unloading. Dual-cycling is a technique that can be used to improve the productivity of quay-side and utility of yard tractor by ship loading and unloading simultaneously. Using the dual-cycling at terminals only necessitates an operational change without purchasing extra equipment. Exactly, Y/T operation method has to be changed the dedicate system to pooling system. This paper presents an efficient ship loading and unloading plan in container terminals, which use the dual-cycling. We propose genetic and tabu search algorithm for this problem.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.269-276
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• 2011

This paper considers the rail crane scheduling problem with minimizing the sum of the range of order completion time and make-span of rail crane simultaneously. The range of order completion time implies the difference between the maximum of completion time and minimum of start time. Make-span refers to the time when all the tasks are completed. At a rail terminal, logistics companies wish to concentrate on their task of loading and unloading container on/from rail freight train at a time in order to increase the efficiency of their equipment such as reach stacker. In other words, they want to reduce the range of their order completion time. As a part of efforts to meet the needs, the crane schedule is rearranged based on worker's experience. We formulate the problem as a mixed integer program. To validate the effectiveness of the model, computational experiments were conducted using a set of data randomly generated.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.110-111
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• 2010

Recently, container terminal managers make an experiment on the double cycle and dual cycle operation, which ship loading and unloading were carried out simultaneously, for increasing the productivity of quay side. However, if we make an experiment on dual cycle operation in a real job site, the efficiency is poor up to terminal operation method as YTs(Yard Tractors)' allocation method, QCs(Quay Cranes)' working speed, and position of export containers. So, this paper examine more efficient terminal operation method, when terminal uses dual cycle operation.

• IE interfaces
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• v.24 no.4
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• pp.281-294
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• 2011

This paper considers the rail crane scheduling problem which is defined as determining the sequence of loading/unloading container on/from a freight train. The objective is to minimize the weighted sum of the range of order completion time and makespan. The range of order completion time implies the difference between the maximum of completion time and minimum of start time of each customer order consisting of jobs. Makespan refers to the time when all the jobs are completed. In a rail freight terminal, logistics firms as a customer wish to reduce the range of their order completion time. To develop a methodology for the crane scheduling, we formulate the problem as a mixed integer program and develop three metaheuristics, namely, genetic algorithm, simulated annealing, and tabu search. To validate the effectiveness of heuristic algorithms, computational experiments are done based on a set of real life data. Results of the experiments show that heuristic algorithms give good solutions for small-size and large-size problems in terms of solution quality and computation time.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.1
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• pp.173-190
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• 1992

Considerable number of offshore platforms have been built in Korean shipyards ever since 1976. Unlike for the cases of building ships, however, negligible efforts have been made to establish planning methodology for building onshore platforms. Severe congestion has been shown in the processes of assemblying modules of platforms. The module which is the upper part of a platform is a steel structure accommodating various types of outfittings and machinaries. The production planned without proper consideration on allocating work loads by trade used to show severe interferences among trades of workers and resulted in delayed completion. In this paper, a method of planning module assembly in consideration of leveling work loads by trade is discussed. A system of planning has been formulated and tested on a exampled case of producing a mix of 72 modules. The test showed a possibility of saving 31% of manpower and trimming 11% of through put time.