• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.198-209
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• 2021

This study evaluated the effects of the dimensional characteristics of containers on the nitrogen status of Quercus serrata, Fraxinus rhynchophylla, and Zelkova serrata in the container nursery stage. Seedlings were grown using 16 container types [four growing densities (100, 144, 196, and 256 seedlings/m²) × four cavity volumes (220, 300, 380, and 460 cm³/cavity)]. Two-way ANOVA was performed to test the differences in nitrogen concentration and seedling content among container types. Additionally, we performed multiple regression analyses to correlate container dimensions and nitrogen content. Container types had a strong influence on nitrogen concentration and the content of the seedling species, with a significant interaction effect between growing density and cavity volume. Cavity volumes were positively correlated with the nitrogen content of the three seedling species, whereas growing density negatively affected those of F. rhynchophylla. Further, nutrient vector analysis revealed that the seedling nutrient loading capacities of the three species, such as efficiency and accumulation, were altered because of the different fertilization effects by container types. The optimal ranges of container dimension by each tree species, obtained multiple regression analysis with nitrogen content, were found to be approximately 180-210 seedlings/m² and 410-460 cm³/cavity for Q. serrata, 100-120 seedlings/m² and 350-420 cm³/cavity for F. rhynchophylla, and 190-220 seedlings/m² and 380-430 cm³/cavity for Z. serrata. This study suggests that an adequate type of container will improve seedling quality with higher nutrient loading capacity production in nursery stages and increase seedling growth in plantation stages.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.723-734
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• 2009

Container Vessel is becoming larger and faster thanks to the rapid growth of global trade and development of technology. Therefore, 15,000TEU vessel is expected to be ordered in near future. Every nations in north-east Asia are facing strong competition to be logistics hub to get the initiatives of logistics in response to the rapid change of logistics environment. According to the globalization of economy and major ports in this region also are trying to catch big shipping line for their survival. Considering above circumstances of the advent of ultra-large container vessel and spoke-and-hub strategy, it is inevitably necessary to make a fast and accurate vessel job in the terminal in order to be a leading port To meet this objective, current vessel planning system has to be improved innovatively. Therefore, this thesis propose multi distributed vessel planning system which enables multi loading/discharging planning with several planner simultaneously for faster and more accurate than existing planning and enhances quality of planning through information sharing among planners. Also this thesis uses simulation through Arena to verify the efficiency of this multi-distributed vessel planning system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.297-302
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• 2004

This paper analyzed productivity of quay cranes on container terminal that have perpendicular yard layout block. In most existing container terminals, quay cranes of single trolley type are used to loading and unloading containers, but quay crane productivity of these type has many limitation about large size containership. For these reasons, recently quay cranes of various type that mn improve productivity are developed and as the representative example, dual trolley, double trolley, supertainer are developing. These cranes are realized that very high productivity bemuse their cycle time is short more than existent single trolley quay crane. Therefore, we analyzed productivity of these cranes that are realized by next generation crane alternatives and as result qf this research, mechaniml productivity by cycle time and net productivity by simulation were measured.

• Journal of Navigation and Port Research
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• v.30 no.3 s.109
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• pp.203-209
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• 2006

Maritime transport has been occupying the biggest part of the container transportation market. With regard to container terminal management, the planning technology and the space allocation system on the yard are very significant factors to secure the stability of ship and to ensure the reliability of schedules of ship throughout keeping barycenter of vessel by right loading and fast handling of cargoes. The purposes of this paper are to illustrate the existing yard management systems such as Grouping method and Random Grounding method, and then to evaluate and compare the efficiency of yard availability between the existing management system(Grouping method) and Random Grouping which uses the forecasted inbound cargo volume at the gate by Time Base Operation.

• Journal of Navigation and Port Research
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• v.36 no.1
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• pp.69-74
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• 2012

Recent global supply chain, improving the efficiency of container shipping process is very important. In the overseas shipping of goods, the voyage of super containership is common to overcome amount of increasing cargo. Thus, container terminal managers make an experiment on the double cycle and dual cycle operation, which ship loading and unloading were carried out simultaneously, for maximizing the productivity of quay side. Yard Tractors(YTs) pooling methods also are introduced for increasing the efficiency of assignment of YTs. In this paper, we analyzed the efficiency of dual cycling through comparing existing pooling methods with the modified method for the dual cycling. We developed a simulation model using simulation analysis software, Arena. The result of experiment shown that the more dual cycling don't always increase the gross crane rate(GCR), which means productivity of quay cranes(QCs) per hour.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.659-665
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• 2008

This thesis describes the key elements for efficient customs clearance system which can facilitate flow of maritime container cargo in the pier area of Busan port, on the basis of considering great changes on international trade environment, development of customs clearance system, variation of commercial container traffic, and diverse views originated from field experience in the distribution industry. To facilitate the flow of maritime containers, reform plan of bonded-transportation and import declaration is proposed to relieve the customs restriction during the days from discharging cargos to taking them into bonded warehouse. Also, various plans to strengthen maritime security, such as customs exam of high-risk export cargos in loading port, pre-declaration of transit container replacement, container tracing system, are proposed to improve Busan port's competitiveness in safety.

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.747-753
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• 2005

In this paper, as an anti-sway control strategy of container cranes, we investigate a variable structure control in which the moving load follows a given trajectory, whereas both the trolley and hoist controllers achieve their positioning problems. It is crucial, in an automated container terminal, that collisions should be avoided during the transference of containers from one place to another. It is also necessary, in the case of a quay crane, to select suitable loading and unloading trajectories of containers, so that possible collisions with surrounding obstacles are avoided. After a brief introduction of the mathematical model, a robust control scheme (i.e., a second-order sliding mode control that guarantees a fast and precise transference and a suppression of the resulted swing) is presented. Despite model uncertainties and unmodeled actuators dynamics, the swing suppression from the given trajectory is obtained by constraining the system motion on suitable sliding surfaces, which include both the desired path and the swing angle. The proposed controller has been tested with a laboratory-size pilot crane. Experimental results are provided.

• Journal of Navigation and Port Research
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• v.34 no.6
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• pp.503-509
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• 2010

Remarshaling is referred to a preparatory task of rearranging containers piled up in a stacking yard to improve the efficiency of loading. Selective remarshaling is required because the time for remarshaling known as large time-consuming task is not enough to remarshal all containers. In this research, we compare two previous researches in more objectively way: heuristic and genetic algorithm based approaches. In addition, we prove the effect of iterative reselection method on dwindling the gap between plan and execution due to the uncertainty of crane operation during execution. Simulation experiments under realistic uncertainty model show that heuristic approaches which have few computational complexity can cope with the uncertainty well when reselection interval is short, but genetic algorithm based approach has advantages when reselection interval that can ensure appropriate number of evolutions is given because of computational complexity for search.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.715-722
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• 2009

In Automated Container Terminal, the remarshaling is the task of rearranging containers for the effective exporting operations. Since available time for the remarshaling is usually restricted, all containers cannot be remarshaled. Therefore, this paper proposes a method that selects some containers from all export containers and then establishes the remarshaling plan with only the selected containers. The experimental results using simulation system shows that our proposal planning method that plans after selecting remarshaling containers is better than plans with all loading containers and remarshals during the available time.

• The Journal of Society for e-Business Studies
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• v.17 no.2
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• pp.149-163
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• 2012

Logistics systems provide their service to customers by coordinating the resources with limited capacity throughout the underlying processes involved to each other. To maintain the high level of service under such complicated condition, it is essential to carry out the real-time monitoring and continuous management of logistics processes. In this study, we propose a method of estimating the service completion time of key processes based on process-state information collected in real time. We first identify the factors that influence the process completion time by modeling and analyzing an influence diagram, and then suggest algorithms for quantifying the factors. We suppose the container terminal logistics and the process of discharging and loading containers to a vessel. The remaining service time of a vessel is estimated using a decision tree which is the result of machine-learning using historical data. We validated the estimation model using container terminal simulation. The proposed model is expected to improve competitiveness of logistics systems by forecasting service completion in real time, as well as to prevent the waste of resources.