• Journal of Navigation and Port Research
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• v.42 no.3
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• pp.207-216
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• 2018

If empty containers from multiple shipping liners are mixed together in the same bay, then the space utilization increases; however, the expected number of re-handles also increases. Formulas for estimating the expected number of re-handles are derived for various storage strategies and two types of handling equipment. The expected number of re-handles is compared, through numerical experiments, among those cases. The results of the numerical experiments are used to analyze the change in the number of expected re-handles according to the change in the retrieval ratio and repair ratio. The impacts of the change in the bay size and the distribution of the storage and retrieval ratio of containers among multiple vessel liners on the expected number of re-handles are analyzed. It is necessary to study efficient operational strategies considering the expected number of re-handles for empty containers.

• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.2056-2063
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• 2012

In a port terminal, containers are stored and transshipped by yard tractors and crane vehicles. For operation efficiency of the terminal, location information of these vehicles is an essential factor. However, most of port terminals try to estimate location of these assets using indirect methods such as event tracking of shipping or unshipping containers. Because these kinds of events are rarely occurred, location of the event includes seriously locating error compared to a real location of vehicle. In this paper, we propose a real-time asset tracking system to obtain accurate and reliable location of terminal assets. The proposed system overcomes a location estimation error caused by container stacks which interrupt wireless communication. In order to mitigate uncertainty and increase accuracy of location estimation, we designed hardwares and multi-step locating system to resolve additional preblems. We implemented system components, and installed these at a port environment for evaluation. The result shows superiority of the system that the accuracy is approximately 5.87 meters (CEP).

• Journal of Korea Port Economic Association
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• v.26 no.2
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• pp.139-149
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• 2010

This paper analyses the relative efficiency of 13 container terminals based on the data for the period 2003-8 to offer a fresh perspective. There has been abundant empirical research undertaken on the technical efficiency of Busan and Gwangyang port. Most studies have focused on the use of parametric and non-parametric techniques to analyse overall technical efficiency. Here, the framework assumes that terminals use two input to produce one output; the former includes container yard and container crane and the latter container volume. Jarque-Bera indicates that three variables are not normally distributed and the positive skewness shows that all the variables have long right tails. This means there are many small-scaled container terminals. This paper also employs heteroscedastic Tobit model to show the effect of the explanatory variables on the container terminal efficiencies. The Tobit model shows that both container yard and container cranes have positive effect on the container terminal efficiency, but container yard has a higher impact on the efficiency than the container crane.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.439-445
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• 2003

Since 1960s. container shipping volume has increased dramatically and continuous on a trend of rapid growth, and so the number of containers handled at the port increases. In order to improve yard crane operating efficiency, the precise position measurement of the yard crane is important. This paper describes the method to measure the absolute position of yard crane using the output pulse of an encoder and infrared sensors. The crane position is calculated by counting the output pulse of an incremental encoder, which is mounted on the wheel in the crane. By the way, the wheel slippage on rail may cause some errors in crane position information obtained from encoder pulses, and the errors in the crane position information are compensated with infrared sensors. The performance of proposed method is verified on experimental results with the simulator of yard crane, the size of which is about 1/10 with the real crane.

• Journal of Intelligence and Information Systems
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• v.12 no.1
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• pp.125-137
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• 2006

One of the important tactical problems for the efficient operation of container terminals is to determine the usage of storage space There are two different strategies for stacking containers; mixing strategy, in which outbound containers and inbound containers are mixed in the same block, and segregating strategy, in which outbound containers and inbound containers are stacked in blocks different from each other The performance of space allocation strategies also depends on the types of handling equipment in the yard and the number of handling equipment allocated to each block. A simulation model is developed considering various handling characteristics of yard cranes. Performances of various space and equipment allocation strategies are evaluated by using the simulation model.

• Journal of the Korea Society for Simulation
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• v.28 no.3
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• pp.25-40
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• 2019

Today, container terminals are fiercely competing to attract an increasing number of containers. As a way to improve terminal productivity, this study proposes two dispatching rules for yard truck allocation priorities. First, Multi-Attribute Dispatching Rule(MADR) is an allocation method to calculate the weighted sum of multiple factors affecting container terminal productivity and priority them. Especially, the workload of the quay crane was considered one of the factors to reduce the residence time of the ship. Second, Cycling Dispatching Rule(CDR) is the effective way to increase the number of double cycles that directly affect terminal productivity. To identify the effects of combinations of pooling and dispatching, a comparative experiments was performed on 8 scenarios that combined them. A simulation environment has been developed for experiments and the results have demonstrated that the combination of terminal level pooling and Multi-attribute Dispatching could be an excellent combination in KPIs consisting of GCR and delayed departure of ships, etc.

• Journal of Korea Port Economic Association
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• v.27 no.4
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• pp.187-205
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• 2011

In considering the size of container logistic flow of Korea, one-port as a hub port is desirable in Busan Port, but as development of Busan Port and Gwangyang Port began as two-ports, they are good as mega hub ports. In case when ports of other regions such as Incheon Port are additionally developed, it is very likely that they become feeder ports rather than mega hub ports. As capital area uses Incheon Port and Pyeongtaek Port for transportation, fierce competition arises due to excessive facilities of terminal companies and it is not easy to be profitable. Therefore, it is more profitable to develop regional hub ports centering on near-sea routes of Korea China Japan rather than local ports such as Incheon Port and Pyeongtaek Port for intensive trade and transportation in the capital area. To mitigate excessive competition between container terminal companies, we need administrative guidance to maintain adequacy through comparing tariffs between ports of Japan and China which are in competitive relations with Korean ports. This study analysed efficiency of container terminal companies in Gwangyang Port, Busan Port and Incheon Port using data for five years from 2006 to 2010. As analytical variables, length of quay, floor area of yard, the number of cranes and employees were analytical variables and a total freight volume was a productive factor.