• Journal of Navigation and Port Research
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• v.31 no.6
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• pp.515-521
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• 2007

To increase the stevedore efficiency and service level at container terminal, it is essential to reduce working time of container crane which has a bottle neck in the logistic flow of container. The working speed and safety are required to be improved by controlling the movement of the trolley as quick as possible without big overshoot and any residual swing motion of container in the vicinity of target position. This paper presents optimal state feedback control using RCGAs in the case of existing constrained conditions

• Journal of Navigation and Port Research
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• v.26 no.3
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• pp.311-316
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• 2002

On this study, to develop the impact absorbing system for spreader, we operated the dynamic response for models of three types consisting of spring and oil damper by the finite element analysis. Also, in the three types of impact absorbing system, we set the restricted stroke of piston to the static variables and the optimum design was operated to have the minimum value of the reaction force for the impact. As the result, the direct model of two degree of freedom system has lowest value, the model of one degree of freedom system has higher value than that and the parallel model of two degree of freedom system has the highest value. And we studied the effect that the change of spring constant and damping coefficient affect to the reaction force and as the result of the optimum design, we found that reaction force has the lowest value in the each of models.

• 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 the Computational Structural Engineering Institute of Korea
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• v.25 no.1
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• pp.27-36
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• 2012

The mobile harbor is a new concept system to solve the problems of a port. These problems are that container ships cannot be anchored at the dock because they have become larger or the waiting times of anchoring the ships are increased due to heavy container traffic. A new system is designed to carry out the loading and unloading of containers between the mobile harbor and the container ship using the mobile harbor crane at sea. The crane plays an important role when transferring the containers. In this research, various types of the mobile harbor crane are proposed and structural optimization for each type of the crane is carried out. The loading conditions consider the rolling and pitching conditions of the unstable sea state and the wind force are considered. The constraints are mainly the regulations made by the Korean Register of Shipping. The structure of the crane is optimized to minimize the mass while various constraints are satisfied.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.57-58
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• 2023

The working time for loading and transporting containers in the container terminal is one of the factors directly related to port productivity, and minimizing working time for these operations can maximize port productivity. Among working time for container operations, the working time of yard tractors(Y/T) responsible for the transportation of containers between berth and yard is a significant portion. However, it is difficult to estimate the working time of yard tractors quantitatively, although it is possible to estimate it based on the practical experience of terminal operators. Recently, a technology based on IoT(Internet of Things), one of the core technologies of the 4th industrial revolution, is being studied to monitoring and tracking logistics resources within the port in real-time and calculate working time, but it is challenging to commercialize this technology at the actual port site. Therefore, this study aims to develop yard tractor working time prediction model to enhance the operational efficiency of the container terminal. To develop the prediction model, we analyze actual port operation data to identify factors that affect the yard tractor's works and predict its working time accordingly.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.4
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• pp.64-72
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• 2008

Recently security is being an important issue in almost every field of industry. This situation has affected port logistics industry deeply. Ports are now leaving operational methods that only focus on productivity, and shifting to new ones which focus on safety and customer services on the basis of it. Thus a lot of companies and institutions have offered various solutions as this issue becomes more and more intense. Among them, most typical solutions involve installing special devices to ordinary containers to improve its security, such as CSD (Container Security Device) of GE (General Electric) and eSeal of Savi Networks. On the other hand, these devices focus only on international standards or technical implementation, and this causes inconvenience to actual users like cargo owners, sea carriers, or stevedoring companies. This is considered to be due to lack of sufficient consideration on user demands. This research uses QFD (Quality Function Deployment) method for deducting system requirements in order to solve the problems of previous security devices and to develop a security system that can not only reflect the demands of the users but also considers real-world conditions. According to the QFD results, a total of 21 system CTO's were deducted under 5 categories.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.250-251
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• 2023

The pallet, typically a form of tertiary packaging, is a flat structure used as a base for the unitization of goods in the supply chain. In addition, standard pallets such as T-11 and T-12 are used throughout the logistics industry to reduce the cost and enhance the efficiency of transportation. However, in the case of special cargo, it is impossible to handle such cargo using a standard pallet due to its size and weight, so many have developed and are now using their customized pallet. Therefore, this study suggests a pallet size optimization method to calculate the optimal pallet size, which minimizes the loss of space on a pallet. The main input features are the specifications and the storage quantity of each cargo, and the optimization method that has modified the Neighborhood Search Algorithm calculates the optimal pallet size. In order to verify the optimality of the developed algorithm, a comparative analysis has been conducted through simulation.

• Journal of Korea Port Economic Association
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• v.39 no.3
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• pp.1-19
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• 2023

After being kept in bonded areas and bonded logistics warehouses, the level of information sharing and progress confirmation on the process until the cargo is released is insufficient, resulting in disputes and legal disputes related to unauthorized and illegal delivery of cargo. This study attempted to present the introduction of standard electronic documents as a way to solve problems such as delivery practices raised in the delivery of existing imported cargo and legal disputes related to unauthorized illegal delivery among import-related entities. The service provider who manages the bonded warehouse/logistics center in the hinterland of Busan New Port and the shipper service user who use the service were classified into two groups, and a survey was conducted to analyze the difference in perception between the two groups. As a result of the analysis, both groups judged that the introduction of standard electronic documents was necessary, and showed high expected effects in preventing and reducing erroneous shipments and preventing and improving unauthorized and illegal shipments. Discussions between related organizations, related parties, and subjects are needed first to introduce standard electronic documents of the entry and warehouse management system, and the actual participation of related entities such as service providers and service users will play a very important role in establishing the system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.255-261
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• 2005

The purpose of this paper is to analyze transport ability of Automated Guided Vehicle(AGV) and Double Stack Vehicle(DSV) at Automated Container Terminal(ACT). Usually, the main difference of AGV and DSV is capacity of container that they can transport between apron and yard block at once. AGV can carry out two 20 feet or one 40 feet maritime containers, but DSV can carry out four 20 feet or two 40 feet maritime containers. Therefore, DSV may improve more efficiency of stevedoring system of container terminal. In this paper, a simulation model using a graphics simulation system is developed to compare the proposed DSV with the current AGV at automated container terminal. The paper includes examples, performance tests and a discussion of simulation results.

• Journal of Korea Port Economic Association
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• v.32 no.3
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• pp.95-108
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• 2016

China has recently advocated a national strategy called "One Belt One Road" and transferred to execution to refine it into detailed action plans and has continued to fix the complement. However, the Korean Peninsula, including the North Korea remains could not be included at all in the Chinese development policy and framework in terms of the International Logistics. Currently it is raised between Korea-China rail ferry system again and that is when we need to make effective policy development on international multimodal transport system in Northeast Asia. This paper introduces the K-LB (Korea LandBridge) as its execution plan and conducted a feasibility study on this. K-LB consists of a Korea-Russian train ferry system based in Pohang Yeongil New Port(light-wing) and a Korea-China train ferry system based in Saemangeum New Port(left-wing). These two wings are linked to the existing rail system in Korea. This study is convinced that the K-LB is an effective international logistics system in the current terms and conditions and also demonstrated that it is feasible to introduce th K-LB on the peninsula. More strictly speaking, through a linear programming under objective function that minimize the transport cost quantified prior to demonstrate the feasibility, the available ranges and conditions for the transportation costs that are ensured the effectiveness of the K-LB are presented as results. According to the results, if the transport cost of K-LB is cheaper about 34.5% than that of sea transport such as container transport, the object goods may be transported by K-LB on this route. It means that the K-LB system has a competitive advantage due to more rapid customs clearance as well as omitted loading and unloading procedures over container transportation system. It also noted that the threshold level may not be large. Therefore, K-LB has competitive enough to prove its introduction in the Northeast Asian logistics system.