• 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 Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.301-306
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• 2016

During the initial stage of propulsion shaft design, the shaft alignment process includes a thorough consideration of lateral vibration to verify the operational safety of the shaft. However, a theoretical method for analyzing forced lateral vibrations has not been clearly established. The methods currently used in classification societies and international standards can only ensure a sufficient margin to avoid the blade-passing frequency resonance speed outside the range of ${\pm}20%$ of the maximum continuous rating (MCR) for the engine. Typically, in shaft alignment analyses, longer center distances between the support bearings promote affirmative results, but the blade order resonance speed can approach the lower limit for lateral vibration. Therefore, this matter requires careful attention by engineers, and a verification of the theoretical analysis by experimental measurements is highly desirable. In this study, both theoretical and experimental analyses were conducted using strain gauges under two draught conditions of vessels used as 50,000-DWT oil/chemical tankers, introduced recently as eco-friendly ships. Based on the analyses, the influence of the lateral vibration on the shafting system and the system's reliability was reviewed.

• Composites Research
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• v.31 no.5
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• pp.227-237
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• 2018

In this paper, the design application for the lightweight and insulation of the manipulator of the mobile welding robot for the closed/narrow space is presented. A variety of robotic platforms have been developed for weld-worker using a welding robot outside a workpiece for welding work in a complex and narrow space such as a ship or an offshore plant. Normally, The development process of robots consists of machine development, electronic device development, control algorithm development and integration verification considering application environment and requirements. In order to develop the robustness of the welding robot, the lightweight design of the robot manipulator considering the environmental conditions was performed in the basic design of the robot platform. Also, The results of the robot selection and validation, analysis and testing for the insulation performance and cooling performance and the results of the research are shown.

• Information Systems Review
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• v.11 no.2
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• pp.209-231
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• 2009

In recent, a general trend is observed towards more customized products and shorter product life cycles in manufacturing enterprises. In these enterprises, customers often wish to influence the product they order and to get a variant of product that meets their requirements. This is called as customer-oriented make-to-order manufacturing environment. This paper establishes a methodology of implementing information system for developing product data integration system (PDIS) which is suitable for customer-oriented make-to-order manufacturing enterprise, and also presents the case of implementing PDIS for a ship engine product in 'H' heavy industry using the established methodology. At present, the implemented PDIS is successfully operating. As a result, PDIS reduces delivery time and improves customer relationships. Moreover, the case shows that PDIS can be used as a tool for improving inter-department coordination within a company during product life cycle.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.2
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• pp.119-125
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• 2009

Recently the construction of bridges crossing navigable waterways is being promoted aiming at expanding social infrastructure and optimizing the overland routes through private investment. The construction, however, tends to focus on more the commercial requirements than the marine safety and efficient port management that it has a big risk not only to fail in ensuring the safety of ship traffic, but also to muse some severe conflicts between the parties concerned. These problems result from the lacking of standards about the design guidelines and discussing process considering the marine traffic safety when designing bridges. This research attempts to show the problems mused by bridge construction and suggest the standard discussing process through the survey and process analysis on Kwangyang Bridge and Incheon Bridge.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.361-373
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• 2020

In Jeju, in order to efficiently manage and coexist fishing boats and passenger ships in narrow ports, it is necessary to establish reasonable policies. The survey was conducted on 99 fishing ports, from December 1 to 31, 2018. A site survey was conducted on 30 parties (15 in Jeju City and 15 in Seogwipo City) concerning with the use of fishing ports in Jeju to review the appropriate conditions for selecting fishing ports as control subjects. The survey determined size of pleasure craft mooring within fishing port (20%), size of fishing boat mooring (20%), and accessibility of fishing port (20%) under on-site survey factors as well as willingness to form a consultative group between fishing boat and pleasure craft users (20%). Upon the request of the survey, positive and negative opinions were collected on the establishment of a safety control center in the fish port. Based on the survey results, the factors mentioned above were applied to each and every fishing port within Jeju. The bottom five fishing ports in Jeju with the lowest total factor scores were identified and selected as control subjects for review and study. Of the five fishing ports selected as control subjects amidst the 99 fishing ports in Jeju, Dodu Fishing Port had the lowest score of 22% among the national fishing harbors. Among the local fishing ports, Hwabuk Fishing Port had the lowest score of 18%, followed by Sagae Fishing Port with a score of 22%. Hamdeok Fishing Port had the lowest score of 24% among the fishing port villages, whereas Ojo Fishing Port had the lowest score of 24% among the small fishing ports.

• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.741-746
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• 2010

It is necessary to estimate more accurately the resistance of barge in still water and waves to compute the break load of towline and towing power for safety towing performance. The method proposed by government has calculated the total resistance of barge which is composed of frictional resistance, wave making resistance and air resistance considering the shape of hull and towing speed. However, the added resistance is equally applied with the significant wave height regardless of the type of vessels. In this study, we have carried out the numerical calculation to estimate the added resistance of wigley model in waves and compared with the experiment data to confirm the accuracy of the method. Then the computation was executed for the barge varying shape of the bow. As a result, added resistance of barge was differently occurred i.e. 0.3∼1.1 ton according to encounter angle, 0.4∼1.2 ton according to towing speed and 0.5∼1.1 ton according to shape of bow.

• Journal of Navigation and Port Research
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• v.31 no.5 s.121
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• pp.377-383
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• 2007

The number of calling ports has been decreased and the degree of inter- and intra-port competition has been increased, which is caused by the market trends that shipping liners have and operate their own terminals, strategic M & A frequency occurs among shipping liners, and container vessel size is increasing. The trends also cause shipping liners to change the evaluation factors for decision to call a particular port such as port preference, potential for growth, port competitiveness, etc. Since the decision of liners greatly influences the policies for port and terminal development, it is worth having interest in the evaluation factors. Therefore, this work intended to evaluate 8 major ports (Port of Singapore, Hong Kong, Shanghai, Busan, Rotterdam, Kaoshing, and Tokyo) with regard to liners' evaluation factors (calling port preference, potential for growth and port competitiveness) and to classify ports by similarity of evaluation factors with the methodologies of ANOVA analysis and Duncan test. The result shows implication for liners' viewpoint to evaluate major ports in the world.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.3
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• pp.258-268
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• 2017

In this study, we aim to converge a technology for analyzing the hydraulic circuit of a loading arm with an- other one for analyzing multi-body dynamics by utilizing analysis software SimulationX. Further, this study intends to overcome the limitations of the existing technology for analyzing a hydraulic circuit with a variation at the rotation center of the moving mass and the difficulty of incorporating the behavior in a gravity field. First, the specifications of the hydraulic circuit components were reflected in an analysis model to secure reliability. Hydraulic circuit modeling was then performed using a single analysis model with a verified reliability. Subsequently, the multi-body system (MBS) model of the loading arm was formed. Finally, the analysis model of the hydraulic circuit and the MBS model were converged to check if the circuit analysis result was exactly reflected in the MBS model. The convergence analysis model has development cost-saving effect because it is capable of predicting the dynamic behavior of an object without the prototype.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.134-136
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• 2019

The International Maritime Organization (IMO) issued 2017 Guidelines on maritime cyber risk management. In accordance with IMO's maritime cyber risk management guidelines, each flag State is required to comply with the Safety Management System (SMS) of the International Safety Management Code (ISM) that the cyber risks should be integrated and managed before the first annual audit following January 1, 2021. In this paper, to identify cyber security management targets and risk factors in the maritime sector and to conduct vulnerability analysis, we catagorized the cyber security sector in management, technical and physical sector in maritime sector based on the industry guidelines and international standards proposed by IMO. In addition, the Risk Matrix was used to conduct a qualitative risk assessment according to risk factors by cyber security sector.