• Proceedings of the CALSEC Conference
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• 1999.11a
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• pp.309-318
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• 1999

조선에서 하나의 선박은 유사한 크기를 가진 수백개의 블럭들로 구성된다. 각 블록은 평블럭과 곡블럭의 두가지 유형으로 분류되며 평블럭은 평블럭 조립공장에서, 곡블럭은 곡블럭 조립공장에서 각각 조립된다. 본 연구에서는 이중 곡블럭 조립공장의 작업일정계획 문제를 대상으로 하고 있다. (중략)

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.38-39
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• 2010

최근들어 항만건설 및 선박블록 운송의 증가로 대형 부선을 예인하는 예부선과 침몰 선박 인양 및 해상교량공사 등을 위한 해상크레인 운송선단의 통항이 매년 증가 추세에 있다. 우리나라에서 이들 선박의 주 항로는 남해와 서해 연안으로, 이 지역은 도서가 산재해 있고 협수로가 많은 지형적 특성과 연안으로 근접하여 항해 시 강한 조류의 영향을 받으며, 또한 어망과 조업중인 어선들과 많이 조우하게 된다. 특히, 돌발적인 해양 기상적 특징을 포함하고 있다. 이러한 영향에 따라서 이 해역을 통항하는 예부선 및 해상크레인 선단의 조종성능이 크게 저하되어 해양사고의 위험성이 고조되고 있다. 이에 따라서, 이 연구에서는 해상크레인의 연안해역 예항시 안전하게 항해할 수 있는 적절한 조종 방법을 고찰하여 안전운항에 기여하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.359-367
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• 2005

In order to increase the productivity of container terminals, automation is being considered seriously in nowadays. A yard is usually automated by running autumated RMGs (rail mounted gantries) which may require somewhat a different stacking strategy to archive a better performance. In this paper, we present a simulation model for RMGs and summarize experimental results with two different stacking strategies applied to a horizontal block which has two non-crossable RMGs. The concentrating strategy, which stacks containers belong to a single ship together and dedicateds each RMG to either ship services or external truck services, showed a good performance in ship unloading. In the contrast, the distributing strategy, which partitions a block into two regions and binds each RMG to one of the regions to improve the productivity of ship services by running each RMG alternately, is suggested for blocks of exporting.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.552-560
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• 2013

In this paper, an optimization algorithm for the block assembly accuracy control assessment is proposed with consideration for the current block assembly process and accuracy control procedure used in the shipbuilding site. The objective function of the proposed algorithm consists of root mean square error of the distances between design and measured data of the other control points with respect to a specific point of the whole control points. The control points are divided into two groups: points on the control line and the other points. The grouped data are used as criteria for determining the combination of 6 degrees of freedom in the registration process when constituting constraints and calculating objective function. The optimization algorithm is developed by using combination of the sampling method and the point to point relation based modified ICP algorithm which has an allowable error check procedure that makes sure that error between design and measured point is under allowable error. According to the results from the application of the proposed algorithm with the design and measured data of two blocks data which are verified and validated by an expert in the shipbuilding site, it implies that the choice of whole control points as target points for the accuracy calculation shows better results than that of the control points on the control line as target points for the accuracy of the calculation and the best optimized result can be acquired from the accuracy calculation with a fixed point on the control line as the reference point of the registration.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.2
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• pp.127-136
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• 2000

Welding deformations reduce the accuracy of ship hull blocks and decrease the productivity due to correction work. Preparing an error-minimizing guide at the design stage will lead to a high quality as well as high productivity. And a precise method to predict the weld deformation is an essential part of it. This paper proposes an efficient method to predict complicated weld deformations based on the inherent strain theory combined with the finite element method. The inherent strain is determined by the highest temperature and the degree of restraint. In order to calculate the inherent strain exactly, it is considered that the degree of restraint becomes different according to the fabrication stages in real structures. A simulation of a stiffened plate shows the applicability of this method to simple ship hull blocks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.4
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• pp.556-561
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• 2022

In this paper, we present a block media communication (BMC) system which employs powerline communication to the equipments used in the welding process for ship-assembly and uses metal block as a communication medium. Inductive couplers are installed on digital feeder and pin jig. Information signal is added to the current generated by the welding gun, and applied to the block. When the welding operation starts, information generated in the field is transmitted to the monitoring server in real-time. The field test on the BMC system confirms that the transmitted data are correctly received at the server. Since the proposed system can be built without any changes to the existing welding process, it is helpful to increase competitiveness of the shipbuilding industry through smart factory of shipyards. It is also possible to quickly respond to emergency situations that may occur to workers in an electromagnetic wave shielding environment or a closed space, the effect of preventing industrial accidents will be great.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.1
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• pp.86-98
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• 2001

Due to the rapid growth of ship building industry and the increment of ship construction in Korea, several hundred thousand of lifting lugs per year, have been installed at the lifting positions of ship block and removed after finishing their function, therefore. appropriate design system for the strength check or the optimal design of each lug structure has been required in order to increase the capability of efficient design. In this study, the design system of D-type lifting lug structure which is most popular and useful in shipyards, was developed for the purpose of initial design of lug structure. Developed system layout and graphic user interface for this design system based on the $C^{++}$ language were explained step by step. Through the illustration of one example of D-type lug designs, the efficiency of this design system was proved. Therefore, more efficient performance of practical lug structural design will be expected on the windows of personal computer using this design system.

• Journal of Navigation and Port Research
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• v.38 no.4
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• pp.335-341
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• 2014

Faced with global agenda of greenhouse abatement program including regulations and $CO_2$ emission trading scheme, shipping companies are enforced to a high level of efficiency in fuel consumption. Accordingly shipbuilding companies worldwide are required to develop fuel-efficient ships which otherwise traditionally consume a great amount of fossil fuels. In this dissertation, relevant to the improvement of fuel efficiency for commercial ships, design methodology through the numerical simulations are intensively described. This work consists of derivation of effective hydrodynamic design practice based on the application of longitudinal grooves to effectively improve the pressure distribution around ship hull. The primary objective of the present study is to improve ship resistance performance using longitudinal grooves which originate from long strips on the abdomen of humpback whale. Several groove shapes have been extensively investigated and the proposed shape efficiently controlled the variation of pressure distributions acting on the hull surface.

• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.107-117
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• 2019

Because shipbuilding is single-product production with limited resources, production management technology is essential to manage the resources effectively and maximize the productivity of ship-process. Therefore, many shipbuilding companies are conducting research on ship production plan and process considering various constraints in the field by applying modeling and simulation. However, it is difficult to provide accurate production plan on sudden schedule and process changes, and to understand the interconnectivity between the processes that produce blocks in existing research. In addition, there are many differences between the production planning and field planning because detailed processes and quantity of blocks can not be considered. In this research, we propose the integrated process-based modeling method considering process-operation sequences, BOM(Bill of materials) and resource constraints of all the scheduled blocks in the indoor system. Through the integrated process-based model, it is easy for the user to grasp the assembly relationship, workspace and preliminary relationship of assembly process between the blocks in indoor system. Also, it is possible to obtain the overall production plan that maximizes resource efficiency without the separate simulation and resource modeling procedures because resource balancing that considers the amount of resource quantity shared in the indoor system is carried out.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.843-848
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• 2013

As the LNG demands are growing, the constructions of LNG FPSO (Floating Production Storage and Off-loading) and LNG carriers have been constantly increased, and the various design of storage tank has been tried. This paper propose that the material of inner storage tanks is made of 5~9% Ni steel plate and perlite powder insulation instead of urethane foam block. It needs essentially to obtain the proper design specifications that are the pressure of perlite, the characteristics of resilient blanket as the pressure absorber, optimum thickness of blanket and design pressure of tank wall, etc. to enable the perlite insulation system to LNG carrier, The results show that the design thickness of blanket should be between 1/4 to 1/3 of insulation width and the optimum rate becomes 30%, and the design pressure be applied below 1,500 Pa with blanket thickness.