• 한국해양공학회지
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• 제31권6호
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• pp.425-430
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• 2017

In order to reduce the cost of corrections and time needed for the block assembly process, the reverse setting method is applied for a back-heated block to neutralize deck deformation. The proper reverse setting shape for a back-heated block to correct deformation improved the deck flatness, but an excessive amount of reverse setting could inversely affect the flatness of the block. A prediction method was developed for the proper reverse setting shape using a back-heated block, considering the complex geometry of blocks, thickness of the deck plate, and thermal loading conditions such as welding and back-heating. The prediction method was developed by combining the re-meshing technique and inherent strain-based deformation analysis using the finite element method. Because the flatness deviation was decreased until the lower critical point and thereafter it tended to increase again, the optimum value for which the flatness was the best case was selected by repeatedly calculating the predefined reverse setting values. Based on this analysis and the study of the back-heating deformation of large assembly blocks, including the reverse setting shape, the mechanism for selecting the optimum reverse setting value was identified. The developed method was applied to the actual blocks of a ship, and it was confirmed that the flatness of the block was improved. It is concluded that the developed prediction method can be used to predict the optimum reverse setting shape value of a ship's block, which will reduce the cost of corrections in the construction stage.

• 산업기술연구
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• 제19권
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• pp.91-99
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• 1999

The dock is the most important resource in shipbuilding yard. Among the shipbuilding schedules, the ship erection schedule in a dock is preferentially built. As results of it, the other schedules(machining in plants, block assembly, pre-painting, pre-rigging, painting and etc) are made. In this study, ship erection scheduling is formulated using ILOG Scheduler. This study is to develop a new problem solving method for ship erection to make an effective schedule based on Constraint Satisfaction Technique(CST).

• 경영과학
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• 제23권2호
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• pp.175-185
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• 2006

How to efficiently manage assembly blocks at shipyard has been a hot management issue in the shipbuilding Industry, because it has significantly influenced on the productivity of shipbuilding process. This paper introduces the real practice of assembly block operations management in Hyundai Heavy Industries (HHI) and the Ship Assembly Block Operations Optimization (SABOO) project that h3s been launched in HHI as an academy-and-industry collaborative project, aimed to diagnose problems, propose possible solutions, and develop a prototype system in order to search ways of improving the assembly block operations management. Through the field interviews, observations, and benchmarking studies, the SABOO project diagnosed the most rudimental and urgent problem and proposed possible solutions. In addition, the SABOO project developed the prototype system that embodied the visual function of monitoring the shipyard on a real-time and the Interactive block assignment function that utilized the assembly block assignment algorithm developed by the project. As a whole, the SABOO project tested the possibility and gained an insight in extending the functions of block transportation/stockyard management system.

• 한국CDE학회논문집
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• 제16권3호
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• pp.207-215
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• 2011

Due to its large size, a ship is first divided into scores of blocks and then each block is constructed through various shops, such as the assembly shop, the painting shop, and the outfitting shop. However, each block may not be directly moved to the next shop and may be temporarily laid on a block stockyard because the working time in each shop is different. If blocks are laid on the block stockyard without any planning, the rearrangement of the blocks by a transporter are required because the blocks have the different in and out time. In this study, an optimal layout method based on the genetic algorithm was proposed in order to minimize the rearrangement of the blocks in the block stockyard. To evaluate the applicability of the proposed method, it was applied to a simple layout problem of the block stockyard.

• 전자공학회논문지CI
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• 제47권6호
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• pp.40-46
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• 2010

조선소에서 트랜스포터와 블록의 정확한 위치를 파악하는 일은 선박건조 생산 능력을 증가시키는 요소이지만, 현재는 관리자 및 숙련공의 판단에 의해 작업이 진행되고 있는 실정이다. 본 논문에서는 조선소의 주요 이동객체인 트랜스포터 및 블록에 대한 실시간 위치 추적 시스템 구축에 대해 소개하고 그 시스템의 주요 기능 가운데 하나인 블록의 상차/하차 상태를 판단하는 방법을 제안하였다. 이 기능을 구현하기 위해 세 가지 센서가 사용되었다. 첫 번째는 대상 블록을 인식하기 위한 RFID 리더이고, 두 번째는 바닥에 매설된 태그를 인식하여 트랜스포터의 위치를 추적하기 위한 RFID 리더이며 또 하나는 물체 인식을 위한 초음파센서이다. 이를 이용하여 조선소 현장에서 두 차례에 걸쳐 시험이 실시되었고 1차 실험에서 나타난 오류를 수정한 후, 최종실험에서는 현장에 적용 가능한 결과를 얻을 수 있음을 확인하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.49-52
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• 2008

최근 지구 온난화 현상에 따른 해수면 상승으로 삼면이 바다에 접한 우리나라는 향 후 많은 피해가 예측되므로 이에 따른 방호개념으로 기존의 단조로운 형상과 비 자연친화형 콘크리트 구조물의 설치 및 연안침식방지 기능부재로 인한 또 다른 피해가 발생된다. 국민소득의 증대와 Waterfront 개념의 빠른 확산으로 연안 어항의 낙후된 시설개선 등에 많은 사업이 추진되고 있으나 이러한 용도에 맞는 자연 친화형 구조물이 개발된 바 없어 기존의 Solid Block, Igloo Block, Tunnel Block 등이 일부 현장에 적용되고 있는 실정이다. 선박이 계류하는 안벽이나 물양장 등에서 항내 진입파와 항파 등으로 인한 반사파의 발생에 의한 공진현상으로 항내파고가 높아져 정온도유지가 어렵고 선박의 계류 및 하역에 지장을 주게 되며, 선박과의 충돌 발생으로 인한 소형선박의 손괴 발생율이 높은 실정이므로 새로운 형태의 블록(Block)개발이 필요하다. 이에 따라 개발한 C.E(Coastal Environments)블록을 현장에서 사용하기 위해서는 전단키 부분의 내하력 평가가 요구 된다. 따라서, 본 연구는 C.E 블록의 연결부 시험편을 제작하여 C.E블록 경계면의 마찰실험을 실시하였으며, C.E블록 연결부의 마찰계수를 측정하여 분석한 다음 C.E블록의 연결부 마찰계수를 평가하고자 한다.

• 수산해양기술연구
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• 제41권2호
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• pp.156-164
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• 2005

The size of the ship's turning circle is influenced by various factors, such as block coefficient, underwater side shape, rudder area ratio, draft, trim and Froude's number. Most of them are already fixed on departure from a port. However, the ship's speed and the rudder angle are controllable factors which operations are able to change optionally during sailing. The DGPS measured the turning circles according to the ship's speed and the rudder angle. The maximum advances by slow and full ahead were 302m and 311m, and the maximum transfers were 460m and 452m, respectively. There occurs almost no difference in size of the turning circle by variation of the ship's speeds. When the rudder angles were changed to $10^{\circ}$, $20^{\circ}$ and $30^{\circ}$, the maximum advances were 447m, 271m and 202m, and then also the maximum transfers 657m, 426m and 285m, respectively. The diameter of the tuning circle was decreased exponentially when the rudder angle was increased. The maneuverability was better when the direction of turning and propulsion of propeller are in the opposite direction rather than in the same one togetherm. The distance of the maximum transfer was always bigger than that of the maximum advance.

• 한국항해학회지
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• 제18권4호
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• pp.49-57
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• 1994

In marine transportation of bulk cargoes such as crude oil. ore, coal etc., a lot of full form ship which have poor manoeuvrability were presented in many countries. Since ship manoeuvrability depends upon many parameters namely hydrodynamic derivatives, interference factors etc., as external forces, it is of great importance that we investigate these values of parameters on analysis of manoeuvrability. In this paper, we investigated and analyzed interaction coefficients among hull-propeller-rudder for a full form ship by captive model test in circulating water channel, and then compared with experimental results by PMM test. A tanker model ship which has 0.83 as block coefficient and MMG mathematical models were used in this experiment. Almost same tendencies were found in qualitative analysis, even though more serial experiments were demanded in quantitative analysis.

• Journal of Ship and Ocean Technology
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• 제10권2호
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• pp.11-23
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• 2006

The model exchange from CAD system to CAE system in valid and effective manner is the major issue of automatic analysis modelling of ship structure. However, model exchange approaches based on the neutral CAD file have resulted in invalid model exchange that could not properly reflect the characteristics of CAD model and CAE model of ship structure. This paper presents the new approach of n-to-n mapping to exchange ship structure model in heterogeneous CAD/CAE environments. In this study, the common model called 'unified ship model for analysis' to directly extract proper information from different CAD systems for ship structural analysis is proposed. Moreover, a command language based model interfacing technique to construct an idealized model for analysis job is also proposed. The proposed approach has been actually implemented in DSME CAD/CAE environment of ship structure such as TRIBON system, PATRAN system and FLUENT system. The applicability and effectiveness of the proposed approach was verified by applying it to the real analysis project for fore-body of ship and block lifting. This application results show that the proposed approach can be effectively used for heterogeneous CAD/CAE environment.

• 대한조선학회지
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• 제13권1호
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• pp.11-16
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• 1976

The effect of the bow shape on the ship motion response in longitudinal regular waves of water of finite depth is investigated by employing the strip theory. The two-dimensional hydrodynamic forces(added mass and damping) were calculated by close-fit method for water of finite depth. The models for investigation are U and V bow ship forms of block coefficient 0.8 with constant after body which were used by Yourkov [2] and recently by Kim [3] for their deep water investigations. The following results are obtained by the present numerical experiments. (1) It is confirmed that the damping coefficient of the V-bow ship is greater than that of U-bow ship and in consquence the amplitude of heave and pitch of V-bow ship is smaller than that of U-bow ship among longitudinal regular head waves in water of finite depth (2) The merit of the V-bow ship on the motion damping is more significant in heave than in pitch, and is decreasing with the shallowness of water depth. (3) The change of bow form gives little effect on the wave exciting force and moment compared with the motion responce.