• 한국해양공학회지
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• 제29권1호
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• pp.9-15
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• 2015

We investigated the Reynolds number effects on the flow over a twisted offshore structure in the range of 3×10³≤ Re ≤ 1 × 10⁴. To analyze the effect of the twisted surface treatment, a large eddy simulation (LES) with a dynamic subgrid model was employed. A simulation of the cylindrical structure was also carried out to compare the results with those of the twisted offshore structure. As Re increased, the mean drag and lift coefficient of the twisted offshore structure increased with the same tendency as those of the cylindrical structure. However, the increases in the mean drag and lift coefficient of the twisted offshore structure were much smaller than those of the cylindrical structure. Furthermore, elongated shear layer and suppressed vortex shedding from the twisted offshore structure occurred compared to those of the cylindrical cylinder, resulting in a drag reduction and suppression of the vortex-induced vibration (VIV). In particular, the twisted offshore structure achieved a significant reduction of over 96% in VIV compared with that of the cylindrical structure, regardless of increasing Re. As a result, we concluded that the twisted offshore structure effectively controlled the flow structures with reductions in the drag and VIV compared with the cylindrical structure, irrespective of increasing Re.

• 한국산학기술학회논문지
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• 제18권5호
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• pp.302-307
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• 2017

북극해 지역은 해수면의 변화와 다양한 환경적 요인들로 인해 유빙들이 형성되고 이는 자원 개발을 위한 해양시스템 및 운항선박과의 충돌사고에 의한 피해를 유발하고 있다. 극지방의 유빙은 운항중인 석박뿐만 아니라 한 장소에서 오랜 기간 작업을 수행하는 해양자원 시추 및 생산 시스템에 대한 잠재적 사고요인이 된다. 유빙과의 충돌사고 방지를 위해 북극해의 해양자원 시추 및 생산 시스템과 북극 항로를 운항하는 선박에서는 위성 영상 정보 및 탐지 레이더를 이용하여 유빙을 탐지하고 있다. 하지만 가시광선 위성영상은 야간 활용이 불가능하고, 레이더에 의한 탐지도 소형 유빙에 대해서는 탐지확률이 현격히 저조해지는 문제가 있다. 본 연구에서는 유빙의 탐지를 위해 주야간 운용이 모두 가능한 열화상 시스템의 이용 방안에 주목하고 유빙의 탐지특성에 관한 실험적 연구를 수행하였다. 열화상 시스템의 야간 운용성을 파악할 수 있도록 실험조건을 설정하고 계측 각도 변화에 따른 열화상을 계측하였으며, 실험과 동일 조건에 대한 유빙과 해수의 복사에너지를 이론적으로 계한함으로써 계측 결과와의 상호 관계를 파악하였다.

• 정보과학회 논문지
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• 제42권7호
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• pp.840-845
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• 2015

최근 빅데이터는 전사적 자원관리 분야뿐만 아니라 해양플랜트내 생산 및 운영 작업 분야에서도 큰 관심을 받고 있다. 이력데이터를 기반으로 미래의 설비에 대한 성능을 예측하는 것은 설비들의 생산성을 향상 시킬 수 있다. 특히 해양플랜트의 주요설비 중 하나인 원심압축기는 고장 시 폭발 할 수 있는 위험한 설비이기 때문에 실시간으로 설비성능을 모니터링 해야 한다. 본 논문에서 원심압축기의 성능을 계산하기 위한 스트림 데이터 처리 구조를 제안한다. 제안하는 시스템은 크게 가상태그 스트림 생성기와 실시간 데이터 스트림 관리자와 같이 두 가지 컴포넌트로 구성된다. 시스템 성능 확장성을 제공하기 위해, 멀티 코어 CPU를 사용하여 대용량 스트림 데이터를 처리할 수 있는 병렬 프로그래밍 접근 방식을 이용하였다. 또한, 실험을 통해 원심압축기의 스트림 데이터 처리에 대한 성능 개선을 보여주었다.

• Strategy21
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• 통권37호
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• pp.193-241
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• 2015

China, Japan and Korea are the world's top 10 energy consumers, and so very interested in the development of seabed hydrocarbon resources in order to meet their energy demands. The East China Sea is the tri-junction area where three countries' entitlements on the maritime boundaries are overlapped. There are abundant oil reserves in the East China Sea, and therefore competitions among countries are growing to get control of them. Although these countries have concluded the bilateral agreements to jointly develop resources in the East China Sea, they do not function as well. Because joint development and management of seabed petroleum resources can lead to stable development system, and to lower possibility of legal and political disputes, the needs for joint development agreement among three countries are urgent. Meanwhile, Northeast Asian seas are semi-closed seas, which are geographically closed and vulnerable to marine pollution. Moreover there are a lot of nuclear power plants in coastal area, and seabed petroleum resources are being developed. So it is likely to occur nuclear and oil spill accidents. Fukushima nuclear disaster and Bohai Bay oil spill accident in 2011 are the cases to exhibit the potential of major marine pollution accidents in this area. It is anticipated that the risks become higher because power plants and offshore oil platforms are extending gradually. Therefore, the ways to seek the joint marine environmental protection agreement focused on regulation of nuclear power plant and offshore oil platform have to be considered. In this paper, we try to find the way to make joint development and joint environmental protection agreement in Northeast Asian seas. We concentrate on the measure to drive joint development of seabed petroleum deposits in East China Sea's overlap area, despite of maritime delimitation and territorial disputes, and we try to drive joint marine environmental protection system to respond to marine pollution and accidents due to offshore oil platform and nuclear power plants. Through these consideration, we seek solutions to deal with lack of energy, disputes of maritime territorial and boundary delimitation, and marine pollution in Northeast Asia.

• 한국해양공학회지
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• 제34권3호
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• pp.217-226
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• 2020

An offshore plant is an offshore platform that can process oil and gas resources in rough seas with a poor working environment. Moreover, it is a complex structure with different types of offshore facilities and a large amount of outfitting that connects different offshore installations. In particular, an enormous amount of various piping materials is installed in a relatively narrow space, and thus, the difficulty of working is relatively high compared to working in ships or ground plants. Generally, when the 3D detailed design is completed, an offshore plant piping process is carried out at the shipyard with ISO 2D fabrication drawings and ISO 2D installation drawings. If a worker wants to understand the three-dimensional piping composition in the working area, he can only use three-dimensional viewers that provide limited functionality. As offshore plant construction progresses, correlating work with predecessors becomes more complicated and rework occurs because of frequent design changes. This viewer function makes it difficult to identify the 3D piping structure of the urgently needed part. This study deals with the process support method based on a system using a 3D simulator to improve the efficiency of the piping process. The 3D simulator is based on the Unity3D engine and can be simulated by considering the classification and priority of 3D models by the piping process in the system. Further, it makes it possible to visualize progress information of the process. In addition, the punch content can be displayed on the 3D model after the pipe inspection. Finally, in supporting the data in relation to the piping process, it is considered that 3D-simulator-supported piping installing could improve the work efficiency by more than 99% compared to the existing method.

• Journal of Advanced Marine Engineering and Technology
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• 제41권1호
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• pp.91-98
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• 2017

본 논문에서는 해양 플랜트 수중 구조물의 감시 제어를 위한 수중 다중 센서 음향통신 기법에 대해 분석한다. 각 구조물의 상태 정보는 구조물에 부착된 센서를 통해 정보가 수중으로 전송되며, 여러 구조물의 정보를 동시에 전송 및 수신하는 최적의 기법을 제시한다. 다중 센서를 통해 동일한 주파수를 이용하여 간섭 없이 성능 열화를 감소시키는 대역확산기법을 이용하여 수중 통신 송수신단 구성을 제시하며, 수중에서의 다중 경로로 인한 성능 열화를 감소시키기 위한 RAKE 기반의 수신모델을 제시한다. 본 논문에서는 센서의 갯수를 세 개로 제한하고 센서의 개수에 따른 성능을 시뮬레이션을 통해 제안한 방식의 효율성을 증명하였다.

• 한국해양공학회지
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• 제28권6호
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• pp.533-539
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• 2014

A maintenance system for an offshore plant uses an optimal maintenance method, process, and period based on operation information data and economic evaluation techniques. Maintenance is performed after one or more indicators show that equipment is going to fail or that equipment performance is deteriorating. A maintenance system is based on the use of real-time data to prioritize and optimize the LNG-FPSO topside equipment resources.

• Structural Engineering and Mechanics
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• 제60권5호
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• pp.851-873
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• 2016

Helidecks are vital structures that act as a last exit in an emergency. They transport people and goods to and from ships and offshore plants. When designing the structure of a helideck, it is necessary to comply with loading conditions and design parameters specified in existing professional design standards and regulations. In the present study, finite element analysis (FEA) was conducted with regard to a steel helideck mounted on the upper deck of a ship considering the emergency landing of the helicopter. The superstructure and substructure were designed, and the influence of various design parameters was analyzed on the basis of the FEA results.

• 산업경영시스템학회지
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• 제46권spc호
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• pp.9-18
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• 2023

In the global manufacturing industry, digital transformation is emerging as an important issue for companies to improve productivity and strengthen industrial competitiveness. The government and shipbuilding companies drive research and development to attain advanced technologies through digital transformation for shipbuilding & offshore plants, one of Korea's representative manufacturing industries. Therefore, the digital transformation of the shipbuilding & offshore plant industry was defined using an input-output analysis model, and the economic interrelationships of industries linked to the digital transformation of the shipbuilding & offshore plant industry were analyzed. According to the analysis, the shipbuilding & offshore plant industry ranks second among all 34 industries regarding the forward linkage effect. The backward linkage effect was ranked 27th, making it a mid-demand industry with a robust forward linkage effect. In addition, the production-induced effect was 0.455, the value-added-induced effect was 0.174, and the employment-induced effect was 1.779 people per billion won. The contribution of this study is that it will provide the basis for establishing policies necessary to strengthen the competitiveness of the shipbuilding & offshore plant industry. Also, it will help analyze the economic effects of digital transformation in other manufacturing industries.

• 한국실내디자인학회논문집
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• 제20권4호
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• pp.201-210
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• 2011

This study is on the space planning of accommodation area in accommodation barge, which is a kind of offshore plant supply vessel providing workers with exclusive accommodation facilities. Firstly, the space layout of accommodation area is analyzed using the general arrangement drawings of 10 actually-built accommodation barges currently in use. Secondary, the design guides and standards for living quarters of offshore plants issued from overseas classification societies such as ABS, NORSOK etc. are analyzed and based on the analysis design guidelines for accommodation area of accommodation barge are newly suggested. Thirdly, a model of accommodation area in accommodation barge is set up and space arrangements and movement lines for each deck of the accommodation area of the model are planned. Fourthly, cabins, dinning room and galley, recreation spaces, and sanitary spaces of the accommodation area of the model are planned. The results of this study may be summarized as follows. An accommodation barge has 'barge deck' for small scale work and material storage, and 'accommodation area' for the living and resting of workers. The accommodation area is made of workers accommodation sector, service sector, crew sector and business sector. The interior design guidelines for accommodation area of accommodation barge should be made soon by Korea Register of Shipping.