• Wind and Structures
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• 제21권6호
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• pp.597-607
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• 2015

With an increasing demand of a renewable energy, new offshore wind turbine farms are being planned in some parts of the world. Foundation installation asks a significant cost of the total budget of offshore wind turbine (OWT) projects. Hence, a cost reduction from foundation parts is a key element when a cost-efficient designing of OWT budget. Mono-piles have been largely used, accounting about 78% of existing OWT foundations, because they are considered as a most economical alternative with a relatively shallow-water, less than 30 m of seawater depth. OWT design standards such as IEC, GL, DNV, API, and Eurocode are being developed in a form of reliability based limit state design method. In this paper, reliability analysis using the response surface method (RSM) and numerical simulation technique for an OWT mono-pile foundation were performed to investigate the sensitivities of mono-pile design parameters, and to find practical implications of RSM reliability analysis.

• 토지주택연구
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• 제11권2호
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• pp.87-94
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• 2020

Offshore renewable energy resources are attractive alternatives in addressing the nation's clean energy policies because of the high demand for electricity in the coastal region. As a large portion of potential resources is in deep and farther water, economically competitive floating systems have been developed. Despite the advancement of floating technologies, the high capital cost remains a primary barrier to go ahead offshore renewable energy projects. The dynamically installed piles (DIPs) have been considered one of the most economical pile concepts due to their simple installation method, resulting in cost and time-saving. Nevertheless, applications to real fields are limited because of uncertainties and underestimated load capacity. Thus, this study suggests the appropriate analytical approach to estimate the inclined load capacity of the DIPs by using the upper bound plastic limit analysis (PLA) method. The validity of the PLA under several conditions is demonstrated through comparison to the finite element (FE) method. The PLA was performed to understand how flukes, soil profiles, and load inclinations can affect the inclined load capacity and to provide reliable evaluations of the total resistance of the DIPs. The studies show that PLA can be a useful framework for evaluating the inclined load capacity of the DIPs under undrained conditions.

• International Journal of Computer Science & Network Security
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• 제22권3호
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• pp.229-235
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• 2022

The process of correcting, upgrading, and improving software products after they have been handed over to the consumer is known as software maintenance. Offshore software maintenance outsourcing (OSMO) clients benefit from cost savings, time savings, and improved quality software through OSMO. In most circumstances, the OSMO vendor makes a lot of money but not in all the cases. Especially, when the OSMO project offer is not properly assessed. An efficient outsourcing contract might yield successful outcomes for outsourced projects. But before sending a detailed proposal to bid on the OSMO project the vendor must have to assess the client's project (business offer) requirements. The purpose of this study is to find out common trends within the assessment of a OSMO project. A case study approach along with semi-structured interviews from eight companies concluded ten common practices and several roles. Among these practices, four (code structure, requirements, communication barriers and required infrastructure) were consistent amongst the responses .The findings, limitations and future work are discussed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.170-173
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• 2006

The remote sensing is powerful oceanographic tools not only for Integrated Coastal Zone Management (ICZM) but also for various areas of oceanography. Thank to effort of Government and local authorities as well as active support of international institutions, many projects on the applied oceanography had and have been caring out in coastal and offshore waters of Vietnam sea. One of the modern methods which has been used in these project is ocean color remote sensing technique. This paper will present some preliminary results obtain from application of these techniques in study of coastal and offshore environment of Vietnam sea.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.249-251
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• 2011

International energy agency(IEA) consisted of OECD countries deals with international energy problems. IEA/Wind ExCo is an execution committee under IEA for the implementing agreement for co-operation in the research, development and deployment of wind energy systems. Currently 22 countries participate the committee and 11 research tasks are in progress. 11 tasks are base technology information exchange, wind energy in cold climates, offshore wind energy technology deployment, integration of wind and hydropower systems, power systems with large amounts of wind power, cost of wind energy, labelling small wind turbines, social acceptance of wind energy projects, MexNext aerodynamics and comparison of dynamic computer codes and models, offshore wind energy and wakebench. At the presentation, activities of major wind energy countries and IEA/Wind ExCo and research tasks are introduced.

• 한국해양환경ㆍ에너지학회지
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• 제16권4호
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• pp.276-289
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• 2013

해상풍력발전 단지를 개발함에 있어 전력수급과 경제성 논리에만 초점이 맞춰짐으로써 여러 가지 환경적 문제들이 발생하고 있으며, 이에 따른 지역사회의 갈등이 유발되고 있는 실정이다. 특히 최근에 국내 해역의 풍황과 해황 조건 등을 중심으로 해상풍력에 대한 입지와 개발량에 대한 연구가 이루어져 왔으나, 해양환경 및 해양생태계에 미치는 영향에 대한 연구는 매우 부족하다. 유럽의 해상풍력발전 선진국에서는 개발 사업에 뒤따르는 환경 모니터링이 활발히 진행되고 있는 데 비해, 국내에서는 해상풍력을 설치하고 운영할 때에 발생할 수 있는 환경적 영향에 관한 모니터링 자료가 전무하다. 따라서 본 연구에서는 국외 해상풍력의 모니터링 사례 및 참고문헌의 사례를 분석함으로써 공사 시와 운영 시의 환경적 영향과 국내 해역에 적합한 환경영향평가 단계에서의 가이드라인을 제시하였다. 이에 따라 궁극적으로는 해상풍력개발에 따른 환경영향을 최소화하고 환경영향평가의 행정절차에 소요되는 협의기간을 단축시키는 데에 목적이 있다.

• 한국항해항만학회지
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• 제45권3호
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• pp.130-137
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• 2021

본 연구의 목적은 울산 부유식 해상풍력발전단지를 대상으로 서식지 등가성 분석법(Habitat Equivalency Analysis : HEA)을 적용한 가치평가를 통해 해당 해양공간 특성평가를 위한 객관적인 평가기준 제시에 있다. 울산 부유식 해상풍력발전단지 설립으로 인해 사용이 금지된 해역(5,017.6ha)에서는 상업적 피해, 생태계 파괴 등 여러 피해가 발생한다. 피해의 경제적 가치 규모 산정을 위한 대체 복원사업을 인공어초사업으로 선정하고 이를 HEA로 추정하였다. 추정 결과, 사회적 할인율 4.5%, 4년째부터 성숙도 100%를 기본 가정으로 한 경우 피해액은 약 457억원으로 나타났다. 본 연구에 사용된 HEA는 객관적이고 명확한 DATA를 기본으로 가치를 산정하기 때문에 해양공간 특성평가 시 발생할 수 있는 불합리성을 해결할 수 있을 것이다. 따라서, 본 연구의 결과는 향후, 해양공간계획의 시행에서 발생 가능한 이해관계자들 간의 갈등 해소에 도움이 될 것이다.

• 가스산업과 기술
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• 제5권1호
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• pp.39-47
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• 2002

With the expansion of natural gas demands in many countries, the necessity of LNG receiving terminals has been increased. The offshore LNG Floating Storage and Regasification Unit (FSRU) attracts attentions not only for a land based LNG receiving terminal alternative, but also for a feasible and economic solution. Nowadays, as the reliability of offshore oil and gas floating facilities and LNG carriers gains with proven worldwide operations, the FSRU can achieve a safety level that can be comparable to an onshore terminal. The design development related with safety features of the FSRU has been extensively carried out by oil and gas companies, shipyards, engineering companies, and equipment vendors, and has been successful so far in many fields. The construction of the FSRU can be achieved by integrating various technologies and experiences from many disciplines and many participating companies and vendors. In this paper, reviews on some of the important design features and design improvements on FSRU together with the practical construction aspects in cargo containment, vaporization system, ESD system, and operation modes, have been covered in comparison with actual LNG carrier, onshore receiving terminal, and FPSO systems. In order to materialize an FSRU project, the technical and economic justification has to be preceded. It is believed that once the safety and technical soundness is convinced, the FSRU can bring a higher project feasibility by reducing the overall construction time and cost. Through this study, an FSRU design readily applicable to an actual project has been developed by incorporating experiences gained from many marine and offshore projects. The wide use of proven standard technologies adopted in the series construction of LNG carriers and offshore FPSOs will bring the project efficiency and reliability.

• 해양환경안전학회지
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• 제29권2호
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• pp.127-138
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• 2023

국제사회는 글로벌 기후위기 극복을 위해 2050년까지 탄소중립(Net Zero)을 목표로 다양한 탈탄소 에너지원 개발을 지속하고 있다. 우리 정부에서도 '재생에너지 3020' 정책을 수립하고 태양광이나 풍력을 이용한 에너지 개발계획을 추진함에 따라 해상 풍력발전단지와 같이 연안해역에서 기존에는 볼 수 없었던 대규모 해양개발사업이 추진되고 있다. 해양시설물은 선박의 입장에서 볼 때는 항행 장애물의 일종이며, 해양시설물 설치에 따라 좁아진 수역에서 선박 간 충돌사고 발생 또는 선박과 해양시설물의 접촉사고 발생시 환경오염 및 인명피해 등의 발생이 우려된다. 이에 국내외의 해상풍력발전단지 개발계획을 살펴보고 풍력단지에서 선박의 안전한 통항을 보장하기 위한 제도적 장치가 완비되어 있는지 분석하였으며, 해외의 입법 사례와 국내 법규를 비교하여 법적 사각지대를 해소하기 위한 새로운 법령안을 제안함으로써 대한민국의 관할해역에서 해양시설물의 안전한 운영과 선박의 안전한 통항을 기대하였다.

• 한국해양공학회지
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• 제31권6호
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• pp.379-387
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• 2017

In this study, a pile-guide mooring system (PGMS) was designed for an offshore liquefied natural gas bunkering terminal (LNG-BT), which is an essential infrastructure for large LNG-fuelled ships. The PGMS consisted of guide piles to restrict five motions of the floater, except for heave, as well as a seabed truss structure to support the guide piles and foundation piles to fix the system to the seabed. Singapore port was considered for a case study because it is a highly probable ports for LNG bunkering projects. The wave height, current speed, and wind speed in Singapore port were investigated to calculate the environmental loads acting on the hull and PGMS. A load and resistance factor approach was used for the structural design, and a finite element analysis was performed for design verification. The steel usage of the PGMS was analyzed and compared with the material usage of a gravity-based structure under similar LNG capacity and water depth criteria. This paper also describes the water depth limit and wave conditions of the PGMS based on estimation of the initial investment and the present value profit difference. It suggests a suitable LNG-BT support system for various design conditions.