• 한국해양공학회지
• /
• 제33권1호
• /
• pp.10-16
• /
• 2019

The aim of this study was to improve the vertical motion performance of floating marina structures and to optimize the shapes of the structures for the Korea coastal environment. The floating body is connected to a plate-shaped submerged body through a connecting line under the water that has a stiff spring that serves to reduce the heave response. This system, which has two degrees of freedom, was modelled to analyze the interaction between the floating body and the submerged body. The vertical motion of the two-body system was compared with the motion of a single body to verify that the system could perform as an optimized model.

• International Journal of Ocean System Engineering
• /
• 제4권1호
• /
• pp.43-48
• /
• 2014

Varying bathymetry significantly affects on the wave propagation and motion response of floating body. Coupled-mode wave theory is adopted to describe the incident wave properly in varying region. The results of waves and motion response are compared to those from numerical wave tank, and the agreement is favorable. The sloped bottom is modeled and its effect on the floating body is discussed.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제6권1호
• /
• pp.1-13
• /
• 2014

A new 5-MW floating offshore wind turbine moored by a spring-tensioned-leg was proposed for installation in about 50m water depth. Its substructure is a platform of the inverted conical cylinder type with massive ballast weight plate at the bottom. A 1:128 scale model was built for the preliminary engineering development. The model tests in waves and wind were carried out to estimate motion characteristics of this platform in the Ocean Engineering Wide Tank of the University of Ulsan. Its motions were measured and the RAOs were compared. The proposed floating offshore wind turbine showed a good stability and decent responses in waves, wind and operation of the wind turbine.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제6권2호
• /
• pp.307-322
• /
• 2014

With the rate of worldwide LNG demand expected to grow faster than that of gas demand, most major oil companies are currently investing their resources to develop floating LNG-FLNG (i.e. LNG FSRU and LNG FPSO). The global Floating LNG (FLNG) market trend will be reviewed based on demand and supply chain relationships. Typical technical issues associated with FLNG design are categorized in terms of global performance evaluation. Although many proven technologies developed through LNG carrier and oil FPSO projects are available for FLNG design, we are still faced with several technical challenges to clear for successful FLNG projects. In this study, some of the challenges encountered during development of the floating LNG facility (i.e. LNG FPSO and FSRU) will be reviewed together with their investigated solution. At the same time, research of new LNG-related technologies such as combined containment system will be presented.

• 한국항해항만학회지
• /
• 제39권4호
• /
• pp.329-334
• /
• 2015

최근 국내 대표적인 플로팅건축물인 세빛섬의 운영 정상화로 플로팅건축물에 대한 이미지가 매우 긍정적인 방향으로 개선되었다. 플로팅건축의 특장점은 특별한 공간체험(29.9%) > 랜드마크(27.6%) > 수해양문화 향유(21.5%) > 관광 및 개발의 거점(16.0%) > 지구온난화에 대비하는 친환경성(4.8%) 순으로 나타났다. 플로팅건축물은 일반인들에게 특별한 공간체험을 제공하며 차별화된 이미지를 가지고 있다. 따라서 플로팅건축물의 공간디자인마케팅은 특별한 공간을 매개로 지자체나 기업이 주민이나 고객들과 아이덴티티와 이미지를 교환하는 형태로 일어난다. 이때, 건축물이 지닌 기본적인 공간 속성에 방문객들의 공간수요를 반영한 프로그램 선정과 사업주체 및 운영주체의 일원화가 중요하다. 플로팅건축의 프로그램은 상업시설이나 문화시설, 친수공간 확보 조건을 활용한 마리나시설이 적절하며, 향후 플로팅건축 시장도 활성화될 것으로 전망된다.

• 한국환경복원기술학회지
• /
• 제4권2호
• /
• pp.84-91
• /
• 2001

This study was carried out to develop the technology of artificial floating island for the wild-life habitat at the reservoir of Korea University farm near Seoul. After the execution of an artificial floating island with 6 cells(each $3{\times}3m$), each cell was planted with 5 different species and one mixed of them, to the reservoir in 1999 through 2000. The monitored results were as follows; 1. Typha orientalis, Zizania latifolia and Oenanthe japonica were died back, but Phragmites communis, Phragmites japonica and Juncus effusus var. decipiens were well growing. 2. The limits of sinking water depth of the planting foundation were different with the plant species, that is, 40cm to the Juncus effusus var. dicipiens and 50cm to Phragmites communis. Accordingly the water depth should be kept differently with each species. 3. 33 species of fauna were monitored in the first year(1999) and 43 species in the second (2000) increasingly. 4. For the more wild-lives inducing to the artificial floating island, establishing the eco-corridor from the surrounding environment was needed.

• 한국소음진동공학회논문집
• /
• 제24권5호
• /
• pp.390-398
• /
• 2014

Heavy-weight floor impact noise is directly related to the impact source and floor vibration property. Dynamic properties of the standard floating floor that is used in Korea was investigated using accelerance, acceleration energy spectral density(ESD), and structural modal test. In the standard floating floor, natural frequency was decreased by the finishing mortar mass and the damping ratio was increased. Bang-machine force spectrum acting on the concrete slab can be calculated using inverse system analysis. Impact force acting on concrete slab is changed by interaction of finishing mortar and resilient material. The amplitude of the bang-machine force spectrum was amplified in low frequency range(below 100 Hz), and over 100 Hz was decreased. Changed force spectrum influence to the response of structure vibration, so the heavy-weight floor impact noise level was changed.

• 대한조선학회논문집
• /
• 제52권1호
• /
• pp.77-87
• /
• 2015

For a floating offshore plant such as FPSO(Floating, Production, Storage, and Off-loading unit), various equipment should be installed in the restricted space, as compared with an onshore plant. The requirement for an optimal layout method of the plant has been increased in these days. Thus, a layout method of the floating offshore plant was proposed in this study. For this, an optimization problem for layout design was mathematically formulated, and then an optimization algorithm based on the genetic algorithm was implemented with C++ language in order to solve it. Finally, the proposed method was applied to an example of FPSO topsides. As a result, it was shown that the proposed method can be applied to layout design of the floating offshore plant such as FPSO.

• 한국CDE학회논문집
• /
• 제19권1호
• /
• pp.1-11
• /
• 2014

In the initial design stage, the technology for estimating and managing the weight of a floating offshore structure, such as a FPSO (Floating, Production, Storage, and Off-loading unit) and an offshore wind turbine, has a close relationship with the basic performance and the price of the structure. In this study, using the genetic programming (GP), being used a lot in the approximate estimating model and etc., the weight estimation model of the floating offshore structure was studied. For this purpose, various data for estimating the weight of the floating offshore structure were collected through the literature survey, and then the genetic programming method for developing the weight estimation model was studied and implemented. Finally, to examine the applicability of the developed model, it was applied to examples of the weight estimation of a FPSO topsides and an offshore wind turbine. As a result, it was shown that the developed model can be applied the weight estimation process of the floating offshore structure at the early design stage.

• 한국CDE학회논문집
• /
• 제18권6호
• /
• pp.439-450
• /
• 2013

In the case of a floating offshore structure such as FPSO(Floating, Production, Storage, and Offloading unit), many equipment should be installed in the limited space, as compared with an onshore structure. Recently, the requirement for an optimal layout method of the structure has been raised. Thus, a layout method of the floating offshore structure was proposed in this study. First, an optimization problem for layout design was mathematically formulated, and then an optimization algorithm was implemented based on the genetic algorithm in order to solve it. To evaluate the applicability of the proposed method, it was applied to examples ofFPSO topsides and an offshore wind turbine. As a result, it was shown that the proposed method can be applied to layout design of the floating offshore structure.