• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.212-213
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• 2018

청항선은 해상 부유물을 수거하는 배로서 청소과정에서 특성상 해상부유물로 인한 선체손상 또는 프로펠러 유입으로 사고의 위험이 있다. 따라서, 건조 시 이를 고려한 설계를 하거나 반영하여야 한다. 그러나 모형시험에서 구현의 문제와 많은 Case로 인해 시간과 비용에 많은 어려움이 있다. 따라서, 이를 예측하기 위해 최근 발전하고 있는 수치해석을 통해 해상 부유물을 구현하였다. 그 후 속도에 따라 부유물을 흘려 프로펠러 주변 유입여부를 확인하였다.

• Journal of Korea Ship Safrty Technology Authority
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• no.7 s.25
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• pp.4-20
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• 2008

부유식 해상구조물은 사용형태나 환경특성이 해상을 항해하는 선박과 차이가 있으므로 선박에 적용되는 검사 및 시설기준을 그대로 적용하기에는 무리가 있으며, 따라서 이동식 시추선과 수상 호텔, 수상식당 등 부유식 해상구조물 실태를 조사 하고, 부유식 해상구조물의 IMO의 MODU Code 등 국내외 시설기준과 이동식시추선 관련 국제기준의 국내 수용방안을 비교 검토하여 국내 실정에 적합한 시설기준을 제안하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.51-56
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• 2006

부유식 해상공항과 같은 초대형 부체 구조물(VLFS)의 연안역 설치 후 발생할 수 있는 배후의 해빈변형을 예측하기 위한 토대를 마련하기 위한 기초 연구를 수행하였다. 이를 위해 일정 사면을 가진 천해역에서의 실험 결과를 통하여 비교적 수심이 깊은 곳에 설치된 매립식 구조물 배후에서의 파랑 및 해빈류를 개관하였으며, 매립식 및 부유식 해상 구조물 설치 시 주변 해역의 파랑 및 해빈류장을 계산하였다. 파랑장에 있어서 라프라스 방정식 토대로 유한요소법을 도입한 3차원 파랑 변형 계산을 수행함으로써 매립식 및 부유식 구조물 모두에 대해 적용 가능하였으며, 해상 구조물의 설치 형식이 매립식 및 부유식 경우에 대해 파랑, 해빈류 분포의 변화를 관찰할 수 있었다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.4-6
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• 2011

부유물 부근을 항해하는 선박의 조종 운동에 미치는 부유물의 영향을 파악하기 위하여 선박과 부유물(40피트 콘테이너)을 형상화 하고 선박과 부유물간의 간섭영향을 수치 계산하였다. 이 논문에서 사용되어진 계산 방법은 충돌 회피를 위한 선박의 자동제어시스템과 해상교통제어시스템 및 항만 건설 등을 위한 초기 설계 단계에서 선박 조종성의 예측에 유용할 것이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.47-49
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• 2013

항만 확장 시 기존의 매립 방식은 건설비용 및 환경 파괴 등의 문제가 발생함으로써, 부유체식 구조물을 이용한 해상 부두의 활용이 국내외에서 주목받고 있다. 이와 관련하여 본 연구에서는 선박의 계류안전성평가에 대한 개념을 정립하고 이를 부유체식 Container Yard에 적용하기 위한 자연환경, 선박 및 부두 모델링을 수행하였다. 본 연구 자료를 토대로 향후 부유체식 Container Yard에 접안한 선박의 환경외력 및 계류삭의 장력 평가, 방충재와 계선주에 작용하는 반력 및 견인력 평가, 부두의 운동에 따른 안전성을 파악하고, 해상 부두로서의 적용 가능성을 검토하여 안전한 부두의 설계 기준 및 활용 방안을 마련하고자 한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.928-936
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• 2022

According to the current status of marine accidents in Korea, the number of accidents is steadily increasing by an approximate average of 8.5% per year, and marine accidents are steadily increasing for ships and structures such as floating barges, tugboats, ferries and floating platforms except for fishing ships. In this study, domestic floating structures were classified according to the type of floating structure, and the regulation system and the scope of the application of floating marine structures were schematically illustrated according to related domestic laws such as the Ship Safety Act, Ship Act and Fishing Management and Promotion Act. In addition, considering the state of the marine environment, it was intended to discover structurally delicate parts and risk factors early in blinded safety spots in applying domestic regulations, and to derive effective improvement measures for the discovered risk factors.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.6
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• pp.275-289
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• 2022

New businesses such as marine leisure and floating construction have recently flourished on the coast. As a result, consideration is given to a floating structure appropriate for marine environments. In this study, we applied a damping plate to increase the stability of a hybrid floating structure that was expanded by vertical and horizontal stacking of mobile unit modules. In the numerical analysis using ANSYS AQWA, the behavioral characteristics of the floating structure were analyzed according to the length change of the damping plate. However, the wave forces acting on a floating structure are excessively calculated by the resonance of fluid surrounded by the structure in the numerical analysis using potential flow. Therefore, we used the damping zone option of the ANSYS AQWA in the frequency domain analysis.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1004-1010
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• 2021

Ship-floating object accidents can lead not only to a delay in ship's operations, but also to large scale casualties. Hence, preventive measures are required to avoid them. This study analyzed the spatiotemporal aspects of such collisions based on the data on ship-floating object accidents in sea areas in the last five years, including the collisions in South Korea's territorial seas and exclusive economic zones. We also provide basic data for related research fields. To understand the distribution of the relative density of accidents involving floating objects, the sea area under analysis was visualized as a grid and a two-dimensional histogram was generated. A multinomial logistic regression model was used to analyze the effect of variables such as time of day and season on the collisions. The spatial analysis revealed that the collision density was highest for the areas extending from Geoje Island to Tongyeong, including Jinhae Bay, and that it was high near Jeongok Port in the West Sea and the northern part of Jeju Island. The temporal analysis revealed that the collisions occurred most frequently during the day (71.4%) and in autumn. Furthermore, the likelihood of collision with floating objects was much higher for professional fishing vessels, leisure vessels, and recreational fishing vessels than for cargo vessels during the day and in autumn. The results of this analysis can be used as primary data for the arrangement of Coast Guard vessels, rigid enforcement of regulations, removal of floating objects, and preparation of countermeasures involving preliminary removal of floating objects to prevent accidents by time and season.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3B
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• pp.315-324
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• 2010

We developed a design chart for very large floating structures through intensive hydroelastic analysis. Using this chart, one can predict the hydroelastic response of very large floating structures preliminarily at design stage without the cost-demanding hydroelastic analysis. This paper presents two new design charts based on the theory of VLFS. The purpose of the first design chart is to determine RAOs of the maximum longitudinal stress of VLFS considering properties of waves and structures. The design chart I can be applied to any sizes of VLFS in same aspect ratios and dimensionless stiffness parameters. The second design chart is developed to take into account the actual wave condition by using the Bretschneider spectrum with Beaufort sea state.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.36 no.1
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• pp.1-10
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• 2024

As increasing demands for a floating structure expanded from offshore industry facilities to living facilities, it has emerged that necessity of techniques to reduce motions of a floating structure. This study present a floating structure with porosity on the outer surface of the floater. Under each regular and irregular wave, responses of the floater was investigated in frequency domain. The proposed structure is composed of inner and outer floaters, which are connected to each other and the outer wall is perforated, and the heave and the pitch of floaters with different perforation rates (0~30%) were compared with at both the center and the edge. The results showed that pitch responses can be decreased by increasing of perforation rate of the floater. Comparing with responses of the non-perforated floater, those of the proposed floating structure were reduced to above 10% and 2%, respectively for regular and irregular wave conditions.