• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.4
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• pp.185-191
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• 2004

A mooring system can be applied to keep the position of a floating structures. In this study, the structural analysis is carried out to analyze the dynamic characteristics of a mooring line for a floating breakwater. A three-dimensional equations of motion for a submerged chain are derived. Bending stiffness is considered for the necessary restoring force in the regions of zero tension. A fortran program is to be developed by employing finite difference method. In the algorithm, an implicit time integration and Newton-Raphson iteration are adopted. The results of simulation show good agreement in tension response pattern with the experimental results of a reference. The results of this study can contribute for the design of mooring system for a floating breakwater.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.165-166
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• 2013

When Coming alongside the shallow water or narrow pier, they apply sea area with small mooring facilities and Floating matter because of the diversity of ships and limitation and effective in cutting expenses. However, when ships, applying Small mooring facilities and Floating matter, come alongside, there can be some impulse by waves between the Floating things and ships which possibly leads to mass disaster. Therefore, there should be forecasts and analysis of the movement caused by waves. On this Study, it introduces the composition and principles of the developed system provides the base of the movement traits through measuring 3-D exercise data and acceleration of the Mooring and Floating matters.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.4
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• pp.360-366
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• 2004

This paper presents a method analyzing the motion of cylindrical buoy moored at 2 points and tensions action on each mooring line under the action of periodic waves. It was found that submersible buoy was more effective than floating one in the severe conditions considering its dynamic motions, wave forces, and mooring line tensions. The wave induced its dynamic responses and mooring line tensions peak when the ratio d/${\lambda}$ of the buoy length d to the waves length ${\lambda}$ was 0.66 due to its natural frequency. The results of this study were in agreement with the existing measurement ones, however, further verifications are needed considering resonance of cylindrical buoy and its displacements to wave height by a series of model tests.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.36 no.3
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• pp.116-127
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• 2024

The floating pier is a representative type of floating structure installed along the coast, primarily used as a facility for berthing and mooring ships. Additionally, ongoing attempts have been made to utilize it for various purposes, such as wave control and wave energy conversion structures. In this study, we experimentally investigated the reflection and motion characteristics of a pile-moored floating pier, which allows heave and limited roll motion, with respect to the presence of perforated structures and the attachment of submerged plates. The hydraulic experiment results indicated that the reflection and motion characteristics of the pile-moored floating pier were significantly influenced by the presence and installation depth of the submerged plates, rather than the presence of perforated structures on the floating body. In particular, the installation of submerged plates increased the reflection coefficient in short-period waves and effectively reduced the heave and roll motions of the floating body.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.571-577
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• 2013

This study was carried out to establish the construction guidelines of soil erosion control structures for a restoration of mountain stream with analysis of water quality around constructed soil erosion control structures in mountain streams. Water pH of the Uidong valleys in Bukhansan (Mt.) was similar between the constructed soil erosion control structures of lower stream areas [pH 6.53(6.25~6.82)] and the non-constructed areas of upper stream areas [pH 6.32(5.73~6.90)]. Mean concentration of dissolved oxygen was also similar between the constructed soil erosion control structures of lower steam areas [10.2 mg/L(9.9~10.4 mg/L)] and the non-constructed areas of upper stream areas [10.3 mg/L (9.6~10.6 mg/L)]. Mean electric conductivity was similar between the lower [$63.9{\mu}S/cm$ ($32.6{\sim}120.4{\mu}S/cm$)]a nd the upper stream areas [$62.2{\mu}S/cm$ ($40.3{\sim}89.5{\mu}S/cm$)]. Mean concentration of anions was also similar between the lower [15.94 mg/L (3.43~7.98 mg/L)] and the upper stream areas [14.51 mg/L (2.56~4.29 mg/L)]. Water pH of the Honggei valleys in Sancheong-gun was similar between the lower [pH 6.86(6.50~7.10)] and the upper stream areas [pH 6.89(6.61~7.12)]. Mean concentration of dissolved oxygen was also similar between the lower [11.9 mg/L(11.5~12.3 mg/L)] and the upper stream areas [12.2 mg/L (11.6~12.6 mg/L)]. Mean electric conductivity was similar between the lower [$633.4{\mu}S/cm$ ($31.6{\sim}34.6{\mu}S/cm$)] and the upper stream areas [$32.7{\mu}S/cm$ ($31.4{\sim}34.3{\mu}S/cm$)]. Mean concentration of anion was also similar to both stream areas [1.0 mg/L (0.1~2.2 mg/L)]. Water quality in the Uidong and the Honggei valleys was not significantly different between the constructed soil erosion control structures of lower stream areas and the non-constructed areas of upper stream areas. It will be needed to study the time-series analysis of water quality before and after the construction of soil erosion control structure the restoration of mountain streams because the water quality in mountain streams could be affected during the construction processes of structures.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.204-208
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• 2002

Mooring is the operation of securing a ship to a wharf or quay by means of rapes or chains. A. moored ship need not necessarily be truly stationary. It may be free to rise and fall with the tick or the loading and unloading of cargo or to oscillate in response to the action of the environmental forces. In this respect a moored ship is restricted to a limited amount of movement within well-defined bounds. This study is intended to analyze the tension of mooring lines by a FEM program, as the current velocities and working directions are varied. The motion of a berthed ship is studied concerning with the wave periods and the direction. Also the behavior of the modeled vessel are investigated for a berthed condition.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.52-54
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• 2011

모바일 하버는 해상에서 대형 컨테이너선과 연결 후 고속으로 정밀하게 컨테이너를 상 하역해 부두로 이송하는 신개념 해상 운송수단이며, 이 모바일 하버의 자동 Docking시스템은 파도와 바람의 끊임없이 움직이는 두 부유체를 안전하고 신속하게 측면으로 밀착해 일정 거리를 유지하여 컨테이너의 상 하역을 안전하게 도와주는 장치로서, 자동 Docking시스템의 주요 핵심 시스템을 소개하고자 한다. 부두나 항구에 정박하는 선박들의 안전하고 빠른 계류 활용을 위한 안벽 계류 시스템으로 경인항 부두에 응용한다면 효율적인 항구 운용, 선박 및 여객선의 빠르고 안전한 계류, 신항만 운용 기술의 선구자 역할을 담당할 것으로 사료되며, 적절하고 효과적인 활용방안에 대해 언급하고자 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.227-227
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• 2020

최근 국내에서는 이상기온으로 인한 국지성 폭우와 여름철 태풍과 집중호우로 인해 다양한 재해 유형 중 산악지역을 중심으로 산지재해의 피해가 증가하는 추세이다. 본 논문에서는 토석류 피해지역 중 토석류가 발생한 메인계류와 해당 하류지역을 대상으로 연간지형변화 및 침·퇴적분석에 대해 기술하였다. 대상지역은 2012년 루사로 인해 토석류 피해가 발생한 인제군(설악산 국립공원)지역으로 거주하는 인원이 없어 민가나 생활시설에 미치는 영향은 크지 않지만 하류지역에 교량 및 도로가 위치하고 있어 토석류가 재발생시 위험한 지역으로 분류할 수 있다. 이에 2012 ~ 2020년까지 LiDAR 촬영을 이용한 현장모니터링을 실시하고 있다. 모니터링 데이터를 종합하여 년도별 지형자료를 구축하였으며 인명피해 위험성이 적어 복구가 늦어지거나 계획이 없는 자연사면지역에서의 지형변화를 살펴보았다. 또한 토석류 계류지역과 하류부를 중심으로 침·퇴적 분석을 실시하였다. 계류지역에서는 횡 넓이, 유동심, 크게는 방향, 식생 등에 대한 변화를 분석하였으며 하류부에 위치한 교량 및 도로 등 구조물, 시설물들에 미치는 영향을 분석하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.225-226
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• 2019

육상에서 발생한 부유쓰레기는 하천을 통해 해상으로 유입되어 선박 프로펠러 파손, 항로 점유 등 선박 운항 안정성에 지대한 영향을 미친다. 본 연구는 육상 기인 부유쓰레기의 해양 확산을 방지하고 나아가 선박 운항 안정성 확보를 위한 차단막과 차단막의 부유쓰레기 차단 성능 확보를 위한 플랫폼 및 계류, 앵커시스템 개발을 연구 목표로 한다. 본 구조물의 우선 설치 대상 해역은 가덕도 남동부 해안으로, 우천시 혹은 태풍 내습시 육상에서 발생하는 많은 해양쓰레기의 확산이 이루어지는 지역이다. 대상 해역의 환경하중 조건에서 플랫폼이 정상기능을 수행하도록 수치해석 기법을 기반으로 플랫폼 및 계류, 앵커시스템을 설계하고 설계 기준 적합성을 평가하였다.

• Journal of Forest and Environmental Science
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• v.17 no.1
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• pp.18-28
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• 2001

This study was carried out to investigate the characteristics of water quality variations by stand water balance in YangPyong-Gun Gejung-Lee small forest watershed. Water quantity. pH, $Cl^-$, $NO_3{^-}$, $SO_4{^{2-}}$, $Na^+$, $NH_4{^+}$, $K^+$, $Mg^{2+}$, $Ca^{2+}$ were monitored in open rainfall for one unit storm and long-term stream water in small forest watershed from January. 1998 to December. 1999. The results were summarized as follows: The runoff rate was 46.4% in 1998 and 52.2% in 1999. The average pH values of rainfall were 4.8 to 6.2 and those of stream water were 6.4 to 7.1 in small forest watershed. Total amount of input anion and cation values (kg/ha) in rainfall were $SO_4{^{2-}}>NO_3{^-}>Ca^{2+}>NH_4{^+}>Cl^->Na^+>K^+>Mg^{2+}$ and in stream water were $NO_3{^-}>Ca^{2+}>SO_4{^{2-}}>Na^+>Cl^->K^+>Mg^{2+}>NH_4{^+}$ in the order, respectively. The dissolved $NH_4{^+}$ was stored 5.29kg/ha and output of the other contents were more flow than input in small forest watershed.