• 한국산업정보학회논문지
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• 제25권3호
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• pp.61-82
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• 2020

본 연구는 멀티채널 환경 내에서 소비자의 쇼루밍에서 웹루밍으로의 쇼핑 행동 전환에 대한 연구로 밀고 당기기 이주 (Push-pull-mooring: PPM) 이론을 적용하였다. 웹루밍 의도에 영향을 미치는 변수로는 푸쉬 효과 (Push effect), 풀 효과 (Pull effect), 그리고 계류 효과 (Mooring effect)로 설정하고, 쇼루밍의 실용적 쇼핑가치의 결핍을 푸쉬 효과로, 웹루밍의 경험적 쇼핑가치를 풀 효과로, 그리고 쇼루밍 락인을 계류 효과로 개념화하였으며, 각각에 영향을 미치는 선행변수들을 문헌연구를 통해 도출하고 연구모형을 설계하였다. 276부의 설문을 대상으로 실증분석을 실시하였으며, 구조방정식 모형을 검증한 결과, 쇼루밍의 실용적 쇼핑가치 결핍과 웹루밍의 경험적 쇼핑가치는 웹루밍 의도에 긍정적인 영향을 미치며, 쇼루밍 계류는 웹루밍 의도에 부정적 영향을 미친다는 것이 확인되었다.

• 한국수산과학회지
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• 제34권6호
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• pp.661-665
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• 2001

해상가두리의 안정성 및 기능성 향상을 위한 최적 계류시스템을 개발하기 위하여 천해역에 적합한 계류시스템을 검토하여 유연부 이 계류시스템을 선정하였다. 이를 위한 해석프로그램을 정립하고, 수리모형실험 결과와 비교하였다. 해석프로그램의 타당성을 확인 한 후, 적용할 만한 계류시스템을 구성하고 수치계산을 통하여 해상가두리를 위한 적정 계류시스템을 제시하였다. 해상가두리의 계류시스템은 유연부이 계류시스템이 권장되며, 계류배치는 탁월 외력환경과 일치하는 방향으로 하고, 수평계류삭인 나일론 로프는 해상가두리 길이의 0.5배 이상, 경사 와이어 로프는 수심의 2배 이상이 바람직한 것으로 나타났다. 또한, 중간부 이의 증설은 계류장력 및 표류변위를 감소시키는 효과를 가질 것으로 판단된다. 차후, 해상가두리의 동적응답 특성을 계류시스템 해석모델의 개발과 계류시스템의 설계가 요구된다.

• Ocean Systems Engineering
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• 제5권2호
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• pp.109-123
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• 2015

In the present study, the coupled dynamic response of a Submerged Floating Tunnel (SFT) and mooring lines under regular waves is solved by using two independent numerical simulation methods, OrcaFlex and CHARM3D, in time domain. Variations of Buoyancy to Weight Ratio (BWR), wave steepness/period, and water/submergence depth are considered as design and environmental parameters in the study. Two different mooring-line configurations, vertical and inclined, are studied to find an optimum design in terms of limiting tunnel motions and minimizing mooring-line tension. The numerical results are successfully validated by direct comparison against published experimental data. The results show that tunnel motions and tether tensions grow with wave height and period and decrease with submergence depth. The inclined mooring system is more effective in restricting tunnel motions compared to the vertical mooring system. Overall, the present study demonstrates the feasibility of this type of structure as an alternative to traditional bridges or under-seabed tunnels.

• International Journal of Ocean System Engineering
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• 제2권2호
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• pp.97-105
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• 2012

A all floating structures operating within a limited area require, stationkeeping to maintain the motions of the floating structure within permissible limits. In this study, methods for selecting and optimizing the mooring system Caisson for floating wind turbines in shallow water are investigated. The design of the mooring system is checked against the governing rules and standards. Adequately verifying the design of floating structures requires both numerical simulations and model testing, the combination of which is referred to as the hybrid method of design verification. The challenge in directly scaling moorings for model tests is the depth and spatial limitations of wave basins. It is therefore important to design and build equivalent mooring systems to ensure accurate static properties (global restoring forces and global stiffness).

• 한국정보기술학회논문지
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• 제16권12호
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• pp.41-47
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• 2018

부이형 수중감시 시스템은 필요시 특정해역에 설치되어 일정기간 운용하고 회수이후, 다른 해역으로 이동하여 수중감시를 수행하는 장비이다. 본 논문에서는 부이형 수중감시 시스템에 적용되는 계류라인에 대하여 설치성을 유지하고 안정적인 운용이 가능하도록 계류방법을 선정하고 계류라인의 구조를 설계하였다. 부이형 수중감시 시스템의 구성요소인 배열센서조립체의 신호전송 케이블의 간섭을 고려하여 2점 계류방법을 선정하였고, 계류라인은 해역 이동에 따른 설치/회수성을 고려하여 부이체인, 나일론 로프, 그리고 앵커체인의 3단 복합구조를 기본 구성으로 설계하였다. 설계 유효성을 검증하기 위하여 수치실험과 조파수조 시험을 수행하여 유사성을 확인하였으며, 최종적으로 해상시험 위치의 환경을 대상으로 계류라인의 설계를 수행하였다. 최종 설계에 의해 제작된 계류라인은 해상시험을 통하여 설계 시 고려한 유의파고 이상에서도 안정적인 계류를 수행함을 확인하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.58-76
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• 2000

An analytical solution method capable of determining the geometric configuration and developed tensile forces of mooring lines associated with fixed plate/pile or drag anchors is presented. The solution method, satisfying complete equilibrium conditions, is capable of analyzing multi-segmented mooring lines that can consist of either chains, cables, or wires embedded in layered seafloor soils. Centrifuge model tests and full -scale field tests were used to calibrate and validate the analytical solution.

• 한국해양공학회지
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• 제23권1호
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• pp.89-95
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• 2009

The purpose of the present study was to evaluate the safety under extreme environmental conditions and the dynamic safety under service environment conditions, of oceanographic buoy mooring systems consisting of a variety of materials, including chain, wire rope, nylon rope, and polypropylene rope. For the static safety assessment of a mooring system, after the calculation of external forces and the division of a mooring system into finite elements, the numerical integral was conducted to yield the elemental static tension until satisfying the geometrical convergence condition. To evaluate the dynamic safety, various processes were considered, including data collection about the anticipated areas for mooring, a determination of the parameters for the interpretation, the interpretation of the dynamic characteristics based on an analytic equation that takes into account the heave motion effect of a buoy hull and a mooring system, and a fatigue analysis of the linear cumulative damage. Based on the analysis results, a supplementary proposal for a wire rope that has a fracture in an actual mooring area was established.

• Ocean Systems Engineering
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• 제7권1호
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• pp.1-19
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• 2017

This paper presents the numerical simulation results for the dynamic responses of two types of submerged floating tunnels (SFT) under wave and/or seismic excitations. Time domain simulations are conducted by the commercial program OrcaFlex (OF) and in-house CHARM3D program (CP). The dynamic performances of a short/rigid/free-end SFT section with vertical and inclined mooring lines are evaluated. The SFT numerical models were validated against Oh et al.'s (2013) model test results under regular wave conditions. Then the numerical models were further applied to the cases of irregular waves or seismic motions. The main results presented are SFT surge/heave motions and mooring tensions. The general trends and magnitudes obtained by the two different software packages reasonably agree to each other along with experimental results. When seabed seismic motions are applied to the SFT system, the dynamic responses of SFTs are small but dynamic mooring tension can significantly be amplified. In particular, horizontal earthquakes greatly increase the dynamic tension of the inclined mooring system, while vertical earthquakes cause similar effect on vertical mooring system.

• 한국해양공학회지
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• 제30권4호
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• pp.253-259
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• 2016

This study demonstrates the result of mooring analysis for five spread-moored FPSOs having different length-to-breadth (L/B) ratios from 4.5–6.5. FPSOs are subjected to four metocean conditions, ones from the Gulf of Mexico (Hurricane/Loop current condition), West Africa, Nigeria, and Brazil Campos Basin, which are amongst the most typical offshore oil and gas fields. With change in design parameters of OBA (Outer bundle angle) and IBA (Inner bundle angle) combinations, a change in the line tension is demonstrated and the OBA-IBA combinations having the smallest line tension are presented for each L/B ratio and sea, respectively. This study is expected to influence the preliminary design layout of an FPSO spread-mooring system as a function of the L/B ratio and metocean conditions.

• Ocean Systems Engineering
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• 제9권1호
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• pp.21-42
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• 2019

In this paper, the Finite-Analytic Navier-Stokes (FANS) code is coupled with an in-house finite-element code to study the dynamic interaction between a floating buoy and its mooring system. Hydrodynamic loads on the buoy are predicted with the FANS module, in which Large Eddy Simulation (LES) is used as the turbulence model. The mooring lines are modeled based on a slender body theory. Their dynamic responses are simulated with a nonlinear finite element module, MOORING3D. The two modules are coupled by transferring the forces and displacements of the buoy and its mooring system at their connections through an interface module. A free-decay model test was used to calibrate the coupled method. In addition, to investigate the capability of the present coupled method, numerical simulations of two degree-of-freedom vortex-induced motion of a CALM buoy in uniform currents were performed. With the study it can be verified that accurate predictions of the motion responses and tension responses of the CALM buoy system can be made with the coupling CFD-FEM method.