• 한국지리정보학회지
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• 제27권1호
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• pp.12-28
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• 2024

본 연구는 제주도의 주요 관광지별 COVID-19 전후 관광객 유동인구 변화 추세를 공간분석을 통하여 확인하고, 이를 통하여 관광객 유동인구 패턴 변화에 대한 이해를 하고자 한다. 제주도의 성산읍과 안덕면을 연구지역으로 선정하였으며, 연구기간은 COVID-19 발생전 1년과 발생후 2년으로 설정하였다. 공간분석을 위하여 이동통신 유동인구 데이터를 정제 및 가공하여 유동인구 분포와 유동인구 증감 데이터를 산출하였으며, 이를 공간데이터화 하여 주요 관광지의 위치데이터와 중첩분석을 실시하였다. 분석결과 실내 관광지와 소규모 시설은 COVID-19 직후 유동인구가 감소하였으며, 개방된 해안지역 또는 대규모 시설의 경우 유동인구 감소가 적거나 오히려 유동인구가 증가한 것으로 확인되었다. 결론적으로 관광개발에서 관광시설 특성에 따른 유동인구의 변화를 파악할 필요가 있으며, 관광지 개발시 팬데믹과 같은 위험상황에 대응할 수 있는 관광시설 및 전략의 개발이 필요하다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.514-514
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• 2017

Floating breakwaters were treated as solid bodies without any perforation in previous studies. In this study, however, a floating breakwater is perforated to allow the partial absorption of the energy produced by incident waves and an air chamber is placed in the upper part to control the breakwater draft. A series of laboratory experiments for a floating breakwater installed with a mooring system are carried out. In general, a mooring system can be classified by the number of mooring points, the shape of the mooring lines, and the degree of line tension. In this study, a four-point mooring is employed since it is relatively easier to analyze the measured results. Furthermore, both the tension-leg and the catenary mooring systems have been adopted to compare the performance of the system. In laboratory experiments, the hydraulic characteristics of a floating breakwater were obtained and analyzed in detail. Also, a hydraulic model test was carried out on variable changes by changing the mooring angle and thickness of perforated wall. A hydraulic model was designed to produce wave energy by generating a vortex with the existing reflection method. Analysis on wave changes was conducted and the flow field around the floating breakwater and draft area, which have elastic behavior, was collected using the PIV system. From the test results the strong vortex was identified in the draft area of the perforated both-sides-type floating breakwater. Also, the wave control performance of the floating breakwater was improved due to the vortex produced as the tension in the mooring line decreased.

• 한국해양공학회지
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• 제33권6호
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• pp.648-656
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• 2019

The ecological changes in the ocean due to the drastic global warming require that action be taken to sustain the productivity of fisheries. Proper ocean facilities could help prevent the loss of the expenditures made on marine aquaculture and reduce the related compensation for various ocean conditions. The aim of this study was to develop a floating ocean wave-breaker using an eco-friendly concrete and conducting a site survey, a structural analysis, and a test of towing the tank. As a result, the wave at the fish farm would be reduced. The results of the holding power of anchors and the capability of moving the floating structures were considered in the design of the wave-breaker. The analyses of the material properties of concrete and the steel structures, as well as the CAPEX and OPEX analyses of the manufacturing and operation processes confirmed the superiority of the floating concrete wave-breaker. In particular, this study demonstrated that the concrete floating breakwater can protect the fish farm against typhoons and reverse-waves, thereby reducing losses of the fish.

• 한국해양공학회지
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• 제35권5호
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• pp.382-392
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• 2021

In recent years, floating offshore wind turbines have attracted more attention as a new renewable energy resource while bottom-fixed offshore wind turbines reach their limit of water depth. Various projects have been proposed with the rapid increase in installed floating wind power capacity, but the economic aspect remains as a biggest issue. To figure out sensible approaches for saving costs, a comparison analysis of the levelized cost of electricity (LCOE) between floating and bottom-fixed offshore wind turbines was carried out. The LCOE was reviewed from a social perspective and a cost breakdown and a literature review analysis were used to itemize the costs into its various components in each level of power plant and system integration. The results show that the highest proportion in capital expenditure of a floating offshore wind turbine results in the substructure part, which is the main difference from a bottom-fixed wind turbine. A floating offshore wind turbine was found to have several advantages over a bottom-fixed wind turbine. Although a similarity in operation and maintenance cost structure is revealed, a floating wind turbine still has the benefit of being able to be maintained at a seaport. After emphasizing the cost-reduction advantages of a floating wind turbine, its LCOE outlook is provided to give a brief overview in the following years. Finally, some estimated cost drivers, such as economics of scale, wind turbine rating, a floater with mooring system, and grid connection cost, are outlined as proposals for floating wind LCOE reduction.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 추계 학술발표회 논문집
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• pp.147-154
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• 2002

Dynamic response analysis are conducted for a floating bridge subjected to multiple support earthquake excitation. The floating bridge used in this study is supported by discrete floating pontoons and horizontal pretension cables supported at both ends of the bridge. The bridge is modeled with finite elements and the hydrodynamic added mass and added damping due to the surrounding fluid around pontoons are obtained using boundary elements. Multiple support excitation is introduced at both ends of the bridge and the time history response is compared to that of a simultaneous excitation. The results shows that the differences between two results are not so large except for cable tension for which the multiple support excitation yields larger values. During the analysis the concept of retardation function is utilized to consider the frequency dependency of the hydrodynamic coefficients.

• 한국항해학회지
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• 제10권1호
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• pp.129-138
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• 1986

A matrix partitioning method is proposed for the 2-D motion analysis of floating bodies. For the numerical solution, the boundary of a floating body is approximated with a series of line segments and the governing integral equation is transformed into a system of linear equations. A new solution procedure of resulting linear equation with complex coefficients is formulated and programmed using a matrix partitioning scheme and the Choleski decomposition. From the case study, it is found that the proposed method is efficient in the motion analysis of floating bodies, especially in the calculation of hydrodynamic coefficients. Also, it requires smaller memory size and less computing time compared with conventional methods.

• 지적과 국토정보
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• 제49권1호
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• pp.181-195
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• 2019

본 연구의 목적은 통신 데이터를 통해 구축한 유동인구 데이터를 활용하여 서울시 도심도보관광코스 내 유동인구 특성을 파악하고 효과적으로 시각화하여 공간적인 맥락을 분석하는 것이다. 도로에 따른 유동인구 추정을 위해 유동인구 데이터 정제 기법을 개발하여 도보관광코스 별 유동인구 데이터를 구축하였다. 도보관광코스 분석에 적합한 형태로 정제하기 도로 주변 유동인구 값을 고려한 유동인구 추정하여 도보관광코스 내 유동인구를 할당하였다. 정제된 데이터를 바탕으로 서울도보관광 18개 코스 각각의 유동인구 특성과 공간 특성을 도출하였다. 도보관광코스 내 유동인구의 공간 밀도와 집중 구간을 분석하기 위해 커널 밀도분석과 Getis-Ord $G^*_i$ 통계를 적용하였으며 3D 시각화를 통해 서울도보관광 18개 코스별 유동인구 특성을 성, 연령, 시간, 요일에 따라 정량적으로 파악하였다. 그 결과 청계천 제1코스, 경희궁-서대문코스, 인사동-운현궁 코스 순으로 유동인구 규모가 크게 나타났으며 주중에는 인사동-운현궁, 주말에는 성북동 코스의 유동인구가 많았다. 남성 유동인구 비율이 가장 높은 코스는 청계천 제1코스, 여성 유동인구 비율이 가장 높은 코스는 몽촌토성 코스였다. 주말 유동인구 비율이 가장 높은 도보관광코스는 성북동 코스임을 확인할 수 있었다.

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

• 한국환경과학회지
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• 제21권7호
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• pp.825-835
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• 2012

This study for the development of water purification Artificial floating island maximizing domestic Artificial floating island patent trends and product development, according to the timing of patent registration was analyzed for trends. In addition, domestic invention patent technology Artificial floating island typed according to the purpose and characteristics of domestic patents were Artificial Floating Island. In particular, domestic leisure space with a growing population and the need for securing emerging role as a reservoir of water only in the past, who do appeal as a tourist destination or as an ecological space utilized, and accordingly will transform and the need to secure a hydrophilic, degrade water quality problems using this aquatic environment (water acquisition and hydrophilic), the requirements are a big obstacle is the reality factor. This patented product differentiation strategy through the analysis of the development of technology progressiveness (Field Application) in terms of water quality improvement and maintenance side, and the hydrophilic side scenery, ecological restoration aspects, and applicability to the field and taking into account existing technology economic aspects of distinction were presented and advertised a lot in terms of cost compared to other techniques without the use of highly efficient methodology for building a water purification and also appears identity appeal, wetlands, rivers, etc. can be applied broadly technician widespread deployment and installation time to less simple and more are expected to spread.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.62.1-62.1
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• 2011

The wind can be stronger and steadier further from shore, but water depth is also deeper. Then bottom-mounted towers are not feasible, and floating turbines are more competitive. There are additional motions in an offshore floating wind turbine, which results in a more complex aerodynamics operating environment for the turbine rotor. Many aerodynamic analysis methods rely on blade element momentum theory to investigate aerodynamic load, which are not valid in vortex ring state that occurs in floating wind turbine operations. So, vortex lattice method, which is more physical, was used in this analysis. Floating platform's prescribed positions were calculated in the time domain by using floating system RAO and waves that are simulated using JONSWAP spectrum. The average value of in-plane aerodynamic force increase, but the value of out-of-plane force decrease. The maximum variation aerodynamic force abruptly increases in severe sea state. Especially, as the pitch motion of the barge platform is large, this motion should be avoided to decrease the aerodynamic load variation.