• Ocean Systems Engineering
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• 제12권1호
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• pp.39-61
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• 2022

Renewable energy such as wave energy has gained popularity as a means of reducing greenhouse gases. However, the high cost and lack of available sea space in some countries have hindered the deployment of wave energy converters (WEC) as alternative means of sustainable energy production. By combining WECs with infrastructures such as floating breakwaters or piers, the idea of electricity generated from WECs will be more appealing. This paper considers the integration of vertical raft-type WEC (commonly known as the vertical flap WEC) with floating breakwater as means to generate electricity and attenuate wave force in the tropical sea. An array of 25 WECs attached to a floating breakwater is considered where their performance and effect on the wave climate are presented. The effects of varying dimensions of the WEC and mooring system of the floating breakwater have on the energy generation are investigated. The integrated WECs and floating breakwater is subjected to both the regular and irregular waves in the tropical sea to assess the performance of the system. The result shows that the integrated vertical flap-floating breakwater system can generate a substantial amount of wave energy and at the same time attenuate the wave force effectively for the tropical sea when optimal dimensions of the WECs are used.

• 신재생에너지
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• 제4권2호
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• pp.12-20
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• 2008

Calculations for the dissolution behavior of liquid CO2 droplets released in the East Sea and the Clipperton Clarion from a moving ship and a fixed pipeline have been carried out in order to estimate the CO2 dissolution characteristics in the ocean. The results show that the injection of liquid CO2 from a moving ship in a high temperature point is an effective method for dissolution. Also, it is noted that the ultimate plume generated from CO2 bubbles repeatsand shrinking due to the peeling from a fixed pipeline, and the presence of hydrate layer on a liquid CO2 droplet acts as a resistant layer in dissolving liquid CO2.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.331-332
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• 2008

Wind energy issued as most spotlight general energy by excellence of actuality as well as economical efficiency, solving environmental problem which caused by creating the energy and possibility of eternal production. Accordingly, government is at the stage of corresponding level by requesting development of new technology to the developed countries as a part of national key industries. The grievous situation from such a rapid movement is meteorological comprehension and assessment as well as the problem of estimation exactness about the wind. In this study, we use the regional meteorological station data, automatic weather station data and QuikSCAT SeaWinds data.

• 무역학회지
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• 제43권4호
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• pp.111-130
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• 2018

온실가스 배출로 인한 지구온난화에 대응하고 지구의 평균 기온상승을 방지하기 위하여 2015년 12월 파리기후협정(Paris Agreement)이 채택되어 신기후체제가 도래하게 되었다. 해수면상승과 삼림고갈, 미세먼지 등과 같은 기후변화로 인한 환경문제에 대응하기 위하여, 신재생에너지의 중요성이 높아졌다. 신재생 에너지의 성장을 위해서는 현실적으로 정부의 지원이 필요하다. 그러나 신재생에너지 산업에 대한 각국 정부의 과다한 지원은 공정 한 경쟁을 저해하고 비용을 높인다는 점에서 문제가 될 수 있으며, 이미 WTO에서도 신재생에너지 보조금과 관련된 제소사례를 찾아볼 수 있다. 본 연구는 WTO의 보조금 및 상계조치 협정과 GATT를 중심으로 하였다. 신재생에너지 보조금에 관련된 WTO 분쟁사례를 살펴보고, 사례에서 쟁점이 되는 조항인 보조금협정의 제2조 특정성과 제3조 (b)항 수입대체보조금, GATT 제20조 일반적 예외를 분석하였다. 기후변화에 대응하는 환경보호적인 관점에서 현재 각 국의 에너지 정책을 반영하고 신재생에너지 산업의 발전을 위하여 보조금협정의 개정 또는 보완이 필요하다. 본 연구에서는 보조금협정 제8조 허용보조금의 재도입 논의 또는 에너지보조금에 관한 특별규정과 같은 방안과 더불어 보조금협정 제3조의 명확한 해석기준이 필요하다고 보았다. 그러나 과도한 정부 보조금의 지급은 무역분쟁을 야기할 수 있으며 환경보호와 자유무역의 형평성, 지속가능한 개발이라는 WTO의 목적에 맞추어 WTO의 규범을 개선해야 한다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.270-273
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• 2008

The integrated power system combining a tidal power plant and two ocean current power parks is suggested. It is characterized by the set up of an ocean current power park in the lake side by installing a number of ocean current turbines generating electricity by using sea water flow discharged into the lake side from the turbine generator of a tidal power plant and an ocean current power park in the sea side by installing a number of ocean current turbines generating electricity by using sea water flow exiting into the sea side through the sluice gate from the lake side. The vision of the integrated power system is demonstrated by the simple theory and simulation results of the SIWHA Tidal Power Plant. And it is shown that the newly proposed integrated power system combining tidal power and ocean current power can produce very high economical benefits.

• 한국해양공학회지
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• 제27권4호
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• pp.22-32
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• 2013

This paper presents the conceptual design procedure for the taut-leg mooring lines of a floating-type combined renewable energy platform. The basic configuration of the platform is determined based on an understanding of floating offshore plants. The main dimensions and mass distribution are determined based on a hydrostatic calculation. To identify the motion history of the floating platform and the tension history of the mooring lines, a hydrodynamic analysis is executed using Ansys.Aqwa. This helps in the selection of the best configuration for the mooring system such as the number of mooring lines, wire types, anchored positions, etc. In addition, the fatigue life of the mooring lines can be predicted from the tension history using the rain-flow cycle counting method.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2001년도 춘계학술대회:발표자료
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• pp.285-302
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• 2001

At the present time the desalination technology of sea water for portable water in islands employs the RO method. The technology which needs complicated pretreatment processes with various chemicals can generate secondary water pollution and the high maintenance costs such as replacements of filters and membranes make islanders nearly impossible to operate. The MVRS technology for desalination of sea water however has several advantages such as constant production of quality portable water and capability of managing broad operating load. The variable-speed turbo-type vapor compressors employed in the system can utilize wind energy which is abundant in most Korean islands. Salt as a by-product can be produced by applying solar energy to the salt-concentrated waste water from the system. This paper discusses the relating topics such as technical and economical viabilities of the new MVRS desalination system for the production of portable water and salt as a by-product using new & renewable sources of energy.

• 에너지공학
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• 제9권1호
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• pp.47-53
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• 2000

This paper is to propose the concept and performance of a gravity engine which could extract energy from sea or river as a clean. renewable and sustainable power. the vertical motion of the buoyancy cylinder of the present gravity engine is converted to the mechanical work directly without any hydraulic loss. The positive net energy between the imposed and harnessed one is achieved by the specific operating procedure. The detailed derivation of the energy balance is made based on the first principle of thermodynamics. The calculation demonstrates that the present gravity engine could harness more energy than the conventional turbine system in the same basin area because of the relatively high efficiency in the energy conversion system and added mass from the buoyancy cylinder.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.630-634
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• 2007

In the past, the use of wave energy has mainly been focused on conversion of large wave energy resources in the far offshore areas. However, with the technological improvement of converting wave energy into electricity, the energy resources at much shallow waters are now considered as a site for possible installation of the devices that obtain energy from the waves. In this respect, the wave energy resources on the east coast of Korea, where the sea is milder than the open ocean, were investigated using the field measurement data obtained at three different locations along the coast. For all the locations, the wave power was greater in winter season, compared to summer season. The estimated wave power varied from 2 to 4.5 kW/m on average, depending on the measurement locations.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1999년도 추계 학술발표회 논문집
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• pp.231-236
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• 1999

This paper is to propose a concept and performance of the gravity engine which could extract energy from sea or river as a clean and renewable and sustainable power, the tidal or hydro-power. The vertical motion of the buoyancy cylinder of the present gravity engine is converted to the mechanical work directly without any hydraulic loss. The increased gravity potential during high tide is harnessed proportional to the length of the buoyancy cylinder times tidal height which is greater than the conventional tidal power using water mill. This energy amplification results from the net energy gain between the resource energy and the imposed energy to extract water out of the buoyancy cylinder. Its efficiency is higher than the conventional water mill due to its direct mechanical conversion.