• Title/Summary/Keyword: 바람 에너지

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The dosimetric impact on treatment planning of the Dynamic MLC leaf gap (동적 다엽콜리메이터의 Leaf gap이 전산화 치료계획에 미치는 영향)

  • Kim, Chong Mi;Yun, In Ha;Hong, Dong Gi;Back, Geum Mun
    • The Journal of Korean Society for Radiation Therapy
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    • v.26 no.2
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    • pp.233-238
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    • 2014
  • Purpose : The Varian's Eclipse radiation treatment planning system is able to correct radiation treatment thought leaf gap which is limitation MLC movement for collision with both MLC. In this study, I'm try to analyze dosimetric effect about the leaf gap in treatment planning system. And then apply to clinical implement. Materials and Methods : The Elclipse version is 10.0. In general, the leaf gap set to 0.05~0.3 mm and must measurement each leaf gap. The leaf gap measured by each LINACs and photons. We applied to measured each leaf gap in IMRT and VMAT. Changing the leaf gap, we evaluated treatment plans by Dmax, CI, etc. Results : When the same plan was evaluated with changing the leaf gap, an increase of 2-5% over the value Dmax, CI increases mm to 0.0~0.50 mm leaf gap. Volumetric modulated and intensity modulated radiation therapy plans all showed the same trend was not found significant between each radiation treatment planning. Conclusion : Generally, the leaf gap setting has a unique measure of the Multileaf collimator. However, the aging of the Multileaf collimator, calibration, and can be changed, after inspection and repair of the lip gap should eventually because these values affect the treatment plan must be applied to the treatment after confirmation. In some cases, may be to maintain the initial setting value of the lip gap, which is undesirable because it can override the influence on the treatment plan.

Littoral Drift by the combined impact of Wind, Wave and Current ant the coastal Development Environment (해안개발환경하에서 바람 ${\cdot}$ 파랑 ${\cdot}$ 흐름의 중첩에 의한 연안표사)

  • Lee, Seung-Chul;Lee, Joong-Woo;Kim, Ki-Dam;Kang, Seok-Jin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2007.12a
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    • pp.141-142
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    • 2007
  • In recent years, the rate of mean sea level rise is increasing rapidly from the phenomena of global warming, together with the increasing trend of the storm scale. The issue of sea level rise is multifaceted and produces a range of environmental problems. Especially, high tides and the tidal currents become higher, and wave base increases, so the energy received at the coastal boundary may increase. This brings that many coastal environments go into disequilibrium, such as damages to the structures, erosion, and deposition Similarly it was known that the problems of nearshore processes and damage of berth and counter facilities during storm period had appeared at the small fishery port. Here we try to analyze the impact of the rearrangement of counter facilities and berth layout adopted for tranquility of its'inner harbor. Because this harbor is being connected to channel and open sea, the rearrangement of the structures might affect to the current speed and direction and wave height, so do to the sea bottom undulation. Therefore, we made model test for the several layouts of the berth and breakwater in this area.

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Development of Direct DME Synthesis Process (DME 직접 합성공정 기술개발)

  • Mo, Yong-Gi;Cho, Won-Jun;Baek, Young-Soon
    • Journal of the Korean Institute of Gas
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    • v.14 no.3
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    • pp.41-45
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    • 2010
  • The physical properties of DME(Dimethyl Ether) are very similar to LPG and well-mixed. As cetane number of DME is similar to diesel fuel that can replace diesel fuel and alternative energy. DME is a clean energy source that can be manufactured from various raw materials such as natural gas, CBM(Coal Bed Methane) and biomass. DME has no carbon-carbon bond in its molecular structure and its combustion essentially generates no soot as well as no SOx. The development of DME process in KOGAS have 4 section. First, syngas section can be manufactured various syngas ratio. This completes the tri-reforming process for the synthesis gas ratio of approximately 4.0 to 1.0 range can be adjusted. Second, $CO_2$ is removed from the $CO_2$ removal section of about 92~99%, so the maximum concentration of $CO_2$ entering the DME synthesis reactor should not exceed 8%. Third, in the DME synthesis section, if the temperature of DME reactor increases, the activity of DME catalyst increased. but for the long-term activity is desirable to maintain the proper temperature. Finally, the purity of DME in the DME purification section is over 99.6%.

Investigation and Evaluation of Algae Removal Technologies Applied in Domestic Rivers and Lakes (국내 하천/호수에 적용된 조류저감기술의 조사 및 평가)

  • Byeon, Kyu Deok;Kim, Ga Young;Lee, Inju;Lee, Saeromi;Park, Jaeroh;Hwang, Taemun;Joo, Jin Chul
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.7
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    • pp.387-394
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    • 2016
  • Commercial 28 algae removal technologies that have been applied in domestic rivers and lakes with green tide were investigated, analyzed and classified. The classification of algae removal technologies was based on the three criteria (i.e., principle, flow rate of water body, and application period). Also, algae removal technologies were evaluated in terms of cost effectiveness, field applicability, effect durability, and eco friendliness. From the analysis results, technologies using physical, chemical, biological, and convergent controls were 32.2%, 25%, 21.4%, and 21.4%, respectively. The 75% of technologies have been applied to stagnant water body (${\leq}0.2m/s$). Also, algae harvesting ship with dissolved air flotation, conveyor belt and filtration processes and natural floating coagulant were found to have better field applicability, compared to other technologies. However, proper algae removal technology in specific rivers and lakes should be chosen after the evaluation of long-term pilot scale field test. Also, development of energy and resource recovery technologies from algae biomass is warranted.

A Study on the Improvement of Animal Waste Composting Operations in Korea (한국(韓國)의 가축(家畜) 배설물(排泄物) 콤포스트화(化) 작업(作業) 개선(改善)에 관(關)한 연구(硏究))

  • Hong, Ji Hyung;Matsuda, Juzo;Ikeuchi, Yoshinori
    • Journal of Biosystems Engineering
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    • v.9 no.1
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    • pp.62-70
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    • 1984
  • 가축배설물(家畜排泄物)의 콤포스트화(化) 작업(作業)의 공학적(工學的)인 국면(局面)은 축산(畜産) 경영(經營)의 축산물(畜産物) 생산성(生産性), 에너지 보전(保全), 공해방지(公害防止)와 분뇨처리(糞尿處理)의 노력(勞力) 절약(節約)에 긴밀(緊密)한 관계(關係)가 있다. 그러나 우리나라에 있어서 축산업(畜産業)의 사양(飼養) 규모(規模)와 두수(頭數)는 매년(每年) 증가(增加)하고 있는 경향(傾向)인바 전통적(傳統的)인 가축(家畜) 배설물(排泄物) 처리(處理) 및 재이용(再利用) 과정(科程)에서 발생(發生)되는 문제점(問題點)에 대(對)한 연구(硏究) 자료(資料)가 없고 특(特)히 콤포스트화(化) 작업(作業)이 원시적(原始的)이므로 개선(改善) 확립(確立)이 절실(切實)히 요구(要求)되는 실정(實定)이다. 본(本) 연구(硏究)의 목적(目的)은 가축(家畜) 분뇨(糞尿)의 콤포스트화(化) 작업(作業) 과정(科程)에서 공학적(工學的)인 제(諸) 문제점(問題點)을 조사(調査) 분석(分析)하여 현상(現狀)을 평가(評價)하고 개선(改善) 방안(方案)을 모색(摸索)하기 위한 기본자료(基本資料)를 제공(提供)하고져 수행(遂行)하였다. 이에 관한 조사(調査)와 분석(分析) 결과(結果)를 요약(要約)하면 다음과 같다. 1. 축산농가(畜産農家)의 가축(家畜) 배설물(排泄物) 처분(處分) 방법(方法)은 대부분(大部分)이 자연건조(自然乾燥), 퇴적(堆積), 혐기적(嫌氣的)인 고형(固形) 또는 액상(液狀) 퇴비화(堆肥化)에 의하여 실시(實施)되고 있었으며 가축분뇨(家畜糞尿)로 인(因)한 공해(公害)는 심각(深刻)하다는 것을 알 수 있었다. 2. 호기성(好氣性) 야적(野積) 콤포스트의 통기작업(通氣作業)은 트랙터에 부착(附着)되어진 전후(前後) 작동식(作動式) 로우더가 바람직하다. 3. 농축산(農畜産) 폐기물(廢棄物)의 콤포스트화(化) 작업(作業)은 축산농가(畜産農家)를 중심(中心)으로 한 콤포스트 센타에서 전체 농가(農家)가 지방(地方) 증진(增進)과 오염(汚染) 방지(防止)를 하기 위해 참여(參與)하여 완전(完全) 공동(共同) 이용(利用) 체계에 따라 일관성(一貫性)있게 수행(遂行)되어야 한다. 4. 호기성(好氣性) 야적(野積) 콤포스트 작업(作業)은 다른 방법(方法)에 비하여 운영비(運營費)가 적게 들어 영세적(零細的)인 축산업(畜産業)의 경우(境遇)에 가장 적당(適當)하고 공해(公害)를 방지(防止)함으로서 한국(韓國) 축산농가(畜産農家)의 콤포스트화(化) 시설(施設)로 전망(展望)이 밝다고 판단(判斷)된다.

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The Coastal Geomorphic System of Sagye, Jeju (제주 사계해안의 지형시스템)

  • Seo, Jong-Cheol;Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.13 no.1
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    • pp.32-42
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    • 2007
  • In Sagye coast of Andeok-myeon, southwestern Jeju, shore platform of noncohesive Hamori Formation, marine terrace deposit of round gravels, coastal dune composed of shell sand and volcanic sand, and back lake are linked closely with each other. In this paper, the formation process of Sagye coastal geomorphic system analysed by using OSL dating method is as follows: Firstly, Hamori Formation is a horizontal stratum filed up of tuff reworked by submarine volcanic eruption during 3$\sim$7.6 ka BP. Hollow at the boundary between Hamori Formation' flat and Kwangheak Basalt's gentle slope become a back lake when block is appeared over the sea level by uplift. Secondly, while Hamori Formation was laid below sea level, gravels which had been broken and abraded at southwestern rocky coast composed of Kwangheak basalt or been transported through the small stream from adjacent hillslope were deposited in rapid flow environment. Thirdly, deposition of round gravels was ceased by earth uplift, and shore platform was constructed by abrasion process of energy of swash moving forward. As altitude of shore platform is equal to high tidal level of spring tide, compared it with present high tidal level of study area, earth is uplifted about 105m since shore platform was formed. Fourthly, much sandy sediments transported from offshore bottom covered shore platforms and marine terrace deposits. Lighter sediments among sandy sediments was blown to back, formed secondary sand dune since about 500 year.

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Installation Analysis of Multibody Systems Dynamics of an Offshore Wind Turbine Using an Offshore Floating Crane (해상 크레인을 이용한 해상 풍력 발전기의 다물체계 동역학 설치 해석)

  • Ku, Nam-Kug;Ha, Sol;Kim, Ki-Su;Roh, Myung-Il
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.4
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    • pp.233-239
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    • 2013
  • Recently, a number of wind turbines are being installed due to the increase of interest in renewable, environment-friendly energy. Especially, an offshore wind turbine is being watched with keen interest in that it has no difficulty in securing a site and can get high quality of wind, as compared with a wind turbine on land. The offshore wind turbine is transferred to and installed on the site by an offshore floating crane after it was made in a factory on land such as shipyard. At this time, it is important to secure the safety of the turbine because of its huge size and expensive cost. Thus, a dynamic analysis of the offshore wind turbine which is connedted with the offshore floating crane was performed based on the multibody systems dynamics in this study. As a result. it is shown that the analysis can be applied to verify the safety of a method for the transportation and installation of the offshore wind turbine suspended by the crane.

Development of an Analytical Framework for Dialogic Argumentation in the Context of Socioscientific Issues: Based on Discourse Clusters and Schemes (과학관련 사회쟁점(SSI) 맥락에서의 소집단 논증활동 분석틀 개발: 담화클러스터와 담화요소의 분석)

  • Ko, Yeonjoo;Choi, Yunhee;Lee, Hyunju
    • Journal of The Korean Association For Science Education
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    • v.35 no.3
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    • pp.509-521
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    • 2015
  • Argumentation is a social and collaborative dialogic process. A large number of researchers have focused on analyzing the structure of students' argumentation occurring in the scientific inquiry context, using the Toulmin's model of argument. Since SSI dialogic argumentation often presents distinctive features (e.g. interdisciplinary, controversial, value-laden, etc.), Toulmin's model would not fit into the context. Therefore, we attempted to develop an analytical framework for SSI dialogic argumentation by addressing the concepts of 'discourse clusters' and 'discourse schemes.' Discourse clusters indicated a series of utterances created for a similar dialogical purpose in the SSI contexts. Discourse schemes denoted meaningful discourse units that well represented the features of SSI reasoning. In this study, we presented six types of discourse clusters and 19 discourse schemes. We applied the framework to the data of students' group discourse on SSIs (e.g. euthanasia, nuclear energy, etc.) in order to verify its validity and applicability. The results indicate that the framework well explained the overall flow, dynamics, and features of students' discourse on SSI.

Development of a Solar Powered Water Pump by Using Low Temperature Phase Change Material ­ System Construction and Operation Analysis ­ (저온 상변화 물질 특성을 이용한 태양열 물펌프 실용화 연구개발(II) ­시스템 구성 및 작동분석)

  • 김영복;이양근;이승규;김성태;나우정;민영봉
    • Journal of Animal Environmental Science
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    • v.9 no.2
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    • pp.69-78
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    • 2003
  • In this study, the energy conversion equipment from the radiation energy to mechanical energy by using n­pentane as the operating fluid was constructed and the performance to pump the water was tested for the utilization of solar powered water pump. The equipment was designed optimally, after the theoretical analyses of the water pumping head and water quantity per cycle were done. The pentane vapour temperature in the condenser and the temperature of the outlet water from the condenser became lowered and the heat transfer rate became higher with decreasing the water inlet level to the condenser. The temperature difference between the condenser and the water tank was significant. Therefore, the distance between the water tank and condenser was recommended to be shorten and the diameter of their connecting pipe was recommended to be narrow in order to reduce the resistance of the fluid passage and improve the heat transfer rate. The amount of water pumped was 1.6­2.4 liters. Mass flow rate of the cooling water became lowered when the cooling water pipe was prolonged from the condenser to improve the heat transfer rate.

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Agricultural Climatology of Cheju Island II. Potential Evapotranspiration Based on Near-Real Time Data Measured by Automated Weather Stations (제주도의 농업기후 분석 II. 무인관측강에 의한 기상실황자료 수집 및 증발산위 계산)

  • 윤진일
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.6
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    • pp.504-511
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    • 1990
  • Weather data acquisition and potential evapotranspiration (PET) calculation procedure were investigated to support the agricultural development efforts in the mid-altitude mountainous region of Cheju Island. Automated weather stations (AWS) were installed at two points representing the east and the west of the study area. A personal computer was employed to collect the near-real time weather data from AWS through the public telephone line. Hourly data were available for solar radiation, air and soil temperature, relative humidity, wind speed and direction, and precipitation. Based on the data for the month of June 1989, daily climatic features were comparatively analyzed for the two areas and the Penman equation was used to calculate PET. Air temperature was higher by 1 to 2 degree C in the east due mainly to the higher solar radiation and partly to the Fohn effect caused by the daytime southwesterly blowing over Mt. Halla. Diurnal march of soil temperature lagged by 4 hours behind that of air temperature and the diurnal range for 10cm subsurface soil was 3 degree C. Wind was consistently stronger and a marked sea-land breeze circulation was detected in the west. Calculated PET values were higher in the east by 6% than in the west. Overall values from the east and the west of the mid-altitude mountainous region were higher by 30% than those of the coastal region, which were estimated from the Class A Pan evaporation measured by the Korea Meteorological Service Offices.

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