• Title/Summary/Keyword: 환경의 달

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Mathematical Prediction of the Lunar Surface Temperature Using the Lumped System Analysis Method (집중계 해석법을 이용한 달 표면온도 예측)

  • Kim, Taig Young;Lee, Jang-Joon;Chang, Su-Young;Kim, Jung-Hoon;Hyun, Bum-Seok;Cheon, Hyeong Yul;Hua, Hang-Pal
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.4
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    • pp.338-344
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    • 2018
  • The lunar surface temperature is important as a environmental parameter for the thermal design of the lunar exploration vehicles such as orbital spacecraft, lander, and rovers. In this study, the temperature is numerically predicted through a simplified lumped system model for the energy conservation. The physical values required for the analysis of the energy equation are derived by considering the geometric shape, and the values presented in the previous research results. The areal specific heat, which is the most important thermo-physical property of the lumped system model, was extracted from the temperature measurements by the Diviner loaded on the LRO, and the value was predicted by calibration of the analytical model to the measurements. The predicted temperature distribution obtained through numerical integration has sufficient accuracy to be applied to the thermal design of the lunar exploration vehicles.

Space Rover Development and Domestic Technology (우주로버의 개발현황과 국내의 관련기술 현황)

  • Ahn, Seok-Min;Lee, Yung-Gyo;Kim, Sung-Phil;Kim, Tae-Sik;Moon, Sang-Man
    • Current Industrial and Technological Trends in Aerospace
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    • v.6 no.1
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    • pp.27-34
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    • 2008
  • One of the purposes of space exploration is to be able to utilize the unlimited natural resources in the universe. For this purpose, plans for lunar and mars bases have been proposed by leading nations. In order to construct bases and search for resources, it is necessary to employ and develop rovers for surface navigation and exploration. With proper knowledge about Lunar surface, technology for lunar rover development can be established without serious obstacles, since robot technology for rover development has been well prepared in Korea. In this paper, lunar rovers and mars rovers developed and planned by other countries as well as the current status of robot technology in Korea have been analyzed.

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Environmental Characteristics of Exochorda serratifolia S.Moore Habitats (가침박달 자생지의 환경특성)

  • Kim, Kyung-Ah;Cheon, Kyeong-Sik;Yoo, Ki-Oug
    • Korean Journal of Plant Resources
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    • v.27 no.2
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    • pp.155-173
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    • 2014
  • The habitats characteristics of Exochorda serratifolia were investigated to compile basic data for conservation and restoration. Natural habitats were located at an altitude of 1 m to 624 m above sea level with angles of inclination ranging from 2 degrees to 81 degrees. A total of 248 vascular plant taxa were identified from 37 quadrats in 16 habitats. The importance value of Exochorda serratifolia is 18.70%, and 5 highly ranked species such as Rhododendron mucronulatum (3.79%), Abelia tyaihyoni (3.27%), Euonymus alatus for. ciliatodentatus, Quercus mongolica (3.23%), and Indigofera kirilowii (2.97%) are considered to be an affinity with Exochorda serratifolia in their habitats. Species diversity was 1.03, dominance and evenness were found to be 0.15 and 0.85, respectively. Average field capacity was 24.19%, the organic matter was 8.21%, pH was 5.52, and available phosphorus was $7.71{\mu}g/g$. Correlation coefficients analysis based on environmental factors, vegetation, and soil analysis shows that the coverage of Exochorda serratifolia is correlated with field capacity and available phosphorus.

A Study on Thermal Characteristics of Stratospheric Airship Considering Radiation Heat Transfer (복사 열전달에 의한 성층권 무인 비행선의 열 특성 연구)

  • Kim Seung-Min;Lee Sang-Myeong;Roh Tae-Seong;Choi Dong-Hwan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.285-288
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    • 2005
  • A Stratospheric airship should stay long to achieve its original mission. Meanwhile, to obtain what the solar radiation and heat transfer have an effect on Stratospheric condition, heat analysis has been done. For this work, Stratospheric heat condition's been examined and for the numerical analysis, by using Gridgen, grids of airship have been generated. And by using STAR-CD, the study about heat characteristic of airship model was carried out. Especially, with changing the position of the Sun, the temperature change of the airship body was focused on. With this background, the possibility of realizing the simulation of the effects solar radiation have on the Stratospheric airship.

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A Study on Thermal Characteristics of Stratospheric Airship Considering Radiation Heat Transfer (복사 열전달에 의한 성층권 무인 비행선의 열 특성 연구)

  • Kim Seung-Min;Lee Sang-Myeong;Park Hwi-Seob;Roh Tae-Seong;Choi Dong-Hwan
    • Journal of the Korean Society of Propulsion Engineers
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    • v.10 no.2
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    • pp.31-38
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    • 2006
  • A study of thermal characteristics of the airship considering radiation heat transfer has been conducted by building a numerical model for the airship in order to identify the possibility to obtain the reliable flight performance in severe stratospheric heat conditions. The variations of distributed temperature of the skin and the inner flow by free convection have been calculated according to the change of the solar position. As the results of the analyses, the stratospheric heat conditions slightly have an influence on the flight performance of the airship.

Extreme Wave Hindcast in the Neighboring Seas of Korea from Loosely Coupled Wave-Tide-Surge Model (약결합된 해파-조석-해일 모형에 의한 한반도 주변해면의 최극해파 추정)

  • 최병호;엄현민
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2000.09a
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    • pp.37-46
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    • 2000
  • 한반도 주변해역은 고조위와 태풍의 내습에 의한 강한 파랑으로 특징지워진다. 저조위때에 나타나는 1700$\textrm{km}^2$에 달하는 갯벌로 이루어진 서해안과 황해 동쪽 지역의 해안의 조건은 경기만에 l0m 범위의 높은 조위 차와 동계 계절풍과 태풍으로 인한 4-5m에 달하는 높은 파고를 발생시키는 고에너지와 높은 탁도 환경을 만들어 내는 매개체가 된다. (중략)

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Investigation of Technical Requirements for a Protective Shield with Lunar Regolith for Human Habitat (월면토를 이용한 달 유인 우주기지 보호층의 기술적 요구조건에 관한 연구)

  • Lee, Jangguen ;Gong, Zheng;Jin, Hyunwoo ;Ryu, Byung Hyun;Kim, Young-Jae
    • Journal of the Korean Geotechnical Society
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    • v.39 no.10
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    • pp.49-55
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    • 2023
  • The discovery of lunar ice in the lunar polar region has fueled international interest in in situ resource utilization (ISRU) and the construction of lunar habitats. Unlike Earth's atmosphere, the Moon presents unique challenges, including frequent meteoroid impacts, direct exposure to space radiation, and extreme temperature variations. To safeguard lunar habitats from these threats, the construction of a protective shield is essential. Lunar regolith, as a construction material, offers distinct advantages, reducing transportation costs and ensuring a sustainable supply of raw materials. Moreover, it streamlines manufacturing, integration schedules, and enables easy repairs and modifications without Earth resupply. Adjusting the shield's thickness within the habitat's structural limits remains feasible as lunar conditions evolve. Although extensive research on protective shields using lunar regolith has been conducted, unresolved conflicts persist regarding shield requirements. This study conducts a comprehensive analysis of the primary lunar threats and suggests a minimum shield thickness of 2 m using lunar regolith. Furthermore, it outlines the necessary technology for the rapid construction of such protective shields.

Characteristics of Accumulated Soil Carbon and Soil Respiration on Vegetation in Namhangang Basin (남한강 수변역식생의 토양탄소축적량과 토양호흡 특성)

  • Jung, Jisun;Yi, Joonseok;Lee, Jaeho;Shim, Kyomoon;Lee, Jaeseok
    • Korean Journal of Environmental Biology
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    • v.32 no.4
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    • pp.363-370
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    • 2014
  • Various ecosystem carry out fundamental function of material circulation and energy flow through interrelationship with many environmental factors. Therefore, it is crucial to scientifically understand the value of nature to deduce correlation between environmental factor and change of ecosystem function. In this study, we determined the accumulated ecosystem carbon and characteristics of soil respiration on grassland vegetation in Namahangang basin in Namhangang Basin. It was found that the rate of soil respiration was highly correlated with the soil temperature in all communities. The measured soil respiration rates were $1,539mgCO_2\;m^{-2}h^{-1}$, $1,200mgCO_2\;m^{-2}h^{-1}$, $1,215mgCO_2\;m^{-2}h^{-1}$ in Miscanthus sacchariflorus, Phragmites japonica, Salix koreensis communities, respectively. Also, carbon quantities accumulated in litter and soil layers were $40.6tCha^{-1}$ (1.9+38.7), $46.9tCha^{-1}$ (43.0+3.9), $31.2tCha^{-1}$ (28.9+2.3) in M. sacchariflorus, P. japonica, S. koreensis communities, respectively.