• 제목/요약/키워드: SELENE

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SGM90d모델을 이용한 달 중력장 분포 및 특징 분석 (Analysis Distribution and Feature of Lunar Gravity Field Using SGM90d Model)

  • 황학;윤홍식;이동하
    • 한국측량학회지
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    • 제27권2호
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    • pp.129-138
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    • 2009
  • 달 중력장은 달의 내부구조와 이분성 및 마그마 바다의 분화 진화과정을 이해하고, 더 나아가 달의 기원과 진화를 규명하기 위한 중요한 자료이다. 본 연구에서는 달 탐사의 역사와 달의 중력장 탐지 및 중력장모델의 발전과정을 고찰하였으며, 최근에 임무를 종료한 일본의 SELENE위성의 관측방식을 소개하고, SELENE위성의 궤도추적자료를 처리하여 개발된 달 중력장모델 SGM90d(SELENE Gravity Model)를 이용해 달 전체의 중력이상을 결정하였으며, 기존의 달 중력장 모델인 LP165P모델과 비교분석을 수행하였다. SGM90d를 분석해 본 결과, SELENE위성의 4중 도플러 관측방식은 달 뒷면의 중력장 직접 관측에 매우 효과적이었으며, 달 뒷면 중력장의 최초 결정은 달의 메스콘과 같은 중력이상의 상세한 분포를 확인하고 달의 이분성을 이해하는데 큰 도움이 되었다.

THE SELENE MISSION AND JAPANESE LUNAR EXPLORATION SCENARIO

  • NODA HIROTOMO;HANADA HIDEO;KAWANO NOBUYUKI;IWATA TAKAHIRO
    • 천문학회지
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    • 제38권2호
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    • pp.311-314
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    • 2005
  • We report the current status of Japanese lunar exploration SELENE (SELenological and ENgineering Explorer). As of the end of 2004, scientific instruments onboard the Main Orbiter are under final checkout before they are provided to the proto-flight-model (PFM) integration test. Also, we present the future perspectives of the lunar based instruments and facilities. 'In-situ Lunar Orientation Mea-surement (ILOM)' experiment measures the lunar rotation with high accuracy by tracking stars on the Moon with a small photo-zenith-tube type optical telescope. A basic idea of a radio telescope array of very low frequency range on the lunar far-side is also mentioned.

GEOLOGICAL AGE AND THICKNESS ESTIMATION OF LAVA AT MARE CRISIUM BY LUNAR SURFACE GIS

  • Kazama, Yoriko;Matsunaga, Tsuneo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.333-336
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    • 2007
  • SELENE, a Japanese lunar mission, has been launched this year. There are large volumes of images that were already archived and will be archived by missions such as SELENE. Automatic image analysis systems, which extract useful information from large amounts of data, are now required. The authors propose Lunar Surface GIS, which archives lunar surface information collected by lunar orbiting spacecraft and conducts geological analysis automatically. This system includes automatic crater detection, automatic age determination, and lava thickness estimation methods. In this paper, methods for automatically determining the age and estimating the lava thickness of lunar mare are described. The lunar surface age was determined by analyzing data of detected crater size and number using a crater chronology method. Lava thickness was estimated by the extent of the overlying material around the crater as well as the composition of underlying terrain units. In this result, the age map at Mare Crisium suggests the mare had been formed 3.0-3.7 b.y. ago. The lava thickness result suggests the thickest part of the mare is distributed around the center of the mare. The Lunar Surface GIS can produce a geological map, age map, and mare lava thickness map, for example.

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In-Space Performance of "KAGUYA" Lunar Explorer Propulsion Subsystem

  • Masuda, Ideo;Goto, Daisuke;Kagawa, Hideshi;Kajiwara, Kenichi;Sasaki, Takeshi;Tamura, Masayuki;Takahashi, Mamoru;Kasuga, Kazuhito;Ikeda, Mizuho
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년 영문 학술대회
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    • pp.407-412
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    • 2008
  • "KAGUYA"(SELENE) is a Japanese Lunar Explorer launched by H-IIA rocket from Tanegashima Space Center on 14 September 2007. The dual-mode bipropellant propulsion subsystem of KAGUYA includes two fuel tanks, an oxidizer tank, propellant and pressurant control components, twelve monopropellant 20N thrusters, eight monopropellant 1N thrusters, and a bipropellant 500N Orbit Maneuver Engine(OME). Once the KAGUYA separated from the rocket, it circled the Earth twice and traveled to the Moon, where it entered lunar orbit. All maneuvers were performed through multiple 500N OME/20N thruster firings. This paper describes the in-space performance of KAGUYA Lunar Explorer bipropellant propulsion subsystem.

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달탐사용 탑재체 개발을 위한 전산응용 개념 설계 (CONCEPTUAL DESIGN BY APPLIED COMPUTATIONAL ENGINEERING FOR THE MOON EXPLORER PAYLOAD DEVELOPMENT)

  • 김정훈;전형열;주광혁;김병수
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.173-178
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    • 2011
  • Nowadays, SELENE-2 is under development for the moon explorer rover in Japan. AXS(Active X-ray Spectrometer) sensor development among the candidated payloads will be on going by the world-wide co-operation. The thermal design, analysis and test will be specially performed by Korean institutes. CFD techniques are used for the conceptual design and analysis. Thin-shell plate meshes being applied by Monte-Carlo Ray Tracing Method are generated for the thermal radiation analysis. Lumped capacity model is employed for the thermal conduction simulation of the AXS payload itself. Various shapes of the payload configuration with thermal boundary conditions are proposed and selected on the purpose of the analysis of the initial design. The results of the analysis are supposed to be used as the baseline for the further detailed design of the AXS payload in the future.

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무인 달 착륙선 설계 사례 분석 (A Case Study of Unmanned Lunar Lander Design)

  • 류동영;주광혁;김성훈;이상률
    • 항공우주산업기술동향
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    • 제8권1호
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    • pp.62-76
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    • 2010
  • 본 논문에서는 최근에 다른 나라에서 진행된 무인 달 착륙선의 설계에 대한 사례 조사를 수행하고 이를 통하여 무인 달 착륙선의 설계 동향을 파악하였다. 무인 달 착륙선으로는 일본의 SELENE-2, 유럽의 LEDA와 MoonNEXT, 미국의 모듈형 소형 우주선을 이용한 달 탐사, 그리고 미국이 제안한 국제 달 탐사 네트워크의 미국 노드인 Anchor Nodes의 임무 수행을 위하여 설계된 달 착륙선 등을 조사의 대상으로 하였다. 각 조사 대상의 착륙선에 대하여 임무 요구 조건을 확인하고, 임무 설계의 내용을 조사하였다. 또한 달 표면에 안전하게 착륙하기 위한 유도제어의 방법, 센서의 구성, 임무 요구 사양을 만족하기 위하여 선정한 센서 및 구동기의 성능 사양 등을 분석하였다.

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Isolation and molecular identification of Vibrio harveyi from the look down fish (Selene vomer)

  • Jun, Jin-Woo;Lee, Young-Ran;Giri, Sib Sankar;Kim, Hyoun-Joong;Yun, Sae-Kil;Chi, Cheng;Kim, Sang-Guen;Koh, Jeong-Rack;Jung, Ji-Yun;Lee, Byeong-Chun;Park, Se-Chang
    • 대한수의학회지
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    • 제56권2호
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    • pp.125-127
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    • 2016
  • Gradual mortality of look down fish (Selene vomer) was observed in a private aquarium in Seoul, showing abnormal swimming behavior and lethargy. A bacterial pathogen from kidney was cultured, identified, and confirmed as Vibrio harveyi using Vitek System 2 and 16S rRNA gene sequencing. A predominant bacterial strain, SNUVh-LW2 was proved to be most closely related to isolates from China by phylogenetic analysis with minimum evolution method. Also, tetracycline was considered as the most sensitive antibiotic agent via antibiotic susceptibility test. The group of fish was treated according to the diagnostic result and no more mortality was observed.

Stunting and Gut Microbiota: A Literature Review

  • Jessy Hardjo;Nathasha Brigitta Selene
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제27권3호
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    • pp.137-145
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    • 2024
  • Stunting, a condition characterized by impaired growth and development in children, remains a major public health concern worldwide. Over the past decade, emerging evidence has shed light on the potential role of gut microbiota modulation in stunting. Gut microbiota dysbiosis has been linked to impaired nutrient absorption, chronic inflammation, altered short-chain fatty acid production, and perturbed hormonal and signaling pathways, all of which may hinder optimal growth in children. This review aims to provide a comprehensive analysis of existing research exploring the bidirectional relationship between stunting and the gut microbiota. Although stunting can alter the gut microbial community, microbiota dysbiosis may exacerbate it, forming a vicious cycle that sustains the condition. The need for effective preventive and therapeutic strategies targeting the gut microbiota to combat stunting is also discussed. Nutritional interventions, probiotics, and prebiotics are among the most promising approaches to modulate the gut microbiota and potentially ameliorate stunting outcomes. Ultimately, a better understanding of the gut microbiota-stunting nexus is vital for guiding evidence-based interventions that can improve the growth and development trajectory of children worldwide, making substantial strides toward reducing the burden of stunting in vulnerable populations.

Investigation of Reflectance Distribution and Trend for the Double Ray Located in the Northwest of Tycho Crater

  • Yi, Eung Seok;Kim, Kyeong Ja;Choi, Yi Re;Kim, Yong Ha;Lee, Sung Soon;Lee, Seung Ryeol
    • Journal of Astronomy and Space Sciences
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    • 제32권2호
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    • pp.161-166
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    • 2015
  • Analysis of lunar samples returned by the US Apollo missions revealed that the lunar highlands consist of anorthosite, plagioclase, pyroxene, and olivine; also, the lunar maria are composed of materials such as basalt and ilmenite. More recently, the remote sensing approach has enabled reduction of the time required to investigate the entire lunar surface, compared to the approach of returning samples. Moreover, remote sensing has also made it possible to determine the existence of specific minerals and to examine wide areas. In this paper, an investigation was performed on the reflectance distribution and its trend. The results were applied to the example of the double ray stretched in parallel lines from the Tycho crater to the third-quadrant of Mare Nubium. Basic research and background information for the investigation of lunar surface characteristics is also presented. For this research, resources aboard the SELenological and ENgineering Explorer (SELENE), a Japanese lunar probe, were used. These included the Multiband Imager (MI) in the Lunar Imager/Spectrometer (LISM). The data of these instruments were edited through the toolkit, an image editing and analysis tool, Exelis Visual Information Solution (ENVI).

Lunar Pit Craters Presumed to be the Entrances of Lava Caves by Analogy to the Earth Lava Tube Pits

  • Hong, Ik-Seon;Yi, Yu;Kim, Eojin
    • Journal of Astronomy and Space Sciences
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    • 제31권2호
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    • pp.131-140
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    • 2014
  • Lava caves could be useful as outposts for the human exploration of the Moon. Lava caves or lava tubes are formed when the external surface of the lava flows cools more quickly to make a hardened crust over subsurface lava flows. The lava flow eventually ceases and drains out of the tube, leaving an empty space. The frail part of the ceiling of lava tube could collapse to expose the entrance to the lava tubes which is called a pit crater. Several pit craters with the diameter of around 100 meters have been found by analyzing the data of SELENE and LRO lunar missions. It is hard to use these pit craters for outposts since these are too large in scale. In this study, small scale pit craters which are fit for outposts have been investigated using the NAC image data of LROC. Several topographic patterns which are believed to be lunar caves have been found and the similar pit craters of the Earth were compared and analyzed to identify caves. For this analysis, the image data of satellites and aerial photographs are collected and classified to construct a database. Several pit craters analogous to lunar pit craters were derived and a morphological pit crater model was generated using the 3D printer based on this database.