• 제목/요약/키워드: ESA

검색결과 260건 처리시간 0.029초

HERSCHEL OBSERVATIONS IN THE AKARI NEP FIELD: INITIAL SOURCE COUNTS

  • Pearson, Chris;Cheale, Ryan;Serjeant, Stephen;Matsuhara, Hideo;White, Glenn J.;Burgarella, Denis;Valtchanov, Ivan;Altieri, Bruno;Clements, David L.;Hopwood, Ros
    • 천문학논총
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    • 제32권1호
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    • pp.219-223
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    • 2017
  • The preliminary data reduction, analysis and first results from the Herschel survey of the AKARI NEP field are presented. Herschel SPIRE observations of the NEP-Wide region and PACS observations of the NEP-Deep region have yielded galaxy catalogues of 4000 and 900 sources respectively down to flux density levels of approximately 15 mJy at 100-250 microns. Source counts produced from these catalogues reach cosmologically significant depths tracing the evolutionary upturn and turnover in the source counts. The source counts are in agreement with other large area surveys carried out with Herschel bridging the gap between the shallow and deep Herschel surveys.

ASTM 규격을 통한 국내 부지조사 기법 개발

  • 안훈기;권영호;박신영;이영훈;공성호
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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    • pp.291-294
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    • 2002
  • The Environmental Site Assessment System(ESAS) in Korea which became effective as of 2002 is very similar to the ASTM standard practice in United States. Unlike the United States, however, we do not have Phase I ESA, enough environmental professionals with approved training and practical experiences, and detailed guidelines for a governmental action. As a result of comparison the ESAS with the ASTM standard practice, the ASTM standard practice is focused on the Innocent Landowner Defense and has a difference in data search process as well as legal and methodological ways from the ESAS. Therefore, the Transaction Screen Process in ASTM E-1528 standard practice is suggested to reduce the risk potentially produced under on-site assessment and to achieve efficient on-site assessment. In addition, social and executive supports are discussed to more activate on-site assessment. In near future this study is expected to be standardized more in detail with activation of on-site assessment and it is also expected to increase the role and responsibility of environmental professionals considerably.

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유도 전동기의 토크신호를 이용한 베어링 고장진단 연구 (A Study on Bearing Diagnosis of Induction Motor using Torque Signature)

  • 홍영희;선현규;박진엽
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.638_639
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    • 2009
  • The motors faults including mechanical rotor imbalances, broken rotor bar, bearing failure and eccentricities problems are reflected in electric, electromagnetic and mechanical quantities. This paper presents a study and the practical implementation of an induction motor for reactor containment fan cooler in nuclear power plant with Electric Signature Analysis(ESA). The results obtained present a good degree of reliability hence; the ESA predictive maintenance tools enable a pro-active evaluation of induction motors performance prior to failure.

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A Theoretical and Experimental Investigation into Pair-induced Quenching in Bismuth Oxide-based Erbium-doped Fiber Amplifiers

  • Jung, Min-Wan;Shin, Jae-Hyun;Jhon, Young-Min;Lee, Ju-Han
    • Journal of the Optical Society of Korea
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    • 제14권4호
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    • pp.298-304
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    • 2010
  • The pair-induced quenching (PIQ) effect in a highly doped bismuth oxide-based erbium-doped fiber amplifier (EDFA) was theoretically and experimentally investigated. In the theoretical investigation, the bismuth oxide-based EDFA was modeled as a 6-level amplifier system that incorporated clustering-induced concentration quenching, cooperative up-conversion, pump excited state absorption (ESA), and signal ESA. The relative number of paired ions in a highly doped bismuth oxide EDF was estimated to be ~6.02%, determined by a comparison between the theoretical and the experimentally measured gain values. The impacts of the PIQ on the gain and the noise figure were also investigated.

세계 우주기구의 Space Link Extension 기술 구축 현황

  • 구인회;안상일
    • 항공우주산업기술동향
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    • 제5권2호
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    • pp.67-76
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    • 2007
  • 세계 각국의 위성임무를 수행하는 기관들은 지구상의 지리적인 제약에 구애받지 않고 자신들의 위성과 언제든지 데이터를 송 수신할 수 있는 기능을 확보하고자 많은 노력을 기울였다. 이런 시대적인 희망사항은 위성과 지상과의 프로토콜 국제 표준을 권고하는 CCSDS(Consultative Committee for Space Data System)에서 Space Link Extension 통신프로토콜 표준을 제정함으로써 Cross Support라는 개념으로 글로벌한 협력환경을 구축할 수 있게 되었다. 이렇게 구축된 Cross Support 환경은 교신할 수 없는 자신들의 위성에 교신을 필요로 할 때 그 위치의 위성과 교신할 수 있는 리소스를 가진 기관이 대신 미션에 대한 송 수신을 하고 지상망을 통하여 데이터를 전달하는 글로벌한 시스템을 이루고 있다. 현재 NASA를 비롯한 유럽의 ESA에서 이미 SLE 서비스가 이슈화되어 개발되었고, 많은 사례가 보고되고 있다. 해외 개발 사례로 현재 NASA와 ESA를 비롯한 해외 우주기관들이 개발한 SLE-SM(Service Management)를 들 수 있다. 이에 항우연에서도 위성운용에 유용하게 사용될 것으로 판단하여, 본 연구에서는 CCSDS에서 제공하는 SLE 서비스에 대한 개념과 해외 구축사례를 기술하였다.

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통신해양기상위성 Ka 대역 통신탑재체의 안전 위험성 분석 연구 (A study on safety hazard analysis for development of Ka band Communication Payload System of COMS)

  • 정철오;이성팔
    • 항공우주시스템공학회지
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    • 제4권1호
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    • pp.27-31
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    • 2010
  • The scope of this paper is to analyze the safety aspects of the Ka-band payload system which are associated with testing, transportation, integration, handling and storage. According to ESA philosophy and the ECSS-Q-40A "Space Product Assurance - Safety", safety hazard analysis of Ka band payload was performed. In this paper, it is indicated the requirements to be satisfied for eliminating, reducing, or controlling the hazards and by showing how they have been implemented in the COMS design. And it shows the safety hazard analysis result which has performed the analysis according to ESA document and also shows the potential hazard cause, potential effects, hazard grade and criteria resolution of Ka band COPS.

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Optimal Design of a Novel Permanent Magnetic Actuator using Evolutionary Strategy Algorithm and Kriging Meta-model

  • Hong, Seung-Ki;Ro, Jong-Suk;Jung, Hyun-Kyo
    • Journal of Electrical Engineering and Technology
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    • 제9권2호
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    • pp.471-477
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    • 2014
  • The novel permanent magnetic actuator (PMA) and its optimal design method were proposed in this paper. The proposed PMA is referred to as the separated permanent magnetic actuator (SPMA) and significantly superior in terms of its cost and performance level over a conventional PMA. The proposed optimal design method uses the evolutionary strategy algorithm (ESA), the kriging meta-model (KMM), and the multi-step optimization. The KMM can compensate the slow convergence of the ESA. The proposed multi-step optimization process, which separates the independent variables, can decrease time and increase the reliability for the optimal design result. Briefly, the optimization time and the poor reliability of the optimum are mitigated by the proposed optimization method.

Forest Fire Monitoring System Using Remote Sensing Data

  • Hwangbo, Ju-Won;Yu, Ki-Yun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.747-749
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    • 2003
  • For forest fire monitoring in relatively cool area like Siberia, design of Decision Support System (DSS) is proposed. The DSS is consisted of three different algorithms to detect potential fires from NOAA AVHRR image. The algorithm developed by CCRS (Canada Center for Remote Sensing) uses fixed thresholds for multi-channel information like one by ESA (European Space Agency). The algorithm of IGBP (International Geosphere Biosphere Program) involves contextual information in deriving fire pixels. CCRS and IGBP algorithms are rather liberal compared to more conservative ESA algorithm. Fire pixel information from the three algorithms is presented to the user. The user considers all these information in making decision about the location fire takes place.

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정전효과를 고려한 반도체 웨이퍼의 입자침착 특성 (Particle Deposition Characteristics with Electrostatic Effect on Semiconductor Wafers)

  • 이건형;채승기;문영준
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.779-785
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    • 2006
  • Particle transport and deposition characteristics on semiconductor wafers inside the chamber were experimentally investigated via a particle generation & deposition system and a wafer surface scanner. Especially the relation between particle size($0.083{\sim}0.495{\mu}m$) and particle deposition velocity with ESA(Electrostatic Attraction) effect was studied. Spot deposition technique with the deposition system using nozzle type outlets of the chamber was newly conducted to derive particle deposition velocity and all experiment results were compared with the previous study and were in a good agreement as well.

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