• 제목/요약/키워드: Space maintenance

검색결과 850건 처리시간 0.042초

Plasmaspheric contribution to the GPS TEC

  • Jee, Geon-Hwa;Lee, Han-Byul;Kim, Yong-Ha;Chung, Jong-Kyun;Cho, Jung-Ho
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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    • pp.30.3-31
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    • 2010
  • We performed a comprehensive comparison between GPS Global Ionosphere Map (GIM) and TOPEX/Jason (T-J) TEC data for the periods of 1998~2009 in order to assess the performance of GIM over the global ocean where the GPS ground stations are very sparse. Using the GIM model constructed by CODE at University of Bern, the GIM TEC values were obtained along the T-J satellite orbit at the locations and times of the measurements and then binned into various geophysical conditions for direct comparison with the T-J TECs. On the whole, the GIM model was able to reproduce the spatial and temporal variations of the global ionosphere as well as the seasonal variations. However, the GIM model was not accurate enough to represent the well-known ionospheric structures such as the equatorial anomaly, the Weddell Sea Anomaly, and the longitudinal wave structure. Furthermore, there seems to be a fundamental limitation of the model showing the unexpected negative differences (i.e., GPS < T-J) in the northern high latitude and the southern middle and high latitude regions. The positive relative differences (i.e., GIM > T-J) at night represent the plasmaspheric contribution to GPS TEC, which is maximized, reaching up to 100% of the corresponding T-J TEC values in the early morning sector. In particular, the relative differences decreased with increasing solar activity and this may indicate that the plasmaspheric contribution to the maintenance of the nighttime ionosphere does not increase with solar activity, which is different from what we normally anticipate. Among these results, the plasmaspheric contribution to the ionospheric GPS TEC will be presented in this talk and the rest of it will presented in the companion paper (poster presentation).

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남극 극지점 기지에서의 얼음 터널 프로젝트 (Snow Tunnelling Project at the South Pole)

  • 지왕률
    • 터널과지하공간
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    • 제13권1호
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    • pp.1-5
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    • 2003
  • The United States Antarctic program (USAP) through its principal Support Contractor Raytheon polar Services Co. (RPSC), has recently finished a 3 years projects, almost 936m length of underground utility tunnels at Amundsen-Scott station. It accommodates the piping that conveys fresh water from current well sites, as well as waste water to repositories in abandoned wells. The under snow tunnels allow year-round access for system operations and maintenance.

MPLS 네트워크 상에서의 CUG 서비스 제공을 위한 구조 설계 (Structure Design for CUG(Closed User Group) Services provision at the MPLS network)

  • 권민희;백승진
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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    • pp.117-120
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    • 2002
  • This paper is proposed structure which it sees currently the problem point which it follows in the independent space for work which the members who do a same work from the environment which is to fall tile at distance, therefore the MPLS based VPN necessary to follow, it forms the small-scale group which is closed again with the CUG(Closed User Group) it will be able to own jointly information to present a structure, the individual small-scale groups are closed from outside and the group members are the CUG authentication Process for the security maintenance the model which is possible.

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설비분야 BIM 설계에 따른 건축환경 변화와 인재양성의 필요성 (The Needs for Training Manpower and the Change in Construction Environment by Equipment Based BIM Design)

  • 김종환
    • 한국산업융합학회 논문집
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    • 제14권4호
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    • pp.157-165
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    • 2011
  • The study figures out the alternatives of training BIM design experts which is the biggest obstacle in training manpower of professional BIM designer, the largest problem when the plant introduce BIM design about the change in Construction Environment by Equipment Based BIM Design in reality of design followed by equipment based BIM design, education institution plan. BIM is the system which is built to make these information be used easier and technique which enables design construction and maintenance in 3-dimensional virtual space by designing buildings in 3-dimensional space, and by data-basing the generated information of every life-cycle information. As the essential contents of the study, educational institutions with the public authority should invest the opening of educational programs, recruit of experts and development of textbooks from a long-term perspective. And also, the role of public institution is important above all for the development of construction industry.

Computational Analysis of the Aerodynamic Performance of a Long-Endurance UAV

  • Jin, Wonjin;Lee, Yung-Gyo
    • International Journal of Aeronautical and Space Sciences
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    • 제15권4호
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    • pp.374-382
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    • 2014
  • This paper presents the computational aerodynamic analysis of a long-endurance UAV that was developed by the Korea Aerospace Research Institute (KARI), named EAV-2. EAV-2 is a technical demonstrator of aerodynamically efficient design, as well as a hybrid electric-propulsion system for future long-endurance UAVs. We evaluated the aerodynamic characteristics of six low-Reynolds number airfoils, using a panel method code, XFOIL, to select an optimal airfoil for the long-endurance mission of EAV-2. The computational results by a CFD code, FLUENT, suggested that the aerodynamic performance of EAV-2 would be notably improved after adopting SG6043 airfoil, and modifying the fuselage design. This reduced the total drag by 43%, compared to that of a previous KARI model, EAV-1, at the target lift of $C_L=1.0$. Also, we achieved a drag reduction of approximately 14% by means of the low-drag fuselage configuration.

지하교통공간 방재안전관리 기준 수립에 관한 연구 (A study on the standard for disaster prevention & safety management in the traffic space under ground)

  • 신태균;윤우진;홍지훈;조원철;이태식
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2007년도 정기총회 및 학술발표대회
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    • pp.246-249
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    • 2007
  • This paper discusses the standards for disaster prevention and safety management of rail tunnel. The purpose is to establish safety management standards and methods of disaster prevention for each underground traffic spaces, after the full revision of the cause of accidents and its effects, the function and selection of safety equipment, and the efficiency and convenience of maintenance, standards based on prevention and reduction is proposed to reaction to disaster.

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도시 내 주민참여형 커뮤니티 가든 계획의 초기단계에 관한 연구 (Initial Stage of Plan for Urban Residents Participation Community Garden)

  • 박은지;이연숙
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2011년도 춘계학술발표대회 논문집
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    • pp.135-140
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    • 2011
  • Recently, people aim for a healthy environment which enhances quality of life, and also there are communication in green space like therapy garden and weekend farm growing. Meanwhile, in Korea, administrative organizations have leaded to plan and proceed in reference to physical regeneration in local areas, and this had caused social and maintenance problems. The purpose of this study was to introduce a concept of community garden which is regarded as green and community space and to insist on a way of residents participation on plan for community garden and its necessity. For that, there were five ways of residents participation on plan for community garden based on literatured and theoretical contemplation and case studies, and these were subject to construction project of community garden in deteriorated area in Jeonju city. This study can provide improvement guidelines for the initial stage of plan for residents participation community garden.

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중형버스의 전복 강도해석 (An Analysis for Rollowver Strength of a Medium Bus)

  • 민한기;김택
    • 한국자동차공학회논문집
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    • 제7권7호
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    • pp.195-201
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    • 1999
  • In Rollover crashes, the development of bus structure to ensure the maintenance of survival space for passengers is very important . So, this paper focuses on understanding the possibility of efficient structural development considering rollover strength through computer simulation using the commercial code, LS-DYNA3D at the initial stage of vehicle development structural members, and impact boundary conditions required by ADR59(Australian Design Rule 59)were applied. In order to confirm the validity of the computational results, the test results. After the usefulness of this method of analysis was confirmed , we have proposed the effective modificationfor rollover strength.

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Galactic Warps in Live Triaxial Halos

  • Jeon, Myoung-Won;Kim, Sung-Soo S.;Ann, Hong-Bae
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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    • pp.30.1-30.1
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    • 2008
  • We investigate the evolution of the initially tilted, self-gravitating disks in a live axisymmetric or triaxial halo. Our study shows how the axisymmetric and triaxiaility of the halo alters the evolution of the warp compared to the spherical case. We attribute the development of warps to the torque between a halo and disk and that between the inner and outer regions of the disk. We discuss if the triaxial halo can be responsible for the formation and maintenance of the warp phenomena even in the presence of dynamical friction between the disk and the halo.

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문서 범주화를 이용한 지식관리시스템에서의 전문가 분류 자동화 (Automation of Expert Classification in Knowledge Management Systems Using Text Categorization Technique)

  • 양근우;허순영
    • Asia pacific journal of information systems
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    • 제14권2호
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    • pp.115-130
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    • 2004
  • This paper proposes how to build an expert profile database in KMS, which provides the information of expertise that each expert possesses in the organization. To manage tacit knowledge in a knowledge management system, recent researches in this field have shown that it is more applicable in many ways to provide expert search mechanisms in KMS to pinpoint experts in the organizations with searched expertise so that users can contact them for help. In this paper, we develop a framework to automate expert classification using a text categorization technique called Vector Space Model, through which an expert database composed of all the compiled profile information is built. This approach minimizes the maintenance cost of manual expert profiling while eliminating the possibility of incorrectness and obsolescence resulted from subjective manual processing. Also, we define the structure of expertise so that we can implement the expert classification framework to build an expert database in KMS. The developed prototype system, "Knowledge Portal for Researchers in Science and Technology," is introduced to show the applicability of the proposed framework.