• Title/Summary/Keyword: Near Space

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Mathematical Modelling on THM Coupling in High-Level Radioactive Waste Repository (고준위 방사성폐기물 처분장에서의 THM 상호반응의 수학적 모델 개발)

  • 황용수;김진웅;강철형
    • Tunnel and Underground Space
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    • v.8 no.1
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    • pp.26-36
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    • 1998
  • To assess the groundwater flow near high-level radioactive waste repositories, it is important to understand the effect of coupling among thermal, hydraulic, and mechanical effects. In this paper, detailed mathematical approach to model the groundwater flow near the waste form surrounded by buffer, influenced by decay heat of radioactive waste along with stress change is developed. Two cases(1) before the full expansion of buffer and (2) after the full expansion of buffer are modelled. Based on the mathematical models in this paper, detailed numerical study shall be pursued later.

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Vibration of elastic and viscoelastic multilayered spaces

  • Karasudhi, P.;Liu, Y.C.
    • Structural Engineering and Mechanics
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    • v.1 no.1
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    • pp.103-118
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    • 1993
  • The near field is discretized into finite elements, and the far field into infinite elements. Closed form far-field solutions to three fundamental problems are used as the shape functions of the infinite elements. Such infinite elements are capable of transmitting all surface and body waves. An efficient scheme to integrate numerically the stiffness and mass matrices of these elements in presented. Results agree closely with those obtained by others.

Design and Performance Analysis of Downlink in Space Communications System for Lunar Exploration

  • Lee, Woo-Ju;Cho, Kyong-Kuk;Yoon, Dong-Weon;Hyun, Kwang-Min
    • Journal of Astronomy and Space Sciences
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    • v.27 no.1
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    • pp.11-20
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    • 2010
  • This paper designs a data link between a Lunar Orbiter (LO) and an Earth Station (ES), and analyzes the downlink performance of a space communications system for lunar exploration, conforming to the recommendations by the Consultative Committee for Space Data Systems (CCSDS). The results provided in the paper can be useful references for the design of reliable communication link for the Korean lunar exploration in the near future.

THE ION ACOUSTIC SOLITARY WAVES AND DOUBLE LAYERS IN THE SOLAR WIND PLASMA

  • Choi C.R.;Lee D.Y.;Kim Yong-Gi
    • Journal of Astronomy and Space Sciences
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    • v.23 no.3
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    • pp.209-216
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    • 2006
  • Ion acoustic solitary wave in a plasma consisting of electrons and ions with an external magnetic field is reinvestigated using the Sagdeev's potential method. Although the Sagdeev potential has a singularity for n < 1, where n is the ion number density, we obtain new solitary wave solutions by expanding the Sagdeev potential up to ${\delta}n^4$ near n = 1. They are compressiv (rarefactive) waves and shock type solitary waves. These waves can exist all together as a superposed wave which may be used to explain what would be observed in the solar wind plasma. We compared our theoretical results with the data of the Freja satellite in the study of Wu et al. (1996). Also it is shown that these solitary waves propagate with a subsonic speed.

Korean ALMA Near-term Technical Activities: Development Plan of Focal Plane Array for ASTE

  • Lee, Jung-Won;Kim, Jongsoo;Lee, Chang-Won;Je, Do-Heung;Kang, Yong-Woo;Lee, Bangwon
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.116.2-116.2
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    • 2014
  • As Korean engineering contribution to ALMA enhancement, development of focal plane arrays(FPAs) for the total power array in ALMA compact array has been projected mainly to increase mapping speed in interferometric multi-pointing observation(mosaicking). To tackle engineering issues expected in order to be compatible with the existing ALMA receivers, we plan to develop a prototype 300-500 GHz heterodyne FPA system including a software spectrometer using GPU clusters for ASTE(Atacama Submillimeter Telescope Experiment) telescope by 2017.

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A Proposal on the Peaceful and Efficient Use of Space Resources for Meeting Increased Satellite Demand in the Asia-Pacific Region

  • HwangBo, Han
    • The Korean Journal of Air & Space Law and Policy
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    • v.9
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    • pp.421-433
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    • 1997
  • The orbit and frequency spectrum allocation for the communication and broadcasting satellite services are coordinated between the concerned parties according to the Radio Regulations of International Telecommunication Union (ITU). Currently, the geostationary orbit is filled with too many satellites for the commercial or military uses. In addition, a number of near earth satellite programs are being introduced. As each country claims for the space orbit and spectrum, the limited space resources are being exhausted. In this paper, the current situations in the worldwide satellite orbit demand are discussed, and some ideas on the peaceful, efficient and equitable use of space resources are proposed.

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A Study on the improvement of Residential Environment in Housing Area (주거단지내의 주거환경개선 방안에 관한 연구 - 이면도로 공간을 중심으로 -)

  • 김한수;송흥수
    • Journal of the Korean housing association
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    • v.8 no.3
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    • pp.197-207
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    • 1997
  • This study is about the improvement of housing environment through the research and analysis on how district-level roads are used and what the residents want about housing environment. The results are as follows: 1. As a result of the research on space usage, we could get the conclusion that street furniture occupies much space in the district-level roads, and the main causes of the space usage problems are from cars. 2. Because much space is used for parking, the district-level roads supposed to be the place for the pleasant and safe housing is changing into the main cause of the housing problems. Therefore we should find how to prevent the housing environment from being deteriorated through pridicting the traffic generation of future residential area. 3. Most residents park their cars near their houses in the district-level roads. In order to solve this problem, we have to secure the parking space and guarantee the safe traffic by designing the road space efficiently in spite of the inconvenience.

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Planning Guidelines for Outdoor Space in the Apartment Complex by Investigating Usage Behavior (이용행태조사를 통한 아파트 외부공간 계획방안에 관한 연구)

  • 김정례;박희진
    • Journal of the Korean housing association
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    • v.12 no.3
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    • pp.1-12
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    • 2001
  • The purpose of this study was to investigate the outdoor space of the recent built apartment complex in Ulsan and to provide the basic information for planning and apartment outdoor space. Multiple methods were utilized such as questionnaire, observation, behavior-mapping, and photography. The sample consisted of 382 residents living in four apartment complex in Ulsan. data were analyzed by frequency and percentage using SPSS PC+. The observation was performed in seven outdoor space, i.e., green area, road area, exercise area, play area, parking area, and approach area. According to the findings of this study, residents did not actively involve in outdoor activities and seldom use the outdoor space. Various changes and erosions were observed as a trace, especially near fence and grass area because of unplanned location of entrances. Finally this study suggested several planning guidelines for outdoor space in apartment complex.

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A Study on the Concept of Learning Environment According to the Philosophy of Child-Centered Education in Europe in the Early 20th Century (20세기 초 유럽의 아동중심 교육철학에 따른 학습환경 개념에 대한 고찰)

  • Rieu, Ho-Seoup
    • Journal of the Korean Institute of Educational Facilities
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    • v.24 no.1
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    • pp.11-22
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    • 2017
  • The main purpose of this research is to consider educational environment, concept, and spatial organization and its characteristic based on the early 20th century European child-centered educational philosophy. For this process, the study of the following have been done : 1) Literature review, which includes educational ideology, perspective of child development of Maria Montessori, Rudolf Steiner, Peter Peterson, and Celestin Freinet. 2) Comparisons of spatial organization and classrooms of schools operated with the educational philosophy of mentioned philosophers from above. These schools have classrooms(or multi-purpose space near classroom) contained self-directed individual learning space, group and collaborative learning space, and training space of practical life. These configuration of learning space intended 1) learning based on individual child's interest, experience 2) developing of responsibility based on freedom 3) sociality and community spirit of children.