• Title/Summary/Keyword: Near Space

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A Study on the Change of Space Configuration of Dentistry in Korea - Focused on the Analysis of School of Dentistry and Dental Hospital located in Seoul (한국 치의 공간구성의 변화에 관한 연구 - 서울시 소재 치과대학/치의학대학원과 치과병원 분석을 중심으로)

  • Jeong, Taejong;Choi, Jaepil
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.23 no.1
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    • pp.25-36
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    • 2017
  • Purpose: The analysis of space configuration of dentistry through examining Korean dental history and comparison are necessary for the development of planning of the dental healthcare system. This study has been started in order to provide basic information for the planning of hospital architecture in dentistry. Methods: Literature review of space configuration and historical background in dentistry have been conducted. The changes of site plan and space configuration of Seoul National University, Yonsei University and Kyunghee University, School of Dentistry and Dental Hospital have been analyzed in dental history of Korea and corresponding spaces. Results: The result of this study can be summarized in three points. The first one is that space configuration of dentistry in Korea is different from that of West. The clinical treatment space had been started first and the education and research space was followed after a short interval. The second one is that the space configuration in School of Dentistry and Dental Hospital shows that dental space had differentiated and specialized to dental education and clinical space in a building. It had spatially divided and separated to the education and research complex and the dental hospital and it had a branch building. The third one is that the dental public health in Korea has not been actively applied until recently and it should be developed in a near future. Implications: It is necessary to analyze space configuration of other dental schools and their hospitals to develop the relationship between space and program in healthcare system.

Integrity Assessment and Verification Procedure of Angle-only Data for Low Earth Orbit Space Objects with Optical Wide-field PatroL-Network (OWL-Net)

  • Choi, Jin;Jo, Jung Hyun;Kim, Sooyoung;Yim, Hong-Suh;Choi, Eun-Jung;Roh, Dong-Goo;Kim, Myung-Jin;Park, Jang-Hyun;Cho, Sungki
    • Journal of Astronomy and Space Sciences
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    • v.36 no.1
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    • pp.35-43
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    • 2019
  • The Optical Wide-field patroL-Network (OWL-Net) is a global optical network for Space Situational Awareness in Korea. The primary operational goal of the OWL-Net is to track Low Earth Orbit (LEO) satellites operated by Korea and to monitor the Geostationary Earth Orbit (GEO) region near the Korean peninsula. To obtain dense measurements on LEO tracking, the chopper system was adopted in the OWL-Net's back-end system. Dozens of angle-only measurements can be obtained for a single shot with the observation mode for LEO tracking. In previous work, the reduction process of the LEO tracking data was presented, along with the mechanical specification of the back-end system of the OWL-Net. In this research, we describe an integrity assessment method of time-position matching and verification of results from real observations of LEO satellites. The change rate of the angle of each streak in the shot was checked to assess the results of the matching process. The time error due to the chopper rotation motion was corrected after re-matching of time and position. The corrected measurements were compared with the simulated observation data, which were taken from the Consolidated Prediction File from the International Laser Ranging Service. The comparison results are presented in the In-track and Cross-track frame.

Numerical Study on the Hydrodynamic Performance Prediction of a Turbopump Inducer (인듀서 성능예측에 대한 수치해석적 연구)

  • Choi, Chang-Ho;Hong, Soon-Sam;Kim, Jin-Han
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.6
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    • pp.72-78
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    • 2003
  • In the present paper, computational studies on the hydrodynamic behavior of the inducer for the rocket-engine turbopump are presented including the effect of the mass flow rate. As the mass flow rate is increased, the inducer showed better performance with weak back flows which may have deleterious effects upon the anti-cavitation ability. But the adopted inducer showed low head rise with high volume flow rates, which may be caused by the small passage area near the trailing edge. The static pressure distributions at the shroud surface are compared with experimental results showing very good agreements except near the leading edge where strong back flows are present. The overall performance of the inducer such as, efficiency, head rise is also compared with experiments. The computational results are generally in good agreements with experimental ones near the design point, but two results show discrepancy at the high flow rate.

Precision Assessment of Near Real Time Precise Orbit Determination for Low Earth Orbiter

  • Choi, Jong-Yeoun;Lee, Sang-Jeong
    • Journal of Astronomy and Space Sciences
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    • v.28 no.1
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    • pp.55-62
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    • 2011
  • The precise orbit determination (POD) of low earth orbiter (LEO) has complied with its required positioning accuracy by the double-differencing of observations between International GNSS Service (IGS) and LEO to eliminate the common clock error of the global positioning system (GPS) satellites and receiver. Using this method, we also have achieved the 1 m positioning accuracy of Korea Multi-Purpose Satellite (KOMPSAT)-2. However double-differencing POD has huge load of processing the global network of lots of ground stations because LEO turns around the Earth with rapid velocity. And both the centimeter accuracy and the near real time (NRT) processing have been needed in the LEO POD applications--atmospheric sounding or urgent image processing--as well as the surveying. An alternative to differential GPS for high accuracy NRT POD is precise point positioning (PPP) to use measurements from one satellite receiver only, to replace the broadcast navigation message with precise post processed values from IGS, and to have phase measurements of dual frequency GPS receiver. PPP can obtain positioning accuracy comparable to that of differential positioning. KOMPSAT-5 has a precise dual frequency GPS flight receiver (integrated GPS and occultation receiver, IGOR) to satisfy the accuracy requirements of 20 cm positioning accuracy for highly precise synthetic aperture radar image processing and to collect GPS radio occultation measurements for atmospheric sounding. In this paper we obtained about 3-5 cm positioning accuracies using the real GPS data of the Gravity Recover and Climate Experiment (GRACE) satellites loaded the Blackjack receiver, a predecessor of IGOR. And it is important to reduce the latency of orbit determination processing in the NRT POD. This latency is determined as the volume of GPS measurements. Thus changing the sampling intervals, we show their latency to able to reduce without the precision degradation as the assessment of their precision.

Statistical Analysis on the trapping boundary of outer radiation belt during geosynchronous electron flux dropout : THEMIS observation

  • Hwang, Jung-A;Lee, Dae-Young;Kim, Kyung-Chan;Choi, Eun-Jin;Shin, Dae-Kyu;Kim, Jin-Hee;Cho, Jung-Hee
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.90.2-90.2
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    • 2012
  • Geosynchronous electron flux dropouts are most likely due to fast drift loss of the particles to the magnetopause (or equivalently, the "magnetopause shadowing effect"). A possible effect related to the drift loss is the radial diffusion of PSD due to gradient of PSD set by the drift loss effect at an outer L region. This possibly implies that the drift loss can affect the flux levels even inside the trapping boundary. We recently investigated the details of such diffusion process by solving the diffusion equation with a set of initial and boundary conditions set by the drift loss. Motivated by the simulation work, we have examined observationally the energy spectrum and pitch angle distribution near trapping boundary during the geosynchronous flux dropouts. For this work, we have first identified a list of geosynchronous flux dropout events for 2007-2010 from GOES satellite electron measurements and solar wind pressures observed by ACE satellite. We have then used the electron data from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft measurements to investigate the particle fluxes. The five THEMIS spacecraft sufficiently cover the inner magnetospheric regions near the equatorial plane and thus provide us with data of much higher spatial resolution. In this paper, we report the results of our investigations on the energy spectrum and pitch angle distribution near trapping boundary during the geosynchronous flux dropout events and discuss implications on the effects of the drift loss on the flux levels at inner L regions.

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A STUDY ON THE IMPROVEMENT OF NEAR-REAL TIME GPS PHASE DATA PROCESSING ALGORITHM (준실시각 GPS 위상자료 처리 알고리즘 성능 개선에 관한 연구)

  • 손동효;조정호;박종욱;임형철;박필호;최규홍
    • Journal of Astronomy and Space Sciences
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    • v.21 no.2
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    • pp.129-140
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    • 2004
  • KAO(Korea Astronomy Observatory) GPS group has developed an iRTK system as a near-real time positioning system using GPS carrier phase data. We focused on improving the accuracy of positioning through the updated capability of data processing of KAO's iRTK system using low-cost L1 carrier phase receiver. The accuracy of a positioning was demonstrated by Extended Kalman filter. Experiments were accomplished using from 30m to 20km baselines. Within 10km, the positioning accuracy was improved by approximately 50-70% to the previous study using one minute observable data. However, it took two minutes to obtain 1m level positioning accuracy at 20km point. We expect that the developed iRTK system can be applied to the various fields of GPS in near-real time positioning.

Observations of the Aurora by Visible All-Sky Camera at Jang Bogo Station, Antarctica

  • Jee, Geonhwa;Ham, Young-Bae;Choi, Yoonseung;Kim, Eunsol;Lee, Changsup;Kwon, Hyuckjin;Trondsen, Trond S.;Kim, Ji Eun;Kim, Jeong-Han
    • Journal of Astronomy and Space Sciences
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    • v.38 no.4
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    • pp.203-215
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    • 2021
  • The auroral observation has been started at Jang Bogo Station (JBS), Antarctica by using a visible All-sky camera (v-ASC) in 2018 to routinely monitor the aurora in association with the simultaneous observations of the ionosphere, thermosphere and magnetosphere at the station. In this article, the auroral observations are introduced with the analysis procedure to recognize the aurora from the v-ASC image data and to compute the auroral occurrences and the initial results on their spatial and temporal distributions are presented. The auroral occurrences are mostly confined to the northern horizon in the evening sector and extend to the zenith from the northwest to cover almost the entire sky disk over JBS at around 08 MLT (magnetic local time; 03 LT) and then retract to the northeast in the morning sector. At near the magnetic local noon, the occurrences are horizontally distributed in the northern sky disk, which shows the auroral occurrences in the cusp region. The results of the auroral occurrences indicate that JBS is located most of the time in the polar cap near the poleward boundary of the auroral oval in the nightside and approaches closer to the oval in the morning sector. At around 08 MLT (03 LT), JBS is located within the auroral oval and then moves away from it, finally being located in the cusp region at the magnetic local noon, which indicates that the location of JBS turns out to be ideal to investigate the variabilities of the poleward boundary of the auroral oval from long-term observations of the auroral occurrences. The future plan for the ground auroral observations near JBS is presented.

Development Status of the SPICA/FPC

  • Pyo, Jeonghyun;Jeong, Woong-Seob;Lee, Dae-Hee;Matsumoto, Toshio;Moon, Bongkon;Tsumura, Kohji;Park, Kwijong;Park, Sung-Joon;Park, Youngsik;Kim, Il-Jung;Park, Won-Kee;Han, Wonyong;Im, Myungshin;Lee, Hyung Mok;Lee, Jeong-Eun
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.82.1-82.1
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    • 2013
  • The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) project is a next-generation infrared space telescope optimized for mid- and far-infrared observation with a cryogenically cooled 3m-class telescope. Owing to unprecedented sensitivity and high spatial resolution, the focal plane instruments are expected to perform the confusion-limited observation. The SPICA will challenge to reveal many astronomical key issues from the star-formation history of the universe to the planetary formation. The Korean 5contribution to SPICA as an international collaboration is the development of the near-infrared instrument, FPC (Focal Plane Camera). The Korean consortium for FPC proposed a key system instrument for the purpose of a fine guiding (FPC-G) complementing the AOCS (Attitude and Orbit Control System). The back-up instrument of FPC-G, FPC-S will be responsible for the scientific observations as well. Through the international review process, we have revised the scientific programs and made the feasibility study for the fine guiding system. Here, we report the current status of SPICA/FPC project.

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A Study on Developing R&D Response Strategy to prepare Hazardous Space Situation (우주위험 대비를 위한 R&D 대응전략 연구)

  • Kim, Syeun;Cho, Sungki;Choi, Eunjung;Hong, Jeongyoo
    • Journal of Korean Society of Disaster and Security
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    • v.9 no.1
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    • pp.25-32
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    • 2016
  • Technical development have broaden human activity ranges and make human possible to defend the disasters which was undependable in the past. However, human's space activity brought a new kind of disaster to human. In the past, natural space objects was the only concern from the space, like the asteroid fallen on Chelyabinsk, Russia. But, nowadays, by the increasing number of the man-made space objects, these space kind of threat have diversified and become very real. So, nationwide safety strategy should be established to protect the people. In this paper, we suggest three points to make the decision for establishing the strategy based on the AHP analysis results.

A Study on Introducing of Green Interior Design for Cultural Space inside Seoul Subway Station (서울시 지하철 역사 내 문화공간의 그린인테리어 도입방안에 관한 연구)

  • Kim, Ji-Hye;Han, Hae-Ryon
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2007.05a
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    • pp.204-209
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    • 2007
  • As people are getting interested in themselves ever than before, the value of culture industry which can satisfy their emotions has been considered much more important. According to this, in terms of the 'space', it is better to represent 'space' not just as a functional space, but the human-centered and making human and nature together. In this society, the most human-centered design can be achieved by pursuing value which is friendlier to nature. And it is sure that the interior design that completes life quality as well as emotions of human will be common in near future. There already has been a try 'Green interior' in subway station in variety ways, and now it is needed to make indoor display in Seoul subway station different in order to satisfy human emotions. If culture space in Seoul subway station applied eco-element interacts with indoor environment, it is surely expected that people have better feeling on subway station as well as help eliminate negative elements which underground have had. In culture space, there are many advantages for displaying space into 'nature', that is, natural space represents the best comfortable and agreeable space, and future-oriented design when it gets interacted with environment. Application of 'Green interior' in Seoul subway station makes special place ness by its symbol and image, so that it derives people to have more natural and comfortable movement distance in subway station, offers more comfortable and cozy place as well. Furthermore, it makes people very moved by experiencing the most special culture space that they have ever had.

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