• 한국전자현미경학회:학술대회논문집
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• 2001.05a
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• pp.41-42
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• 2001

• Journal of Astronomy and Space Sciences
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• v.33 no.4
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• pp.319-321
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• 2016

Reviewing the two MeV-GeV investigations in the field of the HESS J1745-303 performed using Fermi Large Area Telescope data, we confirmed that the emission peak comfortably coincides with 'Region A' in the TeV regime, which is the brightest part of this feature. The MeV-TeV spectrum can be precisely described by a single power-law. Also, recent investigation has shown that the MeV-GeV feature is elongated from 'Region A' toward the north-west, which is similar to the case of largescale atomic/molecular gas distribution.

• Journal of Astronomy and Space Sciences
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• v.4 no.1
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• pp.25-33
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• 1987

For a geostationary satellite north-south keeping maneuver must control the inclination elements. The effects on the orbit plane of maneuvers and natural perturbations may be represented by a plane plot of Wc versus, Ws, since these inclination elements represent the projection of the major axis and the inclination elements are obtained.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.327-329
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• 2017

We report a spatial fluctuation analysis of the sky brightness in the near-infrared from observations towards the north ecliptic pole (NEP) by AKARI at 2.4 and $3.2{\mu}m$. As a follow up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to extend fluctuation analysis at angular scales up to 1000". After pre-processing, additional correction procedures were done to correct time varying components and instrumental effects such as MUXbleed. To remove resolved objects, we applied $2{\sigma}$ clipping and point spread function (PSF) subtraction. We finally obtained mosaicked images which can be used for the study of various diffuse emissions in the near-infrared sky and found that there are spatial structures in the mosaicked images using a power spectrum analysis.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.56.4-57
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• 2016

남북한 천문분야 과학기술협력을 위한 천문분야 활성화 및 협력 방안 연구를 수행하고 있다. 천문학은 과학기술분야 중 남북한 상호 신뢰구축과 민족 동질성 회복에 기여할 수 있는 순수 기초학문으로, 이 과제를 통해 단절된 남북한 천문분야 활성화 및 협력을 기대하고 있다. 또한 통일 후 남북한 천문학 공동 연구를 위한 토대를 마련하고자 한다. 이를 위해 북한의 천문학 연구 인력, 관측기기, 연구 활동 등 인프라를 조사하고 북한 천문학자와의 교류를 위한 접근 방안, 남북한 교류 가능한 천문분야 발굴, 남북한 천문학자 교류를 위한 국제협력 루트를 개발하고자 한다. 분단 후 현재까지 남북 교류의 단절로 북한 천문학자와의 교류는 전무한 실정으로 많은 어려움이 예상되나 중국, 몽골, 스웨덴, 네덜란드 등 국제협력을 통한 네트워크를 마련하여 남북 천문분야 협력방안 및 활성화를 위한 기반을 구축하고자 한다.

• Journal of the Korean earth science society
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• v.21 no.1
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• pp.1-12
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• 2000

The earth science curriculum and textbooks of the secondary school in South Korea and North Korea were analysed comparatively with the modified TIMSS curriculum frameworks. In the secondary school of North Korea, earth science is not provided with separate subject, but partly taught in geography. Geography is taught by two hour per week in the first to fifth grade of secondary school. Especially the first and the fifth grade geography are deeply related to earth science. The major aim of earth science education in South Korea is to develop creative problem solver having with interest and curiosity in searching natural phenomena and with basic science concepts and inquiry process skills. But on the other hand the aim of geography education of North Korea is to cultivate communist revolutionists who are faithful to IL-Sung Kim and Jung-IL Kim. In both Koreas the category of 'earth feature' and 'earth process' are dealt a lot, but 'earth in the universe' is rarely taught in North Korea, which suggests that separate subject of astronomy is instructed in the North. Generally the scope and sequence of earth science of North Korea comes under those of middle school of South Korea. Especially discrepancy in level of meteorology and astronomy area between North and South Korea is great.

• Journal of Astronomy and Space Sciences
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• v.23 no.3
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• pp.245-258
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• 2006

In this paper, an automation algorithm of analyzing and scheduling the station-keeping maneuver is presented for Communication, Ocean and Meteorological Satellite (COMS). The perturbation analysis for keeping the position of the geostationary satellite is performed by analytic methods. The east/west and north/south station-keeping maneuvers we simulated for COMS. Weekly east/west and biweekly north/south station-keeping maneuvers are investigated for a period of one year. Various station-keeping orbital parameters are analyzed. As the position of COMS is not yet decided at either $128.2^{\circ}E\;or\;116.0^{\circ}E$, both cases are simulated. For the case of $128.2^{\circ}E$, east/west station-keeping requires ${\Delta}V$ of 3.50m/s and north/south station-keeping requires ${\Delta}V$ of 52.71m/s for the year 2009. For the case of $116.0^{\circ}E,\;{\Delta}V$ of 3.86m/s and ${\Delta}V$ of 52.71m/s are required for east/west and north/south station-keeping, respectively. The results show that the station-keeping maneuver of COMS is more effective at $128.2^{\circ}E$.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.213-217
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• 2017

The recent updates of the North Ecliptic Pole deep ($0.5deg^2$, NEP-Deep) multi-wavelength survey covering from X-ray to radio-wave is presented. The NEP-Deep provides us with several thousands of $15{\mu}m$ or $18{\mu}m$ selected galaxies, which is the largest sample ever made at these wavelengths. A continuous filter coverage in the mid-infrared wavelength (7, 9, 11, 15, 18, and 24 µm) is unique and vital to diagnose the contributions from starbursts and AGNs in the galaxies out to z=2. The new goal of the project is to resolve the nature of the cosmic star formation history at the violent epoch (e.g. z=1-2), and to find a clue to understand its decline from z=1 to present universe by utilizing the unique power of the multiwavelength survey. The progress in this context is briefly mentioned.

• Journal of Astronomy and Space Sciences
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• v.28 no.3
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• pp.217-223
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• 2011

Precise point positioning (PPP) is increasingly used in several parts such as monitoring of crustal movement and maintaining an international terrestrial reference frame using global positioning system (GPS) measurements. An accuracy of PPP data processing has been increased due to the use of the more precise satellite orbit/clock products. In this study we developed PPP algorithm that utilizes data collected by a GPS receiver. The measurement error modelling including the tropospheric error and the tidal model in data processing was considered to improve the positioning accuracy. The extended Kalman filter has been also employed to estimate the state parameters such as positioning information and float ambiguities. For the verification, we compared our results to other of International GNSS Service analysis center. As a result, the mean errors of the estimated position on the East-West, North-South and Up-Down direction for the five days were 0.9 cm, 0.32 cm, and 1.14 cm in 95% confidence level.

• Journal of Astronomy and Space Sciences
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• v.29 no.3
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• pp.269-274
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• 2012

Kinematic global positioning system precise point positioning (GPS PPP) technology is widely used to the several area such as monitoring of crustal movement and precise orbit determination (POD) using the dual-frequency GPS observations. In this study we developed a kinematic PPP technology and applied 3-pass (forward/backward/forward) filter for the stabilization of the initial state of the parameters to be estimated. For verification of results, we obtained GPS data sets from six international GPS reference stations (ALGO, AMC2, BJFS, GRAZ, IENG and TSKB) and processed in daily basis by using the developed software. As a result, the mean position errors by kinematic PPP showed 0.51 cm in the east-west direction, 0.31 cm in the north-south direction and 1.02 cm in the up-down direction. The root mean square values produced from them were 1.59 cm for the east-west component, 1.26 cm for the south-west component and 2.95 cm for the up-down component.