• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.207-210
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• 2011

Chollian bipropellant propulsion system is composed of one main engine for orbit transfer and fourteen thrusters for on-station operations. The design and analyses of the propulsion system were carried out in the framework of international collaboration. Following the system integration and testings required, the Chollian was transported to Kourou Space Center in French Guiana and launched successfully. After it separated from the launcher, the propulsion system was initialised automatically. Then three times of main engine firing were successfully performed, and the target obit insertion was accomplished.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.59.2-59.2
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• 2015

국립고흥청소년우주체험센터는 2014년부터 덕흥천문대에 설치된 SBIG사의 "Seeing Monitor"로 시상을 측정하고 있다. "Seeing Monitor"는 북극성을 대상으로 TDI(Time Delay and Integration) 방식을 적용하여 얻어진 시상을 분 단위로 저장해준다. 따라서 구름이 없는 맑은 날의 분 단위 시상 자료와 주변 환경 정보를 조합하여 시상에 영향을 미치는지 환경 요인을 정량적으로 분석하는 것이 가능하다. 그 첫 단계로 측정된 시상 자료와 기상청의 온도 습도 풍속 자료, 그리고 GFS(Global Forecast System)의 고도별 상층 풍속 자료를 비교하여 기상정보와 시상과의 관계를 분석해보았다. 습도와 바람이 시상에 가장 큰 영향을 주었으며, 지상 풍속 1~2m/s, 습도 75% 이하, 제트기류 풍속은 250km/h 이하 일 때 좋은 시상 값을 얻을 수 있었다. 이를 통해 덕흥천문대에서 기상정보를 통해 시상이 안정적인 날을 예측할 수 있다면, 앞으로 도입될 1m 망원경으로 훌륭한 관측 자료를 얻을 수 있을 것이라 기대된다.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.59.2-59.2
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• 2017

변광성은 거리를 결정하기 위한 중요한 천체이며, 대표적으로 RR Lyr형 변광성을 사용하여 성단까지의 거리를 결정해왔다. 하지만 성단의 거리를 결정함에 있어 성단 구성원의 multi-population을 고려해야 한다는 의견이 최근 제시되어 왔으며, 이를 위해 RR Lyr형 외에 새로운 지표가 필요한 실정이다. 변광성 중에서 ${\delta}$ Sct와 SX Phe형의 경우 짧은 변광 주기를 가지기 때문에, RR Lyr형을 대신할 새로운 지표로 대두되고 있다. 따라서 본 연구에서는 국립고흥청소년우주체험센터(NYSC)에서 주최하는 천문실습 과정에 참여하여 각각 2개의 ${\delta}$ Sct와 SX Phe 형 변광성을 NYSC 1m 망원경을 사용하여 관측하였다. 실습과정에서 진행된 관측 및 자료처리 과정에 대한 검증을 위해, 관측 대상의 광도곡선을 얻고 문헌의 결과와 비교하고자 한다.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.50.2-50.2
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• 2018

국립청소년우주센터 덕흥천문대의 NYSC 1m 망원경은 청소년을 대상으로 관측제안서를 공개모집하고, 청소년의 전문적인 천문관측을 지원하고 있다. 2017년 한 해, 접수된 청소년의 관측제안은 총 10건이었다. 이외에도 덕흥천문대는 양질의 관측자료를 국내 연구팀과의 공동연구를 통해 제공하고 있으며, 공동연구 장기관측과제 3건을 운영 중에 있다. 덕흥천문대 관측팀은 청소년 관측 및 공동연구를 지원하는 것과 더불어 망원경의 상태를 상시 점검하고 있다. 스티커 및 $CO_2$ 분사를 이용한 경면 세척을 진행하였고, 2017년 하반기에는 1m 망원경의 성능을 최대로 발휘할 수 있도록 CCD 카메라를 Princeton Instruments의 SOPHIA 2048B로 교체하였다. 그리고 앞으로 덕흥천문대에서 진행할 향후 운영 계획에 대해서도 논하고자 한다.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.426-427
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• 2019

본 논문에서는 다양한 양극 활물질을 가지는 리튬이온 배터리를 이용하여 전기 자동차의 구동 전원으로 사용되는 리튬 이차전지의 성능, 신뢰성 및 안전성을 위한 시험 절차 중 하나인 복합 진동 시험을 진행하였다. 고출력과 고용량의 특성을 가지는 배터리를 복합진동 실험에 기반을 두어 배터리 내부의 전기적 특성 파라미터 변화를 분석한다.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1235-1243
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• 2021

Geostationary Ocean Color Imager 2 (GOCI-II) on Geo-KOMPSAT-2 (GK2B)satellite was developed as a mission successor of GOCI on COMS which had been operated for around 10 years since launch in 2010 to observe and monitor ocean color around Korean peninsula. GOCI-II on GK2B was successfully launched in February of 2020 to continue for detection, monitoring, quantification, and prediction of short/long term changes of coastal ocean environment for marine science research and application purpose. GOCI-II had already finished IAC and IOT including early in-orbit calibration and had been handed over to NOSC (National Ocean Satellite Center) in KHOA (Korea Hydrographic and Oceanographic Agency). Radiometric calibration was periodically conducted using on-board solar calibration system in GOCI-II. The final calibrated gain and offset were applied and validated during IOT. And three video parameter sets for one day and 12 video parameter sets for a year was selected and transferred to NOSC for normal operation. Star measurement-based INR (Image Navigation and Registration) navigation filtering and landmark measurement-based image geometric correction were applied to meet the all INR requirements. The GOCI2 INR software was validated through INR IOT. In this paper, status and results of IOT, radiometric calibration and INR of GOCI-II are analysed and described.

• Korean journal of aerospace and environmental medicine
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• v.29 no.3
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• pp.96-100
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• 2019

The present study analyzed all of exotic malaria (EM) cases reported in the Republic of Korea (Korea) and Japan from 2015 to 2017 to assess the trends of incidence overtime to review the risk factors for travelers visiting malaria-endemic countries. We investigated 162 cases of EM in Korea with a cumulative incidence rate (CIR) of 0.105 per 100,000 populations nationwide and the CIR of the oversea travelers was 0.238 per 100,000 travelers, respectively. During the same period in Japan, 152 cases of EM in nationwide with a CIR of 0.041 and in the oversea travelers with a CIR of 0.297 were observed. When compared, the CIR of EM in nationwide was much higher than that in Japan (P<0.01), but a CIR of imported by travelers in Korea was lower than that in Japan (P<0.01).

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1529-1539
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• 2023

The data from Geostationary Ocean Color Imager-II (GOCI-II), which observes the color of the sea to monitor marine environments, undergoes various correction processes in the ground station system, producing data from Raw to Level-2 (L2). Quality issues arising at each processing stage accumulate step by step, leading to an amplification of errors in the satellite data. To address this, improvements were made to the GOCI-II ground station system to measure potential optical quality and geolocation accuracy errors in the Level-1A/B (L1A/B) data. A newly established Radiometric and Geometric Performance Assessment Module (RGPAM) now measures five optical quality factors and four geolocation accuracy factors in near real-time. Testing with GOCI-II data has shown that RGPAM's functions, including data processing, display and download of measurement results, work well. The performance metrics obtained through RGPAM are expected to serve as foundational data for real-time radiometric correction model enhancements, assessment of L1 data quality consistency, and the development of reprocessing strategies to address identified issues related to the GOCI-II detector's sensitivity degradation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.79-87
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• 2017

Korea Aerospace Research Institute has being developed a staged combustion cycle rocket (SCCR) engine with high specific impulse to send a 3-ton class satellite into geostationary orbit while conducted Korean Space Launch Vehicle (KSLV) II project. The SCCR engine is different from the KSLV-II engine, which is open cycle engine using a gas-generator. The SCCR engine with closed cycle is composed of a pre-burner, a turbo pump, and a main combustor. The technology demonstration model (TDM0) was assembled and tested in the 7ton-class engine combustion test facility of Naro Space Center, and the combustion test was successfully conducted. Afterward engine-shaped SCCR engine model (TDM1) is being designed and developed for the next combustion test.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.76-86
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• 2015

KSLV-II, a new launch vehicle of Korea, requires a new launch complex(LC) for its own and proper launch operations. The new launch complex will be constructed in NARO Space Center neighboring KSLV-I launch complex for maximizing operation efficiency and economic matters. The launch complex consists of three ground support equipments, i.e., mechanical, electrical, and fuel in general. The fuel ground support equipment could be defined as a combination of systems for storage and supply of propellants and gases which are required by a launch vehicle. The compositions, functions and capabilities of fuel ground support equipment are introduced in this paper. In addition, basic design results of flame deflector configurations are included.