• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.98-100
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• 2005

This paper describes link analysis on the processed data, HRIT (High Rate Information Transmission) and LRIT (Low Rate Information Transmission), for the preliminary design of interface between COMS (Communication, Ocean and Meteorological Satellite) and ground station. At the MODAC (MeteorologicaVOcean Data Application Center), the processed data are transmitted to user station via COMS with normalization and calibration by pre-processing of MI (Meteorological Imager) data. Due to consider satellite as radio relay, overall analysis containing uplink and downlink is needed. Specific link parameters can be obtained with using the outcomes of SRR (System Requirement Review) which was held on 13-14 June 2005, in Toulouse. From the relation between overall link margin and output power of HPA (High Power Amplifier) of MODAC, it is shown that even though the minimum power related with COMS receiving power range is transmitted at MODAC, the obtained link margin of HRIT could be above 3 dB at user station which antenna elevation angle is 10 degree.

• 천문학회보
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• 제41권1호
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• pp.78.4-79
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• 2016

This study aims to overview research articles on extrasolar planets using Kepler mission data during the period of 2009-2015 in order to discover research trends in them. Kepler space observatory is a NASA space observatory for extrasolar planet expedition launched in March 2009, contributed to the discovery and tracking of extrasolar planets and its candidates. In order to achieve the goal of this study, we classified research subjects from studies on Kepler mission data year by year and found the most frequent research topics each year. We also conducted a comparative analysis on the research subjects based on time series and examined any changes with respect to the goal of Kepler mission. Statistical meta-analysis is employed as the analysis method for the key words presented in the research articles. This study is a part of on-going research to find the correlation between the physical parameters of the host star and extrasolar planets. The results of this study could offer new directions in researches utilizing Kepler mission data as those meta-analyses in social sciences often suggest new opportunities. We have high expectations that more extrasolar planet studies will follow as we make further progresses in various analyses.

• Journal of Astronomy and Space Sciences
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• 제35권4호
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• pp.243-252
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• 2018

In a satellite gravimetry mission similar to GRACE, the precision of inter-satellite ranging is one of the key factors affecting the quality of gravity field recovery. In this paper, the impact of ranging precision on the accuracy of recovered geopotential coefficients is analyzed. Simulated precise orbit determination (POD) data and inter-satellite range data of formation-flying satellites containing white noise were generated, and geopotential coefficients were recovered from these simulated data sets using the crude acceleration approach. The accuracy of the recovered coefficients was quantitatively compared between data sets encompassing different ranging precisions. From this analysis, a rough prediction of the accuracy of geopotential coefficients could be obtained from the hypothetical mission. For a given POD precision, a ranging measurement precision that matches the POD precision was determined. Since the purpose of adopting inter-satellite ranging in a gravimetry mission is to overcome the imprecision of determining orbits, ranging measurements should be more precise than POD. For that reason, it can be concluded that this critical ranging precision matching the POD precision can serve as the minimum precision requirement for an on-board ranging device. Although the result obtained herein is about a very particular case, this methodology can also be applied in cases where different parameters are used.

• 한국항공우주학회지
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• 제49권10호
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• pp.871-877
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• 2021

항공기 결함은 항공기 운영 및 조종사의 생명과 직결된 중요한 사항으로 항공기 조종 중 발생하는 임무 소프트웨어의 결함은 조종사 임무수행 및 안전에 심각한 영향을 미친다. 항공기 개발을 주관하는 단체나 소프트웨어 결함을 개발 초기에 식별하고 제거하기 위해 프로세스를 강화하고 많은 공수와 시간을 할애하고 있지만 임무 소프트웨어의 특성상 타 항전 장비와 강한 기능적 결합도(Coupling) 및 높은 복잡도(Complexity)를 가지고 있어 기존 시험 방법을 통한 소프트웨어 결함 식별 및 제거에 제약이 따른다. 본 연구는 임무 컴퓨터 연동 장비의 통신 데이터 중 피드백 데이터의 기댓값 검증을 자동화하는 도구를 개발하여 데이터 무결성 검증을 통한 임무 소프트웨어 건전성 확보 및 시험 비용 감소 효과를 분석한다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.216-219
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• 2006

This paper analyzes on LHGS (LRIT/HRIT Generation Subsystem) processing timeline for COMS LHGS design. The LHGS shall transmit LRIT/HRIT (Low Rate Information Transmission/ High Rate Information Transmission) data to the users within 15 minutes after the end of the image acquisition. So, this paper performs experiment using MTSAT-1R LRIT/HRIT (11 days) and calculates minimum LHGS processing time. Only HRIT FD (Full Disk) image is considered in this paper because data size of HRIT FD image is the largest. As a result of experiment, COMS LHGS should be able to receive MI Level 1B product within 157 seconds at least.

• 한국군사과학기술학회지
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• 제12권2호
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• pp.248-257
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• 2009

The aim of this paper is to propose fighter aircraft's mission severity model which can be used as one of key factors for designing a structure and determining design life of KF-X. The mission severity is a quantitative data of flight loads and expressed by Nz(Vertical Load Factor) exceedances or occurrences. The severities of the flight loads depended on the circumstances of the countries which operate fighter aircraft. In this paper we have studied on Nz occurrences/exceedances of ROKAF fighter aircraft to generate mission severity model for the KF-X. The analyses of flight data were accomplished by using the Matlab.

• Journal of the Korean Data and Information Science Society
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• 제17권3호
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• pp.861-869
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• 2006

Burn-in is a widely used method to improve the quality of products or systems after they have been produced. In this paper, the problem of determining optimal burn-in time for a system which performs given mission is considered. It is assumed that the given mission time is not a fixed constant but a random variable which follows an exponential distribution. Assuming that the underlying lifetime distribution of a system has an eventually increasing failure rate function, an upper bound for the optimal burn-in time which maximizes the probability of performing given mission is derived. The obtained result is also applied to an illustrative example.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2003년도 한국우주과학회보 제12권2호
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• pp.46-46
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• 2003

Since its launching on 21 December 1999, the KOrea Multi-Purpose SATellite-Ⅰ (KOMPSAT-Ⅰ) has been successfully operated by the Mission Control Element (MCE), which was developed by the Electronics and Telecommunications Research Institute (ETRI). Most of the major functions of the MCE have been successfully demonstrated and verified during the three years of the mission life of the satellite. The Mission Analysis and Planning Subsystem (MAPS), which is one of the four subsystems in the MCE, played a key role in the Launch and Early Orbit Phase (LEOP) operations as well as the on-orbit mission operations. This paper presents the operational performances of the various functions in MAPS. We show the performance and analysis of orbit determinations using ground-based tracking data and GPS navigation solutions. We present four instances of the orbit maneuvers that guided the spacecraft from injection orbit into the nominal on-orbit. We include the ground-based attitude determination using telemetry data and the attitude maneuvers for imaging mission. The event prediction, mission scheduling, and command planning functions in MAPS subsequently generate the spacecraft mission operations and command plan. The fuel accounting and the realtime ground track display also support the spacecraft mission operations. We also present the orbital evolutions during the three years of the mission life of the KOMPSAT-Ⅰ.

• 한국항행학회논문지
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• 제26권5호
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• pp.325-330
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• 2022

항공기에 탑재된 센서들은 임무 수행에 필수 요소이며 센서들을 통해 얻어진 데이터의 융합은 임무 효율을 높이고 조종사의 부담을 줄이기 위해 적용되고 있다. 센서들로부터 얻어진 데이터를 특정 대상에 대해 일관되고 보다 정리된 형태로 조종사에게 제공하기 위해 데이터 융합이 적용되어 발전하고 있다. 현재 운용되고 있는 군용 항공기는 Link-16 과 같은 전술데이터링크에 연동하여 향상된 전술 상황을 조종사에게 전시하여 임무 효율을 높이고 있다. 항공기에 탑재된 센서가 고성능화 되면서 얻어진 정확도가 향상된 센서 데이터와 전술데이터링크를 통해 수신한 전술상황정보를 융합하여 조종사에게 고신뢰성의 전술상황 및 임무 환경을 제공하고 효율적인 임무 수행과 높은 생존성을 기대할 수 있다. 본 논문에서는 항공기 실시간 센서 데이터와 전술데이터링크를 통해 얻어지는 데이터를 종합된 정보 형태로 제공하기 위한 융합 구조를 보인다.

• 천문학회보
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• 제37권1호
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• pp.89.2-89.2
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• 2012

Radiation Belt, discovered by Van Allen in 1958, is a region energetic particles are trapped by the Earth's magnetic field. To measure charged particles and fields in the radiation belt, RBSP(Radiation Belt Storm Probes) mission will be launched in September 2012 by NASA. RBSP mission consists of two spacecraft having orbit from 600 km to 30,000 km and rotates the Earth twice a day. This mission is not designed just for scientific purpose but have operational function broadcasting real time data for space weather monitoring. As a program of KASI-NASA cooperation, KASI is constructing RBSP data receiving antenna that will be installed by April in Daejeon. With this antenna system, NASA can receive RBSP data for 24 hours and KASI also get space weather information to protect Korean GEO satellites. In this presentation, we will discuss how we use RBSP data for space weather forecasting. In addition, we will talk about science topics that can be achieved by RBSP mission. Especially we focus on the dusk-side electron precipitation that has been considered as a main mechanism of electron dropout events. We show the dusk-side precipitation is closely associated with radiation belt electron loss with NOAA-POES data, and why RBSP mission is important to understand radiation belt physics.