• Proceedings of the KSRS Conference
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• 2005.10a
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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.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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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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• v.35 no.4
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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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.10
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• pp.871-877
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• 2021

Aircraft defects are important matters directly related to the operation of the aircraft and the life of the pilot. The defects in the mission software that occur during aircraft control seriously affect the pilot's mission performance and safety. Therefore, the organization in charge of aircraft development or software defects are reinforced in the process to identify and eliminate defects in the early stages of development, and a lot of labor and time are spent, but due to the nature of the mission software, strong functional coupling with other avionics and high complexity, so there are restrictions on the identification and removal of software defects through the existing test method. This study analyzes the effect of securing mission software integrity and reducing test cost through data integrity verification by developing a tool that automates the verification of expected value of feedback data among communication data of mission computer interlocking equipment.

• Proceedings of the KSRS Conference
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• v.1
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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.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.2
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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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• v.17 no.3
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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.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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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.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.325-330
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• 2022

The sensors of aircraft are necessity for mission performance and fusion process of data from them is applied for increase of mission efficiency and decrease of aircraft pilot workload. Data fusion is applied and developed to provide pilot a series of more processed data format about a specific target from sensors in aircraft. Military aircraft currently in operation are linked with a tactical data link such as Link-16 to display improved tactical situation to pilots to increase mission efficiency. By fusing the sensor data with improved accuracy obtained as the sensors' performance mounted on the aircraft become higher and the tactical situation information received through the tactical data link, it provides the pilot with a highly reliable tactical situation and mission environment, and expects efficient mission performance and high survivability. In this paper, a fusion architecture to produce fused data with realtime information from the sensors and data through a tactical data link is shown.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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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.