• 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 Ecology and Environment
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• v.51 no.1
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• pp.105-123
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• 2018

Currently, satellite images act as essential and important data in water resources, environment, and ecology as well as information of geographic information system. In this paper, we will investigate basic characteristics of satellite images, especially application examples in water resources. In recent years, researches on spatial and temporal characteristics of large-scale regions utilizing the advantages of satellite imagery have been actively conducted for fundamental hydrological components such as evapotranspiration, soil moisture and natural disasters such as drought, flood, and heavy snow. Furthermore, it is possible to analyze temporal and spatial characteristics such as vegetation characteristics, plant production, net primary production, turbidity of water bodies, chlorophyll concentration, and water quality by using various image information utilizing various sensor information of satellites. Korea is planning to launch a satellite for water resources and environment in the near future, so various researches are expected to be activated on this field.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.113-116
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• 2013

최근 방송, 의료, 우주산업, 게임, UCC, 핸드폰 등 여러 사업 분야에 걸쳐 실제에 근접한 영상을 요구하고 있고 이것은 3D와 Ultra High Definition (UHD) 영상의 출현으로 현실화 되고 있다. UHD 급에 걸맞는 압축률을 위해 Joint Collaborative Team on Video Coding (JCT-VC) 에서는 MPEG-4 Part 10 AVC/H.264를 뒤이을 차세대 코덱으로 High Efficiency Video Coding (HEVC) 를 개발을 시작했다. HEVC는 기존 MPEG-4 Part 10 AVC/H.264코덱과 비교해 40%이상의 압축률을 나타내지만 복잡도 역시 상승했다. 특히 복호화기에서 복잡도는 중요한 요소이며, 역 코사인변환 (Inverse Discrete Cosine Transform, IDCT) 은 전체 복호화시간의 8% ~ 16%를 차지하는 알고리즘이다. 본 논문에서는 IDCT 의 수행시간을 줄이기 위해 병렬프로그래밍 중의 하나인 SIMD명령어를 사용하여 효율적으로 병렬화 프로그래밍을 하는 기법들을 제안한다. 본 제안 기법은 IDCT 수행시간을 평균 59% 단축하는 결과를 보였다.

• Journal of the Korean Society of Systems Engineering
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• v.10 no.2
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• pp.71-79
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• 2014

To enhance success probability of a system development project, its overall risk level should be minimized through systematically managing schedules, costs, and technical performances. However, Attempts to manage technical performance compared to numerous efforts to control costs and schedules in such projects are deficient. Particularly, a space launch vehicle, a large complex system, development project is much less likely to meet its technical performance objectives due to its technological difficulty, along with schedule delay and cost overrun. The technical performance management (TPM) is a method for tracking and managing technical progress in order to achieve technical performance targets within schedule and budget. In this paper, we investigate applications of the TPM in several space launch vehicle development projects. Then we propose and validate the TPM process to achieve a successful mission in such projects.

• Journal of the Korean Society of Systems Engineering
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• v.2 no.1
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• pp.31-36
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• 2006

Development of launch vehicle needs a large-scale and complicated System Engineering discipline interfacing to small-quantity production with special manufacturing processes. In general, the System Engineering discipline of launch vehicle has its relationship with Production, Operations, Product Assurance and Management disciplines and its internal partitions into the functions of System Engineering Integration & Control, Requirements Engineering, Analysis, Design and Configuration and Verification. As a function of Product Assurance, reliability of launch vehicle plays an significant role in risk management, system safety, flight safety and launch certification through design assurance. Moreover, major functions of systems engineering are integrated by means of reliability in the phases of design and verification. Therefore, derailed identification of system engineering interfaces of reliability, and execution of tasks for reliability assurance is required for successful development of launch vehicle. This paper identifies specific pattern and mechanism of the interfaces between reliability and system engineering.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.894-903
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• 2018

In the case of helicopters, the development of parts technology is rapidly changing, and the complexity is rapidly increasing. Particularly, the surge of various electric and electronic systems is recognized as a problem that is directly related to the safety of the helicopter. Due to these problems, there is a growing interest in reliability evaluation in the face of the problem of confirming and certifying the reliability of parts in the development stage. In this paper, the analysis of the failure mechanism of the wiper system was carried out, and the priority and importance of each failure mode were checked by using the results, and major stress factors were derived and the corresponding acceleration model was selected. Also, the accelerated lifetime test time was calculated according to the life test time, acceleration status and acceleration level of the steady state by using the selected acceleration model and characteristic values.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.332-333
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• 2022

Recently, SpaceX, private enterprise dealing in space development company, has reported a plan for launching of 42,000 low earth orbit satellites until 2031 through Starlink Business, and launched 900 satellites until now. Concretely, it plans tp operate Ku/Ka band satellite, and launch 7,518 of V band satellites for broadband communication. Therefore, we can utilize wireless communication in an ocean, and various solutions through the low earth orbit satellites. This paper deals in a realization of wireless control system employing FPGA (Field Programmable Gate Array) for vessel applications.

• Journal of Space Technology and Applications
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• v.1 no.1
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• pp.33-40
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• 2021

Based on the requirements of a total weight of 42 kg or less, the NEXTSat-2 SAR (synthetic aperture radar) system was developed. As the NEXTSat-2 is a small-sized satellite, the SAR system was designed to account for about 40% of the dry mass of the payload relative to the total mass. Among the major components of the SAR system - which are an antenna, an RF transceiver, a baseband signal processor, and a power unit - a part with a particularly large dry mass is the antenna, the core of the SAR system. Whereas various selections are possible in consideration of gain and efficiency when designing the antenna, the micro-strip patch array antenna was adopted by reflecting the dry mass, power, and resolution required by the NEXTSat-2 project. In order to meet the mission requirement of the NEXTSat-2, the antenna was developed with a frequency of 9.65 GHz, a gain of 42.7 dBi, and a return loss of -15 dB. The performance of the antenna was verified by conducting a field test onboard the vehicle.

• The Journal of Society for e-Business Studies
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• v.20 no.3
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• pp.29-46
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• 2015

Examined how it varied the knowledge network of the country along with R&D changes in planning policy for the research and development of government. Therefore, in this study, chronological Analysis analyzed separately the network between each entity of participate in the industry fusion source technology development business of industry trade and Energy. Planning policy of industrial fusion source technology development business, to change the starting point before and after 2012, before 2012 from selected planning issues at the center "planning committee" and in 2012 'PD' changes to a system for planning issues around. First of all, an attempt to analyze the R&D network based on the "planning committee" current situation of 2009~2011, from 2012 to analyze the variation of the R&D network with the introduction of the 'PD' system after it was analyzed by dividing the time in the current state of up to 2013. The results of the analysis, since the PD system was introduced, such as self-relationship (the form of planning user to run directly challenges the person was planning to challenge participants)is greatly improved, I was able to grasp the effect became clear. The more the self-relation, and the budding scholars considering that there is inequality of the planning, the introduction of the PD scheme, it can be seen to have resulted in a positive effect. These studies, quantitatively analyzed to improve the results to the effects associated with changes in the planning policy of the government, I think that there is a meaning in terms of presenting the future direction of R&D policy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.144-152
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• 2018

Lunar exploration, which was led by the United States and the former Soviet Union, ceased in the 1970s. On the other hand, since massive lunar ice deposits and rare resources were found in 1990s, European Union, China, Japan, and India began to participate in lunar exploration to secure future lunar resource as well as to construct a lunar base. In the near future, it is expected that national space agencies and private industries will participate in the lunar exploration together. Their missions will include the exploration and sample return of lunar resources. Lunar resources have a close relationship with the lunar in-situ resource utilization (ISRU). To construct a lunar base, it is inevitable to bring huge amounts of resources from Earth. Water and oxygen, however, will need to be produced from local lunar resources and lunar terrain feature will need to be used to construct the lunar base. Therefore, in this paper, the global trends on lunar exploration and lunar construction technology are investigated and compared along with the ISRU technology to support human exploration and construct a lunar base on the Moon's surface.