• Journal of Aerospace System Engineering
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• v.18 no.4
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• pp.89-95
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• 2024

This paper introduces an effective and convenient method for utilizing onboard memory space to process remote commands, telemetry, and interplanetary network protocol data in satellite onboard systems. By enhancing the doubly linked list data structure to store and make accessible variable-length communication protocol data either sequentially or at variable locations, the paper enhances memory capacity utilization. The concept of 'grape' is introduced into the doubly linked list data structure to manage variable-length data and its access, with performance verification conducted through its reference implementation. This novel approach to linked lists is termed 'grape.'

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.176.1-176.1
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• 2012

최근 무인 항공기 발전으로 영상 촬영 및 도로 정보 획득과 같은 다양한 분야에서 이를 활용하고 있다. 특히 무인 항공기가 점점 소형화되어가고 있고, 안전하게 이동하고, 한 지점에 머무를 수 있는 기능이 개발되어 최근 ArDrone과 같은 쿼드로터가 각광을 받고 있다. 이와 같은 기술을 위치를 파악할 수 없는 외계 공간에서 활용을 한다면 인간이 지나갈 수 없는 협소한 공간 혹은 위험한 장소를 대신하여 탐색할 수 있어 위험에 처한 인명을 구하는데 큰 도움을 줄 수 있다. 하지만 외계 공간에서는 GPS와 같은 위치를 인식할 수 없어 정해진 임무를 수행하기란 매우 어려운 일이다. 본 논문에서는 최근 각광받고 있는 SLAM 기술을 사용하여 3차원 지도를 생성하고, 이를 기반으로 실시간으로 영상을 인식하여 위치를 파악한 후 외계공간에서 로버를 사용하여 자율 주행이 가능한 시스템에 대한 개념 설계 내용을 설명한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.150-151
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• 2012

우주전파환경이란 지구 전리층, 열권, 자기권 및 행성간의 공간 등 통칭한 전파 전달 환경을 말하며 주로 태양의 활동에 영향을 받는다. 태양은 막대한 복사 및 입자 에너지를 방출하여 지구의 자기권과 전리층에 영향을 주어 방송 통신, 전력, 항법, 위성 등 여러 분야에 걸쳐 피해를 줄 수 있다. 그러므로 우주전파에 취약한 국가주요시설을 분류하여 따로 지정하고 관리해야 한다. 본 논문에서 우리나라의 국가 주요시설은 "국가기반시설", "국가주요시설", "국가보안목표 시설"로 크게 3가지로 조사하였다. 국가중요시설은 "적"이라는 위기요인으로부터 보호해야할 대상이며, 보안 목표시설은 "파괴/태업/비밀누설"이라는 위기요인으로부터 보호해야 할 대상이다. 즉, 국가주요시설과 보안목표시설은 위기요인에 의해 정의된 시설이다. 하지만 국가기반시설은 위기요인이 아니라 r 피해가 국가적으로 핵심적인 시설들로 정의된다. 따라서 우주전파재난을 위한 보호체계는 가장 포괄적인 국가기반시설의 테두리에서 다루어야 한다.

• Journal of Space Technology and Applications
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• v.1 no.2
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• pp.178-198
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• 2021

The Solar Space Environment Division of the Korean Society of Space Science (KSSS) has recently conducted a survey among the domestic researchers affiliated with academia, national research institutes, and for-profit institutes of how the data and models in their professional research field are produced, maintained, and utilized. The primary purpose of this survey is to increase the awareness and utilization of the space environment data and models as well as to promote constructive collaborations among the domestic and international researchers. The models and data surveyed are categorized into three sub-fields: the solar and interplanetary space, the (terrestrial) magnetosphere, and the ionosphere and upper atmosphere. The present paper reports the survey results in the "Magnetosphere" category. The survey shows that the domestically produced data in this category are far less than the data produced in other categories. This can be understood in part as follows: Magnetospheric research relies heavily on the in-situ observations but the development and operation of space-hardened satellites require a significant investment. Nevertheless, the recent publications show an increasing trend of research using the data from the ground stations and the recently launched domestic space missions. In the modeling front, there are first-principles physics models covering from the magnetospheric scale to the sub-ion scale and the models geared towards the space weather prediction. The detailed survey results can be accessed from the KSSS website (http://ksss.or.kr/).

• Journal of The Korean Association For Science Education
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• v.34 no.8
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• pp.703-718
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• 2014

This study sought to investigate learning progressions for astronomical systems which synthesized the motion and structure of Earth, Earth-Moon system, solar system, and the universe. For this purpose we developed ordered multiple-choice items, applied them to elementary and middle school students, and provided validity evidence based on the consequence of assessment for interpretation of learning progressions. The study was conducted according to construct modeling approach. The results showed that the OMCs were appropriate for investigating learning progressions on astronomical systems, i.e., based on item fit analysis, students' responses to items were consistent with the measurement of Rasch model. Wright map analysis also represented that the assessment items were very effective in examining students' hypothetical pathways of development of understanding astronomical systems. At the lower anchor of the learning progression, while students perceived the change of location and direction of celestial bodies with only two-dimensional earth-based view, they failed to connect the locations of celestial bodies with Earth-Moon system model, and they could recognized simple patterns of planets in the solar system and milky way. At the intermediate levels, students interpreted celestial motion using the model of Earth rotation and revolution, Earth-Moon system, and solar system with space-based view, and they could also relate the elements of astronomical structures with the models. At the upper anchor, students showed the perspective change between space-based view and earth-based view, and applied it to celestial motion of astronomical systems, and they understood the correlation among sub-elements of astronomical systems and applied it to the system model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6A
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• pp.609-616
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• 2011

The Delay/Disruption Tolerant Network (DTN) is a network designed to operate effectively using the mobility and storage of intermediate nodes under no end-to-end guaranteed network. This new network paradigm is well-suited for networks which have unstable path and long latencies (e.g. interplanetary network, vehicular network). In this paper, we first found that each taxi has its own regularly visiting area and define this property as spatial regularity. We analyze 4000 taxi trace data in Shanghai and show the existence of spatial regularity experimentally. Based on a spatial regularity in urban environment, we present a new DTN routing method. We introduce a Weighted Center (WC) which represents spatial regularity of each node. Through the association with evenly distributed access points (APs) in urban environment, most of vehicles get their grid locations and calculate their WCs. Since our routing method only uses neighbors' WCs for building routing paths, it can be regarded as distributed and practical protocols. Our experiments involving realistic network scenarios created by the traces of about 1500 Shanghai taxies show that our routing method achieves the higher performance compared to ECT, LET by 10%~110%.