• Title/Summary/Keyword: 우주환경보호

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Structural Test for Assembly Frame of Payload Fairing (페이로드 페어링 체결 프레임에 대한 구조시험)

  • Lee, Jong-Woong;Jang, Young-Soon;Yi, Yeong-Moo;Kong, Cheol-Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.12
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    • pp.1129-1134
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    • 2007
  • Payload fairing protects satellites and electrical equipments from the external environment. Payload fairing is jettisoned before satellite separation. Assembly frame for the separation of payload fairing were assembled with shear bolts. The role of shear bolts is to support structural load during flight and they are cut by explosion of pyro. The assembly frame which is connected by shear bolts is separated after the cutting of shear bolts. In this paper, structural tests and analysis were done for the design of the shear bolt. Compression, bending and shear load apply to the hardware including assembly frame. Test results showed that design of the shear bolt satisfied both structural strength for the support of flight load and required low strength for the cutting of shear bolts.

Power Design of an S-Band Transmitter for KSLV-II with Derating (디레이팅을 고려한 한국형발사체 S-밴드 송신기 전원부 설계)

  • Kim, Seokkwon;Kim, Sung-Wan;Hong, Seung Hyun;Kim, Hyo Jong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.30 no.5
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    • pp.339-347
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    • 2019
  • The power circuit design of an on-board S-band transmitter for KSLV-II with derating(operation of a component at less than its maximum rated specification to enhance reliability) is investigated. The power circuit of the transmitter consists of linear voltage regulators, DC/DC converters for regulating the DC supply, and diodes for reverse voltage protection. After analyzing the load current of the components, derating requirements are explored. Furthermore, power dissipation and junction temperature rise are considered with respect to the load current. The analysis is compared to the results from an engineering model of the transmitter. The temperature of the components is derated by >$40^{\circ}C$ in an environment where the ambient temperature is $+60^{\circ}C$, which is the acceptance test specification of high temperature.

A CONSTRUCTION OF THE REAL TIME MONITORING SYSTEM OF THE SOLAR RADIO DISTURBANCE: II. 2.8GHz RADIO RECEIVER AND RADIO ENVIRONMENT (태양전파교란 실시간 모니터링 시스템구축: II. 2.8GHz 수신기 제작 및 전파환경측정)

  • Kim, Yong-Gi;Park, Sa-Ra;Lee, Dae-Young;Yoon, Joh-Na
    • Journal of Astronomy and Space Sciences
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    • v.25 no.1
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    • pp.61-70
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    • 2008
  • As the second step of the real time monitoring system of the solar radio disturbance, we constructed a 2.8 GHz radio receiver with 500 MHz bandwith. Using the control and observing system (Yoon et al. 2004), we observed the Sun, and found some frequencies, which disturb the Solar radio flux to be observed. DMB and aiport control frequencies are identified as responsible for this disturbance. As well as the testing the receiver, the measurment of the radio environment at 2.8 GHz with 500 MHz bandwith are carried out around Chungbuk National University. In fact, the radio power of the two frequencies, 2.649 GHz and 2.874 GHz is so high that we can not observe the Solar radio signal at 2.8 GHz. We report some results of this measurment and suggest the method to overcome this problem. We conclude also that the frequecies, which are important for the astronomy, should be protected in the future.

Comparison of key management systems across different industries (다양한 산업에서의 키 관리 시스템 비교 분석)

  • Woojoo Kwon;Hangbae Chang
    • Journal of Platform Technology
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    • v.12 no.3
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    • pp.55-61
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    • 2024
  • As the digital environment becomes more complex and cyber attacks become more sophisticated, the importance of data protection is emerging. As various security threats such as data leakage, system intrusion, and authentication bypass increase, secure key management is emerging. Key Management System (KMS) manages the entire encryption key life cycle procedure and is used in various industries. There is a need for a key management system that considers requirements suitable for the environment of various industries including public and finance. The purpose of this paper is to derive the characteristics of the key management system for each industry by comparing and analyzing key management systems used in representative industries. As for the research method, information was collected through literature and technical document analysis and case analysis, and comparative analysis was conducted by industry sector. The results of this paper will be able to provide a practical guide when introducing or developing a key management system suitable for the industrial environment. The limitations are that the analyzed industrial field was insufficient and experimental verification was insufficient. Therefore, in future studies, we intend to conduct specific performance tests through experiments, including key management systems in various fields.

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Analysis of Cable Protection of Duct in Lightning and HIRF Environment of UAM Aircraft and a Proposal for Certification Guidance (UAM 항공기 낙뢰 및 HIRF 환경에서 덕트의 케이블 보호 성능 분석 및 인증기술에 관한 연구)

  • Kim, Dong-Hyeon;Jo, Jae-Hyeon;Kim, Yun-Gon;Lee, Hakjin;Myong, Rho-Shin
    • Journal of Aerospace System Engineering
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    • v.16 no.3
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    • pp.23-34
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    • 2022
  • Cities around the world are increasing their demand for Urban Air Mobility (UAM) aircraft due to traffic congestion with population concentration. Aircraft with various shapes depending on fixed-wing and propulsion systems, are being prepared for commercialization. Airworthiness certification is required as it is a manned transportation vehicle that flies in the city center and transports people on board. UAM aircraft are vulnerable to lightning and HIRF environments due to the increasing use of composite materials, the use of electric motors, and use of electronic equipment. Currently, the development of certification technology, guidelines, and requirements in lightning and HIRF environments for UAM aircraft is incomplete. In this study, the certification procedures for lightning and HIRF indirect impacts of rotorcraft shown in AC 20-136B and AC 20-158A issued by the Federal Aviation Administration (FAA), were verified and applied to the computerized simulation of UAM aircraft. The impact of lightning and HIRF on ducted fan UAM aircraft was analyzed through computerized simulation, and the basis for establishing practical guidelines for certification of UAM aircraft to be operated in the future is presented.

A Moral Approach of Yulgok Philosophy on Environmental Issue (환경문제에 대한 율곡철학의 도덕론적 접근)

  • Jeong, Won-Gyo
    • The Journal of Korean Philosophical History
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    • no.43
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    • pp.33-53
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    • 2014
  • It's the situation that modern technological civilization shakes the life environment fundamentally without a serious reflection on the dangers. The sense of crisis' brought the rise of modern Ecology in awareness of survivability of the humanity. Because the serious reflection is not just a campaign for environmental protection, but is to establish the values which is possible to coexist and to make harmony between the nature and man, man and man, and to form a healthy relationship through philosophical thought and practice has intrinsic value for human and nature. Under these circumstances, if Yulgok lives now and he is questioned by the ecological theorists of the 21st century that "What do you think about the serious environmental problem of present times?", what really would be his explanation? In the presentation methods of the explanation, will question first what contents western ecologists who study Theory of the environment in technology, Deep Ecology, and Social Ecology propose, then will compare and introduce what similarities and differences from theirs. As a result, we'll be found that Yulgok's thought, moral consciousness, about the nature and humanity as a confucian scholar.

Conceptual Design of Structure Subsystem for Geo-stationary Multi-purpose Satellite (정지궤도복합위성 구조계 개념설계)

  • Kim, Chang-Ho;Kim, Kyung-Won;Kim, Sun-Won;Lim, Jae-Hyuk;Kim, Sung-Hoon
    • Journal of Satellite, Information and Communications
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    • v.7 no.3
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    • pp.110-115
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    • 2012
  • Satellite structure should be designed to accommodate and support safely the payload and equipments necessary for its own missions and to secure satellite and payloads from severe launch environments. The launch environments imposed on satellites are quasi-static accelerations, aerodynamic loads, acoustic loads and shock loads. Currently KARI(Korea Aerospace Research Institute) is developing Geo-KOMPSAT-2(Geostationary Earth Orbit KOrea Multi-Purpose Satellite) with technologies which were acquired during COMS(Communication, Ocean and Meteorological Satellite) development. As compared to COMS Geo-KOMPSAT-2 requires more propellant due to mass increase of Advanced Meteorological Payload with high resolution and increase of miss life, it is difficult to apply the design concept of COMS to Geo-KOMPSAT-2. This paper deals with conceptual design of Structural Subsystem for Geo-KOMPSAT-2.

Technique Status of Carbon Fibers-reinforced Composites for Aircrafts (항공기용 탄소섬유강화 복합재료의 기술동향)

  • Kim, Ki-Seok;Park, Soo-Jin
    • Elastomers and Composites
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    • v.46 no.2
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    • pp.118-124
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    • 2011
  • Recently, the need of new materials which have excellent physical properties and functional characteristics has been increased in all industries. In particular, body weight reduction via new materials in aerospace industry was significantly emphasized by the requirement of environmental protection through the fuel savings and reduction of greenhouse gas, i.e., carbon dioxide($CO_2$). Also, for various applications, the development of high performance custom materials with excellent physical properties was the current primary goal of materials science and technology. In this respect, carbon fiber-reinforced composites were the most candidates among the various materials. Indeed, carbon fiber-reinforced composites have been lately used as essential materials for the weight reduction of aircraft and the demand has increased remarkably. Therefore, in this paper, we focused on the need of carbon fiber composites in the fields of aircraft and technique status.

Deficiencies of China's General Aviation Law and its Improvement (중국 일반항공법의 법적 흠결과 개선방향)

  • Zhang, Chrystal;Diao, Weimin
    • The Korean Journal of Air & Space Law and Policy
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    • v.28 no.2
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    • pp.145-181
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    • 2013
  • General aviation is an integral part of civil aviation and involves the widest range of aviation segments except commercial aviation. Featured with different operational procedures and practices to satisfy the economic needs and safety requirements of a sovereign state, general aviation tends to be regulated by an individual state. The last three decades have seen exponential growth of commercial air transport in China, but its general aviation sector has remained disproportionally underdeveloped. With the deepening of the reform of low-altitude airspace, the sector is poised for a radical change and rapid growth. However, legislation governing general aviation activities in China is distorted causing inconsistency and confusions in their application and implementation. This paper aims to analyse China's prevailing legislation regulating general aviation activities. It first discusses the various definitions adopted by ICAO and its member states and reviews the development of general aviation in the US, EU, Australia and China. It then examines the sources of China's general aviation laws, e.g. Chicago Convention and its annexes, and Chinese domestic legislature which covers legislation, laws, directives, rules and procedures. The paper continues to analyse and establish the deficiencies of its prevailing legal framework by pointing out the following: variation of definitions in different regulations, inconsistency of principles in existing laws and regulations, legal vacuum concerning government subsidy, environment protection, safety and security, and other operational areas such as aerial club, sightseeing, and search and rescue. In this process, the paper argues that a coherent, consistent and systematic legal framework is required in order to ensure fair competition and safety for a healthy, progressive and sustainable general aviation growth. Suggestions for rectification and improvement are proposed.

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대순사상의 인문정신과 인류평안의 이념

  • 잔스촹
    • Journal of the Daesoon Academy of Sciences
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    • v.21
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    • pp.199-254
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    • 2013
  • 대순사상은 인간의 행위와 정신적 틀, 즉 몸과 마음을 닦고 세상을 다스리며 백성을 평안하게 하는 도리를 설파하고 있다. 우주 공간의 질서와 깊은 연관을 맺는 이러한 도리는 인간 자신의 인지(認知)와 심신 수양의 내용을 포함하며, 사람이 사회와 우주자연과의 관계를 어떻게 처리해 나갈 것인지에 관한 문제도 다루고 있다. 따라서 대순사상을 인문이라는 관점에 입각하여 분석해 볼 필요가 있다. 이탈리아에서 시작된 서양의 인문주의와 비교해 볼 때, 중국 전통의 인문정신은 인류 개체의 창조력과 그 성과를 인정하고, 인격적 수양과 개선을 주장하며, 사회의 조화를 강조하는 한편, 인류가 반드시 천지인의 조화로운 관계 속에서 개체와 전체의 생존을 파악해야 함을 강조한다. 이러한 인문정신은 『전경』에서도 찾아볼 수 있다. 그 하나가 모악산과 단주(丹朱)에 대한 서술인데, 모악산은 산 즉 '간'(艮)괘이며 단주는 적색에 상응하니 곧 '리'(離)괘가 된다. 이 두 괘가 서로 조합하면 '비(比)'괘가 되며, 『주역』의 비괘와 연관하여 서로 간의 모순을 없애고, '바둑'을 두는 기법을 거울삼아 심성을 다스리며, 인격을 완성하고, 인신이 조화를 이루도록 하며, 사회를 안정시킬 것을 말한다. 대순 신앙의 최종 목표는 지상천국을 건설하는 것인데, 이런 목표를 실현하기 위해서는 인격수양을 그 출발점으로 삼아야 한다. 인격수양의 목표는 바른 도인이 되기 위한 것이며, 이를 위해서는 수도 공부를 해야만 한다. 수도는 춘추시기 노자 이래로 유구한 문화적 전통을 지닌 것이지만, 대순진리회는 한국사회 역사의 경향과 현실의 필요에 부응하여 수도 이론을 새롭게 수립하였다. 이를 살펴보면, 대순진리회는 수도자가 '성(誠), 경(敬), 신(信)'에 힘쓰는 품격 함양을 매우 중시한다. 또 도인들이 가정의 화목에 힘써야 하며, 솔선수범하는 도인으로서 사회의 모범이 되어야 한다고 말한다. 이렇게 볼 때, 대순진리회는 '인도'(人道)를 함양함을 강조하고 있으며, 이것은 전통적인 유가에서 말하는 '수신, 제가' (修身, 齊家)의 정신과 그 의미가 맞닿아 있다. 또한 중국 도교의 '선도(仙道)를 이루고자 하면 먼저 인도(人道)를 행하라'는 사상적 취지와도 일치한다. 대순진리회에서 수도의 최종 목표는 도통이다. 도통은 수도자가 매우 높은 경지에 이르게 되었을 때 가지는 특수한 능력과 정신의 경지이다. '도통'에 대한 기록은 『장자·제물론』, 『문자』의 「부언편>(符言篇) 등에서 찾아볼 수 있는데, 대순진리회가 말하는 도통은 중국의 도가 전통에 보이는 도통과도 연관되지만 강한 인륜수양(人倫修養)적 특색을 지니고 있다는 점에서 차이가 있다. 이것은 대순진리회가 가지는 중요한 인문적 함의라 하겠다. 대순진리회는 수도 공부로써 광제창생·보국안민·지상천국건설의 사회적 이상을 실현하고자 한다. 조화로운 사회적 관계를 수립하기 위한 토대는 대순진리회의 종지 첫 번째인 음양합덕이다. 음양합덕은 대순진리의 인문 취지의 이론적 기초를 형성하는 사상이다. 음양합덕의 철학적 사고는 종지 두 번째인 신인조화(神人調化)의 이상으로 이어진다. 신인조화는 『상서·순전』(尙書·舜典)의 신인이화(神人以和)에서 그 사상적 연원을 찾아 볼 수 있다. 다만 신인이화가 율려 조화의 '결과'를 표현한 것이라면, 신인조화에서 중시하는 것은 '과정'이며 인간과 신의 상호작용이라는 점에 그 특징이 있다. 신인조화를 이루기 위해서는 공부를 해야 하며, 그 배후에는 인본(人本)의 사상이 깃들어 있다. 그것은 종지 세 번째인 '해원상생'의 내용에서 더욱 명확하게 드러난다. 신인조화가 인간과 신의 관계를 조화롭게 하는 것을 말한다면, 해원상생은 인간과 인간의 관계를 조화롭게 하는 것을 말한다. 또 다른 한편으로는 긴 역사의 과정 속에서 맺힌 원을 풀어 우주의 기운을 잘 통할 수 있게 하고 인간 사회의 정상적인 교류를 이루도록 한다. 이러한 내용은 사회적인 인문적 관심과 배려를 다분히 포함하고 있는 것이다. 대순진리회의 종지 네 번째인 도통진경은 수도의 가장 높은 경지를 말하는데, 이러한 이념은 노장 일파의 도가 학자들이 말한 순박한 본성으로 회귀하자는 정신에서 그 원류를 찾을 수 있을 것이다. 또한 이는 한진(漢晉)시대 이래 중국 도교가 추구했던 '진경' 의 의미와도 합치된다. 그러나 시대와 환경이 다름으로 인해, 대순진리회의 '진경'은 사회생활의 의미까지 내포한다. 비록 대순진리회의 경전이 인본(人本)을 명확히 밝히고 있지는 않으나, 대순진리회의 요의(要義) 중 하나인 인존사상은 대순진리회의 인문정신을 말해주는 것이다. 인존사상의 직접적인 기능은 평안(平安)으로서 삶을 이롭게 하는 것이다. 대순진리회는 우주대원의 진리를 '도'라 하였는데 이러한 '도'는 중국의 도가에서 말하는 '도'와 동일하며, 여기에는 '안(安)'의 의미가 포함되어 있다. 대순진리회의 신조 중 '안심', '안신'은 마음을 정(靜)하게 하고, 몸을 편하게 하는 것으로 볼 수 있지만, 심신의 공포와 두려움을 떨쳐내어 안전과 보호를 얻는다는 의미도 있으므로 결국 평안이 전제가 된다. 이렇듯 대순진리회에서는 '평안에 대한 희구'를 근본으로 하여 신앙인들이 열심히 수도에 정진하고 있다. 대순진리회가 인류 평안을 기본으로 하는 종교라는 점에서, 반드시 세인들의 환영을 받을 것임을 믿어 의심치 않는다.