• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.11
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• pp.922-931
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• 2017

This research paper describes design procedures and those verification with multi-body dynamic analysis and an experiment for the development of an unprecedented type of canister cover, named as the separating cover. In order to overcome drawbacks from the precious rupture type and actuator driven cover, the separating cover was suggested. It has the simplest structure composed of the previously developed explosive bolt and a spring-lever driven system. First of all, mechanical feasibility with proposed design parameters based on mathematical modeling was confirmed through dynamic analysis and then its results showed good agreement with the followed empirical results acquired from a high speed camera. On top of that, a parametric study was conducted to identify the effect of each design parameter on separating performance. It is highly expected that this research contributes to provide military industries with a brand new canister cover having simplicity and cost efficiency and thus it will be very useful in MLRS(Multiple Launch Rocket System).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.6
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• pp.423-433
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• 2022

This paper introduces the case studies of launch environmental test for cube nanosatellites and lessons learned of the design and integration from those. Generally, nanosatellites are launched and deployed in space while being contained in nanosatellite deployers, mechanical loads of launch are transferred through the deployer. This characteristic make nanosatellites under larger loads and higher possibilities of mechanical failure. This study represents guidelines of the design and the integration of the nanosatellites by showing the cases of launch environmental test of nanosatellite system. Moreover, it is suggested that the modern nanosatellite deployer with the capability of fixing the internal nanosatellite be preferable to conventional deployer by comparing the test results with those deployers.

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.489-500
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• 2005

The objective of this study is to examine the cognitive process that undergoes a middle student’s conceptual change about the universe by the cognitive conflict, using science history materials as a teaching strategy. Four eighth graders were selected and classified by three cognitive level. Students were interviewed and conducted to an inquiry activities regarding their viewpoint about the universe after each class, and their conceptual change patterns were analysed from pre-test and post-test. This study showed that each student held dissimilar astronomical preconceptions and various misconceptions about celestial motion. Students at the formal operational stage and transitional stage experienced the conceptual change from geocentricism to heliocentricism by instructional model upon the science history materials. Student at the concrete operational stage had either unscientific conception, no conception, or could not have a conceptual change even when being presented with an environment that arouses cognitive conflict ($R^2$: Phase change of Venus and its Rise and set time). They ended up having a cognitive change from geocentricism to heliocentricism by solving another problem ($R^2$: Relation between visible diameter and position of Mars). After the instruction, a conceptual achievement progress was reported with a $10\%$ improvement. Therefore, the instruction model based upon science history was effective on student’s scientific conceptual change.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.581-588
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• 2020

The aging characteristics of exploding foil initiator (EFI) are studied. In order to observe the aging characteristics, the main components of the exploding foil initiator were classified and the failure mechanism was defined. The aging characteristics were defined in terms of power and sensitivity, and the accelerated aging test plan was established based on the activation energy calculated by HFC (Heat Flow Calorimetry) and Arrhenius theory. The performance variation was observed using the sensitivity test (Neyer test) and power test (Dent test) for the aged samples. The aging characteristic was observed on the mean exploding point of the sensitivity test, but long-enough life span was predicted considering the related specification.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.4
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• pp.27-34
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• 2005

The paper discussed on the stability of cantilevered pipe conveying fluid subjected to distributed follower force. Governing equations of motion are derived by extended Hamilton's principle, and the numerical scheme using finite element method is applied to obtain the discretized equations. The critical flow velocity as a function of the distributed follower force for the various mass ratio is determined. The flutter configurations of the pipes at the critical flow velocities are drawn graphically at every twelfth period to define the order of quasi-mode of flutter configuration The critical mass ratios, at which the transference of the eigenvalue branches related to flutter take place, are definitely determined. Also, the effect of damping on the stability of the system is considered.

• The Journal of Korean Medical History
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• v.20 no.2
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• pp.237-247
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• 2007

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.71.1-71.1
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• 2017

WouldYouLike[우주라이크]는 2009년 천문학 전공 대학생들을 중심으로 탄생한 천문우주과학 대중화를 위해 활동하는 비영리 단체이다. 천문우주과학에 대한 정보를 얻기 힘든 사람들을 위해 쉽게 접할 수 있는 콘텐츠를 제작하여 이를 무료로 배포하고 있다. 2012년 무료 배포용 천문학 잡지 우주라이크 창간호를 시작으로 2017년 현재 11호까지 발간되었으며, 이 잡지는 전국 각지의 대학교 캠퍼스와 천문대 및 과학관의 협조를 통해 배포 중이다. 이러한 오프라인 활동과 더불어 SNS(인스타그램, 페이스북)와 홈페이지를 비롯해 현대인들에게 접근성이 높은 온라인 매체를 적극적으로 활용한 천문학 콘텐츠와 팟캐스트 등을 통해 대중에게 다가가고 있다. 특히 우주라이크 페이스북 페이지의 팔로워 수는 약 35,000명이며, 이는 한국천문연구원 페이스북 페이지의 약 6,000명보다 많은 수치이다. 이는 우주라이크 본연의 목적인 천문학 대중화에 우주라이크가 크게 기여하고 있음을 보여준다. 현재 우주라이크는 상기에 기술한 활동들과 함께 NASA에서 운영하는 APOD (Astronomy Picture of the Day)의 한글판 서비스를 공식적으로 번역하여 제공하고 있다. 이 포스터는 국내에서 천문우주과학 대중화의 필요성을 역설하며, 이와 연계해서 우주라이크의 활동 내역과 현재 추진 중인 계획을 소개한다. 그리고 이에 대한 국내 천문학계의 다양한 목소리를 듣고 추후 활동에 반영하고자 한다.

• Journal of Korean Medical classics
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• v.18 no.3 s.30
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• pp.9-16
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• 2005

종의역학적각도간(從醫易學的角度看), 우주적팽창일수축반복가설부합음양소장과정. 우주팽창시(宇宙的膨是)‘양생음장(陽生陰長)’, ‘양성음쇠(陽盛陰衰)’적과정(的過程) ; 우주수축시(宇宙收縮是)‘양살음장(陽殺陰藏)’, ‘음성양쇠(陰盛陽衰)’적과정(的過程). 종수축도팽창(從收縮到膨脹), 종팽창도수축(從膨脹到收縮), 기전환점시양극혹음극적상태(其轉換點是陽極或陰極的狀態), 응용(應用)’음극변양(陰極變陽), 양극변음(陽極變陰)‘적음양극변원리(的陰陽極變原理). ${\lceil}$내경(內經)${\rfloor}$인위물질화시공(認爲物質和時空), 시간화공간본질상시일치적(時間和空間本質上是一致的), 도시종기파생출래적(都是從氣派生出來的). ${\lceil}$내경(內經)${\rfloor}$이경인식도료시공적통일성화상대성(已經認識到了時空的統一性和相對性). 저여애인사탄상대론적시공관유상동지처(這與愛因斯坦相對論的時空觀有相同之處). 서방과학적시공관시통과대물질실체이급물질상호관계적관찰이형성적물리시공관(西方科學的時空觀是通過對物質實體以及物質相互關係的觀察而形成的物理時空觀) ; 의역시공관시통과대포괄인류재내적천지만물적일절생명활동현상적관찰이형성적생명시공관(醫易時空觀是通過對包括人類在內的天地萬物的一切生命活動現象的觀察而形成的生命時空觀).

• The Korean Journal of Air & Space Law and Policy
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• v.15
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• pp.9-34
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• 2002

• The Science & Technology
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• v.33 no.12 s.379
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• pp.42-44
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• 2000

1548년 이탈리아 나폴리 근처에서 태어난 브루노는 가톨릭이 서방을 뒤흔들던 시절 지동설과 범신론을 주장하는 이단자로 몰려 1600년 화형으로 52세를 살다 세상을 떠났다. 1572년 사제서품을 받은 그는 1578년 제네바로 옮겨 개종했지만 개신교도 억압한다는 사실을 알고 비판하기 시작했다. 파리로, 런던으로 전전하면서 신학과 우주관의 논쟁을 계속했다. 이탈리아로 돌아온 그는 교황으로부터 고칠수 없는 이단자로 판정을 받고 화형을 당했는데 죽음의 자리에서 그는 "내가 죽어가면서 고통받는 공포보다는 나를 사형언도하며 받는 공포가 더 두려울 것"이라고 하여 그 당시 협박에 못이겨 지동설을 포기한 갈릴레이와 대조를 이룬다.