• Title/Summary/Keyword: 우주활동

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Changes Detection of Ice Dimension in Cheonji, Baekdu Mountain Using Sentinel-1 Image Classification (Sentinel-1 위성의 영상 분류 기법을 이용한 백두산 천지의 얼음 면적 변화 탐지)

  • Park, Sungjae;Eom, Jinah;Ko, Bokyun;Park, Jeong-Won;Lee, Chang-Wook
    • Journal of the Korean earth science society
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    • v.41 no.1
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    • pp.31-39
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    • 2020
  • Cheonji, the largest caldera lake in Asia, is located at the summit of Baekdu Mountain. Cheonji is covered with snow and ice for about six months of the year due to its high altitude and its surrounding environment. Since most of the sources of water are from groundwater, the water temperature is closely related to the volcanic activity. However, in the 2000s, many volcanic activities have been monitored on the mountain. In this study, we analyzed the dimension of ice produced during winter in Baekdu Mountain using Sentinel-1 satellite image data provided by the European Space Agency (ESA). In order to calculate the dimension of ice from the backscatter image of the Sentinel-1 satellite, 20 Gray-Level Co-occurrence Matrix (GLCM) layers were generated from two polarization images using texture analysis. The method used in calculating the area was utilized with the Support Vector Machine (SVM) algorithm to classify the GLCM layer which is to calculate the dimension of ice in the image. Also, the calculated area was correlated with temperature data obtained from Samjiyeon weather station. This study could be used as a basis for suggesting an alternative to the new method of calculating the area of ice before using a long-term time series analysis on a full scale.

A Study of the Architectural Characteristics Depicted on Andre Courrs Fashion Design (앙드레 꾸레쥬의 패션 디자인에 나타난 건축양식 특성연구)

  • Kyoung-Hee Cho
    • Journal of the Korean Society of Costume
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    • v.23
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    • pp.25-43
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    • 1994
  • 앙드레 꾸레쥬는 자신의 디자인에 건축적 조형미를 표현한 대표적인 디자이너이다. 그의 디자인들은 라인 뿐 아니라 색채, 소재, 액세서리에 이르기까지 건물을 짓듯이 설계, 구성되어 있다. 최근 복식미의 건축적 조형성이 강조되고 있는 것을 감안할 때, 60년대 이미 선구자적인 역할을 하면서 자신의 건축가적인 기호를 유감없이 발휘해온 꾸레쥬를 연구한다는 것은 21세기를 향한 패션의 발전 측면에서 조금이라도 의미가 있지 않을까 생각한다. 본 연구에서는 앙드레 꾸fp쥬가 가장 활발히 활동했던 1974년에서 1970년까지 그의 디자인들을 집중 연구하였는데, 그의 패션디자인에 건축양식의 특징들이 어떻게 나타났는지에 연구의 초점을 맞추었다. 본 연구의 대상으로 사용된 실제의 옷 샘플들은 뉴욕 메트로폴리탄 예술박물관내의 Costume Institute Storage 에 있는 의복과 액세서리들을 직접, 관찰 , 분석한것이고 그 박의 사진들은 패션과 건축에 관한 서적과 잡지, 박물관내의 Slide Library , 그리고 Costume Institute Library Collection에서 발췌 , 비교 연구한 것이다. 일찍이 엔지니어링과 건축을 공부했던 앙드레 꾸레쥬는 50년대의 패션 디자이너의 거장 발렌시아가 밑에서 10년 넘게 일하다가 독립하였는데 그의 디자인 세계는 줄곧 여성들이 입고 편히 활동 할 수 있는 기능성을 강조하면서 단순하고 편안한 의복 구성에 중점을 두었다. 그리고 그는 이러한 자신의 패션 철학과 의복제작 과정들은 현대건물이 갖는 단순성, 기능성의 특징과 일치한다고 믿었다. A. 라인(Line) 앙드레 꾸레쥬는 패션 디자인에서의 비레는 건축에서구조를 쌓아가는 것과 같은 것이라고 생각하고 옷에서의 기본 구성을 기하학적인 라인에 두었다. 그래서 그의 옷들은 A-라인, 사각형, 사다리꼴,,, 등의 분명한 실루엣을 이루고 있는데 이러한 기본라인을 뒷받침이라도 하듯 소매가 아주 짧거나 없는 것이 특징이다. 황금분할이 아닌 1 : 1 구성은 그가 독특하게 사용한 비례방법의 하나인데 그것은 자켓과 스커트의 길이비례, 요크와 몸판간의 면적비례 등에서 잘 나타나고 있다. 그리고 그는 , 의복구성의 비례를 강조하기 위해 사용한 강한 색상의 대비를 현대건물의 인테리어에 빛을 사용하는 것과 같은 이치라고 설명한다. B.색상(Color) 흰색은 그러한 그의 비례강조 의복에 가장 적절한 색으로 사용되었다. 그는 빨강, 오렌지, 녹색, 분홍등 강렬한 원색을 사용하였는데도 불구하고 흰색은 그의 건축양식 발상의 Ideo를 완성시키는 완전한 색이었다. 뜨거운 날씨에 흰색이 가장 기능적인 색인 것처럼 강한 원색 대비를 통해 비례강조를 하면서 동시에 그것을 뒷받침하는 가장 합리적이고 기능적인 색은 흰색이라고 믿었다. C. 소재 (Material) 앙드레 꾸레쥬는 건물을 짓듯이 사람위에 옷을 건축한다고 믿었기 때문에 자연히 둔탁하고 딱딱한 소재가 많이 사용되었다. 비닐, 금속류, 시퀸스처럼 광택나고 투명한 재료 선호는 그 당시 현대 건축에서 선풍적으로 많이 사용되었던 유리, 금속류, 크리스탈 등 비치고 광택나는 건축재료와 일맥상통하는 것이다. 그러한 선국적인 내료 사용결과로 보여진 괴상하고 선정적인 그러면서도 아주 단순한 패션은 미래 지향적인 건축양식 구조의 " Simple", "Plain" 느낌과 정확하게 같은 것이다. 이상과 같이 앙드레 꾸레쥬는 옷을 디자인 했다기 보다는 건축했다. 주목할만한 점은 60년대 말 당시 발표되었던 그의 건축 구조적인 디자인의 특징들이 21세기를 앞둔 90년대에 다시 크게 유행하고있다는 점이다. 꾸레쥬 역시, 최근 자신의 디자인을 통해 건축적 조형미와 미래지향적 이미지를 더욱 강조하고 있는 것을 볼 수있다. 단순하면서 우주공간을 선회하는 듯한 입체적인 라인, 흰색을 비롯한 자연에 가까운 색을 중심으로 하되, 밝은 색조의 하이라이트, 플라스틱, 금속류와 같이 딱딱하고 광택나며 비치는 재료 사용,, 등등이 바로 그것이다. 그리고 이러한 그에 미래 지향적이고 조형적인 디자인들은 앞으로 어떻게 더 모험적인 모습으로 선보일지 우리 모두가 주목할만한 일인 것이다.

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PERIOD CHANGES OF W UMa TYPE CONTACT BINARY SS ARIETIS (W UMa형 접촉쌍성 SS ARIETIS의 공전주기 변화)

  • 김천휘;한원용;윤재혁;나일성
    • Journal of Astronomy and Space Sciences
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    • v.14 no.1
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    • pp.44-58
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    • 1997
  • The BVR CCD photometric observations of W UMa-type eclipsing binary SS Ari were made on ten nights from November 1996 to December 1996. Eight new times of minimum lights were derived. The analysis of times of minima of SS Ari confirms the suggestions of other previous investigators that the orbital period of SS Ari have been suffering from a sinusoidal varition. The amplitude and period for the cyclic period changes were calculated as about $58^{y}$ and $0.^{d}053$, respectively. The period variation has been discussed in terms of two potential mechanisms: 1) the light-time effect due to a hypothetical third body and 2) deformations in the convective envelope of a magnetically active component. In the earlier case, the third body has a mass of $1.3M_{\odot}$, if exist, in the form of a white dwarf or a binary system. It seems that the system velocities from the spectroscopic observations supports this interpretation. Meanwhile in the latter case, the primary component is mainly responsible for the magnetic activity of this system with a theoretical amplitude of $\pm0.^{m}08$. However, we cannot make a conclusion which is reasonable explanation at this point, due to lack of observational data. Moreover, the period variation of SS Ari shows duplication about $14^y$, cyclic period with an amplitude of about $0.^d001$ to the above periodic change. We also cannot make an acceptable conclusion for it at this time.

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Analysis and Evaluation of the Earth Science Content Relevance in the 7th National Science Curriculum (제7차 과학과 교육과정 지구과학 내용의 적정성 분석 및 평가)

  • Lee, Yang-Rak;Kwak, Young-Sun;Kim, Dong-Young
    • Journal of the Korean earth science society
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    • v.26 no.8
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    • pp.759-770
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    • 2005
  • The purpose of this study is to examine the Earth science content relevance of the 7th national science curriculum. For this purpose, we (1) analyzed science curriculum or content standards of Korea, California, England and Japan, (2) compared science textbooks of Korea and Japan, (3) conducted a nationwide survey to gather opinions from students, teachers, professors and textbook authors about the relevance of the science curriculum and textbooks. According to the results, the Earth science contents of the 7th national science curriculum were not appropriate in terms of the objectives of science curriculum and the needs of students and society. The main reasons include the equal division among physics, chemistry, biology and earth science, iack of connection due to fractionation of units, overly strict application of spiral curriculum, and redundant amount of activities and concepts to cover in the textbook. Major suggestions fir securing the relevance of Earth science contents are as follows: First, the science contents and the size of units at each grade level should be determined according to the students' characteristics, not by equal portion rule. Second, the excessive overlapping and repetition of contents due to the spiral curriculum should be avoided. In addition, the number of activities should be reduced and the quality of required science activities should be improved. Third, to raise students' interest in Earth science, real-life applications and real-world Earth science contents should be emphasized including natural disasters, safety, universe and space exploration, and natural resources. Lastly, considering one of the relevance criteria is feasibility, supports for schools and science teachers are needed to realize the goal of the intended science curriculum.

Ionosphere Modeling and Estimation Using Regional GPS Data (지역적인 GPS 관측 데이터를 이용한 이온층 모델링 및 추정)

  • 황유라;박관동;박필호;임형철;조정호
    • Korean Journal of Remote Sensing
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    • v.19 no.4
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    • pp.277-284
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    • 2003
  • We present a GPS-derived regional ionosphere model, which estimates Total Electron Content (TEC) in a rectangular grid on the spherical shell over Korea. After dividing longitude and latitude over Korea with 1$^{\circ}$$\times$1$^{\circ}$ spatial resolution, the TEC at the vertex of the grid was estimated by the Kalman filter. The GPS data received from nine nationwide GPS stations, operated by Korea Astronomy Observatory (KAO), were used for this study. To reduce inherent noises, the pseudorange data were phase-leveled by a linear combination of pseudoranges and carrier phases. The solar-geomagnetic reference frame, which is less variable to the ionosphere movement due to the Sun and the geomagnetic field than an Earth-fixed frame, was used. During a quiet time of solar activity, the KAO's regional ionosphere map indicated 30-45 Total Electron Content Unit at the peak of the diurnal variation. In comparison with the Global ionosphere Map of the Center for Orbit Determination in Europe, RMS differences were at the level of 4-5 TECU for five days.

The Development and Application of an Astronomy Education Program Reflecting Astronomical Thinking: A Case of Planetarium Class at Science Museum (천문학적 사고를 반영한 천문교육 프로그램의 개발 및 적용: 과학관 천체 투영관 수업 사례)

  • Choi, Joontae;Lee, Kiyoung;Park, Jaeyong
    • Journal of the Korean earth science society
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    • v.40 no.1
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    • pp.86-106
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    • 2019
  • The purpose of this study is to develop an astronomy education program reflecting astronomical thinking to be used at science museum and to investigate the effect of the program on the improvement of astronomical thinking ability of high school students. After selecting the components of astronomical thinking through literature studies, we developed an astronomy education program consisting of four stages: demonstration and observation, and question and thinking, support and group discussion, demonstration and assessment. In order to verify the effectiveness of the program, we conducted a covariance analysis on the pre- and post-tests of the experimental group and control group to examine the level of students' thinking before and after using the program in teaching and learning. As a result, it was confirmed that the astronomy education program reflecting astronomical thinking was effective in promoting students' astronomical thinking ability. In particular, this program was effective in enhancing the ability of modeling by reconstructing the observed astronomical phenomenon from the viewpoint of the universe with respect to spatial thinking in the astronomy domain. It was also effective to improve the ability of organizing the system by grasping the relationship between the elements constituting the astronomical system in relation to the system thinking in the astronomy domain. This study is significant in suggesting a specific teaching and learning program to develop students' astronomical thinking.

The Development of an Astronomical Observing Education Program for High School Science Club Activities - Inquiring Distances of Open Clusters Using Small Telescopes - (고등학교 과학동아리 천체 관측 교육 프로그램 개발 - 소형 망원경을 활용한 산개성단의 거리 탐구 -)

  • Choi, Dong-Yeol;Yoon, Ma-Byong
    • Journal of the Korean earth science society
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    • v.40 no.3
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    • pp.300-312
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    • 2019
  • The purpose of this study is to develop an astronomical observing education program that enables high school students to inquire the distance of astronomical bodies based on the research methods (observing open clusters and exploring collected big data) using small telescopes and DSLR cameras. After analyzing the 2015 revised science curriculum, we developed science club activity materials and teacher-student learning contents suitable for high school earth science education. A panel of six teachers and researchers of earth science education and astronomy, participated in developing the educational materials. The validity of the program was verified through establishing the agreement among the panels after in-depth discussions and clarifications. The program, developed with 10 lessons in total, showed high satisfactory content validity (CVI, .89) and conformity of school class (Likert's 5 point scales, 4.17). The feedback of the panels and the Delphi analysis continued to improve the quality of the program. The pilot testing result with high school students (N=9) showed that the students' satisfaction rate was high as 4.48. Using the astronomical observational education program of this study is expected to contribute in improving the convergence educational activity, interest, curiosity, and inquiry ability of students in the universe and the astronomical bodies.

A Discourse Analysis of Science Teachers' Scientific Modeling Activities: A Case from Earth Science Teacher Training (과학 모델링 활동에 나타난 교사의 담화 분석 -지구과학 교사 연수 사례-)

  • Heungjin Eom;Hyunjin Shim
    • Journal of The Korean Association For Science Education
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    • v.44 no.4
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    • pp.301-311
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    • 2024
  • We developed a small-group training program for in-service teachers focused on scientific modeling. We collected the discourses of the teachers who participated in the activity and analyzed them by type. The training program employed a collaborative approach in which a small group completed tasks and produced outputs based on the theme of 'galaxies and the Universe' to enable practical application in classes. Three in-service science teachers participated in the training program. Their discourses were recorded, transcribed, and classified into types based on individual turns and interaction units. The language expressions of the teachers reflected the unique characteristics of the teaching profession, with each participant having preferred language expression types, albeit with a generally low prevalence of specific language expression types across the participants. Differences in discourse characteristics related to the modeling theme, task presentation method, and model types, revealed that variations in the proportion of interaction unit types during the modeling design, build, and evaluation stages were primarily influenced by the teachers' familiarity with the modeling theme. While the task presentation method also influenced interaction types, model types had little impact on the distribution of interaction types. Considering these findings, training programs on modeling for in-service teachers should include a checklist to encourage sufficient interaction between participants as well as propose proper questions that can be effectively addressed through collaboration.

50 W 급 저전력 원통형 이온빔 소스의 개발 및 연구

  • Kim, Ho-Rak;Lee, Seung-Hun;Im, Yu-Bong;Kim, Jun-Beom;Choe, Won-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.192.2-192.2
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    • 2016
  • 전기추력기는 화학식 추력기에 비해 비추력이 높아 인공위성의 자세제어, 궤도수정, 궤도천이를 포함한 행성 탐사활동 및 우주 임무수행을 위한 우주선의 엔진 등으로 다양하게 활용된다. 홀 추력기는 전기추력기 중 하나로 고리형 방전공간을 가진 고리형 추력기와 원통형 방전영역을 가진 원통형 추력기가 있으며, 원통형 추력기는 고리형에 비하여 넓은 방전공간으로 저전력 방전에 적합한 추력기이다. 또한, 저전력 추력기는 큐브셋(cubesat) 및 마이크로 위성(microsatellite)의 증가하는 수요에 따라 필요성이 증가하고 있으며, 활용도가 높아 다양하게 연구 및 개발되고 있다. 홀 추력기는 자기장과 전기장을 서로 수직되게 인가하여, 자화된 전자는 플라즈마 방전을 유지시키고 자화되지 않은 이온은 전기장 방향으로 가속되어 이온빔을 발생시킨다. 하지만, 저전력 소형 추력기는 작은 소모전력과 방전채널로 인한 성능 저하 및 자기장 구조 설계 등 많은 어려움들을 가지고 있다. 본 연구에서는, 약 50 W급의 소모전력을 바탕으로 영구자석을 이용한 저전력 플라즈마 추력기를 개발하였다. 방전 채널은 지름 15 mm, 길이 16 mm, 무게는 약 0.6 kg으로 원통형 구조의 채널로 제작되었으며, 약 1500-2000 G의 자기장 세기를 갖도록 설계하였다. 방전 기체는 제논을 사용하여 1-5 sccm영역에서 방전 특성을 살펴보았으며, 방전 전류는 0.02-0.4 A로 나타났다. 100-550 V영역에서 방전을 시도하였고, 채널길이를 16-24 mm 에서 약 1mN 급의 추력특성을 보였다. 본 발표에서, 홀 추력기의 제작 특성과 성능 및 플라즈마 특성에 대한 더 자세한 연구결과가 발표될 예정이다.

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A DETECTION STUDY OF THE IONOSPHERIC TOTAL ELECTRON CONTENTS VARIATIONS USING GPS NETWORK (GPS 기준국망을 이용한 전리층 총전자수 변화 검출 연구)

  • Choi, Byung-Kyu;Park, Jong-Uk;Lee, Sang-Jeong
    • Journal of Astronomy and Space Sciences
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    • v.24 no.4
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    • pp.269-274
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    • 2007
  • We established a regional ionospheric model for investigating ionospheric TEC (Total Electron Contents) variations over the Korean Peninsula during major geomagnetic storms. In order to monitor the ionospheric TEC variations, we used nine permanent GPS reference stations uniformly distributed in South Korea operated by the Korea Astronomy and Space Science Institute (KASI). The cubic spline smoothing (CSS) interpolation method was used to analyze the characteristics of the ionospheric TEC variations. It has been found that variations of TEC over the Korean Peninsula increase when a major geomagnetic storm occurred on November 20, 2003. The TEC has increased about one and a half of those averaged quite days at the specific time during a geomagnetic storm. It has been indicated that the KASI GPS-derived TEC has a correlation with the geomagnetic storm indices (eq. Kp and Dst indices).