• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.69.3-69.3
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• 2020

우주개발과 활용이 주요 화두가 된 현대에 보다 빠르고 정확한 우주환경 예보는 전략적으로 매우 중요하다. 이에 우리는 광대역태양영상분광망원경(Wide-Field Solar Spectro-Imaging Telescope, Post SOlar Flare Telescope: PSOFT)을 활용한 태양전면 영상분광감시체계를 구성하고자 한다. 전세계 세 곳에 PSOFT를 배치하여 우주환경에 중대한 영향을 주는 요소인 태양의 플레어와 홍염 분출과 같은 현상과 표면의 다양한 활동들을 실시간으로 관측 분석하고자 한다. PSOFT는 30cm 구경의 광학계에 고속영상분광기를 결합하여 태양 전면의 분광영상을 약 1초각의 영상해상도와 5분의 시간해상도로 획득한다. 태양 전면을 슬릿으로 스캔하는 방식으로 H alpha와 Ca II 854.2nm선의 분광정보를 획득하는데 팁틸트 미러를 이용하여 1차적인 시상보정과 함께 스캔모션을 함께 구현함으로써 1)광학계 구조를 단순화하고, 2) 빠른 스캔이 가능하다. PSOFT로 얻은 태양전면 채층분광영상 데이터는 정밀한 우주환경 예보에 필요한 플레어나 홍염분출의 발생초기 정보를 제공할 뿐 아니라 태양 저층대기에서 발생하는 자기재연결, 파동 등에 대한 통계적 연구자료를 제공할 것으로 기대한다.

• Journal of Space Technology and Applications
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• v.3 no.3
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• pp.239-256
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• 2023

The Earth's ionosphere is an area where part of the upper atmosphere is ionized and exists in a plasma state that affects radio waves. It is a field that has been studied for a long time as it directly affects real life in relation to communications. Depending on the altitude, it is divided into D, E, and F layers depending on the main ions that make up the electron density. The density of the neutral atmosphere is very large compared to the electron density, so it should be described as plasma taking that effect into account. It is an area where influences from outside the ionosphere are directly reflected, starting from the sun and extending to the earth's surface, and is a field that involves complex and diverse areas of research. In this paper, we explain the process by which the Earth's upper atmosphere is ionized to form the ionosphere and introduce the characteristics of the ionosphere at low and mid-latitudes. In addition, we introduce the research that domestic researchers have participated in related to the ionosphere to date and hope that it will be used to promote exchange in the field of ionospheric research in the future.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.4
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• pp.495-508
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• 2019

Tidal datums are key and basic information used in fields of navigation, coastal structures' design, maritime boundary delimitation and inundation warning. In Korea, the Approximate Lowest Low Water (ALLW) and the Approximate Highest High Water (AHHW) have been used as levels of tidal datums for depth, coastline and vertical clearances in hydrography and coastal engineering fields. However, recently the major maritime countries including USA, Australia and UK have adopted the Lowest Astronomical Tide (LAT) and the Highest Astronomical Tide (HAT) as the tidal datums. In this study, 1-hr interval 19-year sea level records (1999-2017) observed at 9 tidal observation stations along the west and south coasts of Korea were used to calculate LAT and HAT for each station using 1-minute interval 19-year tidal prediction data yielded through three tidal harmonic methods: 19 year vector average of tidal harmonic constants (Vector Average Method, VA), tidal harmonic analysis on 19 years of continuous data (19-year Method, 19Y) and tidal harmonic analysis on one year of data (1-year Method, 1Y). The calculated LAT and HAT values were quantitatively compared with the ALLW and AHHW values, respectively. The main causes of the difference between them were explored. In this study, we used the UTide, which is capable of conducting 19-year record tidal harmonic analysis and 19 year tidal prediction. Application of the three harmonic methods showed that there were relatively small differences (mostly less than ±1 cm) of the values of LAT and HAT calculated from the VA and 19Y methods, revealing that each method can be mutually and effectively used. In contrast, the standard deviations between LATs and HATs calculated from the 1Y and 19Y methods were 3~7 cm. The LAT (HAT) differences between the 1Y and 19Y methods range from -16.4 to 10.7 cm (-8.2 to 14.3 cm), which are relatively large compared to the LAT and HAT differences between the VA and 19Y methods. The LAT (HAT) values are, on average, 33.6 (46.2) cm lower (higher) than those of ALLW (AHHW) along the west and south coast of Korea. It was found that the S_a and N₂ tides significantly contribute to these differences. In the shallow water constituents dominated area, the M₄ and MS₄ tides also remarkably contribute to them. Differences between the LAT and the ALLW are larger than those between the HAT and the AHHW. The asymmetry occurs because the LAT and HAT are calculated from the amplitudes and phase-lags of 67 harmonic constituents whereas the ALLW and AHHW are based only on the amplitudes of the 4 major harmonic constituents.

• Atmosphere
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• v.33 no.2
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• pp.275-295
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• 2023

In Korea, there are four institutions related to atmospheric science: the university's atmospheric science-related department, the Korea Meteorological Administration (KMA), the ROK Air Force Weather Group, and the Meteorological Industry Association. These four institutions have developed while maintaining a deep cooperative relationship with the Korea Meteorological Society (KMS) for the past 60 years. At the university, 6,986 bachelors, 1,595 masters, and 505 doctors, who are experts in meteorology and climate, have been accredited by 2022 at 7 universities related to atmospheric science. The KMA is carrying out national meteorological tasks to protect people's lives and property and foster the meteorological industry. The ROK Air Force Weather Group is in charge of military meteorological work, and is building an artificial intelligence and space weather support system through cooperation with universities, the KMA, and the KMS. Although the Meteorological Industry Association has a short history, its members, sales, and the number of employees are steadily increasing. The KMS greatly contributed to raising the national meteorological service to the level of advanced countries by supporting the development of universities, the KMA, the Air Force Meteorological Agency, and the Meteorological Industry Association.

• Journal of the Korean earth science society
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• v.21 no.1
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• pp.1-12
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• 2000

The earth science curriculum and textbooks of the secondary school in South Korea and North Korea were analysed comparatively with the modified TIMSS curriculum frameworks. In the secondary school of North Korea, earth science is not provided with separate subject, but partly taught in geography. Geography is taught by two hour per week in the first to fifth grade of secondary school. Especially the first and the fifth grade geography are deeply related to earth science. The major aim of earth science education in South Korea is to develop creative problem solver having with interest and curiosity in searching natural phenomena and with basic science concepts and inquiry process skills. But on the other hand the aim of geography education of North Korea is to cultivate communist revolutionists who are faithful to IL-Sung Kim and Jung-IL Kim. In both Koreas the category of 'earth feature' and 'earth process' are dealt a lot, but 'earth in the universe' is rarely taught in North Korea, which suggests that separate subject of astronomy is instructed in the North. Generally the scope and sequence of earth science of North Korea comes under those of middle school of South Korea. Especially discrepancy in level of meteorology and astronomy area between North and South Korea is great.

• Publications of The Korean Astronomical Society
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• v.30 no.3
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• pp.821-832
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• 2015

As a part of the short-period variability survey (SPVS) at Bohyunsan Optical Astronomy Observatory, we obtained time-series BV CCD images in the region of the open cluster NGC 1039 (M34). The observations were performed for 22 nights from July 29, 2008 to September 26, 2010. We also made LOAO observations for 10 days from September 18, 2009 to October 30, 2010 to confirm the small variabilties of ${\delta}$ Scuti-type variable stars. In this paper we presented the observational properties of 28 variable stars found in the region. They are seven ${\delta}$ Scuti-type variable stars, two ${\gamma}$ Doradus-type variable stars, four-teen eclipsing binary stars and five semi-long periodic or slow irregular variables, respectively. Only three variables were listed in the GCVS and the rest are newly discovered ones. We have performed multiple-frequency analysis to determine pulsation frequencies of the ${\delta}$ Scuti-type and ${\gamma}$ Doradus-type variable stars, using the discrete Fourier transform and linear least-square fitting methods. We also have derived the periods and amplitudes of 12 eclipsing binaries from the phase fitting method, and presented the light curves of all variable stars.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.267-275
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• 2010

The purpose of this study is to investigate student's Acquisition about the conception of the Earth Rotation between difference of their Spatial Sensibility. In this study, four students were selected out of 83 9th graders in Gwangju, Korea. The spatial sensibility test instrument was developed by the Korean Testing Center, and the test instruments of 'the movement of celestial bodies' were developed by Kim (1997). The results were as follows: Students with higher spatial sensibility understood precisely about the Earth's rotation in stereoscopic space. However, those with lower spatial sensibility failed to grasp the Earth's rotation and memorized it as fragmentary concepts. As for gender effect, male student with higher spatial sensibility explained the concepts clearly, while that with lower spatial sensibility has difficulty with the Earth's rotation in relation to the diurnal motion of celestial bodies. On the other hand, female student with higher spatial sensibility explained the concepts correctly in detail, while that with lower spatial sensibility had difficulty explaining the concepts in stereoscopic space. Therefore, students with higher spatial sensibility should be presented with problems in which they form their own solution. Those with lower spatial sensibility should be allowed to understand the phenomena intuitively. In developing teaching methods, female students should interact with the concepts in stereoscopic space directly, while male students should consider the celestial objects from various viewpoints. Then spatial sensibility in relation to the movement of celestial bodies would be expected to improve.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.2
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• pp.327-333
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• 2019

For sustainable lunar exploration, the most required resources should be procured on site because it takes tremendous cost to transfer the resources from the Earth to the Moon. The technologies required for use of lunar resources refers to In-Situ Resource Utilization (ISRU). As the ISRU technology cannot be verified in the Earth, a lunar surface environment simulator is necessary to be prepared in advance. The Moon has no atmosphere, and the average temperature of the lunar surface reaches to $107^{\circ}C$ during the daytime and $-153^{\circ}C$ at night. The lunar surface is also covered with very fine soils with sharp particles that are electrostatically charged by solar radiation and solar wind. In this research, generation of vacuum environment with lunar soil mass in a chamber and simulation of electrostatically charged soils are taken into consideration. It was successful to make a vacuum environment of a chamber including lunar soils without soil disturbance by controlling evacuation rate of a vacuum chamber. And an experiment procedure for simulating the charged lunar soil was suggested by theoretical consideration in charging phenomena on lunar dust.

• Journal of Science Education
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• v.46 no.2
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• pp.151-164
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• 2022

The 2015 revised science curriculum textbook of 6th graders describes 'day and night' as an astronomical phenomenon observed on a daily basis. Textbooks use only visual materials from a space-based perspective to explain the causes of day and night. This study aims to investigate what changes in spatial representations of 5th graders when additional visual materials of the Earth-based perspective were presented to them. It also shows that the Space and the Earth-based perspectives appear to be interconnected. The following are found in this study. First, when students were presented with a visual material of an Earth-based perspective, their spatial representations of both the Earth and the Space-based perspectives changed. Second, the visual material of an Earth-based perspective confirmed the possibility that students' spatial representation types could be different in many ways. Third, the effect on the spatial representation of each perspective is different depending on gender and the level of spatial representation.