• 한국초등과학교육학회지:초등과학교육
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• 제34권3호
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• pp.288-296
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• 2015

This study aimed to analysis of concepts and inquiry activities related to the 'Earth Science' area in the South Korean elementary school textbooks to the current and to seek the improvement of future textbook. For the study, we were collected South Korean elementary school textbooks to the current. After the collection had been made, we were analyzed related to the 'Earth' area in the South Korean elementary school textbooks and were extracted central concepts and inquiry activities. The result of this study: First, there were 'A change in the land', 'Strata and Fossil', 'Volcanoes and Earthquakes', 'Earth and Moon', 'The weather', 'The Solar system and the Star', and 'Seasonal Change' in the central concepts related to the 'Earth' area in the South Korean elementary school textbooks to the current. Second, central concepts were almost the same but the curriculum was changed. Third, inquiry activities also were confirmed to be maintained with little change. This result was believed that it can provide a variety of suggestions at this point in changing the curriculum.

• 한국지구과학회지
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• 제42권4호
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• pp.445-458
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• 2021

Gravity Recovery and Climate Experiment (GRACE) gravimeter satellites observed the Earth gravity field with unprecedented accuracy since 2002. After the termination of GRACE mission, GRACE Follow-on (GFO) satellites successively observe global gravity field, but there is missing period between GRACE and GFO about one year. Many previous studies estimated terrestrial water storage (TWS) changes using hydrological models, vertical displacements from global navigation satellite system observations, altimetry, and satellite laser ranging for a continuity of GRACE and GFO data. Recently, in order to predict TWS changes, various machine learning methods are developed such as artificial neural network and multi-linear regression. Previous studies used hydrological and climate data simultaneously as input data of the learning process. Further, they excluded linear trends in input data and GRACE/GFO data because the trend components obtained from GRACE/GFO data were assumed to be the same for other periods. However, hydrological models include high uncertainties, and observational period of GRACE/GFO is not long enough to estimate reliable TWS trends. In this study, we used convolutional neural networks (CNN) method incorporating only climate data set (temperature, evaporation, and precipitation) to predict TWS variations in the missing period of GRACE/GFO. We also make CNN model learn the linear trend of GRACE/GFO data. In most river basins considered in this study, our CNN model successfully predicts seasonal and long-term variations of TWS change.

• 한국지구과학회지
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• 제31권1호
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• pp.71-87
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• 2010

이 연구의 목적은 '지구'에 대한 8학년 학생들의 심상을 탐색하는 것이다. '지구'에 관해 단어와 그리기로 표현된 중학생들의 심상을 지구계 이해 분석틀로 분석하였다. 학생들의 '지구'에 관한 심상은 시각적 이미지를 형성하게 된주된 영향을 미친 경험과 선행 지식에 따라 달라졌다. 특히 간접적 시각 경험에 의한 지구의 전체 모습에 기반을 둔 천문학적 관점과 직접적 시각 경험에 의한 지표의 풍경과 환경에 기반을 둔 일상적 관점에 따라 지구계 이해가 다르게 나타났다. 대체적으로 학생들의 '지구'에 관한 심상은 시각적 경험에 의해 영향을 받은 것으로 보이며 이러한 학생들의 지구계 이해는 단어라는 형식적 언어의 형태보다는 시각적 심상인 그리기로 더 잘 표상되었다. 지구계 하위계 간의 상호작용에서 학생들의 부정적 이미지가 표상되었다.

• 한국지구과학회지
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• 제26권2호
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• pp.160-165
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• 2005

A series of high resolution spectra of CH Cygni obtained at the Bohyunsan Optical Astronomy Observatory (BOAO) in April 2004 has been analyzed. The emission components of the [O I] 6300 A lines are de-convoluted and fitted with Gaussian functions in order to investigate the characteristics and the structure of CH Cygni system along with the analysis for $H{\alpha}$ and [O III] lines. A present geometrical structure of the components of CH Cygni system is suggested.

• Journal of Positioning, Navigation, and Timing
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• 제3권4호
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• pp.149-154
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• 2014

The BeiDou is a satellite-based positioning and navigation system, which is under construction by the China Satellite Navigation Office. Until the June of 2014, the constellation of BeiDou navigation satellite system consists of 14 satellites including five geostationary earth orbit (GEO), five inclined geosynchronous earth orbit (IGSO) and four medium earth orbit (MEO). In this paper, we present the positioning results using BeiDou B1 code measurements obtained from three GNSS reference stations (BHAO, SKMA, MKPO). Combined Beidou/GPS positioning results are also compared to BeiDou and GPS only. BeiDou-only positioning errors for the east-west and north-south direction had less than 2 meter with root mean square (RMS) value. However, the positioning error for the up-down direction had larger than 10 meter at a 95% confidence level. Our results also suggest that the position precision is improved by combined BeiDou/GPS compared to BeiDou-only.

• 한국지구과학회지
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• 제28권4호
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• pp.431-444
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• 2007

인터넷상에서 관측할 수 있는 36 츠 자동화 망원경이 개발되었다. 이 시스템의 추적 오차는 약 1"/분이고, 지향 정밀도는 적경 방향에서 약 ${\pm}10"$, 적위 방향에서 약 ${\pm}20"$였다. 이것은 계속 개선되어나갈 것이다. 예비관측을 통해 얻은 영상자료를 IRAF를 통해 분석해본 결과 비교적 안정적인 결과를 보여주었다. 이러한 결과는 원격천체관측 교육에 활용할 수 있음을 의미한다.

• 대한원격탐사학회지
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• 제39권5_3호
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• pp.949-965
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• 2023

본 연구에서는 Sentinel-1 synthetic aperture radar 영상을 활용하여 딥러닝 모델인 Swin Transformer로 국내 농업용 저수지의 수표면적을 모니터링 하는 방법을 제시한다. Google Earth Engine 플랫폼을 이용하여 70만톤 급, 90만톤급, 150만톤급 저수지 7개소에 대한 2017년부터 2021년 데이터셋을 구축하였다. 저수지 4개소에 대한 영상 1,283장에 대해서 셔플링(suffling) 및 5-폴드(fold) 교차검증 기법을 적용하여 모델을 학습하였다. 시험평가 결과 모델의 윈도우 크기를 12로 설정한 Swin Transformer Large 모델은 각 폴드에서 평균적으로 99.54%의 정확도와 95.15%의 mean intersection over union (mIoU)을 기록하여 우수한 의미론적 분할 성능을 보여주었다. 최고 성능을 보여준 모델을 나머지 3개소 저수지 데이터셋에 적용하여 성능을 검증한 결과, 모든 저수지에서 정확도 99% 및 mIoU 94% 이상을 달성함을 확인했다. 이러한 결과는 Swint Transformer 모델이 국내의 농업용 저수지의 수표면적 모니터링에 효과적으로 활용될 수 있음을 보여준다.

• Journal of Photoscience
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• 제9권2호
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• pp.267-268
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• 2002

A vertebrate retina is an organ belonging to the central nerve system (CNS), and is usually difficult to regenerate except at an embryonic stage in life. However, certain species of urodele amphibians, such as newts and salamanders, possess the ability to regenerate a functional retina from retinal pigment epithelial (RPE) cells even as adults. After surgical removal of neural retinas from adult newt eyes, the remaining RPE cells lose their pigment granules, transdifferentiate into retinal progenitor cells, which further differentiate into various retinal neurons, and then finally reform a functional neural network. To understand the molecular mechanisms of CNS regeneration, we attempted to investigate the genes expressing in regenerating newt retina. mRNAs were isolated from regenerating retinas at 18-19 days after the surgical removal of the normal retina, and a cDNA library (regenerating retinal cDNA library) were constructed. Our EST analysis of 112 clones in the regenerating cDNA library revealed that about 70% clones are closely related to the genes previously identified. About 40% clones are housekeeping genes, and about 15% clones encode proteins related to the regulation of gene expression and to the proliferation of the cells. Sequences similar to neural retina- and RPE-specific genes were not detected at all. These results led us to suppose that the regenerating retinal cells are in a state considerably different from those of neither neural retina nor RPE cells.

• Journal of the Optical Society of Korea
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• 제16권2호
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• pp.141-144
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• 2012

A mobile Rayleigh Doppler wind LIDAR at an eye-safe wavelength of 355 nm incorporating double-edge technique with triple-channel Fabry-Perot etalon is developed for wind measurement from 5 to 40km. The structure of this LIDAR system is described. An intercomparsion experiment with rawinsonde is made, showing good agreement with expected measurement accuracy. A continuous observation of stratosphere wind field for several days with temporal resolution of 15 min and spatial resolution of 200 m from 5 to 40 km is presented, demonstrating the stability and robustness of the LIDAR. A stratospheric quasi-zero wind layer can be found at around 20 km with a direction change from east to west evident in the continuous observation.

• 한국지구과학회지
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• 제27권5호
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• pp.528-538
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• 2006

이 연구의 목적은 한반도 서남부에 분포하는 중성-염기성 심성암류의 지화학적 특성과 성인을 밝히는데 있다. 이들 중성-염기성암류는 주로 선캠브리아기의 회장암-반려암, 트라이아스기의 각섬석반려암(지리산 지역), 쥬라기의 섬록암-섬장암(지리산 지역과 북부 지역) 그리고 백악기 반려암-섬록암(남부 지역)으로 구성되어 있다. 암괴형의 회장암은 많은 관입체로 구성되어 있으며 반려암-노라이트-트록토라이트와 우백질 반려암으로 이루어진 반려암질암에 의해 관입되어 있다. 주 성분-미량 성분의 변화도, AMF 삼각도와 Pl-Px-Ol 삼각도에서, 우리는 한반도 서남부에 분포하는 중성-염기성암류가 Daly의 값과 유사한 경향을 보이며 칼크-알카리질암류에 속함을 보여준다. REE (La/Yb)cw와 Eu/Sm 값에 따르면 이들 암류는 경희토류가 중희토류보다 부화되어 있으며, 이는 대륙 연변부의 지구조에서 정치한 화성암류의 특징이다.