• Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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• 2003.05a
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• pp.14-14
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• 2003

SAR (Synthetic Aperture Radar) is an imaging radar which can scan and image Earth System targets without solar illumination. Most Earth observation Shh systems operate in X-, C-, S-, L-, and P-band frequencies, where the shortest wavelength is approximately 1.5 cm. This means that most opaque objects in the SAR signal path become transparent and SAR systems can image the planetary surface targets without sunlight and through rain, snow and/or even volcanic ash clouds. Most conventional SAR systems in operation, including the Canada's RADARSAT-1, operate in one frequency and in one polarization. This has resulted in black and with images, with which we are familiar now. However, with the launching of ENVTSAT on March 1 2002, the ASAR system onboard the ENVISAT can image Earth's surface targets with selected polarimetric signals, HH+VV, HH+VH, and VV+HV. In 2004, Canadian Space Agency will launch RADARSAT-II, which is C-band, fully polarimetric HH+VV+VH+HV. Almost same time, the NASDA of Japan will launch ALOS (Advanced land Observation Satellite) which will carry L-band PALSAR system, which is again fully polarimetric. This means that we will have at least three fully polarimetric space-borne SAR system fur civilian operation in less than one year. Are we then ready for this new all weather Earth Observation technology\ulcorner Actual imaging process of a fully polarimetric SAR system is not easy to explain. But, most Earth system scientists, including geologists, are familiar with polarization microscopes and other polarization effects in nature. The spatial resolution of the new generation of SAR systems have also been steadily increased, almost to the limit of highest optical resolution. In this talk some new applications how they are used for Earth system observation purpose.

• Journal of The Korean Association For Science Education
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• v.29 no.8
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• pp.963-977
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• 2009

The purpose of this paper is to identify college students' conceptions of the earth system cycles as learners of earth science education (ESE) and draw educational implications. An eight-week creative story writing project was held with 62 non-science students taking a general course on earth science. Their creative stories were categorized by analyzing the conceptions and types of cycle with a story mapping technique. The cycle conceptions of earth systems were expressed diversely into 32; most of the cycle types were circular and complex, while the others were branch-shaped and linear types that fail to complete the cycles. College students' conceptions of the earth system cycles is biased toward natural-abiotic systems; less than 30% of them are shown to be aware of all three categories: natural-abiotic, natural-biotic, and human systems. It is essential to diversify the content of education on earth system cycles and help learners develop systematic methods of thinking so that they will be able to recognize the impacts of feedback from human activities through ESE.

• Journal of the Korean earth science society
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• v.36 no.4
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• pp.390-403
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• 2015

The purpose of this study was to explore discursive-epistemic mechanisms in high school earth science lessons. A total of 11 video recordings of earth science lessons were collected from three inservice high school teachers. The video recordings were all transcribed and analyzed by employing the discourse analysis framework used in relevant previous studies. In analysis, we identified discursive-epistemic mechanisms as functional assemblies for fulfilling particular epistemic functions in the earth science lessons. The characteristics of these mechanisms were described according to their epistemic functions. The findings of the study were compared with those of previous studies to highlight the characteristics of discursive-epistemic mechanisms in the earth science classrooms. Analyses of middle school science lessons and of science lessons in alternative forms, as well as studies using extended research methods such as indepth interviews with teachers, were suggested as implications for future research.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.649-659
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• 2002

The purpose of this study was to analyse students' achievement of 'Earth Science' in the Third International Mathematics and Science Study-Repeat(TIMSS-R), which was performed in 1999 with 38 nations participating. Korean 8th grade students' achievement of 'Earth Science' was compared with those of other countries and other content areas in science. Average percent correct of items in each subcategory was also analysed. Most of the 'Earth Science' topics were included in the intended curricula of Korea; they were taught to most of the students in science classes. Korean students ' average scale score of 'Earth Science' was significantly higher than the international average, but in comparison with other science content areas, achievement of 'Earth Science' was relatively low. The teachers' confidence in teaching earth science was lower than their confidence in teaching other science areas. The paper presents the results of item analysis and their implications for science education.

• Journal of the Korean earth science society
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• v.23 no.2
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• pp.180-187
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• 2002

The aim of this study was to investigate the factors affecting earth science problem-solving performances of elementary school pre-service teachers. The participants of the study were 81 students attending an elementary school teacher education university. The instruments of the study were paper-and-pencil tests, questionnaires, and interviews. The tests mainly measured the participants' problem solving abilities in the motions of the moon and the planets. Correlation and multiple regression techniques were used for data analysis. The results demonstrated that the pre-service teachers' problem solving abilities were low. Problem-solving performances were affected by the procedural knowledge, the participants' perception of the past earth science performance, self-efficacy, and the prerequisite declarative knowledge. Contrary to our expectation, the spatial visualization ability was not found to be related to the problem-solving performances. Implications of the study are drawn, and suggestions are made for further research.

• Journal of the Korean earth science society
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• v.28 no.6
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• pp.707-719
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• 2007

Teachers play key roles in classroom instruction. The perceptions and orientations of teachers about teaching have substantial effect on the practical context of science teaching. Analyzing science teacher's perceptions and orientations about Earth Systems Education (ESE) offers an opportunity to figure out how the goals of ESE might be dealt with. In this study, lesson plans developed by and in-depth interview results with two teachers were analyzed in terms of ESE perceptions. ESE orientations were also investigated in terms of teaching orientations and integration orientations. Research results showed that the teacher's deep understandings about 'Global Scientific Literacy (GSL)', the ultimate goal of ESE, precede the sound ESE teaching in the classroom. To enhance teachers' GSL, exemplary aspects of various integration, including networked integration, should be provided specifically to teachers. Also, the institutionalized approaches to developing ESE curriculum could help classroom teachers activate ESE teaching in their classroom.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.2
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• pp.117-129
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• 2009

Several researches have been done to estimate the earth pressure on a vertical circular shaft considering three dimensional arching effect and verified them by conducting model tests. However, any equation suggested so far is not applicable in case of multi-layered soils and/or C-${\phi}$ soils. In this study, new equation for estimating the earth pressure acting on the vertical shaft in c-${\phi}$ soils is proposed. A parametric study is performed to investigate the significance of the cohesion when estimating the coefficient of earth pressure in C-${\phi}$ soils and estimating earth pressures in vertical shafts. A method which can estimate the earth pressure on vertical shafts in layered soils is also proposed by assuming a failure surface in layered soils and using the modified equation. This paper is Part I of companion papers focusing on the theoretical aspect of model developments; the experimental verification will be made in Part II.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.33.1-33.1
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• 2011

The plasma sheet of the Earth's magnetosphere is a sheet of hot plasmas in the magnetotail region, dividing the two (northern and southern) lobes of the Earth's magnetic field. It is the key region that is often closely linked to various electromagnetic dynamics in the Earth's magnetosphere-ionosphere system. In particular, it is the region that is most crucial for substorms, which is one of the most dynamic phenomena in the Earth's magnetosphere. The question of substorm triggering remains highly controversial until today, and at the center of the controversy there are several critical physics issues of the plasma sheet. In this talk I will introduce some of the physics issues of the plasma sheet. The specific topics that this talk will cover are (i) the general properties of the plasma sheet, (ii) fast plasma jets and plasma transport problem, (iii) stability/instability problem, and (iv) effects of thin current sheet. I will also present some of our group's recent findings regarding these topics, as obtained by comprehensive analyses of various observational data. The level and content of this talk are designed to be comprehensible to not only space physicists but also the scientists in a related field such as solar and heliospheric physics.

• Journal of the Korean earth science society
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• v.25 no.2
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• pp.116-116
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• 2004

• Journal of the Korean earth science society
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• v.24 no.6
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• pp.592-592
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• 2003