• Journal of the Korean earth science society
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• v.43 no.6
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• pp.712-736
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• 2022

To understand the characteristics of low-level clouds (CLs), environmental variables are composited on each CL using individual surface observations and six-hourly upper-air meteorologies around the globe. Individual CLs has its own distinct environmental conditions. Over the eastern subtropical and western North Pacific Ocean in JJA, stratocumulus (CL5) has a colder sea surface temperature (SST), stronger and lower inversion, and more low-level cloud amount (LCA) than the climatology whereas cumulus (CL12) has the opposite characteristics. Over the eastern subtropical Pacific, CL5 and CL12 are influenced by cold and warm advection within the PBL, respectively but have similar cold advection over the western North Pacific. This indicates that the fundamental physical process distinguishing CL5 and CL12 is not the horizontal temperature advection but the interaction with the underlying sea surface, i.e., the deepening-decoupling of PBL and the positive feedback between shortwave radiation and SST. Over the western North Pacific during JJA, sky-obscuring fog (CL11), no low-level cloud (CL0), and fair weather stratus (CL6) are associated with anomalous warm advection, surface-based inversion, mean upward flow, and moist mid-troposphere with the strongest anomalies for CL11 followed by CL0. Over the western North Pacific during DJF, bad weather stratus (CL7) occurs in the warm front of the extratropical cyclone with anomalous upward flow while cumulonimbus (CL39) occurs on the rear side of the cold front with anomalous downward flow. Over the tropical oceans, CL7 has strong positive (negative) anomalies of temperature in the upper troposphere (PBL), relative humidity, and surface wind speed in association with the mesoscale convective system while CL12 has the opposite anomalies and CL39 is in between.

• Communications of Mathematical Education
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• v.23 no.2
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• pp.429-459
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• 2009

The purpose of this study was to help the students deepen their mathematical understanding and practitioner improve her mathematics lessons. The teacher-researcher developed mathematical situation based problem solving instruction model which was modified from PBL(Problem Based Learning instruction model). Three lessons were performed in the cycle of reflection, plan, and action. As a result of performance, reflective knowledges were noted as followed points; students' mathematical understanding, mathematical situation based problem solving instruction model, improvement of mathematics teachers.

• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.125-132
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• 2021

At a time when non-face-to-face classes are being held for a long time due to Corona (COVD-19), research on non-face-to-face teaching and learning methods is needed. Existing teaching and learning methods are limited in their application to non-face-to-face classes as they present face-to-face practical and experiential teaching methods. In this study, we present a method of utilizing the extended reality (XR: eXtended Reality) technology for the 5AL (5 Activity Learning) teaching method, which is a teaching and learning method selected by the Institute for University Education Innovation. The 5AL teaching method consists of PBL Learning, Havruta Learning, Flipped Learning, Smart Activity Learning, and Gamification Learning. In this study, a method of combining the released extended reality contents with 5AL was presented. In addition, we developed content that integrates the 5 learning methods of 5AL and confirmed the learning effect through testing.

• Journal of Engineering Education Research
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• v.9 no.3
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• pp.5-21
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• 2006

The engineer's creativity is becoming more important as high value-added products are required. In this paper, a new curriculum model for creative engineering education has been developed. This study proposes the method of applying Chem-E-Car to the chemical engineering education for students to develop creativity. The Chem-E-Car is used as a given problem to students for developing safety study, teamwork, communication skill and creativity. The PBL(problem based Learning) is used in the class. The problem in this case is to make the Chem-E-Car, a shoebox sized car powered only by chemical reactions. Four types of Chem-E-Car such as turbine, rocket, voltaic cell and fuel cell are developed through out this program. The fuel cell powered Chem-E-Car is emphasized to students as new problems with constraints. This paper shows how the students solved the problems with creativity.

• Journal of The Korean Association of Information Education
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• v.12 no.2
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• pp.223-234
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• 2008

Educating qualified elementary school teachers depends on excellent pre-service education. The high quality of education is accomplished by various interactions between teachers and learners, as well as active participation by students. In the present study, online problem-based learning and an e-portfolio were used to examine the effect on the computer-curriculum education to reflect social and individual needs, and to enhance the quality of instruction at universities. Students (n=105) participated in six different problem-based learning sessions. At the same time, they developed Blog e-portfolios as individual and group products, and wrote reflective journals that focused on their learning processes and results. A qualitative analysis method was employed to analyze the reflective journals. The results of the analyses showed the following: 1) Increasing the understanding of the computer-curriculum education, 2) enhancing students' competence in using ICT potentially, 3) cultivating student-centered teaching and learning strategies on ICT, and 4) enhancing competence of future teaching activities through experiencing e-portfolio as a performance-assessment tool.

• Asian Journal of Atmospheric Environment
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• v.10 no.1
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• pp.13-21
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• 2016

The vertical distributions of aerosol extinction coefficient were estimated using the scaling height retrieved at Gwangju, Korea ($35.23^{\circ}N$, $126.84^{\circ}E$) during a spring season (March to May) of 2009. The aerosol scaling heights were calculated on a basis of the aerosol optical depth (AOD) and the surface visibilities. During the observation period, the scaling heights varied between 3.55 km and 0.39 km. The retrieved vertical profiles of extinction coefficient from these scaling heights were compared with extinction profile derived from the Light Detection and Ranging (LIDAR) observation. The retrieve vertical profiles of aerosol extinction coefficient were categorized into three classes according to the values of AODs and the surface visibilities: (Case I) the AODs and the surface visibilities are measured as both high, (Case II) the AODs and the surface visibilities are both lower, and (Others) the others. The averaged scaling heights for the three cases were $3.09{\pm}0.46km$, $0.82{\pm}0.27km$, and $1.46{\pm}0.57km$, respectively. For Case I, differences between the vertical profile retrieved from the scaling height and the LIDAR observation was highest. Because aerosols in Case I are considered as dust-dominant, uplifted dust above planetary boundary layer (PBL) was influenced this discrepancy. However, for the Case II and other cases, the modelled vertical aerosol extinction profiles from the scaling heights are in good agreement with the results from the LIDAR observation. Although limitation in the current modelling of vertical structure of aerosols exists for aerosol layers above PBL, the results are promising to assess aerosol profile without high-cost instruments.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.633-634
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• 2020

본 논문에서는 소외계층 초등정보영재를 위한 온라인 머신러닝 교육 프로그램을 개발하였다. 교육 프로그램은 초등정보영재 전문가가 개발하였으며, 인공지능 교육 전문가가 검증하였다. 교육 프로그램은 15차시로 구성하였으며, 인공지능에 대한 이해, 데이터 수집 및 표현, 모델 선택, 훈련, 평가, 실생활 사례 제작, 예측으로 내용을 구성하였다. 교육 프로그램에서 학습 모형은 이재호와 홍창의(2009)의 문제 중심형 e-PBL 학습 모형을 본 연구에 맞게 수정하여 활용하였다. 향후 연구에서는 개발한 교육 프로그램을 소외계층 초등 정보영재에 적용하고, 교육 프로그램을 통한 소외계층 초등정보 영재의 변화를 분석하고자 한다.

• Journal of Environmental Science International
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• v.28 no.3
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• pp.341-356
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• 2019

In this study, the impacts of local meteorology caused by tidal changes in the West Sea on ozone distributions in the Seoul Metropolitan Area (SMA) were analyzed using a meteorological model (WRF) and an air quality (CMAQ) model. This study was carried out during the day (1200-1800 LST) between August 3 and 9, 2016. The total area of tidal flats along with the tidal changes was calculated to be approximately $912km^2$, based on data provided by the Environmental Geographic Information Service (EGIS) and the Ministry of Oceans and Fisheries (MOF). Modeling was carried out based on three experiments, and the land cover of the tidal flats for each experiment was designed using the coastal wetlands, water bodies (i.e., high tide), and the barren or sparsely vegetated areas (i.e., low tide). The land cover parameters of the coastal wetlands used in this study were improved in the herbaceous wetland of the WRF using updated albedo, roughness length, and soil heat capacity. The results showed that the land cover variation during high tide caused a decrease in temperature (maximum $4.5^{\circ}C$) and planetary boundary layer (PBL) height (maximum 1200 m), and an increase in humidity (maximum 25%) and wind speed (maximum $1.5ms^{-1}$). These meteorological changes increased the ozone concentration (about 5.0 ppb) in the coastal areas including the tidal flats. The increase in the ozone concentration during high tide may be caused by a weak diffusion to the upper layer due to a decrease in the PBL height. The changes in the meteorological variables and ozone concentration during low tide were lesser than those occurring during high tide. This study suggests that the meteorological variations caused by tidal changes have a meaningful effect on the ozone concentration in the SMA.

• Journal of Life Science
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• v.17 no.11
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• pp.1492-1496
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• 2007

In vitro IgE class switching could be induced through co-culture of CD40L-expressing KU812 cells and CD40-expressing B cells in the presence of IL-4 or IL-13. It has been generated several B cell lines, which produce rice allergen (RA)-specific IgM antibody by in witγo immunization (IVI) using peripheral blood lymphocyte (PBL). In this study, induction of RA-specific IgE antibody by KU812 cells was attempted. Before co-culture, we determined the CD40 expression in RA-specific B cell lines, RA9G11 and the CD40 ligand (CD40L) expression in activated KU812 cells by treatments with phorbol myristate acetate (PMA) and ionomycin for 6 hrs. Flow cytometric analysis shown that RA9G11 and activated KU812 cells expressed high level of CD40 and CD40L, respectively. RA9G11 cells were cultured with activated KU812 cells for 12 days in the presence of IL-4 for IgE class switching. Mature $C{\varepsilon}$ mRNA level and RA-specific IgE spot forming cells (SFC) were observed in all culture condition, and especially, high level of RA-specific IgE synthesis was determined the same ratio of RA9G11 and activated KU812 cells in the presence of 50U IL-4. Therefore, induction of RA-specific IgE synthesis by activated KU812 cells can be contributed in the application for allergic therapy and prevention.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.196-205
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• 2008

Variability in vertical ozone and meteorological profiles was measured by 2Z electrochemical concentration cells (ECC) ozonesonde at Bangyi in Seoul ($37.52^{\circ}N$, $127.13^{\circ}E$) during June $6{\sim}9$, 2003 in odor to identify the vertical distribution of ozone and its relationship with the lower-atmospheric structure resulted in the high ozone concentrations near the surface. The eight profiles obtained in the early morning and the late afternoon during the study period clearly showed that the substantial change of ozone concentrations in lower atmosphere(${\sim}5\;km$), indicating that it is tightly coupled to the variation of the planetary boundary layer (PBL) structure as well as the background synoptic flow. All profiles observed early in the morning showed very low ozone concentrations near the surface with strong vertical gradients in the nocturnal stable boundary layer due to the photochemical ozone loss caused by surface NO titration under very weak vertical mixing. On the other hand, relatively uniform ozone profiles in the developed mixing layer and the ozone peaks in the upper PBL, were observed in the late afternoon. It was noted that a significant increase in ozone concentrations in the lower atmosphere occurred with the corresponding decrease of the mixing height in the late afternoon on June 8. Ozone in upper layer did not vertically vary much compared to that in PBL but changed significantly on June 6 that was closely associated with the variation of synoptic flows. Interestingly, heavily polluted ozone layers aloft (a maximum value of 115 ppb around 2 km) were formed early in the morning on 6 through 7 June under dominant westerly synoptic flows. This indicates the effects of the transport of pollutants on regional scale and consequently can give a rise to increase the surface ozone concentration by downward mixing processes enhanced in the afternoon.