• Journal of Radiation Protection and Research
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• v.14 no.1
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• pp.34-45
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• 1989

The habitability of a reactor control room in a French 1300 MWe P'4 type PWR has been evaluated through the exposure dose assessment for the reactor operator following a Loss of Coolant Accident. The main hypotheses adopted in this evaluation are based on the French Standard Safety Analysis Report. A simple computer program, named COREX(Control Room EXposure), was developed to calculate : the time-integrated radioactivities released from the reactor building, the volume factors for radionuclides concerned and the resulting time-integrated external whole body and internal thyroid doses to the reactor operators staying in the control room up to 30 days following the LOCA. The results obtained in this study, on the whole, well agreed with those proposed by the EDF(Electricite de France) except for the case of the whole body exposure, which was attributed to the differences in the volume factors for the radionuclides concerned.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2544-2550
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• 2014

The purpose of this paper is to identify the correlation of entrance score by observation and nomination system and performance assessment score for the gifted children in IT. In other words, the purpose of this paper is to investigate the reliability of observation and nomination system by analyzing and comparing entrance scores and performance assessment score during the period of attendance for the gifted children in IT. For this purpose, the gifted children are selected and analyzed in a gifted science center attached to a university at Seoul Metropolitan Area. The analysis results show that there is meaningful correlation between entrance score and performance assessment score. That is, if high scores in entrance exam means high scores in performance assessment scores. The result will be useful to trust and extend observation and nomination system for the selection of gifted children in IT.

• Korean Journal of Remote Sensing
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• v.39 no.3
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• pp.325-338
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• 2023

Korean fir (Abies koreana Wilson) is one of the most important environmental indicator tree species for assessing climate change impacts on coniferous forests in the Korean Peninsula. However, due to the nature of alpine and subalpine regions, it is difficult to conduct regular field surveys of Korean fir, which is mainly distributed in regions with altitudes greater than 1,000 m. Therefore, this study analyzed the vegetation change trend of Korean fir using regularly observed remote sensing data. Specifically, normalized difference vegetation index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS), land surface temperature (LST), and precipitation data from Global Precipitation Measurement (GPM) Integrated Multi-satellitE Retrievalsfor GPM from September 2003 to 2020 for Hallasan and Jirisan were used to analyze vegetation changes and their association with environmental variables. We identified a decrease in NDVI in 2020 compared to 2003 for both sites. Based on the NDVI difference maps, areas for healthy vegetation and high mortality of Korean fir were selected. Long-term NDVI time-series analysis demonstrated that both Hallasan and Jirisan had a decrease in NDVI at the high mortality areas (Hallasan: -0.46, Jirisan: -0.43). Furthermore, when analyzing the long-term fluctuations of Korean fir vegetation through the Hodrick-Prescott filter-applied NDVI, LST, and precipitation, the NDVI difference between the Korean fir healthy vegetation and high mortality sitesincreased with the increasing LST and decreasing precipitation in Hallasan. Thissuggests that the increase in LST and the decrease in precipitation contribute to the decline of Korean fir in Hallasan. In contrast, Jirisan confirmed a long-term trend of declining NDVI in the areas of Korean fir mortality but did not find a significant correlation between the changes in NDVI and environmental variables (LST and precipitation). Further analyses of environmental factors, such as soil moisture, insolation, and wind that have been identified to be related to Korean fir habitats in previous studies should be conducted. This study demonstrated the feasibility of using satellite data for long-term monitoring of Korean fir ecosystems and investigating their changes in conjunction with environmental conditions. Thisstudy provided the potential forsatellite-based monitoring to improve our understanding of the ecology of Korean fir.

• Journal of Science Education
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• v.42 no.2
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• pp.198-213
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• 2018

In recent years, descriptive evaluation has been gaining importance at school. The purpose of this study is to analyse descriptive evaluation items which have been made by school teachers. 300 items for regular examinations are collected from 7 middle schools (grades 1 through 3) in Gyeongnam Province. Distribution and types of items are examined to compare educational objectives of standard achievements and those of evaluation according to Bloom's revised taxonomy of educational objectives. The result shows that there exist a majority of shared subject units for descriptive evaluation. Huge difference of frequency is also found among subject units and standard achievements. Less than 65% of evaluation items are descriptive and the rest is simple completion or short answers. In addition, it reveals only 40.3% of agreement between educational objectives of standard achievements and those of evaluation items. The interviews with 27 teachers indicate that lack of ability to develop proper items and grading are the major obstacles. In conclusion, systematic training courses are to be provided in order to resolve issues over descriptive evaluation.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.3
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• pp.45-53
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• 2020

With the increasing attention of the international community on climate change and biodiversity promotion programmes, the Korean government and public agencies are trying to protect and restore the ecosystem of areas protected by law, such as waterfronts, by acquiring private land. However, the inadequate purchase system has caused various problems. In this study, an efficient and systematic land purchase system was developed through ecological evaluation, focusing on the ecological and landscape conservation areas of the Donggang basin. The ecological evaluation was developed by integrating parcel-level evaluation and regional-specific evaluation, and the overall level of ecological function was established and finalized through on-site verification. As a result of verifying the purchase land of 88 parcels, it showed a relatively high agreement of more than 85.2%, and the rest of parcels (non-agreement) were considered to have had an impact on vegetation, crop harvesting, etc. due to seasonal differences in ecological evaluation and field verification. The purchasing system was ranked according to the ecological evaluation grade based on the endangered species and the distance from the core ecosystem. As a result, the purchase priority was systematically drawn up to the 5th rank for a total of 68 parcels for the private lands of Geoeun-ri, Munsan-ri, Deokcheon-ri, Unchi-ri, Gumam-ri, and Suji-ri. This study is expected to contribute to the preservation, restoration and ecological management of purchased land in the protected area in the future by establishing and proposing a systematic land purchase system based on ecological evaluation.

• Korean Journal of Weed Science
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• v.10 no.4
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• pp.255-260
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• 1990

Seventeen different herbicides were screened to select promising ones for the control of weeds, which may be used in paddy fields transplanted with 8 days old young rice seedlings. Four classes of herbicides were chosen and tested with seedlings grown under different cultivating conditions. Contact herbicides such as diphenyl-ether and oxadiazol showed severe growth retardation of rice seedlings. Carbamate class(dimepiperate), quinoline class (quinclorac), pyrazol class(pyrazolate), acid amide class(mefenacet and pretilachlor), addition of safener (pretilachlor+fenclorim and mefenacet+bensulfuron+dymuron) and unknown class (KC-7079) exhibited normal growth of seedlings. Sulfonyl urea herbicide class(cimosulfuron, bensulfuron, pyrazosulfuron), and oxarane class(tridiphane) showed the slight growth inhibition but recovered shortly.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.554-568
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• 2021

Forests are the largest carbon (C) sinks in terrestrial ecosystems. Recently, as enhancing forest C sequestration capacity has been proposed as a basic direction of the Republic of Korea's "2050 Carbon Neutral Strategy," accurate estimation of forest C sequestration has been emphasized. According to the Intergovernmental Panel on Climate Change guidelines, sequestration quantity is calculated from changes in C stocks in forest C pools, such as biomass, deadwood, litter and soil layer, and harvested wood products. However, in Korea, only the overstory biomass increase is now considered the amount of sequestration quantity, so there can be a significant difference from the actual forest C sequestration. In this study, we quantified forest C exchange through C flux measurement using an eddy covariance system and an automated soil chamber system in a 57-year-old Korean pine plantation located in Mt. Taehwa, Gwangju-si, Gyeonggi-do. Then, the net amount of C sequestration was compared with the amount of the overstory biomass increase. We estimated the annual C stock change in the remaining C pools by comparing the net sequestration amount from the C flux measurement with the overstory biomass increase and C stock change in the litter layer. Therefore, the net C sequestration of the Korean pine plantation estimated from the flux measurement was 5.96 MgC ha^-1, which was about 2.2 times greater than 2.77 MgC ha^-1 of the overstory biomass increase. The annual C stock increase in the litter layer was estimated to be 0.75 MgC ha^-1, resulting in a total annual C stock increase of 2.45 MgC ha^-1 in the remaining C pools. Our results indicate that the domestic forest is a larger C sink than the current methods, implying that more accurate calculations of the C sequestration capacity are necessary to quantify C stock changes in C pools along with the C flux measurement.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.282-291
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• 2020

This study was conducted to explore the effects of students' problem solving ability according to the level of structuring of curriculum tasks in PBL activities. The study was conducted on 60 college students in curriculum classes. Problem solving ability was measured at the beginning of the semester. And after the midterm exam, PBL activities were conducted. 30 experimental groups performed unstructured tasks. 30 comparison groups performed semi-structured problems. After the task was completed, problem solving ability was measured at the end of the semester. Collected data were analyzed using ANCOVA. As a result, it was verified that the experimental group had a statistically significant improvement in information collection, evaluation, and feedback level than the comparative group.

• Journal of Environmental Impact Assessment
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• v.31 no.6
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• pp.423-437
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• 2022

Parts of damaged trees are being transplanted in accordance with the Environmental Impact Assessment Manual. Problems such as death or poor growth are constantly being addressed in the process of transplanting trees from the forest they originally inhabited to temporary and final transplant sites. The purpose of this study is to analyze the differences in soil properties in the surrounding forest, the temporary transplant site, and the construction site and to suggest methods for improving the soil to make it suitable for the growth of transplanted trees. For 10 development projects, 2 soil samples were sampled from the surrounding forest, temporary transplant site, and construction site. A total of 60 soil samples were analyzed for physical and chemical properties. Among the physical properties such as coefficient of permeability, available moisture, and hardness, and chemical properties such as acidity, organic matter content, total nitrogen, and available P showed significant differences among groups. The soil of the construction site is harder than the surrounding forest because of construction equipments, the coefficient of permeability is higherthan the surrounding forest because of high sand content, and the available moisture was low. It does not retain the moisture necessary for plants in the soil and drains immediately. It is necessary to implement tillage to improve the physical properties and structure of the soil. In addition, it is necessary to cover the surface with wood chips or fallen leaves after adding mature organic matter to improve the physical and chemical properties of the soil together.

• Journal of the Korean School Mathematics Society
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• v.6 no.1
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• pp.135-161
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• 2003

This research is how students and teacher apprehend mathematics education, pointing out problem areas as a basis on how to improve students understanding of mathematics through improved guidance by teachers in the future. 1107 high school students and 105 teachers from around Daejeon and Choongnam province were surveyed and the results were as follows. 1. 77 %( 852) of students viewed the "application of problem solving methods" as understanding mathematic problems. 2. Replies to the question on understanding the study of mathematics resulted in 85.7% of teachers saying "it is the understanding of the basic concept to which you solve the problems" 3. For questions relating to the large difference in-class mathematics achievements and mock University entrance exam achievements, students' response that "for in-class tests you only have to learn problems with similar form but the mock tests are not like that" pointed out the problem in the area of mathematics education. 4. For future mathematic education teachers will have to "explain better and more completely the basic principles and concepts before solving problems" , and make an effort to stimulate students by "creating a more fun atmosphere" . There will also be the need to prevent as much as possible, the use of "formula or memory driven problems" and encourage students to initiate problem solving for themselves.; and encourage students to initiate problem solving for themselves.