• Childhood Kidney Diseases
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• v.20 no.1
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• pp.18-22
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• 2016

Purpose: The previous reports regarding VUR resolution were not precise due to early frequent surgical intervention. We evaluated the spontaneous resolution (SR) rate and the incidence of new renal scars in primary VUR, focusing on severe reflux. Methods: Medical records of 334 patients with primary VUR who were on medical prophylaxis without surgery for 1 to 9 years, were retrospectively reviewed. Medical prophylaxis was initiated with low-dose antibiotic prophylaxis or probiotics. Radioisotope cystourethrography was performed every 1 to 3 years until SR of reflux. New renal scar was evaluated with follow-up $^{99m}Tc$ DMSA renal scan. Results: The SR rates decreased as VUR grades were getting higher (P=0.00). The overall and annual SR were 58.4% and 14.9%/yr in grade IV reflux and 37.5% and 9.3%/yr in grade V reflux. The median times of SR were 38 months in grade IV reflux and 66 months in grade V reflux. The probable SR rates in grade IV and V reflux were 7.8% and 8.9% in the 1st year, 46.0% and 30.8% in the 3rd year and 74.4% and 64.4% in the 5th year. The incidences of new renal scars between low to moderate reflux and severe reflux showed no significant difference (P=0.32). Conclusion: The SR rates of severe primary VUR were higher than previously reported and most new renal scars were focal and mild.

• Journal of Korean Elementary Science Education
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• v.37 no.4
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• pp.352-362
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• 2018

With the advent of the 4th industrial revolution, the educational innovation focusing on the key competencies is occurring in the whole world. In September 2015, the Ministry of Education suggested six key competencies such as self-management competency, knowledge/information processing competency, creative thinking competency, aesthetic sensibility competency, communication competency, and community competency for the 2015 revised national curriculum. Also, this era requires for diverse lessons like subject integrated/converged lesson and intramural/extramural education. Thus, the objective of this study is to research/analyze exhibitions of Busan National Science Museum as extramural educational institute and to relate between the 2015 revised curriculum and exhibitions of science museum. First, the exhibitions of permanent exhibition hall in Busan National Science Museum were researched/analyzed. It analyzed the current status, display type, and explained contents of exhibitions. Second, it analyzed the relations between contents of the exhibition and key competencies in the 2015 revised curriculum. Third, the 2015 revised curriculum for the 3rd and 6th grade related to the selected exhibition contents was analyzed. The analysis on the exhibition contents performed by this study would be helpful for follow-up researches connected to exhibitions of Busan National Science Museum.

• Education of Primary School Mathematics
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• v.14 no.1
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• pp.69-79
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• 2011

The purpose of this study is to analyze 3rd, 4th and 5th graders' probability understanding and raise issues concerning instructional methods and search for the possibility of learning probability. For the purpose, a descriptive study through pencil-and-paper test regarding fairness, sample space, probability of event, probability comparison, independence and conditional probability was conducted. The following conclusions were drawn from the results obtained in this study. First, the 3rd, 4th, and 5th grade students scored the highest in the sample space questions. In descending order of skill, the students scored the highest in sample space following probability of events, fairness and probability comparison. Second, however, the level of independence understanding was low. There was no meaningful differences between grades and the conditional probability was the least understood. The independence is difficult to develop naturally according to cognitive development. The conditional probability recognizing the probability of an event changes in non-replacement situations was very difficult for these students. Third, there were significant differences between the 5th graders and the 3rd and 4th graders in the probability comparison questions. It shows that 5th graders understand the concept of proportion when they compare equal ratio probability of an event. The 3rd graers could do different ratio probability of an event more easily than equal ratio probability of an event after they were instructed on probability comparison.

• Korean Journal of Child Studies
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• v.30 no.1
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• pp.11-25
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• 2009

This study aimed to investigate protective factors and risk factors in elementary students' life satisfaction. Participants were 2844 (1524 boys, 1320 girls) children who grades were 4th, 5th, 6th in KYPS (Korea Youth Panel Survey). Data mining decision tree model was performed with sex, appearance, delinquency, family income, attachment to parents, parental monitoring, attachment to teachers, academic achievement, peer delinquency, and attachments to peer. The results revealed that : (1) For 4th graders, academic achievement, attachment to parents, and appearance were significant predictors for life satisfaction. (2) For 5th graders, attachment to parents, academic achievement, parental monitoring and appearance were significant predictors for life satisfaction. (3) For 6th graders, attachment to parents, appearance, parental monitoring and delinquency were significant predictors for life satisfaction. Protective factors and risk factors were changed according to interactions between significant independent variables. These results suggest that children's diverse conditions should be considered individually in programs for children's life satisfaction.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.299-303
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• 2014

Purpose: This study set out to develop a machine for separating shatter-resistant sesame after threshing. Methods: Three grades of sieve and different blower speeds were tested for a separation system that had been designed specifically for shatter-resistant sesame. Performance tests were run to evaluate the sieve and blower systems in terms of the sesame separation and loss ratios. Results: Tests of the first separation stage using the sieve system revealed the optimum sieve perforation size to be 5 mm. Tests of the second separation stage using the blower system identified the optimum blower speed as being 220 rpm. The optimum separation and loss ratios, of 96.5% and 3.5%, respectively, were obtained at a blower speed of 220 rpm. Conclusions: These results will be useful for the design, construction, and operation of threshing harvesters. For shatter-resistant sesame, an optimum blower speed of 220 rpm was identified.

• The Korean Journal of Community Living Science
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• v.23 no.4
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• pp.479-490
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• 2012

This research focuses on the self-concept in children of low-income families. A questionnaire was given to elementary school-aged children(grades 3-6). 454 children from low-income families were surveyed. The major findings were as follows: first, the variables that affected the self-concept among the low-income families children were relatively different. For boys, the major influential individual variables were in the following order: grade, stress, and the father's affective attitude. For girls, the major influential individual variables were in the following order: stress, support from friend, father's affective attitude, and grade. Second, through this comparison, this study examined the relative influence of variables that affected children's self-concept. This study proposes interventions to improve their self-concept mechanisms.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.106-106
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• 2015

In this study, we investigated electrochemically formed nanotube shape on ternary Ti-25Ta-xHf alloys with Hf contents. Ti-25Ta-xHf (x=0~15 wt.%) alloys were manufactured by vacuum arc-melting furnace. The obtained ingots were homogenized in an argon atmosphere at $1050^{\circ}C$ for 2h and then water quenching. The specimens were cut from ingots to 4 mm thickness and first ground and polished using SiC paper (grades from #100 to #2000). The anodization treatments on Ti-25Nb-xHf alloys were carried out at room temperature for experiments. The formation of nanotubular film was conducted by electrochemical method in mixed electrolytes with 1 M $H_3PO_4$ + 0.8 wt. % NaF at 30 V for 2 h. The morphologies of nanotube depended on the Hf content in Ti-25Ta-xHf ternary system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.482-485
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• 2021

In this study, the effect of the workbook-based unplugged activity program on the improvement of computational thinking skills of elementary school students in 3rd and 4th grade was statistically analyzed. The study was conducted with 18 students in the 3rd and 4th grades of G Elementary School located in Chungcheongnam-do, and after conducting a computational thinking ability test in advance, an unplugged program based on the workbook was conducted in a total of 6 sessions with 9 members of the experimental group. After that, a post-mortem examination was conducted to analyze the degree of improvement in computational thinking ability. As a result of the analysis, it was confirmed that the workbook-based unplugged program improved the computational thinking skills of elementary school students in 3rd and 4th grade and had a positive effect.

• Journal of Environmental Policy
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• v.6 no.3
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• pp.115-145
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• 2007

This study was performed for developing upscaling Environmental Conservation Value Assessment Map(ECVAM) of National Land in South Korea and presenting the application method of ECVAM. This ECVAM adopted the least indicator method and uses a Geographic Information System(GIS). This map is made through evaluation of 67 items. As a result, the construction of ECVAM was defined as a process of identifying land use to scientifically assess the physical and environmental value of land and classify conservation value into several grades for the sustainable management of environmental resources. After applying ECVAM criteria of five degrees to the whole of study area, Grade I, showing the highest conservation value, accounted for 29.3% by land area of ECVAM. Grades II, III, IV and V likewise accounted for, respectively, 21.7%, 17.2%, 7.1% and the lowest conservation value of 24.7%. other result, ECVAM and land suitability assessment agreement rate is Grade I 33.05%, Grades II, III, IV and V likewise accounted for 12.92%, 15.05%, 36.93% and last value of 53.28% This study set up "the realization of the improvement ECVAM" as the vision of the advancing strategy. In order to accomplish the vision, this study established the purpose as follow; constructing strategic assessment value relation to ECVAM based on knowledge, arranging the foundation to upscaling assessment value And this study devised preparatory plans to achieve the vision and the purpose as next; construction on base theme map by 1:5,000 scalie, base on land register theme map and precision land cover map. Therefore, for applying the result of this study to the upscaling Environmental Conservation Value Assessment Map(ECVAM), it considers regularly the systematic categorization of preceding item, consideration issue of national environmental geographic information using the ECVAM.

• Journal of the Korean Society for information Management
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• v.34 no.3
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• pp.179-207
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• 2017

The purpose of this study is to analyze the effects of cognitive developmental stages on library behaviors, reading tendency and perception on the library of the elementary students. For this study, a cognitive development tests and a questionnaire survey was conducted with students in their fourth and sixth grades in three elementary schools in Seoul and statistical analysis was carried out with the survey data. As a result, sixth grade students with the higher cognitive development had more requests for library information services than fourth grade students did. However, sixth grade students use library less and preferred to focus on the books for fun and personal interests, comparing with the fourth grade students. Their high level of cognitive development did not always have a positive effect on library behaviors and reading tendency. In addition, perception on the library of sixth grade students was lower than that of fourth grade students and it was influenced by library behaviors and reading tendency. It was also influenced positively by frequent use of library, active support by librarians and reading curriculum-related books. Based on the analysis, it is suggested that school library service should be provided based on the development stage of the upper grades of elementary students.