• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.376-381
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• 2002

The purpose of this study was to analyse the color of natural deciduous teeth in Korean children and to compare with that of composite resin specimens. The subjects were 148 children (80 boys and 68 girls) with good general condition and normal teeth color, aged between 3 and 6 years. The color of middle third of maxillary central incisor in deciduous teeth was examined with shade guide and then measured by means of the colorimeter CV300 which can be measured by CIELAB system. The data were analyzed statistically by SPSS program. The results were summerized as follows; 1. Over 90% of the color for the deciduous anterior teeth was in A1, A2, B1, B2 and P shade. 2. The means of deciduous teeth color were $L^*=58.72,\;a^*=-1.18,\;b^*=-0.63$ by colorimeter CV300. 3. $L^*,\;a^*\;and\;b^*$ prices for A1, A2, B1, B2, P were $L^*=52.52,\;a^*=-1.90,\;b^*=1.18$ in A1 specimen, $L^*=54.90,\;a^*=-1.87,\;b^*=1.60$ in A2 specimen, $L^*=59.80,\;a^*=-2.70,\;b^*=-0.63$ in B1 specimen, $L^*=56.90,\;a^*=-1.70,\;b^*=1.63$ in B2 specimen, $L^*=52.93,\;a^*=-2.33,\;b^*=1.10$ in P specimen. The means of B1 color specimen were most similar to those of deciduous teeth color. The A1 color values were similar to the P color values. 4. The standard deviation of $L^*,\;a^*$ was small among colors, but that of $b^*$, in the yellowish color, was large.

• Korean Journal of School Psychology
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• v.15 no.3
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• pp.459-488
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• 2018

The self-report assessment has been most commonly used to estimate bullying/victimization (B/V) rates in most domestic and international prevalence studies. However, the presence of many potential biasing factors in such an assessment method, including specific operationalization/measurement strategies and testing conditions, has become an issue due to a considerable variability in reported involvement rates across studies. This study analyzed self-reported B/V involvement rates on Olweus Bullying Questionnaire (OBQ) among 690 Korean middle school students by gender and two different cut-offs (generous vs. strict cut-offs) and examined if the involvement rates were significantly varied by testing conditions such as presentation vs. omission of a precise definition of B/V, anonymous vs. non-anonymous/confidential administration, and the use of global vs. specific questions. Chi-square analyses revealed that boys displayed higher involvement rates on global measures of B/V and on items related to direct forms of B/V, with no significant gender differences on specific measures of relational B/V rates. It was also found that a global rate of bullying and specific rates of verbal B/V were 111% to 157% higher when no definition was provided. However, anonymous vs. non-anonymous administration had no significant impacts on rates of involvement, except for one item; there were also no significant differences in reported degrees of frankness and perceived confidentiality of their responses across two adminstration conditions. Finally, when involvement rates were assessed by using specific vs. global items, they were 68% to 148% higher with binominal correlations in low to moderate ranges. Findings also indicated that global items had a high specificity but a relatively low sensitivity. Implications of these findings were fully discussed for researchers and practitioners in the field of B/V assessment.

• Journal of Korean Home Economics Education Association
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• v.18 no.1 s.39
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• pp.17-29
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• 2006

The purpose of this research was to examine the problems, confidence and satisfaction of teachers on the subject ${\ulcorner}technology and home economics{\lrcorner}$ in the 7th national curriculm. For this research, questionnaires were sent by post to teachers who teach technology and home economics in middle schools and high schools. The collected questionnaires were technically analyzed by SPSS/WIN 10.0 program, which measured frequency, percentage, average, standard deviation. According to the types of data, they were also analyzed by t-test and cross tabulation analyses. The results of this research were summarized as follows. 1) There were two teaching types of technology and home economics: the partial charge and the whole charge teaching according to teachers' majors, and both types occurred in similar percentage. The partial charge teaching means that teachers majoring in technology teach only the technology part and teachers majoring in home economics teach only the home economics part when they teach the same subject, technology and home economics. These days the partial charge teaching more often occurs in national or public schools than in private schools, and in coeducational schools than in girls' or boys' schools. 2) The major problems of teaching technology and home economics were caused in order by teachers' lack of skills and knowledge which we not their own major, the lack of students' interests and teaching materials, and burden of tests. 3) Teachers' confidence in teaching the contents of the subject, technology and home economics, made a significant difference according to their majors. Teachers whose major was technology felt more confident when they taught the chapters of the textbooks related to their major, technology, while teachers whose major was home economics felt more confident when they taught the chapters of the textbooks related to their major, home economics. According to implementation types, the partial charge teaching gave higher confidence to the teachers than the whole charge one in teaching almost all the chapters of the textbook. 4) According to implementation types, teachers' satisfaction was showed to be higher in the partial charge teaching than in the whole charge one.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.179-189
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• 2000

The purpose of this research is to complement the existing researches on landfill bottom liners behavior during the periods of freeze and thaw. Landfill-related researches have been typically focused on small-scale soil samples that are often compacted under conditions different from those used in the field. Although these tests have been invaluable in clarifying the problem of freeze and thaw, extending the results of such experimental studies to prototype landfills are questionable. In this investigation, the author utilized a large scale laboratory simulation allowing inclusion of the field depth of the cover systems, layered soil profiles, rainfall simulation, a cold climate and boundary conditions similar to those encountered in the landfill. The soil materials were stabilized soils (mixed clays, cements, and minerals) instead of clays. The bottom liners are made up of drainage layer (30 cm), stabilized layer (75 cm), and leach collection layer (60 cm). The stabilized layers are made up of supporting layer (45 cm) and low permeable layer (30 cm) - consisting of $P_A\; and\; P_B$ layer. As a results, depths of penetration increased by about 2~5 more centimeters at rainfall simulated designs than those at no rainfall simulated designs (that is design 3, design 5 and design 7) - it increased by about 20mm/day in the bottom liners and frost heaves also increased it by a few millimeters. Also, a few cracks appeared partly. According to these results, we can surmise that the compacted stabilized soil is more reliable than the compacted clay liners for construction of the landfill liners.

• Journal of Nutrition and Health
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• v.46 no.5
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• pp.447-460
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• 2013

Dietary supplement use is prevalent and represents an important source of nutrition. This study was conducted in order to assess the dietary maximum exposure of vitamins and minerals from various sources including regular diet, vitamin mineral supplements for non-prescription drug (VMS-NPD), vitamin mineral supplements for health functional foods (VMS-HFF), and fortified foods (FF). A total of 1,407 adolescent boys and girls attending middle or high schools were chosen from various cities and rural communities in Korea. Users of vitamin and mineral supplements (n = 60, 15-18 years of age) were chosen from the above 1,407 students. Intake of vitamins and minerals from a regular diet and FF was assessed by both food record method and direct interview for three days of two weekdays and one weekend, and those from VMS-NPD and VMS-HFF were assessed by both questionnaire and direct interview, and compared with the recommended nutrient intake (RNI) and the tolerable upper intake level (UL) for Korean adolescents. Daily average exposure range of vitamins and minerals from a regular diet was 0.3 to 4.4 times of the RNI. Some subjects had an excessive exposure to the UL in the following areas: from regular diets, vitamin A (1.7%) and niacin (5.0%); from only VMS-NPD, vitamin C (9.1%) and iron (5.6%); and from only VMS-HFF, niacin (8.6%) > vitamin $B_6$ (7.5%) > folic acid (2.9%) > vitamin C (2.3%). Nutrients of daily total intake from regular diet, VMS-NPD, VMS-HFF, and FF higher than the UL included nicotinic acid for 33.3% of subjects, and, then, in order, vitamin C (26.6%) > vitamin A (13.3%), iron (13.3%) > zinc (11.7%) > calcium (5.0%) > vitamin E (1.7%), vitamin $B_6$ (1.7%). Thus, findings of this study showed that subjects may potentially be at risk due to overuse of supplements, even though most of them took enough vitamins and minerals from their regular diet. Therefore, we should encourage adolescents to have sound health care habits through systematic and educational aspects.