• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.44-52
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• 2010

The objective of this in vitro study was to detect and monitor demineralization and remineralization of primary teeth according to restorative materials using quantitative light-induced fluorescence (QLF). A single bur hole was drilled on the each sound forty eight primary anterior teeth, and the specimens were divided into three groups. The cavity was restored with $Filtek^{TM}$ Z250(Group 1), F2000(Group 2), $Ketac^{TM}$ N100(Group 3) following the manufacturer's instructions. The teeth were subjected to the demineralizing buffer for 3 days, and then subjected to a remineralizing buffer for 14 days. The change of mineral loss(${\Delta}Q$) according to the stages was evaluated by QLF and the following results were obtained: 1. When demineralization was done, ${\Delta}Q$ was increased as follows. : Group 1 ($-110.79\;{\pm}\;27.77$) < Group 2 ($-104.84\;{\pm}\;28.95$) < Group 3 ($-90.16\;{\pm}\;21.87$) : Resistance to demineralization was statistically significant in Group 3. 2. There was a statistically significant increase in ${\Delta}Q$ of all groups since 1st day of remineralization 3. The rate of remineralization, ${\Delta}$(${\Delta}Q$)/day, showed significant high value in each group on the 1st day then decreased rapidly. 4. There was no statistically significant difference in the degree of remineralization among restorative materials.

• Food Science and Preservation
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• v.15 no.1
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• pp.118-124
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• 2008

The chemical compositions and antioxidant activities of four different colored rice cultivars (white-colored rice: WCR, brown-colored rice: BCR, brown-colored waxy rice: BCWR, black-colored rice: BKCR) were investigated to evaluate the quality characteristics of the new brown rice cultivars. There was no significant differences in chemical compositions amongst the four rice cultivars, although WCR had higher amount of carbohydrate than did the other rice cultivars. 'The major fatty acids in the four rice cultivars were linoleic, oleic and palmitic acids, which accounted for about 96% of total fatty acids. Of note, higher amounts of saturated fatty acids (24.8%) and lower amount of unsaturated fatty acids (75.2%) were observed in BKCR than in the other rice cultivars. Two brown-colored rice cultivars, BCR and BCWR, possessed higher amounts of linoleic acid (40.8% and 42.1%, respectively) than did the other cultivars. The highest level of ${\alpha}$-tocopherol was found in WCR (51.3mg%), followed by BKCR (38.6mg%), BCWR (37.2 mg%), and BCR (34.5mg%). Free amino acid analysis showed that aspartic and glutamic acids were major amino acids of all cultivars, whereas phenylalanine, lysine, and histidine were minor. Particularly, relatively higher contents of aspartic and glutamic acids were found in BKCR, while relatively higher levels of alanine and ${\gamma}$-aminobutyric acid (GABA) were observed in BCR and BCWR. Also, BKCR had the highest phenolic content and antioxidant activity of any cultivar, followed by the two brown-colored rice cultivars and WCR. These results suggested that the new brown rice cultivars may possess quality characteristics intermediate between those of WCR and BCR.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.739-742
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• 2010

In order to select a superior yeast, 8 kinds of commercial active dry yeasts (Lalvin 1116, Lalvin 1118, Lalvin D-47, Lalvin Bourgovin, Parisienne, Fermivin, Red Star Monrachet, and Red Star Premier Cuvee) were utilized for omija wine fermentation. During fermentation, the physicochemical characteristics and sensory properties of the various omija wines were evaluated. According to the results, pH and titratable acidity were in ranges of 3.0-3.3% and 1.8-2.4%, respectively. Sugar content was $24^{\circ}Bx$ at early fermentation and changed to $8.4-10.2^{\circ}Bx$ at 24 days of fermentation. While the omija wines fermented by Lalvin D-47 and Red Star Premier Cuvee showed the highest alcohol contents (13.0%), the omija wine fermented by Parisienne showed the lowest alcohol content (10.8%). The omija wine fermented by Lalvin 1118 had an alcohol content of 12.0% and showed the lowest yeast count of 5.8 log CFU/mL. Hunter's values (L, a, and b) were all different among the 8 omija wines. Moreover, the omija wine fermented by Lalvin 1118 showed the highest scores for taste ($6.75{\pm}1.68$), swallowing ($6.65{\pm}1.50$), and overall acceptability ($6.70{\pm}1.34$). It is concluded that Lalvin 1118 was the best yeast among 8 tested commercial active dry yeasts, having a high potential for omija wine fermentation.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.836-840
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• 2007

This study was conducted to investigate mineral contents of commercial powdered infant formula for obtaining basic data on infant nutrition. 11 Commercial infant formula based on cow's milk were collected and the contents of macro minerals (calcium, phosphorous, sodium, potassium and magnesium) and trace minerals (iron, zinc and copper) were compared with Dietary Reference Intakes for Koreans (KDRIs). The overall mineral contents in 100 g and in 100 kcal of infant formula satisfied the recommended formula regulation and Codex. In infant formula during 0-5 monthly age, calcium, phosphorous, sodium, potassium, magnesium, zinc and copper could supply 233.1%, 273.5%, 156.7%, 142.0%, 150.8%, 209.3%, 171.1% of recommended daily mineral intakes, respectively. The content of iron in 0-5 monthly age formula supplied2842.6% of recommended daily iron intakes. In infant formula during 6-11 monthly age, calcium, phosphorous, potassium, magnesium, iron, zinc and copper satisfied their recommended daily intakes. However, sodium only supplied 76.6% of its recommended daily intake. Intake ratio between Ca/P, Ca/Mg, Ca/Fe, Na/K and Zn/cu in infant formula during 0-5 monthly age were 1.7±0.2, 11.0±2.4,64.9±10.0, 0.3±0.1, and 9.6±1.0, respectively. Intake ratio between Ca/P, Ca/Mg, Ca/Fe, Na/K and Zn/cu in infant formula during 6-11 monthly age were 1.7${\pm}$0.2, 12.9${\pm}$1.5, 80.1${\pm}$13.8, 0.3, and 9.4${\pm}$1.1,respectively. From this study, evaluation of mineral contents of commercial infant formula was established, which could strengthen the basic information on infant nutrition.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.120-127
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• 1994

To establish an efficient herbicide screening method for purple nutsedge(Cyperus rotundus) control, its sprouting characteristics, tuber production and responses on several herbicides were investigated under greenhouse condition. The tubers stored at $4^{\circ}C$ after sterilization with the diluted prochloraz(Spotac) solution showed higher sprouting than the non-sterilized did. The harvested tubers were not dormant, and the sterilized tubers which stored at low temperature had a sprouting capability of about 80% after 6 months. If the fresh weight of purple nutsedge tubers was decreased to below 48%, they could not sprout. However, the tubers soaked in water and then stored at low temperature could sprout by 88% even 6 months later. Sprouting and initial growth of tuber were much better at $35^{\circ}C$-day/$25^{\circ}C$-night than at 30/$20^{\circ}C$ or 25/$15^{\circ}C$. The half-sected tubers, which were prepared by setting the intact tuber of above 1.2g latitudinally, were shown similar initial growth to the intact but those sected crucifically were not. These results suggest that the half-sected tuber itself can be used as a material on herbicide screening. About 1000 tubers could be harvested when 10 tubers planted in a pot($56{\times}35{\times}16cm$) filled with the artificial soil were cultivated in greenhouse of $35^{\circ}C$-day/$25^{\circ}C$-night for 3 months(April-July, 1993). Chlorimuron, Bentazon and Norflurazon were selected as the standards for the screening because of providing relatively effective control on purple nutsedge in both soil-surface and foliar spray treatment.

• Journal of Korean Home Economics Education Association
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• v.31 no.1
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• pp.137-149
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• 2019

This study described the status of snack intake and personality of middle school students, determined the differences in snack intake and personality according to gender and grade levels, and examined the effect of snack intake on personality. Data were collected from a self-reported survey from students of a middle school in Gwangju city and 717 questionnaires used for the analyses. The data were analyzed for frequency, percentage, mean, standard deviation, Cronbach's α, t-test, ANOVA, Duncan test, and multiple regression analysis using SPSS/PC 18.0 program. The results obtained were as follows. First, as for the snack intake frequency, '1~2 times per a day' had the largest number of responses(42.3%), followed by 'sometimes'(37.6%), '2~3 times per a day'(12.6%), 'never'(7.5%). As for the reason of snack intake, 'habitually'(27.3%) had the largest number of responses, followed by 'insufficient amount of meal'(21.0%), 'skipping meals'(13.6%), and 'stress relief'(8.2%). Mean score of agreeableness was the highest(3.64) among the personality components followed by Openness/intellect(3.42), Extraversion(3.36), Conscientiousness(3.15), and Emotional Stability(3.09) on the 5-point scale. Second, there were statistically significant differences in Emotional Stability depending on the gender. There were statistically significant differences in Extraversion, Agreeableness, and Openness/intellect by the grade level. Third, fruit intake frequency had statistically significant influence on Extraversion(β=.134). Intake frequency of bread(β=-.099), fruit(β=.142), ice cream(β=.092), and rice cake(β=.090) had statistically significant influence on Agreeableness. Intake frequency of bread(β=.105), drink(β=-.113), fruit(β=.113), and flour-based food(β=-.126) had statistically significant influence on Emotional Stability. Intake frequency of fruit(β=.106) and milk(β=.110) had statistically significant influence on Openness/intellect. Intake frequency of fruit had statistically positive influence on all the personality components. Intake frequency of rice cake had statistically positive influence on two personality components. Intake frequency of drinks had statistically negative influence on Emotional Stability. The outcomes indicate that snack intake affects the personality of adolescents.

• 대한공업교육학회지
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• v.44 no.2
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• pp.28-46
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• 2019

The purpose of this study is to use as a basic data of establishing operating Course-based National Technical Qualification(CNTQ) support program by examining the educational needs for operating CNTQ of vocational school teachers, and to contribute to the vocational school settlement of CNTQ course. To achieve those purposes, this study drew 27 tasks performed by teachers operating CNTQ. Also, it surveyed the perceived importance and the performance. The findings of this study are as follows. First, it is showed that 'selection of qualification fields and confirmation of organization criteria, organization of educational training time by competency unit, organization of subjects and establishment of competency unit operating plan by grade and semester, selection of teaching materials, implementation of education and training, establishment of evaluation plan, implementation of evaluation, re-education and re-evaluation students with grades under 40%, guidance of paper evaluation, guidance of practical evaluation, guidance of interview evaluation' are the first priority tasks in the result of the need analysis. Second, it is indicated that 'application of external evaluation, guidance to retake an exam for failure' are the secondary priority tasks. According to these results, the following conclusions were made. First, it will be more positive effects if the educational needs in the next CNTQ support program include contents of the first priority tasks. Second, it is indicated that the priority of the educational needs for tasks of operating plan stages is commonly high. In particular, the highest ranking in the result means that it is completely supported from the first step on operating course. It is expected that the program which teachers on operating the course of similar qualification fields share each operating experience is effective. Third, the priority of the educational needs for external evaluation step ranked high. External evaluation has a different level of difficulty and a form of practical evaluation output according to qualification fields, so the method of guidance has to be different. It needs the program constructed by similar fields.

• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.310-321
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• 1999

In this in vitro study, confocal laser scanning microscopic morphology of dentin-resin interface and its relationship to shear bond strength were investigated after the exposed dentin surfaces were treated with 3 different kinds of dentin adhesive systems[three-step; Scotchbond Multi-Purpose Plus(SMPP), self-priming bonding resin; Single Bond(SB), self-etching primer; Clearfil Liner Bond 2(LB2)]. 52 extracted human molar teeth without caries and/or restorations. The experimental teeth were randomly divided into three groups of seventeen teeth each. In five teeth of each group, class V cavities(depth: 1.5mm) with 900 cavosurface angles were prepared at the cementoenamel junction on buccal and lingual surfaces. Bonding resins of each dentin adhesive system were mixed with rhodamine B. Primer of SMPP was mixed with fluorescein. In group 1. the exposed dentin was conditioned with etchant, applied with above primer and bonding resin of SMPP. In group 2, with etchant and self-priming bonding agent of SB. In group 3, with self-etching primer and bonding agent of LB2. After treatment with dentin adhesive systems, composite resin were applied and photocured. The experimental teeth were cut longitudinally through the center line of restoration and grounded so that about $90{\mu}m$-thick wafers of buccolingually orientated dentin were obtained. And, $70{\sim}80{\mu}m$-thick wafers sectioned horizontally, thus presenting a dentinal tubules at 900 to the cut surface of a remaining tooth, were obtained. Primer of SMPP mixed with rhodamine B was applied to these wafers. Confocal laser scanning microscopic investigations of these wafers were done within of 24 hours after treatment. To measure shear bond strength, the remaining twelve teeth of each group were grounded horizontally below the dentinoenamel junction, so that no enamel remained. After applying dentin adhesive systems on the dentin surface, composite was applied in the shape of cylinder. The cylinder was 5mm in diameter, and 2mm in thickness. Shear bond strength was measured using Instron with a cross-head speed of 0.5mm/min. It was concluded as follows ; 1. Hybrid layer of SMPP(mean: $4.56{\mu}m$) was thicker than that of any other groups. This value was not statistically significant thicker than that of SB(mean: $3.41{\mu}m$, p>0.05), and significant thicker than that of LB2(mean: $1.56{\mu}m$, p<0.05). There was a statistical difference between SB and LB2(p<0.05). 2. Although there were variations in the length of resin tag even in a sample, and in a group, most samples in SMPP and SB showed resin tags extending above $20{\mu}m$. But samples in LB2 showed resin tags of $10{\mu}m$ at best. 3. Besides primer's infiltration into demineralized peritubular dentin and dentinal tubules, fluorophore of primer was detected in the lateral branches of dentinal tubules. 4. All groups demonstrated statistically significant differences from one another(p<0.05), with shear bond strengths given in descending order as follows: SMPP(18.3MPa), SB(16.0MPa) and LB2(12.4MPa). 5. LB2 having thinnest hybrid layer($1.56{\mu}m$) showed the lowest shear bond strength(12.4MPa).

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.151-164
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• 1998

I analyzed the correlation between El-Nino phenomenon and our country's temperature and precipitation laying the stress on the anomaly, and the result of this analysis is as follows: (1) The extraction of the occurrences of El-Nino at the place of sea surface around Nino.3 which was known as the sea area under observation for El-Nino reveals that there are 9 years (1969, 1970, 1973, 1977, 1987, 1992, 1995, 1998) when the temperature anomaly in January is more than 1.0 during the period of research years ($1969{\sim}1998$). (2) The tendency of change of sea surface temperature around Nino.3 and that of our country are about the same, but the anomaly of Pusan and Inchon was much greater than that of Jangki in the East Coast. (3) The anomaly of sea surface temperature around Nino.3 and that of the ground temperature showed the similar changing tendency, the temperature of our country has something to do with that of sea surface as the correlation of ground temperature with the temperature of sea surface showed 0.31. Anomaly warm winter has something to do with El-Nino because the temperature of our country was high when El-Nino phenomenon appeared. (4) As for the precipitation, we can see that it has generally increased after 1989 when the phenomenon of warm climate was intense than before that year. But as we study the change of anomaly, the precipitation has less correlation in comparison with the ground temperature. The precipitation in 1973, 1983 and 1987 which were El-Nino years was correlated with El-Nino. While the change of sea surface temperature has showed a tendency of plus(+)increase since 1990, the precipitation has showed a tendency of minus (-)decrease. Therefore it seems that the temperature of sea surface has little correlation with the amount of rainfall.

• Journal of Science Education
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• v.35 no.1
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• pp.80-90
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• 2011

The purpose of this study is to investigate manual skills of experimental apparatuses of pre-service elementary school teachers by examining and analyzing the process of experiments conducted by pre-teachers. For this study, 24 pre-service elementary school teachers were selected as the subjects and 4 experimental apparatuses were chosen through analyzing science textbooks from 3rd grade to 6th grade in elementary school. The selected experimental apparatuses were alcohol burner, dropper, microscope, instruments for making a prepared specimen. In addition, a task was carefully chosen to conduct an investigation in real settings and a series of evaluation standards was developed. While 3 subjects conducted experiments in separated and independent space at the same time, 3 collaborators observed the experiment process and recorded whether the subject met the evaluation standards or not, using O, X. The study suggests that pre-service elementary school teachers' manual skills of experimental apparatuses were under far below our projections. Particularly, in case of alcohol burner, the subjects showed lower ability to properly light the burners - which is to brush through the lampwick with fire - and to adjust the height of tripods according to the flame. Also, when it comes to dropper, they were not held the way they were supposed to be. In addition, when designing prepared specimen, the subjects used their hands instead of tweezers and often skipped the process of dripping water drop and wiping water with an oilpaper. Moreover, they did not know how to use a microscope properly so there were many times that they could not focus a microscope, failing to observe the objects. Educational implications are discussed.