• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.107-119
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• 1990

The purpose of this study was to evaluate the marginal adaptability of the amalgam restorations in applying the cavity varnish (Copalite$^{(R)}$) and dentin bonding agent (Scotchbond 2$^{(R)}$) under the scanning electron microscope. For this study, eighteen sound extracted human molars were selected. Class I cavities in 12 teeth and class V cavities in 6 teeth were prepared using an air turbine with No. 701 tungsten carbide bur and finished using a low speed handpiece with No. 557 fissure bur. The prepared specimens were then divided into three groups including 4 class I cavities and 2 class V cavities in each group and restored as follows ; Group I. All the prepared cavities were restored with amalgam only (Control). Group II. Two layers of Copalite$^{(R)}$ cavity varnish were applied to the cavities with a gentle stream of air after each application and cavities were restored with amalgam. Group III. The enamel cavity margins were etched with 37% phosphoric acid gel for 60 sec., rinsed for 30 sec. and dried. One layer of visible lightcured Scotchbond Dental Adhesive$^{(R)}$ was applied and immediately cured for 20 seconds with visible light-cure unit and cavities were restored with amalgam. All the specimens were cut at the neck of the teeth and the occlusal halves of specimens were sectioned buccolingually in the longitudinal axis centering the amalgam restorations, using the disk. The cut specimens were ground with sandpapers (400, 600, 800, 1000 grit), and cleaned for 5 minutes in the ultrasonic cleaner (Brason Co. U.S.A.). In the cut surfaces, the amalgam - tooth interfaces were examined under the scanning electron microscope (JSM, 35C type, JEOL). The obtained results were as follows ; 1. The amalgam-tooth interfaces were reduced more significantly in the Copalite$^{(R)}$ and Scotchbond 2$^{(R)}$ application group than in the control group. 2. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed the findings similar to the Copalite$^{(R)}$ application group in the cavity floor, and the marginal adaptability was better in the side wall than in the cavity floor. 3. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed better marginal adaptability in the occlusal margin than in the gingival margin. 4. The marginal adaptability was in the order of the Scothbond 2$^{(R)}$ application group, the Copalite$^{(R)}$ application group and the control group.

• Journal of Preventive Medicine and Public Health
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• v.35 no.1
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• pp.57-64
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• 2002

Objective : To explore the relationship of social class and health behaviors with self-reported morbidity. Methods : The 1995 General Household Survey in Korea was used to investigate self-reported morbidity. Logistic regression was used to examine the relationship of social class and health behaviors with self-reported chronic disease and perceived general health. Results : For chronic disease and general perceived health, age adjusted odds ratios were higher for manual workers, lower-educated group as well as those in the lower income group; this held true for both men and women. Health behaviours had little effect or the relationship between social class and morbidity. The relationship between health behaviors and morbidity was very weak. The lower social class expressed higher levels of negative health behaviors, although this relationship appeared to be very weak in Korea. Conclusions : This study suggests that an understanding of health differentials that addresses the issue of social inequalities in Korea is required.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.299-302
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• 2009

This study is a study on Silver Class' percipience on mobile phone's LCD and a research has been conducted for configuration of an effective menu. First of all, the minimum sizes for Silver Class to perceive LCDs of mobile phones and sizes of icons or fonts within the LCDs were measured, and icons easily perceived by Silver Class were analyzed for configuring menu. These measurements it to understand what kind of display configuration has the highest demand by comparing a general public group in their 25 to 35 and a Silver Class group above 65 and suggest an alternative for that.

• Journal of the Korean Mathematical Society
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• v.55 no.4
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• pp.797-808
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• 2018

In [1], the authors generalize the concept of the class group of an integral domain $D(Cl_t(D))$ by introducing the notion of the S-class group of an integral domain where S is a multiplicative subset of D. The S-class group of D, $S-Cl_t(D)$, is the group of fractional t-invertible t-ideals of D under the t-multiplication modulo its subgroup of S-principal t-invertible t-ideals of D. In this paper we study when $S-Cl_t(D){\simeq}S-Cl_t(D_T)$, where T is a multiplicative subset generated by prime elements of D. We show that if D is a Mori domain, T a multiplicative subset generated by prime elements of D and S a multiplicative subset of D, then the natural homomorphism $S-Cl_t(D){\rightarrow}S-Cl_t(D_T)$ is an isomorphism. In particular, we give an S-version of Nagata's Theorem [13]: Let D be a Krull domain, T a multiplicative subset generated by prime elements of D and S another multiplicative subset of D. If $D_T$ is an S-factorial domain, then D is an S-factorial domain.

• The Journal of Korean Academic Society of Nursing Education
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• v.16 no.2
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• pp.202-212
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• 2010

Purpose: The purpose of this study was to identify the effectiveness of the JigsawⅣ cooperative learning in a facilitative communication class of nursing students. Achievement, communication skill, self-directed learning and experience during the class were measured. Method: This study was a pretest and posttest design with two subject groups. 43 students were in experimental (JigsawⅣ) group and 47 ones were in control (general small discussion) group. Classes were conducted over a 6-week period. The collected data was analyzed by the SPSS 12.0 program. Result: After taking part in the educational program, the experimental group had significantly more improvement in communication skill (F=6.81, p=.002) and self-directed learning (F=11.81, p=.000). In addition, the experimental group showed significantly higher scores for concentration in the class (t=2.26, p=.27), positive emotional state (t=3.01, p=.003) and active participation (t=2.78, p=.007) compared to the control group. However, the achievement between the two groups was not significantly different (F=3.29, p=.073). Conclusion: The findings of this study show that JigsawⅣ cooperative learning has positive effects in improvement of communication skill and self-directed learning. Also, students were excited and interested in the class during cooperative learning. Based on these findings, the author suggests developing additional educational programs focusing on nursing students.

• Korean journal of food and cookery science
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• v.27 no.5
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• pp.611-623
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• 2011

The goal of this study was to understand the reasons for learning about Korean herbal food by examining the actual conditions in a Korean herbal food course during lifestyle education. The general characteristics of the people learning about or working with the food as well as the correlations between the examined factors were analyzed, focusing on each person's dietary lifestyle. We divided the class participants into five dietary lifestyle groups by analyzing their scores. Group 1 was the"taste-seeking type", group 2 was the "quality-seeking type", group 3 was the"economy-seeking type", group 4 was the"convenience and economy-seeking type", and group 5 was the"convenience and health-seeking type". A person with a cooking career was considered to have more experience with Korean herbal food. The highest motivation for Korean herbal food education was for professional reasons, and the class that was most appreciated was learning about Korean traditional herbal foods. The highest satisfaction for the class was based on the instructor's knowledge, followed by food tastes, foodstuffs, educational materials, and the facilities superintendent. Satisfaction with the class tuition and practical utilization was relatively low.

• Journal of the Korean Society of Food Culture
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• v.13 no.4
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• pp.293-305
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• 1998

According to economical status, under-nutrition and over-nutrition coexist in preschool children in Korea. Subjects consumed more than RDA in most nutrients, and children in of the upper income class tended to have more nutrients than those of the low income class. Especially in case of energy, protein, fat, vitamin $B_2$, and P there were significant differences among the different classes. The mean calorie compositions of carbohydrates, protein and fat were $57{\sim}59:\;16{\sim}17:\;26{\sim}27$ and fat calorie percentage was higher than quantity recommended for Korean adults. Energy, protein, Fe, vitamin A, $B_1$ and C intakes were taken mostly from plant food sources. In the upper income class group, intakes of protein and vitamin $B_2$ from animal food sources were higher than in any other income classes. Intakes of iron, vitamin A, $B_1$ and C were largely provided by plant food group. Especially 44-45% of vitamin A were taken from vegetable and fruits group, which indicated that about 50% of vitamin A intake was the form of ${\beta}-carotene$. Also compared with other groups, in the upper income class group, the intakes of energy, protein, Ca, p, vitamin $B_1$ and vitamin $B_2$ from cereal and potatoes were significantly lower, and those of Ca and P from milks and meats, fishes & eggs were significantly higher(p<0.05). The mean fat intake in all subjects was $38{\sim}43g/day$. Regardless of income class, oleic acid($6.6{\sim}8.4g$) and linoleic acid($6.7{\sim}8.1g$) were the most abundant fatty acids contained in the diet. The upper class group consumed significantly more total saturated fatty acids and total monounsaturated fatty acids(p<0.05). In polyunsaturated fatty acids, there were no differences between 3 different income classes, but intakes of total ${\omega}6$ fatty acids in the upper class tended to be higher and those of total o3 fatty acids in low class tended to be higher. Therefore, ${\omega}6/{\omega}3$ tended to be higher in the upper class group. Regardless of income classes, P/M/S and ${\omega}6/{\omega}3$ ratios in all subjects were $0.9{\sim}l.3/1.0{\sim}1.1/1.0$ and $5.2{\sim}7.4/1.0$, respectively and were in a desirable range. Cholesterol intake of subject was 184-218 mg/day, which was comparable to the value of Korean adult intake.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.228-234
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• 2018

The aim of this study was to analyze the empathy represented in the learners' group journal of integrated English class using literature. 15 high school students participated in this class. In this study, integrated English class using literature was carried out by supplementing the point that amount of the English classes using literature had been focused on reading activities. In addition, not only communicative abilities but also learners' empathy to the main character in the literary was taught. In order to analyze the empathy expressed in learners' group journal, the integrated English class using literature was conducted in the second period and the class was recorded by video. The empathy was based on the community competence mentioned in the 2015 revised curriculum, and learners were asked to write the group journal. As a result of the research, the learners showed an understanding of the context in the novel and learners' group journal showed that their empathy to the main character in the novel. It is expected that the data on the empathy represented in the learner group journal of the integrated English class using literature will be used in English class.

• Communications of the Korean Mathematical Society
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• v.32 no.2
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• pp.233-260
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• 2017

Let R be a factorial domain. In this work we investigate the connections between the arithmetic of Int(R) (i.e., the ring of integer-valued polynomials over R) and its monadic submonoids (i.e., monoids of the form {$g{\in}Int(R){\mid}g{\mid}_{Int(R)}f^k$ for some $k{\in}{\mathbb{N}}_0$} for some nonzero $f{\in}Int(R)$). Since every monadic submonoid of Int(R) is a Krull monoid it is possible to describe the arithmetic of these monoids in terms of their divisor-class group. We give an explicit description of these divisor-class groups in several situations and provide a few techniques that can be used to determine them. As an application we show that there are strong connections between Int(R) and its monadic submonoids. If $R={\mathbb{Z}}$ or more generally if R has sufficiently many "nice" atoms, then we prove that the infinitude of the elasticity and the tame degree of Int(R) can be explained by using the structure of monadic submonoids of Int(R).

• Journal of The Korean Association For Science Education
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• v.5 no.1
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• pp.19-34
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• 1985

Teaching inquiry process is one of the most important objectives in science education. To promote students scientific process skills, a science teacher should encourage the students do something by themselves. One method for that purpose which has been used in many schools would be group experiment. The researcher has been experienced a lot of difficulties in controlling or guiding every group to finish the assigned experiment within the given class hour. Therefore, the researcher decided to select several leaders from students and trained them in advance of the given class hour. This leaders are expected to guide the remaining students in the class. As the result of this study, the classroom with and without student leaders showed very significant difference(P>0.001) in their achievement of scientific process skills. The experimental group also showed more positive attitude toward science. The researcher concluded that the use of student leaders is very effective in promoting scientific process skills. This method is also regarded very effective in a large class sized like Korean Schools.