• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.599-612
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• 2007

The present study was designed to compare the morphological and structural differences of craniofacial structures among 146 children with Class I and Class III malocclusions. The results below were obtained from the study. 1. Sphenoethmoidal synchondrosis continues to grow later in Class III. 2. Anteroposterior length of the nasomaxillary complex was significantly shorter in Class III, but the height of the nasomaxillary complex was similar. 3. Mandibular length and mandibular body length were longer in Class III, but had no statistical significance. Lower anterior facial height was shorter in Class III, but had no statistical significance. 4. Dentoalveolar height was similar between Class I and Class III. 5. In Class I, anterior cranial base took part in the anteroposterior length of the nasomaxillary complex and the mandible. 6. In Class III, anterior cranial base and middle cranial base had higher correlation with the mandible with aging. These results suggest that there exist a little differences between Class I and Class III malocclusions at age $7{\sim}11$, but growth patterns are mostly similar. Therefore it is necessary to correct Class III malocclusions at an early age before skeletal differences appear.

• Journal of Educational Research in Mathematics
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• v.8 no.2
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• pp.587-603
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• 1998

Being in Learning-accomplishing rate on mutual cooperation studies of small group by different class, we can find that the sujective class of high group is much more efficient than the compared class of high group and that the subjective class of low group is more efficient than the compared class of low group as times goes. Moreover, in analysis of all directions on mathematical attitude, high group appears to be a great efficient in all areas such as confidence, flexibility, reaction, value, etc. and low group seems to have a little effect, by comparing the subjective class with the compared class. A. The result of a scholastic ability test High group had a great effect in the result of the first (Number and an expression) and second(An equation of a figure) scholastic ability test. As the time of research goes, the difference of average between the subjective class and the compared class has increased. Low group had no effect in the result of the first (Number and an expression) and the second (An equation of figure) scholastic ability test. But the difference of average grade between the subjective class and the compared class proved to be some efficient as time goes. (the first test is 0.94 and the second test is 3.33)We can find that the result of the third test (An exponent and log function) turned out be efficient. B. The change of mathematical attitudeHigh group had a great effect in confidence(+1.21), fiexibility(+1.92), will(-0.06), curiosity(+2.64), reaction(+1.50), value(+1.44). Low group appeared to be a little efficient in comparison between the subjective class and compared class. the average of both the subjective class and the compared class in low group decreased if not the result of pre-test but in that of pose-test. Therefore, we can find that the difference between mathematics of maddle school and that of high school gets bigger in Low group.C. The result of a question examinationAfter this research, the reaction that It is helpful to studying accomplishm- ent is 33.7%, the reaction that It is not helpful is 14.7%. After all, this research appears to be a positive reaction. After this study, the change of studying will seems to be much more not in Low group but in High group.

• Journal of the Korean Geotechnical Society
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• v.29 no.5
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• pp.29-38
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• 2013

The G-class cement is commonly used in practice for geothermal well cementing in order to protect a steel casing that is designed to transport hot water/steam from deep subsurface to ground surface during operating a geothermal power plant. In order to maintain optimal performance of geothermal wells, physical properties of the cementing material should be satisfactory. In this paper, relevant factors (i.e., groutability, uniaxial compression strength, thermal conductivity and free fluid content) of the G-class cement were experimentally examined with consideration of various water-cement (w/c) ratios. Important findings through the experiments herein are as follows. (1) Groutability of the G-class cement increases by adding a small dose of retarder. (2) There would be a structural defect caused when the w/c ratio is kept higher in order to secure groutability. (3) Thermal conductivity of the G-class cement is small enough to prevent heat loss from hot steam or water to the outer ground formation during generating electricity. (4) The G-class cement does not form free water channel in cementing a geothermal well. (5) The Phenolphthalein indicator is applicable to the distinction of the G-class cement from the drilling mud.

• 대한공업교육학회지
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• v.37 no.2
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• pp.147-160
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• 2012

The purpose of this study was to examine the effects on the academic achievement and learning satisfaction according to the presentation method of the multimedia materials for 'transportation technology' units of technology home economics subject. The subjects were assigned in third conditions; Text type explanation class, multimedia class and multimedia video class with narration. The data of six evaluation questions obtained from the survey of 93 high school girl were analyzed using SPSS program. The results of the study were as follows : First, in the learning satisfaction average level(M) of the students' overall responses to the questions, multimedia teaching learning class(experimental group 1) is the first(M=4.14), multimedia video class with narration(experimental group 2) is the second(M=3.16), and instructor-led class(control group) is the third (M=2.63). Therefore, the teaching learning multimedia class(experimental group 1) was most effective. Second, looking at the correlations between the students' responses to the questions, in an interesting class, the students have a retentive memory and comprehension, but a lower concentration can not a retentive memory. Third, multimedia teaching learning class(experimental group 1) has the best degree at the level of academic achievement, but instructor-led class(control group) and multimedia video class with narration(experimental group 2) have similar degree in the second place. To increase academic achievement, an instructor-led class is important to arouse interest and a multimedia video class with narration is required ways to improve level of concentration.

• Journal of Digital Convergence
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• v.10 no.8
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• pp.317-326
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• 2012

The study aims at analyzing and comparing the effect of video teleconferencing English class with native speakers on class satisfaction and self-efficacy of elementary school students according to grades. Revised Kim's self efficacy and researcher's class satisfaction measuring tools were used for this. Grade 3 got the highest score and grade 6 had the lowest one in class satisfaction. In post-testing on self efficacy, average score was lower than in pre-testing except grade 3. Grade 3 got the highest score and grade 6 had the lowest one in self efficacy. I conclude that as students' grade goes up, their interests decrease in teleconferencing class and native speaker teachers.

• Journal of the Korean Home Economics Association
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• v.29 no.2
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• pp.135-154
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• 1991

The purposes of this study are: 1) To find out overall family life issues percieved by the middle-classhousewives in their forties. 2) To examine detailed aspects related to middle years crises, leisure activities, children issues, family economy issues, and housing issues. 3) To clarify solutions to, and provide basic data on family issues raised by the middle-class families. The middle-class housewives in their forties living in the Seoul area were the subject of the survey. The sample size analysed in this study was 422. Data were analysed by the frequency, mean, percentile, standard deviation, X2-test, analysis of variance, multiple classification analysis, analysis of multiple regression, and Scheffe-test as a post-hoc analysis. The conclusions are as follows: First, the middle-class housewives tend to give more importance on children issues, especially on academic achievement and career development. Second, family cohesion of middle-class families is comparatively high and intra-familial conflict is low, and middle years crisis of housewives is comparatively low, too. Third, the stability of middle-class families can be found in household economic management patterns. one fourth of the families own stocks and two fifths of the families own real estate except their own dwelling house. Be based on their property income add to their labor income, middle-class families are showed their economic stability, however, intra-class inequality is found, too. Fourth, the great part of middle-class families that possess their own house, tend to be unsatisfied with their housig scale, and a half of the families expect to enlarge their housing scale for more comfortable and convient living.

• Health Policy and Management
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• v.13 no.4
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• pp.99-114
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• 2003

This study was performed to determine the effect of social class distribution as measured by lower social class rate on all cause and cause specific mortality in Korea. I obtained data on social class, fiscal autonomy of municipalities, number of medical doctors, region(Si/Gun) from 1955 Korea Census Data and Regional Statistics Data. And all of the data on mortality adjusted for age for 1995 for each district from the National Statistics Office. Lower social class rate ranged from 18.9％ for Kangnam gu to 85.7％ for Imsil gun and age standardized mortality ranged from 385/100,000 population for Kangnam go to 803/100,000 population for Sinan gun. Lower social class showed had a significant correlation with total mortality adjusted for age(r=0.81, p<0.0001). The association of the rate to total mortality remained highly significant after adjusted for number of medical doctors per 1,000 population, fiscal autonomy of municipalities and region(p<0.0001). Effects of the lower social class were also found for neoplasm (p=0.0008)； cardiovascular disease (p<0.0001)； infectious disease(p=0.0115)； respiratory disease(p=0.0085)； gastrointestinal disease(p<0.0001)； accident ＆ poisoning (p<0.0001). The findings suggest that policies that deal with the inequality in social class may have an important impact on the health of the population.

• Animal cells and systems
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• v.9 no.1
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• pp.1-7
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• 2005

Class I and class II MHC genes have been identified in most of the jawed vertebrate taxa. In all investigated bony fish species, unlike mammals, the classical class I and class II MHC genes are not linked and even are found on different chromosomes. Linking and clustering of the class I and class II MHC genes is not the only phenomenon clearly detected in the evolution of immune system from cartilaginous to mammals. In all non-mammalian classes the LMP/TAP genes are highly conserved within class I genes region, while these genes are conserved within class II genes region only in mammals. Today we know that LMP/TAP genes in mammals have a crucial role in peptide processing for presentation within class I molecules, as well as in anti-tumor immunity. For these reasons, differences in clustering of LMP/TAP/MHC genes can be responsible for the differences in mechanisms and efficacy of anti-tumor immunity in non-mammalian vertebrates compared to same mechanisms in mammals. Also, the differences in cytokine network and anti-tumor antigens presentation within classes of vertebrates can be explained by toe peculiarity of LMP/TAP/MHC gene clustering.

• Journal of Korean Elementary Science Education
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• v.29 no.2
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• pp.155-165
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• 2010

The purpose of this study is to look into self-concept and teaching anxiety of elementary school teachers about inquiry instruction in science class, and investigate correlations among them. For this study, the survey was carried out on 338 elementary school teachers, and the interview was conducted with 5 of them. The results of this study are as follows; Self-concept of elementary school teachers about inquiry instruction in science class was more positive than usual. And the teachers who were male, older and majored in science education showed more affirmative self-concept about inquiry instruction in science class. Teaching anxiety of elementary school teachers about inquiry instruction in science class was less than usual. And the teachers who were male, older and majored in science education showed less teaching anxiety about inquiry instruction in science class. The correlation of self-concept and teaching anxiety of elementary school teachers about inquiry instruction in science class was an negative interrelation. This presents that the teachers, who have more positive self-concept about inquiry instruction in science class, have less teaching anxiety than those who have more negative one. Consequently, teacher training and retraining programs should be developed and conducted by grasping teachers' self-concept and their anxiety, to reduce anxiety about inquiry instruction in science class.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.76.1-76.1
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• 2014

We investigate the solar flare and CME occurrence rate and probability depending on sunspot class and its area change. These CMEs are front-side, partial and full halo CMEs associated with X-ray flares. For this we use the Solar Region Summary(SRS) from NOAA, NGDC flare catalog, and SOHO/LASCO CME catalog for 16 years (from January 1996 to December 2011). We classify each sunspot class into two sub-groups: "Large" and "Small". In addition, for each class, we classify it into three sub-groups according to sunspot class area change: "Decrease", "Steady", and "Increase". In terms of sunspot class area, the solar flare and CME occurrence probabilities noticeably increase at compact and large sunspot groups (e.g., 'Fkc'). In terms of sunspot area change, solar flare and CME occurrence probabilities for the "Increase" sub-groups are noticeably higher than those for the other sub-groups. For example, in case of the (M+X)-class flares of 'Dkc' class, the flare occurrence probability of the "Increase" sub-group is three times higher than that of the "Steady" sub-group. In case of the 'Eai' class, the CME occurrence probability of the "Increase" sub-groups is five time higher than that of the "Steady" sub-group. Our results demonstrate statistically that magnetic flux and its emergence enhance solar flare and CME occurrence, especially for compact and large sunspot groups.