• Journal of the Korean Society for Heat Treatment
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• v.14 no.6
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• pp.336-344
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• 2001

For the establishment of the world wide unified scales of the Rockwell hardness test with conical indenters, round robin test was carried from 1998 to 2000. The pilot laboratory was MPA-NRW and 12 laboratories from 11 countries participated In this RRT. Rockwell hardness of 74 specially prepared blocks was measured for the scales of C, A, D, 45N, 30N, and 15N and the results were compared. It was found that the geometric form of indenter affects on the results very significantly and standardization in the measurement and evaluation of indenter should be established in short time for the reliable hardness measurement. KRISS showed good results in general for all of the ranges except 15N scale which showed relatively large difference compare to the mean value. It was concluded that poor control in loading velocity of the dash pot was the major reason.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.3
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• pp.307-315
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• 2012

The purpose of this study was to examine the effects of small inquiry method on space perception ability and creative personality. Testees of this research are 36 elementary pre-service teachers taking an astronomical observation class. Doing inquiry activity after 36 elementary pre-service teachers are classified into 6 Jigsaw small inquiry. Learning activity was split into two groups, expert group and a population. To find out research outcome, pre-test was executed space perception ability test, creative personality test. Analysis of test result was accomplished with statistical package SPSS 18.0 paired t testing hypothesis. The results of this study are as follows. First, 'source of season change' class using Jigsaw small inquiry method has effect on space perception ability improvement. This was interpreted that space perception ability improvement was effective because characteristic of Jigsaw small inquiry is made up of lots of semin Second, 'source of season change' class using Jigsaw small inquiry method has no effect on creative personality. This was interpreted that experiment and discussion activity getting accomplished in a short time has no effect on qualitative characterizing Creative Personality improvement.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.289-294
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• 2007

Solid Rocket Motor(SRM) has advantages such as - high specific impulse, operational safety and simplicity in design and manufacturing process, but thrust magnitude can't be controlled. For studying of pintle nozzle that can control the thrust magnitude of SRM, cold flow test and numerical analysis about needle type pintle shape were performed and results were presented in this paper. As the results of this study, pintle tip's shape and nozzle contour were important design parameters because thrust performance and variable thrust range of pintle nozzle depend on them. Especially, the thrust of needle typed pintle nozzle adopted in this test was predicted 13% higher than normal nozzle without pintle.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.11 no.3
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• pp.335-343
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• 2004

Purpose: This study was to evaluate effect of an educational program based upon experiment for smoking prevention in middle school students. Method: A quasi-experimental design was used. The participants were 107 middle school students (53 in the experimental group, 54 in the control group). Students in the experimental group participated in three 45-minute educational programs over a period of 2 weeks. The dependent variables were measured before and 2 & 4 weeks after the treatment. The data were analyzed using $x^2$ test, Fisher's exact test, t-test, and repeated measures ANOVA. SPSS was used to aid analysis. Results: 1) The experimental group showed higher levels of knowledge of smoking prevention compared to the control group. However this program did not affect their attitude towards smoking. 2) There was a higher possibility of smoking in the future among the students who had smoked than those who had not. 3) The majority (84.9%) of the experimental group said that the program was effective. Conclusion: Knowledge of smoking for the experimental group was increased, so it is assumed that the program itself had a positive effect on the students. To change attitudes regarding smoking, smoking prevention programs need to be conducted repeatedly, not just temporarily.

• Journal of the Korean Home Economics Association
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• v.43 no.11 s.213
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• pp.17-30
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• 2005

The purpose of this study was to explore consumption status of scented textile products and to determine differences in consumption behaviors of scented textile products among subject groups separated by demographic (sex, age) and lifestyle (health concern, fashion involvement, innovativenss) characteristics. A total of 530 consumers who had used scented textile products participated in the web survey for the study. Consumer data were analyzed through descriptive statistics, chi-square test, factor analysis, t-test, ANOVA, and LSD test. In the results, the most often used products were small commodities, socks, bedding, and underwear of hub and flower scents. Consumers considered a product test as the most crucial information source and scent as the most significant decision making factor for purchase. Demographic and lifestyle group differences were found in some of the product types in use as well as in purchase behaviors (total spending amount, purchase venue, information source, considering factors when purchasing). The applicability of the study result to the theory of innovation adoption was discussed. Marketing implications were suggested based on the study results.

• Proceedings of the KIEE Conference
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• summer
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• pp.1118-1120
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• 2004

For the first time in Korea, a 100hp high Tc superconducting(HTS) motor has been designed, developed and successfully tested recently. The design was based on 2-dimensional electromagnetic field analysis of cylindrical coordinate. The field winding of rotor was wound with Bi-2223 tapes and tested after assembled with other rotor components. The stator had air-gap type armature windings which allow higher terminal voltage and more sinusoidal voltage waveform than conventional iron cored machines. Steady state open & short-circuit test and resistive load test were conducted also in generator mode. The fabrication and test results of this machine were discussed in this paper.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.3
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• pp.267-274
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• 2012

Purpose : The purpose of this study was to investigate characteristics of the forced pulmonary function test effect by changes in lung function related to postures and by Transverse Abdominis(TrA). Contraction in standing position during forced inspiration and expiration with young female adults. Methods : 10 young female adults were recruited this study. pulmonary Function test was measured with a Master-screen Body (VIASYS Inc., CA, 미국). To check the changes in lung function with different postures, we tested pulmonary function in the standing and supine position each. In the standing position, while the transversus abdominis was activating, we compared the forced inspiration with the forced expiration. Statistical analysis was used Independent t-test to know difference between forced inspiration and expiration of activated TrA. Results : According to the study, the change of pulmonary function were statistically significant difference in the standing compared to the supine position. The contraction of the transversus abdominis causes decrease in the change of forced inspiration and increase in the change of forced expiration. Conclusion : These results indicate that spontaneous contraction of the TrA in standing position helps pulmonary function. And the selective contraction of the transversus abdominis at the end of forced inspiration makes increases in the forced expiration.

• Human Ecology Research
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• v.60 no.4
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• pp.565-576
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• 2022

The purpose of this study is to identify the effect of Home Economics Instruction applying Flipped and Problem-Based Learning (FPBL) on Korean middle-school students' metacognition skill. The study uses a pre-post design test of the same group. There were 151 participants (77 male and 74 female) who were middle-school students in the third grade. Two hours of classes on 'Food Selection and Storage' were given per week for three weeks - a total of six hours. Analysis using the t-test revealed a statistically significant difference between the pre-test and the post-test, supporting the conclusion that participating in the class improved the metacognition, food selection, and storage behavior scores of the middle-school students. All area scores and overall averages of metacognitive sub-elements such as planning, monitoring, regulation, and evaluation also improved after taking FPBL classes. From the results of this study, Home Economics Instruction applying FPBL is an effective teaching method for improving middle-school students' metacognition.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.4
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• pp.618-629
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• 2008

The objectives of this study were to classify body types of 40s, 50s, 60s obese women according to body measurements and to investigate relationships between age and body types of obese women. Body measurement was made on 497 obese women in their 40s, 50s, 60s whose BMI (Body Mass Index) was 25.0 or more when directly measured in 'Size Korea 2004'. Data were analyzed through factor analysis, cluster analysis, Pearson's correlation coefficient, $X^2$-test, t-test, one-way analysis of variance, and Duncan's multiple range test. First. the obesity group with BMI being 25.0-30.0 was composed of 23.1% subjects in their 40s, 43.3% subjects in their 50s, and 50.0% subjects in their 60th, which demonstrates that the older subjects were, the higher the distribution was. Adding the high obesity group with BMI being more than 30.0 to the obesity group, women in their 60s were 56.7%, the most of obese bodies. Second, factor analysis of obese women's BMIs revealed that five factors were elicited, including upper-body circumference related factor, height related factor, lower-body circumference related factor, upper-body width related factor, and upper-body related factor. As a result of analyzing the clusters, three types of body shapes were classified including upper-lower obesity, upper obesity, and lower obesity. Third, obese women were thicker or wider than non-obese individuals in those factors including upper-body circumference, lower-body circumference, and body width, and longer in upper-body length, while non-obese individuals were higher or longer than obese individuals in height related factors.

• Restorative Dentistry and Endodontics
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• v.29 no.1
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• pp.66-72
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• 2004

All-in-one adhesives were recently developed for reducing the technique sensitivity and chair time, but lots of concerns were made on bondability, longevity, and microleakage. The object of this study was to evaluate microleakage and marginal quality of all-in-one adhesives using electrochemical method and SEM analysis quantitatively. After making Class V cavities, they were bulk filled with Heliomolar(#A1 after surface treatment with three adhesives: Adper Prompt (Group A), One up bond F (Group O), Xeno III (Group X) Electrical conductivity (microamphere, ${\mu}A$) was checked two times: before and after cavity filling. Percentage of leaky margin was estimated from SEM image (${\times}1,000$). The data were statistically analysed: ANOVA and Paired T test for electrical conductivity, Kruskal-Wallis and Mann-Whitney test for marginal quality, Spearman s rho test for checking of relationships between 2 methods. The result were as follows: 1. There was no difference in microleakage between adhesive systems and every specimen showed some of microleakage after filling. 2. Microleakage was reduced about 70% with composite resin filling. 3. Marginal quality was the best in group A. decreasing among groups in the following order: group O, followed by group X. There were significant differences between group A and group X (p=0.015), and between group 0 and group X (p=0.019). 4. There was no relationship between the microleakage measured by electrochemical method and marginal quality measured by SEM analysis. Within the results of this study, there was no difference in microleakage among groups by electrical conductivity. However, significant difference in marginal quality was seen among groups. It was believed that these dissimilar results might be induced because of their own characteristics. Analysis of microleakage needs various methods for accuracy.