• Proceedings of the KSME Conference
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• 2002.08a
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• pp.131-134
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• 2002

Compressible gas flow through a convergent-divergent nozzle is choked at the nozzle throat under a certain critical pressure ratio, and then being no longer dependent on the pressure change in the downstream flow field. In practical, the flow field at the divergent part of the critical nozzle can affect the effective critical pressure ratio. In order to investigate details of flow field through a critical nozzle, the present study solves the axisymmetric, compressible, Wavier-Stokes equations. The diameter of the nozzle throat is D=8.26mm and the half angle of the diffuser is changed between $2^{\circ}\;and\;10^{\circ}$ Computational results are compared with the previous experimental ones. The results obtained show that the divergence angle is significantly influences the critical pressure ratio and the present computations predict the experimented discharge coefficient and critical pressure ratio with a good accuracy. It is also found that a nozzle with the half angle of $4^{\circ}$ nearly predicts the theoretical critical pressure ratio.

• Journal of Information Technology Services
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• v.7 no.2
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• pp.197-221
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• 2008

This study is to identify quality factors having influence upon mobile internet service performance theoretically, derive the research model and the hypotheses concerning the cause and effect relationship between these factors and service performance and then analyze them empirically. In order to enhance the model's explanation power, trust and cognitive engagement as interviewing variables are included in the model. The theoretical background of this study was brought from relevant literature in the areas of the theory of reasoned action(TRA). technology acceptance model(TAM), product selection model, cognitive absorption theory and etc. The research model and hypotheses were statistically investigated and analysed through convergent and discriminant validity test, reliability test, and path analyses by means of statistical packages SPSS(12.0) and LISREL(8.72). For these empirical analyses. data were collected through the field survey of 373 users who were willing to continuously use the mobile internet services. Based on the results of the analyses, theoretical and practical significance and future study direction were suggested. The results of this study will be helpful to giving a guideline to companies such as mobile telecom, mobile contents provider and mobile handset manufactures when they have to establish the mobile Internet service marketing strategies.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.35-35
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• 2011

Phase change material(PCM) has thermal energy storage and been attracted attention. Latent heat of the organic PCM can keep maintaining temperature when the change of outside energy conditions influence to PCM. Thus, many researchers have interested to thermal energy storage ability and investigated to applications such as thermal storage of solar energy, bioclimatic building, icebank, medical application, clothing industry and so on. Among the many applications, investigation of the PCM in clothing industry is also important because the people has interest functional factor called health-care in the clothing. In addition, PCM can give them mild environment condition such suitable temperature control or humidity. To fabrics, the PCM has various methods such as microcapsule, padding and modified cross-section formation(Sheath/core). Sheath core PCM fabric has a better benefit of durability than other method. However, PCM sheath/core spinning is difficult. In addition, dyeing property is important to use clothing industry due to visual images. In this study, we investigated dyeing properties of Nylon/PCM sheath/core fabrics. Especially, we observed the relation between dyeing property and PCM including ratio. Various temperature and pH conditions were also studied to optimize dyeing properties as acid dye.

• Journal of Korean Elementary Science Education
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• v.38 no.1
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• pp.1-15
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• 2019

This study aimed to identify the effects of students' empathy ability on group creativity, when elementary school students perform scientific activity designed to express group creativity. A total of 12 elementary students from a fifth-grade science club participated in this study. A pretest to examine the students' empathic ability was performed to classify them into three groups: A group with high, low and heterogeneous empathic members. The linguistic interaction was analyzed to determine the process of group creativity manifestation; the results were classified into 'metacognitive', 'cognitive', and 'social-communicative'. As a result, groups with high empathic ability showed more frequent interaction in monitoring, planning, and divergent thinking. On the other hand, in the case of the group with low level of empathy, it was confirmed that there are many interactions related to regulation, convergent thinking, and noncohesive prosocial interaction. Also, in the case of heterogeneous group with empathy ability, group creativity utterance on all sides was relatively higher than other groups. As a result of this study, we could confirm the influence of empathy as a strategy to help the group creativity and discuss the educational implications.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.141-151
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• 2022

Taking the different inheritance methods of representative successors, dance education at university, and convergent media as a research object, this research discusses the changes in the development direction of inheritance of traditional dances of China's intangible cultural heritage, analyzes the inheritance and development path of traditional dances. The purpose of this research is to realize the inheritance of dance culture and strengthen the influence of Chinese traditional dance culture in the world.

• Journal of Distribution Science
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• v.21 no.3
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• pp.61-69
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• 2023

Purpose: This study's purpose is to conduct empirical research on online comments affect Vietnamese consumers' impulsive buying in e-distribution. This study also considers affecting of browsing toward the urge to buy, and the urge to buy toward impulse buying in e-distribution. Research design, data and methodology: This study used the non-probability method to assemble data from 273 customers' online buying experiences via a Google Forms online survey. By using SmartPLS, the data were examined for reliability, convergent validity, discriminant validity of the variables, and proposed hypothesis testing. Results: The empirical study discovered that internet comments with utilitarian and hedonistic values had a positive effect on browsing, the urge to buy, and impulse purchases in e-distribution. Additionally, the result revealed that browsing had a positive influence on the urge to purchase. Likewise, the findings also disclosed that the urge to buy had a favorable effect on impulse buying. Conclusions: This study offered a thorough conceptual model of internet feedback influencing browsing, urge to buy, and impulsive purchases in e-distribution. Also, to increase impulsive buying, this study will assist e-distribution managers in concentrating on developing innovative marketing strategies and action plans that take into consideration consumers' internet reviews, browsing, and urge to buy.

• Journal of Korean society of Dental Hygiene
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• v.23 no.4
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• pp.323-331
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• 2023

Objectives: This study was conducted to confirm the relationship between role conflict, positive psychological capital, and the psychological well-being of dental hygienists and to provide data for improving professionalism by increasing the psychological well-being of dental hygienists. Methods: From May 21 to June 22, 2023, 190 data were collected through an online community of dental hygienists. The collected data were analyzed IBM SPSS program ver. 23.0 and AMOS ver. 26.0. Statistical analysis methods, convergent validity test, structural equation model analysis, and model fit were performed using independent sample t-test, one-way ANOVA, confirmatory factor analysis, structural model fit test, and path analysis. Results: The lower the role conflict of dental hygienists and the higher the positive psychological capital, the higher the psychological well-being. The lower the role conflict, the higher the positive psychological capital. However, there was no mediating effect between positive psychological capital and role conflict, as it was not statistically significant. Analysis of the total effect of role conflict and positive psychological capital on psychological well-being revealed that positive psychological capital had a greater influence on psychological well-being than role conflict. Conclusions: Psychological well-being was related to positive psychological capital and role conflict. Future efforts are needed to improve positive psychological capital and psychological well-being of dental hygienists and reduce role conflict.

• Geomechanics and Engineering
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• v.35 no.4
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• pp.437-447
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• 2023

The failures of tailing dams have caused irreparable damage to human lives, assets and environment and this has ultimately resulted in great economic, social and environmental challenges worldwide. Due to this, investigation into mechanical behaviour of tailings has received some attention. However, the knowledge and understanding of mechanics of behaviour in iron tailings is still limited. This study investigates the mechanics of iron tailings from Nigeria considering grading, effects of fabric resulting from different sample preparations and the possibility of non-convergent behaviour. This was achieved by conducting series of one-dimensional compression tests in conjunction with index, microstructural, chemical and mineralogical tests. The materials are predominantly poorly graded, non-clayey and non-plastic. The tailings are characterised by angular particles with no obvious particle aggregations and dominated by silicon, iron, aluminium, haematite and quartz. The compression paths do not converge and unique normal compression lines are not found and this is an important feature of the transitional mode of behaviour. The behaviour of these iron tailings therefore depends on initial specific volume. The preparation methods also have effect on the compression paths of the samples. The gradings of the samples have an influence on the degree of transitional behaviour but the preparation methods do affect the degree of convergence. The transitional mode of behaviour in these iron tailings investigated is very strong.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.97-104
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• 2016

This study was to examine relation of oral health knowledge and oral health behavior, targeting university students who major in health-related majors 198 students and health-unrelated majors 203 students. Oral health behavior by general characteristics appears most highest junior and senior sophomore, health-related major, regular dental check-up, dental education experience. 'It is effective in preventing bad breath brushing the tongue when brushing' of oral health knowledge reached 94.5% most highest. The health-related is high 'fluoride helps to prevent cavities.' 'Brushing tongue' of oral health behavior is most highest average 4.20. The health-related is high 'I know the brushing method that's right for me, and enforcement' and 'I am regular scaling for periodontal disease prevention'. To identify influence that general characteristics and oral health knowledge to oral health behavior, regression analysis result Y(oral health behavior)=2.692+0.377(regular dental check-up)+0.145(rental education experience)+ 0.215(method of oral health education)+0.045(oral health knowledge) was come out. Therefore, university students need to improve their oral health, structuring environment where information about oral health is reached out easily.

• Communications of Mathematical Education
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• v.31 no.1
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• pp.49-70
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• 2017

The purpose of this study was to investigate the relative influence of multiple error sources and to find optimal measurement conditions that obtain a desired level of reliability of a creative attitude test in mathematical creativity. This study analyzed the scores of the Creative Attitude Scale-Korea allowed to access publicly of 125 general students and 109 mathematically gifted students by performing a multivariate generalizability analysis. The main results were as follows. First, based on reliability, the Creative Attitude Scale-Korea was measured less precisely for mathematically gifted students. On the contrary, based on the conditional standard error of measurement, it was measured less precisely for general students. However, the Creative Attitude Scale-Korea showed strong reliability in both groups. Second, the optimal weights should adjust to .3, .3, .4 in mathematically gifted students and .4, .4, .2 in general students with three scoring components of divergent attitude, problem solving attitude, and convergent attitude based on the maximum reliability. Third, to approach desirable reliability, it is possible to use one component of divergent attitude in general students but three components of divergent attitude, problem solving attitude, and convergent attitude in mathematically gifted students. Finally this study proposed application plans for the Creative Attitude Scale-Korea and future directions of research.