• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.432-439
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• 2004

Korean certification regulation for particulate filtering respirators requires inward leakage (IL) test as European Standards (EN) and the standard levels of regulation are the same as those of EN. This study was conducted to evaluate particulate filtering respirators being commercially used in the market by using IL and assess the characteristics of IL. The study began with discussing the concept of IL, comparison of IL with fit test, and IL measurement method. Three brands of half masks and 10 brands of filtering facepieces (two top class, four 1st class and four 2nd class), total 13 brands respirators, and 10 test panels (subjects) who were classified in 9 facial grids in accordance with face length and lip length, were selected for IL test. IL tests were conducted in the laboratory of 3M Innovation Center which was established by EN standard. As expected ILs of half masks were lower than those of filtering facepiece mask. ILs of half masks and some filtering facepieces were significantly different in manufacturers. ILs of 1st class filtering facepieces were found to be much more than those of 2nd class and thus the result would cause wearers to get confused to select a mask. Four of six brands being no compliance with standards were thought that they should be tested again for certification because of a lot of differences from standards. There were no significant differences among ILs of five exercises. In 6 out of 13 brands lognormal distribution of ILs may be a better fit distribution and in 7 brands both lognormal and normal distributions were rejected. The result indicates that geometric mean may be better than arithmetic mean to establish standard.

• Mycobiology
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• v.50 no.2
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• pp.121-131
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• 2022

The rare edible and medicinal fungus Antrodia cinnamomea has a substantial potential for development. In this study, Illumina HiSeq 2000 was used to sequence its transcriptome. The results were assembled de novo, and 66,589 unigenes with an N50 of 4413 bp were obtained. Compared with public databases, 6,061, 3,257, and 2,807 unigenes were annotated to the Non-Redundant, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes databases, respectively. The genes related to terpene biosynthesis in the mycelia of A. cinnamomea were analyzed, and acetyl CoA synthase (ACS2 and ACS4), hydroxymethylglutaryl CoA reductase (HMGR), farnesyl transferase (FTase), and squalene synthase (SQS) were found to be upregulated in XZJ (twig of C. camphora) and NZJ (twig of C. kanehirae). Moreover, ACS5 and 2,3-oxidized squalene cyclase (OCS) were highly expressed in NZJ, while heme IX farnesyl transferase (IX-FIT) and ACS3 were significantly expressed in XZJ. The differential expression of ACS1, ACS2, HMGR, IX-FIT, SQS, and OCS was confirmed by real-time quantitative reverse transcription PCR. This study provides a new concept for the additional exploration of the molecular regulatory mechanism of terpenoid biosynthesis and data for the biotechnology of terpenoid production.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.591-596
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• 2022

Since 4-bar linkage widely used in various industrial fields has a fixed link length, it is inconvenient to add an independent link structure or control device to change the movement of output link. Therefore, this paper proposes a new concept of variable 4-bar linkage mechanism to selectively adjust the movement of the output link to fit desired situations, and applied to the commercial table fans, which is a representative product using a 4-bar linkage system. The optimal rotation angle steps for efficiency are determined experimentally and the appropriate lengths of linkage to fit each step are calculated analytically. Changes in the linkage length are implemented by the rotational motion using a grooved cylindrical cam and the feasibility of the proposed variable linkage mechanism is verified through fabrication and measurement. The presented variable link mechanism is expected to improve the efficiency of industrial robots and fuel valve systems.

• Korean Journal of Culture and Social Issue
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• v.29 no.4
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• pp.477-496
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• 2023

The purpose of this study is to examine the relationship between rejection sensitivity and reactive aggression among college students, as well as to determine the mediating effects of self-concept clarity and hostile attribution bias on the relationship between rejection sensitivity and reactive aggression. A self-report questionnaire was conducted online for the purpose of gathering data from university students aged 18 years and older. A total of 250 participants were included in the analysis. SPSS 27.0 was used for data analysis to check the basic statistics of the variables, frequency analysis, reliability analysis, and correlation analysis. In addition, the model fit was checked using Amos 21.0, and the bootstrapping method verified the significance of the indirect effect. The results of this study are as follows. The results of this study are as follows. First, rejection sensitivity positively affects reactive aggression through self-concept clarity. Second, rejection sensitivity increases the hostile attribution bias, leading to an increase in reactive aggression. Third, rejection sensitivity positively influences reactive aggression in an indirect way by sequentially affecting self-concept clarity and hostile attribution bias. These findings have implications as they identify psychological factors that affect reactive aggression in college students. This suggests the importance of utilizing psychological interventions to address reactive aggression associated with social problems, such as crime, and provides a foundation for both treatment and prevention. Finally, implications for further research and limitations of this study are suggested.

• The Research Journal of the Costume Culture
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• v.24 no.5
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• pp.697-708
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• 2016

The term used to describe consumer's valuation of a brand is brand equity. One concept that can be managed and may impact valuation of a prestige brand is "luxuriousness." As the concept of "luxuriousness" appears to be a key factor contributing to the equity of a prestige brand, the purpose of this study was to examine how luxuriousness is related to the brand equity utilizing a model developed by Yoo, Donthu, and Lee (2000). Yoo et al. (2000) identified three dimensions [brand association with awareness (BA), perceived quality (PQ), brand loyalty (BL)] accounted for the equity (OBE) of a brand. We speculated that the five dimensions of luxuriousness (i.e., quality, extended self, hedonism, accessibility, and tradition) would selectively influence the two dimensions of brand equity (BA, PQ) and that loyalty would mediate the relationship between the two dimensions of brand equity (BA, PQ) and overall brand equity. A total of 502 participants aged from 18 to 74 were surveyed in USA. Using AMOS 18, the path analysis was conducted with the maximum-likelihood estimation procedure. The model exhibited a good fit with the data and all hypotheses were supported except one. Quality, accessibility, and hedonism dimensions of luxuriousness affected perceived quality of the equity of a brand. Hedonism and extended self dimensions affected brand association with awareness. However, tradition dimension did not significantly influence brand association with awareness. Overall, this research expands understanding of brand equity as it documents the contributions of luxuriousness, a component that can be controlled by brand managers.

• Journal of The Korean Association of Information Education
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• v.20 no.6
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• pp.563-574
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• 2016

This paper is a research on the curriculums of network and digital creation tools among SW education in order to apply them to SW curriculum in education fields. For doing so, a curriculum model was developed by extracting main key words through the analyses of domestic and foreign SW curriculum, and reorganization of concept understanding and learning activity elements was made so as to be fit to characteristics of each curriculum. And curriculums were remodeled by curriculum such like concept understanding was focussed in network, activities in digital creation tools and its validity was suggested through expert verification by composing contents elements based on the results. Also, this model was proposed so that each school could recompose it easily by combining contents elements of other curriculums. Therefore, the suggested model could be utilized as a basic research data in applying domestic SW curriculum standard model.

• Korean Journal of Human Ecology
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• v.20 no.1
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• pp.205-223
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• 2011

This study examines diagrams of space organization and classroom activity zoning through Korean Childcare Accreditation Criteria, and compares space diagrams with childcare facilities in Daejeon, and looks at similarities and differences between them. Space diagram from accreditation criteria show the classroom, adjoining toilets, napping areas, and community areas for playing, reading, cooking, teaching and holding materials. Classroom zone diagrams show 8 activity zones for entering, washing and toilet, making art, playing, reading, studying science, resting, playing role and wooden block. Six case studies in Daejeon, Korea were surveyed and classified into big, medium and small size facilities by the number of children. The space organization of case studies are similar to the diagrams, except that outdoor playground and indoor playrooms were not large enough at the small and medium size facilities. Classroom activity zoning was very similar to the conceptions, excluding the playarea from classroom, integrating the rest areas for reading, subdividing art into music and art, science, and into math and science, roleplay into roleplay and wooden block. In conclusion childcare centers in Daejeon are designed to the concept diagram of the accreditation criteria, with some flexibility, exclusion, integration, and subdivision of space and activity zones. It has been requested as to make each criteria fit to the facility sizes-big, medium and small.

• Journal of Family Resource Management and Policy Review
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• v.17 no.1
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• pp.139-158
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• 2013

This research aimed to determine how a combined yoga and tea meditation program would affect the happiness of adolescents. The investigation was conducted over a total of 11 sessions held twice a week with 15 female middle-school students. Each session lasted 90 min and comprised preparation for 5 min, Hatha yoga for 50 min, tea meditation for 15 min, the expression of feelings for 15 min, and 5 min were allocated to finishing the program and announcing the next session time. A t-test was performed before and after the program to analyze the effects of the program. A goodness of fit test, which is related to the improvement of happiness, was done through a path analysis. As a result, we were able to determine meaningful changes in the t-test scores of happiness, stress, and quality of life. The scores of mindfulness, physical self-concept, and self efficiency changed positively, but meaningful changes were not shown. To derive a final conclusion, we verified the mediator effect with respect to happiness through a structural model. Consequently, physical self-concept was activated as a promoter for improving self-efficiency and mindfulness. Mindfulness was the key factor that improved the happiness of the adolescent subjects.

• The Mathematical Education
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• v.51 no.1
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• pp.1-19
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• 2012

In this study, contents of 'the 2007 revised curriculum handbook' and 16 kinds of mathematics textbooks were analyzed first. The purpose of this study is to examine the understanding state of students at general high schools by making questionnaires to survey the understanding state on contents of chapter of complex number based on above analysis. Results of research can be summarized as follows. First, the content of chapter of complex number in textbook was not logically organized. In the introduction of imaginary number unit, two kinds of marks were presented without any reason and it has led to two kinds of notation of negative square root. There was no explanation of difference between delimiter symbol and operator symbol at all. The concepts were presented as definition without logical explanations. Second, students who learned with textbook in which problems were pointed out above did not have concept of complex number for granted, and recognized it as expansion of operation of set of real numbers. It meant that they were confused of operation of complex numbers and did not form the image about number system itself of complex number. Implications from this study can be obtained as follows. First, as we came over to the 7th curriculum, the contents of chapter of complex number were too abbreviated to have the logical configuration of chapter in order to remove the burden for learning. Therefore, the quantitative expansion and logical configuration fit to the level for high school students corresponding to the formal operating stage are required for correct configuration of contents of chapter. Second, teachers realize the importance of chapter of complex number and reconstruct the contents of chapter to let students think conceptually and logically.

• Journal of the Korean association of regional geographers
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• v.6 no.3
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• pp.83-99
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• 2000

This paper purposes to provide a new perspective for better development of geography texts. For this purpose, we have applied spatial cognition development theory to children's drawings. We have suggested that children's spatial operation ability has three development stages according to their age: topological space, projective space, euclidean space. This study turns out that Piaget and Inhelder's spatial concept development theory is on the right track. However, we make clear that their division according to the age is not always accurate due to children's individual differences. These findings have educational implications as the following: First, it is dubious that most children can understand pictures, pictorial maps and illustrations in the third grader's textbook. Second, current textbooks require pictorial map understanding and drawing to third grade students and map drawing to fourth grade students. However, according to this study, the placement of these tasks are not fit for children's developmental stage because both tasks correspond to euclidean space operation. Therefore, we should remove them from the textbook for children at the age.