• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.103-106
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• 2005

In order to investigate the catalytic mechanism for the growth of carbon nanotubes (CNTs), a comprehensive study was conducted using carbon materials synthesized at 680 ${^{\circ}C}$ with a gas mixture of CO-H$_2$ after reduction at 800 ${^{\circ}C}$ by H$_2$ gas from iron oxide, and metal Pt. The resulting material was observed by scanning electron microscopy (SEM) and X-ray diffraction patterns (XRD) after a variety of reaction times. The carbon materials synthesized by metal Pt were little affected by reaction time and the sintered particles did not form CNTs. Xray analysis revealed that metal Fe was completely converted to iron carbide (Fe$_3$C) without Fe peaks in the early stage. After 5 min, iron carbide (Fe$_3$C) and carbon (C) phases were observed at the beginning of CNTs growth. It was found that the intensity of the carbon(C) peak gradually increased with the continuous growth of CNTs as reaction time increases. It was also found that the catalyst of growth of CNTs was metal carbide.

• Journal of the Korea Fashion and Costume Design Association
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• v.19 no.1
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• pp.1-14
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• 2017

The purpose of this study is to classify the environmental awareness attitudes of university students and analyze their differences in social support pursuit, and apparel consumption behavior. Questionnaires were administered to 236 college students living in Daegu City and Kyoungbuk province. Frequency, factor analysis, reliability analysis, cluster analysis, ANOVA, Duncan-test, and t-test were used for data analysis. The findings were as follows. The environmental awareness attitudes had factors as recognizing the importance of environmental issues, purchase of eco-friendly products, public opinion legislation awareness, interests on eco-friendly product, and eco-friendly practice. Social support pursuit were found as marginal people support pursuit, emotional support pursuit, informational support pursuit, and problem-solving support pursuit. Apparel consumption behavior were found as planned purchase, social participation attitude, clothes recycling, life practice, low-price orientation, emphasis on designs, clothing-life practice, and consciousness over others. The environmental awareness attitudes of university students were classified into four groups of Consumers of Environment-Awareness, Consumers of Environment-interests, Consumers of Environment-practice, and Consumers of Low Environment-awareness. The groups showed significant difference in social support pursuit, and apparel consumption behavior. Gender of university students showed significant differences the environmental awareness attitudes, social support pursuit, and apparel consumption behavior. It is meaningful to find out the significant relationship in a social context between environment recognition and social support pursuit related by friends. This study also offered a basic information related to social support pursuit by the types of university students' environmental awareness attitude and consumption on clothing, which is necessary for environmental education and green consuming behavior.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.4
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• pp.172-178
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• 2006

In this paper, an advanced demand clustering algorithm which can explore the planned maintenance outage of generators in changed electricity industry is proposed. The major contribution of this paper can be captured in the development of the long-term estimates for the generation availability considering planned maintenance outage. Two conflicting viewpoints, one of which is reliability-focused and the other is economy-focused, are incorporated in the development of estimates of maintenance outage based on the advanced demand clustering algorithm. Based on the advanced clustering algorithm, in each demand cluster, conventional effective outage of generators which conceptually capture maintenance and forced outage of generators, are newly defined in order to properly address the characteristic of the planned maintenance outage in changed electricity markets. First, initial market demand is classified into multiple demand clusters, which are defined by the effective outage rates of generators and by the inherent characteristic of the initial demand. Then, based on the advanced demand clustering algorithm, the planned maintenance outages and corresponding effective outages of generators are reevaluated. Finally, the conventional demand clusters are newly classified in order to reflect the improved effective outages of generation markets. We have found that the revision of the demand clusters can change the number of the initial demand clusters, which cannot be captured in the conventional demand clustering process. Therefore, it can be seen that electricity market situations, which can also be classified into several groups which show similar patterns, can be more accurately clustered. From this the fundamental characteristics of power systems can be more efficiently analyzed, for this advanced classification can be widely applicable to other technical problems in power systems such as generation scheduling, power flow analysis, price forecasts, and so on.

• Journal of the Korean Home Economics Association
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• v.40 no.9
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• pp.127-141
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• 2002

This research aims to examine the influence of facilitative communication between mother and high school daughter on daughter's perceived family cohesion, family adaptability, and satisfaction of mother's working or non-working status. In order to verify statistically the research questions above, experimental tools were made for each variable, and Cluster Sampling with Stratification was conducted among high school girls in Seoul. A total of 670 questionnaire sheets were administered to 13 high schools for girls in December 2001, and only 501 sheets were used for data analysis. The SPSS 10.0 package was used for factor analysis, reliability analysis, multiple regression analysis. The following results were obtained: 1) Mother-high school daughter's facilitative communication significantly influences daughter's perceived family cohesion. In general, mother-high school daughter's facilitative communication had R square of 27.6% with regards to daughter's perceived family cohesion. 2) Mother-high school daughter's facilitative communication significantly influences daughter's perceived family adaptability. In general, mother-high school daughter's facilitative communication had R square of 25.3% with regards to daughter's perceived family adaptability. 3) Mother-high school daughter's facilitative communication significantly influences daughter's perceived satisfaction of mother's working of non-working status. In general, mother-high school daughter's facilitative communication had R square of 24.0% with regards to daughter's perceived satisfaction of mother's working status, and 7.4% with regards to non-working status.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.399-406
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• 2009

The goal of this research is to examine the influence degree of participant of sports on self-esteem of middle school students. By stratified cluster random sampling method 420, middle school student living in D city joined the survey; it was used to derive the result of this research. Among them, 25 results were excepted by the lack of reliability or un-enough answer rate, so 395 results were used for the research. To analyze collected data, used statistical technique statistical analysis technique frequency, factor analysis, t-test and ANOVA. Through such method of study and formality, this study deduced following result. First, self-esteem of middle school students shows change by the frequency of sports activity. Second, self-esteem of middle school students shows change by the interval of sports activity. Third, self-esteem of middle school students shows change by the intensity of sports activity.

• Journal of Convergence for Information Technology
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• v.11 no.9
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• pp.138-144
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• 2021

In the electronic component assembly business, when product defects occur, it is important to track incoming raw material defects or work defects, and it is important to improve suppliers or work sites according to the results. The core task of the smart factory is to build an integrated data hub to process storage, management, and analysis in real time, and to manage cluster processes, energy, environment, and safety. In order to improve reliability through accurate analysis and collection of production data by real-time monitoring of production site management for electronic parts-related small and medium-sized enterprises (SMEs), the establishment of a smart factory is essential. This paper was developed to be utilized in the construction by defining the system configuration method, smart factory-related technology and application cases, considering the characteristics of SMEs related to electronic components that want to introduce a smart factory.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.27-33
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• 2019

The purpose of this study was to explore the moderating effect of learning strategy levels on the relationship between academic grit and career development competence perceived by high school students. The sample for this study comprised 573 high school students, and data analysis was conducted mainly using reliability analysis, correlation analysis, K-mean cluster analysis, hierarchical regression analysis. The results of the study showed that the learning strategy levels moderated the relationship between academic grit and career development competence. This study suggest it is necessary to provide grit enhancement programs coupled with learning strategy levels in order to facilitate career development competence. The future studies need to explore the literature review for logical relationship between academic grit and career development competence, the qualitative approach for drawing on the theoretical models among the related variables, and the relational research to explore mediating or moderating effect of the individual backgrounds and related variables on the relationship between academic grit and career development competence.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.10
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• pp.231-238
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• 2019

Analyzing next-generation genome sequencing data in a conventional way using single server may take several tens of hours depending on the data size. However, in order to cope with emergency situations where the results need to be known within a few hours, it is required to improve the performance of a single genome analysis. In this paper, we propose a parallelized method for pre-processing genome sequence data which can reduce the analysis time by utilizing the big data technology and the highperformance computing cluster which is connected to the high-speed network and shares the parallel file system. For the reliability of analytical data, we have chosen a strategy to parallelize the existing analytical tools and algorithms to the new environment. Parallelized processing, data distribution, and parallel merging techniques have been developed and performance improvements have been confirmed through experiments.

• Journal of Internet of Things and Convergence
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• v.8 no.2
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• pp.55-59
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• 2022

Recently, IoT technology has great attention and plays a key role in 4^th industrial revolution in order to design customized products and services. Additive Manufacturing (AM) is applied to fabricate IoT sensor directly or IoT sensor embedded structure. Also, design methods for AM are developing to consolidate various parts of IoT devices. Part consolidation leads to assembly time and cost reduction, reliability improvement, and lightweight. Therefore, a design method was proposed to guide designers to consolidate parts. The design method helps designers to define product architecture that consists of functions and function-part relations. The product architecture is converted to a network graph and then Girvan Newman algorithm is applied to cluster the graph network. Parts in clusters are candidates for part consolidation. To demonstrate the usefulness of the proposed design method, a case study was performed with e-bike fabricated by additive manufacturing.

• Safety and Health at Work
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• v.11 no.4
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• pp.526-532
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• 2020

Background: The high incidence of work-related diseases and injuries among day-laborers and workers with no legal contracts (informal workers) has received the attention of the Thai authorities. Workers' low occupational health literacy (OHL) has been reasoned as one contributing factor. Absence of a valid tool has prevented assessment of informal workers' OHL. The aim of this study was to create a valid and reliable Occupational Health Literacy Scale within the context of Thai working culture (TOHLS-IF). Methods: This study used the mixed method approach to develop TOHLS-IF. Questions were generated using in-depth interviews and an extensive review of the literature. Experts' assessment confirmed the content validity of TOHLS-IF. The scales of its psychometric properties were assessed in a sample of 400 informal workers using cluster random sampling. Results: The final version of the TOHLS-IF comprises 38 items within 4 dimensions: Ability to Gain Access, Understanding, Evaluation, and Use of occupational health and safety information. Factor analysis identified items explaining 50.22% of the total variance. The final confirmatory analysis confirmed the model estimates were satisfactory for the construct. TOHLS-IF demonstrated a high internal consistency and satisfactory reliability (Cronbach's alpha = .98). Conclusion: The TOHLS-IF is a valid and reliable instrument to assess informal workers' OHL. The structural dimensions of this instrument are based on the concept of health literacy and Thai culture. Thai health professionals are encouraged to benefit from this instrument to assess their workers' OHL and apply findings as guidelines for effective occupational health and safety interventions.