• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.123.2-123.2
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• 2012

We investigate the solar flare occurrence rate and daily flare probability in terms of the sunspot classification supplemented with sunspot area and its changes. For this we use the NOAA active region data and GOES solar flare data for 15 years (from January 1996 to December 2010). We consider the most flare-productive eleven sunspot classes in the McIntosh sunspot group classification. Sunspot area and its changes can be a proxy of magnetic flux and its emergence/cancellation, respectively. We classify each sunspot group into two sub-groups by its area: "Large" and "Small". In addition, for each group, we classify it into three sub-groups according to sunspot area changes: "Decrease", "Steady", and "Increase". As a result, in the case of compact groups, their flare occurrence rates and daily flare probabilities noticeably increase with sunspot group area. We also find that the flare occurrence rates and daily flare probabilities for the "Increase" sub-groups are noticeably higher than those for the other sub-groups. In case of the (M+X)-class flares in the 'Dkc' group, the flare occurrence rate of the "Increase" sub-group is three times higher than that of the "Steady" sub-group. Our results statistically demonstrate that magnetic flux and its emergence enhance the occurrence of major solar flares.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.123-132
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• 2021

Malicious activities of Botnets are responsible for huge financial losses to Internet Service Providers, companies, governments and even home users. In this paper, we try to confirm the possibility of detecting botnet traffic by applying the deep learning model Convolutional Neural Network (CNN) using the CTU-13 botnet traffic dataset. In particular, we classify three classes, such as the C&C traffic between bots and C&C servers to detect C&C servers, traffic generated by bots other than C&C communication to detect bots, and normal traffic. Performance metrics were presented by accuracy, precision, recall, and F1 score on classifying both known and unknown botnet traffic. Moreover, we propose a stackable botnet detection system that can load modules for each botnet type considering scalability and operability on the real field.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.2
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• pp.123-138
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• 2019

The hat on the back of the upper jacket in Scythian, in of northern region surrounding the Black Sea, is described as a typical woolen hood, but until now has been overlooked in Korean costume studies. The purpose of this study is to analyze the hat on the upper jacket in Scythians and to recognize the meaning of the hat. A further purpose is to complete the basic framework of research concerning the Scythian costume by adding the part that was overlooked previously As for the research method, we collected literature, previous research results, the exhibition catalog, and the related artifacts for analysis. The literature was collected at the German Archaeological Research Institute. The analysis of artifacts was based on data collected by the researchers at the Heremitage Museum in Russia and data was taken by the staff of the Heremitage Museum. The conclusions of this study are as follows: Among the artifacts in the northern region of the Black Sea, it was perviously believed that Scythians status was signified by the wearing of hat-tops. Regardless of age, warriors and knights all wore upper jackets with hats, so it appears that the people who are active wore upper jackets with hats. On the other hand, it was assumed that the royal family, who wore ornamented, colorful, and decorative hats were not observed to have worn upper jackets with hats, and therefore did not require a hat. Therefore, it is considered that the hat in the Scythian society was a costume element emphasizing practicality, not necessarily a class symbol.

• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.123-130
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• 2022

Recently, studies on the detection and classification of Android malware based on API Call sequence have been actively carried out. However, API Call sequence based malware classification has serious limitations such as excessive time and resource consumption in terms of malware analysis and learning model construction due to the vast amount of data and high-dimensional characteristic of features. In this study, we analyzed various classification models such as LightGBM, Random Forest, and k-Nearest Neighbors after significantly reducing the dimension of features using PCA(Principal Component Analysis) for CICAndMal2020 dataset containing vast API Call information. The experimental result shows that PCA significantly reduces the dimension of features while maintaining the characteristics of the original data and achieves efficient malware classification performance. Both binary classification and multi-class classification achieve higher levels of accuracy than previous studies, even if the data characteristics were reduced to less than 1% of the total size.

• The Journal of the Acoustical Society of Korea
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• v.26 no.3
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• pp.123-128
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• 2007

This Paper Presents new transient signal classification algorithms for underwater transient signals. In general. the ambient noise has small spectral deviation and energy variation. while a transient signal has large fluctuation. Hence to detect the transient signal, we use the spectral deviation and power variation. To classify the detected transient signal. the feature Parameters are obtained by using the Wigner-Ville distribution based eigenvalue decomposition. The correlation is then calculated between the feature vector of the detected signal and all the feature vectors of the reference templates frame-by-frame basis, and the detected transient signal is classified by the frame mapping rate among the class database.

• Journal of The Korean Association For Science Education
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• v.37 no.1
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• pp.113-123
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• 2017

The purpose of this study is to investigate engineering students' attitude toward convergence and relevance with engineering education accreditation, gender, and academic year and attitude toward convergence. To be specific, fist, we examined whether the instrument for measuring attitudes toward convergence were reliable and valid for engineering students. Second, we compared levels of attitudes toward convergence in terms of engineering education accreditation, gender and academic year. Third, latent classes, which were distinguished in terms of attitudes toward convergence, were identified. Participants were 2076 engineering students. By using factor analysis and Rasch analysis, validity and reliability of instrument measuring attitudes toward convergence were confirmed. The differences in attitude toward convergence in terms of engineering education accreditation experience, gender, and academic year were examined by independent t-test and ANOVA. There were significant differences in attitude towards convergence in terms of engineering education accreditation, gender, and academic year. Students who experience engineering education accreditation program and male and high academic year have higher levels of attitude toward convergence than others. Lastly latent class analysis (LCA) was conducted to identify subgroups underlying engineering students in terms of attitude toward convergence and five latent classes were identified. In addition, the chi-square results showed that there were significant relationships between identified latent classes and engineering education accreditation, gender, and academic year. Based on these results, engineering education considering students' characteristics and diversity in attitude toward convergence were discussed.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.123-137
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• 2004

The study on traffic assignment is actively being performed which reflect networks status using time. Its background is increasing social needs to use traffic assignment models in not only hardware area of road network plan but also software area of traffic management or control. In addition, multi-class traffic assignment model is receiving study in order to fill a gap between theory and practice of traffic assignment model. This model is made up of two, one of which is multi-driver class and the other multi-vehicle class. The latter is the more realistic because it can be combined with dynamic model. On this background, this study is to build multidynamic model combining the above-mentioned two areas. This has been a theoretic pillar of ITS in which dynamic user equilibrium assignment model is now made an issue, therefore more realistic dynamic model is expected to be built by combining it with multi-class model. In case of multi-vehicle, FIFO would be violated which is necessary to build the dynamic assignment model. This means that it is impossible to build multi-vehicle dynamic model with the existing dynamic assignment modelling method built under the conditions of FIFO. This study builds dynamic network model which could relieve the FIFO conditions. At the same time, simulation method, one of the existing network loading method, is modified to be applied to this study. Also, as a solution(algorithm) area, time dependent shortest path algorithm which has been modified from existing shortest path algorithm and the existing MSA modified algorithm are built. The convergence of the algorithm is examined which is built by calculating dynamic user equilibrium solution adopting the model and algorithm and grid network.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.5
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• pp.123-139
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• 2023

Incubating future social entrepreneurs is of increasing importance for governments and industries that aim to create positive social changes through innovative, market-based solutions. Considering the distinct and challenging nature of a social entrepreneurial career, prior research has explored various antecedents of the formation of social entrepreneurial intention. The current research aims to contribute to the literature by examining social class as a potential precursor of individuals' social entrepreneurial intention formation, with a specific focus on social entrepreneurial identity aspiration as the underlying psychological mechanism and communal narcissism as the contingent factor. Using a two-wave survey data collected among 144 potential entrepreneurs from South Korea, we tested a moderated mediation model to validate the research propositions. The findings can be summarized as follows. First, lower social class was associated with higher social entrepreneurial identity aspiration. Second, when communal narcissism was high(low), the negative relationship between social class and social entrepreneurial identity aspiration was stronger(weaker). Third, communal narcissism moderated the negative impact of social class on social entrepreneurial intention via its effect on social entrepreneurial identity aspiration. This study has significant implications on several fronts. First, we explore the motivations that drive individuals from lower-class backgrounds to participate in social entrepreneurship, going beyond the previous notion that a higher-class context promotes entrepreneurial pursuits. Second, we delve into the underlying mechanism and condition that influence the formation of social entrepreneurial intentions, highlighting the pivotal roles played by social entrepreneurial identity aspiration and communal narcissism. Our findings provide practical insights for institutions seeking to foster the involvement of prospective social entrepreneurs from lower-class backgrounds, thereby generating positive outcomes for marginalized communities.

• Korean Journal of Childcare and Education
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• v.3 no.2
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• pp.123-146
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• 2007

This study has attempted to suggest an assistant model for systematic child care accreditation. This has been carried out from the current consciousness of such needs for child care accreditation as large regional disparity in assistant level, no indication to definite contents and method of assistance, demand for assistant professionals with intensified capacity and requirement for the support of financial and human resources. Six stages of assistant process: the stage of establishment and management of preparation class, the stage of application for assistance and consultation, the stage of assistant meeting, the stage of workshop and observation to exemplary institutions, and the stage of practical application and evaluation of visiting assistance have been suggested. Particularly in order to improve the efficiency of assistance, organization of a committee of expert advisors in each area has been indicated. For the guideline of assistant management, operation of preparation class for accreditation, security of assistant committee members, provision of systematic training and assistant manual, development of supervision program and financial support have been suggested. This assistant manual will contribute to systematic and efficient conduct of assistance program of child care accreditation.

• Journal of Korean Elementary Science Education
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• v.24 no.2
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• pp.123-129
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• 2005

The purpose of this study was to investigate the interaction patterns between teachers and students appeared in sixth grade elementary science lessons. To this end, we set research questions as what are the types of SPS (Social Participation Structure) between teachers and students in the class. Eighteen elementary science lessons were observed. Data were collected by video recordings and observation method. The result showed that the types of SPS were classified into nine. 1) A teacher initiates the whole students into interaction with him. 2) The whole students keep silent or carry out specific activities under the teacher's direction. 3) A teacher initiates some students into interaction. 4) A teacher names specific students to read a text. 5) A teacher initiates the whole students into group interactions. 6) Students interact with each other irrespective of the teacher's intention. 7) Students initiate a teacher into interactions with them. 8) A teacher intervenes during the students' activities and this intervention, in turn, produces interactions between the teacher and the students. 9) A teacher directs the whole class to read a learning goal or a learning material. This study shows that SPS-1 and SPS-3 are the most frequently observed interaction patterns in the elementary science lessons.