• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.2
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• pp.92-98
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• 2017

Data clustering determines a group of patterns using similarity measure in a dataset and is one of the most important and difficult technique in data mining. Clustering can be formally considered as a particular kind of NP-hard grouping problem. K-means algorithm which is popular and efficient, is sensitive for initialization and has the possibility to be stuck in local optimum because of hill climbing clustering method. This method is also not computationally feasible in practice, especially for large datasets and large number of clusters. Therefore, we need a robust and efficient clustering algorithm to find the global optimum (not local optimum) especially when much data is collected from many IoT (Internet of Things) devices in these days. The objective of this paper is to propose new Hybrid Simulated Annealing (HSA) which is combined simulated annealing with K-means for non-hierarchical clustering of big data. Simulated annealing (SA) is useful for diversified search in large search space and K-means is useful for converged search in predetermined search space. Our proposed method can balance the intensification and diversification to find the global optimal solution in big data clustering. The performance of HSA is validated using Iris, Wine, Glass, and Vowel UCI machine learning repository datasets comparing to previous studies by experiment and analysis. Our proposed KSAK (K-means+SA+K-means) and SAK (SA+K-means) are better than KSA(K-means+SA), SA, and K-means in our simulations. Our method has significantly improved accuracy and efficiency to find the global optimal data clustering solution for complex, real time, and costly data mining process.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.71-81
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• 2016

The purpose of this study was to investigate the effect of ethical leadership on employees' behaviors (deviant behavior and personal initiative) and to explore the moderating roles of self-efficacy and trust in leader in the relationship between ethical leadership and employees' behaviors. This study developed four hypotheses and tested them using regression and hierarchical regression analyses. The results showed that the negative relationship between ethical leadership and deviant behavior and the positive relationship between ethical leadership and personal initiative were statistically supported. And this study found that self-efficacy and trust in leader played moderating roles in the relationship between ethical leadership and employees' behaviors. Based on the findings of the study, this study presented managerial implications and suggestions for future studies.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.647-653
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• 2017

The purpose of this study was to examine the moderating effect of perceived parental empathy in the relationship between self-esteem and adolescent depression. A sample of 437 adolescents completed self-report measures of self-esteem, depression and parental empathy. The collected data were analyzed by hierarchical regression analysis. As a result, parental empathy moderated relationship between self-esteem and depression. And awareness of emotion, empathic emotional reaction, and cold emotional reaction of father had moderating effect on the relationship between self-esteem and depression. In case of mother's empathy, cold emotional reaction and excessive emotional reaction had moderating effect on the relationship between self-esteem and depression. The significance of this study is to find out the important of parental empathy for depressive adolescents who are experiencing self-esteem of low level.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.635-645
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• 2017

The purpose of this study was to examine the moderating effect of perceived parental empathy in the relationship between adolescent depression and eat problem. For this purpose, we conducted a hierarchical regression analysis for 246 middle and high school boys in the K region. As a result, the relationship between eating problem and depression was controlled by parental sympathy. As a result of analyzing the moderating effects of sub- factors of parental sympathy, in the case of the father, awareness of emotion, cold emotional reaction, and excessive emotional reaction showed moderating effects. And in mothers, awareness of emotion, perspective taking, cold emotional reaction, and excessive emotional reaction moderated the relationship between eating problem and depression. It is significant that this study confirmed that the empathy of parents perceived by adolescents is a control variable to mitigate the adverse effects of depression on eating problems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.317-320
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• 2016

The NH-NongHyup network and servers were paralyzed in 2011, in the 2013 3.20 cyber attack happened and Classified documents of Korea Hydro & Nuclear Power Co. Ltd were leaked on December in 2015. All of them were conducted by a foreign country. These attacks were planned for a long time compared to the script kids attacks and the techniques used were very complex and sophisticated. However, no successful solution has been implemented to defend an APT attack thus far. Therefore, we will use big data analytics to analyze whether or not APT attack has occurred in order to defend against the manipulative attackers. This research is based on the data collected through ISAC monitoring among 3 hierarchical Korean defense system. First, we will introduce related research about big data analytics and machine learning. Then, we design two big data analytics models to detect an APT attack and evaluate the models' accuracy and other results. Lastly, we will present an effective response method to address a detected APT attack.

• Journal of Agricultural Extension & Community Development
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• v.20 no.1
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• pp.143-172
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• 2013

This study aimed at learning the effect of farmers' individual competency on the performance of agricultural organization, and providing the preliminary data about strengthening the competitiveness of agriculture of the country by showing the effect of farmers' individual competency on the performance of agricultural organization. According to the results of our study, among 11 individual competencies, the ability to manage, customer satisfaction, marketing, and getting information have the positive relationship with the performance of agricultural organization, but strategic thinking has the negative relationship with the performance. The relationship between the performance and abstract competencies like teamwork, creativity, innovation, feasibility, and flexibility is not statistically significant. However, the abstract competencies are the core competencies within farmers, so farmers should be educated continuously in the long run in order to raise the performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.9
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• pp.1120-1131
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• 2016

In this paper, we propose a smoker recognition algorithm, detecting smokers in a video sequence in order to prevent fire accidents. We use description-based method in hierarchical approaches to recognize smoker's activity, the algorithm consists of background subtraction, object detection, event search, event judgement. Background subtraction generates slow-motion and fast-motion foreground image from input image using Gaussian mixture model with two different learning-rate. Then, it extracts object locations in the slow-motion image using chain-rule based contour detection. For each object, face is detected by using Haar-like feature and smoke is detected by reflecting frequency and direction of smoke in fast-motion foreground. Hand movements are detected by motion estimation. The algorithm examines the features in a certain interval and infers that whether the object is a smoker. It robustly can detect a smoker among different objects while achieving real-time performance.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.247-252
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• 2021

The purpose of this study is to understand the mediating effect of grit in the relationship between academic achievement satisfaction and academic helplessness of middle school students. To this end, a survey was conducted on 575 middle school students in Changwon, Gyeongsangnam-do, on academic achievement satisfaction, academic helplessness, and grit. This research was carried out by hierarchical regression analysis was conducted to understand the correlation analysis and mediating effect between major variables, and verified by Sobel test. As a result of the study, First, correlation analysis revealed a positive correlation between academic achievement satisfaction, grit, and academic helplessness. Second, regression analysis showed that both perseverance of effort and consistency of interest were partially mediated between academic achievement satisfaction and academic helplessness. This means that academic achievement satisfaction not only directly affects middle school students' academic helplessness, but also has an indirect effect through grit. Finally, a learning counseling plans (Self-analysis program and Environmental control program) was discussed to reduce the academic helplessness of middle school students.

• Journal of The Korean Association of Information Education
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• v.23 no.3
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• pp.273-282
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• 2019

In this study, we have look through the national progress of computer science education in South Korea and analyzed the main subjects and contents of each period. We suggests the ways to evolve the current computer science education in terms of class hours for computer science education, hierarchical instructions, and the limitation of current national curriculum. In South Korea, it has been leaded the computer science education in the world since the it was promoted in earnest since 1995. Based on the recently revised national curriculum, South Korean government are taking efforts to nurture a leader through computer science education in terms of the students' future skills. However, it should be promoted to strengthen the ability of not only problem-solving ability through programming education, but also balanced computing and digital literacy through enhancing the ICT skills. In order to improve the curriculum of computer science education in elementary school of South Korea, a sufficient class hours of computer science education should be secured first.

• Journal of Broadcast Engineering
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• v.23 no.6
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• pp.886-895
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• 2018

In this paper, we introduce a technique to detect the video forgery by using the regularity that occurs in the video compression process. The proposed method uses the hierarchical regularity lost by the video double compression and the frame deletion. In order to extract such irregularities, the depth information of CU and TU, which are basic units of HEVC, is used. For improving performance, we make a depth map of CU and TU using local information, and then create input data by grouping them in GoP units. We made a decision whether or not the video is double-compressed and forged by using a general three-dimensional convolutional neural network. Experimental results show that it is more effective to detect whether or not the video is forged compared with the results using the existing machine learning algorithm.