• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3B
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• pp.274-287
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• 2009

In the Internet environment in which best-effort services are provided, we need to guarantee end-to-end performance rather than hop performance to provide services with a variety of QoS(Quality of Service) requirements. The end-to-end performance is affected by many factors along the path of traffic flow. Most existing simulation studies are concentrated on a single node or a few nodes. We need much different approach considering the simulation execution time to simulate a large-scale network. In this paper, we derive requirements and present methodologies for the implementation of the simulator to simulate it. Then, we design and implement our simulator using OPNET. Performance evaluation is carried out using the simulator for large-scale KII (National Information Infrastructure in Korea). We use a self-similar traffic model and present some results on the end-to-end performance metric for the networks.

• Korean Journal of Social Welfare Studies
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• v.49 no.1
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• pp.297-334
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• 2018

This study focused on accomplishment of successful life development after discharge a child-care facility even though they had a variety of diversity in hard environment on their own past. Furthermore the research analyzed expression progress and detail information of resilience effect on twenty healthy members of society, who lived theirselves for more than 10 years at out of chid-care centers, based on grounded theory methodology participants. As written in the result section of the study, using the paradigm model analysis showed that it was caused by 'Practical planning for the future', 'Organization of positive meaning' and 'Understanding in another's shoe'. The contextual condition appeared as 'Self examination, 'Seeking anchor as ontology' and 'Natural intimacy among family members'. The centralization phenomenon came in 'Living philosophy of internal stabilities'. The intervention condition appeared as 'Rise up through the world' and 'faith all the world'. The action-interaction showed up as 'Strict self-discipline' and 'Growing up own family'. The consequence appeared as 'Making social family' and 'Being a someone's social mentor'. This research shows discussion in depth based on above analyzed result.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.93-98
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• 2021

The change of programming language learning experience on learning motivation was analyzed. Learning a programming language is generally evaluated as a difficult process even for majors. Measuring psychological changes related to programming learning at this point in expanding to non-majors is necessary for learner analysis. The overall learner attitude change was investigated by measuring achievement goals, academic interest, academic self-efficacy, cognitive involvement, and academic self-regulation, which are motivation-related factors. All factors related to learning attitude showed a decrease in the post-test results. This result is interpreted that the difficulty of the learning process decreased the motivation to learn programming. It was found that the greater the difficulty perceived by the learner, the greater the decrease in the motivation to learn. Based on the results of this study, it has implications that a learning environment and learning process that can give feedback and a situation that can reduce the level of learning difficulty felt by learners should be systematically given.

• Environmental and Resource Economics Review
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• v.30 no.3
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• pp.503-533
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• 2021

This paper analyzes the relationships among the energy consumption, renewable energy production, real gross regional domestic product(GRDP), and greenhouse gas(GHG) emissions. It uses the metropolitan city and province level data for Korea from 2010 to 2018, employing a panal vector autoregressive(VAR) model. We find that an increase in energy consumption has a limited impact on boosting renewable energy production or gross regional domestic product, while it leads to an increase in greenhouse gas emissions. A rise in renewable energy production can increase gross regional domestic product, but it has no meaningful effects on energy consumption and the reduction of green house gas emissions. Our finding indicates that it is crucial to expand the supply of renewable energy as well as to decrease energy consumption in order to achieve the goal of reducing greenhouse gas emissions and reaching economic growth.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.419-428
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• 2021

Shadow removal plays a key role for the pre-processing of image processing techniques such as object tracking and detection. With the advances of image recognition based on deep convolution neural networks, researches for shadow removal have been actively conducted. In this paper, we propose a novel method for shadow removal, which utilizes self attention distillation to extract semantic features. The proposed method gradually refines results of shadow detection, which are extracted from each layer of the proposed network, via top-down distillation. Specifically, the training procedure can be efficiently performed by learning the contextual information for shadow removal without shadow masks. Experimental results on various datasets show the effectiveness of the proposed method for shadow removal under real world environments.

• Journal of Korean Public Health Nursing
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• v.35 no.1
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• pp.89-103
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• 2021

Purpose: This study examined the factors associated with depression among Korean graduate students. Specifically, personal (self-efficacy, stress), environmental (violence experience, economic state, and relationship conflict), and behavioral (health behavior) factors were analyzed. Methods: This study used a cross-sectional study design. One hundred and fifty participants currently enrolled in graduate programs were recruited. Google Drive was used for online data collection. Descriptive statistics, correlational analyses, and hierarchical regression analysis were conducted. Results: First, 52% of the participants were male, with an average age of 28.05(±3.19). Master's students comprised the largest proportion (63.3%). Approximately about 38.7% were engineering majors. Second, approximately 27.3% had depressive symptoms; and 7.3% had major depression. Third, there was a significant correlation between personal, environmental (financial burdens), and behavioral factors. Fourth, hierarchical regression analysis revealed a lower depression level to be associated with a higher self-efficacy level and health behavior. In contrast, a higher depression level was related to violence experience. Conclusion: The government should press on establishing rules on the prevention and regulation of violence in universities, and impose strong disciplinary measures to root out the problem. In addition, universities must pay attention to the mental health of graduate students and establish systems to manage them.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.299-305
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• 2019

The purpose of study was to investigate the effects of career decision efficacy, learning Flow, and academic achievement on department adaptation of dental hygiene students. The subjects of the study are self-administered surveys of 200 students who indicated their intention to participate. 181 questionnaires were analyzed using SPSS 18.0. The results of this study show that career decision efficacy, learning flow, academic achievement affect to major satisfaction, major confidences, major attachment. The results of this study show that career decision efficacy, academic achievement affect to major vision. Some dental hygienists students need support systems such as learning methods and educational environment that can improve academic achievement and learning commitment in order to help students adapt to their department. In addition, education and career support for career decision efficacy should be continuously maintained.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.23-28
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• 2019

A track type underwater construction robot(URI-R) which can trench on seabed is being developed by Korea Institute of Ocean Science & Technology. During the underwater trenching work, the robot is exposed high intensive noise and vibration so the underwater localization signal may not be obtained properly by the acoustic tracking system. Therefore it is necessary to research about continuous localization even though the measured position signal comes in intermittently. In this paper, the experiments were carried out on land to simulated the underwater operating environment characteristics. To estimate its position, inertial navigation system and global navigation satellite system are used. The effects of the period variation while localizing is investigated by the experiments, and the application for URI-R is proposed.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.353-361
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• 2018

The purpose of this study was to explore the lived experiences of university students who were placed under academic probation. A qualitative research design was used to understand the experiences of students. The data were collected using individual in-depth interviews with 4 students who had experiences of low academic achievements at least once during 5 semesters. Low self esteem was the main issue in this study and inner struggles were identified within 4 themes: Outstanding students controlled by helpers; A costume play as a outstanding student; Realize that I am a under academic achiever; Realize who I am and what I have to do. This study identified that low academic achievement brings to low self esteem seriously, however, human being has strong resilience in the traumatic circumstances. Thus, it is absolutely necessary devoting efforts to develop suitable student supporting programs in the way of inner and outer network systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.37-49
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• 2019

Recently, most companies are using information technology and its importance is emphasized daily. In an environment where technology is changing rapidly, organizations focus on making good use of reasonable information technology. However, having excellent human resources and reducing turnover is a problem for most organizations. Accordingly, job satisfaction is a factor that can reduce negative factors and enhance positive factors. Therefore, this study explored the factors that can improve job satisfaction. In this regard, this study conducted an empirical analysis on employees who work in small and medium-sized Korean enterprises. We focused on mobile instruction and mobile information sharing as reasonable factors that improve employee job satisfaction. In addition, we examined the effects of employee self-efficacy to increase the influence of reasonable mobile task instruction and mobile information sharing on job satisfaction. Through the results, this research suggests ways to improve employee job satisfaction in the field of small and medium-sized Korean enterprises. It also provides practical implications and discusses future research directions.