• Journal of the Korean Solar Energy Society
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• v.33 no.4
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• pp.39-45
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• 2013

This paper presents the estimation of minimum BESS capacity for regulating the output of wind farms considering power grid operating condition in Jeju Island. To analyze the characteristics of wind farm outputs with a BESS, the real data of wind farms, Sung-San, Sam-dal and Hang-Won wind farm, located in the eastern part of Jeju island is considered. The wind farms are connected to Sung-san substation to transfer the electric power to Jeju power grid. Consequently, at PCC (Point of Common Coupling), it can see a huge wind farm connected to the substation and thus it can be expected that the smoothing effect is affected by not only the different wind speeds for each area but also the different mechanical inertia of wind turbines. In this paper, two kinds of simulation have been carried out. One is to analyze the real data of wind farm outputs during a winter season, and the other is to connect a virtual BESS to eliminate the unintended generating power changes by the uncontrolled wind farm outputs as shown in the former data. In the conclusion, two kinds of simulation results show that BESS installed in the substation is more efficient than each wind farms with BESS, respectively.

• Journal of Internet of Things and Convergence
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• v.7 no.1
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• pp.55-62
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• 2021

The world is changing rapidly as the Internet spreads and various smart devices appear. High-performance PCs and high-speed communication networks are rapidly spreading in every home, and all kinds of the internet sites are emerging. In particular, the high education enthusiasm of Korean parents adds to this, and the ratio of the internet users among teenagers is exploding every day. In the case of adolescents, most of them use the Internet for online games, indicating that online games are the main cause of the internet addiction. This study was conducted using a questionnaire for male and female high school students using the Internet, and demographic and sociological characteristics were used only as basic data. In this study, as much as parents, students and teachers think, the results of the internet addiction type analysis according to academic achievement in humanities high school students are to be investigated to determine whether internet use has an effect on academic achievement.

• Journal of Information Technology Applications and Management
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• v.26 no.6
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• pp.29-46
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• 2019

This study analyzed the factors influencing the technology acceptance of the general public in the drones and ARs, one of the key technologies of the industry 4.0. The theoretical basis was the extended unified theory of acceptance and use of technology model(UTAUT2), which uses performance expectancy, effort expectancy, social influence, facilitating conditions, and hedonic motivation as factors common to both services. The price value factor was excluded considering that most ARs were free, and the perceived risk factors, including privacy, which were not in UTAUT2, were included because they are important factors for ICT technology acceptance. The hypothesis was tested by structure equation model. Social influence and hedonic motivation had a positive(+) effect on intention to use technology. On the other hand, in the case of effort expectancy, neither the AR nor the drone had a significant influence on intention to use technology. Furthermore, performance expectancy had a positive(+) effect on intention to use in AR, but no significant influence was found out in drones. On the contrary, in the case of the facilitating conditions, the influence of the drones was positive (+), but the relation of AR was not investigated. The perceived risk was tested for the negative (-) influence of use intention of AR, but no significant relationship was found out for the drones. Among the significant influencing factors, hedonic motivation was the most powerful factor in AR and drones. Theoretical and practical implications are presented based on these results.

• The Journal of Information Systems
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• v.20 no.4
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• pp.181-204
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• 2011

Recently, the development of ICT(information & communications technology) with the advent of new media paradigm shift in learning has brought a dramatic impact on the competitiveness of universities. The previous studies on the academic performance of e-learning mainly targeted on e-learning users, studying additional synchronization and system quality factors to measure academic performance. This study empirically analyzed the learning flow and academic performance considering both DeLone & McLean model system quality and synchronizing factors based on ARCS model. Relating to quality and synchronization factors, the academic performance of e-learning system was tested, and the difference between learning flow and academic performance was also analyzed based on time-series data, by the test difference(in the beginning, during, and final of the semester). The results of the study are as follows. First, the study shows that both system quality and synchronization directly affected the learning performance. Thus, when designing e-learning system, it is necessary to consider these two factors at the same time. Second, the indirectly mediating effect on the system quality and synchronization factors turned out to be significant in learning flow. Third, the result of regression analysis on the contents of utilizing dummy variable presents that the teacher's explanation has greater influence than multimedia has to the academic performance, and furthermore, the test difference showed no significance. Further research should be undertaken to consider the learner's degree of acceptance which reflects various aspects for building m-learning or u-learning.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.28 no.3
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• pp.79-87
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• 2022

Background: The purpose of this study was to examine the effect of transcranial direct current stimulation (tDCS) on the pain and balance of patients who receive total knee arthroplasty (TKA). Methods: This study subjects were 24 patients in Hospital T, located in Daegu, South Korea who received TKA after being diagnosed with degenerative arthritis. The subjects were randomly divided into and experimental group and a control group, with each group including 12 patients. Both group received superfical thermal therapy, interferential current therapy (ICT), and continue passive motion (CPM), which are conventional knee therapy on the knee joint. The experimental group received the tDCS treatment three times a week for three weeks, from October 1st to October 20th. The visual analogue scale and Wii Balance Board system were used to measure the pain and balancing ability, respectively, of both groups. In the statistical result analysis, to compare about pre and post test difference in each groups was accomplished. Statistical analysis of independent t-test and paired t-test were conducted using SPSS version 23.0. Results: After three weeks of intervation, there were significantly difference in balance ability in pre and post test in the tDCS group. VAS decreased significantly in both groups(p<.05), There was a significantly difference in pain, balance ability in the tDCS group compared to the sham group. Conclusion: These results indicate that applying tDCS together with conventional knee joint therapy for TKA patients is effective in promoting the patients' recovery.

• Journal of Distribution Science
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• v.14 no.11
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• pp.129-138
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• 2016

Purpose - The ICT(information and communications technologies) development is affecting consumer behaviors on selecting channel or distribution system. This study aims to advance our knowledge about the factors influencing omni-channel behaviors. This study considers the positive brand experience as the moderating variable into the relationship between omini-channel use intention and consumer brand relation. Also, the effect of positive brand experience on consumer-brand relation is researched. Research design, data, and methodology - This study conducted an empirical test with the subject as customers who purchase goods or service through on-off cross channel simultaneously. The research model is developed from prior literatures about influencing variables on channel selection. The structure of this study is designed to identify causal relationships between the variables. 268 survey data from the questionnaire survey which is conducted to target customers who use online and offline channels, is used for empirical analysis. This study validates generality with descriptive statistics and data reliability with Cronbach's alpha value. The exploratory factor analysis is used for value purification. Then, the confirmatory factor analysis is conducted for structural equation modeling. Finally, the execute structural equation modeling is analyzed to confirm the hypotheses Results - First, the two causal influences between perceived performance risk and the propensity of omni-channel and between price consciousness and the propensity of omni-channel are verified through the empirical test. Second, the result identifies that the propensity of omni-channel is influenced on consumer-brand relationship. Third, the AMOS analysis proves that the moderating variable, positive brand experience, has significant positive impact on consumer-brand relationship. This significant relationship is highly supported by the regression analysis between brand experience and propensity of omni-channel because it results that positive brand experience has positive impact on the propensity of omni-channel. All hypotheses are verified to be true. Conclusions - Based on the empirical result, this study confirms that perceived performance risk and price consciousness are the important factors influencing propensity of omni-channel. According to the additional analysis, the moderating variable and positive brand experience plays important role between the propensity of omni-channel and consumer-brand relationship. Furthermore, positive brand experience influences more on consumer-brand relationship than non-positive brand experience.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.322-331
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• 2011

Recently, the social issues such as low birth rate, an aging population has brought about decreasing labor productivity and productive population. To relieve these problems, the government has planned to set up smart working infrastructure and will raise the number of smart worker to around 30 percent of the total working population by 2015. This study scrutinizes to the meaning of smart working with the concepts of new work pattern and open innovation. The empirical analysis result shows 56.9% of SMBs thought a need for such system and 60.1% of them answered to adopt it. And the market related to smart working of SMBs will increase to 17.5% every year to the point that by 2014. It will be worth 1.54 trillion won and create up to 38,000 job positions. While prior researches on SMB suggested key drivers and guideline for innovation, this study gives some implications of impact and ripple effect of smart working as an innovation factor based on empirical analysis.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.83-98
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• 2016

This study attempted to test not only the influence of transformational leadership(TFL) on employees' unethical pro-organizational behavior(UPB), but also the mediating effect of organizational identification(OID) between TFL and employees' UPB. This study employed two research methods: literature review and empirical testing of the developed hypotheses. Data were collected through online questionnaire instruments from 229 employees working at companies in Korea. To test the hypotheses, structural equation modeling was employed. The model is shown as adequately fitting to the data. The results showed that there was not a positive and statistically significant relationship between TFL and employees' UPB, and OID played as a mediator in the relationship between TFL and employees' UPB. These findings provide a meaningful implication that the positive impact of TFL is linked to employees' UPB through OID.

• KIISE Transactions on Computing Practices
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• v.22 no.12
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• pp.687-692
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• 2016

The advent of Internet of Things(IoT) has increased the need for development of smart life based on Information and Communication Technology(ICT). By using IoT technology, we are able to control connected appliances using smart devices, such as smart phone. To support the smart life, there is a need to utilize emotion information for human behavior, based on both biorhythm and environment information. Research towards this goal suggests a smart lamp control system that has an effect on the human emotion. According to the PSI theory, the control system calculates the biorhythm with an algorithm that uses the human biorhythm, weather factors and walking amounts. The smart lamp works with the recommended color lights that can control the feelings and emotions of the user. Here, we will show the effect of physical and mental stability, health care, and accident prevention.

• Fashion & Textile Research Journal
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• v.23 no.5
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• pp.611-623
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• 2021

In the era of COVID-19 and advanced ICT technology, retail technologies such as those that use virtual reality(VR) have been drawing significant attention in the fashion industry. This study investigated the impact of shopping motivation and telepresence on consumer attitude, trust, and behavioral intentions in VR fitting room application environments. An online survey was conducted on female consumers in their 20s and 30s after exploring a VR fitting room application. Overall, 225 responses were used for the analysis. The study demonstrated that usefulness had a significant effect on attitude toward product (ATP) and trust toward app (TTA), while enjoyment had a significant effect on ATP, but did not significantly affect TTA. Telepresence did not significantly affect TTA, but had a significant influence on ATP and behavioral intention. TTA had a significant influence on ATP, and both ATP and TTA had significant effects on behavioral intention. Moreover, the effects of usefulness, enjoyment, and telepresence on ATP, TTA, and behavioral intention were significant, as the self-congruity between consumers and avatars increased. The application of the motivation theory and technology acceptance model offers theoretical perspectives for understanding VR fitting room application users' attitudinal and behavioral responses in mobile shopping environments. In addition, this study provides practical implications to mobile retailers that utilize advanced technologies.