• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.186-188
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• 2014

In recent years, domestic as well as LTE wireless network of Wi-Fi and most used. In addition, mobile-intensive services that used mainly in our society makes it easier, SNS, application (APP), and file downloads. As such, the amount of data requested, while living at the time of mobile users will want to be safe from the earliest. And the wireless network communications mortality (3G, 4G (LTE), LTE-A) and Wi-Fi (802.11 n-2.4 G H z z H a c-5, 802.11 G), and users are mainly used in the death 4G (LTE), communication Wi-Fi, 802.11 n-2.4 GHz are used most frequently. As above, use the wireless network in order to safely and quickly developed the technology of the Li-Fi. Li-Fi light (visible light) technology to communicate with, and Wi-Fi (802.11 n-2.4 G z H) 100 times faster, LTE-A 66 times faster. However, the current Li-Fi to commercialise the big issue exists. In this paper, there are a lot of existing problems in the commercialization of Li-Fi being used in Wi-Fi, and a comparative analysis.

• Communications of Mathematical Education
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• v.33 no.3
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• pp.207-229
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• 2019

In the era of the Fourth Industrial Revolution, various attempts have been made to incorporate ICT technology into mathematics teaching and learning, and the necessity and efficiency of classroom instruction using flipped learning, virtual reality and augmented reality have attracted attention. This leads to an increase in demand for instructional contents and their use in education. Therefore, there is a growing need for the development of instructional contents that can be applied in the field and the study of teaching methods. In this point of view, this research classifies the types of teaching-learning, presents the flipped learning instruction and mathematics contents by teaching-learning types using constructivist mathematics education principles and augmented reality-based mobile applications. These methods and lesson plans can provide a useful framework for teaching-learning in mathematics education.

• Communications of Mathematical Education
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• v.33 no.3
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• pp.231-254
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• 2019

As the teacher-centered education is transformed into learning-centered education, the active knowledge construction of learner becomes important. Along with this change, project-based learning is receiving attention. However, there are many problems to apply the results of research to pre-service teachers because most of the previous studies have focused on elementary middle high school students. Therefore, this study examined the changes in perceptions of pre-service mathematics teachers while project-based learning progressed for one year. Pre-service mathematics teachers had less experience with project-based learning than group discussions, group activities. Also their perceptions was classified as five factors: 'Instructional effects', 'Application and participant of project-based learning', 'Achievement', 'Diffusion of project-based learning', 'Student motivation'. Pre-service mathematics teachers responded positive changes in perception that project-based learning could be motivated to students but they responded negative changes in perception that project-based learning could be distributed to school. They responded positive changes in perception that teachers can show their achievements by project-based learning but they responded negative change in perception that teachers would be fun to apply project-based learning. Also, they responded positive changes in perception that teachers and students were easy to apply or utilize project-based learning.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.179-184
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• 2019

In many countries, such as developing countries where electricity is scarce, small wind turbines in the form of Off Grid are an effective solution to solve power supply problems. In some countries, the expansion of power systems and the decline of electricity-intensive areas have led to the use of small wind power in urban road lighting, mobile communications base stations, aquaculture and seawater desalination. With this change, the size of the small wind power industry is expected to have greater potential than large-scale wind power. In the case of small wind power generators, the generator is controlled at a variable speed, and the voltage and current generated by the generator have many harmonic components. To solve this problem, the AC to DC converter to be studied in this paper is a three-phase step-up type converter with a single switch. The inductor current is controlled in discontinuous mode, and has a characteristic of having a unit power factor by eliminating the harmonic of the input current. The proposed converter is composed of LCL filter and three phase rectification boost converter at the input stage and a single phase full bridge for grid connection. It is a control system with energy storage system(ESS) that the system stabilization can be pursued against the electric power.

• Communications of Mathematical Education
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• v.33 no.1
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• pp.1-19
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• 2019

This study deals with the case of student-centered discrete mathematics class with cyber lab. First, we provided lecture notes and cyber labs we developed. In particular, discrete mathematics is a course that covers the principles of algorithms. The purpose of this study is to provide students with basic mathematics, aiming to actively participate in the learning process, to improve their abilities and to reach the ultimate goal of student success with confidence. Second, based on interactions, students were able to prepare for the lectures, review, question, answer, and discussion through an usual learning management system of the school. Third, all the students generated materials through one semester, which were reported, submitted, presented and evaluated. It was possible to improve the learning effectiveness through the discussions and implementation of using some easy open source programming language and codes. Our discrete math laboratory could be practiced without any special knowledge of coding. These lecture models allow students to develop critical thinking skills while describing and presenting their learning and problem-solving processes. We share our experience and our materials including lecture note and cyber lab as well as a possible model of student-centered mathematics class that does not give too much of work load for instructors. This study shares a model that demonstrates that any professor will be able to have an individualized, customized, and creative discrete education without spending much of extra time and assistant, unlike previous research.

• Communications of Mathematical Education
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• v.33 no.1
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• pp.21-34
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• 2019

The purpose of this paper is to investigate the differences of the mathematics anxiety and mathematical achievement of high school students according to math socialization, and to find out which mathematics anxiety causes have more influence on mathematical achievement and how much it is. For this purposes, the problem of this study as follows: firstly, are there any relationship among mathematical grades, mathematics anxiety, interest and math socialization? secondly, are there any math socialization mathematics predict to mathematical grades, mathematics anxiety, interest? lastly, are there any differences in the mathematical grades, mathematics anxiety, interest according to math socialization level? The subjects of this study consist of 479 students selected for a class of unit, in high schools located in Seoul and metropolitan area, Korea. In this study, for students math socialization, Jung(2002)'s scale was used. Mathematical anxiety & interest, Huh(1996)'s Mathematics Anxiety Scale was used. The collected data were analyzed by using the 24.0 SPSS program. The data were also tested by using the t-test, pearson correlation and multiple regression. The major results of this study were as follows: firstly, math socialization, mathematics anxiety, interest and mathematical grades have significantly related each other, secondly, the multiple regression analyses demonstrated that sub factors of math socialization were the significant predictors of mathematical grades, mathematics anxiety and interest, lastly, mathematics grades, and mathematical anxiety and interest have significant differences depending on math socialization.

• Communications of Mathematical Education
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• v.32 no.4
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• pp.495-517
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• 2018

This paper is based on the effects of Zone of Proximal Development and scaffolding theory of social constructivist, Russian psychologist Vygotsky. He insisted that a social interaction play a fundamental role in the development of cognition. This study is to examine the efficient of the scaffolding types in Math class. The ZPD is the distance between a student's ability to perform a task under adult guidances or with peer collaboration and the student's ability solving the problem independently. To conduct the research was grouped into an experimental first grader five students in H high school in Y county. After class, students were questioned through Semi-structured interviews. The results of this study are below. First, Students were satisfied with the class mixed micro-scaffolding types and Macro-scaffolding types and improved their math thinking ability and the ways of solving problems. Second, The results of the class showed that students' ability to perform a task was transferred to the higher level through the help of a teacher or peers. Students could have more time to listen to peers' opinions and to say their own thoughts freely than they were under the lecture method instruction. Third, Students were interested in math through the experimental class. That's because the appropriate help of the scaffolding type, a cooperate study, relative with real life, using an engineering tools. They made a change of perception.

• 재활복지
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• v.20 no.1
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• pp.131-150
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• 2016

This study aims to compare global policies on ICT accessibility and to suggest possible solutions that help to enhance ICT accessibility for socially disadvantaged groups. The results indicated that related laws and standards in Korea are relatively well established than Asian countries' whereas they need improvements when compared to the US or the UK. Particularly, in spite of rapid development in information communication technology industry, incorporating the definition of newly developed technologies into existing laws related to ICT accessibility seemed slow that caused reluctancy of related parties to address accessibility issues the new technologies create. In addition, Korean government seems less effortful to develop policies and standards apart from web and mobile application accessibility. In order to resolve the problems, firstly, the period or process of enacting and amending laws can be shorten. Next, a government affiliated research institute can be established to do research and develop ICT accessibility related to user scenarios so that effective policies and standards could be readily provided. Even though other possible solutions can be suggested, what is more important than that is that any interested parties should sustainably make efforts to provide equal opportunities for the underserved populations.

• 한국노년학
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• v.30 no.1
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• pp.31-47
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• 2010

The purpose of this study is to analyze communication topics in Journal of Korean Gerontological Society from 1980 to 2009. Out of all published over one thousand articles, 54 articles were selected by content analysis. The published time, the number of authors, the author's institutions, type of communication and media, methodologies, and so on were analyzed for this study. The conclusion of this study are as follows; First, the articles regarding on communication published only one throughout in 1980's. However, the articles have been gradually published since 1990's. Second, the authors came mainly from universities especially those who are engaged in social welfare field. Third, the types of communication are concentrated on group communication. Interestingly enough, it is found that mass communication such TV, magazine, and internet were analyzing in-depth. Telephone is one of most important mediated human communication media. On the contrary, mobile phone and computer were researched on not for the usage but for the education purposes. Forth, in methodologies, authors are used mainly survey method and selected content analysis in all media research. In conclusion, the scholars of gerontology and communications should co-operate and help each other to promote aging and communication field.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.1-13
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• 2018

The number of deaths in Korea is higher than the OECD average. Therefore, an e-Call system is being developed as a vehicle ICT-based emergency rescue system that automatically detects an accident in the event of a vehicle accident and transmits related information to the center. In order to overcome the limitations of social acceptability and function of e-Call system, we propose a model that allows users to be aware of the necessity of service voluntarily. We predicted the market share of e-call services according to the proposed business model and analyzed it through B/C analysis. Benefits are calculated on a penetration basis, and device purchase and communications costs are calculated for each period. B/C analysis shows that pessimistic scenarios are 0.98 in 2025 and 1.01 in 2030. In an optimistic scenario, it is 1.05 in 2025 and 1.20 in 2030, which is more economical.