• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.6
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• pp.39-47
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• 2012

As a scheme to efficiently reduce the effects of multipath fading in next generation wireless communication systems, cooperative communication systems have recently come into the spotlight. Since these cooperative communication systems use cooperative relays with diverse fading coefficients to transmit information, having all relays participate in cooperative communication may result in unnecessary waste of resources, and thus relay selection schemes are required to efficiently use wireless resources. In this paper, we propose an efficient relay selection scheme through self-learning in cooperative wireless networks using Q-learning algorithm. In this scheme, we define states, actions and two rewards to achieve good SER (Symbol Error Rate) performance, while selecting a small number of cooperative relays. When these parameters are well-defined, we can obtain good performance. For demonstrating the superiority of the proposed Q-learning, We compared the proposed scheme with Q-learning and a relay selection scheme with a mathematical analysis. The simulation results show that, compared to a scheme that obtains optimum relays through a mathematical analysis, the proposed scheme uses resources efficiently by using smaller numbers of relays with comparable SER performance. According to these simulation results, the proposed scheme can be considered as a good attempt for future wireless communication.

• Journal of Korea Multimedia Society
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• v.23 no.1
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• pp.93-101
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• 2020

Korea, as a leader of Internet and game sector in IT industry, has been playing an important role in increasing its industrial development. This country has won the first place in wireless broadband usage and contributed to Internet game industry development. This means that Korean use smartphones most. It is juveniles that use Internet and smartphones most among Korean who use teenage., the number of the teenagers who overuse smartphones or Internet has surpassed 200,000. The number of the adolescents who spend more time using smartphone and Internet is about 180,000 and the number of the teens who are over-dependent to smartphone having trouble living their lives is over 22,000. The SNS usage rate of the contents that teens are most likely to use has accounted for over 80 percent. Among teens, SNS is being considered as a major means that builds relationship due to smartphone technology and the prevalence of smartphones. However, the use of SNS among youths has two sides; one is positive, the other negative. Not only does SNS have a positive function that it keeps relationship but it also has a negative function that it can lead to smartphone addiction.

• Cartoon and Animation Studies
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• s.50
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• pp.453-478
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• 2018

Mobile learning, which provides educational services with a mobile platform, has been greatly expanding with the increasing spread of digital devices. The transition from PC-based online education to mobile-based education enables users to access online education anytime and anywhere. Despite this expansion of mobile learning, there is a lack of user-oriented content design. Therefore, this study intends to derive a measure to evaluate usefulness of the content design. We conducted a literature survey to reflect characteristics of existing measures, which evaluate usefulness and content of mobile learning. As educational mobile applications have both educational service and mobile device features, they can be representative of pedagogical usability criterion and can be divided into system and content areas to further develop effectiveness of learning. We conducted questionnaires on the use of these applications on 15 experts using the del phi technique. The analysis suggests the ease of use, learning efficiency, aesthetics, and ease of learning to be criteria of pedagogical usability. This study expects to serve as a basis to improve the usability of mobile learning users.

• The Mathematical Education
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• v.56 no.3
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• pp.319-340
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• 2017

The purpose of this study is to develop teaching and learning materials for the mathematics project inquiry subject. Since this subject is newly opened in the 2015 revised mathematics curriculum, there are no textbooks and materials. Hence it is required to help teachers plan lessons of the mathematics project inquiry subject. For this study, developing directions and objectives are established. Ten hours of lesson plan and teaching and learning materials are also developed for the two themes of 'big data' and 'industrial mathematics'. Suitability and validity of the developed material are verified positively from a survey of 8 teachers and 2 professionals. The detailed result findings are as follows. First, teaching and learning notes are suggested for each lesson plan. They are comprised of building inquiry plan, doing inquiry, summarizing results, and presentation. Second, driving questions of each theme are developed as "What is the big data and where is it used for ?" and "How various is the use of the industrial mathematics ?" respectively. Third, poster-types of each project product are developed. Fourth, three inquiry activity sheets and examples which are theme selection, inquiry plan, and group activity are developed. Fifth, 4 assessment sheets of self, peer, group, and teacher-use are developed.

• The Journal of Korean Association of Computer Education
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• v.14 no.1
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• pp.169-174
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• 2011

Recently, Korean government has, enacted "Individuals with Disabilities anti-Discriminatory Act" in 2008, and is actively promoting the law. However, it is still at its infancy in comparison to other advanced countries in terms providing access for all users. Educational digital contents offered through cyber home learning need to be universally designed to include all learners. This study, I have analyzed the accessibility of K cyber home learning contents using FAE tool, and the result showed low scores or failed for 'HTML Standards', 'Scripting' and the 'Text Equivalents.' To assist digital contents' accessibility, UDL 7 principles could be use to improve accessibility and universality for learner-centered designs. Use of UDL will include learners with and without disabilities to learn from educational digital contents.

• International Journal of Contents
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• v.13 no.3
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• pp.25-31
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• 2017

With tremendous advancement of information and communication technologies, mobile learning systems have been widely adopted in language learning contexts, and several frameworks have been developed for identifying and categorizing different factors of mobile-assisted language learning (MALL). However, pre-existing frameworks have limitations when evaluating the importance level of criteria. The purpose of this study is to develop a comprehensive hierarchical framework for identifying and categorizing success factors of MALL and prioritizing them according to the importance level. To do that, AHP method is used to quantitatively estimate weight values of MALL criteria. Results reveal that the priority of MALL criteria is ordered as follows: content, system, learner, language learning. Local weights of each criterion are also analyzed; for example, usefulness, accuracy, and authenticity are critical factors for improving MALL contents. Ease of use and mobility of MALL systems are also considered more critical than other systematic factors. In addition, availability of immediate feedback and self-directness has the highest weight values of importance. The findings of the study are discussed regarding hierarchical orders of MALL criteria and conclude that successful MALL implementation may be achieved if related elements are diversely measured and evaluated. Pedagogical implications and suggestions for further research are also presented.

• ETRI Journal
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• v.42 no.5
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• pp.686-699
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• 2020

In this paper, we propose a supervised-learning-based spatial performance prediction (SLPP) framework for next-generation heterogeneous communication networks (HCNs). Adaptive asset placement, dynamic resource allocation, and load balancing are critical network functions in an HCN to ensure seamless network management and enhance service quality. Although many existing systems use measurement data to react to network performance changes, it is highly beneficial to perform accurate performance prediction for different systems to support various network functions. Recent advancements in complex statistical algorithms and computational efficiency have made machine-learning ubiquitous for accurate data-based prediction. A robust network performance prediction framework for optimizing performance and resource utilization through a linear discriminant analysis-based prediction approach has been proposed in this paper. Comparison results with different machine-learning techniques on real-world data demonstrate that SLPP provides superior accuracy and computational efficiency for both stationary and mobile user conditions.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.932-940
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• 2017

This study investigated the perception of pre - service teachers in order to find out how paper textbooks are used in high school classes and what improvement is needed. Firstly, the results of analyzing the perception about the utilization of textbooks are as follows. First, in the case of Korean language, social studies, mathematics, science, and English, textbooks were used most frequently, and most of the respondents did not use textbooks for arts and physical education subjects. Secondly, Korean language, social studies, mathematics, science, and English textbooks are most frequently used as teaching materials. Third, in the case of Korean, social, mathematics, science, and English subjects, in addition to textbooks, problem collections were used most frequently and arts and physical education subjects showed the most use of prints. Next, the results of analyzing the perception of the improvement method of the textbooks are as follows. First, in the high school class, the response rate was high in that Korean, social, mathematics, science, and English classes needed a textbook. Most of the respondents answered that they were not necessary for the textbooks of arts and physical education subjects. Second, in order to improve the textbooks, the most demanding textbooks focused on the core basic contents, followed by self - directed learning activities, competency centered contents selection, cooperative learning activities, and teacher self - development. The demand for digital textbooks was low.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.4
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• pp.549-567
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• 2011

The purpose of this study was to analyze and to compare the use of illustrations of the elementary practical arts textbooks and to make suggestions for an improvement of the use of illustrations in elementary practical arts textbooks. It is expected that the results of this study can be used by textbook developers, publishers, and teachers in their efforts to improve the quality of elementary practical arts textbooks. For the study, 'Units of Raising Animals' in the sixth grade practical arts textbooks in Korea was selected and analyzed according to the three criteria: kinds of illustrations, sizes of illustrations and purposes of illustrations. In this study, the following facts were found. First, 2007 revised practical arts textbooks have about 5.2 illustrations per page whereas 7th practical arts ones have 4.2. Second, even though 2007 revised practical arts textbooks are highly dependent on photographs, kinds of illustrations of 2007 revised practical arts textbooks have more ratio of pictures, cartoons and diagrams than the ones in the 7th practical arts textbooks. Third, sizes of illustrations of the 2007 revised practical arts textbooks are ordered in small, medium, large size illustrations and there was an increase in medium sized illustrations. Lastly, the purpose of the illustrations from the 2007 revised practical arts textbooks are on the decrease the supply of learning materials but there was an increase in the learning motive induction and guidance for experiment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.7-14
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• 2021

The emergence of the automated smart grid has become an essential device for responding to these problems and is bringing progress toward a smart grid-based society. Smart grid is a new paradigm that enables two-way communication between electricity suppliers and consumers. Smart grids have emerged due to engineers' initiatives to make the power grid more stable, reliable, efficient and safe. Smart grids create opportunities for electricity consumers to play a greater role in electricity use and motivate them to use electricity wisely and efficiently. Therefore, this study focuses on power demand management through machine learning. In relation to demand forecasting using machine learning, various machine learning models are currently introduced and applied, and a systematic approach is required. In particular, the GP learning model has advantages over other learning models in terms of general consumption prediction and data visualization, but is strongly influenced by data independence when it comes to prediction of smart meter data.