• Journal of Korea Multimedia Society
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• v.21 no.10
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• pp.1182-1194
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• 2018

The Dynamic Adaptive Streaming over HTTP(DASH) is envisioned to evolve to meet an increasing demand on providing seamless video streaming services in the near future. The DASH performance heavily depends on the client's adaptive quality selection algorithm that is not included in the standard. The existing conventional algorithms are basically based on a procedural algorithm that is not easy to capture and reflect all variations of dynamic network and traffic conditions in a variety of network environments. To solve this problem, this paper proposes a novel quality selection mechanism based on the Deep Q-Network(DQN) model, the DQN-based DASH Adaptive Bitrate(ABR) mechanism. The proposed mechanism adopts a new reward calculation method based on five major performance metrics to reflect the current conditions of networks and devices in real time. In addition, the size of the consecutive video segment to be downloaded is also considered as a major learning metric to reflect a variety of video encodings. Experimental results show that the proposed mechanism quickly selects a suitable video quality even in high error rate environments, significantly reducing frequency of quality changes compared to the existing algorithm and simultaneously improving average video quality during video playback.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.69-79
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• 2015

As the distribution rate of a smart phone which can actualize even augmented reality is getting higher, the application scope of a smart phone is sharply increasing. However, in spite of various functions of it, there is still lack of learning app. Mobile equipments can bring no spatial-temporal restriction of learning to a learner, but they can tempt a learner into inappropriate spaces. In this sense, learning app is necessarily needed to motivate and keep learner's inner desire. This thesis suggested considerations when learning mobile app is designed by analyzing motivation strategy of ARCS Theory and UI of web based contents. Also, a design method of mobile learning app was suggested based on a procedural model of mobile learning app adapting ARCS Theory.

• Korean Security Journal
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• no.58
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• pp.137-154
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• 2019

Conflict management within a police organization is one of the most significant areas from the organization management point of view. This study aims to explore procedural entrepreneurship of police mangers when they face difficulties in their workplaces. Adopting a case study strategy, this study examines real cases from three police agencies from Japan, the US, and South Korea. Interviewing police officers from theses different countries, six main themes are identified: (1) the pervasiveness of hierarchical authority, (2) procedural conflict, (3) organizational cultures, (4) the origin of their values and assumptions, (5) characteristics of the strategy, and (6) organizational learning. Research findings pointed out that there were more similarities than differences among the three cases, such as the pervasiveness of hierarchical authority, the significance of informal networks, and characteristics of informal networks. The main finding was that police managers used informal networks in order to overcome the procedural conflicts regardless of their nationality. All the participants relied on informal communications to raise the adaptability and survivability of their organizations. It was found that the Asian culture and American culture respectively permeated the three police agencies, supporting the role of informal networks in the formal organizations. This presents a paradox which well reflects the reality of organizations: informality within formality.

• The Journal of Korean Association of Computer Education
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• v.19 no.1
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• pp.101-109
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• 2016

Designing algorithms is a very important learning process in computational thinking education because it requires learner's logical and procedural thinking. But the case studies that have topics of algorithms learning and students' types of errors in learning algorithms are not enough. So the purpose of this study is to analyze students' errors that discovered in the process of learning three control structures of programming using flowchart and provide types of errors in designing algorithms. Results about tests of three types of control structures in university student's algorithms learning class showed different cases of types of errors; types of sequential control error are not presented in the class, types of conditional control error are presented in the case of setting the conditions of nested conditional control, and types of iterative control are showed in the many cases of iterative conditions, statements of single and nested iterative control structure. The results of study will be a good case study about teaching designing algorithms of computational thinking education in elementary, secondary school and university.

• Journal of the Korean Society of Earth Science Education
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• v.3 no.1
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• pp.18-27
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• 2010

The purpose of this study is to investigate effects of instruction with stories on elementary school students' science learning and memory. For the purpose, this researcher sampled 3 classes in their 3th grade from an elementary school. Out of the three classes, two were designated as the comparative group consisting of 70 students and the other, the experimental group, 32 students. The former group was applied instruction treatment under the 7th national curriculum of education. The other group was instructed with a story book that contained stories students already knew which were somewhat rearranged to comply with contents of a relevant curricular course. Results of the study can be described as follows. First, academic achievement test was made immediately after the treatment to show that the experimental group was significantly higher in scores for memory and understanding in the section of 'Finding Constellations' that the other group. Second, the two groups' academic achievements in relation to the section, 'Finding Constellations' were tested 3 months after the treatment to show that the experimental group was significantly higher in scores for memory and understanding than the comparative group. Such achievements within the groups were tested 3 months after the treatment to find that both of the two groups didn't show statistically significant differences.

• Electronics and Telecommunications Trends
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• v.34 no.4
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• pp.43-54
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• 2019

Currently, a majority of artificial intelligence is used to secure big data; however, it is concentrated in a few of major companies. Therefore, automatic data augmentation and efficient learning algorithms for small-scale data will become key elements in future artificial intelligence competitiveness. In addition, it is necessary to develop a technique to learn meanings, correlations, and time-related associations of complex modal knowledge similar to that in humans and expand and transfer semantic prediction/knowledge inference about unknown data. To this end, a neural memory model, which imitates how knowledge in the human brain is processed, needs to be developed to enable knowledge expansion through modality cooperative learning. Moreover, declarative and procedural knowledge in the memory model must also be self-developed through human interaction. In this paper, we reviewed this essential methodology and briefly described achievements that have been made so far.

• Journal of the Korea Society of Computer and Information
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• v.19 no.9
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• pp.185-196
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• 2014

This study has analyzed the learning objectives in 6 Informatics textbooks that were published this year in the basis of 2009 revised curriculum using Anderson's taxonomy of Educational Objectives that was a revision of Bloom's taxonomy and Fuller's taxonomy that was presented for programming activities. Some dimensions of Anderson's taxonomy, such as conceptual and procedural knowledge, understand and apply in cognitive process are much more used in learning objectives in 6 Informatics textbooks. Interpreting and producing dimensions of taxonomy are well presented to balance in 6 Informatics textbooks by analysis of Fuller's taxonomy. This results will be a good case study in research about taxonomy of educational objectives and development of Informatics textbooks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.2
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• pp.503-523
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• 2022

Nowadays, many attendance applications utilise biometric techniques such as the face, fingerprint, and iris recognition. Biometrics has become ubiquitous in many sectors. Due to the advancement of deep learning algorithms, the accuracy rate of biometric techniques has been improved tremendously. This paper proposes a web-based attendance system that adopts facial recognition using open-source deep learning pre-trained models. Face recognition procedural steps using web technology and database were explained. The methodology used the required pre-trained weight files embedded in the procedure of face recognition. The face recognition method includes two important processes: registration of face datasets and face matching. The extracted feature vectors were implemented and stored in an online database to create a more dynamic face recognition process. Finally, user testing was conducted, whereby users were asked to perform a series of biometric verification. The testing consists of facial scans from the front, right (30 - 45 degrees) and left (30 - 45 degrees). Reported face recognition results showed an accuracy of 92% with a precision of 100% and recall of 90%.

• Journal of The Korean Association For Science Education
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• v.35 no.4
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• pp.565-572
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• 2015

The purpose of this paper is to offer an analysis on the research trends of web-based inquiry learning effectiveness in science education, and to present suggestions for future studies. This study compiled data on 43 articles in Korea and international journals. The content analysis of articles published were from academic journals related to science education and educational technology from 2000 to 2014. The results are as follows: Among domestic articles, the participants ranged from school children to high school students. On the contrary, among foreign articles, the participants are centralized on secondary school students; most used experimental studies; most of the studies resulted with web-based inquiry learning in science education showing effectiveness on science learning performance or science inquiry ability; all web-based inquiry learning were designed using different models of teaching and learning, with the result in the case of domestic research, the utilized models refer to the STS learning model, Internet utilization problem-center inquiry learning model, Procedural model, while in the case of overseas research, the utilized models are SCY, IBLE, and TESI model. Implications of the findings are then discussed, which implies considerations for further research related to web-based inquiry learning.

• Journal of the Korean earth science society
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• v.25 no.3
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• pp.194-204
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• 2004

The purpose of this literature review is to investigate what kinds of research have been done about scientific inquiry in terms of scientific argumentation in the classroom context from the upper elementary to the high school levels. First, science educators argued that there had not been differentiation between authentic scientific inquiry by scientists and school scientific inquiry by students in the classroom. This uncertainty of goals or definition of scientific inquiry has led to the problem or limitation of implementing scientific inquiry in the classroom. It was also pointed out that students' learning science as inquiry has been done without opportunities of argumentation to understand how scientific knowledge is constructed. Second, what is scientific argumentation, then? Researchers stated that scientific inquiry in the classroom cannot be guaranteed only through hands-on experimentation. Students can understand how scientific knowledge is constructed through their reasoning skills using opportunities of argumentation based on their procedural skills using opportunities of experimentation. Third, many researchers emphasized the social practices of small or whole group work for enhancing students' scientific reasoning skills through argumentations. Different role of leadership in groups and existence of teachers' roles are found to have potential in enhancing students' scientific reasoning skills to understand science as inquiry. Fourth, what is scientific reasoning? Scientific reasoning is defined as an ability to differentiate evidence or data from theory and coordinate them to construct their scientific knowledge based on their collection of data (Kuhn, 1989, 1992; Dunbar & Klahr, 1988, 1989; Reif & Larkin, 1991). Those researchers found that students skills in scientific reasoning are different from scientists. Fifth, for the purpose of enhancing students' scientific reasoning skills to understand how scientific knowledge is constructed, other researchers suggested that teachers' roles in scaffolding could help students develop those skills. Based on this literature review, it is important to find what kinds of generalizable teaching strategies teachers use for students scientific reasoning skills through scientific argumentation and investigate teachers' knowledge of scientific argumentation in the context of scientific inquiry. The relationship between teachers' knowledge and their teaching strategies and between teachers teaching strategies and students scientific reasoning skills can be found out if there is any.