• ETRI Journal
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• v.38 no.5
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• pp.911-921
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• 2016

This paper presents the description, practical implementation, and stability analysis of a recently proposed, energy-efficient, medium access control protocol for wireless sensor networks, ALOHA-Q, which employs a reinforcement-learning framework as an intelligent transmission strategy. The channel performance is evaluated through a simulation and experiments conducted using a real-world test-bed. The stability of the system against possible changes in the environment and changing channel conditions is studied with a discussion on the resilience level of the system. A Markov model is derived to represent the system behavior and estimate the time in which the system loses its operation. A novel scheme is also proposed to protect the lifetime of the system when the environment and channel conditions do not sufficiently maintain the system operation.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.1
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• pp.34-42
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• 2019

Ten AOC(Air Operation Certificate) holders certified by MOLIT of Korea are operating their own maintenance training program. Though the maintenance training program is approved by the same authority, the contents of the program are different even in the mandatory training courses among AOC holders. The survey interview showed that the maintenance training in mandatory training should have the same contents and requirements. Throughout the survey and focus group discussion, this paper suggests the list and contents of the initial mandatory training and the list, contents and interval for the recurrent mandatory training. This paper also suggests how to implement the on-line training program for recurrent mandatory training to keep the quality of the airline maintenance training program.

• Research in Mathematical Education
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• v.21 no.1
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• pp.35-46
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• 2018

In this perspective paper, we present seven elements of the appropriate educator mindset for teaching in the constructivist elementary mathematics classroom. The elements include supporting students as they construct their own understanding, eliminating deficit view of slow learners, setting new understanding and growth as the learning objective, providing opportunities to co-construct meaning with peers, using student contributions as the source of curricular material, encouraging all students to participate in learning, and providing instruction not bounded by time. In our struggles to provide authentic, inclusive elementary classrooms, we hope that our discussion of the educator mindset can increase discourse on constructivism from philosophy to practice in the community of mathematics education and policy makers.

• Steel and Composite Structures
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• v.31 no.5
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• pp.427-435
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• 2019

The estimation of moment and rotation in steel rack connections could be significantly helpful parameters for designers and constructors in the initial designing and construction phases. Accordingly, Extreme Learning Machine (ELM) has been optimized to estimate the moment and rotation in steel rack connection based on variable input characteristics as beam depth, column thickness, connector depth, moment and loading. The prediction and estimating of ELM has been juxtaposed with genetic programming (GP) and artificial neural networks (ANNs) methods. Test outcomes have indicated a surpass in accuracy predicting and the capability of generalization in ELM approach than GP or ANN. Therefore, the application of ELM has been basically promised as an alternative way to estimate the moment and rotation of steel rack connection. Further particulars are presented in details in results and discussion.

• Smart Media Journal
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• v.11 no.11
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• pp.63-74
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• 2022

Nowadays, lithium-ion battery has become more popular around the world. Knowing when batteries reach their end of life (EOL) is crucial. Accurately predicting the remaining useful life (RUL) of lithium-ion batteries is needed for battery health management systems and to avoid unexpected accidents. It gives information about the battery status and when we should replace the battery. With the rapid growth of machine learning and deep learning, data-driven approaches are proposed to address this problem. Extracting aging information from battery charge/discharge records, including voltage, current, and temperature, can determine the battery state and predict battery RUL. In this work, we first outlined the charging and discharging processes of lithium-ion batteries. We then summarize the proposed techniques and achievements in all published data-driven RUL prediction studies. From that, we give a discussion about the accomplishments and remaining works with the corresponding challenges in order to provide a direction for further research in this area.

• Educational Technology International
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• v.12 no.1
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• pp.1-20
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• 2011

The study described in this paper examined the effectiveness of a multimedia case-based learning environment to teach technology integration to Korean pre-service teachers. The structure and philosophy behind the use of embedded video in an online, multimedia system and the data collected from 103 pre-service teachers are presented and discussed. The overall finding shows that there was no significant difference from pre- to posttest among the lecture, the case-based, and the mixed environment groups. However, low prior knowledge students improved more when they learned about technology integration with the mixed method than with the case-based method alone. Discussion about this result and its educational implications conclude the paper.

• Journal of KIISE:Software and Applications
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• v.32 no.4
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• pp.327-334
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• 2005

Recently, ICT has emerged as an indispensable tool for teaching a variety of subjects in education systems. In this paper, we examine the effect of the instructional models for ICT on the practical ability in the application of information with relation to the levels of self-regulated learning strategies. Students were divided into 3 groups, according to the instructional model for ICT which were problem search learning, problem solution learning, and discussion learning. As an experimental tools, we did pretest using self-regulated learning strategies measurement questionnaire and did pretest and posttest using practical ability in the application of information measurement questionnaire. The results show that higher level of self-regulated teaming strategies group has high practical ability in the application of information than lower level group. Other interesting results are also provided.

• Archives of design research
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• v.16 no.3
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• pp.5-14
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• 2003

This study attempted to explore the guidelines for designing the contents of on-line learning in design field. The studies on the characteristics of design education and design major students as well as the guidelines for on-line learning were also reviewed. The guidelines for designing the contents of distance learning in design field were suggested through the synthesis and analysis of the former studies and the characteristics of design education and the learning style of Korean students. It could be concluded that the considerations were categorized into the following factors; quality of instruction, quality of presentation technique, quality of interaction, quality of evaluation and other surrounding factors. The finding can be used as a helpful guideline for the instructors of the design field who start on-line learning.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.451-460
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• 2010

The purpose of this paper is to present the effective operation method of cyber home learning system 2.0. Cyber home learning system 2.0 which plays an important role to produce and share data of internet users establishing user-centered internet environment is recently introduced as web 2.0 is beginning to appear. This research is based on the case of the operation on cyber home learning system, research literature of web 2.0 as well as expert consulting and performance test. After doing this research, cyber home learning system 2.0 can bring enormous educational effect when it has online education using web-based discussion tool and long distance consulting linking with off line school education. Redundant system configuration, the distributed processing also may be provided by the service was smooth. Moreover, it demands monitoring team consisting of student, parents and teacher in order to provide developmental service.

• Journal of The Korean Association of Information Education
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• v.11 no.3
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• pp.379-387
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• 2007

The purpose of the study was to explore the correlation between in-degree and out-degree centrality Social Network Indices and cognitive and affective learning outcomes measures in an e-Learning environment. Results indicate both the out-degree and in-degree centrality indices are correlated with the cognitive learning outcome measures only. Further, results of the follow-up multiple regression analyses describe the cognitive learning outcome would be predicted by both the in-degree centrality (52%) and out-degree centrality (8%). A discussion is provided to interpret the results and limitations are specified.