• Journal of Korean Association for Spatial Structures
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• v.24 no.1
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• pp.65-72
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• 2024

This paper aims to advance our understanding of extensible beams with multiple cracks by presenting a crack energy and motion equation, and mathematically justifying the energy functions of axial and bending deformations caused by cracks. Utilizing an extended form of Hamilton's principle, we derive a normalized governing equation for the motion of the extensible beam, taking into account crack energy. To achieve a closed-form solution of the beam equation, we employ a simple approach that incorporates the crack's patching condition into the eigenvalue problem associated with the linear part of the governing equation. This methodology not only yields a valuable eigenmode function but also significantly enhances our understanding of the dynamics of cracked extensible beams. Furthermore, we derive a governing equation that is an ordinary differential equation concerning time, based on orthogonal eigenmodes. This research lays the foundation for further studies, including experimental validations, applications, and the study of damage estimation and detection in the presence of cracks.

• Journal of The Korean Association For Science Education
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• v.21 no.2
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• pp.289-298
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• 2001

The effect of the instructional approach that asked students to check their problem-solving processes through a paired think-aloud problem solving after presenting molecular-level pictures and a four stage-problem solving strategy was investigated. Four high school classes (N = 191) were randomly assigned to St group (using Strategy individually), SL group (Solver Listener), St-SL group (using Strategy-Solver Listener), and control group. Although the test scores of the St-SL group on strategy performing ability were significantly higher than those of the control group, there was not significant difference for the scores in the multiple-choice algorithmic problems. Regarding the subcategories of strategy performing ability test, students' ability of understanding given of problems and deriving the proper physical quantity was improved, but their ability of setting up subgoals and reviewing their solving process was very low. The preference to the strategy of the St-SL group was more positive than that of the St group.

• Journal of Digital Convergence
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• v.9 no.3
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• pp.249-260
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• 2011

This study aimed to develop a problem-based learning model for mind study based on the insight into a general problem-based learning and contemplation of mind study. Focusing on the main stages commonly regarded important in precedent studies on problem-based learning process, the procedures were designed as follows: 1) choosing a text 2) setting a goal for learning 3) developing a problem 4) preparing a set of learning materials 5) developing an assessment tool 6) designing a plan for teaching and learning. The content and range of the stages were presented and how the main activities should be conducted was also discussed in a main body. These procedures were specified through examples of problem-based learning on the subject of 'mind'. It also suggested how to play a role of teacher as a guide or coach with presenting various examples of teacher talk and specific activities for learners to keep the intention of primary problem-based learning by performing a set of procedures.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.370-373
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• 2006

Lastly, the problem of filling occurs in the process of concealed joint of adjacent components and was seen in joints between the structure and an electrical or mechanical device. Therefore, the dry processing which replaces wet joint was seen in joints between the structure and a door, ones between the structure and a finishing materials, ones between a gypsum board and electrical device, and ones between a water pipe and a tile finishing. And a process of separating the area of jointed parts in order to eliminate the problem of overlap was seen in joints between a door and a finishing material and ones between a gypsum board on the ceiling and a light. Lastly, an analysis of a process of exposing concealed parts indicated that the problem of filling could be applied to joints between the structure and an electrical or mechanical device and ones between a finishing material and a mechanical device. This study sought out methods to apply Environment Friendly Multi Housing Remodeling that allow easy remodeling as part of environment- preserving policies. It also contains basic data useful to implement long-life houses in the future by presenting a comprehensive design standard for them

• Journal of Korean Association for Spatial Structures
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• v.13 no.2
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• pp.93-99
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• 2013

Korea has been striving for the development of the nation in various aspects. It will also have to make an effort for its continued development in the future. The problems of low-income groups that occur in those processes cannot be simply ignored now. It is needed to provide an equal opportunity to low-income groups so that they can be part of the society. The cycle of economic problem should be disconnected through this process. Farm-Housing is one of the solutions to this problem. Its purposes are not only to provide residence in the complex, but to gain income through various activities, such as production, distribution and consumption, and solve part of the economic problems of the people living in the Farm-Housing. To sell the products of Farm-Housing, the neighboring cities need to be designated as a hinterland. For this reason, Farm-Housing needs to be located in the suburban area of large cities. However, the current laws and policies make it difficult to construct Farm-Housing in suburban areas. Presenting plans to solve such problem is the purpose of this paper.

• Journal of Korean Elementary Science Education
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• v.39 no.1
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• pp.84-99
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• 2020

The purpose of this study is to develop a STEAM program using technological pedagogical and content knowledge (TPACK) model to effectively utilize technology to solve the difficulties in the teaching of 'structure and function of our body' unit in the primary science curriculum and to confirm the effect on the academic achievement, creative problem solving ability and scientific interests of elementary students. The program was developed as the STEAM program of the 8th class by utilizing the construction knowledge of the TPACK model. The developed program was applied to 29 experimental group students in 5th grade. And the textbook-oriented circulatory system learning program was applied to 29 5th graders in the same school. As a result of the application of the program, the experimental group showed significant improvement over the comparison group in its creative problem solving ability and scientific interests, and the satisfaction of the class was also high. This caused a positive effect on students because the process of self-directing information about the circulatory system using smart devices, making outputs creatively using 3D printers, and presenting them through role play using produced outputs.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.2
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• pp.35-47
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• 2004

Though P2P network systems are widely used, not so much research has been done on security issues. One of the serious problem in P2P network is the authentication problem. To resolve this problem, we introduce a new concept, a "self-reputation system" in which a user manages her own reputation. We define self-reputation systems by presenting several requirements. We also give one instance of self-reputation system. The proposed instance satisfies the requirement including the prevention of erasing and the platform independence.ependence.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.100-105
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• 2021

This study examines the effectiveness of the study through a case of PBL(problem-based-learning) class conducted in a balanced culture course called at 00- University in the second semester of 2020. The effects of learning are as follows: First, PBL(problem-based-learning) has sufficient active interaction between the teacher and the learner. In the face of prolonged non-face-to-face learning, the PBL teaching method has sufficient interaction between the professors-learner and the learner. Second, PBL learning can actively utilize various problems that fit the characteristics of the subject and actively utilize the process of role sharing and collaboration. By presenting various problem situations suitable for the subject, students will be able to share roles individually or as a team, and fully experience the process of collaboration and discussion in the process of investigating the data. Third, critical perceptions of problem situations can be extended. In modern times, a variety of problem situations arise and critical perceptions of them must be fully learned. In a mass production and mass consumption society, students should develop the ability to blindly recognize and distinguish between real and fake information in a flood of information. The limitations identified in this class case are, first, the nature of the subject, "Understanding Culture and Philosophy," which makes it possible to discuss the global cultural phenomenon, but it should be discussed in terms of philosophy. Second, it is not easy to work as a team on non-face-to-face online. Nevertheless, PBL is a very effective method of learning in which active interactions and learning activities take place between professors and students, whether face-to-face or face-to-face online learning.

• Human Ecology Research
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• v.60 no.2
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• pp.187-209
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• 2022

The objective of this study was to conduct a 'Theory of Home Economics Education' class using online problem-based learning(PBL) for prospective home economics(HE) teachers. The aim was to enable teachers to analyze the learning experience in the classroom, and to prepare operational strategies for online PBL on this basis. In order to achieve this, online PBL was applied to 31 students participating in the 'Theory of Home Economics Education' at the Department of HE in a university in Seoul, and the results were collected from the learning process. This also involved a reflective journal, a survey on the learning experience and the impacts was conducted. Moreover, analysis was undertaken on the learning activities, learning difficulties, and improvements. The main research results are as follows. Firstly, students accessed Webex, an online video conferencing program, and performed two PBL tasks: 'Making Home Economics Promotion Materials' and 'Presenting Teaching Strategies to Improve Learner's Immersion in Online Classes'. Secondly, learners established their own identity of HE learned about the HE class plans themselves. They also encountered realistic experience as HE teachers and learned communication and collaboration skills. Furthermore, they acquired creative problem-solving and self-directed learning ability, community consciousness, as well as the attitude of consideration and respect. Thirdly, students lacked knowledge of learning content and encountered difficulty in solving data research, analysis processes, and unstructured problems. They were affected by a lack of time and encountered problem in communicating with other team members in an online environment. As an improvement in online class operation, it was considrered necessary to reduce the learning burden by securing time and reducing the number of assignments, as well as to explain active interaction with instructors and PBL.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.1
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• pp.67-86
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• 2013

The purpose of this study is to analyze selection of factors of Schoenfeld's problem solving behavior shown in problem solving process of mathematically gifted students based on brain preference of the students and to present suggestions related to hemispheric lateralization that should be considered in teaching such students. The conclusions based on the research questions are as follows. First, as for problem solving methods of the students in the Gifted Education Center based on brain preference, the students of left brain preference showed more characteristics of the left brain such as preferring general, logical decision, while the students of right brain preference showed more characteristics of the right brain such as preferring subjective, intuitive decision, indicating that there were differences based on brain preference. Second, in the factors of Schoenfeld's problem solving behavior, the students of left brain preference mainly showed factors including standardized procedures such as algorithm, logical and systematical process, and deliberation, while the students of right brain preference mainly showed factors including informal and intuitive knowledge, drawing for understanding problem situation, and overall examination of problem-solving process. Thus, the two types of students were different in selecting the factors of Schoenfeld's problem solving behavior based on the characteristics of their brain preference. Finally, based on the results showing that the factors of Schoenfeld's problem solving behavior were differently selected by brain preference, it may be suggested that teaching problem solving and feedback can be improved when presenting the factors of Schoenfeld's problem solving behavior selected more by students of left brain preference to students of right brain preference and vice versa.