• The Korean Journal of Health Service Management
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• v.11 no.4
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• pp.115-132
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• 2017

Objectives : The purpose of this study was to investigate the depressive change and predictors of chronic illnesses and to examine whether depressive change predictors are different according to chronic disease types. Methods : Data from the 1st to the 10th year of the Korean Welfare Panel of 5,023 adults over 20 years of age who were treated for chronic diseases for more than three months were examined. We assessed demographic, sociological, and socioeconomic factors including depression predictors of chronically ill patients, and analyzed the data using latent growth modeling and multiple group analysis. Results : Depression symptoms of chronically ill patients gradually decreased, showing a linear relationship across time. In addition, multiple group analysis was performed for each type of chronic disease. Conclusions : We described the phenomenon of depression in chronically ill patients, and discussed the practical and policy interventions required to improve depression in chronically ill patients.

• Journal of Korea Foundry Society
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• v.36 no.6
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• pp.208-214
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• 2016

Casting defects, which are closely related to entrapped air bubbles and metallic oxides, occur very frequently in the casting process. Many researchers have shown that these defects can be reduced by adopting an appropriate gating system design. But, it is difficult for field engineers to identify a specific gating system that is more appropriate for their products. In this study, we tried to draw a comparison of gating system designs with and without ceramic foam filters. A ceramic foam filter was added to the horizontal runner just after the sprue to prevent air bubble generation and to reduce turbulence without change of the gating system design. To verify the effects of initial pouring velocity, the experiment was conducted with four different amounts of water volume in the reservoir. Results of the water modeling experiment applying the filter showed remarkably changed flow characteristics. Although the study confirmed that use of the filter may change the flow characteristics, it needs to be noted that only filter use alone cannot solve all the problems caused by a poorly designed gating system.

• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.117-122
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• 2003

Modeling and synthesis of novel hydroxyethyl 2-iminothiazolines were carried out through molecular modification of lead compound, 2-phenyliminothiazolines 1, for the purpose of development of new fungicidal agrochemicals. Oxygen atom of the hydroxyethyl group in 2-iminothiazolines 3 would locate in the proximity of the imino carbon at C-2 of 2-iminothiazoline moiety through neighboring group participation, and so that it would affect the biological activity of the molecule. Reaction of $\gamma$-chloroacetoacetanilides 5 with hydroxyethylureas 6 gave 29 kinds of new corresponding hydroxyethyl 2-iminothiazolines 3 in high yields.

• Bulletin of the Korean Space Science Society
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• 2006.10a
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• pp.58-58
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• 2006

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.958-965
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• 2003

The rapidly changing business environment has required cooperation and coorduiation among functional units n organizations which should Involve group decision-making processes Although many group derision-making support tools and methods have provided the collaborative capabilities for organizational members, they often lack features supporting the dynamic complexity issue frequently occurring at group decision-making processes This study proposes system dynamics modeling as a group decision-making support tool to deal with the group derision-making tasks having properties of dynamic complexity in terms of cognitive fit theory.

• Journal of the Korea Society for Simulation
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• v.12 no.1
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• pp.49-58
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• 2003

There have been growing recognition on the needs of coordination of diverse activities across cross-functional business areas necessarily involving group decision-making processes. Although many group decision-making support tools and methods have been introduced to enable the collaborative processes of group decision-making, they often lack features supporting the dynamic complexity issues. This study proposes system dynamics modeling approach based on simulation techniques to deal with the group decision-making tasks having properties of dynamic complexity.

• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.10-17
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• 2007

The purpose of this study is to reduce the group bully phenomenon of mildly mentally retarded(MR) students in middle schools. Video digital contents have been developed and applied to the class. As a result, the normal students' perception of MR students has improved drastically. Especially in the case of students who appeared in the film; their perception has changed a lot more than the students who didn't. Also, the students showed a tendency to recognize the scenes that were produced intentionally by the researcher In conclusion, it is effective to alter a student's attitude through the self-modeling video contents. Particularly, the self-modeling video contents that made by researcher's precise educational goal are more effective on the alteration of the students' perception and behaviors.

• Journal of the Korean Magnetics Society
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• v.17 no.6
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• pp.259-264
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• 2007

This paper describes the mathematical modeling method for the static magnetic field signature generated by a magnetic scale model. we proposed the equivalent dipole modeling method utilizing a singular value decomposition technique from magnetic field signatures by magnetic sensors are located special depths below the scale model. The proposed dipole modeling method was successfully verified through comparisons with the real measured values in our non-magnetic laboratory. Using the proposed method, it is possible to predict and analyze static magnetic field distributions at any difference depths generated from the real ships as well as a scale model ship.

• Research in Mathematical Education
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• v.25 no.2
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• pp.99-115
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• 2022

This study examined difficulties middle school students have in learning mathematics and proposed a flipped classroom consisting of Khan Academy activities, small-group problem solving, and mathematical modeling to help improve their learning. A mixed-method approach was used to identify difficulties students have in learning mathematics, explore how the flipped classroom helped them reduce the learning difficulties identified, and examine if there were differences in students' mathematics achievement and their affective characteristics after participating in the flipped classroom. Qualitative analyses showed that students had difficulties in understanding mathematical concepts and finding effective ways to learn as well as negative views towards learning mathematics. This study also found that each activity of the flipped classroom had a different impact on student learning. Before class, the Khan Academy activities were most likely to help students understand mathematical concepts. In class, small-group problem solving activities were most helpful for students who had trouble finding effective learning methods and environments. Mathematical modeling activities were most likely effective in changing students' negative views towards mathematics. A quantitative analysis showed that the flipped classroom not only significantly improved the students' mathematics achievement, but also positively affected their confidence and motivation and how much they valued learning mathematics.

• Journal of The Korean Association For Science Education
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• v.40 no.6
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• pp.611-620
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• 2020

The purpose of the study is to find creativity factors of students in the process of small group modeling and relate them to the types of interactions among students. In order to capture students' detailed interactions, this study was conducted as an 'essential case study' through qualitative analysis. We have developed the modules of nine lessons about terraforming, and they were used in an actual classroom. In order to understand the creativity of the students in the process of modeling, students' discourses and interview data were analyzed using 19 creative factors or abilities. The findings are as follows. Frequently found creativity factors are Elaboration, Evaluation, Visualization, Resist premature closer, Originality, Analysis and Concentration. And students' interactions that affect students' creativity in the process of modeling can be classified into four categories: Suggestion, Agreement, Questioning, Refutation, and Conversion. Through each interaction, students demonstrated the process of expressing and modifying their own thoughts and ideas in the modeling process. The findings of the study suggest that it is important to the teachers to understand types of interactions among students and the relationship between the types of interaction and creativity factors for students' creative modeling in modeling-based learning.