• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.9-12
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• 2003

This paper describes a step-by-step method to minimize design iterations in a process of product design change. In the design process, two components are coupled if a change of a component can require the other components change, and design iterations are generated by the coupling. The design iteration is one of main factors that increase design effort. In this study, three matrices are used to solve the design iteration of automatic transmission lever, Requirement-Engineering matrix, Engineering-Components matrix, and DSM(Design Structure Matrix). Firstly, with the DSM, the product architecture and conceptual design process are proposed from product function analysis. Secondly, with the QFD, the Requirement-Engineering matrix and Engineering-Components matrix present the relationship among customer requirements, engineering issues, and product components. Lastly, the results of the QFD analysis are used in the DSM to solve the component interactions and to provide design

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.171-174
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• 2004

Superalloys with many strengthening alloying elements are frequently used in powder form to alleviate harmful effects of alloy segregation. HIP (hot isostatic pressing) and DB (diffusion bonding) as a form of solid-state bonding process is often used to make turbine components, such as integrated turbine rotors. HIP/DB process requires many technical overcomes related to dimensional changes as well as microstructural control. In this research, HIP/DB process for nickel base superalloys, Udimet 720, were investigated with a view to control the dimensional change during the consolidation process. Simple disc-shaped cans were used to select the conceptual die design for the control of the dimensional change especially in radial direction. The change in the shape of consolidated shape was investigated using commercial FE code with constitutive equations for low temperature plasticity and creep deformation.

• Spatial Information Research
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• v.10 no.4
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• pp.515-532
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• 2002

Planning Support System (PSS), an alternative framework of computer-aided planning system combining geographic information system (GIS), urban models, and visualization tools, has been actively researched and applied in many developed countries. This paper introduces a PSS-based land use change model, What if\ulcorner PSS, by applying it to Chongju City, Korea. This model application study used the spatial database, Restricted Development Zone (RDZ), and other hypothetical land supply- and demand-related policies of Chongju City. The collaborative PSS model supported land use planning process by helping users to speedily and easily create and test policy-oriented scenarios. The study found that the fully operational PSS model was readily applicable and useful to Korean local land use planning. The paper discusses the conceptual model framework, data requirement, application process, model output, and practical usage. This study would be considered as a prototypical approach of PSS-based land use plan making for Korean cities.

• Journal of Gifted/Talented Education
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• v.23 no.2
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• pp.237-256
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• 2013

The purpose of this study is to develop program that take a genuine interest in science and motivate students to keep up their study for science gifted children of start period. In this study, we develop and apply the program about sinking and floating for elementary science gifted students, and analyse degree of conceptual change. Students' prior knowledge is analysed for developing the program, and each step is settled about concept of density and buoyancy. Conceptests are arranged into step by step, and we apply the program to 26 science gifted students of 6th grade elementary school. We compare a percentage of correct answers of pre-test and post-test and evaluate Hake gain for analysis of degree of conceptual change. As a result, science gifted students' concepts are changed effectively into scientific concepts by program based on peer instruction for gifted students of start period. And they evaluate the program is novel and useful, also they can be motivated by the program.

• Journal of The Korean Association For Science Education
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• v.18 no.3
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• pp.427-441
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• 1998

The present study tested the hypothesis that adolescents' performance on scientific reasoning tasks and their ability to change theoretical concepts during instruction are mediated by prefrontal-cognitive functions, such as planning and inhibiting. Subjects sampled from four Korean secondary schools were administered a test of scientific reasoning ability and tests of the prefrontal lobe functions. A series of lessons on theoretical concepts was also administered. Subjects' performance on the test of scientific reasoning and pre- to posttest gains in the concept test were used as dependent variables. This study found that students' planning and inhibiting abilities were highly correlated with and they significantly predicted their scientific reasoning ability and conceptual gains. Further, principal component analysis showed prefrontal lobe functions were categorized into two main components. Component 1, which was loaded by planning and working memory functions, was termed as the representing process. Component 2, which was loaded primarily by the inhibiting functions, was termed as the inhibiting process. Scientific reasoning and conceptual change were also linked to these two components, indicating that these cognitive processes are mediated by both representing and inhibiting processes.

• Journal of The Korean Association For Science Education
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• v.30 no.5
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• pp.557-575
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• 2010

The purpose of the study was to suggest the characteristics and goals of the science teaching model for use as criteria in selecting the appropriate teaching model for science in secondary schools. These characteristics and the goals have been organized based on the analyses of the literature on the teaching and/or instructional model. The teaching models have been classified into four areas, and the characteristics and goals of each area have been summarized as follows: $\cdot$ Traditional models: teaching of scientific knowledge through lectures, acquisition of scientific knowledge through discovery, acquisition of inquiry process skills through inquiry-based teaching/learning $\cdot$ Transitional models: demonstration and discovery as teaching strategies, acquisition of inquiry process skills through inquiry approach, acquisition and change of scientific knowledge $\cdot$ Modernistic model - conceptual change models: differentiation of scientific knowledge, exchange of misconceptions for scientific concepts - learning cycle models: conceptual differentiation, exchange of misconceptions, acquisition of science process skills Also described in this paper are the model's characteristics and goals that can be used as the criteria for selecting the appropriate teaching model for the subject that will be taught.

• Journal of The Korean Association For Science Education
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• v.16 no.1
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• pp.61-76
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• 1996

The purpose of this study was to apply the instructional strategies for conceptual change prescribed by Posner et al(1982) to the astronomic content domain taught in the elementary and middle school and to analyze the characteristics of students' knowledge revealed in the test before, during and after the instruction. Also, it was to investigate the intercorrelation of cognitive levels, spatial ability and science achievement. The major findings of this study are as follows: 1. Students had a great variety of misconceptions related to the motion of the moon before the instruction, that is, the phases, the names of phases and the cause of changing phases by the moon's orbit about the earth, the moon's appearance and location at the given time, the relative positions of earth, moon and sun during a lunar eclipse, the cause that a full moon is not at the line of node once a month. In the analysis of students' responses concerning the cause of changing phases of the moon and a lunar eclipse, the results indicate that the great majority of students had rote learning rather than meaningful learning in the middle school. 2. Students' reponses during the instruction concerning the changing phases of the moon and the predictive knowledge about the motions of the earth and the moon were analyzed. 1) According to the results of the test given before and after experiment, after discussion, achievement score of the whole of subjects and groups in both preformal and formal cognitive levels appeared to increase linearly. 2) There was no statistically significant differences of achievement scores before and after experiment, after discussion between preformal group and formal group in cognitive levels. 3. Distribution of achievement scores according to the whole of subjects and groups in preformal and formal cognitive levels shows that there was a statistically significant difference between pretest and posttest. 4. Types of conceptual changes concerning the cause of changing phases of the moon that occurred from pretest to posttest were classified as accommodation, incomplete accommodation, assimilation, no change and no model. Six of the seven students starting instruction with alternative frameworks didn't sustain those alternative models throughout instruction. Five of these six students accommodated completely and the last one partially. Seventy-nine percentage of students taking instruction with fragmental models assimilated correct propositions at the end of the instruction. These results suggest that conceptual change model prescribed by Posner et al(1982) has promised the meaningful learning to students taking with fragmental models, especially in cases where students with misconception enter instruction. 5. High correlation between achievement score of simple-recall items and that of written items in pretest and posttest indicates that the higher students got the score in simple-recall items the better they also performed in written items. However, there was no statistically significant differences among cognitive levels, spatial ability and science achievement in the whole of subjects and groups according to the cognitive levels.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.589-600
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• 1998

The present study tested the hypothesis that adolescent's prefrontal lobe growth plateau and spurt exists and that this plateau and spurt influence students' ability to reason scientifically and to learn theoretical science concepts. In theory, maturation of the prefrontal lobes during early adolescence allows for improvements in students' abilities to inhibit task-irrelevant information and coordinate task-relevant information, which along with both physical and social experience, influences scientific reasoning ability and the ability to reject scientific misconceptions and accept scientific conceptions. Two hundred six students ages 13 to 16 years enrolled in four Korean secondary schools were administered tests of prefrontal lobe functions, scientific reasoning, and theoretical concepts derived from kinetic-molecular theory. A series of 14 lessons designed to teach the concepts were then taught. The concepts test was then re-administered following instruction. As predicted among the 14-year-olds, performance on the measures of prefrontal lobe functions, scientific reasoning, and conceptual change remained similar or regressed. Performance then improved considerably among the 15 and 16-year-olds. Because so few of the present students were able to undergo this apparently necessary conceptual change, the value of introducing theoretical concepts to early adolescent is questioned.

• Journal of The Korean Association For Science Education
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• v.21 no.4
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• pp.658-667
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• 2001

In this study, the relationships among students' cognitive/affective variables, cognitive conflict induced by anomalous data, and conceptual change were investigated. Tests regarding background knowledge, field dependence-independence, learning strategy, logical thinking ability, goal orientation, self-efficacy on prior concept and ability, and control belief were administered. Tests of prior conceptions, responses to anomalous data, conception, and retention of conception were also administered. There were no significant correlations of cognitive conflict induced by anomalous data with students' cognitive and affective variables. However, prior knowledge on molecular motion, field dependence-independence, and learning strategy were significantly correlated with students' conception and retention of conception. Logical thinking ability was also correlated with their conception. Multiple regression analysis indicated that learning strategy significantly predicted students' conception and retention of conception. For the affective variables, self-efficacy on ability was significantly correlated with students' conception and retention of conception, and goal orientation was correlated with their conception. Self-efficacy on ability was a significant predictor on students' conception and retention of conception, and goal orientation on their conception.

• Journal of Science Education
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• v.46 no.3
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• pp.278-292
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• 2022

Researchers in science education have recently focused on service learning as an important educational approach to address environmental challenges including climate change. However, there are a limited number of studies focused on service learning in science education in Korea. In this study, based on existing related literature, the theoretical background of service learning is introduced and a conceptual framework that can be applied in the science education environment in Korea as a new approach to address environmental challenges is proposed. Given this, 112 relevant academic documents collected by searching a global database were analyzed. As a result, the theoretical background of service learning rooted in Dewey's experiential learning is introduced. Specifically, service learning is defined as a form of experiential learning that supports students in helping communities with structured services related to learning content, while at the same time fostering their in-depth understanding of content and engaging in civic and social responsibility as members of their community. In addition, a conceptual framework for service learning to address environmental challenges that can be applied to the science education environment in Korea is proposed. The proposed framework classifies the members of service learning into schools, students, and communities, and presents knowledge, experience, and learning through critical reflection as its core elements. It is important to actively implement service learning in science education to address various environmental challenges including climate change, biodiversity loss, air pollution, and deforestation, as just a few pressing challenges. Therefore, based on the proposed conceptual framework for service learning, studies that apply and verify diverse forms of educational approaches to addressing environmental challenges in local communities at school sites are needed.