• Journal of The Korean Association For Science Education
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• 제27권5호
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• pp.379-393
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• 2007

The purpose of this article is to analyze the conceptual change of nine 11th graders after implementing the model-based instruction of blood circulation by multidimensional framework, and to find some implications about teaching strategies for improving conceptual understanding. The model-based instruction consisted of 4 periods: (1) introduction for inducing students' interests using an episode in the science history of blood circulation, (2) vivisectional experiment on rats, (3) visual-linguistic model instruction using the videotape of heartbeat, and (4) modeling activity on the path of blood flow. Based on the data from pre-test, post-test and interviews, we classified students' models on the path of blood flow, and investigated their ontological features and the conceptual status of blood circulation. Most students could describe the path of blood flow and the changes of substances in blood precisely after the instructions. However, the modeling activity were not sufficient to improve students' understanding of the mechanisms of the blood distribution throughout various organs and the material exchanges between blood and tissues. From the interview of 9 students, we acquired informative results about conceptual status elements that were helpful to, preventing from, or not used for students' understanding. It was also found that conceptual status of students depended on the ontological categories into which students' conceptions of blood circulation fell. The results of this study can help design the effective teaching strategy for the understanding of concept of the equilibrium category.

• Journal of the Korean Society of Earth Science Education
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• 제4권1호
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• pp.57-65
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• 2011

The purposes of this study investigated the effects of placement of analogy on the conceptual changes of air of elementary students, while learning the air conceptions. The subjects consisted of 108 students who are in the sixth grade classes in an elementary school in Busan city. For this study, comparative group(37 members), experimental group I(37 members), and experimental group II(34 memgers) were selected. A pre-test and a post-test on the air conception were done both for the comparative group and the experimental groups. The results are as follows. First, the averages of experiment group I and II are statistically higher than comparative group's. By the way, it just has a small gap between the comparative group and the experimental II. In other words, activity of analogy does not keep always constant to change of air conceptions of elementary students. Therefore, it has a different reason that only before or after during the analogy. Second, it shows that experimental group I has effected on a more change of air conceptions as compared with experimental group II. Then, the first group's result shows better than the other group's result. From this result, six grade students showed a change of air conceptions very well by analogy. It means if the analogy is given to students at the beginning state of chapter, they can understand scientific concepts easily.

• Journal of The Korean Association For Science Education
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• 제13권1호
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• pp.100-120
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• 1993

Middle school students' conceptual changes on physics, chemistry, biology and earth science concepts which were intentionally selected by researchers had been investigated through traditional teaching and learning by paper and pencil tests and P.O.E. The weak points had been studied by individual interviews about the problems of traditional science classroom teaching after students' testing and learning about science concepts. As results, students' conceptual changes could be hardly found through traditional teaching and learning except several concepts in biology, The weak points of traditional science classroom teaching and learning were as follows: 1) Teachers teach science as finding answers. 2) The conventional science test is not performed to find students' concepts out but to recall simple knowledge or calculus. 3) Students hesitate to ask teacher Questions in science class because of their colleagues' or teachers' blame. These mean that science teachers need specially designed teaching methods on the students' concepts and reseachers had to study about science classroom socialogy, what happened in science classrooms.

• Journal of The Korean Association For Science Education
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• 제21권4호
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• pp.689-696
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• 2001

Students who have correct conception didn't show big changes in a test of cognitive conflict, while students who have misconception made significant changes Most students who had misconception were considerably curious about demonstration of an actual phenomenon. On the other hand, according to their own confidence of preconception, the higher confidence of misconception is, the bigger conflicts are and when they meet some different phenomenon unlike their ideas, their psychological shock was big. After a cognitive conflict lesson, students' conception was significantly changed regardless of students' confidence of preconception and the persistence effect new conceptions showed similar result as preceeding research regardless of confidence of preconception. That is, the change decreased from immediate after demonstration of an conflict situation to a week after. After conceptual change, students' confidence of correct conception was generally increased, so it turned out that cognitive conflict lesson had a positive effect on students who had a misconception.

• International Journal of Aeronautical and Space Sciences
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• 제17권2호
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• pp.268-283
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• 2016

Aircraft manufacturing companies have to consider multiple derivatives to satisfy various market requirements. They modify or extend an existing aircraft to meet new market demands while keeping the development time and cost to a minimum. Many researchers have studied the derivative design process, but these research efforts consider baseline and derivative designs together, while using the whole set of design variables. Therefore, an efficient process that can reduce cost and time for aircraft derivative design is needed. In this research, a more efficient design process is proposed which obtains global changes from local changes in aircraft design in order to develop aircraft derivatives efficiently. Sensitivity analysis was introduced to remove unnecessary design variables that have a low impact on the objective function. This prevented wasting computational effort and time on low priority variables for design requirements and objectives. Additionally, uncertainty from the fidelity of analysis tools was considered in design optimization to increase the probability of optimization results. The Reliability Based Design Optimization (RBDO) and Possibility Based Design Optimization (PBDO) methods were proposed to handle the uncertainty in aircraft conceptual design optimization. In this paper, Collaborative Optimization (CO) based framework with RBDO and PBDO was implemented to consider uncertainty. The proposed method was applied for civil jet aircraft derivative design that increases cruise range and the number of passengers. The proposed process provided deterministic design optimization, RBDO, and PBDO results for given requirements.

• Journal of Korean Academy of Nursing
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• 제49권1호
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• pp.14-25
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• 2019

Purpose: This was a methodological study that aimed to develop a measurement scale for aging anxiety among middle-aged women. Methods: In this study, construct factors were extracted, and a conceptual framework was established through an extensive literature review and in-depth interviews with middle-aged women. Under the conceptual framework, 44 preliminary items were constructed, and a preliminary scale of 25 items was completed after two rounds of expert validation and item review. For this study, data were collected from 201 women aged 40~59 years, and the construct validity and reliability of the preliminary scale were verified. Results: To verify the construct validity, exploratory factor analysis was conducted. Four factors containing 19 items were extracted. Concurrent validity of the developed scale was verified with Pearson's correlation analysis. The final scale comprised 4 factors ("Social valueless", "Physical weakness", "Concern about changes in appearance", and "Expectations of old age") and 19 items. The Cronbach's ${\alpha}$ value was .91. Conclusion: The scale for measuring aging anxiety in middle-aged women developed in this study validly reflected the peculiarities of aging anxiety in middle-aged women, who experience many physical, emotional, and social changes. The scale can be said to reflect the cultural background, as it reflected real experiences gained through in-depth interviews with middle-aged women.

• The Journal of Industrial Distribution & Business
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• 제11권2호
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• pp.7-16
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• 2020

Purpose: This study explores how demographic transitions with workforce implications taking place in South Korea are affecting the job market, and proposes a novel conceptual model to analyze the increased role that migrant workers will play as the changes progress in the medium term. Research design, data and methodology: A qualitative approach based on the available published data is used in order to create a conceptual model that could be used to determine the order in which job sector strata will be gradually taken over by migrant workers, as the demographic transitions will create an increasing need for workforce reforms. Results: The study determines that migrant workers will replace domestic Korean workers in a stratified manner, initially in rural areas, followed by regional cities and then in the industrial areas on the edges of big cities, and the strata can be analyzed based on a proposed four-category model to determine where the opportunities will open. Conclusion: It is possible to use a conceptual model for this phenomenon. Extensive Government planning is needed to avoid possible social exclusion problems and to determine how to keep the economies of rural and regional Korean cities economically viable while they are becoming increasingly depopulated.

• Journal of The Korean Association For Science Education
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• 제32권6호
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• pp.1050-1062
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• 2012

Concepts of science have been developed by occupying 'ecological niche' within conceptual ecology. The ecological niche is determined from the mutual effect between intellectual environmental of the learner and new concept, which few studies have been conducted. This study examined how the ecological niche of the concept of photosynthesis in $7^{th}$ grade is changed by instruction. The ecological niche was analyzed using 2 methods: (1) the change in the diversity of concepts, and (2) the change in the proximity of concepts based on the frequency and the relativeness score of the concepts. The concept of photosynthesis was analyzed in the 4 domains in the place of photosynthesis, products of photosynthesis, reactants of photosynthesis, and environmental factors. The results of this study are as follows: (1) reduced diversity of concepts, (2) increased frequency and relativeness score of the scientific concepts, and (3) increased proximity of the scientific concepts by instruction. With these results, the mutual effects of the concepts within the conceptual ecology have become active by class to differentiate the relationships between the concepts, which accordingly displayed their changes in status.

• Journal of the Korean earth science society
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• 제26권8호
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• pp.777-789
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• 2005

Study courses using cognitive conflict strategy about geological stratum were performed on the 6th grade elementary students and their conceptual changes were investigated. Some misconceptions about geological stratum that the students have are as follows: (1) stratum was formed due to volcanic eruption, (2) gneiss composes the geological stratum, (3) folds in the stratum were formed due to vertical pressure from the top. The classes had positive effects on the changes of some the misconceptions: (1) the places where the stratum is filmed, (2) the kind of rock in the stratum, and (3) the reason for folding. However, there were no significant changes in the following items: (1) the reason that every layer consists of different sizes of grains. It shows that some misconceptions can be changed easily by cognitive conflict strategy, while others can not. We checked the students who didn't change their misconceptions after the test. These students have very strong misconceptions that most of the natural phenomena on the earth's surface are due to the internal heat pressure, and volcanic activity. Another affecting the students' misconceptions are the role of teachers in class and mass media, such as TV.

• Journal of Korean Elementary Science Education
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• 제19권2호
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• pp.93-105
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• 2000

The purpose of the study is to find out students' misconceptions and the stability of misconceptions in the domain of mechanics. According to the incorrect choices by grades, three different kinds of conceptual change were identified ; (1) easily overcome misconceptions, (2) stable misconceptions, and (3) reinforced misconceptions. The analyses of the results showed that easily overcome misconceptions occurred in simple or visual concepts, stable misconceptions occurred in the concepts involving EGC(experiential gestalt of causation) or in the concepts overgeneralized in school teaming, and finally, reinforced misconceptions as grade level increases occurred in the concepts EGC with scientific logical procedures. The results on the type of conceptual changes may provide significant cognitive theoretic evidences on the sources of misconceptions.