• Journal of The Korean Association For Science Education
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• v.24 no.5
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• pp.886-901
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• 2004

The purpose of this study was to document the changes in astronomical concepts for preservice and inservice elementary school teachers after being presented with the newly devised Earth Motions Centric Solar System Model. The subjects of the study were 31 preservice and 30 inservice elementary schools teachers in the Jeonbuk Province. First, the author investigated the naive theories of the subjects, and then, compared that data to the data obtained after their exposure to the model. The total number of items on the instrument for this study was 10. These items included questions about the motion of interior planets, the phases and sizes of interior planets, and the motion of exterior planets and comets. After analyzing the answers to the items before the experiment, the author was able to confirm the existence of the naive theories regarding astronomical phenomena. Also, after the experiment, the author was able to observe the conceptual change in thought of the preservice and inservice elementary school teachers. Results showed that learning through the new model had positive effects on the preservice and inservice elementary school teachers' conceptualization of the interior planets' motion, phases and sizes, and the exterior planets' motion.

• Journal of Korea Water Resources Association
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• v.56 no.9
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• pp.563-574
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• 2023

Recently, climate change has affected functional responses of river basins to meteorological variables, emphasizing the importance of rainfall-runoff simulation research. Simultaneously, the growing interest in machine learning has led to its increased application in hydrological studies. However, it is not yet clear whether machine learning models are more advantageous than the conventional conceptual models. In this study, we compared the performance of the conventional GR6J model with the machine learning-based Random Forest model across 38 basins in Korea using both gauged and ungauged basin prediction methods. For gauged basin predictions, each model was calibrated or trained using observed daily runoff data, and their performance was evaluted over a separate validation period. Subsequently, ungauged basin simulations were evaluated using proximity-based parameter regionalization with Leave-One-Out Cross-Validation (LOOCV). In gauged basins, the Random Forest consistently outperformed the GR6J, exhibiting superiority across basins regardless of whether they had strong or weak rainfall-runoff correlations. This suggest that the inherent data-driven training structures of machine learning models, in contrast to the conceptual models, offer distinct advantages in data-rich scenarios. However, the advantages of the machine-learning algorithm were not replicated in ungauged basin predictions, resulting in a lower performance than that of the GR6J. In conclusion, this study suggests that while the Random Forest model showed enhanced performance in trained locations, the existing GR6J model may be a better choice for prediction in ungagued basins.

• 한국지구과학회:학술대회논문집
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• 2006.02a
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• pp.163-166
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• 2006

• Journal of The Korean Association For Science Education
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• v.27 no.5
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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.

• Korean Journal of Logic
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• v.22 no.1
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• pp.43-86
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• 2019

If 1st order ZFC is consistent(has a model($M_1$)) it has a transitive denumerable model($M_2$). This leads to a paradoxical situation called 'Skolem paradox'. This can be easily resolved by Skolem's typical resolution. but In the process, we must accept the model theoretic relativity for the concept of set. This relativity can generate a situation where the meaning of the set concept, for example, is given differently depending on the two models. The problem is next. because the sentence '¬denu(PN)' which indicate that PN is not denumerable is equally true in two models, A indistinguishability problem that the concept <¬denu> is not formally indistinguishable in ZFC arise. First, I will give a detail analysis of what the nature of this problem is. And I will provide three ways of responding to this problem from the standpoint of supporting ZFC. First, I will argue that <¬denu> concept, which can be relative to the different models, can be 'almost' distinguished in ZFC by using the formalization of model theory in ZFC. Second, I will show that <¬denu> can change its meaning intrinsically or naturally, by its contextual dependency from the semantic considerations about quantifier that plays a key role in the relativity of <¬denu>. Thus, I will show the model-relative meaning change of <¬denu> concept is a natural phenomenon external to the language, not a matter of responsible for ZFC.

• 한국정보교육학회:학술대회논문집
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• 2007.01a
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• pp.209-216
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• 2007

고도의 지식정보사회 속에서 논리적 사고력과 창의력, 문제해결력을 길러주는 프로그래밍 교육의 필요성은 더욱 강조되고 있다. 이에 본 연구에서는 초등학생들에게 적합한 교육용 프로그래밍 언어인 JavaMAL을 활용하여, 프로그래밍의 함수개념 형성을 위한 학습모형을 구안 적용하고 일반화 가능성을 탐색하고자 하였다. 먼저 기초적인 프로그래밍 요소 중 함수개념과 관련된 학습요소를 추출하여 차시별 지도계획을 수립하였다. 또한, 프로그래밍의 함수가 수학적 함수의 모방이라는 것에 착안하여 수학의 '규칙성과 함수'지도 단계를 LOGO의 문제해결력 수업모형인 안내된 발견식 교수법(guided discovery teaching method)에 강화한 후, 인터넷을 활용한 문제해결 수업모형을 구안하였다. 기본명령어와 변수개념을 이미 익힌 계발활동 부서 6학년 아동들을 지도 대상으로 한 달간 웹 기반 JavaMAL 환경에서 학습할 수 있도록 하였으며, 게시판 활동 및 활동지를 통해 함수개념 형성 여부를 측정하였다.

• Journal of the Korean Chemical Society
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• v.60 no.5
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• pp.362-373
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• 2016

In this study, ionic compound in the science textbooks developed under the 2009 revised national curriculum were analyzed in terms of the scientific concept and model description and the student understanding through the questionnaires. Analysis of textbooks was performed for science2 of middle school and chemistry I & II of high school. Questionnaire was carried out with 194 students including middle school 2nd grade and high school 1st-3rd grade. The results are as follows: First, as a result of analysis of textbooks, scientific concepts and models used to explain the ionic compound showed differences depending on the types of textbooks. In addition, scientific models were provided with or without explanation for the scientific concepts. Second, analysis of the questionnaire showed that students didn’t properly understood scientific concepts and models in the ion formation, stoichiometric ratio between ions.

• Journal of The Korean Association For Science Education
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• v.35 no.6
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• pp.1049-1062
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• 2015

To understand the synergy of collaboration and to apply this understanding to education, an analysis of how a team solves a problem and the sharing of their mental models is needed. This paper analyzed two things qualitatively to find out the source of synergy in a collaborative problem-solving process. First, the sharing contents in team mental model and second, the process of sharing the team mental model. Ten gifted middle school students collaborated to solve an ill-defined problem called sunshine through foliage problem. The gifted students shared the following results after the collaboration: First, scientific concept prior to common idea or the idea that all group members have before the discussions; second, unique individual ideas of group members; and third, created ideas that were not originally in the personal mental model. With created ideas, the team model becomes more than the sum of individuals. According to the results of process analysis, in the process of sharing mental model, the students proposed and shared the most important variable first. This result implied that the analysis of the order of sharing ideas is important as much as finding shared ideas. Also, the result shows that through their collaboration, the gifted students' shared mental model became more refined and expanded as compared to their individual prior mental models. It is recommended that these results can be used to measure shared mental model and develop collaborative learning models for students.

• Journal of The Korean Association For Science Education
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• v.29 no.4
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• pp.423-436
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• 2009

This study aims to develop an analytic framework that can be used to classify scientific models in science textbooks according to modes and attributes of representation and to investigate types of scientific models presented in the biology section of science textbooks for the $7^{th}$ to $10^{th}$ grades. The results showed that modes of representation of scientific models are related to the nature of sub-areas of biology sections. Generally, the iconic model and symbolic model were in dominant use, including drawings of organs and explanations of working of systems. However, the chapters on 'The Organization of Life' and 'The Continuity of Life' showed a relatively high frequency in use of the actual model. The theoretical model was presented in a part of 'The Continuity of Life', due to its highly abstract characteristics. Moreover, the gestural model and analogical model showed very low frequency. From the perspective of attributes of representation, frequency of the static model was very high, while one of the dynamic models was very low. Therefore, efforts to recognize the properties of scientific concepts more clearly and to develop diverse types of models that can represent the concepts adequately are required. Analysis of these types of scientific models can offer recognition of the usefulness and limitations of models in representing the concepts or phenomena, and can help us to design adequate models depicting particular properties of given concepts. Also, this type of analysis may motivate researchers to strive to reveal correct methods for and limits of using the scientific models that are presented in existing science textbooks, as well as to provide useful information to organize the science textbooks according to the revised $7^{th}$ national science curriculum.

• Korean Journal of Cognitive Science
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• v.9 no.1
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• pp.47-60
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• 1998

The study was designed to investigate implicit and explicit memory effec representations of bilinguals. Hierarchical model of bilingual information processing word naming and translation tasks in the context of semantically categorized or rar Experiments 1 and 2, bilinguals first viewed stimulus words and performed naming or tr then implicit and explicit memory tasks. In experiment I, word recognition times(exp were significantly faster for semantic category condition than random category condi naming task and lexical decision taskOmplicit memory task)showed no difference in e experiment 2, naming task and exlicit memory task showed categorization effect but fOWE a and implcit memory task showed no categorization effect. These findings support the which posits that memory representations of bilinguals are composed of two independer a and one common conceptual store.