• Journal of the Korean Chemical Society
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• v.64 no.1
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• pp.19-29
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• 2020

We analyzed the representations of acid-base models in 4 kinds of Chemistry I and 4 kinds of Chemistry II textbooks of the 2009 revised curriculum, and 9 kinds of Chemistry I textbooks and 6 kinds of chemistry II textbooks of the 2015 revised curriculum in this study. The problems of the textbook were divided into the problems of definitions and the representations of the logical thinking. As a result of the study, the lack of the concept of chemical equilibrium had a problem with the representation of reversible reactions in the definition of the Brønsted-Lowry model in the Chemistry I textbooks of 2009 revised curriculum, it also appeared to persist in Chemistry I textbooks of 2015 revised curriculum which contains the concept of chemical equilibrium. The representations of logical thinking were related to particle kinds of conservation logic, combinational logic, particle number conservation logic, and proportion logic. There were few problems related to representation of logical thinking in Chemistry I textbook in 2009 revision curriculum, but more problems of representations related to logics are presented in Chemistry I textbooks in 2015 revision curriculum. Therefore, as the curriculum is revised, the representations of chemistry textbooks related to acid and base models need to be changed in a way that can help students' understanding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.290-301
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• 2017

This research aimed to develop problem creating worksheets as a teaching & learning material for problem solving activities and assess its effectiveness. Activity worksheets for creative problem development were established. The effectiveness of the problem-creating classes taught to gifted students in invention was evaluated. In addition, effective strategies for encouraging problem creating and question making in teaching & learning processes were explored. The creative problem identification activity consisted of 5 steps, which are idea creation, convergence, execution, and evaluation. The results showed that elementary and middle school students taught in the classes using this problem-identification worksheet were highly satisfied with the program. This study concluded that it requires an educational environment, government level collaboration, and support to create a mature social atmosphere and educational environment motivating students to keep asking questions and identify problems. Through continual modification, additional ongoing efforts to increase the credibility and the quality of the worksheets as a creative problem solving and learning tool will be needed.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.188-194
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• 2005

To assess microbiological indoor air quality in schools, concentrations of viable airborne microorganisms were monitored at classrooms and corridors of 3 middle or high schools in Ulsan. Airborne microorganisms were sampled at various situations during a semester (class-hour, lunchtime, after school) and during a vacation with an impaction-type air sampler. During the semester, the number of bacteria was the highest at lunchtime in corridor with an average of $1,111\;MPN/m^{3}$ and lowest at class-hour in corridor with an average of $132\;MPN/m^{3}$. During the vacation, the bacterial concentrations at classrooms and corridors were only $5{\%}$ and $27{\%}$ of the values during class-hours of the semester, respectively. Among the colonies tested, $60{\%}$ were identified as relatively harmless Micrococcus species and $12{\%}$ were Staphylococcus species. During the semester, the average values of fungal concentrations at each situation ranged from 105 to $213\;MPN/m^{3}$, and the values during the vacation were $32\;MPN/m^{3}$ at classrooms and $83\;MPN/m^{3}$ in corridors. Fungal genera such as Cladosporium, Penicillium, and Aspergillus were identified from the colonies. The obtained data can be considered as a step to set a guideline for bioaerosols in indoor environment of schools.

• Journal of the Korean School Mathematics Society
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• v.23 no.1
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• pp.129-158
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• 2020

In this study, we presented two geometric tasks to three 11th grade students to identify the characteristics of the images that the students had at the beginning of problem-solving in the problem situations and investigated how their images changed during problem-solving and effected their problem-solving behaviors. In the first task, student A had a static image (type 1) at the beginning of his problem-solving process, but later developed into a dynamic image of type 3 and recognized the invariant relationship between the quantities in the problem situation. Student B and student C were observed as type 3 students throughout their problem-solving process. No differences were found in student B's and student C's images of the problem context in the first task, but apparent differences appeared in the second task. In the second task, both student B and student C demonstrated a dynamic image of the problem context. However, student B did not recognize the invariant relationship between the related quantities. In contrast, student C constructed a robust quantitative structure, which seemed to support him to perceive the invariant relationship. The results of this study also show that the success of solving the task 1 was determined by whether the students had reached the level of theoretical generalization with a dynamic image of the related quantities in the problem situation. In the case of task 2, the level of covariational reasoning with the two varying quantities in the problem situation was brought forth differences between the two students.

• Communications of Mathematical Education
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• v.30 no.4
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• pp.499-514
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• 2016

As people get to aware that the traditional teacher-centered education can not develop individual students' diversity and creativity and cope with the rapidly changing future society, Korean government has emphasized the learner-centered education since the 7th curriculum. Under this background, we have analyzed the problems of mathematics education that teachers recognized and the features of mathematics textbooks that they developed within the framework of leaner-centered education on the basis of the resources developed from 'Student-centered mathematics textbook improvement teacher research group in 2015.' As a result of using the framework of 'Learner-centered psychological principles (APA, 1997)' for analysis, teachers pointed out the problems related to the principles of Motivational and emotional influences on learning, Individual differences in learning, Developmental influences on learning, Nature of the learning process, and Construction of knowledge, in order. The features of textbook teachers developed reflected the principles of Nature of the learning process, Construction of knowledge, and Motivational and emotional influences on learning, in order. Finally, as we have compared teachers' recognition of the problems with the features of the textbooks developed, most of the problems teachers recognized are reflected in the textbooks; however, the Cognitive and metacognitive factor takes higher possession on the textbooks compared with the problems being recognized, and the Motivational and affective factor takes lower possession on the textbooks compared with the problems being recognized. Accordingly, we have been able to search for the solution to realize the learner-centered education through math textbooks.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.1
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• pp.19-38
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• 2011

The purpose of this study was to analyze the responses and the behavioral characteristics between mathematically promising students and normal students in solving open-ended problems. For this study, 55 mathematically promising students were selected from the Science Education Institute for the Gifted at Seoul National University of Education as well as 100 normal students from three 6th grade classes of a regular elementary school. The students were given 50 minutes to complete a written test consisting of five open-ended problems. A post-test interview was also conducted and added to the results of the written test. The conclusions of this study were summarized as follows: First, analysis and grouping problems are the most suitable in an open-ended problem study to stimulate the creativity of mathematically promising students. Second, open-ended problems are helpful for mathematically promising students' generative learning. The mathematically promising students had a tendency to find a variety of creative methods when solving open-ended problems. Third, mathematically promising students need to improve their ability to make-up new conditions and change the conditions to solve the problems. Fourth, various topics and subjects can be integrated into the classes for mathematically promising students. Fifth, the quality of students' former education and its effect on their ability to solve open-ended problems must be taken into consideration. Finally, a creative thinking class can be introduce to the general class. A number of normal students had creativity score similar to those of the mathematically promising students, suggesting that the introduction of a more challenging mathematics curriculum similar to that of the mathematically promising students into the general curriculum may be needed and possible.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.68-69
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• 2010

본 연구의 목적은 서울시 소재 과학영재교육원에서 운영하는 프로그램에서 개발된 일부 모듈들에 구현되어있는 과학탐구과정 및 사고과정의 특징이 과학영재프로그램의 목적에 따른 목표를 성취할 수 있는지를 평가하고, 과학탐구과정이나 사고과정의 각 항목을 구현한 탐구의 실제를 알기 위한 것이다. 또, 본 연구의 결과를 토대로 모듈들에 대해 반성하고 개선점을 찾으려는 것이다. 연구 참여자들은 13명이며 연구 목적을 위해 첫째, 영재교육과정 및 평가에 관한 문헌을 근거로 과학영재프로그램의 목적과 목표를 설정, 둘째, 목적과 목표를 근거로 문헌에 제시된 분석틀들을 수정 개발, 셋째, 참여자들이 각자 모듈을 1개 선정하여 분석하고 이를 수정한 후 다시 분석하여 해석, 넷째, 분석결과의 해석을 토대로 반성을 하였다. 각 단계마다 각자 해결한 내용을 공개하고 모든 참여자들이 공개된 내용에 대해 비판하면서 합의하는 과정을 거쳤다. 합의 도출에 의해 첫째, 과학영재프로그램의 목적은 '탐구적 사고과정을 함양하고 지역사회에 유익한 새로운 지식을 창출한다.', 이에 대한 목표는 '자기 주도적인 탐구 계획 능력을 향상한다.'와 '숙달된 탐구 기능을 사용하여 실제문제를 해결할 수 있다.'로 설정하였다. 둘째, 분석틀은 '과학탐구과정' 과 '사고과정'의 두 범주로 구성하였으며, '과학탐구과정'에 해당하는 항목은 '사전탐구, 탐구방법, 해석적 탐구기술, 의사소통능력, 탐구평가, 과학의 본성'으로, '사고과정'에 해당하는 항목들은 '논리적 사고, 창의적 사고'로 구성하였다. 셋째, 선정된 모듈들을 분석한 결과 모듈들은 대체로 탐구방법과 해석적 탐구기술을 많이 강조하였는데, 수정된 모듈들에서는 이 두 항목이 더욱 강조되었다. 특히, 해석적 탐구기술에서 의사소통능력, 탐구평가, 과학의 본성, 창의적 사고를 강조하는 탐구의 실제가 증가하였다. 수정후 증가된 항목들은 앞에서 설정한 두 가지 목표에 도달하는데 도움이 되는 항목들이라고 합의 선정되었던 것이므로, 이에 따라 수정 전 모듈보다 수정 후 모듈이 보다 더 영재프로그램의 목표에 도달하기에 적합한 것으로 판단하였다. 넷째, 연구결과를 토대로 반성한 점은 '목표' 에 '창의적 사고'와 '과학의 본성'에 대한 강조가 부족하다는 것, '목표'에서 '실제문제를 해결'할 수 있어야 한다는 것에 비해 '모듈'에서 다루는 주제는 '실제문제'가 아니라 학문적인 질문에 치우쳐 있다는 것, '자기 주도적인 탐구 계획 능력'을 향상시키는 탐구의 실제가 대체로 적게 제시되어 있다는 것이다. 이러한 반성을 영재프로그램의 각 모듈에서 모두 구현할 수 있는 것은 아니지만 본 연구에서 설정한 목적과 목표에 따라 프로그램을 개발하는 경우 이러한 반성점을 고려하여 모듈을 개발한다면 영재프로그램 전체적으로 볼 때는 모두 구현되어 있을 것이다. 본 연구는 서울시에 소재하는 과학영재교육원들에서 개발하여 사용하는 많은 모듈 중 극히 일부를 대상으로 하였으므로 연구 결과를 모든 과학영재프로그램에 적용하기에는 한계가 있다. 그러나 본 연구처럼 프로그램이나 모듈을 평가하려는 연구자들에게 일련의 평가단계에 대한 시사점을 제공할 수 있을 것으로 생각한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1852-1859
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• 2016

The effectiveness of a binarization algorithm in image processing depends on how to eliminate the uncertainty of determining threshold in a reasonable way and on minimizing information loss due to the binarization effect. Fuzzy binarization technique was proposed to handle that uncertainty with fuzzy logic. However, that method is known to be inefficient when the given image has low intensity contrast. In this paper, we propose an improved fuzzy binarization method to overcome such known drawbacks. Our method proposes a trapezoid type fuzzy membership function instead of most-frequently used triangle type one. We also propose an adaptive ${\alpha}$_cut determination policy. Our proposed method has less information loss than other algorithms since we do not use any stretching based preprocessing for enhancing the intensity contrast. In experiment, our proposed method is verified to be more effective in binarization with less information loss for many different types of images with low intensity contrast such as night scenery, lumber scoliosis, and lipoma images.

• Journal of the Korean Chemical Society
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• v.62 no.4
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• pp.279-287
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• 2018

In this study, we analyzed the explanations and examples of Brønsted-Lowry model in Chemistry I and Chemistry II textbooks of the 2009 revised curriculum. In particular, the definition of the Brønsted-Lowry model, the examples, and the content of experiments were analyzed by the process perspective of chemical equilibrium, emergent process. The analyzed textbooks were 4 kinds of Chemistry I textbooks and 4 kinds of Chemistry II textbooks in 2009 revision curriculum. As a result, Chemical I textbooks did not adequately show the chemical equilibrium viewpoint when explaining the Brønsted-Lowry model. In the Chemistry II textbooks, the examples of Brønsted-Lowry model were not present emergent process viewpoint, and those were described as sequential viewpoint of Arrhenius model. In addition, examples of experiments to demonstrate the Brønsted-Lowry model of Chemistry II textbooks were insufficient. The experimental examples related to the definition of acid bases were at the level of classification by the color change of indicators. The experimental examples for explaining the strength of acid and base were to compare current intensity or amount of hydrogen gas generated from the reaction with metal. In addition, all textbooks presented the state of aqueous solution when describing the Brønsted-Lowry model, causing problems with differentiation from the Arrhenius model. Therefore, it is necessary to develop examples of experiments to help students understand Brønsted-Lowry model by presenting acid and base reaction in the non-aqueous solution state.

• Journal of the Korean Chemical Society
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• v.63 no.5
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• pp.376-386
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• 2019

The purpose of this study was to explore the learning progression of logical thinking in acid and base chemical reactions and to evaluate its validity. For this purpose, we collected 387 participants in 9 schools of elementary, middle and high schools nationwide. The questionnaire developed in this study was composed of nine items. The questionnaire presented the acid and base reactants and products, and the students pictured their thoughts on how these substances change, and answered the reasons of their thoughts. Situation contexts of the questionnaire were divided into two groups: one kind of solute dissolved in a solvent, and two kinds of solute dissolved in a solvent. In this study, six levels of learning progression were assumed by combining material conservation logic, combination logic, proportion logic, and particle number conservation logic. By analyzing the data, Infit and Outfit values of Person reliability, Item reliability, MNSQ and ZSTD were obtained from the Rasch model. As a result of the analysis of data, it was found that lower levels of learning progression prevailed up to the younger grade students till $8^{th}$ grade. The higher levels of learning progression(Level 2~Level 5) prevailed up to the older grade students. However, higher levels of learning progression dropped sharply in Grade 12. The 5 level of learning progression was very low in all grades, and $9^{th}$ grade had highest percentage of students belonging to the 5 level. Interpretation of these unusual results suggests a future research related to explanation differences of textbooks.