• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.87-101
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• 2016

This study analyzes the content validity of descriptive tests developed for elementary schools, in order to acquire basic data to improve them. Various descriptive tests were collected and tested for differences in proportions between two-dimensional classification of educational objectives and the level of behavioral objectives. Results show that the descriptive tests developed by elementary school teachers mainly focused on "knowledge" and "understanding," and that content validity for behavioral levels to be low. Nine elementary school teachers were interviewed to understand the result. From the interviews, we found both internal and external factors that cause low content validity. The main internal factors were teachers' ability to make two-dimensional classification of educational objectives, the teachers' consideration of students' level, item level of difficulty, the ease of scoring, and path dependence. The main external factors were curriculum, parents, and administration. Based on the results, we suggested the factors related to elementary school teachers' PCK of descriptive tests.

• Journal of The Korean Association of Information Education
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• v.25 no.2
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• pp.309-315
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• 2021

This study is about the direction of how to compose the information domain curriculum in the domestic subject matter centered curriculum system. To this end, subject-centered and competency-centered curriculum were compared and analyzed, and how the information domain was organized in two types was suggested. In spite of emphasizing competency, the domestic curriculum was judged to be inclined to the subject-centered curriculum because it emphasized the presentation of national-level educational goals, a subject learning model, and textbooks. As examples of the information domain subject-centered curriculum, the information domain of the elementary practical subject and the middle school information curriculum were presented, and the SW convergence curriculum was presented as an example of a progressive curriculum. Under such circumstances, it was emphasized that in order for the learner to lead a life in an intelligent society in the future through the information domain including SWAI content, it must be explicitly described in a subject-centered perspective with computer science as the parent study.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.4090-4102
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• 2018

After emerging online communications, text mining and sentiment analysis has been frequently applied into analyzing electronic word-of-mouth. This study aims to develop a domain-specific lexicon of sentiment analysis to predict box office success in Korea film market and validate the feasibility of the lexicon. Natural language processing, a machine learning algorithm, and a lexicon-based sentiment classification method are employed. To create a movie domain sentiment lexicon, 233,631 reviews of 147 movies with popularity ratings is collected by a XML crawling package in R program. We accomplished 81.69% accuracy in sentiment classification by the Korean sentiment dictionary including 706 negative words and 617 positive words. The result showed a stronger positive relationship with box office success and consumers' sentiment as well as a significant positive effect in the linear regression for the predicting model. In addition, it reveals emotion in the user-generated content can be a more accurate clue to predict business success.

• Journal of Electrochemical Science and Technology
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• v.9 no.1
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• pp.1-8
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• 2018

The effect of mixing ratio on the corrosion protection of carbon steel coated by a film composed of poly(vinylidene) fluoride (PVDF) and poly(methyl methacrylate) (PMMA) was examined using electrochemical impedance spectroscopy. Surface crystallization behavior and thermal properties of the PVDF/PMMA coated carbon steel were evaluated using polarized optical microscopy and differential scanning calorimetry, respectively. A Maltese cross-pattern spherulite crystal was observed in the PVDF/PMMA coating film, which became more apparent with increasing PVDF content. The highest corrosion protection performance was achieved with 60 wt.% PVDF-coated carbon steel, and delamination and corrosion reactions were observed for 20 wt.% PVDF-coated carbon steel. Further, corrosion protection performance with an amorphous/crystal mixture (PVDF/PMMA, 60/40 (w/w)) was better than those observed in the amorphous domain and the perfect-crystal domain of the PVDF/PMMA blended coating system.

• Journal of Korean Elementary Science Education
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• v.25 no.2
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• pp.109-117
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• 2006

The purpose of this study was to examine the questioning styles of $3rd{\sim}6th$ elementary science textbooks in terms of frequency, type, and placement of questions. This paper also sought to analyse and compare the kinds of scientific inquiry processes elicited by the questions in the content domains of textbooks. The instrument used was the Textbook Questioning Strategies Assessment Instrument (TQSAI). The average number of questions per book was 129 and the ratio of questions to sentences was 31.9%. The results were summarized as followings. First, many science textbook questions were used for the purposes of explanation or identifying levels of teaming. Second, process skills were located in each content domain, although it was not affected meaningfully. Third, the number of text question was below 3 in each elementary science class. Therefore, an effective questioning development framework is clearly needed for elementary science instruction.

• Journal of Environmental Science International
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• v.1 no.2
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• pp.15-23
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• 1992

Development of cumulus is studied by numerically integrating the equation of motion equations of conservation for water vapor mixing ratio, and the thermodynamic energy equuation. We use the terrain-following coordinate system called z'-coordinate system, in which we can easily treat any calculation domain with terrain configuration such as mountains. The model domain of calculation is restricted vertically to 4.Skin and horizontally to 100 km, has a bell-type mountain in the centeral part. Four cases are considered, one in a neutral environment, second in a slightly stable environment, third in a environment decreasing water content with low value of initial water vapor mixing ratio, the fourth in a case with higher vapor gradient. The more the atmosphere is unstable, the more cumulus develops easily and the more water vapors is abundant, the more cumulus develops easily too. More detailed cloud microphysics parameterizations and wet deposition must be conridered to use in air pollutants prediction model.

• Journal of Powder Materials
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• v.1 no.2
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• pp.119-198
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• 1994

The characteristics of various important microstructural factors of WC-base hard- metals (cemented carbides) such as the amount of Co metal binder phase, the carbide grain size, the microstructural defects acting as a fracture source, the solid solubility of tungsten in the binder phase affected by the carbon content, the precipitation of $Co_3W$, the domain size of binder phase, the formation of ${\beta}-free$ layer or Co-rich layer and CVD or PVD coated layer, and the effects of these factors on the flexural strength of the hardmetals are reviewed.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.412-414
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• 2004

본 논문은 이미지 위/변조 검출 린 인증을 위한 고속의 Semi-Fragile 워터마킹 방법을 제안한다. 제안방법은 JPEG 이미지를 허프만 복호화 후에, 양자화 테이블 값에 의한 변화율이 같은 특정 양자화 계수를 비교함으로써 조건을 만족하는 8$\times$8 블록 당 1비트 워터마크 정보를 삽입한다. 이때의 조건은 이미지의 열화를 초래하지 않을 정도의 작은 boundary 값을 기준으로 한다. 제안한 방법이 압축에 강인함을 실험을 통하여 증명하였다.

• Journal of the Korean Magnetics Society
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• v.15 no.6
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• pp.320-324
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• 2005

The core loss of $3\%$ SiFe is strongly dependent on silicon content, impurities, permeability, and domain structure of the SiFe. Domain refining has been proved to be very good method for reduction of core loss in high permeability grain oriented SiFe, and laser scribing is well-blown as an effective and industrially important method of domain refinement. In this work, magnetic domain refinement has been carried out by using a pulsed Nd : YAG laser, and the core losses have been measured and analyzed to and optimal parameters of the laser treatment. The laser hem was focused with a spot size of $100{\mu}m$ and pulse energy of 10${\~}$35mJ and the lines were scribed with a period of ${\~}$5mm. The core loss was improved up to $17\%$ with 30 ns-Nd : YAG laser beam in $3\%$ SiFe.

• Journal of Science Education
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• v.46 no.1
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• pp.53-65
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• 2022

In the application and composition of learning content, the field trip learning of scientific inquiry could provide a positive effect. Also, it can arouse an experience of various inquiry activities through open thinking. In addition, it could take a positive effect by providing the diversity and specificity of wildlife experience for the living organism. The biology inquiry program of the field trip is a necessary process to acquire ecological experiences in the learning context. However, there is some problem to solve before the performance of field trip learning as professional knowledge of the outdoors inquiry. Therefore, this study developed a field trip inquiry program for the plant in a coastal dune using artificial intelligence to assist professional knowledge. The researcher carried out literature reviews and analysis related to studies and programs to investigate learning steps, content, and strategy. Also, this study investigated the effects of the program on the affective domain of gifted elementary science students. According to the results of this study, the program can provide a positive effect on motivation, task commitment, and attitude level. Consequently, the field trip learning program for plant in the coastal dune using artificial intelligence developed in this study can arouse a positive effect on the affective domain. Therefore, additional study is necessary related to inquiry programs of the field trip for various students and sites.