• Publications of The Korean Astronomical Society
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• v.24 no.1
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• pp.65-81
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• 2009

We present the performance test results of VLBI Correlation Subsystem (VCS) trial product which was being developed for 1 year from August 2007. It is a core component of Korea-Japan Joint VLBI Correlator (KJJVC). The aim for developing VCS trial product is to improve the performance of VCS main product to reduce the efforts and cost, and to solve the design problems by performing the preliminary test of the manufactured trial product. The function of VCS trial product is that it is able to process the 2 stations-1 baseline, 8 Gbps/station speed, 1.2 Gbps output speed with FX-type. VCS trial product consists of Read Data Control Board (RDC), Fourier Transform Board (FTB), and Correlation and Accumulation Board (CAB). Almost main functions are integrated in the FTB and CAB board. In order to confirm the performance of VCS trial product functions, the spectral analysis, delay compensation and correlation processing experiments were carried out by using simulation and real observation data. We found that the overflow problem of re-quantization after FFT processing was occurred in the delay compensation experiment. We confirmed that this problem was caused by valid bit-expression of the re-quantized data. To solve this problem, the novel method will be applied to VCS main product. The effectiveness of VCS trial product has been verified through the preliminary experimental results, but the overflow problem was occurred.

• Journal of Family Resource Management and Policy Review
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• v.16 no.4
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• pp.153-170
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• 2012

This study investigated the educational culture experienced by married immigrant women in their own country, as well as their internalizing process of the educational culture in Korea, using a qualitative case study. The purpose of this study was to help married immigrant women solve the problem of acculturation based on their own educational and cultural experiences and to overcome limitations of previous studies, which dealt with the problem of acculturation superficially. Participants were 17 married immigrant women from eight countries who resided in Jeonnam and Jeonbuk provinces. They were selected by the sampling strategy of maximum variation. Data were collected through archives and in-depth interviews and analyzed using within-case analysis and cross-case analysis. The results showed that married immigrant women had no experience of attending private institutions and had good memories of their school life. Based on these kinds of experiences, they criticized Korean mothers who urged their children to attend private institutions. They respected their children's opinions and allowed their children to select private institutions. Despite married immigrant women apparently suffering from acculturation, they educate their children according to their own philosophy and method of education. That is, they solve the problem of acculturation actively and independently. Consequently, in order to help married immigrant women solve the problem of acculturation, it is necessary to respect the difference in the cultures and frame a system that develops the activity and subjectivity of married immigrant women.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.948-962
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• 2015

The purpose of this study was to inquiry of outcomes and challenges of Meister high school' and specialized vocational high school' teachers and industrial workers on problem solving ability domain of test for enhanced employ ability & upgraded proficiency, and what were outcomes and challenges of main factor by Meister high school and specialized vocational high school' teachers and industrial workers. Research subjects and region were teachers of Meister high schools and specialized vocational high schools in Gyeongsangnamdo and industrial workers in Gyeonggido. The sample(N=147) was drawn from Meister high school' teachers(N=90), specialized vocational high school' teachers(N=25) and industrial workers(N=32), and collected data were analyzed with SPSS using average, standard deviation, cross analysis, verification F. The results are as follows: The biggest outcomes of problem solving ability domain of test for enhanced employ ability & upgraded proficiency was change of educational direction for promoting core competency on specialized high school & Meister High School's students. The biggest positive ripple effects of the outcomes was also change of educational direction for promoting core competency on specialized high school & Meister High School's students. The biggest challenges of problem solving ability domain of test for enhanced employ ability & upgraded proficiency was importance of challenges was expansion of teacher training and lecture on the Test for Enhanced Employ ability & Upgraded Proficiency.

• Education of Primary School Mathematics
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• v.18 no.2
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• pp.123-139
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• 2015

The purpose of this study was to investigate the effects of the experiences of productive failures on students' mathematical problem solving abilities and mathematical dispositions. The experiment was conducted with two groups. The treatment group was applied with the productive mathematics failure program, and the comparative group was taught with traditional mathematics lessons. In this study, for quantitative analysis, the students were tested their understanding of mathematical concepts, mathematical reasoning abilities, students' various strategies and mathematical dispositions before and after using the program. For qualitative analysis, the researchers analyzed the discussion processes of the students, students's activity worksheets, and conducted interviews with selected students. The results showed the followings. First, use of productive failures showed students' enhancement in problem solving abilities. Second, the students who experienced productive failures positively affected the changes in students' mathematical dispositions. Along with the more detailed research on productive mathematical failures, the research results should be included in the development of mathematics textbooks and teaching and learning mathematics.

• The KIPS Transactions:PartB
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• v.10B no.3
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• pp.243-248
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• 2003

An incremental kernel principal component analysis (IKPCA) is proposed for the nonlinear feature extraction from the data. The problem of batch kernel principal component analysis (KPCA) is that the computation becomes prohibitive when the data set is large. Another problem is that, in order to update the eigenvectors with another data, the whole eigenspace should be recomputed. IKPCA overcomes these problems by incrementally computing eigenspace model and empirical kernel map The IKPCA is more efficient in memory requirement than a batch KPCA and can be easily improved by re-learning the data. In our experiments we show that IKPCA is comparable in performance to a batch KPCA for the feature extraction and classification problem on nonlinear data set.

• Journal of Science Education
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• v.45 no.2
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• pp.201-218
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• 2021

The purpose of this study is to investigate qualitatively two cases of general citizens' scientific participation and activities responding to fine dust problem. The processes of their scientific actions were investigated and categorized inductively based on three stages: problem recognition stage, information collection and analysis stage, and sharing and spreading stage. As a result, in the 'problem recognition' stage, two participants recognized the seriousness of the fine dust problem as they felt a threat to their health and began to act practically by questioning the accuracy of public data. In the 'information collection and analysis' stage, a participant collected as much information as possible and compared them in order to obtain more accurate information for her situation. On the other hand, another participant conducted various experiments in person to get the information which is appropriate to his situation. Finally, in the 'Sharing and Spreading' stage, both participants created and shared various materials based on online environment, and continued their activities with a sense of contribution through others assistance. Educational implications are discussed in terms of civic science education and scientific literacy.

• Journal of The Korean Association of Information Education
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• v.25 no.5
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• pp.713-721
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• 2021

As the Ministry of Education has introduced AI education in earnest in the 2022 revised curriculum, there is growing sympathy for the need for data-related education along with AI education. In order to develop the competence to understand and utilize artificial intelligence properly, the understanding and utilization competence of data must be based on it. In this study, a data-driven problem solving SW education program using microbit was developed by synthesizing the results of demand analysis and previous research analysis. The data-driven problem solving education program was developed with educational elements that can be applied to elementary school students among the contents of data science. Through the program developed in this study, education that combines various topics and subjects can be linked based on real-life data. Furthermore, based on an understanding of data, it will lay the foundation for a more substantial AI education program.

• Journal of Elementary Mathematics Education in Korea
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• v.19 no.4
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• pp.501-525
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• 2015

This study analyzes arithmetic word problem of multiplication and division in the mathematics textbooks and workbooks of 3rd grade in elementary school according to 2009 revised curriculum. And we analyzes type of the problem solving ability which 4th graders prefer in the course of arithmetic word problem solving and the problem solving ability as per the type in order to seek efficient teaching methods on arithmetic word problem solving of students. First, in the mathematics textbook and workbook of 3rd grade, arithmetic word problem of multiplication and division suggested various things such as thought opening, activities, finish, and let's check. As per the semantic element, multiplication was classified into 5 types of cumulated addition of same number, rate, comparison, arrayal and combination while division was classified into 2 types of division into equal parts and division by equal part. According to result of analysis, the type of cumulated addition of same number was the most one for multiplication while 2 types of division into equal parts and division by equal part were evenly spread in division. Second, according to 1st test result of arithmetic word problem solving ability in the element of arithmetic operation meaning, 4th grade showed type of cumulated addition of same number as the highest correct answer ratio for multiplication. As for division, 4th grade showed 90% correct answer ratio in 4 questionnaires out of 5 questionnaires. And 2nd test showed arithmetic word problem solving ability in the element of arithmetic operation construction, as for multiplication and division, correct answer ratio was higher in the case that 4th grade students did not know the result than the case they did not know changed amount or initial amount. This was because the case of asking the result was suggested in the mathematics textbook and workbook and therefore, it was difficult for students to understand such questions as changed amount or initial amount which they did not see frequently. Therefore, it is required for students to experience more varied types of problems so that they can more easily recognize problems seen from a textbook and then, improve their understanding of problems and problem solving ability.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.65-66
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• 2004

• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.403-406
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• 2009