• Journal of Educational Research in Mathematics
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• v.25 no.4
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• pp.717-754
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• 2015

As a design research, this study aims to identify students' collaborative problems solving patterns using the Wiki and design factors triggering MKB(mathematical knowledge building) in virtual environment. For 70 days, 14 Korean secondary gifted students, who enrolled in calculus II courses in one of gifted institutions in Korea, solved 10 math problems together using the Wiki. In this study, I considered five design factors; motivation, practice of LaTeX, norms of participation, epistemic agency, and two types of educational settings. The primary pattern emergent in students' collaborative problem solving process is identified as 'solutions and refutations' along the double helix consisting of the constructive line and the critical line, which is very similar to the pattern of 'Conjectures and Refutations'(Lakatos, 1976). Despite that most participants had difficulty in using LaTeX for mathematical expressions, this study shows that Wikis are valuable tools for providing Korean secondary students opportunities to learn social virtue such as humility and courage (Lampert, 1990), which is considered to be have been neglected in Korean educational environment but is emphasized as precious for doing mathematics in the field of mathematics education.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.75-94
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• 2011

In this paper, we explore the information diffusion mechanism under social network environments by investigating the effect of message characteristics on the volume and speed of retweeting in Twitter, a popular online social media service. To this end, we select eight main keywords (i.e., '무상급식', '반값등록금', '나가수', '평창', '김연아', '박태환', '아이폰', '갤럭시') that have been popular on online social media in recent days. Each keyword represents various social aspects of Korea that recently grab people's attention such as political issues, entertainment, sports celebrities, and the latest digital products, and eventually holds distinctive message characteristics. Analyzing the frequency and velocity of retweeting for each keyword, we find that more than half of the sample messages posted on Twitter contain personal opinions for the certain keyword, but we also find that the tweets which include objective messages with hyperlink are the fastest ones when being retweeted by other followers. In overall, when being retweeted, the group of messages related to the certain keyword present distinctive diffusion patterns and speed according to message characteristics. From academic perspective, the findings in the study broaden our theoretical knowledge of information diffusion mechanism over online social media. For practitioners, the results also provide managerial implications regarding how to strategically utilize online social media for marketing communications with customers.

• Korean Journal of Childcare and Education
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• v.10 no.5
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• pp.229-248
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• 2014

The purpose of this study is to draw guidelines on how to select traditional games that would efficiently help and develop multiple intelligences in children. Guidelines standard of section inquiries were prepared through a Delphi survey targeting twenty experts in early childhood education and traditional games. As a result, linguistic intelligence questions regarding writing, listening, speaking and vocabulary acquisition were selected. logical-mathematical intelligence questions regarding strategy, counting, patterns, hypothesis, verification, and comparing, contrasting, calculating ability were selected. Spatial intelligence questions regarding drawing, coloring, representation activities, operating and creating were selected, physical performance intelligence questions regarding global muscles, eye-hand coordination, flexibility, accommodation force, balance, agility and muscular strength were selected. Musical intelligence included questions about singing, and playing musical instruments. Interpersonal intelligence included perspective-taking, role-sharing, cooperation and discussion. For intrapersonal intelligence questions regarding personal significance-ties, planning-decision making, emotional expression and problem solving were selected. Finally, in relation to naturalist intelligence, questions regarding living organisms, inanimate objects and seasons were selected. In addition, traditional games were analyzed based on the finalized guidelines, and the results showed that each of the traditional games would not only work with one intelligence at a time but with other different intelligence as well. In the light of that, the study confirmed the validity of the guidelines on how to select traditional games that would develop multiple intelligences in children.

• Education of Primary School Mathematics
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• v.21 no.1
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• pp.55-73
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• 2018

The purpose of this study is to investigate the effects of cognitive activity on cognitive activities that students imagine and cope with continuously changing quantitative changes in functional tasks represented by linguistic expressions, table of value, and geometric patterns, We identified covariational reasoning levels and investigated the characteristics of students' reasoning process according to the levels of covariational reasoning in the elementary quantitative problem situations. Participants were seven 4th grade elementary students using the questionnaires. The selected students were given study materials. We observed the students' activity sheets and conducted in-depth interviews. As a result of the study, the students' covariational reasoning level for two quantities that are continuously covaried was found to be five, and different reasoning process was shown in quantitative problem situations according to students' covariational reasoning levels. In particular, students with low covariational level had difficulty in grasping the two variables and solved the problem mainly by using the table of value, while the students with the level of chunky and smooth continuous covariation were different from those who considered the flow of time variables. Based on the results of the study, we suggested that various problems related with continuous covariation should be provided and the meanings of the tasks should be analyzed by the teachers.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1589-1597
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• 2021

Submarine groundwater discharge (SGD) in coastal areas is gaining importance as a major transport route that bring nutrients and trace metals into the ocean. This paper describes the analysis of the seasonal changes and spatiotemporal characteristicsthrough the modeling monthly SGD for 35 years from 1986 to 2020 for the Nakdong river basin. In this study, we extracted 210 watersheds and SGD estimation points using the SRTM (Shuttle Radar Topography Mission) DEM (Digital Elevation Model). The average annual SGD of the Nakdong River basin was estimated to be 466.7 m²/yr from the FLDAS (Famine Early Warning Systems Network Land Data Assimilation System) recharge data of 10 km which is the highest resolution global model applicable to Korea. There was no significant time-series variation of SGD in the Nakdong river basin, but the concentrated period of SGD was expanded from summer to autumn. In addition, it was confirmed that there is a large amount of SGD regardless of the season in coastal area nearby large rivers, and the trend has slightly increased since the 1980s. The characteristics are considered to be related to the change in the major precipitation period in the study area, and spatially it is due to the high baseflow-groundwater in the vicinity of large rivers. This study is a precedentstudy that presents a modeling technique to explore the characteristics of SGD in Korea, and is expected to be useful as foundational information for coastal management and evaluating the impact of SGD to the ocean.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.133-153
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• 2023

In this paper, we propose a novel approach to investigating brain-signal measurement technology using Electroencephalography (EEG). Traditionally, researchers have combined EEG signals with bio-signals (BSs) to enhance the classification performance of emotional states. Our objective was to explore the synergistic effects of coupling EEG and BSs, and determine whether the combination of EEG+BS improves the classification accuracy of emotional states compared to using EEG alone or combining EEG with pseudo-random signals (PS) generated arbitrarily by random generators. Employing four feature extraction methods, we examined four combinations: EEG alone, EG+BS, EEG+BS+PS, and EEG+PS, utilizing data from two widely-used open datasets. Emotional states (task versus rest states) were classified using Support Vector Machine (SVM) and Long Short-Term Memory (LSTM) classifiers. Our results revealed that when using the highest accuracy SVM-FFT, the average error rates of EEG+BS were 4.7% and 6.5% higher than those of EEG+PS and EEG alone, respectively. We also conducted a thorough analysis of EEG+BS by combining numerous PSs. The error rate of EEG+BS+PS displayed a V-shaped curve, initially decreasing due to the deep double descent phenomenon, followed by an increase attributed to the curse of dimensionality. Consequently, our findings suggest that the combination of EEG+BS may not always yield promising classification performance.

• Journal of Life Science
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• v.34 no.2
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• pp.79-85
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• 2024

SlyA is known as a transcriptional regulator that regulates the expression of hemolysin (HlyE) in E. coli, a member of the Enterobacteriaceae family such as Salmonella. However, Salmonella has the slyA gene but lacks the hlyE gene. Then, because we were curious about the role of SlyA in Salmonella, we constructed and explored a mutant strain with a deletion of the slyA gene. S. Typhimurium CK295 (ΔslyA) was constructed using an allelic exchange approach. In a comparative analysis between the wild-type and the CK295 strain, no significant differences were observed in growth characteristics, motility, total protein analyses, and secreted protein analyses. However, the CK295 strain exhibited slightly reduced biofilm formation compared to the wild-type. Interestingly, as a result of comparing the survival ability in macrophages, the mutant strain showed a 60% decrease in survival ability compared to the wild-type. To evaluate toxicity in mice, mortality was measured after oral administration to 6-week-old BALB/c mice. As a result, the LD₅₀ value of the CK295 (ΔslyA) was more than 100 times higher than that of wild-type S. Typhimurium 𝜒3339 in BALB/c. In conclusion, SlyA is presumed to regulate the expression of genes encoding virulence factors involved in the in vivo survival of Salmonella.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.63-70
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• 2024

This study explored computer vision methods using the OpenCV open-source library to characterize the phenotypes of various horticultural crops. In the case of tomatoes, image color was examined to assess ripeness, while support vector machine (SVM) and histogram of oriented gradients (HOG) methods effectively identified ripe tomatoes. For sweet pepper, we visualized the color distribution and used the Gaussian mixture model for clustering to analyze its post-harvest color characteristics. For the quality assessment of netted melons, the LAB (lightness, a, b) color space, binary images, and depth mapping were used to measure the net patterns of the melon. In addition, a combination of depth and color data proved successful in identifying flowers of different sizes and distances in cucumber greenhouses. This study highlights the effectiveness of these computer vision strategies in monitoring the growth and development, ripening, and quality assessment of fruits and vegetables. For broader applications in agriculture, future researchers and developers should enhance these techniques with plant physiological indicators to promote their adoption in both research and practical agricultural settings.

• Journal of the Economic Geographical Society of Korea
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• v.1 no.1
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• pp.151-172
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• 1998

Over the past two decades, the process of globalization of multinational corporations has increased at a rapid rate. One manifestation of this process is the establishment of corporate head offices in a variety of international centers to administer and coordinate, the day-to-day operations in the host countries. In establishing a subsidiary overseas a firm creates a direct link between the operations of the domestic corporate center and the foreign host center This paper investigates elements of stability and change in the international linkage patterns among domestic parent corporations and host subsidiaries over the past several decades. In particular, it seeks answers to a number of question related to stability and change in linkages among foreign centers of control and those Canadian centers selected to administer the subsidiary operations from 1970 to 1991 over the four primary sectors, namely, resources, manufacturing, services, and finance. By confirming the core stability and dispersed linkages hypotheses, the papar offers some generalizations with respect to the location and stability of subsidiary headquarters centers in Canada and their respective subsector specialties. Finally, it addresses further research avenues fer the quaternary place study.

• Journal of Ethics
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• no.77
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• pp.73-112
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• 2010

This study aims to explore the character and problem of multicultural society in Korea in terms of the concept of moral panics. Its major issues are dealt with as follows: Firstly, this essay will apply two concepts of culture in multiculturalism - the pattern of meaning and a study of perfection- to three degrees of multicultural members: by individual, by groups and by a society as a whole. In this approach, moral panics of multicultural society in Korea have been manipulated by the secondary definitions like Korean government and media. In this study, however, the resource of the panics would be seen as nationalism in Korean history. To remove it in this essay, the conception of the pattern of meaning, which makes members understand others outer their norms, should be harmonized with that of a study of perfection by which they have identities. Secondly, the main subject of multiculturalism in Korea should at least be majority (groups)-Korean, not minority (groups)-foreigners. A stereotype of foreigners by majority is an image distorted by nationalities and races. People, for example, with the white skin from advanced countries are recognized as superior, while those born in the countries of Southeast Asia are, consciously or unconsciously, discriminated and have low positions due to socio-economic stratification in Korea. In this sense, a study of multicultural society in Korea should go forward to the inner direction to majority, because it is one of the real moral panics in Korea. In conclusion, it is important that there must be a study of identity which we can have of others in multicultural studies of Korea. It enables us to meet the conception of diversity. In that Korean government and media have neglected the danger of nationalism, it is also necessary that this study have any foundation of morality in ethics, which can give useful alternatives to the given polices of the secondary definitions.