• Journal of Industrial Convergence
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• v.22 no.8
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• pp.1-17
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• 2024

Recently, interest in edutech has been focused on its fusion with AI technology, and the market in this field is expanding. This study aims to analyze the technological competitiveness and key technological areas of major countries in the AI-edutech field. Additionally, considering that AI-edutech is a convergence of AI technology and edutech, the study seeks to examine the path dependence of AI-edutech in each country to determine whether they are based on existing AI technologies or edutech. To this end, AI-edutech patents were collected and competitiveness was analyzed using patent activity, patent impact, and market acquisition indicators. Path dependence for each country was analyzed using the hurdle negative binomial regression model. The analysis results indicate that the major countries in the AI-edutech field are China, South Korea, the United States, India, and Japan. In terms of patent activity, China had the highest level, followed by South Korea. In terms of patent impact and market securing power, the United States was high in both aspects, Japan had high market securing power, and South Korea had high patent influence. The results of the hurdle negative binomial analysis presented unique findings. The logit part results indicated that the possession of existing AI and edutech did not positively affect the emergence of current AI-edutech, but the count part results showed a positive influence. This suggests that, overall, it is difficult to assert that current AI-edutechs are based on past AI and edutechs. However, once some AI-edutechs based on existing AI and edutechs emerge, they are influenced by the existing technologies. These findings provide implications for future research and technological strategies in this field.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1897-1905
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• 2013

Rheological properties such as yield stress and viscosity is the main parameters to determine the fluidity of the debris flow. In this study, several series of rheometer tests were performed to investigate rheological properties of fine-grained soil samples with various sand contents and various liquidity indices. Test results indicated that the general shape of the flow curves for fine-grained soils had characteristics of a shear thinning fluid, with a decrease in viscosity as shear rate increases. The yield stress and viscosity of fine-grained soil samples with same sand content gradually decreased as the liquidity index increased. At the same liquidity index, yield stress and viscosity of fine-grained soil increased with an increase in sand content. The yield stress and viscosity of fine-grained soil greatly decreased with a slight increase in water content. Also, the yield stress and viscosity tend to increase with increasing concentration by volume($C_v$) of the fluid matrix. The values of the four coefficients ${\alpha}_1$, ${\alpha}_2$, ${\beta}_1$, and ${\beta}_2$ were obtained by regression analysis for each fine-grained soil.