• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.93-97
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• 2022

The purpose of this study is to suggest implications for early childhood SW·AI education considering the characteristics of early childhood education through a survey on SW·AI education in kindergartens. For this study, data were collected from 194 kindergartens through convenience sampling. The data was analyzed using frequency distribution, and it was found that 44% of kindergartens are conducting SW·AI education. 22% are conducting SW·AI education in the form of regular curriculum, and 70% are conducting SW·AI education in the form of special activities after school. SW·AI education was found to be conducted mainly by external instructors (97%) in the classroom (80%). For SW·AI education, block coding-based programs developed by companies such as Naver and the Clova were used, and all of these programs used programs and teaching aids in a package format, including teaching aids and materials developed by companies. 56% answered that they are not currently conducting SW/AI education, and lack of awareness on SW·AI education and lack of human/environmental infrastructure were the main factors. In order to realize SW·AI education considering the characteristics of early childhood education based on this survey, First, SW·AI education programs should be developed to develop play-centered computational thinking skills. Second, systematic teacher education at the national level should be conducted. Finally, the establishment of a department dedicated to early childhood SW·AI consisting of early childhood education experts and SW·AI education experts and financial support at the national level should be provided.

• Journal of the Korean Geotechnical Society
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• v.39 no.10
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• pp.41-48
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• 2023

The presence of abnormalities in the subgrade of roads poses safety risks to users and results in significant maintenance costs. In this study, we aimed to experimentally evaluate the temperature distributions in abnormal areas of subgrade materials using infrared cameras and analyze the data with machine learning techniques. The experimental site was configured as a cubic shape measuring 50 cm in width, length, and depth, with abnormal areas designated for water and air. Concrete blocks covered the upper part of the site to simulate the pavement layer. Temperature distribution was monitored over 23 h, from 4 PM to 3 PM the following day, resulting in image data and numerical temperature values extracted from the middle of the abnormal area. The temperature difference between the maximum and minimum values measured 34.8℃ for water, 34.2℃ for air, and 28.6℃ for the original subgrade. To classify conditions in the measured images, we employed the image analysis method of a convolutional neural network (CNN), utilizing ResNet-101 and SqueezeNet networks. The classification accuracies of ResNet-101 for water, air, and the original subgrade were 70%, 50%, and 80%, respectively. SqueezeNet achieved classification accuracies of 60% for water, 30% for air, and 70% for the original subgrade. This study highlights the effectiveness of CNN algorithms in analyzing subgrade properties and predicting subsurface conditions.

• Composites Research
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• v.37 no.1
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• pp.7-14
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• 2024

Due to the structural characteristic of a double roller, the double roller can have various deformation behaviors depending on a gap block design, even if dimensions and loading conditions for the double roller are the same. Based on this feature, we propose a strategy for designing the gap block of the carbon-fiber reinforced plastic (CFRP) double roller to minimize defects (e.g., sagging and wrinkling), which can be raised during the product conveying process, with the pursue of the lightweight design. In the suggested strategy, analysis cases are first selected by considering main design parameters and engineering tolerances of the gap block, and then deformation behaviors of these selected cases are extracted using the finite element method (FEM). Here, to obtain the optimal gap block parameters that satisfy the purpose of this study, deformation deviations in the contact area are calculated and compared using the extracted deformation behaviors. Note that the contact area in this work is located between the product and the roller. As a result, through the design method of the gap block proposed in this work, it is possible to construct the CFRP double roller that can significantly decrease the defects without changing the overall sizes of the roller. A detailed method is suggested herein, and the results are evaluated in a numerical way.