• Journal of Appropriate Technology
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• v.7 no.1
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• pp.85-92
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• 2021

The research topics of the appropriate technology include environment, medical, education, and energy etc. Therefore, having a review on appropriate technology requires huge efforts of specialists from many difference research areas. Social network analysis has been applied to understand the relationships among the components in the network and to provide insights by visualizing the huge network having many components. In this study, the co-authors and their research topics at the international conference on appropriate technology (ICAT) held by Academic Society for Appropriate Technology (ASAT) from 2017 to 2019 were analyzed using the statistical and visualization tools. The networks between co-authors were analyzed using the pretreated data which were collected from ASAT. The annual trend or characteristics of the general information on ICAT were also analyzed.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.367-375
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• 2021

This study aimed to identify the knowledge structure of researches on 'untact' and derived implications for directions for the studies using text mining. The study included network analysis and topic modelling of keywords and abstracts from 171 thesis published until October 2020. Centrality analysis showed that 'untact' studies had been focused on service, usage, consumption, technology and online. From the topic modelling, 6 topics such as 'COVID-19 and socio-technological change', 'needs and utilization of education contents', 'technology and service for user convenience', 'product marketing and sales', 'service design of the company', 'influence factors of usage and consumption' were extracted. Keywords that connect each topic were technology, service, usage, consumption, needs and factor. Exploratory analysis of 'untact' researches using text mining provides useful results for development of 'untact' studies.

• Journal of the Korean Electrochemical Society
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• v.25 no.2
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• pp.51-68
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• 2022

Although lithium metal batteries have a high energy density, experimental skills capable of solving lots of problems induced by dendrite such as short circuit, low coulomb efficiency, capacity loss, and cycle performance are still only in academic research stage. In this paper, research cases for dendrite growth inhibition on lithium metal electrode were classified into four types: flexible SEI (solid electrolyte interface) layer responding to volume expansion of lithium metal electrode, SEI supporting layer to inhibit dendrite growth physically, SHES (self-healing electrostatic shield) mechanism to adjust lithium growth by leading uniform diffusion of Li⁺ ions, and finally micro-patterning to induce uniform deposition of lithium. We hope to advance the practical use of lithium metal electrode by analyzing pros and cons of this classification.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.8
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• pp.259-268
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• 2022

With prosperous usage of cloud services to improve management efficiency due to the explosive increase in data volume, various cryptographic techniques are being applied in order to preserve data privacy. In spite of the vast computing resources of cloud systems, decrease in storage efficiency caused by redundancy of data outsourced from multiple users acts as a factor that significantly reduces service efficiency. Among several approaches on privacy-preserving data deduplication over encrypted data, in this paper, the research results for improving efficiency of encrypted data deduplication using trusted execution environment (TEE) published in the recent USENIX ATC are analysed in terms of security and efficiency of the participating entities. We present a way to improve the stability of a key-managing server by integrating it with individual clients, resulting in secure deduplication without independent key servers. The experimental results show that the communication efficiency of the proposed approach can be improved by about 30% with the effect of a distributed key server while providing robust security guarantees as the same level of the previous research.

• Journal of The Korean Association of Information Education
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• v.26 no.4
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• pp.265-272
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• 2022

According to the presentation of the new national curriculum, this study aims to analyze teacher's perceptions of the information education for lower grade students in elementary school. Before conducting survey, analyzing overseas and domestic researches were preceded. The questionnaires were collected by an online survey of 166 incumbent elementary school teachers after verification by an expert group. As a result, contrary to the basis of the information education curriculum to be strengthened, teacher's stagnant negative perceptions could be confirmed through various measurement variables. Before the introduction of a new national curriculum in 2024, it is a time when efforts to improve teacher's perceptions of information education for lower graders are particularly necessary.

• Journal of Platform Technology
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• v.11 no.3
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• pp.12-23
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• 2023

In the 2020s, the K-Pop market has been dominated by girl groups over boy groups and the fourth generation over the third generation. This paper presents methods and results on lyric clustering to investigate whether the generation of girl groups has started to change. We collected meta-information data for 1469 songs of 47 groups released from 2013 to 2022 and classified them into lyric information and non-lyric meta-information and quantified them respectively. The lyrics information was preprocessed by applying word-translation frequency vectorization based on previous studies and then selecting only the top vector values. Non-lyric meta-information was preprocessed and applied with One-Hot Encoding to reduce the bias of using only lyric information and show better clustering results. The clustering performance on the preprocessed data is 129%, 45% higher for Spherical K-Means' Silhouette Score and Calinski-Harabasz Score, respectively, compared to Hierarchical Clustering. This paper is expected to contribute to the study of Korean popular song development and girl group lyrics analysis and clustering.

• Journal of Creative Information Culture
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• v.3 no.1
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• pp.29-36
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• 2017

The Ministry of Education announced plans to introduce SW education to elementary and secondary schools in the 2015 curriculum. However, if we examine major foreign countries where SW education strongly implemented it is found that they stress not only coding education but also real life SW education. Especially they emphasized convergence with other different fields. Therefore, it can be concluded SW education in Korea should be differentiated based on levels of students. For the common basic curriculum, it is needed basic concepts and thinking skills of SW development, but for the enriched curriculum, it should be emphasized SW development education that can be applied to real life experiences and other difference fields as well. Therefore, it is necessary to plan SW intensive education to develop programs for the enriched program. In this study, I explored how virtual reality programming education can be applied to the level of elementary and secondary school students as an enrichment program.

• Journal of the Korean Geotechnical Society
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• v.25 no.11
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• pp.75-86
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• 2009

This paper presents the results of a numerical investigation on load carrying capacity of geogrid-encased stone columns to use as load carrying column(s) supporting a foundation load. A validated 3D stress-pore pressure coupled model that can effectively show rapid drainage capability of stone columns and encasement effect of geogrid was adopted and a parametric study was carried out on a number of influencing factors. It is shown that the geogrid encased stone columns can be effectively used as foundation load supporting columns in soft ground. The results of numerical investigation were presented so that the relationship between the load carrying capacity of geogrid-encased stone columns and the influencing factors can be identified. Practical implications of the findings are also discussed.

• Journal of the Korean Geotechnical Society
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• v.25 no.11
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• pp.61-73
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• 2009

In this study, we grasped the resistance state of the back ground which had a notable influence on computing the lateral resistance of the laterally loaded single pile in the homogeneous ground by the model test. In order to grasp a resistance behavior, we have to know the deformation area of the back ground and the side failure angle other than the rotation point of pile and vertical failure angle of back ground which were proposed by Bae & Kim in 2008. We found out in this test the characteristics of the behavior of the back ground in accordance with the shape and size of the pile and ground density. We examined the interrelationship of the relative density of sand, the size and the sectional shape of the pile as well.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.43-50
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• 2022

Claude Debussy's is a solo piano piece written in 1894. However, for unknown reasons, the entire piece was not published until 1977, despite clear evidence that Debussy intended to publish it during his lifetime. Interestingly, the second movement of the three pieces comprised in the work was published independently in February 1896 through the Parisian periodical Le Grand Journal. Partly because the work was recently published, it remains relatively more unknown to pianists and music lovers than other piano solo pieces by Debussy. Thus, this article addresses in detail the compositional background of this work, focusing on why the work was not published during Debussy's lifetime. Furthermore, by analyzing this piece in detail, this article intends to discuss the stylistic characteristics of the work regarding its melody, phrase structure, harmony, and form. This survey, which would help understand the musical style embodied in this piece, aims to contribute to improving the awareness of the work.