• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.391-396
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• 2021

The purpose of this study is to study the possibilities and limitations of arts education by utilizing SKT's ifland metaverse Platform for arts majors. To summarize the performance of the study, it is as follows. The subjects of the study were 50 students(25 experimental group, 25 control group) in Performing Arts, Entertainment and Music department of D University located at Gyeonggi, Korea. As a result of analyzing the difference between the pre-test and the post-test between the experimental group and the control group, it was found that there was a statistically significant effect on the effectiveness of the arts education method using the metaverse of the control group. It is hoped that the results of this study will be a case study that cannot be overlooked in the development of the today's arts educational medium as well as the virtual world in the field of arts and in cultural technology research, arts education is no longer a latecomer, but a leading pioneer and main agent, and I hope that it will become a new perspective for various studies connected with industry like the WAVE.

• Journal of Korean Society of Rural Planning
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• v.27 no.4
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• pp.55-70
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• 2021

In this study, in the field of remote sensing, where the scope of application is rapidly expanding to fields such as land monitoring, disaster prediction, facility safety inspection, and maintenance of cultural properties, monitoring of rural space and surrounding environment using UAV is utilized. It was carried out to verify the possibility, and the following main results were derived. First, the aerial image taken with an unmanned aerial vehicle had a much higher image size and spatial resolution than the aerial image provided by the National Geographic Information Service. It was suitable for analysis due to its high accuracy. Second, the more the number of photographed photos and the more complex the terrain features, the more the point cloud included in the aerial image taken with the UAV was extracted. As the amount of point cloud increases, accurate 3D mapping is possible, For accurate 3D mapping, it is judged that a point cloud acquisition method for difficult-to-photograph parts in the air is required. Third, 3D mapping technology using point cloud is effective for monitoring rural space and rural resources because it enables observation and comparison of parts that cannot be read from general aerial images. Fourth, the digital elevation model(DEM) produced with aerial image taken with an UAV can visually express the altitude and shape of the topography of the study site, so it can be used as data to predict the effects of topographical changes due to changes in rural space. Therefore, it is possible to utilize various results using the data included in the aerial image taken by the UAV. In this study, the superiority of images acquired by UAV was verified by comparison with existing images, and the effect of 3D mapping on rural space monitoring was visually analyzed. If various types of spatial data such as GIS analysis and topographic map production are collected and utilized using data that can be acquired by unmanned aerial vehicles, it is expected to be used as basic data for rural planning to maintain and preserve the rural environment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.20-29
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• 2022

In this study, in order to improve the durability of the cement composite printed with the ME type 3D printer, PDMS, sodium silicate, and a surface hardener were employed. Post-treatment was performed on 3D-printed cement composite by coating after immersion, and the degree of improvement in durability was evaluated. As a result, in all evaluations, the durability performances of the post-processed specimens were improved compared to those of the plain specimens. Water absorption resistance, chloride penetration resistance, and carbonation resistance of the PDMS treated specimens were improved by 36.3 %, 77.1 %, and 50.4 % when compared to plain specimens. Freeze-thaw resistance of the specimens treated with sodium silicate was found to be the most excellent, with an average enhancement of 47.5% compared to plain specimens. It was found that PDMS was the most efficient post-treatment materials for 3D-printed cement composite. However, as suggested in this study, the post-treatment method by coating after immersion may not be applicable to cement composite structures printed with a 3D printer in field. Therefore, a follow-up study needs to be preformed on the durability enhancing materials suitable for 3D printing.

• Journal of Appropriate Technology
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• v.6 no.2
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• pp.94-102
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• 2020

Renewable energy (RE) is essential to comprise sustainable societies, especially, in rural villages of developing countries. Furthermore, application of off-grid RE systems to health care can improve the quality of life. In this research, a RE-based vaccination supply management system was constructed to enlarge the cold-chain in developing countries for the safe storage and delivery of vaccines. The system was comprised of the construction of RE plants and development of vaccine carriers. RE plants were constructed and connected to health posts in local villages. The cooling mechanism of vaccine carriers was improved and monitoring devices were installed. The effect of the system on vaccine cold-chain was evaluated from the field test and topographical analysis in the southern village of Nepal. RE plants were normally operated for the vaccine refrigerator in the health post. The modified vaccine carriers had a longer operation time and better temperature control via monitoring and RE-based recharging functionality. The topographical analysis estimated that the system can cover larger region. The system prototype showed great potential regarding the possibility of a sustainable and enlarged cold-chain. Thus, RE-based vaccine supply management is expected to facilitate vaccine availability while minimizing waste in the supply chain.

• Journal of the Korean GEO-environmental Society
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• v.22 no.6
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• pp.5-15
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• 2021

One of the construction methods applied as a pier foundation type is a single type cast-in-place pile. In applying a pile bent system as a foundation type, the main concern in designing can be said to secure the lateral bearing capacity of pile structure in system. In addition, to increase the rigidity of the pile structure, a method of increasing the lateral bearing capacity by reinforcing the pile structure with a casing has been used. However, although the reinforcing effect and appropriate reinforcing length of casing may vary depending on the soil conditions, there is insufficient studies on this, and for this reason, the entire pile structure in a pile bent system is reinforced with a casing, in the field. In addition, if the length of the entire pile is reinforced with a casing, it may lead to delays in construction and increase in construction costs. That is, in order to more effectively reinforce the pile structure with a casing, it is necessary to study the lateral bearing characteristics of the reinforced pile structure in system. And it should be determined the appropriate reinforcing length of the casing from the evaluated bearing characteristics. Therefore, in this study, the lateral bearing characteristics of piles applied with the reinforcing length of casing for each condition were evaluated through a numerical analysis. And, based on the analysis results, the appropriate reinforcing length of casing was proposed. As a result of the study, it was found that in order to effectively increase the lateral bearing capacity of pile structure, the reinforcing length of casing should be applied twice the influence range of the bending behavior of the pile, 1/β.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.195-201
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• 2022

The main objective of this work is to prepare Rehmannia glutinosa extract (RE) incorporated functional chitosan (CH) based biomaterials and evaluate their physical properties, RE release properties, inhibitory effect of melanogenesis, and antioxidant and elastase inhibitory activities. RE incorporated CH based biomaterials were synthesized by a casting method and UV curing process. The surface and cross sections of prepared biomaterials were characterized by a field emission scanning electron microscope (FE-SEM). The physical properties such as tensile strength and elongation at break were also investigated. To apply the transdermal drug delivery system, RE release properties were examined with pH 4.5, 5.5, and 6.5 buffer solutions and artificial skin test at 36.5 ℃. Results indicated that RE release of RE incorporated biomaterials with/without the addition of plasticizers [glycerol (GL) and citric acid (CA)] at pH 6.5 was about 1.10 times higher than that of at pH 4.5. In addition, results of the artificial skin test verified that RE was released constantly for 6 h. To verify the applicability of the prepared biomaterials, tyrosinase, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and elastase assays were investigated. Results indicated that RE incorporated biomaterials added CA exhibited tyrosinase activation, DPPH radical scavenging activity rate, and elastase activation of 45.12, 89.40, and 59.94%, respectively.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.25-40
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• 2022

This study is about how the quality of M2M big data that provides real-time information affects users. Recently, there are many difficulties in acquiring and managing data because data types such as variety, data volume, and data velocity are changing rapidly and diversified. This not only leads to a decrease in data quality but also it can give a negative impact when making decisions using data. Generally, the quality of data is defined as 'suitability for use', which means that data quality must meet the expectations of user needs. Therefore, data providers need activities to improve data quality for this purpose, and the key is to identify data quality dimensions in each field where data is used and provide data suitable for the level of user needs. In this study, the relationship between the quality area of real-time M2M data used in the traffic information system and user satisfaction was analyzed. Research models and hypotheses were established to analyze the effects between variables related to M2M big data. In order to test the hypothesis, a causal relationship between the major factors was identified by conducting a survey and analyzing the data users.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.553-564
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• 2022

Concrete is a representative composite material that shows excellent performance in the construction field. However, it is a brittle and nonhomogeneous material and exhibits weak behavior against bending and tensile forces. To compensate for such weakens, fiber reinforcement has been utilized, and steel fiber has been recognized as one of the best material for such purpose. However, steel fiber can seriously affect the durability of concrete exposed to the marine environment due to the corrosion caused by chlorine ions. This study intended to evaluate the mechanical performance of steel fiber reinforce concrete during and after repeated wet/dry cycles in salt solution. According to the experimental results, there was no reduction in the relative dynamic modulus of concrete during the repeated wet/dry cycles in salt solution for 37 weeks. Flexural strength was not decreased after completion of repeated wet/dry cycles in salt solution. There was no sign of corrosion in steel fibers after visual observation of fractured surface. However, the flexural toughness was decreased, and this is because about half of the concrete specimen showed failure before reaching the maximum displacement of 3 mm. Although repeated wet/dry cycles in salt solution did not cause cracks in concrete through corrosion of steel fibers, specific attention is required because it can reduce flexural toughness of steel fiber reinforced concrete.

• Journal of the Korean Society for Library and Information Science
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• v.56 no.4
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• pp.239-267
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• 2022

In this study, the adolescents' perception of the Information Search Process(ISP); their anxiety and the need for intervention during the process were investigated based on Kuhlthau's ISP model, and the relationship among the factors was analyzed with structural equations. In addition, the effectiveness of scaffolding strategy to the experimental group during the class was verified. The main findings are as follows. First, as a result of exploring the anxiety felt by learners and the need for intervention in the information search process, it was found that the presentation stage had a significant effect on the anxiety, and the collection, presentation, and assessment stages had significant effects on the need for intervention. Second, as a result of controlling each variable to investigate the anxiety felt by learners and necessity of intervention in the information search process, it was confirmed that among the demographic variables, the difference between the first graders and the second ones was significant; and the difference in the metropolitan area was more significant than that in the Gangwon province. Third, as a result of paired t-test and covariance analysis on the control group and the experimental group, it was confirmed that the anxiety and need for intervention of the experimental group were statistically significantly reduced. The significance of this study lies in the point that it presents a practical basis for applying scaffolding strategies appropriate to information search process in the field of education.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.803-814
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• 2022

The Lao government is continuously developing hydro-power dams in addition to the existing eight power plants in the Nam Ngum River basin and is expanding the power capacity of the existing power plants to meet the expected increase in electricity demand. Accordingly, the Lao government has requested an update on the existing reservoir operating rule curve in order to run the power plants efficiently. To this end, this study reviewed the current independent operating system as well as the joint operating system in order to maximize the annual power generation produced by a power plant by using CSUDP, general-purpose dynamic programming (DP) software. The appropriate operating regulation curve forms (URC/LRC, MRC) were extracted from the DP results, and the annual power generations were simulated by inputting them as the basic operating data of the reservoir operation set of the HEC-ResSim program. By synthesizing the amount of the annual power generation simulated, the existing operation regulation curve, the operational performance, and the opinion of the field operator, the optimal reservoir operation regulation curves that maximize the annual power generation of the target power plant were developed. Results revealed that a system operating in conjunction with the reservoir produces about 2.5 % more power generation than an independent reservoir due to the synergistic effect of the connection.