• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.55-60
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• 2020

The PERC photovoltaic (PV) modules installed in PV power plant are still reports potential-induced degradation (PID) degradation due to high voltage potential differences. This is because Na+ ions in the cover glass of PV modules go through the encapsulant (EVA) and transferred to the surface of solar cells. As positive charges are accumulated at the ARC (SiOx/SiNx) interface where many defects are distributed, shunt-resistance (Rsh) is reduced. As a result, the leakage current is increased, and decrease in solar cell's power output. In this study, to prevent of this phenomenon, a Moth-eye nanostructure was deposited on the rear surface of an optical film using Nano-Imprint Lithography method, and a solar mini-module was constructed by inserting it between the cover glass and the EVA. To analyze the PID phenomenon, a cell-level PID acceleration test based on IEC 62804-1 standard was conducted. Also analyzed power output (Pmax), efficiency, and shunt resistance through Light I-V and Dark I-V. As a result, conventional solar cells were decreased by 6.3% from the initial efficiency of 19.76%, but the improved solar cells with the Moth-eye nanostructured optical film only decreased 0.6%, thereby preventing the PID phenomenon. As of Moth-eye nanostructured optical film, the transmittance was improved by 4%, and the solar module output was improved by 2.5%.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.177-184
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• 2021

While veterinary antibiotics are used only in a part of the dose administered, the rest are excreted as urine or feces. Residual antibiotics enter the adjacent agricultural environments by spraying manure-based composts on farmlands and lead to secondary pollution. Therefore, it is necessary to develop the technique for post management such as regulatory levels of antibiotics in the agricultural environments. This study was conducted to compare by different matrices the amount of residual antibiotics such as tetracyclines and sulfonamides, which are known to be frequently used in Korea and to practice risk assessment by different antibiotics in soils before and after application of composts. Pre-treatment with modified typical method using buffer and solid phase extraction showed the recovery of composts and soils was more than 70% at ppb level and the limits of detection were 0.13-0.46 and 0.05-0.25 ㎍/kg, respectively. Analysis of manure-based composts revealed concentrations from 5.38 to 196.0 ㎍/kg for tetracyclines, from below the detection of limit (BDL) to 259.0 ㎍/kg for sulfonamides. In case of agricultural soils, residual concentrations of selected veterinary antibiotics were ranged 0.30-53.3 ㎍/kg, BDL-4.16 ㎍/kg respectively and the concentration level of tetracyclines, which had higher soil distribution coefficient (Kd) values, was higher than that of sulfonamides. There was a difference in human risk assessment by different antibiotics in soil before and after application of composts. But, it was indicated that detection values of all of 5 antibiotics were very safe on the basis that Hazard Quotient was safe below 1.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.239-250
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• 2021

When considering the introduction of a new technology, it is important to accurately grasp and selectively apply the technical characteristics related to the technology in order to fully utilize the advantages of the technology. In this study, the technical characteristics of high relative importance were analyzed in order to increase the efficiency of new application of blockchain technology by companies. The technical characteristics of the blockchain identified through previous research were reclassified from the perspective of the system hierarchy, and sub-factors of the technical characteristics were derived. In addition, a questionnaire survey on the relative importance of technical characteristics was conducted for internal experts and SI experts using the Analytical Hierarchy Process (AHP) technique. As a result of the analysis, respondents evaluated data protection as the most important factor in the threat of hacking related to security. In addition, it was different that the comparison results of the importance of the technical characteristics between the experts in the company and the SI experts and the priority of the technical characteristics between the expert groups by industry. It is expected that the results of this study will be usefully utilized when using blockchain technology in enterprises in line with the upcoming changes of the 4th industrial revolution. An empirical analysis of the internal and external factors required for adoption of blockchain technology by industry and the effect of technology introduction will be a meaningful study.

• Journal of Korean Society on Water Environment
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• v.38 no.2
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• pp.95-102
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• 2022

Studies for improving the efficiency of the traditional anaerobic digestion process are being actively conducted. To improve anaerobic digestion efficiency, this study tried to derive the optimal pretreatment conditions and mixing conditions by integrating the heat solubilization pretreatment of sewage sludge, livestock manure, and food waste. The soluble chemical oxygen demand (SCOD) increase rate of sewage sludge before and after heat solubilization pretreatment showed an increased rate of 224.7% compared to the control group at 170℃ and 25 min and showed the most stable increase rate. As a result of the biomethane potential test of sewage sludge before and after heat solubilization pretreatment, the total chemical oxygen demand (TCOD) and SCOD removal rates increased as the heat solubilization temperature increased, but did not increase further at temperatures above 170℃. In the case of methane generation, there was no significant change in the cumulative methane generation from 0.134 to 0.203 Sm³-CH₄/kg-COD at 170℃ for 15 min. As a result of the integrated digestion of organic waste, the experimental condition in which 25% of the sewage sludge, 50% of the food waste, and 25% of the livestock manure were mixed showed the highest methane production of 0.3015 m³-CH₄/kg-COD, confirming that it was the optimal mixing ratio condition. In addition, under experimental conditions mixed with all three substrates, M4 conditions mixed with 25% sewage sludge, 50% food waste, and 25% livestock manure showed the highest methane generation at 0.2692 Sm³-CH₄/kg-COD.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.592-608
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• 2022

This study conducted a group reminiscence program for the elderly who use the elderly daycare center. And this study verified the effectiveness of the elderly's mental health related quality of life to identify the relationship between the participating elderly and the non-participating elderly in a group reminiscence program. To this end, in order to examine the effectiveness of a group reminiscence programs for the elderly using the daycare center on MHRQoL, and the difference between the experimental group and the control group was compared with the non-equivalent control group pre-post test design. The research results are as follows. First, the experimental group that conducted the group reminiscence program in this study had a higher quality of life than the control group that did not participate the group reminiscence program. Second, significant results were found in vitality and mental health in the sub-factors of MHRQoL of the experimental group, and emotional role restriction and social function did not show significant results. Based on the results of this study, to develop and improve programs that encompass the entire sub-areas of MHRQoL, and to implement programs that positively affect the psycho-social intervention for the elderly persons. Finally, it was suggested to link and cooperate with senior welfare centers and general social welfare centers.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.167-182
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• 2022

The accident data attributes of the traffic accident report are used not only in traditional traffic safety-related research to identify the cause of traffic accidents, but also as basis data for the development of the automated vehicle driving performance verification scenarios. However, since the data attributes of the traffic accident report are limited for the purpose of reconstructing the traffic situation and developing scenarios, this study aims to provide the directions for improvement of traffic accident report, ultimately for its expanded usability for the automated vehicle test scenarios. The directions for improvement of the traffic accident report are provided by categorizing the traffic situation before the accident (pre-crash), the situation immediately before or during the accident (on-crash), and the situation after the accident (post-crash), respectively. Additional data items or data processing methods are presented. Furthermore, data elements that can be extracted from the traffic accident process data in the unstructured narrative form are explored and provided.

• Journal of Applied Biological Chemistry
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• v.65 no.2
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• pp.101-105
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• 2022

Quercetin is a major flavonoid in onion and known to antimicrobial activity against several pathogenic bacteria. However, the antibacterial activity of quercetin had not been evaluated against plant pathogenic Xanthomonas campestris and Erwinia carotovora. In here, quercetin and the solvent extracts of onion were investigated their antibacterial activity. Quercetin showed a selective inhibitory activity against X. campestris, and the minimal inhibition concentration (MIC) and minimal bactericidal concentration of quercetin were 15.6 and 20.0 ㎍ mL^-1 respectively. Otherwise, it showed no inhibitory activity against E. carotovora, and no the additive and the synergistic effects with streptomycin on X. campestris. And the EtOAc extract from the peel of onion that contained quercetin showed 2-fold lower MIC (500 ㎍ mL^-1) than the EtOH extract, thus EtOAc was suggested as the extraction solvent for quercetin from onion peel.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.5
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• pp.133-138
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• 2022

Recently, as GPU performance has improved in HPC and artificial intelligence, its use is becoming more common, but GPU programming is still a big obstacle in terms of productivity. In particular, due to the difficulty of managing host memory and GPU memory separately, research is being actively conducted in terms of convenience and performance, and various CPU-GPU memory transfer programming methods are suggested. Meanwhile, recently many SoC (System on a Chip) products such as Apple M1 and NVIDIA Tegra that bundle CPU, GPU, and integrated memory into one large silicon package are emerging. In this study, data between CPU and GPU devices are used in such an integrated memory device and performance-related research is conducted during transmission. It shows different characteristics from the existing environment in which the host memory and GPU memory in the CPU are separated. Here, we want to compare performance by CPU-GPU data transmission method in NVIDIA SoC chips, which are integrated memory devices, and NVIDIA SMX-based V100 GPU devices. For the experimental workload for performance comparison, a two-dimensional matrix transposition example frequently used in HPC applications was used. We analyzed the following performance factors: the difference in GPU kernel performance according to the CPU-GPU memory transfer method for each GPU device, the transfer performance difference between page-locked memory and pageable memory, overall performance comparison, and performance comparison by workload size. Through this experiment, it was confirmed that the NVIDIA Xavier can maximize the benefits of integrated memory in the SoC chip by supporting I/O cache consistency.

• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.83-89
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• 2022

Since the pandemic of COVID-19, active investigation to develop immunity to infectious disease by delivering nucleic acids has been proceeded. Particularly, many studies have been conducted on non-viral vector as several vital side-effects which were found on nucleic acid delivery system using viral vectors. In this study, we have developed plasmid DNA (pDNA) loaded-hyaluronic acid derivative (HA) coated-polyethyleneimine (PEI) based polyplex for enhanced nucleic acid delivery efficiency. We have optimized the ratio of pDNA : PEI : HA by measuring size and protein transcription efficiency. The final product, polyplex-HA, was characterized through measuring size, zeta-potential and TEM image. Intracellular uptake and protein transcription efficiency were compared to commercially available transfection reagent, lipofectamine, through fluorescence image and flow cytometry. In conclusion, polyplex-HA presents a novel gene delivery system for efficient and stable protein transcription since it is available for delivering various genetic materials and has less immunoreactivity.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.34 no.1
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• pp.209-238
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• 2023

This study aims to propose the main learning contents, functions and activation plans for building an e-learning platform for libraries through a literature review, case analysis and expert survey. Through the literature review, it was found that libraries must play a role in providing high-quality online education for users in the e-learning ecosystem. Based on the previous studies, a learning function analysis tool was developed for the analysis of the library's e-learning platform. Based on this, the learning contents, learning functions and characteristics of library e-learning platforms were analyzed, and expert surveys and interviews were conducted. As a results, the construction of a platform for effectively applying learning processes and technology is essential for the library's sustainable e-learning services. The contents that should be provided for characteristics of library education, reading guidance, information literacy instruction, library usage instruction, and the latest IT technologies. And The main learning functions include the ability to conduct video lectures and real-time classes among learning types, and learning activity support functions, a cloud platform support function and a personalized environment support function. Additionally, suggested re-education for library staff to improve their technical skills and the formation of an e-learning team.