• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.97-110
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• 2019

Recently, the 4th Industrial Revolution has been emerged and various products are developed and commercialized in preparation of the communication failure. Many solutions are underway in Back-Up Network for IDC Servers, but not in the personal or sensor for low-power system use. Therefore we used the OpenWRT Firmware in Raspberry Pi which can be easily obtained in online market, and it created a low-power load balancer. Therefore, we developed the device that uses LTE Antenna based on USB Interface for communication fault notification and important data. The equipment used in this paper is easy to buy in online shop for anyone. Also, it can be applied in other vendors' boards by using USB. We hope that this paper will contribute to the stability of individual sensor networks.

• Mass Spectrometry Letters
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• v.10 no.2
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• pp.66-70
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• 2019

Rivaroxaban (RRN) is the first available active direct factor Xa inhibitor (anticoagulant) with oral administration. Due to its success in market, there have been efforts to develop various RRN formulations, and the development of good analytical methods for its in vivo evaluation is an essential prerequisite. Thus, here, a simple and efficient method to determine RRN in rat plasma using liquid-liquid extraction (LLE) and liquid chromatography and multiple reaction monitoring (LC-MRM) was presented. The use of ethyl acetate as the LLE solvent results appropriate extraction and purification of RRN and it also helps the significant reduction of rat plasma volume required for RRN quantitation. The developed method showed good analytical performance including specificity, linearity ($r^2{\geq}0.999$ within 0.5 - 500 ng/mL), sensitivity (the lower limit of quantitation at 0.5 ng/mL), accuracy (89.3 - 107.0%), precision (${\geq}12.7%$), and recovery (89.2 - 105.7%). Additionally, RRN in sample extracts showed good stability. Finally, the applicability of the validated method to the PK evaluation of RRN was confirmed after its oral administration to normal rats. The present method is the first analytical method employing LLE for the simple and efficient extraction and purification of RRN in rat plasma. Therefore, the present method can contribute to the development of new RRN formulations as well as to the monitoring of RRN in special clinical situations through its efficient determination in various samples with or without minor modification.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.242-253
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• 2019

There has been a large literature on bank liquidity risk since the 2008 global financial crisis because liquidity risk was at the heart of the crisis. However, there is no study that investigates whether the level of investor protection influences liquidity risk-taking behavior of banks. Therefore, this study aims to explore the relationship between investor protection and liquidity risk as well as to provide policy implications. Using a panel dataset of commercial banks in 21 OECD countries, we found that strong investor protection encourages banks to take lower liquidity risk. Furthermore, this positive role of shareholder protection is more prominent during a crisis, implying that legal protection of investors plays an essential role in bank stability while market discipline is largely ineffective due to extensive government guarantees in turbulent times.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.735-742
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• 2021

Recently, renewable energy-related power generation facilities have been surging due to the government's "Renewable Energy 3020", "Green New Deal", "2050 Carbon Neutrality" and "K-RE100" policies. Most renewable energy facilities are small and distributed, making it difficult to manage efficiently, and small distributed resources less than 1MW are having a hard time with participating in the market due to the limited sales and avoidance of trading. In particular, the intermittency of renewable energy has a significant impact on the stability of the power grid. The government is seeking to address volatility and intermittency issues through 'small distributed resource brokerage trading, and to expand the systematic resourceization and acceptability of heterogeneous large and small distributed resources. In this work, we intend to apply an AI-based power generation prediction model to a distributed resource brokerage trading system so that it can be utilized as a foundation platform for pioneering new energy business markets.

• Journal of Surface Science and Engineering
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• v.55 no.6
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• pp.368-375
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• 2022

YSZ (Yttria Stabilized Zirconia) is used as a thermal barrier coating material for gas turbines due to its low thermal conductivity and high fracture toughness. However, the operating temperature of the gas turbine is rising according to the market demand, and the problem that the coating layer of YSZ is peeled off due to the volume change due to the phase transformation at a high temperature of 1400℃ or higher is emerging. To solve this problem, various studies have been carried out to have phase stability, low thermal conductivity, and high fracture toughness in a high temperature environment of 1400℃ or higher by doping trivalent and tetravalent oxides to YSZ. In this study, the monoclinic phase formation behavior and crystallinity were comparatively analyzed according to the total doping amount of oxides by controlling the doping amounts of Sc₂O₃ and Gd₂O₃, which are trivalent oxides, and TiO₂, which are tetravalent oxides, in YSZ. Through comparative analysis of monoclinic phase formation and crystallinity, the thermal conductivity of the thermal barrier coating layer according to the amount of doping was predicted.

• The Southeast Asian review
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• v.23 no.3
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• pp.1-48
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• 2013

Taking the cases of Korean garment factories in Binh Duong area, this study aims to explain the phases and causes of the wildcat strikes that have rapidly expanded recently in Vietnam. For the purpose, this study raises several questions as follows. Why the strikes sometimes increase and decrease other times? Why the factory workers prefer a wildcat strike even though it is politically risky, unproductive, and complicated? By the same token, why the foreign management cannot or will not preemptively preclude the wildcat strikes that are usually predictable and the workers are mostly able to accomplish their demands? While answering these questions, this study explores the economic, political, and socio-cultural conditions of the wildcat strikes respectively. Based on the fieldwork in around 30 Korean owned garment factories and the interview with around 100 Vietnamese factory workers in Binh Duong, this study confirms several findings on the phases and causes of the strikes in the area in specific and in Vietnam in general. First, the annual trends of the wildcat strikes reflect the macroeconomic conditions in which the consumer prices and the labor market in Vietnamese economy and business conditions in the world economy are pivotal. Second, however, the influence of macroeconomic conditions on both the management and the workers in the garment factories are differential, depending on the financial situations of the multinational corporations and the workers' capability of reproducing their household economies. Thirdly, the possibility of the wildcat strike in each factory is relatively independent on the financial conditions of a factory and rather associated with the stable political structure and active political processes within the factory that enable the management and the workers to efficiently communicate each other. Lastly, the necessity of establishing political stability in a factory arises from the distinctive social and cultural characteristics of the multinational corporation in which foreign managers and native workers inevitably live in separate and different socio-cultural worlds.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.2
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• pp.17-28
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• 2021

The baby-tech industry, which combines IT with existing parenting product, is attracting increasing amounts of attention. Consequently various types of baby products incorporating functionality and design are being launched. In recent years, particularly as the market segments increases for babywearing products, parenting products that account for the child's comfort and parents' convenience are required. Therefore, this study examines the characteristics and consumer perception of babywear products, which are important for the emotional stability, development, and rearing of children. The study utilizes text mining and a network analysis by collecting unstructured text data. An examination of the network, based on the frequency of keywords for each babywear product and the degree of the connection to the centering index, revealed that consumers value convenience and price when purchasing products. The consumer perception and consideration factors that appear individually according to the product were also identified. In addition, studying body parts with high TF-IDF values revealed a difference in the body parts considered by consumers for each product. Lastly, through the visualization data based on the keywords that appeared in public, commonly appearing keywords, and those that appeared individually were examined. Through SNS, product characteristics as well as a new parenting culture that shared child-rearing routines were confirmed. This study suggests planning and marketing directions for the development of babywear products that meet consumer needs.

• Asia-Pacific Journal of Business
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• v.12 no.1
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• pp.151-163
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• 2021

Purpose - The break-even point refers to the point where total profit and total cost coincide, and from this point on, the entrepreneur's decision-making takes a different route. Strategic decisions can be made for more efficient operation and eventually for more likelihood for growth and sustainability if a startup figures out when it recoups the investment and switches to a net profit. Design/methodology/approach - 748 creativity and skill-based sole proprietors in manufacturing industry were examined to demonstrate the effect of the entrepreneur's entrepreneurial experience and education level, the business launch preparation time, or the self-financing on the achievement of break-even point. Findings - While the business launch preparation time lowered the likelihood of reaching a break-even point, self-financing increased the likelihood. As a result of further analysis by subdividing into subgroups according to skill level, only the business launch preparation time was statistically significant in the highly skilled industries. In the low skilled industries, in addition to the business launch preparation time, the CEO's education level and the self-financing were statistically significant. Research implications or Originality - The longer the business launch preparation time, the higher the start-up cost, which increases the burden of initial cost recovery, and the agile response to market changes is thereby delayed, resulting in the business idea losing its appeal. Self-financing not only provides stability and strong motivation for the business operation but also promotes careful spending which contributes to the achievement of break-even point. In particular, it is found that practical experience is more useful than theoretical knowledge in low skilled industries. Due to the limitation of secondary data based on the recollection, the time required to reach a break-even point, percentage of financing sources, etc. may include cognitive errors. In addition, variables are not included that explain the characteristics of creativity and skill-based sole proprietorship, so it is necessary to exercise caution with the actual application.

• Korean Journal of Materials Research
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• v.31 no.11
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• pp.614-618
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• 2021

As the size of market for electric vehicles and energy storage systems grows, the demand for lithium-ion batteries (LIBs) is increasing. Currently, commercial LIBs are fabricated with liquid electrolytes, which have some safety issues such as low chemical stability, which can cause ignition of fire. As a substitute for liquid electrolytes, solid electrolytes are now being extensively studied. However, solid electrolytes have disadvantages of low ionic conductivity and high resistance at interface between electrode and electrolyte. In this study, Li₇La₃Zr₂O₁₂ (LLZO), one of the best ion conducting materials among oxide based solid electrolytes, is fabricated through RF-sputtering and various electrochemical properties are analyzed. Moreover, the electrochemical properties of LLZO are found to significantly improve with co-sputtered Li₂O. An all-solid thin film battery is fabricated by introducing a thin film solid electrolyte and an Li₄Ti₅O₁₂ (LTO) cathode; resulting electrochemical properties are also analyzed. The LLZO/Li₂O (60W) sample shows a very good performance in ionic conductivity of 7.3×10^-8 S/cm, with improvement in c-rate and stable cycle performance.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.23-29
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• 2021

Recently, a situation in which a specific content service is impossible worldwide has occurred due to a failure of the platform service and a significant social and economic problem has been caused in the global service market. In order to secure the stability of platform services, intelligent platform operation management is required. In this study, big data flow management(BDFM) and implementation method were proposed to quickly detect to abnormal service status in the platform operation environment. As a result of analyzing, BDFM technique improved the characteristics of abnormal failure detection by more than 30% compared to the traditional NMS. The big data flow management method has the advantage of being able to quickly detect platform system failures and abnormal service conditions, and it is expected that when connected with AI-based technology, platform management is performed intelligently and the ability to prevent and preserve failures can be greatly improved.