• East Asian Journal of Business Economics (EAJBE)
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• v.10 no.4
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• pp.47-54
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• 2022

Purpose - In today's era of carbon neutrality, railways need to find ways to improve usability and efficiency. Accordingly, this study examines the effect of introducing express highspeed railways into the Korean public transportation system and suggests some practical guidelines. One concern in the Korea railway sector is that low scheduled speeds contrast with the highspeed railway system design. Research design, data, and methodology - Current literature and foreign cases are analyzed. Subsequently, using data from the Korean Railroad Research Institute, a benefit analysis is conducted based on expanded track capacity and the saving of time owing to the introduction of the express highspeed railway. Result - The express highspeed railway system is expected to increase the number of train lines from 262 to 348 and the scheduled speed from 168.3km/h to 192.2km/h. Considering reduced time value, the economic effect is about 80 million won per year. Conclusion - The findings suggest that the express highspeed railway is a promising option to improve efficiency and increase customer utility. This study contributes to the literature by initiating a discussion on the express system in Korea; practically, it offers railway operators guidelines for improving highspeed railway system efficiency that can be transformed into a variety of marketing options.

• The Journal of Economics, Marketing and Management
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• v.10 no.6
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• pp.39-46
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• 2022

Purpose: The purpose of this study is to look at the current status and cases of ESG at home and abroad, and through this, seek ways to activate the ESG strategy of domestic SMEs and suggest a direction. Research design, data and methodology: This study examines the current status of ESG management at home and abroad and examples of companies through related literature on ESG management and performance. Through this, the strategic direction of ESG management of domestic SMEs was presented. Results: Compared to the government and major corporations, SMEs can be said to lack ESG management activities. ESG activities include environmental activities such as carbon neutrality, waste management, eco-friendly supply chain management, establishment of safety and health processes to improve workers' environment, expansion of governance to guarantee autonomy and profitability such as fair trade, protection of social and shareholder rights such as anti-corruption, etc. should be based on Therefore, there are difficulties in ESG activities of SMEs that lack funds and manpower. Conclusions: Compared to the government and major corporations, SMEs can be said to lack ESG management activities However, it will be possible to establish and implement ESG management strategies based on the strengths of SMEs and the characteristics of each company.

• Transactions of Materials Processing
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• v.30 no.3
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• pp.109-118
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• 2021

Recently, there has been an increased interest in the remanufacturing of mechanical parts using metal additive manufacturing processes in regards to resource recycling and carbon neutrality. DED (directed energy deposition) process can create desired metallic shapes on both even and uneven substrate via line-by-line deposition. Hence, DED process is very useful for the repair, retrofit and remanufacturing of mechanical parts with irregular damages. The objective of the current paper is to investigate the effects DED process parameters, including the effects of power and the scan speed of the laser, on deposition and residual stress characteristics for remanufacturing of mechanical parts using experiments and finite element analyses (FEAs). AISI 1045 is used as the substrate material and the feeding powder. The characteristic dimensions of the bead shape and the heat affected zone (HAZ) for different deposition conditions are obtained from the experimental results. Efficiencies of the heat flux model for different deposition conditions are estimated by the comparison of the results of FEAs with those of experiments in terms of the width and the depth of HAZ. In addition, the influence of the process parameters on residual stress distributions in the vicinity of the deposited region is investigated using the results of FEAs. Finally, a suitable deposition condition is predicted in regards to the bead formation and the residual stress.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_2
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• pp.271-278
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• 2022

The solar energy has been widely used to reduce the fossil fuel and prevent the environmental pollution. The renewable energy including solar heat tends to spread due to carbon neutrality for main country of the world. Targets of solar collector are usually acquisitions of hot water or hot air. Especially, air-heating collector using solar heat is known as the technology for obtaining hot air. This study aims to investigate of characteristics of thermal flow when the hot air by air-heating collector using solar heat flows inside of indoor space. The thermal flow of heating indoor space was simulated using ANSYS-CFX program and thus the behaviors of hot air in indoor space were evaluated with standard k-𝜀 turbulence model. As the results, as the inlet velocity was increased, the behaviors of hot air became simple, and temperature range of 25~75℃ had almost no effect on behavior of flow. As the inlet temperature was increased, the temperature curve of indoor space from bottom to top was changed from linear to quadratic. Furthermore, it was confirmed that inlet velocity as well as inlet temperature also should be considered to heat indoor space equally by air-heating collector using solar heat.

• New & Renewable Energy
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• v.17 no.3
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• pp.24-31
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• 2021

Through 'The Renewable Energy 3020 Implementation Plan' for carbon neutrality, the government promised to raise the proportion of renewable energy generation to 20% and renewable energy installation capacity to 63.8% by 2030. Therefore, we plan to test a 5.5 MW offshore wind turbine near Maldo, Gunsan. In this project, we measure the level of public acceptance and perform ordinary least squares (OLS) regression analysis to show the determinants of public acceptance. The regression results are as followed. First, it is judged that the closer the distance to the offshore wind turbine, the more the economic effects considered by residents. Second, especially in Maldo, the experience of being discriminated from the Saemangeum project, is understood to have caused distrust in the surrounding fishing villages chief/Fisheries Cooperatives, converted into a local community effect. Finally, the policy implications are as follows. First, a bottom-up problem-solving method is required to improve public acceptance, based on the Living Lab. Second, the island community may be indifferent to the briefings or forums of outsiders. Therefore, a gradual approach is required through (in)formal channels based on reliability from a long-term perspective with nearby universities and research institutes using SamsØ Energy Academy.

• New & Renewable Energy
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• v.17 no.3
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• pp.16-23
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• 2021

Recently, the Korean government announced a plan to activate renewable energies, with focus on clean energy sources such as solar and wind power as the core and the goal of achieving carbon neutrality by 2050. Unlike other photovoltaic (PV) systems, offshore PV installations are advantageous for large-scale expansion because of the ease of securing sites; they also enable lowering the power generation costs based on construction of large-scale power facilities of megawatt class or higher owing to low noise and landscape damage. However, any power generation should proceed with consideration of the special environmental conditions of the ocean. Above all, when installing large-scale facilities, it is important to reduce fluctuations of the structure and secure stability to actively respond to waves. This study is concerned with the development of a floating body technology that actively responds to waves so as to enable commercialization of offshore solar power. A unit platform for research and development on offshore PV generation was installed in the Saemangeum sea, and the structural fluctuations and stability were analyzed to ensure conformity with the major performance indicators.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3878-3887
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• 2022

For the future energy-mix policy for carbon neutrality, demand for the capability of load-follow operation has emerged in nuclear power plants in order to accommodate the intermittency of renewable energy. The short-term decay heat analysis is also required to evaluate the decay heat level varied by the power level change during the load-follow operation, which is a very important parameter in terms of short-term decay heat removal during a grace time. In this study, the short-term decay heat level for 10 days after the shutdown was evaluated for both seasonal and daily load-follow cases. Additionally, the nuclide-wise contribution to the accumulated decay heat for 10 days was analyzed for further understanding of the short-term decay heat behavior. The result showed that in the seasonal case, the decay heat level was mainly determined by the power level right before the shutdown and the amount of each nuclide was varied with the power variation due to the long variation interval of 90 days. Whereas, in the daily case, the decay heat level was strongly impacted by the average power level during operation and meaningful mass variations for those nuclides were not observed due to the short variation interval of 0.5 days.

• Journal of ILASS-Korea
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• v.27 no.4
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• pp.181-187
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• 2022

For carbon neutrality, direct-injection hydrogen engines are attracting attention as a future power source. It is essential to estimate the transient injection rate of hydrogen for the optimization of hydrogen injection in direct injection engines. However, conventional injection rate measurement techniques for liquid fuels based on the injection-induced fuel pressure change in a test section are difficult to be applied to gaseous fuels due to the compressibility of the gas and the sealing issue of the components. In this study, a momentum flux measurement technique is introduced to obtain the transient injection rate of gaseous fuels using a force sensor. The injection rate calculation models associated with the momentum flux measurement technique are presented first. Then, the volumetric injection rates are estimated based on the momentum flux data and the calculation models and compared with those measured by a volumetric flow rate meter. The results showed that the momentum flux measurement can detect the injection start and end timings and the transient and steady regimes of the fuel injection. However, the estimated volumetric injection rates showed a large difference from the measured injection rates. An alternative method is suggested that corrects the estimated injection rate results based on the measured mean volumetric flow rates.

• Journal of Distribution Science
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• v.20 no.8
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• pp.115-121
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• 2022

Purpose: This article aims to explore the distribution of technological innovation and environmental policy challenges to respond to COVID-19. The study also attempts to tackle a paradigm shift in science and technology policies against the pandemic and a desirable direction for environmental policies. The COVID-19 pandemic has been the one that rapidly changed global people's lifestyle. For the spread of a terrible infectious disease could not be avoided, regardless of a highly industrialized society. Research design, data and methodology: This study basically employs a qualitative approach as a methodology. This study is based on the fact that environmental pollution, various natural disasters continuously occur, and there are many unforeseeable parts, despite remarkable development of scientific technology, and that the circumstances are becoming more complex. Results: This study noted that scientific technology civilization formed due to industrial revolutions can deteriorate environment and increase environmental threat factors. As an alternative to this, this study investigates alternative discussions on how the 4th Industrial Revolution can help scientific technology and human environment to harmoniously coexist and develop. Conclusions: It implies that this study focuses on the possibility of overcoming this crisis through science and technology innovation, although mankind is in crisis of COVID-19 due to excessive human development.

• Journal of the Korean institute of surface engineering
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• v.56 no.4
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• pp.259-264
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• 2023

As the demand for lithium-ion batteries, a key power source in electric vehicles and energy storage systems, continues to increase for achieving global carbon neutrality, there is a growing concern about the environmental impact of disposing of spent batteries. Extensive research is underway to develop efficient recycling methods. While hydrometallurgy and pyrometallurgy methods are commonly used to recover valuable metals from spent cathode materials, they have drawbacks including hazardous waste and complex processes. Hence, alternative recycling methods that are environmentally friendly are being explored. However, recycling spent cathode materials still remains complex and energy-intensive. This study focuses on a novel approach called solid-state synthesis, which aims at regenerating the performance of spent cathode materials. The method offers a simpler process and reduces energy consumption. Optimal heat treatment conditions were identified based on experimental results, contributing to the development of sustainable recycling technologies for lithium-ion batteries.