• Structural Engineering and Mechanics
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• v.82 no.4
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• pp.417-434
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• 2022

In this work, a review of mechanical metamaterials and seismic protection systems that use them is carried out, focusing on passive protection systems. During the last years, a wide variety of classical systems of seismic protection have demonstrated to be an effective and practical way of reducing the seismic vulnerability of buildings, maintaining their health and structural integrity. However, with the emergence of metamaterials, which allow obtaining uncommon mechanical properties, new procedures and devices with high performance have been developed, reducing the seismic risk through novel approaches such as: seismic shields and the redirection of seismic waves; the use of stop band gaps and the construction of buried mass resonators; the design of pentamodal base isolators. These ideas are impacting traditional areas of structural engineering such as the design and building of highly efficient base isolation systems. In this work, recent advances in new seismic protection technologies and researches that integrate mechanical metamaterials are presented. A complete bibliometric analysis was carried out to identify and classify relevant authors and works related with passive seismic protection system based on mechanical metamaterial (pSPSmMMs). Finally, possible future scenarios for study and development of seismic isolators based on mechanical metamaterials are shown, identifying the relevant topics that have not yet been explored, as well as those with the greatest potential for future application.

• Journal of Sport and Applied Science
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• v.6 no.1
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• pp.1-4
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• 2022

Purpose: The purpose of this study is to provide implications for virtual golf safety management in Korea through the literature review of current safety issues of virtual golf industry. Research design, data, and methodology: This study employed a qualitative approach to review prior studies and related documents presenting current safety perspectives of virtual sports facility management. First, the study reviewed the experiences of virtual golf players and safety criteria suggested from previous literatures. Second, two experts in sport facility management reviewed the manuscript including implications and provided their opinions including major implications and insights for virtual sport industry. Views of experts were added to the final manuscript. Results: This study found that installation standards and safety and hygiene standards by industry are enacted for the safety management of sports facilities, however, there is a need for standards to be adjusted because the contents are general, abstract, and lack detail, thus causing difficultly to secure effectiveness. Conclusions: For virtual golf courses, it is necessary to develop a safety inspection checklist that suits the characteristics of indoor virtual golf. In this line, safety criteria need to be developed with the consideration of characteristics of screen golf to establish an efficient safety management system and create a safe use environment.

• The Journal of Industrial Distribution & Business
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• v.13 no.1
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• pp.23-32
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• 2022

Purpose: This study used ESG grade, but defined AESG, adjusted to the size of a company and examines whether it can be used as an investment strategy. Research design, data and methodology: The analysis sample in this study is a company that has given an ESG rating among companies listed on the Korea Stock Exchange. We examine the results through portfolio analysis and Fama-macbeth regression analysis. Results: As result of examining the long-only performance and the long-short performance by constructing quintile portfolios, it was observed that a significant positive return was shown. It was observed that there was an alpha that could not be explained in asset pricing models. Also, AESG had a return prediction effect in the result of a Fama-Macbeth regression that controlled corporate characteristic variables in individual stocks. Next, we confirmed AESG's usage through various portfolio composition. In the portfolio optimization, the Risk Efficient method was the most superior in terms of sharpe ratio and the construct multi-factor model with Value, Momentum and Low Vol showed statistically significant performance improvement. Conclusions: The results of this study suggest that it can be helpful in ESG investment to reflect the ESG rating of relatively small companies more through the scale adjustment of the ESG rating (i.e.AESG).

• The Journal of Asian Finance, Economics and Business
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• v.10 no.1
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• pp.181-187
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• 2023

The study aimed to study the effect of the inflation rate, the real domestic product, the interbank lending interest rate, and the total deposits on credit facilities in Jordan for 2012-2021 through quarterly data. The study adopted the ARDL model. The study used the time series analysis method, as the study tests the stationarity of the time series. The results showed that the impact of inflation on the total credit facilities was negative. In contrast, the impact of each of the total deposits, real GDP, and the interest rate of interbank loans on the total credit facilities was positive and significant. The study recommended the need for the banking sector in Jordan to develop risk management mechanisms in a way that allows it to adapt to economic cycles and crises by conducting stress tests and developing scenarios that ensure the formation of sufficient provisions to meet emergencies. The study also recommended that the macroeconomic policy should be based on creating a stable macroeconomic environment that allows the efficient employment of resources in all economic sectors in a way that achieves high economic growth rates, which contributes to the promotion of economic recovery and is reflected in income. Hence, individuals have a greater ability to repay loans.

• Journal of Wind Energy
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• v.14 no.3
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• pp.100-108
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• 2023

The aim of this study is to develop guidelines for predicting interference between drones and wakes during non-destructive blade inspections in wind power systems. The wake generated by wind towers and blades can affect the stability of drone flights, necessitating the establishment of guidelines to ensure safe and efficient inspections. In order to predict the interference between drones and blades, environmental variables must be considered, including quantification of turbulence intensity in the wake generated by the tower and blades, as well as determining the appropriate distance between the drone and the tower/blades for flight stability. To achieve this, computational fluid dynamics (CFD) analysis was performed using cross-sectional geometries corresponding to the main wind turbine blade and tower span locations. Based on the CFD analysis results, a safe flight path for drones is proposed, which minimizes the risk of collision and interference with towers and blades during maintenance operations of wind power systems. Implementation of the proposed guidelines is expected to enhance the safety and efficiency of maintenance work.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.6
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• pp.1462-1477
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• 2024

With the evolving complexity of connected vehicle features, the volume and diversity of data generated during driving continue to escalate. Enabling data sharing among interconnected vehicles holds promise for improving users' driving experiences and alleviating traffic congestion. Yet, the unintentional disclosure of users' private information through data sharing poses a risk, potentially compromising the interests of vehicle users and, in certain cases, endangering driving safety. Federated learning (FL) is a newly emerged distributed machine learning paradigm, which is expected to play a prominent role for privacy-preserving learning in autonomous vehicles. While FL holds significant potential to enhance the architecture of the Internet of Vehicles (IoV), the dynamic mobility of vehicles poses a considerable challenge to integrating FL with vehicular networks. In this paper, a novel clustered FL framework is proposed which is efficient for reducing communication and protecting data privacy. By assessing the similarity among feature vectors, vehicles are categorized into distinct clusters. An optimal vehicle is elected as the cluster head, which enhances the efficiency of personalized data processing and model training while reducing communication overhead. Simultaneously, the Local Differential Privacy (LDP) mechanism is incorporated during local training to safeguard vehicle privacy. The simulation results obtained from the 20newsgroups dataset and the MNIST dataset validate the effectiveness of the proposed scheme, indicating that the proposed scheme can ensure data privacy effectively while reducing communication overhead.

• Earthquakes and Structures
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• v.27 no.1
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• pp.31-39
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• 2024

The reliability-based seismic design of steel frames is a complex process that incorporates seismic demand with a structural capacity to attain safe buildings aligned with specified constraints. This paper introduces an efficient base shear force formulation to support the reliability-based design process of steel frames. The introduced base shear force equation combines the seismic demand statistics with the reliability objective to calculate a fictitious base shear force for linear static analysis. By concentrating on the seismic demand and promising to meet a certain level of reliability, the equation converts the reliability-based seismic design problem to a deterministic one. Two code-compliant real-size steel moment frames are developed according to different reliability objectives to demonstrate the competency of the proposed formula. The nonlinear dynamic analysis method is used to assess the seismic reliability of the constructed frames, and the numerical results validate the credibility of the suggested formulation. The base shear force calculation method regarding seismic reliability is the main finding of this study. The ease of use makes this approach a potent tool for design professionals and stakeholders to make rapid risk-informed decisions regarding steel moment frame design.

• Journal of Wellbeing Management and Applied Psychology
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• v.7 no.3
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• pp.25-30
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• 2024

Purpose: It is necessary to establish more systematic and efficient accident prevention measures in relation to the promotion of safety activities to prevent safety accidents of foreign workers at construction sites, especially as safety accidents of foreign workers continue to occur among industrial accidents occurring at domestic construction sites. In this study, I would like to suggest ways to respond to legal issues related to the recruitment of foreign workers and ways to promote safety management that can effectively reduce industrial accidents through various safety management measures. Research design, data and methodology: In order to establish systematic safety management measures for foreign workers, in-depth research was attempted by collecting and analyzing various data such as the current status of domestic industrial accidents, employment status of foreign workers, and disaster statistics. Results: In addition, I intend to establish and present a more systematic safety management plan by conducting various analysis and feasibility review such as risk assessment education in terms of accident prevention for foreign workers. Conclusions: By establishing and presenting more systematic management measures, such as foreign employment, employment by occupation, and on-site education, this safety management system can effectively prevent accidents for foreign workers and is expected to contribute to the prevention of accidents at domestic construction sites for both construction companies and construction officials.

• Environmental and Resource Economics Review
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• v.23 no.4
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• pp.583-615
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• 2014

Including the rolling black out in 2011, Korea has suffered from rapid increase of electricity consumption and demand forecasting failure for last five years. In addition, because of the Fukushima disaster, high fuel prices, and introduction of new generation sources such as renewables, the uncertainty on a power supply strategy increases. Consequently, a stable power supply becomes the new agenda and a revisino of strategy for new power generation sources is needed. In the light of this, we appraises the sixth basic plan for long term electricity demand and supply considering the changes of foreign and domestic conditions. We also simulate a strategy for the new power generation sources using a portfolio analysis method. As results, a diversity of power generation sources will increase and the share of renewable power generation will be surged on the assumptions of a cost reduction of renewable power sources and an increase of fuel costs. Particularly, on the range of a risk level(standard deviation) from 0.06 and 0.09, the efficient frontier has the most various power sources. Besides, the existing power plan is not efficient so that an improvement is needed. Lastly, the development of an electricity storage system and energy management system is necessary to make a stable and efficient power supply condition.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.10a
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• pp.1-11
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• 2003

The objectives of this paper are to overview present status of soil pollution in Korea, to review the current policies and management strategies for soil pollution prevention and remediation of contaminated sites, and to suggest some recommendations to be considered toward more efficient policies. Soils in Korea are contaminated mainly by industrial facilities, landfills, underground storage tanks, abandoned/inactive mines, military camps, and other sources. Concentrations of most of soil pollutants were similar to the background levels, except for a few heavily contaminated sites such as industrial sites or abandoned/inactive mines. The Soil Environment Conservation Act (SECA), which was effective from 1995, provides a comprehensive legal framework for both preventing soil pollution and remedying contaminated sites in Korea. The Act includes various management policies such as the designation of standards and soil pollution policy area, soil monitoring networks, management of suspected contamination sources, and extended 'polluter-pays' principle. To make current policies more efficient and reasonable, some policies or strategies such as the establishment of national priority list, more detailed standards, risk-based cleanup goal, fund raise, soil erosion problem, and finally, integrity between soil and groundwater management frameworks may need to be pursued in the long term.