• Journal of the Korean Institute of Gas
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• v.28 no.3
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• pp.87-94
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• 2024

Liquefied hydrogen has advantages in terms of storage efficiency, but there is a risk of volume expansion of 800 times if it fails to maintain temperature. Gaseous hydrogen charging stations are undergoing various risk assessments, but liquefied hydrogen charging stations have not yet been built and developed. In order to derive harmful risk factors of liquefied hydrogen charging stations and control risks, we aim to secure high safety of liquefied hydrogen charging stations by applying the LOPA technique. In this study, the HAZOP technique was applied to derive a scenario and the LOPA technique was applied to ensure high safety against leakage and explosion of a liquefied hydrogen charging station and to analyze the effectiveness of safety and protective devices. In addition, the feasibility of applying the LOPA technique used in existing chemical processes to liquefied hydrogen charging stations was examined and problems were identified.

• Information Systems Review
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• v.8 no.1
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• pp.25-41
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• 2006

This paper is about how to drive a Business Process Management(BPM) implementation project from selecting a target process to BPM deployment. For guidance of BPM implementation, LG CNS BPM Methodology and enPAM(Entrue Process Assessment Model) were used. This paper focuses on the methodology of process selection and presents a case study from the telecommunication industry. The enPAM consists of three major criteria in determining process priority for BPM system deployment: business impact, BPM adequateness and implementation feasibility. These three criteria can be easily modified for other telecommunication business just as we did to suit this telecom case. Moreover, it could provide useful ideas to companies that consider introducing a BPM solution for process management. Although we propose a comprehensive design methodology for selecting a proper target business process for BPM implementation, more work is still needed to extend the results for rigorous and practical method.

• Journal of Environmental Science International
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• v.29 no.6
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• pp.643-658
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• 2020

Recent economic and income growth in Korea has caused people to seek healthier and happier lives. Forests are seen as spaces that provide tourism and recreation. The Korea forest service and local governments are developing and designating recreational forests but previous studies on the subject have only covered customer satisfaction and how forests are used. As such, the current study aims to find issues with designation criteria for recreational forests used by Gwangju city in Gyeonggi province and suggest improvements to the system. Site E was deemed the most adequate in evaluations of five candidate site. The criteria used in the evaluations were problematic due to (1) a lack of differentiating power in evaluation items, (2) blanket coverage of score ranges, (3) a lack of additional points for special sites, and (4) unclear evaluation indices. Based on the identified issues, the current study suggests introducing additional points and clearly detailing evaluation indices and items to enhance the evaluation of recreational forest candidate sites.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.985-992
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• 2007

There are about 40,000 chemicals used in Korea and 300 new types of chemicals are added to the list every year, influencing quality of air, soil and water. Water quality standards that serve as the basis for water quality management have been proved inefficient and insufficient compared to those of advanced countries. This study aims to improve the existing water quality standards. Most importantly, the water quality standards need to take into account not only protection of human health but also aquatic resources. To that end, water quality criteria need to be set by monitoring each watershed every year and conducting risk assessment. Criteria for human health are set at $10^{-6}$ cancer risk level, and for aquatic life at conservative level, adopting the methodology of the U.S. and Australia, respectively. After carrying out technical and economic feasibility studies, more conservative criteria will be used to decide final water quality standards. The development of this system to establish integrated water quality standards for both human health and aquatic resources protection is urgently needed.

• Structural Engineering and Mechanics
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• v.63 no.5
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• pp.639-646
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• 2017

According to the multi-index system of dam safety assessment and the standard of safety, a comprehensive evaluation model for dam safety based on a cloud model is established to determine the basic probability assignment of the Dempster-Shafer theory. The Dempster-Shafer theory is improved to solve the high conflict problems via fusion calculation. Compared with the traditional Dempster-Shafer theory, the application is more extensive and the result is more reasonable. The uncertainty model of dam safety multi-index comprehensive evaluation is applied according to the two theories above. The rationality and feasibility of the model are verified through application to the safety evaluation of a practical arch dam.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1221-1229
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• 2022

In this work, the guided wave de-bonding area-detecting technique was studied for application to containment liner plates in nuclear power plant areas. To apply this technique, an appropriate Lamb wave mode, symmetric and longitudinal dominance, was verified by the frequency shifting technique. The S0 2.7 MHz mm Lamb wave mode was chosen to realize quantitative experimental results and their visualization. Results of the bulk wave, longitudinal wave mode, and comparison experiments indicate that the wave mode was able to distinguish between the de-bonded and bonded areas. Similar to the bulk wave cases, the bonded region could be distinguished from the de-bonded region using the Lamb wave approach. The Lamb wave technique results showed significant correlation to the de-bonding area. As the de-bonding area increased, the Lamb wave energy attenuation effect decreased, which was a prominent factor in the realization of quantitative tomographic visualization. The feasibility of tomographic visualization was studied via the application of Lamb waves. The reconstruction algorithm for the probabilistic inspection of damage (RAPID) technique was applied to the containment liner plate to verify and visualize the de-bonding condition. The results obtained using the tomography image indicated that the Lamb wave-based RAPID algorithm was capable of delineating debonding areas.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.373-380
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• 2004

This paper presents the feasibility of an impedance-based damage detection technique using piezoelectric (PZT) transducers for civil infrastructures such as steel bridges. The impedance-based damage detection method is based on monitoring the changes in the electrical impedance. Those changes in the electrical impedance are due to the electro-mechanical coupling property of the piezoelectric material and structure. An effective integrated structural health monitoring system must include a statistical process of damage detection that is automated and real time assessment of damage in the structure. Once measured, damage sensitive features from this impedance change can be statistically quantified for various damage cases. The results of the experimental study on three kinds of structural members show that cracks or loosened bolts/nuts near the PZT sensors may be effectively detected by monitoring the shifts of the resonant frequencies. The root mean square (RMS) deviations of impedance functions between before and after damages were also considered as a damage indicator. The subsequent statistical methods using the impedance signature of the PZT sensors were investigated.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.2
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• pp.88-97
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• 2024

This study performed the analysis on an economic feasibility of each marine fuel, potential fuel pathways and the relevance of compliance measures to ensure compliance with the FuelEU Maritime regulation. Additionally, it identified certain regulatory gaps to encourage the use of alternative marine fuels. Regarding GHG emissions calculations, the existing GHG regulations for ships applies the Tank-to-Wake (TtW) method, whereas FuelEU Maritime applies the Well-to-Wake (WtW) method. The main results present that important information to establish response strategy for FuelEU Maritime including the costs and benefits of each marine fuel, the minimum blending ratio of alternative fules, and compliance impacts of measures. For the regulatory costs and benefits of marine fuels following the implementation of the FuelEU Maritime from 2025, our findings indicate that while most fossil fuels incur regulatory costs from 2025, most of biofuels and RFNBO fuels do not incur costs until 2050. This will play a role to narrow the price gap between fossil fuels and alternative fuels.

• 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.

• Korean Journal of Radiology
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• v.24 no.5
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• pp.444-453
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• 2023

Objective: Meningeal lymphatic vessels are predominantly located in the parasagittal dural space (PSD); these vessels drain interstitial fluids out of the brain and contribute to the glymphatic system. We aimed to investigate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the dynamic changes in the meningeal lymphatic vessels in PSD. Materials and Methods: Eighteen participants (26-71 years; male:female, 10:8), without neurological or psychiatric diseases, were prospectively enrolled and underwent DCE-MRI. Three regions of interests (ROIs) were placed on the PSD, superior sagittal sinus (SSS), and cortical vein. Early and delayed enhancement patterns and six kinetic curve-derived parameters were obtained and compared between the three ROIs. Moreover, the participants were grouped into the young (< 65 years; n = 9) or older (≥ 65 years; n = 9) groups. Enhancement patterns and kinetic curve-derived parameters in the PSD were compared between the two groups. Results: The PSD showed different enhancement patterns than the SSS and cortical veins (P < 0.001 and P < 0.001, respectively) in the early and delayed phases. The PSD showed slow early enhancement and a delayed wash-out pattern. The six kinetic curve-derived parameters of PSD was significantly different than that of the SSS and cortical vein. The PSD washout rate of older participants was significantly lower (median, 0.09; interquartile range [IQR], 0.01-0.15) than that of younger participants (median, 0.32; IQR, 0.07-0.45) (P = 0.040). Conclusion: This study shows that the dynamic changes of meningeal lymphatic vessels in PSD can be assessed with DCE-MRI, and the results are different from those of the venous structures. Our finding that delayed wash-out was more pronounced in the PSD of older participants suggests that aging may disturb the meningeal lymphatic drainage.