• Journal of the Korea Safety Management & Science
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• v.26 no.1
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• pp.99-106
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• 2024

In the event of an emergency such as facility shutdown during process operation, the by-product gas must be urgently discharged to the vent stack to prevent leakage, fire, and explosion. At this time, the explosion drop value of the released by-product gas is calculated using ISO 10156 formula, which is 27.7 vol%. Therefore, it does not correspond to flammable gas because it is less than 13% of the explosion drop value, which is the standard for flammable gas defined by the Occupational Safety and Health Act, and since the explosion drop value is high, it can be seen that the risk of fire explosion is low even if it is discharged urgently with the vent stock. As a result of calculating the range of explosion hazard sites for hydrogen gas discharged to the Bent Stack according to KS C IEC 60079-10-1, 23 meters were calculated. Since hydrogen is lighter than air, electromechanical devices should not be installed within 23 meters of the upper portion of the Bent Stack, and if it is not possible, an explosion-proof electromechanical device suitable for type 1 of dangerous place should be installed. In addition, the height of the stack should be at least 5 meters so that the diffusion of by-product gas is facilitated in case of emergency discharge, and it should be installed so that there are no obstacles around it.

• Journal of Integrative Natural Science
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• v.17 no.1
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• pp.1-12
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• 2024

Many abnormal climate events are occurring around the world. The cause of abnormal climate is related to temperature. Factors that affect temperature include excessive emissions of carbon and greenhouse gases from a global perspective, and air circulation from a local perspective. Due to the air circulation, many abnormal climate phenomena such as abnormally high temperature and abnormally low temperature are occurring in certain areas, which can cause very serious human damage. Therefore, the problem of abnormal temperature should not be approached only as a case of climate change, but should be studied as a new category of climate crisis. In this study, we proposed a model for the classification of abnormal temperature using random forests based on various meteorological data such as longitudinal observations, yellow dust, ultraviolet radiation from 2018 to 2022 for each region in Korea. Here, the meteorological data had an imbalance problem, so the imbalance problem was solved by oversampling. As a result, we found that the variables affecting abnormal temperature are different in different regions. In particular, the central and southern regions are influenced by high pressure (Mainland China, Siberian high pressure, and North Pacific high pressure) due to their regional characteristics, so pressure-related variables had a significant impact on the classification of abnormal temperature. This suggests that a regional approach can be taken to predict abnormal temperatures from the surrounding meteorological environment. In addition, in the event of an abnormal temperature, it seems that it is possible to take preventive measures in advance according to regional characteristics.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.117-127
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• 2024

Purpose: The purpose is to conduct basic research to save energy and improve the safety of manufacturing plant infrastructure by comprehensively monitoring energy management, temperature, humidity, dust and gas, air quality, and machine operation status in small and medium-sized manufacturing plants. Method: To this end, energy-related data and environmental information were collected in real time through digital power meters and IoT sensors, and research was conducted to disseminate and respond to situations for energy saving through monitoring and analysis based on the collected information. Result: We presented an application plan that takes into account energy management, cost reduction, and safety improvement, which are key indicators of ESG management activities. Conclusion: This study utilized various sensor devices and related devices in a smart factory as a practical case study in a company. Based on the information collected through research, a basic system for energy saving and safety improvement was presented.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.12-18
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• 2024

The accelerated pace of climate crisis due to continuous industrialization and greenhouse gas emissions necessitates sustainable solutions that simultaneously address mitigation and adaptation to climate change. Naturebased Solutions (NbS) have gained prominence as viable approaches, with Green Infrastructure being a representative NbS. Green Infrastructure involves securing green spaces within urban areas, providing diverse climate adaptation functions such as removal of various air pollutants, carbon sequestration, and isolation. The proliferation of Green Infrastructure is influenced by the quantification of improvement effects related to various projects. To support decision-making by assessing the climate vulnerability of Green Infrastructure, the U.S. Department of Agriculture (USDA) has developed i-Tree Tools. This study proposes a comprehensive evaluation approach for climate change adaptation types by quantifying the climate adaptation performance of urban Green Infrastructure. Using i-Tree Canopy, the analysis focuses on five urban green spaces covering more than 30 hectares, considering the tree ratio relative to the total area. The evaluation encompasses aspects of thermal environment, aquatic environment, and atmospheric environment to assess the overall eco-friendliness in terms of climate change adaptation. The results indicate that an increase in the tree ratio correlates with improved eco-friendliness in terms of thermal, aquatic, and atmospheric environments. In particular, it is necessary to prioritize consideration of the water environment sector in order to realize climate change adaptive green infrastructure, such as increasing green space in urban areas, as it has been confirmed that four out of five target sites are specialized in improving the water environment.

• Journal of the Health Care and Life Science
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• v.10 no.2
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• pp.379-386
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• 2022

This study was conducted with 150 pre-service early childhood teachers at G University in G Metropolitan City to find out the perceptions of pre-service early childhood teachers on climate change. The questionnaires were collected and frequency, percentage, and multiple response analysis were conducted. As a result of the study, first, all pre-service early childhood teachers perception of climate change was recognized, and a sufficient understanding of the concept of greenhouse effect, concept of climate change, and types of greenhouse gases was required, and scientific knowledge was insufficient. Second, about the relationship between climate change and humans, the causes of global warming and the signals of climate change were properly recognized. The awareness of the effects of global warming was high, but the comprehensive understanding was insufficient. Third, the convention on climate change knows to some extent how to respond to climate change, and the international community recognizes the subject of climate change prevention, and climate mitigation efforts are limited to individuals. It was found that most of the practical contents for reducing carbon emissions in daily life are being practiced well. These results are intended to provide basic data for the development of educational programs for pre-service early childhood teachers on climate change.

• Steel and Composite Structures
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• v.53 no.2
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• pp.123-144
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• 2024

These days, cement production is increasing due to the growing world population, leading to expanded use of concrete in buildings. Yet, the production of cement significantly increases carbon emissions, putting the future of sustainable development at risk. Geopolymers are under research for their potential to reduce the impact on concrete buildings. In order to tackle this issue, the literature has yet to utilize experiments or numerical modeling to thoroughly investigate the mechanical behavior of columns made of hybrid fiber-reinforced geopolymer concrete (HFRGC) and reinforced with basalt fiber reinforced polymer (BFRP) bars. This research aims to investigate and assess the mechanical performance of steel-reinforced HFRGC columns (SRHC) and BFRP-reinforced HFRGC columns (GRHC) in concentric and eccentric loading conditions through experimental testing and finite element analysis (FEA). HFRGC specimens were prepared using steel and polypropylene fibers. Twelve circular columns, six GRHC, and six SRHC specimens, were constructed with a diameter of 300 mm and a height of 1200 mm. The average axial strength (AS) of GRHC columns was found to be 92.13% of that of SRHC columns, according to the study. Under eccentric stress circumstances, both kinds of specimens showed comparable losses in AS; for example, GRHC specimens with 38 mm spiral spacing showed reductions of 39.01% and 43.12%. Good performance was shown by the suggested analytical relationships that were drawn from the experimental data. The AS of GRHC columns may be predicted using the newly established analytical and FEA models, which are well supported by this comparative analysis that takes into account the wrapping impact of lateral BFRP spirals and the axial participation of primary BFRP bars.

• Journal of Wellbeing Management and Applied Psychology
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• v.7 no.3
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• pp.31-42
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• 2024

Purpose: Open-air dumping is a significant problem in Gilgit City, with limited research analyzing waste generation and its physicochemical impact on the soil. This study aimed to evaluate the effects of open dumping on soil properties and compare them with a controlled site. Research Design, data, and Methodology: Using ANOVA, the study found significant differences in electrical conductivity (EC), soil organic matter (SOM), soil organic carbon (SOC), sand, silt, and clay between the two sites, except for pH. Pearson correlation revealed that pH negatively correlated with EC, sand, and silt, but positively with SOM, SOC, and clay. The control site's mean EC was 6.06 mS/m, whereas the dumping site recorded 8.5 mS/m. EC is inversely related to SOM, SOC, silt, and clay, but directly to sand. SOC and SOM values varied significantly, with notable differences in soil texture components like clay and silt. Results: The research highlights the detrimental effects of unsystematic waste dumping on soil health and its contribution to greenhouse gas emissions, particularly methane, which exacerbates climate change. Conclusion: The study concluded that waste deposition and decomposition significantly impact EC, SOM, SOC, and soil texture, though pH remains unchanged. The unsystematic dumping of solid waste contributes to climate change through methane production, a potent greenhouse gas. To mitigate these impacts, the study recommends regular monitoring, waste prevention, recycling strategies, and continuous training for stakeholders to achieve sustainable development.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.5
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• pp.135-140
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• 2024

DC capacitors used in PV inverters have a relatively short lifespan compared to other power semiconductor devices and have a failure rate of 60%, making them the most vulnerable among the elements that make up a power conversion system (PCS). In addition, the lifespan of the capacitor varies depending on environmental factors, greatly affecting the lifespan and operating conditions of PV inverters and PV power generation systems. Therefore, research is needed on the development of inverter deterioration diagnostic sensor technology optimized for building-integrated and general PV power generation systems and the development of bypass compensation capacitor modules that can maintain the efficiency of the inverter in the event of a failure. Based on this research, the DC capacitor deterioration diagnosis module inside the PV inverter measures the capacity of the actual internal components and can check the trend information of the deterioration state in the long term, enabling rapid response to fires. In addition, it seeks to improve the efficiency of power generation facilities and reduce carbon emissions, and prevents electrical fires, allowing the PV power generation system to be maintained in optimal condition.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1278-1278
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• 2024

Private Finance Initiative (PFI) involves long-term contracts where private entities invest in the construction and maintenance of street lighting facilities. The current implementation of PFI Smart Street Lighting Systems faces challenges in the fulfillment process, including discrepancies in quantities, coordination of power variations, delays in the deployment of smart systems, and issues with performance indicator scoring. These challenges disrupt the smooth execution of contractual obligations. Nevertheless, the adoption of intelligent systems in street lighting presents significant advantages in reducing energy consumption, extending the lifespan of fixtures, and enhancing maintenance efficiency. This study aims to analyze an ongoing project, applying the Fuzzy Analytic Hierarchy Process (FAHP) to identify crucial PFI indicators and their weights. The study explores areas of improvement in the project compared to traditional street lighting, aiming to provide solutions to the mentioned challenges. The results indicate that indicators such as PS3 (Lighting Service Continuity) with a weight of 0.384% and PS4 (Smooth Operation of the Smart Street Lightings Management System) with a weight of 0.274% have the highest impact on service performance. Additionally, the project involves replacing 162,000 streetlights, resulting in a yearly energy consumption reduction of approximately 70%, a decrease in monthly maintenance time from an average of 48 hours to 15 hours, and an expected reduction of 900,000 tons in carbon emissions during the project period. Value for Money (VfM) analysis suggests an annual reduction in government expenditures of NTD 66 million. This reveals that implementing PFI model is more advantageous than traditional street lighting procurement, as it allows the government to leverage contractor financing and alleviate the initial high costs of streetlight replacement, thereby reducing the overall costs of streetlight establishment and maintenance.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.3
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• pp.318-329
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• 2010

The purpose of this study was to develop the $PM_{2.5}$ source profiles for diesel and gasoline-powered vehicles, which contained mass abundances in terms of mass fraction of $PM_{2.5}$ of chemical species. Seven diesel-powered vehicles and nine gasoline-powered vehicles were sampled from a chassis dynamometer exhaust dilution system. The species measured were water-soluble ions, elements, elemental carbon (EC), and organic carbon (OC). From this study, the large abundances of EC (54.5%), OC (26.0%), ${SO_4}^{2-}$ (1.5%), ${NO_3}^-$ (0.8%), and S (0.6%) were observed from the diesel-powered vehicle exhaust showing that carbons were dominant species. The gasoline-powered vehicle exhaust emitted large abundances of OC (38.3%), EC (4.2%), ${SO_4}^{2-}$ (3.6%), ${NH_4}^+$ (3.5%), and ${NO_3}^-$ (3.0%). The abundances of ${SO_4}^{2-}$, ${NH_4}^+$, and ${NO_3}^-$ from gasoline vehicle were greater than those of diesel vehicle. The emissions of P, S, Ca, Fe, and Zn among trace elements for the gasoline vehicle were greater than 1% of the $PM_{2.5}$ mass unlike those for the diesel vehicle. Particularly, the fraction of Zn was five times higher from the gasoline vehicle than that from the diesel vehicle. The source profiles developed in this work were intensively examined by applying chemical mass balance model.