• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1785-1791
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• 2021

Natural and environmental disasters are recently increasing in frequency and complexity worldwide due to the rapid expansion of overpopulation, industrialization, and urbanization. Thus, analyzing past critical events/disasters in deep and preparing for future disasters in terms of risk identification, assessment and management are imperative requirements. In this special issue, we introduce several interesting studies covering disaster risk management and observation technologies for the heat waves, particulate matters, floods, drought, and earthquake using remote sensing and GIS performed by i-SEED (School of Integrated Science for Sustainable Earth & Environmental Disaster at Pukyong National University). We expect that the results of this special issue provide comprehensive information on the risk management and damage prevention of natural and environmental disasters and offer guidance on the application to future disasters to reduce their risks and impacts.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.235-241
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• 2021

Appearance management through hair beauty forms the basis of the beauty industry, while permanent waves using heat are often used in hair salons, but hair damage due to thermal permanent wave treatment is an inevitable reality. Therefore, this study was conducted for the purpose of presenting an efficient method for thermal permanent wave that can further increase hair wave formation ability and minimize customer's hair damage. After collecting virgin hair from the occipital region, thermal rod pretreatment and thermal permanent wave treatment were performed, and hair roughness analysis and 3D-image were studied using an Atomic Force Microscope. As a result of the study, both the average roughness (Ra) and the ten point average roughness (Rz) were calculated as 223 nm and 853 nm for 4 sections, respectively, showing the highest values. Although the number of samples of the experimental data is limited, the wave forming power can be further increased through this study, and it is expected that it will be practically possible to propose an objective method for thermal permanent wave that can minimize hair damage as well as protect the cuticle of the customer's hair.Judge.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.1-10
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• 2022

Recently, due to the frequent occurrence of localized torrential rains and heat waves caused by abnormal climates. For this reason, it is necessary to develop an economical and eco-friendly rainwater detention facility that can secure the groundwater level through rainwater detention as well as flood prevention against concentrated rainfall by simultaneously implementing rainwater permeation and storage. In this study, the structural safety of an eco-friendly rainwater infiltration type detention facility made using eco-friendly inorganic binders including red clay was examined. Static analysis considering the constant load and additional vertical load and dynamic analysis considering the seismic spectrum were performed. As a result, it was found that the eco-friendly prefabricated rainwater infiltration type detention facility developed in this study has a maximum stress of about 68.1% to 75.4% and a maximum displacement of about 0.9% to 9.6% under the same load and seismic conditions compared to the existing PE block rainwater detention facility. It was confirmed that the eco-friendly prefabricated rainwater infiltration type detention facility secured excellent structural stability.

• ETRI Journal
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• v.44 no.4
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• pp.573-587
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• 2022

The agricultural sector is completely different from other sectors since it completely relies on various natural and climatic factors. Climate changes have many effects, including lack of annual rainfall and pests, heat waves, changes in sea level, and global ozone/atmospheric CO₂ fluctuation, on land and agriculture in similar ways. Climate change also affects the environment. Based on these factors, farmers chose their crops to increase productivity in their fields. Many existing agricultural ontologies are either domain-specific or have been created with minimal vocabulary and no proper evaluation framework has been implemented. A new agricultural ontology focused on subdomains is designed to assist farmers using Jaccard relative extractor (JRE) and Naïve Bayes algorithm. The JRE is used to find the similarity between two sentences and words in the agricultural documents and the relationship between two terms is identified via the Naïve Bayes algorithm. In the proposed method, the preprocessing of data is carried out through natural language processing techniques and the tags whose dimensions are reduced are subjected to rule-based formal concept analysis and mapping. The subdomain ontologies of weather, pest, and soil are built separately, and the overall agricultural ontology are built around them. The gold standard for the lexical layer is used to evaluate the proposed technique, and its performance is analyzed by comparing it with different state-of-the-art systems. Precision, recall, F-measure, Matthews correlation coefficient, receiver operating characteristic curve area, and precision-recall curve area are the performance metrics used to analyze the performance. The proposed methodology gives a precision score of 94.40% when compared with the decision tree(83.94%) and K-nearest neighbor algorithm(86.89%) for agricultural ontology construction.

• Journal of Appropriate Technology
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• v.5 no.2
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• pp.118-125
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• 2019

Climate change is one part of 17 Sustainable Development Goals (SDGs). According to the Fifth Assessment Report by the Inter- governmental Panel on Climate Change(IPCC) published in 2014, global warming is caused by greenhouse gas (GHG) emissions. The most important GHG is carbon dioxide (CO₂), which is released by the burning of fossil fuels and, to a lesser extent, by land use practices, followed by nitrous oxide and methane. IPCC predicts that global temperatures will rise 3.7℃ and sea level will rise 0.63 m by 2099 in the case of no strong restraint. According to the report, we can expect a massive species extinctions, changes in storm and drought cycles, altered ocean circulation, and redistribution of vegetation by global warming. However, climate changes, especially global warming, are the largest potential threat to human health and the source of a number of diseases globally. If climate changes are continued uncontrolled, human health will be adversely affected by the accelerating climate change and the natural disaster induced by climate change. It means we will face more serious conditions of injury, disease, and death related to natural disasters such as flood, drought, heat waves, malnutrition, more allergy, air pollution and climate change related infections related to morbidity and mortality. This review emphasizes on the relationship between global climate changes and human health and provides some suggestions for improvement.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.365-379
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• 2023

Purpose - Our previous study (Chang & Lee, 2023) presented observations on the recent changes in the year-on-year (YoY) Consumer Price Index (CPI) of the Republic of Korea (ROK) after the COVID-19 pandemic. The purpose of this article is to present an integrated analysis and interpretation of the recent changes in CPI and the Aggregate Import Price Index (IPI) by incorporating recent data, specifically data from September 2022 to December 2022. Design/methodology/approach - This study collected CPI (YoY) data in the ROK from January 2019 to December 2022 using e-National Indicator System provided by the ROK. Statistical analysis was employed to analyze the data. Findings - First, we confirm the extended results of the existing study by Chang and Lee (2023). Second, we demonstrate that the Aggregate IPI in ROK increased significantly in 2022 compared to 2021. We then provide an integrated interpretation on the significant increase in CPI and aggregate IPI in ROK, which complements Chang and Lee (2023) that limits their discussion to YoY CPI. Moreover, we show that the IPI of the semiconductor in ROK decreased significantly in 2022 compared to 2021. Research implications or Originality - Our results provide important insights into the recent changes in the CPI in the ROK. The results suggest that these changes can be partially attributed to various factors, such as the global supply chain disruptions resulting from the spread of the COVID-19 pandemic and the prolonged war between Russia and Ukraine, the side effect of quantitative easing by the US Federal Reserve, heat waves and droughts caused by climate change in ROK, a surge in demand following a gradual daily recovery, US-China trade conflict, etc. Our study shows statistically comprehensive results compared to the studies that limit their discussion to YoY average growth rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.511-520
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• 2020

Owing to global warming, heat waves have become stronger in the summer, and research on improving the thermal environment of green spaces, such as urban parks, is being conducted. On the other hand, studies on improving the urban thermal environment, which is changing due to the greening pattern and the intensity of the wind, are still insufficient. This study analyzed the temperature of the green spaces on campus to understand the factors affecting the temperature changes. After investigating the covering condition and planting form of the site, factors, such as temperature, humidity, wind direction, wind speed, and illuminance, were measured. The most influential factors on the temperature distribution are evapotranspiration and wind - induced heat transfer. The other major factors affecting the temperature change were the type of cover, wind velocity/wind direction, type of planting, shade / solar irradiance. In the type of cover, the plant was classified as low temperature, and the asphalt pavement was classified as high temperature. In wind speed, instantaneous temperature was reduced by 1.2 ℃ in southern wind, 0.7 ℃ in the westerly wind, 0.4 ℃ in the north wind and 0.5 ℃ in the east wind when a wind of 3.5m/s or more was blown.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.811-823
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• 2019

Slip form method is applied to many cases of a shaft these days because it is safer, more economical and faster than cast-in-place method. Slip-up height of the method is approximately 2.5 to 4.0 m/day. If the temperature of concrete is outside the range of 10 to 30℃, the effects of changes in strength or elastic characteristics are significant. Therefore, it is difficult for slip-up speed to be higher than 3 m/day during winter construction. In addition, concrete has heat caused by hydration, which causes temperature cracking of hardened concrete. Therefore, temperature control of concrete curing is necessary for the continuous slip-up of slip form. In this study, the rebound hardness, time of ultrasonic waves propagation, heat of hydration, and external temperature are measured by developing heating panels and test devices for the continuous slip-up. Based on this, heating slip form is manufactured; this was applied to "Kimpo sites" and "Sinwol sites". The compared slip-up speed samples were 1.9 m/day or 0.200 m/hr on average at Gimpo sites (08:00~17:30) and 2.0 m/day or 0.210 m/hr at Sinwol sites.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.6
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• pp.23-29
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• 2003

Transonic two-phase flow of Saturated humid air, in which relative humidity is 100%, with various condensation processes around thin airfoils is investigated. The study uses an extended transonic small-disturbance(TSD) model of Rusak and Lee [11, 12] which includes effects of heat addition to the flow due to condensation. Two possible limit types of condensation processes are considered. In the nonequilibrium and homogeneous process, the condensate mass fraction is calculated according to classical nucleation and droplet growth rate models. In the equilibrium process, the condensate mass fraction is calculated by assuming an isentropic process. The flow and condensation equations are solved numerical1y by iterative computations. Results under same upstream conditions describe the flow structure, field of condensate, and pressure distribution on airfoil's surfaces. It is found that flow characteristics, such as position and strength of shock waves and airfoil’s pressure distribution, are different for the two condensation processes. Yet, in each case, heat addition as a result of condensation causes significant changes in flow behavior and affects the aerodynamic performance of airfoils.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.154-167
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• 2019

As urban heat environment problems occur due to climate change, urban thermal environmental problems such as heat waves and tropical nights are becoming more serious in cities. In South Korea, forest areas favorable for generating cold air account for about 63 percent of the land area. Furthermore, the Jeongmaek, the axis of the main mountain ranges of Korea, is located close to the cities. Hence, the management of cold air is an effective way to improve the thermal environment of Korean cities. We selected the Nak-nam Jeongmaek located in the southern part of Korean Peninsular as well as two cities (Jinju-si and Sancheong-gun) located at the Jeongmaek to analyze its cold air characteristics and suggest management strategies of cold air. We used KALM (Kaltluftabflussmodell), a cold air simulation model developed in Germany and identified both the cold air flow and the height of cold air layer generated during 6 hours at night. As a result, the cold air flow generated in the Jeongmaek became clear and the height of cold air layer increased with time. Based on the results, we proposed management plans to maintain and expand the cold air flow. For example, forest areas with active cold air generation were designated as 'cold air conservation areas', and areas requiring management for good cold air flow were as 'cold air management areas'. This study is expected to be useful for establishing systematic urban ventilation plan to improve thermal environment in Korea cities.