• Korean Journal of Construction Engineering and Management
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• v.21 no.4
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• pp.38-49
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• 2020

As the quality of life has been improving, people are getting higher interest and higher expectation for safety. However, the accident rate at the construction site is still high. Therefore, it is urgent to secure the safety at the construction work. Due to the nature of the construction industry, construction sites are directly exposed to the external environment. The possibility of accident occurrence is increased due to various factors such as the always variable processes, the diversity of manpower input, the increase in vulnerable class, and the danger of construction equipment..Particularly, the disasters occurring at the small- or medium-sized construction sites (budget ≤ 12 billion KRW) account for 88.9% of the total disasters at construction sites (73.4% for casualty). It was due to the lack of management caused by the absence of supervisors and insufficient safety measures. Moreover, it is difficult for the small- or medium-sized construction sites to apply basic safety measures such as safety education and safety facility installation by themselves in order to prevent disasters because they don't have sufficient safety organizations. It is because they have relatively less safety personnel and poorer technology system than large-sized construction sites. Therefore, in order to reduce accidents in construction, it is necessary to prevent accidents at the small- and medium-sized construction sites. From this point of view, the objectives of this study were to identify the key risk items causing accidents frequently by analyzing the accidents at construction sites and identifying problems associated with safety management, and to secure the safety at the small- and medium-sized construction sites.

• Environmental and Resource Economics Review
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• v.30 no.4
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• pp.627-648
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• 2021

The fine-dust season management system refers to the policy of implementing enhanced reduction measures in transportation, power, business and living sectors in winter, when fine dust levels are high. The fine dust season management system is a regulatory policy that causes social costs and transfers to various economic players. Equity is an important issue for the cost burden. Therefore, in this study, the cost of each power generator was analyzed using the coal power generation reduction amount of each power generator to verify that the cost of the power sector is evenly distributed. In particular, the effect of the fine dust season management system on coal power generation of power generators was analyzed by applying a synthetic control method that can identify the time-variable effect of the policy. It was confirmed that the fine dust season management system reduced volume of fuel and power generation in coal power plants, resulting in an increase in the cost of the power generation sector, even considering the effect of some power demand due to the COVID-19 crisis. However, it could be seen that these costs were not distributed equally among the generators, and that they were more costly to the specific generators.Social costs incurred by fine dust season management need to be improved so that stakeholders are equally burdened.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.247-254
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• 2010

The positive effects of the air quality improvement policy have revealed sufficiently such as 3.3 trillion won of social benefits under the Environmental Zone in five years(K. Choi, 2009). In case of low-income freight truck owner, however, could be burdened with the requirement likes emission decreasing equipment. Eventually, restraint of running in the Environmental Zone would be affected their livelihood seriously. After estimating the scale of low-income freight truck owner for three alternatives with Road Freight Transport Center data, this study calculates decreased VKT to estimate the scale of monetary loss. In the result, decreased income amount of low-income freight truck owner under the restricted running estimated 6.1 trillion won during 5 years, quite exceeding 3.3 trillion won of the positive benefits as improving air quality, which means the necessity of immediate countermeasure. In other words, even though the governmental policy aimed benefits for the majority, the result implies that the total monetary losses of the minority could be exceed against the positives, therefore analysis should be considered carefully before the policy becomes effective.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.5
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• pp.80-88
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• 2020

With the issuance of one-week fine dust emergency reduction measures in March 2019, the public's anxiety about fine dust is increasingly growing. In order to assess the application of air purifying plant-based bio-filters to public facilities, this study presented a method for measuring pollutant reduction effects by creating an indoor environment for continuous discharge of particle pollutants and conducted basic studies to verify whether indoor air quality has improved through the system. In this study conducted in a lecture room in spring, the background concentration was created by using mosquito repellent incense as a pollutant one hour before monitoring. Then, according to the schedule, the fine dust reduction capacity was monitored by irrigating for two hours and venting air for one hour. PM₁₀, PM_2.5, and temperature & humidity sensors were installed two meters front of the bio-filters, and velocity probes were installed at the center of the three air vents to conduct time-series monitoring. The average face velocity of three air vents set up in the bio-filter was 0.38±0.16 m/s. Total air-conditioning air volume was calculated at 776.89±320.16㎥/h by applying an air vent area of 0.29m×0.65m after deducing damper area. With the system in operation, average temperature and average relative humidity were maintained at 21.5-22.3℃, and 63.79-73.6%, respectively, which indicates that it satisfies temperature and humidity range of various conditions of preceding studies. When the effects of raising relatively humidity rapidly by operating system's air-conditioning function are used efficiently, it would be possible to reduce indoor fine dust and maintain appropriate relative humidity seasonally. Concentration of fine dust increased the same in all cycles before operating the bio-filter system. After operating the system, in cycle 1 blast section (C-1, β=-3.83, β=-2.45), particulate matters (PM₁₀) were lowered by up to 28.8% or 560.3㎍/㎥ and fine particulate matters (PM_2.5) were reduced by up to 28.0% or 350.0㎍/㎥. Then, the concentration of find dust (PM₁₀, PM_2.5) was reduced by up to 32.6% or 647.0㎍/㎥ and 32.4% or 401.3㎍/㎥ respectively through reduction in cycle 2 blast section (C-2, β=-5.50, β=-3.30) and up to 30.8% or 732.7㎍/㎥ and 31.0% or 459.3㎍/㎥ respectively through reduction in cycle 3 blast section (C-3, β=5.48, β=-3.51). By referring to standards and regulations related to the installation of vegetation bio-filters in public facilities, this study provided plans on how to set up objective performance evaluation environment. By doing so, it was possible to create monitoring infrastructure more objective than a regular lecture room environment and secure relatively reliable data.

• Korean Journal of Construction Engineering and Management
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• v.19 no.5
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• pp.90-100
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• 2018

Government needs a risk assessment method that is effective in preventing accidents as a part of the three principal projects of the government for protecting the people's lives for establishing preventative measures to prevent accidents in the construction sites, which accounted for more than half of all accidental mortality accidents, and promote the safety-oriented culture for making fundamental changes. Accidents at the medium and small sized construction sites accounted for 88.9% of the total construction accidents. The data indicates that improper management and lack of advanced safety measures due to the absence of a safety supervisor are the biggest problems. It is believed that active measures to evaluate and prevent risks at construction sites are necessary for preventing accidents in the medium and small sized construction sites. The objectives of this study is to identify the key risk items of common accident causes and propose a practical, preemptive, and improved risk assessment method by evaluating the problems in the safety management of construction sites for reducing the accident rate in the medium and small sized construction sites.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.273-281
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• 2019

The energy consumed by buildings among the total national energy consumption is more than 10% of the total. For this reason, Korea has adopted the zero energy building policy since 2025, and research on the energy saving technology of buildings has been demanded. Analysis of buildings' energy consumption patterns shows that lighting, heating and cooling energy account for more than 60% of total energy consumption, which is directly related to solar power acquisition and window opening and closing operation. In this paper, we have developed a low - power IoT sensor module for window system to transfer acquired information to building energy management system. This module transmits the external environment and window opening / closing status information to the building energy management system in real time, and constructs the network to actively take energy saving measures. The power used in the module is designed as an independent power source using solar power among the harvest energy. The topology of the power supply is a Buck converter, which is charged at 4V to the lithium ion battery through MPPT control, and the efficiency is about 85.87%. Communication is configured to be able to transmit in real time by applying WiFi. In order to reduce the power consumption of the module, we analyzed the hardware and software aspects and implemented a low power IoT sensor module.

• Journal of the Korean earth science society
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• v.42 no.2
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• pp.149-163
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• 2021

In this study, the changes in ozone (O3) concentrations due to the removal of power plant emissions were analyzed using a community multi-scale air quality (CMAQ) model. Two different CMAQ model simulations, one considering the emissions from the Hadong power plant and one without considering the emissions, were conducted to investigate the effect of the emissions on the changes in the O3 concentrations in the surrounding areas. Subsequently, the CMAQ simulations exhibited an increase in the O3 concentration (25.24%) despite a decrease in the NOx (-18.87%) and volatile organic carbon (VOC, -11.27%) concentrations, which are major O3 precursors. The changes in the NO and O3 concentrations due to the removal of power plant emissions presented a strong negative correlation (r= -0.72). This indicated that the increase in the O3 concentration was mainly attributed to the significantly decreased NO concentration, thus, mitigating the O3 titration reaction (NO+O3→NO2+O2). Additionally, due to the VOC-limited (i.e., NOx-saturated) conditions in the study region, NO affected the O3 concentration, indicating that the O3 concentrations in a particular region are not only proportional to the increase or decrease in emissions. Therefore, an in-depth understanding of the chemical O3 production and loss in a particular region is necessary to accurately evaluate the effect of emission control on the changes in the O3 concentration.