• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.106-107
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• 2019

Recently, maintenance of old facilities has emerged as a major issue. In particular, the demand for road cutting and excavation is increasing due to the aging of underground facilities such as water supply, sewage and city gas. In addition, the development of eco-friendly equipment is required due to the environmental problems of noise and dust. Therefore, this study intends to analyze the performance in terms of productivity of the eco-friendly road cutter developed as part of the development of eco-friendly equipment, and to derive improvements.

• Journal of Drive and Control
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• v.20 no.1
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• pp.8-15
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• 2023

With the recent trend of intelligence and automation of construction work, a double-blade road cutter is being developed that automatically enables cutting along the cutting line marked on the road using a vision system. The road cutter can recognize the cutting line through the camera and correct the driving route in real-time, and it detects the load of the cutting blade in real-time to control the driving speed in case of overload to protect workers and cutting blades. In this study, a vision system mounted on a double-blade road cutter was developed. A cutting route recognition technology was developed to stably recognize cutting lines displayed on non-uniform road surfaces, and performance was verified in similar environments. In addition, a vision sensor protection module was developed to prevent foreign substances (dust, water, etc.) generated during cutting from being attached to the camera.

• Journal of the Korean Society of School Health
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• v.18 no.1
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• pp.15-25
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• 2005

Purpose: Recently there are scientific evidences for the health effects of Asian dust-storms. Particularly in 2002, the daily average of $PM_10$ exceeded 600 and 700 $\mu{g}/m^3$ in March and April respectively. We examined the effects of Asian dust‐storms on perceived symptoms and preventive behaviors among children, adults, and elders. Method: The subjects of this study were 425 children, 444 adults and 60 elders. A questionnaire survey was carried out on the children and the adults by teachers and on the elders by interviewers to obtain information on demographic variables, perceived symptoms and preventive behaviors, previous respiratory disease, environmental tobacco smoke, and proximity between the house and the road during Asian dust-storms. We analyzed using descriptive statistics, $X^2$ test and multiple logistic regression models. After adjustment for potential confounders, we estimated the odds ratios and 95% confidence intervals of the children and the elders for perceived symptoms and preventive behaviors. Result: The elders had a significantly higher prevalence of respiratory symptoms than the other groups. The children had a significantly higher prevalence than the adults in getting URI (1.51), coughing (1.68), rhinorrhea (1.46), fever (2.39) and medication for allergy or asthma (1.90). The children had better behaviors than the elders in closing windows (3.57), taking less outdoor recreational activity (2.59) and staying home (2.60). Conclusion: This study suggested that children and elders are susceptible to the effects of Asian dust on health. Health educators should inform these populations about the influence of Asian dust and provide health education for preventive behaviors.

• Elastomers and Composites
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• v.54 no.4
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• pp.330-334
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• 2019

Cryogenic crushing techniques have been employed for recycling waste rubber articles and for extracting residual organic additives present in rubber samples. Rubber particulate derived from tire tread abrasion is one of the key components of road dust. Therefore, in this work, we prepared rubber particulates using a cryogenic crusher and characterized their shapes as well as size distributions according to the type of rubber. The rubber particulates exhibited uneven surfaces with the presence of some small pieces. The order of the particle size distribution was observed to be: NR > BR > SBR. Subsequently, carbon black was added; this led to a decrease in the particle size and the shape becoming rougher. The crushed particulates of the carbon black-filled samples comprised agglomerated shapes of small pieces, which were similar in shape to that of wear debris in tire tread. It was discovered that crosslink density was one of the principal factors that led to the formation of small crushed particulates. The small particulates obtained by cryogenic crushing can be utilized as model rubber particulates for researching micro dust.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.394-396
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• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.69-70
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• 2007

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• Clean Technology
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• v.27 no.1
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• pp.39-46
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• 2021

A road structure washing vehicle equipped with a 4 HP, 80 LPM ultrafine bubble generator was used to clean a tunnel wall and the surface of the surrounding structure, consisting of concrete and tiles, in a heavy traffic area around an apartment complex in the city. Ultrafine bubbles were generated by supplying air at 2 to 3 LPM and using a specially designed nozzle, whereas fine bubbles made by an impeller in a gas-liquid mixing self-priming pump were produced with an average diameter of 165.4 nm and 6.81 × 107 particles mL-1. Using a high pressure washer gun that can perform high-pressure cleaning at 150 bar and 30 LPM, ultrafine bubbles were used to wash dust adsorbed on the surface of the road structures. The experimental analysis was divided into before and after washing. The samples were analyzed by applying ISO 8502-3 to measure surface contamination of dust adsorbed on the surface. Using the transparent tape attached to the surface, the removal rate was calculated by measuring the weight of the dust, and the number of particles was calculated using the gravimetric method and the software, ImageJ. The results of the experiment showed that the number of dust particles adsorbed on the tile wall surface before and after washing were 3,063 ± 218 particles mL-1 and 20 ± 5 particles mL-1, respectively, with weights of 580 ± 82 mg and 13 ± 4 mg. Particles on the surface of the concrete structure before and after washing were 8,105 ± 1,738 particles mL-1 and 39 ± 6 particles mL-1, respectively, with weights of 1,448 ± 190 mg and 118 ± 32 mg.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.217-225
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• 2003

Samples of size-fractionated PM10 (airborne particulate matter with aerodynamic diameter less than $10\mu\textrm{m}$) were collected at an urban site in Jeju city from May to September 2002. The mass concentration and chemical composition of the samples were measured. The data sets were then applied to the CMB receptor model to estimate the source contribution of PM10 in Jeju area. The average PM10 mass concentration was 28.80$\mu\textrm{g}/m^3$ ($24.6~33.49\mu\textrm{g}/m^3$), and the FP (fine particle with aerodynamic diameter less than $2.l\mu\textrm{m}$ fraction in PM10 was approximately 8% higher than the CP (coarse particle with aerodynamic diameter greater than $2.l\mu\textrm{m}$ and less than $10\mu\textrm{m}$ fraction in PM10. The CP composition was obviously different from the FP composition, that is, the most abundant water soluble species was nitrate ion in the FP, but sulfate ion in the CP. Also sulfur was the most dominant element in the FP, however, sodium was that in the CP. From CMB receptor model results, it was found that road dust was the largest contributor to the CP mass concentration (45% of the CP) and ammonium nitrate, domestic boiler, and marine aerosol were major sources to the CP mass. However, the secondary aerosol was the most significant contributor to the FP mass concentration (45% of the FP). In this study, it was suggested that the contributions of soil dust and gasoline vehicle became very low due to collinearity with road dust and diesel vehicle, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.4
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• pp.41-45
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• 1981

This study is to be surveyed the rural environmental conditions such as housing, water works, sewerage, road and farm road, land utilization, natural conservation and sightseeing, public damage and disaster, and rural water requirement through the 50 villages (10995 home unit) The brief results summarized in this study are as follows. 1.Modernization of rural housing, toilet room and arrangement of dust materials are getting better than before l0yrs. 2.Water works are highly improved but sewerage problem is still in the serious problems. 3.Rood achievement is quite good but farm road is in still insufficiency 4.Utilization of land resources should be maximaized but land conservation is still insufficient condition and farm land is getting polluted. 5.Natural environmental conservation is much more improved but landscape is still insufficient. 6.Public damages such as water pollution, air pollution, and others are getting greater and greater but meteorological damage should be decreased. 7.Watershed condition is getting better and better but because of the large requiriment of the water use for the crops, agricultural water use should be needed much more than before l0yrs.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1970-1974
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• 2010

This paper is how to improve contaminated air by the pollutant from vehicles through ventilators and entrance at the underground station. We are looking for the environment management to take care of customers. There is two ventilation systems. One is natural ventilation system, the other is forced ventilation system. Usually, subway ventilators were installed low on the sidewalk. There are lots of craps on the ventilators, so these things interrupt influx of outside air. But the gas from the vehicles comes into the station through entrance. There is lots of noise while ventilations run. So we install the supply air vents away from the road for the customers. If it's difficult, we cover around the ventilator with clear plastic plates more than 2M heights. We also install silencer on the ventilators. We install the air curtains on the entrances to prevent dust from outside. Seoul Metropolitan has a plan to make 60M deep underground road. To improve underground road air quality, ventilators should be installed that consider the above information.