• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.57-66
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• 2019

This study carried out on-site investigation and precision monitoring to prepare proper design and operation technical guidelines for the use of bio gas in organic waste resources (fertilizing urine, food waste, food waste, food waste, etc.). According to the government's mid- and long-term policy on bio gasification, the expansion of waste resources is actively being pushed forward. However, facilities that use the biogas produced for urban gas and transportation are still under-efficient. Precision monitoring was carried out for biogasification facilities of organic waste resources in seven locations nationwide. When the results of precision monitoring were summarized with the four-season average, the efficiency analysis of each organic waste resource showed that the organic breakdown rate was 66.3% on average on VS basis. Analysis of biogas characteristics before and after pretreatment revealed that the $H_2S$ average of the entire facility was measured at 949.7 ppm using iron salts and desulfurization (dry, wet) and that the quality refining facility shearing and rear end was 29.0 ppm and 0.3 ppm. The methane content was found to be reduced by 65.6% at the rear of the fire tank, 63.5% at the back and 97.5% at the rear.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.121-132
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• 2018

Weather is an important factor affecting roadway transportation in many aspects such as traffic flow, driver 's driving patterns, and crashes. This study focuses on the relationship between weather and road surface condition and develops a model to estimate the road surface condition using machine learning. A road surface sensor was attached to the probe vehicle to collect road surface condition classified into three categories as 'dry', 'moist' and 'wet'. Road geometry information (curvature, gradient), traffic information (link speed), weather information (rainfall, humidity, temperature, wind speed) are utilized as variables to estimate the road surface condition. A variety of machine learning algorithms examined for predicting the road surface condition, and a two - stage classification model based on 'Random forest' which has the highest accuracy was constructed. 14 days of data were used to train the model and 2 days of data were used to test the accuracy of the model. As a result, a road surface state prediction model with 81.74% accuracy was constructed. The result of this study shows the possibility of estimating the road surface condition using the existing weather and traffic information without installing new equipment or sensors.

• Korean Journal of Pharmacognosy
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• v.50 no.1
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• pp.37-45
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• 2019

Portulaca oleracea L. (PL) has been used in traditional medicine herb for treatment of various diseases, such as diarrhea, dysentery, and skin inflammation. Previous studies have shown that the PL regulates the inflammation by inhibition of pro-inflammatory cytokines. Although PL might have improvement effects of intestinal function and bioactive effects, there are not enough studies to demonstrate. This study investigated the effects of KDC16-2 on the improvement of intestinal function and anti-inflammatory effects in vivo and in vitro. The improvement effect of intestinal function was measured fecal amount, water content and intestinal transit rate in KDC16-2 treated ICR mice. As results, compared with the control group, the KDC16-2 group showed a significant increase in wet fecal weight, dry fecal weight and fecal water content. The intestinal transit rate of KDC16-2 group was significantly increased. Based on the results, KDC16-2 is considered to have effects on improving intestinal function. The effect of anti-inflammatory demonstrated by using dextran sulfate sodium (DSS)-induced colitis mice. The mice were administered 3% DSS along with KDC16-2 (100, 300 mg/kg) for 14 days. DSS-induced colitis mice were significantly ameliorated in KDC16-2 treated group, including body weight loss, colon length shortening, tight junction protein of colon and histological colon injury. The levels of inflammatory mediators (IgG2a, IgA, C-reactive protein and Myeloperoxidase) and pro-inflammatory cytokines (tumor necrosis factor (TNF)-${\alpha}$, Interleukin (IL)-6) which are involved in inflammatory responses were increased in the DSS-treated group as compared to those in the control group, and the levels were significantly decreased in the KDC16-2 groups. In addition, we investigated the impact of KDC16-2 on lipopolysaccharide (LPS)-induced inflammatory responses in J774A.1 cells. KDC16-2 inhibited production of prostaglandin E2 (PGE2) and reactive oxygen species (ROS). These results suggested that the KDC16-2 could effectively alleviate the dysfunction of intestinal and inflammatory mediators. Thus, these KDC16-2 can be potentially used as health functional food of intestinal.

• Korean Chemical Engineering Research
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• v.59 no.3
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• pp.339-344
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• 2021

In order to improve the PEMFC (Proton Exchange Membrane Fuel Cell) durability, it is important to accurately evaluate the durability of the membrane in a short time. Recently, DOE (Department of Energy) reported a protocol that combines the chemical and mechanical durability of membranes to evaluate them effectively. This protocol applies chemical/mechanical deterioration to the membrane by repeating wet/dry while OCV (Open Circuit Voltage) holding. The problem of this protocol is that it is highly affected by electrode degradation due to change cycles in OCV and that the evaluation time is long. By using oxygen instead of air as the cathode gas while leaving the other conditions of the DOE protocol as it is, the durability evaluation time could be reduced from 408 hours to 144 hours. By reducing the number of voltage change cycles to 1/3, the electrode degradation due to the voltage change cycle was reduced to 1/12 when oxygen was used compared to air at the end, thereby enabling more accurate evaluation of polymer membrane durability.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.10-15
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• 2021

'Gwangyoung', a winter forage triticale cultivar (X Triticosecale Wittmack), was developed at the Department of Rice and Winter Cereal Crop, NICS, RDA in 2018. The cultivar 'Gwangyoung' has leaves of wide width, medium length, and green color, and spikes of medium length and yellowish-brown color, and a large grain of yellowish-brown color. The heading date of the cultivar 'Gwangyoung' was April 22 which was similar to check cultivar 'Shinyoung'. Its tolerance or resistance to cold, lodging, wet injury powdery mildew, and leaf rust were also similar to those of the check cultivar. The leaf blade ratio of 'Gwangyoung' (27.5%) was higher than that of 'Shinyoung' (21.2%). The average forage fresh and dry matter yield of cultivar 'Gwangyoung' at milk-ripe stages were 50.0 and 17.6 MT ha-1, respectively, which were higher than those (47.7 and 17.1 MT ha-1) of the check cultivar. The silage quality of 'Gwangyoung' was lower than that of the check cultivar 'Shinyoung' in crude protein content (5.3%) and total digestible nutrients (61.3%), while was higher than the check cultivar in neutral detergent fiber (58.2%) and acid detergent fiber (34.9%). 'Gwangyoung' showed the silage of 1 grade and a grain yield of 6.03 MT ha-1.

• Conservation Science in Museum
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• v.27
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• pp.125-146
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• 2022

The Wooden Gamsil with Inscription of "Botajeon" in the collection of the Dongguk University Museum was made in imitation of the wooden architecture style of the late Joseon period. The Gamsil had suffered exfoliation in the pigment and loss of components and thus underwent conservation treatment. Prior to the conservation treatment, the damage was classified by type and form, scientific analysis was carried out on the fiber and the species of wood, and portable X-ray fluorescence (P-XRF) analysis was conducted for the pigment component analysis. According to the analyses, Korea Pine(Soft pine) was used for most parts of the Gamsil, Manchurian walnut (Jugalns spp.) was used for the signboard, and the fiber used was identified as rice straw (Oryza sativa). The P-XRF identified white lead and zinc oxide in the white pigment, red lead in the red pigment, ultramarine blue in the blue pigment, and emerald green in the green pigment. For the conservation treatment, contaminants attached to the gamsil were removed by both dry and wet cleaning, detached parts were reattached in their original places, and lost parts were restored.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.18-27
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• 2022

In this study, the time-dependent chloride ingress behavior in GGBFS concrete was evaluated considering marine exposure conditions and the properties of concrete mixtures. The concrete mixture for this study had 3 levels of water to binder ratio and the substitution rate of GGBFS, and outdoor exposure tests were performed considering submerged area, tidal area, and splash area. According to the evaluation results of diffusion coefficient considering properties of concrete mixtures, as the substitution rate of GGBFS increased, the decreasing rate of the diffusion coefficient decreased based on exposure periods of 730 days(2 years). As the evaluation result of the diffusion behavior according to the marine exposure conditions, the diffusion coefficient was evaluated in the order of submerged area, tidal area, and splash area. In tidal area, a relatively high diffusion coefficient was evaluated due to the repetition of wet and dry seawater. In this study, the effects of GGBFS substitution rate on the decreasing behavior of apparent chloride diffusion coefficient was analyzed in consideration of exposure conditions and periods. Linear regression analysis was performed with apparent chloride diffusion coefficient as output value and GGBFS substitution rate as input value. After 730 days of exposure, the effect of GGBFS on diffusion coefficient was significantly reduced. Even for OPC concrete, after 730 days, the diffusion coefficient was as low as that of GGBFS concrete, so the gradient of the regression equation decreased significantly. It is thought that improved durability performance for chloride ingress can be secured before 730 days through the use of GGBFS.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.405-412
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• 2021

The objective of this study is to investigate the environmental impact of fine dust generated at the construction waste intermediate treatment plants, and to propose engineering data and measures to suppress the generation of fine dust to cope with the expected strengthened environmental regulations of the government. The following study conclusions are drawn. 1) T he maximum concentration of fine dust in the workplace was measured as 160㎍/m³ from the crushing operation followed by the point of waste unloading, where focused suppression plan of the fine dust generation is needed in the future. 2) Fine dust concentrations of 113㎍/m³ in wet road conditions and 50㎍/m³ in dry conditions were measured, indicating that fine dust could be reduced by 50% with watering alone. 3) The effect of distancing from the dust source was studied. PM10 during operation of the workplace was measured as about 25㎍/m³ higher than those of the neighboring areas. Whereas there was no significant difference in case of PM2.5 between workplace and neighboring areas. 4) The measurement results of the heavy metal contents showed that these metals did not affect neighboring areas.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.1-18
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• 2022

Currently, the Korea Meteorological Administration evaluates the meteorological drought by region using SPI6(standardized precipitation index 6), which is a 6-month cumulative precipitation standard. However, SPI is an index calculated only in consideration of precipitation at 69 weather stations, and the drought phenomenon that appears for complex reasons cannot be accurately determined. Therefore, the purpose of this study is to calculate and compare SPI considering only precipitation and SDCI (Scaled Drought Condition Index) considering precipitation, vegetation index, and temperature in Gyeonggi. In addition, the advantages and disadvantages of the station data-based drought index and the satellite image-based drought index were identified by using results calculated through the comparison of SPI and SDCI. MODIS(MODerate resolution Imaging Spectroradiometer) satellite image data, ASOS(Automated Synoptic Observing System) data, and kriging were used to calculate SDCI. For the duration of precipitation, SDCI1, SDCI3, and SDCI6 were calculated by applying 1-month, 3-month, and 6-month respectively to the 8 points in 2014. As a result of calculating the SDCI, unlike the SPI, drought patterns began to appear about 2-month ago, and drought by city and county in Gyeonggi was well revealed. Through this, it was found that the combination of satellite image data and station data increased efficiency in the pattern of drought index change, and increased the possibility of drought prediction in wet areas along with existing dry areas.

• Clean Technology
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• v.28 no.3
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• pp.203-209
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• 2022

An environmental evaluation was conducted by employing LCA methodology for a mechanical seal manufacturing process that uses recycled silicon recovered from end-of-cycle PV modules. The recycled silicon was purified and reacted with carbon to synthesize β-SiC particles. Then the particles underwent compression molding, calcination and heat treatment to produce a product. Field data were collected and the potential environmental impacts of each stage were calculated using the LCI DB of the Ministry of Environment. The assessment was based on 6 categories, which were abiotic resource depletion, acidification, eutrophication, global warming, ozone depletion and photochemical oxidant creation. The environmental impacts by category were 45 kg CO₂ for global warming and 2.23 kg C₂H₄ for photochemical oxide creation, and the overall environmental impact by photochemical oxide creation, resource depletion and global warming had a high contribution of 98.7% based on weighted analysis. The wet process of fine grinding and mixing the raw silicon and carbon, and SiC granulation were major factors that caused the environmental impacts. These impacts need to be reduced by converting to a dry process and using a system to recover and reuse the solvent emitted to the atmosphere. It was analyzed that the environmental impacts of resource depletion and global warming decreased by 53.9% and 60.7%, respectively, by recycling silicon from end-of-cycle PV modules. Weighted analysis showed that the overall environmental impact decreased by 27%, and the LCA analysis confirmed that recycling waste modules could be a major means of resource saving and realizing carbon neutrality.