• Particle and aerosol research
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• v.6 no.1
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• pp.9-20
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• 2010

This study examined the concentration level of the major air pollutants in public transportation. The study was conducted between February 2009 and March 2008 at Suwon-Yeosu line in Korea. $PM_{10}$ concentration level was $100{\mu}g/m^3$ on average. The $PM_{2.5}$ to PM10 ratio in transport is 0.37, which was lower than the results published by other researches. The result also demonstrated that outdoor $PM_{10}$ concentration was about 56~60% level compared to that of the cabin. $CO_2$ concentration level in the cabin was 1,359ppm, which does not exceed 2,000ppm, which is the guideline concentration level according to the Ministry of Environment. $CO_2$ concentration level in the cabin was $CO_2=23.4{\times}N+460.2$, and about 23.4ppm in $CO_2$ concentration level increased every time one passenger was added on. The experiment conducted on the train demonstrated that the average $PM_{10}$ concentration level was $100{\mu}g/m^3$ in case of the reference cabin while average $PM_{10}$ concentration level of the modified vehicle was $68{\mu}g/m^3$. Likewise, effect of the particle reduction device for the reduction of $PM_{10}$ concentration level was approximately 21%. Meanwhile there was almost no difference in the concentration level between reference and modified cabin in case of $PM_{2.5}$. Using zeolite as an adsorbent was made to reduce the $CO_2$ concentration level in the cabin. Number of passengers was factored in, to calculate the effect of the adsorption device, which demonstrated that about 36% of $CO_2$ concentration level was reduced in the modified cabin effect of the $CO_2$ reduction device. This research analyzed the current status concerning the quality of air in the public transportation and technologies were developed that reduces major air pollutants.

• Journal of the Korean Society of Safety
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• v.35 no.5
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• pp.59-65
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• 2020

For monitoring the status of industrial accidents, many statistical indexes have been developed and applied such as fatal rate, frequency rate, and severity rate. These accident indexes are measured by frequency and loss time according to the accidents in the individual industry level. However, it is less considered to use the index of identifying the industrial concentration of accidents in the holistic view. Thus, this study aims to suggest the accident concentration level among domestic industries through index analysis. The concentration level of industrial accidents is calculated by the accident composition of sub-industries. This concentration level shows whether an industry is comprised of a few sub-industries generating more accidents or an industry consists of sub-industries having the similar number of accidents. To this end, the concentration rate (CR) and concentration index (CI) are proposed to take a look at the industry composition of accidents by embracing the concept of market concentration indexes such as Hirschman-Herfindahl Index. As for the case study, four industries of mining, manufacturing, transportation, and other business (usually service) are analyzed in terms of indexes of accident rate, death(fatality) rate, and CR and CI of accident and death. Finally, we illustrate the positioning map that the accident concentration level is compared with the traditional accident frequency level among industries.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.6
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• pp.666-674
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• 2012

The purpose of this study is to propose management strategies to lower the level of $PM_{10}$ concentration. First, this study analyzes the characteristics of particle sizes in three different areas, the residential, the roadside, and the industrial areas. Second, it has examined the size of particles which can influence on the increase of $PM_{10}$ concentration level. The distribution of particle size for $PM_{10}$ concentration was not different by regions. The highest portion in the observed $PM_{10}$ is near $0.3{\mu}m$. In addition, both near $2.5{\mu}m$ and near $5.0{\mu}m$ are found higher in portion. The fractions of $PM_{1.0}$ and $PM_{2.5}$ in $PM_{10}$ are 68.2% and 75.8% respectively. The fraction of $PM_{1.0}$ in $PM_{2.5}$ is 89.8%. The particle diameters contributed to the increase of $PM_{10}$ concentration are different by regions. In the residential area, the sizes of near $0.6{\mu}m$ and near $3.3{\mu}m$ particles are found to be the cause for the increase of $PM_{10}$ concentration level. However the particle sizes for the increase of $PM_{10}$ concentration level are $0.8{\mu}m$ and $0.5{\mu}m$ in roadside and industrial area respectively. Therefore, fine particles are found as the key factors to raise $PM_{10}$ concentration level in the two areas, while both fine and coarse particles are in the residential areas. When examined the $PM_{10}$ concentration level change, it was categorized by two different time zones, the high concentration level time and the lower concentration time. In high concentration time, the $PM_{10}$ concentration has increased in the morning in the residential and roadside areas. On the contrary, the level has increased in the evening in the industrial area. In low concentration time, the level of $PM_{10}$ concentration in the roadside area is significantly higher in the morning than the concentration level of other times. There is no significantly different concentration level found in the both residential and industrial areas throughout the day.

• Herbal Formula Science
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• v.14 no.2
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• pp.57-66
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• 2006

Objectives : The objective of this study is to observe the effect of Saryuktangkamibang, Saryuktang with Liriopis Tuber, Lycii Fructus, Schizandrae Fructus, and Bombyx Batryticatus, on the experimental diabetes. Methods : In order to induce diabetes experimentally, injected streptozotocin to the vein in the tail of rats and then treated oral administration of Saryuktangkamibang water extracts. In the measurement of the variation levels of glucose, ALP, creatinine, and BUN concentration for each concentration levels for serum (0.2g/100g, 0.4g/l00g, 0.6g/100g), concentration level of glucose significantly decreased in 0.4g/l00g concentration level of Saryuktangkamibang. With this 0.4g/l00g concentration level of Saryuktangkamibang, the following conclusion was derived from the measurement of the serum levels of glucose. ALP, AST, ALT, creatinine, and BUN concentration for the injection of each 4th, 11th, and 18th day. Results : 1. In the measurement for each concentrations, the glucose concentration level in the serum significantly decreased on the 9th day in the Saryuktangkamibang-dosed group. 2. The creatinine and BUN concentration level in the serum significantly decreased on the 9th day in the Saryuktangkamibang-dosed group to which 0.6g/100g injected. 3. In the measurement for each dosage dates, the glucose concentration level in the serum significantly decreased on the 11th day in the Saryuktangkamibang-dosed group to which 0.6g/100g injected. 4. The AST concentration level in the serum significantly decreased on the 11th day in the Saryuktangkamibang-dosed group. Conclusion : Saryuktangkamibang, Saruktang with Liriopis Tuber, Lycii Fructus, Schizandrae Fructus, and Bombyx Batryticatus, has an effect of hypoglycemia, with no hepato-renal dysfunction. For the experimental results above, in that nephrotoxicity significantly decreased on the 0.6g/100g concentration, another research such as study for effect in other ranges and study for effect of dosage term except the concentration range of this study is necessary. Also dosage of appropriate concentration of Saryuktangkamibang is thought to provide valuable aid to cure on diabetes.

• Journal of Power System Engineering
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• v.21 no.5
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• pp.71-78
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• 2017

The purpose of this study is to propose the basic data for the development of a sensor capable of simultaneously measuring the liquid-level, concentration and temperature of a urea tank using ultrasonic and electrical conductivity sensors for diesel vehicles with a urea-SCR system. It was found that the liquid-level of the urea tank using the ultrasonic sensor showed a good linearity with the actual liquid-level, and the urea concentration maintained good linearity in the range of 32.5 wt% to 10 wt%. It was an effective measurement of urea concentration to use the electrical conductivity sensor in the temperature range of $-10{\sim}22^{\circ}C$ and to use the ultrasonic sensor at $22^{\circ}C$ or more. Simultaneous measurement of concentration, liquid-level and temperature of the urea tank will be possible by attaching the electrical conductivity sensor and the ultrasonic sensor (split-type) to one sensor together.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7788-7793
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• 2015

Both export and import sides of grain trade market are analyzed and compared in terms of the static levels and dynamic trends to make new empirical inference on the imperfect competition degree. Export concentration level is high compared to import concentration level. And such states have been sustained since 2001 until 2014. Unlike public concerns, the concentration level of export side seems to be easing by small degree. However, the grain trade market remains imperfect competitive market. Furthermore, overall imperfective competition condition over 2002-2014 has been worsened compared to 2001 level. It is because the reduction level of imports concentration is higher than that of the export concentration. Gini and Atkinson Inequality Index based on Lorenz Curve are newly utilized to analyze market concentration level, instead of the commonly used concentration ratio.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2489-2497
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• 2023

Co and Eu impurities in the SSCs are nuclides that dominantly influence the neutron-induced radioactive inventory in metal and concrete radwastes (radioactive wastes) during NPP decommission. The impurity concentrations provided by NUREG/CR-3474 were used for the practical range of Co and Eu impurity concentrations to be applied to the code calculations. Metal structures near the core were evaluated to be ILW (intermediate-level waste) for the whole range of Co impurity concentration, so the boundary line between ILW and LLW (low-level waste) has no change for the whole concentration range provided by NUREG/CR-3474. Also, the boundary line between VLLW (very low-level waste) and CW (clearance waste) in the concrete shield could alter a little depending on the Eu impurity concentration within the range provided by NUREG/CR-3474. From this work, it is found that the concentration of material impurities of SSCs gives no critical impact on determining radwaste levels.

• Herbal Formula Science
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• v.14 no.2
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• pp.33-44
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• 2006

Objective : The objective of this study is to observe the effect of Yukmijiwhangtangkamibang(YukmD with Liriopis Tuber, Amomi Fructus, Citri Pericarpium, Zizyphi Spinosae Semen, Drynariae Rhizoma Ephedrae Herba, Ginseng Radix, Phellodendri Cortex, on the experimental diabetes. Methods : In order to induce diabetes experimentally, injected streptozoticin to the vein in the tail of rats and then treated oral administration of Yukmi water extracts. In the measurement of the variation levels of glucose, ALP, creatinine, and BUN concentration for each concentration levels for serum (382.5mg/l00g, 510.0mg/100g, 637.5mg/100g), concentration level of glucose significantly decreased in 510.0mg/l00g concentration level of Yukmi. With this 510.0mg/100g concentration level of Yukmijiwhangtanggamibang, the following conclusion was derived from the measurement of the serum levels of glucose, ALP, GOT, GPT, creatinine, and BUN concentration for the streptozotocin injection date of each 4th, 11th, and 18th day. Results : 1. In the measurement for each concentrations. the glucose concentration level in the serum significantly decreased on the 9th day in the Yukmi group. 2. In the measurement for each concentrations, the creatinine concentration level in the serum significantly decreased on the 9th day in the Yukmi group. 3. In the measurement for each dosage dates, the glucose concentration level in the serum significantly decreased on the 18th day in the Yukmi group to which 510.0mg/l00g administrated. 4. In the measurement for each dosage dates, the got concentration level in the serum significantly decreased on the 18th day in the Yukmi group to which 510.0mg/100g administrated. 5. In the measurement for each dosage dates, the creatinine concentration level in the serum significantly decreased on the 18th day in the Yukmi group to which 510.0mg/l00g administrated. Conclusion : Yukmi that is Yukmijiwhangtang with Liriopis Tuber, Amoni Fructus, Citri Pericarpium, Zizyphi Spinosae Semen, Drynariae Rhizoma, Ephedrae Herba, Ginseng Radix and Phellodendri Cortex, is known to have effects to lessen the damages on renal function and liver function without causing damages on liver and kidney.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.47-50
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• 2003

$CO_2$ concentration profile was measured to investigate whether $CO_2$ concentration at one level (i.e., eddy covariance measurement level) can be used to estimate storage term without significant uncertainty at broadleaf deciduous forest at Kwangneung experiment forest in Korea. Based on t-test with significance level of 5％, there was no statistical difference between storage term from one-level $CO_2$ concentration and one from $CO_2$ profile measurement. Storage term constitutes on average 5％ of half hourly net ecosystem exchange (NEE) even at unstable stability (i.e., well mixed condition), indicating that storage term should be considered even at daytime, which is sometimes neglected.

• Journal of Environmental Science International
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• v.16 no.2
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• pp.197-202
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• 2007

Formaldehyde is a typical indoor air pollutant that has numerous adverse health problems in modern living conditions. Phytoremediation that use plants to remove contaminants from polluted media can be applied to improve indoor air quality. Two sets of experiments; 1) two rooms in newly built auditorium and 2) a bed room in 2-year-old apartment; were performed to investigate plant effects on indoor formaldehyde concentration. It was observed from the experiments that plant can help decontaminating formaldehyde at low concentration level (0.1 ppm) but the effects decreased considerably at hish concentration (1ppm). The purification effects of indoor plant also showed the periodic pattern due to its physiological activity. More purification was observed as increasing plant density in the bed room but the formaldehyde concentration returned the original concentration level in two days after removing plants. It was suggested from the results that air purification using plants is an effective means of reduction on indoor formaldehyde level, though, reduction of source is highly desirable when the concentration level is high. The results also suggest that introducing supplementary purifying aids and/or efficient ventilation could be considered due to periodic removal pattern of plant.