• Atmosphere
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• v.34 no.2
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• pp.123-138
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• 2024

Using 18 multi-model-based a Shared Socioeconomic Pathway (SSP) and Representative Concentration Pathways (RCP) climate change scenarios, future changes in temperature and warmth index on the Korean Peninsula in the 21st century (2011~2100) were analyzed. In the analysis of the current climate (1981~2010), the ensemble averaged model results were found to reproduce the observed average values and spatial patterns of temperature and warmth index similarly well. In the future climate projections, temperature and warmth index are expected to rise in the 21st century compared to the current climate. They go further into the future and the higher carbon scenario (SSP5-8.5), the larger the increase. In the 21st century, in the low-carbon scenario (SSP1-2.6), temperature and warmth index are expected to rise by about 2.5℃ and 24.6%, respectively, compared to the present, while in the high-carbon scenario, they are expected to rise by about 6.2℃ and 63.9%, respectively. It was analyzed that reducing carbon emissions could contribute to reducing the increase in temperature and warmth index. The increase in the warmth index due to climate change can be positively analyzed to indicate that the effective heat required for plant growth on the Korean Peninsula will be stably secured. However, it is necessary to comprehensively consider negative aspects such as changes in growth conditions during the plant growth period, increase in extreme weather such as abnormally high temperatures, and decrease in plant diversity. This study can be used as basic scientific information for adapting to climate change and preparing response measures.

• Korean Journal of Remote Sensing
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• v.36 no.2_2
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• pp.309-323
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• 2020

Estimation of chlorophyll a concentration (CHL) on coastal areas using remote sensing has been mostly performed through multi-spectral satellite image analysis. Recently, various studies using hyperspectral imagery have been attempted. In particular, airborne hyperspectral imagery is composed of hundreds of bands with a narrow band width and high spatial resolution, and thus may be more effective in coastal areas than estimation of CHL through conventional satellite image. In this study, comparative analysis of hyperspectral and satellite-based CHL images was performed to estimate CHL in coastal areas. As a result of analyzing CHL and seawater spectrum data obtained by field survey conducted on the south coast of Korea, the seawater spectrum with high CHL peaked near the wavelength bands of 570 and 680 nm. Using this spectral feature, a new band ratio of 570 / 490 nm for estimating CHL was proposed. Through regression analysis between band ratio and the measured CHL were generated new CHL empirical formula. Validation of new empirical formula using the measured CHL showed valid results, with R² of 0.70, RMSE of 2.43 mg m^-3, and mean bias of 3.46 mg m^-3. As a result of applying the new empirical formula to hyperspectral and satellite images, the average RMSE between hyperspectral imagery and the measured CHL was 0.12 mg m^-3, making it possible to estimate CHL with higher accuracy than multi-spectral satellite images. Through these results, it is expected that it is possible to provide more accurate and precise spatial distribution information of CHL in coastal areas by utilizing hyperspectral imagery.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.E
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• pp.39-43
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• 1999

To help idntify the potential sources of volatile organic sulfur compounds within the continental environment, we have conducted preliminary measurements of dimethylsulfide(DMS) during field campains held from three reference sites. These sampling sites were located within a waste reclamation facility in Won Ju City, Kang Won Province. The results of our measurements showed that DMS levels spanned over 1 to 55 pptv with a mean and 1 standard deviation(1SD) of 12 and 18 pptv(N=13). In a comparison of the data derived from the strongest sources, i.e., oceanic environment, the DMS levels in thre reclamation facility were jpronouncingly low with high day-to-night concentration ratios. It was noted that a significant difference in DMS levels between daytime and nighttime periods was mainly driven by a few exceptional data measured during daytime. Despite limitations of our measurement data in deriving meaningful interpretations of spatiotemporal distributions of DMS in inland facilities, the existence of extraordinary trends, i.e., especially "lower-than-expectedL" DMS values, can be explained in terms of mixed effects of several factors. Most importantly, we can infer that the rates of DMS production and of its destruction in the study site are at or near steady-state condition. Another possibility is that DMS is not adequate enough to explain the generally malordorous environment of reclamation sites, of particular in Won Ju area.n Ju area.

• Proceedings of the Korean Society of Toxicology Conference
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• 2006.11a
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• pp.80-86
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• 2006

Bioequivalence is a term in pharmacokinetics used to access the expected in vivo biological equivalence of two proprietary preparations of a drug. Bioequivalence studies are usually performed for generic drugs. Two pharmaceutical products are bioequivalent if they are pharmaceutically equivalent and their bioavailabilioes after administration in the same molar dose are similar. Bioequivalence is usually accessed by single dose in vivo studies in healthy volunteers and the reference product is usually the innovator product that is marketed. Regulatory definition of bioequivalence is based on the statistical analysis of thebioavailability of the reference and test product. In general, two products are evaluated as bioequivalent if the 90% confidence interval of the relative mean Cmaxand AUC of the test to reference product are within 80.00% to 125.00% in the fasting state. Key process in bioequivalence study is development and validation of bioanalytical method, determination of the drug concentration in the biosamples (usually plasma or serum) obtained from volunteers, calculation of the pharmacokinetic parameters and statistical analysis of the pharmacokinetic parameters. Although current guidelines and regulations do not require the bioequivalence studies to be done under good laboratory practice (CLP), the issues to perform the bioequivalence studies under GLP environment is emerged both from the regulatory and industry side. GLP perspectives of bioequivalence studiesare needed to be discussed in respect to achieve quality assurance in bioequivalence studies.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.4
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• pp.11-19
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• 2011

PADDIMOD2 was deloped to estimate nonpoint source pollution from paddy rice fields. The PADDIMOD2 was enhanced to estimate runoff and pollutant load during non-growing as well as growing season and to be easily used for public by development of Excel based system. Nutrient concentration and hydrology were based on Dirac delta function and continuous source function, and tank model for growing season and Event Mean Concentrations (EMCs) and SCS-Curve Number method for non-growing season. The PADDIMOD2 consists of three main component (input data, parameters data, and output data) by including eight Excel spread sheets. As a result of model application, total precipitation and irrigation were 1,051.7 mm and 439.2 mm, respectivley and surface runoff and water loss including infiltration and evapotranspiration were 463.0 mm and 947.9 mm, respectively. Annual nutrient loadings of T-N and T-P from study area were 6.7 kg/$km^2$/day and 0.5 kg/$km^2$/day, respectively. Development of PADDIMOD2 was focused on minimizing input data and maximizing user friendly system and is expected to be useful tool to evaluate various non-structure BMPs and estimate unit load from paddy rice fields for application at Korean TMDL.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.374-383
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• 2012

In this study, we have observed the airborne radon levels in the subway cabins before and after platform screen doors (PSD) installation. The measurements have been conducted at Seoul metropolitan subway lines in 2008, 2009 and 2010. The mean concentration of the radon inside subway cabins were increased by approximately 53% from $20.1Bq/m^3$ to $30.8Bq/m^3$ by installing PSD. After PSD installation, measured values for the different lines were rather different, and varied between 8.2 and $76.5Bq/m^3$. And mean radon concentrations were in the decreasing order for subway lines 5, 6, 7, 8, 3, 4, 2, 9 and 1. It was also found that the indoor radon concentrations in the subway cabins were highly dependent on the management approach of a ventilation system at the subway stations. By assuming an average of $720\;h\;year^{-1}$ and $2,880\;h\;year^{-1}$ spent in subway cabin, effective doses to passengers and employee were estimated. The expected annual effective dose, in case of an equilibrium factor of 0.4, were $0.07mSv\;y^{-1}$ and $0.26mSv\;y^{-1}$, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.82-89
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• 2013

This trial evaluated the effects of dietary supplementation with monensin sodium on dry matter intake, metabolic parameters and milk yield and milk composition of dairy Saanen goats in the periparturient period. Twelve Saanen pregnant dairy goats were assigned to a treatment and a control group. Saanen goats were fed monensin as its 10% sodium salt in the amount of 33 mg/kg of total dry matter intake during 30 d before parturition till d 42 in milk. Blood samples were collected from each goat at d 30, 15 and 7 before expected kidding time and also in d 1, 7, 13, 19, 21, 28, 35 and 42 postpartum. The serum concentrations of ${\beta}$-Hydroxybutyrate (BHBA), non-esterifed fatty acid (NEFA), calcium, magnesium, inorganic phosphorus, cholesterol, triglyceride, urea, total protein, albumin and glucose and aspartate aminotransferase (AST) activity were determined. The BHBA concentration significantly decreased in goats, which received monensin in comparison to controls in the postpartum period (p = 0.049). The concentration of sodium (Na) was significantly influenced by monensin treatment in the postpartum period (p = 0.048). In addition, the difference in dry matter intake was highly significant between the two groups during the pre-partum period. Controls had more dry matter intake (DMI) than treatment goats (p = 0.0001). Mean 3.5% fat corrected milk production was not influenced by monensin treatment. However, milk fat percentage was significantly decreased in monensin treated goats (p = 0.0017).

• KSBB Journal
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• v.18 no.2
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• pp.111-116
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• 2003

Hydrogen producing acidogenic microorganisms were self-immobilized using organic-inorganic hybrid polymer within 5 minutes. During the continuous tratment of synthetic wastewater at a hydraulic retention time of 20 hours, at 37$^{\circ}C$, pH 5.0, the self-immobillized granules were maintained in a stirred tank reactor. The black colored granules gradually became milky. Image analysis showed that the mean diameter of the milky colored granules ranged from 1.5 to 20. mm. The maximum bio-gas procuction rate was 380 ml/L/hy and the concentration of H$_2$was around 50%, while no methane was detected. Granular ECP was extracted and its content was measured to elucidate the role of the organic-inorganic hybrid polymer. Further increases of granule concentration are expected to increase the hydrogen production rate.

• Atmosphere
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• v.18 no.4
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• pp.459-474
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• 2008

Aerosol scattering coefficients for three different wavelengths ($\lambda$=450,550,700 nm) are measured almost continuously by a nephelometer in Seoul for a period of 13 months (February 2007-February 2008), which includes two weeks break in August 2007 for measurements at Daegwallyeong and YoungJongdo. The mean of the daily average scattering coefficients at $\lambda$=550 nm is $194.1{\pm}144.2Mm^{-1}$ and the minimum and maximum are $14.3Mm^{-1}$ and $998.1Mm^{-1}$, respectively. The scattering coefficient shows a general increasing trend with atmospheric relative humidity (RH). When the data are classified according to weather conditions, the days with no major weather events show the smallest scattering coefficient and also the lowest RH. Surprisingly haze/fog days show the largest scattering coefficient and Asian dust days comes in second. Although the variation is large within a season, winter shows the largest and autumn shows the smallest scattering coefficient. The average ${\AA}ngstr{\ddot{o}}m$ exponent is $1.40{\pm}0.32$ for the entire Seoul measurement. As expected, Asian dust days show the smallest ${\AA}ngstr{\ddot{o}}m$ exponent and haze/fog days are the next, suggesting more efficient hygroscopic growth of aerosols for this weather condition. Aerosol scattering coefficient seems to show better correspondence with CCN concentration rather than total aerosol concentration, which may indicate that CCN active aerosols are also good scattering aerosols.

• Journal of Environmental Health Sciences
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• v.44 no.1
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• pp.24-30
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• 2018

Objectives: Based on the amount of amalgam, the duration of exposure, and the water pH, this study aims to investigate the change patterns in the mercury concentrations in water after amalgams have been introduced into sewage water. It is expected that the study results will be useful in improving the system for regulating the amount of mercury that is introduced into the environment. Methods: During the study, a glass test-tube with a cap was washed and disinfected using the glass laboratory device washing method. Then, 1, 2, 3, and 4 tabs were placed into a 10 mL pH 4 solution and 10 mL pH 7 distilled water. Each specimen was prepared in duplicate. The mean of the two mercury concentrations was used as the representative value, and the mercury concentration was measured using a mercury measurement device (DMA-80, Milestone, Italy) a total of eight times at one-week intervals. Results: The results show that the lower was the pH, the higher was the amount of amalgam. Also the longer was the duration, the more significant was the increase of mercury concentration in the water. Conclusions: Dental clinics are collected separately from dental clinics that used them. Given this, dental clinics in Korea must have the necessary facilities to separately collect mercury at their level. In addition, proper disposal systems and social attention to the proper management of dental wastes are required to prevent environmental pollution from mercury.