• The Journal of the Petrological Society of Korea
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• v.17 no.1
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• pp.1-15
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• 2008

The metasedimentary rocks of the Nampo Croup consisting of metaconglomerates, metasandstones, phyllites are exposed in the area of the Daechcon beach and Maryangri, Seocheon-gun. Their typical metamorphic assemblages of Bt-Mus-Grt-Qtz (${\pm}Pl{\pm}Chl$) and Bt-Mus-Qtz (${\pm}Pl{\pm}Chl$) indicate that they have been under intermediate P/T type metamorphism and were metamorphosed to garnet zone grade of amphibolite-facies during the Daebo Orogeny. Pressure-temperature conditions of peak metamorphism estimated from geothermobarometries are $560{\sim}595^{\circ}C$, $6.9{\sim}8.2\;kb$ respectively. The results of K-Ar biotite age determination are $143.2{\pm}3.6\;Ma$, $122.6{\pm}2.4\;Ma$ and $124.8{\pm}2.4\;Ma$ and the last two ages are considered as the results of later-stage thermal perturbation. On the bases of the formation age of Daedong Supergroup of $187{\sim}172\;Ma$ (Han et al., 2006; Jeon et al., 2007) combined with the results of this study, the hypothetical model of tectonometamorphic evolution of the study area during Daebo Orogeny is proposed. Crustal thickening resulted from folding and duplexing of thrusts in the area initiated at around 175 Ma just after sedimentation of Nampo Croup. And then rapid cooling by normal faulting due to crustal extention followed immediately after the peak metamorphism to the closure temperature of biotite.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.1
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• pp.5-13
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• 2003

The purpose of this study is to determine the value of serum concentration of C-reactive protein(CRP) in comparison with ESR and leukocyte as the tools for diagnosis and follow-up study of infection. For this study, thirty-one patients with head and neck infection and thirty-two patients performed the orthognathic surgery were selected for experimental and control groups each other. we analyzed the blood sample daily to measure CRP, ESR and leukocytosis. The results of this study are as the following : 1. Serum C-Reactive Protein levels in the experimental group were higher than control group and the pattern of CRP changes continued to decline in both groups(P<0.001). 2. ESR changes in both groups were scattered without any special pattern. 3. Correlation between CRP and Leukocyte was higher than others(r=0.664, P<0.01). 4. In the Receiver Operating Characteristic(ROC) Curve of experimental group, rapid increase of CRP curve and Area under the curve(AUC) value, 0.774, indicate the high accuracy of estimation. 5. In experimental group, sensitivity of CRP, ESR, and Leukocytosis on recovery day were 83%, 17% and 71%. Based on the results of this study, we could conclude that determination of CRP is more useful method to diagnosis and follow-up study of infection than other commonly used variables in oral and maxillofacial region.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.391-400
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• 2017

Italian ryegrass (IRG) is one of the fastest growing grasses available to farmers. It offers rapid establishment and starts growing early in the following spring and has fast regrowth after defoliation. So, IRG can be utilized as the dominant/single species of grass used in a farming system, or to play a role as a large producing pasture and sacrificial paddock. The objective of this study was to develop the use of unmanned aerial vehicle (UAV) for the evaluation of feed value of IRG. For this study, UAV imagery was taken on the Nonsan regions two times during the IRG growing season. We analyzed the relationships between $NDVI_{UAV}$ and feed value parameters such as fresh matter yield, dry matter yield, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrient (TDN) and crude protein at the season of harvest. Correlation analysis between $NDVI_{UAV}$ and feed value parameters of IRG revealed that $NDVI_{UAV}$ correlated well with crude protein (r = 0.745), and fresh matter yield (r = 0.655). According to the relationship, the variation of $NDVI_{UAV}$ was significant to interpret feed value parameters of IRG. Eight different regression models such as Linear, Logarithmic, Inverse, Quadratic, Cubic, Power, S, and Exponential model were used to estimate IRG feed value parameters. The S and exponential model provided more accurate results to predict fresh matter yield and crude protein than other models based on coefficient of determination, p- and F-value. The spatial distribution map of feed values in IRG plot was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to regression equation. These lead to the result that the characteristics of variations in feed value of IRG according to $NDVI_{UAV}$ were well reflected in the model.

• Korean Journal of Food Science and Technology
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• v.11 no.3
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• pp.157-161
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• 1979

The apparatus and method that permit rapid and continuous determination of thermal conductivity and diffusivity of Kochujang, Korean native semi-solid food, are presented. 1. The thermal conductivities of Kochujang are $0.3517\;kcal/mh^{\circ}C$ at $25^{\circ}C$, $0.3957\;kcal/mh^{\circ}C$ at $50^{\circ}C$ and $0.4221\;kcal/mh^{\circ}C$ at $100^{\circ}C$. Thermal diffusivity of Kochujang is $0.1000\;cm^2/min$ at $50^{\circ}C$, specific heat and density are $0.573\;kcal/kg^{\circ}C$, $1,220\;kg/m^3$, respectively. 2. There exists 6.04% discrepancy between the measured value and the calculated one from specific heat and density values.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.387-395
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• 2014

A highly sensitive analytical method based on stir bar sorptive extraction (SBSE) technique and gas chromatography/tandem mass spectrometry (GC-MS/MS) has been developed, allowing the simultaneous multi-analyte determination of 11 synthetic fragrances (SFs) in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 40 mL of water sample at pH 3 and stirred at 1,100 rpm for 120 min. Other SBSE parameters (salt effect and presence of organic solvent) were optimised. The method shows good linearity (coefficients > 0.990) and reproducibility (RSD < 10.9%). The extraction efficiencies were above 83% for all the compounds. The limits of detections (LOD) and limits of quantification (LOQ) were 2.1~4.1 ng/L and 6.6~12.9 ng/L, respectively. The developed method offers the ability to detect 11 SFs at ultra-low concentration levels with only 40 mL of sample volume. Matrix effects in tap water, river water, wastewater treatment plant (WWTP) final effluent water and seawater were investigated and it was shown that the method is suitable for the analysis of trace level of 11 SFs. The method developed in the present study has the advantage of being rapid, simple, high-sensitive and both user and environmentally friendly.

• Korea journal of population studies
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• v.33 no.2
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• pp.85-111
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• 2010

South Korea has experienced a rapid fertility decline and notable mortality improvement. As the drop in TFR was quicker and greater in terms of tempo and magnitude, it cast a new challenge of population projection - how to improve the forecasting accuracy in the country with a super-low fertility pattern. This study begin with the current status of the national population projection as implemented by Statistics Korea by comparing the 2009 interim projection with the 2006 official national population projection. Secondly, this study compare the population projection system including projection agencies, projection horizons, projection intervals, the number of projection scenarios, and the number of assumptions on fertility, mortality and international migration among super-low fertility countries. Thirdly we illustrate a stochastic population projection for Korea by transforming the population rates into one parameter series. Finally we describe the future challenges of the national population projection, and propose the projection scenarios for the 2011 official population projection. To enhance the accuracy, we suggest that Statistics Korea should update population projections more frequently or distinguish them into short-term and long-term projections. Adding more than four projection scenarios including additional types of "low-variant"fertility could show a variety of future changes. We also expect Statistics Korea topay more attention to the determination of a base population that should include both national and non-national populations. Finally we hope that Statistics Korea will find a wise way to incorporate the ideas underlying the system of stochastic population projection as part of the official national population projection.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.2
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• pp.292-300
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• 1996

Hexavalent chromium($Cr^{+6}$) compounds are considered to be particularly hazardous, primarily because of the associated risk of allergic reaction and cancer. The analytic method of hexavalent chromium such as the s-diphenylcarba-zide(DPC) method and all ether previously used methods are often made uncertain due to significant interferences from organic components. This report can provide a technique for the more rapid and simple determination of total hexavalent chromium. than other currently using methods. The s-diphenylcarbazide method proposed by the U.S. National Institute for Occupational Safety and Health has low recovery rate(15.67 - 48.20%) due to interference, iron chloride and nickel chloride. A microwave oven technique has high recovery rate(about 70%) of insoluble hexavalent chromium. For the difference of ionic charges of $Cr^{+3}$-ethylenediamine tetraacetic acid(EDTA) chelate and $CrO_4{^{-2}}$, we could detect them simultaneously by ion exchanged high performance liquid chromatography. The confirmation of $Cr^{+3}$ and $Cr^{+6}$ were checked by fraction collector and flameless atomic absorption spectrometer. We observed that the small amount of hexavalent chromium is converted to trivalent chromium due to enhancement of chromium reduction by $Fe^{+3}$ or $Ni^{+2}$. As a result of this study, on the analysis of insoluble hexavalent chromium with microwave oven was used for, it may be better and more precise analysis after pretreatment by 2% NaOH-3% $Na_2CO_3$ and then analysis UV-spectrophotometer. It should be done for various studies on insoluble hexavalent chromium on the basis work environmental monitoring so called welding, painting etc.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.235-240
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• 2001

This study was performed to compare the lead levels of 20 quality control standard samples(KOSHA:18-2000) and 72 field samples in lead-acid battery manufacturing plant between ICP and portable-XRF methods. 1. While the proficiencies of 20 quality control standard samples by ICP were 100%, those of analytic result values by XRF were 75%. 2. The correlation coefficient(r) between the reference values for quality control (REF) and the analytic result values by ICP (ICP) was 1.0(p<0.05), and simple linear regression equation and the coefficient(R2) were REF = -0.0009 + 1.016 ICP and 0.9997, respectively. 3. The correlation coefficient(r) between the analytic result values of quality control standard samples by ICP (ICP) and by XRF (XRF) was 0.975(p<0.05), and simple linear regression equation and the coefficient(R2) were ICP = -0.0003 + 1.002 XRF and 0.950, respectively. 4. The correlation coefficient(r) between the analytic result values for lead samples of a lead-acid battery manufacturing plant by ICP (ICP) and by XRF (XRF) was 0.993(p<0.05), and simple linear regression equation and the coefficient(R2) were ICP = -2.058 + 0.996 XRF and 0.987, respectively. 5. While the frequency distributions of XRF /ICP(Ratio) for each ICP concentration levels in a lead-acid battery manufacturing plant revealed high proportion in ratio range of 0.876-1.125 than in ration range of 1.126-1.375. Also, ICP concentration level in ration range of 0.786-1.125 was increased with increase of frequency distribution of XRF/ICP. 6. The limit of detection of XRF on lead was determined to be $6.11{\mu}g$/filter The data presented in this study indicated that relationship for lead level of quality control samples and field samples in a lead -acid battery manufacturing plant by ICP and portable-XRF methods was proved. The practicing industrial hygienist can use portable-XRF to produce a rapid on-site determination of lead exposure that can immediately becommunicated to workers and help identify appropriate levels of personal protection.

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.83-88
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• 2017

We introduced disposable amperometric immunosensors for the detection of Sildenafil and Vardenafil (SDF/VDF) based on screen printed carbon electrodes. The developed immunosensors were used as a non-competitive sandwich-type enzyme immunoassay with a horseradish peroxidase label. The sensors were constructed on screen printed carbon electrodes by the simple electrochemical deposition of a reduced graphene oxide and chitosan (ErGO-CS) composite. To evaluate the sensing chemistry and optimize the sensor characteristics, a series of electrochemical experiments were carried out including electrochemical impedance spectroscopy, cyclic voltammetry and amperometry. The sensors showed a linear response to SDF/VDF concentrations in a range from 100 pg/mL to 300 ng/mL. The lower detection limit was calculated to be 55 pg/mL, the sensitivity was calculated to be $1.02{\mu}Ang/mL/cm^2$, and the sensor performance exhibited good reproducibility with a relative standard deviation (RSD) of 7.1%. The proposed sensing chemistry strategy and the sensor format can be used as a simple, cost-effective, and feasible method for the in-field analysis of SDF/VDF in functional or health supplement food samples.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.716-723
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• 2008

With rapid development of science and technology and recent widening of mankind's range of activities, development of coastal waters and the environment have emerged as global issues. In relation to this, to allow more extensive analyses, the use of satellite images has been on the increase. This study aims at utilizing hyperspectral satellite images in determining the depth of coastal waters more efficiently. For this purpose, a partial image of the research subject was first extracted from an EO-1 Hyperion satellite image, and atmospheric and geometric corrections were made. Minimum noise fraction (MNF) transformation was then performed to compress the bands, and the band most suitable for analyzing the characteristics of the water body was selected. Within the chosen band, the diffuse attenuation coefficient Kd was determined. By deciding the end-member of pixels with pure spectral properties and conducting mapping based on the linear spectral unmixing method, the depth of water at the coastal area in question was ultimately determined. The research findings showed the calculated depth of water differed by an average of 1.2 m from that given on the digital sea map; the errors grew larger when the water to be measured was deeper. If accuracy in atmospheric correction, end-member determination, and Kd calculation is enhanced in the future, it will likely be possible to determine water depths more economically and efficiently.