• Korean Journal of Optics and Photonics
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• v.26 no.2
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• pp.73-82
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• 2015

This work demonstrates the indoor SI-traceable calibration of a transmissometer with a 75-m baseline for the measurement of visibility in MOR (Meteorological Optical Range). The calibration is performed using a set of neutral density (ND) filters (OD 0.1-2.5) and a set of high-transmission quartz glass plates (a bare quartz glass plate and antireflective-coated quartz glass plates), the collection consisting of 20 artifacts in total. The luminous transmittance values of the reference artifacts had been calibrated traceable to the KRISS spectral transmittance scale, which ranges from 0.2 % to 99.5 %. The transmissometer to be calibrated typically consists of a loosely collimated light source based on a white LED (CCT ~5000 K) and a luminous intensity detector with a CIE 1924 V(${\lambda}$) spectral response. As a result of calibration, we obtained the MOR error and its uncertainty for the transmissometer in 20 m - 40 km of MOR. Based on the results, we investigated the applicability of the calibration method and the conformity of the transmissometer to the ICAO's (International Civil Aviation Organization) accuracy requirement for meteorological visibility measurement. We expect that this work will establish the standard procedure for the SI-traceable calibration of a transmissometer.

• Archives of Pharmacal Research
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• v.29 no.4
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• pp.328-332
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• 2006

The bioequivalence and pharmacokinetics of alendronate sodium tablets were examined by determining the plasma concentration of alendronate. Two groups, consisting of 24 healthy volunteers, each received a 70 mg reference alendronate sodium tablet and a test tablet in a $2{\times}2$ crossover study. There was a 6-day washout period between doses. The plasma alendronate concentration was monitored for 7 h after the dose, using HPLC-Fluorescence Detector (FD). The area under the plasma concentration-time curve from time 0 to the last sampling time at 7 h $(AUC_{0-7h})$ was calculated using the linear-log trapezoidal rule. The maximum plasma drug concentration $(C_{max})$ and the time to reach $C_{max}(T_{max})$ were derived from the plasma concentration-time data. Analysis of variance was performed using logarithmically transformed $AUC_{0-7h}\;and\;C_{max}$, and untransformed $T_{max}$. For the test medication versus the reference medication, the $AUC_{0-7h}\;were\;87.63{\pm}29.27\;vs.\;102.44{\pm}69.96ng\;h\;mL^{-1}$ and the $C_{max}$ values were $34.29{\pm}13.77\;vs.\;38.47{\pm}24.39ng\;mL^{-1}$ respectively. The $90\%$ confidence intervals of the mean differences of the logarithmic transformed $AUC_{0-7h}$ and $C_{max}$ values were log 0.8234-log 1.1597 and log 0.8222-log 1.1409, respectively, satisfying the bioequivalence criteria guidelines of both the US Food and Drug Administration and the Korea Food and Drug Administration. The other pharmacokinetic parameters for the test drug versus reference drug, respectively, were: $t_{1/2},\;1.87{\pm}0.62\;vs.\;1.77{\pm}0.54\;h;\;V/F,\;2061.30{\pm}986.49\;vs.\;2576.45{\pm}1826.05\;L;\;CL/F,\;835.32{\pm}357.35\;vs.\;889.48{\pm}485.87\;L\;h^{-1}; K_{el},\;0.42{\pm}0.14\;vs.\;0.40{\pm}0.18\;h^{-1};\;Ka,\;4.46{\pm}3.63\;vs.\;3.80{\pm}3.64\;h^{-1};\;and\;T_{lag},\;0.19{\pm}0.09\;vs.\;0.18{\pm}0.06\;h$. These results indicated that two alendronate formulations(70-mg alendronate sodium) were biologically equivalent and can be prescribed interchangeably.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.90-95
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• 2003

This study was carried out to identify of C3G (cyanidin-3-glucoside) from mulberry fruits and quantify with different varieties. C3G of mulberry fruits was extracted with 1％ HCl-MeOH and purified with open column (5${\times}$90cm) which filled with Amberlite IRC-50 ion exchange resin. The $\lambda$max ranges of the purified C3G on UV/vis spectrum were 516nm and 280nm. Also, molecular weight of C3G from mulberry fruits by LC-Mass was determined as 449. From above results, we concluded that anthocyanin pigment of mulberry fruits was C3G only. The cyanidin-3-glucoside (C3G) was separated and quantified by High Performance Liquid Chromatography (HPLC) system using a Nova-Pack C$\_$18/ column. Mean content of the 35 tested accessions was 0.89％. Also fruity characteristics as well as C3G content to select the desirable mulberry varieties for the production of fruit were researched and analyzed. We selected three suitable varieties such as 'Susungppong', 'Kangsun', and 'Jeolgokchosaeng(Chungpuk)'.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.11
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• pp.457-464
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• 2019

The weight of pig is one of the main factors in determining the health and growth state of pigs, their shipment, the breeding environment, and the ration of feed, and thus measuring the pig's weight is an important issue in productivity perspective. In order to estimate the pig's weight by using the number of pig's pixels from images, acquired from a Top-view camera, the posture determining and the head removal from images are necessary to measure the accurate number of pixels. In this research, we propose the fast and accurate method to determine the pig's posture by using a fast image processing technique, find the head location by using a fast deep learning technique, and remove pig's head by using light weighted image processing technique. First, we determine the pig's posture by comparing the length from the center of the pig's body to the outline of the pig in the binary image. Then, we train the location of pig's head, body, and hip in images using YOLO(one of the fast deep learning based object detector), and then we obtain the location of pig's head and remove an outside area of head by using head location. Finally, we find the boundary of head and body by using Convex-hull, and we remove pig's head. In the Experiment result, we confirmed that the pig's posture was determined with an accuracy of 0.98 and a processing speed of 250.00fps, and the pig's head was removed with an accuracy of 0.96 and a processing speed of 48.97fps.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.384-397
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• 2021

Background: With volatile organic compounds (VOCs) containing aromatic and halogenated hydrocarbons such as benzene, toluene, and xylene that can adversely affect the respiratory and cardiovascular systems when a certain concentration is reached, it is important to accurately evaluate the source and the corresponding health risk effects. Objectives: The purpose of this study is to provide scientific evidence for the city of Seoul's VOC reduction measures by confirming the risk of each VOC emission source. Methods: In 2020, 56 VOCs were measured and analyzed at one-hour intervals using an online flame ionization detector system (GC-FID) at two measuring stations in Seoul (Gangseo: GS, Bukhansan: BHS). The dominant emission source was identified using the Positive Matrix Factorization (PMF) model, and health risk assessment was performed on the main components of VOCs related to the emission source. Results: Gasoline vapor and vehicle combustion gas are the main sources of emissions in GS, a residential area in the city center, and the main sources are solvent usage and aged VOCs in BHS, a greenbelt area. The risk index ranged from 0.01 to 0.02, which is lower than the standard of 1 for both GS and BHS, and was an acceptable level of 5.71×10^-7 to 2.58×10^-6 for carcinogenic risk. Conclusions: In order to reduce the level of carcinogenic risk to an acceptable safe level, it is necessary to improve and reduce the emission sources of vehicle combustion and solvent usage, and eco-car policies are judged to contribute to the reduction of combustion gas as well as providing a response to climate change.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.376-381
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• 2021

Red beet (Beta vulgaris L.) is a root vegetable and a popular functional food ingredient of dark red-purple appearance due largely to betacyanins, principally betanine (75-95%) and its isomer, isobetanine (15-45%). This study developed an analytical method for beet red in terms of betanine and isobetanine in processed food products labeled with beet red as a food additive. High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) was used with a C₁₈ column. Linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision and uncertainty in measurement were calculated for method validation. Matrix-matched calibration was applied to the candy, ice cream, and cocoa product, respectively, and R² was ≥0.9998, showing a high level of linearity. The LOD and LOQ were 0.16 to 0.32 and 0.48 to 0.97 mg/L, respectively. As a result of repeated intra-day and interday experiments to validate the accuracy and precision of the analytical method, the recovery rates were 96.0-103.1% and 100.0-102.2%, respectively and the RSD% was 0.5-3.3% and 0.9-3.8%, respectively. Moreover, the measurement uncertainty was estimated to be 1.71-12.43% depending on the matrix and the measured concentration. In this study, betanine and isobetanine were quantified (8.4-3,823.4 mg/kg) by applying the developed analytical method to processed food products (n= 26; e.g., candy, ice cream, and other processed foods) labeled with beet red as a food additive.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.173-179
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• 2021

Scattered x-ray generated by digital radiography systems also have the advantage of increasing signals, but ultimately detectability is reduced by decreasing resolution and increasing noise of x-ray images transmitted objects. An indirect method of measuring scattered x-ray in a modulation-transfer function (MTF) for evaluating resolution in a spatial-frequency domain can be considered as a drop in the MTF value corresponding to zero-frequency. In this study, polymethyl methacrylate (PMMA) was used as a patient tissue equivalent, and MTFs were obtained for various thicknesses to quantify the effect of scattered x-ray on resolution. X-ray image signals were observed to decrease by 35 ~ 83% with PMMA thickness increasing, which is determined by the absorption or scattering of x-rays in PMMA, resulting in reduced MTF and increased scatter fraction. The method to compensate for MTF degradation by PMMA resulted in the MTF inflation without considering the optical spreading generated by the indirect-conversion type detector. Data fitting or zero-padding are needed to compensate for MTF more reasonably on edge-spread function or line-spread function.

• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.203-212
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• 2019

Objective: A total of five students at same middle school were reported to be diagnosed with pediatric leukemia (n=2), non-Hodgkin's lymphoma (NHL, n=1) and aplastic anemia (n=2) between 2016 and 2017. The aims of this study are to assess exposure to environmental hazardous agents known to be associated with the risk of leukemia and to examine whether the environment of school is associated with the risk leukemia. Method: A total of 11 environmental agents causing childhood leukemia were monitored using international certified method in schools where patients had ever attended. Radon & Thoron detector was used to monitor real-time airborne radon and thoron level ($Bq/m^3$). Clinician interviewed two among nine patients who agreed to participate in this study in order to examine the association of demographic and genetic factors by individually. Leukemia, NHL, and aplastic anemia were grouped into lymphohematopoietic disorder (LHP). Results: Except for airborne radon level, no environmental agents in school and household where patients may be exposed were found to higher than recommended airborne level. Clinical investigation found no individual factors that may be associated with the risk of LHP. Higher airborne radon level than Korea EPA's airborne radon criteria ($148Bq/m^3$) was monitored at most of several after-class room of one elementary school, where two leukemia patients graduated. Significant radon level was not monitored at class-room. Significant exposure to radon of patients was not estimated based on time-activity pattern. Conclusions: Our results have concluded that there have been no environmental factors in school and household environment that may be associated the risk of LHP.

• Journal of radiological science and technology
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• v.42 no.3
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• pp.167-173
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• 2019

The Cobey method and the modified Cobey method are most commonly used in clinical practice. Therefore, the purpose of this study was to investigate the radiological differences between Cobey and modified Cobey and provide radiographic information about changes of hindfoot image with X-ray entrance center and tube angle change in modified Cobey. This study was performed on foot and ankle phantom. First, for image comparison of Cobey and modified Cobey, the images obtained by applying the same X-ray entrance center to the ankle joint were compared and analyzed. Second, in the modified Cobey, the X-ray entrance center is set as ankle joint and lateral malleolus. The X-ray tube angle was varied from $10^{\circ}$ to $40^{\circ}$ at $5^{\circ}$ intervals for each X-ray entrance center. The images obtained by varying the X-ray tube angle from $10^{\circ}$ to $40^{\circ}$ at intervals of $5^{\circ}$ for each X-ray entrance center were compared and analyzed. The irradiation conditions were the same with 110 kVp, 200 mA, 10 ms, and 110 cm of source - image receptor distance (SID). Image evaluation was performed by two radiologists. Measurements were made on the lateral point, middle point, and calcaneus width based on a hypothetical line parallel to the calcaneal tuberosity. Data were analyzed by using descriptive statistics as the mean of the distance to each measurement location. The modified Cobey was longer than the Cobey by an average of 3 to 4 mm lateral and medial points, and the calcaneus width was similar (ICC = 0.939). In modified Cobey method, when the X-ray entrance center is ankle joint, the lateral point is about 3 mm and the medial point is about 4.3 mm longer than lateral malleolus. Also, when the X-ray tube angle is more than $20^{\circ}$, the degree of distortion is large. The ICCs for the lateral, medial point, and calcaneus width were 0.998, 0.961, and 0.997, respectively, as the X-ray entrance center and tube angle were changed. There was no significant difference between Modified Cobey and Cobey. Modified Cobey showed no need to compensate the $20^{\circ}$ detector angle of the Cobey. In addition, we suggest that tube angle should be limited within $20^{\circ}$ when modified Cobey is performed.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.334-339
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• 2019

A procedure based on high-performance liquid chromatography (HPLC) is described to determine ${\beta}-carotene$ in infant formulas. The method for ${\beta}-carotene$ analysis was performed on a C18 reversed-phase column using acetonitrile/methanol/dichloromethane (6:1:3, v/v/v) as a mobile phase. ${\beta}-Carotene$ was determined in HPLC with photo diode array (PDA) detector. The parameters of validation were specificity, linearity, LOD, LOQ, accuracy, precision and repeatability. The specificity was confirmed by the retention time and the linearity ($R^2$), which was over 0.999 in the range of 0.125~2 mg/L. The detection and quantification limits were 0.064 and 0.193 mg/L, respectively. The accuracy and precision of this method using an STD spiked sample were 80~119% and 1.02~2.05% respectively. The method was applied to the analysis of various infant formula and follow-up formulas products containing ${\beta}-carotene$, and all the products contained acceptable levels of ${\beta}-carotene$ for nutrition labeling.