• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.221-232
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• 2016

Models to estimate solar radiation have been used because solar radiation is measured at a smaller number of weather stations than other variables including temperature and rainfall. For example, solar radiation has been estimated using the Angstrom-Prescott (AP) model that depends on two coefficients obtained empirically at a specific site ($AP_{Choi}$) or for a climate zone ($AP_{Frere}$). The objective of this study was to identify the coefficients of the AP model for reliable estimation of solar radiation under a wide range of spatial and temporal conditions. A global optimization was performed for a range of AP coefficients to identify the values of $AP_{max}$ that resulted in the greatest degree of agreement at each of 20 sites for a given month during 30 years. The degree of agreement was assessed using the value of Concordance Correlation Coefficient (CCC). When $AP_{Frere}$ was used to estimate solar radiation, the values of CCC were relatively high for conditions under which crop growth simulation would be performed, e.g., at rural sites during summer. The statistics for $AP_{Frere}$ were greater than those for $AP_{Choi}$ although $AP_{Frere}$ had the smaller statistics than $AP_{max}$ did. The variation of CCC values was small over a wide range of AP coefficients when those statistics were summarized by site. $AP_{Frere}$ was included in each range of AP coefficients that resulted in reasonable accuracy of solar radiation estimates by site, year, and month. These results suggested that $AP_{Frere}$ would be useful to provide estimates of solar radiation as an input to crop models in Korea. Further studies would be merited to examine feasibility of using $AP_{Frere}$ to obtain gridded estimates of solar radiation at a high spatial resolution under a complex terrain in Korea.

• Analytical Science and Technology
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• v.6 no.5
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• pp.463-469
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• 1993

HDBPDA ion exchange resin, {(4, 5) : (13, 14)-Dibenzo-6, 9, 12-trioxa-3, 15, 21, -triazabicyclo [15. 3. 1]heneicosa-(1, 17, 19)(18, 20, 21) triene ion exchange resin : HDBPDA ion exchange resin} had a capacity of 3.8meq/g dry resin. The distribution coefficients of alkali and alkaline earth metal ions on HDBPDA and strongly acidic cation exchange resin, Dowex 50W-X8(200-400mesh) in water, and the various concentrations of hydrochloric acid were determined. Concentration of hydrochloric acid have almost not influenced on the distribution coefficients of alkali and alkaline earth metal ions for the HDBPDA ion exchange resin, but generally the distribution coefficient slightly increased with decreasing concentration of hydrochloric acid. The distribution coefficients of metal ions in water are larger than those in various hydrochloric acid concentration. The distribution coefficients of alkali and alkaline earth metal ions for the Dowex 50W-X8 ion exchange resin increased with decreasing hydrochloric acid concentration. Especially, the distribution coefficients of alkaline earth metal ions increased rapidly compared to those for alkali metal ions. The distribution coefficients of alkali and alkaline earth metal ions on HDBPDA ion exchange resin increased in a linear manner with decreasing acid concentration, and the slope, d log Kd/d log $M_{HCl}$ is about -0.2. Of the distribution cofficients of alkali metal ions on Dowex 50W-X8, at range of moderate hydrochloric acid concentration, the slope is about -1, while the slope for alkaline earth metal ions is about -2. However, at very low hydrochloric acid concentration, the linear variation between distribution coefficient and acid concentration was not occurred, but the slope was deviated from above values at low acid concentration.

• Journal of Food Hygiene and Safety
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• v.34 no.2
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• pp.140-147
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• 2019

An analytical method was developed for the determination of quinoxyfen in agricultural products using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted with 1% acetic acid in acetonitrile and water was removed by liquid-liquid partitioning with $MgSO_4$ (anhydrous magnesium sulfate) and sodium acetate. Dispersive solid-phase extraction (d-SPE) cleanup was carried out using $MgSO_4$, PSA (primary secondary amine), $C_{18}$ (octadecyl) and GCB (graphitized carbon black). The analytes were quantified and confirmed by using LC-MS/MS in positive mode with MRM (multiple reaction monitoring). The matrix-matched calibration curves were constructed using six levels ($0.001-0.25{\mu}g/mL$) and the coefficient of determination ($R^2$) was above 0.99. Recovery results at three concentrations (LOQ, 10 LOQ, and 50 LOQ, n=5) were in the range of 73.5-86.7% with RSDs (relative standard deviations) of less than 8.9%. For inter-laboratory validation, the average recovery was 77.2-95.4% and the CV (coefficient of variation) was below 14.5%. All results were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL 40-1993, 2003) and Food Safety Evaluation Department guidelines (2016). The proposed analytical method was accurate, effective and sensitive for quinoxyfen determination in agricultural commodities. This study could be useful for the safe management of quinoxyfen residues in agricultural products.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.116-124
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• 2011

Purpose: To establish accurate external quality assurance (EQA) test, cross institutional and modality tests were performed using WHO certificated reference material (CRM) and same pooled patients serum. Materials and Methods: Accuracy and precision were evaluated using CRM and pooled patients' serum for AFP, CEA, PSA, CA 125, CA 19-9, T3, T4, Tg, TSH. To evaluate the accuracy and precision, recover test and coefficient variation were measured. RIA test were performed in major 5 RIA laboratory and EIA (CLIA) test were done in 5 major EIA laboratory. same sample of CRM and pooled serum were delivered to each laboratory. Results: In 2009, mean precision of total tumor marker of RIA was $14.8{\pm}4.2%$ and that of EIA(CLIA) was $19.2{\pm}6.9%$. In 2010, mean precision of 5 tumor marker and T3, T4, Tg, TSH was $13.8{\pm}6.1%$ in RIA and $15.5{\pm}7.7%$ in EIA (CLIA). There was no significant difference between RIA and EIA. In RIA, the coefficient variations (CV) of AFP, CEA, PSA, CA 125, T3, T4, TSH were within 20%. The CV of CA 19-9 was over 20% but there was no significant difference with EIA (CLIA) (p=0.345). In recovery test using CRM, AFP, PSA, T4, TSH showed 92~103% of recovery in RIA. In recovery test using commercial material, CEA, CA 125, CA 19-9 showed relatively lower recovery than CRM but there was no significant difference between RIA and EIA (CLIA). Conclusion: By evaluating the precision and accuracy of each test, EQA test could more accurately measured the quality of each test and performance of laboratory.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.298-305
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• 2017

Benzovindiflupyr is a new pyrazole carboxamide fungicide that inhibits succinate dehydrogenase of mitochondrial respiratory chain. This study was carried out to develop an analytical method for the determination of benzovindiflupyr residues in agricultural commodities using LC-MS/MS. The benzovindiflupyr residues in samples were extracted by using acetonitrile, partitioned with dichloromethane, and then purified with silica solid phase extraction (SPE) cartridge. Correlation coefficient ($r^2$) of benzovindiflupyr standard solution was 0.99 over the calibration ranges ($0.001{\sim}0.5{\mu}g/mL$). Recovery tests were conducted on 5 representative agricultural commodities (mandarin, green pepper, potato, soybean, and hulled rice) to validate the analytical method. The recoveries ranged from 79.3% to 110.0% and then relative standard deviation (RSD) was less than 9.1%. Also the limit of detection (LOD) and limit of quantification (LOQ) were 0.0005 and 0.005 mg/kg, respectively. The recoveries of interlaboratory validation ranged from 83.4% to 117.3% and the coefficient of variation (CV) was 9.0%. All results were followed with Codex guideline (CAC/GL 40) and Ministry of Food and Safety guideline (MFDS, 2016). The proposed new analytical method proved to be accurate, effective, and sensitive for benzovindiflupyr determination and would be used as an official analytical method.

• Journal of Korean Academy of Nursing
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• v.10 no.1
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• pp.41-55
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• 1980

The medical care insurance system, being put into practice nearly for three years, seem to have brought about some considerable problems as serious for the government as to consider a revision of that system. As one of the most serious problems of present system, the treatment cost of insurance patients is so remarkably low in comparison with than of non-insurance cases that normal operation of hospitals is threatened and care services of low quality are induced. The researcher carried out this survey to analyze and bring to light several aspects of treatment cost of non-insurance patients as a material for a re-assessment of the cost of insurance cases which shows a a considerable difference in amount at the standpoint of hospitals with than of non-insurance cases and further, hoping the significant blind spot of present insurance system(that is, the absence of regulations' for cost assessment by patterns or types of health care treatment) will be mended in near future. The survey was carried out with the treatment invoice sheets of total 902 in-hospital Patients of a general hospital in Seoul during the period of the 2 nd quarter of the year(1979). Among total 902 patients, 694 cases were used for analysis, because those disease or syndromes shared by less than 10% of the patients were put aside before procession. The data were analyzed by kinds or types of diseases, demographic characteristics of patients, hospitalization patterns, types of nursing treatment, etc. The result of analysis was as follows 1. Among all the non-insurance cases, those who received one or more kinds of nursing treatment mounted up to 96. 7 ％. The invoice issue frequency per person was 7.2 times, while that frequency per day for a person was 0.8, : the treatment cosr per person was ￦22,650 while its daily average was ￦2,430, due to the average 9.3 in-hospital days per person. 2. As to the nursing treatment types by the demographic characteristics of patients and hospitalization patterns. a. The unit cost female patients was generally more expensive them that of males, and independent nursing service was more given than other types of treatment. As to age, higher age groups received independent nursing service most, while the youngest group received instrumental and integrated nursing services. b. As to room grade, the unit cost of I.C.U. cases was the highest : and the cast of private room patients was higher than that of public room patients. By in-hospital days, the curve of function showed L. type : that is, the longer stay, the lower function. 3. State of treatment types by kinds of disease were ; a. Dependent nursing service showed comparatively high availability in surgical and neurologic disease and independent nursing service was most received by medical, obstetrical and urological patients, while instrumental and integrated services were most available for respiratory disease and obstetrical and neurologic diseases next. b. The invoice issue frequency per day for a patient was highest in obstetrical disease 3.8 times, and the unit cost(per one invoice sheet) was also highest in obstertrical disease(￦10,880) and next in neurologic cases(￦ 4,690 ). 4. As to the pertained departments. a. Cost amount per person was highest in department of Psychiatries daily cost was highest in obstetrical cases : while the invoice issue frequency was highest in obstetrics and next in pediatrics. b. In departments in need of surgical operation, dependent nursing care was highly availabl : while in internal medicine and obstetrics, independent service was higher. Psychiatrics showed the highest the of integrate nursing while pediatrics and obstetrics higher of instrumental services. The variation co-efficien of treatment cost came out to be relatively in high in special surgery, opthalmology and internal medicine. 5. State of treatment cost by types of nursing behavior was. a. The average frequency of invoice issue was 3.5 (times). Among the type four types of treatment, instrumetal service (4.3) and independent nursing behavior(3.9) showed higher frequency than average respectively. But as to unit cost (per invoice). dependent (￦5,200) and integrated (￦5,340) nursing care services were higher than average and considerably higher than the other two types. b. In repect patient distribution. independent nursing behavior(80.3% ) was the highest and depend ent nursing (31.7% ) the lowest. The variation co-efficient of treatment cost appeared highest in dependent nursing be havior as a whole, and among that, doctor's diagnosis showed the highest coefficient value (100.7). In conclusion, the variaty of treatment cost(treatment itself ) by various characteristics and treatment types pro- that treatment various sort of patients and treatment cost of various types of nursing behavior cannot be uniform. Therefore, to attain the equalization of health care service and its cost both for insurant and non-insurant patients, a more specific provision for assessment of cost should be added to the present medical care insurance system and, in addition, the cost of nursing treatment is desired to be inserted into the treatment invoice.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.34-37
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• 2012

Purpose: To verify the optimal scan time per bed for clinical application, we evaluated the quality of $^{18}F$-FDG images with varying scan times in a phantom and 20 patients with 38 lesions using a Philips (TOF) PET/CT scanner. Materials and Methods: The PET/CT images of a NEMA IEC body phantom and 20 patients (16 males, 4 females) were acquired for 5 different scan times of 20-100 sec per bed with intervals of 20 sec. The activity ratio of hot spheres (diameter of 17 [H1], 22 [H2] and 28 [H3] mm) to the background region in the IEC body phantom was 8-to-1. The contrast recovery coefficient (CRC) and standard uptake value (SUV) based on ROIs of hot spheres and background region were calculated. The noise in each background region was estimated as the ratio of SD of counts to the mean counts in the background region. On the patient image, the injected dose of $^{18}F$-FDG was $444{\pm}74$ MBq and the SUVs in the 38 hot lesions were measured. Results: The two scan time groups (LT-60 [<60 sec] and GT-60 [${\geq}60$ sec]) were compared. In the phantom study, the coefficient of deviations (CVs, %) of CRC and SUV in LT-60 (H1: 14.2 and 7.3, H2: 11.4 and 7.8, H3: 4.9 and 3.2) were higher than GT-60 (H1: 8.9 and 2.8, H1: 8.2 and 5.0, H3: 2.0 and 1.6). In the patient study, the mean CV of CRC and SUV in LT-60 (4.0) was higher than GT-60 (1.2). Conclusion: This study showed that noise increased as the scan time decreased. High noise for the scan time <60 sec per bed yielded high variation of SUV and CRC. Therefore, considering PET/CT image quality, the scan time per bed in the TOF PET/CT scanner should be at least ${\geq}60$ sec.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.301-312
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• 2016

This study has performed comparative analysis on characteristics of contaminated 35 tributaries on seasonal variation/point discharge load/pollutant distribution of water quality factors(8) in order to understand the effect of the watershed in Nakdong River Basin. As a results, the water quality of $BOD_5$(Biochemical Oxygen Demand), Chl-a(Chlorophyll a) and Fecal E. Coli shows II grade at tributaries of more than 50% without COD(Chemical Oxygen Demand), TP(Total Phosphate), TOC(Total Oxygen Carbon) and TN(Total Nitrogen) factors. The specific discharge(Q) were occupied about 54.4% (19 sites) as $0.05m^3/sec/km^2$ value. Among these results, the contaminant level of Dalseocheon, Hyeonjicheon, Seokkyocheon 1, Uriyeongcheon and Dasancheon was also high, which has to consider a discharged pollutant load(kg/day). The 35 major tributaries of Nakdong River were included in 7 mid-watershed, such as Nakdong Waegwan, Geumho River, Nakdong Goryung, Nakdong Changnyung, Nam River, Nakdong Milyang, Nakdong River Hagueon. Especially, the discharged pollutant load of Nam River and Geumho River also was high according to the amount of discharge such as Kachang dam, Gongsan dam and Nam river dam. Seasonal difference of the water quality factors such as $BOD_5$, TN, SS and Q was observed largely, on the other hand the TP and Chl-a was not. This is guessed due to the precipitation effect of site, biological and physicochemical degradation properties of pollutant and etc. The co-relationship between the seasonal difference and water quality factors was observed using a Pearson correlation coefficients. Besides, the Multiple Regression analysis using a Stepwise Regression method was conducted to understand the effect between seasonal difference and water quality factors/regression equations. As a result, the Multiple Regression analysis was adapted in the spring, summer and autumn without the winter, which was observed high at spring, summer and autumn in the order COD/TP, Chl-a/TOC, TOC/COD/$BOD_5$ water quality factors, respectively.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.466-473
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• 2018

An analytical method of sodium polyacrylate in processed food products was developed and monitored by using size-exclusion chromatography. GF-7M HQ column and UV/VIS detector were selected based on peak shape and linearity. Flow rate, column oven temperature, and mobile phase were selected as 0.6 mL/min, $45^{\circ}C$, and 50 mM sodium phosphate buffer of pH 9.0, respectively. Samples for analysis of sodium polyacrylate were extracted with 50 mM sodium phosphate buffer of pH 7.0 for 3 hr at $20^{\circ}C$ and 150 rpm. Analytical method validation revealed proper selectivity and calibration curve was selected in the range of 50-500 mg/L, and correlation coefficient of calibration curve was more than 0.9985. Limit of detection of sodium polyacrylate was 10.95 mg/kg and limit of quantification was 33.19 mg/kg. Accuracy and coefficient of variation for sodium polyacrylate analysis was 99.6-127.6%, 3.0-8.3% for intra-day and 94.3-121.9%, 1.3-2.6% for inter-day, respectively. Sodium polyacrylate was detected in 40 samples among monitored 125 processed food products. Detected contents were less than 0.2%, limited by the Food Additives Code. Results suggest the established size-exclusion chromatography method could be used to analyze sodium polyacrylate in processed food products.

• Journal of Korea Water Resources Association
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• v.55 no.8
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• pp.603-611
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• 2022

In urban areas, the impermeable area continues to increase due to urbanization, which interferes with the surface penetrating and infiltrating of rainwater, causing most rainwater runoff to the surface, deepening the distortion of water circulation. Distortion of water circulation affects not only flood disasters caused by rainfall and runoff, but also various aspects such as dry stream phenomenon, deterioration of water quality, and destruction of ecosystem balance, and the Ministry of Environment strongly recommends the use of Low Impact development (LID) techniques. In order to apply the LID technique, it is necessary to set a rainwater management target to handle the increase in outflow after the development of the target site, and the current standard sets the rainwater management target using the 10-year daily rainfall. In this study, the difference from the current standards was analyzed through statistical analysis and classification of independent rainfall ideas using inter-event time definition (IETD) in setting the target amount of rainwater management to improve water circulation. Using 30-year rainfall data from 1991 to 2020, methods such as autocorrelation coefficient (AC) analysis, variation coefficient (VC) analysis, and annual average number of rainfall event (NRE) analysis were applied, and IETD was selected according to the target rainfall period. The more samples the population had, the more IETD tended to increase. In addition, by analyzing the duration and time distribution of independent rainfall according to the IETD, a plan was proposed to calculate the standard design rainfall according to the rainwater management target amount. Therefore, it is expected that it will be possible to set an improved rainwater management target amount if sufficient samples of independent rainfall ideas are used through the selection of IETD as in this study.