• Analytical Science and Technology
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• v.29 no.5
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• pp.234-241
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• 2016

The approach presented in this article refers to the bioanalytical method validation for the detection and quantitative determination of arsenic species including arsenite (As(III)), arsenate (As(V)), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) in dog plasma by high-performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP/MS). The arsenic species were separated using an agilent As speciation column by a mobile phase of 2 mM sodium phosphate monobasic, 0.2 mM ethylenediaminetetraacetic acid disodium salt dehydrate, 10 mM sodium acetate, 3 mM sodium nitrate and 1 % ethyl alcohol at pH 11 (adjusted with 1M NaOH). The method validation experiment was obtained selectivity, linearity, accuracy, precision, matrix effect, recovery, system suitability, dilution integrity and various stabilities. All calibration curves showed good linearity (R²>0.999) within test ranges. The lower limit of quantitation (LLOQ) was 5 ng/mL for As(III), As(V) and DMA, and 20 ng/mL for MMA. The system suitability and dilution values were within 6.5 % and 7.7 %. Subsequently, the developed and validated HPLC-ICP/MS method was also successfully applied to determine the arsenic speciation in dog plasma samples, and the recoveries for the spiked samples were in the range of 91.5–102.2 %. Therefore, this method could be applied to the evaluation of arsenic exposure, health effect assessment and other bio-monitoring studies in biological samples.

• Analytical Science and Technology
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• v.29 no.6
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• pp.277-282
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• 2016

British Pharmacopoeia (BP 2013), the United States Pharmacopoeia (USP 39) and the Korean Pharmacopoeia (KP XI) contain monographs for the quality control of raw diosmin using high performance liquid chromatography (HPLC). However, official monographs detailing pharmaceutical formulations for diosmin are not available in foreign pharmacopoeias. In the KP XI, ultraviolet-visible (UV-Vis) spectroscopy-which is less specific than HPLC-is reported for the testing of diosmin capsules. In this study, we present an alternative HPLC assay for such testing that is more specific than UV-Vis methods. Method validation was performed to determine linearity, precision, accuracy, system suitability, and robustness. The linearity of calibration curves in the desired concentration range was high ($r^2$>0.999), while the RSDs for intra- and inter-day precision were 0.15-0.29 % and 1.05-1.74%, respectively. Accuracies ranged from 101.2-103.2 %, while the retention time and peak area RSDs were 0.37 % and 0.06 %, respectively. Additionally, the plate number and asymmetry factor values for diosmin were 3591.293 and 1.35, respectively. Since the intermediate-precision and robustness of the assay were satisfactory, this method will be a valuable addition to the Korean Pharmacopoeia (KP XI).

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.309-317
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• 2015

BACKGROUND: An analytical method was developed using GC-ECD/MS to precisely determine the residue of fipronil, a phenylpyrazole insecticide used to control a wide range of foliar and soil-borne pests.METHOD AND RESULTS: Fipronil residue was extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, Kimchi cabbage, green pepper, and apple. The extract was diluted with saline water, and fipronil was partitioned into n-hexane/dichloromethane (20/80, v/v) to remove polar co-extractives in the aqueous phase. Florisil column chromatography was additionally employed for final purification of the extract. Fipronil was separated and quantitated by GC-ECD using a DB-17 capillary column. Accuracy of the proposed method was validated by the recovery from crop samples fortified with fipronil at 3 levels per crop in each triplication.CONCLUSION: Mean recoveries ranged from 86.6% to 106.0% in five representative agricultural commodities. The coefficients of variation were less than 10%. Limit of quantitation of fipronil was 0.004 mg/kg as verified by the recovery experiment. A confirmatory technique using GC/MS with selected-ion monitoring was also provided to clearly identify the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of fipronil in agricultural commodities.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.305-317
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• 2003

Underwater shape and hook depth in tuna longline gear are important factors to decide fishing performance. It also should be considered that management and analysis of hooked rate data from hooked fish species and sizes, and each fishing would be used as a reference data in the future fishing. In this research, after analyzing underwater shape of tuna longline gear by current direction and speed using simulation, experiments were executed in flume tank to verify accuracy of the analysis. Also using the depth of each hook from the simulation, a database system was setup to process the data of bait and hooked fish species. The results were as follows；1. When the attack angle and the shortening rate are fixed, a decrease of the hook depth is proportion to an increase of current speed. 2. When the shortening rate and current speed are fixed, a decrease of hook depth is proportion to an increase of attack angle. 3. When the attack angle and velocity of flow are fixed, a decrease of hook depth is proportion to an increase of shortening rate 4. As a result of comparison between the underwater shape by simulation and that by model gear, the result of the simulation was very close to that of model gear within $$ {\pm}3%$$ 3% error range. 5. In this research, hooked rate database system using hook depth of simulation can analyze the species and size of fish by the parameter; bait. hook depth, so It could be helpful to manage and analyze the hooked data on the field.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.4
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• pp.359-366
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• 2002

To survey satellites using only GPS can sometimes cause an impossible situation due to the many different geographical conditions as city cannon and obstacles. Although the GLONASS satellite system does not have the ability to survey itself accurately since it currently lacks of the number of usable satellites, it is able to bridge the gap when combined with GPS. This research used the GPS receiver to perform four analyzing methods to bring out the independent surveying method of GPS and combined surveying method of GPS and GLONASS(4 methods - number of satellites able to receive, precision of raw data, standard deviation from known point and RTK surveying). The result of test surveying satellites showed that 11 hours were possible to measure a minimum of 4 satellites when using an independent surveying method and 4 hours in unified surveying method in a month. Also, the precision of raw data using GPS and GLONASS surveying is 0.08~l.8m better than the GPS surveying in standard deviation. The deviation of known points by GPS and GLONASS also showed better accuracy by 3~l1mm. The RTK showed the range of differences in deviation of survey by leaning towards the GPS independent survey in Northing coordinate and leaned towards the Easting coordinate when GPS and GLONASS were combined. Nonetheless, it can't be said that the unified method is better, because it has limits to its capability.

• Journal of Families and Better Life
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• v.14 no.3
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• pp.211-222
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• 1996

The purpose of this study is to classify the expenditure behaviors of housewives into some types and to identify the characteristics of the types focucing on diverse expenditure behaviors of urban households. In this study it is assumed that the expenditure behaviors are classified by there factors-(1)the orientation of money saving (2)the orientation of time saving and (3)the orientation of others. The present study suggests following three questions. (1). Can the expenditure behaviors of urban housewives be classified according to the orientation of money saving the orientation of others? (2) What distictions exist among the types? (3) Which variables are useful in classifying the expenditure behaviors? For empirical analysis the data of the study was collected from 650 housewives living in Seoul. The statistical methods adopted for data analysis are frequency percentage mean Pearson's correlation coefficient factor analysis cluster analysis one way ANOVA Duncun's multiple ran e test and discriminant analysis. As the major findings 4 types were extracted, According to the level of each dimensions the names for the each type were given as "the type of attaching importance to money saving" "the type of attaching importance to time and appearance" "the type of attaching importance to money saving and time" "the type of attaching importance to money saving and time" "the type of attaching importance to money saving and time" "the type of attaching importance to money saving and appearance" In "the type of attaching importance to money saving" the significant portion of housewives have high school degrees and compared with other types this type includes more husbands having sales and service job 55% of housewives of "The type of attaching importance to time and appearance" have graduate or higher degrees. The significant part of earned incomes range from 3 million won to 5 million won. The rate of housewives employed in the professional job is higher than other types. In "The type of attaching importance to money saving and time" the rate of the employment of housewives in this type is the highest among the types. In "The type of attaching importance to money saving and appearance" the significant portion of housewives have graduate degrees. In the jobs of he spouses the management job is major. The consciousness of belonging to the middle class is higher than other types. In this type the level of education is high but that of income is not. The result of the discriminant analysis says that the earned income and the consciousness of belonging to a calss are the most critical variables to classify the expenditure behaviors into 4 type The accuray of the classification of the discrimination equation composed of these variables is 47,5% The accuracy is improved by 10%.

• Journal of Radiation Protection and Research
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• v.38 no.1
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• pp.29-36
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• 2013

The aim of this study was to determine the correlation between exposure index (EI) and dose factors related to radiation dose optimization in digital radiography (DR) system. Two phantoms with built-in regional test object for quantitative assessment of images were used to produce image signals that acquired in chest radiography background. EI and entrane surface dose (ESD) increased proportionally with rise of radiation dose (kVp, mAs) in both DR and CR systems. Especially, DR detector was effective to form good contrast and hence, reached easily to improvement of image quality with minimal dose changes. It made operators possible to expect the accuracy of EI values deeply related to absorbed dose of the detector. The evaluation of images was obtained specially employed calculation of noise to signal ratio (NSR) and contrast to noise ratio (CNR). These measurements were performed for how exposure factors affect image quality. NSR was inversely proportional to kVp and mAs and low NSR represented high signal detection efficiency. Consequently, EI values was the measure of the amount of exposure received by the image receptor and it was proportional to exposure factors. Therefore the EI in a recommended range from manufacturer can offer optimal image quality. Also, continuous monitoring of EI values in the digital radiography can reduce the unnecessary patient dose and help the quality control of the system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.1 s.28
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• pp.1-7
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• 2007

In order to develop the deep ocean water, the characteristics of vertical distribution of dissolved trace metals(Cd, Co, Cu, Ni, Pb, Zn) were investigated from Apr. to Oct., 2005 in the East Sea. Total six sampling sites were selected in Gangwon-Do and Gyeongsangbuk-Do. Accuracy of the analytical procedures was assessed by the SRM(CASS-4) for dissolved metals in seawater. The mean recoveries cf CASS-4 ranged from 89.4% for Co to 99.8% for Cd. In this study, the dissolved metal concentrations varied with space, time and element. The metal concentrations showed wide range in the surface. Cd, Ni and Zn showed a nutrient-type profile with surface depletion and enrichment at depths. However, Co, Cu and Pb were irregular in the vertical distribution. All metal concentrations studied in this study are lower than the criteria cf Korean drinking water.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.65-74
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• 2018

The aim of this study was to obtain the traceability of the software used to analyze lateral cephalometry and to calculate the uncertainty of the measurements. Furthermore, this study aimed to provide a basis for obtaining standard references for measurement values for orthodontic treatment in children. Cephalometric data were collected from 100 children diagnosed with class I malocclusion between the ages 6 to 13 years who visited the pediatric dentist at Seoul National University Dental Hospital. To ensure traceability, a phantom device was created. Correction values were calculated by measuring the length and angle of the phantom device using the software. Type A uncertainty was calculated by obtaining the standard deviation of cephalometric measurements of 100 persons and the standard error of repeated measurements. Determination of the type B uncertainty was induced by minimum resolution and the position of the head. Using these, the combined standard uncertainty was obtained and the expanded uncertainty was calculated. The results of this study confirm that the currently used software has high accuracy and reliability. Furthermore, the uncertainty of orthodontic measurements in Korean children aged 6 to 13 years was calculated, and distribution range for class I malocclusion with 95% confidence interval was suggested.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.1
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• pp.143-157
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• 1992

For the design of structural systems having the prescribed or optimum dynamic characteristics, some design changes of the initially designed system are required. In these cases, if the sensitivity analysis which can predict the changes of dynamic characteristics due to the changes of design variables is applied, the design changes can be carried out rationally and very efficiently. For many structural systems, it is well known that the analysis by the transfer matrix method(TMM) and the combined finite element-transfer matrix method(FETMM) is more efficient than the analysis by the finite element method. However, most known studies on the sensitivity analysis of structural systems premise using the finite element method. In this paper, the sensitivity analysis methods by the TMM and the FETMM are presented and some numerical investigations on the beam-column with elastically restrained ends and intermediate contraints and the stiffened plate having subsystems are carried out. The results of the numerical examples show good accuracy and computational efficiency of the presented methods, and show that the application of sensitivity analysis in the dynamic characteristic reanalysis give good results within the practically changeable range of design variables.