• Journal of electromagnetic engineering and science
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• v.18 no.3
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• pp.169-174
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• 2018

In this paper, we propose an estimation method using multiple in-phase and quadrature (IQ) signals of different frequencies to evaluate the sample-time errors in the sampling oscilloscope. The estimator is implemented by ODRPACK, and a novel iteration scheme is applied to achieve fast convergence without any prior information. Monte-Carlo simulation is conducted to confirm the proposed method. It clearly shows that the multiple IQ approach achieves more accurate results compared to the conventional method. Finally, the criteria for the frequency selection and the signal capture time are investigated.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.66-73
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• 2008

Purpose: CA 19-9 need to examine a number of sample volume, and the postwar 200 U/ml concentration hook effect appears slight. Thus, the antibody-antigen reaction, and by reducing the amount of (sample volume), they can hook effect to minimize the impact of the sample volume and relevance know, I saw the hook effect. In addition, the current maximum of using the standard concentration of the reagent in 240 U/ml increase more than the standard concentration can be seen knows. Material and Method: 5 U/ml and under, make a few low concentration of serum pool from the high concentration of the sample hook effect together with a standard concentration of about 500 to meet the production. The reagents used in experiments are currently using SNUH NM experiment. Orignal method along with the experiment is to 25 ul sample volume (1 / 4), 50 ul (1 / 2), 100 ul (Orignal method) in the experiment. My greatest concentration of the reagent concentration of approximately two times the standard concentration of production. When was the last to make the first experiment, as measured by the standard concentration after that. The new inspection information through a standard solution modified by entering values in them. Results: 100 ul, and to apply the new standard concentration y = 1.3021x - 10.97, $R^2$ = 0.9844. Overall, the results showed a similar orignal method. Because of the concentration in the value of more than 240 U/ml, but it is an overall value that can be made out of a similar value When I put the 50 ul y = 1.045x + 9.5861, $R^2$ = 0.9428. Overall orignal method and the results of a similar value. 50 ul, and to apply the new standard concentration y=1.2006x+11.252, $R^2$=0.9423. Showing a slightly lower value compared with orignal method. Because of the concentration in the value of more than 240 U/ml, but it is an overall value that can be made out of a similar value. When I put the man 25 ul y=0.6012x+24.755, $R^2$=0.4033. Results showed that very small amounts of sample are insecure inside and showed a lower middle cpm orignal method and showed a lot of mismatched. Conclusions: 25 ul of the sample volume is not possible to use the instability had, when I put the 50 ul of the orignal method can be used to show a similar concentration. The new values are slightly lower concentration, The new values are slightly lower concentration, concentration, which are likely due to the lack of data has had a little gap between the sample showed 80 to 200 U/ml additional experiments seem to do. Apply a new 100 ul concentration values are applied to a large crowd is not even in sight. But this way the concentration of 100 to more 400 U/ml gather further experiments should possible adds.

• Analytical Science and Technology
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• v.29 no.6
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• pp.261-268
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• 2016

TXRF is a powerful technique for the soil sample analysis due to its ability to conduct quantitative analysis of powder sample without complicated pre-treatment processes. The conventional internal standard method used for this technique suffers from relatively low accuracy because of varying matrix effects of soil. In order to improve the accuracy, external standard method was applied to analyze two types of soil samples; acid-dissolutionized soil solution and detergent-suspended soil powder. Individual ICP-AES/MS grade standards were mixed, diluted and measured to create standard curves, but applying these curves for analyzing the soil solution sample did not make any improvement in comparison with the internal standard method. On the other hand, standard curves were created with using standard soil powders for the analysis of soil powder samples, and we found that this method increased the accuracy significantly relative to the internal standard method. Especially, Al, Fe, K, Ca, Ti, Ba, Mn, Sr, Rb, Cu was measured with relatively high accuracy (relative error = ${\pm}20%$).

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.76-83
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• 1999

Solid phase microextraction (SPME) was used for the determination of 6 standard solvents (methanol, isopropanol, methyl ethyl ketone, ethyl acetate, cyclohexane, toluene) in food packaging materials. SPME method is a solvent-free sample preparation technique in which a fused silica fiber coated with polymeric organic liquid is introduced into the headspace above the sample. SPME method using fiber coated polydimethylisiloxane (PDMS) was compared with static headspace (SHS) method used as a reference. It was found that the optimal adsorption condition using PDMS-SPME method was 2$0^{\circ}C$ for 15 minutes for the standard solvents. Detection limits, linearity, reproducibility and recovery of both SHS and PDMS-SPME methods have been determined using 6 standard solvents. Both methods were characterized by high reproducibility and good linearity. Using SHS methods, the mean recovery of the 6 standard solvents was ranged from 75.5% to 105.8% with a mean relative standard deviation (RSD) of 0.3% to 4.8%. With PDMS-SPME method, the mean recovery of the 6 standard solvents was ranged from 86.7% to 108.3% with a mean RSD of 0.4% to 2.5%. The detection limits of both methods were the same for toluene, cyclohexane and methyl ethyl ketone; those of PDMS-SPME method were higher than those of SHS method for methanol, isopropanol and ethyl acetate. PDMS-SPME fiber shoed excellent adsorption for non-polar solvents such as toluene, while it showed relatively low adsorption for polar solvents such as methanol.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.139-145
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• 2007

Measurement uncertainty could play an important role in the assessment of test results in laboratories and industries. We investigated measurement uncertainties possibly included in determination of flubendazole, a benzimidazole anthelmintic, in pork by HPLC. The concentration of flubendazole was 62.69 ng/g in a sample of pork. Uncertainty was estimated in the analytical procedure of flubendazole. A model equation was made for determination of flubendazole in pork. The four uncertainty components such as weight of sample, volume of sample, calibration curve, and recovery were selected to estimate measurement uncertainties. Standard uncertainty was calculated for each component and all the standard uncertainties were combined. The combined standard uncertainty was expanded to a sample population as an expanded uncertainty. The expanded uncertainty was calculated using k value on Student's t-table and effective degrees of freedom from Welch-Satterthwaite formula. The expanded uncertainty was calculated as 3.45 with the combined standard uncertainty, 1.584 6 and the k value, 2.18. The final expression can be ($62.69{\pm}3.45$) ng/g (confidence level 95%, k = 2.18). The uncertainty value might be estimated differently depending on the selection of the uncertainty components. It is difficult to estimate all the uncertainty factors. Therefore, it is better to take several big effecting components instead of many small effecting components.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.1
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• pp.85-96
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• 2001

The objective of this study is to develop the water spraying which can effectively by applied to the control or suppression of the fugitive dust generated from the scrap metal handling area at the Port of Inchon. As a first step toward this goal, we carried out some preliminary analyses on the chemical composition, physical shape, and particle size distribution of the sample dust. Next, to quantitatively investigate the effect of adding surfactants to the spraying water on the wettability of the sample dust, the Standard Sink Test was carried out for four different surfactants and at six different concentrations using the surfactants considered in this study. Results of from the preliminary analysis indicated that the main chemical component consisting of the sample dust is Goethite(FeO(OH)) and that the particles smaller than 10 ${\mu}{\textrm}{m}$ in geometric diameter occupy about 36% of the sample dust in mass. This result implies that the fugitive dust generated from the scrap metal handling area at the Port of Inchon should affect the environment nearby more than we have expected. This is because of relatively large mass percentage of the small metal particles less than 10${\mu}{\textrm}{m}$ in geometric diameter, what we may call respirable particles. As for the results of the Standard Sink Test, higher surfactant concentration tends to result in the higher wettability of the sample dust for the surfactants considered in this study, which in turn ensures the high particle collection efficiency of the droplets generated from the water spraying system. Based upon this preliminary results, studies to develop more sophisticated scaled model for dynamic test in underway and the effort to find the best surfactants as well as the optimum operating conditions are being made at the same time.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.715-718
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• 2000

The character of a recombinant bioluminescent bacteria's light emission enables us to monitor toxicity in water, soil and air. In this study, various bioluminescent responses to water samples containing toxic chemicals, such as phenol and mitomycin C, were obtained and analysed through the use of a multi-channel two-stage minibioreactor system. The bioluminescent pattern from each channel can be used as a standard for identifying the degree of toxicity in field samples. When various concentrations of toxic chemicals were injected in a step manner, different bioluminescent patterns were obtained. Also this system showed variation in its bioluminescent pattern as the injection manner was changed, i.e. using a modified version of the bell-curve type injection. In conclusion, the toxicity was shown to be related with the bioluminescent response when using these standard bioluminescent patterns. Comparing this standard with a bioluminescent response from a field sample, we can estimate the degree of which the sample is toxic.

• Journal of the Korean Statistical Society
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• v.33 no.3
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• pp.323-337
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• 2004

This article coined a general class of estimators for various measures in normal population when some' a priori' or guessed value of standard deviation a is available in addition to sample information. The class of estimators is primarily defined for a function of standard deviation. An unbiased estimator and the minimum mean squared error estimator are worked out and the suggested class of estimators is compared with these classical estimators. Numerical computations in terms of percent relative efficiency and absolute relative bias established the merits of the proposed class of estimators especially for small samples. Simulation study confirms the excellence of the proposed class of estimators. The beauty of this article lies in estimation of various measures like standard deviation, variance, Fisher information, precision of sample mean, process capability index $C_{p}$, fourth moment about mean, mean deviation about mean etc. as particular cases of the proposed class of estimators.

• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.8-15
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• 1995

An estimate of a change in radioactivity's circumstances around the nuclear power plant is validated with the results of the radioactivity measurements are compared. In this study, to further enhance the reliability of the results obtained from the environmental radioactivity measurements and analysis around the nuclear power plants that have been carried out up to the present. In the korea standard, there is the technical analysis guide for general stable chemical element's, but there is not the technical analysis guide for the radionuclei. therefore the environmental sample collection, the pretreatment of the sample and radionuclide analysis in the sample, the result's of the environmental radioactivity measurements by each organization, etc. are different. It is not sufficient for the database to forecasting a change in radioactivity's circumstances. A comparative study of collection and pretreatment techniques for the soil sample, the results by comparison, the method of minimizing the relative error are proposed. At one side of sample collection, there are going to considered that the surroundings of sample collection like the lay of the land, the provision of the selection standard for the area and pathway of radionuclide adhesion, the coherence of sample collection, etc.. at another side of pretreatment of the sample and measurement in the case of soil sample, how to do homogeneously the soil particle size and the standard tools, i.e. kinds of meshes, must to be selected.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.43-48
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• 2008

Standard sample for quality control of total coliform measurement was procured by addition of nalidixic acid and cephalexin as bacteriostatic agents to Escherichia coli cultured broth. After making the standard sample, the number of E. coli was measured by fluorescence microscopic count method and plate count method by 12 hr interval. The numbers of E. coli remained unchanged for at least for 48 hr at room temperature which ranged from 3.5 to $4.2{\times}10^5\;cells/ml$ and from 1.0 to $1.2{\times}10^4\;CFU/ml$ by direct fluorescence microscopic count method and plate count method, respectively. This result suggests that microbial standard sample with bacteriostatic agents of nalidixic acid and cephalexin is usable for quantitative quality control.