• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.43-48
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• 2005

In order to facilitate technical exchange among nations and/or institutes through the establishment of mutual recognition and the reliability guarantee of testing results by testing standards standardization, the interlaboratory comparison tests on brake discs and linings between KRRI and CARS were conducted. So far, two ways of comparison tests were performed for a better understanding of mutual recognition and standardization in railroad brake linings between Korea and China. In this paper, the first and second comparison testing results have been summarized, and the suggestions for the future research work are also presented to encourage extensive research on comparison study of railroad brake discs and linings between KRRI and CARS. Eventually, the final goal of the current research will be the establishment of standardization of railroad testing standards.

• Journal of the Korean Geotechnical Society
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• v.15 no.1
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• pp.41-52
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• 1999

In order to assess the quality and depth of ground densification by compaction, SPT and/or CPT are performed before and after compaction. Both methods are intrusive and one point tests, require a substantial time to evaluate a large area, and their results are quite dependent on the operation technique and soil type. In this paper, the quality and extent of ground densification by compaction was evaluated by using in situ SASW test and laboratory resonant column (RC) test results. SASW test was used to determine the shear wave velocity profiles before and after compaction, and RC test was adopted to determine the correlation between the normalized shear wave velocity and the density of the site, which is almost uniquely independent of confinement. Testing and data reduction procedures of both tests were discussed, and a simplified evaluation procedure of ground densification was proposed. Finally, the feasibility of the proposed method was verified by performing field study at Inchon International Airport Project. Field densities determined by the proposed method matched well with those determined by sand cone tests.

• Journal of Korean Society on Water Environment
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• v.30 no.6
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• pp.632-637
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• 2014

Proficiency testing by interlaboratory comparisons is used to determine the performance of individual laboratories. In order to verify the quality of acute toxicity testing with Daphnia magna, National Institute of Environmental Research in South Korea is regularly organizing interlaboratory comparisons to estimate the analytical accuracy of different laboratories. Total 58 laboratories located in South Korea took part in interlaboratory proficiency testing scheme with three proficiency testing samples. TU(Toxic Unit) values of each laboratory were determined and robust z-score was calculated in order to evaluate the proficiency levels. Based on the robust z-score classification, 74% of the participant laboratories showed a satisfactory performance (43 laboratories). The main reason of 'unsatisfactory' performance seemed to be considered that the unsuitable management of test organism incubation system and the lack of experience on the identification of the test organism condition by effect of toxicity.

• 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.

• Analytical Science and Technology
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• v.26 no.3
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• pp.165-173
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• 2013

To establishment of PT Program for Indoor air quality field that manufacture of confidential development PTMs (proficiency testing materials) and examined of proficiency testing evaluation included sampling process whether or not that is valid. Confirmation of homogeneity and stability of PTMs prepared. PTMs were confirmed to be homogeneous enough to be used as proficiency testing materials since withinbottle homogeneities of the RMs were lower than 0.3 times of targeted standard deviation of proficiency testing. The result of this study showed that the Robust RSD of proficiency testing for VOCs (volatile organic compounds) appeared 23~43% in concentration of 50~320 ${\mu}g/m^3$ for Method A(Distribution by adsorption in Tenax-tube of VOCs), but less 13~42% in concentration of 200~1200 ${\mu}g/m^3$, 16~31% in concentration of 100~450 ${\mu}g/m^3$ for Method B (distribution by VOCs of gas phase in 10L Tedalr bag), C (directly sampling of cylinder with high pressure) respectively. The result of this study showed that method C with sampling is most adequate to the proficiency testing for VOCs in indoor air.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.45-49
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• 2020

FEU which is a important device in HCTRS of TICN amplifies transmission signals. Tests of intermodulation distortion and harmonic distortion for FEU have been performed manually, and take a lot of time. This paper improves the test methods using program that set up the measurement instruments and read the data automatically. This proposal allows intermodulation distortion and harmonic distortion test simultaneously. And the new test methods show that the measurement time is shorter than before. Also, it is expected that efficient quality assurance is possible because the test time can be independently managed, unlike the previous methods, where the test time was determined according to the skill level of the operator.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.152-159
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• 2008

The purpose of this study was to determine the accurate quantification of vitamin A in infant formula by comparing two different standard stock solutions as well as various sample weights using high performance liquid chromatography. The sources of uncertainty in measurement, such as sample weight, final smaple vloume, and the instrumental results, were identified and used as parameters to determine the combined standard uncertainty based on GUM(guide to the expression of uncertainty in measurement) and the Draft EURACHEM/CITAC Guide. The uncertainty components in measuring were identified as standard weight, purity, molecular weight, dilution of the standard solution, calibration curve, recovery, reproducibility, sample weight, and final sample volume. Each uncertainty component was evaluated for type A and type B and included to calculate the combined uncertainty. The analytical results and combined standard uncertainties of vitamin A according to the two different methods of stock solution preparation were 627 ${\pm}$ 33 ${\mu}$g R.E./100 g for 1,000 mg/L of stock solution, and 627 ${\pm}$ 49 ${\mu}$g R.E./100 g for 100 mg/L of stock solution. The analytical results and combined standard uncertainties of vitamin A according to the various sample weighs were 622 ${\pm}$ 48 ${\mu}$g R.E./100 g, 627 ${\pm}$ 33 ${\mu}$g R.E./100 g, and 491 ${\pm}$ 23 ${\mu}$g R.E./100 g for 1 g, 2 g, and 5 g of sampling, respectively. These data indicate that the preparation method of standard stock solution and the smaple amount were main sources of uncertainty in the analysis results for vitamin A. Preparing 1,000 mg/L of stock solution for standard material sampling rather than 100 mg, and sampling not more than 2 g of infant formula, would be effective for reducing differences in the results as well as uncertainty.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1673-1674
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• 2008

화력발전소 보일러의 각종 공정은 대부분 비례 적분 미분 제어기에 의해 제어되어 왔다. 이러한 비례 미분 적분 제어기의 최적튜닝은 공정에 있어 가장 중요한 부분 중 하나라고 할 수 있다. 또한 보일러 제어는 다중의 입력과 루프로 구성되어져 있어 이를 튜닝하기가 어려워 현재까지의 최적튜닝은 튜닝전문가의 숙련도에 의해 결정되어져 왔다. 본 논문에서는 고급공정제어기(Advanced Process Control, APC)를 개발하는 과정과 이를 이용해 최종적으로 보일러 제어기에서 제어하고자 하는 대상에 대한 응답특성을 간단한 튜닝을 통해 구현하는 과정에 대하여 설명하고 그 결과를 시뮬레이터를 통해 시험함으로써 검증해 보이고자 한다.

• Analytical Science and Technology
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• v.22 no.1
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• pp.82-91
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• 2009

Preparation and evaluation of the limestone samples for a proficiency test using domestic limestone have been performed. We have used statistical method for evaluation of the XRF and instrumental analysis results. We have found that there were some outliers from XRF and ICP-OES instrumental analysis results for each sample. After removal of 5 outliers among the 50 samples we could obtain the homogeneous samples which have within a reliability of 95% from a statistical analysis result.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.35-42
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• 2015

Although the interest for earth architecture has been expanded and settled as a part of modern architecture, precisely calculating the ratio of water content in practice is still difficult and the calculation is based on empirical analysis yet. This causes many problems in durability and maintenance of earthen architecture. Therefore, this study investigated to find the easiest way to correctly calculate the appropriate level of water content ratio (AWCR), which can be used in practice. Until now, the workers have checked the AWCR based on their own experience with popular but vague manuals. On this awareness, we studied the several testing methods and found the dropping test which uses the pattern of shape after the sample is dropped. In this point, we studied and developed the definite testing method in terms of process, and shape discrimination. Also we suggest the test recording sheet by using the cobalt chloride($CoCl_2$) whose color is instantly changed when contacts with the moisture. It is believed that this result can help improving the quality and durability of the earthen architecture using the rammed earth method and the efficiency in practice.