• Journal of Korean Society on Water Environment
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• v.31 no.1
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• pp.49-54
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• 2015

Acute toxicity test with Daphnia magna has a variety of factors such as incubation condition of test species, food quality and proficiency of laboratory workers. Therefore, proper proficiency testing samples were required for evaluating the competence of laboratory workers. This study aims to propose some appropriate proficiency testing samples for laboratory workers of acute toxicity test with Daphnia magna. Proposed four kinds of standard samples (Sample A, B, C, and D) for proficiency testing were selected from reference materials which were recommended from Canada and USA WET(Whole Effluent Toxicity) authorities. Proposed standard samples were tested by trial application of proficiency testing, homogeneity and stability checks using repeatability test. Sample A, C and D were estimated ad the suitable candidates for proficiency test standard samples except for Sample B. In addition, Sample A was proved to be the most suitable sample.

• 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.

• Analytical Science and Technology
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• v.23 no.3
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• pp.284-294
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• 2010

In this study, river water-based reference materials (RMs), NIER-I08RW and NIER-I09, for trace metal analysis were prepared and certified for Pb, Cd, Cr and Cu with evaluation of uncertainties. The RMs were confirmed to be homogeneous enough to be used as proficiency testing materials since within-bottle homogenieties of the RMs were lower than 0.3 times of targeted standard deviation of proficiency testing. The RMs were distributed to environmental testing laboratories for the proficiency testing and the variation of Z scores of the proficiency testing results were compared for different assigned values. The relative bias, $B_{relative}$, deviations between reference values and consensus values, were lower than ${\pm}$1 except for cadmium of NIERI08RW. The results showed both values were in a good agreement and only 2.9% of Z scores changed by using a different assigned values such as consensus and reference values.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1443_1444
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• 2009

A study on the environmental tests for auxiliary and control circuits of high voltage switchgears, especially testing condition and requirements, according to the relevant international standards has been briefly reviewed in this paper. As the highest supply voltage of electric power systems have been progressed, testing techniques and testing standards such IEC codes improved and revised keeping step with it. Especially IEC 62271 series, which are applicable to the HV-class switchgears and controlgears have been revised in 2008 newly. In this paper, the special consideration and background information of environmental testing condition with mechanical operating performance, e.g. operation in a higher and lower ambient temperature, for the auxiliary and control circuits of switchgears and controlgears and considerable investigation to the related international standards have been provided. Examples of testing performed were showed and analysis of their test results have been described.

• Environmental Engineering Research
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• v.24 no.1
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• pp.91-98
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• 2019

This study was to objectify differences in the results of odor testing according to the characteristics of panel members that participate in air dilution olfactory method (ADOM) testing. When differences in the results of olfactory testing were reviewed in relation to characteristics of the panelists, the result of entire panels for the site boundary Proficiency Testing Materials (PTMs) showed no difference according to panelist sex, age, smoking status, and past participation in ADOM tests. As for the outlet PTMs, distinct differences appeared in relation to the smoking status and age of panelists. The frequency distribution for all the panelists (Dev($D/T_{total}$)) showed a form similar to a normal distribution, so it is thought to be more appropriate for the review of effect of panelist characteristics on the result of air dilution olfactory tests. In addition, the ADOM testing method implemented as the standard method for odor compounds in Korea (Dev($D/T_3$)) will have to be implemented along with a concurrent assessment, for the purpose of identifying the effect of panelist characteristics on administrative dispositions against malodors.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.69-72
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• 2008

This study is designed to understand changes in fire resistance performance of intumescent coating system through follow-up tests on temperature of unexposed surface for the domestic intumescent coating system by environmental testing procedure.

• Journal of Korean Society for Quality Management
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• v.45 no.3
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• pp.447-462
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• 2017

Purpose: This study aims to develop distributable samples that can be used for proficiency testing to verify the ability of the testing laboratory to perform high temperature and low temperature tests. Method: In this study, the temperature-resistance characteristics of the NTC thermistor were used to develop samples. The homogeneity and stability of samples were examined according to the proficiency testing requirements. Results: Thirty samples with homogeneity and stability were developed and used for the proficiency testing. Thus, it was possible to distinguish between the test laboratories that showed satisfactory results and those that did not. Conclusion: It was the first time to develop samples that can be used for proficiency testing in high temperature and low temperature tests. and it was proved that the proficiency test program can be operated using the characteristics of NTC thermistor.

• Analytical Science and Technology
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• v.23 no.3
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• pp.295-303
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• 2010

In this study, the wastewater-based reference material (RM) was prepared and certified for 7 trace metal elements with evaluation of uncertainties. The RM was distributed to 25 laboratories for the interlaboratory comparison testing. The certified values and expanded uncertainties were derived using ISO guideline 35 and the standard uncertainties for homogenieties were 0.43~2.67% of certified values. The analytical results from the interlaboratory comparison testing showed normal distributions and the robust means from the interlaboratory comparison testing were higher than the certified values of the RM for all analytes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.712-717
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• 2004

Recently, the concern for the environmental noise has increased due to the growing of the living standard. The environmental noise regulations based on the equivalent noise level are widely used. However, the noise level, which Is based mainly on the magnitude with A-weighting, the important characteristics of noises in frequency and time domains and the impulsive nature cannot be assessed properly. These can have substantial effects on how human respond to noise. Therefore, the noise evaluation methodology based on the sound quality rather than the equivalent noise level can be more suitable to represent human response to the environmental noise. This paper describes the study on environmental noise quality analysis for various noises. A cluster analysis was carried out and the noises were classified into several clusters using the values of sound quality metrics. The classification was confirmed by comparing time and frequency characteristics of the noises. And then the result of Jury testing was analysis.

• Environmental Engineering Research
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• v.21 no.1
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• pp.22-28
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• 2016

The aim of this study was to recycle the waste livestock blood as one of the waste biomass by turning proteins, the main constituent of blood, into effective biological resources like amino acid. Ultrasonic technology was applied to solubilize the proteins in the waste livestock blood. And of the multiple ultrasonic frequencies tested, 20 kHz was confirmed to yield the highest solubilization rate. The optimum pretreatment conditions were determined to be 30-min treatment at an ultrasonic irradiation density of 0.5 W/mL, which resulted in a solubilization rate of 96.01%. Also, a gel permeation chromatography (GPC) confirmed that a large amount of proteins were solubilized, and in an experiment where ultrasonic treatment was applied to kill bacteria, death rates of general bacteria and total coliforms were found to be reduced by 99.93% and 100%, respectively. Based on these results, ultrasonic technology was confirmed to be a crucial part of treating and recycling the proteins in waste livestock blood.