• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.420-429
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• 2023

GC-MS/MS using liquid-liquid extraction (LLE) and C18 cartridges was used to identify and quantify levels of chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin and permethrin in bulk raw milk. A calibration curve spanning 10 ng/mL to 200 ng/mL was obtained with a satisfactory correlation coefficient of 0.99. The limits of detection (LOD) and limits of quantitation (LOQ) for chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin, and permethrin in the matrix ranged from 0.06 to 1.81 ng/mL and 0.19 to 6.04 ng/mL, respectively. The recoveries of 5 pesticides from spiked samples at 37.5-125 ng/mL ranged from 86.1 to 102.1%. The measurement of uncertainty of the GC-MS/MS method for these five pesticides was developed based on the analytical process and quantification. An analysis method that is easier and faster than the method specified in the Korean food standards codes for analyzing these five pesticides in raw material milk was developed. Moreover, the analytical method for chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin, and permethrin in bulk raw milk by GC-MS/MS was established.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.92-93
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• 2003

간섭계의 광원으로 현재 레이저를 주로 사용하고 있다. 이러한 간섭계용 레이저의 조건은 선폭(linewidth) 이 좁아야 하고, 중심 주파수가 안정화 되어야 한다. 특히 거리용 간섭계의 경우, 주파수 안정화되어 있는 레이저가 사용되어 측정 불확도를 낮춘다. 그러나 점차 다축을 측정하기 위한, 또는 보다 넓은 영역을 측정하기 위해서는 보다 높은 출력의 레이저를 요하고 있다. 그러나 현재의 간섭계용 레이저는 헬륨네온 레이저로서 단일 모드 기준으로 2 mW 이하의 출력을 보이고 있어서 응용 면에 있어서 제약을 받는다. (중략)

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.190.1-190.1
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• 2010

풍력자원평가를 위해 풍력단지 개발대상지의 국지풍황 대표지점에 설치하는 풍황탑(met-tower 또는 풍황마스트; met-mast)은 모노폴(monopole), 삼각단면 트러스 또는 사각단면 트러스 구조를 갖는다. 풍향계 및 풍속계는 이러한 지지구조물에 의한 풍속의 교란 또는 차폐영향을 최소화하기 위하여 긴 붐(boom)의 끝단에 설치되지만 계측기가 풍황탑의 직후방 후류영역에 놓이게 될 경우 차폐영향을 완전히 피하기는 어렵다. 저자들의 선행연구에 따르면 풍황탑 차폐영향은 평균풍력밀도의 경우 2.5% 이상의 오차를 유발할 수 있으므로 풍력자원평가 시 필히 고려되어야 할 불확도 요인인 것이다. 이에 한국에너지기술연구원에서는 풍황탑 주위의 대기유동장을 전산유동해석을 이용하여 차폐영향의 정도를 정량적으로 수치모사함으로써 이를 보정하는 기술을 개발한 바 있다(현재 특허심사 중). KIER-$ShadeFree^{TM}$는 이 특허기술을 프로그램화 한 것으로, 시범적으로 다수의 풍황탑 풍력자원 측정자료에 적용하여 상당한 보정효과에 의한 풍력자원평가의 정확도 향상효과를 볼 수 있었다.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.77-84
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• 2018

The turbine flowmeter is selected for high precision and reproducibility at the time of flow rate measurement but causes various uncertainty factors of measurement in the difference between the standard environmental condition at calibration and the environmental condition at the site. Also, a reliable interpolation method is required for use in sections other than calibrated measurement values. Therefore, in this paper, in order to improve the reliability of the flow rate measurement, we designed and manufactured a device that accurately measures the output signal of the turbine flowmeter, interpolates the value of the calibrated result value, and corrects the temperature change in real time We confirmed the reliability of the measurement at the site to carry out the performance verification.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.228-236
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• 2020

BACKGROUND: The closed chamber method is the most commonly used for measuring greenhouse gas emissions from rice fields. This method has the advantages of being simple, easily available and economical. However, a measurement result using the chamber method is an estimated value and is complete when the uncertainty is estimated. The methane emissions from a rice paddy account for the largest portion of the greenhouse gas emissions in the agriculture sectors. Although assessment of uncertainty components affecting methane emission from a rice paddy is necessary to take account of dispersion characteristics, research on these uncertainty components is very rare to date. The goal of this study was to elucidate influencing factors on measurement uncertainty of methane concentrations measured by a closed automated chamber system from a rice paddy. METHODS AND RESULTS: The methane sampling system is located in the rice paddy in Gyeonggi-do Agricultural Research and Extension Services (37°13'15"N, 127°02'22"E). The primary measurement uncertainty components influencing methane concentrations (influencing factors) investigated in this research were repeatability, reproducibility and calibration in the aspects of methane sampling and analytical instrumentation. The magnitudes of the relative standard uncertainty of each influencing factor were quantified and compared. CONCLUSION: Results of this study showed what influencing factors were more important in determination of methane concentrations measured using the chamber system and analytical instrumentation located in the monitoring site. Quantifying the measurement uncertainty of the methane concentrations in this study would contribute to improving measurement quality of methane fluxes.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.47-54
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• 2013

This paper introduces a W-band millimeter-wave power standard transfer system using the direct comparison method. The transfer system was developed to evaluate the effective efficiency and calibration factor of a W-band waveguide power sensor. The evaluation method and the measured results of the directional coupler that characterizes the calibration system are studied. The uncertainties of the standard transfer system are investigated, and the major uncertainty contributors are discussed as well. The performance of the realized W-band power standard transfer system was verified by comparing results with reference values.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.131-139
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• 2022

The aim of this study was to assess the feasibility of a landfill project to reduce greenhouse gas (GHG) from La Chureca Landfill in Managua, Nicaragua ("Project"). The feasibility study involved surveying the status and composition of waste on its way in to the landfill and projecting GHG emissions from the landfill. A projection of the GHG emissions with the IPCC model based on the survey results indicated the period 2006 to 2043 would see mean yearly GHG emissions of 290,147 ton-CO₂/year with model certainty not considered, and 217,610 ton-CO₂/year with model certainty considered. Thus, the result exceeded the corresponding median and mean values of other CDM projects implemented in Central America, even after model uncertainty was considered together with the conservative estimation of carbon capture efficiency. The similar result was produced even with an analysis of sensitivity to error factors. All the findings of the study are expected to be applicable as basic data for deciding about whether & how to proceed with the Project.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.5-7
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• 2006

In this paper, we analyzed the elements of measurement uncertainty on electrical performance test which are the most important things in photovoltaic module performance test. Repeating the performance test by 6 men, the measurement uncertainty could be calculated. In this experiment, Solar Simulator (A-Class pulse type) used for domestic certificate test of PV module is Pasan IIIb (Balval, Switzerland). The possible elements of the measurement uncertain that could effect electrical performance test of PV module are reference cell, spectrum correction, error from measurement repetition, test condition, stability and uniformity of artificial solar simulator. To find the measurement uncertainty, 6 men repeated the test by 10 times. And the results were that numerical average value was 124.44W and measurement uncertainty was $124.44W{\pm}0.75W$ with 95% confidence level for 125W PV module.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.67-68
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• 2008

전력량의 증가로 인한 대전류 측정의 요구와 전력 시스템의 디지털화에 부응하여 대전류 국가 표준 시스템의 측정 범위의 확장 및 전자식 전류변성기의 평가를 위해 구축된 40 kA급 전류변성기 비교 측정 시스템과 전자식 변성기 평가 시스템을 소개하였다. 또한 전자시변성기 평가시스템의 핵심 장비인 전압-전류 변환기에 대한 비오차 및 위상오차를 평가하였고, $200A{\sim}40kA$ 까지의 로고스키 코일을 평가하였다. 마지막으로 로고스키 코일 평가시의 불화도 요인으로 1차 코일의 위치, 대전류 발생 변압기와의 거리에 따른 측정 불확도를 평가하였다.

• Economic and Environmental Geology
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• v.36 no.3
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• pp.191-200
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• 2003

Investigations on the contaminated lands due to heavy metals from mining activities or hydrocarbons from oil spillage for example, should be planned based on specific fitness-for-purpose criteria(FFP criteria). A FFP criterion is site specific or varies with situation, based on which not only the data quality but also the decision quality can be determined. The limiting factors on the qualities can be, for example, the total budget for the investigation, regulatory guidance or expert's subjective fitness-for-purpose criterion. This paper deals with planning of investigation methods that can satisfy each suggested FFP criterion based on economic factors and the data quality. To this aim, a probabilistic loss function was applied to derive the cost effective investigation method that balances the measurement uncertainty, which estimates the degree of the data quality, with the decision quality. In addition, investigation planning methods when the objectives of investigations do not lie in the classification of the land but simply in producing the estimation of the mean concentration of the contaminant at the site(e.g. for the use in risk assessment), were also suggested. Furthermore, the efficient allocation of resources between sampling and analysis was also devised. These methods were applied to the two contaminated sites in the UK to test the validity of each method.