• 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.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.2
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• pp.199-206
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• 2013

In general, radial velocity of a target can be obtained by acquiring doppler frequency shift in case of a doppler radar, or can be obtained by acquiring range rate in case of a pulse radar. Then radial velocity can be converted to tangential velocity using aspect angle or position variation per unit time. These two ways have the same meaning in physically, but result in different uncertainty finally. In this paper, it is described not only the two transformation procedures to calculate tangential velocity from radar measurement data, but also the result of combined uncertainty comparison between these two procedures.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.3
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• pp.270-276
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• 2014

This survey paper reviews robust control problems in both frequency domain and time domain. Robust control is focused on model uncertainties such as modeling error, system parameter variations, and disturbances. Robust control design problems are discussed according to parameter uncertainty, polytopic uncertainty, and norm-bounded uncertainty. Nowadays, robust control theory is combined with various control theory such as model predictive control, adaptive control, intelligent control, and time delay control.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.797-802
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• 2013

In this paper, using the mass/CG measurement equipment and the MOI measurement equipment developed in-house, Pitch MOI and Roll MOI of test specimen were measured and measurement uncertainties on MOI were studied. The possible factors of the measurement uncertainty that could affect accuracy of MOI measurement were mass, spring, frequency, and length measurement-related elements. The each combined standard uncertainty of pitch MOI and roll MOI was estimated from the uncertainties of the above various factors.

• Journal of the Korean Solar Energy Society
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• v.36 no.4
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• pp.11-20
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• 2016

For accurate wind resource assessment and wind turbine performance test, it is essential to secure wind data covering a rotor plane of wind turbine including a hub height. In general, we can depict wind speed profile by extrapolating or interpolating the wind speed data measured from a meteorological tower where multiple anemometers are mounted at different heights using a power-law of wind speed profile. The most important parameter of a power-law equation is a vertical wind profile exponent which represents local characteristics of terrain and land cover. In this study, we calculated diurnal vertical wind profile exponents of 8 locations in Jeju Island who possesses excellent wind resource according to the GUM (Guide to the Expression of Uncertainty in Measurement) to evaluate its uncertainty. Expanded uncertainty is calculated by combined standard uncertainty, which is the result of composing type A standard uncertainty with type B standard uncertainty. Although pooled standard deviation should be considered to derive type A uncertainty, we used the standard deviation of vertical wind profile exponent of each day avoiding the difficult of uncertainty evaluation of diurnal wind profile variation. It is anticipated that the evaluated uncertainties of diurnal vertical wind profile exponents at 8 locations in Jeju Island are to be registered as a national standard reference data and widely used in the relevant areas.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.606-608
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• 1999

Mutual Recognition Agreement(MRA) between national metrology institutes is started on October 1999 and International Key Comparison is essentially to be used as technical basis for the agreement. High resistance is one of the Key Comparison and high resistance measurement system is established in KRISS for the purpose of the Key Comparison. Total combined uncertainty of the system is about 4ppm in $10M{\Omega}$ and 8ppm in $1G{\Omega}$. With the system, the difference of comparison results for $10M{\Omega}$ and $1G{\Omega}$ among KRISS, VNIIM in Russia and NIM in China is agreed about 6ppm within total combined uncertainty of three institutes.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.859-861
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• 1996

This paper presents the novel fault diagnostic expert system based on dissolved gas analysis(DGA) techniques in power transformer. The uncertainty of key gas analysis, norm threshold, and gas ratio boundaries are managed by using a fuzzy set concept. The uncertainty of rules are handled by fuzzy measures. Trend analysis through the monthly increment of key gas and DGA analysis are combined by the Dempster-Shafer theory, and the state of transformer and confidence factor are yielded by using this combined analysis. To verify the effectiveness of the proposed diagnosis technique, the expert system has been tested by using KEPCO's transformer gas records.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.563-572
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• 2007

Transportation infrastructure is critical to economic growth of a country such as China. Careful evaluation of investments in traffic infrastructure projects is therefore pertinent. As traditional evaluation methods do not consider the uncertainty of future cash flows and mobility during project execution, the real option approach is gradually gaining recognition in the context of valuing construction and infrastructure projects. However, many of the cases only evaluate individual options separately although multiple options often exist in a typical large infrastructure project. Using a highway project in China as a case study, this paper first evaluates a deferment option and a growth option embedded in the project. Subsequently, the values are combined using the fuzzy analytical hierarchy process. It is found that the combined value is less than the sum of the two option values. This finding is consistent with the theoretical observations given in past real option literature despite the use of a different approach.

• Journal of Korea Water Resources Association
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• v.38 no.12 s.161
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• pp.1051-1060
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• 2005

The present study analyzes hydrologic utilization of optimal radar-derived rainfall by using semi-distributed TOPMODEL and evaluates the impacts of radar rainfall and model parametric uncertainty on a hydrologic model. Monte Carlo technique is used to produce the flow ensembles. The simulated flows from the corrected radar rainfalls with real-time bias adjustment scheme are well agreed to observed flows during 22-26 July 2003. It is shown that radar-derived rainfall is useful for simulating streamflow on a basin scale. These results are diagnose with which radar-rainfall Input and parametric uncertainty influence the character of the flow simulation uncertainty. The main conclusions for this uncertainty analysis are that the radar input uncertainty is less influent than the parametric one, and combined uncertainty with radar and Parametric input can be included the highest uncertainty on a streamflow simulation.

• Fire Science and Engineering
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• v.26 no.1
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• pp.16-22
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• 2012

In fire test, accurate heat release rate measurements provide important information to define the fire safety characteristics of products. The calculation of heat release rate depends on the errors of measuring parameters in experimental set-up. In this study, the uncertainty factors of heat release rate in the room corner test facility, which is installed at Korea Railroad Research Institute, were analyzed. Through the fire testings for the KTX interior materials, the uncertainties of heat release rate were calculated. Results showed that uncertainty was high in the initial stage of fire test and gradually decreased with the growth of fire. The oxygen concentration was a major factor contributing to the combined relative standard uncertainty.