• Title/Summary/Keyword: Uncertainty Evaluation

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Surface Color Measurement Uncertainties

  • Hwang, Jisoo;Jeong, Ki-Lyong
    • Journal of the Optical Society of Korea
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    • v.19 no.6
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    • pp.649-657
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    • 2015
  • We present a surface color measurement including quantities of surface color, methods, and uncertainty evaluation. Based on a relation between spectral reflectance and surface color, we study how an uncertainty of spectral reflectance propagates to surface color. In analyzing the uncertainty propagation, we divide the uncertainty into uncorrelated components, fully correlated components, and correlated components with spectrally varying correlations. As an experimental example, we perform spectro-reflectometric measurements for ceramic color plates. With measured spectral reflectance and its uncertainty evaluation, we determine surface color and analyze uncertainties of the ceramic color plates.

Evaluation of Efficiency Uncertainty for Three-phase Induction Motor using Finite Element Analysis (유한요소 해석을 이용한 3상 유도전동기의 효율 불확도 평가)

  • Lee, Ho-Hyun;Park, Han-Seok;Jun, Hee-Deuk;Woo, Kyung-Il
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.4
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    • pp.163-168
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    • 2017
  • This paper presented an evaluation method for the efficiency uncertainty of a three-phase induction motor using finite element analysis. The motor efficiency in the finite element analysis is calculated by the loss separation method as in the actual test. In the process of evaluating the efficiency uncertainty, the difference between the finite element analysis and the actual test is the method of calculating the type-A / B standard uncertainty of the input quantity to estimate the efficiency and each losses. For the input quantities which can confirm the instantaneous values with respect to time, the type-A standard uncertainty in the finite element analysis is calculated from the RMS values or average values having separate periods in the steady state. And, the type-B standard uncertainty in the finite element analysis is assumed to be zero. Also, this paper compared and analyzed the efficiency uncertainty evaluated by the proposed method and the efficiency uncertainty through the actual test.

Evaluation of the Efficiency Uncertainty for an Inverter-fed Three-Phase Induction Motor (인버터 구동 3상 유도전동기의 효율 불확도 평가)

  • Lee, Ho-Hyun;Park, Han-Seok;Jun, Hee-Deuk;Kim, Dae-Kyong;Woo, Kyung-Il
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.6
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    • pp.724-729
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    • 2018
  • This paper presented an evaluation method for the efficiency uncertainty of an inverter-fed three-phase induction motor using FEM. The motor efficiency in the FEM is calculated by the IEC 60034-2-3 as in the actual test. In the process of evaluating the efficiency uncertainty, the difference between the finite element method and the actual test is the method of calculating the type-A / B standard uncertainty of the input quantity to estimate the efficiency and each losses. For the input quantities which can confirm the instantaneous values with respect to time, the type-A standard uncertainty in the FEM is calculated from the RMS values or average values having separate periods in the steady state. And, the type-B standard uncertainty in the finite element method is assumed to be zero. Also, this paper compared and analyzed the efficiency uncertainty evaluated by the proposed method and the efficiency uncertainty through the actual test.

A Nutrition Evaluation System Based on Hierarchical Fuzzy Approach

  • Son, Chang-S.;Jeong, Gu-Beom
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.8 no.2
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    • pp.87-93
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    • 2008
  • In this paper, we propose a hierarchical fuzzy based nutrition evaluation system that can analyze the individuals' nutrition status through the inference results generated by each layer. Moreover, a method to minimize the uncertainty of inference in the evaluated nutrition status is discussed. To show the effect of the uncertainty in fuzzy inference, we compared the results of nutrition evaluation with/without the certainty factor of rules on 132 people over the age of 65. From the experimental results, we can see that the evaluation method with the modified certainty factor provides better reliability than that of the general evaluation method without the certainty factor.

An evaluation of uncertainty of random effects with correlation - gravimetric preparation of standard gas - (상관관계가 있는 우연효과에 대한 불확도 평가 - 중량법에 의한 표준가스 제조 -)

  • Choi, JongOh;Kim, Yong-Doo;Kim, Dal-Ho;Kim, Jin-Seog
    • Analytical Science and Technology
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    • v.16 no.1
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    • pp.90-93
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    • 2003
  • The standard uncertainties of two different approaches using the same data set are compared and evaluated using an example of gravimetric standard gas preparation. It is shown that the correlation between input quantities should be taken into account for the proper evaluation of uncertainty resulting from random effects.

Uncertainty of Water Supply in Agricultural Reservoirs Considering the Climate Change (미래 기후변화에 따른 농업용 저수지 용수공급의 불확실성)

  • Nam, Won-Ho;Hong, Eun-Mi;Choi, Jin-Yong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.2
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    • pp.11-23
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    • 2014
  • The impact and adaption on agricultural water resources considering climate change is significant for reservoirs. The change in rainfall patterns and hydrologic factors due to climate change increases the uncertainty of agricultural water supply and demand. The quantitative evaluation method of uncertainty based on agricultural water resource management under future climate conditions is a major concern. Therefore, it is necessary to improve the vulnerability management technique for agricultural water supply based on a probabilistic and stochastic risk evaluation theory. The objective of this study was to analyse the uncertainty of water resources under future climate change using probability distribution function of water supply in agricultural reservoir and demand in irrigation district. The uncertainty of future water resources in agricultural reservoirs was estimated using the time-specific analysis of histograms and probability distributions parameter, for example the location and the scale parameter. According to the uncertainty analysis, the future agricultural water supply and demand in reservoir tends to increase the uncertainty by the low consistency of the results. Thus, it is recommended to prepare a resonable decision making on water supply strategies in terms of using climate change scenarios that reflect different future development conditions.

Uncertainty Analysis and Improvement of an Altitude TestFacility for Small Jet Engines

  • Jun, Yong-Min;Yang, In-Young;Kim, Chun-Taek;Yang, Soo-Seok;Lee, Dae-Sung
    • International Journal of Aeronautical and Space Sciences
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    • v.5 no.1
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    • pp.46-56
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    • 2004
  • The verification and improvement of the measurement uncertainty have beenperformed in the altitude test facility for small gas turbine engines, which was built atthe Korea Aerospace Research Institute (KARI) in October 1999. This test is performedwith a single spool turbojet engine at several flight conditions. This paper discussesthe evaluation and validation process for the measurement uncertainty improvements usedin the altitude test facility. The evaluation process, defined as tests before the facilitymodification, shows that the major contnbutors to the measurement uncertainty are theflow meter discharge coefficient, the inlet static and total pressures, the cell pressureand the fuel flow rate. The measurement uncertainty is focused on the primary parametersof the engine performance such as airflow rate, thrust and specific fuel consumption (SFC).The validation process, defined as tests after the facility modification, shows that themeasurement uncertainty, in seal level condition, is tmproved to the acceptable level throughthe facility modification. In altitude test conditions, the measurement uncertainties arenot improved as much as the uncertainty in sea level condition.

Measurement Uncertainty of Vibration Testing Result with Including Uncertainty of Testing Facilities (시험장비의 특성을 고려한 진동시험결과에 대한 측정불확도 추정)

  • Moon, Seok-Jun;Chung, Jung-Hoon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.7
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    • pp.781-786
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    • 2016
  • All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by a statement of the associated uncertainty. By international agreement, this uncertainty has a probabilistic basis and reflects incomplete knowledge of the quantity value. The "Guide to the Expression of Uncertainty in Measurement", commonly known as the GUM, is the definitive document on this subject. The requirements for estimation of measurement uncertainty apply to all results provided by calibration laboratories and results produced by testing laboratories under the optional circumstances. In this paper, a procedure for estimation of measurement uncertainty from vibration testing is proposed on KS F 2868:2003 as an example. Both Type A and Type B evaluation of uncertainty are considered to calculate the combined standard uncertainty and expanded uncertainty.

The evaluation of uncertainty on the high voltage measurement (고전압 측정의 불확도 평가)

  • Jeong, Joo-Young;Kim, Ik-Soo;Chul, Heo-Jong;Shin, Young-June
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1629-1630
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    • 2001
  • The high voltage measuring systems used in the testing systems shall be required to maintain the traceability to the national or international standards by the IEC 60060-2. Also all testing laboratories should prepare the documents evaluating the measurement uncertainty of the tests. By the way, this paper introduces the principal of IEC about the maintenance of traceability and evaluation methode of uncertainty.

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