• Journal of the Korea Safety Management & Science
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• v.9 no.1
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• pp.145-156
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• 2007

This paper is to propose model classification and evaluation of measurement uncertainty. In order to obtain type A and B uncertainty, variety of measurement mathematical models are illustrated by example. The four steps to evaluate expanded uncertainty are indicated as following; First, to get type A standard uncertainty, measurement mathematical models of single, double, multiple, design of experiment and serial autocorrelation are shown. Second, to solve type B standard uncertainty measurement mathematical models of empirical probability distributions and multivariate are presented. Third, type A and B combined uncertainty, considering sensitivity coefficient, linearity and correlation are discussed. Lastly, expanded uncertainty, considering degree of freedom for type A, B uncertainty and coverage factor are presented with uncertainty budget. SPC control chart to control expanded uncertainty is shown.

• Research in Community and Public Health Nursing
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• v.13 no.2
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• pp.249-259
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• 2002

Objectives: This study was conducted to investigate the effects of mastery on appraisal of uncertainty in women patients with rheumatoid arthritis. Methods : The study subjects consisted of 168 patients who were recruited from the outpatient clinic of a rheumatic center in Seoul. Self report questionnaires were used to measure the study variables that included uncertainty, mastery, danger appraisal of uncertainty, and opportunity appraisal of uncertainty. Cronbach's alpha reliabilities of these instruments ranged from .72 to .93. For data analysis. the SPSSWIN 10.0 program was utilized to exam descriptive statistics. Pearson's correlation. and regression analysis. Results: The results were as follows.: 1) The uncertainty scores of the subjects ranged from 33 to 87 with the mean score of 63.27. 2) The mastery scores of the subjects ranged from 10 to 27 with a mean score of 18.70. 3) The danger appraisal of uncertainty scores of the subjects ranged from 8 to 32 with a mean score of 20.22. 4) The opportunity appraisal of uncertainty scores of the subjects ranged from 7 to 28 with a mean score of 17.80. 5) Significant factors that explained the danger appraisal of uncertainty were mastery (=-.444. p<.001), and education level (=-.184. p<.05). 6) Significant factor that explained the opportunity appraisal of uncertainty was level of uncertainty (=-.328. p<.001). Conclusion: Among the independent variables. the most significant factor that explained the danger appraisal of uncertainty in the women patients with rheumatoid arthritis was mastery. Therefore, a nursing intervention with strategies to improve sense of mastery should be developed for women patients with rheumatoid arthritis.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.149-153
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• 2011

This study was conducted to examine the uncertainty analysis of the stem density and biomass expansion factor for Pinus rigida in Korea. A total of 57 representative sample trees were harvested. The age class in Pinus rigida forests was divided into two, which were stands with less than 20 years and more than 21 years. The influence of stand ages on biomass expansion factor showed that it was statistically significant (p=0.0001), but it was not significant on stem density (p=0.8070). The results of this study based on the uncertainty evaluation method which were suggested by IPCC guide line indicated that stem density of the stand with less than 20 years were 30.92%, while were 25.12% the stands with more than 21years. The uncertainty in biomass expansion factor of less than 20 years and more than 21 years were 60.32% and 22.42%, respectively. The uncertainty of less than 20 years was higher compared to those stands with more than 21 years. In the case of old stand, it showed the lowest uncertainty results but younger stands showed the highest uncertainty results. This study could be applied to our country's emission factor by using stem density and biomass expansion factors which were less than 20 years and more than 21 years for Pinus rigida in Korea.

• Geomechanics and Engineering
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• v.11 no.2
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• pp.211-234
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• 2016

A total of 99 full-scale field load tests at 22 sites were compiled for this study to elucidate several issues related to the load-displacement behaviour of belled piers under axial uplift loading, including (1) interpretation criteria to define various elastic, inelastic, and "failure" states for each load test from the load-displacement curve; (2) generalized correlations among these states and determinations to the predicted ultimate uplift resistances; (3) uncertainty in the resistance model factor statistics required for reliability-based ultimate limit state (ULS) design; (4) uncertainty associated with the normalized load-displacement curves and the resulting model factor statistics required for reliability-based serviceability limit state (SLS) design; and (5) variations of the combined ULS and SLS model factor statistics for reliability-based limit state designs. The approaches discussed in this study are practical and grounded realistically on the load tests of belled piers with minimal assumptions. The results on the characterization and uncertainty of uplift load-displacement behaviour of belled piers could be served as to extend the early contributions for reliability-based ULS and SLS designs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.338-344
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• 2020

Intolerance of Uncertainty is associated with numerous psychopathologies, including generalized anxiety disorders. However, several studies differ in the factor structures applicable for the Intolerance of Uncertainty Scale (IUS), and there exists a debate regarding the factorial and construct validity. Thus, in the current study, the IUS was newly translated to explore and verify the structures and factors relative to the cultural background of Korea. The study involved an exploratory factor analysis of randomly extracted data from 260 of 533 adults selected. Results determined that a prospective factor of 3 items and inhibitory factor of 5 items was appropriate. In addition, a confirmatory factor analysis and correlation analysis of the remaining 273 data revealed that a structural model comprising of the 8-items two factors model was well suited (x²=37.699, TLI=0.951, CFI=0.969, RMSEA=0.063, SRMR=0.039), and showed significant static correlation with worry, depression, and state-trait anxiety.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.755-763
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• 2020

The critical flow phenomenon has been studied because of its significant effect for design basis accidents in nuclear power plants. Transition points from thermal non-equilibrium to equilibrium are different according to the geometric effect on the critical flow. This study evaluates the uncertainty parameters of the critical flow model for analysis of DBA (Design Basis Accident) with the MARS-KS (Multi-dimensional Analysis for Reactor Safety-KINS Standard) code used as an independent regulatory assessment. The uncertainty of the critical flow model is represented by three parameters including the thermal non-equilibrium factor, discharge coefficient, and length to diameter (L/D) ratio, and their ranges are determined using large-scale Marviken test data. The uncertainty range of the thermal non-equilibrium factor is updated by the MCDA (Model Calibration through Data Assimilation) method. The updated uncertainty range is confirmed using an LBLOCA (Large Break Loss of Coolant Accident) experiment in the LOFT (Loss of Fluid Test) facility. The uncertainty ranges are also used to calculate an LBLOCA of the APR (Advanced Power Reactor) 1400 NPP (Nuclear Power Plants), focusing on the effect of the PCT (Peak Cladding Temperature). The results reveal that break flow is strongly dependent on the degree of the thermal non-equilibrium state in a ruptured pipe with a small L/D ratio. Moreover, this study provides the method to handle the thermal non-equilibrium factor, discharge coefficient, and length to diameter (L/D) ratio in the system code.

• Journal of Industrial Convergence
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• v.20 no.2
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• pp.11-19
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• 2022

This study examines the role of economic uncertainty in stock price determination in the domestic stock market. To this end, we analyzed the relationship between economic uncertainty indices at home and abroad (USA, China) and stock returns for non-financial companies in Korea from January 2000 to 2017. For the analysis model, the 3-factor model of Fama and French (1992) and the 5-factor model including momentum and liquidity were used. As a result of the analysis, a portfolio with a high beta of economic uncertainty showed higher stock returns than a portfolio with a low beta. This was the same as the US analysis result. Also, the analysis results using the US uncertainty index were more significant than the regression analysis results using the Korean economic uncertainty index.

• Corrosion Science and Technology
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• v.8 no.5
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• pp.193-196
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• 2009

For the estimation of uncertainty in potentiodynamic polarization resistance measurement, the type A uncertainty was measured using type 316 stainless steel in an acidified NaCl solution. Sensitivity coefficients were determined for measurand such as scan rate of potential, temperature of solution, concentration of NaCl, concentration of HCl, surface roughness of specimen and flow rate of purging gas. Sensitivity coefficients were large for the measurand such as the scan rate of potential, temperature of solution and roughness of specimen. However, the sensitivity coefficients were not the major factors influencing the combined standard uncertainty of polarization resistance due to the low values of uncertainty in measurements of the measurands. A major influencing factor was the concentration of NaCl. The value of type A uncertainty was 1.1 times the value of type B uncertainty, and the combined standard uncertainty was 10.5 % of the average value of polarization resistance.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.272-288
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• 1990

The uncertainty quantification process in probabilistic Risk Assessment usually involves a specification of the uncertainty in the input data and the propagation of this uncertainty to the final risk results. The distributional sensitivity analysis is to study the impact of the various assumptions made during the quantification of input parameter uncertainties on the final output uncertainty. The uncertainty importance of input parameters, in this case, should reflect the degree of changes in the whole output distribution and not just in a point estimate value. A measure of the uncertainty importance is proposed in the present paper. The measure is called the distributional sensitivity measure(DSM) and explicitly derived from the definition of the Kullback's discrimination information. The DSM is applied to three typical discrimination information. The DSM is applied to three typical cases of input distributional changes: 1) Uncertainty is completely eliminated, 2) Uncertainty range is increased by a factor of 10, and 3) Type of distribution is changed. For all three cases of application, the DSM-based importance ranking agrees very well with the observed changes of output distribution while other statistical parameters are shown to be insensitive.

• Journal of Climate Change Research
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• v.5 no.3
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• pp.199-208
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• 2014

According to "IPCC guide line for national greenhouse gas inventories" each country should develop the 'Country-specific emission factor' and apply it to estimate greenhouse gases emissions from landfill. It could reflect properties of country and make estimation more accurate. For that accuracy, developed country-specific emission factor should be assessed and be verified consistently. Developed emission factors should be assessed in terms of Representative, Emission Property, Accuracy and Uncertainty, but there is no study about weighted assessment factors under each emission variable. This study do survey targeting public officials, professors and other experts for Analytical Hierarchy Process(AHP), mostly use to make decisions, to weight assessment factors. We investigated the weighted values per Emission factor for Representative, Emission property, Accuracy and Uncertainty on AHP survey, and Representative factor was the highest, and then in the order of Emission property (0.26), Accuracy(0.22), Uncertainty (0.15).