• 대한안전경영과학회지
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• 제9권1호
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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.

• 지역사회간호학회지
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• 제13권2호
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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.

• 한국산림과학회지
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• 제100권2호
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• pp.149-153
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• 2011

본 연구는 리기다소나무림의 줄기밀도와 바이오매스 확장계수에 대한 불확실성을 평가하고자 하였다. 총 57본의 표본목을 벌채하였으며, 리기다소나무 20년생 이하의 유령임분과 21년생 이상의 성숙임분을 구분하여 t-검정을 실시한 결과, 줄기밀도는 영급별 차이가 나타나지 않는 반면(p=0.8070), 바이오매스 확장계수는 영급별 차이가 나타났다(p=0.0001). IPCC(Intergovernmental Panel on Climate Change)에서 제시한 불확실성 평가 방법을 이용하여 줄기밀도에 대한 불확실성을 평가한 결과, 20년생 이하에서 30.92%, 21년생 이상에서 25.12%으로 나타났으며, 바이오매스 확장계수에 대한 불확실성은 20년생 이하에서 60.32%, 21년생 이상에서 22.42%으로 나타났다. 줄기밀도의 불확실성은 영급별로 약 5.8%의 차이를 나타낸 반면, 바이오매스 확장계수의 불확실성은 20년생 이하가 21년생 이상 보다 약 37.9%로 매우 높은 것으로 나타났다. 즉, 성숙임분은 불확실성이 상대적으로 작게 나타났으며, 반면에 유령임분은 높게 나타났다. 따라서 줄기밀도와 바이오매스 확장계수를 사용할 경우, 20년생 이하의 영급과 21년생 이상의 영급을 구분하여 줄기밀도와 바이오매스 확장계수를 적용하여야 할 것으로 사료된다.

• Geomechanics and Engineering
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• 제11권2호
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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.

• 한국산학기술학회논문지
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• 제21권9호
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• pp.338-344
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• 2020

불확실성에 대한 인내력 부족은 범불안장애 등 다양한 정신질환과 관련이 있는 것으로 알려져 있다. 하지만 이를 측정하는 척도(IUS: Intolerance of Uncertainty Scale, 이하 IUS)는 여러 연구에서 요인 구조가 다르게 나타나는 바, 본 연구에서는 IUS의 구인 타당도를 검증하고 요인 구조를 명확하게 하고자 하였다. 이를 위해 대학생 533명을 대상으로 자료를 수집하였고, 이 중 임의로 추출한 260명의 자료를 대상으로 탐색적 요인 분석한 결과, 3문항으로 구성된 전향적 요인과 5문항으로 구성된 억제적 요인의 2요인 구조가 적합한 것으로 나타났다. 또한 나머지 273명의 자료를 대상으로 확인적 요인분석과 상관 분석을 한 결과, 8문항 2요인의 구조모형의 적합도가 선행 연구에서 제시한 모형들에 비해 우수하게 나타났다(x²=37.699, TLI=0.951, CFI=0.969, RMSEA=.063, SRMR=.039). 아울러 걱정 및 불안, 우울 관련 측정 도구들과 유의미한 정적 상관을 보였다. 본 연구는 IUS의 구인 타당도를 검증하여 전향적 요인과 억제적 요인으로 구성됨을 확인하고, IUS-08를 제안하여 보다 정확하고 간략한 척도를 개발하였다는 점에서 의의가 있겠다.

• Nuclear Engineering and Technology
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• 제52권4호
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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.

• 산업융합연구
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• 제20권2호
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• pp.11-19
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• 2022

본 연구에서는 국내 주식시장에서 경제적 불확실성이 주식가격 결정에 어떠한 역할을 하는지 살펴보았다. 이를 위해 2000년 1월부터 2017년까지 우리나라의 비금융기업을 대상으로 국내외(미국, 중국)의 경제적 불확실성 지표와 주식수익률의 관련성을 분석하였다. 분석모형은 Fama and French(1992)의 3요인 모형과 모멘텀, 유동성을 포함한 5요인모형을 이용하였다. 분석결과 경제적 불확실성의 베타가 낮은 포트폴리오보다 높은 포트폴리오의 주식수익률이 높게 나타났다. 이는 미국의 분석 결과와도 동일하였다. 또한 한국의 경제적 불확실성 지수를 통한 분석 회귀분석 결과보다 미국의 불확실성 지수를 이용한 분석 결과가 더욱 유의하게 나타났다.

• Corrosion Science and Technology
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• 제8권5호
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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.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1990년도 춘계공동학술대회논문집; 한국과학기술원; 28 Apr. 1990
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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.

• 한국기후변화학회지
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• 제5권3호
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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).