• 제목/요약/키워드: Test uncertainty

검색결과 784건 처리시간 0.023초

국내 콘크리트 표면차수벽형 석괴댐(CFRD) 사력존의 전단파 속도 분포 결정(II): 물성치의 공간 변동성에 의한 불확실성이 고려된 CFRD 사력존의 1차원 전단파 속도 주상도의 결정 (Determination of Representative Shear Wave Velocity Profile for Rockfill Zone of CFRD Considering Uncertainty Caused by Spatial Variation of Material Property)

  • 황혜진;박형춘
    • 한국지반공학회논문집
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    • 제30권5호
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    • pp.17-24
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    • 2014
  • 본 논문에서는 국내 CFRD 사력존을 위한 1차원 전단파 속도 분포를 제안하였다. 이를 위해 선정된 3개의 댐 사면 8곳에서 수행된 표면파 시험 결과를 사용하였다. 다양한 원인에 의해 존재 가능한 사력존 물성치 공간 변동성에 의한 표면파 시험 결과의 불확실성을 고려하고자 시험에서 얻어진 개별 주상도들을 하모닉 웨이브릿 변환을 통해 공간-파수 영역에서 분석하였다. 이를 통해 전단파 속도 주상도에 존재하는 불확실성을 평가하였다. 논문에서 제안된 방법을 통해 사력존에 존재 가능한 1차원 전단파 속도 분포들을 생성하였으며, 생성된 1차원 전단파 속도 분포들을 사용하여 물성치 공간 변동성에 의한 불확실성이 고려된 국내 CFRD 사력존의 1차원 전단파 속도 분포를 결정하였다.

예인수조용 스테레오스코픽 입자영상유속계 시스템의 불확실성 해석 (Uncertainty Assessment of a Towed Underwater Stereoscopic PIV System)

  • 서정화;설동명;한범우;유극상;임태구;박성택;이신형
    • 대한조선학회논문집
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    • 제51권4호
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    • pp.311-320
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    • 2014
  • Test uncertainty of a towed underwater Stereoscopic Particle Image Velocimetry (SPIV) system was assessed in a towing tank. To estimate the systematic error and random error of mean velocity and turbulence properties measurement, velocity field of uniform flow was measured. Total uncertainty of the axial component of mean velocity was 1.45% of the uniform flow speed and total uncertainty of turbulence properties was 3.03%. Besides, variation of particle displacement was applied to identify the change of error distribution. In results for variation of particle displacement, the error rapidly increases with particle movement under one pixel. In addition, a nominal wake of a model ship was measured and compared with existing experimental data by five-hole Pitot tubes, Pitot-static tube, and hot wire anemometer. For mean velocity, small local vortex was identified with high spatial resolution of SPIV, but has serious disagreement in local maxima of turbulence properties due to limited sampling rate.

2개의 기준유량계를 이용한 유량계 교정장치의 측정불확도 평가에 관한 연구 (A Study on the Uncertainty Estimation of Flowmeter Calibrator with Two Master Flowmeters)

  • 최종오;이완규;임기원
    • 대한기계학회논문집B
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    • 제28권10호
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    • pp.1219-1230
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    • 2004
  • Comparing to the gravimetric and volumetric method, the flowmeter calibration based on the master meter method is relatively economical and convenient, especially for high flowrate. The uncertainty of flow quantity and flowrate using the master meter method was evaluated according to the GUM (Guide to the Expression of Uncertainty in Measurement). In order to apply for the wider flow range, two master meters (electromagnetic flow meter) were employed as reference flowmeters. The uncertainty of the master meter was obtained by combining the statistical variation of the repeated measurements and the variation of fluid density and pipe material due to temperature and pressure changes were scrutinized. for a practical application, the uncertainty of calibrator, whose measuring capacity of 1000 ㎥/h obtained by employing two 500 ㎥/h electromagnetic How meters, was evaluated. The uncertainty budget shows the quantitative contribution of each uncertainty component to the overall uncertainty of the calibrator. As a result, it was found that the dominant uncertainties were from the master meter, which was evaluated statistically, and from the process of least squares fitting. On the contrary, the uncertainties arising from the variation of the fluid density and the pipe volume due to the temperature and pressure were negligible.

허리 척추수술환자의 수술 후 불확실성에 미치는 영향요인 (Factors Affecting Post-operative Uncertainty of the Patients Undergone Lumbar Spinal Surgery)

  • 전명희;정지영;김민숙
    • 근관절건강학회지
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    • 제19권3호
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    • pp.294-307
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    • 2012
  • Purpose: The purpose of this study is to identify main factors affecting patients' uncertainty following lumbar spinal surgery. Methods: A survey was conducted of a sample 155 post -operative patients in April to June 2010. Uncertainty and knowledge about self-care after spinal surgery and the back pain evaluation were measured. Data were analyzed with t-test, ANOVA, Pearson correlation, and multiple regressions. Results: The mean score of uncertainty level was $27.66{\pm}6.32$. Levels of uncertainty were different by age, gender, educational level, pain duration, and number of types of pain. Uncertainty was positively correlated with knowledge of post-op self-care, back pain, and mental health. The results of multiple regression indicated that knowledge of post-op self-care and mental health were significant predictors with 35.1% of the variance in uncertainty. Conclusion: A program including post-operative self-care education and mental health promotion is required to reduce uncertainty of patients with lumbar spinal surgery.

재관수 실증실험과 TRACE 코드를 활용한 모델 변수의 불확실도 정량화 (Uncertainty Quantification of Model Parameters Using Reflood Experiments and TRACE Code)

  • 유선오;이경원
    • 한국압력기기공학회 논문집
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    • 제20권1호
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    • pp.32-38
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    • 2024
  • The best estimate plus uncertainty methodologies for loss-of-coolant accident analyses make use of the best-estimate codes and relevant experimental databases. Inherently, best-estimate codes have various uncertainties in the model parameters, which can be quantified by the dedicated experimental database. Therefore, this study was devoted to establishing procedures for identifying the input parameters of predictive models and quantifying their uncertainty ranges. The rod bundle heat transfer experiments were employed as a representative reflood separate effect test, and the TRACE code was utilized as a best-estimate code. In accordance with the present procedure for uncertainty quantification, the integrated list of the influential input parameters and their uncertainty ranges was obtained through local sensitivity calculations and screening criteria. The validity of the procedure was confirmed by applying it to uncertainty analyses, which checks whether the measured data are within computed ranges of the variables of interest. The uncertainty quantification procedure proposed in this study is anticipated to provide comprehensive guidance for the conduct of uncertainty analyses.

인공 고관절 수술 환자에서 지지간호중재가 고관절 기능, 불안 및 불확실성에 미치는 효과 (Effects of Supportive Nursing Care Program on Hip Function, Anxiety and Uncertainty for Patients with Total Hip Arthroplasty)

  • 김선화;이혜진
    • 임상간호연구
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    • 제19권3호
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    • pp.419-431
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    • 2013
  • Purpose: This study was to evaluate the effect of supportive nursing care program for patients with total hip arthroplasty. Methods: Forty-two patients with total hip arthroplasty were enrolled in this study from September, 20, 2011 to January, 3, 2012. The participants were assigned to one of two groups: Twenty-six subjects in the experimental group were provided with supportive nursing care program which comprised of 6 nurse visits pre and post operation and 4 follow-up phone calls after discharge. Another 26 subjects received conventional nursing care program as a control group. Hip function, anxiety, and uncertainty were evaluated before the intervention, and 5 weeks after completion of the intervention. The analysis included descriptive statistics, Chi-square test, and t-test by SPSS 18.0. Results: Hip function was significantly increased in the experimental group (t=-3.31, p<.002). Anxiety and uncertainty group was significantly lower in the experimental group (t=7.12, p<.001 and t=4.66, p<.001). Conclusion: The results of this study indicate that the supportive care intervention for patients receiving total hip arthroplasty could be utilized as a nursing intervention to improve hip function and to reduce anxiety and uncertainty of patients receiving total hip arthroplasty.

UNCERTAINTY ANALYSIS OF DATA-BASED MODELS FOR ESTIMATING COLLAPSE MOMENTS OF WALL-THINNED PIPE BENDS AND ELBOWS

  • Kim, Dong-Su;Kim, Ju-Hyun;Na, Man-Gyun;Kim, Jin-Weon
    • Nuclear Engineering and Technology
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    • 제44권3호
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    • pp.323-330
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    • 2012
  • The development of data-based models requires uncertainty analysis to explain the accuracy of their predictions. In this paper, an uncertainty analysis of the support vector regression (SVR) model, which is a data-based model, was performed because previous research showed that the SVR method accurately estimates the collapse moments of wall-thinned pipe bends and elbows. The uncertainty analysis method used in this study was an analytic uncertainty analysis method, and estimates with a 95% confidence interval were obtained for 370 test data points. From the results, the prediction interval (PI) was very narrow, which means that the predicted values are quite accurate. Therefore, the proposed SVR method can be used effectively to assess and validate the integrity of the wall-thinned pipe bends and elbows.

The Precautionary Behavior of Korean Households under Health Uncertainty

  • Kong, Moon-Kee;Lee, Hoe-Kyung
    • 한국지능정보시스템학회:학술대회논문집
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    • 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
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    • pp.325-329
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    • 2001
  • This paper tests existence of precautionary saving motive under health uncertainty, using household level panel data from Korea. For this purpose, this paper considers a dynamic health capital model with health uncertainty and derives testable equations for changes in consumption and medical expenditures. Under this framework, households who face future health uncertainty will exhibit precautionary behavior by depressing consumption or increasing investment in health. To test this hypothesis, the paper uses the conditional variance of health as the direct measure of health uncertainty, obtained by estimating a multinomial logit model. Empirical results using the Korean Household Panel Study (KHPS, 1993 - 1997) suggest that Korean elderly households follow the precautionary behavior to insure against future health risk.

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고체재료의 유전율 측정용 Cell의 불확도 분석과 보상 (Uncertainty Analysis and Compensation of the Cell for Permittivity Measurement of Solid Materials)

  • 김한준;유광민;강전홍;한상옥
    • 한국전기전자재료학회논문지
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    • 제21권1호
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    • pp.53-56
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    • 2008
  • The commercial parallel plate electrodes system with guard-ring electrode have been widely used for measurement of dielectric constants of solid materials. And the specification of the electrodes system is about 1 % of measurement uncertainty. This measurement uncertainty is only estimated the error come from mechanical measurements such as the area of the electrodes and the gap between the electrodes except the error come from the air gap between the electrodes and dielectric specimen. Because it is impossible to measure the air gap. This study analyze the total measurement uncertainties of the commercial dielectric constant test cell using 3 kinds of Standard Reference Materials. As a results, the total measurement uncertainty is much bigger than 1 % and the most of the uncertainty can be reduced by compensation of the error values evaluated in this study.

입원 환아 어머니의 부모 역할 효능감 영향 요인: 질병에 대한 불확실성, 간호 교육 요구도 (The Contribution of Competence in Parenting: Uncertainty related Children's Diseases, and Nursing Educational Need)

  • 남현아;이화진;김미옥
    • 부모자녀건강학회지
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    • 제17권1호
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    • pp.29-36
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    • 2014
  • Purpose: Competence in parenting helps the parent to recognize the ability to resolve problems arising to children, allowing positive interactions with children through desirable child-rasing behavior and smooth communication with children. This study aims to identify the contribution of uncertainty and educational needs to the competence in parenting. Methods: Total 159 mothers responded a questionnaire developed to measure uncertainty, educational needs, and competence in parenting. t-test, ANOVA, and stepwise multiple regression with the SPSS program were used to analyze the data. Results: We found that uncertainty, nursing educational need, and mothers' age had influence to the competence in parenting. Conclusion: Nursing interventions provided to the mothers of hospitalized children for better parental competence need to include programs for alleviating uncertainty and satisfying the need for nursing education.

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