• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.8
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• pp.107-114
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• 2003

The effect of uncertainties caused by measured parameters, which are propagated to the uncertainty of total-to-total efficiency, are analyzed from a turbine performance test. The degree of reaction is 0.373 at the mean radius on a tested 3-D axial type turbine, and the performance test is conducted at the low pressure and cold temperature status. The uncertainty of turbine inlet and exit total pressure shows the strong propagation effect to the uncertainty of total-to-total efficiency. This means that a high precision pressure measuring system is required to reduce the uncertainty propagated by the pressure. In the uncertainty portion of each measured parameters to the uncertainty of total- to-total efficiency, the uncertainty by torque is the highest and the uncertainty by RPM is the lowest. In case of the total pressure, the effect of the uncertainty by torque is increased with the increasing RPM. The uncertainty of total pressure at the turbine exit is more important than that at the turbine exit.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.123-126
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• 2003

The uncertainties generated by measurement parameters are propagated to the uncertainty of total-to-total efficiency on an experiment. The effect of uncertainties’ propagation are analyzed through a turbine performance test. A tested 3-D axial type turbine has a 0.373 degree of reaction at the mean radius and the performance test is conducted at the low pressure and cold temperature status. The uncertainty of turbine inlet and exit total pressure shows the strong propagation effect to the uncertainty of total-to-total efficiency. This means that a high precision pressure measuring system is required to reduce the uncertainty propagated by the pressure. In the uncertainty portion of each measurement parameters to the uncertainty of total-to-total efficiency, the uncertainty by torque is the highest and the uncertainty by RPM is the lowest. In case of the total pressure, the effect of the uncertainty by torque is increased with the increasing RPM. The uncertainty of total pressure at the turbine exit shows more influence to the results than that at the turbine.

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1079-1089
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• 2018

The majority of existing studies for quantifying uncertainties in climate change impact assessments suggest only the uncertainties of each stage, and not the total uncertainty and its propagation in the whole procedure. Therefore, this study has proposed a new method, the Uncertainty Delta Method (UDM), which can quantify uncertainties using the variances of projections (as the UDM is derived from the first-order Taylor series expansion), to allow for a comprehensive quantification of uncertainty at each stage and also to provide the levels of uncertainty propagation, as follows: total uncertainty, the level of uncertainty increase at each stage, and the percentage of uncertainty at each stage. For quantifying uncertainties at each stage as well as the total uncertainty, all the stages - two emission scenarios (ES), three Global Climate Models (GCMs), two downscaling techniques, and two hydrological models - of the climate change assessment for water resources are conducted. The total uncertainty took 5.45, and the ESs had the largest uncertainty (4.45). Additionally, uncertainties are propagated stage by stage because of their gradual increase: 5.45 in total uncertainty consisted of 4.45 in emission scenarios, 0.45 in climate models, 0.27 in downscaling techniques, and 0.28 in hydrological models. These results indicate the projection of future water resources can be very different depending on which emission scenarios are selected. Moreover, using Fractional Uncertainty Method (FUM) by Hawkins and Sutton (2009), the major uncertainty contributor (emission scenario: FUM uncertainty 0.52) matched with the results of UDM. Therefore, the UDM proposed by this study can support comprehension and appropriate analysis of the uncertainty surrounding the climate change impact assessment, and make possible a better understanding of the water resources projection for future climate change.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.1
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• pp.45-52
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• 2001

This study was carried out to evaluate the uncertainty in the analysis of total alkaloids and reducing sugar content in flue-cured tobacco. The sources of uncertainty associated with the analysis of total alkaloids and reducing sugar were the weighing of sample, the preparation of extracting solution, the addition of extracting solution into the sample, the preparation of standard solution, the precision of calibration curve for standard solution, the reproducibility of analysis, and the determination of water content in tobacco, etc. For the calculating uncertainties, Type A of uncertainty was evaluated by the statistical analysis of a series of observation, and Type B by the information based on supplier’s catalogue and/or certificated of calibration. It was shown that the main source of uncertainty was caused by the calibration curve of standard solution, the reproducibility of analysis, the volume measurement of 1$m\ell$, and the purity of nicotine reference material in the preparation of standard solution. The uncertainty in the addition of extracting solution, the sample weighing, the volume measurement of 100$m\ell$, and the determination of water content of tobacco contributed relatively little to the overall uncertainty. The expanded uncertainty of total alkaloids and reducing sugar in flue-cured tobacco at 95% level of confidence was $\pm$0.12% and $\pm$0.54%, respectively.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.689-698
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• 2004

Uncertainties generated from the individual measured variables have an influence on the uncertainty of the experimental result through a data reduction equation. In this study, a performance test of a single stage axial type turbine is conducted, and total-to-total efficiencies are measured at the various off-design points In the low pressure and cold state. Based on an experimental apparatus, a data reduction equation for turbine efficiency is formulated and six measured variables are selected. Codes are written to calculate the efficiency, the uncertainty of the efficiency, and the sensitivity of the efficiency uncertainty by each of the measured quantities. The influence of each measured variable on the experimental result is figured out. Results show that the largest uncertainty magnification factor (UMF) value is obtained by the inlet total pressure among the six measured variables, and its value is always greater than one. The UMF values of the inlet total temperature, the torque, and the RPM are always one. The uncertainty percentage contribution (UPC) of the RPM shows th, lowest influence on the uncertainty of the turbine efficiency, but the UPC of the torque has the largest influence to the result among the measured variables. These results are applied to find the correct direction for meeting an uncertainty requirement of the experimental result in the planning or development Phase of experiment, and also to offer ideas for preparing a measurement system in the planning phase.

• Women's Health Nursing
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• v.11 no.4
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• pp.316-323
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• 2005

Purpose: The purpose of this study was to explore the relationships among women's total symptom distress, uncertainty and quality of life in women with endometriosis. Method: A total of 121 women who had been diagnosed with endometriosis was given a questionnaire. Data was collected from August 2004 to January 2005. The data was analyzed by frequency, mean, t-test, ANOVA, Pearson correlation coefficient, and multiple linear regression analysis using SPSS WIN 10.0 software. Result: The mean score of TSD was 3.23. 'Menstrual cramping' showed the highest score. The mean score of uncertainty, and quality of life of the subject was 56.6, and 38.3 respectively. TSD was significantly related with coffee intake and uncertainty was significantly related with marital status, economic status, alcohol intake, diagnosis after period, and family history. Quality of life was significantly related with age, and dysmenorrhea. There were significant relationships between total symptom distress and uncertainty, and quality of life. There were significant relationship between uncertainty and quality of life. Conclusion: Endometriosis symptoms showed a significant relationship with uncertainty and quality of life. This study will help to manage women with endometriosis.

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1067-1078
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• 2018

Water resources projection typically consists of several stages including emission scenarios, global circulation models (GCMs), downscaling techniques, and hydrological models, and each stage is a source of total uncertainty in water resources projection. Several studies proposed methods to quantify the relative contribution of each stage to total uncertainty, and we call such analysis uncertainty decomposition. Uncertainty decomposition enables us to investigate the stages yielding large uncertainties and to establish the uncertainty reduction plan that reflects them. Interactions between stages is one of the important issues to be considered in uncertainty decomposition. This study suggests a new uncertainty decomposition method considering interaction effect. The proposed method has an advantage of decomposing the total uncertainty to the uncertainty from each stage considering both the main and interactions effects. We apply the proposed method to streamflow projection for Chungju Dam basin. The results show that the uncertainties from the main effects are larger than the uncertainties from interaction effects in both summer and winter. Using the proposed uncertainty decomposition method, we show that the GCM stage is the largest source of the total uncertainty in summer and the downscaling technique stage is the one in winter among the following four stages: emission scenarios, GCMs, downscaling techniques, and hydrological models.

• Journal of Korean Clinical Nursing Research
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• v.19 no.3
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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.

• Journal of muscle and joint health
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• v.8 no.2
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• pp.230-249
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• 2001

This study was conducted to investigate the affecting factors on the adaptation to uncertainty in patients having rheumatoid arthritis. Subjects of the study constituted 222 patients who visited outpatient of rheumatic center in Seoul. Self report questionnaires were used to measure the variables affecting the adaptation to uncertainty. The variables affecting the adaptation to uncertainty were uncertainty, mastery, appraisal of danger, appraisal of opportunity, emotion focused coping, problem focused coping, pain, depression and activity of daily life(ADL). Reliability coefficients of these instruments were found Cronbach's $Alpha\;=\;.70{\sim}.94$. In data analysis, SPSSWIN 10.0 program was utilized for descriptive statistics, Pearson's correlation, and multiple regression analysis. The results were as follows. 1) The range of total pain scores was from 0 to 147 and the mean score of the pain in rheumatoid arthritis patients was 72.64. 2) The range of total depression scores was from 20 to 72 and the mean score of the depression in rheumatoid arthritis patients was 39.86. 3) The range of total ADL scores was from 22 to 80 and the mean score of the ADL in rheumatoid arthritis patients was 72.56. 4) Among the independent variables, significant factors to explain the adaptation to pain in patients were danger appraisal of uncertainty(p<.05) and emotion focused coping(p<.05). 5) Among the independent variables, significant factors to explain the adaptation to depression in patients were danger appraisal of uncertainty(p<.001), opportunity appraisal of uncertainty(p<.001) and mastery(p<.005). 6) Among the independent variables, significant factors to explain the adaptation to ADL in patients were mastery(p<.001) and danger appraisal of uncertainty(p<.05).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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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.