• Korean Journal of Adult Nursing
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• v.29 no.3
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• pp.323-331
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• 2017

Purpose: The purpose of this study was to examine whether the uncertainty mediates relationship between rehabilitation motivation and social support. Methods: Participants were 123 adults patients diagnosed as stroke in a hospital located in a Metropolitan City. Data were collected by self-administered questionnaires measuring uncertainty, family support and medical team support as social support, rehabilitation motivation. Data were analyzed using t-test, one-way ANOVA, Pearson's correlation, and multiple regression analyses. The significance of mediating effect was analyzed by Sobel test. Results: Family support and uncertainty, respectively, were influential on rehabilitation motivation (${\beta}=.39$, p<.001, ${\beta}=-.18$, p=.011). Uncertainty showed partial mediating effect on relationship between family support and rehabilitation motivation, however, the effect was not significant (Z=1.63, p=.103). Conclusion: Interventions improving family support and decreasing uncertainty may be helpful in enhancing rehabilitation motivation.

• 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.

• Journal of Korean Academy of Nursing
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• v.54 no.2
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• pp.162-177
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• 2024

Purpose: This study aimed to investigate the influence of uncertainty-related factors on the health behavior of individuals with coronary artery disease (CAD) based on Mishel's uncertainty in illness theory (UIT). Methods: We conducted a cross-sectional study and path analysis to investigate uncertainty and factors related to health behavior. The study participants were 228 CAD patients who visited the outpatient cardiology department between September 2020 and June 2021. We used SPSS 25.0 and AMOS 25.0 software to analyze the data. Results: The final model demonstrated a good fit with the data. Eleven of the twelve paths were significant. Uncertainty positively affected danger and negatively affected self-efficacy and opportunity. Danger had a positive effect on perceived risk. Opportunity positively affected social support, self-efficacy, perceived benefit and intention, whereas it negatively affected perceived risk. Social support, self-efficacy, perceived benefit and intention had a positive effect on health behavior. We found that perceived benefit and intention had the most significant direct effects, whereas self-efficacy indirectly affected the relationship between uncertainty and health behavior. Conclusion: The path model is suitable for predicting the health behavior of CAD patients who experience uncertainty. When patients experience uncertainty, interventions to increase their self-efficacy are required first. Additionally, we need to develop programs that quickly shift to appraisal uncertainty as an opportunity, increase perceived benefits of health behavior, and improve intentions.

• Journal of the Korean Solar Energy Society
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• v.36 no.4
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• pp.11-20
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• 2016

For accurate wind resource assessment and wind turbine performance test, it is essential to secure wind data covering a rotor plane of wind turbine including a hub height. In general, we can depict wind speed profile by extrapolating or interpolating the wind speed data measured from a meteorological tower where multiple anemometers are mounted at different heights using a power-law of wind speed profile. The most important parameter of a power-law equation is a vertical wind profile exponent which represents local characteristics of terrain and land cover. In this study, we calculated diurnal vertical wind profile exponents of 8 locations in Jeju Island who possesses excellent wind resource according to the GUM (Guide to the Expression of Uncertainty in Measurement) to evaluate its uncertainty. Expanded uncertainty is calculated by combined standard uncertainty, which is the result of composing type A standard uncertainty with type B standard uncertainty. Although pooled standard deviation should be considered to derive type A uncertainty, we used the standard deviation of vertical wind profile exponent of each day avoiding the difficult of uncertainty evaluation of diurnal wind profile variation. It is anticipated that the evaluated uncertainties of diurnal vertical wind profile exponents at 8 locations in Jeju Island are to be registered as a national standard reference data and widely used in the relevant areas.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.2
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• pp.191-204
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• 2024

This study analyzes the effects of manufacturing firms' R&D investment on sales according to global political economic uncertainty. The variables in this research include the firm's R&D investment, sales, which serves as an indicator of the firm's performance, and the Global Economic Policy Uncertainty (GEPU) index, which reflects situations of global political economic uncertainty. Panel data analysis is conducted by using a total of 96 quarters of data spanning 24 years from 2000 to 2023 based on manufacturing firms in the Wharton Research Data Services' Compustat Database. We study the impact of firm's R&D investment on sales by considering the Global Economic Policy Uncertainty index, which was relatively underestimated in previous research, as moderating variable, and present a new direction for research by analyzing the time lag effect. We suggest effective R&D investment strategy for firms.

• Journal of Korean Academy of Nursing
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• v.37 no.4
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• pp.594-602
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• 2007

Purpose: This study was conducted to investigate the correlation among uncertainty, mastery and appraisal of uncertainty in hospitalized children's mothers. Method: Self report questionnaires were used to measure the variables Variables were uncertainty, mastery and appraisal of uncertainty. In data analysis, the SPSSWIN 12.0 program was utilized for descriptive statistics, Pearson's correlation coefficients, and regression analysis. Result: Reliability of the instruments was cronbach's $alpha=.84{\sim}.94$. Mastery negatively correlated with uncertainty(r=-.444, p=.000) and danger appraisal of uncertainty(r=-.514, p=.000). In regression of danger appraisal of uncertainty, uncertainty and mastery were significant predictors explaining 39.9%. Conclusion: Mastery was a significant mediating factor between uncertainty and danger appraisal of uncertainty in hospitalized children's mothers. Therefore, nursing interventions which improve mastery must be developed for hospitalized children's mothers.

• Nuclear Engineering and Technology
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• v.46 no.3
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• pp.353-362
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• 2014

The effects of nuclear data uncertainties are studied on a typical PWR fuel assembly model in the framework of the OECD Nuclear Energy Agency UAM (Uncertainty Analysis in Modeling) expert working group. The "Fast Total Monte Carlo" method is applied on a model for the Monte Carlo transport and burnup code SERPENT. Uncertainties on $k_{\infty}$, reaction rates, two-group cross sections, inventory and local pin power density during burnup are obtained, due to transport cross sections for the actinides and fission products, fission yields and thermal scattering data.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.715-731
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• 2021

Uncertainties are calculated for pressurized water reactor (PWR) spent nuclear fuel (SNF) characteristics. The deterministic code STREAM is currently being used as an SNF analysis tool to obtain isotopic inventory, radioactivity, decay heat, neutron and gamma source strengths. The SNF analysis capability of STREAM was recently validated. However, the uncertainty analysis is yet to be conducted. To estimate the uncertainty due to nuclear data, STREAM is used to perturb nuclear cross section (XS) and resonance integral (RI) libraries produced by NJOY99. The perturbation of XS and RI involves the stochastic sampling of ENDF/B-VII.1 covariance data. To estimate the uncertainty due to modeling parameters (fuel design and irradiation history), surrogate models are built based on polynomial chaos expansion (PCE) and variance-based sensitivity indices (i.e., Sobol' indices) are employed to perform global sensitivity analysis (GSA). The calculation results indicate that uncertainty of SNF due to modeling parameters are also very important and as a result can contribute significantly to the difference of uncertainties due to nuclear data and modeling parameters. In addition, the surrogate model offers a computationally efficient approach with significantly reduced computation time, to accurately evaluate uncertainties of SNF integral characteristics.

• Korean Journal of Adult Nursing
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• v.18 no.3
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• pp.479-487
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• 2006

Purpose: The purposes of this study were to measure the degree of uncertainty in illness, hope, and spiritual well-being and to examine the relationship among uncertainty in illness, hope, and spiritual well-being of cancer patients. Method: The data were derived from answers to questionnaires obtained from 93 cancer patients at one general hospital in J area from April 6, 2004 to May 8, 2004. The collected data were analyzed by SSPS 10.0. Results: The mean score of uncertainty in illness of cancer patients was 55.96. The mean score of hope of cancer patients was 79.77, and spiritual well-being was 55.20. Uncertainty in illness of cancer patients was related negatively to hope(r=-.57, p=.000). Also uncertainty in illness of cancer patients was related negatively to spiritual well-being(r=-.57, p=.000). However, hope of cancer patients was related positively to spiritual well-being(r=.67, p=.000). Conclusion: Higher uncertainty in illness was related to lower hope and spiritual well-being of cancer patients. Based upon these results, nurses should help patients to improve their hope and spiritual well-being through mediation of uncertainty in illness.

• Journal of Power System Engineering
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• v.4 no.3
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• pp.72-80
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• 2000

In order to design a stable robust controller, nominal model, and the upper bound about the uncertainty which is the error of the model are needed. The problem to estimate the nominal model of controlled system and the upper bound of uncertainty at the same time is called robust identification. When the nominal model of controlled system and the upper bound of uncertainty in relation to robust identification are given, the evaluation of the validity of the model and the upper bound makes it possible to distinguish whether there is a model which explains observation data including disturbance among the model set. This paper suggests a method to identity the uncertainty which removes disturbance and expounds observation data by giving a probable postulation and plural data set to disturbance. It also examines the suggested method through a numerical computation simulation and validates its effectiveness.