• Journal of Korea Water Resources Association
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• v.49 no.8
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• pp.657-671
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• 2016

It is expected that water resources will be changed spatially and temporally due to the global climate change. The quantitative assessment of change in water availability and appropriate water resources management measures are needed for corresponding adaptation. However, there are large uncertainties in climate change impact assessment on water resources. For this reason, development of technology to evaluate the uncertainties quantitatively is required. The objectives of this study are to develop the climate change uncertainty assessment method and to apply it. The 5 RCMs (HadGEM3-RA, RegCM4, MM5, WRF, and RSM), 5 statistical post-processing methods (SPP) and 2 hydrological models (HYM) were applied for evaluation. The results of the uncertainty analysis showed that the RCM was the largest sources of uncertainty in Spring, Summer, Autumn (29.3~68.9%), the hydrological model was the largest source of uncertainty in Winter (46.5%). This method can be possible to analyze the changes in the total uncertainty according to the specific RCM, SPP, HYM model. And then it is expected to provide the method to reduce the total uncertainty.

• 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.

• Women's Health Nursing
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• v.13 no.4
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• pp.290-298
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• 2007

Purpose: This study was to measure the quality of life(QOL) and to identify the related factors in gynecological cancer patients during chemotherapy. Method: The subjects of this study were the patients who had undergone a hysterectomy and were admitted for chemotherapy at S university hospital between November 2006 and April 2007. Data was collected from 106 gynecological cancer patients with the use of a structured questionnaire which measured the QOL(FACT-G), body image, the presence of anxiety & depression, uncertainty, and family support. The data was analyzed by the SPSS win 12.0 program. Results: The mean FACT-total score was 62.1$({\pm}16.7)$ (range; 26-107). Positive correlations were found between QOL and body image(r= .67, p= .00), and QOL and family support(r= .32, p= .00), whereas there were negative correlations between QOL and anxiety(r= -.54, p= .00), QOL and depression(r= -.70, p= .00), and QOL and uncertainty(r= -.59, p= .00). Fifty seven pre cent of the variance in subjective overall QOL can be explained by depression, body image, and uncertainty(Adj $R^2$= .57, F=47.00, p= .00). Conclusion: Our patients had a relatively low QOL score. Factors significantly affecting quality of life were depression, body image and uncertainty. Nursing interventions, therefore, should be focused on improving QOL in gynecological cancer patients during chemotherapy, particularly so in patients with depression, uncertainty or poor body image.

• The Korean Journal of Health Service Management
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• v.9 no.4
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• pp.105-117
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• 2015

Objectives : The aim of this study was to investigate the relationship among uncertainty, self-care agency and physiological index in acute myocardial infarction (AMI) patients who underwent primary percutaneous coronary intervention. Methods : A total of 196 patients who were admitted C National University Hospital from Oct 2014 to Jun 2015 participated in the study. Data were collected with a questionnaire, and the blood pressure, HgA1C, and lipid profile levels of the patients were acquired. Results : The mean age was 69.2 (${\pm}13.0$) years, and 74 % of the patients were men. The mean score for uncertainty in illness was 48.7 (${\pm}8.8$). The mean score for self-care agency was 73.3 (${\pm}13.4$). Self-care agency showed a negative correlation with uncertainty (r=-.579, p<.001), age (r=-.732, p<.001), systolic blood pressure (r=-.265, p=.001) and HgA1C (r=-.293, p<.001). Conclusions : The results of this study can be used to develop a nursing program that prevents AMI and to improve the clinical prognosis of AMI patients.

• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.2048-2054
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• 2022

The coolant temperature feedback coefficient is an important parameter of reactor core power control system. To study the coolant temperature feedback coefficient influence on the core power control system of small PWR, the core power control system is built with the nonlinear model and fuzzy control theory. Then, the uncertainty quantification method of reactor core parameters is established based on the Latin hypercube sampling method and the Bootstrap method. Finally, under the conditions of reactivity step perturbation and coolant inlet temperature step perturbation, uncertainty analysis for two cases is carried out. The result shows that with fuzzy controller and fuzzy PID controller, the uncertainty of the coolant temperature feedback coefficient affects the core power control system, and the maximum uncertainties of core relative power, coolant temperature deviation, fuel temperature deviation and total reactivity are acceptable.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1120-1124
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• 2005

We reviewed controllers with a time delay estimation in this paper. Time delay control (TDC) and sliding mode control (SMC) are well known robust control schemes. Basically, the TDC has a main characteristic called a time delay estimation from which we can estimate the total uncertainty of a system. . The TDC causes the stick-slip in the case of systems with a friction. The so-called TDCSA which are short for TDC with switching action was developed to reduce the stick-slip. The TDC has the additional switching action term in the TDC structure. In the other hand, the SMC dose not have a time delay estimation but instead it can estimate the system uncertainty through the switching action. The SMC has a difficulty to estimate the total uncertainty of a system because it does not have a time delay estimation. In order to solve the difficulty, some control schemes were developed. Among them, we need to focus our attention on two control schemes: SMCPE and SMCTE, which are short for sliding mode control with a perturbation estimation and sliding mode control with a time delay estimation, respectively. In this paper, we analyzed and compared the characteristic of above three controllers. Even though the motives for the development of three control schemes are different, three control schemes have much in common in terms of their controller structures.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.484-497
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• 2021

This paper proposes an extended time uncertainty analysis approach in Level 2 human reliability analysis (HRA) considering severe accident management (SAM) strategies. The method is a time-based model that classifies two time distribution functions-time required and time available-to calculate human failure probabilities from delayed action when implementing SAM strategies. The time required function can be obtained by the combination of four time factors: 1) time for diagnosis and decision by the technical support center (TSC) for a given strategy, 2) time for strategy implementation mainly by the local emergency response organization (ERO), 3) time to verify the effectiveness of the strategy and 4) time for portable equipment transport and installation. This function can vary depending on the given scenario and includes a summation of lognormal distributions and a choice regarding shifting the distribution. The time available function can be obtained via thermal-hydraulic code simulation (MAAP 5.03). The proposed approach was applied to assess SAM strategies that use portable equipment and safety depressurization system valves in a total loss of component cooling water event that could cause reactor vessel failure. The results from the proposed method are more realistic (i.e., not conservative) than other existing methods in evaluating SAM strategies involving the use of portable equipment.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1348-1349
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• 2011

In this paper, The case of power performance test for 3MW wind-turbine system is introduced. For the verification of power curve and the certification of wind-turbine, power performance test is very important. This paper described the power testing results of a 3MW wind turbine and analysed an uncertainty about the testing. The measured power curves are very closely coincide with the calculated. Total uncertainty of measured data for Power Curve is 120~200kW in the rated power.

• Journal of Korean Society for Quality Management
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• v.46 no.4
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• pp.959-972
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• 2018

Purpose: This study developed a simulation model that incorporates the uncertainty of demand and yield to obtain optimized results for supply chain coordination within environmental constraints. The objective of this study is to examine whether yield management for perishable products can achieve the goal of supply chain coordination between a single buyer and a single supplier under a variety of environmental conditions. Methods: We investigated the efficiency of a revenue-sharing contract and a wholesale price contract by considering demand and yield uncertainty, profit maximizing ratio, and success ratio. The implications for environmental variation were derived through a comparative analysis between the wholesale price contract and the revenue-sharing contract. We performed Monte Carlo simulations to give us the results of an optimized supply chain within the environments defined by the experimental factors and parameters. Results: We found that a revised revenue-sharing contracting model was more efficient than the wholesale price contract model and allowed all members of the supply chain to achieve higher profits. First, as the demand variation (${\sigma}$) increased, the profit of the total supply chain increased. Second, as the revenue-sharing ratio (${\Phi}$) increased, the profits of the manufacturer gradually decreased, while the profits of the retailer gradually increased, and this change was linear. Third, as the quality of yield increased, the profits of suppliers appear to increased. At last, success rate was expressed as the profit increased in the revenue-sharing contract compared to the profit increase in the wholesale price contract. Conclusion: The managerial implications of the simulation findings are: (1) a strategic approach to demand and yield uncertainty helps in efficient resource utilization and improved supply chain performance, (2) a revenue-sharing contract amplifies the effect of yield uncertainty, and (3) revised revenue-sharing contracts fetch more profits for both buyers and suppliers in the supply chain.

• Journal of Korean Academy of Nursing
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• v.30 no.4
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• pp.1006-1017
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• 2000

The purpose of this study was to provide basic information for developing a nursing intervention that helps patients learn how to acquire coping to reduce post operation uncertainty and anxiety by investigating the level of uncertainty and anxiety experienced by mastectomy patients. The subjects were 134 patients selected from St. Mary's Kangnam and St. Mary's hospital, and the data collection period was from October to December of 1998. Uncertainty was measured by using Mishel Uncertainty in Illness Scale (MUIS), anxiety measured by using State-Trait Anxiety Inventory(STAI), and coping by using a questionnaire developed by Kim & Yoo (1996). Data were analyzed with SAS program by t-test, ANOVA, Duncan's multiple range test, Pearson correlation coefficients, and stepwise multiple regression. The results were as follows : 1. The mean uncertainty score was 57.6. The results of the correlation between the compliance of medical regimen and demographic characteristics were as follows ; Those who monthly income over 2,010,000 won had lower than above 1,000,000 won, and those with the experience of chemotherapy had higher than those without, and the patient who has 7∼12 months(1 yr.) post operation period had higher than the one below 6months, 25∼36 months(3 yrs.), 37∼60 months(5 yrs.), and over 61 months. 2. The mean anxiety score was 45.9. Anxiety tended to be increased slightly in subjects with low educational background, poor monthly income, experience of chemotherapy, and 7∼12 months(1 yr.) post operation period, but there was no significant difference by general characteristics 3. The mean value of the coping score was 100.7. The study revealed higher score in problem-focused coping than emotion-focused coping. In regard to coping by demographic characteristics were as follows ; those who had monthly income over 2,010,000 won had higher level of coping than those whose monthly income was between 1,010,000 and 2,000,000 won. In terms of problem- focused coping, those who had 25∼36 months of post operation period showed significantly lower level of coping than those below 6 months or 37∼60 months(5 yrs.) or over 61 months of post operation period. Regarding the emotion-focused coping, those with the christianity had significantly lower level of coping than those without it. Also, those whose monthly income over 2,010,000 won had significantly higher coping level than those with income of between 1,010,000 and 2,000,000 won. 4. A positive relationship was found between uncertainty and anxiety. Patients who experienced more uncertainty also showed more anxiety. Problem-focused coping was inversely related to uncertainty and anxiety. 5. The major variable that affected uncertainty was anxiety, explaining 63.3% of the uncertainty. In addition to this, it would explain 66.4% in total when experience of chemotherapy was added.