• Journal of Sensor Science and Technology
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• v.22 no.6
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• pp.415-420
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• 2013

Calibration capabilities for thermometer calibration by comparison method were assessed using high-precision industrial platinum resistance thermometers (IPRT). It was found in the performance assessment that out of 31 laboratories who participated, 28 laboratories resulted magnitude of En number less than 1 at every calibration points they submitted results in the range from 50 to $500^{\circ}C$. The results of about 75% of the laboratories showed the difference from the assigned values less than 1/10 of the tolerance level of the class B IPRT. This indicates that the participating calibration laboratories performed with satisfactory level that was enough to calibrate IPRTs to significant precision. The sensors used in this work were manufactured and chosen by the criteria of long-term instability less than 4 mK and hysteresis less than 8 mK in the temperature range used in this work. Furthermore, the change in the resistance of the sensors in the calibration temperature range were less than the uncertainty of the calibration, 25 mK (k=2).

• Journal of Wetlands Research
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• v.11 no.1
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• pp.49-64
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• 2009

Rainfall-runoff models are used for efficient management, distribution, planning, and design of water resources in accordance with the process of hydrologic cycle. The models simplify the transition of rainfall to runoff as rainfall through different processes including evaporation, transpiration, interception, and infiltration. As the models simplify complex physical processes, gaps between the models and actual rainfall events exist. For more accurate simulation, appropriate models that suit analysis goals are selected and reliable long-term hydrological data are collected. However, uncertainty is inherent in models. It is therefore necessary to evaluate reliability of simulation results from models. A number of studies have evaluated uncertainty ingrained in rainfall-runoff models. In this paper, Meta-Gaussian method proposed by Montanari and Brath(2004) was used to assess uncertainty of simulation outputs from rainfall-runoff models. The model, which estimates upper and lower bounds of the confidence interval from probabilistic distribution of a model's error, can quantify global uncertainty of hydrological models. In this paper, Meta-Gaussian method was applied to analyze uncertainty of simulated runoff outputs from $Vflo^{TM}$, a physically-based distribution model and HEC-HMS model, a conceptual lumped model.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.180-188
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• 1999

${\mu}$-synthesis is applied to design a robust controller for a seeker scan loop system which has model uncertainty and is subject to a external disturbance due to abrupt missile maneuver. The issue of modelling a real-valued parametric uncertainty of a physical seeker scan loop system is discussed. The two-degree-of-frame control structure is employed to obtain better performance. It is shown that ${\mu}$-synthesis provides a superior framework for the robust control design of a seeker scan loop system which exhibits robust performance. The proposed robust control system satisfies design requirements, and especially shows good scanning performances for conical and rosette scan patterns despite parametric uncertainty in real system model.

• Child Health Nursing Research
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• v.4 no.2
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• pp.274-285
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• 1998

Improvements in therapy have resulted in increasing numbers of children being successfully treated for cancer. However the agrressiveness of therapy & uncertainty about prognosis are associated with many adverse effects, psychological as well as physical for both the child & family. The purpose of this study were to measure the degree of perceived uncertainty, self-efficacy & coping, and then to examine the relationship between the perceived uncertainty, self-efficacy & coping in parents of children cancer patients. The subjects of this study consist of 140 parents with pediatric cancer, registered at pediatric cancer ward & Out Patient Department. Data was collected from July 1st to August 15th 1998. The tools used in this study were Mishel's the Parents' Perception of Uncertainty Scale (28 item, 4 likert scale), Shere's Self-Efficacy Scale (17 item, 5 likert scale) & Folkman & Lazarus Ways of Coping Checklist(34 items, 4 likert scale). Data was analyzed by t-test, Anova, Pearson Correlation coefficient. Results of this study are summerized as follows 1. Parents perceived their uncertainty to be slightly high(Mn 2.41). The degree of perceived uncertainty by the four components were followed as lack of clarity (2.60), unpredictability(2.59), ambiguity(2.51) & lack of information(1.90). The degree of perceived uncertainty of parents with pediatric cancer revealed to be influenced significantly by the family outcome, reliability about health care provider & perceived severity of illness. 2. The range of parents' self-efficacy was measured iron 35 to 85 point, so revealed slightly high. The degree of self-efficacy related to be Influenced signiicantly by the sequency of child birth, family religion & degree of perceived support. 3. The degree of parents' coping was measured slightly high (Mn 2.78). The degree of coping related to be influnced significantly by the sequency of child birth, number of sible & degree of perceived support. 4. parents' uncertainty was related inversely to the parents' self-efficacy(r=-.38, p<.001) & coping(r=-.26, p<.001). And also parents' self-efficacy was positively related to coping(r=.56, p<.001) From the above results, it can be concluded that predicting & controlling parents' uncertainty with children cancer are necessary to improve positive coping strategies. This information may be used as a foundation for developing nursing interventions to decrease perceived uncertainty & to foster self-efficacy & coping for parents with children cancer.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.43-50
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• 2009

If an internal combustion engine is operated by consolidated control, the minimum fuel consumption is achieved satisfying the demanded objectives. For this, it is necessary that the engine is operated on the ideal operating line which satisfies minimum fuel consumption. In this context of view, there are many tries to achieve given object. However, the parameter in the internal combustion engines are variable and depend on the operating points. Therefore, it is necessary to cope with the uncertainties such that the optimal operating may be possible. From this point of view, this paper gives a controller design method and a robust stability condition for engine torque control which satisfies the given control performance and robust stability in the presence of physical parameter perturbation. Exactly, the present paper considers a robust stability of this 2DOF servosystem with nonlinear type uncertainty in the engine system, and a robust stability condition for the servosystem is introduced. This result guarantees that if the plant uncertainty is in the permissible set defined by the given condition then a gain tuning can be carried out to suppress the influence of the plant uncertainties.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2215-2219
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• 2009

For model calibration in rainfall-runoff modeling, streamflow data at a specific outlet is obviously required but is not sufficient to identify parameters of a model since numerous parameter combinations can result in very similar model performance measures (i.e. objective functions) and indistinguishable simulated hydrographs. This phenomenon has been called 'equifinality' due to inherent parameter uncertainty involved in rainfall-runoff modeling. This study aims to investigate catchment responses in time and space to various uncertain parameter sets in distributed rainfall-runoff modeling. Seven plausible (or behavioral) parameter sets, which guarantee identically-good model performances, were sampled using deterministic and stochastic optimization methods entitled SCE and SCEM, respectively. Then, we applied them to a computational tracer method linked with a distributed rainfall-runoff model in order to trace and visualize potential origins of streamflow at a catchment outlet. The results showed that all hydrograph simulations based on the plausible parameter sets were performed equally well while internal catchment responses to them showed totally different aspects; different parameter values led to different distributions with respect to the streamflow origins in space and time despite identical simulated hydrographs. Additional information provided by the computational tracer method may be utilized as a complementary constraint for filtering out non-physical parameter set(s) (or reducing parameter uncertainty) in distributed rainfall-runoff modeling.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.11
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• pp.1029-1037
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• 2010

If an internal combustion engine is operated by consolidated control, the minimum fuel consumption is achieved and the demanded objectives are satisfied. For this, it is necessary that the engine is operated on the ideal operating line which satisfies minimum fuel consumption. In this context of view, there are many tries to achieve given object. However, the parameters in the internal combustion engines are variable and depend on the operating points. Therefore, it is necessary to cope with the uncertainties such that the optimal operating may be possible. From this point of view, this paper gives a controller design method and a robust stability condition for engine torque control which satisfies the given control performance and robust stability in the presence of physical parameter perturbation. Exactly, in this paper, we consider the robust stability problem of this 2DOF servosystem with nonlinear type uncertainty in the engine system, and a robust stability condition for the servosystem is shown. This result guarantees that if the plant uncertainty is in the permissible set defined by the given condition, then a gain tuning can be carried out to suppress the influence of the plant uncertainties.

• Journal of Haehwa Medicine
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• v.6 no.1
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• pp.567-584
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• 1997

Most of cancer therapy consists of surgery, chemotherapy and radiotherapy developed by modern western medicine. Often Korean patients use both modem western and oriental medicine through their cancer life. This study tried out to answer the the question : "What are the experience of a Korean cancer patients who follow oriental medicine after cancer diagnosis?" To answer to that, a micro-ethnographic research method was used. Total 6 patients were observed from March, 1996 to February, 1997. Data were obtained through interview, participant observation, audio-tape recording, field recoding, field note-taking, and ralated documents Using an analytical tool known as "pencil and scissors", the data were analyzed. First, I learned patietnts' accounts for cancer experience following oriental medicine, and I could found that they expereinced "feeling of uncertainty" through cancer life. Second, major argument was searched. : Feeling of uncertainty of cancer patients was extremely increased after cancer diagnosis. Oriental Medicine made cancer patients not only expect to improve general physical condition, but also gave them significnat emotional support to overcome their feeling of uncertanty. Third, I examined how did this argument form meanings in the context of individual life. Modem western mediacal service system could not satisfy cancer patients' informational and emotional need. But oriental medicine contribute to relieve the degree of their feeling of uncertainty. As a result of these understandings, I suggest that modern wetern medicine need to be concerned to feeling of uncertainty of cancer patietns and infomational service, and oriental medicine counsel with cancer patients much more systemically. Also nurses must improve cancer education with more accurate and practical information based on empirical data.

• Structural Engineering and Mechanics
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• v.50 no.5
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• pp.697-708
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• 2014

The intentional buckling design of micro-films has various potential applications in engineering. The buckling amplitude and critical strain of micro-films are the crucial parameters for the buckling design. In the reported studies, the film parameters were regarded as deterministic. However, the geometrical and physical parameters uncertainty of micro-films due to manufacturing becomes prominent and needs to be considered. In the present paper, the probabilistic nonlinear buckling analysis of micro-films with uncertain parameters is proposed for design accuracy and reliability. The nonlinear differential equation and its asymptotic solution for the buckling micro-film with nominal parameters are firstly established. The mean values, standard deviations and variation coefficients of the buckling amplitude and critical strain are calculated by using the probability densities of uncertain parameters such as the film span length, thickness, elastic modulus and compressive force, to reveal the effects of the film parameter uncertainty on the buckling deformation. The results obtained illustrate the probabilistic relation between buckling deformation and uncertain parameters, and are useful for accurate and reliable buckling design in terms of probability.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4534-4550
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• 2022

Integrated severe accident codes should be capable of simulating not only specific physical phenomena but also entire plant behaviors, and in a sufficiently fast time. However, significant uncertainty may exist owing to the numerous parametric models and interactions among the various phenomena. The primary objectives of this study are to present best-practice uncertainty and sensitivity analysis results regarding the evolutions of severe accidents (SAs) and fission product source terms and to determine the effects of mitigation measures on them, as expected during a short-term station blackout (STSBO) of a reference pressurized water reactor (optimized power reactor (OPR)1000). Three reference scenarios related to the STSBO accident are considered: one base and two mitigation scenarios, and the impacts of dedicated severe accident mitigation (SAM) actions on the results of interest are analyzed (such as flammable gas generation). The uncertainties are quantified based on a random set of Monte Carlo samples per case scenario. The relative importance values of the uncertain input parameters to the results of interest are quantitatively evaluated through a relevant sensitivity/importance analysis.