• Journal of Korean Clinical Nursing Research
• /
• v.26 no.3
• /
• pp.314-326
• /
• 2020

Purpose: This study was conducted to examine the effects of uncertainty, social support, and sick role behavior on health-related quality of life in patients with peripheral arterial disease. Methods: This study is a descriptive research using self-reporting questionnaire. Data were collected from 167 patients with peripheral arterial disease. Measurement tools were Multidimensional Scale of Perceived Social Support(MSPSS), Mishel's Uncertainty in Illness Scale (MUIS), Sick role behavior measurement tools and SF-36 Version I. The data were analyzed using descriptive statistics, correlation, and regression analysis by using SPSS/WIN 24.0. Results: Factors that significantly influenced physical health-related quality of life were age (β=-.19, p=.010), monthly income (β=.17, p=.027), uncertainty (β=-.29, p<.001), and exercise and rest (β=.28, p<.001) that all together accounted for 32.6% of the variance. Factors that significantly influenced mental health-related quality of life were monthly income (β=.20, p=.015), drinking (β=.17, p=.040), uncertainty (β=-.24, p=.001), and exercise and rest in sick role behavior (β=.26, p=.003) that all together accounted for 18.2% of the variance. Social support was an insignificant factor on physical and mental health-related quality of life. Conclusion: To improve the health-related quality of life of people with peripheral arterial disease, it is necessary to develop a systematic nursing intervention program including a strong support system, education, strategies for alcohol abstinence, and exercise and rest therapy.

• Journal of Mechanical Science and Technology
• /
• v.20 no.7
• /
• pp.961-971
• /
• 2006

A deadweight force standard machine is a mechanical structure that generates force by subjecting deadweights to the local gravitational field. The Korea Research Institute of Standards and Science (KRISS) developed and installed a 100 kN deadweight force standard machine for national force standards. It can generate forces from 2 kN to 110 kN in increments of 1 kN. The uncertainty of the force machine was estimated and declared as $2\times10^{-5}$. This 100 kN deadweight force machine was compared with the 500 kN deadweight force standard machine at KRISS and the 20 kN and 50 kN deadweight force standard machines at the National Metrology Institute of Japan (NMIJ). The measurement results showed good agreement between the deadweight force machines, and the accuracy level of the 100 kN deadweight force machine was verified.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.10
• /
• pp.1163-1170
• /
• 2009

Reliability analysis is of great importance in the advanced product design, which is to evaluate reliability due to the associated uncertainties. There are three types of uncertainties: the first is the aleatory uncertainty which is related with inherent physical randomness that is completely described by a suitable probability model. The second is the epistemic uncertainty, which results from the lack of knowledge due to the insufficient data. These two uncertainties are encountered in the input variables such as dimensional tolerances, material properties and loading conditions. The third is the metamodel uncertainty which arises from the approximation of the response function. In this study, an integrated method for the reliability analysis is proposed that can address all these uncertainties in a single Bayesian framework. Markov Chain Monte Carlo (MCMC) method is employed to facilitate the simulation of the posterior distribution. Mathematical and engineering examples are used to demonstrate the proposed method.

• Nuclear Engineering and Technology
• /
• v.42 no.2
• /
• pp.163-174
• /
• 2010

As pointed out in the OECD BEMUSE Program, when a high computation time is taken to obtain the relevant output values of a complex physical model (or code), the number of statistical samples that must be evaluated through it is a critical factor for the sampling-based uncertainty analysis. Two alternative methods have been utilized to avoid the problem associated with the size of these statistical samples: one is based on Wilks' formula, which is based on simple random sampling, and the other is based on the conventional nonlinear regression approach. While both approaches provide a useful means for drawing conclusions on the resultant uncertainty with a limited number of code runs, there are also some unique corresponding limitations. For example, a conclusion based on the Wilks' formula can be highly affected by the sampled values themselves, while the conventional regression approach requires an a priori estimate on the functional forms of a regression model. The main objective of this paper is to assess the feasibility of the ACE-RSM approach as a complementary method to the Wilks' formula and the conventional regression-based uncertainty analysis. This feasibility was assessed through a practical application of the ACE-RSM approach to the LOFT L2-5 LBLOCA PCT uncertainty analysis, which was implemented as a part of the OECD BEMUSE Phase III program.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.11
• /
• pp.1622-1625
• /
• 2014

The main measurement uncertainty factors in DC high-voltage dividers for a national high-voltage standard are the measurement uncertainty of low-voltage arm and the stability of a high-voltage supply. In this study, the uncertainties by the two factors are greatly improved. As a result the measurement uncertainty for the DC high-voltage divider is reduced from $16{\times}10^{-6}(k=2)$ to $8{\times}10^{-6}(k=2)$ which is at international level.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.34.1-34
• /
• 2001

We deal with robust control problem for singularly perturbed linear systems with norm-bounded structured uncertainty under state constraints. We assume that the norm-bounded uncertainty is composed of repeated scalar-block and full-block forms. In the structured uncertainty, repeated scalar block forms account for uncertain physical parameter value and full-block forms may be some unknown nonlinear dynamics. In order deal with uncertainty and state constraints, we use LMI(Linear Matrix Inequality). The original problem is decomposed into two well behaved reduced order problems. Shinc two LMI problems are completely independent, each solution can be computed simultaneously and work in parallel.

• Journal of Sensor Science and Technology
• /
• v.21 no.2
• /
• pp.109-113
• /
• 2012

We propose an improved interpolating equation to express temperature-resistance characteristics for modern industrial platinum resistance thermometers (PRTs). Callendar-van Dusen equation which has been widely used for platinum resistance thermometer fails to fully describe temperature characteristics of high quality PRTs and leaves systematic residual when the calibration point include temperatures above $300^{\circ}C$. Expanding Callendar-van Dusen to higher-order polynomial drastically improves the uncertainty of the fitting even with reduced degrees of freedom of the fitting. We found that in the fourth-order polynomial fitting, the third-order and fourth-order coefficients have a strong correlation. Using the correlation, we suggest an improved interpolating equation in the form of fourth-order polynomial, but with three fitting parameters. Applying this interpolating equation reduced the uncertainty of the fitting to 32 % of that resulted from the traditional Callendar-van Dusen. This improvement was better than that from a simple third-order polynomial despite that the degrees of the freedom of the fitting was the same.

• Journal of Korean Academy of Nursing
• /
• v.48 no.1
• /
• pp.50-58
• /
• 2018

Purpose: The purpose of this study was to examine the mediating effect of marital intimacy on the impact of uncertainty on the quality of life (QoL) of young breast cancer patients. Methods: This study used a pathway analysis with 154 young breast cancer cases in their early diagnosis stage at a medical center in Korea. Data were collected from November 2016 to February 2017 and analyzed using correlation analysis and pathway analysis. Results: Uncertainty, marital intimacy, and 4 sub-scales of QoL showed a significant correlation. Marital intimacy was directly affected by uncertainty (${\beta}=-.39$, p=.013) and 4 sub-scales of QoL were also affected by uncertainty. Among the 4 sub-scales of QoL, physical well-being (PWB) (${\beta}=.17$, p=.026), social well-being (SWB) (${\beta}=.49$, p=.010), and functional well-being (FWB) (${\beta}=.38$, p=.009) were affected by marital intimacy but emotional well-being (EWB) was not affected by it. The mediating effect of marital intimacy on the impact of uncertainty on QoL was confirmed. Marital intimacy showed a significant indirect effect on PWB (${\beta}=-.07$, p=.024), SWB (${\beta}=-.19$, p=.008), and FWB (${\beta}=-.15$, p=.005), and it means that marital intimacy has a partial mediating effect on the impact of uncertainty on PWB, SWB, and FWB. Conclusion: Effects of uncertainty on QoL was mediated by marital intimacy of young breast cancer patients in their early diagnosis stage. It suggests that marital intimacy needs to be considered in providing nursing intervention for young breast cancer patients.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.64.6-64
• /
• 2002

This paper presents a procedure of implementing a robust controller for a paper-making plant in DCSs. A paper-making process generally has triple problems to automatically tune its output qualities : Long transport delays which are not able to be simply linearized. The transfer matrix of the process is not square. And every plant model has some uncertainty in low and middle frequency region. To tackle these problems, a multi-input / multi-output (MIMO) plant model having some uncertainty was derived by considering some physical and mechanical principles of the process. Then a MIMO robust \ulcornercontroller is designed and implemented in a real DCS as function block type. Som...

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.4
• /
• pp.295-301
• /
• 2012

This paper deals with the design of robust DSMC (Discrete-Time Sliding Mode Control) scheme in order to overcome system uncertainty in steering system with mechanically joined structure. The proposed control scheme is one of robust control schemes based on system dynamics. Therefore, system dynamics required is not obtained from physical law but SCM (Signal Compression Method) through experiment in order to avoid complicate mathematical development and save time. However, SCM has a shortcoming that is the limitation of with $2^{nd}$ order linear model which does not include the dynamic of high-frequency band. Thus, considering system uncertainty, DSMC is designed. In addition, to reduce the chattering problem of DSMC, DSMC is derived from the reaching law and the Lyapunov stability condition. It is found that the proposed control scheme has robustness in spite of the perturbation of system uncertainty through computer simulation.