• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.4
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• pp.55-61
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• 2012

Very important content in performance evaluation of machine tool is positioning accuracy and repeatability precision measurements of feed mechanism. A study analyses the measurement method and uncertainty factors by ISO-based test method. Reliable results can't be derived without the notion of measurement uncertainty. The reason is that the measured value includes a lot of uncertain factors. Finding the factor that affects the measurement of parameter is important for estimation of measurement precision. In this paper, the evaluation of uncertainty analysis about positioning accuracy and repeatability precision measurements of high precision feed mechanism is presented to evaluate the important factors of uncertainty.

• Journal of Korean Academy of Nursing
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• v.47 no.4
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• pp.445-455
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• 2017

Purpose: This study was conducted to develop an Empowerment Education Program (EEP) for kidney transplant patients and to test the program's effects on uncertainty, self-care ability, and compliance. Methods: The research was conducted using a nonequivalent control group with a pretest-posttest design. The participants were 53 outpatients (experimental group: 25, control group: 28) who were receiving hospital treatment after kidney transplants. After the pre-test, patients in the experimental group underwent a weekly EEP for six weeks. The post-test was conducted immediately after, and four weeks after the program's completion in the same manner as the pre-test. For the control group, we conducted a post-test six and ten weeks after the pre-test, without and program intervention. A repeated measure ANOVA was performed to compare the change scores on main outcomes. Results: Uncertainty was significantly lower in the experimental group than in the control group, both immediately after (t=-3.84, p=<.001) and 4 weeks after (t=-4.51 p=<.001) the program, whereas self-care ability (t=5.81, p=<.001), (t=5.84, p=<.001) and compliance (t=5.07, p=<.001), (t=5.45, p=<.001) were significantly higher. Conclusion: Kidney transplant patients who underwent an EEP showed a decrease in uncertainty and an improvement in self-care ability and compliance. Thus, our findings confirmed that an EEP can be an independent intervention method for improving and maintaining the health of kidney transplant patients.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.73-79
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• 2003

The steam turbine efficiency is an important factor in power plant. Accurate evaluation of steam turbine performance is essential. However, it is not easy to evaluate the steam turbine performance due to its high temperature and high pressure circumstance. Therefore most steam turbine performance tests were conducted by air similarity test. This paper described a test program for air similarity test of steam turbine at Korea Aerospace Research Institute. A test facility has been designed and built to evaluate aerodynamic performance of turbines. The test facility consists of air supply system, single stage test section, power absorption system, instrumentation and auxiliary system. For evaluation of steam turbine performance, the test of single stage axial turbine air similarity performance was conducted and uncertainty analysis was performed.

• Journal of Korean Academy of Nursing
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• v.45 no.2
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• pp.271-279
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• 2015

Purpose: This study was done to examine the relation of uncertainty, uncertainty appraisal, and self-management in patients undergoing hemodialysis, and to identify factors influencing self-management. Methods: A convenience sample of 92 patients receiving hemodialysis was selected. Data were collected using a structured questionnaire and medical records. The collected data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlations and multiple regression analysis with the SPSS/WIN 20.0 program. Results: The participants showed a moderate level of uncertainty with the highest score being for ambiguity among the four uncertainty subdomains. Scores for uncertainty danger or opportunity appraisals were under the mid points. The participants were found to perform a high level of self-management such as diet control, management of arteriovenous fistula, exercise, medication, physical management, measurements of body weight and blood pressure, and social activity. The self-management of participants undergoing hemodialysis showed a significant relationship with uncertainty and uncertainty appraisal. The significant factors influencing self-management were uncertainty, uncertainty opportunity appraisal, hemodialysis duration, and having a spouse. These variables explained 32.8% of the variance in self-management. Conclusion: The results suggest that intervention programs to reduce the level of uncertainty and to increase the level of uncertainty opportunity appraisal among patients would improve the self-management of hemodialysis patients.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.139-145
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• 2007

Measurement uncertainty could play an important role in the assessment of test results in laboratories and industries. We investigated measurement uncertainties possibly included in determination of flubendazole, a benzimidazole anthelmintic, in pork by HPLC. The concentration of flubendazole was 62.69 ng/g in a sample of pork. Uncertainty was estimated in the analytical procedure of flubendazole. A model equation was made for determination of flubendazole in pork. The four uncertainty components such as weight of sample, volume of sample, calibration curve, and recovery were selected to estimate measurement uncertainties. Standard uncertainty was calculated for each component and all the standard uncertainties were combined. The combined standard uncertainty was expanded to a sample population as an expanded uncertainty. The expanded uncertainty was calculated using k value on Student's t-table and effective degrees of freedom from Welch-Satterthwaite formula. The expanded uncertainty was calculated as 3.45 with the combined standard uncertainty, 1.584 6 and the k value, 2.18. The final expression can be ($62.69{\pm}3.45$) ng/g (confidence level 95%, k = 2.18). The uncertainty value might be estimated differently depending on the selection of the uncertainty components. It is difficult to estimate all the uncertainty factors. Therefore, it is better to take several big effecting components instead of many small effecting components.

• Child Health Nursing Research
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• v.23 no.1
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• pp.70-80
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• 2017

Purpose: In this study a caregiver's role improvement program was developed and tested to identify the effect on uncertainty, stress, and role performance of caregivers with hospitalized children. Methods: The design of this study was a quasi-experimental study with a nonequivalent control group and a non-synchronized design. Thirty-three caregivers were assigned to the experimental group and 33 to the control group. Data were collected from March 5 2016 to April 10 2016. For the experimental treatment, each individual was given on-site education with situated learning (given 30 minutes each, for 2 sessions), and self-repetition learning activities were performed from the e-book. Data were analyzed using t-test, ${\chi}^2-test$, Fisher's exact test, paired t-test, and independent t-test. Results: The level of uncertainty and stress decreased, and role performance level improved for these caregivers with hospitalized children. Conclusion: The findings of this study show that using on-site education through situated learning and self-repetition learning with an e-book as in the caregiver's role improvement program is an effective intervention. Therefore, utilizing the caregiver role improvement program developed in this study is recommended as an effective intervention for caregivers of hospitalized children.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.9
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• pp.712-719
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• 2008

Light Oil Flow Standard System(LOFSS), as a national oil flow standard system, in Korea Research Institute of Standards and Science(KRISS) was developed for oil flowmeter calibration, and the expanded uncertainty of flow quantity determination was estimated within 0.04 %. In order to improve the reliability of the LOFSS measurement, a proficiency test was carried out in the flow range of 20 and $240\;m^3/h$ (Reynolds number $20,000{\sim}900,000$). A turbine flowmeter was used as a transfer package in round robin test. The water flow standard system of KRISS, the pipe prover of the national calibration and test organization and the master meter calibrator of the turbine flowmeter supplier, which used the different working fluid respectively, were compared with the turbine flowmeter measurement. The maximum difference of measurement was 0.15 % between the LOFSS and the pipe prover. The En numbers of the each system measurement were evaluated at the same Reynolds number. It was found that the En numbers were less than 1 in the comparison, which means the procedures of the uncertainty estimation of the each calibrators were reasonable and reliable.

• Journal of muscle and joint health
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• v.23 no.2
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• pp.114-124
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• 2016

Purpose: The purpose of this study was to investigate the level of uncertainty, physiological risk factors, self-efficacy, and self-management among stroke patients and to identify factors influencing their self-management. Methods: A descriptive correlational design was used for this study. A convenience sample of 149 patients with stroke were enrolled at C national university hospital from February to April in 2016. Data were collected using a structured questionnaire and electronic medical record. Collected data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlations, and multiple regression analysis with the SPSS/WIN 21.0 program. Results: There were significant negative correlations between uncertainty and self-efficacy (r=-.56, p<.001); between uncertainty and self-management (r=-.56, p<.001); and between total cholesterol and self-management (r=-.23, p=.005). There were significant positive correlations between self-efficacy and self-management (r=.78, p<.001); between uncertainty and total cholesterol (r=.24, p=.003). The significant factors influencing self-management were uncertainty and self-efficacy. Theses variables explained 62.7% of the variance in self-management. Conclusion: The results suggest that intervention programs to reduce the level of uncertainty and to increase the level of self-efficacy among patients would improve the self-management of stroke patients.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.8
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• pp.1071-1080
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• 2003

A national standard system was developed in order to calibrate and test the oil flowmeters for the petroleum field. A stop valve and a gyroscopic weighing scale were employed for the primary standard of the flow quantity. It is operated by the standing start and finish mode and the static weighing method. The model equation for uncertainty evaluation was based on the calibration principle of standard system. The sources of the uncertainties were quantified and combined according to the GUM(Guide to the Expression of Uncertainty in Measurement). It was found that the standard system had the relative expanded uncertainty of 0.04 % in the range of 18 - 350 ㎥/ｈ. According to the uncertainty budget, the uncertainties of the fluid density and the volume of pipeline, which were temperature dependent, contributed 92% of final uncertainty in the oil flow standard system.

• Journal of Distribution Science
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• v.16 no.6
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• pp.25-35
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• 2018

Purpose - Although marketing networks are crucial competitive advantage in terms of firm's new information and resource acquisition ability, their impact on new product development performance remains vague, especially under environmental uncertainty. The principal objective of this research is to provide a better understanding of effects of technological uncertainty and volume uncertainty on first tier supplier's perceived performance of new product development under conditions reflecting varying levels of structural holes. Specifically, this research examines the moderating effect of structural holes on the relationship between environmental uncertainty and new product development performance. Research design, data, and methodology - To test the hypotheses, a questionnaire survey was conducted with a Korean engineering firm's major first-tier suppliers in the context of internal network entities, manufacturer-supplier-subsupplier relationships, and to verify the proposed hypotheses, structural equation modeling was established. Construct measures were based on existing measures and previous research. Results - The survey results indicate that technological uncertainty and volume uncertainty differentially affect NPD performance under conditions of high and low structural holes. Conclusions - This study offer some theoretical and practical implications among distribution channel members, especially, this study suggests that interfirm networks have critical competitive advantage in uncertain environments. The distinctiveness of engineering industry might limit the generalizability of the results. Thus, future research should consider a wider range of industries.