• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.14 no.3
• /
• pp.1-6
• /
• 2006

The altitude engine test is a sort of engine performance tests carried out to measure the performance of a engine at the simulated altitude and flight speed environments prior to that at the flight test. During the performance test of a engine, various values such as pressures and temperatures at different positions, air flow rate, fuel flow rate, and the load by thrust are measured. These measured values are used to derive the representative performance values such as the net thrust and the specific fuel consumption through a momentum equation. Hence each of the measured values has certain effects on the total uncertainty of the performance values. In this paper, the combined standard uncertainties of the performance variables at the engine test were estimated by the uncertainty analysis of the measurement values and the repeatability and reproducibility of the altitude test measurement were assessed by the analysis of variation on the repeated test data with different operator groups.

• Journal of muscle and joint health
• /
• v.25 no.3
• /
• pp.187-195
• /
• 2018

Purpose: This study was conducted to develop a video education program for spinal surgery patients and to investigate the effect of the program on patients' uncertainty and educational satisfaction. Methods: This study employed a nonequivalent control group pretest-posttest design. The participants were 54 patients who had undergone spinal surgery in Busan from February to May 2017. The video education program was provided to the experimental group (n=28). The program consisted of providing existing leaflets to patients and repeatedly showing patients educational videos during their hospitalization. Leaflets were also provided to the control group (n=26) as part of traditional care. Patients' reported levels of uncertainty and educational satisfaction were measured. Data were analyzed using the chi-squared test, independent t-test, Mann-Whitney U test, and covariance analysis. Results: A significant difference was observed between the groups in uncertainty pre-post changes (U=239.50, p=.030). With the education variable controlled, there were significant differences between the groups in the educational satisfaction posttest (F=19.79, p<.001). Conclusion: The program was effective in reducing uncertainty and in enhancing educational satisfaction. Therefore, the video education program may be helpful for improving patient satisfaction and outcomes in various clinical fields.

• The KSFM Journal of Fluid Machinery
• /
• v.7 no.5 s.26
• /
• pp.29-35
• /
• 2004

The turbine efficiency is an important factor in power plant, and accurate evaluation of steam turbine performance is the key issue in turbo machinery industry. The difficulty of evaluating the steam turbine performance due to its high steam temperature and pressure environment makes the most steam turbine tests to be replaced by air similarity test. This paper presents how to decide the similarity conditions of the steam turbine test and describes its limitations and assumptions. The test facility was developed and arranged to conduct an air similarity turbine performance test with various inlet pressure, temperature and mass flow rate. The eddy-current type dynamometer measures the turbine-generated shaft power and controls the rotating speed. Pressure ratio of turbine can be controled by back pressure control valve. To verify its test results, uncertainty analysis was performed and relative uncertainty of turbine efficiency was obtained.

• Fashion & Textile Research Journal
• /
• v.15 no.5
• /
• pp.763-776
• /
• 2013

This study investigated the uncertainty, regret experience, and negative behavior intention of fashion consumers according to the types of internet shopping malls. The data was obtained from internet fashion consumers, and 394 responses were used in the data analysis. The statistical analysis methods were frequency analysis, factor analysis, reliability analysis, t-test, ANOVA, and regression analysis. As results, the uncertainty of internet fashion consumers was composed of two factors; information uncertainty and preference uncertainty. The regret experience was composed of function or service regret, suitability regret, and product regret. Also, the negative behavior intention was composed of purchase switching intention and purchase deferral intention. The information uncertainty of fashion consumers positively affected the negative behavior intention in all types of internet shopping malls (e.g., open market, integrated shopping mall, and fashion specialized shopping mall). In open market, the preference uncertainty negatively affected the purchase switching intention; however, the preference uncertainty positively affected the purchase deferral intention. In open market and fashion specialized shopping mall, the product regret of internet fashion consumers positively affected the negative behavior intention. In addition, there were partially significant differences in the factors of uncertainty, regret experience, and negative behavior intention by gender and marital status of demographic characteristics. The results of this study will provide useful information to the marketing strategies considering fashion consumer's negative emotion and behaviors according to the types of internet shopping malls.

• 유체기계공업학회:학술대회논문집
• /
• 2003.12a
• /
• pp.73-79
• /
• 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
• /
• v.18 no.3
• /
• pp.231-238
• /
• 1988

The purpose of this study was to assess and compare discrepancy in the scores of uncertainty perceived by patients and nurses' interperson perception. For this study, 124 hospitalized patients and the same numbered nurses assigned for direct care of each 124 patients were selected from general ward of C. University Hospital in Seoul during the time period from September to November 1987. Degree of uncertainty was measured by 27 items modified from Mishel Uncertainty in Illness Scale (MUIS), and was utilized by a Likert type scale The data were analysed by Mcnemar-test. Unpaired t-test. ANOVA, Scheffe - test and Stepwise multiple regression. The results are summarized as follows : 1. The discrepancy in the scores of uncertainty perceived by patients and nurses' interperson perception showed significant differences in 23 of 27 items : 11 of 23 items showed that the scores of patients' perception of uncertainty were higher than that of nurses' interperson perception of uncertainty. but 12 of 23 items were revealed reversely. 2. With regard to nurse's demographic variables, the discrepancy scores were the higest in the group under 22 years of age (F＝3.20, p＝.026) and in the group less than 1 year of nursing experience among 4 groups (F＝4.41, p＝.006). 3. The discrepancy scores had a tendency to be lowered in the higher age group(r＝ -.27. p＝.0026) and in the longer experienced group (r＝-.25, p＝.0052). 4. The most important variable affecting the discrepancy scores was identified to be the nurses' age which acounted for 7.2% fo the total variances in the stepwise multiple regression analysis. This was followed by patient hospital days which accounted for an additional 4.5% of the total variances. To conclude, the discrepancy in the scores of uncertainty perceived by patients and nurses' interperson perception showed significant differences in 23 of 27 items. The discrepancy scores of uncertainty had a tendancy to be lowered in the higher age group and in the longer experienced group.

• Nuclear Engineering and Technology
• /
• v.52 no.8
• /
• pp.1626-1637
• /
• 2020

This work covers an important point of the benchmark released by the expert group on Uncertainty Analysis in Modeling of Light Water Reactors. This ambitious benchmark aims to determine the uncertainty in light water reactors systems and processes in all stages of calculation, with emphasis on multi-physics (coupled) and multi-scale simulations. The Gesellschaft für Anlagen und Reaktorsicherheit methodology is used to propagate the thermal-hydraulic uncertainty of macroscopic parameters through TRACE5.0p3/PARCSv3.0 coupled code. The main innovative points achieved in this work are i) a new thermal-hydraulic model is developed with a highly-accurate 3D core discretization plus an iterative process is presented to adjust the 3D bypass flow, ii) a control rod insertion occurrence -which data is obtained from a real PWR test- is used as a transient simulation, iii) two approaches are used for the propagation process: maximum response where the uncertainty and sensitivity analysis is performed for the maximum absolute response and index dependent where the uncertainty and sensitivity analysis is performed at each time step, and iv) RESTING MATLAB code is developed to automate the model generation process and, then, propagate the thermal-hydraulic uncertainty. The input uncertainty information is found in related literature or, if not found, defined based on expert judgment. This paper, first, presents the Gesellschaft für Anlagen und Reaktorsicherheit methodology to propagate the uncertainty in thermal-hydraulic macroscopic parameters and, then, shows the results when the methodology is applied to a PWR reactor.

• Journal of the Korea Convergence Society
• /
• v.9 no.6
• /
• pp.311-319
• /
• 2018

The purpose of this study was to identify the degree of uncertainty, uncertainty appraisal, and self-efficacy in pre-discharge arthroscopic patients and to investigate the effects of their uncertainty. This study was carried out from April to October 2016 as a descriptive research study. The subjects were presented with pre-discharge convenience sampling after arthroscopic surgery. The data of 131 patients were analyzed by t-test, ANOVA and Scheffe post-test, Pearson correlation coefficient calculation and multiple regression analysis using SPSS 18.0. As the results of this study, education level, presence of spouse, preoperative korean traditional medicine treatment experience and self-efficacy were found to have significant effects on uncertainty. The results of this study suggest that in hospital and pre-discharge education program development to reduce patient uncertainty after arthroscopic surgery.

• Journal of The Korean Society of Integrative Medicine
• /
• v.10 no.4
• /
• pp.153-163
• /
• 2022

Purpose : The purpose of this study was to investigate the differences between uncertainty of chronic diseases and quality of life with regard to elderly people. Methods : The participants of this study were 350 elderly people, aged over 65 years. The collected data were analyzed using the SPSS Window program and the general characteristics of the participants and sub-domains of quality of life were analyzed by several frequency analyses and descriptive statistics such as mean, standard deviation, skewness, and kurtosis. Further, the differences between the sub-domains of uncertainty and sub-domains of quality of life were analyzed through independent t-test and one-way ANOVA. In order to reach conclusive results, post-test was analyzed by the Scheffe test. In addition, Pearson's correlation analysis was performed to determine the correlation between the target categories. A significance level of 𝛼=.05 was used to verify statistical significance. Results : As a result of examining "uncertainty" with respect to general characteristics, such as older age, low educational background, and chronic diseases, it was observed that the more intense these factors became, the more the level of uncertainty increased. In addition, it was also noted that except "accompanying diseases" in social domain, the participants enjoyed a high level of quality of life. The correlation was noted between domains of complexity and sociality (p<.01), domains of inconsistency and sociality (p<.01), domains of complexity and living environment (p<.01), domains of inconsistency and living environment (p<.01), and total score of uncertainty and total quality of life (p<.01). Conclusion : In this study, differences were found between "uncertainty" and "quality of life" of elderly people; the correlation between the sub-domains based on general traits was found to be negative (-). This suggests that objective evidence can be presented for the prevention of diseases by using mental health programs for the elderly in future.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.29 no.10 s.241
• /
• pp.1130-1138
• /
• 2005

A national standard system for the petroleum field has been developed to calibrate and test the oil flow meters in Korea. The operating system and the uncertainty of the system were evaluated by the peer reviewers of foreign national metrology institutes in 2002. Since the characteristics of the system might be changed by time, the uncertainty of the system is reevaluated with the consideration of the long term stability of the system. It is found that the system has a relative expanded uncertainty of 0.048 $\%$ in the range of $15\~120\;m^3/h$. According to the uncertainty budget, the uncertainties of the fluid density and the final mass measurement, which are temperature dependent, contribute about $94\%$ of the total uncertainty in the oil flow standard system