• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1862-1870
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• 2020

The purpose of this study is to investigate the effect of welding residual stress on operating stress in designing a nuclear turbine welded rotor. A two-dimensional axisymmetric finite element model is employed to calculate the residual stress before and after post weld heat treatment (PWHT), and then the superposition of residual stress after PWHT and operating stress at normal speed and overspeed were discussed. The investigated results show that operating stress can be affected significantly by welding residual stress, and the distribution trend of superposition stress at the weld area is mainly determined by welding residual stress. The superposition of residual stress and operating stress is linear superposition, and the hoop stress distribution of superposition stress is similar with the distribution of residual stress. With the increasing overspeed, the distribution pattern of the hoop superimposed stress remains almost unchanged, while the stress level increases.

• Journal of Environmental Health Sciences
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• v.31 no.1
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• pp.55-60
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• 2005

The occurrence and abundance of protozoa at advanced wastewater treatment plant were compared with operating parameters and effluent quality using statistical procedures. In correlation analysis between the distribution of protozoa and operating parameters, the distribution of protozoa was showed the operating condition of plant. Regression analysis between the distribution of protozoa and effluent quality up to 7 days, showed the R-square values of most regression equation were more than 0.6 and constant was higher than slope and could indicate effluent quality from sampling day to 7 days. Once enough data concerning protozoa, operating parameters and effluent has been gathered, the operator has a valuable tool for predicting plant performance and near-future effluent quality based on microscopic examination. Plant operator manipulates operating conditions if he knows near-future data of effluent is deteriorating. Perhaps more importantly it can be used to actually control the plant to adjust the operating conditions to obtain the protozoal populations that have been shown to provide the best effluent quality.

• Korean Journal of Occupational Health Nursing
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• v.21 no.3
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• pp.229-238
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• 2012

Purpose: The purpose of this study was to measure the fatigue of operating room nurses and examine factors contributing to their fatigue. Methods: The subjects of this study were 115 nurses who worked in operating rooms of three hospitals. Data were collected from September 15, 2009 to September 30, 2009. Fatigue and job stress were measured by using the Symptom's Fatigue Scale and the job stress measurement tools in operating room nurses. Results: The mean score of fatigue level was $3.10{\pm}0.61$. We analyzed fatigue according to characteristics of subjects and found that there were significant differences in marital status, number of children and sleeping hours in general characteristics. Career, daily participation hours in the surgery relating to job related characteristics. Significant positive correlations were found between job stress and fatigue(r=.233, p= .012). Three significant variables influencing fatigue of operation rooms nurses were job stress, daily participation hours in the surgery, and sleeping hours (Adj. $R^2$=0.284, F=4.773, p<.001). Conclusion: An integrative care program that takes job stress, daily participation hours in the surgery and sleeping hours into consideration is essential to reduce fatigue in operating room nurses.

• Journal of Korean Critical Care Nursing
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• v.9 no.1
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• pp.27-39
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• 2016

Purpose: The purpose of this study lies in investigating nursing and medical staff perceptions on the importance of surgical patient safety protocol, teamwork, and patient safety culture, and how their grasp of the factors affects the degree of their performance of the protocol. Methods: A survey was conducted on 249 nurses and medical staff participating in the operating rooms of one higher general hospital in Seoul, using a 5-point scale self-reported questionnaire. Logistic regression analyses were used. Results: Operating room nurses yielded the highest scores on both the importance of the patient safety protocol and its performance. In patient safety culture, the operating medical staff yielded significantly higher scores than those of operating room nurses. Perception of the importance of the patient safety protocol and teamwork had a significant effect on the nurses' complete performance of the protocol. Conclusion: It is important to create a safety culture, where all the staff can actively and freely communicate with one another through team-based training programs. By enhancing teamwork and patient safety culture, it will be possible to establish the surgical patient safety protocol and to improve the performance of the protocol by health professionals.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2654-2663
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• 2000

Steam turbine rotors are the most critical and highly stressed components of a steam power plant; therefore, the life expectancy of the turbine rotor is an important consideration for the safety of a steam power plant. The objective of this paper is to develop a life estimation program for turbine rotors for all possible operating conditions. For this purpose, finite element analysis was carried out for four normal operating modes (cold, warm, hot and very hot starts) using ABAQUS codes. The results are made into databases to evaluate the life expenditure for an actual operating condition. For any other possible abnormal operating condition, the operating data are transmitted to the server (workstation) through a network to carry out finite element analysis. Damage estimation is carried out by transmitting the finite element analysis results to the personal computer, and then the life expectancy is calculated.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.177-179
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• 2006

This paper presents an analysis architecture of embedded operating systems for wireless sensor network. Wireless multi-hop sensor networks use battery-operated computing and sensing device. We expect sensor networks to be deployed in an ad hoc fashion, with very high energy constraints. These characteristics of multi-hop wireless sensor networks and applications motivate an operating system that is different from traditional embedded operating system. These days new wireless sensor network embedded operating system come out with some advances compared with previous ones. The analysis is focusing on understanding differences of dominant wireless sensor network OS, such as TinyOS 2.0 with TinyOS 1.x.

• Journal of Korean Academy of Nursing
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• v.41 no.1
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• pp.36-46
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• 2011

practice in operating room nursing and to examine the learning effects. Methods: Based on content and need analysis, 9 learning modules were developed for nursing care in operating rooms and with operating equipment. To verify the effects of the program, a quasi- experimental pretest-posttest control group design was employed. The participants in this study were 74 third-year nursing students (34 in the experimental and 40 in the control group) from a junior college in G-city, Korea, who were engaged in a one week clinical practicum in an operating unit. Frequencies, $X^2$-test and t-test with the SPSS program 17.0 were used to analyze the data. Results: Knowledge was significantly higher in the experimental group compared to the control group (p=.018). However, there was no significant difference between the two groups in self-directed learning. The experimental group had significantly higher motivation toward learning, which was examined posttest only (p=.027). Conclusion: These results indicate that the implementation of an e-Learning program needs to be continued as an effective educational tool, but more research on the best way to implement e-Learning in students' practicum is needed.

• Journal of the military operations research society of Korea
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• v.35 no.3
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• pp.31-45
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• 2009

Reliability should be done from the initial stage of development to secure performance and safety of system. To establish and achieve target reliability of a system, reliability should be allocated into the subsystems. In the acquisition and development of a system, frequent failures will cause a negative effect on performing mission and occurs increasing operating cost. This study reviewed and evaluated the existing reliability allocation models using operation and maintenance costs to find the correlation between reliability allocation models and its operating cost. A target system reliability on the diesel engine to be developed for naval vessels is allocated into its subsystem based on the existing reliability allocation models. A selection methodology for reliability allocation models was made to minimize operating cost by using simulation based on the given operating diesel engine data for naval vessels.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.9
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• pp.384-391
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• 2006

The harmonic currents generated along with the operating speed of electrical railroad traction are very difficult to analyze because of its nonlinear characteristics. This paper therefore presents probabilistic approach for the evaluation of harmonic currents about the operating speed of the arbitrary single traction. To use probabilistic method for railroad system, PDF(Probability Density Function) using measuring data based on the realistic h 따 monic currents per operating speed is calculated. Measuring data of harmonic current per operating speed is obtained using the result data of PSCAD/EMTDC dynamic simulation based on an IAT(Intra Airport Transit) in Incheon International Airport. The means(expected values) and variances of harmonic currents of single traction also are obtained by the PDF of the operating traction speed and harmonic currents. The uncertainty of harmonic currents can be calculated through the mean and variance of PDF. The probability of harmonic currents generated with the operating of arbitrary many tractions is calculated by the convolution of functions. The harmonics of different number of tractions are systematically investigated to assess the TDD(Total Demand Distortion) for the railroad system. The calculation of TDD was carried out using Monte-Carlo Simulations(MSCs) and the results of TDD evaluation of the power quality in the IAT power feeding system.

• Journal of the Korean Society of Food Culture
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• v.33 no.1
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• pp.26-35
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• 2018

This study conducted an empirical analysis of the effects of job characteristics on work-family conflict relation and quality of life, as well as moderating effects in accordance with operation type, by targeting 245 dietitian/cooks working for contract foodservice companies. The results of this study are as follows. First, the autonomy and feedback had negative (-) effects on work-family conflict while functional diversity had positive (+) effects on work-family conflict. Job identity and job importance had no relation with work-family conflict. Second, work-family conflict had negative (-) effects on job satisfaction, work-family relation, job support, general happiness, and job environment while having positive (+) effects on job stress. Third, in all paths except for the path with effects of work-family conflict on job stress, there were no differences between the group of shops operating 365 days and the group of shops operating 5 days a week. It would be helpful to the effective operation of human resources by emphasizing the necessity of differentiated management for companies with shops operating 365 days and shops operating 5 days a week, as well as managing employees' job characteristic factors, work-family conflict, and even quality of life.