• Nuclear Engineering and Technology
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• 제45권2호
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• pp.265-276
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• 2013

Pressure tubes made of Zr-2.5 wt% Nb alloy are important components consisting reactor coolant pressure boundary of a pressurized heavy water reactor, in which unanticipated through-wall cracks and rupture may occur due to a delayed hydride cracking (DHC). The Canadian Standards Association has provided deterministic and probabilistic structural integrity evaluation procedures to protect pressure tubes against DHC. However, intuitive understanding and subsequent assessment of flaw behaviors are still insufficient due to complex degradation mechanisms and diverse influential parameters of DHC compared with those of stress corrosion cracking and fatigue crack growth phenomena. In the present study, a deterministic flaw assessment program was developed and applied for systematic integrity assessment of the pressure tubes. Based on the examination results dealing with effects of flaw shapes, pressure tube dimensional changes, hydrogen concentrations of pressure tubes and plant operation scenarios, a simple and rough method for effective cooldown operation was proposed to minimize DHC risks. The developed deterministic assessment program for pressure tubes can be used to derive further technical bases for probabilistic damage frequency assessment.

• 한국안전학회지
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• 제39권3호
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• pp.75-83
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• 2024

Accurately assessing and managing risks in any endeavor is crucial. Risk assessment in engineering translates the abstract concept of risk into actionable strategies for systematic risk management. However, risk validation is met with significant skepticism, particularly concerning the uncertainty of probability. This study aims to address the aforementioned uncertainty in a multitude of ways. Firstly, instead of relying on deterministic probability, it acknowledges uncertainty and presents a probabilistic interval. Secondly, considering the uncertainty interval highlighted in OREDA, it delineates the bounds of the probabilistic interval. Lastly, it investigates how much explanatory power deterministic probability has within the defined probabilistic interval. By utilizing fault tree analysis (FTA) and integrating confidence intervals, a probabilistic risk assessment was conducted to scrutinize the explanatory power of deterministic probability. In this context, explanatory power signifies the proportion of probability within the probabilistic risk assessment interval that lies below the deterministic probability. Research results reveal that at a 90% confidence interval, the explanatory power of deterministic probability decreases to 73%. Additionally, it was confirmed that explanatory power reached 100% only with a probability application 36.9 times higher.

• Journal of Advanced Marine Engineering and Technology
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• 제25권5호
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• pp.1058-1064
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• 2001

In this paper, the development of probability distribution estimation program for fatigue crack growth lives was summarize. The probability distribution estimation program of life was developed to increase the reliability of life estimation. In this study, it is considered that the cause of scatter in fatigue crack growth data is due to material inhomogeneity. The material resistance to fatigue crack growth is modelled as a spatial stochastic process, which varies randomly along the crack path. We developed the GUI program to estimate the probability distribution and reliability using the non-Gaussian stochastic process method. This program can be used for the reliability assessment.

• Child Health Nursing Research
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• 제22권2호
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• pp.117-125
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• 2016

Purpose: This study was done to examine the effect of direct practice of newborn health assessment on nursing student's clinical competence and self-efficacy and to propose effective strategies for clinical education on newborn care. Methods: Design was a nonequivalent control group quasi-experimental study. The direct practice program was composed of a lecture, demonstration, drill and feedback using a manikin, and repeated direct practice regarding newborn health assessment. Participants were 65 student nurses taking the pediatric nursing practicum in the nursery room at M hospital. The experimental group (n=33) participated in the direct practice program for newborn health assessment and the control group (n=32) received the traditional practice method. Nursing clinical competence was assessed by two nurse investigators and structured questionnaires were used to measure self-efficacy. Results: The experimental group's clinical competence was significantly higher than that of the control group (t=-4.82, p=.000). However no significant difference was found between the two groups for self-efficacy (t=1.264, p=.211). Conclusion: These findings indicate that the direct practice program is effective in improving nursing student's clinical competence, but it was not effective in increasing self-efficacy. Direct practice in various clinical education settings is recommended and longitudinal effects be evaluated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.453-458
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• 2001

Pipelines have the highest capacity and are the safest and the least environmentally disruptive way for gas or oil transmission. Recently, failures due to corrosion defects have become of major concern in maintaining pipeline integrity. A number of solutions have been developed for the assessment of remaining strength of corroded pipelines. However, these solutions are known to be dependent on material properties and pipeline geometries. In this paper, a Fitness-For-Purpose type limit load solution for corroded gas pipelines made of the X65 steel is proposed. For this purpose, a series of burst tests with various types of corrosion defects are performed. Finite element simulations are carried out to derive an appropriate failure criterion. And then, further, extensive finite element analyses are performed to obtain the FFP type limit load solution for corroded X65 gas pipelines as a function of defect depth, length and pipeline geometry. And also, a window based computer program far the assessment of corrosion defect, which is named as COPAP(COrroded Pipeline Assessment Program) has been developed on the basis of proposed limit load solution.

• Ocean Systems Engineering
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• 제12권3호
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• pp.267-284
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• 2022

A subsea pipeline designed across active shipping lane prones to failure against external interferences such as anchorage activities, hence risk assessment is essential. It requires quantifying the geometric probability derived from ship traffic distribution based on Automatic Identification System (AIS) data. The actual probability density function from historical vessel traffic data is ideal, as for rapid assessment, conceptual study, when the AIS data is scarce or when the local vessels traffic are not utilised with AIS. Recommended practices suggest the probability distribution is assumed as a single peak Gaussian. This study compares several fitted Gaussian distributions and Monte Carlo simulation based on actual ship traffic data in main ship direction in an active shipping lane across a subsea pipeline. The results shows that a Gaussian distribution with five peaks is required to represent the ship traffic data, providing an error of 0.23%, while a single peak Gaussian distribution and the Monte Carlo simulation with one hundred million realisation provide an error of 1.32% and 0.79% respectively. Thus, it can be concluded that the multi-peak Gaussian distribution can represent the actual ship traffic distribution in the main direction, but it is less representative for ship traffic distribution in other direction. The geometric probability is utilised in a quantitative risk assessment (QRA) for subsea pipeline against vessel anchor dropping and dragging and vessel sinking.

• 한국학교보건학회지
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• 제2권2호
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• pp.36-61
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• 1989

The purpose of this study was to identify and name clusters of school health program, and to describe some of the characteristics of administratie supports. The literature, materials and public documents were analysed by the chronological events from 1945 to 1989. The result of this study is as follows : 1. A brief summary of the history of school health program was included as an introduction to the analysis of the current programs of school health. Five current school health-program clusters were identified from findings of a study of programs : 1) physical assessment, laboratory examination and health services for the students, 2) health instruction 3) healthful living condition (environmental health), 4) health clinic management, 5) administrative supports. 2. The earliest school- based efforts focused on communicable disease pevention by the ministry of health and social affairs. Annual medical inspection (health assessment) for school children for eyes, ears, nose, and throat were mandated nation-wide in 1951 by physical assessment Act. 3. In 1979, the health instruction of schools to improve the health status of students was improved by health department in the Ministry of Education 4. Experiences in healthful environment were basic components of the school health program. However, without careful planning and supervision these experiences were not contributed to the goal of school health. The formal program of school health environment were initiated in 1979 5. In 1980, the guidelines of school health clinic management were prepared by Ministry of Education such as guidance of essential degrees and facilities in school health clinic. 6. Two patterns of administration of school health programs existed in Korea. In one the school health department operated its own health program and in the other the physical education department operated the health program within the school system. The school health department was established in Ministry of Education from 1979 to 1982. Improved school health programs will be a key element in the comprehensive national child health policy which I will ask the Ministry of Education to develop for the Department.

• 대한지역사회영양학회지
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• 제19권4호
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• pp.372-385
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• 2014

Objectives: The purpose of this study was to develop web-based self-nutrition management u-Health program for diabetic patients (DMDMG: Diabetes Mellitus Dietary Management Guide) for achieving systematic self-management of diet. Methods: The program consisted of five parts with different contents according to the results of needs assessment. Five major parts were 1) meal management part which contains calorie prescription, meals recording and dietary assessment, 2) prevention of disease part with information of diabetes and assessment of dietary behavior, 3) dietary behavior modification part with an education on dietary behavior modification plan and dietary behavior plan, 4) meal plan containing a training section for meal plan and self constructing part for meal planning by making tables, and 5) information about myself which composed with general and physical information. The system proposed in this study provides nutrients intake results right after input of diet intake, which is possible with simultaneous calculation of input data in the server with 3,495 food and 1,821 meal data base. The nutrients analysis program was evaluated with 26 diabetic patients with two-day 24 hr recall. Results: The differences of nutrients intakes between DMDMG and CANPRO 3.0 ranged from 13.5-16.5%, which was caused by the differences of databases of the two programs. The characteristics of DMDMG were; 1) it can provide an interactive tailored nutrition management, 2) it is a practical tool of diabetes nutritional management, 3) the program gives motivation for the dietary behavior modification. Conclusions: The effectiveness of whole program needs to be conducted, but the program was an innovative tool for self-management of nutrient intakes, diet behaviors, meal management and tailored nutrition education.

• 환경위생공학
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• 제4권2호
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• pp.61-90
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• 1989

The purpose of this study was to identify and name clusters of school health program, and to describe some of the characteristics of administrative supports. The literature, materials and public documents were analysed by the chronological events from 1945 to 1989. The result of this study is as follows : 1. A brief summary of the history of school health program was included as an introduction to the analysis of the current programs of school health. Five current school health-program clusters were identified from findings of a study of programs ; 1) Physical assessment, laboratory examination and health services for the students, 2) health insturction 3) healthful living condition(environmental health), 4) health clinic management 5) administrative supports. 2. The earliest school-based efforts focused on communicable disease prevention by the ministry of health and social affairs. Annual medical inspection(health assessment) for school children for eyes, ears, nose, and throat were mandated nation-wide in 1951 by physical Assessment Act. 3. In 1979, the health instruction of schools to improve the health status of students was improved by health department in the Ministry of Education. 4. Experiences in healthful environment were basic components of the school health program. However, without careful planning and supervision these experiences were not contributed to the goal of school health. The formal program of school health environment were initiated in 1979. 5. In 1980, the guidelines of school health clinic management were prepared by Ministry of Education such as guidance of essential degrees and facilities in school health clinic. 6. Two patterns of administration of school health programs existed in Korea. In one the school health department operated its own health program and in the other the physical education department operated the health program within the school system. The school health department was established in Ministry of Education from 1979 to 1982. Improved school health programs will be a key element in the comprehensive national child health policy whic I will ask the Ministry of Education to develop for the Department.

• The Korean Journal of Pain
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• 제1권2호
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• pp.137-144
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• 1988

The assessment of pain, an essentially subjective experience is an elusive and complex undertaking but is one of main problems as well as treatment in pain medicine. It is important to measure quality and quantity of pain for accurate diagnosis and establishing the treatment program and evaluating treatment outcome. Author review several measures of assessment of pain and suggest some elements for ideal form of korean pain scale.