• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.61-75
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• 1997

The social demand urges us to use some equipments and structures in high temperature environment. By this occasion, the necessity of studying the fatigue crack growth is an important aspect of new materials. However, the present situation is rarely to accumulate the fatigue data. Especially, 1Cr-1Mo-0.25V steel and 304 stainless steel have been increased to be used under the severe condition of high temperature. And so, the fatigue estimation of those materials is important and appropriate. Fatigue tests have been carried out to examine the crack initiation, growth behaviour for the small fatigue crack of 1Cr-1Mo-0.25V steel and 304 stainless steel at room temperature and 538^{\circ}C$. The remote measurement system which has many merits of checking and saving the image for detailed examination was applied to closely detect the crack length. Generally, the fatigue crack initiated in the form of multiple cracks and grew each other. And then it coalesced to become a major crack. The major crack governed the rest of the fatigue life. In the growing process, each peripheral cracks interact and grow for a certain period. After then, it coalesced and fractured. On the basis of the above experimental data for the small crack, a simulation program was developed to predict the residual life time and to estimate the integrity of machine elements and structures. At the same time, the simulation was extended to 1Cr-1Mo-0.25V steel. The simulation results have shown a good agreement to those of the experimental ones for both materials of 1Cr-1Mo-0.25V steel and 304 stainless steel with small cracks. The NASCRAC has applied to compare the fatigue life with the experimental results. And so, it can be said that the simulation program is valuable tools to the industrial fields.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.301-311
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• 2018

Purpose: The purpose of this study was to examine the effects of the simulation-based cooperation program on self-efficacy, social problem-solving ability and college life adjustment of health college students. Methods: A nonequivalent control group pre-posttest design was used. Sixty-eight students were in the experimental group receiving the simulation-based cooperation program, and 68 were in the control group with no treatment. Results: There were significant increases in self-efficacy(z=-4.70, p<.001) and college life adjustment(t=2.03, p<.05) in the experimental group compared to the control group. However, there was no difference in the social problem-solving ability (z=-1.87, p=.061) between the experimental and control groups. Conclusion: The findings indicate that the simulation-based cooperation program has a significant effect on improving self-efficacy and college life adjustment in health college students. Thus the simulation-based cooperation program to promote the social problem-solving ability needs to be more developed and research related with cooperation program is further needed.

• Women's Health Nursing
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• v.29 no.3
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• pp.229-238
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• 2023

Purpose: This study analyzed the effects of virtual reality simulation-based problem-based learning on nursing students' critical thinking ability, problem-solving ability, and self-efficacy in the nursing care of women undergoing induction of labor. Methods: A nonequivalent control group pretest and posttest design was employed. The study participants included 52 nursing students (24 in the experimental group and 28 in the control group). The experimental group took a problem-based learning (PBL) class in the first week, and then engaged in self-directed learning using virtual reality simulation. In the second week, lectures about emergency nursing care for induction of labor and drug administration were given. The control group participated in PBL in the first week and lectures in the second week. The study was conducted from April 17 to May 19, 2023. Data were analyzed using the chi-square test, Fisher exact test, analysis of variance, and the independent t-test. Results: Before-and-after differences between the two groups were statistically significant in problem solving ability (t=-5.47, p<.001) and self-efficacy (t=-5.87, p<.001). Critical thinking ability did not show a statistically significant difference between the two groups. The score for satisfaction with the virtual reality simulation program was 3.64±5.88 out of 5 in the experimental group. Conclusion: PBL education using a virtual reality simulation was found to be an effective way of teaching. Although convenience sampling was used, PBL education using virtual reality can be used as an educational strategy to enhance nursing students' problem-solving ability and self-efficacy.

• The Korean Journal of Emergency Medical Services
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• v.15 no.3
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• pp.5-17
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• 2011

purpose : The purpose of this study was to analyze the effect of basic life support performance by video simulation training. Methods : The subjects in this study consisted of 24 persons of experimental group and 24 persons of control group in freshmen and sophomore EMT students. The data were collected from September 1 to 30, 2010. Results : 1. Hypothesis one: experimental group is meaningful higher than control group at the operation point (p<0.05) of adult/infant's basic life support for one person. In subcategory that identifying breath, artificial respiration, pulse rate, 30 compressions, Ability to perform all the processes, the experimental group showed statistically higher score (p<0.05) than control group, and sequence from checking reaction to keeping airway management isn't statistically significant difference between experimental group and control. 2. Hypothesis two: In the hypothesis, the experimental group's point of adult basic life support by two persons and use of Automated External Defibrillator is good in experimental group than control group's point(p<0.05). As the result of researching 11 contents of check list about adult basic life support by two persons and Automated External Defibrillator(AED), by dividing into 7 subcategories, every subcategory shows that the experimental group is significant higher than control group(p<0.05). 3. Hypothesis three: In the hypothesis, the experimental group gets higher point of infant basic life support by one or two persons than the control group (p<0.05). As the results of researching 15 contents of check list about infant basic life support by one or two persons, by dividing into 8 subcategories, the experimental group is statistically meaningful higher (p<0.05) than the control group in process of keeping airway, indentifying breathing, identifying pulse, 30 compressions, Ability to perform all the processes. There isn't statistically significant difference between the groups in process of checking reaction, reporting 119, and artificial respiration by giving 2 breaths(p<0.05). Conclusion : As summarizing the results, the group, receiving using video, gets higher points of knowledge of basic life support and operating skill than the general educated group. It is found that the Video simulation training could be effective, because of these positive effects to improve clinical working performance of students, who participate in the department of Emergency Medical Technology.

• Physical Therapy Rehabilitation Science
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• v.13 no.1
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• pp.18-25
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• 2024

Objective: This study is a single-group pre-post experimental study to determine the effects of simulation-based practice education on nursing students' self-efficacy, performance confidence, and educational satisfaction. Design: Single-group pre-post experimental studies Methods: This study was conducted from September 1, 2023 to November 30, 2023 for nursing undergraduate students in a simulation based practical education program. The subjects were provided with learning materials about an acute myocardial infarction case with chest pain for preliminary learning. After that, they were divided into teams of 6 people and asked to do self-study for 2 hours per team, twice a week, before conducting simulation practice. For the simulation based practical education, the participants were divided into 9 teams of 6 people each, and each team had 10 minutes for orientation, 15 minutes for scenario operation, and 50 minutes for debriefing. Results: After the simulation based practical education, self-efficacy increased statistically significantly from a mean of 3.51 before training to a mean of 3.80 after training (t=-2.12, p=0.038). However, there was no significant difference in performance confidence. There was a significant positive correlation between self-efficacy and performance confidence (r=0.62, p<0.001) and training satisfaction (r=0.67, p<0.001) after the simulation based practical education. Self-confidence was also significantly correlated with educational satisfaction (r=0.76, p<0.001). Conclusions: The results of this study showed that utilizing simulation-based practical education can increase nursing students' self-efficacy, which positively affects their performance confidence and educational satisfaction. Therefore, simulation-based practical education is an effective nursing education method that can improve nursing students' practical skills.

• Computers and Concrete
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• v.18 no.2
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• pp.235-266
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• 2016

A rock mass containing non-persistent joints can only fail if the joints propagate and coalesce through an intact rock bridge. Shear strength of rock mass containing non-persistent joints is highly affected by the both, mechanical behavior and geometrical configuration of non-persistent joints located in a rock mass. Existence of rock joints and rock bridges are the most important factors complicating mechanical responses of a rock mass to stress loading. The joint-bridge interaction and bridge failure dominates mechanical behavior of jointed rock masses and the stability of rock excavations. The purpose of this review paper is to present techniques, progresses and the likely future development directions in experimental and numerical modelling of a non-persistent joint failure behaviour. Such investigation is essential to study the fundamental failures occurring in a rock bridge, for assessing anticipated and actual performances of the structures built on or in rock masses. This paper is divided into two sections. In the first part, experimental investigations have been represented followed by a summarized numerical modelling. Experimental results showed failure mechanism of a rock bridge under different loading conditions. Also effects of the number of non-persistent joints, angle between joint and a rock bridge, lengths of the rock bridge and the joint were investigated on the rock bridge failure behaviour. Numerical simulation results are used to validate experimental outputs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7812-7819
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• 2015

Nursing students experienced anxiety and fear of building relationships with psychiatric patients due to lack of professional knowledge about metal illness and skill to take care of the patients. The simulation education is known as an effective teaching-learning method since being performed in a non-threatening environment similar to clinical setting. The purpose of this nonequivalent quasi-experimental study was to identify the effect of simulation on anxiety and self-confidence about the psychiatric-mental health nursing practice. The third year nursing students at a three year nursing program were participated in this study. For the experimental group (N=28) the simulation education using the standardized patient based on the scenario for patients with schizophrenia was performed, and for the control group (N=18), the debated education applying the case study same as for the experimental group was made in the class. Using SPSS, t-test and ANCOVA were analyzed to compare the anxiety and self-confidence between the experimental and control groups. As a result of the study, the anxiety score on psychiatric-mental health nursing clinical practice of the experimental group significantly decreased, compared to that of the control group, but the self-confidence score for the performance of psychiatric nursing care showed no significant differences between the groups. Accordingly the simulation education can be an effective educational method to reduce anxiety about psychiatric-mental health nursing clinical practice for nursing students.

• Journal of the Korea Society for Simulation
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• v.13 no.2
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• pp.23-34
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• 2004

Regenerative simulation (RS) is a method of stochastic steady-state simulation in which output data are collected and analysed within regenerative cycles (RCs). Since data collected during consecutive RCs are independent and identically distributed, there is no problem with the initial transient period in simulated processes, which is a perennial issue of concern in all other types of steady-state simulation. In this paper, we address the issue of experimental analysis of the quality of sequential regenerative simulation in the sense of the coverage of the final confidence intervals of mean values. The ultimate purpose of this study is to determine the best version of RS to be implemented in Akaroa2 [1], a fully automated controller of distributed stochastic simulation in LAN environments.

• Journal of the Korean Society for Railway
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• v.10 no.3 s.40
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• pp.306-312
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• 2007

This paper presents the optimal design method of the train repair facility based on the simulation analysis. The train is divided into the power car, motorized car and passenger car for the simulation process analysis and train repair facility is composed of each subsystems such as a blast, dry and wash workshop. In simulation analysis, we consider the critical (dependent) factors and design (independent) factors for the optimal design. Therefore, a simulation optimization uses Evolution Strategy (ES) in order to find the optimal design factors. Experimental results indicate that simulation design factors are sufficient to satisfy the conditions of dependent variables. The proposed analysis method demonstrates that simulation design factors determined by the simulation optimization are appropriate for real design factors in a real situation and the accuracy and confidence for the simulation results are increased.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.346-351
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• 1987

In this study, digital simulation with nonlinear modeling is carried out to analyse the performance of a hydraulic servomotor system developed for the position control of a large inertia. Nonlinear element, such as nonlinear pressure flow relationships of servovalve, valve spool limits, nonlinear friction, and backlash and resilience of gear system are included in the simulation along with the dynamic characteristics of variable delivery pump compensation mechanism. Simulation results are compared with experimental results for both step and sinusoidal inputs. Independent of input magnitude, both results are in good agreement with minor differences in detail.