• Nuclear Engineering and Technology
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• v.55 no.11
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• pp.4146-4158
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• 2023

This paper proposes a combined plastic and creep constitutive model of A533B1 pressure vessel steel to simulate progressive deformation of nuclear pressure vessels under severe accident conditions. To develop the model, recent tensile test data covering a wide range of temperatures (from RT to 1,100 ℃) and strain rates (from 0.001%/s to 1.0%/s) was used. Comparison with experimental data confirms that the proposed combined plastic and creep model can well reflect effects of temperature and strain rate on tensile behaviour up to failure. In the companion paper (Part II), the proposed model will be used to simulate OECD lower head failure (OLHF) test data.

• Safety and Health at Work
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• v.10 no.2
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• pp.205-212
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• 2019

Background: Workforce health is one of the primary and most challenging issues, particularly in industrialized countries. This article aims at modeling the major factors affecting accidents in the workplace, including general health, work-family conflict, effort-reward imbalance, and internal and external locus of control. Methods: A cross-sectional study was conducted in Esfahan Steel Company in Iran. A total of 450 participants were divided into two groups-control and case-and the questionnaires were distributed among them. Data were collected through a 7-part questionnaire. Finally, the results were analyzed using SPSS 22.0 and Amos software. Results: All the studied variables had a significant relationship with the accident proneness. In the case group, general health with a coefficient of -0.37, worke-family conflict with 0.10, effort-reward imbalance with 0.10, internal locus of control with -0.07, and external locus of control with 0.40 had a direct effect on occupational stress. Occupational stress also had a positive direct effect on accident proneness with a coefficient of 0.47. In addition, fitness indices of control group showed general health (-0.35), worke-family conflict (0.36), effort-reward imbalance (0.13), internal locus of control (-0.15), and external locus of control (0.12) have a direct effect on occupational stress. Besides, occupational stress with a coefficient of 0.09 had a direct effect on accident proneness. Conclusion: It can be concluded that although previous studies and the present study showed the effect of stress on accident and accident proneness, some hidden and external factors such as work-family conflict, effort-reward imbalance, and external locus of control that affect stress should also be considered. It helps industries face less occupational stress and, consequently, less occurrence rates of accidents.

• Korean Journal of Occupational Health Nursing
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• v.27 no.4
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• pp.224-234
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• 2018

Purpose: In this study, we attempted to analyze the occupational accident experience rate by working life cycle of Korean workers considering entrance and turnover in their jobs. The specific goal of this study was to calculate the accident experience rate according to workers' turnover history and previous accident experience. Methods: We constructed a cumulative data set of 90,338 cases of workers' accident experiences in their jobs from the Fourth Korean Working Conditions Survey. The accident experience rates according to workers' turnover and previous accident experiences were analyzed using descriptive statistics and analysis of variance. Results: In this study, the cumulative accident experience rate of Korean workers was found to be 5.2%. It was confirmed that the accident experience rate of workers increased as the turnover frequencies increased. In addition, we analyzed only the data of the workers who had experienced turnover and found that the accident experience rate after turnover increased about 7.5 times when workers had experienced accidents in the past. Conclusion: To prevent occupational accidents in workers, safety strategies should consider a worker's previous job history and injury experiences. It will also be necessary to focus preventive efforts on new and young workers through ongoing monitoring and on-the-job training.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.72-78
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• 2020

The accident fatality rate has decreased by more than 90% compared to 2006, due to the safety management and safety investment based on the Rail Safety Act. Most railway safety indicators, including fatality rates, have improved significantly from 60% to 80%, reaching the level of developed countries in terms of most railway safety indicators. However, the only staff fatality rate at work is not improved, and it is 3 to 5 times higher than that of developed countries. Most of the fatality occurred during employee's work recently occurred due to accidents hit by train while track work. In principle, when operating track need to check or maintenance, the operation of the train should be stopped and the work carried out. However, in Korea, due to the highest passenger density and train operating density in the world, it is caused by a structural problem that requires workers to enter the track while the train is running and perform various tasks such as maintenance and inspection. In this study, we analyzed the risk of accidents caused by hit by trains on the track, which is the biggest cause of staff fatality, using the main statistics of the last 10 years. In detail, the scenarios of the main causes of hit by trains and workers were formed to suggest the effectiveness of the current preventive measures and supplementary.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.92-99
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• 2008

The rapid economic growth in Korea raised the increase of transportation demands about the passengers and the goods, and caused the concentration on cities. By the rise of a nation's income level, a automobile is necessary in our modern life. However, the traffic delays and traffic accidents that are raised by automobiles decrease the evaluation about a nation's economy and then the government practices the traffic safety improvement project. In this study, by performing the improvement project, we expect to achieve the following objectives. First, this study analyses the degree of effectiveness whether or not success in the improvement. Second, to supply the data on the effectiveness of the improvement and to inform the necessity of improvement. Third, to supply the information on the improvement project to the parties concerned. In this paper, through the study about identification of high accident locations, the effectiveness for the number of accidents and accident rates before-after the improvement is analyzed. Also, the B/C analysis about this locations is performed. This study shows that the number of accident and accident rates are decreased after the improvement, and there is economic validity about improvement of high accident locations.

• Journal of the Ergonomics Society of Korea
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• v.22 no.1
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• pp.81-94
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• 2003

The British railway safety research group has developed a risk assessment model for the railway infrastructure and major railway accidents. The major hazardous factors of the railway infrastructure were identified and classified in the model. The frequency rates of critical top events were predicted by the fault tree analysis method using failure data of the railway system components and ratings of railway maintenance experts, The consequences of critical top events were predicted by the event tree analysis method. They classified the Joss of accident due to railway system into personal. commercial and environmental damages. They also classified 110 hazardous event due to railway system into three categories. train accident. movement accident and non-movement accident. The risk assessment model of the British railway system has been designed to take full account of both the high frequency low consequence type events (events occurring routinely for which there is significant quantity of recorded data) and the low frequency high consequence events (events occurring rarely for which there is little recorded data). The results for each hazardous event were presented in terms of the frequency of occurrence (number of events/year) and the risk (number of equivalent fatalities per year).

• The Korean Journal of Health Service Management
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• v.13 no.3
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• pp.13-26
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• 2019

Objectives: To investigate whether medical institutions can prevent accidents by analyzing the root cause of a medical accident and identifying the tendencies. Methods: A total of 345 medical cases were used for the RCA(Root Cause Analysis). The root causes were classified using the SHELL model. The suitability of the model was confirmed by SPSS's MDPREF and Euclidean distance. An SPSS20.0 hierarchical regression analysis was used as an influencing factor on the degree of injury resulting from medical accidents. Results: The SHELL model was suitable for classification. The rates of accident causes were LS49%, L34%, LL10.2%, LE3.7%, LH2.3%. The order in which the degree of a patient's injury was affected were: Risk Threshold (${\beta}=.180$), Time (${\beta}=.175$), Surgical stage (${\beta}=-.166$), Do not use procedure (${\beta}=.147$). Conclusions: Health care institutions should remove priorities through system improvement and training. For patients' safety, the five factors of the SHELL model should be managed in harmony.

• Nuclear Engineering and Technology
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• v.34 no.2
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• pp.117-131
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• 2002

Core disruptive accidents have been investigated at Korea Atomic Energy Research Institute(KAERI) as part of the work to demonstrate the inherent and ultimate safety of conceptual design of the Korea Advanced Liquid Metal Reactor(KALIMER), a 150 MWe pool- type sodium cooled prototype fast reactor that uses U-Pu-Zr metallic fuel. In this study, a simple method and associated computer program, SCHAMBETA, was developed using a modified Bethe-Tait method to simulate the kinetics and thermodynamic behavior of a homogeneous spherical core over the period of the super-prompt critical power excursion induced by the ramp reactivity insertion. Calculations of the energy release during excursions in the sodium-voided core of the KALIMER were subsequently performed using the SCHAMBETA code for various reactivity insertion rates up to 100 S/s, which has been widely considered to be the upper limit of ramp rates due to fuel compaction. Benchmark calculations were made to compare with the results of more detailed analysis for core meltdown energetics of the oxide fuelled fast reactor. A set of parametric studies were also performed to investigate the sensitivity of the results on the various thermodynamics and reactor parameters.

• Korean Journal of Construction Engineering and Management
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• v.24 no.4
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• pp.44-51
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• 2023

Occupational safety and health management cost (OSHMC) is helpful for managing safety in construction sites. However, OSHMC has been criticized for various aspects, including the fact that OSHMC cannot reflect features of individual constructions when counting up and executing OSHMC. This study proposes the approach to distribute OSHMC by project size and activity type with the consideration of accident rates for various activities. Using 1,046 data obtained from Construction Safety Management Integrated Information (CSI), this study calculated the relative risk factors for each activity. The distribution of OSHMC is proposed based on the risk factors. The results were validated by industry expert interviews. The distribution proposed in this study will help construction managers establish and execute OSHMC usage plan effectively.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.153-165
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• 2017

PURPOSES : With the increasing number of older drivers in an aging society, there is a growing need for research and planning on traffic safety for the older drivers using an improved road geometry design. This study also proposed a modified urban road interchange design, which aims to keep the older drivers away from accident-prone and high-traffic areas of the city. METHODS : In this study, we examined accident data records of older drivers to identify accident-prone zones and intersections; we studied the road geometry at these zones and analyzed if it was an underlying cause for higher number of accidents. Based on the research and subsequent analysis, we suggested plans for improvement of road geometry design at these intersections. RESULTS :By studying historic data and analyzing factors that affect the likelihood of accidents of vehicles driven by older drivers and after studying suitable traffic accident prediction models, we identified the major variables that need to be modified at accident-prone intersections, such as the width of a left turn lane at an intersection and the radius of the right turn lane at a street corner. The results have a significance probability of less than 0.001 and a 95% confidence level. To improve safety at the identified intersection, this study suggests the installation of a left-turn-lane-shaped Positive Offset and a right-turn-lane-shaped Slip Lane concept and an adjustment of intervals between intersections.