• Nuclear Engineering and Technology
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• v.46 no.1
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• pp.11-26
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• 2014

The analyses carried out within the Seismic Probabilistic Risk Assessments (SPRAs) of Nuclear Power Plants (NPPs) are affected by significant aleatory and epistemic uncertainties. These uncertainties have to be represented and quantified coherently with the data, information and knowledge available, to provide reasonable assurance that related decisions can be taken robustly and with confidence. The amount of data, information and knowledge available for seismic risk assessment is typically limited, so that the analysis must strongly rely on expert judgments. In this paper, a Dempster-Shafer Theory (DST) framework for handling uncertainties in NPP SPRAs is proposed and applied to an example case study. The main contributions of this paper are two: (i) applying the complete DST framework to SPRA models, showing how to build the Dempster-Shafer structures of the uncertainty parameters based on industry generic data, and (ii) embedding Bayesian updating based on plant specific data into the framework. The results of the application to a case study show that the approach is feasible and effective in (i) describing and jointly propagating aleatory and epistemic uncertainties in SPRA models and (ii) providing 'conservative' bounds on the safety quantities of interest (i.e. Core Damage Frequency, CDF) that reflect the (limited) state of knowledge of the experts about the system of interest.

• Journal of Navigation and Port Research
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• v.36 no.4
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• pp.279-284
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• 2012

This study aims to identify the degree of safety when mariners take their actions in several different situations. We have carried out many experiments to observe mariners' behavior and then measured the safety level based on their actions to avoid dangerous situations of ships collision. One of the most important actions that mariners have to take, either as their daily routine or when they are in a collision situation and then want to avoid that situation is the lookout. In this paper, behaviors on the lookout have been defined as a standard sequence of three steps which are "time of first detection", "time of recognition as risky vessel" and "time of starting avoiding action", and the suitability and applicability of the definition have been shown. And also we propose the risk assessment on ships collision and the recommendation for reducing ships collision at sea. Some analyzing results and the application of the results are reported. By combining these knowledge and some systematic studies, we propose the risk assessment on ships collision and the recommendation for reducing ships collision at sea.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.16-18
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• 2011

This study aims to identify the degree of safety when mariners take their actions in several different situations. We have carried out many experiments in order to observe mariners' behavior, and then measured the safety level that is based on their actions to avoid dangerous collision situations. One of the most important actions that mariners have to take, either as their daily routine or when they are in a collision situation and then want to avoid that situation is the lookout. In this paper, behaviors on the lookout have been defined as a standard sequence of three steps that are "time of first detection", "time of recognition as risky vessel" and "time of starting avoiding action", and the suitability and applicability of the definition have been shown. And also we propose the risk assessment on the collision and the recommendation for reducing the collision at sea. Some analyzing results and the application of the results are reported. The sequence of lookout is also understood. By combining these knowledge and some systematic studies, we propose the risk assessment on the collision and the recommendation for reducing the collision at sea.

• Korean Journal of Human Ecology
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• v.20 no.3
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• pp.637-649
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• 2011

The purpose of this study was to analyze employees' practice levels and knowledge of sanitation at school foodservice operations, to examine the sanitation conditions of current school foodservice, and to suggest an effective sanitary training program. A questionnaire survey was conducted on a total of 578 subjects and 501 reponses were made available for this study. The collected data was analyzed using SPSS of windows. The main results can be summarized as follows: Training through handouts was the most effective (53.2%) and lack of time caused by overwork (57.1%) made the practice of sanitation training difficult. The degree of employees' perceptions of the necessity of sanitary training programs was marked at 4.18 points. According to the foodservice employees' evaluation about the knowledge of sanitation concerning the sanitary training program contents, the area of environmental sanitation (96.3%) was the highest while food poisoning control (72.9%) was lowest. Foodservice employees' practice levels was ranked above 4 points (out of 5 points) in 9 areas. Practice levels of cleaning and disinfection management were highest while that of safety management was lowest. About the food service employees' practice levels of sanitation, the degree of practice and the application of knowledge was 4.39 points. There was a significantly positive correlation between the practice level of sanitation and sanitation knowledge(p<.01). Thus, educational material needs to be standardized in order to improve employees' sanitation practice level.

• Journal of Fisheries and Marine Sciences Education
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• v.11 no.2
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• pp.115-138
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• 1999

Since the STCW-F convention was adopted, The states concerned, has been investigated in many ways to adopt the prevailing circumstance and condition, accordingly, all preparation will be provided to accept the STCW-F convention to promote the safety of life and prevention of pollution. Prior to enter into force of this convention, we have to investigate the matter of policies, and must have great international concern to the seamen's education. Especially, we should discuss functional skill and knowledge matrix of fishing vessel seamen's education with the supplementary studies, and therefore, we should reflect to the contents, methods of education, inducement of advanced technics, application of education all aids to meet the acceptance of STCW-F convention. Also, we are attempt to implement to accept high quality of fishing vessel seamen's education as the application of simulator and any other advanced devices in future.

• Korean journal of food and cookery science
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• v.32 no.5
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• pp.619-626
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• 2016

Purpose: This study aims to provide important methods to increase egg usage eggs in communal food services, based on the knowledge and awareness of the dietician. Methods: A survey on 200 dieticians in various aspects, such as egg purchase, utility, importance of egg dishes and allergy awareness was conducted. Result: Dieticians' highest consideration in purchasing eggs were cost (41.5%) and food safety certification (41.0%); the 88.6% of purchases were general egg. The most inconvenient issues in the purchase were inability to confirm freshness (42.0%), frequent breakage (23.5%) and inconvenience in shell disposal (18.5%). During the process of cooking, cracking egg shells (49.5%) and disposal of shells (14.0%) were marked as the major inconveniences. When questioned on intention to purchase liquid and powder eggs to overcome the shell disposal inconvenience, 64% answered no, with distrust in food safety (44.5%) being the major concern. The frequency of using eggs as the main ingredient was 1~2 times per week, with 49.0%. Food service customers favored rolled omelet (36.7%) and steamed egg (20.6%), and the most used utensil was the frying pan (56.5%). When important factors in egg dishes, namely diverse menu, taste, nutrition, consumer satisfaction and allergic reaction were surveyed, most answered that all 5 factors were important. Conclusion: For increasing egg dish inclusions in communal food service, the safety assurance, increase in liquid and processed egg use, and supply of cooking utilities are necessary.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.396-416
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• 2021

Objectives: This study was conducted to analyze the trends of government R&D (R&D) projects related to laboratory safety over the past 20 years. Methods: We collected publications from various databases(DBs) with words such as laboratory(ies), lab(s), researcher(s), laboratory worker(s), safety, environment, hazard(s), risk(s), and so on. Selected publications were analyzed by the research funds and the number of projects according to the investment subject and research characteristics. Results: About 93% of the total R&D budget went to government policy projects, not scientific research. Second, from the perspective of 'safety management activities', most of the research is related to management and inspection at the organizational level. Issues that need to be discussed at the national level like policy governance are not included. Third, focusing on the 'safety management cycle', there were few studies related to 'prediction' or 'post-response'. Fourth, when an analysis framework combining the perspectives of 'safety management activities' and 'safety management cycle' is applied, most of the budget is spent on infrastructure such as digital management systems, whereas basic knowledge for prevention and production of evidence was very few. Conclusions: In order to prevent policy planning without policy evaluation, implementation without strategy, and evaluation without evidence, it is necessary to expand investment in empirical research on risks, research on the effectiveness of current application methods, and research on theory development. The government budget for laboratory safety-related projects should be managed separately from the R&D budget for scientific research. Although less than 5% of the budget allocated to scientific research is the total budget, an optical illusion occurs because both the project budget and the scientific research budget are counted as R&D budgets.

• Nuclear Engineering and Technology
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• v.41 no.1
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• pp.1-10
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• 2009

The safe and reliable performance of fusion and fission plants depends on the choice of suitable materials and an assessment of long-term materials degradation. These materials are degraded by their exposure to extreme conditions; it is necessary, therefore, to address the issue of long-term damage evolution of materials under service exposure in advanced plants. The empirical approach to the study of structural materials and fuels is reaching its limit when used to define and extrapolate new materials, new environments, or new operating conditions due to a lack of knowledge of the basic principles and mechanisms present. Materials designed for future Gen IV systems require significant innovation for the new environments that the materials will be exposed to. Thus, it is a challenge to understand the materials more precisely and to go far beyond the current empirical design methodology. Breakthrough technology is being achieved with the incorporation in design codes of a fundamental understanding of the properties of materials. This paper discusses the multi-scale, multi-code computations and multi-dimensional modelling undertaken to understand the mechanical properties of these materials. Such an approach is envisaged to probe beyond currently possible approaches to become a predictive tool in estimating the mechanical properties and lifetimes of materials.

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.240-252
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• 2015

In the original licensing application for the prototype fast-breeder reactor, MONJU, the event progression during an unprotected loss of flow (ULOF), which is one of the technically inconceivable events postulated beyond design basis, was evaluated. Through this evaluation, it was confirmed that radiological consequences could be suitably limited even if mechanical energy was released. Following the Fukushima-Daiichi accident, a new nuclear safety regulation has become effective in Japan. The conformity of MONJU to this new regulation should hence be investigated. The objectives of the present study are to conduct a preliminary evaluation of ULOF for MONJU, reflecting the knowledge obtained after the original licensing application through CABRI experiments and EAGLE projects, and to gain the prospect of in-vessel retention for the conformity of MONJU to the new regulation. The preliminary evaluation in the present study showed that no significant mechanical energy release would take place, and that thermal failure of the reactor vessel could be avoided by the stable cooling of disrupted-core materials. This result suggests that the prospect of in-vessel retention against ULOF, which lies within the bounds of the original licensing evaluation and conforms to the new nuclear safety regulation, will be gained.

• Journal of the Korean Society of Radiology
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• v.6 no.2
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• pp.115-120
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• 2012

According to the development of laser technology, applications of laser in medical area, and the resulting risks are increasing. To ensure the safe use of laser, it is necessary to assign a person who has the knowledge of laser safety as MLSO(medical laser safety officer). In many countries, the system of laser safety officer management is operating. MLSO has the responsibilities and duties of the operation of the laser safety program, training, and education. In this study, we analyzed the adoption of MLSO through the investigation of the MLSO management status in United States.