• 한국안전학회지
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• 제34권1호
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• pp.14-20
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• 2019

This paper presents a safety assessment based approach for the safe operation for PCS(Power Conditioning System) of photovoltaic and energy storage systems, applying FTA. The approach established top events as power outage and a failure likely to cause the largest damage among the potential risks of PCS. Then the Minimal Cut Set (MCS) and the importance of basic events were analyzed for implementing risk assessment. To cope with the objects, the components and their functions of PCS were categorized. To calculate the MCS frequency based on IEEE J Photovolt 2013, IEEE Std. 493-2007 and RAC (EPRD, NPRD), the failure rate and failure mode were produced regarding the basic events. In order to analyze the top event of failure and power outage, it was assumed that failures occurred in DC breaker, AC breaker, SMPS, DC filter, Inverter, CT, PT, DSP board, HMI, AC reactor, MC and EMI filter and Fault Tree was drawn. It is expected that the MCS and the importance of basic event resulting from this study will help find and remove the causes of failure and power outage in PCS for efficient safety management.

• 대한조선학회논문집
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• 제40권6호
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• pp.30-36
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• 2003

To improve survivability of damaged ship, assessment of stability and structural safety, and behavior analysis in wave is required. Prediction of sinking time, damage stability and structural strength considering progressive flooding and dynamic force in wave is very important. To do it, a geometric model which can be express damaged ship is prepared. This paper described the geometric modeler for survivability assessment of damaged ship. The modeler is developed based on 3-D geometric modeling kernel, ACIS. The hull form and compartment definition is available fundamentally. And requirement for modeler contains data generation and interface for hydrostatic calculation, behavior analysis, and longitudinal strength analysis and so on. To easy access modeling system by conventional user such as crew, user interface is developing.

• 한국정밀공학회지
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• 제21권6호
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• pp.179-187
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• 2004

In this study, for a safety assessment of wheelchair occupant in frontal and side impact of wheelchair loaded vehicle, a sled impact test was perfumed. Each test was carried out total 6 times, by using Hybrid III 50th-percentile male dummy in light weight and electric wheelchair. We estimate MC(Motion Criteria), CIC(Combined Injury Criteria), HIC(Head Injury Criteria), HNIC(Head and Neck Injury Criteria) based on measured data. Through this study, we make an assessment of risk analysis of wheelchair occupant and wheelchair. Through this study, safety standard of wheelchair is to be evaluated.

• Nuclear Engineering and Technology
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• 제33권6호
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• pp.596-604
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• 2001

This paper quantitatively presents the effects of important factors of the probabilistic safety assessment (PSA) of safety-critical digital systems. The result which is quantified using fault tree analysis methodology shows that these factors remarkably affect the system safety. In this paper we list the factors which should be represented by the model for PSA. Based on the PSA experience, we select three important factors which are expected to dominate the system unavailability. They are the avoidance of common cause failure, the coverage of fault tolerant mechanisms and software failure probability. We Quantitatively demonstrate the effect of these three factors. The broader usage of digital equipment in nuclear power plants gives rise to the safety problems. Even though conventional PSA methods are immature for applying to microprocessor-based digital systems, practical needs force us to apply it because the result of PSA plays an important role in proving the safety of a designed system. We expect the analysis result to provide valuable feedback to the designers of digital safety- critical systems.

• 대한안전경영과학회지
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• 제17권2호
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• pp.27-34
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• 2015

If examining utilization by completion of National Competency Standards development, efforts are made so as to organize curriculum matched to education or training and perform subjects based on competence unit educationally in specialized high schools, colleges and university. However, National Competency Standards is insignificantly utilized in enterprises and on the spot due to characteristics of occupation type and diversity of process. This thesis intended to measures of safety efficiency improvement of final enterprise through the human resources assessment system of National Competency Standards based enterprise. Therefore, various methodologies were introduced and results of analysis by Balanced ScoreCard method were suggested for policy measures improving final safety efficiency. The results of this analysis are expected to make contribution to improving the effectiveness of the government's industrial safety and health policies through the establishment of systematic safety and health systems according to the risk level of individual business.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.956-963
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• 2020

Dose optimization for Radioactive Occupational Personal (ROP) is an important subject in nuclear and radiation safety field. The geometric environment of a nuclear facility is complex and the work area is radioactive, so traditional navigation model and radioactive data field cannot form an effective environment model for dose assessment and dose optimization. The environment model directly affects dose assessment and indirectly affects dose optimization, this is an urgent problem needed to be solved. Therefore, this paper focuses on an environment model used for Dose Assessment and Dose Optimization (DA&DO). We designed a multi-layer radiation field coupling modeling method, and then explored the influence of the environment model to DA&DO by virtual simulation. Then, a simulation test is done, the multi-layer radiation field coupling model for nuclear facilities is demonstrated to be effective for dose assessment and dose optimization through the experiments and analysis.

• 한국연안방재학회지
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• 제5권4호
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• pp.193-201
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• 2018

The recent increase in size and speed of ships resulted in the existing maritime routes becoming narrow relative to the size of new ships. At the same time, as the improvement and optimization in marine transportation take place and the construction of structures in seas and harbor improvements pick up speed, there is an increasing probability of marine accidents. Due to these environmental changes, the need to professionally analyze the effect of marine structures on navigation arose to ensure safety of ships and a law was enacted and introduced for the Maritime Traffic Safety Audit (MTSA). In this study, a Qualitative assessment for verifying the effectiveness of MTSA was carried out with case analysis and analysis model in other similar audit scheme. It is expected that an analyzed result for effectiveness of MTSA will be a steppingstone for enhancing the MTSA and keeping maritime traffic safety as its own purpose.

• 한국안전학회지
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• 제39권2호
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• pp.75-86
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• 2024

Hydrogen has been selected as one of the key technologies for reducing CO₂ emissions to achieve carbon neutrality by 2050. However, hydrogen safety issues should be fully guaranteed before the commercial and widespread utilization of hydrogen. Here, a bow-tie risk assessment is conducted for the hydrogen fuel supply system in a gas turbine power plant, which can be a mass consumption application of hydrogen. The bow-tie program is utilized for a qualitative risk assessment, allowing the analysis of the causes and consequences according to the stages of accidents. This study proposed an advanced bow-tie method, which includes the barrier criticality matrix and visualized maps of quantitative risk reduction. It is based on evaluating the importance of numerous barriers for the extent of their impact. In addition, it emphasizes the prioritization and concentrated management of high-importance barriers. The radar chart of a bow tie allows the visual comparison of risk levels before/after the application of barriers (safety measures). The risk reduction methods are semi-quantitatively analyzed utilizing the criticality matrix and radar chart, and risk factors from multiple aspects are derived. For establishing a secure hydrogen fuel storage system, the improvements suggested by the bow-tie risk assessment results, such as 'Ergonomic equipment design to prevent human error' and 'Emergency shutdown system,' will enhance the safety level. It attempts to contribute to the development and enhancement of an efficient safety management system by suggesting a method of calculating the importance of barriers based on the bow-tie risk assessment.

• Safety and Health at Work
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• 제4권2호
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• pp.95-99
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• 2013

Background: Work-related stress is one of the major causes of occupational ill health. In line with the regulatory framework on occupational health and safety (OSH), adequate models for assessing and managing risk need to be identified so as to minimize the impact of this stress not only on workers' health, but also on productivity. Methods: After close analysis of the Italian and European reference regulatory framework and workrelated stress assessment and management models used in some European countries, we adopted the UK Health and Safety Executive's (HSE) Management Standards (MS) approach, adapting it to the Italian context in order to provide a suitable methodological proposal for Italy. Results: We have developed a work-related stress risk assessment strategy, meeting regulatory requirements, now available on a specific web platform that includes software, tutorials, and other tools to assist companies in their assessments. Conclusion: This methodological proposal is new on the Italian work-related stress risk assessment scene. Besides providing an evaluation approach using scientifically validated instruments, it ensures the active participation of occupational health professionals in each company. The assessment tools provided enable companies not only to comply with the law, but also to contribute to a database for monitoring and assessment and give access to a reserved area for data analysis and comparisons.

• 자동차안전학회지
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• 제14권4호
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• pp.43-52
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• 2022

Recently, the government has been expanding the supply of hydrogen vehicles according to the roadmap for vitalizing the hydrogen economy, but is developing safety assessment and inspection technology for the relevant vehicles. This study analyzed the prevention of hydrogen bus accidents' economic effect that arises from the application and development of large-capacity CHSS oil pressure repetition-test assessment technology, hydrogen bus internal chamber pressure transmission and emission volume inspection technology, among various technologies capable of assessing the safety of a hydrogen bus fuel system. To this end, the contingent valuation method (CVM), one of the value evaluation methods of non-market goods, was applied to investigate users' willingness to pay for each inspection technology. The survey for users' willingness to pay was conducted by attaching posters to promote surveys on the internet and within buses to the entire public. As a result of the analysis, the average WTP of the hydrogen bus internal chamber pressure transmission volume inspection technology was 25.3 KRW, the average WTP of the hydrogen bus internal chamber pressure emission volume inspection technology was 18.6 KRW, and the average WTP of the large-capacity CHSS oil pressure repetition-test assessment technology was measured at 16.7 KRW. In addition, the costs and benefits of the introduction of the relevant inspection technology were defined through the interviewing of experts at related research institutions and businesses. As a result of conducting an economic analysis (4.5% discount rate) according to the development of each inspection technology, economic feasibility was seen in all assessment and inspection technologies. As much as the technology is indispensable for the safe use of hydrogen buses, it shows that investment in related technology is very necessary in the future. However, because it was decided that the relevant analysis will differ according to the distribution rate of hydrogen buses, further analysis following this future distribution rate of hydrogen buses is needed, and future users should be made clearly aware of the safety and environmental nature of the technology.