• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.15-23
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• 2008

This paper describes the structural analysis results of KARI General Small-scaled Rotor Test System (GSRTS) operated in KARI to verify operational safety. This GSRTS was developed to conduct a froude and mach small-scaled rotor test. This analysis was performed to investigate the structural Factor of Safety for the various small-scale rotor system like articulated or hingeless rotor and to check the operational capability using given operational design load. Specially, drive system has several bearings, mechanical gears, shaft, etc. and these parts must be required to achieve an operational safety. The calculation was done by using geometric data and material properties by analytical method. This rotor test system should be operated within these calculated Factor of Safety. Furthermore, the operational limitation should be defined as applied to small-scale rotor system of KUH in future.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.1-7
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• 2015

This study first addresses the ineffectiveness of indirect regulation on industrial machines. Analysis of causes of industrial accidents associated with industrial machines further reveals the fact that technical causes need to be resolved at the manufacturing stage to reduce the frequency and strength of industrial accidents. Balanced safety certification on manufacturers and safety inspection on users of industrial machines are then suggested to effectively resolve such technical causes. The effectiveness of such safety certification and safety inspection can be justified by cost-benefit analysis. Particularly, balance in expected benefits of safety certification and safety inspection is a key issue for validity of such analysis. The accumulated benefit-costs for press brake and portable sawing machine confirm the effectiveness of such safety system.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3435-3449
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• 2024

Considering that system analysis codes are used for the evaluation of the performance of Passive Safety Systems (PSSs), it is important to investigate the capability of the system analysis code to reliably predict the heat transfer and natural circulation flow, which are the main phenomena governing the performance of a PSS. Since MARS-KS has been widely validated for heat transfer models, this study focuses on evaluating its capability to predict the single and two-phase pressure drops and natural circulation flow. The straight pipe simulation results indicate that the pressure drop predictions are reliable within ±5 % error margin for the single-phase flow and the errors of pressure drop up to - 30 % for the two-phase flow. Through single-phase natural circulation flow analysis, it is concluded that the use of the appropriate K-factor modeling based on the flow regimes is important since the natural circulation flow rate in MARS-KS is mainly affected by the form loss factor modeling. With two-phase natural circulation flow analysis, this study emphasizes the behavior of the system could change significantly depending on the two-phase wall friction and pressure loss modeling. With the analysis results, modeling considerations for the PSS performance evaluation with the system analysis codes are proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.410-417
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• 2018

System design errors are more likely to occur in modern systems because of their steadily increasing size and complexity. Failures due to system design errors can cause safety-related accidents in the system, resulting in extensive damage to people and property. Therefore, international standards organizations, such as the U.S. Department of Defense and the International Electrotechnical Commission, have established international safety standards to ensure system safety, and recommend that system design and safety activities should be integrated. Recently, the safety of a system has been verified by modeling through a model-based system design. On the other hand, system design and safety activities have not been integrated because the model for system design and the failure model for safety analysis and verification were developed using different modeling language platforms. Furthermore, studies using UML or SysML-based failure models for deriving safety requirements have shown that these models have limited applicability to safety analysis and verification. To solve this problem, it is essential to extend the existing methods for failure model implementation. First, an improved SysML-based failure model capable of integrating system design and safety verification activities should be produced. Next, this model should help verify whether the safety requirements derived via the failure model are reflected properly in the system design. Therefore, this paper presents the concept and method of developing a SysML-based failure model for an automotive system. In addition, the failure model was simulated to verify the safety of the automotive system. The results show that the improved SysML-based failure model can support the integration of system design and safety verification activities.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1669-1679
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• 2010

Related to the on-going "Train Control System Project of Pilot Line Construction for Urban MAGLEV Train", activities by each phase shall be conducted to achieve SIL4 level and obtain safety certification from the Independent Safety Assessment(ISA), based on the IEC standards((IEC 62278/62279 and IEC 62425) for the first time in Korea. This thesis describes the introduction of IEC standards, system assurance activities (such as plan, analysis, test, verification and validation) in compliance with requirements management and project life-cycle and relations with the safety assessment activities; and certification activities (such as document reviews and audits) through system RAMS activities, software quality assurance activities and safety assessment, for the purpose of achieving a successful safety certification at the time of completing the project as system assurance activities including software and safety certification activities in order to acquire the safety certification for train control system which does not exist at all in domestic cases. It is believed that overall system safety assurance activities in this project will contribute to develop more upgraded products of the domestic train control system on the quality and safety point of view, find overseas markets and establish a bridgehead in the future.

• Journal of the Korean Society of Safety
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• v.31 no.4
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• pp.90-96
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• 2016

This study proposes a dynamic reliability analysis of control system as a method of quantitative evaluation of its performance in probabilistic terms. In this dynamic reliability analysis, the failure event is defined as an event that the dynamic response of the structural system exceeds a displacement limit, whereas the conventional reliability analysis method has limitations that do not properly assess the actual time history response of the structure subjected to dynamic loads, such as earthquakes and high winds, by taking the static response into account in the failure event. In this first paper, we discuss the control effect of the viscous damper on the seismic performance of the member-level failure where the failure event of the structural member consists of the union set of time-sequential member failures during the earthquake excitations and the failure probability of the earthquake-excited structural member is computed using system reliability approach to consider the statistical dependence of member failures between the subsequent time points. Numerical results demonstrate that the proposed approach can present a reliable assessment of the control performance of the viscous damper system in comparison with MCS method. The most important advantage of the proposed approach can provide us more accurate estimate of failure probability of the structural control system by using the actual time-history responses obtained by dynamic response analysis.

• Proceedings of the Safety Management and Science Conference
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• 2010.11a
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• pp.283-297
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• 2010

This study carried out the investigation about the actual conditions of the management, disaster analysis and safety awareness on excavator in one of construction equipment and tried to make it's preventive measures. To achieve this, first of all, the accident of the internal Construction Industry process Investigation and Analysis, and then analyze an cause of accident based on it. Next, For the conditions of safety management conduct a survey to Investigation and Analysis and Propose preventive measures. The results of this study can be summarized as follows. 1st, Status of safety awareness and management of construction equipment tend to seek quickly and easily for the interests of sight. 2nd, Half the precincts of the equipment is causing major disaster. 3rd, The risk of excavator operation's indicators and drivers is so much potential. 4th, The preventive measures are needed for strengthening safety education, professional legal education, changes in safety awareness, the development of prevention system.

• Journal of the Korea Safety Management & Science
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• v.12 no.3
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• pp.81-91
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• 2010

This study carried out the investigation about the actual conditions of the management, disaster analysis and safety awareness on excavator in one of construction equipment and tried to make it's preventive measures. To achieve this, first of all, the accident of the internal Construction Industry process Investigation and Analysis, and then analyze an cause of accident based on it. Next, For the conditions of safety management conduct a survey to Investigation and Analysis and Propose preventive measures. The results of this study can be summarized as follows. 1st, Status of safety awareness and management of construction equipment tend to seek quickly and easily for the interests of sight. 2nd, Half the precincts of the equipment is causing major disaster. 3rd, The risk of excavator operation's indicators and drivers is so much potential. 4th, The preventive measures are needed for strengthening safety education, professional legal education, changes in safety awareness, the development of prevention system.

• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.32-39
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• 2014

To ensure the reliability of the safety system so that handing large quantities of hazardous materials in chemical plant is considered basic information in chemical process design. However, the reliability of the production system may be reduced when the reliability of the safety system emphasized in order to ensure the safety of chemical process. It is necessary to balance the reliability of the production system and reliability of the safety. In this study, a quantitative risk assessment was performed by selecting the furnace process, which is widely used in the chemical plant in order to suggest a way to ensure the safety and productivity of chemical process, based on the quantitative data. Quantitative risk assessment methodology have been used directed graph analysis methodology. It is possible to evaluate the reliability of the safety system and the production system. In this study, the optimum system design requirement to improve the safety and the productivity of the furnace is two-out-of-three logic for TT and PT.

• Journal of the Korean Society of Safety
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• v.36 no.3
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• pp.15-23
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• 2021

By analyzing the current status and type of industrial safety accidents caused by industrial machinery, this study aims to examine the importance and necessity of the safety devices that are installed on-site. Additionally, this study aims to determine the implications for Korea by analyzing the status of industrial accidents in major countries and the responses to the accidents. We found that workers could easily access and operate the safety devices and that productivity and convenience were more important than safety. Thus, safety devices need to be mandatorily installed on-site for the safety of workers, and only management supervisors should be given the authority to operate them to afford a sense of safety responsibility to the workers.