• Fire Science and Engineering
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• v.30 no.4
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• pp.103-110
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• 2016

While the demand for the gas system fire extinguishers increases every year, there are insufficient safety measures for assessing the extinguishing performance, such as system safety and reliability in the preparation of increasing demand, which has emerged as a social problem. One of the most critical causes of accidents occurring with the gas extinguishing system is pressure leakage from the extinguishing agent storage container. This is considered to be one of the critical factors on which the success of fire suppression depends. In this study, its safety measure was studied, Because it was deemed urgently necessary. The newly developed pressure leakage monitoring system is a system monitoring storage condition, pressure, leakage and discharge of the storage container related to agent concentration, which is one of the critical factors for fire suppression. This was developed to be applicable to the $CO_2$ and HFC-23 systems. Therefore, for structural safety analysis, the safety performance was verified by the fluid structure coupling analysis of the safety problems that may occur when the pressure leakage monitoring system is applied to the gas fire extinguisher. For analysis programs, the FloEFD program from Mentor Graphics was used for computational fluid dynamics analysis and ABAQUS from Dassault Systems was used for structural analysis. From the result of numerical analysis, the structure of $CO_2$ did not develop plastic deformation and its safety was verified. However, plastic deformation and deviation issue occurred with the HFC-23 monitoring system and therefore verified the structural safety of pressure leakage monitoring system by data obtained from redesigning and adjusting the condition of numerical interpretation three times.

• Journal of the Korean Society of Safety
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• v.30 no.2
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• pp.9-13
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• 2015

This paper describes the analysis of deterioration characteristics for connection factor used in grounding system. The connection method of grounding system is specified in IEC standard. In order to analyze the deterioration characteristics for connection factor, deterioration test was carried out when the connection factor was buried in salt water and underground. The test connection factors were C-type sleeve, clamp, and exothermic welding. As a consequence, most of the connection factor was corroded, and the electrical resistance decreased after deterioration. The analytical results can be used to establish the safety of grounding system.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.553-554
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• 2004

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.105-112
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• 2006

The main function of a reactor protection system is to maintain the reactor core integrity and the reactor coolant system pressure boundary. Generally, the reactor protection system adopts the 2-out-of-m redundant architecture to assure a reliable operation. This paper describes the safety assessment of a digital reactor protection system using the fault tree analysis technique. The fault tree technique can be expressed in terms of combinations of the basic event failures such as the random hardware failures, common cause failures, operator errors, and the fault tolerance mechanisms implemented in the reactor protection system. In this paper, a prediction method of the hardware failure rate is suggested for a digital reactor protection system, and applied to the reactor protection system being developed in Korea to identify design weak points from a safety point of view.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.105-112
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• 1996

A practical approach for the assessment of system reliability-based safety and load carring capacity under vehicle traffics is proposed for the realistic evaluation of safety and rating of cable-stayed bridges. A partial event tree analysis model incorporating major critical failure paths is suggested as a practical tool for the system reliability analysis and system reliability-based capacity rating. The proposed approach for the system reliability analysis and system reliability-based rating is applied to the safety assessment of the Jindo Bridge which is one of two existing cable-stayed bridges in Korea. The results of analyses at the system level based on the system reliability are compared with those at the element level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.2895-2902
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• 2012

The Occupational health and safety is an important factor in the competitiveness of an enterprise. In this paper, activation strategies of OHSMS(Occupational health and safety management system) were systematically and quantitatively analyzed and suggested using SWOT/AHP(Strengths, Weaknesses, Opportunity, Threat/Analytic Hierarchy Process) analysis. In these results, activation strategies of this system can be suggested as followings ; Making worker safety-friendly image of enterprise, developing the quantitative indices related to management results in accreditation programs of OHSMS, constructing the relationship between OHSMS and product safety management, and developing the customized integrated accreditation system.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.219-230
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• 2023

With the development of autonomous driving technology, as the use of software in vehicles increases, the complexity of the system increases and the difficulty of development increases. Developments that meet ISO 26262 must be carried out to reduce the malfunctions that may occur in vehicles where the system is becoming more complex. ISO 26262 for the functional safety of the vehicle industry proposes to consider functional safety from the design stage to all stages of development. Specifically at the software level, the requirements to be complied with during development and the requirements to be complied with during verification are defined. However, it is not clearly expressed about specific design methods or development methods, and it is necessary to supplement development guidelines. The importance of analysis and verification of requirements is increasing due to the development of technology and the increase of system complexity. The vehicle industry must carry out developments that meet functional safety requirements while carrying out various development activities. We propose a process that reflects the perspective of system engineering to meet the smooth application and developmentrequirements of ISO 26262. In addition, the safety analysis/verification FMEA processforthe safety of the proposed ISO 26262 function was conducted based on the FCAS (Forward Collision Avoidance Assist System) function applied to autonomous vehicles and the results were confirmed. In addition, the safety analysis/verification FMEA process for the safety of the proposed ISO 26262 function was conducted based on the FCAS (Forward Collision Avoidance Assist System) function applied to the advanced driver assistance system and the results were confirmed.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.739-745
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• 2006

The role of maintenance in railway is going to be extended to improve the reliability of railway system in the aspect of Asset management gradually. In this paper, the meaning of reliability and safety in RCM which has been applied in order to improve the efficiency of maintenance is deduced. And the analysis task of reliability and safely which has been recommended in railway standards such as EN50126 and IEC62278 is reviewed in the aspect of RCM. Finally, the several ways are proposed to apply RCM to railway system through the comparison between the RCM procedure and the analysis procedure for the reliability and safety in railway standards. Hereafter, if the analysis of reliability and safety is performed with the concept of RCM in the beginning of railway business, it will be more efficient to improve the reliability and manage the railway asset.

• Journal of the Korea Institute of Construction Safety
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• v.3 no.1
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• pp.18-24
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• 2020

The purpose of this study is to propose a system improvement plan to prevent ground sinking accidents. To do this, follow the procedure below. First, it defines terms that are used interchangeably, such as ground subsidence and ground depression. Second, analysis of the current status and cause of ground sink, and the analysis of the correlation between rainfall and ground sink causes, derives priority management causes. Third, we propose a system improvement plan for the cause of priority management. As a result, damage to underground pipes and inadequate underground works were identified as the cause of priority management, and two system improvement plans to manage them were proposed. The results of this study can be used as basic data for improving the system for more effective prevention of underground sink in the future.

• Journal of the Korean Society of Safety
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• v.37 no.5
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• pp.22-32
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• 2022

The domestic smart factory is being built and spread rapidly, mainly by mid-sized companies and large enterprises according to the government's active introduction and support policy. But these factories only promote production system and efficiency, so harmfulness and risk factors are not considered. Therefore, to derive harmful risk factors in terms of industrial safety for 12,983 government-supported smart factory workplaces from 2014 to 2019, industrial accident status analysis compared workplaces with automation facilities and government-supported workplaces with automation facilities. Also, to reduce risks associated with domestic smart factory processes, twenty government-supported workplaces with automation facilities underwent analysis, evaluating risks through a status survey using the process evaluation table. In addition, the status survey considered region, size, industry, construction level, and accident rate; the difference in risk according to the structure of the process was confirmed. Based on the smart factory process evaluation results, statistical analysis confirmed that serial, parallel, and hybrid structures pose different risk levels and that the risks of mixed structures are greater. Finally, safety control system application was presented for risk assessment and reduction in the smart factory process, reflecting the results of disaster analysis and actual condition investigation.