• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.21-34
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• 2021

The use of Field-Programmable Gate Arrays (FPGAs) in the development of safety-related Human-Machine Interface (HMI) systems has gained much momentum in nuclear applications. Recently, one of the application areas for the Advanced Power Reactor 1400 (APR1400) is in the development of the advanced Component Interface Module (CIM) of the Engineered Safety Features Actuation System (ESFAS). Using systems engineering approach, we have developed a new FPGA-based advanced CIM software. The first step of our software development process involves the Preliminary Hazard Analysis (PHA) based on the previous CIM design. In this paper, we describe the qualitative approach used in performing the preliminary hazard analysis. The paper presents the methodology for applying a modified Hazard and Operability (HAZOP) procedure for the conduct of PHA which resulted in a qualitative risk-ranking scheme that informed the decisions for the safety criteria in the requirements specification phase. The qualitative approach provided the justification for design changes during the advanced CIM software development process.

• Journal of the Korean Institute of Gas
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• v.10 no.4 s.33
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• pp.63-69
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• 2006

With the increased interest in reducing air pollution, supply of natural gas for gas vehicles is increasing. Thus, the number of establishments of LNG and CNG stations is increasing as well. However, due to major gas accidents such as the fire and explosion accident of a Bucheon LPG station in 1998, it is difficult to establish a new station. In this research, we conducted qualitative hazard analysis fer LCNG/LNG multi-station by using the K-PSR method and proposed recommendations for hazard mitigation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.385-393
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• 2019

Potential fire, explosion and safety hazards exist in medium- or small-scale chemical plants using radical batch reaction processes due to the various conditions of materials, works or products. To minimize the potential damage, a study was conducted on qualitative hazard analysis using the HAZOP technique, which is a typical method for a qualitative risk assessment and analysis of the potential risks encountered in these chemical plants. For this purpose, a domestic chemical plant, which produces the acrylic resin by a radical batch reaction process, was selected and a risk assessment and analysis according to the procedure of HAZOP method was performed for the process. As the result of the study, to prevent the hazard, the input of inert gas and the installation of a pressure gauge were indispensable. In addition, the initiator and monomer should also be separated, and inhibiting substances and equipment are also necessary to prevent a runaway reaction.

• Journal of Environmental Impact Assessment
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• v.6 no.2
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• pp.113-121
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• 1997

LHR(Landfill Hazard Ranking Model) was developed for assessing the relative hazard of landfills by using the method of value-structured approach. LHR consists of combining a multiattribute decision-making method with a qualitative risk assessment approach. A pairwise comparision method was applied to determine weights of landfill factors related. To prove the validity of weights allocation of landfill hazard evaluation factors, sensitivity analysis was applied. Firstly, the impact on landfill hazard score according to variations of weights of landfill hazard factors was analyzed. Secondly, the impact on landfill hazard score according to conditions change of landfill hazard factors was analyzed. As a result of sensitivity analysis, LHR composite scores are largely influenced by some factors following sequential order such as waste volume, proximity to sensitive environments, containment facilities, distance from drinking water supplies, and waste toxicity. The relative order of landfill hazard evaluated by LHR is not influenced by the weights change of individual factors. Therefore, LHR seems to be a credible model to determine priorities of landfill remediation based on the vulnerability of water resources.

• Journal of KIISE:Software and Applications
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• v.27 no.2
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• pp.120-133
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• 2000

Major obstruction of using formal methods for hybrid real-time systems in industry is the difficulty that engineers have in understanding and applying the quantitative methods in an abstract requirements phase. While formal methods technology in safety-critical systems can help increase confidence of software, difficulty and complexity in using them can cause another hazard. In order to overcome this obstruction, we propose a framework for qualitative requirements engineering of the hybrid real-time systems. It consists of a qualitative method for requirements specification, called QFM (Qualitative Formal Method), and a safety analysis method for the requirements based on a causality information, called CRSA (Causal Requirements Safety Analysis). QFM emphasizes the idea of a causal and qualitative reasoning in formal methods to reduce the cognitive burden of designers when specifying and validating the software requirements of hybrid safety systems. CRSA can evaluate the logical contribution of the software elements to the physical hazard of systems by utilizing the causality information that is kept during specification by QFM. Using the Shutdown System 2 of Wolsong nuclear power plants as a realistic example, we demonstrate the effectiveness of our approach.

• Korean Journal of Occupational Health Nursing
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• v.15 no.2
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• pp.94-103
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• 2006

Purpose: This study was to understand foreign workers' experiences exposed hazard chemical materials in korean industry. Method: The research subjects were 92 foreign workers worked in seoul, namyangju, ansan, suwon, pocheon, incheon, jincheon, and daejeon. It was that grounded theory method as qualitative approach was applied with in-depth interview, recording and dictation, and collected data was analysed line-by-line by research teams. The analysis process of in depth interview data was three phase. Results: The first phase was that find out meaningful data and confronted data for meaningful data was 53 meaningful items. The second phase was coding process of meaningful data, total coding items were 9, difficulty of new environment, existence of health hazard factors originated in work, performance of basic health management, management of hazard materials in work-site, self care of hazard materials in work-site, discrimination of disaster-compensation originated in work, perception of work stress, motivation of leaving position, satisfaction for present life. The third phase was 5 adaptation process, copying phase for new environment, management phase for health hazard factors, health change phase, life change phase, illegal stay phase. Conclusion: In summary, as a results it was concluded that foreign workers was experienced new environment and then has various problems in working site. But these evidences were not different from korean workers basically, undoubtedly reality of a korean small and medium enterprise. And foreign workers with long time stay have had many health problems probably, but they have want to long stay and so reach an unexpected result, illegal long stay. Therefore, we should make efforts for adequate foreign workers' health management at work-site and overall life in governmental and industrial nursing level.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.1
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• pp.65-72
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• 2020

In this study, the purpose is to identify the risks of the facilities of packaged hydrogen stations. As a risk identification method, failure mode & effect analysis (FMEA), a qualitative risk assessment, was used to analyze failure mode and effects of component of each facility. The analysis criteria were used to derive the risk priority number (RPN) using the 5-point method according to severity, incidence, and detectability. The study analyzed a total of 141 components of 23 types that can be identified on the design of the packaged hydrogen filling station. As a result, 683 types of failures and their causes and effects were identified. and the RPN was number of a total of 1,485. Of these, 10 failure types with a RPN value of 40 or more were deemed necessary. In addition, a list of failure types with a severity score of 5 was identified and analyzed.

• Journal of IKEEE
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• v.16 no.2
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• pp.145-152
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• 2012

This paper is the Software Hazard Analysis (SWHA) which will study the managerial process and the technical methode and techniques inherent in the performance of software safety task within the Military Aircraft System Safety program. This SWHA identifies potential hazardous effects on the software intensive systems and provides a comprehensive and qualitative assessment of the software safety. The purpose of this paper is to identify safety critical functions of software in Military A/C. The identified software hazards associated with the design or function will be evaluated for risks and operational constraint to further improve the software design requirement, analysis and testing efforts for safety critical software. This common SWHA, the first time analysis in KOREA, was review all avionics OFP(Operational Flight Program), and focus only on software segments which are safety critical. This paper provides a important understanding between the customer and developer as to how the software safety for the Military A/C will be accomplished. It will also provide the current best solution which may as one consider the necessary step in establishing a credible and cost-effective software safety program.

• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.131-140
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• 2003

An accident involving a boiler can result in a disaster since it handles high-pressurized steam so that it may cause an explosion. Therefore, the boiler is very susceptible to industrial accidents. This thesis aimed to develop counter-plans to prevent industrial accidents involved the boiler. At first after collecting accident cases involving boilers, a survey on the trait of them was carried out. Ant on the other hand a qualitative analysis was conducted to draw out hazardous components in the boiler itself and their inherent relative importance was assessed. Through this procedure, 'negligence of unsafe condition' was noted as the major cause for unsafe acts whereas 'fault in work procedure' for unsafe condition. In the meanwhile, results of a hazard analysis using FMEA technique ranked gas safety devices, a switch preventing gas from under-pressurization, protect relays high. In particular, it was pointed out that the water feeding and steam subsystem has more components in hazard than other subsystems. Considering these analyses results, counter-plans to improve safety management was suggested also.

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.95-100
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• 2012

This study is about the qualitative safety assessment for hydrogen gas filling facilities in Korea operating with one-bank type. The purpose of this safety assessment is about the development of components for design, fabrication, assembly, operability of dispenser and systems of the safety. For the qualitative safety assessment method, the study used FMEA(failure mode & effect analysis) and HAZOP(hazard & operability). This study evaluated the safety through FMEA and HAZOP then by referring to P&ID and PFD of hydrogen dispenser, thereby examining the dangerousness of the equipments, defects of the structure and problems of the operation.