• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1379-1384
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• 2017

To guarantee safety and reliability, RAMS(Reliability Availability Maintainability and Safety) activity for a communication software in train communication network is studied. In this paper, preliminary hazard analysis in RAMS activities is studied for the communication software. Preliminary hazard analysis is done through library for communication software that the specification is defined by IEC 61375. The hazards are defined, then causes and consequence for each hazard are defined. The total 36 preliminary hazards are classified. For high severity hazards are changed to acceptable level by upgrading of system requirement specification.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.3
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• pp.97-103
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• 2015

To achieve the safety and reliability, RAMS activity for a railway signal system of Near Surface Transit is studied. In this paper, preliminary hazard analysis in RAMS activities is studied for the railway signal system of Near Surface Transit. Preliminary hazard analysis is done through automatic train protection, automatic train operation and automatic train supervision. The hazards are defined, then causes and consequence for each hazard are defined. The total 75 preliminary hazards are classified. For high severity hazards are changed to acceptable level by upgrading of system requirement specification.

• 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 Industrial Technology
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• v.33 no.A
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• pp.3-8
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• 2013

Reduction of risk plays a pivotal role in the development of medical instruments. A hyperbaric oxygen chamber, as a medical device, is known to help medical therapy for diversity of diseases through provision of high purity oxygen. The use of hyperbaric oxygen is expected to increase in the future and study to rigorously examine reliability and safety is needed. We have performed risk assessment for a newly developed hyperbaric oxygen chamber in this study. We first briefly discussed the system structure and concept of risk assessment for the study. Based on the hazards identified, we performed preliminary hazard analysis for the chamber.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.151-156
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• 2005

The objective of this study is to devise an accident scenario analysis method adept at creating accident scenarios at the Preliminary Hazard Analysis(PHA) step of a hazard analysis for railway system. This approach was inspired by the Quality Function Deployment(QFD) method, which is conventionally used in quality management and was used at the systematic accident scenario analysis(SASA) for the design of safer products. In this study, the QFD provides a formal and systematic schema to devise accident scenarios while maintaining objective. The accident scenario analysis method first identifies the hazard factors that cause railway accidents and explains the situation characteristics surrounding the accident. This method includes a feasibility test, a clustering process and a pattering process for a clearer understanding of the accident situation. Since this method enables an accident scenario analysis method to be performed systematically as well as objectively, this method is useful in building better accident prevention strategies. Therefore, this study can serve to reduce railway accident and be an effective tool for a hazard analysis.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1253-1258
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• 2004

The system safety must be ensured before customization. There was no specific requirement representing system safety in Korea until now. So we should draw safety requirements to guarantee system safety for the first time. In this paper, the Preliminary Hazard Analysis (PHA) to derive the safety requirements on the train control system was carried out. To analyze hazard, we have to deduce system functions, identify related hazards, derive the effects of the hazards, analyze current risks, define the target risks of the system, and deduce the alternative plans to reduce the effects of the hazards. For the case study, the detailed analysis on vehicle collision that was a main hazard of the train control system was carried out.

• Earthquakes and Structures
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• v.10 no.2
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• pp.389-408
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• 2016

Recently, seismic hazard analysis has become a very significant issue. New systems and available data have been also developed that could help scientists to explain the earthquakes phenomena and its physics. Scientists have begun to accept the role of uncertainty in earthquake issues and seismic hazard analysis. However, handling the existing uncertainty is still an important problem and lack of data causes difficulties in precisely quantifying uncertainty. Ground Motion Prediction Equation (GMPE) values are usually obtained in a statistical method: regression analysis. Each of these GMPEs uses the preliminary data of the selected earthquake. In this paper, a new fuzzy method was proposed to select suitable GMPE at every intensity (earthquake magnitude) and distance (site distance to fault) according to preliminary data aggregation in their area using ${\alpha}$ cut. The results showed that the use of this method as a GMPE could make a significant difference in probabilistic seismic hazard analysis (PSHA) results instead of selecting one equation or using logic tree. Also, a practical example of this new method was described in Iran as one of the world's earthquake-prone areas.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1-6
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• 2005

To improve safety management of railway and cope with the factors to threat technical and social safety, we need to establish railway safety management system based on analysis of hazards and assessment of risk for railway system. So we have to conduct PHA(Preliminary Hazard Analysis) first to understand weak points and factors to possibly threat safety using analysis of related data such as past accident/incident data and safety regulation and classification standards of hazards/causes of railway accidents. Therefore in this research, we led types/dangerous events/causes of risks/factors of risks from hazard log developed based on railway accident classification and hazards of railway accident. PHA model for domestic railway system will be used in risk analysis and risk assessment of railway accident.

• International Journal of Quality Innovation
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• v.6 no.1
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• pp.58-73
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• 2005

The objective of this study is to evaluate the equipment risk before and after SEMI S2-93A implementation, thus providing a guideline for safety improvement. Semiconductor Plant A located in Taiwan's Hsinchu Science Based Industrial Park with 147 manufacturing machines was used for risk assessment. This study was carried out in three steps. First, a preliminary hazard analysis was conducted. A detailed process safety evaluation was conducted (Hazard and Operability Study, HAZOP); and finally, the equipment risk comparison before and after Semiconductor Equipment Manufacturing Instruction (SEMI S2-93A) implementation. The preliminary hazard analysis results showed high risk in 21.77% of the manufacturing machines under risk assessment at Plant A. The largest percentage existed in the Diffusion Department. The machine types specified by the hazardous work site review and inspection according to Article 26 of Labor Inspection Regulation (the machines that use such chemicals as, $SiH_4$, HF, HCL, etc. and that are determined to be highly hazardous through preliminary hazard analysis) were added to the detailed process analysis and evaluation. In the third part of this evaluation, the machines at Plant A used for detailed process safety assessment were divided into two groups based on the manufacturing data before and after 1993. The severity, possibility, and actual accident analysis before and after SEMI S2-93A implementation were compared. The Semiconductor Equipment Manufacturing Instruction (SEMI S2-93A) implementation can reduce the severity and possibility of hazard occurrence.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1819-1827
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• 2015

ICT-based on-board oriented train control system has been proposed to improve operation efficiency in low-density railway line. It is also needed to develop a new ICT-based local control center which relates to existing centralized traffic control lines. In order to meet the qualitative target of these developing system, RAMS activities are required. In this paper, through preliminary hazard analysis, hazards and their contributing factors are addressed, then countermeasures are established to control the risk to an acceptable level.