• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2220-2227
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• 2008

The safety equipments of railway level crossing which are installed at intersections between roads and railway lines prevent level crossing accidents by informing all of the vehicles and pedestrians of approaching trains. The intelligent safety system for level crossing which employs information and communication technology has been developed in USA and Japan, etc. But, in Korea, the relevant research has not been performed. In this paper, we analyze the cause of railway level crossing accidents and the inherent problem of the existing safety equipments. Based on analyzed results, we design the intelligent safety system which prevent collision between a train and a vehicle. This system displays train approaching information in real-time at roadside warning devices, informs approaching train of the detected obstacle in crossing areas, and is interconnected with traffic signal to empty the crossing area before train comes. Especially, we present the video based obstacle detection algorithm and verify its performance with prototype H/W since the abrupt obstacles in crossing areas are the main cause of level crossing accidents. We identify that the presented scheme detects both pedestrian and vehicle with good performance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2030-2036
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• 2016

This paper presents a hardware development procedure of the ASB(Active Seat Belt) control system to comply with ISO 26262. The ASIL(Automotive Safety Integrity Level) of an ASB system is determined through the HARA(Hazard Analysis and Risk Assessment) and the safety mechanism is applied to meet the reqired ASIL. The hardware architecture of the controller consists of a microcontroller, H-bridge circuits, passive components, and current sensors which are used for the input comparison. The required ASIL for the control systems is shown to be satisfied with the safety mechanism by calculation of the SPFM(Single Point Fault Metric) and the LFM(Latent Fault Metric) for the design circuits.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1335-1342
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• 2013

Subway is electrified railway system nowadays, in which liquid dielectric transformers have been widely used, though mold type transformers are replacing it. The transformers supplies large electric power and have innate hazards causing accidents under operation. A number of researcher have carried out on failures of it and have oriented to identify transformer's failure causes and how to maintain it healthy state. The transformer failures can cause serious accidents which can provoke economic loss and leads persons to kill. In this paper, we carried out a safety activity to reveal hazards and to estimate risk of subway liquid dielectric transformers using FMEA, HAZOP and What-if methods. In case of installing safety devices in oil immersed transformer, we tried to evaluate an effect on a subsystem's failure rate. We proposed how to design subsystem failure rate and safety device failure rates.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.140-143
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• 1993

Station Blackout(SBO) event means the complete loss of alternating current(AC) electrical power to the essential & nonessential switchgear buses in a nuclear power plants. Since many safety systems in nuclear power plants depend upon alternative current power, the SBO event could be an important contributor to damage of reactor core. Therefore, the SBO events have been considered as a very important safety issues in a nuclear power plants. In this paper, as evaluating the design characteristics of offsite & emergency power systems, an acceptable minimum SBO duration is calculated. And it is presented that the design method for alternative AC(AAC) sources to cope with the SBO events.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1272-1274
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• 2002

It is very important to ensure system safety during the process of developing a system, Railway system is also devoting a great portion for the safety. Nowadays many countries leading railway industry have their own system assessment process according to the situation of their train control system. In this paper, a preprocess to establish system safety requirement is represented in the railway signalling system. We also adopt electronic interlocking system for an example.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.201-203
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• 2007

Safety critical systems are those in which a failure can have serious and irreversible consequences. Nowadays digital technology has been rapidly applied to critical system such as railways, airplanes, nuclear power plants, vehicles. The main difference between analog system and digital system is that the software is the key component of the digital system. The digital system performs more varying and highly complex functions efficiently compared to the existing analog system because software can be flexibly designed and implemented. The flexible design make it difficult to predict the software failures. This paper reviews safety standard and criteria for safety critical system such as railway system and suggests software development methodology for more detail description.

• 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 KIEE Conference
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• summer
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• pp.1400-1402
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• 2004

The safety of staff, customers and of general Public in general viewed as one of the most important requirements in the urban transit. The maintenance computerization system for car of urban transit is a part of standardization and development of urban transit system. and We have been performed the establishment of maintenance computerization system from 2001 to 2005. The RAMS (reliability. availability. maintainability and safety) estimation for maintenance computerization system are utilized in a variety of computerization system for user's convenience and safety in maintenance. Ever since its inception though. the urban transit has searched for ways to improve reliability. availability. maintainability and safety of the railway subsystem. Provision of a reliable maintenance system include RAMS of the vehicles plays a very important role in achieving a safe system.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1556-1558
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• 2005

As a result of the advancement of radio communications technologies, some investigations are in progress to apply this technologies to a train control system. Most of these investigations are focused on the train safety distance control between a preceding train and a succeeding train, an interlocking system uses train circuits to control the railway path. To make the best use of advantages and improve the safety of radio communications based train control systems, the interlocking system must use radio communications technologies. And the safety level of this system must be equal to track circuit based interlocking systems. This paper describes the train location detection method, the system configuration and the system safety of the new system.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1332-1334
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• 2003

Safety of breaking facility is very important in subway safety, especially in case of subway that many people used, breaking capability is connected directly with safety and capability of vehicle. Recently, direction of subway technical development is established as passenger's convenience and agreeableness. However, we are known importance of safety in subway through Dae-gu subway incendiary case. Subway accident not happen only fire, vehicle collisions or passenger's fall to the track can happen. In this case, safety standard of breaking facilities is very important. so this paper define safety of breaking facilities and take proper that standard.