• Proceedings of the KSR Conference
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• 2007.11a
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• pp.638-645
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• 2007

Computers are increasingly being introduced into safety and reliability critical systems. The safe and reliable operation of these systems cannot be taken for granted. Malfunctions of these systems can have potentially catastrophic consequences and they have already been involved in serious accidents. Software fault prevention, fault tolerance, fault removal and fault forecasting are the techniques to be used, implemented and verified for embedded software in critical systems as the contributors to safety and reliability of the software. To use them when developing a software product, a relationship must be established between them and the development processes, the methods and techniques to be used to develop software, as well as with the different product architectures. Railroad signaling system software is a safety-critical embedded software with realtime and high reliability requirements. The primary purpose of the safety management is to prevent the loss of lives or physical damages arising from potential hazards in the railroad signaling system. This study provides a systematic approach to analysis of potential hazards for their management during the system life cycle to assure the identification and definition of the most appropriate hazards.

• Journal of the Ergonomics Society of Korea
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• v.20 no.3
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• pp.61-76
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• 2001

This study is for analyzing the explosion accidents in the tunnels, roads, subways, streets and various kinds of building construction area with the use of Fault Tree Analysis(FTA). based on the police Department and Guns & Explosives Safety Technology Association's researching materials. the explosion accidents have been investigated and analyzed between 1988 and 1977. As the result, we can find out that the majority of the explosion accidents in Korea is the accidents by flown stones(45.7%), like in Japan. So we make the research chart which is needed for analyzing the explosion accident, and then analyze these accidents systematically. using the investigation codes of the industrial accidents. After that, the FTA was performed on the accidents by flown stones. They result fromm non-observance of the safety rules, and lees knowledge of the safety and so on. Moreover several causes are combined and then the accidents are apt to happen. So according to the results of this study, for the protection of the explosion accidents, the specialized safety education is badly needed and the enough investigation of the places before the work along with the management for safety in working must be planned.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2267-2273
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• 2009

In this paper, in order to monitor and manage an electrical risk factor like as leakage current, load current, and arc-fault, a real time monitoring and management system being operated in the ubiquitous environment was developed, and a plan of construction of an electrical safety grid using the system was proposed. For confirmation of usefulness and reliability of the proposed safety system and grid, the developed intelligent panels were applied to 28 Korean traditional houses in Jeonjoo city, and the grid including the panels was operated. If the proposed National Electrical Safety Grid is completely constructed in the houses of general electrical users, the Grid will have an effect on that a main manager on electrical safety transfers from management system by general people to real-time management system by expert. As a result, the electrical fires caused by an over-load, an arc-fault, and an earth-fault will be prevented.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10b
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• pp.582-584
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• 1998

객체 지향 설계 명세를 대상으로한 시스템의 안전성에 대한 검사를 하여, 표(Table)조작에 기초한 검증법을 제안하였다[4]. 제안한 검증법에서는 전문 분야별로 준비된 안정성 기준(Safety Standard)과 노우하우(Knowhow)를 이용하여, 안전성에 관한 이벤트(Event)와 액션(Action)의 관계표를 작성하였다. 그러나, 많은 실제 개발 현장에서는 실제 존재하는 안전성 기준의 부족 등으로 인하여, 이러한 검증법의 기용이 어렵다는 문제점이 있다. 이에 본 논문에서는 신뢰성 분석의 한 방법인 FTA(Fault Tree Analysis)의 FT(Fault Tree)도를 이용한 안정성 체크리스트(Check list)를 작성하여, 이를 바탕으로 관계표를 작성하는 새로운 방법을 제안하고자 한다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.79-86
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• 1999

This paper aims to propose a method that helps maintenance engineers to evaluate the damage states of bridge systems by using a Fuzzy Fault Tree Analysis(FFTA). It may be stated that Fuzzy Fault Tree Analysis may be may useful for the systematic md rational condition and safety assessment for real bridge systems problems because the approach is able to effectively deal with all the related bridge system damages in terms of the linguistic variables that incorporate systematically experts experiences and subjective judgement.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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• pp.475-483
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• 1997

Industrial safety management program consists of three part which is education, technology and control. The effectiveness of industrial safety control program rely on the ability of controlling hardware system, technology and software, training and management. How to design and develop the sharing machine fault and safety diagnosis system using expert system technique is presented on this paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.12
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• pp.13-17
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• 2014

In this paper, the risk of electric shock is analyzed through analysis for characterization of potential distribution analysis and ground fault current analysis near the area where there are occurred a ground fault at electric vehicle wireless charging system using 20kHz. Studies for electric vehicle wireless charging system are in the works for development of efficiency increase, pickup shape design and communication module as a fundamental research step. But the research related to electrical safety and is still scarce state so that more studies are necessary to commercialize. As a result of analysis, it is verified that induced voltage is arisen more up to 45V near the a area of accident during ground fault and fault current has been maintained continuously without clearing fault condition by operating characteristics for circuit breaker and inverter.

• Journal of Auto-vehicle Safety Association
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• v.14 no.2
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• pp.26-38
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• 2022

This paper proposes multiple RLS and actuator performance index-based adaptive actuator fault-tolerant control and detection algorithms for longitudinal autonomous driving. The proposed algorithm computes the desired acceleration using feedback law for longitudinal autonomous driving. When actuator fault or performance degradation exists, it is designed that the desired acceleration is adjusted with the calculated feedback gains based on multiple RLS and gradient descent method for fault-tolerant control. In order to define the performance index, the error between the desired and actual accelerations is used. The window-based weighted error standard deviation is computed with the design parameters. Fault level decision algorithm that can represent three fault levels such as normal, warning, emergency levels is proposed in this study. Performance evaluation under various driving scenarios with actuator fault was conducted based on co-simulation of Matlab/Simulink and commercial software (CarMaker).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.3
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• pp.52-58
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• 2008

The importance of. identifying the causes of electrical faults cannot be overstated because of the accidents caused by over-current that take place at the home, the office and electrical facilities due to misuse, poor products and system faults. It is necessary to gather objective, scientific data pertaining to electrical fault investigation in a product liability(PL) environment. To date, no database(DB) has been built concerning the accurate cause analysis of faultyfacilities. In this paper, accident hazard and arc scattering when over-current flows in copper wire was investigated. It was found that when over-current flows in a copper wire, the copper wire became heated and bent and beads were scattered around the wire with a flash. It was determinedthat the fusing current and time was related to the current rise per second. For example, when the current rise per second was largethe fusing current was higher than when the current rise per second was small, and the beads dispersed along a wide area. Fusing time, however, was shorter. The possibility of electrical fault became highest when the fusing current was higher. As the current rise per second is short, the dendrite structure is distributed in the surface of the copper wire. These experimental results can be utilized for a fault process DB system in the investigation and the prevention of electrical faults.

• Geomechanics and Engineering
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• v.14 no.4
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• pp.337-344
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• 2018

The study of the mining effect influenced by a normal fault has great significance concerning the prediction and prevention of fault rock burst. According to the occurrence condition of a normal fault, the stress evolution of the working face and fault plane, the movement characteristics of overlying strata, and the law of fault slipping when the working face advances from footwall to hanging wall are studied utilizing UDEC numerical simulation. Then the inducing-mechanism of fault rock burst is revealed. Results show that in pre-mining, the in situ stress distribution of two fault walls in the fault-affected zone is notably different. When the working face mines in the footwall, the abutment stress distributes in a "double peak" pattern. The ratio of shear stress to normal stress and the fault slipping have the obvious spatial and temporal characteristics because they vary gradually from the higher layer to the lower one orderly. The variation of roof subsidence is in S-shape which includes slow deformation, violent slipping, deformation induced by the hanging wall strata rotation, and movement stability. The simulation results are verified via several engineering cases of fault rock burst. Moreover, it can provide a reference for prevention and control of rock burst in a fault-affected zone under similar conditions.