• 한국안전학회지
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• 제22권5호
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• pp.71-76
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• 2007

Failures of equipments for train control systems are linked directly to extensive damages of human lives or financial losses from the increasing uses of train control equipments utilizing computers. Then safety activities for assuring safety and reliability are needed during the system life-cycle. Risk analysis is important phase to increase safety from determining the risk presented by the identified hazard. In this paper, we investigated several methods for risk estimation of safety activities, and then we drew a comparison between original methods to suggest optimized one in the application to train control systems. In the result of the comparison, we had plan to propose the risk analysis method called Best-Practice(BP) risk method combining advantages of the qualitative and the quantitative analysis. In addition, we attempted to apply the BP-risk method to domestic train control systems handling in Korea.

• 자동차안전학회지
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• 제9권3호
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• pp.39-45
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• 2017

Two-wheeled motorcycles rarely use windscreen wipers in general. However, if two or more wheeled motorcycles with upper body employ windscreen wiper systems, clear visibility should be ensured regardless of weather conditions. The windscreen wiper systems include washers, defrosting, and demisting. As demands for the personal mobility are rapidly increased, the related global safety standards for motorcycles with upper body have been revised accordingly. Currently only EU regulations issue the provisions of windscreen wiper systems for L-category vehicles, which characterize two or more wheeled motorcycles. Therefore, in order to agree with international safety standards, it is necessary to revise KMVSS (Korea Motor Vehicle Safety Standards) for motorcycles. Here, KMVSS regarding windscreen wiper systems for motorcycles are studied considering the EU regulations. It is expected that the findings in this study are useful for future amendment of KMVSS.

• 품질경영학회지
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• 제41권4호
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• pp.725-735
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• 2013

Purpose: The purpose of this study is to propose an Integrated Safety Evaluation Process (ISEP) that can enhances the safety aspect of the safety-critical system. This process utilizes the advantages of the iterative Systems Engineering process combined with the safety assessment process that is commonly and well defined in many standards and/or guidelines for railway, aerospace, and other safety-critical systems. Methods: The proposed process model is based on the predefined system lifecycle, in each phase of which the appropriate safety assessment activities and the safety data are identified. The interfaces between Systems Engineering process and the safety assessment process are identified before the two processes are integrated. For the integration, the elements at lower level of Systems Engineering process are combined with the relevant elements of safety assessment process. This combined process model is represented as Enhanced Functional Flow Block Diagram (EFFBD) by using CORE(R) that is commercial modelling tool. Results: The proposed model is applied to the lifecycle and management process of the United States aircraft system. The US aircraft systems engineering process are composed of twelve key elements, among which the requirements management, functional analysis, and Synthesis processes are considered for examplenary application of the proposed process. To synchronize the Systems Engineering process and the safety assessment process, the Systems Engineering milestones are utilized, where the US aircraft system has thirteen milestones. Taking into account of the nine steps in the maturity level, the integrated process models are proposed in some phases of lifecycle. The flows of processes are simulated using CORE(R), confirming the flows are timelined without any conflict between the Systems Engineering process and the safety assessment process. Conclusion: ISEP allows the timeline analysis for identifying activity and data flows. Also, the use of CORE(R) is shown to be effective in the management and change of process data, which helps for the ISEP to apply for the development of safety critical system. In this study, only the first few phases of lifecyle are considered, however, the implementation through operation phases can be revised by combining the elements of safety activities regarding those phases.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.676-682
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• 2019

After the Fukushima Daiichi accident, there has been an increasing preference for passive safety features in the nuclear power industry. Some passive safety systems require limited active components to trigger subsequent passive operation. Under very serious accident conditions, passive safety features could be rendered inoperable or damaged. This study evaluates (i) the performance and effectiveness of the passive safety features of iPOWER (innovative Power Reactor), and (ii) whether a severe accident condition could be reached if the passive safety systems are damaged, namely the case of heat exchanger tube rupture. Analysis results show that the reactor coolant system remains in the hot shutdown condition without operator actions or electricity for over 72 h when the passive auxiliary feedwater systems (PAFSs) are operable without damage. However, heat exchanger tube rupture in the PAFS leads to core damage after about 18 h. Such results demonstrate that, to enhance the safety of iPOWER, maintaining the integrity of the PAFS is critical, and therefore additional protections for PAFS are necessary. To improve the reliability of iPOWER, additional battery sets are necessary for the passive safety systems using limited active components for accident mitigation under such extreme circumstances.

• 대한안전경영과학회지
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• 제15권3호
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• pp.105-112
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• 2013

To meet the growing needs from a variety of stakeholders, the development of modern systems is getting more complex and thus, the systems failure in the actual operations can potentially become more serious. This is why several international or military standards on systems safety have been published. In spite of the importance of meeting those standards such as IEC 61508 and ISO 26262 in the systems development, the associated practical methods seem deficient since those standards do not provide them. The objective of this paper is to present a method to identify potential hazards in fulfilling the requirements of the safety standards. In particular, the approach taken here is based on applying the functional analysis that covers several levels of the system under development. Note, however, that in the most of the conventional methods for hazards identification, the analysis has been focused on the failure at or underneath the component level of the system. The hazards identification method in this paper would cover the level up to the system by utilizing the functions-oriented approach. The case study of the safety enhancement for locomotive cabs is also discussed.

• 정보처리학회논문지D
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• 제14D권6호
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• pp.633-640
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• 2007

실생활과 밀접한 임베디드 시스템들이 인터넷에 연결되어 점차 복잡해지고 시스템 사용 패턴 또한 다양해짐에 따라 임베디드 시스템의 안전성 문제가 대두되고 있다. 임베디드 시스템의 상호작용에 대한 안전성을 분석하기 위서는 시스템 모델을 정형적으로 기술하고 이를 이용하는 체계적인 안전성 분석 방법이 필요하다. 이 연구에서는 Labeled Transition Systems (LTS)를 이용하여 시스템 모델과 속성 모델을 기술하고 안전성 속성이 만족되는지 검사하는 방법을 제공한다. 이 연구에서는 기존 합성적 안전성 분석 방법의 문제점을 해결하기 위해 시스템 모델을 속성모델 관점에서 축약하여 생성한 후에 두 모델 간의 행위 일치 관계를 이용하여 안전성 분석을 수행한다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2000년도 International Symposium:on the Maritime Management Systems for Safer and Cleaner Seas in the New Millennium
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• pp.38-51
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• 2000

This paper gives an overview of maritime safety and security systems in china. Law and legislation aspects are introduced. It includes a brief look on governmental structure in maritime safety and security related issues. Designated functions and organizations structure of authorities is described. In the conclusion, new development and outlook of changes in the maritime safety and security systems in China are made.

• 대한안전경영과학회지
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• 제16권4호
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• pp.123-131
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• 2014

Modern weapon systems are getting more complex in terms of the functionality and also the conditions on the environment and range in which they are deployed and used. Therefore, many development programs can easily be exposed to a variety of risks, resulting in delayed schedules and cost overrun. As such, effective means are necessary to keep the defence budget at an affordable level while competitive edges on technological aspects are retained. As one way to meet those need, modeling and simulation (M&S) methods have widely been used, particularly in the test and evaluation (T&E) process for weapon systems development. The result of M&S-based systems development should be evaluated by the verification, validation & accreditation (VV&A) process to assure keeping reliability at a desired level. On the other hand, due to the explosiveness, the weapons systems development naturally requires to consider safety issues in both the T&E and operational periods. The purpose of this paper is to improve the VV&A process by reflecting the safety requirements therein. To do so, the VV&A process has been analyzed and graphically modeled first and then safety elements have been incorporated effectively. The use of the improved process in the war ships development has also been discussed. Based on the process proposed and the consequent database constructed, the target system can be expected to benefit from reducing development risks while assuring systems safety.

• 한국멀티미디어학회논문지
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• 제15권1호
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• pp.115-130
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• 2012

오늘날 대다수의 안전필수 시스템들(Safety-Critical Systems)에는 컴퓨터, 전기 및 전자 부품이나 장치들에 소프트웨어를 칩에 내장하거나 제어용 소프트웨어 시스템이 탑재되어 구축되고 있다. 이에 따라, 컴퓨터 소프트웨어를 내장하였거나 탑재한 시스템들의 안전성을 평가하기 위한 여러 가지의 결함 분석 기법들이 제안되어져 오고 있다. 이러한 소프트웨어 결함 분석 기법들은 전통적으로는 하나의 안전필수 시스템을 분석하는데 단지 하나의 방법으로만 분석해 왔으나, 시스템의 종류와 특성이 다양해지면서 그 시스템에 가장 알맞은 결함 분석 기법이 동원되어야 함은 필수적이다. 본 연구에서는, 안전필수 시스템에서 소프트웨어의 크기가 비교적 작고, 안전성과 관련한 시스템 제어 반응 시간이 특별히 민감하지 않는 소프트웨어의 안전성을 평가하는 방법으로 결함트리 분석(FTA)과 소프트웨어 고장 유형 및 영향 분석(FMEA)을 결합한 시스템 결함 분석 방법을 제안하고 유비쿼터스 헬스케어 시스템을 이용하여 사례연구를 수행하고자 한다.

• 한국항공운항학회지
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• 제17권2호
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• pp.23-30
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• 2009

The problem of establishing weapon system safety especially during the development process has been one of the very important fields related with public safety in advanced countries such as USA, UK and so on. These countries have launched strong policies on system safety to reduce the chance of accidents. However, the Republic of Korea (ROK) has limited experiences and application of the system safety on domestically produced weapon systems. Therefore, it is imperative that the government starts a comprehensive and systematic policy on system safety to reduce the occurrence of potential accidents during the development of weapon systems. In this paper, we analyze system-level activities needed through the life-cycle of the weapon systems and provide a suggestion for application of the system safety.