• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.316-318
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• 2006

It can be considered that the safety of software is combined with that of hardware, and also directly connected to system safety. Because the software in the railway system takes the form of Embedded that let it behave at the system level, instead of independent operation, the safety of the railway S/W is also important. The approach, for ensuring the quality and safety of those software, can be considered with two points of view. Those are views seeing from products, and from processes. The two points of approach are all necessary in the railway system. For the first of all, the process approach is to validate maturity of the organizations in accordance to the judging processes of organizations, which are specified by CMMI(Capability Maturity Model Integration) or SPICE(Software Process Improvement and Capability dEtermination: ISO/IECl5504). In this paper, as the first step of them, we are trying to find approaches to estimate the maturity of manufacturer and assessment organization in the railway system.

• Nuclear Engineering and Technology
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• 제50권4호
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• pp.570-581
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• 2018

Recently, a software program has been used in nuclear power plants (NPPs) to digitalize many instrumentation and control systems. To guarantee NPP safety, the reliability of the software used in safetycritical instrumentation and control systems must be quantified and verified with proper test cases and test environment. In this study, a software testing method using a simulation-based software test bed is proposed. The test bed is developed by emulating the microprocessor architecture of the programmable logic controller used in NPP safety-critical applications and capturing its behavior at each machine instruction. The effectiveness of the proposed method is demonstrated via a case study. To represent the possible states of software input and the internal variables that contribute to generating a dedicated safety signal, the software test cases are developed in consideration of the digital characteristics of the target system and the plant dynamics. The method provides a practical way to conduct exhaustive software testing, which can prove the software to be error free and minimize the uncertainty in software reliability quantification. Compared with existing testing methods, it can effectively reduce the software testing effort by emulating the programmable logic controller behavior at the machine level.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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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.

• 한국철도학회논문집
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• 제20권1호
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• pp.55-63
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• 2017

철도에 사용되고 있는 Safety critical systems 중 하나인 연동장치는 relay-based systems에서 computer-based systems으로 급속히 변환되고 있다. computer-based interlocking systems (CBI)의 안전성확보가 중요한 문제 중 하나로 떠오르고 있다. CBI를 구성하는 연동논리 software는 시스템 안전성에 직접적으로 영향을 미치는 부분 중 하나이다. Formal methods 중 하나인 "Z"notation은 이 software 안전성 확보를 위해 software 명세에 많이 사용되고 있다. 본 논문에서는 "Z"notation을 이용하여 연동논리 일부분을 구현하였으며, Z/EVES를 이용하여 검증을 하였다.

• 전기학회논문지P
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• 제58권2호
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• pp.108-115
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• 2009

Recent advances in computer technology have brought more dependence on software to train control systems. Hence, the safety assurance of the vital software running on the railway system is very critical task and yet, not many works have been done. While much efforts have been reported to improve electronic hardware's safety, not so much systematic approaches to evaluate software's safety, especially for the vital software running on board train controllers. In this paper, we have developed the static software testing tool for railway signaling, especially Fagan Inspection module and checklists supporting module. This static testing tool for railway signaling can be utilized at the assessment phase, and also usefully at the software development stage also. It is anticipated that it will be greatly helpful for the evaluation on the software for railway signalling system.

• 한국멀티미디어학회논문지
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• 제21권9호
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• pp.1099-1109
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• 2018

Most of the automotive electronic systems are equipped with control software. ISO 26262 standard has been published to prevent unreasonable risk due to E/E system malfunction. And many automotive companies apply ISO 26262 for safe series product. In ISO 26262 standard, the product quality improves through deductive and inductive safety analysis in all processes including system and software development phase. However, there are few studies on software safety analysis than systems. In the paper, we study the software FMEA(Failure Mode Effect Analysis) technique for product quality of vehicular embedded software. And we propose an effective guideline of software FMEA as EPB industrial practice.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1014-1015
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• 2008

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, and 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 development process, ordering management and assessment process for railway software with more detail description.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.158-160
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• 2008

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, and 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 development methodology, ordering management and assessment process for railway software with more detail description.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2005년도 춘계학술대회
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• pp.129-135
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• 2005

This paper proposes the interated and balanced project management system for software and IT by considering BSC, MBNQA, ISO 9001, Six Sigma, CMM and SPICE. This system can be extended to assess the various project management practices.

• 소프트웨어공학소사이어티 논문지
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• 제29권1호
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• pp.7-12
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• 2020

최근 기능 안전에 대한 관심이 높아짐에 따라 다양한 산업 분야에서 기능 안전 표준의 적용이 요구되고 있다. 기능 안전 표준은 시스템의 오작동을 방지하기 위해 필요한 기능 안전 관련 활동들을 정의한 문서이다. 이 표준에 정의된 모든 활동들은 시스템의 위험 분석 및 평가를 통해 산출된 등급 분류 결과에 따라 차등적으로 요구된다. 국내 무기체계 분야에는 방위사업청에서 발간한 무기체계 소프트웨어 개발 및 관리 매뉴얼이 존재한다. 이 매뉴얼은 기능 안전 관련 활동으로 소프트웨어 정적 및 동적 분석 활동을 요구한다. 하지만 해당 매뉴얼에는 선행 활동으로 요구되는 위험 분석 및 평가를 통한 등급 분류 활동 관련 내용이 구체적으로 언급되고 있지 않다. 따라서 본 연구에서는 대표적인 기능 안전 표준들을 기반으로 무기체계 소프트웨어 개발 및 관리 매뉴얼의 문제점을 분석하고 이에 대한 개선 방안을 제시하도록 한다.