• 한국철도학회논문집
• /
• 제9권5호
• /
• pp.601-605
• /
• 2006

Reliability of the Railway signaling system which is safety critical is determined by reliability of hardware and software. Reliability of hardware is easily predicted and demonstrated through lots of different studies and environmental tests, while that of software is estimated by the iterative test outcomes so estimates of reliability will depend on the inputs. Combinations of inputs to and outputs from the software may be mostly combinatoric and therefore all the combinations could not be tested. As a result, it has been more important to calculate reliability by means of a simpler method. This paper identifies the reliability prediction equation applicable to reliability prediction for railway signaling system software, and performs the simulation of onboard equipment of automatic train control for high speed train to review reliability prediction and validity.

• 항공우주시스템공학회지
• /
• 제17권1호
• /
• pp.33-41
• /
• 2023

보잉 737 맥스 사고사례에서 볼 수 있듯이 항공기 소프트웨어는 비중이 급속도로 증가하고 있으나 안전문제에서 취약한 것이 드러났다. 국내의 경우, 자체중량 150kg 이하 무인동력비행장치를 운용하려면 초경량비행장치 안전성인증이 요구되지만, 소프트웨어 인증 절차는 포함되지 않는다. 다만, 최근 무인동력비행장치의 활용이 증대됨에 따라 소프트웨어 검증이 요구되는 추세이다. 본 논문은 항공 소프트웨어 인증 규격인 DO-178C를 참조하여 무인동력비행장치에 적용할 수 있는 무인동력비행장치 소프트웨어 체크리스트를 제안하였다. 국내외 선진기업 및 기관에서 활용 중인 모델기반개발(Model-based Development) 기반의 헬리콥터 비행 제어 컴퓨터(FCC) 프로젝트에 제안된 체크리스트를 적용하는 사례연구를 수행하였다.

• Nuclear Engineering and Technology
• /
• 제47권2호
• /
• pp.212-218
• /
• 2015

We describe a comparative analysis of different tools used to assess safety-critical software used in nuclear power plants. To enhance the credibility of safety assessments and to optimize safety justification costs, $Electricit{\acute{e}}$ de France (EDF) investigates the use of methods and tools for source code semantic analysis, to obtain indisputable evidence and help assessors focus on the most critical issues. EDF has been using the PolySpace tool for more than 10 years. Currently, new industrial tools based on the same formal approach, Abstract Interpretation, are available. Practical experimentation with these new tools shows that the precision obtained on one of our shutdown systems software packages is substantially improved. In the first part of this article, we present the analysis principles of the tools used in our experimentation. In the second part, we present the main characteristics of protection-system software, and why these characteristics are well adapted for the new analysis tools. In the last part, we present an overview of the results and the limitations of the tools.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.185-187
• /
• 2005

The reactor protection system is the most important function for the safe operation of nuclear powerplants (NPPs) in that such system protects a nuclear reactor tore whose damage can cause an enormous disaster to the nuclear facility and the public. A digital reactor protection system (DRPS) is being developed in KAERI for use in the newly-constructed NPPs and also for replacing the existing analog-type reactor Protection systems. In this paper, an software verification and validation (V&V) activities for DRPS, which are independent of the DRPS development processes, are described according to the software development life cycle. The main activities of DRPS V&V processes are the software planning documentations, the verification of software requirements specification (SRS) and software design specification (SDS), the verification of codes, the tests of the integrated software and system. Moreover, the software safety analysis and the software configuration management are involved in the DRPS V&V processes. All of the V&V activities are described, in detail, in this paper.

• Journal of Information Processing Systems
• /
• 제14권2호
• /
• pp.309-321
• /
• 2018

In the conventional computing environment, users use only a small number of software systems intensively. So it had been enough to check and guarantee the functional correctness and safety of a small number of giant systems in order to protect the user systems and their information inside the systems from outside attacks. However, checking the correctness and safety of giant systems is not enough anymore, since users are using various software systems or web services provided by unskilled developers. To prove or guarantee the safety of software system, a lot of research has been conducted in diverse areas of computer science. We will discuss the on-going approaches for guaranteeing or verifying the safety of software systems in this paper. We also discuss the future research challenge which must be solved with better solutions in the near future.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.163-165
• /
• 2008

A S/W testing for vital railway signaling system have been important because of the increase of software usage for signaling. And also the safety of vital signaling system is required by int'l std. such as IEC 61508. While much efforts have been reported to improve electronic hardware's safety, not so much systematic approaches to assessment software's safety. In this paper, we propose a automation schemen of software testing tool for railway signaling system. From that, we show the functional architecture and internal components of the tool.

• Journal of Electrical Engineering and Technology
• /
• 제10권4호
• /
• pp.1915-1920
• /
• 2015

ISO 26262 is an international standard for the functional safety of electric and electronic systems in vehicles, and this standard has become a major issue in the automotive industry. In this paper, a functional safety compliant electronic control unit (ECU) for an electric power steering (EPS) system and a demonstration purposed EPS system are developed, and a software and hardware structure for a safety critical system is presented. EPS is the most recently introduced power steering technology for vehicles, and it can improve driver’s convenience and fuel efficiency. In conformity with the design process specified in ISO 26262, the Automotive Safety Integrity Level (ASIL) of an EPS system is evaluated, and hardware and software are designed based on an asymmetric dual processing unit architecture and an external watchdog. The developed EPS system effectively demonstrates the fault detection and diagnostic functions of a functional safety compliant ECU as well as the basic EPS functions.

• Nuclear Engineering and Technology
• /
• 제26권4호
• /
• pp.502-506
• /
• 1994

안전등급 컴퓨터계통 설계에 대해서 노심보호계산기계통 소프트웨어 설계와 검증시험을 중심으로 살펴보았다. 안전계통에 컴퓨터계통을 사용하면, 하드웨어뿐만 아니라 소프트웨어에 대한 철저한 검중시험이 요구된다. 노심보호계산기계통에 대한 검증시험은 두개의 소프트웨어 버전을 개발하여, 수행결과를 서로 비교함으로써 수행된다. 하나는 어셈블리언어로, 또 다른 하나는 포트란으로 구현된다. 검증시험은 순차적이고 중첩되게 수행된다. 일차 시험은 모든 브랜치 루틴을 수행하여 각 소프트웨어 모듈이 바르게 구현되었음을 확인하는 작업이다. 이차 시험은 통합된 소프트웨어가 모든 요건을 만족하는가 그리고 시간요건을 만족하는 지를 검증한다. 이러한 철저한 검증시험을 통해서 영광 3, 4호기 노심보호계산기계통이 올바르고 완벽하게 구현되어 요건서를 만족함이 확인되었다.

• 정보보호학회논문지
• /
• 제23권2호
• /
• pp.243-250
• /
• 2013

스마트 시대로 진입하면서, 다양한 임베디드 소프트웨어, 특히 SCADA 소프트웨어와 자동차 소프트웨어 등은 신뢰도와 고 안전성뿐만이 아니라 높은 보안성도 중요하게 되었다. 따라서 해커가 공격하는 데 사용하는 소프트웨어 취약점(vulnerability)의 근본 원인인 소프트웨어 보안 약점(weakness)을 개발 단계에서 제거하는 것이 매우 중요하게 되었다. 기능성 중심의 MISRA-C와 같은 코딩 룰은 보안성 중심의 시큐어 코딩규칙으로 확대가 될 필요가 있다. 본 논문에서는 고 안전성 소프트웨어의 데모용으로 개발 중인 원자력 관련 소프트웨어를 CERT-C 시큐어 코딩 규칙으로 조사하여 얼마나 많은 보안약점을 내재하고 있는 지를 분석하여, 이러한 보안약점을 소프트웨어 개발 시에 제거하는 방법에 대하여 제안한다.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2002년도 춘계학술대회
• /
• pp.177-177
• /
• 2002