• KIPS Transactions on Software and Data Engineering
• /
• v.2 no.10
• /
• pp.661-668
• /
• 2013

A safety critical system is a system that leads to injury of people, damage of property and environment due to functional failures or occurrence of undesired condition. Therefore, to ensure the safety of a system, system engineers should consider the inherent hazards of the system at design phase of the system development, and also should design the prevention actions to minimize damage when an accident occurred. The objective of these actions is preventing the serious damage from accidents that can occur due to unforeseen circumstance. Recently, many studies have been performed to identify and analyze their hazards at design phase of safety critical systems. This paper suggests a safety analysis technique for analyzing the collision among those prevention actions to reduce accident and its effect by the collision of these actions that did not mentioned in previous studies. Through the proposed technique, it would improve robustness of safety and would help the design of prevention actions into system for the occurrence of accidents.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06b
• /
• pp.135-137
• /
• 2012

Safety Critical 시스템은 예상치 못한 오류가 발생했을 시 인명, 재산 및 심각한 환경 피해 등이 발생 할 수 있는 임베디드 시스템이다. Safety Critical 시스템에는 많은 위험성들이 잠재적으로 존재하기 때문에 치명적인 사고가 발생할 수 있다. 이러한 문제를 방지하기 위해 시스템에 존재하는 위험성을 분석하는 활동이 중요시 되고 있다. 본 연구에서는 Safety Critical 시스템의 잠재적인 위험성들을 분석하고 이를 아키텍처 설계에 반영함으로써 시스템의 안전성을 향상시키기 위한 Hazard Perspective를 제안한다. 제안하는 Hazard Perspective는 위험성 분석으로 산출된 정보들과 SSR(System Safety Requirement)을 시스템의 안전을 보장하기 위해 제시된 여러 Safety Architectural Tactics와 매핑하여 아키텍처 설계에 반영시킴으로써 시스템의 안전성을 향상시키도록 한다.

• Journal of Korea Multimedia Society
• /
• v.15 no.1
• /
• pp.115-130
• /
• 2012

These days, most of safety-critical systems, which are systems those failures or malfunction may result in death or serious injury to people, or loss or severe damage to social systems, or environmental harm, are being built of embedded software or loaded controlling software systems on computers, electrical and electronic components or devices. There are a lot kind of fault analysis methods to evaluate safety of the safety-critical systems equipped computers, electrical and electronic components or devices with software. However, the only assessment method to evaluate software safety of a safety-critical system is not enough to analysis properly on account of the various types and characteristic of software systems by progress of information technology. Therefore, this paper proposes the integrated evaluation method and carries out a case study for the software safety of safety-critical system which embedded or loaded software sizes are small and control response times are not sensitive by use of two security analysis methods which are Fault Tree Analysis (FTA) and Fault Modes and Effect Analysis (FMEA) for ubiquitous healthcare system.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04a
• /
• pp.595-597
• /
• 2001

오늘날 우리가 사용하고 있는 시스템은 날이 갈수록 규모 면에서 대형화되고, 기능면에서 복잡해지고 있다. 이런 복잡성의 증가로 시스템 에러 발생가능성은 더욱 높아졌다. 특히, safety-critical 시스템의 경우 에러가 발생했을 때 인간과 생태계에 엄청난 영향을 미치기 때문에 더욱 신중한 개발 과정이 필요하다. 따라서 정형기법을 이용한 safety-critical 시스템의 개발방법론이 나오게 되었다. 본 논문에서는 대표적인 safety-critical 시스템인 원자력 발전소 시스템에서 Digital Plant Protection System(DPPS)를 가지고 어떻게 방법론이 적용되는지를 보여준다. Software Cost Reduction(SCR)이라는 정형 명세 도구로 명세를 하였고, SPIN 이라는 정형 검증 도구로 그 특성(property)을 검증하였다.

• Journal of Information Technology and Architecture
• /
• v.9 no.4
• /
• pp.443-453
• /
• 2012

In order to minimize the damage from system failures, systems over various fields are requested to contain the safety-critical features. In this paper, we deliver the considerable issues, especially, in the cyber physical systems that is recently used as a safety-critical system, as well as we propose the model driven architecture based on time as its the important factor. Based on meta-modeling approach, we introduce the time-based architecture which is associated with deadline, transition state, and threshold, and also we work out a design for this by using model driven architecture. We propose a realizable safety-critical architecture by means of showing failure handling components with safety transaction model from the meta-model. In the detailed models and the example, we design a basic safety processing state, a multiple safety processing state, and a compound safety processing state for completing the safety-critical system architecture.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.8
• /
• pp.813-822
• /
• 2010

Integrated data processing for display of flight critical data and mission critical data was conducted without additional display instruments using glass cockpit design. Based on a pre-designed flight critical system and a mission critical system, this paper shows an optimal design of subsystem integration. The design satisfies safety requirements of flight control systems(FCS) and requires minimized modification of pre-designed systems. By conducting integration test using System Integration laboratory(SIL), it is confirmed that the introduced design approach meets the safety requirements of the MEP system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.10
• /
• pp.3885-3892
• /
• 2010

Safety-Critical systems, such as Plant Protection Systems in nuclear power plant, plays a key role that the facilities can be operated without undue risk to the health and safety of public and environment, and those systems shall be designed, fabricated, installed, and tested to quality standards commensurate with the importance of the functions to be performed. Computer-based Instrumentation and Control Systems to perform the safety-critical function have Real Time Operating Systems to control and monitoring the sub-system and executing the application software. The safety-critical Real Time Operating Systems shall be designed, analyzed, tested and evaluated to have capability to maintain a high integrity and quality. However, local nuclear power plants have applied the real time operating systems on safety critical systems through Commercial Grade Item Dedication method, and this is the reason of lack of detailed methodology on assessing the safety of real time operating systems, expecially to the new developed one. This paper presents the methodology and experiences of safety evaluation on safety-critical Real Time Operating Systems based upon design requirements. This paper may useful to develop and evaluate the safety-critical Real Time Operating Systems in other industry to ensure the safety of public and environment.

• Journal of Advanced Navigation Technology
• /
• v.19 no.2
• /
• pp.91-97
• /
• 2015

This paper specifies several considerations about assessing safety-critical software in the aerospace domain. In order to evaluate safety critical software in the aerospace industry, it is required to identify an information of evaluation criteria of software under evaluation. The information is specified in the standard, but determination of evaluation criteria cannot be decided by itself and depends on the results of safety assessment of a system and system design. Thus, this paper explains required information of system development standard and safety assessment standard to determine software evaluation criteria. It surveys existing methodologies about evaluating software, and suggests method which is adapted to evaluation of an advanced surface movement guidance and control system (A-SMGCS) software.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10a
• /
• pp.486-488
• /
• 2000

본 연구는 정형기법을 사용하여 Safety-Critical System의 개발 방법론을 제시한다. Safety-Critical System의 전체적인 개발 과정을 제시하고 Safety-Critical System 중의 하나인 원자력 발전소 시스템 중 Reactor Protection System(RPS)을 정형 명세(Formal Specification)하고 정형 검증(Formal Verification)하는 과정과 그에 따른 각 과정의 Compliance를 확인하는 예를 든다. 여기서 정형 명세에는 Software Cost Reduction(SCR)이하는 도구가 사용되었고, 정형 검증에는 SPIN이, Compliance를 확인하는 데에는 Prototype Verification System(PVS)를 사용하였다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10b
• /
• pp.271-273
• /
• 2003

내장형 시스템의 기능이 복잡해지면서, 내장형 소프트웨어에 대한 테스팅이 중요하게 인식되고 있다. 특히 원자력 발전소 계통 기기와 같이 안전에 대한 치명도가 높은 Safety-Critical Embedded System일수록 탑재되는 내장형 소프트웨어에 대한 철저한 테스팅이 요구되기 때문에 본 논문에서는 대상 시스템에 탑재되는 소프트웨어 테스트를 중심으로 하여 Safety-Critical Embedded System을 위한 테스트 프로세스 및 이에 필요한 테스팅 기법을 제안한다.