• 한국항공우주학회지
• /
• 제44권3호
• /
• pp.256-265
• /
• 2016

소프트웨어 기반의 고장허용이란 장비의 일부분에 소프트웨어 고장이 발생하더라도 허용할 수 있도록 장비를 설계하는 것을 의미힌다. 고장허용을 위한 설계 방법은 크게 하드웨어 기반 고장허용 설계 방법과 소프트웨어 기반 고장허용 설계 방법이 있으며, 시스템의 특징에 따라 적절한 방법의 고장허용 설계 방법 선택이 필요하다. 본 논문에서는 하드웨어적으로 이중화로 구성된 비행조종컴퓨터의 소프트웨어 기반 고장허용 설계 기법에 대하여 기술하였다. 소프트웨어 기반의 고장허용 설계를 위하여 소프트웨어 고장을 분류하고, 고장에 대한 검출 방법을 설계한 후, 고장발생시 복구 방법을 설계하였다. 설계된 방법의 유효성을 확인하기 위하여 전용 소프트웨어 시험 환경을 통해 설계된 소프트웨어 기반 고장허용 설계의 타당성을 검증하였다.

• 대한전기학회논문지:전력기술부문A
• /
• 제54권2호
• /
• pp.73-78
• /
• 2005

The management of technological systems will become increasingly complex. Safe and reliable software operation is a significant requirement for many types of system. So, with software fault tolerance, we want to prevent failures by tolerating faults whose occurrences are known when errors are detected. This paper presents a fault location algorithm for single-phase-to-ground faults on the teed circuit of a parallel transmission line using software fault tolerance technique. To find the fault location of transmission line, we have to solve the 3rd order transmission line equation. A significant improvement in the identification of the fault location was accomplished using the N-Version Programming (NVP) design paradigm. The delivered new algorithm has been tested with the simulation data obtained from the versatile EMTP simulator.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
• /
• pp.875-877
• /
• 2003

This paper use fault location algorithm for single-phase-to-ground faults on the teed circuit of a parallel transmission line that use only local end voltage and current information. When Newton-Raphson iteration method is used, the Initial value may cause error or cause not suitable result. Suggested new calculation model uses NVP methodology, which is one of the fault tolerance technology to solve this problem. EMTP simulation result has shown effectiveness of the algorithm under various conditions.

• 한국군사과학기술학회지
• /
• 제18권6호
• /
• pp.762-770
• /
• 2015

Fault tolerance is a crucial design for a mission-critical computer such as engagement control computer that has to maintain its operation for long mission time. In recent years, software fault-tolerant design is becoming important in terms of cost-effectiveness and high-efficiency. In this paper, we propose MPCMCC which is a model-based software component to implement fault tolerance in mission-critical computers. MPCMCC is a fault tolerance design that synchronizes shared data between two computers by using the one-way message-passing scheme which is easy to use and more stable than the shared memory scheme. In addition, MPCMCC can be easily reused for future work by employing the model based development methodology. We verified the functions of the software component and analyzed its performance in the simulation environment by using two mission-critical computers. The results show that MPCMCC is a suitable software component for fault tolerance in mission-critical computers.

• Journal of Information Processing Systems
• /
• 제8권1호
• /
• pp.21-54
• /
• 2012

As we know every software development process is pretty large and consists of different modules. This raises the idea of prioritizing different software modules so that important modules can be tested by preference. In the software testing process, it is not possible to test each and every module regressively, which is due to time and cost constraints. To deal with these constraints, this paper proposes an approach that is based on the fuzzy multi-criteria approach for prioritizing several software modules and calculates optimal time and cost for software testing by using fuzzy logic and the fault tolerance approach.

• 한국철도학회논문집
• /
• 제12권6호
• /
• pp.1043-1048
• /
• 2009

열차제어시스템의 소프트웨어 발전에 의해 PES가 사용되고 있다. PES는 현재 세계적으로 널리 사용하고 있고, 하드웨어, 펌웨어, 응용 소프트웨어로 구성되어 있다. PES의 실행이 높은 유연성을 가지고 있기 때문에 PES는 많은 응용분야에 쉽게 적용할 수 있다. 많은 안전 필수 기능들은 소프트웨어를 통해 수행되고 있다. 보통 PES는 매우 복잡하여 결함의 근원을 발견하기 쉽지 않다. 그래서 소프트웨어 결함허용 기법을 이용한 신뢰도 해석이 필요하다. 현재 소프트웨어 결함허용 기법에는 복구블록, 분산 복구 블록, N-버전 프로그래밍, N 자기검사 프로그램이 있다. 본 논문에서는 마르코프 모델을 이용하여 소프트웨어 결함허용 기법 중에 복구 블록과 N-버전 프로그래밍의 모델을 제시하였다. 또한 열차제어시스템의 신뢰도를 시간 변화에 따라 분석하였다. 프로그램의 결함 발생률, 수용테스트 결함발생률, 보터의 결함발생률은 고정시켰다. 그래서 시간과 신뢰도 사이의 관계를 Matlab 프로그램을 이용하여서 제시하였다. 같은 수의 대체블록이 있는 경우에 신뢰도 분석결과 복구 블록의 신뢰도는 N-버전 프로그래밍의 신뢰도보다 높게 해석되었다.

• 제어로봇시스템학회논문지
• /
• 제16권6호
• /
• pp.601-607
• /
• 2010

For commercial success of emerging service robots, the fault tolerant technology for system reliability and human safety is crucial. Traditionally fault tolerance methods have been implemented in application level. However, from our studies on the common design patterns in fault tolerance, we argue that a framework-based approach provides many benefits in providing reliability for system development. To demonstrate the benefits, we build a framework-based fault tolerant engine for OPRoS (Open Platform for Robotic Services) standards. The fault manager in framework provides a set of fault tolerant measures of detection, isolation, and recovery. The system integrators choose the appropriate fault handling tools by declaring XML configuration descriptors, considering the constraints of components and operating environment. By building a fault tolerant navigation application from the non-faulttolerant components, we demonstrate the usability and benefits of the proposed framework-based approach.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.297-299
• /
• 2006

Many distributed applications is developed in various environment such as operating system, software platform. So, they exhibit different types of system behavior, status, during the course of their operation. Each such behavior may have different functional and non-functional requirements. Therefore, many distributed application need to fault-tolerance solution. Personal robot provide various service or application. Because personal robot has many application or service, it need to fault-tolerance architecture. A flexible architecture is required to provide dependability. In this paper, it is suggested a fault-tolerant architecture for module-based personal robot with module fault-tolerance, service fault-tolerance.

• 전자공학회지
• /
• 제5권1호
• /
• pp.31-37
• /
• 1978

시스템의 좋고 나쁨의 구별에 결정적인 역할을 하는 신뢰성에 대하여 설명하였다. 신뢰성은 단순히 정확성보다는 결함포용성에 의존함이 크며 주 통제 및 제어장치가 컴퓨터인 시스템에 있어서는 설계시에 Software에서의 결함포용설계의 중요성을 강조하였다. 결함포용설계의 일반적인 방법과 주요부분의 이중화에 대하여 컴퓨터의 이중화방식과 이중화의 장단점을 살펴보고, 결함포용설계의 한 예로써 GTK-500 EPABX를 설명하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권3호
• /
• pp.1321-1332
• /
• 2016

Wireless sensor networks (WSN) are self-organized networks that typically consist of thousands of low-cost, low-powered sensor nodes. The reliability and availability of WSNs can be affected by faults, including those from radio interference, battery exhaustion, hardware and software failures, communication link errors, malicious attacks, and so on. Thus, we propose a novel multi-agent fault tolerant system for wireless sensor networks. Since a major requirement of WSNs is to reduce energy consumption, we use multi-agent and mobile agent configurations to manage WSNs that provide energy-efficient services. Mobile agent architecture have inherent advantages in that they provide energy awareness, scalability, reliability, and extensibility. Our multi-agent system consists of a resource manager, a fault tolerance manager and a load balancing manager, and we also propose fault-tolerant protocols that use multi-agent and mobile agent setups.