• International Journal of Aeronautical and Space Sciences
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• 제4권2호
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• pp.37-50
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• 2003

A next generation small satellite HAUSAT-1, the first picosatellite developed in Korea, is being developed as one of the international CubeSat program by Space System Research Lab. of Hankuk Aviation University. A fault-tolerant incremental design methodology has been addressed in this paper. In this study, the effect of system redundancy on reliability was in details analyzed in accordance with the implementation of fault-tolerant system. Four different system recovery levels are proposed for HAUSAT-1 fault-tolerant system optimization. As a result, the HAUSAT-1 fault-tolerant system architecture design and reliability analysis has acquired about 11% reliability improvement.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 추계학술발표대회
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• pp.79-80
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• 2009

최근 UAV(Unmanned Aerial Vehicle)의 OFP(Operation Flight Program)에 대한 많은 연구가 진행되고 있다. UAV의 OFP는 경성 소프트웨어 일종으로 Time deadline과 수많은 요인으로 인한 Fault에 대하여 소프트웨어의 높은 신뢰성이 요구가 된다. 본 논문에서는 UAV의 OFP에 대하여 STR(Primary-Shadow TMO replication)기반의 fault tolerant Architecture에 대하여 제안을 한다.

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

• 대한전기학회논문지:시스템및제어부문D
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• 제51권4호
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• pp.144-151
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• 2002

This paper presents a fault-tolerant duplex architecture to build a high-reliability microcontroller using commercial VLSI processors. The architecture supports fail-silence under all single-failure situations and facilitates recovery from transient failures. The paper implements the duplex architecture using two Motorola MC68360 processors and evaluates its fault tolerance in a real application environment.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1997년도 추계학술대회 발표논문집:21세기를 향한 정보통신 기술의 전망
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• pp.417-433
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• 1997

A real-time operating system has focused primary on techniques to minimize processing time, with a secondary emphasis on system reliability issues. Conversely, fault-tolerant system has concentrated on using recourse and information redundancy to maximize the availability and reliability of the system, with a lesser emphasis on performance. We have developed a fault-tolerant and real-time operations system which support a powerful concurrent runtime environment under the above requirements. In this paper, we present an overview of real-time systems, design and implementation of a duplex architecture using advanced concepts and technologies such as fast " fault detection", "fault isolation" and "fault recovery" Because the duplex architecture has two dentical hardware elements and has several recovery steps and hierarchy to facilitate a fast recovery which must be proceeded by a prompt fault detection and isolation. Thus it makes possible to minimize the overhead of the systems including hardware and software and guarantee the service continuity of he systems.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권6호
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• pp.615-628
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• 2015

CGRA (Coarse-Grained Reconfigurable Architecture) based multi-core architecture can be considered as a suitable solution for the fault-tolerant computing. However, there have been a few research projects based on fault-tolerant CGRA without exploiting the strengths of CGRA as well as their works are limited to single CGRA. Therefore, in this paper, we propose two approaches to enable exploiting the inherent redundancy and reconfigurability of the multi-CGRA for fault-recovery. One is a resilient inter-CGRA fabric that is ring-based sharing fabric (RSF) with minimal interconnection overhead. Another is a novel intra/inter-CGRA reconfiguration technique on RSF for maximizing utilization of the resources when faults occur. Experimental results show that the proposed approaches achieve up to 94% faulty recoverability with reducing area/delay/power by up to 15%/28.6%/31% when compared with completely connected fabric (CCF).

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2000년도 추계학술발표논문집 (하)
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• pp.1199-1202
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• 2000

CORBA 환경에서 지속적이고 안정적인 객체 서비스틀 제공하기 위해 기존 CORBA에 고장 감내 기능을 부여한 Fault-Tolerant CORBA가 필요하게 되었다. Orbix+ISIS, Eletra 등이 CORBA에서 고장 감내 기능을 제공하고 있으며 OMG에서도 Fault-Tolerant CORBA 규격에 관한 작업을 진행 중이다. CORBA 환경에서 고장 감내 기능을 ORB 에 추가하는 방법은 통합 방식(Integration Approach), 서비스 방식(Service Approach), 인터셉트 방식(Intercept Approach) 등이 있다. 본 논문에서는 OMG에서 작업 중인 Fault-Tolerant CORBA 규격을 기본으로 하여 통합 방식과 서비스 방식을 결합하여 클라이언트 응용에게 투명하게 고장 감내 기능을 제공하는 Fault-Tolerant CORBA 구조를 설계하였다.

• Advances in aircraft and spacecraft science
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• 제6권5호
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• pp.349-369
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• 2019

In the design of flight control systems there are issues that deserve special consideration and attention such as external perturbations or systems failures. A Simple Adaptive Controller (SAC) that does not require a-priori knowledge of the faults is proposed in this paper with the aim of realizing a fault tolerant flight control system capable of leading the pitch motion of an aircraft. The main condition for obtaining a stable adaptive controller is the passivity of the plant; however, since real systems generally do not satisfy such requirement, a properly defined Parallel Feedforward Compensator (PFC) is used to let the augmented system meet the passivity condition. The design approach used in this paper to synthesize the PFC and to tune the invariant gains of the SAC is the Population Decline Swarm Optimization ($P_DSO$). It is a modification of the Particle Swarm Optimization (PSO) technique that takes into account a decline demographic model to speed up the optimization procedure. Tuning and flight mechanics results are presented to show both the effectiveness of the proposed $P_DSO$ and the fault tolerant capability of the proposed scheme to control the aircraft pitch motion even in presence of elevator failures.

• 제어로봇시스템학회논문지
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• 제4권2호
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• pp.264-272
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• 1998

This paper proposes a fault detection and recovery mechanism for a fault-tolerant Mini-MAP system, and provides detailed techniques for its implementation. This paper considers the fault-tolerant Mini-MAP system which has dual layer structure from the LLC sublayer down to the physical layer to cope with the faults of those layers. For a good fault detection, a redundant and hierarchical fault supervision architecture is proposed and its implementation technique for a stable detection operation is provided. Information for the fault location is provided from data reported with a fault detection and obtained by an additional network diagnosis. The faults are recovered by the stand-by sparing method applied for a dual network composed of two equivalent networks. A network switch mechanism is proposed to achieve a reliable and stable network function. A fault-tolerant Mini-MAP system is implemented by applying the proposed fault detection and recovery mechanism.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.450-455
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• 2003

This paper is to discuss the hardware redundancy architecture of fault-tolerance system with using redundancy. Each architecture will be studied to implement fault-tolerance in classifying hardware redundancy architecture as passive, active and hybrid hardware redundancy. Therefore Fault-Masking and Fault-Detecting Techniques in each redundancy architecture is studied.