• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 추계학술발표논문집
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• pp.461-465
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• 2009

Normally, a distributed computing environment is flexible in controlling complex embedded systems but their software components are becoming complex as these systems are equipped with several platforms and attached to various electronic devices, sensors, and actuators. These systems requires inter-object communication mechanisms to provide fault tolerant and QoS-enabled middleware service support in a distributed system. Generally, a middleware performs analysis of the parameters to ensure the availability and reliability of data dissemination. This paper focuses in particular to designing an application middleware for the specific scenario to improve the high availability and fault tolerance of data thus improving the QoS (Quality of Service) of a distributed system. The performance of an adaptive and highly reliable middleware can be significant based on the selection of vital parameters of the system.

• 한국정보과학회논문지:시스템및이론
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• 제31권1_2호
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• pp.19-26
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• 2004

이 논문에서는 정점이나 에지 고장이 있는 이중 루프 네트워크에서 임의의 두 정점을 연결하는 고장 없는 최장 경로를 고찰하여, 고장인 요소의 수가 둘 흑은 그 이하인 경우 이분 그래프인 이중 루프 네트워크 G(mn；1, m)은 강한 해밀톤 laceable 그래프임을 보인다. G(mn；1, m)은 m이 홀수이고 n이 짝수일 경우에만 이분 그래프이다.

• 한국시뮬레이션학회논문지
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• 제3권1호
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• pp.89-98
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• 1994

In this paper, a criteria for selecting an appropriate load redistribution algorithm is devised so that a fault-tolerance distributed system can operte at its optimal efficience. To present the guideline for selecting redistributing algorithms, simulation models of fault-tolerant system including redistribution algorithms are developed using SLAM II. The job arrival rate, service rate, failure and repair rate of nodes, and communication delay time due to load migration are used as parameters of simulation. The result of simulation shows that the job arrival rate and the failure rate of nodes are not deciding factors in affecting the relative efficiency of algorithms. Algorithm B shows relatively a consistent performance under various environments, although its performance is between those of other algorithms. If the communication delay time is longer than average job processing time, the performance of algorithm B is better than others. If the repair rate is relatively small or communication delay time is longer than service time, algorithm A leads to good performance. But in opposite environments, algorithm C is superior to other algorithms.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.6-10
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• 2003

The reliability of power electronics system is very important In industrial, commercial and military applications. This paper presents the principles for NPC inverter as an available technology for the design and implementation of adaptive fault tolerant systems. The fault tolerance is obtained by the use of the particular construction. The control method is proposed to get the sinusoidal load current with constant amplitude. The strategy described in this paper is expected to provide an economic alternative to more expensive redundancy techniques which find justification only in a few specialized application.

• 한국정보통신학회논문지
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• 제15권1호
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• pp.41-50
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• 2011

DNS(Domain Name System)는 인터넷상의 호스트의 도메인주소를 IP주소로 변환하거나 IP주소를 도메인주소로 변환하는 이름해결 메카니즘을 총칭한다. 본 논문에서는 1차 DNS 서버가 오류로 인해 정지하더라도 2차 DNS 서버가 대신하여 서비스를 지속할 수 있도록 하는 결함내성을 갖는 DNS 시스템 구축에 관해 연구하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2298-2300
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• 2002

In this paper, we introduced a fault tolerant control system with the aim of achieving higher degree of reliability for a PLC control system in the field network. The system reliability was evaluated by MTBF(Mean Time Between Failure). The design of the fault tolerant system through CC-Link of Mitsubisi's MELSEC network was presented. In addition, the PLC data is transmitted from the field network's PC to the host PC by TCP/IP Window socket.

• 한국군사과학기술학회지
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• 제10권2호
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• pp.107-114
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• 2007

This paper describes the Petri Net(PN) model for reliability analysis of fault-tolerant dual Ethernet which Is applied in Naval Combat System. The network for Naval Combat System performs failure detection and auto path recovery by handling redundant path in case of temporary link failure. After studying the behavior of this kind of network, the reliability analysis model is proposed using stochastic Petri Net and continuous-time Markov chains. Finally, the numerical result is analyzed according to changing the failure rate and the recover rate of link.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (A)
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• pp.40-42
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• 2005

Jini는 네트워크를 통해 사람이나, 기기, 프로그램이 특정 자원을 찾거나 사용하고자 할 때, 관리자의 개입 없이 유연하게 동작하게 하는 분산 미들웨어의 하나이다. 기존의 Jini 서비스는 Lookup Service 데몬(Httpd, Reggie. Rmid)이 실행되어 Discovery, Join, Lookup, Service Invocation의 과정을 통해 이루어지는데, 데몬 fault 발생 시 어떠한 해결점이 없다는 것이 문제점이다. 이에 본 논문에서는 Jini 서비스 데몬 손실로 인한 Jini 서비스의 Fault 문제를 해결하기 위해 Grid환경 하에서 그리드 서비스를 사용하여 Jini 서비스에 Fault Tolerance를 제공하는 시스템의 구조와 방법을 제시한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1566-1582
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• 2019

Silent Data Corruptions (SDCs) is a serious reliability issue in many domains of computer system. The identification and protection of the program instructions that cause SDCs is one of the research hotspots in computer reliability field at present. A lot of solutions have already been proposed to solve this problem. However, many of them are hard to be applied widely due to time-consuming and expensive costs. This paper proposes an intelligent approach named SDCPredictor to identify the instructions that cause SDCs. SDCPredictor identifies SDC-causing Instructions depending on analyzing the static and dynamic features of instructions rather than fault injections. The experimental results demonstrate that SDCPredictor is highly accurate in predicting the SDCs proneness. It can achieve higher fault coverage than previous similar techniques in a moderate time cost.

• 한국산업융합학회 논문집
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• 제24권6_1호
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• pp.659-667
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• 2021

This paper develops the theory for a novel fault-tolerant, permanent magnet biased, 4-active-pole, double plane, homopolar magnetic bearing. The Lagrange Multiplier optimization with equality constraints is utilized to calculate the optimal distribution matrices for the failed bearing. If any of the 4 coils fail, the remaining three coil currents change via a novel distribution matrix such that the same opposing pole, C-core type, control fluxes as those of the un-failed bearing are produced. Magnetic flux coupling in the magnetic bearing core and the optimal current distribution helps to produce the same c-core fluxes as those of unfailed bearing even if one coil suddenly fails. Thus the magnetic forces and the load capacity of the bearing remain invariant throughout the failure event. It is shown that the control fluxes to each active pole planes are successfully isolated. A numerical example is provided to illustrate the new theory.