• The KIPS Transactions:PartA
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• v.13A no.5 s.102
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• pp.421-428
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• 2006

This paper proposes an integrated recovery approach applying retry and rollback techniques to recover the TMR failure. Combining the time redundancy techniques with W system is apparently effective to recover the TMR failure(or masked error) primarily caused by transient faults. These policies need fewer reconfigurations at the cost of extra time required for the time redundant schemes. The optimal numbers of retry and rollback to minimize the mean execution time of tasks are derived for the proposed method through computing the likelihoods of all possible states of the failed system. The effectiveness of the proposed method is validated through examining certain numerical examples and simulations conducted with a variety of parameters governing environmental characteristics.

• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.188-196
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• 2004

To optimize and limit the axial length of baffle in KSR-III engine, stability rating tests using pulse gun as one of artificial disturbance devices have been done. Decay time and other parameters for the evaluation of stabilization ability of engine to external perturbation have been analyzed to quantify stabilization capacity of engine, in other words, dynamic stability margin. If baffle does not cover flame zone enough which can be considered as collision region of injector, it wasn't be able to suppress external perturbation sufficiently. The limit of combustion stability margin of engine is assumed to be 50 mm length baffle.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.9
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• pp.700-706
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• 2013

In this paper, we propose a method for applying random linear network coding in satellite communication to improve reliability. In the proposed protocol, network-coded redundancy (NC-R) packets are transmitted in the PEP (Performance Enhancement Proxy). Therefore, if data packets is lost by wireless channel error, they can be recovered by NC-R packets. We also develop the TCP performance model of the proposed protocol and evaluate the performance of the proposed protocol. In the simulation results, It is shown that the proposed protocol can improve the TCP throughput as compared with that of the conventional TCP because the NC-R packets is sent by the sender-side PEP and the receiver-side PEP use these packets to recover the lost packets, resulting in reducing the packet loss in TCP.

• 비료회보
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• s.573
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• pp.10-21
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• 2005

데이비드 헤이스는 지역의 천연가스 수요의 계속적인 증가 및 국가보조금의 삭감으로 인한 여분 천연가스 원료물질의 부족이 증가하고 있는 추세에 대해 인도네시아 요소 산업이 어떻게 대처하고 있는지에 대하여 보고한다.

• The Science & Technology
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• s.473
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• pp.30-33
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• 2008

• Annual Conference of KIPS
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• 2006.05a
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• pp.1341-1344
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• 2006

임베디드 시스템의 신인도(Dependability)를 확보하기 위해 하드웨어적으로 여분을 두는 결함 허용(Fault-tolerant) 기법을 적용하는 것은 임베디드 시스템의 설치공간, 비용 및 전원 공급의 부족 등의 이유로 무리가 있다. 본 논문에서는 소프트웨어 결함 허용 기법의 일종인 시간 여분(Time-redundancy) 개념을 적용한 Extended Temporal Error Detection (E-TED) 기법을 연구하였으며, 실험을 통해 제안한 E-TED 기법이 기존의 TED 기법에 비해 데이터 오류의 감지 확률이 높은 것을 확인하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.11
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• pp.1279-1289
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• 1992

Fault-tolerant system in improved the reliability and safety by using hardware and software redundancy. Fault mask and detection, identification techniques are conditionally used with system's application areas. Here DMR system is operated with standby and fail-safe module method that has minimal hardware and software redundancy, then its reliablity and safety comparison is presented respectively. Also this paper proposed an effective methods of dealing with transient faults as compared system's MTTFs to transient faults tolerance capabilities of self-diagnosis program.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.200-202
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• 2004

용접이 진행되는 아크 범위 내에 용접재료로서 아크를 일으키지 않는 여분의 Wire를 삽입하고자 하는 시도는 이미 여러 용접 Process 에 응용되어 행해진 바 있다. (중략)

• KOREAN POULTRY JOURNAL
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• v.20 no.5 s.223
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• pp.54-56
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• 1988

서울근교에 위치한 김포육계분회(분회장 : 김기환 사장)까지는 신촌에서 직행버스를 40여분 남짓한 거리에 있다. 국제적으로 한국의 관문인 김포국제공항을 포함하는 이곳 김포육계분회는 생산물의 대부분을 서울로 직송하는 곳이기도 하다.

• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.179-187
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• 2004

We consider some problems of the Modified SPRT(Sequential Probability Ratio Test) method for fault detection and isolation of inertial redundant sensor systems and propose an Advanced SPRT method which solves the problems of the Modified SPRT method. The problems of the Modified SPRT method to apply to inertial sensor system come from the effect of inertial sensor errors and the correlation of parity vector components. We use a two-stage Kalman filter to remove effects of the inertial sensor errors and propose the modified parity vector and the controlled parity vector which reduces the effect of correlation of parity vector components. The Advanced SPRT method is derived form the modified parity vector and the controlled party vector. Some simulation results are presented to show the usefulness of the Advanced SPRT method to redundant inertial sensor systems.