• 제목/요약/키워드: Failure mechanism

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공격받은 IEEE802.17 Resilient Packet Ring(RPR) 망의 Resiliency를 위한 신속한 망 복원방안 (A new Fast Recovery Scheme for Resiliency of Attacked Resilient Packet Ring(RPR))

  • 이영주;구도정
    • 융합보안논문지
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    • 제8권2호
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    • pp.57-62
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    • 2008
  • 본 논문은 RPR 망에서 외부의 공격으로 인해 새로운 노드의 추가, 제거 혹은 링크의 단절과 같은 상황이 발생하였을 때, 보다 신속하게 망을 복원할 수 있도록 새로운 방안을 제안한다. 망 복원에 소요되는 시간은 크게 문제를 감지하는데 소요되는 시간과 이를 복원하는데 소요되는 시간으로 나눌 수 있다. 본 논문에서는 이러한 시간들을 각각 단축함으로써 신속한 망 복원을 가능하게 하는 방법을 제안한다. 기존의 복구 방식에서는 망 복원용으로 사용되는 프로텍션 메시지의 전송으로 링크 또는 노드의 상태를 지속적으로 보고하며, 이러한 프로텍션 메시지의 전송 간격은 지수증가 한다. 프로텍션 메시지의 전송 간격이 지수증가 함으로써 야기되는 문제점은, 프로텍션 메시지의 전송 실패로 인해, 링크 또는 노드의 상태 보고가 지연될 수 있다는 것이다. 이를 해결하기 위해서 본 논문에서는 노드간의 자동 대역조절을 위하여 1ms주기로 전송되는 b형 공평메시지에 링크 또는 노드의 상태 정보를 실어서 전송하는 방법을 제안한다. 또한, 기존의 링크의 단절을 보다 신속히 감지하기 위한 방법도 제안한다.

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Bearing capacity of micropiled-raft system

  • Hwang, Tae-Hyun;Kim, Kang-Hyun;Shin, Jong-Ho
    • Structural Engineering and Mechanics
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    • 제63권3호
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    • pp.417-428
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    • 2017
  • The micropile has been mainly used under the concept of supplementing structural support or reinforcing soft ground. For the micropiled-raft system which uses a micropile and a raft in combination in particular, it is generally considered as ground reinforcement rather than foundation components considering the bearing capacity of the micropile in many cases. In this study, the bearing capacity mechanism of the micropiled-raft system is investigated through a physical model test and numerical method. The numerical results have shown that not only the slender-pile-effect of the micropile, but also the ground reinforcement effect, increase the bearing capacity considerably. The bearing capacity formula of the micropiled-raft system is derived based on the failure mechanism obtained through model tests. The formula is verified and proposed as a design chart.

앵커 형식별 인발거동과 설계법 개발 (Pullout Behavior of Typical friction Anchors and Development of Design Method)

  • 송일준;김가야;홍석우
    • 한국해양공학회지
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    • 제17권4호
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    • pp.43-51
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    • 2003
  • The resistance mechanism of anchor changes according to the types of anchor. Friction anchors are classified into tension and compression types. In this study, the characteristics and mechanism of pullout are analysed, and the design method of anchor and computer program for design are developed through compression test results of anchor body grout. The characteristics of compression anchor, compared with tension anchor, are summarized mainly as follows: (1) The effect of progressive failure of compression anchor body are much smaller than those of tension anchor during pullout of anchor: (2) The skin friction resistance is increased by Possion effect of grout (anchor body) during pullout of compression anchor.

Inclined yield lines in flange outstands

  • Bambach, M.R.
    • Structural Engineering and Mechanics
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    • 제29권6호
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    • pp.623-642
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    • 2008
  • While spatial plastic mechanism analysis has been widely and successfully applied to thinwalled steel structures to analyse the post-failure behaviour of sections and connections, there remains some contention in the literature as to the basic capacity of an inclined yield line. The simple inclined hinge commonly forms as part of the more complex spatial mechanism, which may involve a number of hinges perpendicular or inclined to the direction of thrust. In this paper some of the existing theories are compared with single inclined yield lines that form in flange outstands, by comparing the theories with plate tests of plates simply supported on three sides with the remaining (longitudinal) edge free. The existing mechanism theories do not account for different in-plane displacement gradients of the loaded edge, nor the slenderness of the plates, and produce conservative results. A modified theory is presented whereby uniform and non-uniform in-plane displacements of the loaded edge of the flange, and the slenderness of the flange, are accounted for. The modified theory is shown to compare well with the plate test data, and its application to flanges that are components of sections in compression and/or bending is presented.

전투체계 시스템을 위한 실시간 환경에서의 비동기 이중화 기법 연구 (A Study on Real Time Asynchronous Data Duplication Method for the Combat System)

  • 이재승;류존하
    • 한국군사과학기술학회지
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    • 제10권2호
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    • pp.61-68
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    • 2007
  • In a naval combat system, the information processing node is a key functional equipment and performs major combat management functions including control sensor and weapon systems. Therefore, a failure of one of the node causes fatal impacts on overall combat system capability. There were many methodologies to enhance system availability by reducing the impact of system failure like a fault tolerant method. This paper proposes a fault tolerant mechanism for information processing node using a replication algorithm with hardware duplication. The mechanism is designed as a generic algorithm and does not require any special hardware. Therefore all applications in combat system can use this functionality. The asynchronous characteristic of this mechanism provides the capability to adapt this algorithm to the module which has low performance hardware.

적응적 PMTU 발견 메커니즘을 통한 IPSec 터널 모드에서의 통신 불능 현상 해소에 관한 시뮬레이션 연구 (A Simulation Study for Resolving Communication Failure in IPSec Tunnel Mode with Adaptive PMTU Discovery Mechanism)

  • 김은성;안성진;정진욱;이도훈;윤재우
    • 한국시뮬레이션학회논문지
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    • 제11권1호
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    • pp.31-44
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    • 2002
  • VPN which cuts down on expense and assures security and reliance, has increased its market shares quickly because the requirement of enterprise on security has increased. But Fragmentation may raise communication failure when VPN has been implemented using IPSec. In our paper, we have given careful consideration to various reasons Preventing us from communicating stable and have presented the existing solutions about them. Also we hate provided adaptive PMTU discovery mechanism to improve: the solutions. We have proven a prowess of this mechanism through simulation

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