• 제목/요약/키워드: Channel Failure and Recovery

검색결과 15건 처리시간 0.018초

Protection of a Multicast Connection Request in an Elastic Optical Network Using Shared Protection

  • BODJRE, Aka Hugues Felix;ADEPO, Joel;COULIBALY, Adama;BABRI, Michel
    • International Journal of Computer Science & Network Security
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    • 제21권1호
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    • pp.119-124
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    • 2021
  • Elastic Optical Networks (EONs) allow to solve the high demand for bandwidth due to the increase in the number of internet users and the explosion of multicast applications. To support multicast applications, network operator computes a tree-shaped path, which is a set of optical channels. Generally, the demand for bandwidth on an optical channel is enormous so that, if there is a single fiber failure, it could cause a serious interruption in data transmission and a huge loss of data. To avoid serious interruption in data transmission, the tree-shaped path of a multicast connection may be protected. Several works have been proposed methods to do this. But these works may cause the duplication of some resources after recovery due to a link failure. Therefore, this duplication can lead to inefficient use of network resources. Our work consists to propose a method of protection that eliminates the link that causes duplication so that, the final backup path structure after link failure is a tree. Evaluations and analyses have shown that our method uses less backup resources than methods for protection of a multicast connection.

ECAP으로 제조된 초미세립 알루미늄 합금의 동적 변형거동에 미치는 어닐링 온도의 영향 (Effect of Annealing Temperature on Dynamic Deformation Behavior of Ultra-Fine-Grained Aluminum Alloys Fabricated by Equal Channel Angular Pressing)

  • 김양곤;고영건;신동혁;이종수;이성학
    • 대한금속재료학회지
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    • 제46권9호
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    • pp.563-571
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    • 2008
  • The influence of annealing treatment on dynamic deformation behavior of ultra-fine grained aluminum alloys was investigated in this study. After equal-channel angular pressing at $200^{\circ}C$, most of the grains were considerably reduced to nearly equiaxed grains of $0.3{\mu}m$ in size. With an increment of various annealing treatments for 1 hour, resultant microstructures were found to be fairly stable at temperatures up to $200^{\circ}C$, suggesting that static recovery would be dominantly operative, whereas grain growth was pronounced above $250^{\circ}C$. The tensile test results showed that yield and ultimate tensile strengths decreased, but elongation-to-failure and strain hardening rate increased with increasing annealing temperature. The dynamic deformation behavior retrieved with a series of torsional tests was explored with respect to annealed microstructures. Such mechanical response was analyzed in relation to resultant microstructure and fracture mode.

ECAP 가공된 초미세 결정립 Al-4.4%Mg 합금의 동적 변형 및 파괴거동에 미치는 후-열처리 온도의 영향 (Effect of Subsequent Annealing Temperature on Dynamic Deformation and Fracture Behavior of Submicrocrystalline Al-4.4%Mg Alloy via Equal-Channel Angular Pressing)

  • 김양곤;고영건;신동혁;이종수;이성학
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2008년도 춘계학술대회 논문집
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    • pp.427-430
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    • 2008
  • The influence of subsequent annealing treatment on the dynamic deformation and the fracture behavior of submicrocrystalline Al-4.4%Mg alloy is investigated in this study. After inducing an effective strain of 8 via equal-channel angular pressing at $200^{\circ}C$, most of the grains are considerably reduced to nearly equiaxed grains of $0.3{\mu}m$ in size. With an increment of various subsequent heat treatments for 1 hour, resultant microstructures are found to be fairly stable at temperatures up to $200^{\circ}C$, suggesting that static recovery will be dominantly operative, whereas grain growth is pronounced above $250^{\circ}C$. The results of tensile tests show that yield and ultimate tensile strength decrease, but elongation-to-failure and strain hardening rate increase with an increase in annealing temperatures. The dynamic deformation and the fracture behavior retrieved with a series of torsional tests are explored with respect to annealed microstructures. Such mechanical response is analyzed in relation to resultant microstructure and fracture mode.

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고신뢰성 발사통제시스템을 위한 고장허용 통신 미들웨어 설계 및 구현 (Design and Implementation of Fault-tolerant Communication Middleware for a High-reliable Launch Control System)

  • 송대기;장부철;이철훈
    • 한국콘텐츠학회논문지
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    • 제8권8호
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    • pp.37-46
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    • 2008
  • 발사통제시스템(Launch Control System)은 유도무기체계에서 유도탄의 발사와 관련된 일련의 절차들을 제어하는 시스템이다. 이 시스템은 지정된 시간 안에 목표물에 대한 교전계획을 생성하고 이 정보를 탄에 장입하며 탄의 발사 제어를 수행해야 한다. 이 때문에 시스템의 하드웨어, 소프트웨어 고장뿐만 아니라 정해진 수행 시간의 초과 때문에도 임무가 실패될 수 있다. 본 논문에서 제안한 것은 발사통제시스템과 같은 내장형 실시간 시스템을 위한 고장허용 이더넷으로 별도의 하드웨어나 소프트웨어 없이 기존 상용의 이더넷 디바이스를 이중화하여 네트워크에 고장허용 기능을 제공하는 방법이다. 이를 위해 시스템의 각 구성 노드들을 이중의 네트워크 채널로 중복 시키고, 네트워크 트래픽에 대한 고장탐지 및 복구를 위해 통신 미들웨어를 설계하고 개발하였다. 이중채녈 기반의 통신 미들웨어를 통해 처리 시간이 중요한 시스템에 네트워크 고장으로 인한 시스템 중지를 방지하고 노드에 통신 손실이 발생하지 않도록 하였다.

손해평고(损害评估): 대전자구비행소적탐색성고찰(对电子口碑行销的探索性考察) (Assessing the Damage: An Exploratory Examination of Electronic Word of Mouth)

  • Funches, Venessa Martin;Foxx, William;Park, Eun-Joo;Kim, Eun-Young
    • 마케팅과학연구
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    • 제20권2호
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    • pp.188-198
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    • 2010
  • 此研究旨在考察负口碑(即NWOM)对在线行销的影响, 着重分析服务失败的描述以及通信服务商的意向是如何影响消费者对企业竞争力的评估, 对企业的态度, 以及积极的口碑行销和行为意向. 对通信说服力的研究着重于 "谁说了什么; 对谁;通过何渠道;有何影响(Chiu 2007)". 在此我们研究了电子网络发布, 尤其是 "什么" 的两个方面: 通信服务失败的等级以及个人发布的知觉意向. 电子负口碑看似正在毁掉产品或企业的声誉, 这也就不难理解为什么人们总对它带有偏见, 认为其不可靠. 根据归因理论, 人们总会寻求事件的原因, 尤其是那些消极的意外的事件(Weiner 2006). Hennig-Thurau和Walsh (2003)提出 "既然读者的知识和对在线信息的作者信任度都很有限, 可以把电子口碑当做是表达-行为关系的有效调节. 此据此我们提出以下假设: 假设1. 在衡量(a)企业竞争力, (b)人们对企业的态度, (c)积极的口碑, 以及(d)行为意向时, 面临高等级服务失败电子负口碑的对象得分低于面临低等级服务失败电子负口碑的对象. 假设2. 在衡量(a)企业竞争力, (b)人们对企业的态度, (c)积极的口碑, 以及(d)行为意向时, 面临警告意向电子负口碑的对象得分低于面临报复意向电子负口碑的对象假设3. 在电子负口碑中, 服务失败的等级和知觉意向互相影响, 因此在衡量(a)企业竞争力, (b)人们对企业的态度, (c)积极的口碑, 以及(d)行为意向时, 警告意向的电子负口碑的平均反应值大于报复意向的电子负口碑. 主要研究包括一个2 (服务失败的严重性) x 2(警告意向VS报复意向的负口碑)的析因实验. 将通过模拟的在线网络发布信息刺激在线对象. 这一方案描述的服务失败是在传统的零售机构不接受礼物卡, 通过一家在线的研究公司从全国抽样. 共有113个对象参与此研究, 共分析了104份调查问卷. 研究对象认为该方案很现实, 92.3%对此反应强烈. 方案的运作相当令人满意, 所有的措施都经预先的测试验证, 各个项目也经分析证实可靠并有效. 多变量方差分析结果显示多变量间无明显的互相影响, 因此我们只研究主要影响-后倾向和服务失败的严重性. 后倾向主要影响对企业的态度, 积极的口碑和行为意向. 服务失败的严重性主要影响4个因变量: 企业的竞争力, 对企业的态度, 积极的口碑和行为意向. 需特别指出的是, 当电子负口碑描述为严重的服务失败时, 企业的竞争力低于电子负口碑描述为较轻的服务失败时. 当电子负口碑描述为严重的服务失败时, 对企业的态度差于电子负口碑描述为较轻的服务失败时. 当电子负口碑描述为严重的服务失败时, 企业的口碑差于电子负口碑描述为较轻的服务失败时. 当电子负口碑描述为严重的服务失败时, 行为意向低于电子负口碑描述为较轻的服务失败时. 因此, 假设1中的abcd都得到了支持. 另外, 衡量对企业的态度时, 警告意向的电子负口碑得分低于报复意向的电子负口碑. 衡量企业的口碑时, 警告意向的电子负口碑得分低于报复意向的电子负口碑. 衡量行为意向时, 警告意向的电子负口碑得分低于报复意向的电子负口碑. 因此与假设2中的a项不符, 尽管结果指向的是假设方向. 除此之外, 在假设的三个变量中, 后倾向对服务失败的严重性无明显的多变量或单变量影响. 因此, 假设3被推翻. 此研究有研究和管理的双重蕴涵, 如之前的研究一样, 此研究结果证实了服务失败的严重性影响消费者知觉, 态度, 积极的口碑以及行为意向(Weun et al. 2004). 关于进一步的相关性, 在线内容证实了该反应, 这意味着企业需要努力进行服务补救. 至于电子负口碑的知觉意向, 如之前的研究一样, 此研究结果意味着读者对原始资料的意向影响其对知觉, 态度, 积极口碑和行为意向的作用大小. 对管理者的蕴涵在于, 当消费者发现在线交流可靠且有影响力时, 不是所有的交流都同等重要. 电子口碑的好处在于它可以监测潜在的问题并提供纠正的可能性, 即使有潜在的危害.