• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2006.07a
• /
• pp.743-743
• /
• 2006

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.16 no.6
• /
• pp.832-841
• /
• 2016

The voltage-frequency island (VFI) design paradigm has strong potential for achieving high energy efficiency in communication centric manycore system-on-chip (SoC) design called network-on-chip (NoC). However, because of the diminished scaling of wire-dimension and supply voltage as well as threshold voltage in modern CMOS technology, the vulnerability to link failure in VFI NoC is becoming a crucial challenge. In this paper, we propose an energy-optimized topology generation technique for VFI NoC to cope with permanent link failures. Based on the energy consumption model, we exploit the on-chip communication traffic patterns and characteristics of link failures in the early design stage to accommodate diverse applications and architectures. Experimental results using a number of multimedia application benchmarks show the effectiveness of the proposed three-step custom topology generation method in terms of energy consumption and latency without any degradation in the fault coverage metric.

• Fibers and Polymers
• /
• v.7 no.3
• /
• pp.310-316
• /
• 2006

In this article, an attempt has been made to explain the failure mechanism of spun yams. The mechanism includes the aspects of generation and distribution of forces on a fibre under the tensile loading of a yam, the free body diagram of forces, the conditions for gripping and slipping of a fibre, and the initiation, propagation, and ultimate yam rupture in its weakest link. A simple mathematical model for the tenacity of spun yams has been proposed. The model is based on the translation of fibre bundle tenacity into the yam tenacity.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06d
• /
• pp.273-276
• /
• 2011

최근 소셜 네트워킹, 멀티미디어 서비스의 사용량이 증가됨에 따라 인터넷의 트래픽은 이전보다 빠르게 증가되고 있다. 이에 링크나 노드의 failure 같은 네트워크 failure 발생은 서비스 이용자들에게 큰 영향을 미치게 된다. 이러한 failure로 부터 빠르게 회복하기 위한 다양한 Fast Reroute scheme들이 제안되었다. 하지만 이러한 Fast Reroute의 Back-path는 특정 링크에게 과도한 트래픽을 유발하게 된다. 본 논문에서는 이러한 점을 해결하기 위한 실제적인 Link Cost를 고려한 Load-Balancing기법을 제안한다. 실험결과 평균 degree가 높을수록 대체가능한 경로들이 증가되기 때문에 FIR에 비해 성능이 향상됨을 확인할 수 있었다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.777-781
• /
• 1997

One of the spring-link mechanisms, the air circuit breaker(ACB), was studied to improve the shock-proof characteristics of it. The low-cycle fatigue fracture phenomenon was occurred on the critical link, called h-link, of ACB for the repeated rapid closing and opening operations. To analyze the cause of failure, dynamic FE-analysis on the h-link part of ACB was accomplished with considered the velocity and acceleration of the links per time as boundary conditions, which were obtained by using ADAMS. Then, to reduce the maximum tensile stress on the h-link, three types of h-link were suggested and one of them was selected. Fmm this study, we suggested the process of analysis on the high-speed motion behavior part related low-cycle fatigue fractures.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.4
• /
• pp.9-15
• /
• 2013

Most of recent studies on data center networks are based on the assumption of symmetrical multi-rooted tree topologies such as a Fat-Tree. While packet scatter schemes are very effective for such a network topology, it is known that various failures can result in an asymmetric topology which degrades TCP performance. In this paper, we reexamine the effects of link failures on packet scatter schemes in Fat-Trees. Our simulation results show that in case of a single link failure in a large-scale Fat-Tree, packet reordering does not occur enough to degrade TCP performance. This implies that we do not necessarily need a complex scheme to make packet schemes robust to link failures.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.2
• /
• pp.10-16
• /
• 2016

For higher reliability against a link failure of a control network in railway vehicles, a recovery mechanism is needed. We introduce a problem that, when a link failure occurs in a ring-topology control network, a node may experience a significant increase of transmission delay depending on its relative position within the network. We then propose two mechanisms to solve this problem: (1) differentiating and prioritizing node traffic in forwarding; and (2) switching some nodes to a backup bus-topology network. Our simulation study shows that, while the first mechanism achieves a limited gain by only compensating queuing delay, the second one gets a sufficient gain which is impacted by the number of nodes switched to the bus network.

• International Journal of Computer Science & Network Security
• /
• v.21 no.1
• /
• pp.119-124
• /
• 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.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.4
• /
• pp.158-164
• /
• 2003

The air circuit breaker (ACB) with the spring-actuated mechanism was studied to improve the fatigue-proof characteristics of its link. The low-cycle fatigue fracture phenomenon occurred on the critical link, called h-link, of ACB from the repeated rapid closing and opening operations. To analyze the cause of failure, dynamic FE-analysis on the b-link part of ACB was performed considering tile velocity and acceleration of the links per time as boundary conditions, which were obtained by using ADAMS. Also, the S-N curve obtained by experiments was used to investigate requirement on the fatigue-proof characteristics. Then, to reduce the maximum tensile stress on the h-link, three types of h-link were examined and one of them was selected.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.5B
• /
• pp.357-364
• /
• 2012

In Visible Light Communication (VLC) system, with the limitation of transmission range and Field Of View (FOV), LOS (Line of Sight) link between two transceivers should be guaranteed due to the straightness of the visible-light signal. Especially for indoor applications, link recovery is an advantage method to remain the link connection because of the link failure in which caused by movement obstacle. Link recovery schemes try to keep link dynamically without re-initialing connection. This article proposes a new link recover scheme for VLC system by using cooperative communication. Our propose scheme focuses on the QoS reservation resource by GTS in IEEE 802.15.7 specification in which the requested QoS resource from client should be guarantee during the application time. With the link recovery scheme, we will try to continue the link connection as long as possible when unexpected disconnect link. The mathematical analysis and simulation results show that proposed scheme increases the overall reliability of the VLC system.