The Experts below are selected from a list of 5346 Experts worldwide ranked by ideXlab platform

Chinghwa Cheng - One of the best experts on this subject based on the ideXlab platform.

  • ASP-DAC - A Quantity Evaluation and Reconfiguration Mechanism for Signal- and Power-Interconnections in 3D-Stacking System
    2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC), 2020
    Co-Authors: Chinghwa Cheng
    Abstract:

    Due to the high integration required for system application, the three-dimensional chip may resolve this requirement. The three-dimensional vertically stacking (3D-stacking) systems have been proposed to satisfy these requirements. However, the 3D-stacking system contains several design risks from its long layer interconnections. For a 3D-stacking system, it is difficult to identify where the numerous power and signal-interconnection are open-, shorted-fault, or resistive-short has accrued. Therefore, solving these interconnection problems is necessary. A feasible interconnection quality-evaluation, fault-diagnosis, and connection-reconfigurable Mechanism are proposed. The proposed interconnection-measurement-recovery (IMR) Mechanism will make it easy to find interconnection faults and make recovery in 3D-Stacking systems. The proposed IMR can detect interconnection open, short, bridge and resistive defects with the path-reroute Mechanism. Future more, the signal transmission quality can be measured. This measurement provides to monitor signal propagation in pico-second accuracy. IMR has less extra area and power consumption overhead. The feasibilities of the proposed Mechanism have been justified by 2D-chip and 3D-stacking MorPack both systems.

  • a quantity evaluation and Reconfiguration Mechanism for signal and power interconnections in 3d stacking system
    Asia and South Pacific Design Automation Conference, 2020
    Co-Authors: Chinghwa Cheng
    Abstract:

    Due to the high integration required for system application, the three-dimensional chip may resolve this requirement. The three-dimensional vertically stacking (3D-stacking) systems have been proposed to satisfy these requirements. However, the 3D-stacking system contains several design risks from its long layer interconnections. For a 3D-stacking system, it is difficult to identify where the numerous power and signal-interconnection are open-, shorted-fault, or resistive-short has accrued. Therefore, solving these interconnection problems is necessary. A feasible interconnection quality-evaluation, fault-diagnosis, and connection-reconfigurable Mechanism are proposed. The proposed interconnection-measurement-recovery (IMR) Mechanism will make it easy to find interconnection faults and make recovery in 3D-Stacking systems. The proposed IMR can detect interconnection open, short, bridge and resistive defects with the path-reroute Mechanism. Future more, the signal transmission quality can be measured. This measurement provides to monitor signal propagation in pico-second accuracy. IMR has less extra area and power consumption overhead. The feasibilities of the proposed Mechanism have been justified by 2D-chip and 3D-stacking MorPack both systems.

A K Aggarwal - One of the best experts on this subject based on the ideXlab platform.

  • topology Reconfiguration Mechanism for traffic engineering in wdm optical network
    High Performance Computing Systems and Applications, 2005
    Co-Authors: B Gillani, Robert D Kent, A K Aggarwal
    Abstract:

    Optical wavelength division multiplexed (WDM) networks provide an excellent transmission medium for voice and data traffic, streaming media, and high performance and grid computing needs. Rearrangeability is one compelling characteristic of WDM optical networks that allows network operators to rearrange the networks in response to changing traffic demands and element failures to provide improved network performance. Under changing traffic flows and abhorrent network conditions Reconfiguration is an ongoing process. Available approaches are not able to handle extreme load conditions, traffic bursts, and element failures and, so far, these approaches cover only limited aspects of the problem of automated Reconfiguration. In this work we present an adaptive Reconfiguration Mechanism for WDM optical networks (ARWON). Two heuristically based algorithms, combination algorithm (CA) and multi lightpath change (MLPC) algorithm, are also proposed to support implementation of ARWON. Simulation experiments covered all ranges of traffic flows and element failure scenario and performance of ARWON was validated with an established contemporary Reconfiguration algorithm. Results show that under all loading conditions and link failure scenario ARWON performed better than the comparison algorithm. Under extreme loading conditions ARWON incurred 11 times less traffic loss than single lightpath change (SLPC) algorithm and on average SLPC was carrying 20 more lightpaths than ARWON, per observation cycle, that were 100 percent loaded. Under link failure scenario ARWON recovered faster and rerouted the traffic in one step, whereas SLPC recovered slowly and recovery took much longer duration than ARWON. For other loading conditions, ranging from low to high loading, it was observed that during early stages of simulation ARWON performs at par or marginally better than SLPC. Performance of ARWON steadily improves as simulation progresses over longer duration.

  • HPCS - Topology Reconfiguration Mechanism for traffic engineering in WDM optical network
    19th International Symposium on High Performance Computing Systems and Applications (HPCS'05), 2005
    Co-Authors: B Gillani, Robert D Kent, A K Aggarwal
    Abstract:

    Optical wavelength division multiplexed (WDM) networks provide an excellent transmission medium for voice and data traffic, streaming media, and high performance and grid computing needs. Rearrangeability is one compelling characteristic of WDM optical networks that allows network operators to rearrange the networks in response to changing traffic demands and element failures to provide improved network performance. Under changing traffic flows and abhorrent network conditions Reconfiguration is an ongoing process. Available approaches are not able to handle extreme load conditions, traffic bursts, and element failures and, so far, these approaches cover only limited aspects of the problem of automated Reconfiguration. In this work we present an adaptive Reconfiguration Mechanism for WDM optical networks (ARWON). Two heuristically based algorithms, combination algorithm (CA) and multi lightpath change (MLPC) algorithm, are also proposed to support implementation of ARWON. Simulation experiments covered all ranges of traffic flows and element failure scenario and performance of ARWON was validated with an established contemporary Reconfiguration algorithm. Results show that under all loading conditions and link failure scenario ARWON performed better than the comparison algorithm. Under extreme loading conditions ARWON incurred 11 times less traffic loss than single lightpath change (SLPC) algorithm and on average SLPC was carrying 20 more lightpaths than ARWON, per observation cycle, that were 100 percent loaded. Under link failure scenario ARWON recovered faster and rerouted the traffic in one step, whereas SLPC recovered slowly and recovery took much longer duration than ARWON. For other loading conditions, ranging from low to high loading, it was observed that during early stages of simulation ARWON performs at par or marginally better than SLPC. Performance of ARWON steadily improves as simulation progresses over longer duration.

Dominique Sauter - One of the best experts on this subject based on the ideXlab platform.

  • FAULT TOLERANT CONTROL IN DYNAMIC SYSTEMS
    IFAC Proceedings Volumes, 2016
    Co-Authors: Dominique Sauter, Frédéric Hamelin, Hassan Noura, Didier Theilliol
    Abstract:

    Abstract In this paper a method for fault tolerant control in dynamic systems is presented. In an integrated design, the proposed approach is composed of two stages. The first step is the detection and isolation of the failed component while the second step is represented by the Reconfiguration Mechanism. It consists in the estimation of new control parameters after evaluation of the performance degradation. In this paper, we mainly focus on the Reconfiguration Mechanism. A simulation is given to illustrate the proposed approach.

  • Fault tolerant control of HVAC systems for energy efficient buildings
    2015
    Co-Authors: Dominique Sauter
    Abstract:

    System-level or operational faults in building Heating Ventilation and Air Conditioning (HVAC) systems, can have significant impact on the desired and expected building en- ergy performance and user comfort. Fault-tolerant control systems is characterized by its capability, after fault occur- rence, to recover performance close to the nominal desired performance. In this paper a method for fault decoupling in dynamic systems is presented. In an integrated design, the proposed approach is composed of two stages : The first step is the detection and isolation of the fault based on the generation of directional residuals while the second step is represented by the Reconfiguration Mechanism which consists in the estimation of new control parameters after evaluation of the performance degradation.

  • Design of fault isolation filter for control Reconfiguration : application to energy efficiency control in buildings
    2015
    Co-Authors: Dominique Sauter, Joseph J. Yame, Christophe Aubrun, Frédéric Hamelin
    Abstract:

    In this paper, fault adaptive control is developed for building Heating Ventilation and Air Conditioning (HVAC) systems. That is, the control system parameters and objective functions are adapted/reconfigured in the presence of a fault or performance deviation by means of an intermediate reconfigurable control layer. It allows maintaining building and HVAC operation within its specified energy and comfort performance requirements when a mechanical or operational fault takes place, until the fault is corrected. An integrated design, composed of two levels, respectively fault diagnosis and Reconfiguration Mechanism is proposed to recover performances after fault occurrence. This approach is applied to a 3 zones building and simulation results are given to show its effectiveness.

  • Trajectory-based fault accommodation in winder turbine systems
    2014
    Co-Authors: Tushar Jain, Joseph J. Yame, Dominique Sauter
    Abstract:

    This paper presents a trajectory-based online controller Reconfiguration Mechanism to tolerate faults in a wind turbine (WT) system. The system is a benchmark WT model which includes FAST coded simulator designed by the U.S. National Renewable Energy Laboratory's. The novelty of the proposed Mechanism is that no a priori information about the model of the turbine is used in real-time. Instead, we use online measurements generated by the WT, which in fact captures the behaviour of the wind turbine. Based on the given control specifications, and the observed measurements an occurring fault is accommodated by reconfiguring the controller such that the WT generates the rated power even under faulty conditions.

  • Model-free Reconfiguration Mechanism for fault tolerance
    International Journal of Applied Mathematics and Computer Science, 2012
    Co-Authors: Tushar Jain, Joseph J. Yame, Dominique Sauter
    Abstract:

    Model-free Reconfiguration Mechanism for fault toleranceThe problem of fault tolerant control is studied from the behavioral point of view. In this mathematical framework, the concept of interconnection among the variables describing the system is a key point. The problem is that the behavior we intend to control is not known. Therefore, we are interested in designing a fault accommodation scheme for an unknown behavior through an appropriate behavioral interconnection. Here we deal simply with the trajectories that are generated by the system in real time. These trajectories determine the behavior of a system in various faulty/healthy modes. Based on the desired interconnected behavior, only the trajectories that obey certain laws are selected. These laws, representing the desired behavior, can indeed be achieved by a regular interconnection. Thus, when the trajectories do not belong to a certain desired behavior, it is considered to be due to the occurrence of a fault in the system. The vantage point is that the fault tolerant control problem now becomes completely a model-free scheme. Moreover, no explicit fault diagnosis module is required in our approach. The proposed fault tolerance Mechanism is illustrated on an aircraft during the landing phase.

Susumu Nakayashiki - One of the best experts on this subject based on the ideXlab platform.

  • Mac Reconfiguration Mechanism for a dual‐ring lan
    Electronics and Communications in Japan Part I-communications, 2007
    Co-Authors: Susumu Nakayashiki, Jiro Kashios, Takeshi Harakawa
    Abstract:

    In a Reconfiguration Mechanism for improving the RAS of a ring LAN, it is necessary to guarantee the proper functioning of communication functions up to the medium access control (MAC) layer. This paper proposes a Reconfiguration Mechanism for distributed-control dual ring LANs which maximizes the size of the ring while maintaining MAC layer communication functions by automatic ring merging and wrapback. Each station bases its actions on the state of the two input links. When a link fails, the failed segment is isolated by ring wrap-back and the ring operates in wrapback mode. When multiple failures occur, the ring is wrapped back further into a smaller ring or several rings until the MAC layer functions are recovered. On the other hand, when the MAC layer functions of the failed segment are recovered, wrapback is released and the failed segment is merged into the active ring. With this Reconfiguration Mechanism, the largest ring possible to maintain MAC layer functions is formed automatically regardless of failures, powering up or down, etc. This Mechanism is represented using finite state machine (FSM) diagrams. The recovery times from multiple failures are evaluated using the specifications of the international LAN standard (ISO 8802-5). This Reconfiguration Mechanism has been approved as the IEEE standard (recommended practice) for a dual-ring Reconfiguration Mechanism, and its effectiveness has been proven by field trials.

  • mac Reconfiguration Mechanism for a dual ring lan
    Electronics and Communications in Japan Part I-communications, 1993
    Co-Authors: Susumu Nakayashiki, Jiro Kashios, Takeshi Harakawa
    Abstract:

    In a Reconfiguration Mechanism for improving the RAS of a ring LAN, it is necessary to guarantee the proper functioning of communication functions up to the medium access control (MAC) layer. This paper proposes a Reconfiguration Mechanism for distributed-control dual ring LANs which maximizes the size of the ring while maintaining MAC layer communication functions by automatic ring merging and wrapback. Each station bases its actions on the state of the two input links. When a link fails, the failed segment is isolated by ring wrap-back and the ring operates in wrapback mode. When multiple failures occur, the ring is wrapped back further into a smaller ring or several rings until the MAC layer functions are recovered. On the other hand, when the MAC layer functions of the failed segment are recovered, wrapback is released and the failed segment is merged into the active ring. With this Reconfiguration Mechanism, the largest ring possible to maintain MAC layer functions is formed automatically regardless of failures, powering up or down, etc. This Mechanism is represented using finite state machine (FSM) diagrams. The recovery times from multiple failures are evaluated using the specifications of the international LAN standard (ISO 8802-5). This Reconfiguration Mechanism has been approved as the IEEE standard (recommended practice) for a dual-ring Reconfiguration Mechanism, and its effectiveness has been proven by field trials.

  • Wrapback Reconfiguration Mechanism of a counter‐rotating dual token ring
    Electronics and Communications in Japan Part I-communications, 1991
    Co-Authors: Susumu Nakayashiki, Takeshi Harakawa, Jiro Kashio, Hiroyuki Wada
    Abstract:

    In the distributed-control ring LAN (local area networks), a Reconfiguration control is required to cope with the independent asynchronous failure detection in the stations. This paper proposes a wrapback Reconfiguration Mechanism in the dual-token ring LAN with a parallel dual structure of distributed-control token-ring LAN. Here, the ring is wrapped back automatically by the distributed-control of the stations when a fault is detected in the communication function in the physical layer or MAC (medium access control) layer. Each station connected by the dual ring determines its operation based only on the state of the two input links. When an abnormality is detected in a link, a failure-detecting beacon is transmitted and the failure domain is located by the reception priority competition control, where the transmission is stopped by receiving the beacon. The stations adjacent to the failure domain artificially generate a fault in the output link paired to the failure link, so that the station to wrap back the ring at both sides of the failure link-pair can be located by the same procedure as for the localization of the failure domain. In parallel to the ring wrapback, the active monitor is established, which is needed in the initialization of the ring. Each station discriminates between the current link and standby link, and the ring wrapback by the failure of the standby link is avoided. Applying the international standard (IEEE 802.5) to the token-ring LAN, the failure recovery time is evaluated. The effectiveness of the proposed Reconfiguration Mechanism has already been verified by an experiment using the actual equipment.

  • wrapback Reconfiguration Mechanism of a counter rotating dual token ring
    Electronics and Communications in Japan Part I-communications, 1991
    Co-Authors: Susumu Nakayashiki, Takeshi Harakawa, Jiro Kashio, Hiroyuki Wada
    Abstract:

    In the distributed-control ring LAN (local area networks), a Reconfiguration control is required to cope with the independent asynchronous failure detection in the stations. This paper proposes a wrapback Reconfiguration Mechanism in the dual-token ring LAN with a parallel dual structure of distributed-control token-ring LAN. Here, the ring is wrapped back automatically by the distributed-control of the stations when a fault is detected in the communication function in the physical layer or MAC (medium access control) layer. Each station connected by the dual ring determines its operation based only on the state of the two input links. When an abnormality is detected in a link, a failure-detecting beacon is transmitted and the failure domain is located by the reception priority competition control, where the transmission is stopped by receiving the beacon. The stations adjacent to the failure domain artificially generate a fault in the output link paired to the failure link, so that the station to wrap back the ring at both sides of the failure link-pair can be located by the same procedure as for the localization of the failure domain. In parallel to the ring wrapback, the active monitor is established, which is needed in the initialization of the ring. Each station discriminates between the current link and standby link, and the ring wrapback by the failure of the standby link is avoided. Applying the international standard (IEEE 802.5) to the token-ring LAN, the failure recovery time is evaluated. The effectiveness of the proposed Reconfiguration Mechanism has already been verified by an experiment using the actual equipment.

Takeshi Harakawa - One of the best experts on this subject based on the ideXlab platform.

  • Mac Reconfiguration Mechanism for a dual‐ring lan
    Electronics and Communications in Japan Part I-communications, 2007
    Co-Authors: Susumu Nakayashiki, Jiro Kashios, Takeshi Harakawa
    Abstract:

    In a Reconfiguration Mechanism for improving the RAS of a ring LAN, it is necessary to guarantee the proper functioning of communication functions up to the medium access control (MAC) layer. This paper proposes a Reconfiguration Mechanism for distributed-control dual ring LANs which maximizes the size of the ring while maintaining MAC layer communication functions by automatic ring merging and wrapback. Each station bases its actions on the state of the two input links. When a link fails, the failed segment is isolated by ring wrap-back and the ring operates in wrapback mode. When multiple failures occur, the ring is wrapped back further into a smaller ring or several rings until the MAC layer functions are recovered. On the other hand, when the MAC layer functions of the failed segment are recovered, wrapback is released and the failed segment is merged into the active ring. With this Reconfiguration Mechanism, the largest ring possible to maintain MAC layer functions is formed automatically regardless of failures, powering up or down, etc. This Mechanism is represented using finite state machine (FSM) diagrams. The recovery times from multiple failures are evaluated using the specifications of the international LAN standard (ISO 8802-5). This Reconfiguration Mechanism has been approved as the IEEE standard (recommended practice) for a dual-ring Reconfiguration Mechanism, and its effectiveness has been proven by field trials.

  • mac Reconfiguration Mechanism for a dual ring lan
    Electronics and Communications in Japan Part I-communications, 1993
    Co-Authors: Susumu Nakayashiki, Jiro Kashios, Takeshi Harakawa
    Abstract:

    In a Reconfiguration Mechanism for improving the RAS of a ring LAN, it is necessary to guarantee the proper functioning of communication functions up to the medium access control (MAC) layer. This paper proposes a Reconfiguration Mechanism for distributed-control dual ring LANs which maximizes the size of the ring while maintaining MAC layer communication functions by automatic ring merging and wrapback. Each station bases its actions on the state of the two input links. When a link fails, the failed segment is isolated by ring wrap-back and the ring operates in wrapback mode. When multiple failures occur, the ring is wrapped back further into a smaller ring or several rings until the MAC layer functions are recovered. On the other hand, when the MAC layer functions of the failed segment are recovered, wrapback is released and the failed segment is merged into the active ring. With this Reconfiguration Mechanism, the largest ring possible to maintain MAC layer functions is formed automatically regardless of failures, powering up or down, etc. This Mechanism is represented using finite state machine (FSM) diagrams. The recovery times from multiple failures are evaluated using the specifications of the international LAN standard (ISO 8802-5). This Reconfiguration Mechanism has been approved as the IEEE standard (recommended practice) for a dual-ring Reconfiguration Mechanism, and its effectiveness has been proven by field trials.

  • Wrapback Reconfiguration Mechanism of a counter‐rotating dual token ring
    Electronics and Communications in Japan Part I-communications, 1991
    Co-Authors: Susumu Nakayashiki, Takeshi Harakawa, Jiro Kashio, Hiroyuki Wada
    Abstract:

    In the distributed-control ring LAN (local area networks), a Reconfiguration control is required to cope with the independent asynchronous failure detection in the stations. This paper proposes a wrapback Reconfiguration Mechanism in the dual-token ring LAN with a parallel dual structure of distributed-control token-ring LAN. Here, the ring is wrapped back automatically by the distributed-control of the stations when a fault is detected in the communication function in the physical layer or MAC (medium access control) layer. Each station connected by the dual ring determines its operation based only on the state of the two input links. When an abnormality is detected in a link, a failure-detecting beacon is transmitted and the failure domain is located by the reception priority competition control, where the transmission is stopped by receiving the beacon. The stations adjacent to the failure domain artificially generate a fault in the output link paired to the failure link, so that the station to wrap back the ring at both sides of the failure link-pair can be located by the same procedure as for the localization of the failure domain. In parallel to the ring wrapback, the active monitor is established, which is needed in the initialization of the ring. Each station discriminates between the current link and standby link, and the ring wrapback by the failure of the standby link is avoided. Applying the international standard (IEEE 802.5) to the token-ring LAN, the failure recovery time is evaluated. The effectiveness of the proposed Reconfiguration Mechanism has already been verified by an experiment using the actual equipment.

  • wrapback Reconfiguration Mechanism of a counter rotating dual token ring
    Electronics and Communications in Japan Part I-communications, 1991
    Co-Authors: Susumu Nakayashiki, Takeshi Harakawa, Jiro Kashio, Hiroyuki Wada
    Abstract:

    In the distributed-control ring LAN (local area networks), a Reconfiguration control is required to cope with the independent asynchronous failure detection in the stations. This paper proposes a wrapback Reconfiguration Mechanism in the dual-token ring LAN with a parallel dual structure of distributed-control token-ring LAN. Here, the ring is wrapped back automatically by the distributed-control of the stations when a fault is detected in the communication function in the physical layer or MAC (medium access control) layer. Each station connected by the dual ring determines its operation based only on the state of the two input links. When an abnormality is detected in a link, a failure-detecting beacon is transmitted and the failure domain is located by the reception priority competition control, where the transmission is stopped by receiving the beacon. The stations adjacent to the failure domain artificially generate a fault in the output link paired to the failure link, so that the station to wrap back the ring at both sides of the failure link-pair can be located by the same procedure as for the localization of the failure domain. In parallel to the ring wrapback, the active monitor is established, which is needed in the initialization of the ring. Each station discriminates between the current link and standby link, and the ring wrapback by the failure of the standby link is avoided. Applying the international standard (IEEE 802.5) to the token-ring LAN, the failure recovery time is evaluated. The effectiveness of the proposed Reconfiguration Mechanism has already been verified by an experiment using the actual equipment.