5,066 research outputs found

    Development of Active Idle Stop System for Automotive Vehicle During Uphill Driving

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    This manuscript discusses the Active Idle Stop (AIS) system for a passenger vehicle system which is used to improve the dynamic performance of the vehicle when traveling uphill. The AIS function is developed mainly to improve the drawback in the existing vehicle system when driving uphill. Vehicles face unwanted deceleration and rollback when they are started on an incline. In this study, a control strategy using a Proportional-IntegralDerivative controller is used to improve the deceleration and rollback conditions during an idle stop on an uphill road gradient. A nonlinear vehicle longitudinal model has been used as the testing platform for the AIS function. Meanwhile, an optimization tool known as the Genetic Algorithm is used to improve the controller parameters according to the desired response of the vehicle. Based on the simulation results, it is possible to improve the vehicle’s performance using the AIS system to improve the rollback effect where the deceleration effect on the vehicle is reduced significantly

    A Backward/Forward Recovery Approach for the Preconditioned Conjugate Gradient Algorithm

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    Several recent papers have introduced a periodic verification mechanism to detect silent errors in iterative solvers. Chen [PPoPP'13, pp. 167--176] has shown how to combine such a verification mechanism (a stability test checking the orthogonality of two vectors and recomputing the residual) with checkpointing: the idea is to verify every dd iterations, and to checkpoint every c×dc \times d iterations. When a silent error is detected by the verification mechanism, one can rollback to and re-execute from the last checkpoint. In this paper, we also propose to combine checkpointing and verification, but we use algorithm-based fault tolerance (ABFT) rather than stability tests. ABFT can be used for error detection, but also for error detection and correction, allowing a forward recovery (and no rollback nor re-execution) when a single error is detected. We introduce an abstract performance model to compute the performance of all schemes, and we instantiate it using the preconditioned conjugate gradient algorithm. Finally, we validate our new approach through a set of simulations

    Constraint integration and violation handling for BPEL processes

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    Autonomic, i.e. dynamic and fault-tolerant Web service composition is a requirement resulting from recent developments such as on-demand services. In the context of planning-based service composition, multi-agent planning and dynamic error handling are still unresolved problems. Recently, business rule and constraint management has been looked at for enterprise SOA to add business flexibility. This paper proposes a constraint integration and violation handling technique for dynamic service composition. Higher degrees of reliability and fault-tolerance, but also performance for autonomously composed WS-BPEL processes are the objectives

    FADI: a fault-tolerant environment for open distributed computing

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    FADI is a complete programming environment that serves the reliable execution of distributed application programs. FADI encompasses all aspects of modern fault-tolerant distributed computing. The built-in user-transparent error detection mechanism covers processor node crashes and hardware transient failures. The mechanism also integrates user-assisted error checks into the system failure model. The nucleus non-blocking checkpointing mechanism combined with a novel selective message logging technique delivers an efficient, low-overhead backup and recovery mechanism for distributed processes. FADI also provides means for remote automatic process allocation on the distributed system nodes

    An approach to rollback recovery of collaborating mobile agents

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    Fault-tolerance is one of the main problems that must be resolved to improve the adoption of the agents' computing paradigm. In this paper, we analyse the execution model of agent platforms and the significance of the faults affecting their constituent components on the reliable execution of agent-based applications, in order to develop a pragmatic framework for agent systems fault-tolerance. The developed framework deploys a communication-pairs independent check pointing strategy to offer a low-cost, application-transparent model for reliable agent- based computing that covers all possible faults that might invalidate reliable agent execution, migration and communication and maintains the exactly-one execution property
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