Tivadar Szemethy

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An important problem in the control of complex systems, and one that inherently exhibits hybrid dynamics, is fault management and recovery. If a component fails in a system, the continuous behavior will suddenly change. In an autonomous system, the controller must be adaptive to ensure continued useful operation when faults occur. Fault-adaptive control(More)
—The Internet's universality is based on its decentralization and diversity. However, its distributed nature leads to operational brittleness and difficulty in identifying the root causes of performance and availability issues, especially when the involved systems span multiple administrative domains. The first step to address this fragmentation is(More)
In this paper we argue for UML-based metamodeling and pattern-based graph transformation techniques in computer-based systems development through an illustrative example from the domain of embedded systems. We present a tool that uses advanced graph-rewriting techniques to generate a schedule that satisfies hard real-time constraints for multi-modal(More)
– The energy consumption of telecommunication networks can be reduced using dynamic power management techniques, which allow network performance to be traded off against energy consumption. Such techniques can be applied on devices by means of hardware-specific local control policies. Distributed power management across heterogeneous hardware requires a(More)
– Complex control applications require capabilities for accommodating faults in the controlled plant. Fault accommodation involves the detection and isolation of faults, and then taking appropriate control actions to mitigate the fault effects and maintain control. This requires the integration of fault diagnostics with control in a feedback loop. This(More)
– Fault adaptive systems must adapt and reconfigure themselves to the changes in the environment or the system itself, and have to maintain operation even in case of system failures. In order to avoid performance degradation due to system reconfi-gurations, adequate reconfiguration management is necessary. This paper describes a fault-adaptive control(More)
–Recently, a number of approaches based on dynamic power management techniques have been proposed to reduce the energy consumption of telecommunication networks and devices. They are able to optimize the tradeoff between network performance and energy requirements. It is possible to execute and extend these techniques to the whole network, by using local(More)