ÐThis paper presents a class of count-and-threshold mechanisms, collectively named -count, which are able to discriminate between transient faults and intermittent faults in computing systems. For many years, commercial systems have been using transient fault discrimination via threshold-based techniques. We aim to contribute to the utility of count-and-threshold schemes, by exploring their eff...

We address the problem of how to integrate fault-tolerant external and internal clock synchronization. In this paper we propose a new external/internal clock synchronization algorithm which provides both external and internal clock synchronization for as long as a majority of the reference time servers (servers with access to reference time) stay correct. When half or more of the reference time...

This paper presents the application of neural networks for the non-differential protection of salient-pole synchronous generator against internal faults in any winding of the stator. The direct phase quantities and modified winding function approach has been used to simulate different types of internal and external faults using electrical parameters of generators installed by utilities. The cas...

This paper proposes a novel directional pilot protection method based on the transient energy for bipolar HVDC line. Supposing the positive direction of current is from DC bus to the DC line, in the case of an internal line fault, the transient energies detected on both sides of the line are all negative within a short time, which denotes the positive direction fault; while for an external faul...

This paper presents an efficient wavelet and neural network (WNN) based algorithm for distinguishing magnetizing inrush currents from internal fault currents in three phase power transformers. The wavelet transform is applied first to decompose the current signals of the power transformer into a series of detailed wavelet components. The values of the detailed coefficients obtained can accurate...

The difficulty of CNC machine tools fault diagnosis is bigger than other general equipments because of the complex structure and the coupling among subsystems. The fault diagnosis model based on multi-level information fusion and hybrid intelligence is studied to improve reliability of fault diagnosis. Information from built-in sensors is used to monitor the status of CNC machine tools. The dia...

[1] We examine the frictional behavior of a range of lithified rocks used as analogs for fault rocks, cataclasites and ultracataclasites at seismogenic depths and compare them with gouge powders commonly used in experimental studies of faults. At normal stresses of ∼50 MPa, the frictional strength of lithified, isotropic hard rocks is generally higher than their powdered equivalents, whereas fo...

We address the problem of how to integrate faulttolerant internal and external clock synchronization. We propose a new algorithm which provides both external and internal clock synchronization for as long as no more than F reference time servers out of a total of 2F+1 are faulty. When the number of faulty reference time servers exceeds F , the algorithm degrades to a fault-tolerant internal clo...

There is an increasing trend towards N+1 UPS architectures – rather than 2N – as IT fault tolerance through software continues to improve. There are two common ways N+1 can be achieved: paralleling multiple unitary UPSs together or deploying a single UPS frame with multiple internal modules configured for N+1 redundancy. In this paper, we quantify key tradeoffs between an internal “modular” red...