Bearings are widely used in rotating machines. Its health status is a significant index to indicate whether machines run continually or not. Detecting the bearing faults timely is very important for the maintenance decision making. In this paper, a new fault diagnosis method based on envelope analysis and Euclidean Distance is developed. Envelope analysis is used to enable the fault frequencies...

The aim of the relay coordination is that protection systems detect and isolate the faulted part as fast and selective as possible. On the other hand, in order to reduce the fault clearing time, distance protection relays are usually equipped with pilot protection schemes. Such schemes can be considered in the distance and directional overcurrent relays (D&DOCRs) coordination to achieve faster ...

This paper presents a new approach to intelligent fault diagnosis based on statistics analysis, an improved distance evaluation technique and adaptive neuro-fuzzy inference system (ANFIS). The approach consists of three stages. First, different features, including time-domain statistical characteristics, frequency-domain statistical characteristics and empirical mode decomposition (EMD) energy ...

We study automata-theoretic properties of distances and quasi-distances between words. We show that every additive distance is nite. We also show that every additive quasi-distance is regularity-preserving, that is, the neighborhood of any radius of a regular language with respect to an additive quasi-distance is regular. As an application we present a simple algorithm that constructs a metric ...

We use a lifecycle model in which individuals differ by age and by wage in order to analyze a pairwise majority voting process on the legal retirement age. We consider two different retirement regimes. In the first one the retirees do not return to the labor market, regardless the new retirement age. In the second one, they have to return if this ∗Corresponding author. Juan Antonio Lacomba, Dep...

Two-dimensional, numerical models of a linear fault embedded within a linear elastic medium show the generation of off-fault tensile failure that results from inelastic slip along the fault. We explore quasistatic models with slip-weakening friction to assess the effects of spatially and temporally variable friction on the damage patterns. Tensile fractures form where tangential normal stresses...

In this paper, precise fault location in electrical traction network systems is discussed in the high-frequency domain. Based on the analysis of the equivalent impedance at the measurement terminal, the relationship between the fault distance and the frequency spectrum extreme points of the system impedance are derived. The exact fault location can be obtained from the relationship curves accor...

[1] Radiating shear and Rayleigh waves from supershear ruptures form Mach waves that transmit large-amplitude ground motion and stresses to locations far from the fault. We simulate bilateral ruptures on a finite-width vertical strike-slip fault (of width W and half-length L with L W) breaking the surface of an elastic half-space, and focus on the wavefield out to distances comparable to L. At ...

This paper deals with two new methods, based on k-NN algorithm, for fault detection and classification in distance protection. In these methods, by finding the distance between each sample and its fifth nearest neighbor in a predefault window, the fault occurrence time and the faulty phases are determined. The maximum value of the distances in case of detection and classification procedures is ...