Search results for "Fault model"
showing 8 items of 8 documents
Elusive active faults in a low strain rate region (Sicily, Italy): Hints from a multidisciplinary land-to-sea approach
2022
Low Strain Rate regions (LSRrs), i.e., areas undergoing tectonic deformation at rates of 1 mm/yr or less, often host important cities and highly vulnerable anthropogenic assets, and due to their subdued topography and relatively infrequent seismicity, are often considered low seismic hazard areas. Despite this, infrequent but high-magnitude earthquakes in such regions suggest that identifying active structures in the LSRr is one of the primary challenges for both the scientific community and modern societies. In such regions, one of the main issues in identifying active faults is the lack of valuable outcrop data due to erosional/sedimentation rates overwhelming the fault deformation, causi…
Simple Circuit Models for Studying Global Earthing Systems
2007
The paper proposes three simple circuit models for the simulation of the behaviour of a global earthing system during different fault events. The models allow one the evaluation of the maximum earth potential rise at every possible fault location and for every possible fault event. The three considered fault events are: single-line-to-earth fault inside a MV/LV substation, double-earth-fault in a MV line, single-line-to-earth fault inside a HV/MV station. After having illustrated the hypotheses at the basis of the study, the circuit models for the three fault events are presented and a numerical example shows how to use them in order to check the "global safety" of the interconnected earthi…
Reliability Analysis of Systems Containing Complex Control Loops
1986
Abstract Many Process Plants employ complex control and trip systems to improve process safety. Reliability prediction requires determination of the failure mechanisms followed by quantification of the failure rates. The fault tree technique is often used for reliability prediction. Fault tree construction is a skilled task and can be complex for systems containing multiple protective devices. The paper compares 3 approaches to the problem of fault tree construction. The problems of quantification and common mode failure is also considered.
Long-term earthquake potential of active faults by using coastal and off-shore geological and morphological indicators
2017
Seismogenic fault models and active deformation ones coupled with models of both earthquake rate and earthquake probability were recently used in a time-independent modelling. The integration of models allows to estimates the magnitude, location, and likelihood of potentially damaging earthquake ruptures in regions with high natural seismic hazard. Improvements of these models imply the recognition of the spatial geometry of the larger, active faults, deemed to be the source of the most damaging future earthquakes. However, identifying active faults and calculating their geologic slip rates for deriving earthquake rates are not easy tasks in regions inaccessible to direct field studies like…
Analysis of the influence of processor hidden registers on the accuracy of fault injection techniques
2004
Modern processors tend to increase the number of registers, being part of them not accessible by the instruction set. Traditionally, the effect of faults in these hidden registers has not been considered during system validation using fault injection. In this paper, a study of the importance of faults in hidden registers is performed. Firstly, we have analysed the sensitivity of hidden registers to faults in combinational logic. In a second phase, we have analysed the impact of the faults occurred in hidden registers on system behaviour. A broad set of permanent and transient faults have been injected into the models of two typical commercial microcontrollers, using a VHDL-based fault injec…
Data-Driven Adaptive Observer for Fault Diagnosis
2012
Published version of an article from the journal: Mathematical Problems in Engineering. Also available from the publisher:http://dx.doi.org/10.1155/2012/832836 This paper presents an approach for data-driven design of fault diagnosis system. The proposed fault diagnosis scheme consists of an adaptive residual generator and a bank of isolation observers, whose parameters are directly identified from the process data without identification of complete process model. To deal with normal variations in the process, the parameters of residual generator are online updated by standard adaptive technique to achieve reliable fault detection performance. After a fault is successfully detected, the iso…
Run-Time Reconfiguration for Emulating Transient Faults in VLSI Systems
2006
Advances in circuitry integration increase the probability of occurrence of transient faults in VLSI systems. A confident use of these systems requires the study of their behaviour in the presence of such faults. This study can be conducted using model-based fault injection techniques. In that context, field-programmable gate arrays (FPGAs) offer a great promise by enabling those techniques to execute models faster. This paper focuses on how run-time reconfiguration techniques can be used for emulating the occurrence of transient faults in VLSI models. Although the use of FPGAs for that purpose has been restricted so far to the well-known bit-flip fault model, recent studies in fault repres…
Efficient techniques for fault detection and location of multiple controlled Toffoli-based reversible circuit
2021
It is very important to detect and correct faults for ensuring the validity and reliability of these circuits. In this regard, a comparative study with related existing techniques is undertaken. Two techniques to achieve the testability of reversible circuits are introduced that have been improved in terms of quantum cost and fault coverage rate. Considering this aspect, the main focus of these techniques is on the efficient detection and location of faults with 100% accuracy. These techniques for fault detection in reversible circuit design, in addition to being able to produce the correct outputs, can also provide information for fault location that has already been done at a higher cost.…