Search results for "fault"
showing 10 items of 610 documents
Fuzzy modelling of HEART methodology: application in safety analyses of accidental exposure in irradiation plants
2009
The present paper refers to the obtained results by using Fuzzy Fault Tree analyses of accidental scenarios which entail the potential exposure of operators working in irradiation industrial plants. For these analyses the HEART methodology, a first generation of the Human Reliability Analysis method, has been employed to evaluate the probability of human erroneous actions. This technique has been modified by us on the basis of fuzzy set concept to more directly take into account the uncertainties of the so called error-promoting factors, on which the method is grounded. The results allow also to provide some recommendations on procedures and safety equipments to reduce the radiological expo…
Mobile agents principles of operation
2004
Publisher Summary This chapter discusses the mobile agent technology and summarizes their features, principles of operation and implementation elements. Some development tools are also discussed. The chapter provides general description of mobile agents as an advanced software paradigm, which extends object oriented programming. Then it discusses principles of operation starting from agent intelligent behavior and continuing with mobility, communication, coordination, and fault tolerance. Finally, as for related topics, monitoring, performances, and security issues are discussed in the chapter. Agent monitoring techniques are very useful because they allow users to know which agents are run…
State feedback control against sensor faults for Lipschitz nonlinear systems via new sliding mode observer techniques
2011
This paper investigates the problem of simultaneous state and fault estimation and observer-based fault tolerant controller design for Lipschitz nonlinear systems with sensor failure. A new estimation technique is presented in this paper to deal with this design problem. In the proposed approaches, the original system is first augmented by a descriptor model transformation, then a new Proportional and Derivative sliding mode observer technique is developed to obtain accurate estimations of both system states and sensor faults. The designing observer is generalized from the PD observer in [3], but is not a trivial extension. Based on the state estimates, a observer-based control strategy is …
Comment on "Displacement along the Karakoram fault, NW Himalaya, estimated from LA-ICP-MS U Pb dating of offset geologic markers" published by Shifen…
2013
International audience; Field evidence for syn-deformation migmatization and crystallization along the Karakorum fault contradicts the study of Wang et al. (2012). The ages of such magmatic rocks provide minimum ages for the onset of deformation at similar to 23 Ma in North Ayilari and similar to 19 Ma in Tangtse. The onset of deformation at 12 Ma in the Ayilari range inferred by Wang et al. (2012) from a muscovite Ar/Ar age is a cooling age, thus only a minimum age. The similar to 60 Ma granodiorite bodies, the ophiolitic rocks and the south Kailash thrust that are correlated across the fault to provide a 52 +/- 2 km finite offset do not define reliable piercing points. Such observations a…
A methodology for the semi-automatic generation of analytical models in manufacturing
2018
International audience; Advanced analytics can enable manufacturing engineers to improve product quality and achieve equipment and resource efficiency gains using large amounts of data collected during manufacturing. Manufacturing engineers, however, often lack the expertise to apply advanced analytics, relying instead on frequent consultations with data scientists. Furthermore, collaborations between manufacturing engineers and data scientists have resulted in highly specialized applications that are not relevant to broader use cases. The manufacturing industry can benefit from the techniques applied in these collaborations if they can be generalized for a wide range of manufacturing probl…
Robust Output-Feedback Based Fault-Tolerant Control of Active Suspension with Finite-Frequency Constraint ★ ★This work is partly supported by Nationa…
2015
Abstract In this paper, the H∞ fault-tolerant control (FTC) problem of active suspensions with finite-frequency constraints is investigated. A full-car model is employed in the controller design such that the heave, pitch and roll motions can be simultaneously controlled. Both the actuator faults and external disturbance are considered in the controller design. As the human body is more sensitive to the vertical vibration in 4-8Hz, robust H∞ control with finite frequency constraints is designed. From the practical perspective, a robust dynamic output-feedback controller with fault tolerant ability is proposed, while other performances such as suspension deflection and actuator saturation ar…
DC series arc faults in PV systems. Detection methods and experimental characterization
2020
This work is focused on the arc faults phenomenon in DC photovoltaic (PV) systems. The paper gives an overview of arc detection methods proposed in literature and presents a preliminary experimental characterization of the arcing current, focusing the attention on series arcs, whose detection is particularly challenging. Experimental tests are carried out, both in laboratory and on field, in order to investigate some relevant characteristics in the arcing current, which can be feasible for the arc detection purpose. Both arcing and non-arcing current signals are acquired and compared in both time and frequency domain. On-field measurements are carried out on a real photovoltaic system, in a…
Marqueurs d'une structuration extensive jurassique en arrière de la marge nord-téthysienne (monts du Mâconnais, Bourgogne, France)
2000
Structural analysis of extensional faults in the Mâconnais Hills shows that low-intensity extensional phenomena occurred back from the passive margin of the Ligurian Tethys, the axis of which lay some 400 km southeast of the study area in Mid-Jurassic times. Storm-induced rip current directions and coral lens positions suggest that the palaeotopography was maintained by early faulting.
Tectono-sedimentary evolution of the Pliocene to Lower Pleistocene succession of the Apricena-Lesina-Poggio Imperiale quarrying district (western Gar…
2010
The post-Miocene marine succession of the «Apricena horst» is described with the purpose to verify the chronostratigraphic constraints for the type-locality of the Pirro Nord Faunal Unit. The stratigraphic succession has been subdivided in four units bounded by ubiquitous unconformities with evidence of subaerial exposure. The two basal units (dated late Zanclean to at most early Piacenzian) are formally grouped in the Lago di Varano Fm. that on the whole consists of sediments ranging from lagoonal to circalittoral environments. Within the lowermost unit, a megabreccia is interpreted as the product of a tsunami event. The third unit, Gelasian in age, is informally cited as Calcari a Briozoi…
Tectono-climatic evolution of a Neogene intramontane basin (Late Miocene Carboneras subbasin, southeast Spain): revelations from basin mapping and bi…
2002
Exceptional 3-D exposures of fault blocks forming a 5km x 10 km clastic sediment-starved, marine basin (Carboneras subbasin, southeast Spain) allow a test of the response of carbonate sequence stratigraphic architectures to climatic and tectonic forcing. Temperate and tropical climatic periods recorded in biofacies serve as a chronostratigraphic framework to reconstruct the status of the basin within three time-slices (late Tortonian---early Messinian, late Messinian, Pliocene). Structural maps and isopach maps trace out the distribution of fault blocks, faults, and over time, their relative motions, propagational patterns and life times, which demonstrate a changing layout of the basin bec…