Search results for "Fault"
showing 10 items of 610 documents
A real-space approach to the analysis of stacking faults in close-packed metals: Modelling and Q-space feedback Longo Alessandro
2020
An R-space approach to the simulation and fitting of a structural model to the experimental pair distribution function is described, to investigate the structural disorder (distance distribution and stacking faults) in close-packed metals. This is carried out by transferring the Debye function analysis into R space and simulating the low-angle and high-angle truncation for the evaluation of the relevant Fourier transform. The strengths and weaknesses of the R-space approach with respect to the usual Q-space approach are discussed.
Questions and controversies in the study of time-varying functional connectivity in resting fMRI.
2020
The brain is a complex, multiscale dynamical system composed of many interacting regions. Knowledge of the spatiotemporal organization of these interactions is critical for establishing a solid understanding of the brain’s functional architecture and the relationship between neural dynamics and cognition in health and disease. The possibility of studying these dynamics through careful analysis of neuroimaging data has catalyzed substantial interest in methods that estimate time-resolved fluctuations in functional connectivity (often referred to as “dynamic” or time-varying functional connectivity; TVFC). At the same time, debates have emerged regarding the application of TVFC analyses to re…
Cell degradation detection based on an inter-cell approach
2017
Fault management is a crucial part of cellular network management systems. The status of the base stations is usually monitored by well-defined key performance indicators (KPIs). The approaches for cell degradation detection are based on either intra-cell or inter-cell analysis of the KPIs. In intra-cell analysis, KPI profiles are built based on their local history data whereas in inter-cell analysis, KPIs of one cell are compared with the corresponding KPIs of the other cells. In this work, we argue in favor of the inter-cell approach and apply a degradation detection method that is able to detect a sleeping cell that could be difficult to observe using traditional intra-cell methods. We d…
Effects of Transcranial Direct Current Stimulation on Brain Networks Related to Creative Thinking
2020
AbstractHuman creative thinking is unique and capable of generating novel and valuable ideas. Recent research has clarified the contribution of different brain networks (default mode network, DN; executive control network; salience network) to creative thinking. However, the effects of brain stimulation on brain networks during creative thinking and on creative performance have not been clarified. The present study was designed to examine the changes in functional connectivity (FC) and effective connectivity (EC) of the large-scale brain network, and the ensuing changes in creative performance, induced by transcranial direct current stimulation (tDCS). Fourteen healthy male students underwe…
DEFAULT MODE NETWORK AND WORKING MEMORY NETWORK DURING AN FMRI WORKING MEMORY TASK: DIFFERENCES AND CORRELATIONS WITH BEHAVIORAL PERFORMANCE
2013
INTRODUCTION Previous neuroimaging studies have shown that working memory load has marked effects on regional neural activation[1-5]. However, the mechanism through which working memory load modulates brain connectivity is still unclear. During a working memory task, two of the most involved networks are the default mode network (DMN) and the working memory network (WMN)[6-7]: the selective focus on these networks can be useful in better understanding the load effects. Spatial independent component analysis (ICA)[8] has becomes a reliable technique to investigate the networks involved during an fMRI task, as it extracts spatiotemporal patterns of neural activity maximizing spatial independe…
Corporate board and default risk of financial firms
2022
This paper analyses the impact of corporate board structure on default risk of European banking firms. We focus on four core aspects of boards that have been addressed in Directive 2013/36/ EU to strengthen the corporate governance of banks: the size of boards, their independence, the participation of female directors and CEO duality. We employ panel data analysis to study the 109 European listed banks between 2002 and 2019. Default risk is estimated by Merton’s (1974) distance to default. We take into account the presence of unobservable heterogeneity, simultaneity and dynamic endogeneity and estimate the model using the dynamic difference and dynamic system GMM methodologies. The results …
Notations et écarts de rentabilité : le marché français avant l'euro
2003
The main task of this paper is to confront two classical measures of default risk of the issuer, the rating and the spread. The first is attributed by agencies specialized in this activity (Standard and Poor's or Moody's) while the second results directly from the market price of the bond. This article studies this link over a period of two years for about forty French denominated bonds. Two measures of the spread are used and the results obtained show the very partial consideration of this information by the investors on the French bond market.
Robust fault detection for switched systems with time-varying delay using delta operator approach
2014
Quantitative Rotor Broken Bar Evaluation in Double Squirrel Cage Induction Machines under Dynamic Operating Conditions
2013
Advanced monitoring techniques leading to fault diagnosis and prediction of induction machine faults, operating under non-stationary conditions have gained strength because of its considerable influence on the operational continuation of many industrial processes. In case of rotor broken bars, fault detection based on sideband components issued from currents, flux, instantaneous control or power signals under different load conditions, may fail due to the presence of inter-bar currents that reduce the degree of rotor asymmetry, especially for double squirrel cage induction motors. But the produced core vibrations in the axial direction, can be investigated to overcome the limitation of the …
An overview of a novel LC resonant device able to improve Power Quality in active and passive distribution networks
2004
Nowadays power distribution systems are under a rapid evolution. The widespread penetration of distributed generation is bringing about new operating conflicts, which are adding to traditional power quality issues. The paper aims to analyse the performance of a new LC device able to improve power quality in electrical distribution systems, even in presence of distributed generation units. The different possible applications of the device are shown and the performances are proved by means of computer simulation. The first experimental results are also presented.