883 research outputs found
Privatized distributed anomaly detection for large-scale nonlinear uncertain systems
In this article two limitations in current distributed model based approaches for anomaly detection in large-scale uncertain nonlinear systems are addressed. The first limitation regards the high conservativeness of deterministic detection thresholds, against which a novel family of set-based thresholds is proposed. Such set-based thresholds are defined in a way to guarantee robustness in a user-defined probabilistic sense, rather than a deterministic sense. They are obtained by solving a chance-constrained optimization problem, thanks to a randomization technique based on the Scenario Approach. The second limitation regards the requirement, in distributed anomaly detection architectures, for different parties to regularly communicate local measurements. In settings where these parties want to preserve their privacy, communication may be undesirable. In order to preserve privacy and still allow for distributed detection to be implemented, a novel privacy-preserving mechanism is proposed and a so-called privatized communication protocol is introduced. Theoretical guarantees on the achievable level of privacy, along with a characterization of the robustness properties of the proposed distributed threshold set design, taking into account the privatized communication scheme, are provided. Finally, simulation studies are included to illustrate our theoretical developments
The Correlation Between Historical and Instrumental Seismicity in the Sansepolcro Basin, Northern Apennines, Italy
The area investigated, the Sansepolcro basin, is characterized by the
presence of important earthquakes in the past with estimated intensity
even larger than IX MCS (the 1352 Monterchi earthquake, the 1389
Boccaserriola, the 1458 Citta’ di Castello, the 1781 Cagliese and the
1917 Monterchi-Citerna earthquakes, CPTI Working Group, 2004) and
by a surprisingly scarce instrumental seismicity compared to the
adjacent areas struck by high seismicity (Castello et al., 2005; Ciaccio
et al., 2006). The area north of Sansepolcro has been struck in recent
years by four minor sequences, occurred between 1987 and 2001 with
magnitude ranging from Ml3.0 to Mw4.7. In this work we analyse the
most important earthquakes of the 20th century occurred in the
Altotiberina Valley in 1917, 1918, 1919 and 1948; in particular
instrumental relocation, focal mechanisms and Ms and Mw magnitude
estimation are re-evaluated. The relocation of these earthquakes is
particularly critical and is an important issue. An instrumental and
precise location is critical for the complexity of the problems associated
with the study of seismograms prior to the first half of the twentieth
century and is relevant because in the surrounding regions higher
seismicity is observed. Regarding this peculiarity of the area, it’s very
important to detect the location of the historical earthquakes: in particular,
the 1917 event is often associated to the possibility that the
regional low angle Altotiberina Fault (Barchi et al., 1998) is able or not
to nucleate large- or moderate-magnitude events, being historically
located close to its surface (Boncio and Lavecchia, 2000)
Structure, stability and stress properties of amorphous and nanostructured carbon films
Structural and mechanical properties of amorphous and nanocomposite carbon
are investigated using tight-binding molecular dynamics and Monte Carlo
simulations. In the case of amorphous carbon, we show that the variation of
sp^3 fraction as a function of density is linear over the whole range of
possible densities, and that the bulk moduli follow closely the power-law
variation suggested by Thorpe. We also review earlier work pertained to the
intrinsic stress state of tetrahedral amorphous carbon. In the case of
nanocomposites, we show that the diamond inclusions are stable only in dense
amorphous tetrahedral matrices. Their hardness is considerably higher than that
of pure amorphous carbon films. Fully relaxed diamond nanocomposites possess
zero average intrinsic stress.Comment: 10 pages, 6 figure
EP-1526: Analysis of dose deposition in lung lesions: a modified PTV for a more robust optimization
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Analysis of the damage effect of femtosecond-laser irradiation on extreme ultraviolet Mo/Si multilayer coating
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Orchestrating Tuple-based Languages
The World Wide Web can be thought of as a global computing architecture supporting the deployment of distributed networked applications. Currently, such applications can be programmed by resorting mainly to two distinct paradigms: one devised for orchestrating distributed services, and the other designed for coordinating distributed (possibly mobile) agents. In this paper, the issue of designing a pro-
gramming language aiming at reconciling orchestration and coordination is investigated. Taking as starting point the orchestration calculus Orc and the tuple-based coordination language Klaim, a new formalism is introduced combining concepts and primitives of the original calculi.
To demonstrate feasibility and effectiveness of the proposed approach, a prototype implementation of the new formalism is described and it is then used to tackle a case study dealing with a simplified but realistic electronic marketplace, where a number of on-line stores allow client
applications to access information about their goods and to place orders
LHC as and Collider
We propose an experiment at the LHC with leading neutron production.The
latter can be used to extract from it the total cross-sections. With
two leading neutrons we can get access to the total
cross-sections. In this note we give some estimates and discuss related
problems and prospects.Comment: 22 pages, 18 figures, 8 tables, to be publishe
Guidelines for training in cardiovascular magnetic resonance (CMR)
These "Guidelines for training in Cardiovascular Magnetic Resonance" were developed by the Certification Committee of the Society for Cardiovascular Magnetic Resonance (SCMR) and approved by the SCMR Board of Trustees
Inverse magnetic catalysis in field theory and gauge-gravity duality
We investigate the surface of the chiral phase transition in the
three-dimensional parameter space of temperature, baryon chemical potential and
magnetic field in two different approaches, the field-theoretical
Nambu-Jona-Lasinio (NJL) model and the holographic Sakai-Sugimoto model. The
latter is a top-down approach to a gravity dual of QCD with an asymptotically
large number of colors and becomes, in a certain limit, dual to an NJL-like
model. Our main observation is that, at nonzero chemical potential, a magnetic
field can restore chiral symmetry, in apparent contrast to the phenomenon of
magnetic catalysis. This "inverse magnetic catalysis" occurs in the
Sakai-Sugimoto model and, for sufficiently large coupling, in the NJL model and
is related to the physics of the lowest Landau level. While in most parts our
discussion is a pedagogical review of previously published results, we include
new analytical results for the NJL approach and a thorough comparison of
inverse magnetic catalysis in the two approaches.Comment: 37 pages, 11 figures, to appear in Lect. Notes Phys. "Strongly
interacting matter in magnetic fields" (Springer), edited by D. Kharzeev, K.
Landsteiner, A. Schmitt, H.-U. Ye
A Bayesian Modelling of Wildfires in Portugal
In the last decade wildfires became a serious problem in Portugal due to
different issues such as climatic characteristics and nature of Portuguese forest. In
order to analyse wildfire data, we employ beta regression for modelling the proportion
of burned forest area, under a Bayesian perspective. Our main goal is to find
out fire risk factors that influence the proportion of area burned and what may make
a forest type susceptible or resistant to fire. Then, we analyse wildfire data in Portugal
during 1990-1994 through Bayesian beta models t
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