Roma Tre University

About: Roma Tre University is a education organization based out in Rome, Lazio, Italy. It is known for research contribution in the topics: Large Hadron Collider & Galaxy. The organization has 4434 authors who have published 15352 publications receiving 374888 citations. The organization is also known as: Universita degli Studi Roma Tre & RomaTre.

Mathematical Analysis of Partial Differential Equations Modeling Electrostatic MEMS

Abstract: Micro- and nanoelectromechanical systems (MEMS and NEMS), which combine electronics with miniature-size mechanical devices, are essential components of modern technology It is the mathematical model describing 'electrostatically actuated' MEMS that is addressed in this monograph Even the simplified models that the authors deal with still lead to very interesting second- and fourth-order nonlinear elliptic equations (in the stationary case) and to nonlinear parabolic equations (in the dynamic case) While nonlinear eigenvalue problems - where the stationary MEMS models fit - are a well-developed field of PDEs, the type of inverse square nonlinearity that appears here helps shed a new light on the class of singular supercritical problems and their specific challenges Besides the practical considerations, the model is a rich source of interesting mathematical phenomena Numerics, formal asymptotic analysis, and ODE methods give lots of information and point to many conjectures However, even in the simplest idealized versions of electrostatic MEMS, one essentially needs the full available arsenal of modern PDE techniques to do the required rigorous mathematical analysis, which is the main objective of this volume This monograph could therefore be used as an advanced graduate text for a motivational introduction to many recent methods of nonlinear analysis and PDEs through the analysis of a set of equations that have enormous practical significance

Measurement of W + W - production in pp collisions at √s=7 TeV with the ATLAS detector and limits on anomalous WWZ and WWγ couplings

Abstract: This paper presents a measurement of the W+W- production cross section in pp collisions at root s = 7 TeV. The leptonic decay channels are analyzed using data corresponding to an integrated luminosity of 4: 6 fb(-1) collected with the ATLAS detector at the Large Hadron Collider. The W+W- production cross section sigma(pp -> W+W- + X) is measured to be 51.9 +/- 2.0(stat) +/- 3.9(syst) +/- 2.0(lumi) pb, compatible with the Standard Model prediction of 44.7(-1.9)(+2.1) pb. A measurement of the normalized fiducial cross section as a function of the leading lepton transverse momentum is also presented. The reconstructed transverse momentum distribution of the leading lepton is used to extract limits on anomalous WWZ and WW gamma couplings.

The VIMOS Public Extragalactic Redshift Survey (VIPERS). Full spectroscopic data and auxiliary information release (PDR-2)

Abstract: We present the full public data release (PDR-2) of the VIMOS Public Extragalactic Redshift Survey (VIPERS), performed at the ESO VLT. We release redshifts, spectra, CFHTLS magnitudes and ancillary information (as masks and weights) for a complete sample of 86 775 galaxies (plus 4732 other objects, including stars and serendipitous galaxies); we also include their full photometrically-selected parent catalogue. The sample is magnitude limited to i AB ≤ 22.5, with an additional colour-colour pre-selection devised as to exclude galaxies at z h 3 Mpc-3 . The total area spanned by the final data set is ≃ 23.5 deg2 , corresponding to 288 VIMOS fields with marginal overlaps, split over two regions within the CFHTLS-Wide W1 and W4 equatorial fields (at RA ≃ 2 and ≃ 22 h, respectively). Spectra were observed at a resolution R = 220, covering a wavelength range 5500−9500 A. Data reduction and redshift measurements were performed through a fully automated pipeline; all redshift determinations were then visually validated and assigned a quality flag. Measurements with a quality flag ≥ 2 are shown to have a confidence level of 96% or larger and make up 88% of all measured galaxy redshifts (76 552 out of 86 775), constituting the VIPERS prime catalogue for statistical investigations. For this sample the rms redshift error, estimated using repeated measurements of about 3000 galaxies, is found to be σ z = 0.00054(1 + z ). All data are available at http://vipers.inaf.it and on the ESO Archive.

Analysis of country-wide internet outages caused by censorship

Abstract: In the first months of 2011, Internet communications were disrupted in several North African countries in response to civilian protests and threats of civil war In this paper, we analyze episodes of these disruptions in two countries: Egypt and Libya Our analysis relies on multiple sources of large-scale data already available to academic researchers: BGP interdomain routing control plane data, unsolicited data plane traffic to unassigned address space, active macroscopic traceroute measurements, RIR delegation files, and MaxMind's geolocation database We used the latter two data sets to determine which IP address ranges were allocated to entities within each country, and then mapped these IP addresses of interest to BGP-announced address ranges (prefixes) and origin autonomous systems (ASs) using publicly available BGP data repositories in the US and Europe We then analyzed observable activity related to these sets of prefixes and ASs throughout the censorship episodes Using both control plane and data plane data sets in combination allowed us to narrow down which forms of Internet access disruption were implemented in a given region over time Among other insights, we detected what we believe were Libya's attempts to test firewall-based blocking before they executed more aggressive BGP-based disconnection Our methodology could be used, and automated, to detect outages or similar macroscopically disruptive events in other geographic or topological regions