3,760 research outputs found
A time-domain veto for binary inspirals search
We describe a test to distinguish between actual gravitational waves from binary inspiral and false noise triggers. The test operates in the time domain, and considers the time evolution of the correlator and its statistical distribution. It should distinguish true versus noisy events with the same signal-to-noise ratio and chi-square frequency distribution. A similar test has been applied to S1 LIGO data
Adaptive spectral identification techniques in presence of undetected non linearities
The standard procedure for detection of gravitational wave coalescing
binaries signals is based on Wiener filtering with an appropriate bank of
template filters. This is the optimal procedure in the hypothesis of addictive
Gaussian and stationary noise. We study the possibility of improving the
detection efficiency with a class of adaptive spectral identification
techniques, analyzing their effect in presence of non stationarities and
undetected non linearities in the noiseComment: 4 pages, 2 figures, uses ws-procs9x6.cls Proceedings of "Non linear
physics: theory and experiment. II", Gallipoli (Lecce), 200
Low-latency analysis pipeline for compact binary coalescences in the advanced gravitational wave detector era
The multi-band template analysis (MBTA) pipeline is a low-latency coincident
analysis pipeline for the detection of gravitational waves (GWs) from compact
binary coalescences. MBTA runs with a low computational cost, and can identify
candidate GW events online with a sub-minute latency. The low computational
running cost of MBTA also makes it useful for data quality studies. Events
detected by MBTA online can be used to alert astronomical partners for
electromagnetic follow-up. We outline the current status of MBTA and give
details of recent pipeline upgrades and validation tests that were performed in
preparation for the first advanced detector observing period. The MBTA pipeline
is ready for the outset of the advanced detector era and the exciting prospects
it will bring.Comment: 18 pages, 10 figure
Principali tecniche e strumenti per il rilievo tridimensionale in ambito archeologico
The increase of 3D acquisition and modeling techniques applied to archeology is due principally to (i) their capacity to survey archeological artifacts with high precision and a non-contact approach and (ii) the possibility to create 3D digital models useful for data analysis, simulation and preservation. These benefits in terms of knowledge oblige the contemporary archaeologist to acquire a better understanding of 3D acquisition and modeling principles and practice. This evidence arises from the necessity of adopting a common language for experts in 3D data management and archaeologists with the principal aim being the understanding of each other’s requirements and sharing of the purposes of the project. In this article the authors propose a concise but exhaustive explanation of the working principles of active and passive 3D acquisition techniques. For each one a description of instruments and methodologies is developed, pointing out pros and cons of every technique. In conclusion, a sensor fusion approach is presented as an interesting solution to increase the instrument performances while obtaining at the same time a quality improvement of 3D acquisition and modeling results. A final multi-resolution application about Pompeii Forum 3D modeling follows and closes the article
Principali tecniche e strumenti per il rilievo tridimensionale in ambito archeologico
The increase of 3D acquisition and modeling techniques applied to archeology is due principally to (i) their capacity to survey archeological artifacts with high precision and a non-contact approach and (ii) the possibility to create 3D digital models useful for data analysis, simulation and preservation. These benefits in terms of knowledge oblige the contemporary archaeologist to acquire a better understanding of 3D acquisition and modeling principles and practice. This evidence arises from the necessity of adopting a common language for experts in 3D data management and archaeologists with the principal aim being the understanding of each other’s requirements and sharing of the purposes of the project. In this article the authors propose a concise but exhaustive explanation of the working principles of active and passive 3D acquisition techniques. For each one a description of instruments and methodologies is developed, pointing out pros and cons of every technique. In conclusion, a sensor fusion approach is presented as an interesting solution to increase the instrument performances while obtaining at the same time a quality improvement of 3D acquisition and modeling results. A final multi-resolution application about Pompeii Forum 3D modeling follows and closes the article
Observation of charge-density-wave excitations in manganites
In the optical conductivity of four different manganites with commensurate
charge order (CO), strong peaks appear in the meV range below the ordering
temperature T_{CO}. They are similar to those reported for one-dimensional
charge density waves (CDW) and are assigned to pinned phasons. The peaks and
their overtones allow one to obtain, for La{1-n/8}Ca{n/8}$MnO{3} with n = 5, 6,
the electron-phonon coupling, the effective mass of the CO system, and its
contribution to the dielectric constant. These results support a description of
the CO in La-Ca manganites in terms of moderately weak-coupling and of the CDW
theory.Comment: To be published on Phys. Rev. Let
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