274 research outputs found
Localization of short duration gravitational-wave transients with the early advanced LIGO and Virgo detectors
The Laser Interferometer Gravitational wave Observatory (LIGO) and Virgo,
advanced ground-based gravitational-wave detectors, will begin collecting
science data in 2015. With first detections expected to follow, it is important
to quantify how well generic gravitational-wave transients can be localized on
the sky. This is crucial for correctly identifying electromagnetic counterparts
as well as understanding gravitational-wave physics and source populations. We
present a study of sky localization capabilities for two search and parameter
estimation algorithms: \emph{coherent WaveBurst}, a constrained likelihood
algorithm operating in close to real-time, and \emph{LALInferenceBurst}, a
Markov chain Monte Carlo parameter estimation algorithm developed to recover
generic transient signals with latency of a few hours. Furthermore, we focus on
the first few years of the advanced detector era, when we expect to only have
two (2015) and later three (2016) operational detectors, all below design
sensitivity. These detector configurations can produce significantly different
sky localizations, which we quantify in detail. We observe a clear improvement
in localization of the average detected signal when progressing from
two-detector to three-detector networks, as expected. Although localization
depends on the waveform morphology, approximately 50% of detected signals would
be imaged after observing 100-200 deg in 2015 and 60-110 deg in 2016,
although knowledge of the waveform can reduce this to as little as 22 deg.
This is the first comprehensive study on sky localization capabilities for
generic transients of the early network of advanced LIGO and Virgo detectors,
including the early LIGO-only two-detector configuration.Comment: 18 pages, 8 figure
Regulation of Information Relations in CustomsAuthorities of the Russian Federation (on the Example of Measures for EnsuringInformation Security and Protection of Intellectual Property)
The article discusses some of the aspects that define the role and place of legal regulation of information relations arising in the sphere of ensuring information security of the customs bodies of the Russian Federation
About Legal Responsibility for Violations of the Low of the Russian Federation in the Field of Information Security: Problems and Prospects
The author analyses the legislation of the Russian Federation and foreign countries which establishes legal responsibility for irregularities in the field of information security. The research of crime dynamics has been done, the problems have been revealed and the prospects for the legislation development have been outlined. The article contains theoretical materials by such authors as D. N. Bakhrakh, I. L. Bachilo, T. A. Kukharenko, dissertation research А. А. Streltsov, as well as background information S. I. Ozhegov and N. Yu Shvedova
Polycrystalline Cubic Boron Nitride (PCBN) Tool Life and Wear in Turning of Amorphous-Crystalline Iron-Based Coatings
The paper presents PCBN-Ciborit cutting tools life and wear test results. The effects of the machining regime when turning amorphous-crystalline Fe80B20 and Fe79Cr16B5 coating systems applied to conventional workpiece materials were assessed. It has been shown that the observed tool wear mechanisms are complex in their character and are dominated by abrasive-mechanical, adhesive and chemical effects in the cutting zone. Under changing turning conditions tool life is affected by the structural-phase composition and by the non-homogeneous structure of the coating. Specifically, when turning gas-flame coatings deposited with a Fe80B20 electrode and electro-arc coatings with a Fe79Cr16B5 electrode the lowest wear and the highest tool life was achieved at cutting speeds of nu = 1.1 to 1.2 m/s and a back rake angle of gamma = -10 degrees It has been demonstrated that a change of the back rake angle from gamma = 0 to -10 degrees does not have a great effect on tool life contraty to the case with gamma = -20 degrees
Radio Astronomical Monitoring in Virtual Environment
We present StarWatch, our application for real-time analysis of radio astronomical data in Virtual Environment. Serving as an interface to radio astronomical databases or being applied to live data from the radio telescopes, the application supports various data filters measuring signal-to-noise ratio (SNR), Doppler's drift, degree of signal localization on celestial sphere and other useful tools for signal extraction and classification. Originally designed for the database of narrow band signals from SETI Institute (setilive.org), the application has been recently extended for the detection of wide band periodic signals, necessary for the search of pulsars. We will also address the detection of week signals possessing arbitrary waveforms and present several data filters suitable for this purpose
Radio Astronomical Monitoring in Virtual Environment
AbstractWe present StarWatch, our application for real-time analysis of radio astronomical data in Virtual Environment. Serving as an interface to radio astronomical databases or being applied to live data from the radio telescopes, the application supports various data filters measuring signal-to-noise ratio (SNR), Doppler's drift, degree of signal localization on celestial sphere and other useful tools for signal extraction and classification. Originally designed for the database of narrow band signals from SETI Institute (setilive.org), the application has been recently extended for the detection of wide band periodic signals, necessary for the search of pulsars. We will also address the detection of week signals possessing arbitrary waveforms and present several data filters suitable for this purpose
Sensitivity Comparison of Searches for Binary Black Hole Coalescences with Ground-based Gravitational-Wave Detectors
Searches for gravitational-wave transients from binary black hole
coalescences typically rely on one of two approaches: matched filtering with
templates and morphology-independent excess power searches. Multiple
algorithmic implementations in the analysis of data from the first generation
of ground-based gravitational wave interferometers have used different
strategies for the suppression of non-Gaussian noise transients, and targeted
different regions of the binary black hole parameter space. In this paper we
compare the sensitivity of three such algorithms: matched filtering with full
coalescence templates, matched filtering with ringdown templates and a
morphology-independent excess power search. The comparison is performed at a
fixed false alarm rate and relies on Monte-carlo simulations of binary black
hole coalescences for spinning, non-precessing systems with total mass 25-350
solar mass, which covers the parameter space of stellar mass and intermediate
mass black hole binaries. We find that in the mass range of 25 -100 solar mass
the sensitive distance of the search, marginalized over source parameters, is
best with matched filtering to full waveform templates, to within 10 percent at
a false alarm rate of 3 events per year. In the mass range of 100-350 solar
mass, the same comparison favors the morphology-independent excess power search
to within 20 percent. The dependence on mass and spin is also explored.Comment: 11 pages, 2 tables, 25 figure
Regression of Environmental Noise in LIGO Data
We address the problem of noise regression in the output of
gravitational-wave (GW) interferometers, using data from the physical
environmental monitors (PEM). The objective of the regression analysis is to
predict environmental noise in the gravitational-wave channel from the PEM
measurements. One of the most promising regression method is based on the
construction of Wiener-Kolmogorov filters. Using this method, the seismic noise
cancellation from the LIGO GW channel has already been performed. In the
presented approach the Wiener-Kolmogorov method has been extended,
incorporating banks of Wiener filters in the time-frequency domain,
multi-channel analysis and regulation schemes, which greatly enhance the
versatility of the regression analysis. Also we presents the first results on
regression of the bi-coherent noise in the LIGO data
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