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Sample records for integral burst alert

  1. Swift Burst Alert Telescope (BAT) Instrument Response

    International Nuclear Information System (INIS)

    Parsons, A.; Barthelmy, S.; Cummings, J.; Gehrels, N.; Hullinger, D.; Krimm, H.; Markwardt, C.; Tueller, J.; Fenimore, E.; Palmer, D.; Sato, G.; Takahashi, T.; Nakazawa, K.; Okada, Y.; Takahashi, H.; Suzuki, M.; Tashiro, M.

    2004-01-01

    The Burst Alert Telescope (BAT), a large coded aperture instrument with a wide field-of-view (FOV), provides the gamma-ray burst triggers and locations for the Swift Gamma-Ray Burst Explorer. In addition to providing this imaging information, BAT will perform a 15 keV - 150 keV all-sky hard x-ray survey based on the serendipitous pointings resulting from the study of gamma-ray bursts, and will also monitor the sky for transient hard x-ray sources. For BAT to provide spectral and photometric information for the gamma-ray bursts, the transient sources and the all-sky survey, the BAT instrument response must be determined to an increasingly greater accuracy. This paper describes the spectral models and the ground calibration experiments used to determine the BAT response to an accuracy suitable for gamma-ray burst studies

  2. Burst Alert Robotic Telescope and Optical Afterglows

    Czech Academy of Sciences Publication Activity Database

    Nekola, Martin; Hudec, René; Jelínek, M.; Kubánek, P.; Polášek, Cyril; Štrobl, Jan

    2009-01-01

    Roč. 18, 3/4 (2009), s. 374-378 ISSN 1392-0049. [INTEGRAL/BART workshop 2009. Karlovy Vary, 26.03.2009-29.03.2009] R&D Projects: GA ČR GA205/08/1207 Grant - others:ESA(XE) ESA-PECS project No. 98023; Spanish Ministry of Education and Science(ES) AP2003-1407 Institutional research plan: CEZ:AV0Z10030501 Keywords : gamma rays bursts, * observations * robotic telescopes Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.032, year: 2009

  3. Testing and Performance of UFFO Burst Alert & Trigger Telescope

    DEFF Research Database (Denmark)

    Rípa, Jakub; Bin Kim, Min; Lee, Jik

    2014-01-01

    The Ultra-Fast Flash Observatory pathfinder (UFFO-p) is a new space mission dedicated to detect Gamma-Ray Bursts (GRBs) and rapidly follow their afterglows in order to provide early optical/ultraviolet measurements. A GRB location is determined in a few seconds by the UFFO Burst Alert & Trigger t...

  4. Swift Burst Alert Telescope Data Products and Analysis Software

    International Nuclear Information System (INIS)

    Krimm, Hans A.; Barbier, Louis M.; Barthelmy, Scott D.; Cummings, Jay R.; Gehrels, Neil; Parsons, Ann M.; Tueller, Jack; Fenimore, Edward E.; Palmer, David M.; Hullinger, Derek D.; Markwardt, Craig B.

    2004-01-01

    The Burst Alert Telescope (BAT) on the Swift gamma-ray burst mission serves as the GRB trigger for Swift as well as a sensitive imaging telescope for the energy range of 15-150 keV. All BAT data products will be available to the astronomical community along with a complete set of analysis tools. Gamma-ray burst data products include rapid discovery messages delivered immediately via the GRB Coordinates Network, and event-by-event data from which light curves and spectra of the burst are generated. During nominal operations, the instrument provides accumulated survey histograms with 5-minute time sampling and appropriate energy resolution. These survey accumulations are analyzed in a pipeline to detect new sources and derive light curves of known sources. The 5-minute surveys will also be combined to produce the BAT all sky hard X-ray survey. In addition, the instrument accumulates high time resolution light curves of the brightest BAT sources in multiple energy bands, which are merged into a source light curve database on the ground. The BAT science data products and analysis tools will be described in this paper

  5. The Second SWIFT Burst Alert Telescope (BAT) Gamma-Ray Burst Catalog

    Science.gov (United States)

    Sakamoto, T.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.; Fenimore, E. E.; Gehrels, N.; Krimm, H. A.; Markwardt, C. B.; Palmer, D. M.; Parsons, A. M.; hide

    2012-01-01

    We present the second Swift Burst Alert Telescope (BAT) catalog of gamma-ray bursts. (GRBs), which contains 476 bursts detected by the BAT between 2004 December 19 and 2009 December 21. This catalog (hereafter the BAT2 catalog) presents burst trigger time, location, 90% error radius, duration, fluence, peak flux, time-averaged spectral parameters and time-resolved spectral parameters measured by the BAT. In the correlation study of various observed parameters extracted from the BAT prompt emission data, we distinguish among long-duration GRBs (L-GRBs), short-duration GRBs (S-GRBs), and short-duration GRBs with extended emission (S-GRBs with E.E.) to investigate differences in the prompt emission properties. The fraction of L-GRBs, S-GRBs and S-GRBs with E.E. in the catalog are 89%, 8% and 2% respectively. We compare the BAT prompt emission properties with the BATSE, BeppoSAX and HETE-2 GRB samples.. We also correlate the observed prompt emission properties with the redshifts for the GRBs with known redshift. The BAT T(sub 90) and T(sub 50) durations peak at 70 s and 30 s, respectively. We confirm that the spectra of the BAT S-GRBs are generally harder than those of the L-GRBs.

  6. Design and implementation of the UFFO burst alert and trigger telescope

    DEFF Research Database (Denmark)

    Kim, J.E.; Ahmad, S.; Barrillon, P.

    2012-01-01

    The Ultra Fast Flash Observatory pathfinder (UFFO-p) is a telescope system designed for the detection of the prompt optical/UV photons from Gamma-Ray Bursts (GRBs), and it will be launched onboard the Lomonosov spacecraft in 2012. The UFFO-p consists of two instruments: the UFFO Burst Alert and T...

  7. THE THIRD SWIFT BURST ALERT TELESCOPE GAMMA-RAY BURST CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Lien, Amy; Baumgartner, Wayne H.; Cannizzo, John K.; Collins, Nicholas R.; Krimm, Hans A.; Troja, Eleonora [Center for Research and Exploration in Space Science and Technology (CRESST) and NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sakamoto, Takanori [Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa 252-5258 (Japan); Barthelmy, Scott D.; Cummings, Jay R.; Gehrels, Neil; Markwardt, Craig B. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Chen, Kevin [Department of Physics, University of California, Berkeley, 366 LeConte Hall MC 7300, Berkeley, CA 9472 (United States); Palmer, David M.; Ukwatta, T. N. [Space and Remote Sensing (ISR-2), Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Stamatikos, Michael [Department of Physics, Department of Astronomy and Center for Cosmology and AstroParticle Physics, Ohio State University, Columbus, OH 43210 (United States)

    2016-09-20

    To date, the Burst Alert Telescope (BAT) onboard Swift has detected ∼1000 gamma-ray bursts (GRBs), of which ∼360 GRBs have redshift measurements, ranging from z = 0.03 to z = 9.38. We present the analyses of the BAT-detected GRBs for the past ∼11 years up through GRB 151027B. We report summaries of both the temporal and spectral analyses of the GRB characteristics using event data (i.e., data for each photon within approximately 250 s before and 950 s after the BAT trigger time), and discuss the instrumental sensitivity and selection effects of GRB detections. We also explore the GRB properties with redshift when possible. The result summaries and data products are available at http://swift.gsfc.nasa.gov/results/batgrbcat/index.html. In addition, we perform searches for GRB emissions before or after the event data using the BAT survey data. We estimate the false detection rate to be only one false detection in this sample. There are 15 ultra-long GRBs (∼2% of the BAT GRBs) in this search with confirmed emission beyond ∼1000 s of event data, and only two GRBs (GRB 100316D and GRB 101024A) with detections in the survey data prior to the starting of event data.

  8. THE SECOND SWIFT BURST ALERT TELESCOPE GAMMA-RAY BURST CATALOG

    International Nuclear Information System (INIS)

    Sakamoto, T.; Baumgartner, W. H.; Cummings, J. R.; Krimm, H. A.; Barthelmy, S. D.; Gehrels, N.; Markwardt, C. B.; Parsons, A. M.; Tueller, J.; Fenimore, E. E.; Palmer, D. M.; Sato, G.; Stamatikos, M.; Ukwatta, T. N.; Zhang, B.

    2011-01-01

    We present the second Swift Burst Alert Telescope (BAT) catalog of gamma-ray bursts (GRBs), which contains 476 bursts detected by the BAT between 2004 December 19 and 2009 December 21. This catalog (hereafter the BAT2 catalog) presents burst trigger time, location, 90% error radius, duration, fluence, peak flux, time-averaged spectral parameters, and time-resolved spectral parameters measured by the BAT. In the correlation study of various observed parameters extracted from the BAT prompt emission data, we distinguish among long-duration GRBs (L-GRBs), short-duration GRBs (S-GRBs), and short-duration GRBs with extended emission (S-GRBs with E.E.) to investigate differences in the prompt emission properties. The fraction of L-GRBs, S-GRBs, and S-GRBs with E.E. in the catalog are 89%, 8%, and 2%, respectively. We compare the BAT prompt emission properties with the BATSE, BeppoSAX, and HETE-2 GRB samples. We also correlate the observed prompt emission properties with the redshifts for the GRBs with known redshift. The BAT T 90 and T 50 durations peak at 70 s and 30 s, respectively. We confirm that the spectra of the BAT S-GRBs are generally harder than those of the L-GRBs. The time-averaged spectra of the BAT S-GRBs with E.E. are similar to those of the L-GRBs. Whereas, the spectra of the initial short spikes of the S-GRBs with E.E. are similar to those of the S-GRBs. We show that the BAT GRB samples are significantly softer than the BATSE bright GRBs and that the time-averaged E obs peak of the BAT GRBs peaks at 80 keV, which is significantly lower energy than those of the BATSE sample, which peak at 320 keV. The time-averaged spectral properties of the BAT GRB sample are similar to those of the HETE-2 GRB samples. By time-resolved spectral analysis, we find that only 10% of the BAT observed photon indices are outside the allowed region of the synchrotron shock model. We see no obvious observed trend in the BAT T 90 and the observed spectra with redshifts. The T 90

  9. INTEGRAL and XMM-Newton observations of the weak gamma-ray burst GRB 030227

    DEFF Research Database (Denmark)

    Mereghetti, S.; Gotz, D.; Tiengo, A.

    2003-01-01

    We present International Gamma-Ray Astrophysical Laboratory ( INTEGRAL) and XMM-Newton observations of the prompt gamma-ray emission and the X-ray afterglow of GRB 030227, the first gamma-ray burst for which the quick localization obtained with the INTEGRAL Burst Alert System has led...

  10. Comparison cosmic ray irradiation simulation and particle beam test on UFFO Burst Alert & Trigger telescope(UBAT) detectors

    DEFF Research Database (Denmark)

    Jeong, H. M.; Jeong, S.; Kim, M. B.

    2017-01-01

    Ultra-Fast Flash Observatory pathfinder(UFFO-p) was launched onboard Lomonosov on 28th of April, 2016, and now is under various types of calibration for detection of Gamma Ray Bursts (GRBs). Since last September UFFO-p has taken X-ray data in space with UFFO Burst Alert &Trigger telescope (UBAT),...

  11. Prospects for rapid gamma-ray burst localization with INTEGRAL

    DEFF Research Database (Denmark)

    Mereghetti, S.; Jennings, D.; Pedersen, H.

    1999-01-01

    The SPI and IRIS instruments on INTEGRAL will detect greater than or similar to 1 GRB/month within their large fields of view. The accuracy of localization with IBIS will be a few arcminutes, hence adequate for follow-up studies at large, ground-based telescopes. We report on the current studies ...... and simulation activities aimed at designing at the ISDC an effective INTEGRAL Burst Alert System (IBAS) aisle to automatically distribute the positions of GRBs within a few tens of seconds from the event occurrence....

  12. DO THE FERMI GAMMA-RAY BURST MONITOR AND SWIFT BURST ALERT TELESCOPE SEE THE SAME SHORT GAMMA-RAY BURSTS?

    International Nuclear Information System (INIS)

    Burns, Eric; Briggs, Michael S.; Connaughton, Valerie; Zhang, Bin-Bin; Lien, Amy; Goldstein, Adam; Pelassa, Veronique; Troja, Eleonora

    2016-01-01

    Compact binary system mergers are expected to generate gravitational radiation detectable by ground-based interferometers. A subset of these, the merger of a neutron star with another neutron star or a black hole, are also the most popular model for the production of short gamma-ray bursts (GRBs). The Swift Burst Alert Telescope (BAT) and the Fermi Gamma-ray Burst Monitor (GBM) trigger on short GRBs (SGRBs) at rates that reflect their relative sky exposures, with the BAT detecting 10 per year compared to about 45 for GBM. We examine the SGRB populations detected by Swift BAT and Fermi GBM. We find that the Swift BAT triggers on weaker SGRBs than Fermi GBM, providing they occur close to the center of the BAT field of view, and that the Fermi GBM SGRB detection threshold remains flatter across its field of view. Overall, these effects combine to give the instruments the same average sensitivity, and account for the SGRBs that trigger one instrument but not the other. We do not find any evidence that the BAT and GBM are detecting significantly different populations of SGRBs. Both instruments can detect untriggered SGRBs using ground searches seeded with time and position. The detection of SGRBs below the on-board triggering sensitivities of Swift BAT and Fermi GBM increases the possibility of detecting and localizing the electromagnetic counterparts of gravitational wave (GW) events seen by the new generation of GW detectors

  13. DO THE FERMI GAMMA-RAY BURST MONITOR AND SWIFT BURST ALERT TELESCOPE SEE THE SAME SHORT GAMMA-RAY BURSTS?

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Eric; Briggs, Michael S. [University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Connaughton, Valerie [Universities Space Research Association, Science and Technology Institute, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Zhang, Bin-Bin [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Lien, Amy [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Goldstein, Adam [NASA Postdoctoral Program, Space Science Office, VP62, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Pelassa, Veronique [Smithsonian Astrophysical Observatory, P.O. Box 97, Amado, AZ 85645 (United States); Troja, Eleonora, E-mail: eb0016@uah.edu [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-02-20

    Compact binary system mergers are expected to generate gravitational radiation detectable by ground-based interferometers. A subset of these, the merger of a neutron star with another neutron star or a black hole, are also the most popular model for the production of short gamma-ray bursts (GRBs). The Swift Burst Alert Telescope (BAT) and the Fermi Gamma-ray Burst Monitor (GBM) trigger on short GRBs (SGRBs) at rates that reflect their relative sky exposures, with the BAT detecting 10 per year compared to about 45 for GBM. We examine the SGRB populations detected by Swift BAT and Fermi GBM. We find that the Swift BAT triggers on weaker SGRBs than Fermi GBM, providing they occur close to the center of the BAT field of view, and that the Fermi GBM SGRB detection threshold remains flatter across its field of view. Overall, these effects combine to give the instruments the same average sensitivity, and account for the SGRBs that trigger one instrument but not the other. We do not find any evidence that the BAT and GBM are detecting significantly different populations of SGRBs. Both instruments can detect untriggered SGRBs using ground searches seeded with time and position. The detection of SGRBs below the on-board triggering sensitivities of Swift BAT and Fermi GBM increases the possibility of detecting and localizing the electromagnetic counterparts of gravitational wave (GW) events seen by the new generation of GW detectors.

  14. Development of an integrated campus security alerting system ...

    African Journals Online (AJOL)

    This work presents an integrated alerting system which uses both the Internet Protocol (IP) cameras and micro-switches for monitoring security situations thereby providing an immediate alerting signal to the security personnel. The system has the input unit, processing unit, control unit and the power supply unit as its ...

  15. A photospheric radius-expansion burst observed from XTE J1701-407 by INTEGRAL: an update on distance

    Science.gov (United States)

    Chenevez, J.; Falanga, M.; Brandt, S.; Galloway, D.; Kuulkers, E.; Cumming, A.; Schatz, H.; Lund, N.; Ooestbroek, T.; Ferrigno, C.

    2010-08-01

    On 2010-08-22 00:56:19 the INTEGRAL Burst Alert System (IBAS) triggered on an event ((GCN 11132, Gotz & Ferrigno, 2009) from the known burst source XTE J1701-407 (Falanga et al., A&A 496, 333, 2009; Linares et al., MNRAS 392, L11, 2009) during an observation of the field around SNR RXJ1713.7-3946 (PI R. Terrier). As part of our monitoring of long thermonuclear X-ray bursts with INTEGRAL, we have analysed both the JEM-X and ISGRI data covering this event, and we identify it as another type I (thermonuclear) X-ray burst.

  16. Probing the Cosmic Gamma-Ray Burst Rate with Trigger Simulations of the Swift Burst Alert Telescope

    Science.gov (United States)

    Lien, Amy; Sakamoto, Takanori; Gehrels, Neil; Palmer, David M.; Barthelmy, Scott D.; Graziani, Carlo; Cannizzo, John K.

    2013-01-01

    The gamma-ray burst (GRB) rate is essential for revealing the connection between GRBs, supernovae and stellar evolution. Additionally, the GRB rate at high redshift provides a strong probe of star formation history in the early universe. While hundreds of GRBs are observed by Swift, it remains difficult to determine the intrinsic GRB rate due to the complex trigger algorithm of Swift. Current studies of the GRB rate usually approximate the Swift trigger algorithm by a single detection threshold. However, unlike the previously own GRB instruments, Swift has over 500 trigger criteria based on photon count rate and additional image threshold for localization. To investigate possible systematic biases and explore the intrinsic GRB properties, we develop a program that is capable of simulating all the rate trigger criteria and mimicking the image threshold. Our simulations show that adopting the complex trigger algorithm of Swift increases the detection rate of dim bursts. As a result, our simulations suggest bursts need to be dimmer than previously expected to avoid over-producing the number of detections and to match with Swift observations. Moreover, our results indicate that these dim bursts are more likely to be high redshift events than low-luminosity GRBs. This would imply an even higher cosmic GRB rate at large redshifts than previous expectations based on star-formation rate measurements, unless other factors, such as the luminosity evolution, are taken into account. The GRB rate from our best result gives a total number of 4568 +825 -1429 GRBs per year that are beamed toward us in the whole universe.

  17. A photospheric radius-expansion burst observed from XTE J1701-407 by INTEGRAL: an update on distance

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Maurizio, F.; Brandt, Søren Kristian

    2010-01-01

    On 2010-08-22 00:56:19 the INTEGRAL Burst Alert System (IBAS) triggered on an event ((GCN 11132, Gotz & Ferrigno, 2009) from the known burst source XTE J1701-407 (Falanga et al., A&A 496, 333, 2009; Linares et al., MNRAS 392, L11, 2009) during an observation of the field around SNR RXJ1713.7-3946...... (Falanga et al., 2009). Light curves of the burst can be obtained from the following adress: ftp://ftp.spacecenter.dk/pub/Jerome/Science/XTE_J1701-407/...

  18. INTEGRAL monitoring of unusually long X-ray bursts

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Falanga, M.; Kuulkers, E.

    2008-01-01

    of exceptional burst events lasting more than ~10 minutes. Half of the dozen so-called intermediate long bursts registered so far have been observed by INTEGRAL. The goal is to derive a comprehensive picture of the relationship between the nuclear ignition processes and the accretion states of the system leading...... up to such long bursts. Depending on the composition of the accreted material, these bursts may be explained by either the unstable burning of a large pile of mixed hydrogen and helium, or the ignition of a thick pure helium layer. Intermediate long bursts are particularly expected to occur at very...

  19. QKD-Based Secured Burst Integrity Design for Optical Burst Switched Networks

    Science.gov (United States)

    Balamurugan, A. M.; Sivasubramanian, A.; Parvathavarthini, B.

    2016-03-01

    The field of optical transmission has undergone numerous advancements and is still being researched mainly due to the fact that optical data transmission can be done at enormous speeds. It is quite evident that people prefer optical communication when it comes to large amount of data involving its transmission. The concept of switching in networks has matured enormously with several researches, architecture to implement and methods starting with Optical circuit switching to Optical Burst Switching. Optical burst switching is regarded as viable solution for switching bursts over networks but has several security vulnerabilities. However, this work exploited the security issues associated with Optical Burst Switching with respect to integrity of burst. This proposed Quantum Key based Secure Hash Algorithm (QKBSHA-512) with enhanced compression function design provides better avalanche effect over the conventional integrity algorithms.

  20. ESA's Integral detects closest cosmic gamma-ray burst

    Science.gov (United States)

    2004-08-01

    should emit similar amounts of gamma-ray energy. The fraction of it detected at Earth should then depend on the 'width' (opening angle) and orientation of the beam as well as on the distance. The energy received should be larger when the beam is narrow or points towards us and smaller when the beam is broad or points away from us. New data collected with ESA's high energy observatories, Integral and XMM-Newton, now show that this picture is not so clear-cut and that the amount of energy emitted by GRBs can vary significantly. "The idea that all GRBs spit out the same amount of gamma rays, or that they are 'standard candles' as we call them, is simply ruled out by the new data," said Dr Sergey Sazonov, from the Space Research Institute of the Russian Academy of Sciences, Moscow (Russia) and the Max-Planck Institute for Astrophysics, Garching near Munich (Germany). Sazonov and an international team of researchers studied the GRB detected by Integral on 3 December 2003 and given the code-name of GRB 031203. Within a record 18 seconds of the burst, the Integral Burst Alert System had pinpointed the approximate position of GRB 031203 in the sky and sent the information to a network of observatories around the world. A few hours later one of them, ESA's XMM-Newton, determined a much more precise position for GRB 031203 and detected a rapidly fading X-ray source, which was subsequently seen by radio and optical telescopes on the ground. This wealth of data allowed astronomers to determine that GRB 031203 went off in a galaxy less than 1300 million light years away, making it the closest GRB ever observed. Even so, the way in which GRB 031203 dimmed with time and the distribution of its energy were not different from those of distant GRBs. Then, scientists started to realise that the concept of the 'standard candle' may not hold. "Being so close should make GRB 031203 appear very bright, but the amount of gamma-rays measured by Integral is about one thousand times less than what

  1. Long X-ray burst monitoring with INTEGRAL

    DEFF Research Database (Denmark)

    X-ray bursts are thermonuclear explosions on the surface of accreting neutron stars in low mass X-ray binary systems. In the frame of the INTEGRAL observational Key Programme over the Galactic Center a good number of the known X-ray bursters are frequently being monitored. An international...... collaboration lead by the JEM-X team at the Danish National Space Center has proposed to exploit the improved sensitivity of the INTEGRAL instruments to investigate the observational properties and physics up to high energies of exceptional burst events lasting between a few tens of minutes and several hours....... Of special interest are low luminosity bursting sources that exhibit X-ray bursts of very different durations allowing to study the transition from a hydrogen-rich bursting regime to a pure helium regime and from helium burning to carbon burning. I will present results obtained from INTEGRAL archive data...

  2. The 60 Month All-Sky Burst Alert Telescope Survey of Active Galactic Nucleus and the Anisotropy of Nearby AGNs

    Science.gov (United States)

    Ajello, M.; Alexander, D. M.; Greiner, J.; Madejeski, G. M.; Gehrels, N.; Burlon, D.

    2014-01-01

    Surveys above 10 keV represent one of the best resources to provide an unbiased census of the population of active galactic nuclei (AGNs). We present the results of 60 months of observation of the hard X-ray sky with Swift/Burst Alert Telescope (BAT). In this time frame, BAT-detected (in the 15-55 keV band) 720 sources in an all-sky survey of which 428 are associated with AGNs, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of approx. 2 larger over similarly complete sets of AGNs. Our sample contains (at least) 15 bona fide Compton-thick AGNs and 3 likely candidates. Compton-thick AGNs represent approx. 5% of AGN samples detected above 15 keV. We use the BAT data set to refine the determination of the log N-log S of AGNs which is extremely important, now that NuSTAR prepares for launch, toward assessing the AGN contribution to the cosmic X-ray background. We show that the log N-log S of AGNs selected above 10 keV is now established to approx. 10% precision. We derive the luminosity function of Compton-thick AGNs and measure a space density of 7.9(+4.1/-2.9)× 10(exp -5)/cubic Mpc for objects with a de-absorbed luminosity larger than 2 × 10(exp 42) erg / s. As the BAT AGNs are all mostly local, they allow us to investigate the spatial distribution of AGNs in the nearby universe regardless of absorption. We find concentrations of AGNs that coincide spatially with the largest congregations of matter in the local (much < 85 Mpc) universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions..

  3. The Swift Burst Alert Telescope Detected Seyfert 1 Galaxies: X-Ray Broadband Properties and Warm Absorbers

    Science.gov (United States)

    Winter, Lisa M.; Veilleux, Sylvain; McKernan, Barry; Kallman, T.

    2012-01-01

    We present results from an analysis of the broadband, 0.3-195 keV, X-ray spectra of 48 Seyfert 1-1.5 sources detected in the very hard X-rays with the Swift Burst Alert Telescope (BAT). This sample is selected in an all-sky survey conducted in the 14-195 keV band. Therefore, our sources are largely unbiased toward both obscuration and host galaxy properties. Our detailed and uniform model fits to Suzaku/BAT and XMM-Newton/BAT spectra include the neutral absorption, direct power-law, reflected emission, soft excess, warm absorption, and narrow Fe I K[alpha] emission properties for the entire sample. We significantly detect O VII and O VIII edges in 52% of our sample. The strength of these detections is strongly correlated with the neutral column density measured in the spectrum. Among the strongest detections, X-ray grating and UV observations, where available, indicate outflowing material. The ionized column densities of sources with O VII and O VIII detections are clustered in a narrow range with Nwarm [approx] 1021 cm-2, while sources without strong detections have column densities of ionized gas an order of magnitude lower. Therefore, we note that sources without strong detections likely have warm ionized outflows present but at low column densities that are not easily probed with current X-ray observations. Sources with strong complex absorption have a strong soft excess, which may or may not be due to difficulties in modeling the complex spectra of these sources. Still, the detection of a flat [Gamma] [approx] 1 and a strong soft excess may allow us to infer the presence of strong absorption in low signal-to-noise active galactic nucleus spectra. Additionally, we include a useful correction from the Swift BAT luminosity to bolometric luminosity, based on a comparison of our spectral fitting results with published spectral energy distribution fits from 33 of our sources.

  4. Alertness Modulates Conflict Adaptation and Feature Integration in an Opposite Way

    Science.gov (United States)

    Chen, Jia; Huang, Xiting; Chen, Antao

    2013-01-01

    Previous studies show that the congruency sequence effect can result from both the conflict adaptation effect (CAE) and feature integration effect which can be observed as the repetition priming effect (RPE) and feature overlap effect (FOE) depending on different experimental conditions. Evidence from neuroimaging studies suggests that a close correlation exists between the neural mechanisms of alertness-related modulations and the congruency sequence effect. However, little is known about whether and how alertness mediates the congruency sequence effect. In Experiment 1, the Attentional Networks Test (ANT) and a modified flanker task were used to evaluate whether the alertness of the attentional functions had a correlation with the CAE and RPE. In Experimental 2, the ANT and another modified flanker task were used to investigate whether alertness of the attentional functions correlate with the CAE and FOE. In Experiment 1, through the correlative analysis, we found a significant positive correlation between alertness and the CAE, and a negative correlation between the alertness and the RPE. Moreover, a significant negative correlation existed between CAE and RPE. In Experiment 2, we found a marginally significant negative correlation between the CAE and the RPE, but the correlation between alertness and FOE, CAE and FOE was not significant. These results suggest that alertness can modulate conflict adaptation and feature integration in an opposite way. Participants at the high alerting level group may tend to use the top-down cognitive processing strategy, whereas participants at the low alerting level group tend to use the bottom-up processing strategy. PMID:24250824

  5. Alertness modulates conflict adaptation and feature integration in an opposite way.

    Directory of Open Access Journals (Sweden)

    Peiduo Liu

    Full Text Available Previous studies show that the congruency sequence effect can result from both the conflict adaptation effect (CAE and feature integration effect which can be observed as the repetition priming effect (RPE and feature overlap effect (FOE depending on different experimental conditions. Evidence from neuroimaging studies suggests that a close correlation exists between the neural mechanisms of alertness-related modulations and the congruency sequence effect. However, little is known about whether and how alertness mediates the congruency sequence effect. In Experiment 1, the Attentional Networks Test (ANT and a modified flanker task were used to evaluate whether the alertness of the attentional functions had a correlation with the CAE and RPE. In Experimental 2, the ANT and another modified flanker task were used to investigate whether alertness of the attentional functions correlate with the CAE and FOE. In Experiment 1, through the correlative analysis, we found a significant positive correlation between alertness and the CAE, and a negative correlation between the alertness and the RPE. Moreover, a significant negative correlation existed between CAE and RPE. In Experiment 2, we found a marginally significant negative correlation between the CAE and the RPE, but the correlation between alertness and FOE, CAE and FOE was not significant. These results suggest that alertness can modulate conflict adaptation and feature integration in an opposite way. Participants at the high alerting level group may tend to use the top-down cognitive processing strategy, whereas participants at the low alerting level group tend to use the bottom-up processing strategy.

  6. development of an integrated campus security alerting system

    African Journals Online (AJOL)

    user

    Keywords: Campus Security, Microcontroller, Internet Protocol Camera, Integrated system, Micro-switches. 1. INTRODUCTION .... personnel can fall back to the information captured/stored ...... Adetoba A. O. "Design and Construction of a Car.

  7. INTEGRAL monitoring of unusually long X-ray bursts

    DEFF Research Database (Denmark)

    of the accreted material, these bursts may be explained by either the unstable burning of a large pile of mixed hydrogen and helium, or the ignition of a thick pure helium layer. Long duration bursts are particularly expected at very low accretion rates and make possible to study the transition from a hydrogen......Thermonuclear bursts on the surface of accreting neutron stars in low mass X-ray binaries have been studied for many years and have in a few cases confirmed theoretical models of nuclear ignition and burning mechanisms. The large majority of X-ray bursts last less than 100s. A good number......-rich bursting regime to a pure helium regime. Moreover, a handful of long bursts have shown, before the extended decay phase, an initial spike similar to a normal short X-ray burst. Such twofold bursts might be a sort of link between short and super-bursts, where the premature ignition of a carbon layer could...

  8. The sample of INTEGRAL SPI-ACS gamma-ray bursts

    International Nuclear Information System (INIS)

    Rau, A.; Kienlin, A. von; Licht, G.G.; Hurley, K.

    2005-01-01

    The anti-coincidence system of the spectrometer on board INTEGRAL is operated as a nearly omni directional gamma-ray burst detector above ∼ 75 KeV. During the elapsed mission time 324 burst candidates were detected. As part of the 3rd Interplanetary Network of gamma-ray detectors the cosmic origin of 115 burst was confirmed. Here we present a preliminary analysis of the SPI-ACS gamma-ray burst sample. In particular we discuss the origin of a significant population of short events (duration < 0.2 s) and a possible method for a flux calibration of the data

  9. Rock Burst Monitoring by Integrated Microseismic and Electromagnetic Radiation Methods

    Science.gov (United States)

    Li, Xuelong; Wang, Enyuan; Li, Zhonghui; Liu, Zhentang; Song, Dazhao; Qiu, Liming

    2016-11-01

    For this study, microseismic (MS) and electromagnetic radiation (EMR) monitoring systems were installed in a coal mine to monitor rock bursts. The MS system monitors coal or rock mass ruptures in the whole mine, whereas the EMR equipment monitors the coal or rock stress in a small area. By analysing the MS energy, number of MS events, and EMR intensity with respect to rock bursts, it has been shown that the energy and number of MS events present a "quiet period" 1-3 days before the rock burst. The data also show that the EMR intensity reaches a peak before the rock burst and this EMR intensity peak generally corresponds to the MS "quiet period". There is a positive correlation between stress and EMR intensity. Buckling failure of coal or rock depends on the rheological properties and occurs after the peak stress in the high-stress concentration areas in deep mines. The MS "quiet period" before the rock burst is caused by the heterogeneity of the coal and rock structures, the transfer of high stress into internal areas, locked patches, and self-organized criticality near the stress peak. This study increases our understanding of coal and rock instability in deep mines. Combining MS and EMR to monitor rock burst could improve prediction accuracy.

  10. Two-phase X-ray burst from GX 3+1 observed by INTEGRAL

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Falanga, M.F.; Brandt, Søren

    2006-01-01

    INTEGRAL detected on August 31, 2004, an unusual thermonuclear X-ray burst from the low-mass X-ray binary GX 3 3+1. Its duration was 30 min, which is between the normal burst durations for this source (less than or similar to 10 s) and the superburst observed in 1998 ( several hours). We see...... emission up to 30 keV energy during the first few seconds of the burst where the bolometric peak luminosity approaches the Eddington limit. This peculiar burst is characterized by two distinct phases: an initial short spike of similar to 6 s consistent with being similar to a normal type I X-ray burst...... in the present case); and 3) limited carbon burning at an unusually shallow depth triggered by unstable helium ignition. Though none of these provide a satisfactory description of this uncommon event, the former one seems the most probable....

  11. MID-INFRARED PROPERTIES OF THE SWIFT BURST ALERT TELESCOPE ACTIVE GALACTIC NUCLEI SAMPLE OF THE LOCAL UNIVERSE. I. EMISSION-LINE DIAGNOSTICS

    International Nuclear Information System (INIS)

    Weaver, K. A.; Melendez, M.; Mushotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth, E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.; Winter, L. M.; Armus, L.

    2010-01-01

    We compare mid-infrared emission-line properties from high-resolution Spitzer spectra of a hard X-ray (14-195 keV) selected sample of nearby (z < 0.05) active galactic nuclei (AGNs) detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity distribution for the mid-infrared emission lines, [O IV] 25.89 μm, [Ne II] 12.81 μm, [Ne III] 15.56 μm, and [Ne V] 14.32/24.32 μm, and hard X-ray continuum show no differences between Seyfert 1 and Seyfert 2 populations; however, six newly discovered BAT AGNs are under-luminous in [O IV], most likely the result of dust extinction in the host galaxy. The overall tightness of the mid-infrared correlations and BAT fluxes and luminosities suggests that the emission lines primarily arise in gas ionized by the AGNs. We also compare the mid-infrared emission lines in the BAT AGNs with those from published studies of ULIRGs, Palomar-Green quasars, star-forming galaxies, and LINERs. We find that the BAT AGN sample falls into a distinctive region when comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] ratios. These line ratios are lower in sources that have been previously classified in the mid-infrared/optical as AGNs than those found for the BAT AGNs, suggesting that, in our X-ray selected sample, the AGNs represent the main contribution to the observed line emission. These ratios represent a new emission line diagnostic for distinguishing between AGNs and star-forming galaxies.

  12. Diverse Long-term Variability of Five Candidate High-mass X-Ray Binaries from Swift Burst Alert Telescope Observations

    Energy Technology Data Exchange (ETDEWEB)

    Corbet, Robin H. D. [University of Maryland, Baltimore County, MD 21250 (United States); Coley, Joel B. [NASA Postdoctoral Program, and Astroparticle Physics Laboratory, Code 661 NASA Goddard Space Flight Center, Greenbelt Road, MD 20771 (United States); Krimm, Hans A., E-mail: corbet@umbc.edu [Universities Space Research Association, 10211 Wincopin Circle, Suite 500, Columbia, MD 21044 (United States)

    2017-09-10

    We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s pulsations were previously found with XMM-Newton . Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was previously proposed to be a Be star system with an orbital period of ∼30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although they might be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be star mass donors.

  13. 75 FR 26269 - Draft Programmatic Environmental Assessment for the Integrated Public Alert and Warning Program's...

    Science.gov (United States)

    2010-05-11

    ... system to alert and warn the American people in situations of war, terrorist attack, natural disaster, or... Order 13407, Public Alert and Warning System, by providing robust and survivable power generation, fuel... of interoperable public alert and warning systems, to identify technologies and standards that...

  14. Performance evaluation of a burst-mode EDFA in an optical packet and circuit integrated network.

    Science.gov (United States)

    Shiraiwa, Masaki; Awaji, Yoshinari; Furukawa, Hideaki; Shinada, Satoshi; Puttnam, Benjamin J; Wada, Naoya

    2013-12-30

    We experimentally investigate the performance of burst-mode EDFA in an optical packet and circuit integrated system. In such networks, packets and light paths can be dynamically assigned to the same fibers, resulting in gain transients in EDFAs throughout the network that can limit network performance. Here, we compare the performance of a 'burst-mode' EDFA (BM-EDFA), employing transient suppression techniques and optical feedback, with conventional EDFAs, and those using automatic gain control and previous BM-EDFA implementations. We first measure gain transients and other impairments in a simplified set-up before making frame error-rate measurements in a network demonstration.

  15. Does integrating nonurgent, clinically significant radiology alerts within the electronic health record impact closed-loop communication and follow-up?

    Science.gov (United States)

    O'Connor, Stacy D; Dalal, Anuj K; Sahni, V Anik; Lacson, Ronilda; Khorasani, Ramin

    2016-03-01

    To assess whether integrating critical result management software--Alert Notification of Critical Results (ANCR)--with an electronic health record (EHR)-based results management application impacts closed-loop communication and follow-up of nonurgent, clinically significant radiology results by primary care providers (PCPs). This institutional review board-approved study was conducted at a large academic medical center. Postintervention, PCPs could acknowledge nonurgent, clinically significant ANCR-generated alerts ("alerts") within ANCR or the EHR. Primary outcome was the proportion of alerts acknowledged via EHR over a 24-month postintervention. Chart abstractions for a random sample of alerts 12 months preintervention and 24 months postintervention were reviewed, and the follow-up rate of actionable alerts (eg, performing follow-up imaging, administering antibiotics) was estimated. Pre- and postintervention rates were compared using the Fisher exact test. Postintervention follow-up rate was compared for EHR-acknowledged alerts vs ANCR. Five thousand nine hundred and thirty-one alerts were acknowledged by 171 PCPs, with 100% acknowledgement (consistent with expected ANCR functionality). PCPs acknowledged 16% (688 of 4428) of postintervention alerts in the EHR, with the remaining in ANCR. Follow-up was documented for 85 of 90 (94%; 95% CI, 88%-98%) preintervention and 79 of 84 (94%; 95% CI, 87%-97%) postintervention alerts (P > .99). Postintervention, 11 of 14 (79%; 95% CI, 52%-92%) alerts were acknowledged via EHR and 68 of 70 (97%; 95% CI, 90%-99%) in ANCR had follow-up (P = .03). Integrating ANCR and EHR provides an additional workflow for acknowledging nonurgent, clinically significant results without significant change in rates of closed-loop communication or follow-up of alerts. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Intermediate-duration burst from AX J1754.2-2754 detected by INTEGRAL

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Beeck, Sarah; Brandt, Søren

    2017-01-01

    any emission from the source, and we infer a 3-σ upper limit on the persistent flux of 10-10 erg/cm2/s between 3-40 keV. We tentatively interpret this as an intermediate-duration burst (see, e.g., Cumming et al., ApJ 646, 429, 2006) with a superexpansion phase (see in 't Zand & Weinberg, A&A 520, 81...... is not detected outside the burst interval, with a 3-σ upper limit of 4 mCrab in the JEM-X range, and the burst is only marginally detected by the IBIS/ISGRI instrument in the 20-40 keV energy band. Previous observations regularly taken since February 13, when the region became visible by INTEGRAL, do not reveal....... At this distance, the upper-limit on the persistent emission translates to a 3-40 keV luminosity of 5.2×1035 erg/s, which is consistent with previous values measured when the source was observed in outburst with Chandra (Jonker & Keek 2008, ATel #1643) and Swift (Maccarone et al. 2012, ATel #4109). INTEGRAL...

  17. Reduced multimodal integration of memory features following continuous theta burst stimulation of angular gyrus.

    Science.gov (United States)

    Yazar, Yasemin; Bergström, Zara M; Simons, Jon S

    Lesions of the angular gyrus (AnG) region of human parietal cortex do not cause amnesia, but appear to be associated with reduction in the ability to consciously experience the reliving of previous events. We used continuous theta burst stimulation to test the hypothesis that the cognitive mechanism implicated in this memory deficit might be the integration of retrieved sensory event features into a coherent multimodal memory representation. Healthy volunteers received stimulation to AnG or a vertex control site after studying stimuli that each comprised a visual object embedded in a scene, with the name of the object presented auditorily. Participants were then asked to make memory judgments about the studied stimuli that involved recollection of single event features (visual or auditory), or required integration of event features within the same modality, or across modalities. Participants' ability to retrieve context features from across multiple modalities was significantly reduced after AnG stimulation compared to stimulation of the vertex. This effect was observed only for the integration of cross-modal context features but not for integration of features within the same modality, and could not be accounted for by task difficulty as performance was matched across integration conditions following vertex stimulation. These results support the hypothesis that AnG is necessary for the multimodal integration of distributed cortical episodic features into a unified conscious representation that enables the experience of remembering. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. INTEGRAL detects an X-ray burst from SAX J1747.0-2853 with no detectable persistent emission

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Brandt, Søren Kristian; Kuulkers, Erik

    2009-01-01

    A new season of observations for the INTEGRAL Galactic Bulge monitoring (see ATel #438) has started on 2009 Feb. 21st. During the latest observation between 2009 Feb 25 13:21 and 17:02 (UT) a type I X-ray burst from SAX J1747.0-2853 (1A 1743-288, aka GX .2-0.2) was detected by JEM-X at UT 14:50:5...

  19. The Design and Implementation of a Prototype Web-Portal for the Integrated Mobile Alerting System (IMAS)

    National Research Council Canada - National Science Library

    Le, Phong D; Hsu, Michael

    2006-01-01

    .... It demonstrates that a web-portal written in PHP script supported by a relational database is a good configuration for IMAS. Additionally, a proof of concept system that converts messages into disseminated mobile alerts is presented. This thesis marks the founding steps in developing the IMAS.

  20. VERY HIGH ENERGY OBSERVATIONS OF GAMMA-RAY BURSTS WITH STACEE

    International Nuclear Information System (INIS)

    Jarvis, A.; Ong, R. A.; Ball, J.; Carson, J. E.; Zweerink, J.; Williams, D. A.; Aune, T.; Covault, C. E.; Driscoll, D. D.; Fortin, P.; Mukherjee, R.; Gingrich, D. M.; Hanna, D. S.; Kildea, J.; Lindner, T.; Mueller, C.; Ragan, K.

    2010-01-01

    Gamma-ray bursts (GRBs) are the most powerful explosions known in the universe. Sensitive measurements of the high-energy spectra of GRBs can place important constraints on the burst environments and radiation processes. Until recently, there were no observations during the first few minutes of GRB afterglows in the energy range between 30 GeV and ∼1 TeV. With the launch of the Swift GRB Explorer in late 2004, GRB alerts and localizations within seconds of the bursts became available. The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) was a ground-based, gamma-ray telescope with an energy threshold of ∼150 GeV for sources at zenith. At the time of Swift's launch, STACEE was in a rare position to provide >150 GeV follow-up observations of GRBs as fast as three minutes after the burst alert. In addition, STACEE performed follow-up observations of several GRBs that were localized by the HETE-2 and INTEGRAL satellites. Between 2002 June and 2007 July, STACEE made follow-up observations of 23 GRBs. Upper limits are placed on the high-energy gamma-ray fluxes from 21 of these bursts.

  1. Can past gamma-ray bursts explain both INTEGRAL and ATIC/PAMELA/Fermi anomalies simultaneously?

    International Nuclear Information System (INIS)

    Calvez, Antoine; Kusenko, Alexander

    2010-01-01

    Gamma-ray bursts (GRBs) have been invoked to explain both the 511 keV emission from the Galactic bulge and the high-energy positron excess inferred from the ATIC, PAMELA, and Fermi data. While independent explanations can be responsible for these phenomena, we explore the possibility of their common GRB-related origin by modeling the GRB distribution and estimating the rates. For an expected Milky Way long GRB rate, neither of the two signals is generic; the local excess requires a 2% coincidence while the signal from the Galactic center requires a 20% coincidence with respect to the timing of the latest GRB. The simultaneous explanation requires a 0.4% coincidence. Considering the large number of statistical 'trials' created by multiple searches for new physics, the coincidences of a few percent cannot be dismissed as unlikely. Alternatively, both phenomena can be explained by GRB if the Galactic rate is higher than expected. We also show that a similar result is difficult to obtain assuming a simplified short GRB distribution.

  2. Integration of Dust Prediction Systems and Vegetation Phenology to Track Pollen for Asthma Alerts in Public Health

    Science.gov (United States)

    Luvall, Jeffrey C.; Sprigg, W. A.; Huete, A.; Nickovic, S.; Pejanovic, G.; Levetin, E.; Van de water, P.; Myers, O.; Budge, A. M.; Krapfl, H.; hide

    2011-01-01

    greenness, dry-down and pollen release. Ground based observational records of pollen release timing and quantities will be used as verification. Techniques developed using MOD09 surface reflectance products will be directly applicable to the next generation sensors such as VIIRS. The resulting deterministic model for predicting and simulating pollen emission and downwind concentration to study details of phenology and meteorology and their dependencies. This information will be used to support the Centers for Disease Control and Prevention (CDC)'s National Environmental Public Health Tracking Program (EPHT) and the State of New Mexico environmental public health decision support for asthma and allergies alerts

  3. A repeating fast radio burst.

    Science.gov (United States)

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  4. Alert Exchange Process Protocol

    Science.gov (United States)

    Groen, Frank

    2015-01-01

    The National Aeronautics and Space Administration of the United States of America (NASA), and the European Space Agency (ESA), and the Japanese Aerospace Exploration Agency (JAXA), acknowledging that NASA, ESA and JAXA have a mutual interest in exchanging Alerts and Alert Status Lists to enhance the information base for each system participant while fortifying the general level of cooperation between the policy agreement subscribers, and each Party will exchange Alert listings on regular basis and detailed Alert information on a need to know basis to the extent permitted by law.

  5. INTEGRAL/JEM-X detection of a type-I X-ray burst from MAXI J1421-613

    DEFF Research Database (Denmark)

    Bozzo, E.; Bazzano, A.; Kuulkers, Erik

    2014-01-01

    . The onset of the burst occurred on 2014 January 10 at 19:05 UTC, and the total event as observed by JEM-X lasted for about 20 s (3-25 keV). The average spectrum of the burst could be roughly described by using a black-body model with temperature kT~1 keV. The corresponding flux was 1.7E-9 erg/cm^2/s...... (translating into a luminosity of 1.3E37 erg/s at 8 kpc; 3-10 keV). We estimated a persistent flux outside the burst of 7E-10 erg/cm^2/s (3-25 keV). This detection reveals that MAXI J1421-613 is a newly discovered X-ray bursting transient source, thus hosting an accreting neutron star....

  6. BURST AND OUTBURST CHARACTERISTICS OF MAGNETAR 4U 0142+61

    Energy Technology Data Exchange (ETDEWEB)

    Göğüş, Ersin; Chakraborty, Manoneeta; Kaneko, Yuki [Sabancı University, Orhanlı-Tuzla, İstanbul 34956 (Turkey); Lin, Lin [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Roberts, Oliver J. [School of Physics, University College Dublin, Stillorgan Road, Belfield, Dublin 4 (Ireland); Gill, Ramandeep; Granot, Jonathan [Department of Natural Sciences, The Open University of Israel, 1 University Road, P.O. Box 808, Ranana 43537 (Israel); Horst, Alexander J. van der; Kouveliotou, Chryssa; Younes, George [Department of Physics, The George Washington University, Washington, DC 20052 (United States); Watts, Anna L. [Anton Pannekoek Institute for Astronomy, University of Amsterdam, Postbus 94249, NL-1090 GE Amsterdam (Netherlands); Baring, Matthew [Department of Physics and Astronomy, Rice University, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Huppenkothen, Daniela [Center for Data Science, New York University, 726 Broadway, 7th Floor, NY 10003 (United States)

    2017-01-20

    We have compiled the most comprehensive burst sample from magnetar 4U 0142+61, comprising 27 bursts from its three burst-active episodes in 2011, 2012 and the latest one in 2015 observed with Swift /Burst Alert Telescope and Fermi /Gamma-ray Burst Monitor. Bursts from 4U 0142+61 morphologically resemble typical short bursts from other magnetars. However, 4U 0142+61 bursts are less energetic compared to the bulk of magnetar bursts. We uncovered an extended tail emission following a burst on 2015 February 28, with a thermal nature, cooling over a timescale of several minutes. During this tail emission, we also uncovered pulse peak phase aligned X-ray bursts, which could originate from the same underlying mechanism as that of the extended burst tail, or an associated and spatially coincident but different mechanism.

  7. FAKE STAR FORMATION BURSTS: BLUE HORIZONTAL BRANCH STARS MASQUERADE AS YOUNG MASSIVE STARS IN OPTICAL INTEGRATED LIGHT SPECTROSCOPY

    International Nuclear Information System (INIS)

    Ocvirk, P.

    2010-01-01

    Model color-magnitude diagrams of low-metallicity globular clusters (GCs) usually show a deficit of hot evolved stars with respect to observations. We investigate quantitatively the impact of such modeling inaccuracies on the significance of star formation history reconstructions obtained from optical integrated spectra. To do so, we analyze the sample of spectra of galactic globular clusters of Schiavon et al. with STECKMAP (Ocvirk et al.), and the stellar population models of Vazdekis et al. and Bruzual and Charlot, and focus on the reconstructed stellar age distributions. First, we show that background/foreground contamination correlates with E(B - V), which allows us to define a clean subsample of uncontaminated GCs, on the basis of an E(B - V) filtering. We then identify a 'confusion zone' where fake young bursts of star formation pop up in the star formation history although the observed population is genuinely old. These artifacts appear for 70%-100% of cases depending on the population model used, and contribute up to 12% of the light in the optical. Their correlation with the horizontal branch (HB) ratio indicates that the confusion is driven by HB morphology: red HB clusters are well fitted by old stellar population models while those with a blue HB require an additional hot component. The confusion zone extends over [Fe/H] = [ - 2, - 1.2], although we lack the data to probe extreme high and low metallicity regimes. As a consequence, any young starburst superimposed on an old stellar population in this metallicity range could be regarded as a modeling artifact, if it weighs less than 12% of the optical light, and if no emission lines typical of an H II region are present. This work also provides a practical method for constraining HB morphology from high signal to noise integrated light spectroscopy in the optical. This will allow post-asymptotic giant branch evolution studies in a range of environments and at distances where resolving stellar populations

  8. The INTEGRAL science data centre (ISDC)

    DEFF Research Database (Denmark)

    Courvoisier, T.J.L.; Walter, Rasmus; Beckmann, V.

    2003-01-01

    The INTEGRAL Science Data Centre (ISDC) provides the INTEGRAL data and means to analyse them to the scientific community. The ISDC runs a gamma ray burst alert system that provides the position of gamma ray bursts on the sky within seconds to the community. It operates a quick-look analysis...... of the data within few hours that detects new and unexpected sources as well as it monitors the instruments. The ISDC processes the data through a standard analysis the results of which are provided to the observers together with their data....

  9. Alerts and Advisories

    Science.gov (United States)

    ... in Select Bottles of Muscle Strength and Nighttime Recovery Product Because of Undeclared Milk Allergen on The Label ( FDA 04/06/18 ) Independent Nutrition, Inc Issues Allergy Alert On Undeclared Milk in ...

  10. Medical alert bracelet (image)

    Science.gov (United States)

    People with diabetes should always wear a medical alert bracelet or necklace that emergency medical workers will be able to find. Medical identification products can help ensure proper treatment in an ...

  11. DDBS DB Alert

    Data.gov (United States)

    Social Security Administration — Data store used by the database area for monitoring of database objects. It is used to generate alerts that the DBAs investigate to determine if any action needs to...

  12. Lower alert rates by clustering of related drug interaction alerts

    NARCIS (Netherlands)

    Heringa, M.; Siderius, Hidde; Schreudering, A.; De Smet, Peter Agm; Bouvy, M.L.

    OBJECTIVE: We aimed to investigate to what extent clustering of related drug interaction alerts (drug-drug and drug-disease interaction alerts) would decrease the alert rate in clinical decision support systems (CDSSs). METHODS: We conducted a retrospective analysis of drug interaction alerts

  13. Project "Hypertension Alert."

    Science.gov (United States)

    Sailors, Emma Lou

    1983-01-01

    "Hypertension Alert," a 1979-80 blood pressure screening-awareness project of the Yonkers, New York Public Schools, is described. Data is analyzed in tables for ethnic composition, and range of blood pressure readings for the high school, junior high school, and elementary school students tested. (Author/JMK)

  14. Sensor Alerting Capability

    Science.gov (United States)

    Henriksson, Jakob; Bermudez, Luis; Satapathy, Goutam

    2013-04-01

    There is a large amount of sensor data generated today by various sensors, from in-situ buoys to mobile underwater gliders. Providing sensor data to the users through standardized services, language and data model is the promise of OGC's Sensor Web Enablement (SWE) initiative. As the amount of data grows it is becoming difficult for data providers, planners and managers to ensure reliability of data and services and to monitor critical data changes. Intelligent Automation Inc. (IAI) is developing a net-centric alerting capability to address these issues. The capability is built on Sensor Observation Services (SOSs), which is used to collect and monitor sensor data. The alerts can be configured at the service level and at the sensor data level. For example it can alert for irregular data delivery events or a geo-temporal statistic of sensor data crossing a preset threshold. The capability provides multiple delivery mechanisms and protocols, including traditional techniques such as email and RSS. With this capability decision makers can monitor their assets and data streams, correct failures or be alerted about a coming phenomena.

  15. Swift: A gamma ray burst MIDEX

    International Nuclear Information System (INIS)

    Barthelmy, Scott

    2001-01-01

    Swift is a first of its kind multiwavelength transient observatory for gamma-ray burst astronomy. It has the optimum capabilities for the next breakthroughs in determining the origin of gamma-ray bursts and their afterglows as well as using bursts to probe the early Universe. Swift will also perform the first sensitive hard X-ray survey of the sky. The mission is being developed by an international collaboration and consists of three instruments, the Burst Alert Telescope (BAT), the X-ray Telescope (XRT), and the Ultraviolet and Optical Telescope (UVOT). The BAT, a wide-field gamma-ray detector, will detect ∼1 gamma-ray burst per day with a sensitivity 5 times that of BATSE. The sensitive narrow-field XRT and UVOT will be autonomously slewed to the burst location in 20 to 70 seconds to determine 0.3-5.0 arcsec positions and perform optical, UV, and X-ray spectrophotometry. On-board measurements of redshift will also be done for hundreds of bursts. Swift will incorporate superb, low-cost instruments using existing flight-spare hardware and designs. Strong education/public outreach and follow-up programs will help to engage the public and astronomical community. Swift has been selected by NASA for development and launch in late 2003

  16. ToxAlerts: a Web server of structural alerts for toxic chemicals and compounds with potential adverse reactions.

    Science.gov (United States)

    Sushko, Iurii; Salmina, Elena; Potemkin, Vladimir A; Poda, Gennadiy; Tetko, Igor V

    2012-08-27

    The article presents a Web-based platform for collecting and storing toxicological structural alerts from literature and for virtual screening of chemical libraries to flag potentially toxic chemicals and compounds that can cause adverse side effects. An alert is uniquely identified by a SMARTS template, a toxicological endpoint, and a publication where the alert was described. Additionally, the system allows storing complementary information such as name, comments, and mechanism of action, as well as other data. Most importantly, the platform can be easily used for fast virtual screening of large chemical datasets, focused libraries, or newly designed compounds against the toxicological alerts, providing a detailed profile of the chemicals grouped by structural alerts and endpoints. Such a facility can be used for decision making regarding whether a compound should be tested experimentally, validated with available QSAR models, or eliminated from consideration altogether. The alert-based screening can also be helpful for an easier interpretation of more complex QSAR models. The system is publicly accessible and tightly integrated with the Online Chemical Modeling Environment (OCHEM, http://ochem.eu). The system is open and expandable: any registered OCHEM user can introduce new alerts, browse, edit alerts introduced by other users, and virtually screen his/her data sets against all or selected alerts. The user sets being passed through the structural alerts can be used at OCHEM for other typical tasks: exporting in a wide variety of formats, development of QSAR models, additional filtering by other criteria, etc. The database already contains almost 600 structural alerts for such endpoints as mutagenicity, carcinogenicity, skin sensitization, compounds that undergo metabolic activation, and compounds that form reactive metabolites and, thus, can cause adverse reactions. The ToxAlerts platform is accessible on the Web at http://ochem.eu/alerts, and it is constantly

  17. 75 FR 67201 - Flightcrew Alerting

    Science.gov (United States)

    2010-11-02

    ... two different senses for warning and caution alerts. Identifying an alert and determining corrective... pilots to the urgency that should be associated with the meaning of these colors, which could increase... consistent and standardized color usage is desirable to ensure the pilot understands the urgency of an alert...

  18. Swift pointing and gravitational-wave bursts from gamma-ray burst events

    International Nuclear Information System (INIS)

    Sutton, Patrick J; Finn, Lee Samuel; Krishnan, Badri

    2003-01-01

    The currently accepted model for gamma-ray burst phenomena involves the violent formation of a rapidly rotating solar-mass black hole. Gravitational waves should be associated with the black-hole formation, and their detection would permit this model to be tested. Even upper limits on the gravitational-wave strength associated with gamma-ray bursts could constrain the gamma-ray burst model. This requires joint observations of gamma-ray burst events with gravitational and gamma-ray detectors. Here we examine how the quality of an upper limit on the gravitational-wave strength associated with gamma-ray bursts depends on the relative orientation of the gamma-ray-burst and gravitational-wave detectors, and apply our results to the particular case of the Swift Burst-Alert Telescope (BAT) and the LIGO gravitational-wave detectors. A result of this investigation is a science-based 'figure of merit' that can be used, together with other mission constraints, to optimize the pointing of the Swift telescope for the detection of gravitational waves associated with gamma-ray bursts

  19. Geo-targeted Weather Alerts Coming to Millions of Mobile Devices

    Science.gov (United States)

    Gerber, M.

    2011-12-01

    The Personal Localized Alert Network (PLAN), aka Commercial Mobile Alert System (CMAS), is readying for roll out and will be broadcasting emergency public alerts to millions of cell phones by the middle of 2012. Learn how the National Weather Serivce (NWS) is supplying PLAN with geo-referenced weather alert information in the industry standard Common Alerting Protocol (CAP) format and how you can access this same information for integration with mobile devices, other consumer electronics, and decision support systems. Information will also be provided on the NWS' new collaborative venue that encourages wide participation in the evolution and use of NWS CAP alerts in a variety of applications.

  20. An Integrated WRF-CAMx Modeling Approach for Impact Analysis of Implementing the Emergency PM2.5 Control Measures during Red Alerts in Beijing in December 2015

    Science.gov (United States)

    Jia, J.; Cheng, S.; Lei, L.; Lang, J.

    2017-12-01

    In December 2015, the Beijing-Tianjin-Hebei (BTH) region experienced several episodes of heavy air pollution. Beijing municipal government therefore issued 2 red alerts on December 7 and 19, respectively, and also implemented emergency control measures to alleviate the negative effects of pollution. It is estimated that the heavy pollutions in 2 red alert periods in Beijing were due mainly to the accumulation of air pollutants from local emission sources and the transboundary transport of pollutants from surrounding areas. The collected meteorological and PM2.5 data indicate that the severity of air pollutions were enlarged by the poor meteorological conditions along with lower mixing layer height. In this study, the WRF-CAMx modeling system was utilized not only for analyzing the contributions of PM2.5 from different sources, but also for quantitatively assessing the effects of implementing various emergency control measures on PM2.5 pollution control during the red alert periods. The modeling results show that local emissions were the most dominant contributors (64.8%-83.5%) among all emission sources, while the main external contributions came from the city of Baoding (3.4%-9.3%). In addition, among 5 different emission source categories, coal and traffic were the two dominant contributors to PM2.5 concentration in urban area of Beijing. Then four pollution control scenarios were designed particularly to investigate the effectiveness of the emergency control measures, and the results show that, generally these emergency control measures have positive effects on air pollution reduction. In particular, restrictive measures of traffic volume control and industrial activity shutdown/suspension have been found as the most effective measures in comparison to other emergency control measures. It is recommended that such effective measures should be considered to implement when next time similar heavy air pollutions occur in the city of Beijing.

  1. X-ray bursts observed with JEM-X

    DEFF Research Database (Denmark)

    Brandt, Søren Kristian; Chenevez, Jérôme; Lund, Niels

    2006-01-01

    We report on the search for X-ray bursts in the JEM-X X-ray monitor on INTEGRAL during the first two years of operations. More than 350 bursts from 25 different type-I X-ray burst sources were found.......We report on the search for X-ray bursts in the JEM-X X-ray monitor on INTEGRAL during the first two years of operations. More than 350 bursts from 25 different type-I X-ray burst sources were found....

  2. Observation of early photons from gamma-ray bursts with the Lomonosov / UFFO-pathfinder

    DEFF Research Database (Denmark)

    Jeong, S.; Brandt, Søren; Budtz-Jørgensen, Carl

    2014-01-01

    UFFO-pathfinder is a pioneering space mission to observe the early evolution of Gamma-ray Bursts using a fast slewing strategy. It consists of the Slewing Mirror Telescope, for rapid pointing at UV/optical wavelengths and the UFFO Burst Alert and Trigger Telescope. It has a total weight of ~ 20 k...

  3. Hα Intensity Map of the Repeating Fast Radio Burst FRB 121102 Host Galaxy from Subaru/Kyoto 3DII AO-assisted Optical Integral-field Spectroscopy

    Science.gov (United States)

    Kokubo, Mitsuru; Mitsuda, Kazuma; Sugai, Hajime; Ozaki, Shinobu; Minowa, Yosuke; Hattori, Takashi; Hayano, Yutaka; Matsubayashi, Kazuya; Shimono, Atsushi; Sako, Shigeyuki; Doi, Mamoru

    2017-08-01

    We present the Hα intensity map of the host galaxy of the repeating fast radio burst FRB 121102 at a redshift of z = 0.193 obtained with the AO-assisted Kyoto 3DII optical integral-field unit mounted on the 8.2 m Subaru Telescope. We detected a compact Hα-emitting (I.e., star-forming) region in the galaxy, which has a much smaller angular size (GMOS z\\prime -band image (≃ 1\\buildrel{\\prime\\prime}\\over{.} 4 (4.6 kpc) at FWHM with ellipticity b/a=0.45). The spatial offset between the centroid of the Hα emission region and the position of the radio bursts is 0\\buildrel{\\prime\\prime}\\over{.} 08+/- 0\\buildrel{\\prime\\prime}\\over{.} 02 (0.26 ± 0.07 kpc), indicating that FRB 121102 is located within the star-forming region. This close spatial association of FRB 121102 with the star-forming region is consistent with expectations from young pulsar/magnetar models for FRB 121102, and it also suggests that the observed Hα emission region can make a major dispersion measure (DM) contribution to the host galaxy DM component of FRB 121102. Nevertheless, the largest possible value of the DM contribution from the Hα emission region inferred from our observations still requires a significant amount of ionized baryons in intergalactic medium (IGM; the so-called “missing” baryons) as the DM source of FRB 121102, and we obtain a 90% confidence level lower limit on the cosmic baryon density in the IGM in the low-redshift universe as {{{Ω }}}{IGM}> 0.012. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  4. Inhibition of Pre-Supplementary Motor Area by Continuous Theta Burst Stimulation Leads to More Cautious Decision-making and More Efficient Sensory Evidence Integration.

    Science.gov (United States)

    Tosun, Tuğçe; Berkay, Dilara; Sack, Alexander T; Çakmak, Yusuf Ö; Balcı, Fuat

    2017-08-01

    Decisions are made based on the integration of available evidence. The noise in evidence accumulation leads to a particular speed-accuracy tradeoff in decision-making, which can be modulated and optimized by adaptive decision threshold setting. Given the effect of pre-SMA activity on striatal excitability, we hypothesized that the inhibition of pre-SMA would lead to higher decision thresholds and an increased accuracy bias. We used offline continuous theta burst stimulation to assess the effect of transient inhibition of the right pre-SMA on the decision processes in a free-response two-alternative forced-choice task within the drift diffusion model framework. Participants became more cautious and set higher decision thresholds following right pre-SMA inhibition compared with inhibition of the control site (vertex). Increased decision thresholds were accompanied by an accuracy bias with no effects on post-error choice behavior. Participants also exhibited higher drift rates as a result of pre-SMA inhibition compared with the vertex inhibition. These results, in line with the striatal theory of speed-accuracy tradeoff, provide evidence for the functional role of pre-SMA activity in decision threshold modulation. Our results also suggest that pre-SMA might be a part of the brain network associated with the sensory evidence integration.

  5. Toxic substances alert program

    Science.gov (United States)

    Junod, T. L.

    1978-01-01

    A toxicity profile is provided, of 187 toxic substances procured by NASA Lewis Research Center during a 3 1/2 year period, including 27 known or suspected carcinogens. The goal of the program is to assure that the center's health and safety personnel are aware of the procurement and use of toxic substances and to alert and inform the users of these materials as to the toxic characteristics and the control measures needed to ensure their safe use. The program also provides a continuing record of the toxic substances procured, who procured them, what other toxic substances the user has obtained in the past, and where similar materials have been used elsewhere at the center.

  6. The LOFT Burst Alert System and its Burst On-board Trigger

    DEFF Research Database (Denmark)

    Schanne, Stephane; Götz, Diego; Provost, Herve Le

    2014-01-01

    The ESA M3 candidate mission LOFT (Large Observatory For x-ray Timing) has been designed to study strong gravitational fields by observing compact objects, such as black-hole binaries or neutron-star systems and supermassive black-holes, based on the temporal analysis of photons collected...

  7. Cosmic gamma bursts

    International Nuclear Information System (INIS)

    Ehstulin, I.V.

    1980-01-01

    A brief consideration is being given to the history of cosmic gamma burst discovery and modern knowledge of their properties. The time dependence of gamma bursts is described and their possible sources are discussed

  8. Evaluation of epidemic intelligence systems integrated in the early alerting and reporting project for the detection of A/H5N1 influenza events.

    Directory of Open Access Journals (Sweden)

    Philippe Barboza

    Full Text Available The objective of Web-based expert epidemic intelligence systems is to detect health threats. The Global Health Security Initiative (GHSI Early Alerting and Reporting (EAR project was launched to assess the feasibility and opportunity for pooling epidemic intelligence data from seven expert systems. EAR participants completed a qualitative survey to document epidemic intelligence strategies and to assess perceptions regarding the systems performance. Timeliness and sensitivity were rated highly illustrating the value of the systems for epidemic intelligence. Weaknesses identified included representativeness, completeness and flexibility. These findings were corroborated by the quantitative analysis performed on signals potentially related to influenza A/H5N1 events occurring in March 2010. For the six systems for which this information was available, the detection rate ranged from 31% to 38%, and increased to 72% when considering the virtual combined system. The effective positive predictive values ranged from 3% to 24% and F1-scores ranged from 6% to 27%. System sensitivity ranged from 38% to 72%. An average difference of 23% was observed between the sensitivities calculated for human cases and epizootics, underlining the difficulties in developing an efficient algorithm for a single pathology. However, the sensitivity increased to 93% when the virtual combined system was considered, clearly illustrating complementarities between individual systems. The average delay between the detection of A/H5N1 events by the systems and their official reporting by WHO or OIE was 10.2 days (95% CI: 6.7-13.8. This work illustrates the diversity in implemented epidemic intelligence activities, differences in system's designs, and the potential added values and opportunities for synergy between systems, between users and between systems and users.

  9. Evaluation of Epidemic Intelligence Systems Integrated in the Early Alerting and Reporting Project for the Detection of A/H5N1 Influenza Events

    Science.gov (United States)

    Barboza, Philippe; Vaillant, Laetitia; Mawudeku, Abla; Nelson, Noele P.; Hartley, David M.; Madoff, Lawrence C.; Linge, Jens P.; Collier, Nigel; Brownstein, John S.; Yangarber, Roman; Astagneau, Pascal; on behalf of the Early Alerting, Reporting Project of the Global Health Security Initiative

    2013-01-01

    The objective of Web-based expert epidemic intelligence systems is to detect health threats. The Global Health Security Initiative (GHSI) Early Alerting and Reporting (EAR) project was launched to assess the feasibility and opportunity for pooling epidemic intelligence data from seven expert systems. EAR participants completed a qualitative survey to document epidemic intelligence strategies and to assess perceptions regarding the systems performance. Timeliness and sensitivity were rated highly illustrating the value of the systems for epidemic intelligence. Weaknesses identified included representativeness, completeness and flexibility. These findings were corroborated by the quantitative analysis performed on signals potentially related to influenza A/H5N1 events occurring in March 2010. For the six systems for which this information was available, the detection rate ranged from 31% to 38%, and increased to 72% when considering the virtual combined system. The effective positive predictive values ranged from 3% to 24% and F1-scores ranged from 6% to 27%. System sensitivity ranged from 38% to 72%. An average difference of 23% was observed between the sensitivities calculated for human cases and epizootics, underlining the difficulties in developing an efficient algorithm for a single pathology. However, the sensitivity increased to 93% when the virtual combined system was considered, clearly illustrating complementarities between individual systems. The average delay between the detection of A/H5N1 events by the systems and their official reporting by WHO or OIE was 10.2 days (95% CI: 6.7–13.8). This work illustrates the diversity in implemented epidemic intelligence activities, differences in system's designs, and the potential added values and opportunities for synergy between systems, between users and between systems and users. PMID:23472077

  10. Evaluation of epidemic intelligence systems integrated in the early alerting and reporting project for the detection of A/H5N1 influenza events.

    Science.gov (United States)

    Barboza, Philippe; Vaillant, Laetitia; Mawudeku, Abla; Nelson, Noele P; Hartley, David M; Madoff, Lawrence C; Linge, Jens P; Collier, Nigel; Brownstein, John S; Yangarber, Roman; Astagneau, Pascal

    2013-01-01

    The objective of Web-based expert epidemic intelligence systems is to detect health threats. The Global Health Security Initiative (GHSI) Early Alerting and Reporting (EAR) project was launched to assess the feasibility and opportunity for pooling epidemic intelligence data from seven expert systems. EAR participants completed a qualitative survey to document epidemic intelligence strategies and to assess perceptions regarding the systems performance. Timeliness and sensitivity were rated highly illustrating the value of the systems for epidemic intelligence. Weaknesses identified included representativeness, completeness and flexibility. These findings were corroborated by the quantitative analysis performed on signals potentially related to influenza A/H5N1 events occurring in March 2010. For the six systems for which this information was available, the detection rate ranged from 31% to 38%, and increased to 72% when considering the virtual combined system. The effective positive predictive values ranged from 3% to 24% and F1-scores ranged from 6% to 27%. System sensitivity ranged from 38% to 72%. An average difference of 23% was observed between the sensitivities calculated for human cases and epizootics, underlining the difficulties in developing an efficient algorithm for a single pathology. However, the sensitivity increased to 93% when the virtual combined system was considered, clearly illustrating complementarities between individual systems. The average delay between the detection of A/H5N1 events by the systems and their official reporting by WHO or OIE was 10.2 days (95% CI: 6.7-13.8). This work illustrates the diversity in implemented epidemic intelligence activities, differences in system's designs, and the potential added values and opportunities for synergy between systems, between users and between systems and users.

  11. Localization of Gamma-Ray Bursts Using the Fermi Gamma-Ray Burst Monitor

    NARCIS (Netherlands)

    Connaughton, V.; Briggs, M.S.; Goldstein, A.; Meegan, C.A.; Paciesas, W.S.; Preece, R.D.; Wilson-Hodge, C.A.; Gibby, M.H.; Greiner, J.; Gruber, D.; Jenke, P.; Kippen, R.M.; Pelassa, V.; Xiong, S.; Yu, H-F.; Bhat, P.N.; Burgess, J.M.; Byrne, D.; Fitzpatrick, G.; Foley, S.; Giles, M.M.; Guiriec, S.; van der Horst, A.J.; von Kienlin, A.; McBreen, S.; McGlynn, S.; Tierney, D.; Zhang, B..B.

    2015-01-01

    The Fermi Gamma-ray Burst Monitor (GBM) has detected over 1400 gamma-ray bursts (GRBs) since it began science operations in 2008 July. We use a subset of over 300 GRBs localized by instruments such as Swift, the Fermi Large Area Telescope, INTEGRAL, and MAXI, or through triangulations from the

  12. INTEGRAL and XMM-Newton observations of the low-luminosity and X-ray-rich burst GRB 040223

    Energy Technology Data Exchange (ETDEWEB)

    McGlynn, S.; Hanlon, L.; Foley, S. [College Univ., Dublin (Iran, Islamic Republic of). Department of Experimental Physics; McBreen, S. [ESTEC, Noordwijk (Netherlands). Astrophysics Mission Division, RSSD of ESA; Moran, L. [Southampton Univ., Southampton (United Kingdom). School of Physics and Astronomy; Preece, R. [Alabama Univ., Huntsville (United States); Kienlin, A. von [Max-Planck-Institut fur extraterrestrische Physik, Garching (Germany); Williams, O.R. [SCI-SDG, Noordwijk (Netherlands). Science Operation and Data Systems Division of ESA-ESTEC

    2005-07-15

    GRB 040223 was observed by INTEGRAL and XMM-Newton. GRB 040223 has a peak flux of (1.6{+-}0.13) x 10{sup -8} ergs cm{sup -2} s{sup -1}, a fluence of (4.4{+-}0.4) x 10{sup -7} ergs cm{sup -2} and a steep photon power law index of -2.3{+-}0.2, in the energy range 20-200 keV. The steep spectrum implies it is an X-ray-rich GRB with emission up to 200 keV and E{sub peak} < 20 keV. If E{sub peak} is < 10 keV, it would qualify as an X-ray flash with high-energy emission. The X-ray data has a spectral index {beta}{sub x} = -1.7{+-}0.2, a temporal decay of t{sup -0.75{+-}}{sup 0.25} and a large column density of 1.8 x 10{sup 22} cm{sup -2}. The luminosity-lag relationship was used to obtain a redshift z 0.1{sub -0.02}{sup +0.04}. The isotropic energy radiated in {gamma}-rays and X-ray luminosity after 10 hours are factors of 1000 and 100 less than classical GRBs. GRB 040223 is consistent with the extrapolation of the Amati relation into the region that includes XRF 030723 and XRF 020903.

  13. Education and Training Module in Alertness Management

    Science.gov (United States)

    Mallis, M. M.; Brandt, S. L.; Oyung, R. L.; Reduta, D. D.; Rosekind, M. R.

    2006-01-01

    The education and training module (ETM) in alertness management has now been integrated as part of the training regimen of the Pilot Proficiency Awards Program ("WINGS") of the Federal Aviation Administration. Originated and now maintained current by the Fatigue Countermeasures Group at NASA Ames Research Center, the ETM in Alertness Management is designed to give pilots the benefit of the best and most recent research on the basics of sleep physiology, the causes of fatigue, and strategies for managing alertness during flight operations. The WINGS program is an incentive program that encourages pilots at all licensing levels to participate in recurrent training, upon completion of which distinctive lapel or tie pins (wings) and certificates of completion are awarded. In addition to flight training, all WINGS applicants must attend at least one FAA-sponsored safety seminar, FAA-sanctioned safety seminar, or industry recurrent training program. The Fatigue Countermeasures Group provides an FAA-approved industry recurrent training program through an on-line General Aviation (GA) WINGS ETM in alertness management to satisfy this requirement. Since 1993, the Fatigue Countermeasures Group has translated fatigue and alertness information to operational environments by conducting two-day ETM workshops oriented primarily toward air-carrier operations subject to Part 121 of the Federal Aviation Regulations pertaining to such operations. On the basis of the information presented in the two-day ETM workshops, an ETM was created for GA pilots and was transferred to a Web-based version. To comply with the requirements of the WINGS Program, the original Web-based version has been modified to include hypertext markup language (HTML) content that makes information easily accessible, in-depth testing of alertness-management knowledge, new interactive features, and increased informational resources for GA pilots. Upon successful completion of this training module, a participant

  14. A new CERN Alerter mechanism

    CERN Multimedia

    2007-01-01

    A new version of the CERN Alerter used for sending urgent messages was installed in July on all centrally managed NICE computers. This latest version is based on RSS (Really Simple Syndication) and all alerts are now displayed in an Internet Explorer window (see the picture). You can print the window by right-clicking on the alert background and selecting the Print option from the menu. If the message is not urgent, then the alert will only appear as a "balloon" window the following morning or at next logon. Non-Windows computers can also subscribe to this service by using their browser as an RSS reader (Really Simple Syndication). All recent web browsers can act as RSS readers, including Firefox and Safari. Simply subscribe to the following RSS feed: http://cern.ch/cernalerts/alerts.aspx to see all messages sent by the central services. More information on the CERN Alerter is available at: https://cern.ch/winservices/Help/?kbid=060810. Documentation on reading RSS feeds fr...

  15. A new CERN Alerter mechanism

    CERN Multimedia

    2007-01-01

    A new version of the CERN Alerter used for sending urgent messages was installed in July on all centrally managed NICE computers. This latest version is based on RSS (Really Simple Syndication) and all alerts are now displayed in an Internet Explorer window (see picture). You can print the window by right-clicking on the alert background and selecting the Print option from the menu. If the message is not urgent, the alert will only appear as a "balloon" window the following morning or at next log-on. Non-Windows computers can also subscribe to this service by using their browser as an RSS reader. All recent web browsers can act as RSS readers, including Firefox and Safari. Simply subscribe to the following RSS feed: http://cern.ch/cernalerts/alerts.aspx to see all messages sent by the central services. More information on the CERN Alerter is available at: https://cern.ch/winservices/Help/?kbid=060810. Documentation on reading RSS fee...

  16. The Common Alerting Protocol (CAP) adaption in National Early Warning Alerting Systems of China

    Science.gov (United States)

    Li, Chao

    2017-04-01

    The Common Alerting Protocol (CAP) [1] is an XML-based data format for exchanging public warnings and emergencies between alerting technologies. In China, from local communities to entire nations, there was a patchwork of specialized hazard public alerting systems. And each system was often designed just for certain emergency situations and for certain communications media. Application took place in the NEWAS (National Early Warning Alerting Systems) [2]project where CAP serves as central message to integrate all kind of hazard situations, including the natural calamity, accident disaster, public health emergency , social safety etc. Officially operated on May 2015, NEWAS now has completed docking work with 14 departments including civil administration, safety supervision, forestry, land, water conservancy, earthquake, traffic, meteorology, agriculture, tourism, food and drug supervision, public security and oceanic administration. Thus, several items in CAP has been modified, redefined and extended according to the various grading standards and publishing strategies, as well as the characteristics of Chinese Geocoding. NEWAS successfully delivers information to end users through 4 levels (i.e. State, province, prefecture and county) structure and by various means. [1] CAP, http://www.oasis-emergency.org/cap [2] http://www.12379.cn/

  17. Swift-BAT: The First Year of Gamma-Ray Burst Detections

    Science.gov (United States)

    Krimm, Hans A.

    2006-01-01

    The Burst Alert Telescope (BAT) on the Swift has been detecting gamma-ray bursts (GRBs) since Dec. 17,2004 and automated burst alerts have been distributed since Feb. 14,2005. Since commissioning the BAT has triggered on more than 100 GRBs, nearly all of which have been followed up by the narrow-field instruments on Swift through automatic repointing, and by ground and other satellite telescopes after rapid notification. Within seconds of a trigger the BAT produces and relays to the ground a position good to three arc minutes and a four channel light curve. A full ten minutes of event data follows on subsequent ground station passes. The burst archive has allowed us to determine ensemble burst parameters such as fluence, peak flux and duration. An overview of the properties of BAT bursts and BAT'S performance as a burst monitor will be presented in this talk. BAT is a coded aperture imaging system with a wide (approx.2 sr) field of view consisting of a large coded mask located 1 m above a 5200 cm2 array of 32.768 CdZnTe detectors. All electronics and other hardware systems on the BAT have been operating well since commissioning and there is no sign of any degradation on orbit. The flight and ground software have proven similarly robust and allow the real time localization of all bursts and the rapid derivation of burst light curves, spectra and spectral fits on the ground.

  18. The Drift Burst Hypothesis

    OpenAIRE

    Christensen, Kim; Oomen, Roel; Renò, Roberto

    2016-01-01

    The Drift Burst Hypothesis postulates the existence of short-lived locally explosive trends in the price paths of financial assets. The recent US equity and Treasury flash crashes can be viewed as two high profile manifestations of such dynamics, but we argue that drift bursts of varying magnitude are an expected and regular occurrence in financial markets that can arise through established mechanisms such as feedback trading. At a theoretical level, we show how to build drift bursts into the...

  19. Definition hierarchically integrated of sustainability indicators applied to a system of alert early, in orinoquia and Colombian amazonia; as example: First advance in investigation

    International Nuclear Information System (INIS)

    Bustamante Zamudio, C.; Botero Garcia, R.

    1996-01-01

    It is necessary to establish the approaches that should be involved to the sustainability concept, clearly of agreement with the concrete objectives that it wants to reach (sustainable agriculture, economic, institutional sustainability, politics) as well as to evaluate and to discern the varied interpretations on the methodologies of sustainability determination. The urgency of understanding like an integrality the development problems in the countries of the third world, related with their, agricultural sectors, the state and potentiality of their resources, the exchange relationships in the international market and the raw materials, allow the presentation of different roads for the identification of strategies in the search of the sustainability

  20. Searches for hard X-ray gamma-ray burst afterglows with the BAT on Swift

    International Nuclear Information System (INIS)

    Krimm, Hans A.; Ozawa, Hideki; Weidenspointner, Georg; Barbier, Louis M.; Barthelmy, Scott D.; Gehrels, Neil; Parsons, Ann M.; Tueller, Jack; Eftekharzadeh, Ardeshir; Hullinger, Derek D.; Markwardt, Craig; Fenimore, Edward E.; Palmer, David M.

    2003-01-01

    The Burst Alert Telescope (BAT) on the Swift gamma ray burst mission will continue to observe the fields of all detected gamma-ray bursts for several days after the prompt emission has faded. Utilizing first event-by-event data, then one minute and later five minute survey accumulations, the BAT will be extremely sensitive to the hard X-ray afterglow known to be associated with many bursts. This data will cover the crucial transition of the afterglow from rapid variability to the smoothly decaying power law in time and will extend observations of the tails of individual bursts to longer time scales than have been achievable so far. Since Swift is sensitive to short duration GRBs, we will also be able to determine whether hard X-ray afterglows are associated with short GRBs. The BAT will provide high resolution spectra of burst afterglows, allowing us to study in detail the time evolution of GRB spectra

  1. Gamma Ray Bursts - Observations

    Science.gov (United States)

    Gehrels, N.; Cannizzo, J. K.

    2010-01-01

    We are in an exciting period of discovery for gamma-ray bursts. The Swift observatory is detecting 100 bursts per year, providing arcsecond localizations and sensitive observations of the prompt and afterglow emission. The Fermi observatory is observing 250 bursts per year with its medium-energy GRB instrument and about 10 bursts per year with its high-energy LAT instrument. In addition, rapid-response telescopes on the ground are providing new capabilities to study optical emission during the prompt phase and spectral signatures of the host galaxies. The combined data set is enabling great advances in our understanding of GRBs including afterglow physics, short burst origin, and high energy emission.

  2. Gérer et alerter

    Directory of Open Access Journals (Sweden)

    Valérie November

    2009-03-01

    Full Text Available Sur la base de deux événements d’inondation ayant touché récemment, dans des contextes politiques, organisationnels et hydrologiques bien différents, de nouveaux quartiers d’habitation, cet article rend compte des pratiques des acteurs impliqués dans des situations d’alerte et de crise en Suisse. Le recensement des acteurs – à travers leur rôle et leur place dans les mécanismes de préparation, d’alerte et de gestion –, ainsi que l’inventaire des documents mobilisés par ceux-ci, ont été réalisés dans les deux cas. Cette analyse a permis d’évaluer la gestion des événements, de déceler les changements organisationnels qui ont suivi les crises et de connaître la conception et le degré de formalisation du risque dont étaient dotés les différents acteurs avant et après les inondations. Plus encore, l’analyse a documenté les nouveaux processus d’alerte et de prévision qui ont été mis en place suite aux événements. Il s’avère ainsi que les épisodes d’inondation agissent de façon décisive sur la production de connaissances, à un degré variable selon les acteurs. Ces épisodes révèlent aussi parfois l’existence de connaissances « en attente » qui ne sont pas encore intégrées dans les procédures institutionnelles. Tant du point de vue de la prévision que de la gestion de la crise, ils permettent aussi de tester les canaux de l’information et de combler les déficits d’organisation, de collaboration et de sécurisation des dispositifs de communication. En outre, les risques et les crises liés aux inondations modifient les dynamiques et les politiques territoriales, conséquences du réajustement des réseaux d’acteurs. La mise en place de dispositifs d’intervention et de gestion de crise se montre cependant plus efficace que la refonte des dispositifs d’aménagement, généralement longue. Toutefois, la mémoire des événements se dégradant avec le temps, une inscription

  3. Automated attendance management and alert system | Rahim ...

    African Journals Online (AJOL)

    Automated attendance management and alert system. ... Journal of Fundamental and Applied Sciences ... AAMAS provides various functions, from managing and recording students' attendance record, to sending automatic alerts to students ...

  4. Bubble bursting at an interface

    Science.gov (United States)

    Kulkarni, Varun; Sajjad, Kumayl; Anand, Sushant; Fezzaa, Kamel

    2017-11-01

    Bubble bursting is crucial to understanding the life span of bubbles at an interface and more importantly the nature of interaction between the bulk liquid and the outside environment from the point of view of chemical and biological material transport. The dynamics of the bubble as it rises from inside the liquid bulk to its disappearance on the interface after bursting is an intriguing process, many aspects of which are still being explored. In our study, we make detailed high speed imaging measurements to examine carefully the hole initiation and growth in bursting bubbles that unearth some interesting features of the process. Previous analyses available in literature are revisited based on our novel experimental visualizations. Using a combination of experiments and theory we investigate the role of various forces during the rupturing process. This work aims to further our current knowledge of bubble dynamics at an interface with an aim of predicting better the bubble evolution from its growth to its eventual integration with the liquid bulk.

  5. A mobile care system with alert mechanism.

    Science.gov (United States)

    Lee, Ren-Guey; Chen, Kuei-Chien; Hsiao, Chun-Chieh; Tseng, Chwan-Lu

    2007-09-01

    Hypertension and arrhythmia are chronic diseases, which can be effectively prevented and controlled only if the physiological parameters of the patient are constantly monitored, along with the full support of the health education and professional medical care. In this paper, a role-based intelligent mobile care system with alert mechanism in chronic care environment is proposed and implemented. The roles in our system include patients, physicians, nurses, and healthcare providers. Each of the roles represents a person that uses a mobile device such as a mobile phone to communicate with the server setup in the care center such that he or she can go around without restrictions. For commercial mobile phones with Bluetooth communication capability attached to chronic patients, we have developed physiological signal recognition algorithms that were implemented and built-in in the mobile phone without affecting its original communication functions. It is thus possible to integrate several front-end mobile care devices with Bluetooth communication capability to extract patients' various physiological parameters [such as blood pressure, pulse, saturation of haemoglobin (SpO2), and electrocardiogram (ECG)], to monitor multiple physiological signals without space limit, and to upload important or abnormal physiological information to healthcare center for storage and analysis or transmit the information to physicians and healthcare providers for further processing. Thus, the physiological signal extraction devices only have to deal with signal extraction and wireless transmission. Since they do not have to do signal processing, their form factor can be further reduced to reach the goal of microminiaturization and power saving. An alert management mechanism has been included in back-end healthcare center to initiate various strategies for automatic emergency alerts after receiving emergency messages or after automatically recognizing emergency messages. Within the time

  6. Building a Communication, Education, an Outreach Program for the ShakeAlert National Earthquake Early Warning Program - Recommendations for Public Alerts Via Cell Phones

    Science.gov (United States)

    DeGroot, R. M.; Long, K.; Strauss, J. A.

    2017-12-01

    The United States Geological Survey (USGS) and its partners are developing the ShakeAlert Earthquake Early Warning System for the West Coast of the United States. To be an integral part of successful implementation, ShakeAlert engagement programs and materials must integrate with and leverage broader earthquake risk programs. New methods and products for dissemination must be multidisciplinary, cost effective, and consistent with existing hazards education and communication efforts. The ShakeAlert Joint Committee for Communication, Education, and Outreach (JCCEO), is identifying, developing, and cultivating partnerships with ShakeAlert stakeholders including Federal, State, academic partners, private companies, policy makers, and local organizations. Efforts include developing materials, methods for delivery, and reaching stakeholders with information on ShakeAlert, earthquake preparedness, and emergency protective actions. It is essential to develop standards to ensure information communicated via the alerts is consistent across the public and private sector and achieving a common understanding of what actions users take when they receive a ShakeAlert warning. In February 2017, the JCCEO convened the Warning Message Focus Group (WMFG) to provide findings and recommendations to the Alliance for Telecommunications Industry Solutions on the use of earthquake early warning message content standards for public alerts via cell phones. The WMFG represents communications, education, and outreach stakeholders from various sectors including ShakeAlert regional coordinators, industry, emergency managers, and subject matter experts from the social sciences. The group knowledge was combined with an in-depth literature review to ensure that all groups who could receive the message would be taken into account. The USGS and the participating states and agencies acknowledge that the implementation of ShakeAlert is a collective effort requiring the participation of hundreds of

  7. Les lanceurs d’alerte

    OpenAIRE

    Foegle, Jean-Philippe

    2014-01-01

    Le lanceur ou « donneur » d'alerte, ou, en langue anglaise, whistleblower est défini par l'assemblée parlementaire du conseil de l'Europe (Résolution 1729 (2010), §1) comme « toute personne soucieuse qui tire la sonnette d’alarme afin de faire cesser des agissements pouvant représenter un risque pour autrui ». Le présent mémoire vise, en menant une étude comparée France-Etats-Unis du droit encadrant le phénomène du « lancement d'alerte », à cerner les éléments principaux de la notion. Le prem...

  8. Advances in gamma-ray burst astronomy

    International Nuclear Information System (INIS)

    Cline, T.L.; Desai, U.D.

    1976-01-01

    Work at Goddard is presently being carried out in three major areas of gamma-ray burst research: (1) A pair of simultaneously operating 0.8-m 2 burst detectors were successfully balloon-borne at locations 800 miles apart on 9 May, 1975, each to atmospheric depths of 3 to 4 g cm -2 , for a 20-h period of coincident data coverage. This experiment investigates the size spectrum of bursts in the 10 -7 to 10 -6 erg cm -2 size region where dozens of events per day are expected on a -1.5 index integral power-law extrapolation. Considerable separation in latitude was used to avoid possible atmospheric and auroral secondary effects. Its results are not yet available. (2) A deep-space burst detector, the first spacecraft instrument built specifically for gamma-ray burst studies, was recently successfully integrated into the Helios-B space probe. Its use at distances of up to 2 AU will make possible the first high-resolution directional study of gamma-ray burst source locations. Similar modifications to several other space vehicles are also being prepared. (3) The gamma-ray instrument on the IMP-7 satellite is presently the most sensitive burst detector still operating in orbit. Its results have shown that all measured event-average energy spectra are consistent with being alike. Using this characteristic spectrum to select IMP-7 candidate events of smaller size than those detected using other spacecraft in coincidence, a size spectrum is constructed which fits the -1.5 index power law down to 2.5 x 10 -5 erg cm -2 per event, at an occurrence rate of about once per month. (Auth.)

  9. Ultra-fast flash observatory for detecting the early photons from gamma-ray bursts

    DEFF Research Database (Denmark)

    Lim, H.; Jeong, S.; Ahn, K.-B.

    ) for the fast measurement of the UV-optical photons from GRBs, and a gamma-ray monitor for energy measurement. The triggering is done by the UFFO burst Alert & Trigger telescope (UBAT) using the hard X-ray from GRBs and the UV/optical Trigger Assistant Telescope (UTAT) using the UV/optical photons from GRBs...

  10. Study on cosmic gamma bursts in the ''KONUS'' experiment

    International Nuclear Information System (INIS)

    Mazets, E.P.; Golenetskij, S.V.; Il'inskij, V.N.; Panov, V.N.; Aptekar', R.L.; Gur'yan, Yu.A.; Sokolov, I.A.; Sokolova, Z.Ya.; Kharitonova, T.V.

    1979-01-01

    Made are the investigations of cosmic gamma bursts with the help of the ''Konus'' apparatus, positioned on the ''Venera 11'' and ''Venera 12'' automatic interplanetary stations. 37 gamma bursts have been recorded in the energy range from 50 to 150 keV during the observation period from September to December 1978. Time profiles of bursts on 4, 9 and 24.11.1978 are presented. For the most events the time of burst increase and decrease constitute parts and units of seconds. Differential energy spectra are measured for all recorded bursts. In many cases the spectrum shape is similar to the grade one with the 1.5-2.3 index. In a graphical form built up are the integral distributions of gamma bursts appearence frequency in dependence on their intensity and maximum capacity in the burst peak. Galaxy coordinates of the 17-teen bursts, for which a simple localization is possible, are put on the celestial sphere map. The type of the integral distributions and the source distribution about the celestial sphere show that the gamma burst sources are whithin the Galaxy

  11. False alerts in air traffic control conflict alerting system: is there a "cry wolf" effect?

    Science.gov (United States)

    Wickens, Christopher D; Rice, Stephen; Keller, David; Hutchins, Shaun; Hughes, Jamie; Clayton, Krisstal

    2009-08-01

    The aim is to establish the extent to which the high false-alarm rate of air traffic control midair conflict alerts is responsible for a "cry wolf' effect-where true alerts are not responded to and all alerts are delayed in their response. Some aircraft collisions have been partly attributed to the cry wolf effect, and in other domains (health care and systems monitoring), there is a causal connection between false-alarm rate and cry wolf behavior. We hypothesized that a corresponding relationship exists in air traffic control (ATC). Aircraft track and alert system behavior data surrounding 495 conflict alerts were analyzed to identify true and false alerts, trajectory type, and controller behavior. Forty-five percent of the alerts were false, ranging from 0.28 to 0.58. Although centers with more false alerts contributed to more nonresponses, there was no evidence that these were nonresponses to true alerts or that response times were delayed in those centers. Instead, controllers showed desirable anticipatory behavior by issuing trajectory changes prior to the alert. Those trajectory pairs whose conflicts were more difficult to visualize induced more reliance on, and less compliance with, the alerting system. The high false-alarm rate does not appear to induce cry wolf behavior in the context of en route ATC conflict alerts. There is no need to substantially modify conflict alert algorithms, but the conflict alert system may be modified to address difficult-to-visualize conflicts.

  12. CISN ShakeAlert Earthquake Early Warning System Monitoring Tools

    Science.gov (United States)

    Henson, I. H.; Allen, R. M.; Neuhauser, D. S.

    2015-12-01

    CISN ShakeAlert is a prototype earthquake early warning system being developed and tested by the California Integrated Seismic Network. The system has recently been expanded to support redundant data processing and communications. It now runs on six machines at three locations with ten Apache ActiveMQ message brokers linking together 18 waveform processors, 12 event association processes and 4 Decision Module alert processes. The system ingests waveform data from about 500 stations and generates many thousands of triggers per day, from which a small portion produce earthquake alerts. We have developed interactive web browser system-monitoring tools that display near real time state-of-health and performance information. This includes station availability, trigger statistics, communication and alert latencies. Connections to regional earthquake catalogs provide a rapid assessment of the Decision Module hypocenter accuracy. Historical performance can be evaluated, including statistics for hypocenter and origin time accuracy and alert time latencies for different time periods, magnitude ranges and geographic regions. For the ElarmS event associator, individual earthquake processing histories can be examined, including details of the transmission and processing latencies associated with individual P-wave triggers. Individual station trigger and latency statistics are available. Detailed information about the ElarmS trigger association process for both alerted events and rejected events is also available. The Google Web Toolkit and Map API have been used to develop interactive web pages that link tabular and geographic information. Statistical analysis is provided by the R-Statistics System linked to a PostgreSQL database.

  13. The Drift Burst Hypothesis

    DEFF Research Database (Denmark)

    Christensen, Kim; Oomen, Roel; Renò, Roberto

    are an expected and regular occurrence in financial markets that can arise through established mechanisms such as feedback trading. At a theoretical level, we show how to build drift bursts into the continuous-time Itô semi-martingale model in such a way that the fundamental arbitrage-free property is preserved......, currencies and commodities. We find that the majority of identified drift bursts are accompanied by strong price reversals and these can therefore be regarded as “flash crashes” that span brief periods of severe market disruption without any material longer term price impacts....

  14. Cosmic gamma-ray burst

    International Nuclear Information System (INIS)

    Yamagami, Takamasa

    1985-01-01

    Ballon experiments for searching gamma-ray burst were carried out by employing rotating-cross modulation collimators. From a very long observation of total 315 hours during 1975 to 1979, three gamma-ray intensity anomalies were observed which were speculated as a gamma-ray burst. As for the first gamma-ray intensity anomaly observed in 1975, the burst source could be located precisely but the source, heavenly body, could not be specified. Gamma-ray burst source estimation was made by analyzing distribution of burst source in the celestial sphere, burst size distribution, and burst peak. Using the above-mentioned data together with previously published ones, apparent inconsistency was found between the observed results and the adopted theory that the source was in the Galaxy, and this inconsistency was found due to the different time profiles of the burst observed with instruments of different efficiency. It was concluded by these analysis results that employment of logN - logP (relation between burst frequency and burst count) was better than that of logN - logS (burst size) in the examination of gamma-ray burst because the former was less uncertain than the latter. Analyzing the author's observed gamma-ray burst data and the related published data, it was clarified that the burst distribution was almost P -312 for the burst peak value larger than 10 -6 erg/cm 2 .sec. The author could indicate that the calculated celestial distribution of burst source was consistent with the observed results by the derivation using the logN - logP relationship and that the burst larger than 10 -6 erg/cm 2 .sec happens about one thousand times a year, about ten times of the previous value. (Takagi, S.)

  15. Scientific Applications Performance Evaluation on Burst Buffer

    KAUST Repository

    Markomanolis, George S.

    2017-10-19

    Parallel I/O is an integral component of modern high performance computing, especially in storing and processing very large datasets, such as the case of seismic imaging, CFD, combustion and weather modeling. The storage hierarchy includes nowadays additional layers, the latest being the usage of SSD-based storage as a Burst Buffer for I/O acceleration. We present an in-depth analysis on how to use Burst Buffer for specific cases and how the internal MPI I/O aggregators operate according to the options that the user provides during his job submission. We analyze the performance of a range of I/O intensive scientific applications, at various scales on a large installation of Lustre parallel file system compared to an SSD-based Burst Buffer. Our results show a performance improvement over Lustre when using Burst Buffer. Moreover, we show results from a data hierarchy library which indicate that the standard I/O approaches are not enough to get the expected performance from this technology. The performance gain on the total execution time of the studied applications is between 1.16 and 3 times compared to Lustre. One of the test cases achieved an impressive I/O throughput of 900 GB/s on Burst Buffer.

  16. The development of a burst criterion for zircaloy fuel cladding under LOCA conditions

    International Nuclear Information System (INIS)

    Neitzel, H.J.; Rossinger, H.E.

    1980-02-01

    A burst criterion model, which assumes that deformation is controlled by steady-state creep, has been developed for a thin-walled cladding, in this case Zircaloy-4, subjected to a differential pressure and high temperature. The creep equation is integrated to obtain a burst time at the singularity of the strain. Once the burst time is known, the burst temperature and burst pressure can be calculated from the known temperature and pressure histories. A further relationship between burst stress and burst temperature is used to calculate the burst strain. Comparison with measured burst data shows good agreement between theory and experiment was found that, if the heating rate is constant, the burst temperature increases with decreasing stress, and that, if the stress level is constant, the burst temperature increases with increasing heating rate. It was also found that anisotropy alters the burst temperature and burst strain, and that test conditions in the α-Zr temperature range have no influence on the burst data. (auth)

  17. The γ-ray burst-detection system of SPI

    International Nuclear Information System (INIS)

    Lichti, G.G.; Georgii, R.; Kienlin, A. von; Schoenfelder, V.; Wunderer, C.; Jung, H.-J.; Hurley, K.

    2000-01-01

    The determination of precise locations of γ-ray bursts is a crucial task of γ-ray astronomy. Although γ-ray burst locations can be obtained nowadays from single experiments (BATSE, COMPTEL, BeppoSax) the location of bursts via triangulation using the interplanetary network is still important because not all bursts will be located precisely enough by these single instruments. In order to get location accuracies down to arcseconds via triangulation one needs long baselines. At the beginning of the next decade several spacecrafts which explore the outer planetary system (the Mars-Surveyor-2001 Orbiter and probably Ulysses) will carry γ-ray burst instruments. INTEGRAL as a near-earth spacecraft is the ideal counterpart for these satellites. The massive anticoincidence shield of the INTEGRAL-spectrometer SPI allows the measurement of γ-ray bursts with a high sensitivity. Estimations have shown that with SPI some hundred γ-ray bursts per year on the 5σ level can be measured. This is equivalent to the BATSE sensitivity. We describe the γ-ray burst-detection system of SPI, present its technical features and assess the scientific capabilities

  18. Wearable PPG sensor based alertness scoring system.

    Science.gov (United States)

    Dey, Jishnu; Bhowmik, Tanmoy; Sahoo, Saswata; Tiwari, Vijay Narayan

    2017-07-01

    Quantifying mental alertness in today's world is important as it enables the person to adopt lifestyle changes for better work efficiency. Miniaturized sensors in wearable devices have facilitated detection/monitoring of mental alertness. Photoplethysmography (PPG) sensors through Heart Rate Variability (HRV) offer one such opportunity by providing information about one's daily alertness levels without requiring any manual interference from the user. In this paper, a smartwatch based alertness estimation system is proposed. Data collected from PPG sensor of smartwatch is processed and fed to machine learning based model to get a continuous alertness score. Utility functions are designed based on statistical analysis to give a quality score on different stages of alertness such as awake, long sleep and short duration power nap. An intelligent data collection approach is proposed in collaboration with the motion sensor in the smartwatch to reduce battery drainage. Overall, our proposed wearable based system provides a detailed analysis of alertness over a period in a systematic and optimized manner. We were able to achieve an accuracy of 80.1% for sleep/awake classification along with alertness score. This opens up the possibility for quantifying alertness levels using a single PPG sensor for better management of health related activities including sleep.

  19. Nanolensed Fast Radio Bursts

    Science.gov (United States)

    Eichler, David

    2017-12-01

    It is suggested that fast radio bursts can probe gravitational lensing by clumpy dark matter objects that range in mass from 10-3 M ⊙-102 M ⊙. They may provide a more sensitive probe than observations of lensings of objects in the Magellanic Clouds, and could find or rule out clumpy dark matter with an extended mass spectrum.

  20. Fermi/GAMMA-RAY BURST MONITOR OBSERVATIONS OF SGR J0501+4516 BURSTS

    International Nuclear Information System (INIS)

    Lin Lin; Zhang Shuangnan; Kouveliotou, Chryssa; Baring, Matthew G.; Van der Horst, Alexander J.; Finger, Mark H.; Guiriec, Sylvain; Preece, Robert; Chaplin, Vandiver; Bhat, Narayan; Woods, Peter M.; Goegues, Ersin; Kaneko, Yuki; Scargle, Jeffrey; Granot, Jonathan; Von Kienlin, Andreas; Watts, Anna L.; Wijers, Ralph A. M. J.; Gehrels, Neil; Harding, Alice

    2011-01-01

    We present our temporal and spectral analyses of 29 bursts from SGR J0501+4516, detected with the gamma-ray burst monitor on board the Fermi Gamma-ray Space Telescope during 13 days of the source's activation in 2008 (August 22- September 3). We find that the T 90 durations of the bursts can be fit with a log-normal distribution with a mean value of ∼123 ms. We also estimate for the first time event durations of soft gamma repeater (SGR) bursts in photon space (i.e., using their deconvolved spectra) and find that these are very similar to the T 90 values estimated in count space (following a log-normal distribution with a mean value of ∼124 ms). We fit the time-integrated spectra for each burst and the time-resolved spectra of the five brightest bursts with several models. We find that a single power law with an exponential cutoff model fits all 29 bursts well, while 18 of the events can also be fit with two blackbody functions. We expand on the physical interpretation of these two models and we compare their parameters and discuss their evolution. We show that the time-integrated and time-resolved spectra reveal that E peak decreases with energy flux (and fluence) to a minimum of ∼30 keV at F = 8.7 x 10 -6 erg cm -2 s -1 , increasing steadily afterward. Two more sources exhibit a similar trend: SGRs J1550-5418 and 1806-20. The isotropic luminosity, L iso , corresponding to these flux values is roughly similar for all sources (0.4-1.5 x 10 40 erg s -1 ).

  1. Sky alert! when satellites fail

    CERN Document Server

    Johnson, Les

    2013-01-01

    How much do we depend on space satellites? Defense, travel, agriculture, weather forecasting, mobile phones and broadband, commerce...the list seems endless. But what would our live be like if the unimaginable happened and, by accident or design, those space assets disappeared? Sky Alert! explores what our world would be like, looking in turn at areas where the loss could have catastrophic effects. The book - demonstrates our dependence on space technology and satellites; - outlines the effect on our economy, defense, and daily lives if satellites and orbiting spacecraft were destroyed; - illustrates the danger of dead satellites, spent rocket stages, and space debris colliding with a functioning satellites; - demonstrates the threat of dramatically increased radiation levels associated with geomagnetic storms; - introduces space as a potential area of conflict between nations.

  2. Operational experiences with automated acoustic burst classification by neural networks

    International Nuclear Information System (INIS)

    Olma, B.; Ding, Y.; Enders, R.

    1996-01-01

    Monitoring of Loose Parts Monitoring System sensors for signal bursts associated with metallic impacts of loose parts has proved as an useful methodology for on-line assessing the mechanical integrity of components in the primary circuit of nuclear power plants. With the availability of neural networks new powerful possibilities for classification and diagnosis of burst signals can be realized for acoustic monitoring with the online system RAMSES. In order to look for relevant burst signals an automated classification is needed, that means acoustic signature analysis and assessment has to be performed automatically on-line. A back propagation neural network based on five pre-calculated signal parameter values has been set up for identification of different signal types. During a three-month monitoring program of medium-operated check valves burst signals have been measured and classified separately according to their cause. The successful results of the three measurement campaigns with an automated burst type classification are presented. (author)

  3. Auditory alert systems with enhanced detectability

    Science.gov (United States)

    Begault, Durand R. (Inventor)

    2008-01-01

    Methods and systems for distinguishing an auditory alert signal from a background of one or more non-alert signals. In a first embodiment, a prefix signal, associated with an existing alert signal, is provided that has a signal component in each of three or more selected frequency ranges, with each signal component in each of three or more selected level at least 3-10 dB above an estimated background (non-alert) level in that frequency range. The alert signal may be chirped within one or more frequency bands. In another embodiment, an alert signal moves, continuously or discontinuously, from one location to another over a short time interval, introducing a perceived spatial modulation or jitter. In another embodiment, a weighted sum of background signals adjacent to each ear is formed, and the weighted sum is delivered to each ear as a uniform background; a distinguishable alert signal is presented on top of this weighted sum signal at one ear, or distinguishable first and second alert signals are presented at two ears of a subject.

  4. 47 CFR 80.1111 - Distress alerting.

    Science.gov (United States)

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) Operating Procedures for Distress and Safety Communications § 80.1111 Distress alerting. (a) The transmission of a distress alert indicates...

  5. 21 CFR 26.20 - Alert system.

    Science.gov (United States)

    2010-04-01

    ... PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN... Provisions for Pharmaceutical Good Manufacturing Practices § 26.20 Alert system. (a) The details of an alert... concerning quality, which could necessitate additional controls or suspension of the distribution of the...

  6. The development of a burst criterion for Zircaloy fuel cladding under LOCA conditions

    International Nuclear Information System (INIS)

    Neitzel, H.J.; Rosinger, H.E.

    1980-10-01

    A burst criterion model, which assumes that deformation is controlled by steady-state creep, has been developed for a thin-walled cladding, in this case Zircaloy-4, subjected to a differential pressure and high temperature. The creep equation is integrated to obtain a burst time at the singularity of the strain. Once that urst time is known, the burst temperature and burst pressure can be calculated from the known temperature and pressure histories. A further relationship between burst stress and burst temperature is used to calculate the burst strain. Comparison with measured burst data shows good agreement between theory and experiment. It was found that, if the heating rate is constant, the burst temperature increases with decreasing stress, and that, if the stress level is constant, the burst temperature increases with increasing heating rate. It was also found that anisotropy alters the burst temperature and burst strain, and that thest conditions in the α-Zr temperature range have no influence on the burst data. (orig.) [de

  7. Gamma-ray bursts

    CERN Document Server

    Wijers, Ralph A M J; Woosley, Stan

    2012-01-01

    Cosmic gamma ray bursts (GRBs) have fascinated scientists and the public alike since their discovery in the late 1960s. Their story is told here by some of the scientists who participated in their discovery and, after many decades of false starts, solved the problem of their origin. Fourteen chapters by active researchers in the field present a detailed history of the discovery, a comprehensive theoretical description of GRB central engine and emission models, a discussion of GRB host galaxies and a guide to how GRBs can be used as cosmological tools. Observations are grouped into three sets from the satellites CGRO, BeppoSAX and Swift, and followed by a discussion of multi-wavelength observations. This is the first edited volume on GRB astrophysics that presents a fully comprehensive review of the subject. Utilizing the latest research, Gamma-ray Bursts is an essential desktop companion for graduate students and researchers in astrophysics.

  8. Multiparameter Monitoring and Prevention of Fault-Slip Rock Burst

    Directory of Open Access Journals (Sweden)

    Shan-chao Hu

    2017-01-01

    Full Text Available Fault-slip rock burst is one type of the tectonic rock burst during mining. A detailed understanding of the precursory information of fault-slip rock burst and implementation of monitoring and early warning systems, as well as pressure relief measures, are essential to safety production in deep mines. This paper first establishes a mechanical model of stick-slip instability in fault-slip rock bursts and then reveals the failure characteristics of the instability. Then, change rule of mining-induced stress and microseismic signals before the occurrence of fault-slip rock burst are proposed, and multiparameter integrated early warning methods including mining-induced stress and energy are established. Finally, pressure relief methods targeting large-diameter boreholes and coal seam infusion are presented in accordance with the occurrence mechanism of fault-slip rock burst. The research results have been successfully applied in working faces 2310 of the Suncun Coal Mine, and the safety of the mine has been enhanced. These research results improve the theory of fault-slip rock burst mechanisms and provide the basis for prediction and forecasting, as well as pressure relief, of fault-slip rock bursts.

  9. UBAT of UFFO/ Lomonosov: The X-Ray Space Telescope to Observe Early Photons from Gamma-Ray Bursts

    Science.gov (United States)

    Jeong, S.; Panasyuk, M. I.; Reglero, V.; Connell, P.; Kim, M. B.; Lee, J.; Rodrigo, J. M.; Ripa, J.; Eyles, C.; Lim, H.; Gaikov, G.; Jeong, H.; Leonov, V.; Chen, P.; Castro-Tirado, A. J.; Nam, J. W.; Svertilov, S.; Yashin, I.; Garipov, G.; Huang, M.-H. A.; Huang, J.-J.; Kim, J. E.; Liu, T.-C.; Petrov, V.; Bogomolov, V.; Budtz-Jørgensen, C.; Brandt, S.; Park, I. H.

    2018-02-01

    The Ultra-Fast Flash Observatory (UFFO) Burst Alert and Trigger Telescope (UBAT) has been designed and built for the localization of transient X-ray sources such as Gamma Ray Bursts (GRBs). As one of main instruments in the UFFO payload onboard the Lomonosov satellite (hereafter UFFO/ Lomonosov), the UBAT's roles are to monitor the X-ray sky, to rapidly locate and track transient sources, and to trigger the slewing of a UV/optical telescope, namely Slewing Mirror Telescope (SMT). The SMT, a pioneering application of rapid slewing mirror technology has a line of sight parallel to the UBAT, allowing us to measure the early UV/optical GRB counterpart and study the extremely early moments of GRB evolution. To detect X-rays, the UBAT utilizes a 191.1 cm2 scintillation detector composed of Yttrium Oxyorthosilicate (YSO) crystals, Multi-Anode Photomultiplier Tubes (MAPMTs), and associated electronics. To estimate a direction vector of a GRB source in its field of view, it employs the well-known coded aperture mask technique. All functions are written for implementation on a field programmable gate array to enable fast triggering and to run the device's imaging algorithms. The UFFO/ Lomonosov satellite was launched on April 28, 2016, and is now collecting GRB observation data. In this study, we describe the UBAT's design, fabrication, integration, and performance as a GRB X-ray trigger and localization telescope, both on the ground and in space.

  10. Evaluation of Visual Alerts in the Maritime Domain

    National Research Council Canada - National Science Library

    Roberts, Shelley; Foster-Hunt, Tara

    2008-01-01

    .... As the auditory modality is overloaded in the current alerting system, one method of potentially reducing perceptual overload is to replace auditory alerts with alerts presented in the visual domain...

  11. Alertness function of thalamus in conflict adaptation.

    Science.gov (United States)

    Wang, Xiangpeng; Zhao, Xiaoyue; Xue, Gui; Chen, Antao

    2016-05-15

    Conflict adaptation reflects the ability to improve current conflict resolution based on previously experienced conflict, which is crucial for our goal-directed behaviors. In recent years, the roles of alertness are attracting increasing attention when discussing the generation of conflict adaptation. However, due to the difficulty of manipulating alertness, very limited progress has been made in this line. Inspired by that color may affect alertness, we manipulated background color of experimental task and found that conflict adaptation significantly presented in gray and red backgrounds but did not in blue background. Furthermore, behavioral and functional magnetic resonance imaging results revealed that the modulation of color on conflict adaptation was implemented through changing alertness level. In particular, blue background eliminated conflict adaptation by damping the alertness regulating function of thalamus and the functional connectivity between thalamus and inferior frontal gyrus (IFG). In contrast, in gray and red backgrounds where alertness levels are typically high, the thalamus and the right IFG functioned normally and conflict adaptations were significant. Therefore, the alertness function of thalamus is determinant to conflict adaptation, and thalamus and right IFG are crucial nodes of the neural circuit subserving this ability. Present findings provide new insights into the neural mechanisms of conflict adaptation. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. A CCTV system with SMS alert (CMDSA): An implementation of pixel processing algorithm for motion detection

    Science.gov (United States)

    Rahman, Nurul Hidayah Ab; Abdullah, Nurul Azma; Hamid, Isredza Rahmi A.; Wen, Chuah Chai; Jelani, Mohamad Shafiqur Rahman Mohd

    2017-10-01

    Closed-Circuit TV (CCTV) system is one of the technologies in surveillance field to solve the problem of detection and monitoring by providing extra features such as email alert or motion detection. However, detecting and alerting the admin on CCTV system may complicate due to the complexity to integrate the main program with an external Application Programming Interface (API). In this study, pixel processing algorithm is applied due to its efficiency and SMS alert is added as an alternative solution for users who opted out email alert system or have no Internet connection. A CCTV system with SMS alert (CMDSA) was developed using evolutionary prototyping methodology. The system interface was implemented using Microsoft Visual Studio while the backend components, which are database and coding, were implemented on SQLite database and C# programming language, respectively. The main modules of CMDSA are motion detection, capturing and saving video, image processing and Short Message Service (SMS) alert functions. Subsequently, the system is able to reduce the processing time making the detection process become faster, reduce the space and memory used to run the program and alerting the system admin instantly.

  13. Automated acute kidney injury alerts.

    Science.gov (United States)

    Kashani, Kianoush B

    2018-05-02

    Acute kidney injury (AKI) is one of the most common and probably one of the more consequential complications of critical illnesses. Recent information indicates that it is at least partially preventable; however, progress in its prevention, management, and treatment has been hindered by the scarcity of knowledge for effective interventions, inconsistencies in clinical practices, late identification of patients at risk for or with AKI, and limitations of access to best practices for prevention and management of AKI. Growing use of electronic health records has provided a platform for computer science to engage in data mining and processing, not only for early detection of AKI but also for the development of risk-stratification strategies and computer clinical decision-support (CDS) systems. Despite promising perspectives, the literature regarding the impact of AKI electronic alerts and CDS systems has been conflicting. Some studies have reported improvement in care processes and patient outcomes, whereas others have shown no effect on clinical outcomes and yet demonstrated an increase in the use of resources. These discrepancies are thought to be due to multiple factors that may be related to technology, human factors, modes of delivery of information to clinical providers, and level of expectations regarding the impact on patient outcomes. This review appraises the current body of knowledge and provides some outlines regarding research into and clinical aspects of CDS systems for AKI. Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  14. Gamma-Ray Bursts

    Science.gov (United States)

    Pellizza, L. J.

    Gamma-ray bursts are the brightest transient sources in the gamma-ray sky. Since their discovery in the late 1960s, the investigation of the astrophysical sys- tems in which these phenomena take place, and the physical mechanisms that drive them, has become a vast and prolific area of modern astrophysics. In this work I will briefly describe the most relevant observations of these sources, and the models that describe their nature, emphasizing on the in- vestigations about the progenitor astrophysical systems. FULL TEXT IN SPANISH

  15. Gamma Ray Bursts

    Science.gov (United States)

    Gehrels, Neil; Meszaros, Peter

    2012-01-01

    Gamma-ray bursts (GRBs) are bright flashes of gamma-rays coming from the cosmos. They occur roughly once per day ,last typically lOs of seconds and are the most luminous events in the universe. More than three decades after their discovery, and after pioneering advances from space and ground experiments, they still remain mysterious. The launch of the Swift and Fermi satellites in 2004 and 2008 brought in a trove of qualitatively new data. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.

  16. Puzzling thermonuclear burst behaviour from the transient low-mass X-ray binary IGR J17473-2721

    DEFF Research Database (Denmark)

    Chenevez, Jérôme

    2010-01-01

    We investigate the thermonuclear bursting behaviour of IGR J17473-2721, an X-ray transient that in 2008 underwent a six month long outburst, starting (unusually) with an X-ray burst. We detected a total of 57 thermonuclear bursts throughout the outburst with AGILE, Swift, RXTE, and INTEGRAL...... it dropped (at a persistent flux corresponding to 15%of m˙ Edd) a few days before the outburst peak, after which bursts were not detected for a month. As the persistent emission subsequently decreased, the bursting activity resumed at a much lower rate than during the outburst rise. This hysteresis may arise...... produced a similar quenching of burst activity....

  17. Gamma-ray burst spectra

    International Nuclear Information System (INIS)

    Teegarden, B.J.

    1982-01-01

    A review of recent results in gamma-ray burst spectroscopy is given. Particular attention is paid to the recent discovery of emission and absorption features in the burst spectra. These lines represent the strongest evidence to date that gamma-ray bursts originate on or near neutron stars. Line parameters give information on the temperature, magnetic field and possibly the gravitational potential of the neutron star. The behavior of the continuum spectrum is also discussed. A remarkably good fit to nearly all bursts is obtained with a thermal-bremsstrahlung-like continuum. Significant evolution is observed of both the continuum and line features within most events

  18. UWB dual burst transmit driver

    Science.gov (United States)

    Dallum, Gregory E [Livermore, CA; Pratt, Garth C [Discovery Bay, CA; Haugen, Peter C [Livermore, CA; Zumstein, James M [Livermore, CA; Vigars, Mark L [Livermore, CA; Romero, Carlos E [Livermore, CA

    2012-04-17

    A dual burst transmitter for ultra-wideband (UWB) communication systems generates a pair of precisely spaced RF bursts from a single trigger event. An input trigger pulse produces two oscillator trigger pulses, an initial pulse and a delayed pulse, in a dual trigger generator. The two oscillator trigger pulses drive a gated RF burst (power output) oscillator. A bias driver circuit gates the RF output oscillator on and off and sets the RF burst packet width. The bias driver also level shifts the drive signal to the level that is required for the RF output device.

  19. SGR J1550-5418 BURSTS DETECTED WITH THE FERMI GAMMA-RAY BURST MONITOR DURING ITS MOST PROLIFIC ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Van der Horst, A. J.; Finger, M. H. [Universities Space Research Association, NSSTC, Huntsville, AL 35805 (United States); Kouveliotou, C. [Space Science Office, VP62, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Gorgone, N. M. [Connecticut College, New London, CT 06320 (United States); Kaneko, Y.; Goegues, E.; Lin, L. [Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul 34956 (Turkey); Baring, M. G. [Department of Physics and Astronomy, Rice University, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Guiriec, S.; Bhat, P. N.; Chaplin, V. L.; Goldstein, A. [University of Alabama, Huntsville, CSPAR, Huntsville, AL 35805 (United States); Granot, J. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Watts, A. L. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Bissaldi, E.; Gruber, D. [Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, Postfach 1312, 85748 Garching (Germany); Gehrels, N.; Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gibby, M. H.; Giles, M. M., E-mail: A.J.VanDerHorst@uva.nl [Jacobs Technology, Inc., Huntsville, AL (United States); and others

    2012-04-20

    We have performed detailed temporal and time-integrated spectral analysis of 286 bursts from SGR J1550-5418 detected with the Fermi Gamma-ray Burst Monitor (GBM) in 2009 January, resulting in the largest uniform sample of temporal and spectral properties of SGR J1550-5418 bursts. We have used the combination of broadband and high time-resolution data provided with GBM to perform statistical studies for the source properties. We determine the durations, emission times, duty cycles, and rise times for all bursts, and find that they are typical of SGR bursts. We explore various models in our spectral analysis, and conclude that the spectra of SGR J1550-5418 bursts in the 8-200 keV band are equally well described by optically thin thermal bremsstrahlung (OTTB), a power law (PL) with an exponential cutoff (Comptonized model), and two blackbody (BB) functions (BB+BB). In the spectral fits with the Comptonized model, we find a mean PL index of -0.92, close to the OTTB index of -1. We show that there is an anti-correlation between the Comptonized E{sub peak} and the burst fluence and average flux. For the BB+BB fits, we find that the fluences and emission areas of the two BB functions are correlated. The low-temperature BB has an emission area comparable to the neutron star surface area, independent of the temperature, while the high-temperature BB has a much smaller area and shows an anti-correlation between emission area and temperature. We compare the properties of these bursts with bursts observed from other SGR sources during extreme activations, and discuss the implications of our results in the context of magnetar burst models.

  20. SGR J1550-5418 Bursts Detected with the Fermi Gamma-Ray Burst Monitor during Its Most Prolific Activity

    Science.gov (United States)

    vanderHorst, A. J.; Kouveliotou, C.; Gorgone, N. M.; Kaneko, Y.; Baring, M. G.; Guiriec, S.; Gogus, E,; Granot, J.; Watts, A. L.; Lin, L.; hide

    2012-01-01

    We have performed detailed temporal and time-integrated spectral analysis of 286 bursts from SGR J1550-5418 detected with the Fermi Gamma-ray Burst Monitor (GBM) in 2009 January, resulting in the largest uniform sample of temporal and spectral properties of SGR J1550-5418 bursts. We have used the combination of broadband and high time-resolution data provided with GBM to perform statistical studies for the source properties.We determine the durations, emission times, duty cycles, and rise times for all bursts, and find that they are typical of SGR bursts. We explore various models in our spectral analysis, and conclude that the spectra of SGR J15505418 bursts in the 8-200 keV band are equally well described by optically thin thermal bremsstrahlung (OTTB), a power law (PL) with an exponential cutoff (Comptonized model), and two blackbody (BB) functions (BB+BB). In the spectral fits with the Comptonized model, we find a mean PL index of -0.92, close to the OTTB index of -1. We show that there is an anti-correlation between the Comptonized E(sub peak) and the burst fluence and average flux. For the BB+BBfits, we find that the fluences and emission areas of the two BB functions are correlated. The low-temperature BB has an emission area comparable to the neutron star surface area, independent of the temperature, while the high temperature BB has a much smaller area and shows an anti-correlation between emission area and temperature.We compare the properties of these bursts with bursts observed from other SGR sources during extreme activations, and discuss the implications of our results in the context of magnetar burst models.

  1. Solar radiation alert system : final report.

    Science.gov (United States)

    2009-03-01

    The Solar Radiation Alert (SRA) system continuously evaluates measurements of high-energy protons made by instruments on GOES satellites. If the measurements indicate a substantial elevation of effective dose rates at aircraft flight altitudes, the C...

  2. Radiation Alert Immediate Disclosure, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Invocon's Radiation Alert Immediate Disclosure (RAID) system is a miniature, low-power, real-time, active radiation badge. It is designed for monitoring personnel,...

  3. Alertness management : strategic naps in operational settings

    Science.gov (United States)

    1995-01-01

    Managing fatigue in complex operational settings requires attention to multiple factors, including hours of service, scheduling, education and training, countermeasures, technology, and research. Alertness-management strategies can be used to promote...

  4. Optical and X-Ray Early Follow-Up of ANTARES Neutrino Alerts

    Science.gov (United States)

    Adrian-Martinez, S.; Ageron, M.; Albert, A.; Samarai, I. Al; Andre, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Baret, B.; Barrios-Marti, J.; hide

    2016-01-01

    High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. Even with the recent detection of extraterrestrial high-energy neutrinos by the IceCube experiment, no astrophysical neutrinosource has yet been discovered. Transient sources, such as gamma-ray bursts, core-collapse supernovae, or active galactic nuclei are promising candidates. Multi-messenger programs offer a unique opportunity to detect these transient sources. By combining the information provided by the ANTARES neutrino telescope with information coming from other observatories, the probability of detecting a source is enhanced, allowing the possibility of identifyinga neutrino progenitor from a single detected event. A method based on optical and X-ray follow-ups of high-energy neutrino alerts has been developed within the ANTARES collaboration. This method does not require any assumptions on the relation between neutrino and photon spectra other than time-correlation. This program, denoted as TAToO, triggers a network of robotic optical telescopes (TAROTand ROTSE) and the Swift-XRT with a delay of only a few seconds after a neutrino detection, and is therefore well-suited to search for fast transient sources. To identify an optical or Xraycounterpart to a neutrino signal, the images provided by the follow-up observations areanalysed with dedicated pipelines. A total of 42 alerts with optical and 7 alerts with X-ray images taken with a maximum delay of 24 hours after the neutrino trigger have been analyzed. No optical or X-ray counterparts associated to the neutrino triggers have been found, and upper limits on transient source magnitudes have been derived. The probability to reject the gamma-ray burst origin hypothesis has been computed for each alert.

  5. Optical and X-ray early follow-up of ANTARES neutrino alerts

    International Nuclear Information System (INIS)

    Adrián-Martínez, S.; Ardid, M.; Ageron, M.; Al Samarai, I.; Aubert, J.-J.; Albert, A.; André, M.; Anton, G.; Baret, B.; Barrios-Martí, J.

    2016-01-01

    High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. Even with the recent detection of extraterrestrial high-energy neutrinos by the IceCube experiment, no astrophysical neutrino source has yet been discovered. Transient sources, such as gamma-ray bursts, core-collapse supernovae, or active galactic nuclei are promising candidates. Multi-messenger programs offer a unique opportunity to detect these transient sources. By combining the information provided by the ANTARES neutrino telescope with information coming from other observatories, the probability of detecting a source is enhanced, allowing the possibility of identifying a neutrino progenitor from a single detected event. A method based on optical and X-ray follow-ups of high-energy neutrino alerts has been developed within the ANTARES collaboration. This method does not require any assumptions on the relation between neutrino and photon spectra other than time-correlation. This program, denoted as TAToO, triggers a network of robotic optical telescopes (TAROT and ROTSE) and the Swift-XRT with a delay of only a few seconds after a neutrino detection, and is therefore well-suited to search for fast transient sources. To identify an optical or X-ray counterpart to a neutrino signal, the images provided by the follow-up observations are analysed with dedicated pipelines. A total of 42 alerts with optical and 7 alerts with X-ray images taken with a maximum delay of 24 hours after the neutrino trigger have been analysed. No optical or X-ray counterparts associated to the neutrino triggers have been found, and upper limits on transient source magnitudes have been derived. The probability to reject the gamma-ray burst origin hypothesis has been computed for each alert

  6. Optical and X-ray early follow-up of ANTARES neutrino alerts

    Science.gov (United States)

    Adrián-Martínez, S.; Ageron, M.; Albert, A.; Samarai, I. Al; André, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bogazzi, C.; Bormuth, R.; Bou-Cabo, M.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Dekeyser, I.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Dumas, A.; Eberl, T.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fermani, P.; Folger, F.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Gracia-Ruiz, R.; Graf, K.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herrero, A.; Hößl, J.; Hofestädt, J.; Hugon, C.; James, C. W.; de Jong, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kooijman, P.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, G.; Lattuada, D.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martínez-Mora, J. A.; Martini, S.; Mathieu, A.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Neff, M.; Nezri, E.; Păvălaš, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Richter, R.; Roensch, K.; Rostovtsev, A.; Saldaña, M.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schulte, S.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Sánchez-Losa, A.; Taiuti, M.; Tamburini, C.; Trovato, A.; Tselengidou, M.; Tönnis, C.; Turpin, D.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Vecchi, M.; Visser, E.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.; Klotz, A.; Boer, M.; Le Van Suu, A.; Akerlof, C.; Zheng, W.; Evans, P.; Gehrels, N.; Kennea, J.; Osborne, J. P.; Coward, D. M.

    2016-02-01

    High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. Even with the recent detection of extraterrestrial high-energy neutrinos by the IceCube experiment, no astrophysical neutrino source has yet been discovered. Transient sources, such as gamma-ray bursts, core-collapse supernovae, or active galactic nuclei are promising candidates. Multi-messenger programs offer a unique opportunity to detect these transient sources. By combining the information provided by the ANTARES neutrino telescope with information coming from other observatories, the probability of detecting a source is enhanced, allowing the possibility of identifying a neutrino progenitor from a single detected event. A method based on optical and X-ray follow-ups of high-energy neutrino alerts has been developed within the ANTARES collaboration. This method does not require any assumptions on the relation between neutrino and photon spectra other than time-correlation. This program, denoted as TAToO, triggers a network of robotic optical telescopes (TAROT and ROTSE) and the Swift-XRT with a delay of only a few seconds after a neutrino detection, and is therefore well-suited to search for fast transient sources. To identify an optical or X-ray counterpart to a neutrino signal, the images provided by the follow-up observations are analysed with dedicated pipelines. A total of 42 alerts with optical and 7 alerts with X-ray images taken with a maximum delay of 24 hours after the neutrino trigger have been analysed. No optical or X-ray counterparts associated to the neutrino triggers have been found, and upper limits on transient source magnitudes have been derived. The probability to reject the gamma-ray burst origin hypothesis has been computed for each alert.

  7. Neutron stars as X-ray burst sources. II. Burst energy histograms and why they burst

    International Nuclear Information System (INIS)

    Baan, W.A.

    1979-01-01

    In this work we explore some of the implications of a model for X-ray burst sources where bursts are caused by Kruskal-Schwarzschild instabilities at the magnetopause of an accreting and rotating neutron star. A number of simplifying assumptions are made in order to test the model using observed burst-energy histograms for the rapid burster MXB 1730--335. The predicted histograms have a correct general shape, but it appears that other effects are important as well, and that mode competition, for instance, may suppress the histograms at high burst energies. An explanation is ventured for the enhancement in the histogram at the highest burst energies, which produces the bimodal shape in high accretion rate histograms. Quantitative criteria are given for deciding when accreting neutron stars are steady sources or burst sources, and these criteria are tested using the X-ray pulsars

  8. GRB 090926A AND BRIGHT LATE-TIME FERMI LARGE AREA TELESCOPE GAMMA-RAY BURST AFTERGLOWS

    International Nuclear Information System (INIS)

    Swenson, C. A.; Roming, P. W. A.; Vetere, L.; Kennea, J. A.; Maxham, A.; Zhang, B. B.; Zhang, B.; Schady, P.; Holland, S. T.; Kuin, N. P. M.; Oates, S. R.; De Pasquale, M.; Page, K. L.

    2010-01-01

    GRB 090926A was detected by both the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. Swift follow-up observations began ∼13 hr after the initial trigger. The optical afterglow was detected for nearly 23 days post trigger, placing it in the long-lived category. The afterglow is of particular interest due to its brightness at late times, as well as the presence of optical flares at T0+10 5 s and later, which may indicate late-time central engine activity. The LAT has detected a total of 16 gamma-ray bursts; nine of these bursts, including GRB 090926A, also have been observed by Swift. Of the nine Swift-observed LAT bursts, six were detected by UVOT, with five of the bursts having bright, long-lived optical afterglows. In comparison, Swift has been operating for five years and has detected nearly 500 bursts, but has only seen ∼30% of bursts with optical afterglows that live longer than 10 5 s. We have calculated the predicted gamma-ray fluence, as would have been seen by the Burst Alert Telescope (BAT) on board Swift, of the LAT bursts to determine whether this high percentage of long-lived optical afterglows is unique, when compared to BAT-triggered bursts. We find that, with the exception of the short burst GRB 090510A, the predicted BAT fluences indicate that the LAT bursts are more energetic than 88% of all Swift bursts and also have brighter than average X-ray and optical afterglows.

  9. A systematic review of the effectiveness of interruptive medication prescribing alerts in hospital CPOE systems to change prescriber behavior and improve patient safety.

    Science.gov (United States)

    Page, N; Baysari, M T; Westbrook, J I

    2017-09-01

    about the amount and type of decision support that should be integrated into CPOE systems to increase safety while reducing the risk of alert fatigue. Virtually no studies have sought to investigate the impact on changes to prescriber behavior and outcomes overall when alerts from multiple categories are incorporated within the same system. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Designing a Free Academic Early Alert System

    Directory of Open Access Journals (Sweden)

    Adam C Welch

    2016-10-01

    Full Text Available This manuscript describes the development and implementation of a cloud-based, academic early alert system using Google Sheets. It was written for a non-computer savvy person to be able to develop the early alert system. By creating a Master Sheet and using the syntax from the share function of Google Sheets, a unique sheet can be created for each advisor that limits information sharing of their specific advisees. By adding a Google Form to the sheet, advisor interventions can be captured that reflect interventions made as a result of the early alert sheet. Approximately 52% of students were identified on the early alert sheet by having at least one non-passing score on an exam. There were 35-50% of faculty advisors who documented their interventions in the sheet. The template and coding used to develop this academic early alert sheet may be applied to other central documentation needs, such as professionalism early alert. Conflict of Interest Dr. Welch reports owning stock in Alphabet, Inc, however, was not involved in the selection of Google as the preferred platform at this institution.   Type: Note

  11. Understanding the Generation of Network Bursts by Adaptive Oscillatory Neurons

    Directory of Open Access Journals (Sweden)

    Tanguy Fardet

    2018-02-01

    Full Text Available Experimental and numerical studies have revealed that isolated populations of oscillatory neurons can spontaneously synchronize and generate periodic bursts involving the whole network. Such a behavior has notably been observed for cultured neurons in rodent's cortex or hippocampus. We show here that a sufficient condition for this network bursting is the presence of an excitatory population of oscillatory neurons which displays spike-driven adaptation. We provide an analytic model to analyze network bursts generated by coupled adaptive exponential integrate-and-fire neurons. We show that, for strong synaptic coupling, intrinsically tonic spiking neurons evolve to reach a synchronized intermittent bursting state. The presence of inhibitory neurons or plastic synapses can then modulate this dynamics in many ways but is not necessary for its appearance. Thanks to a simple self-consistent equation, our model gives an intuitive and semi-quantitative tool to understand the bursting behavior. Furthermore, it suggests that after-hyperpolarization currents are sufficient to explain bursting termination. Through a thorough mapping between the theoretical parameters and ion-channel properties, we discuss the biological mechanisms that could be involved and the relevance of the explored parameter-space. Such an insight enables us to propose experimentally-testable predictions regarding how blocking fast, medium or slow after-hyperpolarization channels would affect the firing rate and burst duration, as well as the interburst interval.

  12. 47 CFR 80.277 - Ship Security Alert System (SSAS).

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Ship Security Alert System (SSAS). 80.277... Security Alert System (SSAS). (a) Vessels equipped with a Ship Security Alert System pursuant to the Safety..., “RTCM Standard 11020.0—Ship Security Alert Systems (SSAS) using the Cospas-Sarsat System,” Version 1.0...

  13. Burst Mode ASIC-Based Modem

    Science.gov (United States)

    1997-01-01

    The NASA Lewis Research Center is sponsoring the Advanced Communication Technology Insertion (ACTION) for Commercial Space Applications program. The goal of the program is to expedite the development of new technology with a clear path towards productization and enhancing the competitiveness of U.S. manufacturers. The industry has made significant investment in developing ASIC-based modem technology for continuous-mode applications and has made investigations into East, reliable acquisition of burst-mode digital communication signals. With rapid advances in analog and digital communications ICs, it is expected that more functions will be integrated onto these parts in the near future. In addition custom ASIC's can also be developed to address the areas not covered by the other IC's. Using the commercial chips and custom ASIC's, lower-cost, compact, reliable, and high-performance modems can be built for demanding satellite communication application. This report outlines a frequency-hop burst modem design based on commercially available chips.

  14. Quantum key based burst confidentiality in optical burst switched networks.

    Science.gov (United States)

    Balamurugan, A M; Sivasubramanian, A

    2014-01-01

    The optical burst switching (OBS) is an emergent result to the technology concern that could achieve a feasible network in future. They are endowed with the ability to meet the bandwidth requirement of those applications that require intensive bandwidth. There are more domains opening up in the OBS that evidently shows their advantages and their capability to face the future network traffic. However, the concept of OBS is still far from perfection facing issues in case of security threat. The transfer of optical switching paradigm to optical burst switching faces serious downfall in the fields of burst aggregation, routing, authentication, dispute resolution, and quality of service (QoS). This paper deals with employing RC4 (stream cipher) to encrypt and decrypt bursts thereby ensuring the confidentiality of the burst. Although the use of AES algorithm has already been proposed for the same issue, by contrasting the two algorithms under the parameters of burst encryption and decryption time, end-to-end delay, it was found that RC4 provided better results. This paper looks to provide a better solution for the confidentiality of the burst in OBS networks.

  15. Quantum Key Based Burst Confidentiality in Optical Burst Switched Networks

    Directory of Open Access Journals (Sweden)

    A. M. Balamurugan

    2014-01-01

    Full Text Available The optical burst switching (OBS is an emergent result to the technology concern that could achieve a feasible network in future. They are endowed with the ability to meet the bandwidth requirement of those applications that require intensive bandwidth. There are more domains opening up in the OBS that evidently shows their advantages and their capability to face the future network traffic. However, the concept of OBS is still far from perfection facing issues in case of security threat. The transfer of optical switching paradigm to optical burst switching faces serious downfall in the fields of burst aggregation, routing, authentication, dispute resolution, and quality of service (QoS. This paper deals with employing RC4 (stream cipher to encrypt and decrypt bursts thereby ensuring the confidentiality of the burst. Although the use of AES algorithm has already been proposed for the same issue, by contrasting the two algorithms under the parameters of burst encryption and decryption time, end-to-end delay, it was found that RC4 provided better results. This paper looks to provide a better solution for the confidentiality of the burst in OBS networks.

  16. SC-228 Inclusion of DAA Warning Alert for TCAS Interoperability

    Science.gov (United States)

    Fern, Lisa

    2016-01-01

    alerting system is to provide critical timing information to the pilot about the potential for a loss of well clear with another aircraft. This is done by employing both temporal and spatial thresholds that indicate to the pilot the likelihood and imminence of a loss of well clear. The design of the DAA alerting thresholds is a balancing act between eliciting the desired pilot response in real loss of well clear threat events and reducing excessive, unnecessary, and/or uncoordinated UAS maneuvering within the air traffic environment; larger thresholds, both spatially and temporally, may increase the likelihood of a pilot avoiding a loss of well clear, but it can also increase the frequency of maneuvering - especially in cases where a maneuver is not actually needed to maintain well clear. A series of human in the loop (HITL) simulations have been conducted as part of NASA's Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. The purpose of these HITLs has been to provide empirical results in order to inform development of the minimum human-machine interface requirements for the DAA system. This white paper will present those results which provide evidence of a human performance benefit (in terms of response times and ability to remain well clear of other aircraft) of the DAA warning alert both with and without a collision avoidance system on board the aircraft.

  17. Thermal Energy for Space Cooling--Federal Technology Alert

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Daryl R.

    2000-12-31

    Cool storage technology can be used to significantly reduce energy costs by allowing energy-intensive, electrically driven cooling equipment to be predominantly operated during off peak hours when electricity rates are lower. This Federal Technology Alert, which is sponsored by DOE's Federal Energy Management Program (FEMP), describes the basic types of cool storage technologies and cooling system integration options. In addition, it defines the savings potential in the federal sector, presents application advice, and describes the performance experience of specific federal users. The results of a case study of a GSA building using cool storage technology are also provided.

  18. Light Dawns on Dark Gamma-ray Bursts

    Science.gov (United States)

    2010-12-01

    data with new observations made using GROND [2] - a dedicated gamma-ray burst follow-up observation instrument, which is attached to the 2.2-metre MPG/ESO telescope at La Silla in Chile. In doing so, astronomers have conclusively solved the puzzle of the missing optical afterglow. What makes GROND exciting for the study of afterglows is its very fast response time - it can observe a burst within minutes of an alert coming from Swift using a special system called the Rapid Response Mode - and its ability to observe simultaneously through seven filters covering both the visible and near-infrared parts of the spectrum. By combining GROND data taken through these seven filters with Swift observations, astronomers were able to accurately determine the amount of light emitted by the afterglow at widely differing wavelengths, all the way from high energy X-rays to the near-infrared. The astronomers used this information to directly measure the amount of obscuring dust that the light passed through en route to Earth. Previously, astronomers had to rely on rough estimates of the dust content [3]. The team used a range of data, including their own measurements from GROND, in addition to observations made by other large telescopes including the ESO Very Large Telescope, to estimate the distances to nearly all of the bursts in their sample. While they found that a significant proportion of bursts are dimmed to about 60-80 percent of the original intensity by obscuring dust, this effect is exaggerated for the very distant bursts, letting the observer see only 30-50 percent of the light [4]. The astronomers conclude that most dark gamma-ray bursts are therefore simply those that have had their small amount of visible light completely stripped away before it reaches us. "Compared to many instruments on large telescopes, GROND is a low cost and relatively simple instrument, yet it has been able to conclusively resolve the mystery surrounding dark gamma-ray bursts," says Greiner. Notes

  19. Solar microwave bursts - A review

    Science.gov (United States)

    Kundu, M. R.; Vlahos, L.

    1982-01-01

    Observational and theoretical results on the physics of microwave bursts that occur in the solar atmosphere are reviewed. Special attention is given to the advances made in burst physics over the last few years with the great improvement in spatial and time resolution, especially with instruments like the NRAO three-element interferometer, the Westerbork Synthesis Radio Telescope, and more recently the Very Large Array. Observations made on the preflare build-up of an active region at centimeter wavelengths are reviewed. Three distinct phases in the evolution of cm bursts, namely the impulsive phase, the post-burst phase, and the gradual rise and fall, are discussed. Attention is also given to the flux density spectra of centimeter bursts. Descriptions are given of observations of fine structures with temporal resolution of 10-100 ms in the intensity profiles of cm-wavelength bursts. High spatial resolution observations are analyzed, with special reference to the one- and two-dimensional maps of cm burst sources.

  20. Burst firing enhances neural output correlation

    Directory of Open Access Journals (Sweden)

    Ho Ka eChan

    2016-05-01

    Full Text Available Neurons communicate and transmit information predominantly through spikes. Given that experimentally observed neural spike trains in a variety of brain areas can be highly correlated, it is important to investigate how neurons process correlated inputs. Most previous work in this area studied the problem of correlation transfer analytically by making significant simplifications on neural dynamics. Temporal correlation between inputs that arises from synaptic filtering, for instance, is often ignored when assuming that an input spike can at most generate one output spike. Through numerical simulations of a pair of leaky integrate-and-fire (LIF neurons receiving correlated inputs, we demonstrate that neurons in the presence of synaptic filtering by slow synapses exhibit strong output correlations. We then show that burst firing plays a central role in enhancing output correlations, which can explain the above-mentioned observation because synaptic filtering induces bursting. The observed changes of correlations are mostly on a long time scale. Our results suggest that other features affecting the prevalence of neural burst firing in biological neurons, e.g., adaptive spiking mechanisms, may play an important role in modulating the overall level of correlations in neural networks.

  1. Automatic recognition of coronal type II radio bursts: The ARBIS 2 method and first observations

    Science.gov (United States)

    Lobzin, Vasili; Cairns, Iver; Robinson, Peter; Steward, Graham; Patterson, Garth

    Major space weather events such as solar flares and coronal mass ejections are usually accompa-nied by solar radio bursts, which can potentially be used for real-time space weather forecasts. Type II radio bursts are produced near the local plasma frequency and its harmonic by fast electrons accelerated by a shock wave moving through the corona and solar wind with a typi-cal speed of 1000 km s-1 . The coronal bursts have dynamic spectra with frequency gradually falling with time and durations of several minutes. We present a new method developed to de-tect type II coronal radio bursts automatically and describe its implementation in an extended Automated Radio Burst Identification System (ARBIS 2). Preliminary tests of the method with spectra obtained in 2002 show that the performance of the current implementation is quite high, ˜ 80%, while the probability of false positives is reasonably low, with one false positive per 100-200 hr for high solar activity and less than one false event per 10000 hr for low solar activity periods. The first automatically detected coronal type II radio bursts are also presented. ARBIS 2 is now operational with IPS Radio and Space Services, providing email alerts and event lists internationally.

  2. A Temporal Correlation in Quiescent Gamma-Ray Burst Prompt Emission: Evidence for Prognitor Memory

    Science.gov (United States)

    Patton, Thomas L.; Giblin, Timothy; Hakkila, Jon E.

    2018-06-01

    In spite of the insight gained into the nature of the Gamma-Ray Bursts (GRB) from early and late-time X-Ray observations in the Swift era, GRB prompt emission continues to provide clues and new insight into the activity of the central engine. A comprehensive understanding of all emission components observed in GRBs, from the traditional prompt GRB emission to the long lived X-Ray and optical decay super- imposed with late-time flaring activity, currently remains allusive. Using data from the Swift Burst Alert Telescope (BAT), we've identified and measured durations observed in GRBs that exhibit multi-episodic prompt emission behavior. Duration analysis of the burst attributes revealed no significant correlations between emissions and quiet time durations. This variability allows us to extrapolate that the central engine is constantly active.

  3. Designing a Free Academic Early Alert System

    OpenAIRE

    Adam C Welch; Adam Greever; Carmen Linne

    2016-01-01

    This manuscript describes the development and implementation of a cloud-based, academic early alert system using Google Sheets. It was written for a non-computer savvy person to be able to develop the early alert system. By creating a Master Sheet and using the syntax from the share function of Google Sheets, a unique sheet can be created for each advisor that limits information sharing of their specific advisees. By adding a Google Form to the sheet, advisor interventions can be captured tha...

  4. Phenomenological vessel burst investigations

    International Nuclear Information System (INIS)

    Hippelein, K.W.; Julisch, P.; Muz, J.; Schiedermaier, J.

    1985-07-01

    Fourteen burst experiments have been carried out using vessels with circumferential and longitudinal flaws, for investigation of the fracture behaviour, i.e. the time-related fracture opening. The vessels had dimensions (outer diameter x wall thickness = 800 x 47 mm) which correspond to the dimensions of the main coolant piping of a 1300 MW e PWR. The test specimens had been made of the base-safe material 20 MnMoNi 55 and of a special, 22 NiMoCr 37 base alloy. The experimental conditions with regard to pressure and temperature have been chosen so as to correspond to normal operating conditions of a PWR (p∝17.5 MPa, T∝300 0 C), i.e. the flaws have been so dimensioned that failure was to be expected at a pressure of p∝17.5 MPa. As a rule, water has been used as the pressure medium, or in some cases air, in order to influence the time-dependent pressure decrease. Fluid and structural dynamics calculations have also been made. In order to determine the impact of a fast propagating crack on the leak-to-fracture curve, which normally is defined by quasistationary experiments, suitable tests have been made with large-volume, cylindrical vessels (outer diameter x wall thickness x length = 3000 x 21 x 14000 mm) made of the material WSt E 43. The leak-before-fracture criterion has been confirmed. (orig./HP) [de

  5. Solar X-ray bursts

    International Nuclear Information System (INIS)

    Urnov, A.M.

    1980-01-01

    In the popular form the consideration is given to the modern state tasks and results of X-ray spectrometry of solar bursts. The operation of X-ray spectroheliograph is described. Results of spectral and polarization measurings of X-ray radiation of one powerful solar burst are presented. The conclusion has been drawn that in the process of burst development three characteristic stages may be distingwished: 1) the initial phase; just in this period processes which lead to observed consequences-electromagnetic and corpuscular radiation are born; 2) the impulse phase, or the phase of maximum, is characterised by sharp increase of radiation flux. During this phase the main energy content emanates and some volumes of plasma warm up to high temperatures; 3) the phase of burst damping, during which plasma cools and reverts to the initial condition

  6. 30 CFR 57.3461 - Rock bursts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Rock bursts. 57.3461 Section 57.3461 Mineral...-Underground Only § 57.3461 Rock bursts. (a) Operators of mines which have experienced a rock burst shall— (1) Within twenty four hours report to the nearest MSHA office each rock burst which: (i) Causes persons to...

  7. Chimera states in bursting neurons

    OpenAIRE

    Bera, Bidesh K.; Ghosh, Dibakar; Lakshmanan, M.

    2015-01-01

    We study the existence of chimera states in pulse-coupled networks of bursting Hindmarsh-Rose neurons with nonlocal, global and local (nearest neighbor) couplings. Through a linear stability analysis, we discuss the behavior of stability function in the incoherent (i.e. disorder), coherent, chimera and multi-chimera states. Surprisingly, we find that chimera and multi-chimera states occur even using local nearest neighbor interaction in a network of identical bursting neurons alone. This is i...

  8. Stacked search for time shifted high energy neutrinos from gamma ray bursts with the Antares neutrino telescope

    International Nuclear Information System (INIS)

    Adrian-Martinez, S.; Ardid, M.; Felis, I.; Martinez-Mora, J.A.; Saldana, M.; Albert, A.; Drouhin, D.; Racca, C.; Andre, M.; Anghinolfi, M.; Anton, G.; Eberl, T.; Enzenhoefer, A.; Fehn, K.; Folger, F.; Geisselsoeder, S.; Geyer, K.; Gleixner, A.; Graf, K.; Hallmann, S.; Hoessl, J.; Hofestaedt, J.; James, C.W.; Kalekin, O.; Katz, U.; Kiessling, D.; Lahmann, R.; Richter, R.; Roensch, K.; Schmid, J.; Schnabel, J.; Seitz, T.; Sieger, C.; Tselengidou, M.; Wagner, S.; Aubert, J.J.; Bertin, V.; Brunner, J.; Busto, J.; Carr, J.; Costantini, H.; Coyle, P.; Dornic, D.; Mathieu, A.; Vallee, C.; Baret, B.; Barrios-Marti, J.; Hernandez-Rey, J.J.; Sanchez-Losa, A.; Toennis, C.; Zornoza, J.D.; Zuniga, J.; Basa, S.; Marcelin, M.; Nezri, E.; Biagi, S.; Coniglione, R.; Distefano, C.; Piattelli, P.; Riccobene, G.; Sapienza, P.; Trovato, A.; Bormuth, R.; Jong, M. de; Samtleben, D.F.E.; Bouwhuis, M.C.; Heijboer, A.J.; Michael, T.; Steijger, J.J.M.; Visser, E.; Bruijn, R.; Capone, A.; De Bonis, G.; Fermani, P.; Perrina, C.; Caramete, L.; Pavalas, G.E.; Popa, V.; Chiarusi, T.; Circella, M.; Creusot, A.; Galata, S.; Gracia-Ruiz, R.; Van Elewyck, V.; Dekeyser, I.; Lefevre, D.; Tamburini, C.; Deschamps, A.; Hello, Y.; Donzaud, C.; Dumas, A.; Gay, P.; Elsaesser, D.; Kadler, M.; Kreter, M.; Mueller, C.; Fusco, L.A.; Margiotta, A.; Pellegrino, C.; Spurio, M.; Giordano, V.; Haren, H. van; Hugon, C.; Taiuti, M.; Kooijman, P.; Kouchner, A.; Kreykenbohm, I.; Wilms, J.; Kulikovskiy, V.; Leonora, E.; Loucatos, S.; Marinelli, A.; Migliozzi, P.; Moussa, A.; Pradier, T.; Sanguineti, M.; Schuessler, F.; Stolarczyk, T.; Vallage, B.; Vivolo, D.

    2017-01-01

    A search for high-energy neutrino emission correlated with gamma-ray bursts outside the electromagnetic prompt-emission time window is presented. Using a stacking approach of the time delays between reported gamma-ray burst alerts and spatially coincident muon-neutrino signatures, data from the Antares neutrino telescope recorded between 2007 and 2012 are analysed. One year of public data from the IceCube detector between 2008 and 2009 have been also investigated. The respective timing profiles are scanned for statistically significant accumulations within 40 days of the Gamma Ray Burst, as expected from Lorentz Invariance Violation effects and some astrophysical models. No significant excess over the expected accidental coincidence rate could be found in either of the two data sets. The average strength of the neutrino signal is found to be fainter than one detectable neutrino signal per hundred gamma-ray bursts in the Antares data at 90% confidence level. (orig.)

  9. Stacked search for time shifted high energy neutrinos from gamma ray bursts with the Antares neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Adrian-Martinez, S.; Ardid, M.; Felis, I.; Martinez-Mora, J.A.; Saldana, M. [Universitat Politecnica de Valencia, Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Gandia (Spain); Albert, A.; Drouhin, D.; Racca, C. [GRPHE-Institut Universitaire de Technologie de Colmar, 34 rue du Grillenbreit, BP 50568, Colmar (France); Andre, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Vilanova i la Geltru, Barcelona (Spain); Anghinolfi, M. [INFN-Sezione di Genova, Genoa (Italy); Anton, G.; Eberl, T.; Enzenhoefer, A.; Fehn, K.; Folger, F.; Geisselsoeder, S.; Geyer, K.; Gleixner, A.; Graf, K.; Hallmann, S.; Hoessl, J.; Hofestaedt, J.; James, C.W.; Kalekin, O.; Katz, U.; Kiessling, D.; Lahmann, R.; Richter, R.; Roensch, K.; Schmid, J.; Schnabel, J.; Seitz, T.; Sieger, C.; Tselengidou, M.; Wagner, S. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen (Germany); Aubert, J.J.; Bertin, V.; Brunner, J.; Busto, J.; Carr, J.; Costantini, H.; Coyle, P.; Dornic, D.; Mathieu, A.; Vallee, C. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Baret, B.; Barrios-Marti, J.; Hernandez-Rey, J.J.; Sanchez-Losa, A.; Toennis, C.; Zornoza, J.D.; Zuniga, J. [CSIC-Universitat de Valencia, IFIC-Instituto de Fisica Corpuscular, Edificios Investigacion de Paterna, Paterna, Valencia (Spain); Basa, S.; Marcelin, M.; Nezri, E. [Pole de l' Etoile Site de Chateau-Gombert, LAM-Laboratoire d' Astrophysique de Marseille, Marseille Cedex 13 (France); Biagi, S.; Coniglione, R.; Distefano, C.; Piattelli, P.; Riccobene, G.; Sapienza, P.; Trovato, A. [INFN-Laboratori Nazionali del Sud (LNS), Catania (Italy); Bormuth, R.; Jong, M. de; Samtleben, D.F.E. [Nikhef, Science Park, Amsterdam (Netherlands); Universiteit Leiden, Leids Instituut voor Onderzoek in Natuurkunde, Leiden (Netherlands); Bouwhuis, M.C.; Heijboer, A.J.; Michael, T.; Steijger, J.J.M.; Visser, E. [Nikhef, Science Park, Amsterdam (Netherlands); Bruijn, R. [Nikhef, Science Park, Amsterdam (Netherlands); Universiteit van Amsterdam, Instituut voor Hoge-Energie Fysica, Amsterdam (Netherlands); Capone, A.; De Bonis, G.; Fermani, P.; Perrina, C. [INFN-Sezione di Roma, Rome (Italy); Dipartimento di Fisica dell' Universita La Sapienza, Rome (Italy); Caramete, L.; Pavalas, G.E.; Popa, V. [Institute for Space Sciences, Bucharest, Magurele (Romania); Chiarusi, T. [INFN-Sezione di Bologna, Bologna (Italy); Circella, M. [INFN-Sezione di Bari, Bari (Italy); Creusot, A.; Galata, S.; Gracia-Ruiz, R.; Van Elewyck, V. [APC, Universite Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite, Paris (France); Dekeyser, I.; Lefevre, D.; Tamburini, C. [Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Marseille Cedex 9 (France); Universite du Sud Toulon-Var, CNRS-INSU/IRD UM 110, La Garde Cedex (France); Deschamps, A.; Hello, Y. [Geoazur, Universite Nice Sophia-Antipolis, CNRS/INSU, IRD, Observatoire de la Cote d' Azur, Sophia Antipolis (France); Donzaud, C. [APC, Universite Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite, Paris (France); Universite Paris-Sud, Orsay Cedex (France); Dumas, A.; Gay, P. [Clermont Universite, Universite Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique Corpusculaire, BP 10448, Clermont-Ferrand (France); Elsaesser, D.; Kadler, M.; Kreter, M.; Mueller, C. [Universitaet Wuerzburg, Institut fuer Theoretische Physik und Astrophysik, Wuerzburg (Germany); Fusco, L.A.; Margiotta, A.; Pellegrino, C.; Spurio, M. [INFN-Sezione di Bologna, Bologna (Italy); Dipartimento di Fisica dell' Universita, Bologna (Italy); Giordano, V. [INFN-Sezione di Catania, Catania (Italy); Haren, H. van [Royal Netherlands Institute for Sea Research (NIOZ), ' t Horntje, Texel (Netherlands); Hugon, C.; Taiuti, M. [INFN-Sezione di Genova, Genoa (Italy); Dipartimento di Fisica dell' Universita, Genoa (Italy); Kooijman, P. [Nikhef, Science Park, Amsterdam (Netherlands); Universiteit Utrecht, Faculteit Betawetenschappen, Utrecht (Netherlands); Universiteit van Amsterdam, Instituut voor Hoge-Energie Fysica, Amsterdam (Netherlands); Kouchner, A. [APC, Universite Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite, Paris (France); Institut Universitaire de France, Paris (France); Kreykenbohm, I.; Wilms, J. [Universitaet Erlangen-Nuernberg, Dr. Remeis-Sternwarte and ECAP, Bamberg (Germany); Kulikovskiy, V. [INFN-Laboratori Nazionali del Sud (LNS), Catania (Italy); Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Leonora, E. [INFN-Sezione di Catania, Catania (Italy); Dipartimento di Fisica ed Astronomia dell' Universita, Catania (Italy); Loucatos, S. [APC, Universite Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite, Paris (France); CEA Saclay, Direction des Sciences de la Matiere, Institut de recherche sur les lois fondamentales de l' Univers, Service de Physique des Particules, Gif-sur-Yvette Cedex (France); Marinelli, A. [INFN-Sezione di Pisa, Pisa (Italy); Dipartimento di Fisica dell' Universita, Pisa (Italy); Migliozzi, P. [INFN-Sezione di Napoli, Naples (IT); Moussa, A. [University Mohammed I, Laboratory of Physics of Matter and Radiations, Oujda (MA); Pradier, T. [Universite de Strasbourg et CNRS/IN2P3, IPHC-Institut Pluridisciplinaire Hubert Curien, 23 rue du Loess, BP 28, Strasbourg Cedex 2 (FR); Sanguineti, M. [Dipartimento di Fisica dell' Universita, Genoa (IT); Schuessler, F.; Stolarczyk, T.; Vallage, B. [CEA Saclay, Direction des Sciences de la Matiere, Institut de recherche sur les lois fondamentales de l' Univers, Service de Physique des Particules, Gif-sur-Yvette Cedex (FR); Vivolo, D. [INFN-Sezione di Napoli, Naples (IT); Dipartimento di Fisica dell' Universita Federico II di Napoli, Naples (IT)

    2017-01-15

    A search for high-energy neutrino emission correlated with gamma-ray bursts outside the electromagnetic prompt-emission time window is presented. Using a stacking approach of the time delays between reported gamma-ray burst alerts and spatially coincident muon-neutrino signatures, data from the Antares neutrino telescope recorded between 2007 and 2012 are analysed. One year of public data from the IceCube detector between 2008 and 2009 have been also investigated. The respective timing profiles are scanned for statistically significant accumulations within 40 days of the Gamma Ray Burst, as expected from Lorentz Invariance Violation effects and some astrophysical models. No significant excess over the expected accidental coincidence rate could be found in either of the two data sets. The average strength of the neutrino signal is found to be fainter than one detectable neutrino signal per hundred gamma-ray bursts in the Antares data at 90% confidence level. (orig.)

  10. Burst protected nuclear reactor plant with PWR

    International Nuclear Information System (INIS)

    Harand, E.; Michel, E.

    1978-01-01

    In the PWR, several integrated components from the steam raising unit and the main coolant pump are grouped around the reactor pressure vessel in a multiloop circuit and in a vertical arrangement. For safety reasons all primary circuit components and pipelines are situated in burst protection covers. To reduce the area of the plant straight tube steam raising units with forced circulation are used as steam raising units. The boiler pumps are connected to the vertical tubes and to the pressure vessel via double pipelines made as twin chamber pipes. (DG) [de

  11. Detection circuit for gamma-ray burst

    International Nuclear Information System (INIS)

    Murakami, Hiroyuki; Yamagami, Takamasa; Mori, Kunishiro; Uchiyama, Sadayuki.

    1982-01-01

    A new gamma-ray burst detection system is described. The system was developed as an environmental monitor of an accelerator, and can be used as the burst detection system. The system detects the arrival time of burst. The difference between the arrival times detected at different places will give information on the burst source. The frequency of detecting false burst was estimated, and the detection limit under the estimated frequency of false burst was also calculated. Decision whether the signal is false or true burst was made by the statistical treatment. (Kato, T.)

  12. Gamma-ray burst models.

    Science.gov (United States)

    King, Andrew

    2007-05-15

    I consider various possibilities for making gamma-ray bursts, particularly from close binaries. In addition to the much-studied neutron star+neutron star and black hole+neutron star cases usually considered good candidates for short-duration bursts, there are also other possibilities. In particular, neutron star+massive white dwarf has several desirable features. These systems are likely to produce long-duration gamma-ray bursts (GRBs), in some cases definitely without an accompanying supernova, as observed recently. This class of burst would have a strong correlation with star formation and occur close to the host galaxy. However, rare members of the class need not be near star-forming regions and could have any type of host galaxy. Thus, a long-duration burst far from any star-forming region would also be a signature of this class. Estimates based on the existence of a known progenitor suggest that this type of GRB may be quite common, in agreement with the fact that the absence of a supernova can only be established in nearby bursts.

  13. Solar Drift-Pair Bursts

    Science.gov (United States)

    Stanislavsky, A.; Volvach, Ya.; Konovalenko, A.; Koval, A.

    2017-08-01

    In this paper a new sight on the study of solar bursts historically called drift pairs (DPs) is presented. Having a simple morphology on dynamic spectra of radio records (two short components separated in time, and often they are very similar) and discovered at the dawn of radio astronomy, their features remain unexplained totally up to now. Generally, the DPs are observed during the solar storms of type III bursts, but not every storm of type III bursts is linked with DPs. Detected by ground-based instruments at decameter and meter wavelengths, the DP bursts are limited in frequency bandwidth. They can drift from high frequencies to low ones and vice versa. Their frequency drift rate may be both lower and higher than typical rates of type III bursts at the same frequency range. The development of low-frequency radio telescopes and data processing provide additional possibilities in the research. In this context the fresh analysis of DPs, made from recent observations in the summer campaign of 2015, are just considered. Their study was implemented by updated tools of the UTR-2 radio telescope at 9-33 MHz. During 10-12 July of 2015, DPs forming the longest patterns on dynamic spectra are about 7% of the total number of recorded DPs. Their marvelous resemblance in frequency drift rates with the solar S-bursts is discussed.

  14. THE FERMI –GBM THREE-YEAR X-RAY BURST CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Jenke, P. A. [CSPAR, SPA University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Linares, M. [Instituto de Astrofísica de Canarias, c/Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Connaughton, V.; Camero-Arranz, A.; Finger, M. H. [Universities Space Research Association, Huntsville, AL 35805 (United States); Beklen, E. [Department of Physics, Suleyman Demirel University, 32260, Isparta (Turkey); Wilson-Hodge, C. A. [Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2016-08-01

    The Fermi Gamma-ray Burst Monitor (GBM) is an all-sky gamma-ray monitor well known in the gamma-ray burst (GRB) community. Although GBM excels in detecting the hard, bright extragalactic GRBs, its sensitivity above 8 keV and its all-sky view make it an excellent instrument for the detection of rare, short-lived Galactic transients. In 2010 March, we initiated a systematic search for transients using GBM data. We conclude this phase of the search by presenting a three-year catalog of 1084 X-ray bursts. Using spectral analysis, location, and spatial distributions we classified the 1084 events into 752 thermonuclear X-ray bursts, 267 transient events from accretion flares and X-ray pulses, and 65 untriggered gamma-ray bursts. All thermonuclear bursts have peak blackbody temperatures broadly consistent with photospheric radius expansion (PRE) bursts. We find an average rate of 1.4 PRE bursts per day, integrated over all Galactic bursters within about 10 kpc. These include 33 and 10 bursts from the ultra-compact X-ray binaries 4U 0614+09 and 2S 0918-549, respectively. We discuss these recurrence times and estimate the total mass ejected by PRE bursts in our Galaxy.

  15. [Health alert management and emerging risk].

    Science.gov (United States)

    Pillonel, J

    2010-12-01

    Following health crisis that have occurred in the nineties (contaminated blood, mad cow, asbestos, etc.) and more recently those generated by the heat wave in 2003 or by emerging infectious pathogens (SARS, West Nile, Chikungunya, H5N1, H1N1…), a real health vigilance system has been progressively developed in France. After a brief historical overview of the health alert system, this article will give the guiding principles of its current organization in France and will present two examples of recent health alerts (Chikungunya in the Reunion Island in 2005-2006 and hepatitis A outbreak in the Côtes-d'Armor in August 2007), that have needed the implementation of preventive measures regarding the blood donor selection. These two examples have shown that the position of the alert in the French health vigilance system needs to be very close to the event. In that case, health alert is a very useful tool for decision making especially when measures have to be taken to prevent transfusion-transmitted pathogens. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  16. Understanding the context of network traffic alerts

    NARCIS (Netherlands)

    Cappers, B.C.M.; van Wijk, J.J.; Best, D.M.; Staheli, D.; Prigent, N.; Engle, S.; Harrison, L.

    2016-01-01

    For the protection of critical infrastructures against complex virus attacks, automated network traffic analysis and deep packet inspection are unavoidable. However, even with the use of network intrusion detection systems, the number of alerts is still too large to analyze manually. In addition,

  17. Alerting or Somnogenic Light: Pick Your Color

    Science.gov (United States)

    Bourgin, Patrice; Hubbard, Jeffrey

    2016-01-01

    In mammals, light exerts pervasive effects on physiology and behavior in two ways: indirectly through clock synchronization and the phase adjustment of circadian rhythms, and directly through the promotion of alertness and sleep, respectively, in diurnal and nocturnal species. A recent report by Pilorz and colleagues describes an even more complex role for the acute effects of light. In mice, blue light acutely causes behavioral arousal, whereas green wavelengths promote sleep. These opposing effects are mediated by melanopsin-based phototransduction through different neural pathways. These findings reconcile nocturnal and diurnal species through a common alerting response to blue light. One can hypothesize that the opposite responses to natural polychromatic light in night- or day-active animals may reflect higher sensitivity of nocturnal species to green, and diurnals to blue wavelengths, resulting in hypnogenic and alerting effects, respectively. Additional questions remain to be clarified. How do different light wavelengths affect other behaviors such as mood and cognition? How do those results apply to humans? How does light pose either a risk or benefit, depending on whether one needs to be asleep or alert? Indeed, in addition to timing, luminance levels, and light exposure duration, these findings stress the need to understand how best to adapt the color spectrum of light to our needs and to take this into account for the design of daily lighting concepts—a key challenge for today’s society, especially with the emergence of LED light technology. PMID:27525420

  18. CEI-PEA Alert, Summer 2006

    Science.gov (United States)

    Center for Educational Innovation - Public Education Association, 2006

    2006-01-01

    The "CEI-PEA Alert" is an advocacy newsletter that deals with topics of interest to all concerned with the New York City public schools. This issue includes: (1) Practical Skills & High Academic Standards: Career Technical Education; (2) Parents: Help Your Children Gain "Soft Skills" for the Workforce; (3) Culinary Arts…

  19. IR panoramic alerting sensor concepts and applications

    Science.gov (United States)

    de Jong, Arie N.; Schwering, Piet B. W.

    2003-09-01

    During the last decade, protection of military and civilian operational platforms against weapons like guns, grenades, missiles, Unmanned Combat Aerial (and surface) Vehicles (UCAV's) and mines, has been an issue of increased importance due to the improved kill-probability of these threats. The standard countermeasure package of armour, guns, decoys, jammers, camouflage nets and smokes is inadequate when not accompanied by a suitable sensor package, primarily consisting of an alerting device, triggering consecutive steps in the countermeasure-chain. In this process of alert four different detection techniques are considered: pre-alert, giving the directions of possible attack, detection of an action of attack, identification of the threat and finally the precise localization (3-D). The design of the alerting device is greatly depending on the platform, on which it will be used, the associated and affordable cost and the nature of the threat. A number of sensor packages, considered, developed and evaluated at TNO-FEL is presented for simple, medium size and large and expensive platforms. In recent years the requirements for these sensors have become more and more strigent due to the growing number of scenarios. The attack can practically be from any direction, implying the need for a large Field of Regard (FOR), the attack range can vary considerably and the type of threat can be very diverse, implying great flexibility and dynamic range and rapid response of the sensor. Especially the localization at short ranges is a challenging issue. Various configurations including advantages and drawbacks are discussed.

  20. Alerting or Somnogenic Light: Pick Your Color.

    Directory of Open Access Journals (Sweden)

    Patrice Bourgin

    2016-08-01

    Full Text Available In mammals, light exerts pervasive effects on physiology and behavior in two ways: indirectly through clock synchronization and the phase adjustment of circadian rhythms, and directly through the promotion of alertness and sleep, respectively, in diurnal and nocturnal species. A recent report by Pilorz and colleagues describes an even more complex role for the acute effects of light. In mice, blue light acutely causes behavioral arousal, whereas green wavelengths promote sleep. These opposing effects are mediated by melanopsin-based phototransduction through different neural pathways. These findings reconcile nocturnal and diurnal species through a common alerting response to blue light. One can hypothesize that the opposite responses to natural polychromatic light in night- or day-active animals may reflect higher sensitivity of nocturnal species to green, and diurnals to blue wavelengths, resulting in hypnogenic and alerting effects, respectively. Additional questions remain to be clarified. How do different light wavelengths affect other behaviors such as mood and cognition? How do those results apply to humans? How does light pose either a risk or benefit, depending on whether one needs to be asleep or alert? Indeed, in addition to timing, luminance levels, and light exposure duration, these findings stress the need to understand how best to adapt the color spectrum of light to our needs and to take this into account for the design of daily lighting concepts-a key challenge for today's society, especially with the emergence of LED light technology.

  1. 77 FR 41331 - Commercial Mobile Alert System

    Science.gov (United States)

    2012-07-13

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 10 [PS Docket No. 07-287; FCC 08-164] Commercial... with the Commission's Commercial Mobile Alert System (CMS), Second Report and Order (``CMAS Second..., for a period of three years, the information collection requirements relating to the Commercial Mobile...

  2. FACT. Flare alerts from blazar monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Dorner, Daniela [Universitaet Wuerzburg (Germany); Bretz, Thomas [RWTH Aachen (Germany); Collaboration: FACT-Collaboration

    2015-07-01

    One of the major goals of the First G-APD Cherenkov Telescope is the longterm monitoring of bright TeV blazars. For more than three years, FACT has observed the blazars Mrk 421 and Mrk 501 and a few other sources on a regular basis. To understand these highly variable objects, simultaneous data at different wavelengths are very useful. FACT is not only taking part in multi-wavelength campaigns, but also sending alerts to other instruments in case of enhanced flux, to study flares within the multi-wavelength frame. To send fast alerts, an automatic quick look analysis was set up on site. Once the data are written on disk, they are automatically processed, and the analysis results are published on a website where other observers can monitor the activity of the source in the very high energy band. In addition, alerts are sent in case the flux is higher than a certain predefined value. In 2014, more than five alerts have been sent. Results from three years of monitoring are presented.

  3. Fermi/GBM Observations of SGRJ0501 + 4516 Bursts

    Science.gov (United States)

    Lin, Lin; Kouveliotou, Chryssa; Baring, Matthew G.; van der Horst, Alexander J.; Guiriec, Sylvain; Woods, Peter M.; Goegues, Ersin; Kaneko, Yuki; Scargle, Jeffrey; Granot, Jonathan; hide

    2011-01-01

    We present our temporal and spectral analyses of 29 bursts from SGRJ0501+4516, detected with the Gamma-ray Burst Monitor onboard the Fermi Gamma-ray Space Telescope during the 13 days of the source activation in 2008 (August 22 to September 3). We find that the T(sub 90) durations of the bursts can be fit with a log-normal distribution with a mean value of approx. 123 ms. We also estimate for the first time event durations of Soft Gamma Repeater (SGR) bursts in photon space (i.e., using their deconvolved spectra) and find that these are very similar to the T(sub 90)s estimated in count space (following a log-normal distribution with a mean value of approx. 124 ms). We fit the time-integrated spectra for each burst and the time-resolved spectra of the five brightest bursts with several models. We find that a single power law with an exponential cutoff model fits all 29 bursts well, while 18 of the events can also be fit with two black body functions. We expand on the physical interpretation of these two models and we compare their parameters and discuss their evolution. We show that the time-integrated and time-resolved spectra reveal that E(sub peak) decreases with energy flux (and fluence) to a minimum of approx. 30 keV at F = 8.7 x 10(exp -6)erg/sq cm/s, increasing steadily afterwards. Two more sources exhibit a similar trend: SGRs J1550 - 5418 and 1806 - 20. The isotropic luminosity, L(sub iso), corresponding to these flux values is roughly similar for all sources (0.4 - l.5 x 10(exp 40) erg/s.

  4. X-ray bursts: Observation versus theory

    Science.gov (United States)

    Lewin, W. H. G.

    1981-01-01

    Results of various observations of common type I X-ray bursts are discussed with respect to the theory of thermonuclear flashes in the surface layers of accreting neutron stars. Topics covered include burst profiles; irregular burst intervals; rise and decay times and the role of hydrogen; the accuracy of source distances; accuracy in radii determination; radius increase early in the burst; the super Eddington limit; temperatures at burst maximum; and the role of the magnetic field.

  5. Two New Bursting Neutron Star Low-mass X-Ray Binaries: Swift J185003.2-005627 and Swift J1922.7-1716

    NARCIS (Netherlands)

    Degenaar, N.; Linares, M.; Altamirano, D.; Wijnands, R.

    2012-01-01

    We discuss the origin of two triggers of Swift's Burst Alert Telescope (BAT) that occurred in 2011. The triggers were identified with Swift J185003.2-005627, a previously unknown X-ray source, and the known but unclassified X-ray transient Swift J1922.7-1716. We investigate the BAT data and

  6. Communication of Unexpected and Significant Findings on Chest Radiographs With an Automated PACS Alert System.

    LENUS (Irish Health Repository)

    Hayes, Sara A

    2014-08-01

    An integral part of realizing the enormous potential of imaging in patient care is close communication between radiologists and referring physicians. One key element of this process is the communication of unexpected significant findings. The authors examined the performance of a PACS-based alert system in the appropriate communication of reports containing unexpected significant findings to referring physicians.

  7. MedWatch Safety Alerts for Human Medical Products

    Data.gov (United States)

    U.S. Department of Health & Human Services — MedWatch alerts provide timely new safety information on human drugs, medical devices, vaccines and other biologics, dietary supplements, and cosmetics. The alerts...

  8. Heterogeneity in Short Gamma-Ray Bursts

    Science.gov (United States)

    Norris, Jay P.; Gehrels Neil; Scargle, Jeffrey D.

    2011-01-01

    We analyze the Swift/BAT sample of short gamma-ray bursts, using an objective Bayesian Block procedure to extract temporal descriptors of the bursts' initial pulse complexes (IPCs). The sample comprises 12 and 41 bursts with and without extended emission (EE) components, respectively. IPCs of non-EE bursts are dominated by single pulse structures, while EE bursts tend to have two or more pulse structures. The medians of characteristic timescales - durations, pulse structure widths, and peak intervals - for EE bursts are factors of approx 2-3 longer than for non-EE bursts. A trend previously reported by Hakkila and colleagues unifying long and short bursts - the anti-correlation of pulse intensity and width - continues in the two short burst groups, with non-EE bursts extending to more intense, narrower pulses. In addition we find that preceding and succeeding pulse intensities are anti-correlated with pulse interval. We also examine the short burst X-ray afterglows as observed by the Swift/XRT. The median flux of the initial XRT detections for EE bursts (approx 6 X 10(exp -10) erg / sq cm/ s) is approx > 20 x brighter than for non-EE bursts, and the median X-ray afterglow duration for EE bursts (approx 60,000 s) is approx 30 x longer than for non-EE bursts. The tendency for EE bursts toward longer prompt-emission timescales and higher initial X-ray afterglow fluxes implies larger energy injections powering the afterglows. The longer-lasting X-ray afterglows of EE bursts may suggest that a significant fraction explode into more dense environments than non-EE bursts, or that the sometimes-dominant EE component efficiently p()wers the afterglow. Combined, these results favor different progenitors for EE and non-EE short bursts.

  9. HETEROGENEITY IN SHORT GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Norris, Jay P.; Gehrels, Neil; Scargle, Jeffrey D.

    2011-01-01

    We analyze the Swift/BAT sample of short gamma-ray bursts, using an objective Bayesian Block procedure to extract temporal descriptors of the bursts' initial pulse complexes (IPCs). The sample is comprised of 12 and 41 bursts with and without extended emission (EE) components, respectively. IPCs of non-EE bursts are dominated by single pulse structures, while EE bursts tend to have two or more pulse structures. The medians of characteristic timescales-durations, pulse structure widths, and peak intervals-for EE bursts are factors of ∼2-3 longer than for non-EE bursts. A trend previously reported by Hakkila and colleagues unifying long and short bursts-the anti-correlation of pulse intensity and width-continues in the two short burst groups, with non-EE bursts extending to more intense, narrower pulses. In addition, we find that preceding and succeeding pulse intensities are anti-correlated with pulse interval. We also examine the short burst X-ray afterglows as observed by the Swift/X-Ray Telescope (XRT). The median flux of the initial XRT detections for EE bursts (∼6x10 -10 erg cm -2 s -1 ) is ∼>20x brighter than for non-EE bursts, and the median X-ray afterglow duration for EE bursts (∼60,000 s) is ∼30x longer than for non-EE bursts. The tendency for EE bursts toward longer prompt-emission timescales and higher initial X-ray afterglow fluxes implies larger energy injections powering the afterglows. The longer-lasting X-ray afterglows of EE bursts may suggest that a significant fraction explode into denser environments than non-EE bursts, or that the sometimes-dominant EE component efficiently powers the afterglow. Combined, these results favor different progenitors for EE and non-EE short bursts.

  10. The effect of phasic auditory alerting on visual perception

    DEFF Research Database (Denmark)

    Petersen, Anders; Petersen, Annemarie Hilkjær; Bundesen, Claus

    2017-01-01

    /no-alerting design with a pure accuracy-based single-letter recognition task. Computational modeling based on Bundesen’s Theory of Visual Attention was used to examine the effect of phasic alertness on visual processing speed and threshold of conscious perception. Results show that phasic auditory alertness affects...

  11. The effect of phasic auditory alerting on visual perception.

    Science.gov (United States)

    Petersen, Anders; Petersen, Annemarie Hilkjær; Bundesen, Claus; Vangkilde, Signe; Habekost, Thomas

    2017-08-01

    Phasic alertness refers to a short-lived change in the preparatory state of the cognitive system following an alerting signal. In the present study, we examined the effect of phasic auditory alerting on distinct perceptual processes, unconfounded by motor components. We combined an alerting/no-alerting design with a pure accuracy-based single-letter recognition task. Computational modeling based on Bundesen's Theory of Visual Attention was used to examine the effect of phasic alertness on visual processing speed and threshold of conscious perception. Results show that phasic auditory alertness affects visual perception by increasing the visual processing speed and lowering the threshold of conscious perception (Experiment 1). By manipulating the intensity of the alerting cue, we further observed a positive relationship between alerting intensity and processing speed, which was not seen for the threshold of conscious perception (Experiment 2). This was replicated in a third experiment, in which pupil size was measured as a physiological marker of alertness. Results revealed that the increase in processing speed was accompanied by an increase in pupil size, substantiating the link between alertness and processing speed (Experiment 3). The implications of these results are discussed in relation to a newly developed mathematical model of the relationship between levels of alertness and the speed with which humans process visual information. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Framework to Define Structure and Boundaries of Complex Health Intervention Systems: The ALERT Project

    DEFF Research Database (Denmark)

    Boriani, Elena; Esposito, Roberto; Frazzoli, Chiara

    2017-01-01

    of a framework with focus on systems and system boundaries of interdisciplinary projects. As an example on how to apply our framework, we analyzed ALERT [an integrated sensors and biosensors’ system (BEST) aimed at monitoring the quality, health, and traceability of the chain of the bovine milk......], a multidisciplinary and interdisciplinary project based on the application of measurable biomarkers at strategic points of the milk chain for improved food security (including safety), human, and ecosystem health (1). In fact, the European food safety framework calls for science-based support to the primary producers......’ mandate for legal, scientific, and ethical responsibility in food supply. Because of its multidisciplinary and interdisciplinary approach involving human, animal, and ecosystem health, ALERT can be considered as a One Health project. Within the ALERT context, we identified the need to take into account...

  13. Alerting, Orienting or Executive Attention Networks: Differential Patters of Pupil Dilations

    Directory of Open Access Journals (Sweden)

    Ronny eGeva

    2013-10-01

    Full Text Available Attention capacities, alerting responses, orienting to sensory stimulation, and executive monitoring of performance are considered independent yet interrelated systems. These operations play integral roles in regulating the behavior of diverse species along the evolutionary ladder. Each of the primary attention constructs—alerting, orienting, and executive monitoring— involves salient autonomic correlates as evidenced by changes in reactive pupil dilation (PD, heart rate, and skin conductance. Recent technological advances that use remote high-resolution recording may allow the discernment of temporo-spatial attributes of autonomic responses that characterize the alerting, orienting, and executive monitoring networks during free viewing, irrespective of voluntary performance. This may deepen the understanding of the roles of autonomic regulation in these mental operations and may deepen our understanding of behavioral changes in verbal as well as in non-verbal species.The aim of this study was to explore differences between psychosensory pupil dilation responses in alerting, orienting, and executive conflict monitoring tasks to generate estimates of concurrent locus coeruleus (LC noradrenergic input trajectories in healthy human adults using the attention networks test (ANT. The analysis revealed a construct-specific pattern of pupil responses: alerting is characterized by an early component (Pa, its acceleration enables covert orienting, and executive control is evidenced by a prominent late component (Pe. Pupil dilation characteristics seem to be task-sensitive, allowing exploration of mental operations irrespective of conscious voluntary responses. These data may facilitate development of studies designed to assess mental operations in diverse species using autonomic responses.

  14. Investigating Driver Fatigue versus Alertness Using the Granger Causality Network

    Directory of Open Access Journals (Sweden)

    Wanzeng Kong

    2015-08-01

    Full Text Available Driving fatigue has been identified as one of the main factors affecting drivers’ safety. The aim of this study was to analyze drivers’ different mental states, such as alertness and drowsiness, and find out a neurometric indicator able to detect drivers’ fatigue level in terms of brain networks. Twelve young, healthy subjects were recruited to take part in a driver fatigue experiment under different simulated driving conditions. The Electroencephalogram (EEG signals of the subjects were recorded during the whole experiment and analyzed by using Granger-Causality-based brain effective networks. It was that the topology of the brain networks and the brain’s ability to integrate information changed when subjects shifted from the alert to the drowsy stage. In particular, there was a significant difference in terms of strength of Granger causality (GC in the frequency domain and the properties of the brain effective network i.e., causal flow, global efficiency and characteristic path length between such conditions. Also, some changes were more significant over the frontal brain lobes for the alpha frequency band. These findings might be used to detect drivers’ fatigue levels, and as reference work for future studies.

  15. Universal Safety Distance Alert Device for Road Vehicles

    Directory of Open Access Journals (Sweden)

    Matic Virant

    2016-04-01

    Full Text Available Driving with too short of a safety distance is a common problem in road traffic, often with traffic accidents as a consequence. Research has identified a lack of vehicle-mountable devices for alerting the drivers of trailing vehicles about keeping a sufficient safe distance. The principal requirements for such a device were defined. A conceptual study was performed in order to select the components for the integration of the device. Based on the results of this study, a working prototype of a flexible, self-contained device was designed, built and tested. The device is intended to be mounted on the rear of a vehicle. It uses radar as the primary distance sensor, assisted with a GPS receiver for velocity measurement. A Raspberry Pi single-board computer is used for data acquisition and processing. The alerts are shown on an LED-matrix display mounted on the rear of the host vehicle. The device software is written in Python and provides automatic operation without requiring any user intervention. The tests have shown that the device is usable on almost any motor vehicle and performs reliably in simulated and real traffic. The open issues and possibilities for future improvements are presented in the Discussion.

  16. Rapid deployable global sensing hazard alert system

    Science.gov (United States)

    Cordaro, Joseph V; Tibrea, Steven L; Shull, Davis J; Coleman, Jerry T; Shuler, James M

    2015-04-28

    A rapid deployable global sensing hazard alert system and associated methods of operation are provided. An exemplary system includes a central command, a wireless backhaul network, and a remote monitoring unit. The remote monitoring unit can include a positioning system configured to determine a position of the remote monitoring unit based on one or more signals received from one or more satellites located in Low Earth Orbit. The wireless backhaul network can provide bidirectional communication capability independent of cellular telecommunication networks and the Internet. An exemplary method includes instructing at least one of a plurality of remote monitoring units to provide an alert based at least in part on a location of a hazard and a plurality of positions respectively associated with the plurality of remote monitoring units.

  17. Optical observations of Gamma-Ray Bursts

    International Nuclear Information System (INIS)

    Hjorth, J.; Pian, E.; Fynbo, J.P.U.

    2004-01-01

    We briefly review the status and recent progress in the field of optical observations of gamma-ray burst afterglows. We will focus on the fundamental observational evidence for the relationship between gamma-ray bursts and the final evolutionary phases of massive stars. In particular, we will address (i) gamma-ray burst host galaxies, (ii) optically dark gamma-ray burst afterglows, (iii) the gamma-ray burst-supernova connection, and (iv) the relation between X-ray flashes, gamma-ray bursts, and supernovae

  18. From Demonstration System to Prototype: ShakeAlert Beta Users Provide Feedback to Improve Alert Delivery

    Science.gov (United States)

    Strauss, J. A.; Vinci, M.; Steele, W. P.; Allen, R. M.; Hellweg, M.

    2013-12-01

    Earthquake Early Warning (EEW) is a system that can provide a few to tens of seconds to minutes of warning prior to ground shaking at a given location. The goal and purpose of such a system is to reduce the damage, costs, and casualties resulting from an earthquake. A prototype earthquake early warning system (ShakeAlert) is in development by the UC Berkeley Seismological Laboratory, Caltech, ETH Zurich, University of Washington, and the USGS. Events are published to the UserDisplay--ShakeAlert's Java based graphical interface, which is being tested by a small group of beta users throughout California. The beta users receive earthquake alerts in real-time and are providing feedback on their experiences. For early warning alerts to be useful, people, companies, and institutions must know beforehand what actions they will perform when they receive the information. Beta user interactions allow the ShakeAlert team to discern: which alert delivery options are most effective, what changes would make the UserDisplay more useful in a pre-disaster situation, and most importantly, what actions users plan to take for various scenarios. We also collect feedback detailing costs of implementing actions and challenges within the beta user organizations, as well as anticipated benefits and savings. Thus, creating a blueprint for a fully operational system that will meet the needs of the public. New California users as well as the first group of Pacific Northwest users are slated to join the ShakeAlert beta test group in the fall of 2013.

  19. AMDIS Case Conference: Intrusive Medication Safety Alerts.

    Science.gov (United States)

    Graham, J; Levick, D; Schreiber, R

    2010-01-01

    Clinical decision support that provides enhanced patient safety at the point of care frequently encounters significant pushback from clinicians who find the process intrusive or time-consuming. We present a hypothetical medical center's dilemma about its allergy alerting system and discuss similar problems faced by real hospitals. We then share some lessons learned and best practices for institutions who wish to implement these tools themselves.

  20. AMDIS Case Conference: Intrusive Medication Safety Alerts

    OpenAIRE

    Graham, J.; Levick, D.; Schreiber, R.

    2010-01-01

    Clinical decision support that provides enhanced patient safety at the point of care frequently encounters significant pushback from clinicians who find the process intrusive or time-consuming. We present a hypothetical medical center’s dilemma about its allergy alerting system and discuss similar problems faced by real hospitals. We then share some lessons learned and best practices for institutions who wish to implement these tools themselves.

  1. Commercial Mobile Alert Service (CMAS) Scenarios

    Science.gov (United States)

    2012-05-01

    Commercial Mobile Alert Service (CMAS) Scenarios The WEA Project Team May 2012 SPECIAL REPORT CMU/SEI-2012-SR-020 CERT® Division, Software ...Homeland Security under Contract No. FA8721-05-C-0003 with Carnegie Mellon University for the operation of the Software Engineering Institute, a federally...DISTRIBUTES IT “AS IS.” References herein to any specific commercial product, process, or service by trade name, trade mark, manufacturer, or otherwise

  2. Static Analysis Alert Audits: Lexicon and Rules

    Science.gov (United States)

    2016-11-04

    1 Audit Rules and Lexicon Date 00, 2016 © 2016 Carnegie Mellon University [DISTRIBUTION STATEMENT A] This material has been approved for public...DISTRIBUTION STATEMENT A] This material has been approved for public release and unlimited distribution. REV-03.18.2016.0 Static Analysis Alert Audits ...Lexicon And Rules William Snavely 2 Audit Rules and Lexicon Date 00, 2016 © 2016 Carnegie Mellon University [DISTRIBUTION STATEMENT A] This material

  3. Cosmic gamma-ray bursts

    International Nuclear Information System (INIS)

    Hurley, K.

    1989-01-01

    This paper reviews the essential aspects of the gamma-ray burst (GRB) phenomenon, with emphasis on the more recent results. GRBs are introduced by their time histories, which provide some evidence for a compact object origin. The energy spectra of bursts are presented and they are seen to demonstrate practically unambiguously that the origin of some GRBs involves neutron stars. Counterpart searches are reviewed briefly and the statistical properties of bursters treated. This paper presents a review of the three known repeating bursters (the Soft Gamma Repeaters). Extragalactic and galactic models are discussed and future prospects are assessed

  4. Feasibility of seismic alert systems in India

    International Nuclear Information System (INIS)

    Chauhan, P.K.S.; Pandey, Y.

    2012-01-01

    Natural disasters like flood, earthquakes and cyclones are very frequent in India since historical times. As far as the casualties are concerned, globally earthquakes are second in the list after the flood. The loss of property due to these earthquakes is huge and enormous. In the light of the present knowledge base, earthquake prediction is far from being a reality. An early earthquake warning has potential to save the precious human lives. In the present day scenario seismic instrumentation and telecommunication permits the implementation of seismic alert system (SAS) based on the real-time measurement of ground motions near the source. SAS is capable of providing a warning of several seconds before the arrival of destructive seismic waves caused by a large earthquake. SAS is successfully operational in many countries of the world. In a country, like India where earthquakes are taking heavy toll on the human lives and property, seismic alert system may prove to be very important step in natural hazard mitigation strategy. In this paper, an attempt has been made to compute the available alarm time before the destructive earthquake waves reaches to the cities like Delhi, Lucknow, Patna and Kolkata taking Himalaya as the source and feasibility of seismic alert system in Indian scenario. (author)

  5. Spiking and bursting patterns of fractional-order Izhikevich model

    Science.gov (United States)

    Teka, Wondimu W.; Upadhyay, Ranjit Kumar; Mondal, Argha

    2018-03-01

    Bursting and spiking oscillations play major roles in processing and transmitting information in the brain through cortical neurons that respond differently to the same signal. These oscillations display complex dynamics that might be produced by using neuronal models and varying many model parameters. Recent studies have shown that models with fractional order can produce several types of history-dependent neuronal activities without the adjustment of several parameters. We studied the fractional-order Izhikevich model and analyzed different kinds of oscillations that emerge from the fractional dynamics. The model produces a wide range of neuronal spike responses, including regular spiking, fast spiking, intrinsic bursting, mixed mode oscillations, regular bursting and chattering, by adjusting only the fractional order. Both the active and silent phase of the burst increase when the fractional-order model further deviates from the classical model. For smaller fractional order, the model produces memory dependent spiking activity after the pulse signal turned off. This special spiking activity and other properties of the fractional-order model are caused by the memory trace that emerges from the fractional-order dynamics and integrates all the past activities of the neuron. On the network level, the response of the neuronal network shifts from random to scale-free spiking. Our results suggest that the complex dynamics of spiking and bursting can be the result of the long-term dependence and interaction of intracellular and extracellular ionic currents.

  6. An IDS Alerts Aggregation Algorithm Based on Rough Set Theory

    Science.gov (United States)

    Zhang, Ru; Guo, Tao; Liu, Jianyi

    2018-03-01

    Within a system in which has been deployed several IDS, a great number of alerts can be triggered by a single security event, making real alerts harder to be found. To deal with redundant alerts, we propose a scheme based on rough set theory. In combination with basic concepts in rough set theory, the importance of attributes in alerts was calculated firstly. With the result of attributes importance, we could compute the similarity of two alerts, which will be compared with a pre-defined threshold to determine whether these two alerts can be aggregated or not. Also, time interval should be taken into consideration. Allowed time interval for different types of alerts is computed individually, since different types of alerts may have different time gap between two alerts. In the end of this paper, we apply proposed scheme on DAPRA98 dataset and the results of experiment show that our scheme can efficiently reduce the redundancy of alerts so that administrators of security system could avoid wasting time on useless alerts.

  7. Alerts Visualization and Clustering in Network-based Intrusion Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dr. Li [University of Tennessee; Gasior, Wade C [ORNL; Dasireddy, Swetha [University of Tennessee

    2010-04-01

    Today's Intrusion detection systems when deployed on a busy network overload the network with huge number of alerts. This behavior of producing too much raw information makes it less effective. We propose a system which takes both raw data and Snort alerts to visualize and analyze possible intrusions in a network. Then we present with two models for the visualization of clustered alerts. Our first model gives the network administrator with the logical topology of the network and detailed information of each node that involves its associated alerts and connections. In the second model, flocking model, presents the network administrator with the visual representation of IDS data in which each alert is represented in different color and the alerts with maximum similarity move together. This gives network administrator with the idea of detecting various of intrusions through visualizing the alert patterns.

  8. BATSE/OSSE Rapid Burst Response

    National Research Council Canada - National Science Library

    Matz, S. M; Grove, J. E; Johnson, W. N; Kurfess, J. D; Share, G. H; Fishman, G. J; Meegan, Charles A

    1995-01-01

    ...) slew the OSSE detectors to burst locations determined on-board by BATSE. This enables OSSE to make sensitive searches for prompt and delayed post-burst line and continuum emission above 50 keV...

  9. US Army Nuclear Burst Detection System (NBDS)

    International Nuclear Information System (INIS)

    Glaser, R.F.

    1980-07-01

    The Nuclear Burst Detection System (NBDS) was developed to meet the Army requirements of an unattended, automatic nuclear burst reporting system. It provides pertinent data for battlefield commanders on a timely basis with high reliability

  10. Short duration gamma ray bursts

    Indian Academy of Sciences (India)

    Observations have revealed that long bursts, with recorded afterglow, tend to reside in the star forming regions of normal galaxies. Moreover, GRB 980425 ... observer is negligible due to the special relativistic time dilation. However, because of deceleration, eventually Γ−1 > θj and thereafter, sideways expansion becomes.

  11. Optothermally actuated capillary burst valve

    DEFF Research Database (Denmark)

    Eriksen, Johan; Bilenberg, Brian; Kristensen, Anders

    2017-01-01

    be burst by raising the temperature due to the temperature dependence of the fluid surface tension. We address individual valves by using a local heating platform based on a thin film of near infrared absorber dye embedded in the lid used to seal the microfluidic device [L. H. Thamdrup et al., Nano Lett...

  12. Dark gamma-ray bursts

    Science.gov (United States)

    Brdar, Vedran; Kopp, Joachim; Liu, Jia

    2017-03-01

    Many theories of dark matter (DM) predict that DM particles can be captured by stars via scattering on ordinary matter. They subsequently condense into a DM core close to the center of the star and eventually annihilate. In this work, we trace DM capture and annihilation rates throughout the life of a massive star and show that this evolution culminates in an intense annihilation burst coincident with the death of the star in a core collapse supernova. The reason is that, along with the stellar interior, also its DM core heats up and contracts, so that the DM density increases rapidly during the final stages of stellar evolution. We argue that, counterintuitively, the annihilation burst is more intense if DM annihilation is a p -wave process than for s -wave annihilation because in the former case, more DM particles survive until the supernova. If among the DM annihilation products are particles like dark photons that can escape the exploding star and decay to standard model particles later, the annihilation burst results in a flash of gamma rays accompanying the supernova. For a galactic supernova, this "dark gamma-ray burst" may be observable in the Čerenkov Telescope Array.

  13. FULCRUM - A dam safety management and alert system

    Energy Technology Data Exchange (ETDEWEB)

    Butt, Cameron; Greenaway, Graham [Knight Piesold Ltd., Vancouver, (Canada)

    2010-07-01

    Efficient management of instrumentation, monitoring and inspection data are the keys to safe performance and dam structure stability. This paper presented a data management system, FULCRUM, developed for dam safety management. FULCRUM is a secure web-based data management system which simplifies the process of data collection, processing and analysis of the information. The system was designed to organize and coordinate dam safety management requirements. Geotechnical instrumentation such as piezometers or inclinometers and operating data can be added to the database. Data from routine surveillance and engineering inspection can also be incorporated into the database. The system provides users with immediate access to historical and recent data. The integration of a GIS system allows for rapid assessment of the project site. Customisable alerting protocols can be set to identify and respond quickly to significant changes in operating conditions and potential impacts on dam safety.

  14. Need of a disaster alert system for India through a network of real-time monitoring of sea-level and other meteorological events

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desai, R.G.P.

    Need of a disaster alert system (DAS) capable of online transmission of real-time integrated sea-level and surface meteorological data is discussed. In addition to INSAT platform transmit terminal, VHF, etc., the ubiquitous cellular phone network...

  15. A Service-Oriented Healthcare Message Alerting Architecture in an Asia Medical Center: A Case Study

    Directory of Open Access Journals (Sweden)

    Jin-Shin Lai

    2009-06-01

    Full Text Available This paper illustrates how our development team has used some information technologies to let physicians obtain an instant abnormal laboratory result report for critical patient care services. We have implementeda healthcare message alerting system (HMAS on a healthcare short message service (HSMS engine and the distributed healthcare-oriented service environment (DiHOSE in the National Taiwan University Hospital (NTUH. The HSMS engine has a general interface for all applications which could easily send any kind of alerting messages. Fundamentally, the DiHOSE uses HL7 standard formats to process the information exchange behaviors and can be flexibly extended for reasonable user requirements. The disease surveillance subsystem is an integral part of NTUH new hospital information system which is based on DiHOSE and the disease surveillance subsystem would send alerting messages through the HSMS engine. The latest cell phone message alerting subsystem, a case study, in NTUH proved that the DiHOSE could integrate the user required functions without much work. We concluded that both HSMS and DiHOSE can generalize and extend application demands efficiently.

  16. Stellar Sources of Gamma-ray Bursts

    OpenAIRE

    Luchkov, B. I.

    2011-01-01

    Correlation analysis of Swift gamma-ray burst coordinates and nearby star locations (catalog Gliese) reveals 4 coincidences with good angular accuracy. The random probability is 4\\times 10^{-5}, so evidencing that coincident stars are indeed gamma-ray burst sources. Some additional search of stellar gamma-ray bursts is discussed.

  17. Detecting pipe bursts by monitoring water demand

    NARCIS (Netherlands)

    Bakker, M.; Vreeburg, J.H.G.; Van der Roer, M.; Sperber, V.

    2012-01-01

    An algorithm which compares measured and predicted water demands to detect pipe bursts was developed and tested on three data sets of water demand and reported pipe bursts of three years. The algorithm proved to be able to detect bursts where the water loss exceeds 30% of the average water demand in

  18. Fine structure in fast drift storm bursts

    International Nuclear Information System (INIS)

    McConnell, D.; Ellis, G.R.A.

    1981-01-01

    Recent observations with high time resolution of fast drift storm (FDS) solar bursts are described. A new variety of FDS bursts characterised by intensity maxima regularly placed in the frequency domain is reported. Possible interpretations of this are mentioned and the implications of the short duration of FDS bursts are discussed. (orig.)

  19. PleurAlert: an augmented chest drainage system with electronic sensing, automated alerts and internet connectivity.

    Science.gov (United States)

    Leeson, Cory E; Weaver, Robert A; Bissell, Taylor; Hoyer, Rachel; McClain, Corinne; Nelson, Douglas A; Samosky, Joseph T

    2012-01-01

    We have enhanced a common medical device, the chest tube drainage container, with electronic sensing of fluid volume, automated detection of critical alarm conditions and the ability to automatically send alert text messages to a nurse's cell phone. The PleurAlert system provides a simple touch-screen interface and can graphically display chest tube output over time. Our design augments a device whose basic function dates back 50 years by adding technology to automate and optimize a monitoring process that can be time consuming and inconvenient for nurses. The system may also enhance detection of emergency conditions and speed response time.

  20. Bursting pressure of autofrettaged cylinders with inclined external cracks

    International Nuclear Information System (INIS)

    Seifi, Rahman; Babalhavaeji, Majid

    2012-01-01

    Autofrettaging a pressure vessel improves its pressure capacity. This is reliable if there isn’t any crack or other type of flaws. In this paper, the effects of external surface cracks on bursting pressure of autofrettaged cylinders are studied. It is observed that bursting pressure decreases considerably (up to 30%) due to external cracks in the cylinders without autofrettage. This reduction increases for high levels of the applied autofrettage. External axial cracks have more effects than inclined cracks. Comparing experimental and numerical results show that the numerical methods can acceptably predict the bursting pressure of the autofrettaged cracked cylinders. These predictions are valid when the fracture parameter (J-Integral) is calculated from the modified equation that takes into account the effects of residual stresses. - Highlights: ► Modified J-Integral can be used for study of autofrettaged cracked cylinders. ► External axial cracks reduce considerably the pressure capacity of cylinders. ► External circumferential cracks have not considerable effects on bursting pressure. ► Autofrettage has contrary effects on external crack in compared with internal crack.

  1. Bursting pressure of autofrettaged cylinders with inclined external cracks

    Energy Technology Data Exchange (ETDEWEB)

    Seifi, Rahman, E-mail: rseifi@basu.ac.ir [Mechanical Engineering Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Babalhavaeji, Majid [Mechanical Engineering Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

    2012-01-15

    Autofrettaging a pressure vessel improves its pressure capacity. This is reliable if there isn't any crack or other type of flaws. In this paper, the effects of external surface cracks on bursting pressure of autofrettaged cylinders are studied. It is observed that bursting pressure decreases considerably (up to 30%) due to external cracks in the cylinders without autofrettage. This reduction increases for high levels of the applied autofrettage. External axial cracks have more effects than inclined cracks. Comparing experimental and numerical results show that the numerical methods can acceptably predict the bursting pressure of the autofrettaged cracked cylinders. These predictions are valid when the fracture parameter (J-Integral) is calculated from the modified equation that takes into account the effects of residual stresses. - Highlights: Black-Right-Pointing-Pointer Modified J-Integral can be used for study of autofrettaged cracked cylinders. Black-Right-Pointing-Pointer External axial cracks reduce considerably the pressure capacity of cylinders. Black-Right-Pointing-Pointer External circumferential cracks have not considerable effects on bursting pressure. Black-Right-Pointing-Pointer Autofrettage has contrary effects on external crack in compared with internal crack.

  2. Using GRB 080723B to cross-calibrate Fermi/GBM and INTEGRAL

    International Nuclear Information System (INIS)

    Kienlin, A. von; Briggs, M. S.; Connoughton, V.; Preece, R. D.; McBreen, S.; Sazonov, Sergey; Tsygankov, Sergey; Wilson-Hodge, C. A.

    2009-01-01

    On July 23, 2008 GRB 080723B, a bright GRB lasting about 105 s was detected by the INTEGRAL burst alert system. This burst was also detected by the Fermi Gamma-ray burst monitor. At this time no Fermi/GBM GCN notices were distributed to the public because Fermi was still in commissioning phase. The simultaneous detection of a bright GRB by both satellites gives us the opportunity to cross-calibrate the GBM with the already well-calibrated instruments on-board INTEGRAL, the Spectrometer SPI and the Imager IBIS. Time-resolved spectroscopy of this long and structured GRB is of special importance because Fermi was slewing during the GRB was still ongoing. In this paper we present a first and still preliminary analysis of the GBM spectra and compare them to those obtained by SPI for the same selection of time intervals. A more accurate cross-calibration will be forthcoming when the improved in-flight calibration of GBM is available and the corresponding data and responses can be reprocessed.

  3. Solar Radio Bursts and Space Weather

    Science.gov (United States)

    Gopalswamy, Natchimuthuk,

    2012-01-01

    Radio bursts from the Sun are produced by electron accelerated to relativistic energies by physical processes on the Sun such as solar flares and coronal mass ejections (CMEs). The radio bursts are thus good indicators of solar eruptions. Three types of nonthermal radio bursts are generally associated with CMEs. Type III bursts due to accelerated electrons propagating along open magnetic field lines. The electrons are thought to be accelerated at the reconnection region beneath the erupting CME, although there is another view that the electrons may be accelerated at the CME-driven shock. Type II bursts are due to electrons accelerated at the shock front. Type II bursts are also excellent indicators of solar energetic particle (SEP) events because the same shock is supposed accelerate electrons and ions. There is a hierarchical relationship between the wavelength range of type /I bursts and the CME kinetic energy. Finally, Type IV bursts are due to electrons trapped in moving or stationary structures. The low frequency stationary type IV bursts are observed occasionally in association with very fast CMEs. These bursts originate from flare loops behind the erupting CME and hence indicate tall loops. This paper presents a summary of radio bursts and their relation to CMEs and how they can be useful for space weather predictions.

  4. Disease spreading with epidemic alert on small-world networks

    International Nuclear Information System (INIS)

    Han, Xiao-Pu

    2007-01-01

    Base on two-dimension small-world networks, a susceptible-infected model with epidemic alert is proposed in this Letter. In this model, if some parts of the network are alarmed as dangerous, a fraction of edges between the alarmed parts and others will be removed, and two cases of alerting rules that the degree and frequency of contacts kept unchanged are considered respectively. The numerical simulations show that the spreading velocity is reduced by the accurate and timely epidemic alert, and the more accurate and timely, the stronger the deceleration effect. This model indicates that to broadcast epidemic alert timely is helpful and necessary in the control of epidemic spreading, and in agreement with the general view of epidemic alert. This work is helpful to understand the effects of epidemic alert on disease spreading

  5. Electronic Immunization Alerts and Spillover Effects on Other Preventive Care.

    Science.gov (United States)

    Kim, Julia M; Rivera, Maria; Persing, Nichole; Bundy, David G; Psoter, Kevin J; Ghazarian, Sharon R; Miller, Marlene R; Solomon, Barry S

    2017-08-01

    The impact of electronic health record (EHR) immunization clinical alert systems on the delivery of other preventive services remains unknown. We assessed for spillover effects of an EHR immunization alert on delivery of 6 other preventive services, in children 18 to 30 months of age needing immunizations. We conducted a secondary data analysis, with additional primary data collection, of a randomized, historically controlled trial to improve immunization rates with EHR alerts, in an urban, primary care clinic. No significant differences were found in screening for anemia, lead, development, nutrition, and injury prevention counseling in children prompting EHR immunization alerts (n = 129), compared with controls (n = 135). Significant increases in oral health screening in patients prompting EHR alerts (odds ratio = 4.8, 95% CI = 1.8-13.0) were likely due to practice changes over time. An EHR clinical alert system targeting immunizations did not have a spillover effect on the delivery of other preventive services.

  6. Some polarization features of solar microwave bursts

    Energy Technology Data Exchange (ETDEWEB)

    Uralov, A M; Nefed' ev, V P [AN SSSR, Irkutsk. Sibirskij Inst. Zemnogo Magnetizma Ionosfery i Rasprostraneniya Radiovoln

    1977-01-01

    Consequences of the thermal microwave burst model proposed earlier have been considered. According to the model the centimeter burst is generated at the heat propagation to the upper atmosphere. The polarization features of the burst are explained: a change of the polarization sign in a frequency range, a rapid change of the polarization sign in the development of a burst at a fixed frequency, a lack of time coincidence of the moments of the burst maximum of the polarization and of the total flux. From the model the consequences are obtained, which are still not confirmed by experiment. An ordinary-type wave prevails in the burst radiation, in the course of which the polarization degree falls on the ascending branch of bursts development. At the change of the polarization sign at the fixed frequency prior to the sign change an ordinary-type wave should be present in excess and later an extreordinary type wave.

  7. Stimulus induced bursts in severe postanoxic encephalopathy.

    Science.gov (United States)

    Tjepkema-Cloostermans, Marleen C; Wijers, Elisabeth T; van Putten, Michel J A M

    2016-11-01

    To report on a distinct effect of auditory and sensory stimuli on the EEG in comatose patients with severe postanoxic encephalopathy. In two comatose patients admitted to the Intensive Care Unit (ICU) with severe postanoxic encephalopathy and burst-suppression EEG, we studied the effect of external stimuli (sound and touch) on the occurrence of bursts. In patient A bursts could be induced by either auditory or sensory stimuli. In patient B bursts could only be induced by touching different facial regions (forehead, nose and chin). When stimuli were presented with relatively long intervals, bursts persistently followed the stimuli, while stimuli with short intervals (encephalopathy can be induced by external stimuli, resulting in stimulus-dependent burst-suppression. Stimulus induced bursts should not be interpreted as prognostic favourable EEG reactivity. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  8. A case study of pediatric asthma alerts from the beacon community program in cincinnati: technology is just the first step.

    Science.gov (United States)

    Trudnak, Tara; Mansour, Mona; Mandel, Keith; Sauers, Hadley; Pandzik, Gerry; Donisi, Carl; Fairbrother, Gerry

    2014-01-01

    The Beacon Community in Cincinnati, Ohio was an innovative, community-wide initiative to use technology to transform care. One important feature was the development of regional alerts to notify practices when patients were hospitalized or seen in the emergency department. The purpose of this paper is to describe the way in which technology engages the improvement process, and to describe the early stages of learning how to use technology to enhance quality improvement. We interviewed key Beacon leaders as well as providers and office staff in selected practices. We also collected preliminary data from practices that reflected handling of alerts, including the number of asthma related alerts received and followed up. Regional alerts, supplied by the community-wide health information exchange, were a significant addition to the quality improvement effort in that they enabled practices to identify and follow up with additional children at risk. An important finding was the substantial effort at the practice level to integrate technology into ongoing patient care. Developing the technology for community wide alerts represented a significant endeavor in the Cincinnati Beacon Community. However, the technology was just the first step. Despite extra effort and time required on the part of individual practices, they reported that the value of having alerts was high. Hospital and ED visits represent some of the most costly aspects of care, and an efficient process for intervening with children using these costly services was seen as of significant value.

  9. UFFO/Lomonosov: The Payload for the Observation of Early Photons from Gamma Ray Bursts

    DEFF Research Database (Denmark)

    Park, I. H.; Panasyuk, M. I.; Reglero, V.

    2018-01-01

    . Fast response measurements of the optical emission of GRB will be made by a Slewing Mirror Telescope (SMT), a key instrument of the payload, which will open a new frontier in transient studies by probing the early optical rise of GRBs with a response time in seconds for the first time. The SMT employs...... a rapidly slewing mirror to redirect the optical axis of the telescope to a GRB position prior determined by the UFFO Burst Alert Telescope (UBAT), the other onboard instrument, for the observation and imaging of X-rays. UFFO/Lomonosov was launched successfully from Vostochny, Russia on April 28, 2016...

  10. Sleepiness and alertness in American industries

    International Nuclear Information System (INIS)

    Coleman, R.M.; Dillingham, J.; Dement, W.C.

    1989-01-01

    Recent evidence that industrial accidents may be caused in part by shiftworkers' lack of alertness has caused growing concern at the US Nuclear Regulatory Commission and within the scientific community. The purpose of the study reported in this paper was threefold: (1) Is sleepiness on the job specific to utility plants? (2) Are performance and safety problems caused by sleepiness specific to utility plants? (3) Are specific shift schedules associated with a higher prevalence of sleepiness? Findings indicate sleepiness on the job among shiftworkers is a widespread problem, not limited to the nuclear power industry. The most common solution in American industry is to overstaff each shift and discipline sleeping employees. Results show this is not effective. A more proactive solution is recommended including some of the following: (1) Provide employees education to assist adjustment to shiftwork. (2) Design and implement shift schedules that are more compatible with human physiological capabilities. (3) Allow officially sanctioned napping on shift as is done in Japan. (4) Divide 6-, 8-, or 12-h shifts into smaller blocks of 2 to 3 h of primary duty. (5) make the environment where employees work more conductive to alertness. (6) Develop a firehouse type of schedule where some employees sleep throughout the night, but are awakened if operational problems arise. (7) Provide incentives to employees to adjust their life style to the night shift and reward them with time off

  11. Sleepiness and alertness in American industries

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, R.M.; Dillingham, J.; Dement, W.C.

    1989-01-01

    Recent evidence that industrial accidents may be caused in part by shiftworkers' lack of alertness has caused growing concern at the US Nuclear Regulatory Commission and within the scientific community. The purpose of the study reported in this paper was threefold: (1) Is sleepiness on the job specific to utility plants (2) Are performance and safety problems caused by sleepiness specific to utility plants (3) Are specific shift schedules associated with a higher prevalence of sleepiness Findings indicate sleepiness on the job among shiftworkers is a widespread problem, not limited to the nuclear power industry. The most common solution in American industry is to overstaff each shift and discipline sleeping employees. Results show this is not effective. A more proactive solution is recommended including some of the following: (1) Provide employees education to assist adjustment to shiftwork. (2) Design and implement shift schedules that are more compatible with human physiological capabilities. (3) Allow officially sanctioned napping on shift as is done in Japan. (4) Divide 6-, 8-, or 12-h shifts into smaller blocks of 2 to 3 h of primary duty. (5) make the environment where employees work more conductive to alertness. (6) Develop a firehouse type of schedule where some employees sleep throughout the night, but are awakened if operational problems arise. (7) Provide incentives to employees to adjust their life style to the night shift and reward them with time off.

  12. The rapid decline of the prompt emission in Gamma-Ray Bursts

    CERN Document Server

    Dado, Shlomo; De Rújula, Alvaro

    2008-01-01

    Many gamma ray bursts (GRBs) have been observed with the Burst-Alert and X-Ray telescopes of the SWIFT satellite. The successive `pulses' of these GRBs end with a fast decline and a fast spectral softening, until they are overtaken by another pulse, or the last pulse's decline is overtaken by a less rapidly-varying `afterglow'. The fast decline-phase has been attributed, in the standard fireball model of GRBs, to `high-latitude' synchrotron emission from a collision of two conical shells. This interpretation does not agree with the observed spectral softening. The temporal behaviour and the spectral evolution during the fast-decline phase agree with the predictions of the cannonball model of GRBs.

  13. Predicting rock bursts in mines

    Science.gov (United States)

    Spall, H.

    1979-01-01

    In terms of lives lost, rock bursts in underground mines can be as hazardous as earthquakes on the surface. So it is not surprising that fo the last 40 years the U.S Bureau of Mines has been using seismic methods for detecting areas in underground mines where there is a high differential stress which could lead to structural instability of the rock mass being excavated.

  14. NICER Eyes on Bursting Stars

    Science.gov (United States)

    Kohler, Susanna

    2018-03-01

    What happens to a neutron stars accretion disk when its surface briefly explodes? A new instrument recently deployed at the International Space Station (ISS) is now watching bursts from neutron stars and reporting back.Deploying a New X-Ray MissionLaunch of NICER aboard a Falcon 9 rocket in June 2017. [NASA/Tony Gray]In early June of 2017, a SpaceX Dragon capsule on a Falcon 9 rocket launched on a resupply mission to the ISS. The pressurized interior of the Dragon contained the usual manifest of crew supplies, spacewalk equipment, and vehicle hardware. But the unpressurized trunk of the capsule held something a little different: the Neutron star Interior Composition Explorer (NICER).In the two weeks following launch, NICER was extracted from the SpaceX Dragon capsule and installed on the ISS. And by the end of the month, the instrument was already collecting its first data set: observations of a bright X-ray burst from Aql X-1, a neutron star accreting matter from a low-mass binary companion.Impact of BurstsNICERs goal is to provide a new view of neutron-star physics at X-ray energies of 0.212 keV a window that allows us to explore bursts of energy that neutron stars sometimes emit from their surfaces.Artists impression of an X-ray binary, in which a compact object accretes material from a companion star. [ESA/NASA/Felix Mirabel]In X-ray burster systems, hydrogen- and helium-rich material from a low-mass companion star piles up in an accretion disk around the neutron star. This material slowly funnels onto the neutron stars surface, forming a layer that gravitationally compresses and eventually becomes so dense and hot that runaway nuclear fusion ignites.Within seconds, the layer of material is burned up, producing a burst of emission from the neutron star that outshines even the inner regions of the hot accretion disk. Then more material funnels onto the neutron star and the process begins again.Though we have a good picture of the physics that causes these bursts

  15. Alerts in mobile healthcare applications: requirements and pilot study.

    Science.gov (United States)

    Kafeza, Eleanna; Chiu, Dickson K W; Cheung, S C; Kafeza, Marina

    2004-06-01

    Recent advances in mobile technologies have greatly extended traditional communication technologies to mobile devices. At the same time, healthcare environments are by nature "mobile" where doctors and nurses do not have fixed workspaces. Irregular and exceptional events are generated in daily hospital routines, such as operations rescheduling, laboratory/examination results, and adverse drug events. These events may create requests that should be delivered to the appropriate person at the appropriate time. Those requests that are classified as urgent are referred to as alerts. Efficient routing and monitoring of alerts are keys to quality and cost-effective healthcare services. Presently, these are generally handled in an ad hoc manner. In this paper, we propose the use of a healthcare alert management system to handle these alert messages systematically. We develop a model for specifying alerts that are associated with medical tasks and a set of parameters for their routing. We design an alert monitor that matches medical staff and their mobile devices to receive alerts, based on the requirements of these alerts. We also propose a mechanism to handle and reroute, if necessary, an alert message when it has not been acknowledged within a specific deadline.

  16. Detection of artifacts from high energy bursts in neonatal EEG.

    Science.gov (United States)

    Bhattacharyya, Sourya; Biswas, Arunava; Mukherjee, Jayanta; Majumdar, Arun Kumar; Majumdar, Bandana; Mukherjee, Suchandra; Singh, Arun Kumar

    2013-11-01

    Detection of non-cerebral activities or artifacts, intermixed within the background EEG, is essential to discard them from subsequent pattern analysis. The problem is much harder in neonatal EEG, where the background EEG contains spikes, waves, and rapid fluctuations in amplitude and frequency. Existing artifact detection methods are mostly limited to detect only a subset of artifacts such as ocular, muscle or power line artifacts. Few methods integrate different modules, each for detection of one specific category of artifact. Furthermore, most of the reference approaches are implemented and tested on adult EEG recordings. Direct application of those methods on neonatal EEG causes performance deterioration, due to greater pattern variation and inherent complexity. A method for detection of a wide range of artifact categories in neonatal EEG is thus required. At the same time, the method should be specific enough to preserve the background EEG information. The current study describes a feature based classification approach to detect both repetitive (generated from ECG, EMG, pulse, respiration, etc.) and transient (generated from eye blinking, eye movement, patient movement, etc.) artifacts. It focuses on artifact detection within high energy burst patterns, instead of detecting artifacts within the complete background EEG with wide pattern variation. The objective is to find true burst patterns, which can later be used to identify the Burst-Suppression (BS) pattern, which is commonly observed during newborn seizure. Such selective artifact detection is proven to be more sensitive to artifacts and specific to bursts, compared to the existing artifact detection approaches applied on the complete background EEG. Several time domain, frequency domain, statistical features, and features generated by wavelet decomposition are analyzed to model the proposed bi-classification between burst and artifact segments. A feature selection method is also applied to select the

  17. GRB 110205A: ANATOMY OF A LONG GAMMA-RAY BURST

    International Nuclear Information System (INIS)

    Gendre, B.; Stratta, G.; Atteia, J. L.; Klotz, A.; Boër, M.; Colas, F.; Vachier, F.; Kugel, F.; Rinner, C.; Laas-Bourez, M.; Strajnic, J.

    2012-01-01

    The Swift burst GRB 110205A was a very bright burst visible in the Northern Hemisphere. GRB 110205A was intrinsically long and very energetic and it occurred in a low-density interstellar medium environment, leading to delayed afterglow emission and a clear temporal separation of the main emitting components: prompt emission, reverse shock, and forward shock. Our observations show several remarkable features of GRB 110205A: the detection of prompt optical emission strongly correlated with the Burst Alert Telescope light curve, with no temporal lag between the two; the absence of correlation of the X-ray emission compared to the optical and high-energy gamma-ray ones during the prompt phase; and a large optical re-brightening after the end of the prompt phase, that we interpret as a signature of the reverse shock. Beyond the pedagogical value offered by the excellent multi-wavelength coverage of a gamma-ray burst with temporally separated radiating components, we discuss several questions raised by our observations: the nature of the prompt optical emission and the spectral evolution of the prompt emission at high energies (from 0.5 keV to 150 keV); the origin of an X-ray flare at the beginning of the forward shock; and the modeling of the afterglow, including the reverse shock, in the framework of the classical fireball model.

  18. Fuzzy-Based Adaptive Hybrid Burst Assembly Technique for Optical Burst Switched Networks

    Directory of Open Access Journals (Sweden)

    Abubakar Muhammad Umaru

    2014-01-01

    Full Text Available The optical burst switching (OBS paradigm is perceived as an intermediate switching technology for future all-optical networks. Burst assembly that is the first process in OBS is the focus of this paper. In this paper, an intelligent hybrid burst assembly algorithm that is based on fuzzy logic is proposed. The new algorithm is evaluated against the traditional hybrid burst assembly algorithm and the fuzzy adaptive threshold (FAT burst assembly algorithm via simulation. Simulation results show that the proposed algorithm outperforms the hybrid and the FAT algorithms in terms of burst end-to-end delay, packet end-to-end delay, and packet loss ratio.

  19. Intermediate long X-ray bursts from the ultra-compact binary candidate SLX1737-282

    DEFF Research Database (Denmark)

    Falanga, M.; Chenevez, Jérôme; Cumming, A.

    2008-01-01

    . The observed intermediate long burst properties from SLX 1737-282 are consistent with helium ignition at the column depth of 5-8 × 109 g cm-2 and a burst energy release of 1041 erg. The apparent recurrence time of ≃86 days between the intermediate long bursts from SLX 1737-282 suggests a regime of unstable...... bursts. Methods: Up to now only four bursts, all with duration between ≃15{-}30 min, have been recorded for SLX 1737-282. The properties of three of these intermediate long X-ray bursts observed by INTEGRAL are investigated and compared to other burster sources. The broadband spectrum of the persistent...

  20. NAPS as an Alertness Management Strategy

    Science.gov (United States)

    Rosekind, Mark R.; Smith, Roy M.; Miller, Donna L.; Co, Elizabeth L.; Gregory, Kevin B.; Gander, Philippa H.; Lebacqz, J. Victor

    2001-01-01

    Today, 24-hour operations are necessary to meet the demands of our society and the requirements of our industrialized global economy. These around-the-clock demands pose unique physiological challenges for the humans who remain central to safe and productive operations. Optimal alertness and performance are critical factors that are increasingly challenged by unusual, extended, or changing work/rest schedules. Technological advancements and automated systems can exacerbate the challenges faced by the human factor in these environments. Shift work, transportation demands, and continuous operations engender sleep loss and circadian disruption. Both of these physiological factors can lead to increased sleepiness, decreased performance, and a reduced margin of safety. These factors can increase vulnerability to incidents and accidents in operational settings. The consequences can have both societal effects (e.g., major destructive accidents such as Three Mile Island, Exxon Valdez, Bhopal) and personal effects (e.g., an accident driving home after a night shift).

  1. Stability of alert survivable forces during reductions

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1998-01-01

    The stability of current and projected strategic forces are discussed within a framework that contains elements of current US and Russian analyses. For current force levels and high alert, stability levels are high, as are the levels of potential strikes, due to the large forces deployed. As force levels drop towards those of current value target sets, the analysis becomes linear, concern shifts from stability to reconstitution, and survivable forces drop out. Adverse marginal costs generally provide disincentives for the reduction of vulnerable weapons, but the exchange of vulnerable for survivable weapons could reduce cost while increasing stability even for aggressive participants. Exchanges between effective vulnerable and survivable missile forces are studied with an aggregated, probabilistic model, which optimizes each sides` first and determines each sides` second strikes and costs by minimizing first strike costs.

  2. An Artificial Intelligence Classification Tool and Its Application to Gamma-Ray Bursts

    Science.gov (United States)

    Hakkila, Jon; Haglin, David J.; Roiger, Richard J.; Giblin, Timothy; Paciesas, William S.; Pendleton, Geoffrey N.; Mallozzi, Robert S.

    2004-01-01

    Despite being the most energetic phenomenon in the known universe, the astrophysics of gamma-ray bursts (GRBs) has still proven difficult to understand. It has only been within the past five years that the GRB distance scale has been firmly established, on the basis of a few dozen bursts with x-ray, optical, and radio afterglows. The afterglows indicate source redshifts of z=1 to z=5, total energy outputs of roughly 10(exp 52) ergs, and energy confined to the far x-ray to near gamma-ray regime of the electromagnetic spectrum. The multi-wavelength afterglow observations have thus far provided more insight on the nature of the GRB mechanism than the GRB observations; far more papers have been written about the few observed gamma-ray burst afterglows in the past few years than about the thousands of detected gamma-ray bursts. One reason the GRB central engine is still so poorly understood is that GRBs have complex, overlapping characteristics that do not appear to be produced by one homogeneous process. At least two subclasses have been found on the basis of duration, spectral hardness, and fluence (time integrated flux); Class 1 bursts are softer, longer, and brighter than Class 2 bursts (with two second durations indicating a rough division). A third GRB subclass, overlapping the other two, has been identified using statistical clustering techniques; Class 3 bursts are intermediate between Class 1 and Class 2 bursts in brightness and duration, but are softer than Class 1 bursts. We are developing a tool to aid scientists in the study of GRB properties. In the process of developing this tool, we are building a large gamma-ray burst classification database. We are also scientifically analyzing some GRB data as we develop the tool. Tool development thus proceeds in tandem with the dataset for which it is being designed. The tool invokes a modified KDD (Knowledge Discovery in Databases) process, which is described as follows.

  3. Transitions to Synchrony in Coupled Bursting Neurons

    Science.gov (United States)

    Dhamala, Mukeshwar; Jirsa, Viktor K.; Ding, Mingzhou

    2004-01-01

    Certain cells in the brain, for example, thalamic neurons during sleep, show spike-burst activity. We study such spike-burst neural activity and the transitions to a synchronized state using a model of coupled bursting neurons. In an electrically coupled network, we show that the increase of coupling strength increases incoherence first and then induces two different transitions to synchronized states, one associated with bursts and the other with spikes. These sequential transitions to synchronized states are determined by the zero crossings of the maximum transverse Lyapunov exponents. These results suggest that synchronization of spike-burst activity is a multi-time-scale phenomenon and burst synchrony is a precursor to spike synchrony.

  4. Transitions to synchrony in coupled bursting neurons

    International Nuclear Information System (INIS)

    Dhamala, Mukeshwar; Jirsa, Viktor K.; Ding Mingzhou

    2004-01-01

    Certain cells in the brain, for example, thalamic neurons during sleep, show spike-burst activity. We study such spike-burst neural activity and the transitions to a synchronized state using a model of coupled bursting neurons. In an electrically coupled network, we show that the increase of coupling strength increases incoherence first and then induces two different transitions to synchronized states, one associated with bursts and the other with spikes. These sequential transitions to synchronized states are determined by the zero crossings of the maximum transverse Lyapunov exponents. These results suggest that synchronization of spike-burst activity is a multi-time-scale phenomenon and burst synchrony is a precursor to spike synchrony

  5. 77 FR 33661 - Review of the Emergency Alert System

    Science.gov (United States)

    2012-06-07

    ... Commission's Review of the Emergency Alert System, Fifth Report and Order (Order). This document is... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 11 [EB Docket No. 04-296; FCC 12-7] Review of the Emergency Alert System AGENCY: Federal Communications Commission. ACTION: Final rule; announcement of...

  6. A new method for determining a sector alert

    Science.gov (United States)

    2008-09-29

    The Traffic Flow Management System (TFMS) currently declares an alert for any 15-minute interval in which the predicted demand exceeds the Monitor/Alert Parameter (MAP) for any airport, sector, or fix. For a sector, TFMS predicts the demand for each ...

  7. Fast Radio Burst/Gamma-Ray Burst Cosmography

    Science.gov (United States)

    Gao, He; Li, Zhuo; Zhang, Bing

    2014-06-01

    Recently, both theoretical arguments and observational evidence suggested that a small fraction of fast radio bursts (FRBs) could be associated with gamma-ray bursts (GRBs). If such FRB/GRB association systems are commonly detected in the future, the combination of dispersion measures (DM) derived from FRBs and redshifts derived from GRBs makes these systems a plausible tool to conduct cosmography. We quantify uncertainties in deriving the redshift-dependent DM_{IGM} as a function of z and test how well dark energy models can be constrained with Monte Carlo simulations. We show that with several tens of FRB/GRB systems potentially detected in a decade or so, one may reach reasonable constraints on wCDM models. When combined with Type Ia supernova (SN Ia) data, unprecedented constraints on the dark energy equation of state may be achieved, thanks to the prospects of detecting FRB/GRB systems at relatively high redshifts. The ratio between the mean value \\lt {DM_IGM} (z)\\gt and luminosity distance (D L(z)) is insensitive to dark energy models. This gives the prospect of applying SN Ia data to calibrate \\lt {DM_IGM} (z)\\gt using a relatively small sample of FRB/GRB systems, allowing a reliable constraint on the baryon inhomogeneity distribution as a function of redshift. The methodology developed in this paper can also be applied if the FRB redshifts can be measured by other means. Some caveats of putting this method into practice are also discussed.

  8. Fast radio burst/gamma-ray burst cosmography

    International Nuclear Information System (INIS)

    Gao, He; Zhang, Bing; Li, Zhuo

    2014-01-01

    Recently, both theoretical arguments and observational evidence suggested that a small fraction of fast radio bursts (FRBs) could be associated with gamma-ray bursts (GRBs). If such FRB/GRB association systems are commonly detected in the future, the combination of dispersion measures (DM) derived from FRBs and redshifts derived from GRBs makes these systems a plausible tool to conduct cosmography. We quantify uncertainties in deriving the redshift-dependent DM IGM as a function of z and test how well dark energy models can be constrained with Monte Carlo simulations. We show that with several tens of FRB/GRB systems potentially detected in a decade or so, one may reach reasonable constraints on wCDM models. When combined with Type Ia supernova (SN Ia) data, unprecedented constraints on the dark energy equation of state may be achieved, thanks to the prospects of detecting FRB/GRB systems at relatively high redshifts. The ratio between the mean value and luminosity distance (D L (z)) is insensitive to dark energy models. This gives the prospect of applying SN Ia data to calibrate using a relatively small sample of FRB/GRB systems, allowing a reliable constraint on the baryon inhomogeneity distribution as a function of redshift. The methodology developed in this paper can also be applied if the FRB redshifts can be measured by other means. Some caveats of putting this method into practice are also discussed.

  9. Fast radio burst/gamma-ray burst cosmography

    Energy Technology Data Exchange (ETDEWEB)

    Gao, He; Zhang, Bing [Department of Physics and Astronomy, University of Nevada Las Vegas, NV 89154 (United States); Li, Zhuo, E-mail: gaohe@physics.unlv.edu, E-mail: zhang@physics.unlv.edu, E-mail: zhuo.li@pku.edu.cn [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China)

    2014-06-20

    Recently, both theoretical arguments and observational evidence suggested that a small fraction of fast radio bursts (FRBs) could be associated with gamma-ray bursts (GRBs). If such FRB/GRB association systems are commonly detected in the future, the combination of dispersion measures (DM) derived from FRBs and redshifts derived from GRBs makes these systems a plausible tool to conduct cosmography. We quantify uncertainties in deriving the redshift-dependent DM{sub IGM} as a function of z and test how well dark energy models can be constrained with Monte Carlo simulations. We show that with several tens of FRB/GRB systems potentially detected in a decade or so, one may reach reasonable constraints on wCDM models. When combined with Type Ia supernova (SN Ia) data, unprecedented constraints on the dark energy equation of state may be achieved, thanks to the prospects of detecting FRB/GRB systems at relatively high redshifts. The ratio between the mean value and luminosity distance (D {sub L}(z)) is insensitive to dark energy models. This gives the prospect of applying SN Ia data to calibrate using a relatively small sample of FRB/GRB systems, allowing a reliable constraint on the baryon inhomogeneity distribution as a function of redshift. The methodology developed in this paper can also be applied if the FRB redshifts can be measured by other means. Some caveats of putting this method into practice are also discussed.

  10. Validation of the CME Geomagnetic forecast alerts under COMESEP alert system

    Science.gov (United States)

    Dumbovic, Mateja; Srivastava, Nandita; Khodia, Yamini; Vršnak, Bojan; Devos, Andy; Rodriguez, Luciano

    2017-04-01

    An automated space weather alert system has been developed under the EU FP7 project COMESEP (COronal Mass Ejections and Solar Energetic Particles: http://comesep.aeronomy.be) to forecast solar energetic particles (SEP) and coronal mass ejection (CME) risk levels at Earth. COMESEP alert system uses automated detection tool CACTus to detect potentially threatening CMEs, drag-based model (DBM) to predict their arrival and CME geo-effectiveness tool (CGFT) to predict their geomagnetic impact. Whenever CACTus detects a halo or partial halo CME and issues an alert, DBM calculates its arrival time at Earth and CGFT calculates its geomagnetic risk level. Geomagnetic risk level is calculated based on an estimation of the CME arrival probability and its likely geo-effectiveness, as well as an estimate of the geomagnetic-storm duration. We present the evaluation of the CME risk level forecast with COMESEP alert system based on a study of geo-effective CMEs observed during 2014. The validation of the forecast tool is done by comparing the forecasts with observations. In addition, we test the success rate of the automatic forecasts (without human intervention) against the forecasts with human intervention using advanced versions of DBM and CGFT (self standing tools available at Hvar Observatory website: http://oh.geof.unizg.hr). The results implicate that the success rate of the forecast is higher with human intervention and using more advanced tools. This work has received funding from the European Commission FP7 Project COMESEP (263252). We acknowledge the support of Croatian Science Foundation under the project 6212 „Solar and Stellar Variability".

  11. Chaotic bursting in semiconductor lasers

    Science.gov (United States)

    Ruschel, Stefan; Yanchuk, Serhiy

    2017-11-01

    We investigate the dynamic mechanisms for low frequency fluctuations in semiconductor lasers subjected to delayed optical feedback, using the Lang-Kobayashi model. This system of delay differential equations displays pronounced envelope dynamics, ranging from erratic, so called low frequency fluctuations to regular pulse packages, if the time scales of fast oscillations and envelope dynamics are well separated. We investigate the parameter regions where low frequency fluctuations occur and compute their Lyapunov spectra. Using the geometric singular perturbation theory, we study this intermittent chaotic behavior and characterize these solutions as bursting slow-fast oscillations.

  12. Helium bubble bursting in tungsten

    International Nuclear Information System (INIS)

    Sefta, Faiza; Juslin, Niklas; Wirth, Brian D.

    2013-01-01

    Molecular dynamics simulations have been used to systematically study the pressure evolution and bursting behavior of sub-surface helium bubbles and the resulting tungsten surface morphology. This study specifically investigates how bubble shape and size, temperature, tungsten surface orientation, and ligament thickness above the bubble influence bubble stability and surface evolution. The tungsten surface is roughened by a combination of adatom “islands,” craters, and pinholes. The present study provides insight into the mechanisms and conditions leading to various tungsten topology changes, which we believe are the initial stages of surface evolution leading to the formation of nanoscale fuzz

  13. Alert Messaging in the CMS Distributed Workflow System

    International Nuclear Information System (INIS)

    Maxa, Zdenek

    2012-01-01

    WMAgent is the core component of the CMS workload management system. One of the features of this job managing platform is a configurable messaging system aimed at generating, distributing and processing alerts: short messages describing a given alert-worthy information or pathological condition. Apart from the framework's sub-components running within the WMAgent instances, there is a stand-alone application collecting alerts from all WMAgent instances running across the CMS distributed computing environment. The alert framework has a versatile design that allows for receiving alert messages also from other CMS production applications, such as PhEDEx data transfer manager. We present implementation details of the system, including its Python implementation using ZeroMQ, CouchDB message storage and future visions as well as operational experiences. Inter-operation with monitoring platforms such as Dashboard or Lemon is described.

  14. Do family physicians retrieve synopses of clinical research previously read as email alerts?

    Science.gov (United States)

    Grad, Roland; Pluye, Pierre; Johnson-Lafleur, Janique; Granikov, Vera; Shulha, Michael; Bartlett, Gillian; Marlow, Bernard

    2011-11-30

    A synopsis of new clinical research highlights important aspects of one study in a brief structured format. When delivered as email alerts, synopses enable clinicians to become aware of new developments relevant for practice. Once read, a synopsis can become a known item of clinical information. In time-pressured situations, remembering a known item may facilitate information retrieval by the clinician. However, exactly how synopses first delivered as email alerts influence retrieval at some later time is not known. We examined searches for clinical information in which a synopsis previously read as an email alert was retrieved (defined as a dyad). Our study objectives were to (1) examine whether family physicians retrieved synopses they previously read as email alerts and then to (2) explore whether family physicians purposefully retrieved these synopses. We conducted a mixed-methods study in which a qualitative multiple case study explored the retrieval of email alerts within a prospective longitudinal cohort of practicing family physicians. Reading of research-based synopses was tracked in two contexts: (1) push, meaning to read on email and (2) pull, meaning to read after retrieval from one electronic knowledge resource. Dyads, defined as synopses first read as email alerts and subsequently retrieved in a search of a knowledge resource, were prospectively identified. Participants were interviewed about all of their dyads. Outcomes were the total number of dyads and their type. Over a period of 341 days, 194 unique synopses delivered to 41 participants resulted in 4937 synopsis readings. In all, 1205 synopses were retrieved over an average of 320 days. Of the 1205 retrieved synopses, 21 (1.7%) were dyads made by 17 family physicians. Of the 1205 retrieved synopses, 6 (0.5%) were known item type dyads. However, dyads also occurred serendipitously. In the single knowledge resource we studied, email alerts containing research-based synopses were rarely retrieved

  15. Neutrino burst identification in underground detectors

    International Nuclear Information System (INIS)

    Fulgione, W.; Mengotti-Silva, N.; Panaro, L.

    1996-01-01

    We discuss the problem of neutrino burst identification in underground ν-telescopes. First the usual statistical analysis based on the time structure of the events is reviewed, with special attention to the statistical significance of burst candidates. Next, we propose a second level analysis that can provide independent confirmation of burst detection. This exploits the spatial distribution of the single events of a burst candidate, and uses the formalism of the entropy of information. Examples of both techniques are shown, based on the LVD experiment at Gran Sasso. (orig.)

  16. Evaluation of burst pressure prediction models for line pipes

    International Nuclear Information System (INIS)

    Zhu, Xian-Kui; Leis, Brian N.

    2012-01-01

    Accurate prediction of burst pressure plays a central role in engineering design and integrity assessment of oil and gas pipelines. Theoretical and empirical solutions for such prediction are evaluated in this paper relative to a burst pressure database comprising more than 100 tests covering a variety of pipeline steel grades and pipe sizes. Solutions considered include three based on plasticity theory for the end-capped, thin-walled, defect-free line pipe subjected to internal pressure in terms of the Tresca, von Mises, and ZL (or Zhu-Leis) criteria, one based on a cylindrical instability stress (CIS) concept, and a large group of analytical and empirical models previously evaluated by Law and Bowie (International Journal of Pressure Vessels and Piping, 84, 2007: 487–492). It is found that these models can be categorized into either a Tresca-family or a von Mises-family of solutions, except for those due to Margetson and Zhu-Leis models. The viability of predictions is measured via statistical analyses in terms of a mean error and its standard deviation. Consistent with an independent parallel evaluation using another large database, the Zhu-Leis solution is found best for predicting burst pressure, including consideration of strain hardening effects, while the Tresca strength solutions including Barlow, Maximum shear stress, Turner, and the ASME boiler code provide reasonably good predictions for the class of line-pipe steels with intermediate strain hardening response. - Highlights: ► This paper evaluates different burst pressure prediction models for line pipes. ► The existing models are categorized into two major groups of Tresca and von Mises solutions. ► Prediction quality of each model is assessed statistically using a large full-scale burst test database. ► The Zhu-Leis solution is identified as the best predictive model.

  17. Evaluation of burst pressure prediction models for line pipes

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xian-Kui, E-mail: zhux@battelle.org [Battelle Memorial Institute, 505 King Avenue, Columbus, OH 43201 (United States); Leis, Brian N. [Battelle Memorial Institute, 505 King Avenue, Columbus, OH 43201 (United States)

    2012-01-15

    Accurate prediction of burst pressure plays a central role in engineering design and integrity assessment of oil and gas pipelines. Theoretical and empirical solutions for such prediction are evaluated in this paper relative to a burst pressure database comprising more than 100 tests covering a variety of pipeline steel grades and pipe sizes. Solutions considered include three based on plasticity theory for the end-capped, thin-walled, defect-free line pipe subjected to internal pressure in terms of the Tresca, von Mises, and ZL (or Zhu-Leis) criteria, one based on a cylindrical instability stress (CIS) concept, and a large group of analytical and empirical models previously evaluated by Law and Bowie (International Journal of Pressure Vessels and Piping, 84, 2007: 487-492). It is found that these models can be categorized into either a Tresca-family or a von Mises-family of solutions, except for those due to Margetson and Zhu-Leis models. The viability of predictions is measured via statistical analyses in terms of a mean error and its standard deviation. Consistent with an independent parallel evaluation using another large database, the Zhu-Leis solution is found best for predicting burst pressure, including consideration of strain hardening effects, while the Tresca strength solutions including Barlow, Maximum shear stress, Turner, and the ASME boiler code provide reasonably good predictions for the class of line-pipe steels with intermediate strain hardening response. - Highlights: Black-Right-Pointing-Pointer This paper evaluates different burst pressure prediction models for line pipes. Black-Right-Pointing-Pointer The existing models are categorized into two major groups of Tresca and von Mises solutions. Black-Right-Pointing-Pointer Prediction quality of each model is assessed statistically using a large full-scale burst test database. Black-Right-Pointing-Pointer The Zhu-Leis solution is identified as the best predictive model.

  18. Prevention and forecasting of rock burst hazards in coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Lin-ming Dou; Cai-ping Lu; Zong-long Mu; Ming-shi Gao [China University of Mining & Technology, Xuzhou (China). State Key Laboratory for Coal Resource and Mine Safety

    2009-09-15

    Rock bursts signify extreme behavior in coal mine strata and severely threaten the safety of the lives of miners, as well as the effectiveness and productivity of miners. In our study, an elastic-plastic-brittle model for the deformation and failure of coal/rock was established through theoretical analyses, laboratory experiments and field testing, simulation and other means, which perfectly predict sudden and delayed rock bursts. Based on electromagnetic emission (EME), acoustic emission (AE) and microseismic (MS) effects in the process from deformation until impact rupture of coal-rock combination samples, a multi-parameter identification of premonitory technology was formed, largely depending on these three forms of emission. Thus a system of classification for forecasting rock bursts in space and time was established. We have presented the intensity weakening theory for rock bursts and a strong-soft-strong (3S) structural model for controlling the impact on rock surrounding roadways, with the objective of laying a theoretical foundation and establishing references for parameters for the weakening control of rock bursts. For the purpose of prevention, key technical parameters of directional hydraulic fracturing are revealed. Based on these results, as well as those from deep-hole controlled blasting in coal seams and rock, integrated control techniques were established and anti-impact hydraulic props, suitable for roadways subject to hazards from rockbursts have also been developed. These technologies have been widely used in most coal mines in China, subject to these hazards and have achieved remarkable economic and social benefits. 28 refs., 9 figs., 1 tab.

  19. LOCALIZATION OF GAMMA-RAY BURSTS USING THE FERMI GAMMA-RAY BURST MONITOR

    Energy Technology Data Exchange (ETDEWEB)

    Connaughton, V.; Briggs, M. S.; Burgess, J. M. [CSPAR and Physics Department, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35899 (United States); Goldstein, A.; Wilson-Hodge, C. A. [Astrophysics Office, ZP12, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Meegan, C. A.; Jenke, P.; Pelassa, V.; Xiong, S.; Bhat, P. N. [CSPAR, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35899 (United States); Paciesas, W. S. [Universities Space Research Association, Huntsville, AL (United States); Preece, R. D. [Department of Space Science, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35899 (United States); Gibby, M. H. [Jacobs Technology, Inc., Huntsville, AL (United States); Greiner, J.; Yu, H.-F. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Gruber, D. [Planetarium Südtirol, Gummer 5, I-39053 Karneid (Italy); Kippen, R. M. [Los Alamos National Laboratory, NM 87545 (United States); Byrne, D.; Fitzpatrick, G.; Foley, S., E-mail: valerie@nasa.gov [School of Physics, University College Dublin, Belfield, Stillorgan Road, Dublin 4 (Ireland); and others

    2015-02-01

    The Fermi Gamma-ray Burst Monitor (GBM) has detected over 1400 gamma-ray bursts (GRBs) since it began science operations in 2008 July. We use a subset of over 300 GRBs localized by instruments such as Swift, the Fermi Large Area Telescope, INTEGRAL, and MAXI, or through triangulations from the InterPlanetary Network, to analyze the accuracy of GBM GRB localizations. We find that the reported statistical uncertainties on GBM localizations, which can be as small as 1°, underestimate the distance of the GBM positions to the true GRB locations and we attribute this to systematic uncertainties. The distribution of systematic uncertainties is well represented (68% confidence level) by a 3.°7 Gaussian with a non-Gaussian tail that contains about 10% of GBM-detected GRBs and extends to approximately 14°. A more complex model suggests that there is a dependence of the systematic uncertainty on the position of the GRB in spacecraft coordinates, with GRBs in the quadrants on the Y axis better localized than those on the X axis.

  20. Analysis of historic bursts and burst detection in water supply areas of different size

    NARCIS (Netherlands)

    Bakker, M.; Trietsch, E.A.; Vreeburg, J.H.G.; Rietveld, L.C.

    2014-01-01

    Pipe bursts in water distribution networks lead to water losses and a risk of damaging the urban environment. We studied hydraulic data and customer contact records of 44 real bursts for a better understanding of the phenomena. We found that most bursts were reported to the water company shortly

  1. Spike and burst coding in thalamocortical relay cells.

    Directory of Open Access Journals (Sweden)

    Fleur Zeldenrust

    2018-02-01

    Full Text Available Mammalian thalamocortical relay (TCR neurons switch their firing activity between a tonic spiking and a bursting regime. In a combined experimental and computational study, we investigated the features in the input signal that single spikes and bursts in the output spike train represent and how this code is influenced by the membrane voltage state of the neuron. Identical frozen Gaussian noise current traces were injected into TCR neurons in rat brain slices as well as in a validated three-compartment TCR model cell. The resulting membrane voltage traces and spike trains were analyzed by calculating the coherence and impedance. Reverse correlation techniques gave the Event-Triggered Average (ETA and the Event-Triggered Covariance (ETC. This demonstrated that the feature selectivity started relatively long before the events (up to 300 ms and showed a clear distinction between spikes (selective for fluctuations and bursts (selective for integration. The model cell was fine-tuned to mimic the frozen noise initiated spike and burst responses to within experimental accuracy, especially for the mixed mode regimes. The information content carried by the various types of events in the signal as well as by the whole signal was calculated. Bursts phase-lock to and transfer information at lower frequencies than single spikes. On depolarization the neuron transits smoothly from the predominantly bursting regime to a spiking regime, in which it is more sensitive to high-frequency fluctuations. The model was then used to elucidate properties that could not be assessed experimentally, in particular the role of two important subthreshold voltage-dependent currents: the low threshold activated calcium current (IT and the cyclic nucleotide modulated h current (Ih. The ETAs of those currents and their underlying activation/inactivation states not only explained the state dependence of the firing regime but also the long-lasting concerted dynamic action of the two

  2. The effect of automated alerts on provider ordering behavior in an outpatient setting.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available BACKGROUND: Computerized order entry systems have the potential to prevent medication errors and decrease adverse drug events with the use of clinical-decision support systems presenting alerts to providers. Despite the large volume of medications prescribed in the outpatient setting, few studies have assessed the impact of automated alerts on medication errors related to drug-laboratory interactions in an outpatient primary-care setting. METHODS AND FINDINGS: A primary-care clinic in an integrated safety net institution was the setting for the study. In collaboration with commercial information technology vendors, rules were developed to address a set of drug-laboratory interactions. All patients seen in the clinic during the study period were eligible for the intervention. As providers ordered medications on a computer, an alert was displayed if a relevant drug-laboratory interaction existed. Comparisons were made between baseline and postintervention time periods. Provider ordering behavior was monitored focusing on the number of medication orders not completed and the number of rule-associated laboratory test orders initiated after alert display. Adverse drug events were assessed by doing a random sample of chart reviews using the Naranjo scoring scale. The rule processed 16,291 times during the study period on all possible medication orders: 7,017 during the pre-intervention period and 9,274 during the postintervention period. During the postintervention period, an alert was displayed for 11.8% (1,093 out of 9,274 of the times the rule processed, with 5.6% for only "missing laboratory values," 6.0% for only "abnormal laboratory values," and 0.2% for both types of alerts. Focusing on 18 high-volume and high-risk medications revealed a significant increase in the percentage of time the provider stopped the ordering process and did not complete the medication order when an alert for an abnormal rule-associated laboratory result was displayed

  3. Spatial variation in automated burst suppression detection in pharmacologically induced coma.

    Science.gov (United States)

    An, Jingzhi; Jonnalagadda, Durga; Moura, Valdery; Purdon, Patrick L; Brown, Emery N; Westover, M Brandon

    2015-01-01

    Burst suppression is actively studied as a control signal to guide anesthetic dosing in patients undergoing medically induced coma. The ability to automatically identify periods of EEG suppression and compactly summarize the depth of coma using the burst suppression probability (BSP) is crucial to effective and safe monitoring and control of medical coma. Current literature however does not explicitly account for the potential variation in burst suppression parameters across different scalp locations. In this study we analyzed standard 19-channel EEG recordings from 8 patients with refractory status epilepticus who underwent pharmacologically induced burst suppression as medical treatment for refractory seizures. We found that although burst suppression is generally considered a global phenomenon, BSP obtained using a previously validated algorithm varies systematically across different channels. A global representation of information from individual channels is proposed that takes into account the burst suppression characteristics recorded at multiple electrodes. BSP computed from this representative burst suppression pattern may be more resilient to noise and a better representation of the brain state of patients. Multichannel data integration may enhance the reliability of estimates of the depth of medical coma.

  4. Mobile Traffic Alert and Tourist Route Guidance System Design Using Geospatial Data

    Science.gov (United States)

    Bhattacharya, D.; Painho, M.; Mishra, S.; Gupta, A.

    2017-09-01

    The present study describes an integrated system for traffic data collection and alert warning. Geographical information based decision making related to traffic destinations and routes is proposed through the design. The system includes a geospatial database having profile relating to a user of a mobile device. The processing and understanding of scanned maps, other digital data input leads to route guidance. The system includes a server configured to receive traffic information relating to a route and location information relating to the mobile device. Server is configured to send a traffic alert to the mobile device when the traffic information and the location information indicate that the mobile device is traveling toward traffic congestion. Proposed system has geospatial and mobile data sets pertaining to Bangalore city in India. It is envisaged to be helpful for touristic purposes as a route guidance and alert relaying information system to tourists for proximity to sites worth seeing in a city they have entered into. The system is modular in architecture and the novelty lies in integration of different modules carrying different technologies for a complete traffic information system. Generic information processing and delivery system has been tested to be functional and speedy under test geospatial domains. In a restricted prototype model with geo-referenced route data required information has been delivered correctly over sustained trials to designated cell numbers, with average time frame of 27.5 seconds, maximum 50 and minimum 5 seconds. Traffic geo-data set trials testing is underway.

  5. MOBILE TRAFFIC ALERT AND TOURIST ROUTE GUIDANCE SYSTEM DESIGN USING GEOSPATIAL DATA

    Directory of Open Access Journals (Sweden)

    D. Bhattacharya

    2017-09-01

    Full Text Available The present study describes an integrated system for traffic data collection and alert warning. Geographical information based decision making related to traffic destinations and routes is proposed through the design. The system includes a geospatial database having profile relating to a user of a mobile device. The processing and understanding of scanned maps, other digital data input leads to route guidance. The system includes a server configured to receive traffic information relating to a route and location information relating to the mobile device. Server is configured to send a traffic alert to the mobile device when the traffic information and the location information indicate that the mobile device is traveling toward traffic congestion. Proposed system has geospatial and mobile data sets pertaining to Bangalore city in India. It is envisaged to be helpful for touristic purposes as a route guidance and alert relaying information system to tourists for proximity to sites worth seeing in a city they have entered into. The system is modular in architecture and the novelty lies in integration of different modules carrying different technologies for a complete traffic information system. Generic information processing and delivery system has been tested to be functional and speedy under test geospatial domains. In a restricted prototype model with geo-referenced route data required information has been delivered correctly over sustained trials to designated cell numbers, with average time frame of 27.5 seconds, maximum 50 and minimum 5 seconds. Traffic geo-data set trials testing is underway.

  6. Burst pressure and leak rate from fretted SG tubes

    International Nuclear Information System (INIS)

    Hwang, Seong Sik; Jung, Man Kyo; Kim, Hong Pyo; Kim, Joung Soo

    2005-01-01

    Steam generator(SG) tubes of a pressurized water reactor(PWR) have suffered from various types of corrosion, such as pitting, wastage and stress corrosion cracking (SCC) on both the primary and secondary side. Recently, fretting/wear degradation at the tube support region has been reported in some Korean nuclear power plants. In order to prevent the primary coolant from leaking to the secondary side, the tubes are repaired by a sleeving or plugging. It is important to establish the repair criteria to assure a reactor integrity and yet maintain the plugging ratio within the limits needed for an efficient operation. The objective of the burst test is to obtain a relationship between the burst/leak rate and the shape of the fretted flaws machined with an electro discharge machining (EDM)

  7. Multifrequency Observations of Gamma-Ray Burst

    OpenAIRE

    Greiner, J.

    1995-01-01

    Neither a flaring nor a quiescent counterpart to a gamma-ray burst has yet been convincingly identified at any wavelength region. The present status of the search for counterparts of classical gamma-ray bursts is given. Particular emphasis is put on the search for flaring counterparts, i.e. emission during or shortly after the gamma-ray emission.

  8. Observations of short gamma-ray bursts.

    Science.gov (United States)

    Fox, Derek B; Roming, Peter W A

    2007-05-15

    We review recent observations of short-hard gamma-ray bursts and their afterglows. The launch and successful ongoing operations of the Swift satellite, along with several localizations from the High-Energy Transient Explorer mission, have provoked a revolution in short-burst studies: first, by quickly providing high-quality positions to observers; and second, via rapid and sustained observations from the Swift satellite itself. We make a complete accounting of Swift-era short-burst localizations and proposed host galaxies, and discuss the implications of these observations for the distances, energetics and environments of short bursts, and the nature of their progenitors. We then review the physical modelling of short-burst afterglows: while the simplest afterglow models are inadequate to explain the observations, there have been several notable successes. Finally, we address the case of an unusual burst that threatens to upset the simple picture in which long bursts are due to the deaths of massive stars, and short bursts to compact-object merger events.

  9. Neutrino bursts and gravitational waves experiments

    Energy Technology Data Exchange (ETDEWEB)

    Castagnoli, C; Galeotti, P; Saavedra, O [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica

    1978-05-01

    Several experiments have been performed in many countries to observe gravitational waves or neutrino bursts. Since their simultaneous emission may occur in stellar collapse, the authors evaluate the effect of neutrino bursts on gravitational wave antennas and suggest the usefulness of a time correlation among the different detectors.

  10. Polarization of a periodic solar microwave burst

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, P [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica

    1976-09-01

    No fluctuations in polarization have been found during a 7 GHz solar burst showing 17s periodic pulses in intensity. Polarization effects can be produced by the propagation media in the active centre, which are not affected directly by the burst source, but situated more deeply than the observed heights at that microwave frequency.

  11. Gaia Science Alerts: Early Validation Phase Data from Gaia

    Science.gov (United States)

    Walton, Nicholas; Hodgkin, Simon; van Leeuwen, Floor

    2015-08-01

    The ESA Gaia satellite launched Dec 2013, and after successful completion of its in orbit commissioning in July 2014, begun routine operations, with the aim to accurately measure the astrometric and astrophysical properties of more than a billion stars in our Milky Way.As a significant by product of its observational scanning law, where each point on the sky is observed multiple times (~80 revisits on average) over the nominal 5 year mission, Gaia has significant utility in detecting new transients, both flux (e.g. Supernovae, Flare stars) and positional (e.g. Asteroids).We will present the current status of the Gaia Photometric Science Alerts (PSA) system that has been developed within the Gaia DPAC. The PSA pipeline provides a quick look analysis of the daily data stream from Gaia, and identifies new photometric alerts, from analysis of the object photometric and the low resolution spectro-photometric data. Via a set of filters, those identified as astrophysical in nature, are published to the community. The information provided currently includes positional and flux information.The Gaia Alerts working group has organised a significant early stage followup campaign, providing access to a wide variety of followup facilities. These have been used to provide classification spectra of the Gaia alert candidates, with the early phase data confirming that the alerts issued are indeed largely astrophysical transients, with only a small contamination rate.The presentation will address the early phase issues that have been addressed in localising and classifying alerts in the early phase of Gaia observations (for instance, how lack of early knowledge of the sky as seen by Gaia was mitigated by reference to external image data), and how the alert rate published by the PSA will ramp up towards the end of 2015, with the availability of more Gaia sky data.Information concerning the Gaia alerts system can be found at http://gaia.ac.uk/selected-gaia-science-alerts

  12. Perceptual evaluation of visual alerts in surveillance videos

    Science.gov (United States)

    Rogowitz, Bernice E.; Topkara, Mercan; Pfeiffer, William; Hampapur, Arun

    2015-03-01

    Visual alerts are commonly used in video monitoring and surveillance systems to mark events, presumably making them more salient to human observers. Surprisingly, the effectiveness of computer-generated alerts in improving human performance has not been widely studied. To address this gap, we have developed a tool for simulating different alert parameters in a realistic visual monitoring situation, and have measured human detection performance under conditions that emulated different set-points in a surveillance algorithm. In the High-Sensitivity condition, the simulated alerts identified 100% of the events with many false alarms. In the Lower-Sensitivity condition, the simulated alerts correctly identified 70% of the targets, with fewer false alarms. In the control condition, no simulated alerts were provided. To explore the effects of learning, subjects performed these tasks in three sessions, on separate days, in a counterbalanced, within subject design. We explore these results within the context of cognitive models of human attention and learning. We found that human observers were more likely to respond to events when marked by a visual alert. Learning played a major role in the two alert conditions. In the first session, observers generated almost twice as many False Alarms as in the No-Alert condition, as the observers responded pre-attentively to the computer-generated false alarms. However, this rate dropped equally dramatically in later sessions, as observers learned to discount the false cues. Highest observer Precision, Hits/(Hits + False Alarms), was achieved in the High Sensitivity condition, but only after training. The successful evaluation of surveillance systems depends on understanding human attention and performance.

  13. Self-indicating radiation alert dosemeter (SIRAD)

    International Nuclear Information System (INIS)

    Riel, G. K.; Winters, P.; Patel, G.; Patel, P.

    2006-01-01

    In an event of a nuclear or dirty bomb explosion and a radiological accident, there is a need for self-indicating instant radiation dosemeter for monitoring radiation exposure. The self-indicating instant radiation alert dosemeter (SIRAD) is a credit card size radiation dosemeter for monitoring ionising radiation from a few hundredths of a Gray to a few Gray. It is always active and is ready to use. It needs no battery. The dosemeter develops colour instantly upon exposure, and the colour intensifies with dose. It has a colour chart so that the dose on the active element may be read by matching its colour with the chart that is printed next to it on the card. However, in this work, the dose is measured by the optical density of the element. The dosemeter cannot be reset. The response changes by 3 y at room temperature. It contains no hazardous materials. The dosemeter would meet the requirements of instantly monitoring high dose in an event of a nuclear or dirty bomb explosion or a radiation accident. (authors)

  14. Self-indicating radiation alert dosemeter (SIRAD).

    Science.gov (United States)

    Riel, Gordon K; Winters, Patrick; Patel, Gordhan; Patel, Paresh

    2006-01-01

    In an event of a nuclear or dirty bomb explosion and a radiological accident, there is a need for self-indicating instant radiation dosemeter for monitoring radiation exposure. The self-indicating instant radiation alert dosemeter (SIRAD) is a credit card size radiation dosemeter for monitoring ionising radiation from a few hundredths of a Gray to a few Gray. It is always active and is ready to use. It needs no battery. The dosemeter develops colour instantly upon exposure, and the colour intensifies with dose. It has a colour chart so that the dose on the active element may be read by matching its colour with the chart that is printed next to it on the card. However, in this work, the dose is measured by the optical density of the element. The dosemeter cannot be reset. The response changes by 3 y at room temperature. It contains no hazardous materials. The dosemeter would meet the requirements of instantly monitoring high dose in an event of a nuclear or dirty bomb explosion or a radiation accident.

  15. Real-time alerts and reminders using information systems.

    Science.gov (United States)

    Wanderer, Jonathan P; Sandberg, Warren S; Ehrenfeld, Jesse M

    2011-09-01

    Adoption of information systems throughout the hospital environment has enabled the development of real-time physiologic alerts and clinician reminder systems. These clinical tools can be made available through the deployment of anesthesia information management systems (AIMS). Creating usable alert systems requires understanding of technical considerations. Various successful implementations are reviewed, encompassing cost reduction, improved revenue capture, timely antibiotic administration, and postoperative nausea and vomiting prophylaxis. Challenges to the widespread use of real-time alerts and reminders include AIMS adoption rates and the difficulty in choosing appropriate areas and approaches for information systems support. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Burst suppression probability algorithms: state-space methods for tracking EEG burst suppression

    Science.gov (United States)

    Chemali, Jessica; Ching, ShiNung; Purdon, Patrick L.; Solt, Ken; Brown, Emery N.

    2013-10-01

    Objective. Burst suppression is an electroencephalogram pattern in which bursts of electrical activity alternate with an isoelectric state. This pattern is commonly seen in states of severely reduced brain activity such as profound general anesthesia, anoxic brain injuries, hypothermia and certain developmental disorders. Devising accurate, reliable ways to quantify burst suppression is an important clinical and research problem. Although thresholding and segmentation algorithms readily identify burst suppression periods, analysis algorithms require long intervals of data to characterize burst suppression at a given time and provide no framework for statistical inference. Approach. We introduce the concept of the burst suppression probability (BSP) to define the brain's instantaneous propensity of being in the suppressed state. To conduct dynamic analyses of burst suppression we propose a state-space model in which the observation process is a binomial model and the state equation is a Gaussian random walk. We estimate the model using an approximate expectation maximization algorithm and illustrate its application in the analysis of rodent burst suppression recordings under general anesthesia and a patient during induction of controlled hypothermia. Main result. The BSP algorithms track burst suppression on a second-to-second time scale, and make possible formal statistical comparisons of burst suppression at different times. Significance. The state-space approach suggests a principled and informative way to analyze burst suppression that can be used to monitor, and eventually to control, the brain states of patients in the operating room and in the intensive care unit.

  17. Bursting synchronization in scale-free networks

    International Nuclear Information System (INIS)

    Batista, C.A.S.; Batista, A.M.; Pontes, J.C.A. de; Lopes, S.R.; Viana, R.L.

    2009-01-01

    Neuronal networks in some areas of the brain cortex present the scale-free property, i.e., the neuron connectivity is distributed according to a power-law, such that neurons are more likely to couple with other already well-connected ones. Neuron activity presents two timescales, a fast one related to action-potential spiking, and a slow timescale in which bursting takes place. Some pathological conditions are related with the synchronization of the bursting activity in a weak sense, meaning the adjustment of the bursting phase due to coupling. Hence it has been proposed that an externally applied time-periodic signal be applied in order to control undesirable synchronized bursting rhythms. We investigated this kind of intervention using a two-dimensional map to describe neurons with spiking-bursting activity in a scale-free network.

  18. X-Ray Bursts from NGC 6652

    Science.gov (United States)

    Morgan, Edward

    The possibly transient X-ray Source in the globular cluster NGC 6652 has been seen by BeppoSax and the ASM on RXTE to undergo X-ray bursts, possibly Type I. Very little is known about this X-ray source, and confirmation of its bursts type-I nature would identify it as a neutron star binary. Type I bursts in 6 other sources have been shown to exhibit intervals of millisecond ocsillation that most likely indicate the neutron star spin period. Radius-expansion bursts can reveal information about the mass and size of the neutron star. We propose to use the ASM to trigger an observation of this source to maximize the probability of catching a burst in the PCA.

  19. Growth dynamics explain the development of spatiotemporal burst activity of young cultured neuronal networks in detail.

    Directory of Open Access Journals (Sweden)

    Taras A Gritsun

    Full Text Available A typical property of isolated cultured neuronal networks of dissociated rat cortical cells is synchronized spiking, called bursting, starting about one week after plating, when the dissociated cells have sufficiently sent out their neurites and formed enough synaptic connections. This paper is the third in a series of three on simulation models of cultured networks. Our two previous studies [26], [27] have shown that random recurrent network activity models generate intra- and inter-bursting patterns similar to experimental data. The networks were noise or pacemaker-driven and had Izhikevich-neuronal elements with only short-term plastic (STP synapses (so, no long-term potentiation, LTP, or depression, LTD, was included. However, elevated pre-phases (burst leaders and after-phases of burst main shapes, that usually arise during the development of the network, were not yet simulated in sufficient detail. This lack of detail may be due to the fact that the random models completely missed network topology .and a growth model. Therefore, the present paper adds, for the first time, a growth model to the activity model, to give the network a time dependent topology and to explain burst shapes in more detail. Again, without LTP or LTD mechanisms. The integrated growth-activity model yielded realistic bursting patterns. The automatic adjustment of various mutually interdependent network parameters is one of the major advantages of our current approach. Spatio-temporal bursting activity was validated against experiment. Depending on network size, wave reverberation mechanisms were seen along the network boundaries, which may explain the generation of phases of elevated firing before and after the main phase of the burst shape.In summary, the results show that adding topology and growth explain burst shapes in great detail and suggest that young networks still lack/do not need LTP or LTD mechanisms.

  20. Synchronization of bursting neurons with a slowly varying d. c. current

    International Nuclear Information System (INIS)

    Upadhyay, Ranjit Kumar; Mondal, Argha

    2017-01-01

    Highlights: • To examine synchronization, noisy chemical and electrical coupling have been considered for a coupled bursting M-L neurons. • Bursting presents the precursor to spike synchronization and coupling strength increases the locking between neurons (anti phase and in phase). • The stability of synchronization is established via similarity function. • The necessary condition to occur CS state is observed using master stability function. • A network of four M-L neurons is considered to observe the synchronization. - Abstract: Bursting of neuronal firing is an interesting dynamical consequences depending on fast/slow dynamics. Certain cells in different brain regions produce spike-burst activity. We study such firing activity and its transitions to synchronization using identical as well as non-identical coupled bursting Morris-Lecar (M-L) neurons. Synchronization of different firing activity is a multi-time-scale phenomenon and burst synchronization presents the precursor to spike synchronization. Chemical synapses are one of the dynamical means of information processing between neurons. Electrical synapses play a major role for synchronous activity in a certain network of neurons. Synaptically coupled neural cells exhibit different types of synchronization such as in phase or anti-phase depending on the nature and strength of coupling functions and the synchronization regimes are analyzed by similarity functions. The sequential transitions to synchronization regime are examined by the maximum transverse Lyapunov exponents. Synchronization of voltage traces of two types of planar bursting mechanisms is explored for both kind of synapses under realistic conditions. The noisy influence effects on the transmission of signals and strongly acts to the firing activity (such as periodic firing and bursting) and integration of signals for a network. It has been examined using the mean interspike interval analysis. The transition to synchronization states of

  1. Spatiotemporal chaos from bursting dynamics

    International Nuclear Information System (INIS)

    Berenstein, Igal; De Decker, Yannick

    2015-01-01

    In this paper, we study the emergence of spatiotemporal chaos from mixed-mode oscillations, by using an extended Oregonator model. We show that bursting dynamics consisting of fast/slow mixed mode oscillations along a single attractor can lead to spatiotemporal chaotic dynamics, although the spatially homogeneous solution is itself non-chaotic. This behavior is observed far from the Hopf bifurcation and takes the form of a spatiotemporal intermittency where the system locally alternates between the fast and the slow phases of the mixed mode oscillations. We expect this form of spatiotemporal chaos to be generic for models in which one or several slow variables are coupled to activator-inhibitor type of oscillators

  2. Contributors to Frequent Telehealth Alerts Including False Alerts for Patients with Heart Failure: A Mixed Methods Exploration

    Science.gov (United States)

    Radhakrishna, K.; Bowles, K.; Zettek-Sumner, A.

    2013-01-01

    Summary Background Telehealth data overload through high alert generation is a significant barrier to sustained adoption of telehealth for managing HF patients. Objective To explore the factors contributing to frequent telehealth alerts including false alerts for Medicare heart failure (HF) patients admitted to a home health agency. Materials and Methods A mixed methods design that combined quantitative correlation analysis of patient characteristic data with number of telehealth alerts and qualitative analysis of telehealth and visiting nurses’ notes on follow-up actions to patients’ telehealth alerts was employed. All the quantitative and qualitative data was collected through retrospective review of electronic records of the home heath agency. Results Subjects in the study had a mean age of 83 (SD = 7.6); 56% were female. Patient co-morbidities (ppatient characteristics along with establishing patient-centered telehealth outcome goals may allow meaningful generation of telehealth alerts. Reducing avoidable telehealth alerts could vastly improve the efficiency and sustainability of telehealth programs for HF management. PMID:24454576

  3. Provider and pharmacist responses to warfarin drug–drug interaction alerts: a study of healthcare downstream of CPOE alerts

    Science.gov (United States)

    Boro, Maureen S; Korman, Nancy E; Davoren, J Ben

    2011-01-01

    Objective To categorize the appropriateness of provider and pharmacist responses to warfarin critical drug–drug interaction (cDDI) alerts, assess responses and actions to the cDDI, and determine the occurrence of warfarin adverse drug events (ADE) after alerts. Design An 18-month, retrospective study of acute care admissions at a single Veterans Affairs medical center using computerized provider order entry (CPOE). Measurements Patients included had at least one warfarin cDDI alert. Chart reviews included baseline laboratory values and demographics, provider actions, patient outcomes, and associated factors, including other interacting medications and number of simultaneously processed alerts. Results 137 admissions were included (133 unique patients). Amiodarone, vitamin E in a multivitamin, sulfamethoxazole, and levothyroxine accounted for 75% of warfarin cDDI. Provider responses were clinically appropriate in 19.7% of admissions and pharmacist responses were appropriate in 9.5% of admissions. There were 50 ADE (36.6% of admissions) with warfarin; 80% were rated as having no or mild clinical effect. An increased number of non-critical alerts at the time of the reference cDDI alert was the only variable associated with an inappropriate provider response (p=0.01). Limitations This study was limited by being a retrospective review and the possibility of confounding variables, such as other interacting medications. Conclusion The large number of CPOE alerts may lead to inappropriate responses by providers and pharmacists. The high rate of ADE suggests a need for improved medication management systems for patients on warfarin. This study highlights the possibility of alert fatigue contributing to the high prevalence of inappropriate alert over-ride text responses. PMID:22037888

  4. Gamma-ray bursts and their use as cosmic probes

    Science.gov (United States)

    2017-01-01

    Since the launch of the highly successful and ongoing Swift mission, the field of gamma-ray bursts (GRBs) has undergone a revolution. The arcsecond GRB localizations available within just a few minutes of the GRB alert has signified the continual sampling of the GRB evolution through the prompt to afterglow phases revealing unexpected flaring and plateau phases, the first detection of a kilonova coincident with a short GRB, and the identification of samples of low-luminosity, ultra-long and highly dust-extinguished GRBs. The increased numbers of GRB afterglows, GRB-supernova detections, redshifts and host galaxy associations has greatly improved our understanding of what produces and powers these immense, cosmological explosions. Nevertheless, more high-quality data often also reveal greater complexity. In this review, I summarize some of the milestones made in GRB research during the Swift era, and how previous widely accepted theoretical models have had to adapt to accommodate the new wealth of observational data. PMID:28791158

  5. Observing a Burst with Sunglasses

    Science.gov (United States)

    2003-11-01

    Unique Five-Week VLT Study of the Polarisation of a Gamma-Ray Burst Afterglow "Gamma-ray bursts (GRBs)" are certainly amongst the most dramatic events known in astrophysics. These short flashes of energetic gamma-rays, first detected in the late 1960's by military satellites, last from less than one second to several minutes. GRBs have been found to be situated at extremely large ("cosmological") distances. The energy released in a few seconds during such an event is larger than that of the Sun during its entire lifetime of more than 10,000 million years. The GRBs are indeed the most powerful events since the Big Bang known in the Universe, cf. ESO PR 08/99 and ESO PR 20/00. During the past years circumstantial evidence has mounted that GRBs signal the collapse of extremely massive stars, the so-called hypernovae. This was finally demonstrated some months ago when astronomers, using the FORS instrument on ESO's Very Large Telescope (VLT), documented in unprecedented detail the changes in the spectrum of the light source ("the optical afterglow") of the gamma-ray burst GRB 030329 (cf. ESO PR 16/03). A conclusive and direct link between cosmological gamma-ray bursts and explosions of very massive stars was provided on this occasion. Gamma-Ray Burst GRB 030329 was discovered on March 29, 2003 by NASA's High Energy Transient Explorer spacecraft. Follow-up observations with the UVES spectrograph at the 8.2-m VLT KUEYEN telescope at the Paranal Observatory (Chile) showed the burst to have a redshift of 0.1685 [1]. This corresponds to a distance of about 2,650 million light-years, making GRB 030329 the second-nearest long-duration GRB ever detected. The proximity of GRB 030329 resulted in very bright afterglow emission, permitting the most extensive follow-up observations of any afterglow to date. A team of astronomers [2] led by Jochen Greiner of the Max-Planck-Institut für extraterrestrische Physik (Germany) decided to make use of this unique opportunity to study the

  6. Report: Management Alert - Salary Increases for Certain Administratively Determined Positions

    Science.gov (United States)

    Report #18-N-0154, April 16, 2018. The purpose of this alert is to notify the EPA of certain factual info while our audit of the Office of the Administrator's (present and prior administrations) use of administratively determined positions continues.

  7. Office of Child Support and Enforcement (OCSE) State Wage Alerts

    Data.gov (United States)

    Social Security Administration — The OCSE State Wage Alert is a quarterly match which detects SSI overpayments by identifying unreported wage and unemployment data provided to the Office of Child...

  8. Usability of Smartphones for dose alerts

    International Nuclear Information System (INIS)

    Kaireit, T.; Stamm, G.; Wacker, F.K.; Hoeschen, C.

    2013-01-01

    Purpose: Smartphone apps for measuring ionizing radiation use the capability of (CMOS) camera chips to detect not only perceivable light but also electromagnetic wave radiation. The present study evaluates the accuracy of hardware and software and defines possible applications for the detection of X-ray radiation fields. Materials and Methods: 2 apps and 2 different devices were tested in comparison with a calibrated ionization chamber and a personal electronic dosimeter. A calibration curve was determined for dose rates between 12 700 μSv/h and 5.7 μSv/h generated by a C-arm system. Results: The measured scattered radiation produced by an Alderson-Rando phantom ranged from 117 μSv/h (at a distance of 2 m) to 5910 μSv/h (at a distance of 0.3 m) and was 1.4 times less than the values of the ionization chamber. The exposure rate for the operator's thyroid was within 4200 - 4400 μSv/h. We found a strong dependence of the measurements on the angulation of the Smartphone, especially for short distances from the phantom (at a distance of 0.3 m, a 45 rotation downwards in a vertical direction caused a decrease from 3000 μSv/h to 972 μSv/h, while an upwards rotation resulted in an increase to 5000 μSv/h). For a distance of 1 m, this effect was remarkably smaller. Conclusion: Smartphones can be used to detect ionizing radiation but showed limited accuracy and are heavily dependent on the angulation of the device. Qualitative measurements and utilization for dose alerts are possible. (orig.)

  9. [Usability of smartphones for dose alerts].

    Science.gov (United States)

    Kaireit, T; Stamm, G; Hoeschen, C; Wacker, F K

    2013-06-01

    Smartphone apps for measuring ionizing radiation use the capability of (CMOS) camera chips to detect not only perceivable light but also electromagnetic wave radiation. The present study evaluates the accuracy of hardware and software and defines possible applications for the detection of X-ray radiation fields. 2 apps and 2 different devices were tested in comparison with a calibrated ionization chamber and a personal electronic dosimeter. A calibration curve was determined for dose rates between 12 700 µSv/h and 5.7 µSv/h generated by a C-arm system. The measured scattered radiation produced by an Alderson-Rando phantom ranged from 117 µSv/h (at a distance of 2 m) to 5910 µSv/h (at a distance of 0.3 m) and was 1.4 times less than the values of the ionization chamber. The exposure rate for the operator's thyroid was within 4200 - 4400 µSv/h. We found a strong dependence of the measurements on the angulation of the Smartphone, especially for short distances from the phantom (at a distance of 0.3 m, a 45° rotation downwards in a vertical direction caused a decrease from 3000 µSv/h to 972 µSv/h, while an upwards rotation resulted in an increase to 5000 µSv/h). For a distance of 1 m, this effect was remarkably smaller. Smartphones can be used to detect ionizing radiation but showed limited accuracy and are heavily dependent on the angulation of the device. Qualitative measurements and utilization for dose alerts are possible. © Georg Thieme Verlag KG Stuttgart · New York.

  10. THE BURST CLUSTER: DARK MATTER IN A CLUSTER MERGER ASSOCIATED WITH THE SHORT GAMMA-RAY BURST, GRB 050509B

    International Nuclear Information System (INIS)

    Dahle, H.; Sarazin, C. L.; Lopez, L. A.; Kouveliotou, C.; Patel, S. K.; Rol, E.; Van der Horst, A. J.; Wijers, R. A. M. J.; Fynbo, J.; Michałowski, M. J.; Burrows, D. N.; Grupe, D.; Gehrels, N.; Ramirez-Ruiz, E.

    2013-01-01

    We have identified a merging galaxy cluster with evidence of two distinct subclusters. The X-ray and optical data suggest that the subclusters are presently moving away from each other after closest approach. This cluster merger was discovered from observations of the first well-localized short-duration gamma-ray burst (GRB), GRB 050509B. The Swift/Burst Alert Telescope error position of the source is coincident with a cluster of galaxies ZwCl 1234.0+02916, while the subsequent Swift/X-Ray Telescope localization of the X-ray afterglow found the GRB coincident with 2MASX J12361286+2858580, a giant red elliptical galaxy in the cluster. Deep multi-epoch optical images were obtained in this field to constrain the evolution of the GRB afterglow, including a total of 27,480 s exposure in the F814W band with Hubble Space Telescope Advanced Camera for Surveys, among the deepest imaging ever obtained toward a known galaxy cluster in a single passband. We perform a weak gravitational lensing analysis based on these data, including mapping of the total mass distribution of the merger system with high spatial resolution. When combined with Chandra X-ray Observatory Advanced CCD Imaging Spectrometer and Swift/XRT observations, we are able to investigate the dynamical state of the merger to better understand the nature of the dark matter component. Our weak gravitational lensing measurements reveal a separation of the X-ray centroid of the western subcluster from the center of the mass and galaxy light distributions, which is somewhat similar to that of the famous 'Bullet cluster', and we conclude that this 'Burst cluster' adds another candidate to the previously known merger systems for determining the nature of dark matter, as well as for studying the environment of a short GRB. Finally, we discuss potential connections between the cluster dynamical state and/or matter composition, and compact object mergers, which is currently the leading model for the origin of short GRBs

  11. THE BURST CLUSTER: DARK MATTER IN A CLUSTER MERGER ASSOCIATED WITH THE SHORT GAMMA-RAY BURST, GRB 050509B

    Energy Technology Data Exchange (ETDEWEB)

    Dahle, H. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, NO-0315 Oslo (Norway); Sarazin, C. L. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Lopez, L. A. [MIT-Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, 37-664H, Cambridge, MA 02139 (United States); Kouveliotou, C. [Space Science Office, ZP12, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Patel, S. K. [Optical Sciences Corporation, 6767 Old Madison Pike, Suite 650, Huntsville, AL 35806 (United States); Rol, E.; Van der Horst, A. J.; Wijers, R. A. M. J. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam (Netherlands); Fynbo, J.; Michalowski, M. J. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries vej 30, DK-2100 Copenhagen (Denmark); Burrows, D. N.; Grupe, D. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Gehrels, N. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ramirez-Ruiz, E., E-mail: hdahle@astro.uio.no [Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95060 (United States)

    2013-07-20

    We have identified a merging galaxy cluster with evidence of two distinct subclusters. The X-ray and optical data suggest that the subclusters are presently moving away from each other after closest approach. This cluster merger was discovered from observations of the first well-localized short-duration gamma-ray burst (GRB), GRB 050509B. The Swift/Burst Alert Telescope error position of the source is coincident with a cluster of galaxies ZwCl 1234.0+02916, while the subsequent Swift/X-Ray Telescope localization of the X-ray afterglow found the GRB coincident with 2MASX J12361286+2858580, a giant red elliptical galaxy in the cluster. Deep multi-epoch optical images were obtained in this field to constrain the evolution of the GRB afterglow, including a total of 27,480 s exposure in the F814W band with Hubble Space Telescope Advanced Camera for Surveys, among the deepest imaging ever obtained toward a known galaxy cluster in a single passband. We perform a weak gravitational lensing analysis based on these data, including mapping of the total mass distribution of the merger system with high spatial resolution. When combined with Chandra X-ray Observatory Advanced CCD Imaging Spectrometer and Swift/XRT observations, we are able to investigate the dynamical state of the merger to better understand the nature of the dark matter component. Our weak gravitational lensing measurements reveal a separation of the X-ray centroid of the western subcluster from the center of the mass and galaxy light distributions, which is somewhat similar to that of the famous 'Bullet cluster', and we conclude that this 'Burst cluster' adds another candidate to the previously known merger systems for determining the nature of dark matter, as well as for studying the environment of a short GRB. Finally, we discuss potential connections between the cluster dynamical state and/or matter composition, and compact object mergers, which is currently the leading model for the

  12. Acute alerting effects of light: A systematic literature review.

    Science.gov (United States)

    Souman, Jan L; Tinga, Angelica M; Te Pas, Susan F; van Ee, Raymond; Vlaskamp, Björn N S

    2018-01-30

    Periodic, well timed exposure to light is important for our health and wellbeing. Light, in particular in the blue part of the spectrum, is thought to affect alertness both indirectly, by modifying circadian rhythms, and directly, giving rise to acute effects. We performed a systematic review of empirical studies on direct, acute effects of light on alertness to evaluate the reliability of these effects. In total, we identified 68 studies in which either light intensity, spectral distribution, or both were manipulated, and evaluated the effects on behavioral measures of alertness, either subjectively or measured in reaction time performance tasks. The results show that increasing the intensity of polychromatic white light has been found to increase subjective ratings of alertness in a majority of studies, though a substantial proportion of studies failed to find significant effects, possibly due to small sample sizes or high baseline light intensities. The effect of the color temperature of white light on subjective alertness is less clear. Some studies found increased alertness with higher color temperatures, but other studies reported no detrimental effects of filtering out the short wavelengths from the spectrum. Similarly, studies that used monochromatic light exposure showed no systematic pattern for the effects of blue light compared to longer wavelengths. Far fewer studies investigated the effects of light intensity or spectrum on alertness as measured with reaction time tasks and of those, very few reported significant effects. In general, the small sample sizes used in studies on acute alerting effects of light make it difficult to draw definitive conclusions and better powered studies are needed, especially studies that allow for the construction of dose-response curves. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Monitoring alert and drowsy states by modeling EEG source nonstationarity

    Science.gov (United States)

    Hsu, Sheng-Hsiou; Jung, Tzyy-Ping

    2017-10-01

    Objective. As a human brain performs various cognitive functions within ever-changing environments, states of the brain characterized by recorded brain activities such as electroencephalogram (EEG) are inevitably nonstationary. The challenges of analyzing the nonstationary EEG signals include finding neurocognitive sources that underlie different brain states and using EEG data to quantitatively assess the state changes. Approach. This study hypothesizes that brain activities under different states, e.g. levels of alertness, can be modeled as distinct compositions of statistically independent sources using independent component analysis (ICA). This study presents a framework to quantitatively assess the EEG source nonstationarity and estimate levels of alertness. The framework was tested against EEG data collected from 10 subjects performing a sustained-attention task in a driving simulator. Main results. Empirical results illustrate that EEG signals under alert versus drowsy states, indexed by reaction speeds to driving challenges, can be characterized by distinct ICA models. By quantifying the goodness-of-fit of each ICA model to the EEG data using the model deviation index (MDI), we found that MDIs were significantly correlated with the reaction speeds (r  =  -0.390 with alertness models and r  =  0.449 with drowsiness models) and the opposite correlations indicated that the two models accounted for sources in the alert and drowsy states, respectively. Based on the observed source nonstationarity, this study also proposes an online framework using a subject-specific ICA model trained with an initial (alert) state to track the level of alertness. For classification of alert against drowsy states, the proposed online framework achieved an averaged area-under-curve of 0.745 and compared favorably with a classic power-based approach. Significance. This ICA-based framework provides a new way to study changes of brain states and can be applied to

  14. Alert management for home healthcare based on home automation analysis.

    Science.gov (United States)

    Truong, T T; de Lamotte, F; Diguet, J-Ph; Said-Hocine, F

    2010-01-01

    Rising healthcare for elder and disabled people can be controlled by offering people autonomy at home by means of information technology. In this paper, we present an original and sensorless alert management solution which performs multimedia and home automation service discrimination and extracts highly regular home activities as sensors for alert management. The results of simulation data, based on real context, allow us to evaluate our approach before application to real data.

  15. Correlative Spectral Analysis of Gamma-Ray Bursts using Swift-BAT and GLAST-GBM

    International Nuclear Information System (INIS)

    Stamatikos, Michael; Sakamoto, Taka; Band, David L.

    2008-01-01

    We discuss the preliminary results of spectral analysis simulations involving anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs) using Swift's Burst Alert Telescope (BAT) and the Gamma-Ray Large Area Space Telescope's (GLAST) Burst Monitor (GLAST-GBM), resulting in joint spectral fits, including characteristic photon energy (E peak ) values, for a conservative annual estimate of ∼30 GRBs. The addition of BAT's spectral response will (i) complement in-orbit calibration efforts of GBM's detector response matrices, (ii) augment GLAST's low energy sensitivity by increasing the ∼20-100 keV effective area, (iii) facilitate ground-based follow-up efforts of GLAST GRBs by increasing GBM's source localization precision, and (iv) help identify a subset of non-triggered GRBs discovered via off-line GBM data analysis. Such multi-wavelength correlative analyses, which have been demonstrated by successful joint-spectral fits of Swift-BAT GRBs with other higher energy detectors such as Konus-WIND and Suzaku-WAM, would enable the study of broad-band spectral and temporal evolution of prompt GRB emission over three energy decades, thus potentially increasing science return without placing additional demands upon mission resources throughout their contemporaneous orbital tenure over the next decade.

  16. Correlative Spectral Analysis of Gamma-Ray Bursts using Swift-BAT and GLAST-GBM

    International Nuclear Information System (INIS)

    Stamatikos, Michael; Sakamoto, Takanori; Band, David L.

    2008-01-01

    We discuss the preliminary results of spectral analysis simulations involving anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs) using Swift's Burst Alert Telescope (BAT) and the Gamma-Ray Large Area Space Telescope's (GLAST) Burst Monitor (GLAST-GBM), resulting in joint spectral fits, including characteristic photon energy (E peak ) values, for a conservative annual estimate of ∼30 GRBs. The addition of BAT/s spectral response will (i) complement in-orbit calibration efforts of GBM's detector response matrices, (ii) augment GLAST's low energy sensitivity by increasing the ∼20-100 keV effective area, (iii) facilitate ground-based follow-up efforts of GLAST GRBs by increasing GBM's source localization precision, and (iv) help identify a subset of non-triggered GRBs discovered via off-line GBM data analysis. Such multi-wavelength correlative analyses, which have been demonstrated by successful joint-spectral fits of Swift-BAT GRBs with other higher energy detectors such as Konus-WIND and Suzaku-WAM, would enable the study of broad-band spectral and temporal evolution of prompt GRB emission over three energy decades, thus potentially increasing science return without placing additional demands upon mission resources throughout their contemporaneous orbital tenure over the next decade

  17. A Search for High-Energy Counterparts to Fast Radio Bursts

    Science.gov (United States)

    Cunningham, Virginia A.; Cenko, Bradley

    2018-01-01

    We report on a search for high-energy counterparts to Fast Radio Bursts (FRBs) with the Fermi Gamma-ray Burst Monitor (GBM), Fermi Large Area Telescope (LAT), and the Swift Burst Alert Telescope (BAT). We find no significant associations for any of the 14 FRBs in our sample, but report upper limits to the high-energy fluence for each on timescales of ∼0.1, 1, 10, and 100 s. We report lower limits on the radio to high-energy fluence, fr / fγ, for timescales of ∼0.1 and 100 s. The non-detection of high-energy emission is expected if FRBs are analogous to the giant pulses seen from the Crab pulsar, but the observed radio fluences of FRBs are orders of magnitude larger than even the most extreme giant pulses would be at the implied cosmological distances. It has also been proposed that events similar to magnetar hyperflares produce FRBs; this might be a viable model, but our fr / fγ lower limits are in tension with the fr / fγ upper limit for the 2004 superburst of SGR 1806‑20, for 6 out of the 12 FRBs that we study. This demonstrates the utility of analyses of high-energy data for FRBs in tracking down the nature of these elusive sources.

  18. The DOPA decarboxylase (DDC) gene is associated with alerting attention.

    Science.gov (United States)

    Zhu, Bi; Chen, Chuansheng; Moyzis, Robert K; Dong, Qi; Chen, Chunhui; He, Qinghua; Li, Jin; Li, Jun; Lei, Xuemei; Lin, Chongde

    2013-06-03

    DOPA decarboxylase (DDC) is involved in the synthesis of dopamine, norepinephrine and serotonin. It has been suggested that genes involved in the dopamine, norepinephrine, and cholinergic systems play an essential role in the efficiency of human attention networks. Attention refers to the cognitive process of obtaining and maintaining the alert state, orienting to sensory events, and regulating the conflicts of thoughts and behavior. The present study tested seven single nucleotide polymorphisms (SNPs) within the DDC gene for association with attention, which was assessed by the Attention Network Test to detect three networks of attention, including alerting, orienting, and executive attention, in a healthy Han Chinese sample (N=451). Association analysis for individual SNPs indicated that four of the seven SNPs (rs3887825, rs7786398, rs10499695, and rs6969081) were significantly associated with alerting attention. Haplotype-based association analysis revealed that alerting was associated with the haplotype G-A-T for SNPs rs7786398-rs10499695-rs6969081. These associations remained significant after correcting for multiple testing by max(T) permutation. No association was found for orienting and executive attention. This study provides the first evidence for the involvement of the DDC gene in alerting attention. A better understanding of the genetic basis of distinct attention networks would allow us to develop more effective diagnosis, treatment, and prevention of deficient or underdeveloped alerting attention as well as its related prevalent neuropsychiatric disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Possible galactic origin of. gamma. -ray bursts

    Energy Technology Data Exchange (ETDEWEB)

    Manchanda, R K; Ramsden, D [Southampton Univ. (UK). Dept. of Physics

    1977-03-31

    It is stated that extragalactic models for the origin of non-solar ..gamma..-ray bursts include supernova bursts in remote galaxies, and the collapse of the cores of active stars, whilst galactic models are based on flare stars, thermonuclear explosions in neutron stars and the sudden accretion of cometary gas on to neutron stars. The acceptability of any of these models may be tested by the observed size spectrum of the ..gamma..-ray bursts. The extragalactic models predict a power law spectrum with number index -1.5, whilst for the galactic models the number index will be -1. Experimental data on ..gamma..-ray bursts is, however, still meagre, and so far only 44 confirmed events have been recorded by satellite-borne instruments. The number spectrum of the observed ..gamma..-ray bursts indicates that the observed distribution for events with an energy < 10/sup -4/ erg/cm/sup 2/ is flat; this makes the choice of any model completely arbitrary. An analysis of the observed ..gamma..-ray events is here presented that suggests very interesting possibilities for their origin. There appears to be a preferred mean energy for ..gamma..-ray bursts; some 90% of the recorded events show a mean energy between 5 x 10/sup -5/ and 5 x 10/sup -4/ erg/cm/sup 2/, contrary to the predicted characteristics of the number spectrum of various models. A remarkable similarity is found between the distribution of ..gamma..-ray bursts and that of supernova remnants, suggesting a genetic relationship between the two and the galactic origin of the ..gamma..-ray bursts, and the burst source could be identified with completely run down neutron stars, formed during supernova explosions.

  20. Bursting neurons and ultrasound avoidance in crickets

    Directory of Open Access Journals (Sweden)

    Gary eMarsat

    2012-07-01

    Full Text Available Decision making in invertebrates often relies on simple neural circuits composed of only a few identified neurons. The relative simplicity of these circuits makes it possible to identify the key computation and neural properties underlying decisions. In this review, we summarize recent research on the neural basis of ultrasound avoidance in crickets, a response that allows escape from echolocating bats. The key neural property shaping behavioral output is high-frequency bursting of an identified interneuron, AN2, which carries information about ultrasound stimuli from receptor neurons to the brain. AN2's spike train consists of clusters of spikes –bursts– that may be interspersed with isolated, non-burst spikes. AN2 firing is necessary and sufficient to trigger avoidance steering but only high-rate firing, such as occurs in bursts, evokes this response. AN2 bursts are therefore at the core of the computation involved in deciding whether or not to steer away from ultrasound. Bursts in AN2 are triggered by synaptic input from nearly synchronous bursts in ultrasound receptors. Thus the population response at the very first stage of sensory processing –the auditory receptor- already differentiates the features of the stimulus that will trigger a behavioral response from those that will not. Adaptation, both intrinsic to AN2 and within ultrasound receptors, scales the burst-generating features according to the stimulus statistics, thus filtering out background noise and ensuring that bursts occur selectively in response to salient peaks in ultrasound intensity. Furthermore AN2’s sensitivity to ultrasound varies adaptively with predation pressure, through both developmental and evolutionary mechanisms. We discuss how this key relationship between bursting and the triggering of avoidance behavior is also observed in other invertebrate systems such as the avoidance of looming visual stimuli in locusts or heat avoidance in beetles.

  1. Relativistic motion in gamma-ray bursts

    International Nuclear Information System (INIS)

    Krolik, J.H.; Pier, E.A.

    1991-01-01

    Three fundamental problems affect models of gamma-ray bursts, i.e., the energy source, the ability of high-energy photons to escape the radiation region, and the comparative weakness of X-ray emission. It is indicated that relativistic bulk motion of the gamma-ray-emitting plasma generically provides a solution to all three of these problems. Results show that, if the plasma that produces gamma-ray bursts has a bulk relativistic velocity with Lorentz factor gamma of about 10, several of the most troubling problems having to do with gamma-ray bursts are solved. 42 refs

  2. Frequency chirping during a fishbone burst

    International Nuclear Information System (INIS)

    Marchenko, V.S.; Reznik, S.N.

    2011-01-01

    It is shown that frequency chirping during fishbone activity can be attributed to the reactive torque exerted on the plasma during the instability burst, which slows down plasma rotation inside the q = 1 surface and reduces the mode frequency in the lab frame. Estimates show that the peak value of this torque can exceed the neutral beam torque in modern tokamaks. The simple line-broadened quasilinear burst model (Berk et al 1995 Nucl. Fusion 35 1661), properly adapted for the fishbone case, is capable of reproducing the key features of the bursting mode. (letter)

  3. Ballerina - pirouettes in search of gamma bursts

    DEFF Research Database (Denmark)

    Brandt, Søren Kristian; Lund, Niels; Pedersen, Henrik

    1999-01-01

    The cosmological origin of gamma ray bursts has now been established with reasonable certainty, Many more bursts will need to be studied to establish the typical distance scale, and to map out the large diversity in properties which have been indicated by the first handful of events. We are propo...... are proposing Ballerina, a small satellite to provide accurate positions and new data on the gamma-ray bursts. We anticipate a detection rate an order of magnitude larger than obtained from Beppo-SAX....

  4. Speech Auditory Alerts Promote Memory for Alerted Events in a Video-Simulated Self-Driving Car Ride.

    Science.gov (United States)

    Nees, Michael A; Helbein, Benji; Porter, Anna

    2016-05-01

    Auditory displays could be essential to helping drivers maintain situation awareness in autonomous vehicles, but to date, few or no studies have examined the effectiveness of different types of auditory displays for this application scenario. Recent advances in the development of autonomous vehicles (i.e., self-driving cars) have suggested that widespread automation of driving may be tenable in the near future. Drivers may be required to monitor the status of automation programs and vehicle conditions as they engage in secondary leisure or work tasks (entertainment, communication, etc.) in autonomous vehicles. An experiment compared memory for alerted events-a component of Level 1 situation awareness-using speech alerts, auditory icons, and a visual control condition during a video-simulated self-driving car ride with a visual secondary task. The alerts gave information about the vehicle's operating status and the driving scenario. Speech alerts resulted in better memory for alerted events. Both auditory display types resulted in less perceived effort devoted toward the study tasks but also greater perceived annoyance with the alerts. Speech auditory displays promoted Level 1 situation awareness during a simulation of a ride in a self-driving vehicle under routine conditions, but annoyance remains a concern with auditory displays. Speech auditory displays showed promise as a means of increasing Level 1 situation awareness of routine scenarios during an autonomous vehicle ride with an unrelated secondary task. © 2016, Human Factors and Ergonomics Society.

  5. The genesis of period-adding bursting without bursting-chaos in the Chay model

    International Nuclear Information System (INIS)

    Yang Zhuoqin; Lu Qishao; Li Li

    2006-01-01

    According to the period-adding firing patterns without chaos observed in neuronal experiments, the genesis of the period-adding 'fold/homoclinic' bursting sequence without bursting-chaos is explored by numerical simulation, fast/slow dynamics and bifurcation analysis of limit cycle in the neuronal Chay model. It is found that each periodic bursting, from period-1 to period-7, is separately generated by the corresponding periodic spiking pattern through two period-doubling bifurcations, except for the period-1 bursting occurring via a Hopf bifurcation. Consequently, it can be revealed that this period-adding bursting bifurcation without chaos has a compound bifurcation structure with transitions from spiking to bursting, which is closely related to period-doubling bifurcations of periodic spiking in essence

  6. The genesis of period-adding bursting without bursting-chaos in the Chay model

    International Nuclear Information System (INIS)

    Yang Zhuoqin; Lu Qishao; Li Li

    2006-01-01

    According to the period-adding firing patterns without chaos observed in neuronal experiments, the genesis of the period-adding 'fold/homoclinic' bursting sequence without bursting-chaos is explored by numerical simulation, fast/slow dynamics and bifurcation analysis of limit cycle in the neuronal Chay model. It is found that each periodic bursting, from period-1 to 7, is separately generated by the corresponding periodic spiking pattern through two period-doubling bifurcations, except for the period-1 bursting occurring via a Hopf bifurcation. Consequently, it can be revealed that this period-adding bursting bifurcation without chaos has a compound bifurcation structure with transitions from spiking to bursting, which is closely related to period-doubling bifurcations of periodic spiking in essence

  7. Two Early Gamma-ray Bursts Optical Afterglow Detections with TAOS Telescopes--GRB 071010B and GRB 071112C

    International Nuclear Information System (INIS)

    Huang, K. Y.; Wang, S. Y.; Urata, Y.

    2009-01-01

    We present on two early detections of GRB afterglows with the Taiwanese-American Occltation Sruvey (TAOS) telescopes. The robotic TAOS system has been devised so that the routine Kuiper Belt Object (KBO) survey is interrupted when a GRB alert is triggered. Our first detection, GRB 071010B was detected by TAOS 62 s after the burst and showed a weak early brightening during the observations. No significant correction with the prompt gamma-ray emission indicated that our optical emission detected is afterglow emission. The second detection of TAOS, GRB 071112C was detected 96 s after the burst, also showed a possible initial raising then followed a steep decay in the R-band light curve.

  8. On Gamma-Ray Bursts

    CERN Document Server

    Ruffini, Remo; Bianco, Carlo Luciano; Caito, Letizia; Chardonnet, Pascal; Cherubini, Christian; Dainotti, Maria Giovanna; Fraschetti, Federico; Geralico, Andrea; Guida, Roberto; Patricelli, Barbara; Rotondo, Michael; Hernandez, Jorge Armando Rueda; Vereshchagin, Gregory; Xue, She-Sheng

    2008-01-01

    (Shortened) We show by example how the uncoding of Gamma-Ray Bursts (GRBs) offers unprecedented possibilities to foster new knowledge in fundamental physics and in astrophysics. After recalling some of the classic work on vacuum polarization in uniform electric fields by Klein, Sauter, Heisenberg, Euler and Schwinger, we summarize some of the efforts to observe these effects in heavy ions and high energy ion collisions. We then turn to the theory of vacuum polarization around a Kerr-Newman black hole, leading to the extraction of the blackholic energy, to the concept of dyadosphere and dyadotorus, and to the creation of an electron-positron-photon plasma. We then present a new theoretical approach encompassing the physics of neutron stars and heavy nuclei. It is shown that configurations of nuclear matter in bulk with global charge neutrality can exist on macroscopic scales and with electric fields close to the critical value near their surfaces. These configurations may represent an initial condition for the...

  9. Ligament rupture and unstable burst behaviors of axial flaws in steam generator U-bends

    Energy Technology Data Exchange (ETDEWEB)

    Bahn, Chi Bum, E-mail: bahn@pusan.ac.kr [Pusan National University, 2 Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Oh, Young-Jin [KEPCO Engineering & Construction Co. Inc., Seongnam 463-870 (Korea, Republic of); Majumdar, Saurin [Argonne National Laboratory, Lemont, IL 60439 (United States)

    2015-11-15

    Highlights: • Ligament rupture and unstable burst pressure tests were conducted with U-bends. • In general, U-bends showed higher ligament rupture and burst pressures than straight tubes. • U-bend test data was bounded by 90% lower limit of the probabilistic models for straight tubes. • Prediction models for straight tubes could be conservatively applied to U-bends. - Abstract: Incidents of U-bend cracking in steam generator (SG) tubes have been reported, some of which have led to tube rupture. Experimental and analytical modeling efforts to determine the failure criteria of flawed SG U-bends are limited. To evaluate structural integrity of flawed U-bends, ligament rupture and unstable burst pressure tests were conducted on 57 and 152 mm bend radius U-bends with axial electrical discharge machining notches. In general, the ligament rupture and burst pressures of the U-bends were higher than those of straight tubes with similar notches. To quantitatively address the test data scatter issue, probabilistic models were introduced. All ligament rupture and burst pressures of U-bends were bounded by 90% lower limits of the probabilistic models for straight tubes. It was concluded that the prediction models for straight tubes could be applied to U-bends to conservatively evaluate the ligament rupture and burst pressures of U-bends with axial flaws.

  10. Ligament rupture and unstable burst behaviors of axial flaws in steam generator U-bends

    International Nuclear Information System (INIS)

    Bahn, Chi Bum; Oh, Young-Jin; Majumdar, Saurin

    2015-01-01

    Highlights: • Ligament rupture and unstable burst pressure tests were conducted with U-bends. • In general, U-bends showed higher ligament rupture and burst pressures than straight tubes. • U-bend test data was bounded by 90% lower limit of the probabilistic models for straight tubes. • Prediction models for straight tubes could be conservatively applied to U-bends. - Abstract: Incidents of U-bend cracking in steam generator (SG) tubes have been reported, some of which have led to tube rupture. Experimental and analytical modeling efforts to determine the failure criteria of flawed SG U-bends are limited. To evaluate structural integrity of flawed U-bends, ligament rupture and unstable burst pressure tests were conducted on 57 and 152 mm bend radius U-bends with axial electrical discharge machining notches. In general, the ligament rupture and burst pressures of the U-bends were higher than those of straight tubes with similar notches. To quantitatively address the test data scatter issue, probabilistic models were introduced. All ligament rupture and burst pressures of U-bends were bounded by 90% lower limits of the probabilistic models for straight tubes. It was concluded that the prediction models for straight tubes could be applied to U-bends to conservatively evaluate the ligament rupture and burst pressures of U-bends with axial flaws.

  11. Complex transitions between spike, burst or chaos synchronization states in coupled neurons with coexisting bursting patterns

    International Nuclear Information System (INIS)

    Gu Hua-Guang; Chen Sheng-Gen; Li Yu-Ye

    2015-01-01

    We investigated the synchronization dynamics of a coupled neuronal system composed of two identical Chay model neurons. The Chay model showed coexisting period-1 and period-2 bursting patterns as a parameter and initial values are varied. We simulated multiple periodic and chaotic bursting patterns with non-(NS), burst phase (BS), spike phase (SS), complete (CS), and lag synchronization states. When the coexisting behavior is near period-2 bursting, the transitions of synchronization states of the coupled system follows very complex transitions that begins with transitions between BS and SS, moves to transitions between CS and SS, and to CS. Most initial values lead to the CS state of period-2 bursting while only a few lead to the CS state of period-1 bursting. When the coexisting behavior is near period-1 bursting, the transitions begin with NS, move to transitions between SS and BS, to transitions between SS and CS, and then to CS. Most initial values lead to the CS state of period-1 bursting but a few lead to the CS state of period-2 bursting. The BS was identified as chaos synchronization. The patterns for NS and transitions between BS and SS are insensitive to initial values. The patterns for transitions between CS and SS and the CS state are sensitive to them. The number of spikes per burst of non-CS bursting increases with increasing coupling strength. These results not only reveal the initial value- and parameter-dependent synchronization transitions of coupled systems with coexisting behaviors, but also facilitate interpretation of various bursting patterns and synchronization transitions generated in the nervous system with weak coupling strength. (paper)

  12. Relativistic effects in gamma-ray bursts

    International Nuclear Information System (INIS)

    Eriksen, Erik; Groen, Oeyvind

    1999-01-01

    According to recent models of the sources of gamma-ray bursts the extremely energetic emission is caused by shells expanding with ultrarelativistic velocity. With the recent identification of optical sources at the positions of some gamma-ray bursts these ''fireball'' models have acquired an actuality that invites to use them as a motivating application when teaching special relativity. We demonstrate several relativistic effects associated with these models which are very pronounced due to the great velocity of the shell. For example a burst lasting for a month in the rest frame of an element of the shell lasts for a few seconds only, in the rest frame of our detector. It is shown how the observed properties of a burst are modified by aberration and the Doppler effect. The apparent luminosity as a function of time is calculated. Modifications due to the motion of the star away from the observer are calculated. (Author)

  13. Solar energetic particles and radio burst emission

    Directory of Open Access Journals (Sweden)

    Miteva Rositsa

    2017-01-01

    Full Text Available We present a statistical study on the observed solar radio burst emission associated with the origin of in situ detected solar energetic particles. Several proton event catalogs in the period 1996–2016 are used. At the time of appearance of the particle origin (flare and coronal mass ejection we identified radio burst signatures of types II, III and IV by inspecting dynamic radio spectral plots. The information from observatory reports is also accounted for during the analysis. The occurrence of solar radio burst signatures is evaluated within selected wavelength ranges during the solar cycle 23 and the ongoing 24. Finally, we present the burst occurrence trends with respect to the intensity of the proton events and the location of their solar origin.

  14. Bursts from the very early universe

    International Nuclear Information System (INIS)

    Silk, J.; Stodolsky, L.

    2006-01-01

    Bursts of weakly interacting particles such as neutrinos or even more weakly interacting particles such as wimps and gravitons from the very early universe would offer a much deeper 'look back time' to early epochs than is possible with photons. We consider some of the issues related to the existence of such bursts and their detectability. Characterizing the burst rate by a probability P per Hubble four-volume we find, for events in the radiation-dominated era, that the natural unit of description is the present intensity of the CMB times P. The existence of such bursts would make the observation of phenomena associated with very early times in cosmology at least conceptually possible. One might even hope to probe the transplanckian epoch if complexes more weakly interacting than the graviton can exist. Other conceivable applications include the potential detectability of the formation of 'pocket universes' in a multiverse

  15. Bursts from the very early universe

    Energy Technology Data Exchange (ETDEWEB)

    Silk, J. [Department of Physics, University of Oxford, Oxford OX1 3RH (United Kingdom); Stodolsky, L. [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)]. E-mail: les@mppmu.mpg.de

    2006-07-27

    Bursts of weakly interacting particles such as neutrinos or even more weakly interacting particles such as wimps and gravitons from the very early universe would offer a much deeper 'look back time' to early epochs than is possible with photons. We consider some of the issues related to the existence of such bursts and their detectability. Characterizing the burst rate by a probability P per Hubble four-volume we find, for events in the radiation-dominated era, that the natural unit of description is the present intensity of the CMB times P. The existence of such bursts would make the observation of pheno associated with very early times in cosmology at least conceptually possible. One might even hope to probe the transplanckian epoch if complexes more weakly interacting than the graviton can exist. Other conceivable applications include the potential detectability of the formation of 'pocket universes' in a multiverse.

  16. Observations of gamma-ray bursts

    International Nuclear Information System (INIS)

    Strong, I.B.; Klebesadel, R.W.; Evans, W.D.

    1975-01-01

    Observational data on gamma-ray bursts are reviewed. Information is grouped into temporal properties, energy fluxes and spectral properties, and directions and distributions of the sources in space. (BJG)

  17. Damping of type III solar radio bursts

    International Nuclear Information System (INIS)

    Levin, B.N.

    1982-01-01

    The meter- and decameter-wavelength damping of type III bursts may be attributable to stabilization of the Langmuir-wave instability of the fast-electron streams through excitation of cyclotron-branch plasma waves

  18. Optimal Codes for the Burst Erasure Channel

    Science.gov (United States)

    Hamkins, Jon

    2010-01-01

    Deep space communications over noisy channels lead to certain packets that are not decodable. These packets leave gaps, or bursts of erasures, in the data stream. Burst erasure correcting codes overcome this problem. These are forward erasure correcting codes that allow one to recover the missing gaps of data. Much of the recent work on this topic concentrated on Low-Density Parity-Check (LDPC) codes. These are more complicated to encode and decode than Single Parity Check (SPC) codes or Reed-Solomon (RS) codes, and so far have not been able to achieve the theoretical limit for burst erasure protection. A block interleaved maximum distance separable (MDS) code (e.g., an SPC or RS code) offers near-optimal burst erasure protection, in the sense that no other scheme of equal total transmission length and code rate could improve the guaranteed correctible burst erasure length by more than one symbol. The optimality does not depend on the length of the code, i.e., a short MDS code block interleaved to a given length would perform as well as a longer MDS code interleaved to the same overall length. As a result, this approach offers lower decoding complexity with better burst erasure protection compared to other recent designs for the burst erasure channel (e.g., LDPC codes). A limitation of the design is its lack of robustness to channels that have impairments other than burst erasures (e.g., additive white Gaussian noise), making its application best suited for correcting data erasures in layers above the physical layer. The efficiency of a burst erasure code is the length of its burst erasure correction capability divided by the theoretical upper limit on this length. The inefficiency is one minus the efficiency. The illustration compares the inefficiency of interleaved RS codes to Quasi-Cyclic (QC) LDPC codes, Euclidean Geometry (EG) LDPC codes, extended Irregular Repeat Accumulate (eIRA) codes, array codes, and random LDPC codes previously proposed for burst erasure

  19. Nature of gamma-ray burst sources

    International Nuclear Information System (INIS)

    Ventura, J.

    1983-01-01

    Observational evidence suggests that gamma ray bursts have a local galactic origin involving neutron stars. In this light we make a critical review of physics of the thermonuclear runaway model placing emphasis on self-consistency. We further show that some of the proposed models can be observationally excluded in the light of existing data from the Einstein Observatory. The possibility of gamma bursts arising in low mass binaries is finally discussed in the light of evolutionary scenarios leading to low luminosity systems

  20. A Fast Radio Burst Host Galaxy

    OpenAIRE

    Keane, E. F.; Johnston, S.; Bhandari, S.; Barr, E.; Bhat, N. D. R.; Burgay, M.; Caleb, M.; Flynn, C.; Jameson, A.; Kramer, M.; Petroff, E.; Possenti, A.; van Straten, W.; Bailes, M.; Burke-Spolaor, S.

    2016-01-01

    In recent years, millisecond duration radio signals originating from distant galaxies appear to have been discovered in the so-called Fast Radio Bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity which, in tandem with a redshift measurement, can be used for fundamental physical investigations. While every fast radio burst has a dispersion measurement, none before now have had a redshift measurement, due to the difficulty in...

  1. 76 FR 54245 - Agency Information Collection Activities: Submission for OMB Review; Comment Request, Integrated...

    Science.gov (United States)

    2011-08-31

    ... system to alert and warn the American people in situations of war, terrorist attack, natural disaster, or... Request, Integrated Public Alert and Warning Systems (IPAWS) Inventory AGENCY: Federal Emergency... will continue to consist of the public alert and warning systems, as well as the communication systems...

  2. Balloon observation of gamma-ray burst

    International Nuclear Information System (INIS)

    Nishimura, Jun; Fujii, Masami; Yamagami, Takamasa; Oda, Minoru; Ogawara, Yoshiaki

    1978-01-01

    Cosmic gamma-ray burst is an interesting high energy astrophysical phenomenon, but the burst mechanism has not been well understood. Since 1975, long duration balloon flight has been conducted to search for gamma-ray bursts and to determine the source locations. A rotating cross-modulation collimator was employed to determine the locations of sources, and four NaI(Tl) scintillation counters were employed to detect hard X-ray with energy from 20 to 200 keV. The balloon light was performed at altitude of 8.3 mb from September 28, 1977, and the observation time of 79 hours was achieved. In this experiment, the monitor counter was not mounted. The count increase was observed at 16 h 22 m 31 s JST on October 1, 1977. The event disappeared after 1 sec. The total flux is estimated to be 1.6 x 10 -6 erg/cm 2 sec at the top of the atmosphere. When this event was observed, the solar-terrestrial environment was also quiet. Thus, this event was attributed to a small gamma-ray burst. Unfortunately, the duration of the burst was so short that the position of the burst source was not able to be determined. (Yoshimori, M.)

  3. Gamma Ray Bursts-Afterglows and Counterparts

    Science.gov (United States)

    Fishman, Gerald J

    1998-01-01

    Several breakthrough discoveries were made last year of x-ray, optical and radio afterglows and counterparts to gamma-ray bursts, and a redshift has been associated with at least one of these. These discoveries were made possible by the fast, accurate gamma-ray burst locations of the BeppoSAX satellite. It is now generally believed that the burst sources are at cosmological distances and that they represent the most powerful explosions in the Universe. These observations also open new possibilities for the study of early star formation, the physics of extreme conditions and perhaps even cosmology. This session will concentrate on recent x-ray, optical and radio afterglow observations of gamma-ray bursts, associated redshift measurements, and counterpart observations. Several review and theory talks will also be presented, along with a summary of the astrophysical implications of the observations. There will be additional poster contributions on observations of gamma-ray burst source locations at wavelengths other than gamma rays. Posters are also solicited that describe new observational capabilities for rapid follow-up observations of gamma-ray bursts.

  4. Comparison of methods of alert acknowledgement by critical care clinicians in the ICU setting

    Directory of Open Access Journals (Sweden)

    Andrew M. Harrison

    2017-03-01

    Full Text Available Background Electronic Health Record (EHR-based sepsis alert systems have failed to demonstrate improvements in clinically meaningful endpoints. However, the effect of implementation barriers on the success of new sepsis alert systems is rarely explored. Objective To test the hypothesis time to severe sepsis alert acknowledgement by critical care clinicians in the ICU setting would be reduced using an EHR-based alert acknowledgement system compared to a text paging-based system. Study Design In one arm of this simulation study, real alerts for patients in the medical ICU were delivered to critical care clinicians through the EHR. In the other arm, simulated alerts were delivered through text paging. The primary outcome was time to alert acknowledgement. The secondary outcomes were a structured, mixed quantitative/qualitative survey and informal group interview. Results The alert acknowledgement rate from the severe sepsis alert system was 3% (N = 148 and 51% (N = 156 from simulated severe sepsis alerts through traditional text paging. Time to alert acknowledgement from the severe sepsis alert system was median 274 min (N = 5 and median 2 min (N = 80 from text paging. The response rate from the EHR-based alert system was insufficient to compare primary measures. However, secondary measures revealed important barriers. Conclusion Alert fatigue, interruption, human error, and information overload are barriers to alert and simulation studies in the ICU setting.

  5. Space Debris Alert System for Aviation

    Science.gov (United States)

    Sgobba, Tommaso

    2013-09-01

    Despite increasing efforts to accurately predict space debris re-entry, the exact time and location of re-entry is still very uncertain. Partially, this is due to a skipping effect uncontrolled spacecraft may experience as they enter the atmosphere at a shallow angle. Such effect difficult to model depends on atmospheric variations of density. When the bouncing off ends and atmospheric re-entry starts, the trajectory and the overall location of surviving fragments can be precisely predicted but the time to impact with ground, or to reach the airspace, becomes very short.Different is the case of a functional space system performing controlled re-entry. Suitable forecasts methods are available to clear air and maritime traffic from hazard areas (so-called traffic segregation).In US, following the Space Shuttle Columbia accident in 2003, a re-entry hazard areas location forecast system was putted in place for the specific case of major malfunction of a Reusable Launch Vehicles (RLV) at re-entry. The Shuttle Hazard Area to Aircraft Calculator (SHAAC) is a system based on ground equipment and software analyses and prediction tools, which require trained personnel and close coordination between the organization responsible for RLV operation (NASA for Shuttle) and the Federal Aviation Administration. The system very much relies on the operator's capability to determine that a major malfunction has occurred.This paper presents a US pending patent by the European Space Agency, which consists of a "smart fragment" using a GPS localizer together with pre- computed debris footprint area and direct broadcasting of such hazard areas.The risk for aviation from falling debris is very remote but catastrophic. Suspending flight over vast swath of airspace for every re-entering spacecraft or rocket upper stage, which is a weekly occurrence, would be extremely costly and disruptive.The Re-entry Direct Broadcasting Alert System (R- DBAS) is an original merging and evolution of the Re

  6. Optimizing the response to surveillance alerts in automated surveillance systems.

    Science.gov (United States)

    Izadi, Masoumeh; Buckeridge, David L

    2011-02-28

    Although much research effort has been directed toward refining algorithms for disease outbreak alerting, considerably less attention has been given to the response to alerts generated from statistical detection algorithms. Given the inherent inaccuracy in alerting, it is imperative to develop methods that help public health personnel identify optimal policies in response to alerts. This study evaluates the application of dynamic decision making models to the problem of responding to outbreak detection methods, using anthrax surveillance as an example. Adaptive optimization through approximate dynamic programming is used to generate a policy for decision making following outbreak detection. We investigate the degree to which the model can tolerate noise theoretically, in order to keep near optimal behavior. We also evaluate the policy from our model empirically and compare it with current approaches in routine public health practice for investigating alerts. Timeliness of outbreak confirmation and total costs associated with the decisions made are used as performance measures. Using our approach, on average, 80 per cent of outbreaks were confirmed prior to the fifth day of post-attack with considerably less cost compared to response strategies currently in use. Experimental results are also provided to illustrate the robustness of the adaptive optimization approach and to show the realization of the derived error bounds in practice. Copyright © 2011 John Wiley & Sons, Ltd.

  7. Infant Responsiveness, Alertness, Hemoglobin and Growth in Rural Sidama, Ethiopia

    Science.gov (United States)

    Aubuchon-Endsley, Nicki L.; Grant, Stephanie L.; Thomas, David G.; Kennedy, Tay S.; Berhanu, Getenesh; Stoecker, Barbara J.; Hubbs-Tait, Laura; Hambidge, K. Michael

    2011-01-01

    Several recent studies have supported relations between infant behavior (alertness and responsiveness) and nutrition (e.g. Dempsey 2008, Wachs et al 2005) in addition to investigating infant behavior within the context of changes in iron status over time (e.g. Black et al. 2004, Murray-Kolb & Beard 2009). Existing research is typically limited to investigation of the effects of a single vitamin or mineral and no studies have been found that examined the influence that early alertness and responsiveness have on growth in early infancy, despite the fact that relations between behavior and nutritional status may be bidirectional (Hulthén 2003). The current study used a sample of Ethiopian infants and investigated anthropometrics, hemoglobin, the frequency of alertness, and the frequency of responsiveness at 6 and 9 months of age. Six-month weight-for-age predicted 9-month frequency of alertness, while 6-month hemoglobin predicted 9-month frequency of responsiveness. Compared to responsive infants, non-responsive infants at 6 months remained more non-responsive at 9 months, though weight-for-age for both groups converged at 9 months. Results support relations between nutrition and behavior (alertness and responsiveness) and provide evidence of a potentially useful tool (the Laboratory Temperament Assessment Battery [Lab-TAB]) that was adapted to evaluate these relations in Ethiopia. PMID:22233352

  8. Gamma Ray Burst Discoveries with the Swift Mission

    Science.gov (United States)

    Gehrels, Neil; Tueller, Jack

    2007-01-01

    There is a great synergy between the Swift and INTEGRAL missions. Swift provides wide-field hard x-ray monitoring and sensitive x-ray and UV/optical observations. INTEGRAL provides optical through gamma-ray coverage with emphasis on hard xray imaging and gamma-ray spectroscopy. For hard x-ray survey studies, the BAT and IBIS instruments are complementary with BAT covering the full sky every day and IBIS scanning the galactic plane. For GRBs, Swift follows up bursts detected by INTEGRAL. X-ray and optical observations give arcsecond positions and afterglow lightcurves. For IGR sources, X-ray observations identify counterparts. The joint BAT and IBIS survey data are giving the most complete picture of the hard x-ray sky ever obtained. This talk will review Swift capabilities and discuss joint observations that are taking place and planned

  9. The Second Swift BAT Gamma-Ray Burst Catalog

    Science.gov (United States)

    Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.; Fenimore, E. E.; Gehrels, N.; Krimm, H. A.; Markwardt, C. B.; Palmer, D. M.; Parsons, A. M.; Sato, G.; hide

    2010-01-01

    We present the second Swift Burst Alert Telescope (BAT) catalog of gamma-ray bursts (GRBs), which contains 476 bursts detected by the BAT between 2004 December 19 and 2009 December 21. This catalog (hereafter the BAT2 catalog) presents burst trigger time, location, 90% error radius, duration, fluence, peak flux, time-averaged spectral parameters and time-resolved spectral parametert:; measured by the BAT. In the correlation study of various observed parameters extracted from the BAT prompt emission data, we distinguish among long-duration GRBs (L-GRBs), short-duration GRBs (S-GRBs), and short-duration GRBs with extended emission (S-GRBs with E.E.) to investigate differences in the prompt emission properties. The fraction of L-GRBs, S-GRBs and S-GRBs with E.E. in the catalog are 89%, 8% and 2% respectively. We compare the BAT prompt emission properties with the BATSE, BeppoSAX and HETE-2 GRB samples. We also correlate the observed prompt emission properties with the redshifts for the GRBs with known redshift. The BAT T90 and T50 durations peak at 70 s and 30 s, respectively. We confirm that the spectra of the BAT S-GRBs are generally harder than those of the L-GRBs. The time-averaged spectra of the BAT S GRBs with E.E. are similar to those of the L-GRBs. Whereas, the spectra of the initial short spikes of the S-GRBs with E.E. are similar to those of the S-GRBs. We show that the BAT GRB samples are significantly softer than the BATSE bright GRBs, and that the time-averaged E obs/peak of the BAT GRBs peaks at 80 keV which is significantly lower energy than those of the BATSE sample which peak at 320 keV. The time-averaged spectral properties of the BAT GRB sample are similar to those of the HETE-2 GRB samples. By time-resolved spectral analysis, we find that 10% of the BAT observed photon indices are outside the allowed region of the synchrotron shock model. The observed durations of the BAT high redshift GRBs are not systematically longer than those of the moderate

  10. Wireless alerting system using vibration for vehicles dashboard

    Science.gov (United States)

    Raj, Sweta; Rai, Shweta; Magaramagara, Wilbert; Sivacoumar, R.

    2017-11-01

    This paper aims at improving the engine life of any vehicle through a continuous measurement and monitoring of vital engine operational parameters and providing an effective alerting to drivers for any abnormality. Vehicles currently are using audio and visible alerting signals through alarms and light as a warning to the driver but these are not effective in noisy environments and during daylight. Through the use of the sense of feeling a driver can be alerted effectively. The need to no other vehicle parameter needs to be aided through the mobile display (phone).Thus a system is designed and implements to measure engine temperature, RPM, Oil level and Coolant level using appropriate sensors and a wireless communication (Bluetooth) is established to actuate a portable vibration control device and to read the different vehicle sensor readings through an android application for display and diagnosis.

  11. Dynamic malware containment under an epidemic model with alert

    Science.gov (United States)

    Zhang, Tianrui; Yang, Lu-Xing; Yang, Xiaofan; Wu, Yingbo; Tang, Yuan Yan

    2017-03-01

    Alerting at the early stage of malware invasion turns out to be an important complement to malware detection and elimination. This paper addresses the issue of how to dynamically contain the prevalence of malware at a lower cost, provided alerting is feasible. A controlled epidemic model with alert is established, and an optimal control problem based on the epidemic model is formulated. The optimality system for the optimal control problem is derived. The structure of an optimal control for the proposed optimal control problem is characterized under some conditions. Numerical examples show that the cost-efficiency of an optimal control strategy can be enhanced by adjusting the upper and lower bounds on admissible controls.

  12. Coronal mass ejections and solar radio bursts

    International Nuclear Information System (INIS)

    Kundu, M.R.

    1990-01-01

    The properties of coronal mass ejection (CME) events and their radio signatures are discussed. These signatures are mostly in the form of type II and type IV burst emissions. Although type II bursts are temporally associated with CMEs, it is shown that there is no spatial relationship between them. Type II's associated with CMEs have in most cases a different origin, and they are not piston-driven by CMEs. Moving type IV and type II bursts can be associated with slow CMEs with speeds as low as 200 km/s, contrary to the earlier belief that only CMEs with speeds >400 km/s are associated with radio bursts. A specific event has been discussed in which the CME and type IV burst has nearly the same speed and direction, but the type II burst location was behind the CME and its motion was transverse. The speed and motion of the type II burst strongly suggest that the type II shock was decoupled from the CME and was probably due to a flare behind the limb. Therefore only the type IV source could be directly associated with the slow CME. The electrons responsble for the type IV emission could be produced in the flare or in the type II and then become trapped in a plasmoid associated with the CME. The reconnected loop could then move outwards as in the usual palsmoid model. Alternatively, the type IV emission could be interpreted as due to electrons produced by acceleration in wave turbulence driven by currents in the shock front driven by the CME. The lower-hybrid model Lampe and Papadopoulos (1982), which operates at both fast and slow mode shocks, could be applied to this situation. (author). 31 refs., 12 figs

  13. Integration

    DEFF Research Database (Denmark)

    Emerek, Ruth

    2004-01-01

    Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration......Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration...

  14. Alert Workplace From Healthcare Workers' Perspective: Behavioral and Environmental Strategies to Improve Vigilance and Alertness in Healthcare Settings.

    Science.gov (United States)

    Sagah Zadeh, Rana; Shepley, Mardelle; Sadatsafavi, Hessam; Owora, Arthur Hamie; Krieger, Ana C

    2018-04-01

    This study aims to identify the behavioral and environmental strategies that healthcare workers view as helpful for managing sleepiness, improving alertness, and therefore optimizing workplace safety. Reduced alertness is a common issue in healthcare work environments and is associated with impaired cognitive performance and decision-making ability as well as increased errors and injuries. We surveyed 136 healthcare professionals at a primary care clinic, an acute care hospital, and a mental health clinic. Nonstructured, semistructured, and structured questionnaires were used to elicit relevant information which was analyzed using qualitative content analysis and logistic regression models, respectively. In order by frequency of endorsement: dietary intervention; physical mobility; cognitive, sensory, or social stimulation; personal lifestyle strategies; and rest/nap opportunities were reported as behavioral strategies used to address workplace alertness. Compared to other environmental features, daylight and thermal comfort were perceived to be more important to addressing workplace alertness ( p based guidelines is needed to address sleepiness and alertness to improve workplace safety in healthcare facilities.

  15. The agile alert system for gamma-ray transients

    International Nuclear Information System (INIS)

    Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Fioretti, V.; Tavani, M.; Argan, A.; Trois, A.; Scalise, E.; Parmiggiani, N.; Beneventano, D.; Chen, A. W.; Vercellone, S.; Pittori, C.; Verrecchia, F.; Lucarelli, F.; Santolamazza, P.; Fanari, G.; Giommi, P.; Longo, F.; Pellizzoni, A.

    2014-01-01

    In recent years, a new generation of space missions has offered great opportunities for discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) on board the AGILE space mission. AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many γ-ray transients of both galactic and extragalactic origin. This work presents the AGILE innovative approach to fast γ-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe (1) the AGILE Gamma-Ray Alert System, (2) a new algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for γ-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, via e-mail, and via push notifications from an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in γ-ray astrophysics.

  16. The agile alert system for gamma-ray transients

    Energy Technology Data Exchange (ETDEWEB)

    Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Fioretti, V. [INAF/IASF-Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Tavani, M.; Argan, A.; Trois, A.; Scalise, E. [INAF/IASF-Roma, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Parmiggiani, N.; Beneventano, D. [University of Modena and Reggio Emilia, Dipartimento di Science e Metodi dell' Ingegneria (Italy); Chen, A. W. [INAF/IASF-Milano, Via E. Bassini 15, I-20133 Milano (Italy); Vercellone, S. [School of Physics, University of the Witwatersrand, Johannesburg Wits 2050 (South Africa); Pittori, C.; Verrecchia, F.; Lucarelli, F.; Santolamazza, P.; Fanari, G.; Giommi, P. [INAF/IASF-Palermo, Via U. La Malfa 153, I-90146 Palermo (Italy); Longo, F. [ASI-ASDC, Via G. Galilei, I-00044 Frascati (Roma) (Italy); Pellizzoni, A. [INFN Trieste, I-34127 Trieste (Italy); and others

    2014-01-20

    In recent years, a new generation of space missions has offered great opportunities for discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) on board the AGILE space mission. AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many γ-ray transients of both galactic and extragalactic origin. This work presents the AGILE innovative approach to fast γ-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe (1) the AGILE Gamma-Ray Alert System, (2) a new algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for γ-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, via e-mail, and via push notifications from an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in γ-ray astrophysics.

  17. The AGILE Alert System for Gamma-Ray Transients

    Science.gov (United States)

    Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Tavani, M.; Parmiggiani, N.; Fioretti, V.; Chen, A. W.; Vercellone, S.; Pittori, C.; Verrecchia, F.; Lucarelli, F.; Santolamazza, P.; Fanari, G.; Giommi, P.; Beneventano, D.; Argan, A.; Trois, A.; Scalise, E.; Longo, F.; Pellizzoni, A.; Pucella, G.; Colafrancesco, S.; Conforti, V.; Tempesta, P.; Cerone, M.; Sabatini, P.; Annoni, G.; Valentini, G.; Salotti, L.

    2014-01-01

    In recent years, a new generation of space missions has offered great opportunities for discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) on board the AGILE space mission. AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many γ-ray transients of both galactic and extragalactic origin. This work presents the AGILE innovative approach to fast γ-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe (1) the AGILE Gamma-Ray Alert System, (2) a new algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for γ-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, via e-mail, and via push notifications from an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in γ-ray astrophysics.

  18. Mutagenic and carcinogenic structural alerts and their mechanisms of action.

    Science.gov (United States)

    Plošnik, Alja; Vračko, Marjan; Dolenc, Marija Sollner

    2016-09-01

    Knowing the mutagenic and carcinogenic properties of chemicals is very important for their hazard (and risk) assessment. One of the crucial events that trigger genotoxic and sometimes carcinogenic effects is the forming of adducts between chemical compounds and nucleic acids and histones. This review takes a look at the mechanisms related to specific functional groups (structural alerts or toxicophores) that may trigger genotoxic or epigenetic effects in the cells. We present up-to-date information about defined structural alerts with their mechanisms and the software based on this knowledge (QSAR models and classification schemes).

  19. Hanford Site Emergency Alerting System siren testing report

    International Nuclear Information System (INIS)

    Weidner, L.B.

    1997-01-01

    The purpose of the test was to determine the effective coverage of the proposed upgrades to the existing Hanford Site Emergency Alerting System (HSEAS). The upgrades are to enhance the existing HSEAS along the Columbia River from the Vernita Bridge to the White Bluffs Boat Launch as well as install a new alerting system in the 400 Area on the Hanford Site. Five siren sites along the Columbia River and two sites in the 400 Area were tested to determine the site locations that will provide the desired coverage

  20. Bursting and large-scale intermittency in turbulent convection with differential rotation

    DEFF Research Database (Denmark)

    Garcia, O.E.; Bian, N.H.

    2003-01-01

    The tilting mechanism, which generates differential rotation in two-dimensional turbulent convection, is shown to produce relaxation oscillations in the mean flow energy integral and bursts in the global fluctuation level, akin to Lotka-Volterra oscillations. The basic reason for such behavior...

  1. Prospects for Gamma-Ray Burst detection by the Cherenkov Telescope Array

    Directory of Open Access Journals (Sweden)

    Bissaldi E.

    2017-01-01

    Full Text Available The Large Area Telescope (LAT on the Fermi satellite is expected to publish a catalogue with more than 100 Gamma-Ray Bursts (GRBs detected above 100 MeV thanks to a new detection algorithm and a new event reconstruction. This work aims at revising the prospects for GRB alerts with the Cherenkov Telescope Array (CTA based on the new LAT results. We start considering the simulation of the observations with the full CTA of two extremely bright events, the long GRB 130427A and the short GRB 090510, then we investigate how these GRBs would be observed by a particular configuration of the array with the telescopes pointing to different directions in what is called the “coupled divergent mode”.

  2. Sources of type III solar microwave bursts

    Directory of Open Access Journals (Sweden)

    Zhdanov D.A.

    2016-06-01

    Full Text Available Microwave fine structures allow us to study plasma evolution in an energy release region. The Siberian Solar Radio Telescope (SSRT is a unique instrument designed to examine fine structures at 5.7 GHz. A complex analysis of data from RATAN-600, 4–8 GHz spectropolarimeter, and SSRT, simultaneously with EUV data, made it possible to localize sources of III type microwave bursts in August 10, 2011 event within the entire frequency band of burst occurrence, as well as to determine the most probable region of primary energy release. To localize sources of III type bursts from RATAN-600 data, an original method for data processing has been worked out. At 5.7 GHz, the source of bursts was determined along two coordinates, whereas at 4.5, 4.7, 4.9, 5.1, 5.3, 5.5, and 6.0 GHz, their locations were identified along one coordinate. The size of the burst source at 5.1 GHz was found to be maximum as compared to those at other frequencies.

  3. Bursting synchronization in clustered neuronal networks

    International Nuclear Information System (INIS)

    Yu Hai-Tao; Wang Jiang; Deng Bin; Wei Xi-Le

    2013-01-01

    Neuronal networks in the brain exhibit the modular (clustered) property, i.e., they are composed of certain subnetworks with differential internal and external connectivity. We investigate bursting synchronization in a clustered neuronal network. A transition to mutual-phase synchronization takes place on the bursting time scale of coupled neurons, while on the spiking time scale, they behave asynchronously. This synchronization transition can be induced by the variations of inter- and intracoupling strengths, as well as the probability of random links between different subnetworks. Considering that some pathological conditions are related with the synchronization of bursting neurons in the brain, we analyze the control of bursting synchronization by using a time-periodic external signal in the clustered neuronal network. Simulation results show a frequency locking tongue in the driving parameter plane, where bursting synchronization is maintained, even in the presence of external driving. Hence, effective synchronization suppression can be realized with the driving parameters outside the frequency locking region. (interdisciplinary physics and related areas of science and technology)

  4. Best practices: an electronic drug alert program to improve safety in an accountable care environment.

    Science.gov (United States)

    Griesbach, Sara; Lustig, Adam; Malsin, Luanne; Carley, Blake; Westrich, Kimberly D; Dubois, Robert W

    2015-04-01

    The accountable care organization (ACO), one of the most promising and talked about new models of care, focuses on improving communication and care transitions by tying potential shared savings to specific clinical and financial benchmarks. An important factor in meeting these benchmarks is an ACO's ability to manage medications in an environment where medical and pharmacy care has been integrated. The program described in this article highlights the critical components of Marshfield Clinic's Drug Safety Alert Program (DSAP), which focuses on prioritizing and communicating safety issues related to medications with the goal of reducing potential adverse drug events. Once the medication safety concern is identified, it is reviewed to evaluate whether an alert warrants sending prescribers a communication that identifies individual patients or a general communication to all physicians describing the safety concern. Instead of basing its decisions regarding clinician notification about drug alerts on subjective criteria, the Marshfield Clinic's DSAP uses an internally developed scoring system. The scoring system includes criteria developed from previous drug alerts, such as level of evidence, size of population affected, severity of adverse event identified or targeted, litigation risk, available alternatives, and potential for duration of medication use. Each of the 6 criteria is assigned a weight and is scored based upon the content and severity of the alert received.  In its first 12 months, the program targeted 6 medication safety concerns involving the following medications: topiramate, glyburide, simvastatin, citalopram, pioglitazone, and lovastatin. Baseline and follow-up prescribing data were gathered on the targeted medications. Follow-up review of prescribing data demonstrated that the DSAP provided quality up-to-date safety information that led to changes in drug therapy and to decreases in potential adverse drug events. In aggregate, nearly 10,000 total

  5. [Integrity].

    Science.gov (United States)

    Gómez Rodríguez, Rafael Ángel

    2014-01-01

    To say that someone possesses integrity is to claim that that person is almost predictable about responses to specific situations, that he or she can prudentially judge and to act correctly. There is a closed interrelationship between integrity and autonomy, and the autonomy rests on the deeper moral claim of all humans to integrity of the person. Integrity has two senses of significance for medical ethic: one sense refers to the integrity of the person in the bodily, psychosocial and intellectual elements; and in the second sense, the integrity is the virtue. Another facet of integrity of the person is la integrity of values we cherish and espouse. The physician must be a person of integrity if the integrity of the patient is to be safeguarded. The autonomy has reduced the violations in the past, but the character and virtues of the physician are the ultimate safeguard of autonomy of patient. A field very important in medicine is the scientific research. It is the character of the investigator that determines the moral quality of research. The problem arises when legitimate self-interests are replaced by selfish, particularly when human subjects are involved. The final safeguard of moral quality of research is the character and conscience of the investigator. Teaching must be relevant in the scientific field, but the most effective way to teach virtue ethics is through the example of the a respected scientist.

  6. Reduced Effectiveness of Interruptive Drug-Drug Interaction Alerts after Conversion to a Commercial Electronic Health Record.

    Science.gov (United States)

    Wright, Adam; Aaron, Skye; Seger, Diane L; Samal, Lipika; Schiff, Gordon D; Bates, David W

    2018-05-15

    Drug-drug interaction (DDI) alerts in electronic health records (EHRs) can help prevent adverse drug events, but such alerts are frequently overridden, raising concerns about their clinical usefulness and contribution to alert fatigue. To study the effect of conversion to a commercial EHR on DDI alert and acceptance rates. Two before-and-after studies. 3277 clinicians who received a DDI alert in the outpatient setting. Introduction of a new, commercial EHR and subsequent adjustment of DDI alerting criteria. Alert burden and proportion of alerts accepted. Overall interruptive DDI alert burden increased by a factor of 6 from the legacy EHR to the commercial EHR. The acceptance rate for the most severe alerts fell from 100 to 8.4%, and from 29.3 to 7.5% for medium severity alerts (P fell by 50.5%, and acceptance of Tier 1 alerts rose from 9.1 to 12.7% (P < 0.01). Changing from a highly tailored DDI alerting system to a more general one as part of an EHR conversion decreased acceptance of DDI alerts and increased alert burden on users. The decrease in acceptance rates cannot be fully explained by differences in the clinical knowledge base, nor can it be fully explained by alert fatigue associated with increased alert burden. Instead, workflow factors probably predominate, including timing of alerts in the prescribing process, lack of differentiation of more and less severe alerts, and features of how users interact with alerts.

  7. Fuzzy correlations of gamma-ray bursts

    International Nuclear Information System (INIS)

    Hartmann, D.H.; Linder, E.V.; Blumenthal, G.R.

    1991-01-01

    The origin of gamma-ray bursts is not known, both in the sense of the nature of the source emitting the radiation and literally, the position of the burst on the sky. Lacking unambiguously identified counterparts in any wavelength band studied to date, statistical approaches are required to determine the burster distance scale. Angular correlation analysis is one of the most powerful tools in this regard. However, poor detector resolution gives large localization errors, effectively beam smearing the positions. The resulting fuzzy angular correlation function is investigated and the generic isotropization that smearing induces on any intrinsic clustering is discussed. In particular, the extent to which gamma-ray burst observations by the BATSE detector aboard the Gamma-Ray Observatory might recover an intrinsic source correlation is investigated. 16 refs

  8. Gamma-ray burst polarimeter (GAP)

    International Nuclear Information System (INIS)

    Mihara, Tatehiro; Murakami, Toshio; Yonetoku, Daisuke; Gunji, Shuichi; Kubo, Shin

    2013-01-01

    The gamma-ray burst polarimeter (GAP: GAmma-ray burst Polarimeter), which had been almost handcrafted by scientists, has succeeded in working normally in interplanetary space, and in detecting the polarization of the gamma-ray from a mysterious astronomical object 'gamma-ray burst'. It is the first result of the detectors in the world exclusively aiming at detecting gamma-ray polarization. We mainly describe the hardware of our GAP equipment and show the method of preparing equipment to work in the cosmic space with a tight budget. The mechanical structure, the electronic circuits, the software on the equipment, the data analysis on the earth, and the scientific results gained by the observation just over one year, are presented after explaining the principle of gamma-ray polarization detection. Our design to protect equipment against mechanical shock and cosmic radiation may provide useful information for future preparation of compact satellite. (J.P.N.)

  9. Gamma-ray burst theory after Swift.

    Science.gov (United States)

    Piran, Tsvi; Fan, Yi-Zhong

    2007-05-15

    Afterglow observations in the pre-Swift era confirmed to a large extend the relativistic blast wave model for gamma-ray bursts (GRBs). Together with the observations of properties of host galaxies and the association with (type Ic) SNe, this has led to the generally accepted collapsar origin of long GRBs. However, most of the afterglow data was collected hours after the burst. The X-ray telescope and the UV/optical telescope onboard Swift are able to slew to the direction of a burst in real time and record the early broadband afterglow light curves. These observations, and in particular the X-ray observations, resulted in many surprises. While we have anticipated a smooth transition from the prompt emission to the afterglow, many observed that early light curves are drastically different. We review here how these observations are changing our understanding of GRBs.

  10. High sensitivity neutron bursts detecting system

    International Nuclear Information System (INIS)

    Shyam, A.; Kaushik, T.C.; Srinivasan, M.; Kulkarni, L.V.

    1993-01-01

    Technique and instrumentation to detect multiplicity of fast neutrons, emitted in sharp bursts, has been developed. A bank of 16 BF 3 detectors, in an appropriate thermalising assembly, efficiency ∼ 16%, is used to detect neutron bursts. The output from this setup, through appropriate electronics, is divided into two paths. The first is directly connected to a computer controlled scalar. The second is connected to another similar scalar through a delay time unit (DTU). The DTU design is such that once it is triggered by a count pulse than it does not allow any counts to be recorded for a fixed dead time set at ∼ 100 μs. The difference in counts recorded directly and through DTU gives the total number of neutrons produced in bursts. This setup is being used to study lattice cracking, anomalous effects in solid deuterium systems and various reactor physics experiments. (author). 3 refs., 1 fig

  11. Gamma-Ray Bursts: A Radio Perspective

    Directory of Open Access Journals (Sweden)

    Poonam Chandra

    2016-01-01

    Full Text Available Gamma-ray bursts (GRBs are extremely energetic events at cosmological distances. They provide unique laboratory to investigate fundamental physical processes under extreme conditions. Due to extreme luminosities, GRBs are detectable at very high redshifts and potential tracers of cosmic star formation rate at early epoch. While the launch of Swift and Fermi has increased our understanding of GRBs tremendously, many new questions have opened up. Radio observations of GRBs uniquely probe the energetics and environments of the explosion. However, currently only 30% of the bursts are detected in radio bands. Radio observations with upcoming sensitive telescopes will potentially increase the sample size significantly and allow one to follow the individual bursts for a much longer duration and be able to answer some of the important issues related to true calorimetry, reverse shock emission, and environments around the massive stars exploding as GRBs in the early Universe.

  12. Localised Microwave Bursts During ELMs on MAST

    Directory of Open Access Journals (Sweden)

    Freethy Simon

    2015-01-01

    Full Text Available Bursts of microwave emission are observed during ELM events on the Mega Ampère Spherical Tokamak. In agreement with observations on other machines, these bursts are up to 3 orders of magnitude more intense than the thermal background, but are electron cyclotron in nature. The peak in microwave emission is ~20μ before the peak in midplane Dα emission. Using the Synthetic Aperture Microwave Imaging radiometer, we are able to demonstrate that these bursts are often highly spatially localised and preferentially occur at the tokamak midplane. It is hypothesised that the localisation is a result of Doppler resonance broadening for electron Bernstein waves and the high perpendicular electron energies could be the result of pitch angle scattering in high collisionality regions of the plasma.

  13. Frequency Chirping during a Fishbone Burst

    Energy Technology Data Exchange (ETDEWEB)

    Marchenko, V.; Reznik, S., E-mail: march@kinr.kiev.ua [Institute for Nuclear Research, Kyiv (Ukraine)

    2012-09-15

    Full text: It is shown that gradual (more than a factor of two, in some cases - down to zero in the lab frame) reduction of the mode frequency (the so called frequency chirping) can be attributed to the reactive torque exerted on the plasma during the fishbone instability burst, which slows down the plasma rotation inside the q = 1 surface and reduces the mode frequency in the lab frame, while frequency in the plasma frame remains constant. This torque arises due to imbalance between the power transfered to the mode by energeric ions and the power of the mode dissipation by thermal species. Estimates show that the peak value of this torque exceeds the neutral beam torque in modern tokamaks and in ITER. The line-broadened quasilinear burst model, properly adapted for the fishbone case, is capable of reproducing the key features of the bursting mode. (author)

  14. Interaction function of coupled bursting neurons

    International Nuclear Information System (INIS)

    Shi Xia; Zhang Jiadong

    2016-01-01

    The interaction functions of electrically coupled Hindmarsh–Rose (HR) neurons for different firing patterns are investigated in this paper. By applying the phase reduction technique, the phase response curve (PRC) of the spiking neuron and burst phase response curve (BPRC) of the bursting neuron are derived. Then the interaction function of two coupled neurons can be calculated numerically according to the PRC (or BPRC) and the voltage time course of the neurons. Results show that the BPRC is more and more complicated with the increase of the spike number within a burst, and the curve of the interaction function oscillates more and more frequently with it. However, two certain things are unchanged: ϕ = 0, which corresponds to the in-phase synchronization state, is always the stable equilibrium, while the anti-phase synchronization state with ϕ = 0.5 is an unstable equilibrium. (paper)

  15. Constraining the High-Energy Emission from Gamma-Ray Bursts with Fermi

    Science.gov (United States)

    Gehrels, Neil; Harding, A. K.; Hays, E.; Racusin, J. L.; Sonbas, E.; Stamatikos, M.; Guirec, S.

    2012-01-01

    We examine 288 GRBs detected by the Fermi Gamma-ray Space Telescope's Gamma-ray Burst Monitor (GBM) that fell within the field-of-view of Fermi's Large Area Telescope (LAT) during the first 2.5 years of observations, which showed no evidence for emission above 100 MeV. We report the photon flux upper limits in the 0.1-10 GeV range during the prompt emission phase as well as for fixed 30 s and 100 s integrations starting from the trigger time for each burst. We compare these limits with the fluxes that would be expected from extrapolations of spectral fits presented in the first GBM spectral catalog and infer that roughly half of the GBM-detected bursts either require spectral breaks between the GBM and LAT energy bands or have intrinsically steeper spectra above the peak of the nuF(sub v) spectra (E(sub pk)). In order to distinguish between these two scenarios, we perform joint GBM and LAT spectral fits to the 30 brightest GBM-detected bursts and find that a majority of these bursts are indeed softer above E(sub pk) than would be inferred from fitting the GBM data alone. Approximately 20% of this spectroscopic subsample show statistically significant evidence for a cut-off in their high-energy spectra, which if assumed to be due to gamma gamma attenuation, places limits on the maximum Lorentz factor associated with the relativistic outflow producing this emission. All of these latter bursts have maximum Lorentz factor estimates that are well below the minimum Lorentz factors calculated for LAT-detected GRBs, revealing a wide distribution in the bulk Lorentz factor of GRB outflows and indicating that LAT-detected bursts may represent the high end of this distribution.

  16. New decoding methods of interleaved burst error-correcting codes

    Science.gov (United States)

    Nakano, Y.; Kasahara, M.; Namekawa, T.

    1983-04-01

    A probabilistic method of single burst error correction, using the syndrome correlation of subcodes which constitute the interleaved code, is presented. This method makes it possible to realize a high capability of burst error correction with less decoding delay. By generalizing this method it is possible to obtain probabilistic method of multiple (m-fold) burst error correction. After estimating the burst error positions using syndrome correlation of subcodes which are interleaved m-fold burst error detecting codes, this second method corrects erasure errors in each subcode and m-fold burst errors. The performance of these two methods is analyzed via computer simulation, and their effectiveness is demonstrated.

  17. Broadband Spectral Investigations of Magnetar Bursts

    Science.gov (United States)

    Kırmızıbayrak, Demet; Şaşmaz Muş, Sinem; Kaneko, Yuki; Göğüş, Ersin

    2017-09-01

    We present our broadband (2-250 keV) time-averaged spectral analysis of 388 bursts from SGR J1550-5418, SGR 1900+14, and SGR 1806-20 detected with the Rossi X-ray Timing Explorer (RXTE) here and as a database in a companion web-catalog. We find that two blackbody functions (BB+BB), the sum of two modified blackbody functions (LB+LB), the sum of a blackbody function and a power-law function (BB+PO), and a power law with a high-energy exponential cutoff (COMPT) all provide acceptable fits at similar levels. We performed numerical simulations to constrain the best fitting model for each burst spectrum and found that 67.6% of burst spectra with well-constrained parameters are better described by the Comptonized model. We also found that 64.7% of these burst spectra are better described with the LB+LB model, which is employed in the spectral analysis of a soft gamma repeater (SGR) for the first time here, than with the BB+BB and BB+PO models. We found a significant positive lower bound trend on photon index, suggesting a decreasing upper bound on hardness, with respect to total flux and fluence. We compare this result with bursts observed from SGR and AXP (anomalous X-ray pulsar) sources and suggest that the relationship is a distinctive characteristic between the two. We confirm a significant anticorrelation between burst emission area and blackbody temperature, and find that it varies between the hot and cool blackbody temperatures differently than previously discussed. We expand on the interpretation of our results in the framework of a strongly magnetized neutron star.

  18. Broadband Spectral Investigations of Magnetar Bursts

    Energy Technology Data Exchange (ETDEWEB)

    Kırmızıbayrak, Demet; Şaşmaz Muş, Sinem; Kaneko, Yuki; Göğüş, Ersin, E-mail: demetk@sabanciuniv.edu [Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı Tuzla, Istanbul 34956 (Turkey)

    2017-09-01

    We present our broadband (2–250 keV) time-averaged spectral analysis of 388 bursts from SGR J1550−5418, SGR 1900+14, and SGR 1806−20 detected with the Rossi X-ray Timing Explorer ( RXTE ) here and as a database in a companion web-catalog. We find that two blackbody functions (BB+BB), the sum of two modified blackbody functions (LB+LB), the sum of a blackbody function and a power-law function (BB+PO), and a power law with a high-energy exponential cutoff (COMPT) all provide acceptable fits at similar levels. We performed numerical simulations to constrain the best fitting model for each burst spectrum and found that 67.6% of burst spectra with well-constrained parameters are better described by the Comptonized model. We also found that 64.7% of these burst spectra are better described with the LB+LB model, which is employed in the spectral analysis of a soft gamma repeater (SGR) for the first time here, than with the BB+BB and BB+PO models. We found a significant positive lower bound trend on photon index, suggesting a decreasing upper bound on hardness, with respect to total flux and fluence. We compare this result with bursts observed from SGR and AXP (anomalous X-ray pulsar) sources and suggest that the relationship is a distinctive characteristic between the two. We confirm a significant anticorrelation between burst emission area and blackbody temperature, and find that it varies between the hot and cool blackbody temperatures differently than previously discussed. We expand on the interpretation of our results in the framework of a strongly magnetized neutron star.

  19. FAB (Functionally Alert Behavior Strategies) to Improve Self-Control

    Science.gov (United States)

    Pagano, John

    2015-01-01

    This paper describes the FAB (Functionally Alert Behavior) Strategies approach to improve behavior in children and adolescents with complex behavioral challenges. FAB Strategies include evidence-based environmental adaptations, sensory modulation, positive behavioral support, and physical self-regulation strategies. FAB Strategies can be used by…

  20. Do repeated rumble strip hits improve driver alertness?

    NARCIS (Netherlands)

    Watling, C.N.; Akerstedt, T.; Kecklund, L.G.; Anund, A.

    2016-01-01

    Driving while sleepy is associated with increased crash risk. Rumble strips are designed to alert a sleepy or inattentive driver when they deviate outside their driving lane. The current study sought to examine the effects of repeated rumble strip hits on levels of physiological and subjective

  1. 44 CFR 208.36 - Reimbursement for Alert.

    Science.gov (United States)

    2010-10-01

    ... § 208.41 of this part. (4) Food and beverages for Task Force Members and Support Specialists when DHS does not provide meals during the Alert. DHS will limit food and beverage reimbursement to the amount... where such food and beverages were provided, multiplied by the number of personnel who received them. (b...

  2. Global Trade Alert | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Global Trade Alert (GTA) will provide information in real time on national measures taken during the current global economic downturn that are likely to discriminate against foreign commerce. GTA will complement and go beyond World Trade Organization (WTO) and World Bank monitoring initiatives by identifying affected ...

  3. Patient Blood Pressure and Pulse Rate Monitoring With an Alert ...

    African Journals Online (AJOL)

    2012-12-01

    Dec 1, 2012 ... an Alert System Using the Omron 790it Blood Pressure. Monitor ... detailed medical information on the vital signs of patients and will save many lives that may be lost. Keywords: Omron .... at rest, in beats per minute (BPM):.

  4. 47 CFR 80.1114 - False distress alerts.

    Science.gov (United States)

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) Operating Procedures for Distress and Safety Communications § 80.1114 False distress alerts. The provisions of §§ 80.334 and 80.335 apply to...

  5. 47 CFR 80.1113 - Transmission of a distress alert.

    Science.gov (United States)

    2010-10-01

    ... Section 80.1113 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) Operating Procedures for Distress and Safety Communications § 80.1113 Transmission of a distress alert. (a) The...

  6. Comparing alertness and injury severity following motor vehicular ...

    African Journals Online (AJOL)

    Background: From casual observation of injury patterns in Motor Vehicular Accidents (MVAs), it was sometimes observed that if the victim had been more alert and reacts protectively, injury severity might be reduced. Protective response is often expected to minimize the severity of injuries. Objective: To determine the ...

  7. Abonnez-vous aux alertes de financement | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Afrique subsaharienne. Si vous ne voulez plus recevoir les alertes de financement, vous pouvez toujours vous désabonner. Ce que nous faisons · Financement · Ressources · À propos du CRDI. Savoir. Innovation. Solutions. Carrières · Communiquez avec nous · Plan du site. Abonnez-vous à notre bulletin pour recevoir les ...

  8. Alerting, Orienting, and Executive Attention in Children with ADHD

    Science.gov (United States)

    Mullane, Jennifer C.; Corkum, Penny V.; Klein, Raymond M.; McLaughlin, Elizabeth N.; Lawrence, Michael A.

    2011-01-01

    Objective: This study evaluated the alerting, orienting, and executive attention abilities of children with ADHD and their typically developing (TD) peers using a modified version of the adult attention network test (ANT-I). Method: A total of 25 children with ADHD, Combined Type (ADHD-C, mean age = 9.20 years), 20 children with ADHD,…

  9. RSS based CERN Alerter. Information broadcast to all CERN offices.

    CERN Multimedia

    Otto, R

    2007-01-01

    Nearly every large organization uses a tool to broadcast messages and information across the internal campus (messages like alerts announcing interruption in services or just information about upcoming events). These tools typically allow administrators (operators) to send "targeted" messages which are sent only to specific groups of users or computers, e/g only those located in a specified building or connected to a particular computing service. CERN has a long history of such tools: CERNVMS€™s SPM_quotMESSAGE command, Zephyr and the most recent the NICE Alerter based on the NNTP protocol. The NICE Alerter used on all Windows-based computers had to be phased out as a consequence of phasing out NNTP at CERN. The new solution to broadcast information messages on the CERN campus continues to provide the service based on cross-platform technologies, hence minimizing custom developments and relying on commercial software as much as possible. The new system, called CERN Alerter, is based on RSS (Really Simpl...

  10. INVESTIGATION OF PRIMORDIAL BLACK HOLE BURSTS USING INTERPLANETARY NETWORK GAMMA-RAY BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Ukwatta, T. N. [Director' s Postdoctoral Fellow, Space and Remote Sensing (ISR-2), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hurley, K. [University of California, Berkeley, Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); MacGibbon, J. H. [Department of Physics, University of North Florida, Jacksonville, FL 32224 (United States); Svinkin, D. S.; Aptekar, R. L.; Golenetskii, S. V.; Frederiks, D. D.; Pal' shin, V. D. [Ioffe Physical Technical Institute, St. Petersburg, 194021 (Russian Federation); Goldsten, J. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Boynton, W. [Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721 (United States); Kozyrev, A. S. [Space Research Institute, 84/32, Profsoyuznaya, Moscow 117997 (Russian Federation); Rau, A.; Kienlin, A. von; Zhang, X. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, Postfach 1312, Garching, D-85748 (Germany); Connaughton, V. [University of Alabama in Huntsville, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Yamaoka, K. [Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara, Kanagawa 229-8558 (Japan); Ohno, M. [Department of Physics, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Ohmori, N. [Department of Applied Physics, University of Miyazaki, 1-1 Gakuen kibanadai-nishi, Miyazaki-shi, Miyazaki 889-2192 (Japan); Feroci, M. [INAF/IAPS-Roma, via Fosso del Cavaliere 100, I-00133, Roma (Italy); Frontera, F., E-mail: tilan@lanl.gov [Department of Physics and Earth Science, University of Ferrara, via Saragat 1, I-44122 Ferrara (Italy); and others

    2016-07-20

    The detection of a gamma-ray burst (GRB) in the solar neighborhood would have very important implications for GRB phenomenology. The leading theories for cosmological GRBs would not be able to explain such events. The final bursts of evaporating primordial black holes (PBHs), however, would be a natural explanation for local GRBs. We present a novel technique that can constrain the distance to GRBs using detections from widely separated, non-imaging spacecraft. This method can determine the actual distance to the burst if it is local. We applied this method to constrain distances to a sample of 36 short-duration GRBs detected by the Interplanetary Network (IPN) that show observational properties that are expected from PBH evaporations. These bursts have minimum possible distances in the 10{sup 13}–10{sup 18} cm (7–10{sup 5} au) range, which are consistent with the expected PBH energetics and with a possible origin in the solar neighborhood, although none of the bursts can be unambiguously demonstrated to be local. Assuming that these bursts are real PBH events, we estimate lower limits on the PBH burst evaporation rate in the solar neighborhood.

  11. Bursting Smoke as an Infrared Countermeasure

    OpenAIRE

    Amarjit Singh; P. J. Kamale; S. A. Joshi; L. K. Bankar

    1998-01-01

    This paper describes the experimental setup for the evaluation of bursting smoke for anti-infrared role using SR-5000 spectroradiometer and a source of IR radiation (8-13 micrometer) using cadmium-mercury-telluride (CMI) detector cooled by liquid nitrogen. The particle size and shape of the powders used in the bursting smokes were determined microscopically using Carl Zeiss Jena Neophot- 21. Highest attenuation of 97 -lOO percent was produced for about 12 s using a mixture of bronze fl...

  12. Radon and rock bursts in deep mines

    International Nuclear Information System (INIS)

    Bulashevich, Yu.P.; Utkin, V.I.; Yurkov, A.K.; Nikolaev, V.V.

    1996-01-01

    Variation fields of radon concentration in time to ascertain stress-strain state of the North Ural bauxite mines have been studied. It is shown that dynamic changes in the stress-strain state of the rocks prior to the rock burst bring about variations in radon concentration in the observation wells. Depending on mutual positioning of the observation points and the rock burst epicenter, the above-mentioned variations differ in principle, reduction of radon concentration in the near zone and its increase in the far zone are observed [ru

  13. Spike Bursts from an Excitable Optical System

    Science.gov (United States)

    Rios Leite, Jose R.; Rosero, Edison J.; Barbosa, Wendson A. S.; Tredicce, Jorge R.

    Diode Lasers with double optical feedback are shown to present power drop spikes with statistical distribution controllable by the ratio of the two feedback times. The average time between spikes and the variance within long time series are studied. The system is shown to be excitable and present bursting of spikes created with specific feedback time ratios and strength. A rate equation model, extending the Lang-Kobayashi single feedback for semiconductor lasers proves to match the experimental observations. Potential applications to construct network to mimic neural systems having controlled bursting properties in each unit will be discussed. Brazilian Agency CNPQ.

  14. Evaluation of health alerts from an early illness warning system in independent living.

    Science.gov (United States)

    Rantz, Marilyn J; Scott, Susan D; Miller, Steven J; Skubic, Marjorie; Phillips, Lorraine; Alexander, Greg; Koopman, Richelle J; Musterman, Katy; Back, Jessica

    2013-06-01

    Passive sensor networks were deployed in independent living apartments to monitor older adults in their home environments to detect signs of impending illness and alert clinicians so they can intervene and prevent or delay significant changes in health or functional status. A retrospective qualitative deductive content analysis was undertaken to refine health alerts to improve clinical relevance to clinicians as they use alerts in their normal workflow of routine care delivery to older adults. Clinicians completed written free-text boxes to describe actions taken (or not) as a result of each alert; they also rated the clinical significance (relevance) of each health alert on a scale of 1 to 5. Two samples of the clinician's written responses to the health alerts were analyzed after alert algorithms had been adjusted based on results of a pilot study using health alerts to enhance clinical decision-making. In the first sample, a total of 663 comments were generated by seven clinicians in response to 385 unique alerts; there are more comments than alerts because more than one clinician rated the same alert. The second sample had a total of 142 comments produced by three clinicians in response to 88 distinct alerts. The overall clinical relevance of the alerts, as judged by the content of the qualitative comments by clinicians for each alert, improved from 33.3% of the alerts in the first sample classified as clinically relevant to 43.2% in the second. The goal is to produce clinically relevant alerts that clinicians find useful in daily practice. The evaluation methods used are described to assist others as they consider building and iteratively refining health alerts to enhance clinical decision making.

  15. Finite-Fault and Other New Capabilities of CISN ShakeAlert

    Science.gov (United States)

    Boese, M.; Felizardo, C.; Heaton, T. H.; Hudnut, K. W.; Hauksson, E.

    2013-12-01

    Over the past 6 years, scientists at Caltech, UC Berkeley, the Univ. of Southern California, the Univ. of Washington, the US Geological Survey, and ETH Zurich (Switzerland) have developed the 'ShakeAlert' earthquake early warning demonstration system for California and the Pacific Northwest. We have now started to transform this system into a stable end-to-end production system that will be integrated into the daily routine operations of the CISN and PNSN networks. To quickly determine the earthquake magnitude and location, ShakeAlert currently processes and interprets real-time data-streams from several hundred seismic stations within the California Integrated Seismic Network (CISN) and the Pacific Northwest Seismic Network (PNSN). Based on these parameters, the 'UserDisplay' software predicts and displays the arrival and intensity of shaking at a given user site. Real-time ShakeAlert feeds are currently being shared with around 160 individuals, companies, and emergency response organizations to gather feedback about the system performance, to educate potential users about EEW, and to identify needs and applications of EEW in a future operational warning system. To improve the performance during large earthquakes (M>6.5), we have started to develop, implement, and test a number of new algorithms for the ShakeAlert system: the 'FinDer' (Finite Fault Rupture Detector) algorithm provides real-time estimates of locations and extents of finite-fault ruptures from high-frequency seismic data. The 'GPSlip' algorithm estimates the fault slip along these ruptures using high-rate real-time GPS data. And, third, a new type of ground-motion prediction models derived from over 415,000 rupture simulations along active faults in southern California improves MMI intensity predictions for large earthquakes with consideration of finite-fault, rupture directivity, and basin response effects. FinDer and GPSlip are currently being real-time and offline tested in a separate internal

  16. Model error assessment of burst capacity models for energy pipelines containing surface cracks

    International Nuclear Information System (INIS)

    Yan, Zijian; Zhang, Shenwei; Zhou, Wenxing

    2014-01-01

    This paper develops the probabilistic characteristics of the model errors associated with five well-known burst capacity models/methodologies for pipelines containing longitudinally-oriented external surface cracks, namely the Battelle and CorLAS™ models as well as the failure assessment diagram (FAD) methodologies recommended in the BS 7910 (2005), API RP579 (2007) and R6 (Rev 4, Amendment 10). A total of 112 full-scale burst test data for cracked pipes subjected internal pressure only were collected from the literature. The model error for a given burst capacity model is evaluated based on the ratios of the test to predicted burst pressures for the collected data. Analysis results suggest that the CorLAS™ model is the most accurate model among the five models considered and the Battelle, BS 7910, API RP579 and R6 models are in general conservative; furthermore, the API RP579 and R6 models are markedly more accurate than the Battelle and BS 7910 models. The results will facilitate the development of reliability-based structural integrity management of pipelines. - Highlights: • Model errors for five burst capacity models for pipelines containing surface cracks are characterized. • Basic statistics of the model errors are obtained based on test-to-predicted ratios. • Results will facilitate reliability-based design and assessment of energy pipelines

  17. Burst Pressure Failure of Titanium Tanks Damaged by Secondary Plumes from Hypervelocity Impacts on Aluminum Shields

    Science.gov (United States)

    Nahra, Henry; Ghosn, Louis; Christiansen, Eric; Davis, B. Alan; Keddy, Chris; Rodriquez, Karen; Miller, Joshua; Bohl, William

    2011-01-01

    Metallic pressure tanks used in space missions are inherently vulnerable to hypervelocity impacts from micrometeoroids and orbital debris; thereby knowledge of impact damage and its effect on the tank integrity is crucial to a spacecraft risk assessment. This paper describes tests that have been performed to assess the effects of hypervelocity impact (HVI) damage on Titanium alloy (Ti-6Al-4V) pressure vessels burst pressure and characteristics. The tests consisted of a pair of HVI impact tests on water-filled Ti-6Al-4V tanks (water being used as a surrogate to the actual propellant) and subsequent burst tests as well as a burst test on an undamaged control tank. The tanks were placed behind Aluminum (Al) shields and then each was impacted with a 7 km/s projectile. The resulting impact debris plumes partially penetrated the Ti-6Al-4V tank surfaces resulting in a distribution of craters. During the burst tests, the tank that failed at a lower burst pressure did appear to have the failure initiating at a crater site with observed spall cracks. A fracture mechanics analysis showed that the tanks failure at the impact location may have been due to a spall crack that formed upon impact of a fragmentation on the Titanium surface. This result was corroborated with a finite element analysis from calculated Von-Mises and hoop stresses.

  18. Powerful Radio Burst Indicates New Astronomical Phenomenon

    Science.gov (United States)

    2007-09-01

    Astronomers studying archival data from an Australian radio telescope have discovered a powerful, short-lived burst of radio waves that they say indicates an entirely new type of astronomical phenomenon. Region of Strong Radio Burst Visible-light (negative greyscale) and radio (contours) image of Small Magellanic Cloud and area where burst originated. CREDIT: Lorimer et al., NRAO/AUI/NSF Click on image for high-resolution file ( 114 KB) "This burst appears to have originated from the distant Universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer, Assistant Professor of Physics at West Virginia University (WVU) and the National Radio Astronomy Observatory (NRAO). The research team led by Lorimer consists of Matthew Bailes of Swinburne University in Australia, Maura McLaughlin of WVU and NRAO, David Narkevic of WVU, and Fronefield Crawford of Franklin and Marshall College in Lancaster, Pennsylvania. The astronomers announced their findings in the September 27 issue of the online journal Science Express. The startling discovery came as WVU undergraduate student David Narkevic re-analyzed data from observations of the Small Magellanic Cloud made by the 210-foot Parkes radio telescope in Australia. The data came from a survey of the Magellanic Clouds that included 480 hours of observations. "This survey had sought to discover new pulsars, and the data already had been searched for the type of pulsating signals they produce," Lorimer said. "We re-examined the data, looking for bursts that, unlike the usual ones from pulsars, are not periodic," he added. The survey had covered the Magellanic Clouds, a pair of small galaxies in orbit around our own Milky Way Galaxy. Some 200,000 light-years from Earth, the Magellanic Clouds are prominent features in the Southern sky. Ironically, the new discovery is not part of these galaxies, but rather is much more distant

  19. Burst firing and modulation of functional connectivity in cat striate cortex.

    Science.gov (United States)

    Snider, R K; Kabara, J F; Roig, B R; Bonds, A B

    1998-08-01

    We studied the influences of the temporal firing patterns of presynaptic cat visual cortical cells on spike generation by postsynaptic cells. Multiunit recordings were dissected into the activity of individual neurons within the recorded group. Cross-correlation analysis was then used to identify directly coupled neuron pairs. The 22 multiunit groups recorded typically showed activity from two to six neurons, each containing between 1 and 15 neuron pairs. From a total of 241 neuron pairs, 91 (38%) had a shifted cross-correlation peak, which indicated a possible direct connection. Only two multiunit groups contained no shifted peaks. Burst activity, defined by groups of two or more spikes with intervals of bursts (of any length) in eliciting a time-related response spike averaged 18.53% across all measurements as compared with the effectiveness of single spikes, which averaged 9.53%. Longer bursts were more effective than shorter ones. Effectiveness was reduced with spatially nonoptimal, as opposed to optimal, stimuli. The effectiveness of both bursts and single spikes decreased by the same amount across measurements with nonoptimal orientations, spatial frequencies and contrasts. At similar firing rates and burst lengths, the decrease was more pronounced for nonoptimal orientations than for lower contrasts, suggesting the existence of a mechanism that reduces effectiveness at nonoptimal orientations. These results support the hypothesis that neural information can be emphasized via instantaneous rate coding that is not preserved over long intervals or over trials. This is consistent with the integrate and fire model, where bursts participate in temporal integration.

  20. Framework to Define Structure and Boundaries of Complex Health Intervention Systems: The ALERT Project

    Directory of Open Access Journals (Sweden)

    Elena Boriani

    2017-07-01

    Full Text Available Health intervention systems are complex and subject to multiple variables in different phases of implementation. This constitutes a concrete challenge for the application of translational science in real life. Complex systems as health-oriented interventions call for interdisciplinary approaches with carefully defined system boundaries. Exploring individual components of such systems from different viewpoints gives a wide overview and helps to understand the elements and the relationships that drive actions and consequences within the system. In this study, we present an application and assessment of a framework with focus on systems and system boundaries of interdisciplinary projects. As an example on how to apply our framework, we analyzed ALERT [an integrated sensors and biosensors’ system (BEST aimed at monitoring the quality, health, and traceability of the chain of the bovine milk], a multidisciplinary and interdisciplinary project based on the application of measurable biomarkers at strategic points of the milk chain for improved food security (including safety, human, and ecosystem health (1. In fact, the European food safety framework calls for science-based support to the primary producers’ mandate for legal, scientific, and ethical responsibility in food supply. Because of its multidisciplinary and interdisciplinary approach involving human, animal, and ecosystem health, ALERT can be considered as a One Health project. Within the ALERT context, we identified the need to take into account the main actors, interactions, and relationships of stakeholders to depict a simplified skeleton of the system. The framework can provide elements to highlight how and where to improve the project development when project evaluations are required.

  1. V-Alert: Description and Validation of a Vulnerable Road User Alert System in the Framework of a Smart City.

    Science.gov (United States)

    Hernandez-Jayo, Unai; De-la-Iglesia, Idoia; Perez, Jagoba

    2015-07-29

    V-Alert is a cooperative application to be deployed in the frame of Smart Cities with the aim of reducing the probability of accidents involving Vulnerable Road Users (VRU) and vehicles. The architecture of V-Alert combines short- and long-range communication technologies in order to provide more time to the drivers and VRU to take the appropriate maneuver and avoid a possible collision. The information generated by mobile sensors (vehicles and cyclists) is sent over this heterogeneous communication architecture and processed in a central server, the Drivers Cloud, which is in charge of generating the messages that are shown on the drivers' and cyclists' Human Machine Interface (HMI). First of all, V-Alert has been tested in a simulated scenario to check the communications architecture in a complex scenario and, once it was validated, all the elements of V-Alert have been moved to a real scenario to check the application reliability. All the results are shown along the length of this paper.

  2. Emergency Communications: The Emergency Alert System (EAS) and All-Hazard Warnings

    National Research Council Canada - National Science Library

    Moore, Linda K; Reese, Shawn

    2005-01-01

    ... tested. Much has been accomplished in recent years but the current hodgepodge of warning and alert systems is inadequate for fully alerting the public about terrorist attacks or natural disasters...

  3. GRB 120422A: a Low-Luminosity Gamma-Ray Burst Driven by a Central Engine

    Science.gov (United States)

    Zhang, Bin-Bin; Fan, Yi-Zhong; Shen, Rong-Feng; Xu, Dong; Zhang, Fu-Wen; Wei, Da-Ming; Burrows, David N.; Zhang, Bing; Gehrels, Neil

    2012-01-01

    GRB 120422A is a low-luminosity gamma-ray burst (GRB) associated with a bright supernova, which distinguishesitself by its relatively short T(sub 90) (approximately 5 s) and an energetic and steep-decaying X-ray tail. We analyze the Swift BurstAlert Telescope and X-ray Telescope data and discuss the physical implications. We show that the steep declineearly in the X-ray light curve can be interpreted as the curvature tail of a late emission episode around 58-86 s,with a curved instantaneous spectrum at the end of the emission episode. Together with the main activity in thefirst 20 s and the weak emission from 40 s to 60 s, the prompt emission is variable, which points to a centralengine origin in contrast to a shock-breakout origin, which is used to interpret some other nearby low-luminosity supernova GRBs. Both the curvature effect model and interpreting the early shallow decay as the coasting externalforward shock emission in a wind medium provide a constraint on the bulk Lorentz factor to be around several.Comparing the properties ofGRB 120422A and other supernova GRBs,we find that themain criterion to distinguish engine-driven GRBs from shock-breakout GRBs is the time-averaged -ray luminosity. Engine-driven GRBs likelyhave a luminosity above approximately 10(sup 48) erg s(sup -1).

  4. On the Nature of the Gamma-ray Bursts

    Directory of Open Access Journals (Sweden)

    Kyung-Ai Hong

    1987-12-01

    Full Text Available Review of the γ-ray burst phenomena are presented. History of the γ-ray bursts, characteristics, and three radiation mechanisms of thermal bremsstrahlung, thermal synchrotron, and inverse Compton scattering processes are considered.

  5. THE FIVE YEAR FERMI/GBM MAGNETAR BURST CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Collazzi, A. C. [SciTec, Inc., 100 Wall Street, Princeton, NJ 08540 (United States); Kouveliotou, C.; Horst, A. J. van der; Younes, G. A. [Department of Physics, The George Washington University, 725 21st Street NW, Washington, DC 20052 (United States); Kaneko, Y.; Göğüş, E. [Sabancı University, Orhanlı-Tuzla, İstanbul 34956 (Turkey); Lin, L. [François Arago Centre, APC, 10 rue Alice Domon et Léonie Duquet, F-75205 Paris (France); Granot, J. [Department of Natural Sciences, The Open University of Israel, 1 University Road, P.O. Box 808, Raanana 43537 (Israel); Finger, M. H. [Universities Space Research Association, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Chaplin, V. L. [School of Medicine, Vanderbilt University, 1161 21st Avenue S, Nashville, TN 37232 (United States); Huppenkothen, D. [Center for Data Science, New York University, 726 Broadway, 7th Floor, New York, NY 10003 (United States); Watts, A. L. [Anton Pannekoek Institute, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Kienlin, A. von [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Baring, M. G. [Department of Physics and Astronomy, Rice University, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Gruber, D. [Planetarium Südtirol, Gummer 5, I-39053 Karneid (Italy); Bhat, P. N. [CSPAR, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35899 (United States); Gibby, M. H., E-mail: acollazzi@scitec.com [Jacobs Technology, Inc., Huntsville, AL (United States); and others

    2015-05-15

    Since launch in 2008, the Fermi Gamma-ray Burst Monitor (GBM) has detected many hundreds of bursts from magnetar sources. While the vast majority of these bursts have been attributed to several known magnetars, there is also a small sample of magnetar-like bursts of unknown origin. Here, we present the Fermi/GBM magnetar catalog, providing the results of the temporal and spectral analyses of 440 magnetar bursts with high temporal and spectral resolution. This catalog covers the first five years of GBM magnetar observations, from 2008 July to 2013 June. We provide durations, spectral parameters for various models, fluences, and peak fluxes for all the bursts, as well as a detailed temporal analysis for SGR J1550–5418 bursts. Finally, we suggest that some of the bursts of unknown origin are associated with the newly discovered magnetar 3XMM J185246.6+0033.7.

  6. THE FERMI-GBM X-RAY BURST MONITOR: THERMONUCLEAR BURSTS FROM 4U 0614+09

    International Nuclear Information System (INIS)

    Linares, M.; Chakrabarty, D.; Connaughton, V.; Bhat, P. N.; Briggs, M. S.; Preece, R.; Jenke, P.; Kouveliotou, C.; Wilson-Hodge, C. A.; Van der Horst, A. J.; Camero-Arranz, A.; Finger, M.; Paciesas, W. S.; Beklen, E.; Von Kienlin, A.

    2012-01-01

    Thermonuclear bursts from slowly accreting neutron stars (NSs) have proven difficult to detect, yet they are potential probes of the thermal properties of the NS interior. During the first year of a systematic all-sky search for X-ray bursts using the Gamma-ray Burst Monitor aboard the Fermi Gamma-ray Space Telescope we have detected 15 thermonuclear bursts from the NS low-mass X-ray binary 4U 0614+09 when it was accreting at nearly 1% of the Eddington limit. We measured an average burst recurrence time of 12 ± 3 days (68% confidence interval) between 2010 March and 2011 March, classified all bursts as normal duration bursts and placed a lower limit on the recurrence time of long/intermediate bursts of 62 days (95% confidence level). We discuss how observations of thermonuclear bursts in the hard X-ray band compare to pointed soft X-ray observations and quantify such bandpass effects on measurements of burst radiated energy and duration. We put our results for 4U 0614+09 in the context of other bursters and briefly discuss the constraints on ignition models. Interestingly, we find that the burst energies in 4U 0614+09 are on average between those of normal duration bursts and those measured in long/intermediate bursts. Such a continuous distribution in burst energy provides a new observational link between normal and long/intermediate bursts. We suggest that the apparent bimodal distribution that defined normal and long/intermediate duration bursts during the last decade could be due to an observational bias toward detecting only the longest and most energetic bursts from slowly accreting NSs.

  7. BACODINE/3rd Interplanetary Network burst localization

    International Nuclear Information System (INIS)

    Hurley, K.; Barthelmy, S.; Butterworth, P.; Cline, T.; Sommer, M.; Boer, M.; Niel, M.; Kouveliotou, C.; Fishman, G.; Meegan, C.

    1996-01-01

    Even with only two widely separated spacecraft (Ulysses and GRO), 3rd Interplanetary Network (IPN) localizations can reduce the areas of BATSE error circles by two orders of magnitude. Therefore it is useful to disseminate them as quickly as possible following BATSE bursts. We have implemented a system which transmits the light curves of BACODINE/BATSE bursts directly by e-mail to UC Berkeley immediately after detection. An automatic e-mail parser at Berkeley watches for these notices, determines the Ulysses crossing time window, and initiates a search for the burst data on the JPL computer as they are received. In ideal cases, it is possible to retrieve the Ulysses data within a few hours of a burst, generate an annulus of arrival directions, and e-mail it out to the astronomical community by local nightfall. Human operators remain in this loop, but we are developing a fully automated routine which should remove them, at least for intense events, and reduce turn-around times to an absolute minimum. We explain the current operations, the data types used, and the speed/accuracy tradeoffs

  8. Gamma-ray bursts at high redshift

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1999-01-01

    Gamma-ray bursts are much brighter than supernovae, and could therefore possibly probe the Universe to high redshift. The presently established GRB redshifts range from 0.83 to 5, and quite possibly even beyond that. Since most proposed mechanisms for GRB link them closely to deaths of massive

  9. Robust Bayesian detection of unmodelled bursts

    International Nuclear Information System (INIS)

    Searle, Antony C; Sutton, Patrick J; Tinto, Massimo; Woan, Graham

    2008-01-01

    We develop a Bayesian treatment of the problem of detecting unmodelled gravitational wave bursts using the new global network of interferometric detectors. We also compare this Bayesian treatment with existing coherent methods, and demonstrate that the existing methods make implicit assumptions on the distribution of signals that make them sub-optimal for realistic signal populations

  10. Extragalactic dispersion measures of fast radio bursts

    International Nuclear Information System (INIS)

    Xu, Jun; Han, J. L.

    2015-01-01

    Fast radio bursts show large dispersion measures, much larger than the Galactic dispersion measure foreground. Therefore, they evidently have an extragalactic origin. We investigate possible contributions to the dispersion measure from host galaxies. We simulate the spatial distribution of fast radio bursts and calculate the dispersion measures along the sightlines from fast radio bursts to the edge of host galaxies by using the scaled NE2001 model for thermal electron density distributions. We find that contributions to the dispersion measure of fast radio bursts from the host galaxy follow a skew Gaussian distribution. The peak and the width at half maximum of the dispersion measure distribution increase with the inclination angle of a spiral galaxy, to large values when the inclination angle is over 70°. The largest dispersion measure produced by an edge-on spiral galaxy can reach a few thousand pc cm −3 , while the dispersion measures from dwarf galaxies and elliptical galaxies have a maximum of only a few tens of pc cm −3 . Notice, however, that additional dispersion measures of tens to hundreds of pc cm −3 can be produced by high density clumps in host galaxies. Simulations that include dispersion measure contributions from the Large Magellanic Cloud and the Andromeda Galaxy are shown as examples to demonstrate how to extract the dispersion measure from the intergalactic medium. (paper)

  11. Radio Afterglows of Gamma Ray Bursts

    Indian Academy of Sciences (India)

    Lekshmi Resmi

    2017-09-12

    Sep 12, 2017 ... ments on-board high energy missions like BeppoSAX1,. CGRO2, HETE3, .... rest energy of a solar mass object (GRB 080916C; Abdo et al. 2009). ..... Though the same afterglow physics applies to short bursts too, there are.

  12. PHYSICAL CONSTRAINTS ON FAST RADIO BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Luan, Jing; Goldreich, Peter, E-mail: jingluan@caltech.edu [California Institute of Technology, Pasadena, CA 91125 (United States)

    2014-04-20

    Fast radio bursts (FRBs) are isolated, ms radio pulses with dispersion measure (DM) of order 10{sup 3} pc cm{sup –3}. Galactic candidates for the DM of high latitude bursts detected at GHz frequencies are easily dismissed. DM from bursts emitted in stellar coronas are limited by free-free absorption and those from H II regions are bounded by the nondetection of associated free-free emission at radio wavelengths. Thus, if astronomical, FRBs are probably extragalactic. FRB 110220 has a scattering tail of ∼5.6 ± 0.1 ms. If the electron density fluctuations arise from a turbulent cascade, the scattering is unlikely to be due to propagation through the diffuse intergalactic plasma. A more plausible explanation is that this burst sits in the central region of its host galaxy. Pulse durations of order ms constrain the sizes of FRB sources implying high brightness temperatures that indicates coherent emission. Electric fields near FRBs at cosmological distances would be so strong that they could accelerate free electrons from rest to relativistic energies in a single wave period.

  13. Magnetized environs of a repeating radio burst

    Science.gov (United States)

    Metzger, Brian D.

    2018-03-01

    One of the astrophysical sources that gives rise to the mysterious transients known as fast radio bursts is embedded in a highly magnetized environment, such as the vicinity of an accreting massive black hole or the birth nebula of a highly magnetized neutron star.

  14. PHYSICAL CONSTRAINTS ON FAST RADIO BURSTS

    International Nuclear Information System (INIS)

    Luan, Jing; Goldreich, Peter

    2014-01-01

    Fast radio bursts (FRBs) are isolated, ms radio pulses with dispersion measure (DM) of order 10 3 pc cm –3 . Galactic candidates for the DM of high latitude bursts detected at GHz frequencies are easily dismissed. DM from bursts emitted in stellar coronas are limited by free-free absorption and those from H II regions are bounded by the nondetection of associated free-free emission at radio wavelengths. Thus, if astronomical, FRBs are probably extragalactic. FRB 110220 has a scattering tail of ∼5.6 ± 0.1 ms. If the electron density fluctuations arise from a turbulent cascade, the scattering is unlikely to be due to propagation through the diffuse intergalactic plasma. A more plausible explanation is that this burst sits in the central region of its host galaxy. Pulse durations of order ms constrain the sizes of FRB sources implying high brightness temperatures that indicates coherent emission. Electric fields near FRBs at cosmological distances would be so strong that they could accelerate free electrons from rest to relativistic energies in a single wave period

  15. The relations between de-alerting nuclear force and nuclear strategy

    International Nuclear Information System (INIS)

    Li Zhimin

    2001-01-01

    De-alerting nuclear force is a hot-point issue in recent years. The relations between de-alerting and strategy (including nuclear force, target doctrine and use principle et al.), stability, advanced conventional force and NMD of the United States are analyzed, the impact of de-alerting on Chinese nuclear force were discussed and the proposal of de-alerting by stages is presented

  16. 3rd Interplanetary Network Gamma-Ray Burst Website

    Science.gov (United States)

    Hurley, Kevin

    1998-05-01

    We announce the opening of the 3rd Interplanetary Network web site at http://ssl.berkeley.edu/ipn3/index.html This site presently has four parts: 1. A bibliography of over 3000 publications on gamma-ray bursts, 2. IPN data on all bursts triangulated up to February 1998, 3. A master list showing which spacecraft observed which bursts, 4. Preliminary IPN data on the latest bursts observed.

  17. BurstMem: A High-Performance Burst Buffer System for Scientific Applications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Teng [Auburn University, Auburn, Alabama; Oral, H Sarp [ORNL; Wang, Yandong [Auburn University, Auburn, Alabama; Settlemyer, Bradley W [ORNL; Atchley, Scott [ORNL; Yu, Weikuan [Auburn University, Auburn, Alabama

    2014-01-01

    The growth of computing power on large-scale sys- tems requires commensurate high-bandwidth I/O system. Many parallel file systems are designed to provide fast sustainable I/O in response to applications soaring requirements. To meet this need, a novel system is imperative to temporarily buffer the bursty I/O and gradually flush datasets to long-term parallel file systems. In this paper, we introduce the design of BurstMem, a high- performance burst buffer system. BurstMem provides a storage framework with efficient storage and communication manage- ment strategies. Our experiments demonstrate that BurstMem is able to speed up the I/O performance of scientific applications by up to 8.5 on leadership computer systems.

  18. Time-warp invariant pattern detection with bursting neurons

    International Nuclear Information System (INIS)

    Gollisch, Tim

    2008-01-01

    Sound patterns are defined by the temporal relations of their constituents, individual acoustic cues. Auditory systems need to extract these temporal relations to detect or classify sounds. In various cases, ranging from human speech to communication signals of grasshoppers, this pattern detection has been found to display invariance to temporal stretching or compression of the sound signal ('linear time-warp invariance'). In this work, a four-neuron network model is introduced, designed to solve such a detection task for the example of grasshopper courtship songs. As an essential ingredient, the network contains neurons with intrinsic bursting dynamics, which allow them to encode durations between acoustic events in short, rapid sequences of spikes. As shown by analytical calculations and computer simulations, these neuronal dynamics result in a powerful mechanism for temporal integration. Finally, the network reads out the encoded temporal information by detecting equal activity of two such bursting neurons. This leads to the recognition of rhythmic patterns independent of temporal stretching or compression

  19. Gravitational radiation from stellar collapse: The initial burst

    International Nuclear Information System (INIS)

    Shapiro, S.L.

    1977-01-01

    The burst of gravitational radiation emitted during the initial collapse and rebound of a homogeneous, uniformly rotating spheroid with internal pressure is analyzed numerically. The surface of the collapsing spheroid is assumed to start at rest from infinity with negligible eccentricity (''zero-energy collapse''). The adopted internal pressure function is constant on self-similar spheroidal surfaces, and its central value is described by a polytropic law with index n< or =3. The Newtonian equations of motion are integrated numerically to follow the initial collapse and rebound of the configuration for the special case in which the collapse is time-reversal invariant about the moment of maximum compression, and the total energy and frequency spectrum of the emitted quadrupole radiation are computed. The results are employed to estimate the (approx.minimum) total energy and frequency distribution of the initial burst of gravitational radiation emitted during the formation of low-mass (Mapproximately-less-thanM/sub sun/) neutron stars and during the collapse of supermassive gas clouds

  20. Discriminating between true-positive and false-positive clinical mastitis alerts from automatic milking systems

    NARCIS (Netherlands)

    Steeneveld, W.; Gaag, van der L.C.; Ouweltjes, W.; Mollenhorst, H.; Hogeveen, H.

    2010-01-01

    Automatic milking systems (AMS) generate alert lists reporting cows likely to have clinical mastitis (CM). Dutch farmers indicated that they use non-AMS cow information or the detailed alert information from the AMS to decide whether to check an alerted cow for CM. However, it is not yet known to

  1. Self-Alert Training: Volitional Modulation of Autonomic Arousal Improves Sustained Attention

    Science.gov (United States)

    O'Connell, Redmond G.; Bellgrove, Mark A.; Dockree, Paul M.; Lau, Adam; Fitzgerald, Michael; Robertson, Ian H.

    2008-01-01

    The present study examines a new alertness training strategy (Self-Alert Training, SAT) designed to explore the relationship between the top-down control processes governing arousal and sustained attention. In order to maximally target frontal control systems SAT combines a previously validated behavioural self-alerting technique [Robertson, I.…

  2. 75 FR 81556 - Solicitation of New Safe Harbors and Special Fraud Alerts

    Science.gov (United States)

    2010-12-28

    ... statute (section 1128B(b) of the Social Security Act), as well as developing new OIG Special Fraud Alerts... of New Safe Harbors and Special Fraud Alerts AGENCY: Office of Inspector General (OIG), HHS. ACTION... the public on recommendations for developing new or revised safe harbors and Special Fraud Alerts...

  3. 77 FR 76434 - Solicitation of New Safe Harbors and Special Fraud Alerts

    Science.gov (United States)

    2012-12-28

    ... statute (section 1128B(b) of the Social Security Act), as well as developing new OIG Special Fraud Alerts... of New Safe Harbors and Special Fraud Alerts AGENCY: Office of Inspector General (OIG), HHS. ACTION... revised safe harbors and Special Fraud Alerts. Please assist us by referencing the file code OIG-121-N...

  4. 78 FR 78807 - Solicitation of New Safe Harbors and Special Fraud Alerts

    Science.gov (United States)

    2013-12-27

    ... statute (section 1128B(b) of the Social Security Act), as well as developing new OIG Special Fraud Alerts... of New Safe Harbors and Special Fraud Alerts AGENCY: Office of Inspector General (OIG), HHS. ACTION... revised safe harbors and Special Fraud Alerts. Please assist us by referencing the file code OIG-122-N...

  5. Imaging assessment of vertebral burst fracture

    International Nuclear Information System (INIS)

    Ding Jianlin; Liang Lihua; Wang Yujia

    2006-01-01

    Objective: To investigate the diagnostic value of radiography, CT and MRI in diagnosis of vertebral burst fracture. Methods: 51 patients with vertebral burst fracture were evaluated with X-ray, CT and MRI, including 3 cases in cervical vertebra, 18 cases in thoracic vertebra, and 30 cases in lumbar vertebra. The imaging features were comparatively studied. Results: Radiography showed decreased height of the vertebral body, increased antero-posterior diameter and the transverse diameter, and/or the widened interpedicle distance, the inter-spinous distance, as well as the bony fragment inserted into the vertebral canal in 28 cases(54.90%). X-ray findings similar to the compression fracture were revealed in 20 cases(39.21%). And missed diagnosis was made in 3 cases (5.88%). CT clearly demon-strated the vertebral body vertically or transversely burst crack in 49 cases (96.07%); bony fragment inserted into the vertebral canal and narrowed vertebral canal in 35 cases(68. 62% ); fracture of spinal appendix in 22 cases(43.14%). Meanwhile MRI showed abnormal signals within the spinal cord in 35 cases (68.62%),injured intervertebral disk in 29 cases(56.86% ), extradural hematoma in 12 cases(23.52% ) and torn posterior longitudinal ligament in 6 cases (11.76%). Conclusions: Radiography is the routine examination, while with limited diagnostic value in vertebral burst fracture. These patients who have nervous symptoms with simple compression fracture or unremarkable on X-ray should receive the CT or MRI examination. CT is better than MRI in demonstrating the fracture and the displaced bony fragment, while MRI is superior to CT in showing nervous injuries. CT and MRI will provide comprehensive information guiding clinical treatment of vertebral burst fracture. (authors)

  6. Aliasing of the Schumann resonance background signal by sprite-associated Q-bursts

    Science.gov (United States)

    Guha, Anirban; Williams, Earle; Boldi, Robert; Sátori, Gabriella; Nagy, Tamás; Bór, József; Montanyà, Joan; Ortega, Pascal

    2017-12-01

    spectral aliasing can occur even when 12-min spectral integrations are considered. The statistical result shows that for a 12-min spectrum, events above 16 CSD are capable of producing significant frequency aliasing of the modal frequencies, although the intensity aliasing might have a negligible effect unless the events are exceptionally large (∼200 CSD). The spectral CSD methodology may be used to extract the time of arrival of the Q-burst transients. This methodology may be combined with a hyperbolic ranging, thus becoming an effective tool to detect TLEs globally with a modest number of networked observational stations.

  7. Gamma-ray burst observations: the present situation

    International Nuclear Information System (INIS)

    Vedrenne, G.

    1984-01-01

    Recent results in gamma ray burst investigations concerning the spectral variability on a short time scale, precise locations, and the discovery of optical flashes in gamma ray burst positions on archival plates are presented. The implications of optical and X-ray observations of gamma ray burst error boxes are also discussed. 72 references

  8. Gamma ray bursts: Current status of observations and theory

    International Nuclear Information System (INIS)

    Meegan, C.A.

    1990-04-01

    Gamma ray bursts display a wide range of temporal and spectral characteristics, but typically last several seconds and emit most of their energy in a low energy, gamma ray region. The burst sources appear to be isotropically distributed on the sky. Several lines of evidence suggest magnetic neutron stars as sources for bursts. A variety of energy sources and emission mechanisms are proposed

  9. Heuristic burst detection method using flow and pressure measurements

    NARCIS (Netherlands)

    Bakker, M.; Vreeburg, J.H.G.; Roer, Van de M.; Rietveld, L.C.

    2014-01-01

    Pipe bursts in a drinking water distribution system lead to water losses, interruption of supply, and damage to streets and houses due to the uncontrolled water flow. To minimize the negative consequences of pipe bursts, an early detection is necessary. This paper describes a heuristic burst

  10. IGR J17254-3257, a new bursting neutron star

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Falanga, M.; Kuulkers, E.

    2007-01-01

    Aims. The study of the observational properties of uncommonly long bursts from low luminosity sources is important when investigating the transition from a hydrogen - rich bursting regime to a pure helium regime and from helium burning to carbon burning as predicted by current burst theories. On ...

  11. A search for optical bursts from the repeating fast radio burst FRB 121102

    Science.gov (United States)

    Hardy, L. K.; Dhillon, V. S.; Spitler, L. G.; Littlefair, S. P.; Ashley, R. P.; De Cia, A.; Green, M. J.; Jaroenjittichai, P.; Keane, E. F.; Kerry, P.; Kramer, M.; Malesani, D.; Marsh, T. R.; Parsons, S. G.; Possenti, A.; Rattanasoon, S.; Sahman, D. I.

    2017-12-01

    We present a search for optical bursts from the repeating fast radio burst FRB 121102 using simultaneous observations with the high-speed optical camera ULTRASPEC on the 2.4-m Thai National Telescope and radio observations with the 100-m Effelsberg Radio Telescope. A total of 13 radio bursts were detected, but we found no evidence for corresponding optical bursts in our 70.7-ms frames. The 5σ upper limit to the optical flux density during our observations is 0.33 mJy at 767 nm. This gives an upper limit for the optical burst fluence of 0.046 Jy ms, which constrains the broad-band spectral index of the burst emission to α ≤ -0.2. Two of the radio pulses are separated by just 34 ms, which may represent an upper limit on a possible underlying periodicity (a rotation period typical of pulsars), or these pulses may have come from a single emission window that is a small fraction of a possible period.

  12. Integrated nuclear radiation detector and monitor

    International Nuclear Information System (INIS)

    Biehl, B.L.; Lieberman, S.I.

    1982-01-01

    A battery powered device which can continuously monitor and detect nuclear radiation utilizing fully integrated circuitry and which is provided with an alarm which alerts persons when the radiation level exceeds a predetermined threshold

  13. An Investigation of an RFID-based Patient-tracking and Mobile Alert System

    Directory of Open Access Journals (Sweden)

    C.L. Yeung

    2011-02-01

    Full Text Available In the modern era, patient health is no longer the only concern for hospitals. Hospitals have to bear the responsibility of the patient safety and the patient comfort. However, due to the overcrowded and understaffed clinical areas with complex workflow patterns, there are different forms of medical care errors arisen in the healthcare system. According to recent statistic from World Health Organization, ten of milions of patient around the world are injured or dead every yearas a result of incorrect medical care. Rroughly 10% patients admitted to hospital in developed countries suffered some forms of medical care errors or medical adverse events. It is about 1.4 million of world population.In order to enhance the patient safety and patient comfort in the current medical service system, an RFID‐based Patient Tracking and Mobile Alert System integrated with information communications technology was designed and developed. Apart from identifying different patient’s whereabouts, instant alerts are generated through mobile devices so as to enhance patients’ safety and comfort. With a view of investigating the feasibility of RFID and mobile technology in the healthcare environment, a pilot study was conducted in Mindset Club in the Castle Peak Hospital in Hong Kong.

  14. Revisiting the Correlations of Peak Luminosity with Spectral Lag and Peak Energy of the Observed Gamma-ray Bursts

    Directory of Open Access Journals (Sweden)

    Yun-A Jo

    2016-12-01

    Full Text Available An analysis of light curves and spectra of observed gamma-ray bursts in gamma-ray ranges is frequently demanded because the prompt emission contains immediate details regarding the central engine of gamma-ray bursts (GRBs. We have revisited the relationship between the collimation-corrected peak luminosity and the spectral lag, investigating the lag-luminosity relationships in great detail by focusing on spectral lags resulting from all possible combinations of channels. Firstly, we compiled the opening angle data and demonstrated that the distribution of opening angles of 205 long GRBs is represented by a double Gaussian function having maxima at ~ 0.1 and ~ 0.3 radians. We confirmed that the peak luminosity and the spectral lag are anti-correlated, both in the observer frame and in the source frame. We found that, in agreement with our previous conclusion, the correlation coefficient improves significantly in the source frame. It should be noted that spectral lags involving channel 2 (25-50 keV yield high correlation coefficients, where Swift/Burst Alert Telescope (BAT has four energy channels (channel 1: 15-25 keV, channel 2: 25-50 keV, channel 3: 50-100 keV, channel 4: 100-200 keV. We also found that peak luminosity is positively correlated with peak energy.

  15. Reduction in alert fatigue in an assisted electronic prescribing system, through the Lean Six Sigma methodology.

    Science.gov (United States)

    Cuéllar Monreal, Mª Jesús; Reig Aguado, Jorge; Font Noguera, Isabel; Poveda Andrés, José Luis

    2017-01-01

    To reduce the alert fatigue in our Assisted Electronic Prescribing System (AEPS), through the Lean Six Sigma (LSS) methodology. An observational (transversal) and retrospective study, in a general hospital with 850 beds and AEPS. The LSS methodology was followed in order to evaluate the alert fatigue situation in the AEPS system, to implement improvements, and to assess outcomes. The alerts generated during two trimesters studied (before and after the intervention) were analyzed. In order to measure the qualitative indicators, the most frequent alert types were analyzed, as well as the molecules responsible for over 50% of each type of alert. The action by the prescriber was analyzed in a sample of 496 prescriptions that generated such alerts. For each type of alert and molecule, there was a prioritization of the improvements to be implemented according to the alert generated and its quality. A second survey evaluated the pharmacist action for the alerts most highly valued by physicians. The problem, the objective, the work team and the project schedule were defined. A survey was designed in order to understand the opinion of the client about the alert system in the program. Based on the surveys collected (n = 136), the critical characteristics and the quanti/qualitative indicators were defined. Sixty (60) fields in the alert system were modified, corresponding to 32 molecules, and this led to a 28% reduction in the total number of alerts. Regarding quality indicators, false po sitive results were reduced by 25% (p < 0.05), 100% of those alerts ignored with justification were sustained, and there were no significant differences in user adherence to the system. The project improvements and outcomes were reviewed by the work team. LSS methodology has demonstrated being a valid tool for the quantitative and qualitative improvement of the alert system in an Assisted Electronic Prescription Program, thus reducing alert fatigue. Copyright AULA MEDICA EDICIONES 2014

  16. A deep-learning-based emergency alert system

    Directory of Open Access Journals (Sweden)

    Byungseok Kang

    2016-06-01

    Full Text Available Emergency alert systems serve as a critical link in the chain of crisis communication, and they are essential to minimize loss during emergencies. Acts of terrorism and violence, chemical spills, amber alerts, nuclear facility problems, weather-related emergencies, flu pandemics, and other emergencies all require those responsible such as government officials, building managers, and university administrators to be able to quickly and reliably distribute emergency information to the public. This paper presents our design of a deep-learning-based emergency warning system. The proposed system is considered suitable for application in existing infrastructure such as closed-circuit television and other monitoring devices. The experimental results show that in most cases, our system immediately detects emergencies such as car accidents and natural disasters.

  17. Brain-computer interface for alertness estimation and improving

    Science.gov (United States)

    Hramov, Alexander; Maksimenko, Vladimir; Hramova, Marina

    2018-02-01

    Using wavelet analysis of the signals of electrical brain activity (EEG), we study the processes of neural activity, associated with perception of visual stimuli. We demonstrate that the brain can process visual stimuli in two scenarios: (i) perception is characterized by destruction of the alpha-waves and increase in the high-frequency (beta) activity, (ii) the beta-rhythm is not well pronounced, while the alpha-wave energy remains unchanged. The special experiments show that the motivation factor initiates the first scenario, explained by the increasing alertness. Based on the obtained results we build the brain-computer interface and demonstrate how the degree of the alertness can be estimated and controlled in real experiment.

  18. ECG Holter monitor with alert system and mobile application

    Science.gov (United States)

    Teron, Abigail C.; Rivera, Pedro A.; Goenaga, Miguel A.

    2016-05-01

    This paper proposes a new approach on the Holter monitor by creating a portable Electrocardiogram (ECG) Holter monitor that will alert the user by detecting abnormal heart beats using a digital signal processing software. The alarm will be triggered when the patient experiences arrhythmias such as bradycardia and tachycardia. The equipment is simple, comfortable and small in size that fit in the hand. It can be used at any time and any moment by placing three leads to the person's chest which is connected to an electronic circuit. The ECG data will be transmitted via Bluetooth to the memory of a selected mobile phone using an application that will store the collected data for up to 24 hrs. The arrhythmia is identified by comparing the reference signals with the user's signal. The diagnostic results demonstrate that the ECG Holter monitor alerts the user when an arrhythmia is detected thru the Holter monitor and mobile application.

  19. Microcontroller based driver alertness detection systems to detect drowsiness

    Science.gov (United States)

    Adenin, Hasibah; Zahari, Rahimi; Lim, Tiong Hoo

    2018-04-01

    The advancement of embedded system for detecting and preventing drowsiness in a vehicle is a major challenge for road traffic accident systems. To prevent drowsiness while driving, it is necessary to have an alert system that can detect a decline in driver concentration and send a signal to the driver. Studies have shown that traffc accidents usually occur when the driver is distracted while driving. In this paper, we have reviewed a number of detection systems to monitor the concentration of a car driver and propose a portable Driver Alertness Detection System (DADS) to determine the level of concentration of the driver based on pixelated coloration detection technique using facial recognition. A portable camera will be placed at the front visor to capture facial expression and the eye activities. We evaluate DADS using 26 participants and have achieved 100% detection rate with good lighting condition and a low detection rate at night.

  20. Utilizing Computer Integration to Assist Nursing

    OpenAIRE

    Hujcs, Marianne

    1990-01-01

    As the use of computers in health care continues to increase, methods of using these computers to assist nursing practice are also increasing. This paper describes how integration within a hospital information system (HIS) contributed to the development of a report format and computer generated alerts used by nurses. Discussion also includes how the report and alerts impact those nurses providing bedside care as well as how integration of an HIS creates challenges for nursing.

  1. Red alert. The worldwide dangers of nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J

    1986-01-01

    The book 'Red Alert' considers the problems and hazards of nuclear power. The politics behind the nuclear power programmes in the United Kingdom and other countries are examined, along with the sequence of events in Britain which led to the building of the Magnox and Advanced Gas-Cooled nuclear reactors. Health hazards of radiation, radioactive waste management, nuclear weapons programmes, and radiation accidents including the Chernobyl accident, are also discussed. (U.K.).

  2. Conflict resolution and alert zone estimation in air traffic management

    Science.gov (United States)

    Kuo, Vincent Hao-Hung

    The current air traffic control (ATC) system provides separations among all aircraft through pre-defined routes and flight procedures, and active controller participation. In particular, en route separations are achieved by choices of different flight routes, different flight levels, and speed control. During the final descent approach over an extended terminal area, aircraft separations are achieved by speed changes, altitude changes, and path stretching. Recently, a concept of free flight has been proposed for future air traffic management. In the proposed free flight environment, aircraft operators can change flight paths in real time, in order to achieve the best efficiency for the aircraft. Air traffic controllers are only supposed to intervene when situation warrants, to resolve potential conflicts among aircraft. In both cases, there is a region around each aircraft called alert zone. As soon as another aircraft touches the alert zone of own aircraft, either the own aircraft or both aircraft must initiate avoidance maneuvers to resolve a potential conflict. This thesis develops a systematic approach based on nonlinear optimal control theories to estimate alert zones in two aircraft conflict scenarios. Specifically, point-mass aircraft models are used to describe aircraft motions. Separate uses of heading, speed, and altitude control are first examined, and then the synergetic use of two control authorities are studied. Both cooperative maneuvers (in which both aircraft act) and non-cooperative maneuvers (in which the own aircraft acts alone) are considered. Optimal control problems are formulated to minimize the initial relative separation between the two aircraft for all possible initial conditions, subject to the requirement that inter-aircraft separation at any time satisfies the separation requirement. These nonlinear optimal control problems are solved numerically using a collation approach and the NPSOL software line for nonlinear programming. In

  3. Alert-derivative bimodal space power and propulsion systems

    International Nuclear Information System (INIS)

    Houts, M.G.; Ranken, W.A.; Buksa, J.J.

    1994-01-01

    Safe, reliable, low-mass bimodal space power and propulsion systems could have numerous civilian and military applications. This paper discusses potential bimodal systems that could be derived from the ALERT space fission power supply concept. These bimodal concepts have the potential for providing 5 to 10 kW of electrical power and a total impulse of 100 MN-s at an average specific impulse of 770 s. System mass is on the order of 1000 kg

  4. Diagnostics from three rising submillimeter bursts

    International Nuclear Information System (INIS)

    Zhou, Ai-Hua; Li, Jian-Ping; Wang, Xin-Dong

    2016-01-01

    In this paper we investigate three novel rising submillimeter (THz) bursts that occurred sequentially in Super Active Region NOAA 10486. The average rising rate of the flux density above 200 GHz is only 20 sfu GHz −1 (corresponding to spectral index α of 1.6) for the THz spectral components of the 2003 October 28 and November 4 bursts, but it attained values of 235 sfu GHz −1 (α = 4.8) in the 2003 November 2 burst. The steeply rising THz spectrum can be produced by a population of highly relativistic electrons with a low-energy cutoff of 1 MeV, but it only requires a low-energy cutoff of 30 keV for the two slowly rising THz bursts, via gyrosynchrotron (GS) radiation based on our numerical simulations of burst spectra in the magnetic dipole field case. The electron density variation is much larger in the THz source than in the microwave (MW) source. It is interesting that the THz source radius decreased by 20%–50% during the decay phase for the three events, but the MW source increased by 28% for the 2003 November 2 event. In the paper we will present a formula that can be used to calculate the energy released by ultrarelativistic electrons, taking the relativistic correction into account for the first time. We find that the energy released by energetic electrons in the THz source exceeds that in the MW source due to the strong GS radiation loss in the THz range, although the modeled THz source area is 3–4 orders smaller than the modeled MW source one. The total energies released by energetic electrons via the GS radiation in radio sources are estimated, respectively, to be 5.2 × 10 33 , 3.9 × 10 33 and 3.7 × 10 32 erg for the October 28, November 2 and 4 bursts, which are 131, 76 and 4 times as large as the thermal energies of 2.9 × 10 31 , 2.1 × 10 31 and 5.2 × 10 31 erg estimated from soft X-ray GOES observations. (paper)

  5. The effects of Project ALERT one year past curriculum completion.

    Science.gov (United States)

    Ringwalt, Chris L; Clark, Heddy Kovach; Hanley, Sean; Shamblen, Stephen R; Flewelling, Robert L

    2010-06-01

    School-based drug prevention curricula constitute the nation's most prevalent strategy to prevent adolescent drug use. We evaluated the effects of one such curriculum, Project ALERT, on adolescent substance use. In particular, we sought to determine if a single effect on 30-day alcohol use, noted shortly following the completion of the 2-year program, could be detected 1 year later. We also looked for delayed effects on other outcomes of interest, namely lifetime alcohol use, and 30-day and lifetime use of cigarettes, marijuana, and inhalants. We employed a randomized controlled trial that used school as the unit of assignment. Thirty-four schools with grades 6-8 from 11 states completed the study. Seventy-one Project ALERT instructors taught 11 core lessons to sixth graders and 3 booster lessons to seventh graders. Students were assessed prior to the onset of the intervention, as sixth graders, after the completion of the 2-year curriculum, as seventh graders, and again 1 year later as eighth graders. This paper examines data from the pretest and final posttest. Using hierarchical nonlinear modeling, we found that our earlier effect on 30-day alcohol use did not persist. Further, we continued to find no effects for lifetime alcohol use and both the lifetime and 30-day use of cigarettes, marijuana, and inhalants. Our findings do not support the long-term effectiveness of Project ALERT, when delivered to sixth graders.

  6. IP telephony based danger alert communication system and its implementation

    Science.gov (United States)

    Rezac, Filip; Safarik, Jakub; Voznak, Miroslav; Tomala, Karel; Partila, Pavol

    2013-05-01

    This article discusses a danger alert system created as a part of the research project at Department of Telecommunications of Technical University of Ostrava. The aim of the system is to distribute pre-recorded voice messages in order to alert the called party in danger. This article describes individual technologies, which the application uses for its operation as well as issues relating to hardware requirements and transfer line bandwidth load. The article also describes new algorithms, which had to be developed in order to ensure the reliability of the system. Our intent is focused on disaster management, the message, which should be delivered within specified time span, is typed in the application and text-to-speech module ensures its transformation to a speech format, after that a particular scenario or warned area is selected and a target group is automatically unloaded. For this purpose, we have defined XML format for delivery of phone numbers which are located in the target area and these numbers are obtained from mobile BTS's (Base transmission stations). The benefit of such communication compared to others, is the fact, that it uses a phone call and, therefore, it is possible to get feedback who accepted the message and to improve efficiency of alert system. Finally, the list of unanswered calls is exported and these users can be informed via SMS.

  7. AN AUTOMATED NETWORK SECURITYCHECKING AND ALERT SYSTEM: A NEW FRAMEWORK

    Directory of Open Access Journals (Sweden)

    Vivek Kumar Yadav

    2013-09-01

    Full Text Available Network security checking is a vital process to assess and to identify weaknesses in network for management of security. Insecure entry points of a network provide attackers an easy target to access and compromise. Open ports of network components such as firewalls, gateways and end systems are analogues to open gates of a building through which any one can get into. Network scanning is performed to identify insecure entry points in the network components. To find out vulnerabilities on these points vulnerability assessment is performed. So security checking consists of both activities- network scanning as well as vulnerability assessment. A single tool used for the security checking may not give reliable results. This paper presents a framework for assessing the security of a network using multiple Network Scanning and Vulnerability Assessment tools. The proposed framework is an extension of the framework given by Jun Yoon and Wontae Sim [1] which performs vulnerability scanning only. The framework presented here adds network scanning, alerting and reporting system to their framework. Network scanning and vulnerability tools together complement each other and make it amenable for centralized control and management. The reporting system of framework sends an email to the network administrator which contains detailed report (as attachment of security checking process. Alerting system sends a SMS message as an alert to the network administrator in case of severe threats found in the network. Initial results of the framework are encouraging and further work is in progress.

  8. Treatment of measurement uncertainties at the power burst facility

    International Nuclear Information System (INIS)

    Meyer, L.C.

    1980-01-01

    The treatment of measurement uncertainty at the Power Burst Facility provides a means of improving data integrity as well as meeting standard practice reporting requirements. This is accomplished by performing the uncertainty analysis in two parts, test independent uncertainty analysis and test dependent uncertainty analysis. The test independent uncertainty analysis is performed on instrumentation used repeatedly from one test to the next, and does not have to be repeated for each test except for improved or new types of instruments. A test dependent uncertainty analysis is performed on each test based on the test independent uncertainties modified as required by test specifications, experiment fixture design, and historical performance of instruments on similar tests. The methodology for performing uncertainty analysis based on the National Bureau of Standards method is reviewed with examples applied to nuclear instrumentation

  9. Hierarchic Analysis Method to Evaluate Rock Burst Risk

    Directory of Open Access Journals (Sweden)

    Ming Ji

    2015-01-01

    Full Text Available In order to reasonably evaluate the risk of rock bursts in mines, the factors impacting rock bursts and the existing grading criterion on the risk of rock bursts were studied. By building a model of hierarchic analysis method, the natural factors, technology factors, and management factors that influence rock bursts were analyzed and researched, which determined the degree of each factor’s influence (i.e., weight and comprehensive index. Then the grade of rock burst risk was assessed. The results showed that the assessment level generated by the model accurately reflected the actual risk degree of rock bursts in mines. The model improved the maneuverability and practicability of existing evaluation criteria and also enhanced the accuracy and science of rock burst risk assessment.

  10. Impulsive EUV bursts observed in C IV with OSO-8

    International Nuclear Information System (INIS)

    Grant Athay, R.; White, O.R.; Lites, B.W.

    1980-01-01

    Time sequences of profiles of the lambda 1548 line of C IV containing 51 EUV bursts observed in or near active regions are analyzed to determine the brightness. Doppler shift and line broadening characteristics of the bursts. The bursts have mean lifetimes of approximately 150s, and mean increases in brightness at burst maximum of four-fold as observed with a field of view of 2'' x 20''. Mean burst diameters are estimated to be 3'', or smaller. All but three of the bursts show Doppler shift with velocities sometimes exceeding 75 km s -1 ; 31 are dominated by red shifts and 17 are dominated by blue shifts. Approximately half of the latter group have red-shifted precursors. We interpret the bursts as prominence material, such as surges and coronal rain, moving through the field of view of the spectrometer. (orig.)

  11. Bursting behaviours in cascaded stimulated Brillouin scattering

    International Nuclear Information System (INIS)

    Liu Zhan-Jun; He Xian-Tu; Zheng Chun-Yang; Wang Yu-Gang

    2012-01-01

    Stimulated Brillouin scattering is studied by numerically solving the Vlasov—Maxwell system. A cascade of stimulated Brillouin scattering can occur when a linearly polarized laser pulse propagates in a plasma. It is found that a stimulated Brillouin scattering cascade can reduce the scattering and increase the transmission of light, as well as introduce a bursting behaviour in the evolution of the laser-plasma interaction. The bursting time in the reflectivity is found to be less than half the ion acoustic period. The ion temperature can affect the stimulated Brillouin scattering cascade, which can repeat several times at low ion temperatures and can be completely eliminated at high ion temperatures. For stimulated Brillouin scattering saturation, higher-harmonic generation and wave—wave interaction of the excited ion acoustic waves can restrict the amplitude of the latter. In addition, stimulated Brillouin scattering cascade can restrict the amplitude of the scattered light. (physics of gases, plasmas, and electric discharges)

  12. A review of gamma ray bursts

    CERN Document Server

    Rees, Martin J

    2000-01-01

    Gamma-ray bursts, an enigma for more than 25 years, are now coming into focus. They involve extraordinary power outputs, and highly relativistic dynamics. The 'trigger' involves stellar-mass compact objects. The most plausible progenitors, ranging from neutron star binary mergers to collapsars (sometimes called 'hypernovae') eventually lead to the formation of a black hole with a torus of hot neutron-density material around it, the extractable energy being up to 10 sup 5 sup 4 ergs. Magnetic fields may exceed 10 sup 1 sup 5 G and particles may be accelerated up to > or approx. 10 sup 2 sup 0 eV. Details of the afterglow may be easier to understand than the initial trigger. Bursts at very high redshift can be astronomically-important as probes of the distant universe.

  13. Environmental Effects of Gamma Ray Bursts

    International Nuclear Information System (INIS)

    Martin, Osmel; Zarauza, Dario; Cardenas, Rolando

    2007-01-01

    Gamma rays bursts, coming from very massive stars, are the most powerful explosions in our Universe. Some authors have linked them to some of the climatic changes and consequent biological mass extinctions of the Phanerozoic eon. However, the consequences of their direct impact on primitive Earth, is today a hot topic of debate. On the other hand, it is usually assumed that they were more common in earlier stages of our galaxy. So it is important to evaluate its potential effects on terrestrial paleoenvironments. We outline some simple models to estimate their influence mainly on the primordial atmospheric chemistry of Earth and on the climate in general. To do that, we consider different scenarios where the atmospheric composition diverges substantially from the atmosphere today, and compute the evolution of principal chemical species under the intense radiational stress of a gamma ray burst. Furthermore, the possible impact on the isotopic composition, geochemistry and the biosphere are mentioned in general way

  14. Coherent combining pulse bursts in time domain

    Science.gov (United States)

    Galvanauskas, Almantas

    2018-01-09

    A beam combining and pulse stacking technique is provided that enhances laser pulse energy by coherent stacking pulse bursts (i.e. non-periodic pulsed signals) in time domain. This energy enhancement is achieved by using various configurations of Fabry-Perot, Gires-Tournois and other types of resonant cavities, so that a multiple-pulse burst incident at either a single input or multiple inputs of the system produces an output with a solitary pulse, which contains the summed energy of the incident multiple pulses from all beams. This disclosure provides a substantial improvement over conventional coherent-combining methods in that it achieves very high pulse energies using a relatively small number of combined laser systems, thus providing with orders of magnitude reduction in system size, complexity, and cost compared to current combining approaches.

  15. Explaining fast radio bursts through Dicke's superradiance

    Science.gov (United States)

    Houde, Martin; Mathews, Abhilash; Rajabi, Fereshteh

    2018-03-01

    Fast radio bursts (FRBs), characterized by strong bursts of radiation intensity at radio wavelengths lasting on the order of a millisecond, have yet to be firmly associated with a family, or families, of astronomical sources. It follows that despite the large number of proposed models, no well-defined physical process has been identified to explain this phenomenon. In this paper, we demonstrate how Dicke's superradiance, for which evidence has recently been found in the interstellar medium, can account for the characteristics associated with FRBs. Our analysis and modelling of previously detected FRBs suggest they could originate from regions in many ways similar to those known to harbour masers or megamasers, and result from the coherent radiation emanating from populations of molecules associated with large-scale entangled quantum mechanical states. We estimate this entanglement to involve as many as ˜1030 to ˜1032 molecules over distances spanning 100-1000 au.

  16. Identifying crucial parameter correlations maintaining bursting activity.

    Directory of Open Access Journals (Sweden)

    Anca Doloc-Mihu

    2014-06-01

    Full Text Available Recent experimental and computational studies suggest that linearly correlated sets of parameters (intrinsic and synaptic properties of neurons allow central pattern-generating networks to produce and maintain their rhythmic activity regardless of changing internal and external conditions. To determine the role of correlated conductances in the robust maintenance of functional bursting activity, we used our existing database of half-center oscillator (HCO model instances of the leech heartbeat CPG. From the database, we identified functional activity groups of burster (isolated neuron and half-center oscillator model instances and realistic subgroups of each that showed burst characteristics (principally period and spike frequency similar to the animal. To find linear correlations among the conductance parameters maintaining functional leech bursting activity, we applied Principal Component Analysis (PCA to each of these four groups. PCA identified a set of three maximal conductances (leak current, [Formula: see text]Leak; a persistent K current, [Formula: see text]K2; and of a persistent Na+ current, [Formula: see text]P that correlate linearly for the two groups of burster instances but not for the HCO groups. Visualizations of HCO instances in a reduced space suggested that there might be non-linear relationships between these parameters for these instances. Experimental studies have shown that period is a key attribute influenced by modulatory inputs and temperature variations in heart interneurons. Thus, we explored the sensitivity of period to changes in maximal conductances of [Formula: see text]Leak, [Formula: see text]K2, and [Formula: see text]P, and we found that for our realistic bursters the effect of these parameters on period could not be assessed because when varied individually bursting activity was not maintained.

  17. Thermonuclear model for γ-ray bursts

    International Nuclear Information System (INIS)

    Woosley, S.E.

    1981-01-01

    The evolution of magnetized neutron stars with field strengths of approx. 10 12 gauss that are accreting mass onto kilometer-sized polar regions at a rate of approx. 13 M 0 yr -1 is examined. Based on the results of one-dimensional calculations, one finds that stable hydrogen burning, mediated by the hot CNO-cycle, will lead to a critical helium mass in the range 10 20 to 10 22 g km -2 . Owing to the extreme degeneracy of the electron gas providing pressure support, helium burning occurs as a violent thermonuclear runaway which may propagate either as a convective deflagration (Type I burst) or as a detonation wave (Type II burst). Complete combustion of helium into 56 Ni releases from 10 38 to 10 40 erg km -2 and pushes hot plasma with β > 1 above the surface of the neutron star. Rapid expansion of the plasma channels a substantial fraction of the explosion energy into magnetic field stress. Spectral properties are expected to be complex with emission from both thermal and non-thermal processes. The hard γ-outburst of several seconds softens as the event proceeds and is followed by a period, typically of several minutes duration, of softer x-ray emission as the subsurface ashes of the thermonuclear explosion cool. In this model, most γ-ray bursts currently being observed are located at a distance of several hundred parsecs and should recur on a timescale of months to centuries with convective deflagrations (Type I bursts) being the more common variety. An explanation for Jacobson-like transients is also offered

  18. Gamma-ray bursts - a critical review

    International Nuclear Information System (INIS)

    Tudose, Valeriu; Biermann, Peter

    2003-01-01

    We present a short general introduction into the field of gamma-ray bursts (GRBs) research, summarizing the past and the present status. We give an general view of the GRBs observations to date, both in the prompt emission phase as well as in the afterglow phase, and a brief primer into the theory, mainly in the frame-work of the fireball model. (authors)

  19. The behaviour of neutron bursts in matter

    International Nuclear Information System (INIS)

    Syros, C.

    1978-01-01

    An exact method is developed for solving the time-dependent linear transport equation for neutrons. The problem of finding the behaviour of neutron bursts in matter have been considered. The method leads to a new kind of perturbation theory applicable to the transport theoretical reactor dynamics. Applications of the theory are given for discontinuously or continuously distributed initial values of the neutron population. The boundary and initial conditions are exactly fulfilled. (author)

  20. Adiabatic burst evaporation from bicontinuous nanoporous membranes

    Science.gov (United States)

    Ichilmann, Sachar; Rücker, Kerstin; Haase, Markus; Enke, Dirk

    2015-01-01

    Evaporation of volatile liquids from nanoporous media with bicontinuous morphology and pore diameters of a few 10 nm is an ubiquitous process. For example, such drying processes occur during syntheses of nanoporous materials by sol–gel chemistry or by spinodal decomposition in the presence of solvents as well as during solution impregnation of nanoporous hosts with functional guests. It is commonly assumed that drying is endothermic and driven by non-equilibrium partial pressures of the evaporating species in the gas phase. We show that nearly half of the liquid evaporates in an adiabatic mode involving burst-like liquid-to-gas conversions. During single adiabatic burst evaporation events liquid volumes of up to 107 μm3 are converted to gas. The adiabatic liquid-to-gas conversions occur if air invasion fronts get unstable because of the built-up of high capillary pressures. Adiabatic evaporation bursts propagate avalanche-like through the nanopore systems until the air invasion fronts have reached new stable configurations. Adiabatic cavitation bursts thus compete with Haines jumps involving air invasion front relaxation by local liquid flow without enhanced mass transport out of the nanoporous medium and prevail if the mean pore diameter is in the range of a few 10 nm. The results reported here may help optimize membrane preparation via solvent-based approaches, solution-loading of nanopore systems with guest materials as well as routine use of nanoporous membranes with bicontinuous morphology and may contribute to better understanding of adsorption/desorption processes in nanoporous media. PMID:25926406

  1. Revealing the functional neuroanatomy of intrinsic alertness using fMRI: methodological peculiarities.

    Science.gov (United States)

    Clemens, Benjamin; Zvyagintsev, Mikhail; Sack, Alexander T; Sack, Alexander; Heinecke, Armin; Willmes, Klaus; Sturm, Walter

    2011-01-01

    Clinical observations and neuroimaging data revealed a right-hemisphere fronto-parietal-thalamic-brainstem network for intrinsic alertness, and additional left fronto-parietal activity during phasic alertness. The primary objective of this fMRI study was to map the functional neuroanatomy of intrinsic alertness as precisely as possible in healthy participants, using a novel assessment paradigm already employed in clinical settings. Both the paradigm and the experimental design were optimized to specifically assess intrinsic alertness, while at the same time controlling for sensory-motor processing. The present results suggest that the processing of intrinsic alertness is accompanied by increased activity within the brainstem, thalamus, anterior cingulate gyrus, right insula, and right parietal cortex. Additionally, we found increased activation in the left hemisphere around the middle frontal gyrus (BA 9), the insula, the supplementary motor area, and the cerebellum. Our results further suggest that rather minute aspects of the experimental design may induce aspects of phasic alertness, which in turn might lead to additional brain activation in left-frontal areas not normally involved in intrinsic alertness. Accordingly, left BA 9 activation may be related to co-activation of the phasic alertness network due to the switch between rest and task conditions functioning as an external warning cue triggering the phasic alertness network. Furthermore, activation of the intrinsic alertness network during fixation blocks due to enhanced expectancy shortly before the switch to the task block might, when subtracted from the task block, lead to diminished activation in the typical right hemisphere intrinsic alertness network. Thus, we cautiously suggest that--as a methodological artifact--left frontal activations might show up due to phasic alertness involvement and intrinsic alertness activations might be weakened due to contrasting with fixation blocks, when assessing the

  2. Time to Detection with BacT/Alert FA Plus Compared to BacT/Alert FA Blood Culture Media.

    Science.gov (United States)

    Nutman, A; Fisher Even-Tsur, S; Shapiro, G; Braun, T; Schwartz, D; Carmeli, Y

    2016-09-01

    Rapid identification of the causative pathogen in patients with bacteremia allows adjustment of antibiotic therapy and improves patient outcomes. We compared in vitro and real-life time to detection (TTD) of two blood culture media, BacT/Alert FA (FA) and BacT/Alert FA Plus (FA Plus), for the nine most common species of bacterial pathogens recovered from blood samples. Experimental data from simulated cultures was compared with microbiology records of TTD for both culture media with growth of the species of interest in clinical blood cultures. In the experimental conditions, median TTD was 3.8 hours (23.9 %) shorter using FA Plus media. The magnitude of reduction differed between species. Similarly, in real life data, FA Plus had shorter TTD than FA media; however, the difference between culture media was smaller, and median TTD was only 1 hour (8.5 %) less. We found shorter TTD with BacT/Alert FA Plus culture media, both experimentally and in real-life conditions and unrelated to antibiotic neutralization, highlighting the importance of appropriate blood culture media selection.

  3. Non-visual effects of light on melatonin, alertness and cognitive performance: can blue-enriched light keep us alert?

    Directory of Open Access Journals (Sweden)

    Sarah Laxhmi Chellappa

    Full Text Available BACKGROUND: Light exposure can cascade numerous effects on the human circadian process via the non-imaging forming system, whose spectral relevance is highest in the short-wavelength range. Here we investigated if commercially available compact fluorescent lamps with different colour temperatures can impact on alertness and cognitive performance. METHODS: Sixteen healthy young men were studied in a balanced cross-over design with light exposure of 3 different light settings (compact fluorescent lamps with light of 40 lux at 6500K and at 2500K and incandescent lamps of 40 lux at 3000K during 2 h in the evening. RESULTS: Exposure to light at 6500K induced greater melatonin suppression, together with enhanced subjective alertness, well-being and visual comfort. With respect to cognitive performance, light at 6500K led to significantly faster reaction times in tasks associated with sustained attention (Psychomotor Vigilance and GO/NOGO Task, but not in tasks associated with executive function (Paced Visual Serial Addition Task. This cognitive improvement was strongly related with attenuated salivary melatonin levels, particularly for the light condition at 6500K. CONCLUSIONS: Our findings suggest that the sensitivity of the human alerting and cognitive response to polychromatic light at levels as low as 40 lux, is blue-shifted relative to the three-cone visual photopic system. Thus, the selection of commercially available compact fluorescent lights with different colour temperatures significantly impacts on circadian physiology and cognitive performance at home and in the workplace.

  4. Black Hole Accretion in Gamma Ray Bursts

    Directory of Open Access Journals (Sweden)

    Agnieszka Janiuk

    2017-02-01

    Full Text Available We study the structure and evolution of the hyperaccreting disks and outflows in the gamma ray bursts central engines. The torus around a stellar mass black hole is composed of free nucleons, Helium, electron-positron pairs, and is cooled by neutrino emission. Accretion of matter powers the relativistic jets, responsible for the gamma ray prompt emission. The significant number density of neutrons in the disk and outflowing material will cause subsequent formation of heavier nuclei. We study the process of nucleosynthesis and its possible observational consequences. We also apply our scenario to the recent observation of the gravitational wave signal, detected on 14 September 2015 by the two Advanced LIGO detectors, and related to an inspiral and merger of a binary black hole system. A gamma ray burst that could possibly be related with the GW150914 event was observed by the Fermi satellite. It had a duration of about 1 s and appeared about 0.4 s after the gravitational-wave signal. We propose that a collapsing massive star and a black hole in a close binary could lead to the event. The gamma ray burst was powered by a weak neutrino flux produced in the star remnant’s matter. Low spin and kick velocity of the merged black hole are reproduced in our simulations. Coincident gravitational-wave emission originates from the merger of the collapsed core and the companion black hole.

  5. Burst fracture of the fifth lumber vertebra

    International Nuclear Information System (INIS)

    Cao Hetao; Hu Zhenmin; Shi Yuxin

    1999-01-01

    Objective: To investigate the stability of the fifth lumber vertebra after burst fracture. Methods: 7 patients with burst fracture of the fifth lumber vertebra were examined by X-ray and CT, and followed for 6-36 months. The changes of wedge index, lordosis, degree of spinal canal stenosis and neurological features were observed during the episode and followed up. Results: The three spinal column structure was disrupted in 6 of 7 patients. The anterior and mid columns were involved in 1 case. Spinal stenosis of first and second degrees was seen in 3 cases, and in one case, there was no spinal canal stenosis. Lower lumber motor-root deficits were found in 2 of 7 patients and resolved in follow up. There was no tendency of progressive collapse of the vertebral body and spinal stenosis. Conclusions: Burst fracture of the fifth lumber vertebra was specific, most of them were stable fractures, although two or three columns of the spine were disrupted and accompanied by spinal canal stenosis

  6. Burst fracture of the fifth lumber vertebra

    Energy Technology Data Exchange (ETDEWEB)

    Hetao, Cao; Zhenmin, Hu; Yuxin, Shi [Affiliated Hosptial of Nantong Medical College, JS, Nantong (China). Dept. of Radiology

    1999-04-01

    Objective: To investigate the stability of the fifth lumber vertebra after burst fracture. Methods: 7 patients with burst fracture of the fifth lumber vertebra were examined by X-ray and CT, and followed for 6-36 months. The changes of wedge index, lordosis, degree of spinal canal stenosis and neurological features were observed during the episode and followed up. Results: The three spinal column structure was disrupted in 6 of 7 patients. The anterior and mid columns were involved in 1 case. Spinal stenosis of first and second degrees was seen in 3 cases, and in one case, there was no spinal canal stenosis. Lower lumber motor-root deficits were found in 2 of 7 patients and resolved in follow up. There was no tendency of progressive collapse of the vertebral body and spinal stenosis. Conclusions: Burst fracture of the fifth lumber vertebra was specific, most of them were stable fractures, although two or three columns of the spine were disrupted and accompanied by spinal canal stenosis

  7. Rock burst prevention at steep seam mining

    Energy Technology Data Exchange (ETDEWEB)

    Efremov, G D

    1988-09-01

    At steep shield longwalls one method of preventing rock bursts is to avoid sharp angles during working. Stress in coal and rock body that appears when steep seams are worked where rock bursts occur at corners of set-up entries is discussed. The dynamic interaction between gas and rock pressure is assessed. Maintains that in order to avoid rock bursts at these places it is necessary to turn the protruding coal wall by 20-30 degrees towards the coal body to divert the action of shift forces. At the same time the face should also be inclined (by 10-15 degrees) to move the zones of increased stress away from the corner into the coal and rock body. Stress at workings with round cross-sections is 3-4 times lower than at square cross-sections. Recommendations are given that concern shearer loader operation (semi-spherical shape of the face), borehole drilling and water injection. Initial distance of 10-15 m between boreholes is suggested. 3 refs.

  8. Radio Flares from Gamma-ray Bursts

    Science.gov (United States)

    Kopač, D.; Mundell, C. G.; Kobayashi, S.; Virgili, F. J.; Harrison, R.; Japelj, J.; Guidorzi, C.; Melandri, A.; Gomboc, A.

    2015-06-01

    We present predictions of centimeter and millimeter radio emission from reverse shocks (RSs) in the early afterglows of gamma-ray bursts (GRBs) with the goal of determining their detectability with current and future radio facilities. Using a range of GRB properties, such as peak optical brightness and time, isotropic equivalent gamma-ray energy, and redshift, we simulate radio light curves in a framework generalized for any circumburst medium structure and including a parameterization of the shell thickness regime that is more realistic than the simple assumption of thick- or thin-shell approximations. Building on earlier work by Mundell et al. and Melandri et al. in which the typical frequency of the RS was suggested to lie at radio rather than optical wavelengths at early times, we show that the brightest and most distinct RS radio signatures are detectable up to 0.1-1 day after the burst, emphasizing the need for rapid radio follow-up. Detection is easier for bursts with later optical peaks, high isotropic energies, lower circumburst medium densities, and at observing frequencies that are less prone to synchrotron self-absorption effects—typically above a few GHz. Given recent detections of polarized prompt gamma-ray and optical RS emission, we suggest that detection of polarized radio/millimeter emission will unambiguously confirm the presence of low-frequency RSs at early time.

  9. RADIO FLARES FROM GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Kopač, D.; Mundell, C. G.; Kobayashi, S.; Virgili, F. J.; Harrison, R.; Japelj, J.; Gomboc, A.; Guidorzi, C.; Melandri, A.

    2015-01-01

    We present predictions of centimeter and millimeter radio emission from reverse shocks (RSs) in the early afterglows of gamma-ray bursts (GRBs) with the goal of determining their detectability with current and future radio facilities. Using a range of GRB properties, such as peak optical brightness and time, isotropic equivalent gamma-ray energy, and redshift, we simulate radio light curves in a framework generalized for any circumburst medium structure and including a parameterization of the shell thickness regime that is more realistic than the simple assumption of thick- or thin-shell approximations. Building on earlier work by Mundell et al. and Melandri et al. in which the typical frequency of the RS was suggested to lie at radio rather than optical wavelengths at early times, we show that the brightest and most distinct RS radio signatures are detectable up to 0.1–1 day after the burst, emphasizing the need for rapid radio follow-up. Detection is easier for bursts with later optical peaks, high isotropic energies, lower circumburst medium densities, and at observing frequencies that are less prone to synchrotron self-absorption effects—typically above a few GHz. Given recent detections of polarized prompt gamma-ray and optical RS emission, we suggest that detection of polarized radio/millimeter emission will unambiguously confirm the presence of low-frequency RSs at early time

  10. Secured Hash Based Burst Header Authentication Design for Optical Burst Switched Networks

    Science.gov (United States)

    Balamurugan, A. M.; Sivasubramanian, A.; Parvathavarthini, B.

    2017-12-01

    The optical burst switching (OBS) is a promising technology that could meet the fast growing network demand. They are featured with the ability to meet the bandwidth requirement of applications that demand intensive bandwidth. OBS proves to be a satisfactory technology to tackle the huge bandwidth constraints, but suffers from security vulnerabilities. The objective of this proposed work is to design a faster and efficient burst header authentication algorithm for core nodes. There are two important key features in this work, viz., header encryption and authentication. Since the burst header is an important in optical burst switched network, it has to be encrypted; otherwise it is be prone to attack. The proposed MD5&RC4-4S based burst header authentication algorithm runs 20.75 ns faster than the conventional algorithms. The modification suggested in the proposed RC4-4S algorithm gives a better security and solves the correlation problems between the publicly known outputs during key generation phase. The modified MD5 recommended in this work provides 7.81 % better avalanche effect than the conventional algorithm. The device utilization result also shows the suitability of the proposed algorithm for header authentication in real time applications.

  11. Enhanced 911/global position system wizard: a telemedicine application for the prevention of severe hypoglycemia--monitor, alert, and locate.

    Science.gov (United States)

    Dassau, Eyal; Jovanovic, Lois; Doyle, Francis J; Zisser, Howard C

    2009-11-01

    Intensive insulin therapy has an inherent risk of hypoglycemia that can lead to loss of consciousness, cardiac arrhythmia, seizure, and death ("dead-in-bed syndrome"). This risk of hypoglycemia is a major concern for patients, families, and physicians. The need for an automated system that can alert in the event of severe hypoglycemia is evident. In engineering systems, where there is a risk of malfunction of the primary control system, alert and safety mechanisms are implemented in layers of protection. This concept has been adopted in the proposed system that integrates a hypoglycemia prediction algorithm with a global position system (GPS) locator and short message service such that the current glucose value with the rate of change (ROC) and the location of the subject can be communicated to a predefined list. Furthermore, if the system is linked to the insulin pump, it can suspend the pump or decrease the basal insulin infusion rate to prevent the pending event. The system was evaluated on clinical datasets of glucose tracings from the DexCom Seven system. Glucose tracings were analyzed for hypoglycemia events and then a text message was broadcast to a predefined list of people who were notified with the glucose value, ROC, GPS coordinates, and a Google map of the location. In addition to providing a safety layer to a future artificial pancreas, this system also can be easily implemented in current continuous glucose monitors to help provide information and alerts to people with diabetes.

  12. A closed-loop anesthetic delivery system for real-time control of burst suppression

    Science.gov (United States)

    Liberman, Max Y.; Ching, ShiNung; Chemali, Jessica; Brown, Emery N.

    2013-08-01

    Objective. There is growing interest in using closed-loop anesthetic delivery (CLAD) systems to automate control of brain states (sedation, unconsciousness and antinociception) in patients receiving anesthesia care. The accuracy and reliability of these systems can be improved by using as control signals electroencephalogram (EEG) markers for which the neurophysiological links to the anesthetic-induced brain states are well established. Burst suppression, in which bursts of electrical activity alternate with periods of quiescence or suppression, is a well-known, readily discernible EEG marker of profound brain inactivation and unconsciousness. This pattern is commonly maintained when anesthetics are administered to produce a medically-induced coma for cerebral protection in patients suffering from brain injuries or to arrest brain activity in patients having uncontrollable seizures. Although the coma may be required for several hours or days, drug infusion rates are managed inefficiently by manual adjustment. Our objective is to design a CLAD system for burst suppression control to automate management of medically-induced coma. Approach. We establish a CLAD system to control burst suppression consisting of: a two-dimensional linear system model relating the anesthetic brain level to the EEG dynamics; a new control signal, the burst suppression probability (BSP) defining the instantaneous probability of suppression; the BSP filter, a state-space algorithm to estimate the BSP from EEG recordings; a proportional-integral controller; and a system identification procedure to estimate the model and controller parameters. Main results. We demonstrate reliable performance of our system in simulation studies of burst suppression control using both propofol and etomidate in rodent experiments based on Vijn and Sneyd, and in human experiments based on the Schnider pharmacokinetic model for propofol. Using propofol, we further demonstrate that our control system reliably

  13. The INTEGRAL view of intermediate long X-ray bursts

    DEFF Research Database (Denmark)

    a degenerated helium white dwarf. Of special interest are bursters showing events with very different durations, thus allowing us to study transitions between different nuclear burning regimes. Depending on the actual accretion rate, either the burning of a large amount of H is triggered by an He flash...

  14. Workplace lighting for improving alertness and mood in daytime workers.

    Science.gov (United States)

    Pachito, Daniela V; Eckeli, Alan L; Desouky, Ahmed S; Corbett, Mark A; Partonen, Timo; Rajaratnam, Shantha Mw; Riera, Rachel

    2018-03-02

    Exposure to light plays a crucial role in biological processes, influencing mood and alertness. Daytime workers may be exposed to insufficient or inappropriate light during daytime, leading to mood disturbances and decreases in levels of alertness. To assess the effectiveness and safety of lighting interventions to improve alertness and mood in daytime workers. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, seven other databases; ClinicalTrials.gov and the World Health Organization trials portal up to January 2018. We included randomised controlled trials (RCTs), and non-randomised controlled before-after trials (CBAs) that employed a cross-over or parallel-group design, focusing on any type of lighting interventions applied for daytime workers. Two review authors independently screened references in two stages, extracted outcome data and assessed risk of bias. We used standardised mean differences (SMDs) and 95% confidence intervals (CI) to pool data from different questionnaires and scales assessing the same outcome across different studies. We combined clinically homogeneous studies in a meta-analysis. We used the GRADE system to rate quality of evidence. The search yielded 2844 references. After screening titles and abstracts, we considered 34 full text articles for inclusion. We scrutinised reports against the eligibility criteria, resulting in the inclusion of five studies (three RCTs and two CBAs) with 282 participants altogether. These studies evaluated four types of comparisons: cool-white light, technically known as high correlated colour temperature (CCT) light versus standard illumination; different proportions of indirect and direct light; individually applied blue-enriched light versus no treatment; and individually applied morning bright light versus afternoon bright light for subsyndromal seasonal affective disorder.We found no studies comparing one level of illuminance versus another.We found two CBA

  15. Structure alerts for carcinogenicity, and the Salmonella assay system: a novel insight through the chemical relational databases technology.

    Science.gov (United States)

    Benigni, Romualdo; Bossa, Cecilia

    2008-01-01

    In the past decades, chemical carcinogenicity has been the object of mechanistic studies that have been translated into valuable experimental (e.g., the Salmonella assays system) and theoretical (e.g., compilations of structure alerts for chemical carcinogenicity) models. These findings remain the basis of the science and regulation of mutagens and carcinogens. Recent advances in the organization and treatment of large databases consisting of both biological and chemical information nowadays allows for a much easier and more refined view of data. This paper reviews recent analyses on the predictive performance of various lists of structure alerts, including a new compilation of alerts that combines previous work in an optimized form for computer implementation. The revised compilation is part of the Toxtree 1.50 software (freely available from the European Chemicals Bureau website). The use of structural alerts for the chemical biological profiling of a large database of Salmonella mutagenicity results is also reported. Together with being a repository of the science on the chemical biological interactions at the basis of chemical carcinogenicity, the SAs have a crucial role in practical applications for risk assessment, for: (a) description of sets of chemicals; (b) preliminary hazard characterization; (c) formation of categories for e.g., regulatory purposes; (d) generation of subsets of congeneric chemicals to be analyzed subsequently with QSAR methods; (e) priority setting. An important aspect of SAs as predictive toxicity tools is that they derive directly from mechanistic knowledge. The crucial role of mechanistic knowledge in the process of applying (Q)SAR considerations to risk assessment should be strongly emphasized. Mechanistic knowledge provides a ground for interaction and dialogue between model developers, toxicologists and regulators, and permits the integration of the (Q)SAR results into a wider regulatory framework, where different types of

  16. 'Integration'

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2011-01-01

    , while the countries have adopted disparate policies and ideologies, differences in the actual treatment and attitudes towards immigrants and refugees in everyday life are less clear, due to parallel integration programmes based on strong similarities in the welfare systems and in cultural notions...... of equality in the three societies. Finally, it shows that family relations play a central role in immigrants’ and refugees’ establishment of a new life in the receiving societies, even though the welfare society takes on many of the social and economic functions of the family....

  17. Simulating X-ray bursts during a transient accretion event

    Science.gov (United States)

    Johnston, Zac; Heger, Alexander; Galloway, Duncan K.

    2018-06-01

    Modelling of thermonuclear X-ray bursts on accreting neutron stars has to date focused on stable accretion rates. However, bursts are also observed during episodes of transient accretion. During such events, the accretion rate can evolve significantly between bursts, and this regime provides a unique test for burst models. The accretion-powered millisecond pulsar SAX J1808.4-3658 exhibits accretion outbursts every 2-3 yr. During the well-sampled month-long outburst of 2002 October, four helium-rich X-ray bursts were observed. Using this event as a test case, we present the first multizone simulations of X-ray bursts under a time-dependent accretion rate. We investigate the effect of using a time-dependent accretion rate in comparison to constant, averaged rates. Initial results suggest that using a constant, average accretion rate between bursts may underestimate the recurrence time when the accretion rate is decreasing, and overestimate it when the accretion rate is increasing. Our model, with an accreted hydrogen fraction of X = 0.44 and a CNO metallicity of ZCNO = 0.02, reproduces the observed burst arrival times and fluences with root mean square (rms) errors of 2.8 h, and 0.11× 10^{-6} erg cm^{-2}, respectively. Our results support previous modelling that predicted two unobserved bursts and indicate that additional bursts were also missed by observations.

  18. Dynamic encoding of natural luminance sequences by LGN bursts.

    Directory of Open Access Journals (Sweden)

    Nicholas A Lesica

    2006-07-01

    Full Text Available In the lateral geniculate nucleus (LGN of the thalamus, visual stimulation produces two distinct types of responses known as tonic and burst. Due to the dynamics of the T-type Ca(2+ channels involved in burst generation, the type of response evoked by a particular stimulus depends on the resting membrane potential, which is controlled by a network of modulatory connections from other brain areas. In this study, we use simulated responses to natural scene movies to describe how modulatory and stimulus-driven changes in LGN membrane potential interact to determine the luminance sequences that trigger burst responses. We find that at low resting potentials, when the T channels are de-inactivated and bursts are relatively frequent, an excitatory stimulus transient alone is sufficient to evoke a burst. However, to evoke a burst at high resting potentials, when the T channels are inactivated and bursts are relatively rare, prolonged inhibitory stimulation followed by an excitatory transient is required. We also observe evidence of these effects in vivo, where analysis of experimental recordings demonstrates that the luminance sequences that trigger bursts can vary dramatically with the overall burst percentage of the response. To characterize the functional consequences of the effects of resting potential on burst generation, we simulate LGN responses to different luminance sequences at a range of resting potentials with and without a mechanism for generating bursts. Using analysis based on signal detection theory, we show that bursts enhance detection of specific luminance sequences, ranging from the onset of excitatory sequences at low resting potentials to the offset of inhibitory sequences at high resting potentials. These results suggest a dynamic role for burst responses during visual processing that may change according to behavioral state.

  19. A Novel Design for Drug-Drug Interaction Alerts Improves Prescribing Efficiency.

    Science.gov (United States)

    Russ, Alissa L; Chen, Siying; Melton, Brittany L; Johnson, Elizabette G; Spina, Jeffrey R; Weiner, Michael; Zillich, Alan J

    2015-09-01

    Drug-drug interactions (DDIs) are common in clinical care and pose serious risks for patients. Electronic health records display DDI alerts that can influence prescribers, but the interface design of DDI alerts has largely been unstudied. In this study, the objective was to apply human factors engineering principles to alert design. It was hypothesized that redesigned DDI alerts would significantly improve prescribers' efficiency and reduce prescribing errors. In a counterbalanced, crossover study with prescribers, two DDI alert designs were evaluated. Department of Veterans Affairs (VA) prescribers were video recorded as they completed fictitious patient scenarios, which included DDI alerts of varying severity. Efficiency was measured from time-stamped recordings. Prescribing errors were evaluated against predefined criteria. Efficiency and prescribing errors were analyzed with the Wilcoxon signed-rank test. Other usability data were collected on the adequacy of alert content, prescribers' use of the DDI monograph, and alert navigation. Twenty prescribers completed patient scenarios for both designs. Prescribers resolved redesigned alerts in about half the time (redesign: 52 seconds versus original design: 97 seconds; p<.001). Prescribing errors were not significantly different between the two designs. Usability results indicate that DDI alerts might be enhanced by facilitating easier access to laboratory data and dosing information and by allowing prescribers to cancel either interacting medication directly from the alert. Results also suggest that neither design provided adequate information for decision making via the primary interface. Applying human factors principles to DDI alerts improved overall efficiency. Aspects of DDI alert design that could be further enhanced prior to implementation were also identified.

  20. Sporotrichosis with Bone Involvement: An Alert to an Occupational Disease

    Directory of Open Access Journals (Sweden)

    Felipe de Carvalho Aguinaga

    2014-04-01

    Full Text Available Sporotrichosis is a subacute or chronic mycosis caused by a fungus of the genus Sporothrix, which is found in soil. It can be acquired by trauma to the skin. Bone and joint lesions are very rare. The city of Rio de Janeiro is undergoing an epidemic transmitted by cats, and this should be an alert for the risk to professionals in contact with these animals. The patient was a veterinarian who developed occupational sporotrichosis with osteoarticular involvement transmitted by a cat during a consultation.

  1. The Low-Level Wind Shear Alert System (LLWSAS)

    Science.gov (United States)

    1980-05-01

    ALERT SYSTEM (LLWSAS). (May R.. a.-ol - 8..’P" Imng Organization Report No, 9, Perfo~ring Or~ni-otlon Ro-r. -andAddress 10. Work Unit No. (TRAIS) Federal...rather than electronic approach. The 2-minute average adheres to recommended International Civil Aviation Organization (ICAO) standards (referernce 14...speed of 140 knots. **Cold front. 80 ’ # 90 0 STRONG CASES: COFF , 1975 80 9STRONG CASES: UNPU1BLISHED 70 60 A STRONG CASES: COFF , et al., 1978 50 \\ 50 -0

  2. Simulation and Proposed Handover Alert Algorithm for Mobile Communication System

    Directory of Open Access Journals (Sweden)

    Muzhir Shaban Al-Ani

    2009-10-01

    Full Text Available this paper deals with the simulation and presentation of a novel approach to design and implementation of algorithm to realize hand over process for a mobile communication system during mobile network. This algorithm performs the ability of the system to extract important information features about the received signal. When the strength of the received signal is dropped below a certain threshold value then an alert process is activated to achieve the continuity of the transmission due to a ready scan which is existed on time.

  3. Development of a Remote Monitoring System Using Meteor Burst Technology

    International Nuclear Information System (INIS)

    Ewanic, M.A.; Dunstan, M.T.; Reichhardt, D.K.

    2006-01-01

    Monitoring the cleanup and closure of contaminated sites requires extensive data acquisition, processing, and storage. At remote sites, the task of monitoring often becomes problematical due to the lack of site infrastructure (i.e., electrical power lines, telephone lines, etc.). MSE Technology Applications, Inc. (MSE) has designed an economical and efficient remote monitoring system that will handle large amounts of data; process the data, if necessary; and transmit this data over long distances. Design criteria MSE considered during the development of the remote monitoring system included: the ability to handle multiple, remote sampling points with independent sampling frequencies; robust (i.e., less susceptible to moisture, heat, and cold extremes); independent of infrastructure; user friendly; economical; and easy to expand system capabilities. MSE installed and tested a prototype system at the Mike Mansfield Advanced Technology Center (MMATC), Butte, Montana, in June 2005. The system MSE designed and installed consisted of a 'master' control station and two remote 'slave' stations. Data acquired at the two slave stations were transmitted to the master control station, which then transmits a complete data package to a ground station using meteor burst technology. The meteor burst technology has no need for hardwired land-lines or man-made satellites. Instead, it uses ionized particles in the Earth's atmosphere to propagate a radio signal. One major advantage of the system is that it can be configured to accept data from virtually any type of device, so long as the signal from the device can be read and recorded by a standard data-logger. In fact, MSE has designed and built an electrical resistivity monitoring system that will be powered and controlled by the meteor burst system components. As sites move through the process of remediation and eventual closure, monitoring provides data vital to the successful long term management of the site. The remote

  4. PWR clad ballooning: The effect of circumferential clad temperature variations on the burst strain/burst temperature relationship

    International Nuclear Information System (INIS)

    Barlow, P.

    1983-01-01

    By experiment, it has been shown by other workers that there is a reduction in the creep ductility of Zircaloy 4 in the α+β phase transition region. Results from single rod burst tests also show a reduction in burst strain in the α+β phase region. In this report it is shown theoretically that for single rod burst tests in the presence of circumferential temperature gradients, the temperature dependence of the mean burst strain is not determined by temperature variations in creep ductility, but is governed by the temperature sensitivity of the creep strain rate, which is shown to be a maximum in the α+β phase transition region. To demonstrate this effect, the mean clad strain at burst was calculated for creep straining at different temperature levels in the α, α+β and β phase regions. Cross-pin temperature gradients were applied which produced strain variations around the clad which were greatest in the α+β phase region. The mean strain at burst was determined using a maximum local burst strain (i.e. a creep ductility) which is independent of temperature. By assuming cross-pin temperature gradients which are typical of those observed during burst tests, then the calculated mean burst strain/burst temperature relationship gave good agreement with experiment. The calculations also show that when circumferential temperature differences are present, the calculated mean strain at burst is not sensitive to variations in the magnitude of the assumed creep ductility. This reduces the importance of the assumed burst criterion in the calculations. Hence a temperature independent creep ductility (e.g. 100% local strain) is adequate as a burst criterion for calculations under PWR LOCA conditions. (author)

  5. Study on the possibility of assessment of alertness using subsidiary behaviors

    International Nuclear Information System (INIS)

    Hirose, Ayako; Nagasaka, Akihiko

    2003-01-01

    The aim of this study is to explore the possibility of assessment of alertness using subsidiary behaviors. Using the previous experimental data, 8 subjects' subsidiary behaviors, which appeared during 3 monotonous VDU tasks, were picked up by 3 experimenters. These behaviors were classified into 13 categories according to their similarity. As a physiological index, electroencephalogram (EEG), which was known as the most sensitive index for measuring alertness, was measured. To investigate whether the number of these behaviors could be utilized for assessment of alertness, the following studies were carried out: 1) the relationships among the task performance, categorized behaviors and EEG were analyzed to make sure whether alertness had an impact on the task performance and the behaviors, 2) using the task performance, the level of alertness was classified tentatively, then the behaviors that were changed by the classified level of alertness were specified, 3) to testify the possibility of assessment of alertness, discriminant analysis was conducted using the behaviors which were specified above, and 4) quantification analysis III and cross correlation analysis were carried out to explore if the behaviors could estimate a decline in alertness before the performance deteriorated. As the results of the above 4 points, the followings were suggested: 1) some subsidiary behaviors were influenced by alertness, to say nothing of performance, 2) regardless of individual differences, there were some behaviors that were changed by the level of alertness which was tentatively classified in this study, 3) the level of alertness at the point could assess using some behaviors, such as 'rub, pinch, and scratch', 'ease the stiffness', 'postural adjustments', 'movement of eye's and mouth', 'action of low alertness', and 4) some behaviors indicated the premonitory sign of a decline in alertness, the other increased when a decline in alertness had been observed. Also, depends on

  6. Review of GRANAT observations of gamma-ray bursts

    DEFF Research Database (Denmark)

    Terekhov, O.; Denissenko, D.; Sunyaev, R.

    1995-01-01

    The GRANAT observatory was launched into a high apogee orbit on 1 December, 1989. Three instruments onboard GRANAT - PHEBUS, WATCH and SIGMA are able to detect gamma-ray bursts in a very broad energy range from 6 keV up to 100 MeV. Over 250 gamma-ray bursts were detected. We discuss the results...... of the observations of the time histories and spectral evolution of the detected events provided by the different instruments in different energy ranges. Short Gamma-Ray Bursts ( 2 s) events. Evidence of the existence...... of four differently behaving componenents in gamma-ray burst spectra is discussed. Statistical properties of the gamma-ray burst sources based on the 5 years of observations with (∼ 10−6 erg/cm2) sensitivity as well as the results of high sensitivity (∼ 10−8 erg/cm2) search for Gamma-Ray Bursts within...

  7. Observation of cosmic gamma ray burst by Hinotori

    International Nuclear Information System (INIS)

    Okudaira, Kiyoaki; Yoshimori, Masato; Hirashima, Yo; Kondo, Ichiro.

    1982-01-01

    The solar gamma ray detecor (SGR) on Hinotori has no collimator, and the collimator of a hard X-ray monitor is not effective for gamma ray with energy more than 100 KeV. Accordingly, the detection system can detect cosmic gamma ray burst, and two bursts were observed. The first burst was detected on February 28, 1981, and the source of the burst was in the direction of 81 degree from Venus. The time profile and the spectrum were observed. In July 21, 1981, the second burst was detected. The time profile obtained with the SGR was compared with those of PVO (Pioneer Venus Orbiter) and LASL-ISEE. The time difference among the data of time profiles indicated that the source of the burst was not the sun. The spectrum was also measured. (Kato, T.)

  8. Gamma-Ray Bursts: 4th Huntsville Symposium. Proceedings

    International Nuclear Information System (INIS)

    Meegan, C.A.; Preece, R.D.; Koshut, T.M.

    1998-01-01

    These proceedings represent papers presented at the Fourth Huntsville Gamma-Ray Bursts Symposium held in September, 1997 in Huntsville, Alabama, USA. This conference occurred at a crucial time in the history of the gamma-ray burst research. In early 1997, 30 years after the detection of the first gamma-ray burst by the Vela satellites, counterparts to bursts were finally detected at optical and radio wavelengths. The symposium attracted about 200 scientists from 16 countries. Some of the topics discussed include gamma-ray burst spectra, x-ray observations, optical observations, radio observations, host galaxies, shocks and afterglows and models of gamma-ray bursts. There were 183 papers presented, out of these, 16 have been abstracted for the Energy Science and Technology database

  9. Implications of fast radio bursts for superconducting cosmic strings

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yun-Wei [Institute of Astrophysics, Central China Normal University, 152 Luoyu Road, Wuhan 430079 (China); Cheng, Kwong-Sang [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Shiu, Gary; Tye, Henry, E-mail: yuyw@phy.ccnu.edu.cn, E-mail: hrspksc@hku.hk, E-mail: shiu@ust.hk, E-mail: iastye@ust.hk [Department of Physics and Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong (China)

    2014-11-01

    Highly beamed, short-duration electromagnetic bursts could be produced by superconducting cosmic string (SCS) loops oscillating in cosmic magnetic fields. We demonstrated that the basic characteristics of SCS bursts such as the electromagnetic frequency and the energy release could be consistently exhibited in the recently discovered fast radio bursts (FRBs). Moreover, it is first showed that the redshift distribution of the FRBs can also be well accounted for by the SCS burst model. Such agreements between the FRBs and SCS bursts suggest that the FRBs could originate from SCS bursts and thus they could provide an effective probe to study SCSs. The obtained values of model parameters indicate that the loops generating the FRBs have a small length scale and they are mostly formed in the radiation-dominated cosmological epoch.

  10. Implications of fast radio bursts for superconducting cosmic strings

    International Nuclear Information System (INIS)

    Yu, Yun-Wei; Cheng, Kwong-Sang; Shiu, Gary; Tye, Henry

    2014-01-01

    Highly beamed, short-duration electromagnetic bursts could be produced by superconducting cosmic string (SCS) loops oscillating in cosmic magnetic fields. We demonstrated that the basic characteristics of SCS bursts such as the electromagnetic frequency and the energy release could be consistently exhibited in the recently discovered fast radio bursts (FRBs). Moreover, it is first showed that the redshift distribution of the FRBs can also be well accounted for by the SCS burst model. Such agreements between the FRBs and SCS bursts suggest that the FRBs could originate from SCS bursts and thus they could provide an effective probe to study SCSs. The obtained values of model parameters indicate that the loops generating the FRBs have a small length scale and they are mostly formed in the radiation-dominated cosmological epoch

  11. Gamma ray bursts of black hole universe

    Science.gov (United States)

    Zhang, T. X.

    2015-07-01

    Slightly modifying the standard big bang theory, Zhang recently developed a new cosmological model called black hole universe, which has only a single postulate but is consistent with Mach's principle, governed by Einstein's general theory of relativity, and able to explain existing observations of the universe. In the previous studies, we have explained the origin, structure, evolution, expansion, cosmic microwave background radiation, quasar, and acceleration of black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present state with hundred billion-trillions of solar masses by accreting ambient matter and merging with other black holes. This study investigates gamma ray bursts of black hole universe and provides an alternative explanation for the energy and spectrum measurements of gamma ray bursts according to the black hole universe model. The results indicate that gamma ray bursts can be understood as emissions of dynamic star-like black holes. A black hole, when it accretes its star or merges with another black hole, becomes dynamic. A dynamic black hole has a broken event horizon and thus cannot hold the inside hot (or high-frequency) blackbody radiation, which flows or leaks out and produces a GRB. A star when it collapses into its core black hole produces a long GRB and releases the gravitational potential energy of the star as gamma rays. A black hole that merges with another black hole produces a short GRB and releases a part of their blackbody radiation as gamma rays. The amount of energy obtained from the emissions of dynamic star-like black holes are consistent with the measurements of energy from GRBs. The GRB energy spectra derived from this new emission mechanism are also consistent with the measurements.

  12. Emergent synchronous bursting of oxytocin neuronal network.

    Directory of Open Access Journals (Sweden)

    Enrico Rossoni

    2008-07-01

    Full Text Available When young suckle, they are rewarded intermittently with a let-down of milk that results from reflex secretion of the hormone oxytocin; without oxytocin, newly born young will die unless they are fostered. Oxytocin is made by magnocellular hypothalamic neurons, and is secreted from their nerve endings in the pituitary in response to action potentials (spikes that are generated in the cell bodies and which are propagated down their axons to the nerve endings. Normally, oxytocin cells discharge asynchronously at 1-3 spikes/s, but during suckling, every 5 min or so, each discharges a brief, intense burst of spikes that release a pulse of oxytocin into the circulation. This reflex was the first, and is perhaps the best, example of a physiological role for peptide-mediated communication within the brain: it is coordinated by the release of oxytocin from the dendrites of oxytocin cells; it can be facilitated by injection of tiny amounts of oxytocin into the hypothalamus, and it can be blocked by injection of tiny amounts of oxytocin antagonist. Here we show how synchronized bursting can arise in a neuronal network model that incorporates basic observations of the physiology of oxytocin cells. In our model, bursting is an emergent behaviour of a complex system, involving both positive and negative feedbacks, between many sparsely connected cells. The oxytocin cells are regulated by independent afferent inputs, but they interact by local release of oxytocin and endocannabinoids. Oxytocin released from the dendrites of these cells has a positive-feedback effect, while endocannabinoids have an inhibitory effect by suppressing the afferent input to the cells.

  13. Near stellar sources of gamma-ray bursts

    OpenAIRE

    Luchkov, B. I.; Markin, P. D.

    2012-01-01

    Correlation analysis of gamma-ray burst coordinates and nearby stars, registered on 2008-2011, revealed 5 coincidences with angular accuracy better than 0.1 degree. The random probability is $7\\times 10^{-7}$, so evidencing that coincident stars are indeed gamma-ray burst sources. The proposed method should be continued in order to provide their share in common balance of cosmic gamma-ray bursts.

  14. On Burst Detection and Prediction in Retweeting Sequence

    Science.gov (United States)

    2015-05-22

    We conduct a comprehensive empirical analysis of a large microblogging dataset collected from the Sina Weibo and report our observations of burst...whether and how accurate we can predict bursts using classifiers based on the extracted features. Our empirical study of the Sina Weibo data shows the...feasibility of burst prediction using appropriately extracted features and classic classifiers. 1 Introduction Microblogging, such as Twitter and Sina

  15. Voltage interval mappings for an elliptic bursting model

    OpenAIRE

    Wojcik, Jeremy; Shilnikov, Andrey

    2013-01-01

    We employed Poincar\\'e return mappings for a parameter interval to an exemplary elliptic bursting model, the FitzHugh-Nagumo-Rinzel model. Using the interval mappings, we were able to examine in detail the bifurcations that underlie the complex activity transitions between: tonic spiking and bursting, bursting and mixed-mode oscillations, and finally, mixed-mode oscillations and quiescence in the FitzHugh-Nagumo-Rinzel model. We illustrate the wealth of information, qualitative and quantitati...

  16. The velocities of type II solar radio bursts

    International Nuclear Information System (INIS)

    Tlamicha, A.; Karlicky, M.

    1976-01-01

    A list is presented of type II radio bursts identified at Ondrejov between January 1973 and December 1974 in the frequency range of the dynamic spectrum 70 to 810 MHz. The velocities of shock waves in the individual cases of type II bursts are given using the fourfold Newkirk model. Some problems associated with type II radio bursts and with the propagation of the shock wave into the interplanetary space and into the region of the Earth are also discussed. (author)

  17. Infrared and X-ray bursts from the rapid burster

    International Nuclear Information System (INIS)

    Apparao, K.M.V.; Chitre, S.M.

    1979-01-01

    Studies on sudden bursts from the cosmic X-ray sources are reported. The processes occuring from the rise in luminosity of an x-ray source to its collapse are described. Records of the x-ray burst from the globular cluster NGC 6624 and the 'Rapid Burster' are shown. The Infra-red bursts from the Rapid Burster are also explained. (A.K.)

  18. Physical characterization of the Skua fast burst assembly

    International Nuclear Information System (INIS)

    Paternoster, R.; Bounds, J.; Sanchez, R.; Miko, D.

    1994-01-01

    In this paper we discuss the system design and ongoing efforts to characterize the machine physics and operating properties of the Skua fast burst assembly. The machine is currently operating up to prompt critical while we await approval for super-prompt burst operations. Efforts have centered on characterizing neutron kinetic properties, comparing calculated and measured temperature coefficients and power distributions, improving the burst reproducibility, examining the site-wide dose characteristics, and fitting the machine with cooling and filtration systems

  19. Self-regulation of turbulence bursts and transport barriers

    International Nuclear Information System (INIS)

    Floriani, E; Ciraolo, G; Ghendrih, Ph; Sarazin, Y; Lima, R

    2013-01-01

    The interplay between turbulent bursts and transport barriers is analyzed with a simplified model of interchange turbulence in magnetically confined plasmas. The turbulent bursts spread into the transport barriers and, depending on the competing magnitude of the burst and stopping capability of the barrier, can burn through. Simulations of two models of transport barriers are presented: a hard barrier where interchange turbulence modes are stable in a prescribed region and a soft barrier with external plasma biasing. The response of the transport barriers to the non-linear perturbations of the turbulent bursts, addressed in a predator–prey approach, indicates that the barriers monitor an amplification factor of the turbulent bursts, with amplification smaller than one for most bursts and, in some cases, amplification factors that can significantly exceed unity. The weak barriers in corrugated profiles and magnetic structures, as well as the standard barriers, are characterized by these transmission properties, which then regulate the turbulent burst transport properties. The interplays of barriers and turbulent bursts are modeled as competing stochastic processes. For different classes of the probability density function (PDF) of these processes, one can predict the heavy tail properties of the bursts downstream from the barrier, either exponential for a leaky barrier, or with power laws for a tight barrier. The intrinsic probing of the transport barriers by the turbulent bursts thus gives access to the properties of the barriers. The main stochastic variables are the barrier width and the spreading distance of the turbulent bursts within the barrier, together with their level of correlation. One finds that in the case of a barrier with volumetric losses, such as radiation or particle losses as addressed in our present simulations, the stochastic model predicts a leaky behavior with an exponential PDF of escaping turbulent bursts in agreement with the simulation

  20. Optical burst switching based satellite backbone network

    Science.gov (United States)

    Li, Tingting; Guo, Hongxiang; Wang, Cen; Wu, Jian

    2018-02-01

    We propose a novel time slot based optical burst switching (OBS) architecture for GEO/LEO based satellite backbone network. This architecture can provide high speed data transmission rate and high switching capacity . Furthermore, we design the control plane of this optical satellite backbone network. The software defined network (SDN) and network slice (NS) technologies are introduced. Under the properly designed control mechanism, this backbone network is flexible to support various services with diverse transmission requirements. Additionally, the LEO access and handoff management in this network is also discussed.

  1. Decay time of type III solar bursts

    International Nuclear Information System (INIS)

    Alvarez, H.; Haddock, F.T.

    1972-01-01

    Sixty-four Type III bursts that drifted to frequencies below 600 kHz between March 1968 and February 1970 were analyzed. Decay times were measured and combined with published data ranging up to about 200 MHz. By fitting power functions to the computed and observed decay times, and using the local plasma hypothesis, it was found that the ratio rho of computed to observed values varies with radiocentric radial distance according to a power function rho = 3r 0 . 7 . (U.S.)

  2. Gamma ray bursts from extragalactic sources

    Science.gov (United States)

    Hoyle, Fred; Burbidge, Geoffrey

    1992-01-01

    The properties of gamma ray bursts of classical type are found to be explicable in terms of high speed collisions between stars. A model is proposed in which the frequency of such collisions can be calculated. The model is then applied to the nuclei of galaxies in general on the basis that galaxies, or at least some fraction of them, originate in the expulsion of stars from creation centers. Evidence that low level activity of this kind is also taking place at the center of our own Galaxy is discussed. The implications for galactic evolution are discussed and a negative view of black holes is taken.

  3. Capabilities of the Power Burst Facility

    International Nuclear Information System (INIS)

    Spencer, W.A.; Jensen, A.M.; McCardell, R.K.

    1982-01-01

    The unique and diverse test capabilities of the Power Burst Facility (PBF) are described in this paper. The PBF test reactor, located at the Idaho National Engineering Laboratory, simulates normal, off-normal, and accident operating conditions of light water reactor fuel rods. An overview description is given, with specific detail on design and operating characteristics of the driver core, experiment test loop, fission product detection system, test train assembly facility, and support equipment which make the testing capability of the PBF so versatile

  4. Burst-Mode Asynchronous Controllers on FPGA

    Directory of Open Access Journals (Sweden)

    Duarte L. Oliveira

    2008-01-01

    Full Text Available FPGAs have been mainly used to design synchronous circuits. Asynchronous design on FPGAs is difficult because the resulting circuit may suffer from hazard problems. We propose a method that implements a popular class of asynchronous circuits, known as burst mode, on FPGAs based on look-up table architectures. We present two conditions that, if satisfied, guarantee essential hazard-free implementation on any LUT-based FPGA. By doing that, besides all the intrinsic advantages of asynchronous over synchronous circuits, they also take advantage of the shorter design time and lower cost associated with FPGA designs.

  5. Prompt Emission Observations of Swift BAT Bursts

    Science.gov (United States)

    Barthelmy, Scott

    2009-01-01

    We review the prompt emission properties of Swift BAT gamma-ray bursts (GRBs). We present the global properties of BAT GRBs based on their spectral and temporal characteristics. The BAT T90 and T50 durations peak at 80 and 20 s, respectively. The peak energy (Epeak) of about 60% of BAT GRBs is very likely to be less than 1.00 keV. We also present the BAT characteristics of GRBs with soft spectra, so called Xray flashes (XRFs). We will compare the BAT GRBs and XRFs parameter distribution to the other missions.

  6. Accident analysis for US fast burst reactors

    International Nuclear Information System (INIS)

    Paternoster, R.; Flanders, M.; Kazi, H.

    1994-01-01

    In the US fast burst reactor (FBR) community there has been increasing emphasis and scrutiny on safety analysis and understanding of possible accident scenarios. This paper summarizes recent work in these areas that is going on at the different US FBR sites. At this time, all of the FBR facilities have or in the process of updating and refining their accident analyses. This effort is driven by two objectives: to obtain a more realistic scenario for emergency response procedures and contingency plans, and to determine compliance with changing regulatory standards

  7. Solar energetic particles and radio burst emission

    Czech Academy of Sciences Publication Activity Database

    Miteva, R.; Samwel, S. W.; Krupař, Vratislav

    2017-01-01

    Roč. 7 (2017), č. článku A37. ISSN 2115-7251 R&D Projects: GA ČR(CZ) GJ17-06818Y Institutional support: RVO:68378289 Keywords : solar energetic particles * solar radio burst emission * solar cycle Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.446, year: 2016 https://www.swsc-journal.org/ articles /swsc/abs/2017/01/swsc170028/swsc170028.html

  8. Frequency of fast, narrow γ-ray bursts

    International Nuclear Information System (INIS)

    Norris, J.P.; Maryland Univ., College Park; Cline, T.L.; Desai, U.D.; Teegarden, B.J.

    1984-01-01

    The paper describes the existence of two γ-ray burst populations detected by the ISEE-3 experiment. Data from the distribution of 123 Venera 13 and 14 events (60 detected by both spacecraft) also suggests two γ-ray burst populations in each experiment sample, the domains separated with a minimum near 1 or 2 s. The authors point out that the results of the Goddard ISEE-3 γ-ray burst spectrometer actually enhance the appearance of two burst populations suggested in the Venera data. (author)

  9. Multiparameter Monitoring and Prevention of Fault-Slip Rock Burst

    OpenAIRE

    Hu, Shan-chao; Tan, Yun-liang; Ning, Jian-guo; Guo, Wei-Yao; Liu, Xue-sheng

    2017-01-01

    Fault-slip rock burst is one type of the tectonic rock burst during mining. A detailed understanding of the precursory information of fault-slip rock burst and implementation of monitoring and early warning systems, as well as pressure relief measures, are essential to safety production in deep mines. This paper first establishes a mechanical model of stick-slip instability in fault-slip rock bursts and then reveals the failure characteristics of the instability. Then, change rule of mining-i...

  10. Type III bursts in interplanetary space - Fundamental or harmonic?

    Science.gov (United States)

    Dulk, G. A.; Steinberg, J. L.; Hoang, S.

    1984-01-01

    ISEE-3 spacecraft observation of 120 relatively simple, isolated bursts in the 30-1980 kHz range are the basis of the present study of Type III bursts in the solar wind. Several characteristics are identified for many of these bursts which imply that the mode of emission changes from predominantly fundamental plasma radiation during the rise phase to predominantly second harmonic during decay. The fundamental emission begins in time coincidence with the start of Langmuir waves, confirming the conventional belief in these waves' causation of Type III bursts. Attention is given to the characteristics of fundamental components, by comparison to harmonics, at km-wavelengths.

  11. Coupled hydro-neutronic calculations for fast burst reactor accidents

    International Nuclear Information System (INIS)

    Paternoster, R.; Kimpland, R.; Jaegers, P.; McGhee, J.

    1994-01-01

    Methods are described for determining the fully coupled neutronic/hydrodynamic response of fast burst reactors (FBR) under disruptive accident conditions. Two code systems, PAD (1 -D Lagrangian) and NIKE-PAGOSA (3-D Eulerian) were used to accomplish this. This is in contrast to the typical methodology that computes these responses by either single point kinetics or in a decoupled manner. This methodology is enabled by the use of modem supercomputers (CM-200). Two examples of this capability are presented: an unreflected metal fast burst assembly, and a reflected fast burst assembly typical of the Skua or SPR-III class of fast burst reactor

  12. Limits of the memory coefficient in measuring correlated bursts

    Science.gov (United States)

    Jo, Hang-Hyun; Hiraoka, Takayuki

    2018-03-01

    Temporal inhomogeneities in event sequences of natural and social phenomena have been characterized in terms of interevent times and correlations between interevent times. The inhomogeneities of interevent times have been extensively studied, while the correlations between interevent times, often called correlated bursts, are far from being fully understood. For measuring the correlated bursts, two relevant approaches were suggested, i.e., memory coefficient and burst size distribution. Here a burst size denotes the number of events in a bursty train detected for a given time window. Empirical analyses have revealed that the larger memory coefficient tends to be associated with the heavier tail of the burst size distribution. In particular, empirical findings in human activities appear inconsistent, such that the memory coefficient is close to 0, while burst size distributions follow a power law. In order to comprehend these observations, by assuming the conditional independence between consecutive interevent times, we derive the analytical form of the memory coefficient as a function of parameters describing interevent time and burst size distributions. Our analytical result can explain the general tendency of the larger memory coefficient being associated with the heavier tail of burst size distribution. We also find that the apparently inconsistent observations in human activities are compatible with each other, indicating that the memory coefficient has limits to measure the correlated bursts.

  13. X-ray echoes from gamma-ray bursts

    International Nuclear Information System (INIS)

    Dermer, C.D.; Hurley, K.C.; Hartmann, D.H.

    1991-01-01

    The identification of an echo of reflected radiation in time histories of gamma-ray burst spectra can provide important information about the existence of binary companions or accretion disks in gamma-ray burst systems. Because of the nature of Compton scattering, the spectrum of the echo will be attenuated at gamma-ray energies compared with the spectrum of the primary burst emission. The expected temporal and spectral signatures of the echo and a search for such echoes are described, and implications for gamma-ray burst models are discussed. 35 refs

  14. Proposing alerts for pre and pro-haptens (QSAR2016) ...

    Science.gov (United States)

    Predictive testing to identify and characterise substances for their skin sensitisation potential has historically been based on animal tests such as the Local Lymph Node Assay (LLNA). In recent years, regulations in the cosmetics and chemicals sectors has provided a strong impetus to develop and evaluate non-animal alternative methods. The 3 test methods that have undergone extensive development and validation are the direct peptide reactivity assay (DPRA), the KeratinoSensTM and the human Cell Line Activation Test (h-CLAT). Whilst these methods have been shown to perform relatively well in predicting LLNA results (accuracy ~ 80%), a particular concern that has been raised is their ability to predict chemicals that need to be activated to act as sensitisers (either abiotically on the skin (pre-hapten) or metabolically in the skin (pro-hapten)). This study reviewed an EURL ECVAM dataset containing 271 substances for which information was available in the LLNA and for one or more of the three non-animal test methods. The chemical structures of the substances were inspected and each assigned to a reaction mechanistic domain. Fifty-three substances were expected to require activation. Plausible reaction pathways were considered for each of the substances from which three structural alerts were hypothesised: autoxidation to hydroperoxides, aromatic ortho and para-diamino or di phenol derivatives, and aromatic meta-diamino/hydroxy derivatives. For each alert, the av

  15. Towards cross-lingual alerting for bursty epidemic events.

    Science.gov (United States)

    Collier, Nigel

    2011-10-06

    Online news reports are increasingly becoming a source for event-based early warning systems that detect natural disasters. Harnessing the massive volume of information available from multilingual newswire presents as many challanges as opportunities due to the patterns of reporting complex spatio-temporal events. In this article we study the problem of utilising correlated event reports across languages. We track the evolution of 16 disease outbreaks using 5 temporal aberration detection algorithms on text-mined events classified according to disease and outbreak country. Using ProMED reports as a silver standard, comparative analysis of news data for 13 languages over a 129 day trial period showed improved sensitivity, F1 and timeliness across most models using cross-lingual events. We report a detailed case study analysis for Cholera in Angola 2010 which highlights the challenges faced in correlating news events with the silver standard. The results show that automated health surveillance using multilingual text mining has the potential to turn low value news into high value alerts if informed choices are used to govern the selection of models and data sources. An implementation of the C2 alerting algorithm using multilingual news is available at the BioCaster portal http://born.nii.ac.jp/?page=globalroundup.

  16. Electronic alerts and clinician turnover: the influence of user acceptance.

    Science.gov (United States)

    Hysong, Sylvia J; Spitzmuller, Christiane; Espadas, Donna; Sittig, Dean F; Singh, Hardeep

    2014-11-01

    Use of certain components of electronic health records (EHRs), such as EHR-based alerting systems (EASs), might reduce provider satisfaction, a strong precursor to turnover. We examined the impact of factors likely to influence providers' acceptance of an alerting system, designed to facilitate electronic communication in outpatient settings, on provider satisfaction, intentions to quit, and turnover. We conducted a cross-sectional Web-based survey of EAS-related practices from a nationwide sample of primary care providers (PCPs) practicing at Department of Veterans Affairs (VA) medical facilities. Of 5001 invited VA PCPs, 2590 completed the survey. We relied on Venkatesh's Unified Theory of Acceptance and Use of Technology to create survey measures of 4 factors likely to impact user acceptance of EAS: supportive norms, monitoring/ feedback, training, and providers' perceptions of the value (PPOV) of EASs to provider effectiveness. Facility-level PCP turnover was measured via the VA's Service Support Center Human Resources Cube. Hypotheses were tested using structural equation modeling. After accounting for intercorrelations among predictors, monitoring/feedback regarding EASs significantly predicted intention to quit (b = 0.30, P < .01), and PPOV of EASs predicted both overall provider satisfaction (b = 0.58, P < .01) and facility-level provider turnover levels (b = -0.19, P < .05), all without relying on any intervening mechanisms. Design, implementation, and use of EASs might impact provider satisfaction and retention. Institutions should consider strategies to help providers perceive greater value in these clinical tools.

  17. Towards cross-lingual alerting for bursty epidemic events

    Directory of Open Access Journals (Sweden)

    Collier Nigel

    2011-10-01

    Full Text Available Abstract Background Online news reports are increasingly becoming a source for event-based early warning systems that detect natural disasters. Harnessing the massive volume of information available from multilingual newswire presents as many challanges as opportunities due to the patterns of reporting complex spatio-temporal events. Results In this article we study the problem of utilising correlated event reports across languages. We track the evolution of 16 disease outbreaks using 5 temporal aberration detection algorithms on text-mined events classified according to disease and outbreak country. Using ProMED reports as a silver standard, comparative analysis of news data for 13 languages over a 129 day trial period showed improved sensitivity, F1 and timeliness across most models using cross-lingual events. We report a detailed case study analysis for Cholera in Angola 2010 which highlights the challenges faced in correlating news events with the silver standard. Conclusions The results show that automated health surveillance using multilingual text mining has the potential to turn low value news into high value alerts if informed choices are used to govern the selection of models and data sources. An implementation of the C2 alerting algorithm using multilingual news is available at the BioCaster portal http://born.nii.ac.jp/?page=globalroundup.

  18. Alert system for students with visual disabilities at the UTM

    Directory of Open Access Journals (Sweden)

    Marely del Rosario Cruz Felipe

    2018-01-01

    Full Text Available In the transfer of students with visual disabilities at the Technical University of Manabí (UTM accidents have been reported when going through some ramps and other obstacles, especially on rainy days. This article belongs to an investigation into the realization of an alert system for students with visual disabilities. The objective of the implementation of this system is to guide students with visual disabilities on different obstacles that exist in their transfer through the university. To carry out the implementation of this system, the alert systems and the technologies that are currently used as a result of a recording studio in the national and international scope were analyzed, the tools and technologies used in the developed solution are described. (Definition, technologies for the change of people, software, programming languages, etc. that allowed an efficient implementation in a short time of the proposed system by means of RFID (Radio Frequency Identification technology. The above is reflected in the positive orientation for the transfer of 32 students with visual disabilities through the university and by those who have contributed to improving their quality of life.

  19. Relationship between alertness, performance, and body temperature in humans

    Science.gov (United States)

    Wright, Kenneth P Jr; Hull, Joseph T.; Czeisler, Charles A.

    2002-01-01

    Body temperature has been reported to influence human performance. Performance is reported to be better when body temperature is high/near its circadian peak and worse when body temperature is low/near its circadian minimum. We assessed whether this relationship between performance and body temperature reflects the regulation of both the internal biological timekeeping system and/or the influence of body temperature on performance independent of circadian phase. Fourteen subjects participated in a forced desynchrony protocol allowing assessment of the relationship between body temperature and performance while controlling for circadian phase and hours awake. Most neurobehavioral measures varied as a function of internal biological time and duration of wakefulness. A number of performance measures were better when body temperature was elevated, including working memory, subjective alertness, visual attention, and the slowest 10% of reaction times. These findings demonstrate that an increased body temperature, associated with and independent of internal biological time, is correlated with improved performance and alertness. These results support the hypothesis that body temperature modulates neurobehavioral function in humans.

  20. Bar Code Medication Administration Technology: Characterization of High-Alert Medication Triggers and Clinician Workarounds.

    Science.gov (United States)

    Miller, Daniel F; Fortier, Christopher R; Garrison, Kelli L

    2011-02-01

    Bar code medication administration (BCMA) technology is gaining acceptance for its ability to prevent medication administration errors. However, studies suggest that improper use of BCMA technology can yield unsatisfactory error prevention and introduction of new potential medication errors. To evaluate the incidence of high-alert medication BCMA triggers and alert types and discuss the type of nursing and pharmacy workarounds occurring with the use of BCMA technology and the electronic medication administration record (eMAR). Medication scanning and override reports from January 1, 2008, through November 30, 2008, for all adult medical/surgical units were retrospectively evaluated for high-alert medication system triggers, alert types, and override reason documentation. An observational study of nursing workarounds on an adult medicine step-down unit was performed and an analysis of potential pharmacy workarounds affecting BCMA and the eMAR was also conducted. Seventeen percent of scanned medications triggered an error alert of which 55% were for high-alert medications. Insulin aspart, NPH insulin, hydromorphone, potassium chloride, and morphine were the top 5 high-alert medications that generated alert messages. Clinician override reasons for alerts were documented in only 23% of administrations. Observational studies assessing for nursing workarounds revealed a median of 3 clinician workarounds per administration. Specific nursing workarounds included a failure to scan medications/patient armband and scanning the bar code once the dosage has been removed from the unit-dose packaging. Analysis of pharmacy order entry process workarounds revealed the potential for missed doses, duplicate doses, and doses being scheduled at the wrong time. BCMA has the potential to prevent high-alert medication errors by alerting clinicians through alert messages. Nursing and pharmacy workarounds can limit the recognition of optimal safety outcomes and therefore workflow processes

  1. Regulatory alerts for dietary supplements in Canada and the United States, 2005-13.

    Science.gov (United States)

    Abe, Andrew M; Hein, Darren J; Gregory, Philip J

    2015-06-01

    Dietary supplement regulatory alerts published by the Food and Drug Administration (FDA) and Health Canada were evaluated and characterized. FDA MedWatch and Health Canada websites were reviewed to identify regulatory alerts regarding dietary supplements from January 1, 2005, through December 31, 2013. Alerts were analyzed to identify product characteristics that may be predictive of product quality issues and potential patient harm. A total of 1560 dietary supplement-related regulatory alerts were identified. Of those, 1287 (83%) were identified through Health Canada, and 273 (18%) were identified through FDA MedWatch. The country of origin of dietary supplements associated with regulatory alerts was not provided in most regulatory alerts; however, when their origin was provided, the United States was the most common. Dietary supplements intended for sexual enhancement were the subject of 33% of all regulatory alerts identified. Products purchased online were the most likely to be associated with a regulatory alert. Dietary supplements intended for sexual enhancement, weight loss, and bodybuilding or athletic performance appeared to pose the greatest risk for patient harm due to product contamination with a pharmaceutical such as a phosphodiesterase-5 inhibitor or sibutramine. Analysis of Canadian and U.S. regulatory alerts concerning dietary supplements revealed that more than 80% of the composite alerts were issued by Health Canada. The most common intended uses of supplements for which alerts were issued were sexual enhancement, weight loss, and bodybuilding or athletic performance. The most common reason for alerts was the presence of a pharmaceutical contaminant. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  2. Changes in decibel scale wavelength properties of EEG with alertness levels while performing sustained attention tasks.

    Science.gov (United States)

    Arjunan, Sridhar P; Kumar, Dinesh K; Jung, Tzyy-Ping

    2009-01-01

    Loss of alertness can have dire consequences for people controlling motorized equipment or for people in professions such as defense. Electroencephalogram (EEG) is known to be related to alertness of the person, but due to high level of noise and low signal strength, the use of EEG for such applications has been considered to be unreliable. This study reports the fractal analysis of EEG and identifies the use of maximum fractal length (MFL) as a feature that is inversely correlated with the alertness of the subject. The results show that MFL (of only single channel of EEG) indicates the loss of alertness of the individual with mean (inverse) correlation coefficient = 0.82.

  3. The results of the Seismic Alert System of Mexico SASMEX, during the earthquakes of 7 and 19 of September 2017

    Science.gov (United States)

    Espinosa Aranda, J. M., Sr.; Cuellar Martinez, A.

    2017-12-01

    The Seismic Alert System of Mexico, SASMEX began in 1991, is integrated by the seismic alert system of Mexico City and the seismic alert system of Oaxaca. SASMEX has 97 seismic sensors which are distributed in the seismic regions of the Pacific coast and the South of the Trans-Mexican Volcanic Belt of states of Jalisco, Colima, Michoacán, Guerrero, Oaxaca and Puebla. The alert dissemination covers the cities of: Acapulco, Chilpancingo, Morelia, Puebla, Oaxaca, Toluca and Mexico City, reaching the earthquake warnings to more than 25 millions of people. SASMEX has detected correctly more than 5600 earthquakes and warned 156. Mexico City has different alert dissemination systems like several Radio and Tv commercial broadcasters, dedicated radio receivers, EAS-SAME-SARMEX radio receivers and more tha 6700 public loud speakers. The other cities have only some of those systems. The Mw 8.2 Chiapas earthquake on September 7, despite the epicentral distance far of the first seismic detections (more than 180 km) and the low amplitudes of the P waves, the earthquake warning time gave more than 90 seconds to Mexico City before the arrivals of S waves with minor damages to the city in contrast with high damages in towns in the coast. This earthquake offered an opportunity to show the developments and lacks to reduce the risk, such as the need to increase the seismic detection coverage and the earthquake warning dissemination in towns with high seismic vulnerability. The Mw 7.1 Morelos earthquake on September 19 caused thousands of damages and hundreds of deaths and injuries in Mexico City, this earthquake is the second with the most damages after the Mw 8.1 Michoacán earthquake of September 19 on 1985. The earthquake early warning gave 11 seconds after the arrivals of S waves, however the activation occurred few seconds after the P waves arrives to Mexico City, and due to the seismic focus was near to the city, the P waves were felt for the people. The Accelerographic Network

  4. Star bursts and giant HII regions

    International Nuclear Information System (INIS)

    Pagel, B.E.J.

    1990-01-01

    Massive star formation bursts occur in a variety of galactic environments and can temporarily dominate the light output of a galaxy even when a relatively small proportion of its mass is involved. Inferences about their ages, the IMF and its dependence on chemical composition are still somewhat wobbly owing to an excess of unknowns, but certain things can be deduced from emission spectra of associated H II regions when due regard is paid to the effects of chemical composition and ionization parameter: In particular, largest ionization parameters and effective temperatures of exciting stars, at any given oxygen abundance, are anti-correlated with the abundance, and the second effect suggests an increasing proportion of more massive stars at lower abundances, although this is not yet satisfactorily quantified. A new blue compact galaxies could be very young, but it is equally possible that there is an older population of low surface brightness. Some giant H II regions may be self-polluted with nitrogen and helium due to winds from massive stars in the associated burst. (orig.)

  5. Effects of intermittent theta burst stimulation on spasticity after stroke.

    Science.gov (United States)

    Kim, Dae Hyun; Shin, Ji Cheol; Jung, Seungsoo; Jung, Tae-Min; Kim, Deog Young

    2015-07-08

    Spasticity is a common cause of long-term disability in poststroke hemiplegic patients. We investigated whether intermittent theta burst stimulation (iTBS) could reduce upper-limb spasticity after a stroke. Fifteen hemiplegic stroke patients were recruited for a double-blind sham-controlled cross-over design study. A single session of iTBS or sham stimulation was delivered on the motor hotspot of the affected flexor carpi radialis muscle in a random and counterbalanced order with a 1-week interval. Modified Ashworth scale (MAS), modified Tardieu scale (MTS), H-wave/M-wave amplitude ratio, peak torque (PT), peak torque angle (PTA), work of affected wrist flexor, and rectified integrated electromyographic activity of the flexor carpi radialis muscle were measured before, immediately after, 30 min after, and 1 week after iTBS or sham stimulation. Repeated-measures analysis of variance showed a significant interaction between time and intervention for the MAS, MTS, PT, PTA, and rectified integrated electromyographic activity (PiTBS compared with sham stimulation. However, the H-wave/M-wave amplitude ratio and work were not affected. MAS and MTS significantly improved for at least 30 min after iTBS, but the other parameters only improved immediately after iTBS (PiTBS on the affected hemisphere may help to reduce poststroke spasticity transiently.

  6. The Arcminute Microkelvin Imager catalogue of gamma-ray burst afterglows at 15.7 GHz

    Science.gov (United States)

    Anderson, G. E.; Staley, T. D.; van der Horst, A. J.; Fender, R. P.; Rowlinson, A.; Mooley, K. P.; Broderick, J. W.; Wijers, R. A. M. J.; Rumsey, C.; Titterington, D. J.

    2018-01-01

    We present the Arcminute Microkelvin Imager (AMI) Large Array catalogue of 139 gamma-ray bursts (GRBs). AMI observes at a central frequency of 15.7 GHz and is equipped with a fully automated rapid-response mode, which enables the telescope to respond to high-energy transients detected by Swift. On receiving a transient alert, AMI can be on-target within 2 min, scheduling later start times if the source is below the horizon. Further AMI observations are manually scheduled for several days following the trigger. The AMI GRB programme probes the early-time (<1 d) radio properties of GRBs, and has obtained some of the earliest radio detections (GRB 130427A at 0.36 and GRB 130907A at 0.51 d post-burst). As all Swift GRBs visible to AMI are observed, this catalogue provides the first representative sample of GRB radio properties, unbiased by multiwavelength selection criteria. We report the detection of six GRB radio afterglows that were not previously detected by other radio telescopes, increasing the rate of radio detections by 50 per cent over an 18-month period. The AMI catalogue implies a Swift GRB radio detection rate of ≳ 15 per cent, down to ∼0.2 mJy beam-1. However, scaling this by the fraction of GRBs AMI would have detected in the Chandra & Frail sample (all radio-observed GRBs between 1997 and 2011), it is possible ∼ 44-56 per cent of Swift GRBs are radio bright, down to ∼0.1-0.15 mJy beam-1. This increase from the Chandra & Frail rate (∼30 per cent) is likely due to the AMI rapid-response mode, which allows observations to begin while the reverse-shock is contributing to the radio afterglow.

  7. The Earth Observation Monitor - Automated monitoring and alerting for spatial time-series data based on OGC web services

    Science.gov (United States)

    Eberle, J.; Hüttich, C.; Schmullius, C.

    2014-12-01

    Spatial time series data are freely available around the globe from earth observation satellites and meteorological stations for many years until now. They provide useful and important information to detect ongoing changes of the environment; but for end-users it is often too complex to extract this information out of the original time series datasets. This issue led to the development of the Earth Observation Monitor (EOM), an operational framework and research project to provide simple access, analysis and monitoring tools for global spatial time series data. A multi-source data processing middleware in the backend is linked to MODIS data from Land Processes Distributed Archive Center (LP DAAC) and Google Earth Engine as well as daily climate station data from NOAA National Climatic Data Center. OGC Web Processing Services are used to integrate datasets from linked data providers or external OGC-compliant interfaces to the EOM. Users can either use the web portal (webEOM) or the mobile application (mobileEOM) to execute these processing services and to retrieve the requested data for a given point or polygon in userfriendly file formats (CSV, GeoTiff). Beside providing just data access tools, users can also do further time series analyses like trend calculations, breakpoint detections or the derivation of phenological parameters from vegetation time series data. Furthermore data from climate stations can be aggregated over a given time interval. Calculated results can be visualized in the client and downloaded for offline usage. Automated monitoring and alerting of the time series data integrated by the user is provided by an OGC Sensor Observation Service with a coupled OGC Web Notification Service. Users can decide which datasets and parameters are monitored with a given filter expression (e.g., precipitation value higher than x millimeter per day, occurrence of a MODIS Fire point, detection of a time series anomaly). Datasets integrated in the SOS service are

  8. Building a Communication, Education, an Outreach Program for the ShakeAlert National Earthquake Early Warning Program

    Science.gov (United States)

    DeGroot, R. M.; Strauss, J. A.; Given, D. D.; Cochran, E. S.; Burkett, E. R.; Long, K.

    2016-12-01

    Earthquake Early Warning (EEW) systems can provide as much as tens of seconds of warning to people and automated systems before strong shaking arrives. The United States Geological Survey (USGS) and its partners are developing an EEW system for the West Coast of the United States. To be an integral part of successful implementation, EEW engagement programs and materials must integrate with and leverage broader earthquake risk programs. New methods and products for dissemination must be multidisciplinary, cost effective, and consistent with existing hazards education efforts. Our presentation outlines how the USGS and its partners will approach this effort in the context of the EEW system through the work of a multistate and multiagency committee that participates in the design, implementation, and evaluation of a portfolio of programs and products. This committee, referred to as the ShakeAlert Joint Committee for Communication, Education, and Outreach (ShakeAlert CEO), is working to identify, develop, and cultivate partnerships with EEW stakeholders including Federal, State, academic partners, private companies, policy makers, and local organizations. Efforts include developing materials, methods for delivery, and reaching stakeholders with information on EEW, earthquake preparedness, and emergency protective actions. It is essential to develop standards to ensure information communicated via the EEW alerts is consistent across the public and private sector and achieving a common understanding of what actions users take when they receive an EEW warning. The USGS and the participating states and agencies acknowledge that the implementation of EEW is a collective effort requiring the participation of hundreds of stakeholders committed to ensuring public accessibility.

  9. Frontoparietal regions may become hypoactive after intermittent theta burst stimulation over the contralateral homologous cortex in humans.

    Science.gov (United States)

    He, Xiaofei; Lan, Yue; Xu, Guangqing; Mao, Yurong; Chen, Zhenghong; Huang, Dongfeng; Pei, Zhong

    2013-12-01

    Brain injury to the dorsal frontoparietal networks, including the posterior parietal cortex (PPC) and dorsolateral prefrontal cortex (DLPFC), commonly cause spatial neglect. However, the interaction of these different regions in spatial attention is unclear. The aim of the present study was to investigate whether hyperexcitable neural networks can cause an abnormal interhemispheric inhibition. The Attention Network Test was used to test subjects following intermittent theta burst stimulation (iTBS) to the left or right frontoparietal networks. During the Attention Network Test task, all subjects tolerated each conditioning iTBS without any obvious iTBS-related side effects. Subjects receiving real-right-PPC iTBS showed significant enhancement in both alerting and orienting efficiency compared with those receiving either sham-right-PPC iTBS or real-left-PPC iTBS. Moreover, subjects exposed to the real-right-DLPFC iTBS exhibited significant improvement in both alerting and executive control efficiency, compared with those exposed to either the sham-right-DLPFC or real-left-DLPFC conditioning. Interestingly, compared with subjects exposed to the sham-left-PPC stimuli, subjects exposed to the real-left-PPC iTBS had a significant deficit in the orienting index. The present study indicates that iTBS over the contralateral homologous cortex may induce the hypoactivity of the right PPC through interhemispheric competition in spatial orienting attention.

  10. SMM observation of a cosmic gamma-ray burst from 20 keV to 100 MeV

    Science.gov (United States)

    Share, G. H.; Matz, S. M.; Messina, D. C.; Nolan, P. L.; Chupp, E. L.

    1986-01-01

    The Solar Maximum Mission gamma-ray spectrometer has detected an intense gamma-ray burst that occurred on August 5, 1984. The burst originated from a source in the constellation Hydra and lasted about 45 s. Its integral fluence at 20 keV was 0.003 erg/sq cm. Spectral evolution similar to other bursts detected by SMM was observed. The overall shape of the spectrum from 20 keV to 100 MeV, on timescales as short as 2 s, is relatively constant. This shape can be fitted by the sum of an exponential-type function and a power law. There is no evidence for narrow or broadened emission lines.

  11. Single-pulse and burst-mode ablation of gold films measured by quartz crystal microbalance

    Science.gov (United States)

    Andrusyak, Oleksiy G.; Bubelnik, Matthew; Mares, Jeremy; McGovern, Theresa; Siders, Craig W.

    2005-02-01

    Femtosecond ablation has several distinct advantages: the threshold energy fluence for the onset of damage and ablation is orders of magnitude less than for traditional nanosecond laser machining, and by virtue of the rapid material removal of approximately an optical penetration depth per pulse, femtosecond machined cuts can be cleaner and more precise than those made with traditional nanosecond or longer pulse lasers. However, in many materials of interest, especially metals, this limits ablation rates to 10-100 nm/pulse. We present the results of using multiple pulse bursts to significantly increase the per-burst ablation rate compared to a single pulse with the same integrated energy, while keeping the peak intensity of each individual pulse below the air ionization limit. Femtosecond ablation with pulses centered at 800-nm having integrated energy of up to 30 mJ per pulse incident upon thin gold films was measured via resonance frequency shifts in a gold-electrode-coated quartz-crystal oscillator. Measurements were performed using Michelson-interferometer-based burst generators, with up to 2 ns pulse separations, as well as pulse shaping by programmable acousto-optic dispersive filter (Dazzler from FastLite) with up to 2 ps pulse separations.

  12. Burst Mode Composite Photography for Dynamic Physics Demonstrations

    Science.gov (United States)

    Lincoln, James

    2018-01-01

    I am writing this article to raise awareness of burst mode photography as a fun and engaging way for teachers and students to experience physics demonstration activities. In the context of digital photography, "burst mode" means taking multiple photographs per second, and this is a feature that now comes standard on most digital…

  13. Observation of gamma-ray bursts with GINGA

    International Nuclear Information System (INIS)

    Murakami, Toshio; Fujii, Masami; Nishimura, Jun

    1989-01-01

    Gamma-ray Burst Detector System (GBD) on board the scientific satellite 'GINGA' which was launched on Feb. 5, 1987, was realized as an international cooperation between ISAS and LANL. It has recorded more than 40 Gamma-Ray Burst candidates during 20 months observation. Although many observational evidences were accumulated in past 20 years after the discovery of gamma-ray burst by LANL scientists, there are not enough evidence to determine the origin and the production mechanism of the gamma-ray burst. GBD consists of a proportional counter and a NaI scintillation counter so that it became possible to observe energy spectrum of the gamma-ray burst with high energy resolution over wide range of energy (1.5-380 keV) together with high time resolution. As the result of observation, the following facts are obtained: (1) A large fraction of observed gamma-ray bursts has a long X-ray tail after the harder part of gamma-ray emission has terminated. (2) Clear spectral absorption features with harmonic in energy was observed in some of the energy spectrum of gamma-ray bursts. These evidences support the hypothesis that the strongly magnetized neutron star is the origin of gamma-ray burst. (author)

  14. Gamma ray bursts observed with WATCH‐EURECA

    DEFF Research Database (Denmark)

    Brandt, Søren; Lund, Niels; Castro-Tirado, A. J.

    1994-01-01

    The WATCH wide field x‐ray monitor has the capability of independently locating bright Gamma Ray Bursts to 1° accuracy. We report the preliminary positions of 12 Gamma Ray Bursts observed with the WATCH monitor flown on the ES spacecraft EURECA during its 11 month mission. Also the recurrence...

  15. The many phases of gamma-ray burst afterglows

    NARCIS (Netherlands)

    Leventis, K.

    2013-01-01

    Gamma-ray bursts are the brightest sources in the universe. Their afterglows have been observed for about 15 years now, and their study has greatly advanced our understanding of these, mysterious until recently, events. In a way, gamma-ray bursts can be seen as huge cosmic bombs which convert

  16. Hydrodynamics of burst swimming fish larvae; a conceptual model approach

    NARCIS (Netherlands)

    Verhagen, J.H.G.

    2004-01-01

    Burst swimming of fish larvae is analysed from a hydrodynamic point of view. A picture of the expected flow pattern is presented based on information in literature on unsteady-flow patterns around obstacles in the intermediate Reynolds number region. It is shown that the acceleration stage of burst

  17. Supernova sheds light on gamma-ray bursts

    CERN Multimedia

    2003-01-01

    On 29 March the HETE-II satellite detected the most violent explosion in the universe to date - an enormous burst of gamma rays. Observers across the world recorded and studied the event. It appears to prove that gamma ray bursts originate in supernovae (1 page)

  18. Jet simulations and gamma-ray burst afterglow jet breaks

    NARCIS (Netherlands)

    van Eerten, H.J.; Meliani, Z.; Wijers, R.A.M.J.; Keppens, R.

    2011-01-01

    The conventional derivation of the gamma-ray burst afterglow jet break time uses only the blast wave fluid Lorentz factor and therefore leads to an achromatic break. We show that in general gamma-ray burst afterglow jet breaks are chromatic across the self-absorption break. Depending on

  19. Jet simulations and gamma-ray burst afterglow jet breaks

    NARCIS (Netherlands)

    van Eerten, H. J.; Meliani, Z.; Wijers, R.A.M.J.; Keppens, R.

    2010-01-01

    The conventional derivation of the gamma-ray burst afterglow jet break time uses only the blast wave fluid Lorentz factor and therefore leads to an achromatic break. We show that in general gamma-ray burst afterglow jet breaks are chromatic across the self-absorption break. Depending on

  20. Fast Radio Burst Discovered in the Arecibo Pulsar ALFA Survey

    NARCIS (Netherlands)

    Spitler, L.G.; Cordes, J.M.; Hessels, J.W.T.; Lorimer, D.R.; McLaughlin, M.A.; Chatterjee, S.; Crawford, F.; Deneva, J.S.; Kaspi, V.M.; Wharton, R.S.; Allen, B.; Bogdanov, S.; Brazier, A.; Camilo, F.; Freire, P.C.C.; Jenet, F.A.; Karako-Argaman, C.; Knispel, B.; Lazarus, P.; Lee, K.J.; van Leeuwen, J.; Lynch, R.; Ransom, S.M.; Scholz, P.; Siemens, X.; Stairs, I.H.; Stovall, K.; Swiggum, J.K.; Venkataraman, A.; Zhu, W.W.; Aulbert, C.; Fehrmann, H.

    2014-01-01

    Recent work has exploited pulsar survey data to identify temporally isolated, millisecond-duration radio bursts with large dispersion measures (DMs). These bursts have been interpreted as arising from a population of extragalactic sources, in which case they would provide unprecedented opportunities