352 research outputs found
Bird detection in audio : a survey and a challenge
Many biological monitoring projects rely on acoustic detection of birds. Despite increasingly large datasets, this detection is often manual or semi-automatic, requiring manual tuning/postprocessing. We review the state of the art in automatic bird sound detection, and identify a widespread need for tuning-free and species-agnostic approaches. We introduce new datasets and an IEEE research challenge to address this need, to make possible the development of fully automatic algorithms for bird sound detection
Thomson Scattering of Coherent Diffraction Radiation by an Electron Bunch
The paper considers the process of Thomson scattering of coherent diffraction
radiation (CDR) produced by the preceding bunch of the accelerator on one of
the following bunches. It is shown that the yield of scattered hard photons is
proportional to N, where N is the number of electrons per bunch. A
geometry is chosen for the CDR generation and an expression is obtained for the
scattered photon spectrum with regard to the geometry used, that depends in an
explicit form on the bunch size. A technique is proposed for measuring the
bunch length using scattered radiation characteristics.Comment: 14 pages, LATEX, 6 ps.gz figures, submitted to Phys.Rev.
Inter-annual decrease in pulse rate and peak frequency of Southeast Pacific blue whale song types
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Malige, F., Patris, J., Buchan, S. J., Stafford, K. M., Shabangu, F., Findlay, K., Hucke-Gaete, R., Neira, S., Clark, C. W., & Glotin, H. Inter-annual decrease in pulse rate and peak frequency of Southeast Pacific blue whale song types. Scientific Reports, 10(1), (2020): 8121, doi:10.1038/s41598-020-64613-0.A decrease in the frequency of two southeast Pacific blue whale song types was examined over decades, using acoustic data from several different sources in the eastern Pacific Ocean ranging between the Equator and Chilean Patagonia. The pulse rate of the song units as well as their peak frequency were measured using two different methods (summed auto-correlation and Fourier transform). The sources of error associated with each measurement were assessed. There was a linear decline in both parameters for the more common song type (southeast Pacific song type n.2) between 1997 to 2017. An abbreviated analysis, also showed a frequency decline in the scarcer southeast Pacific song type n.1 between 1970 to 2014, revealing that both song types are declining at similar rates. We discussed the use of measuring both pulse rate and peak frequency to examine the frequency decline. Finally, a comparison of the rates of frequency decline with other song types reported in the literature and a discussion on the reasons of the frequency shift are presented.The authors thank the help of Explorasub diving center (Chile), Agrupación turística Chañaral de Aceituno (Chile), ONG Eutropia (Chile), Valparaiso university (Chile), the international institutions and research programs CTBTO, IWC, BRILAM STIC AmSud 17-STIC-01. S.J.B. thanks support from the Center for Oceanographic Research COPAS Sur-Austral, CONICYT PIA PFB31, Biology Department of Woods Hole Oceanographic Institution, the Office of Naval Research Global (awards N62909-16-2214 and N00014-17-2606), and a grant to the Centro de Estudios Avanzados en Zonas Ãridas (CEAZA) “Programa Regional CONICYT R16A10003”. We thank SABIOD MI CNRS, EADM MaDICS CNRS and ANR-18-CE40-0014 SMILES supporting this research. We are grateful to colleagues at DCLDE 2018 and SOLAMAC 2018 conferences for useful comments on the preliminary version of this work. In this work we used only the free and open-source softwares Latex, Audacity and OCTAVE
All-sky Search for High-Energy Neutrinos from Gravitational Wave Event GW170104 with the ANTARES Neutrino Telescope
Advanced LIGO detected a significant gravitational wave signal (GW170104)
originating from the coalescence of two black holes during the second
observation run on January 4, 2017. An all-sky high-energy
neutrino follow-up search has been made using data from the ANTARES neutrino
telescope, including both upgoing and downgoing events in two separate
analyses. No neutrino candidates were found within s around the GW
event time nor any time clustering of events over an extended time window of
months. The non-detection is used to constrain isotropic-equivalent
high-energy neutrino emission from GW170104 to less than
erg for a spectrum
The ANTARES Collaboration: Contributions to ICRC 2017 Part I: Neutrino astronomy (diffuse fluxes and point sources)
Papers on neutrino astronomy (diffuse fluxes and point sources, prepared for
the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by
the ANTARES Collaboratio
The ANTARES Collaboration: Contributions to ICRC 2017 Part III: Searches for dark matter and exotics, neutrino oscillations and detector calibration
Papers on the searches for dark matter and exotics, neutrino oscillations and
detector calibration, prepared for the 35th International Cosmic Ray Conference
(ICRC 2017, Busan, South Korea) by the ANTARES Collaboratio
The ANTARES Collaboration: Contributions to ICRC 2017 Part II: The multi-messenger program
Papers on the ANTARES multi-messenger program, prepared for the 35th
International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the
ANTARES Collaboratio
The Antares Collaboration : Contributions to the 34th International Cosmic Ray Conference (ICRC 2015, The Hague)
The ANTARES detector, completed in 2008, is the largest neutrino telescope in the Northern hemisphere. Located at a depth of 2.5 km in the Mediterranean Sea, 40 km off the Toulon shore, its main goal is the search for astrophysical high energy neutrinos. In this paper we collect the 21 contributions of the ANTARES collaboration to the 34th International Cosmic Ray Conference (ICRC 2015). The scientific output is very rich and the contributions included in these proceedings cover the main physics results, ranging from steady point sources, diffuse searches, multi-messenger analyses to exotic physics
ANTARES search for point-sources of neutrinos using astrophysical catalogs: a likelihood stacking analysis
A search for astrophysical point-like neutrino sources using the data
collected by the ANTARES detector between January 29, 2007 and December 31,
2017 is presented. A likelihood stacking method is used to assess the
significance of an excess of muon neutrinos inducing track-like events in
correlation with the location of a list of possible sources. Different sets of
objects are tested in the analysis: a) a sub-sample of the \textit{Fermi} 3LAC
catalog of blazars, b) a jet-obscured AGN population, c) a sample of soft
gamma-ray selected radio galaxies, d) a star-forming galaxy catalog , and e) a
public sample of 56 very-high-energy track events from the IceCube experiment.
None of the tested sources shows a significant association with the sample of
neutrinos detected by ANTARES. The smallest p-value is obtained for the radio
galaxies catalog with an equal weights hypothesis, with a pre-trial p-value
equivalent to a excess, equivalent to
post-trial.
In addition, the results of a dedicated analysis for the blazar MG3
J225517+2409 are also reported: this source is found to be the most significant
within the \textit{Fermi} 3LAC sample, with 5 ANTARES events located at less
than one degree from the source. This blazar showed evidence of flaring
activity in \textit{Fermi} data, in space-time coincidence with a high-energy
track detected by IceCube. An \emph{a posteriori} significance of for the combination of ANTARES and IceCube data is reported
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